Adding option to configure cgroup to start cri-containerd

Signed-off-by: Abhinandan Prativadi <abhi@docker.com>

cmd/cri-containerd/cri_containerd.go

@@ -46,6 +46,7 @@ func main() {
 		o.NetworkPluginConfDir,
 		o.StreamServerAddress,
 		o.StreamServerPort,
+		o.CgroupPath,
 	)
 	if err != nil {
 		glog.Exitf("Failed to create CRI containerd service %+v: %v", o, err)

cmd/cri-containerd/options/options.go

@@ -44,6 +44,8 @@ type CRIContainerdOptions struct {
 	StreamServerAddress string
 	// StreamServerPort is the port streaming server is listening on.
 	StreamServerPort string
+	// CgroupPath is the path for the cgroup that cri-containerd is placed in.
+	CgroupPath string
 }
 
 // NewCRIContainerdOptions returns a reference to CRIContainerdOptions
@@ -71,6 +73,7 @@ func (c *CRIContainerdOptions) AddFlags(fs *pflag.FlagSet) {
 		"", "The ip address streaming server is listening on. Default host interface is used if this is empty.")
 	fs.StringVar(&c.StreamServerPort, "stream-port",
 		"10010", "The port streaming server is listening on.")
+	fs.StringVar(&c.CgroupPath, "cgroup-path", "", "The cgroup that cri-containerd is part of. By default cri-containerd is not placed in a cgroup")
 }
 
 // InitFlags must be called after adding all cli options flags are defined and

pkg/server/helpers.go

@@ -24,12 +24,14 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/containerd/cgroups"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/docker/distribution/reference"
 	imagedigest "github.com/opencontainers/go-digest"
 	"github.com/opencontainers/image-spec/identity"
 	imagespec "github.com/opencontainers/image-spec/specs-go/v1"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"golang.org/x/net/context"
 	"k8s.io/kubernetes/pkg/kubelet/apis/cri/v1alpha1/runtime"
 
@@ -352,3 +354,23 @@ func resolveSymbolicLink(path string) (string, error) {
 	}
 	return filepath.EvalSymlinks(path)
 }
+
+// loadCgroup loads the cgroup associated with path if it exists and moves the current process into the cgroup. If the cgroup
+// is not created it is created and returned.
+func loadCgroup(cgroupPath string) (cgroups.Cgroup, error) {
+	cg, err := cgroups.Load(cgroups.V1, cgroups.StaticPath(cgroupPath))
+	if err != nil {
+		if err != cgroups.ErrCgroupDeleted {
+			return nil, err
+		}
+		if cg, err = cgroups.New(cgroups.V1, cgroups.StaticPath(cgroupPath), &specs.LinuxResources{}); err != nil {
+			return nil, err
+		}
+	}
+	if err := cg.Add(cgroups.Process{
+		Pid: os.Getpid(),
+	}); err != nil {
+		return nil, err
+	}
+	return cg, nil
+}

pkg/server/service.go

@@ -84,6 +84,8 @@ type criContainerdService struct {
 	client *containerd.Client
 	// streamServer is the streaming server serves container streaming request.
 	streamServer streaming.Server
+	// cgroupPath in which the cri-containerd is placed in
+	cgroupPath string
 }
 
 // NewCRIContainerdService returns a new instance of CRIContainerdService
@@ -95,13 +97,20 @@ func NewCRIContainerdService(
 	networkPluginBinDir,
 	networkPluginConfDir,
 	streamAddress,
-	streamPort string) (CRIContainerdService, error) {
+	streamPort string,
+	cgroupPath string) (CRIContainerdService, error) {
 	// TODO(random-liu): [P2] Recover from runtime state and checkpoint.
 
 	client, err := containerd.New(containerdEndpoint, containerd.WithDefaultNamespace(k8sContainerdNamespace))
 	if err != nil {
 		return nil, fmt.Errorf("failed to initialize containerd client with endpoint %q: %v", containerdEndpoint, err)
 	}
+	if cgroupPath != "" {
+		_, err := loadCgroup(cgroupPath)
+		if err != nil {
+			return nil, fmt.Errorf("failed to load cgroup for cgroup path %v: %v", cgroupPath, err)
+		}
+	}
 
 	c := &criContainerdService{
 		os:                  osinterface.RealOS{},
@@ -118,6 +127,7 @@ func NewCRIContainerdService(
 		eventService:        client.EventService(),
 		contentStoreService: client.ContentStore(),
 		client:              client,
+		cgroupPath:          cgroupPath,
 	}
 
 	netPlugin, err := ocicni.InitCNI(networkPluginConfDir, networkPluginBinDir)

vendor.conf

@@ -3,6 +3,8 @@ github.com/boltdb/bolt v1.3.0-58-ge9cf4fa
 github.com/containerd/containerd cf09e32618398fc59fcb45bcfe9b4c0335972733
 github.com/containerd/continuity cf279e6ac893682272b4479d4c67fd3abf878b4e
 github.com/containerd/fifo fbfb6a11ec671efbe94ad1c12c2e98773f19e1e6
+github.com/containerd/cgroups 7a5fdd8330119dc70d850260db8f3594d89d6943
+github.com/coreos/go-systemd d2196463941895ee908e13531a23a39feb9e1243
 github.com/containernetworking/cni v0.6.0
 github.com/containernetworking/plugins v0.6.0
 github.com/cri-o/ocicni 0f90d35d89e9ab7e972a9edeb36b0aaffa250335
@@ -11,6 +13,7 @@ github.com/docker/distribution b38e5838b7b2f2ad48e06ec4b500011976080621
 github.com/docker/docker cc4da8112814cdbb00dbf23370f9ed764383de1f
 github.com/docker/go-events 9461782956ad83b30282bf90e31fa6a70c255ba9
 github.com/docker/spdystream 449fdfce4d962303d702fec724ef0ad181c92528
+github.com/docker/go-units 0dadbb0345b35ec7ef35e228dabb8de89a65bf52
 github.com/emicklei/go-restful ff4f55a206334ef123e4f79bbf348980da81ca46
 github.com/fsnotify/fsnotify 7d7316ed6e1ed2de075aab8dfc76de5d158d66e1
 github.com/ghodss/yaml 73d445a93680fa1a78ae23a5839bad48f32ba1ee
@@ -22,6 +25,7 @@ github.com/go-openapi/jsonpointer 46af16f9f7b149af66e5d1bd010e3574dc06de98
 github.com/go-openapi/jsonreference 13c6e3589ad90f49bd3e3bbe2c2cb3d7a4142272
 github.com/go-openapi/spec 6aced65f8501fe1217321abf0749d354824ba2ff
 github.com/go-openapi/swag 1d0bd113de87027671077d3c71eb3ac5d7dbba72
+github.com/godbus/dbus 97646858c46433e4afb3432ad28c12e968efa298
 github.com/jpillora/backoff 06c7a16c845dc8e0bf575fafeeca0f5462f5eb4d
 github.com/juju/ratelimit 5b9ff866471762aa2ab2dced63c9fb6f53921342
 github.com/mailru/easyjson d5b7844b561a7bc640052f1b935f7b800330d7e0

vendor/github.com/containerd/cgroups/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/containerd/cgroups/README.md

@@ -0,0 +1,112 @@
+# cgroups
+
+[![Build Status](https://travis-ci.org/containerd/cgroups.svg?branch=master)](https://travis-ci.org/containerd/cgroups)
+
+[![codecov](https://codecov.io/gh/containerd/cgroups/branch/master/graph/badge.svg)](https://codecov.io/gh/containerd/cgroups)
+
+Go package for creating, managing, inspecting, and destroying cgroups.
+The resources format for settings on the cgroup uses the OCI runtime-spec found
+[here](https://github.com/opencontainers/runtime-spec).
+
+## Examples
+
+### Create a new cgroup
+
+This creates a new cgroup using a static path for all subsystems under `/test`.
+
+* /sys/fs/cgroup/cpu/test
+* /sys/fs/cgroup/memory/test
+* etc....
+
+It uses a single hierarchy and specifies cpu shares as a resource constraint and
+uses the v1 implementation of cgroups.
+
+
+```go
+shares := uint64(100)
+control, err := cgroups.New(cgroups.V1, cgroups.StaticPath("/test"), &specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+})
+defer control.Delete()
+```
+
+### Create with systemd slice support
+
+
+```go
+control, err := cgroups.New(cgroups.Systemd, cgroups.Slice("system.slice", "runc-test"), &specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+})
+
+```
+
+### Load an existing cgroup
+
+```go
+control, err = cgroups.Load(cgroups.V1, cgroups.StaticPath("/test"))
+```
+
+### Add a process to the cgroup
+
+```go
+if err := control.Add(cgroups.Process{Pid:1234}); err != nil {
+}
+```
+
+###  Update the cgroup 
+
+To update the resources applied in the cgroup
+
+```go
+shares = uint64(200)
+if err := control.Update(&specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+}); err != nil {
+}
+```
+
+### Freeze and Thaw the cgroup
+
+```go
+if err := control.Freeze(); err != nil {
+}
+if err := control.Thaw(); err != nil {
+}
+```
+
+### List all processes in the cgroup or recursively
+
+```go
+processes, err := control.Processes(cgroups.Devices, recursive)
+```
+
+### Get Stats on the cgroup
+
+```go
+stats, err := control.Stat()
+```
+
+By adding `cgroups.IgnoreNotExist` all non-existent files will be ignored, e.g. swap memory stats without swap enabled
+```go
+stats, err := control.Stat(cgroups.IgnoreNotExist)
+```
+
+### Move process across cgroups
+
+This allows you to take processes from one cgroup and move them to another.
+
+```go
+err := control.MoveTo(destination)
+```
+
+### Create subcgroup
+
+```go
+subCgroup, err := control.New("child", resources)
+```

vendor/github.com/containerd/cgroups/blkio.go

@@ -0,0 +1,323 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewBlkio(root string) *blkioController {
+	return &blkioController{
+		root: filepath.Join(root, string(Blkio)),
+	}
+}
+
+type blkioController struct {
+	root string
+}
+
+func (b *blkioController) Name() Name {
+	return Blkio
+}
+
+func (b *blkioController) Path(path string) string {
+	return filepath.Join(b.root, path)
+}
+
+func (b *blkioController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(b.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.BlockIO == nil {
+		return nil
+	}
+	for _, t := range createBlkioSettings(resources.BlockIO) {
+		if t.value != nil {
+			if err := ioutil.WriteFile(
+				filepath.Join(b.Path(path), fmt.Sprintf("blkio.%s", t.name)),
+				t.format(t.value),
+				defaultFilePerm,
+			); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (b *blkioController) Update(path string, resources *specs.LinuxResources) error {
+	return b.Create(path, resources)
+}
+
+func (b *blkioController) Stat(path string, stats *Stats) error {
+	stats.Blkio = &BlkioStat{}
+	settings := []blkioStatSettings{
+		{
+			name:  "throttle.io_serviced",
+			entry: &stats.Blkio.IoServicedRecursive,
+		},
+		{
+			name:  "throttle.io_service_bytes",
+			entry: &stats.Blkio.IoServiceBytesRecursive,
+		},
+	}
+	// Try to read CFQ stats available on all CFQ enabled kernels first
+	if _, err := os.Lstat(filepath.Join(b.Path(path), fmt.Sprintf("blkio.io_serviced_recursive"))); err == nil {
+		settings = append(settings,
+			blkioStatSettings{
+				name:  "sectors_recursive",
+				entry: &stats.Blkio.SectorsRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_service_bytes_recursive",
+				entry: &stats.Blkio.IoServiceBytesRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_serviced_recursive",
+				entry: &stats.Blkio.IoServicedRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_queued_recursive",
+				entry: &stats.Blkio.IoQueuedRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_service_time_recursive",
+				entry: &stats.Blkio.IoServiceTimeRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_wait_time_recursive",
+				entry: &stats.Blkio.IoWaitTimeRecursive,
+			},
+			blkioStatSettings{
+				name:  "io_merged_recursive",
+				entry: &stats.Blkio.IoMergedRecursive,
+			},
+			blkioStatSettings{
+				name:  "time_recursive",
+				entry: &stats.Blkio.IoTimeRecursive,
+			},
+		)
+	}
+
+	devices, err := getDevices("/dev")
+	if err != nil {
+		return err
+	}
+
+	for _, t := range settings {
+		if err := b.readEntry(devices, path, t.name, t.entry); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (b *blkioController) readEntry(devices map[deviceKey]string, path, name string, entry *[]BlkioEntry) error {
+	f, err := os.Open(filepath.Join(b.Path(path), fmt.Sprintf("blkio.%s", name)))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		if err := sc.Err(); err != nil {
+			return err
+		}
+		// format: dev type amount
+		fields := strings.FieldsFunc(sc.Text(), splitBlkioStatLine)
+		if len(fields) < 3 {
+			if len(fields) == 2 && fields[0] == "Total" {
+				// skip total line
+				continue
+			} else {
+				return fmt.Errorf("Invalid line found while parsing %s: %s", path, sc.Text())
+			}
+		}
+		major, err := strconv.ParseUint(fields[0], 10, 64)
+		if err != nil {
+			return err
+		}
+		minor, err := strconv.ParseUint(fields[1], 10, 64)
+		if err != nil {
+			return err
+		}
+		op := ""
+		valueField := 2
+		if len(fields) == 4 {
+			op = fields[2]
+			valueField = 3
+		}
+		v, err := strconv.ParseUint(fields[valueField], 10, 64)
+		if err != nil {
+			return err
+		}
+		*entry = append(*entry, BlkioEntry{
+			Device: devices[deviceKey{major, minor}],
+			Major:  major,
+			Minor:  minor,
+			Op:     op,
+			Value:  v,
+		})
+	}
+	return nil
+}
+
+func createBlkioSettings(blkio *specs.LinuxBlockIO) []blkioSettings {
+	settings := []blkioSettings{
+		{
+			name:   "weight",
+			value:  blkio.Weight,
+			format: uintf,
+		},
+		{
+			name:   "leaf_weight",
+			value:  blkio.LeafWeight,
+			format: uintf,
+		},
+	}
+	for _, wd := range blkio.WeightDevice {
+		settings = append(settings,
+			blkioSettings{
+				name:   "weight_device",
+				value:  wd,
+				format: weightdev,
+			},
+			blkioSettings{
+				name:   "leaf_weight_device",
+				value:  wd,
+				format: weightleafdev,
+			})
+	}
+	for _, t := range []struct {
+		name string
+		list []specs.LinuxThrottleDevice
+	}{
+		{
+			name: "throttle.read_bps_device",
+			list: blkio.ThrottleReadBpsDevice,
+		},
+		{
+			name: "throttle.read_iops_device",
+			list: blkio.ThrottleReadIOPSDevice,
+		},
+		{
+			name: "throttle.write_bps_device",
+			list: blkio.ThrottleWriteBpsDevice,
+		},
+		{
+			name: "throttle.write_iops_device",
+			list: blkio.ThrottleWriteIOPSDevice,
+		},
+	} {
+		for _, td := range t.list {
+			settings = append(settings, blkioSettings{
+				name:   t.name,
+				value:  td,
+				format: throttleddev,
+			})
+		}
+	}
+	return settings
+}
+
+type blkioSettings struct {
+	name   string
+	value  interface{}
+	format func(v interface{}) []byte
+}
+
+type blkioStatSettings struct {
+	name  string
+	entry *[]BlkioEntry
+}
+
+func uintf(v interface{}) []byte {
+	return []byte(strconv.FormatUint(uint64(*v.(*uint16)), 10))
+}
+
+func weightdev(v interface{}) []byte {
+	wd := v.(specs.LinuxWeightDevice)
+	return []byte(fmt.Sprintf("%d:%d %d", wd.Major, wd.Minor, wd.Weight))
+}
+
+func weightleafdev(v interface{}) []byte {
+	wd := v.(specs.LinuxWeightDevice)
+	return []byte(fmt.Sprintf("%d:%d %d", wd.Major, wd.Minor, wd.LeafWeight))
+}
+
+func throttleddev(v interface{}) []byte {
+	td := v.(specs.LinuxThrottleDevice)
+	return []byte(fmt.Sprintf("%d:%d %d", td.Major, td.Minor, td.Rate))
+}
+
+func splitBlkioStatLine(r rune) bool {
+	return r == ' ' || r == ':'
+}
+
+type deviceKey struct {
+	major, minor uint64
+}
+
+// getDevices makes a best effort attempt to read all the devices into a map
+// keyed by major and minor number. Since devices may be mapped multiple times,
+// we err on taking the first occurrence.
+func getDevices(path string) (map[deviceKey]string, error) {
+	// TODO(stevvooe): We are ignoring lots of errors. It might be kind of
+	// challenging to debug this if we aren't mapping devices correctly.
+	// Consider logging these errors.
+	devices := map[deviceKey]string{}
+	if err := filepath.Walk(path, func(p string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		switch {
+		case fi.IsDir():
+			switch fi.Name() {
+			case "pts", "shm", "fd", "mqueue", ".lxc", ".lxd-mounts":
+				return filepath.SkipDir
+			default:
+				return nil
+			}
+		case fi.Name() == "console":
+			return nil
+		default:
+			if fi.Mode()&os.ModeDevice == 0 {
+				// skip non-devices
+				return nil
+			}
+
+			st, ok := fi.Sys().(*syscall.Stat_t)
+			if !ok {
+				return fmt.Errorf("%s: unable to convert to system stat", p)
+			}
+
+			key := deviceKey{major(st.Rdev), minor(st.Rdev)}
+			if _, ok := devices[key]; ok {
+				return nil // skip it if we have already populated the path.
+			}
+
+			devices[key] = p
+		}
+
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return devices, nil
+}
+
+func major(devNumber uint64) uint64 {
+	return (devNumber >> 8) & 0xfff
+}
+
+func minor(devNumber uint64) uint64 {
+	return (devNumber & 0xff) | ((devNumber >> 12) & 0xfff00)
+}

vendor/github.com/containerd/cgroups/cgroup.go

@@ -0,0 +1,389 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// New returns a new control via the cgroup cgroups interface
+func New(hierarchy Hierarchy, path Path, resources *specs.LinuxResources) (Cgroup, error) {
+	subsystems, err := hierarchy()
+	if err != nil {
+		return nil, err
+	}
+	for _, s := range subsystems {
+		if err := initializeSubsystem(s, path, resources); err != nil {
+			return nil, err
+		}
+	}
+	return &cgroup{
+		path:       path,
+		subsystems: subsystems,
+	}, nil
+}
+
+// Load will load an existing cgroup and allow it to be controlled
+func Load(hierarchy Hierarchy, path Path) (Cgroup, error) {
+	subsystems, err := hierarchy()
+	if err != nil {
+		return nil, err
+	}
+	// check the the subsystems still exist
+	for _, s := range pathers(subsystems) {
+		p, err := path(s.Name())
+		if err != nil {
+			return nil, err
+		}
+		if _, err := os.Lstat(s.Path(p)); err != nil {
+			if os.IsNotExist(err) {
+				return nil, ErrCgroupDeleted
+			}
+			return nil, err
+		}
+	}
+	return &cgroup{
+		path:       path,
+		subsystems: subsystems,
+	}, nil
+}
+
+type cgroup struct {
+	path Path
+
+	subsystems []Subsystem
+	mu         sync.Mutex
+	err        error
+}
+
+// New returns a new sub cgroup
+func (c *cgroup) New(name string, resources *specs.LinuxResources) (Cgroup, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return nil, c.err
+	}
+	path := subPath(c.path, name)
+	for _, s := range c.subsystems {
+		if err := initializeSubsystem(s, path, resources); err != nil {
+			return nil, err
+		}
+	}
+	return &cgroup{
+		path:       path,
+		subsystems: c.subsystems,
+	}, nil
+}
+
+// Subsystems returns all the subsystems that are currently being
+// consumed by the group
+func (c *cgroup) Subsystems() []Subsystem {
+	return c.subsystems
+}
+
+// Add moves the provided process into the new cgroup
+func (c *cgroup) Add(process Process) error {
+	if process.Pid <= 0 {
+		return ErrInvalidPid
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	return c.add(process)
+}
+
+func (c *cgroup) add(process Process) error {
+	for _, s := range pathers(c.subsystems) {
+		p, err := c.path(s.Name())
+		if err != nil {
+			return err
+		}
+		if err := ioutil.WriteFile(
+			filepath.Join(s.Path(p), cgroupProcs),
+			[]byte(strconv.Itoa(process.Pid)),
+			defaultFilePerm,
+		); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Delete will remove the control group from each of the subsystems registered
+func (c *cgroup) Delete() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	var errors []string
+	for _, s := range c.subsystems {
+		if d, ok := s.(deleter); ok {
+			sp, err := c.path(s.Name())
+			if err != nil {
+				return err
+			}
+			if err := d.Delete(sp); err != nil {
+				errors = append(errors, string(s.Name()))
+			}
+			continue
+		}
+		if p, ok := s.(pather); ok {
+			sp, err := c.path(s.Name())
+			if err != nil {
+				return err
+			}
+			path := p.Path(sp)
+			if err := remove(path); err != nil {
+				errors = append(errors, path)
+			}
+		}
+	}
+	if len(errors) > 0 {
+		return fmt.Errorf("cgroups: unable to remove paths %s", strings.Join(errors, ", "))
+	}
+	c.err = ErrCgroupDeleted
+	return nil
+}
+
+// Stat returns the current stats for the cgroup
+func (c *cgroup) Stat(handlers ...ErrorHandler) (*Stats, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return nil, c.err
+	}
+	if len(handlers) == 0 {
+		handlers = append(handlers, errPassthrough)
+	}
+	var (
+		stats = &Stats{}
+		wg    = &sync.WaitGroup{}
+		errs  = make(chan error, len(c.subsystems))
+	)
+	for _, s := range c.subsystems {
+		if ss, ok := s.(stater); ok {
+			sp, err := c.path(s.Name())
+			if err != nil {
+				return nil, err
+			}
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				if err := ss.Stat(sp, stats); err != nil {
+					for _, eh := range handlers {
+						if herr := eh(err); herr != nil {
+							errs <- herr
+						}
+					}
+				}
+			}()
+		}
+	}
+	wg.Wait()
+	close(errs)
+	for err := range errs {
+		return nil, err
+	}
+	return stats, nil
+}
+
+// Update updates the cgroup with the new resource values provided
+//
+// Be prepared to handle EBUSY when trying to update a cgroup with
+// live processes and other operations like Stats being performed at the
+// same time
+func (c *cgroup) Update(resources *specs.LinuxResources) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	for _, s := range c.subsystems {
+		if u, ok := s.(updater); ok {
+			sp, err := c.path(s.Name())
+			if err != nil {
+				return err
+			}
+			if err := u.Update(sp, resources); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// Processes returns the processes running inside the cgroup along
+// with the subsystem used, pid, and path
+func (c *cgroup) Processes(subsystem Name, recursive bool) ([]Process, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return nil, c.err
+	}
+	return c.processes(subsystem, recursive)
+}
+
+func (c *cgroup) processes(subsystem Name, recursive bool) ([]Process, error) {
+	s := c.getSubsystem(subsystem)
+	sp, err := c.path(subsystem)
+	if err != nil {
+		return nil, err
+	}
+	path := s.(pather).Path(sp)
+	var processes []Process
+	err = filepath.Walk(path, func(p string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !recursive && info.IsDir() {
+			if p == path {
+				return nil
+			}
+			return filepath.SkipDir
+		}
+		dir, name := filepath.Split(p)
+		if name != cgroupProcs {
+			return nil
+		}
+		procs, err := readPids(dir, subsystem)
+		if err != nil {
+			return err
+		}
+		processes = append(processes, procs...)
+		return nil
+	})
+	return processes, err
+}
+
+// Freeze freezes the entire cgroup and all the processes inside it
+func (c *cgroup) Freeze() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	s := c.getSubsystem(Freezer)
+	if s == nil {
+		return ErrFreezerNotSupported
+	}
+	sp, err := c.path(Freezer)
+	if err != nil {
+		return err
+	}
+	return s.(*freezerController).Freeze(sp)
+}
+
+// Thaw thaws out the cgroup and all the processes inside it
+func (c *cgroup) Thaw() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	s := c.getSubsystem(Freezer)
+	if s == nil {
+		return ErrFreezerNotSupported
+	}
+	sp, err := c.path(Freezer)
+	if err != nil {
+		return err
+	}
+	return s.(*freezerController).Thaw(sp)
+}
+
+// OOMEventFD returns the memory cgroup's out of memory event fd that triggers
+// when processes inside the cgroup receive an oom event
+func (c *cgroup) OOMEventFD() (uintptr, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return 0, c.err
+	}
+	s := c.getSubsystem(Memory)
+	if s == nil {
+		return 0, ErrMemoryNotSupported
+	}
+	sp, err := c.path(Memory)
+	if err != nil {
+		return 0, err
+	}
+	return s.(*memoryController).OOMEventFD(sp)
+}
+
+// State returns the state of the cgroup and its processes
+func (c *cgroup) State() State {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.checkExists()
+	if c.err != nil && c.err == ErrCgroupDeleted {
+		return Deleted
+	}
+	s := c.getSubsystem(Freezer)
+	if s == nil {
+		return Thawed
+	}
+	sp, err := c.path(Freezer)
+	if err != nil {
+		return Unknown
+	}
+	state, err := s.(*freezerController).state(sp)
+	if err != nil {
+		return Unknown
+	}
+	return state
+}
+
+// MoveTo does a recursive move subsystem by subsystem of all the processes
+// inside the group
+func (c *cgroup) MoveTo(destination Cgroup) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.err != nil {
+		return c.err
+	}
+	for _, s := range c.subsystems {
+		processes, err := c.processes(s.Name(), true)
+		if err != nil {
+			return err
+		}
+		for _, p := range processes {
+			if err := destination.Add(p); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (c *cgroup) getSubsystem(n Name) Subsystem {
+	for _, s := range c.subsystems {
+		if s.Name() == n {
+			return s
+		}
+	}
+	return nil
+}
+
+func (c *cgroup) checkExists() {
+	for _, s := range pathers(c.subsystems) {
+		p, err := c.path(s.Name())
+		if err != nil {
+			return
+		}
+		if _, err := os.Lstat(s.Path(p)); err != nil {
+			if os.IsNotExist(err) {
+				c.err = ErrCgroupDeleted
+				return
+			}
+		}
+	}
+}

vendor/github.com/containerd/cgroups/control.go

@@ -0,0 +1,58 @@
+package cgroups
+
+import (
+	"os"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+const (
+	cgroupProcs    = "cgroup.procs"
+	defaultDirPerm = 0755
+)
+
+// defaultFilePerm is a var so that the test framework can change the filemode
+// of all files created when the tests are running.  The difference between the
+// tests and real world use is that files like "cgroup.procs" will exist when writing
+// to a read cgroup filesystem and do not exist prior when running in the tests.
+// this is set to a non 0 value in the test code
+var defaultFilePerm = os.FileMode(0)
+
+type Process struct {
+	// Subsystem is the name of the subsystem that the process is in
+	Subsystem Name
+	// Pid is the process id of the process
+	Pid int
+	// Path is the full path of the subsystem and location that the process is in
+	Path string
+}
+
+// Cgroup handles interactions with the individual groups to perform
+// actions on them as them main interface to this cgroup package
+type Cgroup interface {
+	// New creates a new cgroup under the calling cgroup
+	New(string, *specs.LinuxResources) (Cgroup, error)
+	// Add adds a process to the cgroup
+	Add(Process) error
+	// Delete removes the cgroup as a whole
+	Delete() error
+	// MoveTo moves all the processes under the calling cgroup to the provided one
+	// subsystems are moved one at a time
+	MoveTo(Cgroup) error
+	// Stat returns the stats for all subsystems in the cgroup
+	Stat(...ErrorHandler) (*Stats, error)
+	// Update updates all the subsystems with the provided resource changes
+	Update(resources *specs.LinuxResources) error
+	// Processes returns all the processes in a select subsystem for the cgroup
+	Processes(Name, bool) ([]Process, error)
+	// Freeze freezes or pauses all processes inside the cgroup
+	Freeze() error
+	// Thaw thaw or resumes all processes inside the cgroup
+	Thaw() error
+	// OOMEventFD returns the memory subsystem's event fd for OOM events
+	OOMEventFD() (uintptr, error)
+	// State returns the cgroups current state
+	State() State
+	// Subsystems returns all the subsystems in the cgroup
+	Subsystems() []Subsystem
+}

vendor/github.com/containerd/cgroups/cpu.go

@@ -0,0 +1,120 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewCpu(root string) *cpuController {
+	return &cpuController{
+		root: filepath.Join(root, string(Cpu)),
+	}
+}
+
+type cpuController struct {
+	root string
+}
+
+func (c *cpuController) Name() Name {
+	return Cpu
+}
+
+func (c *cpuController) Path(path string) string {
+	return filepath.Join(c.root, path)
+}
+
+func (c *cpuController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(c.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if cpu := resources.CPU; cpu != nil {
+		for _, t := range []struct {
+			name   string
+			ivalue *int64
+			uvalue *uint64
+		}{
+			{
+				name:   "rt_period_us",
+				uvalue: cpu.RealtimePeriod,
+			},
+			{
+				name:   "rt_runtime_us",
+				ivalue: cpu.RealtimeRuntime,
+			},
+			{
+				name:   "shares",
+				uvalue: cpu.Shares,
+			},
+			{
+				name:   "cfs_period_us",
+				uvalue: cpu.Period,
+			},
+			{
+				name:   "cfs_quota_us",
+				ivalue: cpu.Quota,
+			},
+		} {
+			var value []byte
+			if t.uvalue != nil {
+				value = []byte(strconv.FormatUint(*t.uvalue, 10))
+			} else if t.ivalue != nil {
+				value = []byte(strconv.FormatInt(*t.ivalue, 10))
+			}
+			if value != nil {
+				if err := ioutil.WriteFile(
+					filepath.Join(c.Path(path), fmt.Sprintf("cpu.%s", t.name)),
+					value,
+					defaultFilePerm,
+				); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func (c *cpuController) Update(path string, resources *specs.LinuxResources) error {
+	return c.Create(path, resources)
+}
+
+func (c *cpuController) Stat(path string, stats *Stats) error {
+	f, err := os.Open(filepath.Join(c.Path(path), "cpu.stat"))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	// get or create the cpu field because cpuacct can also set values on this struct
+	stats.cpuMu.Lock()
+	cpu := stats.Cpu
+	if cpu == nil {
+		cpu = &CpuStat{}
+		stats.Cpu = cpu
+	}
+	stats.cpuMu.Unlock()
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		if err := sc.Err(); err != nil {
+			return err
+		}
+		key, v, err := parseKV(sc.Text())
+		if err != nil {
+			return err
+		}
+		switch key {
+		case "nr_periods":
+			cpu.Throttling.Periods = v
+		case "nr_throttled":
+			cpu.Throttling.ThrottledPeriods = v
+		case "throttled_time":
+			cpu.Throttling.ThrottledTime = v
+		}
+	}
+	return nil
+}

vendor/github.com/containerd/cgroups/cpuacct.go

@@ -0,0 +1,112 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+const nanosecondsInSecond = 1000000000
+
+var clockTicks = getClockTicks()
+
+func NewCpuacct(root string) *cpuacctController {
+	return &cpuacctController{
+		root: filepath.Join(root, string(Cpuacct)),
+	}
+}
+
+type cpuacctController struct {
+	root string
+}
+
+func (c *cpuacctController) Name() Name {
+	return Cpuacct
+}
+
+func (c *cpuacctController) Path(path string) string {
+	return filepath.Join(c.root, path)
+}
+
+func (c *cpuacctController) Stat(path string, stats *Stats) error {
+	user, kernel, err := c.getUsage(path)
+	if err != nil {
+		return err
+	}
+	total, err := readUint(filepath.Join(c.Path(path), "cpuacct.usage"))
+	if err != nil {
+		return err
+	}
+	percpu, err := c.percpuUsage(path)
+	if err != nil {
+		return err
+	}
+	stats.cpuMu.Lock()
+	cpu := stats.Cpu
+	if cpu == nil {
+		cpu = &CpuStat{}
+		stats.Cpu = cpu
+	}
+	stats.cpuMu.Unlock()
+	cpu.Usage.Total = total
+	cpu.Usage.User = user
+	cpu.Usage.Kernel = kernel
+	cpu.Usage.PerCpu = percpu
+	return nil
+}
+
+func (c *cpuacctController) percpuUsage(path string) ([]uint64, error) {
+	var usage []uint64
+	data, err := ioutil.ReadFile(filepath.Join(c.Path(path), "cpuacct.usage_percpu"))
+	if err != nil {
+		return nil, err
+	}
+	for _, v := range strings.Fields(string(data)) {
+		u, err := strconv.ParseUint(v, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+		usage = append(usage, u)
+	}
+	return usage, nil
+}
+
+func (c *cpuacctController) getUsage(path string) (user uint64, kernel uint64, err error) {
+	statPath := filepath.Join(c.Path(path), "cpuacct.stat")
+	data, err := ioutil.ReadFile(statPath)
+	if err != nil {
+		return 0, 0, err
+	}
+	fields := strings.Fields(string(data))
+	if len(fields) != 4 {
+		return 0, 0, fmt.Errorf("%q is expected to have 4 fields", statPath)
+	}
+	for _, t := range []struct {
+		index int
+		name  string
+		value *uint64
+	}{
+		{
+			index: 0,
+			name:  "user",
+			value: &user,
+		},
+		{
+			index: 2,
+			name:  "system",
+			value: &kernel,
+		},
+	} {
+		if fields[t.index] != t.name {
+			return 0, 0, fmt.Errorf("expected field %q but found %q in %q", t.name, fields[t.index], statPath)
+		}
+		v, err := strconv.ParseUint(fields[t.index+1], 10, 64)
+		if err != nil {
+			return 0, 0, err
+		}
+		*t.value = v
+	}
+	return (user * nanosecondsInSecond) / clockTicks, (kernel * nanosecondsInSecond) / clockTicks, nil
+}

vendor/github.com/containerd/cgroups/cpuset.go

@@ -0,0 +1,139 @@
+package cgroups
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewCputset(root string) *cpusetController {
+	return &cpusetController{
+		root: filepath.Join(root, string(Cpuset)),
+	}
+}
+
+type cpusetController struct {
+	root string
+}
+
+func (c *cpusetController) Name() Name {
+	return Cpuset
+}
+
+func (c *cpusetController) Path(path string) string {
+	return filepath.Join(c.root, path)
+}
+
+func (c *cpusetController) Create(path string, resources *specs.LinuxResources) error {
+	if err := c.ensureParent(c.Path(path), c.root); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(c.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if err := c.copyIfNeeded(c.Path(path), filepath.Dir(c.Path(path))); err != nil {
+		return err
+	}
+	if resources.CPU != nil {
+		for _, t := range []struct {
+			name  string
+			value *string
+		}{
+			{
+				name:  "cpus",
+				value: &resources.CPU.Cpus,
+			},
+			{
+				name:  "mems",
+				value: &resources.CPU.Mems,
+			},
+		} {
+			if t.value != nil {
+				if err := ioutil.WriteFile(
+					filepath.Join(c.Path(path), fmt.Sprintf("cpuset.%s", t.name)),
+					[]byte(*t.value),
+					defaultFilePerm,
+				); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func (c *cpusetController) getValues(path string) (cpus []byte, mems []byte, err error) {
+	if cpus, err = ioutil.ReadFile(filepath.Join(path, "cpuset.cpus")); err != nil && !os.IsNotExist(err) {
+		return
+	}
+	if mems, err = ioutil.ReadFile(filepath.Join(path, "cpuset.mems")); err != nil && !os.IsNotExist(err) {
+		return
+	}
+	return cpus, mems, nil
+}
+
+// ensureParent makes sure that the parent directory of current is created
+// and populated with the proper cpus and mems files copied from
+// it's parent.
+func (c *cpusetController) ensureParent(current, root string) error {
+	parent := filepath.Dir(current)
+	if _, err := filepath.Rel(root, parent); err != nil {
+		return nil
+	}
+	// Avoid infinite recursion.
+	if parent == current {
+		return fmt.Errorf("cpuset: cgroup parent path outside cgroup root")
+	}
+	if cleanPath(parent) != root {
+		if err := c.ensureParent(parent, root); err != nil {
+			return err
+		}
+	}
+	if err := os.MkdirAll(current, defaultDirPerm); err != nil {
+		return err
+	}
+	return c.copyIfNeeded(current, parent)
+}
+
+// copyIfNeeded copies the cpuset.cpus and cpuset.mems from the parent
+// directory to the current directory if the file's contents are 0
+func (c *cpusetController) copyIfNeeded(current, parent string) error {
+	var (
+		err                      error
+		currentCpus, currentMems []byte
+		parentCpus, parentMems   []byte
+	)
+	if currentCpus, currentMems, err = c.getValues(current); err != nil {
+		return err
+	}
+	if parentCpus, parentMems, err = c.getValues(parent); err != nil {
+		return err
+	}
+	if isEmpty(currentCpus) {
+		if err := ioutil.WriteFile(
+			filepath.Join(current, "cpuset.cpus"),
+			parentCpus,
+			defaultFilePerm,
+		); err != nil {
+			return err
+		}
+	}
+	if isEmpty(currentMems) {
+		if err := ioutil.WriteFile(
+			filepath.Join(current, "cpuset.mems"),
+			parentMems,
+			defaultFilePerm,
+		); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isEmpty(b []byte) bool {
+	return len(bytes.Trim(b, "\n")) == 0
+}

vendor/github.com/containerd/cgroups/devices.go

@@ -0,0 +1,74 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+const (
+	allowDeviceFile = "devices.allow"
+	denyDeviceFile  = "devices.deny"
+	wildcard        = -1
+)
+
+func NewDevices(root string) *devicesController {
+	return &devicesController{
+		root: filepath.Join(root, string(Devices)),
+	}
+}
+
+type devicesController struct {
+	root string
+}
+
+func (d *devicesController) Name() Name {
+	return Devices
+}
+
+func (d *devicesController) Path(path string) string {
+	return filepath.Join(d.root, path)
+}
+
+func (d *devicesController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(d.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	for _, device := range resources.Devices {
+		file := denyDeviceFile
+		if device.Allow {
+			file = allowDeviceFile
+		}
+		if err := ioutil.WriteFile(
+			filepath.Join(d.Path(path), file),
+			[]byte(deviceString(device)),
+			defaultFilePerm,
+		); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (d *devicesController) Update(path string, resources *specs.LinuxResources) error {
+	return d.Create(path, resources)
+}
+
+func deviceString(device specs.LinuxDeviceCgroup) string {
+	return fmt.Sprintf("%c %s:%s %s",
+		&device.Type,
+		deviceNumber(device.Major),
+		deviceNumber(device.Minor),
+		&device.Access,
+	)
+}
+
+func deviceNumber(number *int64) string {
+	if number == nil || *number == wildcard {
+		return "*"
+	}
+	return fmt.Sprint(*number)
+}

vendor/github.com/containerd/cgroups/errors.go

@@ -0,0 +1,31 @@
+package cgroups
+
+import (
+	"errors"
+	"os"
+)
+
+var (
+	ErrInvalidPid               = errors.New("cgroups: pid must be greater than 0")
+	ErrMountPointNotExist       = errors.New("cgroups: cgroup mountpoint does not exist")
+	ErrInvalidFormat            = errors.New("cgroups: parsing file with invalid format failed")
+	ErrFreezerNotSupported      = errors.New("cgroups: freezer cgroup not supported on this system")
+	ErrMemoryNotSupported       = errors.New("cgroups: memory cgroup not supported on this system")
+	ErrCgroupDeleted            = errors.New("cgroups: cgroup deleted")
+	ErrNoCgroupMountDestination = errors.New("cgroups: cannot found cgroup mount destination")
+)
+
+// ErrorHandler is a function that handles and acts on errors
+type ErrorHandler func(err error) error
+
+// IgnoreNotExist ignores any errors that are for not existing files
+func IgnoreNotExist(err error) error {
+	if os.IsNotExist(err) {
+		return nil
+	}
+	return err
+}
+
+func errPassthrough(err error) error {
+	return err
+}

vendor/github.com/containerd/cgroups/freezer.go

@@ -0,0 +1,69 @@
+package cgroups
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func NewFreezer(root string) *freezerController {
+	return &freezerController{
+		root: filepath.Join(root, string(Freezer)),
+	}
+}
+
+type freezerController struct {
+	root string
+}
+
+func (f *freezerController) Name() Name {
+	return Freezer
+}
+
+func (f *freezerController) Path(path string) string {
+	return filepath.Join(f.root, path)
+}
+
+func (f *freezerController) Freeze(path string) error {
+	if err := f.changeState(path, Frozen); err != nil {
+		return err
+	}
+	return f.waitState(path, Frozen)
+}
+
+func (f *freezerController) Thaw(path string) error {
+	if err := f.changeState(path, Thawed); err != nil {
+		return err
+	}
+	return f.waitState(path, Thawed)
+}
+
+func (f *freezerController) changeState(path string, state State) error {
+	return ioutil.WriteFile(
+		filepath.Join(f.root, path, "freezer.state"),
+		[]byte(strings.ToUpper(string(state))),
+		defaultFilePerm,
+	)
+}
+
+func (f *freezerController) state(path string) (State, error) {
+	current, err := ioutil.ReadFile(filepath.Join(f.root, path, "freezer.state"))
+	if err != nil {
+		return "", err
+	}
+	return State(strings.ToLower(strings.TrimSpace(string(current)))), nil
+}
+
+func (f *freezerController) waitState(path string, state State) error {
+	for {
+		current, err := f.state(path)
+		if err != nil {
+			return err
+		}
+		if current == state {
+			return nil
+		}
+		time.Sleep(1 * time.Millisecond)
+	}
+}

vendor/github.com/containerd/cgroups/hierarchy.go

@@ -0,0 +1,4 @@
+package cgroups
+
+// Hierarchy enableds both unified and split hierarchy for cgroups
+type Hierarchy func() ([]Subsystem, error)

vendor/github.com/containerd/cgroups/hugetlb.go

@@ -0,0 +1,92 @@
+package cgroups
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewHugetlb(root string) (*hugetlbController, error) {
+	sizes, err := hugePageSizes()
+	if err != nil {
+		return nil, err
+	}
+
+	return &hugetlbController{
+		root:  filepath.Join(root, string(Hugetlb)),
+		sizes: sizes,
+	}, nil
+}
+
+type hugetlbController struct {
+	root  string
+	sizes []string
+}
+
+func (h *hugetlbController) Name() Name {
+	return Hugetlb
+}
+
+func (h *hugetlbController) Path(path string) string {
+	return filepath.Join(h.root, path)
+}
+
+func (h *hugetlbController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(h.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	for _, limit := range resources.HugepageLimits {
+		if err := ioutil.WriteFile(
+			filepath.Join(h.Path(path), strings.Join([]string{"hugetlb", limit.Pagesize, "limit_in_bytes"}, ".")),
+			[]byte(strconv.FormatUint(limit.Limit, 10)),
+			defaultFilePerm,
+		); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (h *hugetlbController) Stat(path string, stats *Stats) error {
+	stats.Hugetlb = make(map[string]HugetlbStat)
+	for _, size := range h.sizes {
+		s, err := h.readSizeStat(path, size)
+		if err != nil {
+			return err
+		}
+		stats.Hugetlb[size] = s
+	}
+	return nil
+}
+
+func (h *hugetlbController) readSizeStat(path, size string) (HugetlbStat, error) {
+	var s HugetlbStat
+	for _, t := range []struct {
+		name  string
+		value *uint64
+	}{
+		{
+			name:  "usage_in_bytes",
+			value: &s.Usage,
+		},
+		{
+			name:  "max_usage_in_bytes",
+			value: &s.Max,
+		},
+		{
+			name:  "failcnt",
+			value: &s.Failcnt,
+		},
+	} {
+		v, err := readUint(filepath.Join(h.Path(path), strings.Join([]string{"hugetlb", size, t.name}, ".")))
+		if err != nil {
+			return s, err
+		}
+		*t.value = v
+	}
+	return s, nil
+}

vendor/github.com/containerd/cgroups/memory.go

@@ -0,0 +1,304 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"golang.org/x/sys/unix"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewMemory(root string) *memoryController {
+	return &memoryController{
+		root: filepath.Join(root, string(Memory)),
+	}
+}
+
+type memoryController struct {
+	root string
+}
+
+func (m *memoryController) Name() Name {
+	return Memory
+}
+
+func (m *memoryController) Path(path string) string {
+	return filepath.Join(m.root, path)
+}
+
+func (m *memoryController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(m.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.Memory == nil {
+		return nil
+	}
+	if resources.Memory.Kernel != nil {
+		// Check if kernel memory is enabled
+		// We have to limit the kernel memory here as it won't be accounted at all
+		// until a limit is set on the cgroup and limit cannot be set once the
+		// cgroup has children, or if there are already tasks in the cgroup.
+		for _, i := range []int64{1, -1} {
+			if err := ioutil.WriteFile(
+				filepath.Join(m.Path(path), "memory.kmem.limit_in_bytes"),
+				[]byte(strconv.FormatInt(i, 10)),
+				defaultFilePerm,
+			); err != nil {
+				return checkEBUSY(err)
+			}
+		}
+	}
+	return m.set(path, getMemorySettings(resources))
+}
+
+func (m *memoryController) Update(path string, resources *specs.LinuxResources) error {
+	if resources.Memory == nil {
+		return nil
+	}
+	g := func(v *int64) bool {
+		return v != nil && *v > 0
+	}
+	settings := getMemorySettings(resources)
+	if g(resources.Memory.Limit) && g(resources.Memory.Swap) {
+		// if the updated swap value is larger than the current memory limit set the swap changes first
+		// then set the memory limit as swap must always be larger than the current limit
+		current, err := readUint(filepath.Join(m.Path(path), "memory.limit_in_bytes"))
+		if err != nil {
+			return err
+		}
+		if current < uint64(*resources.Memory.Swap) {
+			settings[0], settings[1] = settings[1], settings[0]
+		}
+	}
+	return m.set(path, settings)
+}
+
+func (m *memoryController) Stat(path string, stats *Stats) error {
+	f, err := os.Open(filepath.Join(m.Path(path), "memory.stat"))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	stats.Memory = &MemoryStat{}
+	if err := m.parseStats(f, stats.Memory); err != nil {
+		return err
+	}
+	for _, t := range []struct {
+		module string
+		entry  *MemoryEntry
+	}{
+		{
+			module: "",
+			entry:  &stats.Memory.Usage,
+		},
+		{
+			module: "memsw",
+			entry:  &stats.Memory.Swap,
+		},
+		{
+			module: "kmem",
+			entry:  &stats.Memory.Kernel,
+		},
+		{
+			module: "kmem.tcp",
+			entry:  &stats.Memory.KernelTCP,
+		},
+	} {
+		for _, tt := range []struct {
+			name  string
+			value *uint64
+		}{
+			{
+				name:  "usage_in_bytes",
+				value: &t.entry.Usage,
+			},
+			{
+				name:  "max_usage_in_bytes",
+				value: &t.entry.Max,
+			},
+			{
+				name:  "failcnt",
+				value: &t.entry.Failcnt,
+			},
+			{
+				name:  "limit_in_bytes",
+				value: &t.entry.Limit,
+			},
+		} {
+			parts := []string{"memory"}
+			if t.module != "" {
+				parts = append(parts, t.module)
+			}
+			parts = append(parts, tt.name)
+			v, err := readUint(filepath.Join(m.Path(path), strings.Join(parts, ".")))
+			if err != nil {
+				return err
+			}
+			*tt.value = v
+		}
+	}
+	return nil
+}
+
+func (m *memoryController) OOMEventFD(path string) (uintptr, error) {
+	root := m.Path(path)
+	f, err := os.Open(filepath.Join(root, "memory.oom_control"))
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+	fd, _, serr := unix.RawSyscall(unix.SYS_EVENTFD2, 0, unix.FD_CLOEXEC, 0)
+	if serr != 0 {
+		return 0, serr
+	}
+	if err := writeEventFD(root, f.Fd(), fd); err != nil {
+		unix.Close(int(fd))
+		return 0, err
+	}
+	return fd, nil
+}
+
+func writeEventFD(root string, cfd, efd uintptr) error {
+	f, err := os.OpenFile(filepath.Join(root, "cgroup.event_control"), os.O_WRONLY, 0)
+	if err != nil {
+		return err
+	}
+	_, err = f.WriteString(fmt.Sprintf("%d %d", efd, cfd))
+	f.Close()
+	return err
+}
+
+func (m *memoryController) parseStats(r io.Reader, stat *MemoryStat) error {
+	var (
+		raw  = make(map[string]uint64)
+		sc   = bufio.NewScanner(r)
+		line int
+	)
+	for sc.Scan() {
+		if err := sc.Err(); err != nil {
+			return err
+		}
+		key, v, err := parseKV(sc.Text())
+		if err != nil {
+			return fmt.Errorf("%d: %v", line, err)
+		}
+		raw[key] = v
+		line++
+	}
+	stat.Cache = raw["cache"]
+	stat.RSS = raw["rss"]
+	stat.RSSHuge = raw["rss_huge"]
+	stat.MappedFile = raw["mapped_file"]
+	stat.Dirty = raw["dirty"]
+	stat.Writeback = raw["writeback"]
+	stat.PgPgIn = raw["pgpgin"]
+	stat.PgPgOut = raw["pgpgout"]
+	stat.PgFault = raw["pgfault"]
+	stat.PgMajFault = raw["pgmajfault"]
+	stat.InactiveAnon = raw["inactive_anon"]
+	stat.ActiveAnon = raw["active_anon"]
+	stat.InactiveFile = raw["inactive_file"]
+	stat.ActiveFile = raw["active_file"]
+	stat.Unevictable = raw["unevictable"]
+	stat.HierarchicalMemoryLimit = raw["hierarchical_memory_limit"]
+	stat.HierarchicalSwapLimit = raw["hierarchical_memsw_limit"]
+	stat.TotalCache = raw["total_cache"]
+	stat.TotalRSS = raw["total_rss"]
+	stat.TotalRSSHuge = raw["total_rss_huge"]
+	stat.TotalMappedFile = raw["total_mapped_file"]
+	stat.TotalDirty = raw["total_dirty"]
+	stat.TotalWriteback = raw["total_writeback"]
+	stat.TotalPgPgIn = raw["total_pgpgin"]
+	stat.TotalPgPgOut = raw["total_pgpgout"]
+	stat.TotalPgFault = raw["total_pgfault"]
+	stat.TotalPgMajFault = raw["total_pgmajfault"]
+	stat.TotalInactiveAnon = raw["total_inactive_anon"]
+	stat.TotalActiveAnon = raw["total_active_anon"]
+	stat.TotalInactiveFile = raw["total_inactive_file"]
+	stat.TotalActiveFile = raw["total_active_file"]
+	stat.TotalUnevictable = raw["total_unevictable"]
+	return nil
+}
+
+func (m *memoryController) set(path string, settings []memorySettings) error {
+	for _, t := range settings {
+		if t.value != nil {
+			if err := ioutil.WriteFile(
+				filepath.Join(m.Path(path), fmt.Sprintf("memory.%s", t.name)),
+				[]byte(strconv.FormatInt(*t.value, 10)),
+				defaultFilePerm,
+			); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+type memorySettings struct {
+	name  string
+	value *int64
+}
+
+func getMemorySettings(resources *specs.LinuxResources) []memorySettings {
+	mem := resources.Memory
+	var swappiness *int64
+	if mem.Swappiness != nil {
+		v := int64(*mem.Swappiness)
+		swappiness = &v
+	}
+	return []memorySettings{
+		{
+			name:  "limit_in_bytes",
+			value: mem.Limit,
+		},
+		{
+			name:  "memsw.limit_in_bytes",
+			value: mem.Swap,
+		},
+		{
+			name:  "kmem.limit_in_bytes",
+			value: mem.Kernel,
+		},
+		{
+			name:  "kmem.tcp.limit_in_bytes",
+			value: mem.KernelTCP,
+		},
+		{
+			name:  "oom_control",
+			value: getOomControlValue(mem),
+		},
+		{
+			name:  "swappiness",
+			value: swappiness,
+		},
+	}
+}
+
+func checkEBUSY(err error) error {
+	if pathErr, ok := err.(*os.PathError); ok {
+		if errNo, ok := pathErr.Err.(syscall.Errno); ok {
+			if errNo == unix.EBUSY {
+				return fmt.Errorf(
+					"failed to set memory.kmem.limit_in_bytes, because either tasks have already joined this cgroup or it has children")
+			}
+		}
+	}
+	return err
+}
+
+func getOomControlValue(mem *specs.LinuxMemory) *int64 {
+	if mem.DisableOOMKiller != nil && *mem.DisableOOMKiller {
+		i := int64(1)
+		return &i
+	}
+	return nil
+}

vendor/github.com/containerd/cgroups/named.go

@@ -0,0 +1,23 @@
+package cgroups
+
+import "path/filepath"
+
+func NewNamed(root string, name Name) *namedController {
+	return &namedController{
+		root: root,
+		name: name,
+	}
+}
+
+type namedController struct {
+	root string
+	name Name
+}
+
+func (n *namedController) Name() Name {
+	return n.name
+}
+
+func (n *namedController) Path(path string) string {
+	return filepath.Join(n.root, string(n.name), path)
+}

vendor/github.com/containerd/cgroups/net_cls.go

@@ -0,0 +1,42 @@
+package cgroups
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewNetCls(root string) *netclsController {
+	return &netclsController{
+		root: filepath.Join(root, string(NetCLS)),
+	}
+}
+
+type netclsController struct {
+	root string
+}
+
+func (n *netclsController) Name() Name {
+	return NetCLS
+}
+
+func (n *netclsController) Path(path string) string {
+	return filepath.Join(n.root, path)
+}
+
+func (n *netclsController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(n.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.Network != nil && resources.Network.ClassID != nil && *resources.Network.ClassID > 0 {
+		return ioutil.WriteFile(
+			filepath.Join(n.Path(path), "net_cls.classid"),
+			[]byte(strconv.FormatUint(uint64(*resources.Network.ClassID), 10)),
+			defaultFilePerm,
+		)
+	}
+	return nil
+}

vendor/github.com/containerd/cgroups/net_prio.go

@@ -0,0 +1,50 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewNetPrio(root string) *netprioController {
+	return &netprioController{
+		root: filepath.Join(root, string(NetPrio)),
+	}
+}
+
+type netprioController struct {
+	root string
+}
+
+func (n *netprioController) Name() Name {
+	return NetPrio
+}
+
+func (n *netprioController) Path(path string) string {
+	return filepath.Join(n.root, path)
+}
+
+func (n *netprioController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(n.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.Network != nil {
+		for _, prio := range resources.Network.Priorities {
+			if err := ioutil.WriteFile(
+				filepath.Join(n.Path(path), "net_prio_ifpriomap"),
+				formatPrio(prio.Name, prio.Priority),
+				defaultFilePerm,
+			); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func formatPrio(name string, prio uint32) []byte {
+	return []byte(fmt.Sprintf("%s %d", name, prio))
+}

vendor/github.com/containerd/cgroups/paths.go

@@ -0,0 +1,88 @@
+package cgroups
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+)
+
+type Path func(subsystem Name) (string, error)
+
+func RootPath(subsysem Name) (string, error) {
+	return "/", nil
+}
+
+// StaticPath returns a static path to use for all cgroups
+func StaticPath(path string) Path {
+	return func(_ Name) (string, error) {
+		return path, nil
+	}
+}
+
+// NestedPath will nest the cgroups based on the calling processes cgroup
+// placing its child processes inside its own path
+func NestedPath(suffix string) Path {
+	paths, err := parseCgroupFile("/proc/self/cgroup")
+	if err != nil {
+		return errorPath(err)
+	}
+	return existingPath(paths, suffix)
+}
+
+// PidPath will return the correct cgroup paths for an existing process running inside a cgroup
+// This is commonly used for the Load function to restore an existing container
+func PidPath(pid int) Path {
+	p := fmt.Sprintf("/proc/%d/cgroup", pid)
+	paths, err := parseCgroupFile(p)
+	if err != nil {
+		return errorPath(errors.Wrapf(err, "parse cgroup file %s", p))
+	}
+	return existingPath(paths, "")
+}
+
+func existingPath(paths map[string]string, suffix string) Path {
+	// localize the paths based on the root mount dest for nested cgroups
+	for n, p := range paths {
+		dest, err := getCgroupDestination(string(n))
+		if err != nil {
+			return errorPath(err)
+		}
+		rel, err := filepath.Rel(dest, p)
+		if err != nil {
+			return errorPath(err)
+		}
+		if rel == "." {
+			rel = dest
+		}
+		paths[n] = filepath.Join("/", rel)
+	}
+	return func(name Name) (string, error) {
+		root, ok := paths[string(name)]
+		if !ok {
+			if root, ok = paths[fmt.Sprintf("name=%s", name)]; !ok {
+				return "", fmt.Errorf("unable to find %q in controller set", name)
+			}
+		}
+		if suffix != "" {
+			return filepath.Join(root, suffix), nil
+		}
+		return root, nil
+	}
+}
+
+func subPath(path Path, subName string) Path {
+	return func(name Name) (string, error) {
+		p, err := path(name)
+		if err != nil {
+			return "", err
+		}
+		return filepath.Join(p, subName), nil
+	}
+}
+
+func errorPath(err error) Path {
+	return func(_ Name) (string, error) {
+		return "", err
+	}
+}

vendor/github.com/containerd/cgroups/perf_event.go

@@ -0,0 +1,21 @@
+package cgroups
+
+import "path/filepath"
+
+func NewPerfEvent(root string) *PerfEventController {
+	return &PerfEventController{
+		root: filepath.Join(root, string(PerfEvent)),
+	}
+}
+
+type PerfEventController struct {
+	root string
+}
+
+func (p *PerfEventController) Name() Name {
+	return PerfEvent
+}
+
+func (p *PerfEventController) Path(path string) string {
+	return filepath.Join(p.root, path)
+}

vendor/github.com/containerd/cgroups/pids.go

@@ -0,0 +1,69 @@
+package cgroups
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+func NewPids(root string) *pidsController {
+	return &pidsController{
+		root: filepath.Join(root, string(Pids)),
+	}
+}
+
+type pidsController struct {
+	root string
+}
+
+func (p *pidsController) Name() Name {
+	return Pids
+}
+
+func (p *pidsController) Path(path string) string {
+	return filepath.Join(p.root, path)
+}
+
+func (p *pidsController) Create(path string, resources *specs.LinuxResources) error {
+	if err := os.MkdirAll(p.Path(path), defaultDirPerm); err != nil {
+		return err
+	}
+	if resources.Pids != nil && resources.Pids.Limit > 0 {
+		return ioutil.WriteFile(
+			filepath.Join(p.Path(path), "pids.max"),
+			[]byte(strconv.FormatInt(resources.Pids.Limit, 10)),
+			defaultFilePerm,
+		)
+	}
+	return nil
+}
+
+func (p *pidsController) Update(path string, resources *specs.LinuxResources) error {
+	return p.Create(path, resources)
+}
+
+func (p *pidsController) Stat(path string, stats *Stats) error {
+	current, err := readUint(filepath.Join(p.Path(path), "pids.current"))
+	if err != nil {
+		return err
+	}
+	var max uint64
+	maxData, err := ioutil.ReadFile(filepath.Join(p.Path(path), "pids.max"))
+	if err != nil {
+		return err
+	}
+	if maxS := strings.TrimSpace(string(maxData)); maxS != "max" {
+		if max, err = parseUint(maxS, 10, 64); err != nil {
+			return err
+		}
+	}
+	stats.Pids = &PidsStat{
+		Current: current,
+		Limit:   max,
+	}
+	return nil
+}

vendor/github.com/containerd/cgroups/state.go

@@ -0,0 +1,12 @@
+package cgroups
+
+// State is a type that represents the state of the current cgroup
+type State string
+
+const (
+	Unknown  State = ""
+	Thawed   State = "thawed"
+	Frozen   State = "frozen"
+	Freezing State = "freezing"
+	Deleted  State = "deleted"
+)

vendor/github.com/containerd/cgroups/stats.go

@@ -0,0 +1,109 @@
+package cgroups
+
+import "sync"
+
+type Stats struct {
+	cpuMu sync.Mutex
+
+	Hugetlb map[string]HugetlbStat
+	Pids    *PidsStat
+	Cpu     *CpuStat
+	Memory  *MemoryStat
+	Blkio   *BlkioStat
+}
+
+type HugetlbStat struct {
+	Usage   uint64
+	Max     uint64
+	Failcnt uint64
+}
+
+type PidsStat struct {
+	Current uint64
+	Limit   uint64
+}
+
+type CpuStat struct {
+	Usage      CpuUsage
+	Throttling Throttle
+}
+
+type CpuUsage struct {
+	// Units: nanoseconds.
+	Total  uint64
+	PerCpu []uint64
+	Kernel uint64
+	User   uint64
+}
+
+type Throttle struct {
+	Periods          uint64
+	ThrottledPeriods uint64
+	ThrottledTime    uint64
+}
+
+type MemoryStat struct {
+	Cache                   uint64
+	RSS                     uint64
+	RSSHuge                 uint64
+	MappedFile              uint64
+	Dirty                   uint64
+	Writeback               uint64
+	PgPgIn                  uint64
+	PgPgOut                 uint64
+	PgFault                 uint64
+	PgMajFault              uint64
+	InactiveAnon            uint64
+	ActiveAnon              uint64
+	InactiveFile            uint64
+	ActiveFile              uint64
+	Unevictable             uint64
+	HierarchicalMemoryLimit uint64
+	HierarchicalSwapLimit   uint64
+	TotalCache              uint64
+	TotalRSS                uint64
+	TotalRSSHuge            uint64
+	TotalMappedFile         uint64
+	TotalDirty              uint64
+	TotalWriteback          uint64
+	TotalPgPgIn             uint64
+	TotalPgPgOut            uint64
+	TotalPgFault            uint64
+	TotalPgMajFault         uint64
+	TotalInactiveAnon       uint64
+	TotalActiveAnon         uint64
+	TotalInactiveFile       uint64
+	TotalActiveFile         uint64
+	TotalUnevictable        uint64
+
+	Usage     MemoryEntry
+	Swap      MemoryEntry
+	Kernel    MemoryEntry
+	KernelTCP MemoryEntry
+}
+
+type MemoryEntry struct {
+	Limit   uint64
+	Usage   uint64
+	Max     uint64
+	Failcnt uint64
+}
+
+type BlkioStat struct {
+	IoServiceBytesRecursive []BlkioEntry
+	IoServicedRecursive     []BlkioEntry
+	IoQueuedRecursive       []BlkioEntry
+	IoServiceTimeRecursive  []BlkioEntry
+	IoWaitTimeRecursive     []BlkioEntry
+	IoMergedRecursive       []BlkioEntry
+	IoTimeRecursive         []BlkioEntry
+	SectorsRecursive        []BlkioEntry
+}
+
+type BlkioEntry struct {
+	Op     string
+	Device string
+	Major  uint64
+	Minor  uint64
+	Value  uint64
+}

vendor/github.com/containerd/cgroups/subsystem.go

@@ -0,0 +1,94 @@
+package cgroups
+
+import (
+	"fmt"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// Name is a typed name for a cgroup subsystem
+type Name string
+
+const (
+	Devices   Name = "devices"
+	Hugetlb   Name = "hugetlb"
+	Freezer   Name = "freezer"
+	Pids      Name = "pids"
+	NetCLS    Name = "net_cls"
+	NetPrio   Name = "net_prio"
+	PerfEvent Name = "perf_event"
+	Cpuset    Name = "cpuset"
+	Cpu       Name = "cpu"
+	Cpuacct   Name = "cpuacct"
+	Memory    Name = "memory"
+	Blkio     Name = "blkio"
+)
+
+// Subsystems returns a complete list of the default cgroups
+// avaliable on most linux systems
+func Subsystems() []Name {
+	n := []Name{
+		Hugetlb,
+		Freezer,
+		Pids,
+		NetCLS,
+		NetPrio,
+		PerfEvent,
+		Cpuset,
+		Cpu,
+		Cpuacct,
+		Memory,
+		Blkio,
+	}
+	if !isUserNS {
+		n = append(n, Devices)
+	}
+	return n
+}
+
+type Subsystem interface {
+	Name() Name
+}
+
+type pather interface {
+	Subsystem
+	Path(path string) string
+}
+
+type creator interface {
+	Subsystem
+	Create(path string, resources *specs.LinuxResources) error
+}
+
+type deleter interface {
+	Subsystem
+	Delete(path string) error
+}
+
+type stater interface {
+	Subsystem
+	Stat(path string, stats *Stats) error
+}
+
+type updater interface {
+	Subsystem
+	Update(path string, resources *specs.LinuxResources) error
+}
+
+// SingleSubsystem returns a single cgroup subsystem within the base Hierarchy
+func SingleSubsystem(baseHierarchy Hierarchy, subsystem Name) Hierarchy {
+	return func() ([]Subsystem, error) {
+		subsystems, err := baseHierarchy()
+		if err != nil {
+			return nil, err
+		}
+		for _, s := range subsystems {
+			if s.Name() == subsystem {
+				return []Subsystem{
+					s,
+				}, nil
+			}
+		}
+		return nil, fmt.Errorf("unable to find subsystem %s", subsystem)
+	}
+}

vendor/github.com/containerd/cgroups/systemd.go

@@ -0,0 +1,101 @@
+package cgroups
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	systemdDbus "github.com/coreos/go-systemd/dbus"
+	"github.com/godbus/dbus"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+const (
+	SystemdDbus  Name = "systemd"
+	defaultSlice      = "system.slice"
+)
+
+func Systemd() ([]Subsystem, error) {
+	root, err := v1MountPoint()
+	if err != nil {
+		return nil, err
+	}
+	defaultSubsystems, err := defaults(root)
+	if err != nil {
+		return nil, err
+	}
+	s, err := NewSystemd(root)
+	if err != nil {
+		return nil, err
+	}
+	// make sure the systemd controller is added first
+	return append([]Subsystem{s}, defaultSubsystems...), nil
+}
+
+func Slice(slice, name string) Path {
+	if slice == "" {
+		slice = defaultSlice
+	}
+	return func(subsystem Name) (string, error) {
+		return filepath.Join(slice, unitName(name)), nil
+	}
+}
+
+func NewSystemd(root string) (*SystemdController, error) {
+	conn, err := systemdDbus.New()
+	if err != nil {
+		return nil, err
+	}
+	return &SystemdController{
+		root: root,
+		conn: conn,
+	}, nil
+}
+
+type SystemdController struct {
+	mu   sync.Mutex
+	conn *systemdDbus.Conn
+	root string
+}
+
+func (s *SystemdController) Name() Name {
+	return SystemdDbus
+}
+
+func (s *SystemdController) Create(path string, resources *specs.LinuxResources) error {
+	slice, name := splitName(path)
+	properties := []systemdDbus.Property{
+		systemdDbus.PropDescription(fmt.Sprintf("cgroup %s", name)),
+		systemdDbus.PropWants(slice),
+		newProperty("DefaultDependencies", false),
+		newProperty("Delegate", true),
+		newProperty("MemoryAccounting", true),
+		newProperty("CPUAccounting", true),
+		newProperty("BlockIOAccounting", true),
+	}
+	_, err := s.conn.StartTransientUnit(name, "replace", properties, nil)
+	return err
+}
+
+func (s *SystemdController) Delete(path string) error {
+	_, name := splitName(path)
+	_, err := s.conn.StopUnit(name, "replace", nil)
+	return err
+}
+
+func newProperty(name string, units interface{}) systemdDbus.Property {
+	return systemdDbus.Property{
+		Name:  name,
+		Value: dbus.MakeVariant(units),
+	}
+}
+
+func unitName(name string) string {
+	return fmt.Sprintf("%s.slice", name)
+}
+
+func splitName(path string) (slice string, unit string) {
+	slice, unit = filepath.Split(path)
+	return strings.TrimSuffix(slice, "/"), unit
+}

vendor/github.com/containerd/cgroups/ticks.go

@@ -0,0 +1,10 @@
+package cgroups
+
+func getClockTicks() uint64 {
+	// The value comes from `C.sysconf(C._SC_CLK_TCK)`, and
+	// on Linux it's a constant which is safe to be hard coded,
+	// so we can avoid using cgo here.
+	// See https://github.com/containerd/cgroups/pull/12 for
+	// more details.
+	return 100
+}

vendor/github.com/containerd/cgroups/utils.go

@@ -0,0 +1,280 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	units "github.com/docker/go-units"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+var isUserNS = runningInUserNS()
+
+// runningInUserNS detects whether we are currently running in a user namespace.
+// Copied from github.com/lxc/lxd/shared/util.go
+func runningInUserNS() bool {
+	file, err := os.Open("/proc/self/uid_map")
+	if err != nil {
+		// This kernel-provided file only exists if user namespaces are supported
+		return false
+	}
+	defer file.Close()
+
+	buf := bufio.NewReader(file)
+	l, _, err := buf.ReadLine()
+	if err != nil {
+		return false
+	}
+
+	line := string(l)
+	var a, b, c int64
+	fmt.Sscanf(line, "%d %d %d", &a, &b, &c)
+	/*
+	 * We assume we are in the initial user namespace if we have a full
+	 * range - 4294967295 uids starting at uid 0.
+	 */
+	if a == 0 && b == 0 && c == 4294967295 {
+		return false
+	}
+	return true
+}
+
+// defaults returns all known groups
+func defaults(root string) ([]Subsystem, error) {
+	h, err := NewHugetlb(root)
+	if err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	s := []Subsystem{
+		NewNamed(root, "systemd"),
+		NewFreezer(root),
+		NewPids(root),
+		NewNetCls(root),
+		NewNetPrio(root),
+		NewPerfEvent(root),
+		NewCputset(root),
+		NewCpu(root),
+		NewCpuacct(root),
+		NewMemory(root),
+		NewBlkio(root),
+	}
+	// only add the devices cgroup if we are not in a user namespace
+	// because modifications are not allowed
+	if !isUserNS {
+		s = append(s, NewDevices(root))
+	}
+	// add the hugetlb cgroup if error wasn't due to missing hugetlb
+	// cgroup support on the host
+	if err == nil {
+		s = append(s, h)
+	}
+	return s, nil
+}
+
+// remove will remove a cgroup path handling EAGAIN and EBUSY errors and
+// retrying the remove after a exp timeout
+func remove(path string) error {
+	delay := 10 * time.Millisecond
+	for i := 0; i < 5; i++ {
+		if i != 0 {
+			time.Sleep(delay)
+			delay *= 2
+		}
+		if err := os.RemoveAll(path); err == nil {
+			return nil
+		}
+	}
+	return fmt.Errorf("cgroups: unable to remove path %q", path)
+}
+
+// readPids will read all the pids in a cgroup by the provided path
+func readPids(path string, subsystem Name) ([]Process, error) {
+	f, err := os.Open(filepath.Join(path, cgroupProcs))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	var (
+		out []Process
+		s   = bufio.NewScanner(f)
+	)
+	for s.Scan() {
+		if t := s.Text(); t != "" {
+			pid, err := strconv.Atoi(t)
+			if err != nil {
+				return nil, err
+			}
+			out = append(out, Process{
+				Pid:       pid,
+				Subsystem: subsystem,
+				Path:      path,
+			})
+		}
+	}
+	return out, nil
+}
+
+func hugePageSizes() ([]string, error) {
+	var (
+		pageSizes []string
+		sizeList  = []string{"B", "kB", "MB", "GB", "TB", "PB"}
+	)
+	files, err := ioutil.ReadDir("/sys/kernel/mm/hugepages")
+	if err != nil {
+		return nil, err
+	}
+	for _, st := range files {
+		nameArray := strings.Split(st.Name(), "-")
+		pageSize, err := units.RAMInBytes(nameArray[1])
+		if err != nil {
+			return nil, err
+		}
+		pageSizes = append(pageSizes, units.CustomSize("%g%s", float64(pageSize), 1024.0, sizeList))
+	}
+	return pageSizes, nil
+}
+
+func readUint(path string) (uint64, error) {
+	v, err := ioutil.ReadFile(path)
+	if err != nil {
+		return 0, err
+	}
+	return parseUint(strings.TrimSpace(string(v)), 10, 64)
+}
+
+func parseUint(s string, base, bitSize int) (uint64, error) {
+	v, err := strconv.ParseUint(s, base, bitSize)
+	if err != nil {
+		intValue, intErr := strconv.ParseInt(s, base, bitSize)
+		// 1. Handle negative values greater than MinInt64 (and)
+		// 2. Handle negative values lesser than MinInt64
+		if intErr == nil && intValue < 0 {
+			return 0, nil
+		} else if intErr != nil &&
+			intErr.(*strconv.NumError).Err == strconv.ErrRange &&
+			intValue < 0 {
+			return 0, nil
+		}
+		return 0, err
+	}
+	return v, nil
+}
+
+func parseKV(raw string) (string, uint64, error) {
+	parts := strings.Fields(raw)
+	switch len(parts) {
+	case 2:
+		v, err := parseUint(parts[1], 10, 64)
+		if err != nil {
+			return "", 0, err
+		}
+		return parts[0], v, nil
+	default:
+		return "", 0, ErrInvalidFormat
+	}
+}
+
+func parseCgroupFile(path string) (map[string]string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return parseCgroupFromReader(f)
+}
+
+func parseCgroupFromReader(r io.Reader) (map[string]string, error) {
+	var (
+		cgroups = make(map[string]string)
+		s       = bufio.NewScanner(r)
+	)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+		var (
+			text  = s.Text()
+			parts = strings.SplitN(text, ":", 3)
+		)
+		if len(parts) < 3 {
+			return nil, fmt.Errorf("invalid cgroup entry: %q", text)
+		}
+		for _, subs := range strings.Split(parts[1], ",") {
+			if subs != "" {
+				cgroups[subs] = parts[2]
+			}
+		}
+	}
+	return cgroups, nil
+}
+
+func getCgroupDestination(subsystem string) (string, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			return "", err
+		}
+		fields := strings.Fields(s.Text())
+		for _, opt := range strings.Split(fields[len(fields)-1], ",") {
+			if opt == subsystem {
+				return fields[3], nil
+			}
+		}
+	}
+	return "", ErrNoCgroupMountDestination
+}
+
+func pathers(subystems []Subsystem) []pather {
+	var out []pather
+	for _, s := range subystems {
+		if p, ok := s.(pather); ok {
+			out = append(out, p)
+		}
+	}
+	return out
+}
+
+func initializeSubsystem(s Subsystem, path Path, resources *specs.LinuxResources) error {
+	if c, ok := s.(creator); ok {
+		p, err := path(s.Name())
+		if err != nil {
+			return err
+		}
+		if err := c.Create(p, resources); err != nil {
+			return err
+		}
+	} else if c, ok := s.(pather); ok {
+		p, err := path(s.Name())
+		if err != nil {
+			return err
+		}
+		// do the default create if the group does not have a custom one
+		if err := os.MkdirAll(c.Path(p), defaultDirPerm); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func cleanPath(path string) string {
+	if path == "" {
+		return ""
+	}
+	path = filepath.Clean(path)
+	if !filepath.IsAbs(path) {
+		path, _ = filepath.Rel(string(os.PathSeparator), filepath.Clean(string(os.PathSeparator)+path))
+	}
+	return filepath.Clean(path)
+}

vendor/github.com/containerd/cgroups/v1.go

@@ -0,0 +1,65 @@
+package cgroups
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// V1 returns all the groups in the default cgroups mountpoint in a single hierarchy
+func V1() ([]Subsystem, error) {
+	root, err := v1MountPoint()
+	if err != nil {
+		return nil, err
+	}
+	subsystems, err := defaults(root)
+	if err != nil {
+		return nil, err
+	}
+	var enabled []Subsystem
+	for _, s := range pathers(subsystems) {
+		// check and remove the default groups that do not exist
+		if _, err := os.Lstat(s.Path("/")); err == nil {
+			enabled = append(enabled, s)
+		}
+	}
+	return enabled, nil
+}
+
+// v1MountPoint returns the mount point where the cgroup
+// mountpoints are mounted in a single hiearchy
+func v1MountPoint() (string, error) {
+	f, err := os.Open("/proc/self/mountinfo")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		if err := scanner.Err(); err != nil {
+			return "", err
+		}
+		var (
+			text   = scanner.Text()
+			fields = strings.Split(text, " ")
+			// safe as mountinfo encodes mountpoints with spaces as \040.
+			index               = strings.Index(text, " - ")
+			postSeparatorFields = strings.Fields(text[index+3:])
+			numPostFields       = len(postSeparatorFields)
+		)
+		// this is an error as we can't detect if the mount is for "cgroup"
+		if numPostFields == 0 {
+			return "", fmt.Errorf("Found no fields post '-' in %q", text)
+		}
+		if postSeparatorFields[0] == "cgroup" {
+			// check that the mount is properly formated.
+			if numPostFields < 3 {
+				return "", fmt.Errorf("Error found less than 3 fields post '-' in %q", text)
+			}
+			return filepath.Dir(fields[4]), nil
+		}
+	}
+	return "", ErrMountPointNotExist
+}

vendor/github.com/coreos/go-systemd/LICENSE

@@ -0,0 +1,191 @@
+Apache License
+Version 2.0, January 2004
+http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+"License" shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+"Licensor" shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+"Legal Entity" shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, "control" means (i) the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the
+outstanding shares, or (iii) beneficial ownership of such entity.
+
+"You" (or "Your") shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+"Source" form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+"Object" form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+"Work" shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+"Derivative Works" shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+"Contribution" shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+"submitted" means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as "Not a Contribution."
+
+"Contributor" shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+2. Grant of Copyright License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+3. Grant of Patent License.
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+4. Redistribution.
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+If the Work includes a "NOTICE" text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+5. Submission of Contributions.
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+6. Trademarks.
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty.
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+8. Limitation of Liability.
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability.
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets "[]" replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same "printed page" as the copyright notice for easier identification within
+third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/coreos/go-systemd/README.md

@@ -0,0 +1,54 @@
+# go-systemd
+
+[![Build Status](https://travis-ci.org/coreos/go-systemd.png?branch=master)](https://travis-ci.org/coreos/go-systemd)
+[![godoc](https://godoc.org/github.com/coreos/go-systemd?status.svg)](http://godoc.org/github.com/coreos/go-systemd)
+
+Go bindings to systemd. The project has several packages:
+
+- `activation` - for writing and using socket activation from Go
+- `dbus` - for starting/stopping/inspecting running services and units
+- `journal` - for writing to systemd's logging service, journald
+- `sdjournal` - for reading from journald by wrapping its C API
+- `machine1` - for registering machines/containers with systemd
+- `unit` - for (de)serialization and comparison of unit files
+
+## Socket Activation
+
+An example HTTP server using socket activation can be quickly set up by following this README on a Linux machine running systemd:
+
+https://github.com/coreos/go-systemd/tree/master/examples/activation/httpserver
+
+## Journal
+
+Using the pure-Go `journal` package you can submit journal entries directly to systemd's journal, taking advantage of features like indexed key/value pairs for each log entry.
+The `sdjournal` package provides read access to the journal by wrapping around journald's native C API; consequently it requires cgo and the journal headers to be available.
+
+## D-Bus
+
+The `dbus` package connects to the [systemd D-Bus API](http://www.freedesktop.org/wiki/Software/systemd/dbus/) and lets you start, stop and introspect systemd units. The API docs are here:
+
+http://godoc.org/github.com/coreos/go-systemd/dbus
+
+### Debugging
+
+Create `/etc/dbus-1/system-local.conf` that looks like this:
+
+```
+<!DOCTYPE busconfig PUBLIC
+"-//freedesktop//DTD D-Bus Bus Configuration 1.0//EN"
+"http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+    <policy user="root">
+        <allow eavesdrop="true"/>
+        <allow eavesdrop="true" send_destination="*"/>
+    </policy>
+</busconfig>
+```
+
+## machined
+
+The `machine1` package allows interaction with the [systemd machined D-Bus API](http://www.freedesktop.org/wiki/Software/systemd/machined/).
+
+## Units
+
+The `unit` package provides various functions for working with [systemd unit files](http://www.freedesktop.org/software/systemd/man/systemd.unit.html).

vendor/github.com/coreos/go-systemd/dbus/dbus.go

@@ -0,0 +1,213 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Integration with the systemd D-Bus API.  See http://www.freedesktop.org/wiki/Software/systemd/dbus/
+package dbus
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/godbus/dbus"
+)
+
+const (
+	alpha        = `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`
+	num          = `0123456789`
+	alphanum     = alpha + num
+	signalBuffer = 100
+)
+
+// needsEscape checks whether a byte in a potential dbus ObjectPath needs to be escaped
+func needsEscape(i int, b byte) bool {
+	// Escape everything that is not a-z-A-Z-0-9
+	// Also escape 0-9 if it's the first character
+	return strings.IndexByte(alphanum, b) == -1 ||
+		(i == 0 && strings.IndexByte(num, b) != -1)
+}
+
+// PathBusEscape sanitizes a constituent string of a dbus ObjectPath using the
+// rules that systemd uses for serializing special characters.
+func PathBusEscape(path string) string {
+	// Special case the empty string
+	if len(path) == 0 {
+		return "_"
+	}
+	n := []byte{}
+	for i := 0; i < len(path); i++ {
+		c := path[i]
+		if needsEscape(i, c) {
+			e := fmt.Sprintf("_%x", c)
+			n = append(n, []byte(e)...)
+		} else {
+			n = append(n, c)
+		}
+	}
+	return string(n)
+}
+
+// Conn is a connection to systemd's dbus endpoint.
+type Conn struct {
+	// sysconn/sysobj are only used to call dbus methods
+	sysconn *dbus.Conn
+	sysobj  dbus.BusObject
+
+	// sigconn/sigobj are only used to receive dbus signals
+	sigconn *dbus.Conn
+	sigobj  dbus.BusObject
+
+	jobListener struct {
+		jobs map[dbus.ObjectPath]chan<- string
+		sync.Mutex
+	}
+	subscriber struct {
+		updateCh chan<- *SubStateUpdate
+		errCh    chan<- error
+		sync.Mutex
+		ignore      map[dbus.ObjectPath]int64
+		cleanIgnore int64
+	}
+}
+
+// New establishes a connection to any available bus and authenticates.
+// Callers should call Close() when done with the connection.
+func New() (*Conn, error) {
+	conn, err := NewSystemConnection()
+	if err != nil && os.Geteuid() == 0 {
+		return NewSystemdConnection()
+	}
+	return conn, err
+}
+
+// NewSystemConnection establishes a connection to the system bus and authenticates.
+// Callers should call Close() when done with the connection
+func NewSystemConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		return dbusAuthHelloConnection(dbus.SystemBusPrivate)
+	})
+}
+
+// NewUserConnection establishes a connection to the session bus and
+// authenticates. This can be used to connect to systemd user instances.
+// Callers should call Close() when done with the connection.
+func NewUserConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		return dbusAuthHelloConnection(dbus.SessionBusPrivate)
+	})
+}
+
+// NewSystemdConnection establishes a private, direct connection to systemd.
+// This can be used for communicating with systemd without a dbus daemon.
+// Callers should call Close() when done with the connection.
+func NewSystemdConnection() (*Conn, error) {
+	return NewConnection(func() (*dbus.Conn, error) {
+		// We skip Hello when talking directly to systemd.
+		return dbusAuthConnection(func() (*dbus.Conn, error) {
+			return dbus.Dial("unix:path=/run/systemd/private")
+		})
+	})
+}
+
+// Close closes an established connection
+func (c *Conn) Close() {
+	c.sysconn.Close()
+	c.sigconn.Close()
+}
+
+// NewConnection establishes a connection to a bus using a caller-supplied function.
+// This allows connecting to remote buses through a user-supplied mechanism.
+// The supplied function may be called multiple times, and should return independent connections.
+// The returned connection must be fully initialised: the org.freedesktop.DBus.Hello call must have succeeded,
+// and any authentication should be handled by the function.
+func NewConnection(dialBus func() (*dbus.Conn, error)) (*Conn, error) {
+	sysconn, err := dialBus()
+	if err != nil {
+		return nil, err
+	}
+
+	sigconn, err := dialBus()
+	if err != nil {
+		sysconn.Close()
+		return nil, err
+	}
+
+	c := &Conn{
+		sysconn: sysconn,
+		sysobj:  systemdObject(sysconn),
+		sigconn: sigconn,
+		sigobj:  systemdObject(sigconn),
+	}
+
+	c.subscriber.ignore = make(map[dbus.ObjectPath]int64)
+	c.jobListener.jobs = make(map[dbus.ObjectPath]chan<- string)
+
+	// Setup the listeners on jobs so that we can get completions
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal', interface='org.freedesktop.systemd1.Manager', member='JobRemoved'")
+
+	c.dispatch()
+	return c, nil
+}
+
+// GetManagerProperty returns the value of a property on the org.freedesktop.systemd1.Manager
+// interface. The value is returned in its string representation, as defined at
+// https://developer.gnome.org/glib/unstable/gvariant-text.html
+func (c *Conn) GetManagerProperty(prop string) (string, error) {
+	variant, err := c.sysobj.GetProperty("org.freedesktop.systemd1.Manager." + prop)
+	if err != nil {
+		return "", err
+	}
+	return variant.String(), nil
+}
+
+func dbusAuthConnection(createBus func() (*dbus.Conn, error)) (*dbus.Conn, error) {
+	conn, err := createBus()
+	if err != nil {
+		return nil, err
+	}
+
+	// Only use EXTERNAL method, and hardcode the uid (not username)
+	// to avoid a username lookup (which requires a dynamically linked
+	// libc)
+	methods := []dbus.Auth{dbus.AuthExternal(strconv.Itoa(os.Getuid()))}
+
+	err = conn.Auth(methods)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func dbusAuthHelloConnection(createBus func() (*dbus.Conn, error)) (*dbus.Conn, error) {
+	conn, err := dbusAuthConnection(createBus)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = conn.Hello(); err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	return conn, nil
+}
+
+func systemdObject(conn *dbus.Conn) dbus.BusObject {
+	return conn.Object("org.freedesktop.systemd1", dbus.ObjectPath("/org/freedesktop/systemd1"))
+}

vendor/github.com/coreos/go-systemd/dbus/methods.go

@@ -0,0 +1,565 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"errors"
+	"path"
+	"strconv"
+
+	"github.com/godbus/dbus"
+)
+
+func (c *Conn) jobComplete(signal *dbus.Signal) {
+	var id uint32
+	var job dbus.ObjectPath
+	var unit string
+	var result string
+	dbus.Store(signal.Body, &id, &job, &unit, &result)
+	c.jobListener.Lock()
+	out, ok := c.jobListener.jobs[job]
+	if ok {
+		out <- result
+		delete(c.jobListener.jobs, job)
+	}
+	c.jobListener.Unlock()
+}
+
+func (c *Conn) startJob(ch chan<- string, job string, args ...interface{}) (int, error) {
+	if ch != nil {
+		c.jobListener.Lock()
+		defer c.jobListener.Unlock()
+	}
+
+	var p dbus.ObjectPath
+	err := c.sysobj.Call(job, 0, args...).Store(&p)
+	if err != nil {
+		return 0, err
+	}
+
+	if ch != nil {
+		c.jobListener.jobs[p] = ch
+	}
+
+	// ignore error since 0 is fine if conversion fails
+	jobID, _ := strconv.Atoi(path.Base(string(p)))
+
+	return jobID, nil
+}
+
+// StartUnit enqueues a start job and depending jobs, if any (unless otherwise
+// specified by the mode string).
+//
+// Takes the unit to activate, plus a mode string. The mode needs to be one of
+// replace, fail, isolate, ignore-dependencies, ignore-requirements. If
+// "replace" the call will start the unit and its dependencies, possibly
+// replacing already queued jobs that conflict with this. If "fail" the call
+// will start the unit and its dependencies, but will fail if this would change
+// an already queued job. If "isolate" the call will start the unit in question
+// and terminate all units that aren't dependencies of it. If
+// "ignore-dependencies" it will start a unit but ignore all its dependencies.
+// If "ignore-requirements" it will start a unit but only ignore the
+// requirement dependencies. It is not recommended to make use of the latter
+// two options.
+//
+// If the provided channel is non-nil, a result string will be sent to it upon
+// job completion: one of done, canceled, timeout, failed, dependency, skipped.
+// done indicates successful execution of a job. canceled indicates that a job
+// has been canceled  before it finished execution. timeout indicates that the
+// job timeout was reached. failed indicates that the job failed. dependency
+// indicates that a job this job has been depending on failed and the job hence
+// has been removed too. skipped indicates that a job was skipped because it
+// didn't apply to the units current state.
+//
+// If no error occurs, the ID of the underlying systemd job will be returned. There
+// does exist the possibility for no error to be returned, but for the returned job
+// ID to be 0. In this case, the actual underlying ID is not 0 and this datapoint
+// should not be considered authoritative.
+//
+// If an error does occur, it will be returned to the user alongside a job ID of 0.
+func (c *Conn) StartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StartUnit", name, mode)
+}
+
+// StopUnit is similar to StartUnit but stops the specified unit rather
+// than starting it.
+func (c *Conn) StopUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StopUnit", name, mode)
+}
+
+// ReloadUnit reloads a unit.  Reloading is done only if the unit is already running and fails otherwise.
+func (c *Conn) ReloadUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadUnit", name, mode)
+}
+
+// RestartUnit restarts a service.  If a service is restarted that isn't
+// running it will be started.
+func (c *Conn) RestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.RestartUnit", name, mode)
+}
+
+// TryRestartUnit is like RestartUnit, except that a service that isn't running
+// is not affected by the restart.
+func (c *Conn) TryRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.TryRestartUnit", name, mode)
+}
+
+// ReloadOrRestart attempts a reload if the unit supports it and use a restart
+// otherwise.
+func (c *Conn) ReloadOrRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadOrRestartUnit", name, mode)
+}
+
+// ReloadOrTryRestart attempts a reload if the unit supports it and use a "Try"
+// flavored restart otherwise.
+func (c *Conn) ReloadOrTryRestartUnit(name string, mode string, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.ReloadOrTryRestartUnit", name, mode)
+}
+
+// StartTransientUnit() may be used to create and start a transient unit, which
+// will be released as soon as it is not running or referenced anymore or the
+// system is rebooted. name is the unit name including suffix, and must be
+// unique. mode is the same as in StartUnit(), properties contains properties
+// of the unit.
+func (c *Conn) StartTransientUnit(name string, mode string, properties []Property, ch chan<- string) (int, error) {
+	return c.startJob(ch, "org.freedesktop.systemd1.Manager.StartTransientUnit", name, mode, properties, make([]PropertyCollection, 0))
+}
+
+// KillUnit takes the unit name and a UNIX signal number to send.  All of the unit's
+// processes are killed.
+func (c *Conn) KillUnit(name string, signal int32) {
+	c.sysobj.Call("org.freedesktop.systemd1.Manager.KillUnit", 0, name, "all", signal).Store()
+}
+
+// ResetFailedUnit resets the "failed" state of a specific unit.
+func (c *Conn) ResetFailedUnit(name string) error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.ResetFailedUnit", 0, name).Store()
+}
+
+// getProperties takes the unit name and returns all of its dbus object properties, for the given dbus interface
+func (c *Conn) getProperties(unit string, dbusInterface string) (map[string]interface{}, error) {
+	var err error
+	var props map[string]dbus.Variant
+
+	path := unitPath(unit)
+	if !path.IsValid() {
+		return nil, errors.New("invalid unit name: " + unit)
+	}
+
+	obj := c.sysconn.Object("org.freedesktop.systemd1", path)
+	err = obj.Call("org.freedesktop.DBus.Properties.GetAll", 0, dbusInterface).Store(&props)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make(map[string]interface{}, len(props))
+	for k, v := range props {
+		out[k] = v.Value()
+	}
+
+	return out, nil
+}
+
+// GetUnitProperties takes the unit name and returns all of its dbus object properties.
+func (c *Conn) GetUnitProperties(unit string) (map[string]interface{}, error) {
+	return c.getProperties(unit, "org.freedesktop.systemd1.Unit")
+}
+
+func (c *Conn) getProperty(unit string, dbusInterface string, propertyName string) (*Property, error) {
+	var err error
+	var prop dbus.Variant
+
+	path := unitPath(unit)
+	if !path.IsValid() {
+		return nil, errors.New("invalid unit name: " + unit)
+	}
+
+	obj := c.sysconn.Object("org.freedesktop.systemd1", path)
+	err = obj.Call("org.freedesktop.DBus.Properties.Get", 0, dbusInterface, propertyName).Store(&prop)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Property{Name: propertyName, Value: prop}, nil
+}
+
+func (c *Conn) GetUnitProperty(unit string, propertyName string) (*Property, error) {
+	return c.getProperty(unit, "org.freedesktop.systemd1.Unit", propertyName)
+}
+
+// GetServiceProperty returns property for given service name and property name
+func (c *Conn) GetServiceProperty(service string, propertyName string) (*Property, error) {
+	return c.getProperty(service, "org.freedesktop.systemd1.Service", propertyName)
+}
+
+// GetUnitTypeProperties returns the extra properties for a unit, specific to the unit type.
+// Valid values for unitType: Service, Socket, Target, Device, Mount, Automount, Snapshot, Timer, Swap, Path, Slice, Scope
+// return "dbus.Error: Unknown interface" if the unitType is not the correct type of the unit
+func (c *Conn) GetUnitTypeProperties(unit string, unitType string) (map[string]interface{}, error) {
+	return c.getProperties(unit, "org.freedesktop.systemd1."+unitType)
+}
+
+// SetUnitProperties() may be used to modify certain unit properties at runtime.
+// Not all properties may be changed at runtime, but many resource management
+// settings (primarily those in systemd.cgroup(5)) may. The changes are applied
+// instantly, and stored on disk for future boots, unless runtime is true, in which
+// case the settings only apply until the next reboot. name is the name of the unit
+// to modify. properties are the settings to set, encoded as an array of property
+// name and value pairs.
+func (c *Conn) SetUnitProperties(name string, runtime bool, properties ...Property) error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.SetUnitProperties", 0, name, runtime, properties).Store()
+}
+
+func (c *Conn) GetUnitTypeProperty(unit string, unitType string, propertyName string) (*Property, error) {
+	return c.getProperty(unit, "org.freedesktop.systemd1."+unitType, propertyName)
+}
+
+type UnitStatus struct {
+	Name        string          // The primary unit name as string
+	Description string          // The human readable description string
+	LoadState   string          // The load state (i.e. whether the unit file has been loaded successfully)
+	ActiveState string          // The active state (i.e. whether the unit is currently started or not)
+	SubState    string          // The sub state (a more fine-grained version of the active state that is specific to the unit type, which the active state is not)
+	Followed    string          // A unit that is being followed in its state by this unit, if there is any, otherwise the empty string.
+	Path        dbus.ObjectPath // The unit object path
+	JobId       uint32          // If there is a job queued for the job unit the numeric job id, 0 otherwise
+	JobType     string          // The job type as string
+	JobPath     dbus.ObjectPath // The job object path
+}
+
+type storeFunc func(retvalues ...interface{}) error
+
+func (c *Conn) listUnitsInternal(f storeFunc) ([]UnitStatus, error) {
+	result := make([][]interface{}, 0)
+	err := f(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	status := make([]UnitStatus, len(result))
+	statusInterface := make([]interface{}, len(status))
+	for i := range status {
+		statusInterface[i] = &status[i]
+	}
+
+	err = dbus.Store(resultInterface, statusInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return status, nil
+}
+
+// ListUnits returns an array with all currently loaded units. Note that
+// units may be known by multiple names at the same time, and hence there might
+// be more unit names loaded than actual units behind them.
+func (c *Conn) ListUnits() ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnits", 0).Store)
+}
+
+// ListUnitsFiltered returns an array with units filtered by state.
+// It takes a list of units' statuses to filter.
+func (c *Conn) ListUnitsFiltered(states []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsFiltered", 0, states).Store)
+}
+
+// ListUnitsByPatterns returns an array with units.
+// It takes a list of units' statuses and names to filter.
+// Note that units may be known by multiple names at the same time,
+// and hence there might be more unit names loaded than actual units behind them.
+func (c *Conn) ListUnitsByPatterns(states []string, patterns []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsByPatterns", 0, states, patterns).Store)
+}
+
+// ListUnitsByNames returns an array with units. It takes a list of units'
+// names and returns an UnitStatus array. Comparing to ListUnitsByPatterns
+// method, this method returns statuses even for inactive or non-existing
+// units. Input array should contain exact unit names, but not patterns.
+func (c *Conn) ListUnitsByNames(units []string) ([]UnitStatus, error) {
+	return c.listUnitsInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitsByNames", 0, units).Store)
+}
+
+type UnitFile struct {
+	Path string
+	Type string
+}
+
+func (c *Conn) listUnitFilesInternal(f storeFunc) ([]UnitFile, error) {
+	result := make([][]interface{}, 0)
+	err := f(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	files := make([]UnitFile, len(result))
+	fileInterface := make([]interface{}, len(files))
+	for i := range files {
+		fileInterface[i] = &files[i]
+	}
+
+	err = dbus.Store(resultInterface, fileInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return files, nil
+}
+
+// ListUnitFiles returns an array of all available units on disk.
+func (c *Conn) ListUnitFiles() ([]UnitFile, error) {
+	return c.listUnitFilesInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitFiles", 0).Store)
+}
+
+// ListUnitFilesByPatterns returns an array of all available units on disk matched the patterns.
+func (c *Conn) ListUnitFilesByPatterns(states []string, patterns []string) ([]UnitFile, error) {
+	return c.listUnitFilesInternal(c.sysobj.Call("org.freedesktop.systemd1.Manager.ListUnitFilesByPatterns", 0, states, patterns).Store)
+}
+
+type LinkUnitFileChange EnableUnitFileChange
+
+// LinkUnitFiles() links unit files (that are located outside of the
+// usual unit search paths) into the unit search path.
+//
+// It takes a list of absolute paths to unit files to link and two
+// booleans. The first boolean controls whether the unit shall be
+// enabled for runtime only (true, /run), or persistently (false,
+// /etc).
+// The second controls whether symlinks pointing to other units shall
+// be replaced if necessary.
+//
+// This call returns a list of the changes made. The list consists of
+// structures with three strings: the type of the change (one of symlink
+// or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) LinkUnitFiles(files []string, runtime bool, force bool) ([]LinkUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.LinkUnitFiles", 0, files, runtime, force).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]LinkUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+// EnableUnitFiles() may be used to enable one or more units in the system (by
+// creating symlinks to them in /etc or /run).
+//
+// It takes a list of unit files to enable (either just file names or full
+// absolute paths if the unit files are residing outside the usual unit
+// search paths), and two booleans: the first controls whether the unit shall
+// be enabled for runtime only (true, /run), or persistently (false, /etc).
+// The second one controls whether symlinks pointing to other units shall
+// be replaced if necessary.
+//
+// This call returns one boolean and an array with the changes made. The
+// boolean signals whether the unit files contained any enablement
+// information (i.e. an [Install]) section. The changes list consists of
+// structures with three strings: the type of the change (one of symlink
+// or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) EnableUnitFiles(files []string, runtime bool, force bool) (bool, []EnableUnitFileChange, error) {
+	var carries_install_info bool
+
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.EnableUnitFiles", 0, files, runtime, force).Store(&carries_install_info, &result)
+	if err != nil {
+		return false, nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]EnableUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return false, nil, err
+	}
+
+	return carries_install_info, changes, nil
+}
+
+type EnableUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// DisableUnitFiles() may be used to disable one or more units in the system (by
+// removing symlinks to them from /etc or /run).
+//
+// It takes a list of unit files to disable (either just file names or full
+// absolute paths if the unit files are residing outside the usual unit
+// search paths), and one boolean: whether the unit was enabled for runtime
+// only (true, /run), or persistently (false, /etc).
+//
+// This call returns an array with the changes made. The changes list
+// consists of structures with three strings: the type of the change (one of
+// symlink or unlink), the file name of the symlink and the destination of the
+// symlink.
+func (c *Conn) DisableUnitFiles(files []string, runtime bool) ([]DisableUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.DisableUnitFiles", 0, files, runtime).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]DisableUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type DisableUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// MaskUnitFiles masks one or more units in the system
+//
+// It takes three arguments:
+//   * list of units to mask (either just file names or full
+//     absolute paths if the unit files are residing outside
+//     the usual unit search paths)
+//   * runtime to specify whether the unit was enabled for runtime
+//     only (true, /run/systemd/..), or persistently (false, /etc/systemd/..)
+//   * force flag
+func (c *Conn) MaskUnitFiles(files []string, runtime bool, force bool) ([]MaskUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.MaskUnitFiles", 0, files, runtime, force).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]MaskUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type MaskUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// UnmaskUnitFiles unmasks one or more units in the system
+//
+// It takes two arguments:
+//   * list of unit files to mask (either just file names or full
+//     absolute paths if the unit files are residing outside
+//     the usual unit search paths)
+//   * runtime to specify whether the unit was enabled for runtime
+//     only (true, /run/systemd/..), or persistently (false, /etc/systemd/..)
+func (c *Conn) UnmaskUnitFiles(files []string, runtime bool) ([]UnmaskUnitFileChange, error) {
+	result := make([][]interface{}, 0)
+	err := c.sysobj.Call("org.freedesktop.systemd1.Manager.UnmaskUnitFiles", 0, files, runtime).Store(&result)
+	if err != nil {
+		return nil, err
+	}
+
+	resultInterface := make([]interface{}, len(result))
+	for i := range result {
+		resultInterface[i] = result[i]
+	}
+
+	changes := make([]UnmaskUnitFileChange, len(result))
+	changesInterface := make([]interface{}, len(changes))
+	for i := range changes {
+		changesInterface[i] = &changes[i]
+	}
+
+	err = dbus.Store(resultInterface, changesInterface...)
+	if err != nil {
+		return nil, err
+	}
+
+	return changes, nil
+}
+
+type UnmaskUnitFileChange struct {
+	Type        string // Type of the change (one of symlink or unlink)
+	Filename    string // File name of the symlink
+	Destination string // Destination of the symlink
+}
+
+// Reload instructs systemd to scan for and reload unit files. This is
+// equivalent to a 'systemctl daemon-reload'.
+func (c *Conn) Reload() error {
+	return c.sysobj.Call("org.freedesktop.systemd1.Manager.Reload", 0).Store()
+}
+
+func unitPath(name string) dbus.ObjectPath {
+	return dbus.ObjectPath("/org/freedesktop/systemd1/unit/" + PathBusEscape(name))
+}

vendor/github.com/coreos/go-systemd/dbus/properties.go

@@ -0,0 +1,237 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"github.com/godbus/dbus"
+)
+
+// From the systemd docs:
+//
+// The properties array of StartTransientUnit() may take many of the settings
+// that may also be configured in unit files. Not all parameters are currently
+// accepted though, but we plan to cover more properties with future release.
+// Currently you may set the Description, Slice and all dependency types of
+// units, as well as RemainAfterExit, ExecStart for service units,
+// TimeoutStopUSec and PIDs for scope units, and CPUAccounting, CPUShares,
+// BlockIOAccounting, BlockIOWeight, BlockIOReadBandwidth,
+// BlockIOWriteBandwidth, BlockIODeviceWeight, MemoryAccounting, MemoryLimit,
+// DevicePolicy, DeviceAllow for services/scopes/slices. These fields map
+// directly to their counterparts in unit files and as normal D-Bus object
+// properties. The exception here is the PIDs field of scope units which is
+// used for construction of the scope only and specifies the initial PIDs to
+// add to the scope object.
+
+type Property struct {
+	Name  string
+	Value dbus.Variant
+}
+
+type PropertyCollection struct {
+	Name       string
+	Properties []Property
+}
+
+type execStart struct {
+	Path             string   // the binary path to execute
+	Args             []string // an array with all arguments to pass to the executed command, starting with argument 0
+	UncleanIsFailure bool     // a boolean whether it should be considered a failure if the process exits uncleanly
+}
+
+// PropExecStart sets the ExecStart service property.  The first argument is a
+// slice with the binary path to execute followed by the arguments to pass to
+// the executed command. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#ExecStart=
+func PropExecStart(command []string, uncleanIsFailure bool) Property {
+	execStarts := []execStart{
+		execStart{
+			Path:             command[0],
+			Args:             command,
+			UncleanIsFailure: uncleanIsFailure,
+		},
+	}
+
+	return Property{
+		Name:  "ExecStart",
+		Value: dbus.MakeVariant(execStarts),
+	}
+}
+
+// PropRemainAfterExit sets the RemainAfterExit service property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#RemainAfterExit=
+func PropRemainAfterExit(b bool) Property {
+	return Property{
+		Name:  "RemainAfterExit",
+		Value: dbus.MakeVariant(b),
+	}
+}
+
+// PropType sets the Type service property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.service.html#Type=
+func PropType(t string) Property {
+	return Property{
+		Name:  "Type",
+		Value: dbus.MakeVariant(t),
+	}
+}
+
+// PropDescription sets the Description unit property. See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit#Description=
+func PropDescription(desc string) Property {
+	return Property{
+		Name:  "Description",
+		Value: dbus.MakeVariant(desc),
+	}
+}
+
+func propDependency(name string, units []string) Property {
+	return Property{
+		Name:  name,
+		Value: dbus.MakeVariant(units),
+	}
+}
+
+// PropRequires sets the Requires unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Requires=
+func PropRequires(units ...string) Property {
+	return propDependency("Requires", units)
+}
+
+// PropRequiresOverridable sets the RequiresOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiresOverridable=
+func PropRequiresOverridable(units ...string) Property {
+	return propDependency("RequiresOverridable", units)
+}
+
+// PropRequisite sets the Requisite unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Requisite=
+func PropRequisite(units ...string) Property {
+	return propDependency("Requisite", units)
+}
+
+// PropRequisiteOverridable sets the RequisiteOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequisiteOverridable=
+func PropRequisiteOverridable(units ...string) Property {
+	return propDependency("RequisiteOverridable", units)
+}
+
+// PropWants sets the Wants unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Wants=
+func PropWants(units ...string) Property {
+	return propDependency("Wants", units)
+}
+
+// PropBindsTo sets the BindsTo unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#BindsTo=
+func PropBindsTo(units ...string) Property {
+	return propDependency("BindsTo", units)
+}
+
+// PropRequiredBy sets the RequiredBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiredBy=
+func PropRequiredBy(units ...string) Property {
+	return propDependency("RequiredBy", units)
+}
+
+// PropRequiredByOverridable sets the RequiredByOverridable unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiredByOverridable=
+func PropRequiredByOverridable(units ...string) Property {
+	return propDependency("RequiredByOverridable", units)
+}
+
+// PropWantedBy sets the WantedBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#WantedBy=
+func PropWantedBy(units ...string) Property {
+	return propDependency("WantedBy", units)
+}
+
+// PropBoundBy sets the BoundBy unit property.  See
+// http://www.freedesktop.org/software/systemd/main/systemd.unit.html#BoundBy=
+func PropBoundBy(units ...string) Property {
+	return propDependency("BoundBy", units)
+}
+
+// PropConflicts sets the Conflicts unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Conflicts=
+func PropConflicts(units ...string) Property {
+	return propDependency("Conflicts", units)
+}
+
+// PropConflictedBy sets the ConflictedBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#ConflictedBy=
+func PropConflictedBy(units ...string) Property {
+	return propDependency("ConflictedBy", units)
+}
+
+// PropBefore sets the Before unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Before=
+func PropBefore(units ...string) Property {
+	return propDependency("Before", units)
+}
+
+// PropAfter sets the After unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#After=
+func PropAfter(units ...string) Property {
+	return propDependency("After", units)
+}
+
+// PropOnFailure sets the OnFailure unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#OnFailure=
+func PropOnFailure(units ...string) Property {
+	return propDependency("OnFailure", units)
+}
+
+// PropTriggers sets the Triggers unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#Triggers=
+func PropTriggers(units ...string) Property {
+	return propDependency("Triggers", units)
+}
+
+// PropTriggeredBy sets the TriggeredBy unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#TriggeredBy=
+func PropTriggeredBy(units ...string) Property {
+	return propDependency("TriggeredBy", units)
+}
+
+// PropPropagatesReloadTo sets the PropagatesReloadTo unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#PropagatesReloadTo=
+func PropPropagatesReloadTo(units ...string) Property {
+	return propDependency("PropagatesReloadTo", units)
+}
+
+// PropRequiresMountsFor sets the RequiresMountsFor unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.unit.html#RequiresMountsFor=
+func PropRequiresMountsFor(units ...string) Property {
+	return propDependency("RequiresMountsFor", units)
+}
+
+// PropSlice sets the Slice unit property.  See
+// http://www.freedesktop.org/software/systemd/man/systemd.resource-control.html#Slice=
+func PropSlice(slice string) Property {
+	return Property{
+		Name:  "Slice",
+		Value: dbus.MakeVariant(slice),
+	}
+}
+
+// PropPids sets the PIDs field of scope units used in the initial construction
+// of the scope only and specifies the initial PIDs to add to the scope object.
+// See https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/#properties
+func PropPids(pids ...uint32) Property {
+	return Property{
+		Name:  "PIDs",
+		Value: dbus.MakeVariant(pids),
+	}
+}

vendor/github.com/coreos/go-systemd/dbus/set.go

@@ -0,0 +1,47 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+type set struct {
+	data map[string]bool
+}
+
+func (s *set) Add(value string) {
+	s.data[value] = true
+}
+
+func (s *set) Remove(value string) {
+	delete(s.data, value)
+}
+
+func (s *set) Contains(value string) (exists bool) {
+	_, exists = s.data[value]
+	return
+}
+
+func (s *set) Length() int {
+	return len(s.data)
+}
+
+func (s *set) Values() (values []string) {
+	for val, _ := range s.data {
+		values = append(values, val)
+	}
+	return
+}
+
+func newSet() *set {
+	return &set{make(map[string]bool)}
+}

vendor/github.com/coreos/go-systemd/dbus/subscription.go

@@ -0,0 +1,250 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"errors"
+	"time"
+
+	"github.com/godbus/dbus"
+)
+
+const (
+	cleanIgnoreInterval = int64(10 * time.Second)
+	ignoreInterval      = int64(30 * time.Millisecond)
+)
+
+// Subscribe sets up this connection to subscribe to all systemd dbus events.
+// This is required before calling SubscribeUnits. When the connection closes
+// systemd will automatically stop sending signals so there is no need to
+// explicitly call Unsubscribe().
+func (c *Conn) Subscribe() error {
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal',interface='org.freedesktop.systemd1.Manager',member='UnitNew'")
+	c.sigconn.BusObject().Call("org.freedesktop.DBus.AddMatch", 0,
+		"type='signal',interface='org.freedesktop.DBus.Properties',member='PropertiesChanged'")
+
+	err := c.sigobj.Call("org.freedesktop.systemd1.Manager.Subscribe", 0).Store()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Unsubscribe this connection from systemd dbus events.
+func (c *Conn) Unsubscribe() error {
+	err := c.sigobj.Call("org.freedesktop.systemd1.Manager.Unsubscribe", 0).Store()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *Conn) dispatch() {
+	ch := make(chan *dbus.Signal, signalBuffer)
+
+	c.sigconn.Signal(ch)
+
+	go func() {
+		for {
+			signal, ok := <-ch
+			if !ok {
+				return
+			}
+
+			if signal.Name == "org.freedesktop.systemd1.Manager.JobRemoved" {
+				c.jobComplete(signal)
+			}
+
+			if c.subscriber.updateCh == nil {
+				continue
+			}
+
+			var unitPath dbus.ObjectPath
+			switch signal.Name {
+			case "org.freedesktop.systemd1.Manager.JobRemoved":
+				unitName := signal.Body[2].(string)
+				c.sysobj.Call("org.freedesktop.systemd1.Manager.GetUnit", 0, unitName).Store(&unitPath)
+			case "org.freedesktop.systemd1.Manager.UnitNew":
+				unitPath = signal.Body[1].(dbus.ObjectPath)
+			case "org.freedesktop.DBus.Properties.PropertiesChanged":
+				if signal.Body[0].(string) == "org.freedesktop.systemd1.Unit" {
+					unitPath = signal.Path
+				}
+			}
+
+			if unitPath == dbus.ObjectPath("") {
+				continue
+			}
+
+			c.sendSubStateUpdate(unitPath)
+		}
+	}()
+}
+
+// Returns two unbuffered channels which will receive all changed units every
+// interval.  Deleted units are sent as nil.
+func (c *Conn) SubscribeUnits(interval time.Duration) (<-chan map[string]*UnitStatus, <-chan error) {
+	return c.SubscribeUnitsCustom(interval, 0, func(u1, u2 *UnitStatus) bool { return *u1 != *u2 }, nil)
+}
+
+// SubscribeUnitsCustom is like SubscribeUnits but lets you specify the buffer
+// size of the channels, the comparison function for detecting changes and a filter
+// function for cutting down on the noise that your channel receives.
+func (c *Conn) SubscribeUnitsCustom(interval time.Duration, buffer int, isChanged func(*UnitStatus, *UnitStatus) bool, filterUnit func(string) bool) (<-chan map[string]*UnitStatus, <-chan error) {
+	old := make(map[string]*UnitStatus)
+	statusChan := make(chan map[string]*UnitStatus, buffer)
+	errChan := make(chan error, buffer)
+
+	go func() {
+		for {
+			timerChan := time.After(interval)
+
+			units, err := c.ListUnits()
+			if err == nil {
+				cur := make(map[string]*UnitStatus)
+				for i := range units {
+					if filterUnit != nil && filterUnit(units[i].Name) {
+						continue
+					}
+					cur[units[i].Name] = &units[i]
+				}
+
+				// add all new or changed units
+				changed := make(map[string]*UnitStatus)
+				for n, u := range cur {
+					if oldU, ok := old[n]; !ok || isChanged(oldU, u) {
+						changed[n] = u
+					}
+					delete(old, n)
+				}
+
+				// add all deleted units
+				for oldN := range old {
+					changed[oldN] = nil
+				}
+
+				old = cur
+
+				if len(changed) != 0 {
+					statusChan <- changed
+				}
+			} else {
+				errChan <- err
+			}
+
+			<-timerChan
+		}
+	}()
+
+	return statusChan, errChan
+}
+
+type SubStateUpdate struct {
+	UnitName string
+	SubState string
+}
+
+// SetSubStateSubscriber writes to updateCh when any unit's substate changes.
+// Although this writes to updateCh on every state change, the reported state
+// may be more recent than the change that generated it (due to an unavoidable
+// race in the systemd dbus interface).  That is, this method provides a good
+// way to keep a current view of all units' states, but is not guaranteed to
+// show every state transition they go through.  Furthermore, state changes
+// will only be written to the channel with non-blocking writes.  If updateCh
+// is full, it attempts to write an error to errCh; if errCh is full, the error
+// passes silently.
+func (c *Conn) SetSubStateSubscriber(updateCh chan<- *SubStateUpdate, errCh chan<- error) {
+	c.subscriber.Lock()
+	defer c.subscriber.Unlock()
+	c.subscriber.updateCh = updateCh
+	c.subscriber.errCh = errCh
+}
+
+func (c *Conn) sendSubStateUpdate(path dbus.ObjectPath) {
+	c.subscriber.Lock()
+	defer c.subscriber.Unlock()
+
+	if c.shouldIgnore(path) {
+		return
+	}
+
+	info, err := c.GetUnitProperties(string(path))
+	if err != nil {
+		select {
+		case c.subscriber.errCh <- err:
+		default:
+		}
+	}
+
+	name := info["Id"].(string)
+	substate := info["SubState"].(string)
+
+	update := &SubStateUpdate{name, substate}
+	select {
+	case c.subscriber.updateCh <- update:
+	default:
+		select {
+		case c.subscriber.errCh <- errors.New("update channel full!"):
+		default:
+		}
+	}
+
+	c.updateIgnore(path, info)
+}
+
+// The ignore functions work around a wart in the systemd dbus interface.
+// Requesting the properties of an unloaded unit will cause systemd to send a
+// pair of UnitNew/UnitRemoved signals.  Because we need to get a unit's
+// properties on UnitNew (as that's the only indication of a new unit coming up
+// for the first time), we would enter an infinite loop if we did not attempt
+// to detect and ignore these spurious signals.  The signal themselves are
+// indistinguishable from relevant ones, so we (somewhat hackishly) ignore an
+// unloaded unit's signals for a short time after requesting its properties.
+// This means that we will miss e.g. a transient unit being restarted
+// *immediately* upon failure and also a transient unit being started
+// immediately after requesting its status (with systemctl status, for example,
+// because this causes a UnitNew signal to be sent which then causes us to fetch
+// the properties).
+
+func (c *Conn) shouldIgnore(path dbus.ObjectPath) bool {
+	t, ok := c.subscriber.ignore[path]
+	return ok && t >= time.Now().UnixNano()
+}
+
+func (c *Conn) updateIgnore(path dbus.ObjectPath, info map[string]interface{}) {
+	c.cleanIgnore()
+
+	// unit is unloaded - it will trigger bad systemd dbus behavior
+	if info["LoadState"].(string) == "not-found" {
+		c.subscriber.ignore[path] = time.Now().UnixNano() + ignoreInterval
+	}
+}
+
+// without this, ignore would grow unboundedly over time
+func (c *Conn) cleanIgnore() {
+	now := time.Now().UnixNano()
+	if c.subscriber.cleanIgnore < now {
+		c.subscriber.cleanIgnore = now + cleanIgnoreInterval
+
+		for p, t := range c.subscriber.ignore {
+			if t < now {
+				delete(c.subscriber.ignore, p)
+			}
+		}
+	}
+}

vendor/github.com/coreos/go-systemd/dbus/subscription_set.go

@@ -0,0 +1,57 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dbus
+
+import (
+	"time"
+)
+
+// SubscriptionSet returns a subscription set which is like conn.Subscribe but
+// can filter to only return events for a set of units.
+type SubscriptionSet struct {
+	*set
+	conn *Conn
+}
+
+func (s *SubscriptionSet) filter(unit string) bool {
+	return !s.Contains(unit)
+}
+
+// Subscribe starts listening for dbus events for all of the units in the set.
+// Returns channels identical to conn.SubscribeUnits.
+func (s *SubscriptionSet) Subscribe() (<-chan map[string]*UnitStatus, <-chan error) {
+	// TODO: Make fully evented by using systemd 209 with properties changed values
+	return s.conn.SubscribeUnitsCustom(time.Second, 0,
+		mismatchUnitStatus,
+		func(unit string) bool { return s.filter(unit) },
+	)
+}
+
+// NewSubscriptionSet returns a new subscription set.
+func (conn *Conn) NewSubscriptionSet() *SubscriptionSet {
+	return &SubscriptionSet{newSet(), conn}
+}
+
+// mismatchUnitStatus returns true if the provided UnitStatus objects
+// are not equivalent. false is returned if the objects are equivalent.
+// Only the Name, Description and state-related fields are used in
+// the comparison.
+func mismatchUnitStatus(u1, u2 *UnitStatus) bool {
+	return u1.Name != u2.Name ||
+		u1.Description != u2.Description ||
+		u1.LoadState != u2.LoadState ||
+		u1.ActiveState != u2.ActiveState ||
+		u1.SubState != u2.SubState
+}

vendor/github.com/docker/go-units/LICENSE

@@ -0,0 +1,191 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        https://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   Copyright 2015 Docker, Inc.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       https://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/docker/go-units/README.md

@@ -0,0 +1,16 @@
+[![GoDoc](https://godoc.org/github.com/docker/go-units?status.svg)](https://godoc.org/github.com/docker/go-units)
+
+# Introduction
+
+go-units is a library to transform human friendly measurements into machine friendly values.
+
+## Usage
+
+See the [docs in godoc](https://godoc.org/github.com/docker/go-units) for examples and documentation.
+
+## Copyright and license
+
+Copyright © 2015 Docker, Inc.
+
+go-units is licensed under the Apache License, Version 2.0.
+See [LICENSE](LICENSE) for the full text of the license.

vendor/github.com/docker/go-units/duration.go

@@ -0,0 +1,35 @@
+// Package units provides helper function to parse and print size and time units
+// in human-readable format.
+package units
+
+import (
+	"fmt"
+	"time"
+)
+
+// HumanDuration returns a human-readable approximation of a duration
+// (eg. "About a minute", "4 hours ago", etc.).
+func HumanDuration(d time.Duration) string {
+	if seconds := int(d.Seconds()); seconds < 1 {
+		return "Less than a second"
+	} else if seconds == 1 {
+		return "1 second"
+	} else if seconds < 60 {
+		return fmt.Sprintf("%d seconds", seconds)
+	} else if minutes := int(d.Minutes()); minutes == 1 {
+		return "About a minute"
+	} else if minutes < 46 {
+		return fmt.Sprintf("%d minutes", minutes)
+	} else if hours := int(d.Hours() + 0.5); hours == 1 {
+		return "About an hour"
+	} else if hours < 48 {
+		return fmt.Sprintf("%d hours", hours)
+	} else if hours < 24*7*2 {
+		return fmt.Sprintf("%d days", hours/24)
+	} else if hours < 24*30*2 {
+		return fmt.Sprintf("%d weeks", hours/24/7)
+	} else if hours < 24*365*2 {
+		return fmt.Sprintf("%d months", hours/24/30)
+	}
+	return fmt.Sprintf("%d years", int(d.Hours())/24/365)
+}

vendor/github.com/docker/go-units/size.go

@@ -0,0 +1,108 @@
+package units
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// See: http://en.wikipedia.org/wiki/Binary_prefix
+const (
+	// Decimal
+
+	KB = 1000
+	MB = 1000 * KB
+	GB = 1000 * MB
+	TB = 1000 * GB
+	PB = 1000 * TB
+
+	// Binary
+
+	KiB = 1024
+	MiB = 1024 * KiB
+	GiB = 1024 * MiB
+	TiB = 1024 * GiB
+	PiB = 1024 * TiB
+)
+
+type unitMap map[string]int64
+
+var (
+	decimalMap = unitMap{"k": KB, "m": MB, "g": GB, "t": TB, "p": PB}
+	binaryMap  = unitMap{"k": KiB, "m": MiB, "g": GiB, "t": TiB, "p": PiB}
+	sizeRegex  = regexp.MustCompile(`^(\d+(\.\d+)*) ?([kKmMgGtTpP])?[bB]?$`)
+)
+
+var decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
+var binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
+
+func getSizeAndUnit(size float64, base float64, _map []string) (float64, string) {
+	i := 0
+	unitsLimit := len(_map) - 1
+	for size >= base && i < unitsLimit {
+		size = size / base
+		i++
+	}
+	return size, _map[i]
+}
+
+// CustomSize returns a human-readable approximation of a size
+// using custom format.
+func CustomSize(format string, size float64, base float64, _map []string) string {
+	size, unit := getSizeAndUnit(size, base, _map)
+	return fmt.Sprintf(format, size, unit)
+}
+
+// HumanSizeWithPrecision allows the size to be in any precision,
+// instead of 4 digit precision used in units.HumanSize.
+func HumanSizeWithPrecision(size float64, precision int) string {
+	size, unit := getSizeAndUnit(size, 1000.0, decimapAbbrs)
+	return fmt.Sprintf("%.*g%s", precision, size, unit)
+}
+
+// HumanSize returns a human-readable approximation of a size
+// capped at 4 valid numbers (eg. "2.746 MB", "796 KB").
+func HumanSize(size float64) string {
+	return HumanSizeWithPrecision(size, 4)
+}
+
+// BytesSize returns a human-readable size in bytes, kibibytes,
+// mebibytes, gibibytes, or tebibytes (eg. "44kiB", "17MiB").
+func BytesSize(size float64) string {
+	return CustomSize("%.4g%s", size, 1024.0, binaryAbbrs)
+}
+
+// FromHumanSize returns an integer from a human-readable specification of a
+// size using SI standard (eg. "44kB", "17MB").
+func FromHumanSize(size string) (int64, error) {
+	return parseSize(size, decimalMap)
+}
+
+// RAMInBytes parses a human-readable string representing an amount of RAM
+// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
+// returns the number of bytes, or -1 if the string is unparseable.
+// Units are case-insensitive, and the 'b' suffix is optional.
+func RAMInBytes(size string) (int64, error) {
+	return parseSize(size, binaryMap)
+}
+
+// Parses the human-readable size string into the amount it represents.
+func parseSize(sizeStr string, uMap unitMap) (int64, error) {
+	matches := sizeRegex.FindStringSubmatch(sizeStr)
+	if len(matches) != 4 {
+		return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
+	}
+
+	size, err := strconv.ParseFloat(matches[1], 64)
+	if err != nil {
+		return -1, err
+	}
+
+	unitPrefix := strings.ToLower(matches[3])
+	if mul, ok := uMap[unitPrefix]; ok {
+		size *= float64(mul)
+	}
+
+	return int64(size), nil
+}

vendor/github.com/docker/go-units/ulimit.go

@@ -0,0 +1,118 @@
+package units
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// Ulimit is a human friendly version of Rlimit.
+type Ulimit struct {
+	Name string
+	Hard int64
+	Soft int64
+}
+
+// Rlimit specifies the resource limits, such as max open files.
+type Rlimit struct {
+	Type int    `json:"type,omitempty"`
+	Hard uint64 `json:"hard,omitempty"`
+	Soft uint64 `json:"soft,omitempty"`
+}
+
+const (
+	// magic numbers for making the syscall
+	// some of these are defined in the syscall package, but not all.
+	// Also since Windows client doesn't get access to the syscall package, need to
+	//	define these here
+	rlimitAs         = 9
+	rlimitCore       = 4
+	rlimitCPU        = 0
+	rlimitData       = 2
+	rlimitFsize      = 1
+	rlimitLocks      = 10
+	rlimitMemlock    = 8
+	rlimitMsgqueue   = 12
+	rlimitNice       = 13
+	rlimitNofile     = 7
+	rlimitNproc      = 6
+	rlimitRss        = 5
+	rlimitRtprio     = 14
+	rlimitRttime     = 15
+	rlimitSigpending = 11
+	rlimitStack      = 3
+)
+
+var ulimitNameMapping = map[string]int{
+	//"as":         rlimitAs, // Disabled since this doesn't seem usable with the way Docker inits a container.
+	"core":       rlimitCore,
+	"cpu":        rlimitCPU,
+	"data":       rlimitData,
+	"fsize":      rlimitFsize,
+	"locks":      rlimitLocks,
+	"memlock":    rlimitMemlock,
+	"msgqueue":   rlimitMsgqueue,
+	"nice":       rlimitNice,
+	"nofile":     rlimitNofile,
+	"nproc":      rlimitNproc,
+	"rss":        rlimitRss,
+	"rtprio":     rlimitRtprio,
+	"rttime":     rlimitRttime,
+	"sigpending": rlimitSigpending,
+	"stack":      rlimitStack,
+}
+
+// ParseUlimit parses and returns a Ulimit from the specified string.
+func ParseUlimit(val string) (*Ulimit, error) {
+	parts := strings.SplitN(val, "=", 2)
+	if len(parts) != 2 {
+		return nil, fmt.Errorf("invalid ulimit argument: %s", val)
+	}
+
+	if _, exists := ulimitNameMapping[parts[0]]; !exists {
+		return nil, fmt.Errorf("invalid ulimit type: %s", parts[0])
+	}
+
+	var (
+		soft int64
+		hard = &soft // default to soft in case no hard was set
+		temp int64
+		err  error
+	)
+	switch limitVals := strings.Split(parts[1], ":"); len(limitVals) {
+	case 2:
+		temp, err = strconv.ParseInt(limitVals[1], 10, 64)
+		if err != nil {
+			return nil, err
+		}
+		hard = &temp
+		fallthrough
+	case 1:
+		soft, err = strconv.ParseInt(limitVals[0], 10, 64)
+		if err != nil {
+			return nil, err
+		}
+	default:
+		return nil, fmt.Errorf("too many limit value arguments - %s, can only have up to two, `soft[:hard]`", parts[1])
+	}
+
+	if soft > *hard {
+		return nil, fmt.Errorf("ulimit soft limit must be less than or equal to hard limit: %d > %d", soft, *hard)
+	}
+
+	return &Ulimit{Name: parts[0], Soft: soft, Hard: *hard}, nil
+}
+
+// GetRlimit returns the RLimit corresponding to Ulimit.
+func (u *Ulimit) GetRlimit() (*Rlimit, error) {
+	t, exists := ulimitNameMapping[u.Name]
+	if !exists {
+		return nil, fmt.Errorf("invalid ulimit name %s", u.Name)
+	}
+
+	return &Rlimit{Type: t, Soft: uint64(u.Soft), Hard: uint64(u.Hard)}, nil
+}
+
+func (u *Ulimit) String() string {
+	return fmt.Sprintf("%s=%d:%d", u.Name, u.Soft, u.Hard)
+}

vendor/github.com/godbus/dbus/LICENSE

@@ -0,0 +1,25 @@
+Copyright (c) 2013, Georg Reinke (<guelfey at gmail dot com>), Google
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+1. Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/godbus/dbus/README.markdown

@@ -0,0 +1,44 @@
+[![Build Status](https://travis-ci.org/godbus/dbus.svg?branch=master)](https://travis-ci.org/godbus/dbus)
+
+dbus
+----
+
+dbus is a simple library that implements native Go client bindings for the
+D-Bus message bus system.
+
+### Features
+
+* Complete native implementation of the D-Bus message protocol
+* Go-like API (channels for signals / asynchronous method calls, Goroutine-safe connections)
+* Subpackages that help with the introspection / property interfaces
+
+### Installation
+
+This packages requires Go 1.1. If you installed it and set up your GOPATH, just run:
+
+```
+go get github.com/godbus/dbus
+```
+
+If you want to use the subpackages, you can install them the same way.
+
+### Usage
+
+The complete package documentation and some simple examples are available at
+[godoc.org](http://godoc.org/github.com/godbus/dbus). Also, the
+[_examples](https://github.com/godbus/dbus/tree/master/_examples) directory
+gives a short overview over the basic usage. 
+
+#### Projects using godbus
+- [notify](https://github.com/esiqveland/notify) provides desktop notifications over dbus into a library.
+- [go-bluetooth](https://github.com/muka/go-bluetooth) provides a bluetooth client over bluez dbus API.
+
+Please note that the API is considered unstable for now and may change without
+further notice.
+
+### License
+
+go.dbus is available under the Simplified BSD License; see LICENSE for the full
+text.
+
+Nearly all of the credit for this library goes to github.com/guelfey/go.dbus.

vendor/github.com/godbus/dbus/auth.go

@@ -0,0 +1,253 @@
+package dbus
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"os"
+	"strconv"
+)
+
+// AuthStatus represents the Status of an authentication mechanism.
+type AuthStatus byte
+
+const (
+	// AuthOk signals that authentication is finished; the next command
+	// from the server should be an OK.
+	AuthOk AuthStatus = iota
+
+	// AuthContinue signals that additional data is needed; the next command
+	// from the server should be a DATA.
+	AuthContinue
+
+	// AuthError signals an error; the server sent invalid data or some
+	// other unexpected thing happened and the current authentication
+	// process should be aborted.
+	AuthError
+)
+
+type authState byte
+
+const (
+	waitingForData authState = iota
+	waitingForOk
+	waitingForReject
+)
+
+// Auth defines the behaviour of an authentication mechanism.
+type Auth interface {
+	// Return the name of the mechnism, the argument to the first AUTH command
+	// and the next status.
+	FirstData() (name, resp []byte, status AuthStatus)
+
+	// Process the given DATA command, and return the argument to the DATA
+	// command and the next status. If len(resp) == 0, no DATA command is sent.
+	HandleData(data []byte) (resp []byte, status AuthStatus)
+}
+
+// Auth authenticates the connection, trying the given list of authentication
+// mechanisms (in that order). If nil is passed, the EXTERNAL and
+// DBUS_COOKIE_SHA1 mechanisms are tried for the current user. For private
+// connections, this method must be called before sending any messages to the
+// bus. Auth must not be called on shared connections.
+func (conn *Conn) Auth(methods []Auth) error {
+	if methods == nil {
+		uid := strconv.Itoa(os.Getuid())
+		methods = []Auth{AuthExternal(uid), AuthCookieSha1(uid, getHomeDir())}
+	}
+	in := bufio.NewReader(conn.transport)
+	err := conn.transport.SendNullByte()
+	if err != nil {
+		return err
+	}
+	err = authWriteLine(conn.transport, []byte("AUTH"))
+	if err != nil {
+		return err
+	}
+	s, err := authReadLine(in)
+	if err != nil {
+		return err
+	}
+	if len(s) < 2 || !bytes.Equal(s[0], []byte("REJECTED")) {
+		return errors.New("dbus: authentication protocol error")
+	}
+	s = s[1:]
+	for _, v := range s {
+		for _, m := range methods {
+			if name, data, status := m.FirstData(); bytes.Equal(v, name) {
+				var ok bool
+				err = authWriteLine(conn.transport, []byte("AUTH"), []byte(v), data)
+				if err != nil {
+					return err
+				}
+				switch status {
+				case AuthOk:
+					err, ok = conn.tryAuth(m, waitingForOk, in)
+				case AuthContinue:
+					err, ok = conn.tryAuth(m, waitingForData, in)
+				default:
+					panic("dbus: invalid authentication status")
+				}
+				if err != nil {
+					return err
+				}
+				if ok {
+					if conn.transport.SupportsUnixFDs() {
+						err = authWriteLine(conn, []byte("NEGOTIATE_UNIX_FD"))
+						if err != nil {
+							return err
+						}
+						line, err := authReadLine(in)
+						if err != nil {
+							return err
+						}
+						switch {
+						case bytes.Equal(line[0], []byte("AGREE_UNIX_FD")):
+							conn.EnableUnixFDs()
+							conn.unixFD = true
+						case bytes.Equal(line[0], []byte("ERROR")):
+						default:
+							return errors.New("dbus: authentication protocol error")
+						}
+					}
+					err = authWriteLine(conn.transport, []byte("BEGIN"))
+					if err != nil {
+						return err
+					}
+					go conn.inWorker()
+					go conn.outWorker()
+					return nil
+				}
+			}
+		}
+	}
+	return errors.New("dbus: authentication failed")
+}
+
+// tryAuth tries to authenticate with m as the mechanism, using state as the
+// initial authState and in for reading input. It returns (nil, true) on
+// success, (nil, false) on a REJECTED and (someErr, false) if some other
+// error occured.
+func (conn *Conn) tryAuth(m Auth, state authState, in *bufio.Reader) (error, bool) {
+	for {
+		s, err := authReadLine(in)
+		if err != nil {
+			return err, false
+		}
+		switch {
+		case state == waitingForData && string(s[0]) == "DATA":
+			if len(s) != 2 {
+				err = authWriteLine(conn.transport, []byte("ERROR"))
+				if err != nil {
+					return err, false
+				}
+				continue
+			}
+			data, status := m.HandleData(s[1])
+			switch status {
+			case AuthOk, AuthContinue:
+				if len(data) != 0 {
+					err = authWriteLine(conn.transport, []byte("DATA"), data)
+					if err != nil {
+						return err, false
+					}
+				}
+				if status == AuthOk {
+					state = waitingForOk
+				}
+			case AuthError:
+				err = authWriteLine(conn.transport, []byte("ERROR"))
+				if err != nil {
+					return err, false
+				}
+			}
+		case state == waitingForData && string(s[0]) == "REJECTED":
+			return nil, false
+		case state == waitingForData && string(s[0]) == "ERROR":
+			err = authWriteLine(conn.transport, []byte("CANCEL"))
+			if err != nil {
+				return err, false
+			}
+			state = waitingForReject
+		case state == waitingForData && string(s[0]) == "OK":
+			if len(s) != 2 {
+				err = authWriteLine(conn.transport, []byte("CANCEL"))
+				if err != nil {
+					return err, false
+				}
+				state = waitingForReject
+			}
+			conn.uuid = string(s[1])
+			return nil, true
+		case state == waitingForData:
+			err = authWriteLine(conn.transport, []byte("ERROR"))
+			if err != nil {
+				return err, false
+			}
+		case state == waitingForOk && string(s[0]) == "OK":
+			if len(s) != 2 {
+				err = authWriteLine(conn.transport, []byte("CANCEL"))
+				if err != nil {
+					return err, false
+				}
+				state = waitingForReject
+			}
+			conn.uuid = string(s[1])
+			return nil, true
+		case state == waitingForOk && string(s[0]) == "REJECTED":
+			return nil, false
+		case state == waitingForOk && (string(s[0]) == "DATA" ||
+			string(s[0]) == "ERROR"):
+
+			err = authWriteLine(conn.transport, []byte("CANCEL"))
+			if err != nil {
+				return err, false
+			}
+			state = waitingForReject
+		case state == waitingForOk:
+			err = authWriteLine(conn.transport, []byte("ERROR"))
+			if err != nil {
+				return err, false
+			}
+		case state == waitingForReject && string(s[0]) == "REJECTED":
+			return nil, false
+		case state == waitingForReject:
+			return errors.New("dbus: authentication protocol error"), false
+		default:
+			panic("dbus: invalid auth state")
+		}
+	}
+}
+
+// authReadLine reads a line and separates it into its fields.
+func authReadLine(in *bufio.Reader) ([][]byte, error) {
+	data, err := in.ReadBytes('\n')
+	if err != nil {
+		return nil, err
+	}
+	data = bytes.TrimSuffix(data, []byte("\r\n"))
+	return bytes.Split(data, []byte{' '}), nil
+}
+
+// authWriteLine writes the given line in the authentication protocol format
+// (elements of data separated by a " " and terminated by "\r\n").
+func authWriteLine(out io.Writer, data ...[]byte) error {
+	buf := make([]byte, 0)
+	for i, v := range data {
+		buf = append(buf, v...)
+		if i != len(data)-1 {
+			buf = append(buf, ' ')
+		}
+	}
+	buf = append(buf, '\r')
+	buf = append(buf, '\n')
+	n, err := out.Write(buf)
+	if err != nil {
+		return err
+	}
+	if n != len(buf) {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}

vendor/github.com/godbus/dbus/auth_external.go

@@ -0,0 +1,26 @@
+package dbus
+
+import (
+	"encoding/hex"
+)
+
+// AuthExternal returns an Auth that authenticates as the given user with the
+// EXTERNAL mechanism.
+func AuthExternal(user string) Auth {
+	return authExternal{user}
+}
+
+// AuthExternal implements the EXTERNAL authentication mechanism.
+type authExternal struct {
+	user string
+}
+
+func (a authExternal) FirstData() ([]byte, []byte, AuthStatus) {
+	b := make([]byte, 2*len(a.user))
+	hex.Encode(b, []byte(a.user))
+	return []byte("EXTERNAL"), b, AuthOk
+}
+
+func (a authExternal) HandleData(b []byte) ([]byte, AuthStatus) {
+	return nil, AuthError
+}

vendor/github.com/godbus/dbus/auth_sha1.go

@@ -0,0 +1,102 @@
+package dbus
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/rand"
+	"crypto/sha1"
+	"encoding/hex"
+	"os"
+)
+
+// AuthCookieSha1 returns an Auth that authenticates as the given user with the
+// DBUS_COOKIE_SHA1 mechanism. The home parameter should specify the home
+// directory of the user.
+func AuthCookieSha1(user, home string) Auth {
+	return authCookieSha1{user, home}
+}
+
+type authCookieSha1 struct {
+	user, home string
+}
+
+func (a authCookieSha1) FirstData() ([]byte, []byte, AuthStatus) {
+	b := make([]byte, 2*len(a.user))
+	hex.Encode(b, []byte(a.user))
+	return []byte("DBUS_COOKIE_SHA1"), b, AuthContinue
+}
+
+func (a authCookieSha1) HandleData(data []byte) ([]byte, AuthStatus) {
+	challenge := make([]byte, len(data)/2)
+	_, err := hex.Decode(challenge, data)
+	if err != nil {
+		return nil, AuthError
+	}
+	b := bytes.Split(challenge, []byte{' '})
+	if len(b) != 3 {
+		return nil, AuthError
+	}
+	context := b[0]
+	id := b[1]
+	svchallenge := b[2]
+	cookie := a.getCookie(context, id)
+	if cookie == nil {
+		return nil, AuthError
+	}
+	clchallenge := a.generateChallenge()
+	if clchallenge == nil {
+		return nil, AuthError
+	}
+	hash := sha1.New()
+	hash.Write(bytes.Join([][]byte{svchallenge, clchallenge, cookie}, []byte{':'}))
+	hexhash := make([]byte, 2*hash.Size())
+	hex.Encode(hexhash, hash.Sum(nil))
+	data = append(clchallenge, ' ')
+	data = append(data, hexhash...)
+	resp := make([]byte, 2*len(data))
+	hex.Encode(resp, data)
+	return resp, AuthOk
+}
+
+// getCookie searches for the cookie identified by id in context and returns
+// the cookie content or nil. (Since HandleData can't return a specific error,
+// but only whether an error occured, this function also doesn't bother to
+// return an error.)
+func (a authCookieSha1) getCookie(context, id []byte) []byte {
+	file, err := os.Open(a.home + "/.dbus-keyrings/" + string(context))
+	if err != nil {
+		return nil
+	}
+	defer file.Close()
+	rd := bufio.NewReader(file)
+	for {
+		line, err := rd.ReadBytes('\n')
+		if err != nil {
+			return nil
+		}
+		line = line[:len(line)-1]
+		b := bytes.Split(line, []byte{' '})
+		if len(b) != 3 {
+			return nil
+		}
+		if bytes.Equal(b[0], id) {
+			return b[2]
+		}
+	}
+}
+
+// generateChallenge returns a random, hex-encoded challenge, or nil on error
+// (see above).
+func (a authCookieSha1) generateChallenge() []byte {
+	b := make([]byte, 16)
+	n, err := rand.Read(b)
+	if err != nil {
+		return nil
+	}
+	if n != 16 {
+		return nil
+	}
+	enc := make([]byte, 32)
+	hex.Encode(enc, b)
+	return enc
+}

vendor/github.com/godbus/dbus/call.go

@@ -0,0 +1,36 @@
+package dbus
+
+import (
+	"errors"
+)
+
+// Call represents a pending or completed method call.
+type Call struct {
+	Destination string
+	Path        ObjectPath
+	Method      string
+	Args        []interface{}
+
+	// Strobes when the call is complete.
+	Done chan *Call
+
+	// After completion, the error status. If this is non-nil, it may be an
+	// error message from the peer (with Error as its type) or some other error.
+	Err error
+
+	// Holds the response once the call is done.
+	Body []interface{}
+}
+
+var errSignature = errors.New("dbus: mismatched signature")
+
+// Store stores the body of the reply into the provided pointers. It returns
+// an error if the signatures of the body and retvalues don't match, or if
+// the error status is not nil.
+func (c *Call) Store(retvalues ...interface{}) error {
+	if c.Err != nil {
+		return c.Err
+	}
+
+	return Store(c.Body, retvalues...)
+}

vendor/github.com/godbus/dbus/conn.go

@@ -0,0 +1,683 @@
+package dbus
+
+import (
+	"errors"
+	"io"
+	"os"
+	"reflect"
+	"strings"
+	"sync"
+)
+
+var (
+	systemBus     *Conn
+	systemBusLck  sync.Mutex
+	sessionBus    *Conn
+	sessionBusLck sync.Mutex
+	sessionEnvLck sync.Mutex
+)
+
+// ErrClosed is the error returned by calls on a closed connection.
+var ErrClosed = errors.New("dbus: connection closed by user")
+
+// Conn represents a connection to a message bus (usually, the system or
+// session bus).
+//
+// Connections are either shared or private. Shared connections
+// are shared between calls to the functions that return them. As a result,
+// the methods Close, Auth and Hello must not be called on them.
+//
+// Multiple goroutines may invoke methods on a connection simultaneously.
+type Conn struct {
+	transport
+
+	busObj BusObject
+	unixFD bool
+	uuid   string
+
+	names    []string
+	namesLck sync.RWMutex
+
+	serialLck  sync.Mutex
+	nextSerial uint32
+	serialUsed map[uint32]bool
+
+	calls    map[uint32]*Call
+	callsLck sync.RWMutex
+
+	handler Handler
+
+	out    chan *Message
+	closed bool
+	outLck sync.RWMutex
+
+	signalHandler SignalHandler
+
+	eavesdropped    chan<- *Message
+	eavesdroppedLck sync.Mutex
+}
+
+// SessionBus returns a shared connection to the session bus, connecting to it
+// if not already done.
+func SessionBus() (conn *Conn, err error) {
+	sessionBusLck.Lock()
+	defer sessionBusLck.Unlock()
+	if sessionBus != nil {
+		return sessionBus, nil
+	}
+	defer func() {
+		if conn != nil {
+			sessionBus = conn
+		}
+	}()
+	conn, err = SessionBusPrivate()
+	if err != nil {
+		return
+	}
+	if err = conn.Auth(nil); err != nil {
+		conn.Close()
+		conn = nil
+		return
+	}
+	if err = conn.Hello(); err != nil {
+		conn.Close()
+		conn = nil
+	}
+	return
+}
+
+func getSessionBusAddress() (string, error) {
+	sessionEnvLck.Lock()
+	defer sessionEnvLck.Unlock()
+	address := os.Getenv("DBUS_SESSION_BUS_ADDRESS")
+	if address != "" && address != "autolaunch:" {
+		return address, nil
+	}
+	return getSessionBusPlatformAddress()
+}
+
+// SessionBusPrivate returns a new private connection to the session bus.
+func SessionBusPrivate() (*Conn, error) {
+	address, err := getSessionBusAddress()
+	if err != nil {
+		return nil, err
+	}
+
+	return Dial(address)
+}
+
+// SessionBusPrivate returns a new private connection to the session bus.
+func SessionBusPrivateHandler(handler Handler, signalHandler SignalHandler) (*Conn, error) {
+	address, err := getSessionBusAddress()
+	if err != nil {
+		return nil, err
+	}
+	return DialHandler(address, handler, signalHandler)
+}
+
+// SystemBus returns a shared connection to the system bus, connecting to it if
+// not already done.
+func SystemBus() (conn *Conn, err error) {
+	systemBusLck.Lock()
+	defer systemBusLck.Unlock()
+	if systemBus != nil {
+		return systemBus, nil
+	}
+	defer func() {
+		if conn != nil {
+			systemBus = conn
+		}
+	}()
+	conn, err = SystemBusPrivate()
+	if err != nil {
+		return
+	}
+	if err = conn.Auth(nil); err != nil {
+		conn.Close()
+		conn = nil
+		return
+	}
+	if err = conn.Hello(); err != nil {
+		conn.Close()
+		conn = nil
+	}
+	return
+}
+
+// SystemBusPrivate returns a new private connection to the system bus.
+func SystemBusPrivate() (*Conn, error) {
+	return Dial(getSystemBusPlatformAddress())
+}
+
+// SystemBusPrivateHandler returns a new private connection to the system bus, using the provided handlers.
+func SystemBusPrivateHandler(handler Handler, signalHandler SignalHandler) (*Conn, error) {
+	return DialHandler(getSystemBusPlatformAddress(), handler, signalHandler)
+}
+
+// Dial establishes a new private connection to the message bus specified by address.
+func Dial(address string) (*Conn, error) {
+	tr, err := getTransport(address)
+	if err != nil {
+		return nil, err
+	}
+	return newConn(tr, newDefaultHandler(), newDefaultSignalHandler())
+}
+
+// DialHandler establishes a new private connection to the message bus specified by address, using the supplied handlers.
+func DialHandler(address string, handler Handler, signalHandler SignalHandler) (*Conn, error) {
+	tr, err := getTransport(address)
+	if err != nil {
+		return nil, err
+	}
+	return newConn(tr, handler, signalHandler)
+}
+
+// NewConn creates a new private *Conn from an already established connection.
+func NewConn(conn io.ReadWriteCloser) (*Conn, error) {
+	return NewConnHandler(conn, newDefaultHandler(), newDefaultSignalHandler())
+}
+
+// NewConnHandler creates a new private *Conn from an already established connection, using the supplied handlers.
+func NewConnHandler(conn io.ReadWriteCloser, handler Handler, signalHandler SignalHandler) (*Conn, error) {
+	return newConn(genericTransport{conn}, handler, signalHandler)
+}
+
+// newConn creates a new *Conn from a transport.
+func newConn(tr transport, handler Handler, signalHandler SignalHandler) (*Conn, error) {
+	conn := new(Conn)
+	conn.transport = tr
+	conn.calls = make(map[uint32]*Call)
+	conn.out = make(chan *Message, 10)
+	conn.handler = handler
+	conn.signalHandler = signalHandler
+	conn.nextSerial = 1
+	conn.serialUsed = map[uint32]bool{0: true}
+	conn.busObj = conn.Object("org.freedesktop.DBus", "/org/freedesktop/DBus")
+	return conn, nil
+}
+
+// BusObject returns the object owned by the bus daemon which handles
+// administrative requests.
+func (conn *Conn) BusObject() BusObject {
+	return conn.busObj
+}
+
+// Close closes the connection. Any blocked operations will return with errors
+// and the channels passed to Eavesdrop and Signal are closed. This method must
+// not be called on shared connections.
+func (conn *Conn) Close() error {
+	conn.outLck.Lock()
+	if conn.closed {
+		// inWorker calls Close on read error, the read error may
+		// be caused by another caller calling Close to shutdown the
+		// dbus connection, a double-close scenario we prevent here.
+		conn.outLck.Unlock()
+		return nil
+	}
+	close(conn.out)
+	conn.closed = true
+	conn.outLck.Unlock()
+
+	if term, ok := conn.signalHandler.(Terminator); ok {
+		term.Terminate()
+	}
+
+	if term, ok := conn.handler.(Terminator); ok {
+		term.Terminate()
+	}
+
+	conn.eavesdroppedLck.Lock()
+	if conn.eavesdropped != nil {
+		close(conn.eavesdropped)
+	}
+	conn.eavesdroppedLck.Unlock()
+
+	return conn.transport.Close()
+}
+
+// Eavesdrop causes conn to send all incoming messages to the given channel
+// without further processing. Method replies, errors and signals will not be
+// sent to the appropiate channels and method calls will not be handled. If nil
+// is passed, the normal behaviour is restored.
+//
+// The caller has to make sure that ch is sufficiently buffered;
+// if a message arrives when a write to ch is not possible, the message is
+// discarded.
+func (conn *Conn) Eavesdrop(ch chan<- *Message) {
+	conn.eavesdroppedLck.Lock()
+	conn.eavesdropped = ch
+	conn.eavesdroppedLck.Unlock()
+}
+
+// getSerial returns an unused serial.
+func (conn *Conn) getSerial() uint32 {
+	conn.serialLck.Lock()
+	defer conn.serialLck.Unlock()
+	n := conn.nextSerial
+	for conn.serialUsed[n] {
+		n++
+	}
+	conn.serialUsed[n] = true
+	conn.nextSerial = n + 1
+	return n
+}
+
+// Hello sends the initial org.freedesktop.DBus.Hello call. This method must be
+// called after authentication, but before sending any other messages to the
+// bus. Hello must not be called for shared connections.
+func (conn *Conn) Hello() error {
+	var s string
+	err := conn.busObj.Call("org.freedesktop.DBus.Hello", 0).Store(&s)
+	if err != nil {
+		return err
+	}
+	conn.namesLck.Lock()
+	conn.names = make([]string, 1)
+	conn.names[0] = s
+	conn.namesLck.Unlock()
+	return nil
+}
+
+// inWorker runs in an own goroutine, reading incoming messages from the
+// transport and dispatching them appropiately.
+func (conn *Conn) inWorker() {
+	for {
+		msg, err := conn.ReadMessage()
+		if err == nil {
+			conn.eavesdroppedLck.Lock()
+			if conn.eavesdropped != nil {
+				select {
+				case conn.eavesdropped <- msg:
+				default:
+				}
+				conn.eavesdroppedLck.Unlock()
+				continue
+			}
+			conn.eavesdroppedLck.Unlock()
+			dest, _ := msg.Headers[FieldDestination].value.(string)
+			found := false
+			if dest == "" {
+				found = true
+			} else {
+				conn.namesLck.RLock()
+				if len(conn.names) == 0 {
+					found = true
+				}
+				for _, v := range conn.names {
+					if dest == v {
+						found = true
+						break
+					}
+				}
+				conn.namesLck.RUnlock()
+			}
+			if !found {
+				// Eavesdropped a message, but no channel for it is registered.
+				// Ignore it.
+				continue
+			}
+			switch msg.Type {
+			case TypeMethodReply, TypeError:
+				serial := msg.Headers[FieldReplySerial].value.(uint32)
+				conn.callsLck.Lock()
+				if c, ok := conn.calls[serial]; ok {
+					if msg.Type == TypeError {
+						name, _ := msg.Headers[FieldErrorName].value.(string)
+						c.Err = Error{name, msg.Body}
+					} else {
+						c.Body = msg.Body
+					}
+					c.Done <- c
+					conn.serialLck.Lock()
+					delete(conn.serialUsed, serial)
+					conn.serialLck.Unlock()
+					delete(conn.calls, serial)
+				}
+				conn.callsLck.Unlock()
+			case TypeSignal:
+				iface := msg.Headers[FieldInterface].value.(string)
+				member := msg.Headers[FieldMember].value.(string)
+				// as per http://dbus.freedesktop.org/doc/dbus-specification.html ,
+				// sender is optional for signals.
+				sender, _ := msg.Headers[FieldSender].value.(string)
+				if iface == "org.freedesktop.DBus" && sender == "org.freedesktop.DBus" {
+					if member == "NameLost" {
+						// If we lost the name on the bus, remove it from our
+						// tracking list.
+						name, ok := msg.Body[0].(string)
+						if !ok {
+							panic("Unable to read the lost name")
+						}
+						conn.namesLck.Lock()
+						for i, v := range conn.names {
+							if v == name {
+								conn.names = append(conn.names[:i],
+									conn.names[i+1:]...)
+							}
+						}
+						conn.namesLck.Unlock()
+					} else if member == "NameAcquired" {
+						// If we acquired the name on the bus, add it to our
+						// tracking list.
+						name, ok := msg.Body[0].(string)
+						if !ok {
+							panic("Unable to read the acquired name")
+						}
+						conn.namesLck.Lock()
+						conn.names = append(conn.names, name)
+						conn.namesLck.Unlock()
+					}
+				}
+				go conn.handleSignal(msg)
+			case TypeMethodCall:
+				go conn.handleCall(msg)
+			}
+		} else if _, ok := err.(InvalidMessageError); !ok {
+			// Some read error occured (usually EOF); we can't really do
+			// anything but to shut down all stuff and returns errors to all
+			// pending replies.
+			conn.Close()
+			conn.callsLck.RLock()
+			for _, v := range conn.calls {
+				v.Err = err
+				v.Done <- v
+			}
+			conn.callsLck.RUnlock()
+			return
+		}
+		// invalid messages are ignored
+	}
+}
+
+func (conn *Conn) handleSignal(msg *Message) {
+	iface := msg.Headers[FieldInterface].value.(string)
+	member := msg.Headers[FieldMember].value.(string)
+	// as per http://dbus.freedesktop.org/doc/dbus-specification.html ,
+	// sender is optional for signals.
+	sender, _ := msg.Headers[FieldSender].value.(string)
+	signal := &Signal{
+		Sender: sender,
+		Path:   msg.Headers[FieldPath].value.(ObjectPath),
+		Name:   iface + "." + member,
+		Body:   msg.Body,
+	}
+	conn.signalHandler.DeliverSignal(iface, member, signal)
+}
+
+// Names returns the list of all names that are currently owned by this
+// connection. The slice is always at least one element long, the first element
+// being the unique name of the connection.
+func (conn *Conn) Names() []string {
+	conn.namesLck.RLock()
+	// copy the slice so it can't be modified
+	s := make([]string, len(conn.names))
+	copy(s, conn.names)
+	conn.namesLck.RUnlock()
+	return s
+}
+
+// Object returns the object identified by the given destination name and path.
+func (conn *Conn) Object(dest string, path ObjectPath) BusObject {
+	return &Object{conn, dest, path}
+}
+
+// outWorker runs in an own goroutine, encoding and sending messages that are
+// sent to conn.out.
+func (conn *Conn) outWorker() {
+	for msg := range conn.out {
+		err := conn.SendMessage(msg)
+		conn.callsLck.RLock()
+		if err != nil {
+			if c := conn.calls[msg.serial]; c != nil {
+				c.Err = err
+				c.Done <- c
+			}
+			conn.serialLck.Lock()
+			delete(conn.serialUsed, msg.serial)
+			conn.serialLck.Unlock()
+		} else if msg.Type != TypeMethodCall {
+			conn.serialLck.Lock()
+			delete(conn.serialUsed, msg.serial)
+			conn.serialLck.Unlock()
+		}
+		conn.callsLck.RUnlock()
+	}
+}
+
+// Send sends the given message to the message bus. You usually don't need to
+// use this; use the higher-level equivalents (Call / Go, Emit and Export)
+// instead. If msg is a method call and NoReplyExpected is not set, a non-nil
+// call is returned and the same value is sent to ch (which must be buffered)
+// once the call is complete. Otherwise, ch is ignored and a Call structure is
+// returned of which only the Err member is valid.
+func (conn *Conn) Send(msg *Message, ch chan *Call) *Call {
+	var call *Call
+
+	msg.serial = conn.getSerial()
+	if msg.Type == TypeMethodCall && msg.Flags&FlagNoReplyExpected == 0 {
+		if ch == nil {
+			ch = make(chan *Call, 5)
+		} else if cap(ch) == 0 {
+			panic("dbus: unbuffered channel passed to (*Conn).Send")
+		}
+		call = new(Call)
+		call.Destination, _ = msg.Headers[FieldDestination].value.(string)
+		call.Path, _ = msg.Headers[FieldPath].value.(ObjectPath)
+		iface, _ := msg.Headers[FieldInterface].value.(string)
+		member, _ := msg.Headers[FieldMember].value.(string)
+		call.Method = iface + "." + member
+		call.Args = msg.Body
+		call.Done = ch
+		conn.callsLck.Lock()
+		conn.calls[msg.serial] = call
+		conn.callsLck.Unlock()
+		conn.outLck.RLock()
+		if conn.closed {
+			call.Err = ErrClosed
+			call.Done <- call
+		} else {
+			conn.out <- msg
+		}
+		conn.outLck.RUnlock()
+	} else {
+		conn.outLck.RLock()
+		if conn.closed {
+			call = &Call{Err: ErrClosed}
+		} else {
+			conn.out <- msg
+			call = &Call{Err: nil}
+		}
+		conn.outLck.RUnlock()
+	}
+	return call
+}
+
+// sendError creates an error message corresponding to the parameters and sends
+// it to conn.out.
+func (conn *Conn) sendError(err error, dest string, serial uint32) {
+	var e *Error
+	switch em := err.(type) {
+	case Error:
+		e = &em
+	case *Error:
+		e = em
+	case DBusError:
+		name, body := em.DBusError()
+		e = NewError(name, body)
+	default:
+		e = MakeFailedError(err)
+	}
+	msg := new(Message)
+	msg.Type = TypeError
+	msg.serial = conn.getSerial()
+	msg.Headers = make(map[HeaderField]Variant)
+	if dest != "" {
+		msg.Headers[FieldDestination] = MakeVariant(dest)
+	}
+	msg.Headers[FieldErrorName] = MakeVariant(e.Name)
+	msg.Headers[FieldReplySerial] = MakeVariant(serial)
+	msg.Body = e.Body
+	if len(e.Body) > 0 {
+		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(e.Body...))
+	}
+	conn.outLck.RLock()
+	if !conn.closed {
+		conn.out <- msg
+	}
+	conn.outLck.RUnlock()
+}
+
+// sendReply creates a method reply message corresponding to the parameters and
+// sends it to conn.out.
+func (conn *Conn) sendReply(dest string, serial uint32, values ...interface{}) {
+	msg := new(Message)
+	msg.Type = TypeMethodReply
+	msg.serial = conn.getSerial()
+	msg.Headers = make(map[HeaderField]Variant)
+	if dest != "" {
+		msg.Headers[FieldDestination] = MakeVariant(dest)
+	}
+	msg.Headers[FieldReplySerial] = MakeVariant(serial)
+	msg.Body = values
+	if len(values) > 0 {
+		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(values...))
+	}
+	conn.outLck.RLock()
+	if !conn.closed {
+		conn.out <- msg
+	}
+	conn.outLck.RUnlock()
+}
+
+func (conn *Conn) defaultSignalAction(fn func(h *defaultSignalHandler, ch chan<- *Signal), ch chan<- *Signal) {
+	if !isDefaultSignalHandler(conn.signalHandler) {
+		return
+	}
+	handler := conn.signalHandler.(*defaultSignalHandler)
+	fn(handler, ch)
+}
+
+// Signal registers the given channel to be passed all received signal messages.
+// The caller has to make sure that ch is sufficiently buffered; if a message
+// arrives when a write to c is not possible, it is discarded.
+//
+// Multiple of these channels can be registered at the same time.
+//
+// These channels are "overwritten" by Eavesdrop; i.e., if there currently is a
+// channel for eavesdropped messages, this channel receives all signals, and
+// none of the channels passed to Signal will receive any signals.
+func (conn *Conn) Signal(ch chan<- *Signal) {
+	conn.defaultSignalAction((*defaultSignalHandler).addSignal, ch)
+}
+
+// RemoveSignal removes the given channel from the list of the registered channels.
+func (conn *Conn) RemoveSignal(ch chan<- *Signal) {
+	conn.defaultSignalAction((*defaultSignalHandler).removeSignal, ch)
+}
+
+// SupportsUnixFDs returns whether the underlying transport supports passing of
+// unix file descriptors. If this is false, method calls containing unix file
+// descriptors will return an error and emitted signals containing them will
+// not be sent.
+func (conn *Conn) SupportsUnixFDs() bool {
+	return conn.unixFD
+}
+
+// Error represents a D-Bus message of type Error.
+type Error struct {
+	Name string
+	Body []interface{}
+}
+
+func NewError(name string, body []interface{}) *Error {
+	return &Error{name, body}
+}
+
+func (e Error) Error() string {
+	if len(e.Body) >= 1 {
+		s, ok := e.Body[0].(string)
+		if ok {
+			return s
+		}
+	}
+	return e.Name
+}
+
+// Signal represents a D-Bus message of type Signal. The name member is given in
+// "interface.member" notation, e.g. org.freedesktop.D-Bus.NameLost.
+type Signal struct {
+	Sender string
+	Path   ObjectPath
+	Name   string
+	Body   []interface{}
+}
+
+// transport is a D-Bus transport.
+type transport interface {
+	// Read and Write raw data (for example, for the authentication protocol).
+	io.ReadWriteCloser
+
+	// Send the initial null byte used for the EXTERNAL mechanism.
+	SendNullByte() error
+
+	// Returns whether this transport supports passing Unix FDs.
+	SupportsUnixFDs() bool
+
+	// Signal the transport that Unix FD passing is enabled for this connection.
+	EnableUnixFDs()
+
+	// Read / send a message, handling things like Unix FDs.
+	ReadMessage() (*Message, error)
+	SendMessage(*Message) error
+}
+
+var (
+	transports = make(map[string]func(string) (transport, error))
+)
+
+func getTransport(address string) (transport, error) {
+	var err error
+	var t transport
+
+	addresses := strings.Split(address, ";")
+	for _, v := range addresses {
+		i := strings.IndexRune(v, ':')
+		if i == -1 {
+			err = errors.New("dbus: invalid bus address (no transport)")
+			continue
+		}
+		f := transports[v[:i]]
+		if f == nil {
+			err = errors.New("dbus: invalid bus address (invalid or unsupported transport)")
+			continue
+		}
+		t, err = f(v[i+1:])
+		if err == nil {
+			return t, nil
+		}
+	}
+	return nil, err
+}
+
+// dereferenceAll returns a slice that, assuming that vs is a slice of pointers
+// of arbitrary types, containes the values that are obtained from dereferencing
+// all elements in vs.
+func dereferenceAll(vs []interface{}) []interface{} {
+	for i := range vs {
+		v := reflect.ValueOf(vs[i])
+		v = v.Elem()
+		vs[i] = v.Interface()
+	}
+	return vs
+}
+
+// getKey gets a key from a the list of keys. Returns "" on error / not found...
+func getKey(s, key string) string {
+	for _, keyEqualsValue := range strings.Split(s, ",") {
+		keyValue := strings.SplitN(keyEqualsValue, "=", 2)
+		if len(keyValue) == 2 && keyValue[0] == key {
+			return keyValue[1]
+		}
+	}
+	return ""
+}

vendor/github.com/godbus/dbus/conn_darwin.go

@@ -0,0 +1,33 @@
+package dbus
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+const defaultSystemBusAddress = "unix:path=/opt/local/var/run/dbus/system_bus_socket"
+
+func getSessionBusPlatformAddress() (string, error) {
+	cmd := exec.Command("launchctl", "getenv", "DBUS_LAUNCHD_SESSION_BUS_SOCKET")
+	b, err := cmd.CombinedOutput()
+
+	if err != nil {
+		return "", err
+	}
+
+	if len(b) == 0 {
+		return "", errors.New("dbus: couldn't determine address of session bus")
+	}
+
+	return "unix:path=" + string(b[:len(b)-1]), nil
+}
+
+func getSystemBusPlatformAddress() string {
+	address := os.Getenv("DBUS_LAUNCHD_SESSION_BUS_SOCKET")
+	if address != "" {
+		return fmt.Sprintf("unix:path=%s", address)
+	}
+	return defaultSystemBusAddress
+}

vendor/github.com/godbus/dbus/conn_other.go

@@ -0,0 +1,42 @@
+// +build !darwin
+
+package dbus
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+const defaultSystemBusAddress = "unix:path=/var/run/dbus/system_bus_socket"
+
+func getSessionBusPlatformAddress() (string, error) {
+	cmd := exec.Command("dbus-launch")
+	b, err := cmd.CombinedOutput()
+
+	if err != nil {
+		return "", err
+	}
+
+	i := bytes.IndexByte(b, '=')
+	j := bytes.IndexByte(b, '\n')
+
+	if i == -1 || j == -1 {
+		return "", errors.New("dbus: couldn't determine address of session bus")
+	}
+
+	env, addr := string(b[0:i]), string(b[i+1:j])
+	os.Setenv(env, addr)
+
+	return addr, nil
+}
+
+func getSystemBusPlatformAddress() string {
+	address := os.Getenv("DBUS_SYSTEM_BUS_ADDRESS")
+	if address != "" {
+		return fmt.Sprintf("unix:path=%s", address)
+	}
+	return defaultSystemBusAddress
+}

vendor/github.com/godbus/dbus/dbus.go

@@ -0,0 +1,427 @@
+package dbus
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+var (
+	byteType        = reflect.TypeOf(byte(0))
+	boolType        = reflect.TypeOf(false)
+	uint8Type       = reflect.TypeOf(uint8(0))
+	int16Type       = reflect.TypeOf(int16(0))
+	uint16Type      = reflect.TypeOf(uint16(0))
+	intType         = reflect.TypeOf(int(0))
+	uintType        = reflect.TypeOf(uint(0))
+	int32Type       = reflect.TypeOf(int32(0))
+	uint32Type      = reflect.TypeOf(uint32(0))
+	int64Type       = reflect.TypeOf(int64(0))
+	uint64Type      = reflect.TypeOf(uint64(0))
+	float64Type     = reflect.TypeOf(float64(0))
+	stringType      = reflect.TypeOf("")
+	signatureType   = reflect.TypeOf(Signature{""})
+	objectPathType  = reflect.TypeOf(ObjectPath(""))
+	variantType     = reflect.TypeOf(Variant{Signature{""}, nil})
+	interfacesType  = reflect.TypeOf([]interface{}{})
+	interfaceType   = reflect.TypeOf((*interface{})(nil)).Elem()
+	unixFDType      = reflect.TypeOf(UnixFD(0))
+	unixFDIndexType = reflect.TypeOf(UnixFDIndex(0))
+)
+
+// An InvalidTypeError signals that a value which cannot be represented in the
+// D-Bus wire format was passed to a function.
+type InvalidTypeError struct {
+	Type reflect.Type
+}
+
+func (e InvalidTypeError) Error() string {
+	return "dbus: invalid type " + e.Type.String()
+}
+
+// Store copies the values contained in src to dest, which must be a slice of
+// pointers. It converts slices of interfaces from src to corresponding structs
+// in dest. An error is returned if the lengths of src and dest or the types of
+// their elements don't match.
+func Store(src []interface{}, dest ...interface{}) error {
+	if len(src) != len(dest) {
+		return errors.New("dbus.Store: length mismatch")
+	}
+
+	for i := range src {
+		if err := storeInterfaces(src[i], dest[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func storeInterfaces(src, dest interface{}) error {
+	return store(reflect.ValueOf(dest), reflect.ValueOf(src))
+}
+
+func store(dest, src reflect.Value) error {
+	if dest.Kind() == reflect.Ptr {
+		return store(dest.Elem(), src)
+	}
+	switch src.Kind() {
+	case reflect.Slice:
+		return storeSlice(dest, src)
+	case reflect.Map:
+		return storeMap(dest, src)
+	default:
+		return storeBase(dest, src)
+	}
+}
+
+func storeBase(dest, src reflect.Value) error {
+	return setDest(dest, src)
+}
+
+func setDest(dest, src reflect.Value) error {
+	if !isVariant(src.Type()) && isVariant(dest.Type()) {
+		//special conversion for dbus.Variant
+		dest.Set(reflect.ValueOf(MakeVariant(src.Interface())))
+		return nil
+	}
+	if isVariant(src.Type()) && !isVariant(dest.Type()) {
+		src = getVariantValue(src)
+	}
+	if !src.Type().ConvertibleTo(dest.Type()) {
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: cannot convert %s to %s",
+			src.Type(), dest.Type())
+	}
+	dest.Set(src.Convert(dest.Type()))
+	return nil
+}
+
+func kindsAreCompatible(dest, src reflect.Type) bool {
+	switch {
+	case isVariant(dest):
+		return true
+	case dest.Kind() == reflect.Interface:
+		return true
+	default:
+		return dest.Kind() == src.Kind()
+	}
+}
+
+func isConvertibleTo(dest, src reflect.Type) bool {
+	switch {
+	case isVariant(dest):
+		return true
+	case dest.Kind() == reflect.Interface:
+		return true
+	case dest.Kind() == reflect.Slice:
+		return src.Kind() == reflect.Slice &&
+			isConvertibleTo(dest.Elem(), src.Elem())
+	case dest.Kind() == reflect.Struct:
+		return src == interfacesType
+	default:
+		return src.ConvertibleTo(dest)
+	}
+}
+
+func storeMap(dest, src reflect.Value) error {
+	switch {
+	case !kindsAreCompatible(dest.Type(), src.Type()):
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"map: cannot store a value of %s into %s",
+			src.Type(), dest.Type())
+	case isVariant(dest.Type()):
+		return storeMapIntoVariant(dest, src)
+	case dest.Kind() == reflect.Interface:
+		return storeMapIntoInterface(dest, src)
+	case isConvertibleTo(dest.Type().Key(), src.Type().Key()) &&
+		isConvertibleTo(dest.Type().Elem(), src.Type().Elem()):
+		return storeMapIntoMap(dest, src)
+	default:
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"map: cannot convert a value of %s into %s",
+			src.Type(), dest.Type())
+	}
+}
+
+func storeMapIntoVariant(dest, src reflect.Value) error {
+	dv := reflect.MakeMap(src.Type())
+	err := store(dv, src)
+	if err != nil {
+		return err
+	}
+	return storeBase(dest, dv)
+}
+
+func storeMapIntoInterface(dest, src reflect.Value) error {
+	var dv reflect.Value
+	if isVariant(src.Type().Elem()) {
+		//Convert variants to interface{} recursively when converting
+		//to interface{}
+		dv = reflect.MakeMap(
+			reflect.MapOf(src.Type().Key(), interfaceType))
+	} else {
+		dv = reflect.MakeMap(src.Type())
+	}
+	err := store(dv, src)
+	if err != nil {
+		return err
+	}
+	return storeBase(dest, dv)
+}
+
+func storeMapIntoMap(dest, src reflect.Value) error {
+	if dest.IsNil() {
+		dest.Set(reflect.MakeMap(dest.Type()))
+	}
+	keys := src.MapKeys()
+	for _, key := range keys {
+		dkey := key.Convert(dest.Type().Key())
+		dval := reflect.New(dest.Type().Elem()).Elem()
+		err := store(dval, getVariantValue(src.MapIndex(key)))
+		if err != nil {
+			return err
+		}
+		dest.SetMapIndex(dkey, dval)
+	}
+	return nil
+}
+
+func storeSlice(dest, src reflect.Value) error {
+	switch {
+	case src.Type() == interfacesType && dest.Kind() == reflect.Struct:
+		//The decoder always decodes structs as slices of interface{}
+		return storeStruct(dest, src)
+	case !kindsAreCompatible(dest.Type(), src.Type()):
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"slice: cannot store a value of %s into %s",
+			src.Type(), dest.Type())
+	case isVariant(dest.Type()):
+		return storeSliceIntoVariant(dest, src)
+	case dest.Kind() == reflect.Interface:
+		return storeSliceIntoInterface(dest, src)
+	case isConvertibleTo(dest.Type().Elem(), src.Type().Elem()):
+		return storeSliceIntoSlice(dest, src)
+	default:
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"slice: cannot convert a value of %s into %s",
+			src.Type(), dest.Type())
+	}
+}
+
+func storeStruct(dest, src reflect.Value) error {
+	if isVariant(dest.Type()) {
+		return storeBase(dest, src)
+	}
+	dval := make([]interface{}, 0, dest.NumField())
+	dtype := dest.Type()
+	for i := 0; i < dest.NumField(); i++ {
+		field := dest.Field(i)
+		ftype := dtype.Field(i)
+		if ftype.PkgPath != "" {
+			continue
+		}
+		if ftype.Tag.Get("dbus") == "-" {
+			continue
+		}
+		dval = append(dval, field.Addr().Interface())
+	}
+	if src.Len() != len(dval) {
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"destination struct does not have "+
+				"enough fields need: %d have: %d",
+			src.Len(), len(dval))
+	}
+	return Store(src.Interface().([]interface{}), dval...)
+}
+
+func storeSliceIntoVariant(dest, src reflect.Value) error {
+	dv := reflect.MakeSlice(src.Type(), src.Len(), src.Cap())
+	err := store(dv, src)
+	if err != nil {
+		return err
+	}
+	return storeBase(dest, dv)
+}
+
+func storeSliceIntoInterface(dest, src reflect.Value) error {
+	var dv reflect.Value
+	if isVariant(src.Type().Elem()) {
+		//Convert variants to interface{} recursively when converting
+		//to interface{}
+		dv = reflect.MakeSlice(reflect.SliceOf(interfaceType),
+			src.Len(), src.Cap())
+	} else {
+		dv = reflect.MakeSlice(src.Type(), src.Len(), src.Cap())
+	}
+	err := store(dv, src)
+	if err != nil {
+		return err
+	}
+	return storeBase(dest, dv)
+}
+
+func storeSliceIntoSlice(dest, src reflect.Value) error {
+	if dest.IsNil() || dest.Len() < src.Len() {
+		dest.Set(reflect.MakeSlice(dest.Type(), src.Len(), src.Cap()))
+	}
+	if dest.Len() != src.Len() {
+		return fmt.Errorf(
+			"dbus.Store: type mismatch: "+
+				"slices are different lengths "+
+				"need: %d have: %d",
+			src.Len(), dest.Len())
+	}
+	for i := 0; i < src.Len(); i++ {
+		err := store(dest.Index(i), getVariantValue(src.Index(i)))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func getVariantValue(in reflect.Value) reflect.Value {
+	if isVariant(in.Type()) {
+		return reflect.ValueOf(in.Interface().(Variant).Value())
+	}
+	return in
+}
+
+func isVariant(t reflect.Type) bool {
+	return t == variantType
+}
+
+// An ObjectPath is an object path as defined by the D-Bus spec.
+type ObjectPath string
+
+// IsValid returns whether the object path is valid.
+func (o ObjectPath) IsValid() bool {
+	s := string(o)
+	if len(s) == 0 {
+		return false
+	}
+	if s[0] != '/' {
+		return false
+	}
+	if s[len(s)-1] == '/' && len(s) != 1 {
+		return false
+	}
+	// probably not used, but technically possible
+	if s == "/" {
+		return true
+	}
+	split := strings.Split(s[1:], "/")
+	for _, v := range split {
+		if len(v) == 0 {
+			return false
+		}
+		for _, c := range v {
+			if !isMemberChar(c) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// A UnixFD is a Unix file descriptor sent over the wire. See the package-level
+// documentation for more information about Unix file descriptor passsing.
+type UnixFD int32
+
+// A UnixFDIndex is the representation of a Unix file descriptor in a message.
+type UnixFDIndex uint32
+
+// alignment returns the alignment of values of type t.
+func alignment(t reflect.Type) int {
+	switch t {
+	case variantType:
+		return 1
+	case objectPathType:
+		return 4
+	case signatureType:
+		return 1
+	case interfacesType:
+		return 4
+	}
+	switch t.Kind() {
+	case reflect.Uint8:
+		return 1
+	case reflect.Uint16, reflect.Int16:
+		return 2
+	case reflect.Uint, reflect.Int, reflect.Uint32, reflect.Int32, reflect.String, reflect.Array, reflect.Slice, reflect.Map:
+		return 4
+	case reflect.Uint64, reflect.Int64, reflect.Float64, reflect.Struct:
+		return 8
+	case reflect.Ptr:
+		return alignment(t.Elem())
+	}
+	return 1
+}
+
+// isKeyType returns whether t is a valid type for a D-Bus dict.
+func isKeyType(t reflect.Type) bool {
+	switch t.Kind() {
+	case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
+		reflect.Int16, reflect.Int32, reflect.Int64, reflect.Float64,
+		reflect.String, reflect.Uint, reflect.Int:
+
+		return true
+	}
+	return false
+}
+
+// isValidInterface returns whether s is a valid name for an interface.
+func isValidInterface(s string) bool {
+	if len(s) == 0 || len(s) > 255 || s[0] == '.' {
+		return false
+	}
+	elem := strings.Split(s, ".")
+	if len(elem) < 2 {
+		return false
+	}
+	for _, v := range elem {
+		if len(v) == 0 {
+			return false
+		}
+		if v[0] >= '0' && v[0] <= '9' {
+			return false
+		}
+		for _, c := range v {
+			if !isMemberChar(c) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// isValidMember returns whether s is a valid name for a member.
+func isValidMember(s string) bool {
+	if len(s) == 0 || len(s) > 255 {
+		return false
+	}
+	i := strings.Index(s, ".")
+	if i != -1 {
+		return false
+	}
+	if s[0] >= '0' && s[0] <= '9' {
+		return false
+	}
+	for _, c := range s {
+		if !isMemberChar(c) {
+			return false
+		}
+	}
+	return true
+}
+
+func isMemberChar(c rune) bool {
+	return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') ||
+		(c >= 'a' && c <= 'z') || c == '_'
+}

vendor/github.com/godbus/dbus/decoder.go

@@ -0,0 +1,228 @@
+package dbus
+
+import (
+	"encoding/binary"
+	"io"
+	"reflect"
+)
+
+type decoder struct {
+	in    io.Reader
+	order binary.ByteOrder
+	pos   int
+}
+
+// newDecoder returns a new decoder that reads values from in. The input is
+// expected to be in the given byte order.
+func newDecoder(in io.Reader, order binary.ByteOrder) *decoder {
+	dec := new(decoder)
+	dec.in = in
+	dec.order = order
+	return dec
+}
+
+// align aligns the input to the given boundary and panics on error.
+func (dec *decoder) align(n int) {
+	if dec.pos%n != 0 {
+		newpos := (dec.pos + n - 1) & ^(n - 1)
+		empty := make([]byte, newpos-dec.pos)
+		if _, err := io.ReadFull(dec.in, empty); err != nil {
+			panic(err)
+		}
+		dec.pos = newpos
+	}
+}
+
+// Calls binary.Read(dec.in, dec.order, v) and panics on read errors.
+func (dec *decoder) binread(v interface{}) {
+	if err := binary.Read(dec.in, dec.order, v); err != nil {
+		panic(err)
+	}
+}
+
+func (dec *decoder) Decode(sig Signature) (vs []interface{}, err error) {
+	defer func() {
+		var ok bool
+		v := recover()
+		if err, ok = v.(error); ok {
+			if err == io.EOF || err == io.ErrUnexpectedEOF {
+				err = FormatError("unexpected EOF")
+			}
+		}
+	}()
+	vs = make([]interface{}, 0)
+	s := sig.str
+	for s != "" {
+		err, rem := validSingle(s, 0)
+		if err != nil {
+			return nil, err
+		}
+		v := dec.decode(s[:len(s)-len(rem)], 0)
+		vs = append(vs, v)
+		s = rem
+	}
+	return vs, nil
+}
+
+func (dec *decoder) decode(s string, depth int) interface{} {
+	dec.align(alignment(typeFor(s)))
+	switch s[0] {
+	case 'y':
+		var b [1]byte
+		if _, err := dec.in.Read(b[:]); err != nil {
+			panic(err)
+		}
+		dec.pos++
+		return b[0]
+	case 'b':
+		i := dec.decode("u", depth).(uint32)
+		switch {
+		case i == 0:
+			return false
+		case i == 1:
+			return true
+		default:
+			panic(FormatError("invalid value for boolean"))
+		}
+	case 'n':
+		var i int16
+		dec.binread(&i)
+		dec.pos += 2
+		return i
+	case 'i':
+		var i int32
+		dec.binread(&i)
+		dec.pos += 4
+		return i
+	case 'x':
+		var i int64
+		dec.binread(&i)
+		dec.pos += 8
+		return i
+	case 'q':
+		var i uint16
+		dec.binread(&i)
+		dec.pos += 2
+		return i
+	case 'u':
+		var i uint32
+		dec.binread(&i)
+		dec.pos += 4
+		return i
+	case 't':
+		var i uint64
+		dec.binread(&i)
+		dec.pos += 8
+		return i
+	case 'd':
+		var f float64
+		dec.binread(&f)
+		dec.pos += 8
+		return f
+	case 's':
+		length := dec.decode("u", depth).(uint32)
+		b := make([]byte, int(length)+1)
+		if _, err := io.ReadFull(dec.in, b); err != nil {
+			panic(err)
+		}
+		dec.pos += int(length) + 1
+		return string(b[:len(b)-1])
+	case 'o':
+		return ObjectPath(dec.decode("s", depth).(string))
+	case 'g':
+		length := dec.decode("y", depth).(byte)
+		b := make([]byte, int(length)+1)
+		if _, err := io.ReadFull(dec.in, b); err != nil {
+			panic(err)
+		}
+		dec.pos += int(length) + 1
+		sig, err := ParseSignature(string(b[:len(b)-1]))
+		if err != nil {
+			panic(err)
+		}
+		return sig
+	case 'v':
+		if depth >= 64 {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		var variant Variant
+		sig := dec.decode("g", depth).(Signature)
+		if len(sig.str) == 0 {
+			panic(FormatError("variant signature is empty"))
+		}
+		err, rem := validSingle(sig.str, 0)
+		if err != nil {
+			panic(err)
+		}
+		if rem != "" {
+			panic(FormatError("variant signature has multiple types"))
+		}
+		variant.sig = sig
+		variant.value = dec.decode(sig.str, depth+1)
+		return variant
+	case 'h':
+		return UnixFDIndex(dec.decode("u", depth).(uint32))
+	case 'a':
+		if len(s) > 1 && s[1] == '{' {
+			ksig := s[2:3]
+			vsig := s[3 : len(s)-1]
+			v := reflect.MakeMap(reflect.MapOf(typeFor(ksig), typeFor(vsig)))
+			if depth >= 63 {
+				panic(FormatError("input exceeds container depth limit"))
+			}
+			length := dec.decode("u", depth).(uint32)
+			// Even for empty maps, the correct padding must be included
+			dec.align(8)
+			spos := dec.pos
+			for dec.pos < spos+int(length) {
+				dec.align(8)
+				if !isKeyType(v.Type().Key()) {
+					panic(InvalidTypeError{v.Type()})
+				}
+				kv := dec.decode(ksig, depth+2)
+				vv := dec.decode(vsig, depth+2)
+				v.SetMapIndex(reflect.ValueOf(kv), reflect.ValueOf(vv))
+			}
+			return v.Interface()
+		}
+		if depth >= 64 {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		length := dec.decode("u", depth).(uint32)
+		v := reflect.MakeSlice(reflect.SliceOf(typeFor(s[1:])), 0, int(length))
+		// Even for empty arrays, the correct padding must be included
+		dec.align(alignment(typeFor(s[1:])))
+		spos := dec.pos
+		for dec.pos < spos+int(length) {
+			ev := dec.decode(s[1:], depth+1)
+			v = reflect.Append(v, reflect.ValueOf(ev))
+		}
+		return v.Interface()
+	case '(':
+		if depth >= 64 {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		dec.align(8)
+		v := make([]interface{}, 0)
+		s = s[1 : len(s)-1]
+		for s != "" {
+			err, rem := validSingle(s, 0)
+			if err != nil {
+				panic(err)
+			}
+			ev := dec.decode(s[:len(s)-len(rem)], depth+1)
+			v = append(v, ev)
+			s = rem
+		}
+		return v
+	default:
+		panic(SignatureError{Sig: s})
+	}
+}
+
+// A FormatError is an error in the wire format.
+type FormatError string
+
+func (e FormatError) Error() string {
+	return "dbus: wire format error: " + string(e)
+}

vendor/github.com/godbus/dbus/default_handler.go

@@ -0,0 +1,283 @@
+package dbus
+
+import (
+	"bytes"
+	"reflect"
+	"strings"
+	"sync"
+)
+
+func newIntrospectIntf(h *defaultHandler) *exportedIntf {
+	methods := make(map[string]Method)
+	methods["Introspect"] = exportedMethod{
+		reflect.ValueOf(func(msg Message) (string, *Error) {
+			path := msg.Headers[FieldPath].value.(ObjectPath)
+			return h.introspectPath(path), nil
+		}),
+	}
+	return newExportedIntf(methods, true)
+}
+
+func newDefaultHandler() *defaultHandler {
+	h := &defaultHandler{
+		objects:     make(map[ObjectPath]*exportedObj),
+		defaultIntf: make(map[string]*exportedIntf),
+	}
+	h.defaultIntf["org.freedesktop.DBus.Introspectable"] = newIntrospectIntf(h)
+	return h
+}
+
+type defaultHandler struct {
+	sync.RWMutex
+	objects     map[ObjectPath]*exportedObj
+	defaultIntf map[string]*exportedIntf
+}
+
+func (h *defaultHandler) PathExists(path ObjectPath) bool {
+	_, ok := h.objects[path]
+	return ok
+}
+
+func (h *defaultHandler) introspectPath(path ObjectPath) string {
+	subpath := make(map[string]struct{})
+	var xml bytes.Buffer
+	xml.WriteString("<node>")
+	for obj, _ := range h.objects {
+		p := string(path)
+		if p != "/" {
+			p += "/"
+		}
+		if strings.HasPrefix(string(obj), p) {
+			node_name := strings.Split(string(obj[len(p):]), "/")[0]
+			subpath[node_name] = struct{}{}
+		}
+	}
+	for s, _ := range subpath {
+		xml.WriteString("\n\t<node name=\"" + s + "\"/>")
+	}
+	xml.WriteString("\n</node>")
+	return xml.String()
+}
+
+func (h *defaultHandler) LookupObject(path ObjectPath) (ServerObject, bool) {
+	h.RLock()
+	defer h.RUnlock()
+	object, ok := h.objects[path]
+	if ok {
+		return object, ok
+	}
+
+	// If an object wasn't found for this exact path,
+	// look for a matching subtree registration
+	subtreeObject := newExportedObject()
+	path = path[:strings.LastIndex(string(path), "/")]
+	for len(path) > 0 {
+		object, ok = h.objects[path]
+		if ok {
+			for name, iface := range object.interfaces {
+				// Only include this handler if it registered for the subtree
+				if iface.isFallbackInterface() {
+					subtreeObject.interfaces[name] = iface
+				}
+			}
+			break
+		}
+
+		path = path[:strings.LastIndex(string(path), "/")]
+	}
+
+	for name, intf := range h.defaultIntf {
+		if _, exists := subtreeObject.interfaces[name]; exists {
+			continue
+		}
+		subtreeObject.interfaces[name] = intf
+	}
+
+	return subtreeObject, true
+}
+
+func (h *defaultHandler) AddObject(path ObjectPath, object *exportedObj) {
+	h.Lock()
+	h.objects[path] = object
+	h.Unlock()
+}
+
+func (h *defaultHandler) DeleteObject(path ObjectPath) {
+	h.Lock()
+	delete(h.objects, path)
+	h.Unlock()
+}
+
+type exportedMethod struct {
+	reflect.Value
+}
+
+func (m exportedMethod) Call(args ...interface{}) ([]interface{}, error) {
+	t := m.Type()
+
+	params := make([]reflect.Value, len(args))
+	for i := 0; i < len(args); i++ {
+		params[i] = reflect.ValueOf(args[i]).Elem()
+	}
+
+	ret := m.Value.Call(params)
+
+	err := ret[t.NumOut()-1].Interface().(*Error)
+	ret = ret[:t.NumOut()-1]
+	out := make([]interface{}, len(ret))
+	for i, val := range ret {
+		out[i] = val.Interface()
+	}
+	if err == nil {
+		//concrete type to interface nil is a special case
+		return out, nil
+	}
+	return out, err
+}
+
+func (m exportedMethod) NumArguments() int {
+	return m.Value.Type().NumIn()
+}
+
+func (m exportedMethod) ArgumentValue(i int) interface{} {
+	return reflect.Zero(m.Type().In(i)).Interface()
+}
+
+func (m exportedMethod) NumReturns() int {
+	return m.Value.Type().NumOut()
+}
+
+func (m exportedMethod) ReturnValue(i int) interface{} {
+	return reflect.Zero(m.Type().Out(i)).Interface()
+}
+
+func newExportedObject() *exportedObj {
+	return &exportedObj{
+		interfaces: make(map[string]*exportedIntf),
+	}
+}
+
+type exportedObj struct {
+	interfaces map[string]*exportedIntf
+}
+
+func (obj *exportedObj) LookupInterface(name string) (Interface, bool) {
+	if name == "" {
+		return obj, true
+	}
+	intf, exists := obj.interfaces[name]
+	return intf, exists
+}
+
+func (obj *exportedObj) AddInterface(name string, iface *exportedIntf) {
+	obj.interfaces[name] = iface
+}
+
+func (obj *exportedObj) DeleteInterface(name string) {
+	delete(obj.interfaces, name)
+}
+
+func (obj *exportedObj) LookupMethod(name string) (Method, bool) {
+	for _, intf := range obj.interfaces {
+		method, exists := intf.LookupMethod(name)
+		if exists {
+			return method, exists
+		}
+	}
+	return nil, false
+}
+
+func (obj *exportedObj) isFallbackInterface() bool {
+	return false
+}
+
+func newExportedIntf(methods map[string]Method, includeSubtree bool) *exportedIntf {
+	return &exportedIntf{
+		methods:        methods,
+		includeSubtree: includeSubtree,
+	}
+}
+
+type exportedIntf struct {
+	methods map[string]Method
+
+	// Whether or not this export is for the entire subtree
+	includeSubtree bool
+}
+
+func (obj *exportedIntf) LookupMethod(name string) (Method, bool) {
+	out, exists := obj.methods[name]
+	return out, exists
+}
+
+func (obj *exportedIntf) isFallbackInterface() bool {
+	return obj.includeSubtree
+}
+
+func newDefaultSignalHandler() *defaultSignalHandler {
+	return &defaultSignalHandler{}
+}
+
+func isDefaultSignalHandler(handler SignalHandler) bool {
+	_, ok := handler.(*defaultSignalHandler)
+	return ok
+}
+
+type defaultSignalHandler struct {
+	sync.RWMutex
+	closed  bool
+	signals []chan<- *Signal
+}
+
+func (sh *defaultSignalHandler) DeliverSignal(intf, name string, signal *Signal) {
+	sh.RLock()
+	defer sh.RUnlock()
+	if sh.closed {
+		return
+	}
+	for _, ch := range sh.signals {
+		ch <- signal
+	}
+}
+
+func (sh *defaultSignalHandler) Init() error {
+	sh.Lock()
+	sh.signals = make([]chan<- *Signal, 0)
+	sh.Unlock()
+	return nil
+}
+
+func (sh *defaultSignalHandler) Terminate() {
+	sh.Lock()
+	sh.closed = true
+	for _, ch := range sh.signals {
+		close(ch)
+	}
+	sh.signals = nil
+	sh.Unlock()
+}
+
+func (sh *defaultSignalHandler) addSignal(ch chan<- *Signal) {
+	sh.Lock()
+	defer sh.Unlock()
+	if sh.closed {
+		return
+	}
+	sh.signals = append(sh.signals, ch)
+
+}
+
+func (sh *defaultSignalHandler) removeSignal(ch chan<- *Signal) {
+	sh.Lock()
+	defer sh.Unlock()
+	if sh.closed {
+		return
+	}
+	for i := len(sh.signals) - 1; i >= 0; i-- {
+		if ch == sh.signals[i] {
+			copy(sh.signals[i:], sh.signals[i+1:])
+			sh.signals[len(sh.signals)-1] = nil
+			sh.signals = sh.signals[:len(sh.signals)-1]
+		}
+	}
+}

vendor/github.com/godbus/dbus/doc.go

@@ -0,0 +1,69 @@
+/*
+Package dbus implements bindings to the D-Bus message bus system.
+
+To use the message bus API, you first need to connect to a bus (usually the
+session or system bus). The acquired connection then can be used to call methods
+on remote objects and emit or receive signals. Using the Export method, you can
+arrange D-Bus methods calls to be directly translated to method calls on a Go
+value.
+
+Conversion Rules
+
+For outgoing messages, Go types are automatically converted to the
+corresponding D-Bus types. The following types are directly encoded as their
+respective D-Bus equivalents:
+
+     Go type     | D-Bus type
+     ------------+-----------
+     byte        | BYTE
+     bool        | BOOLEAN
+     int16       | INT16
+     uint16      | UINT16
+     int         | INT32
+     uint        | UINT32
+     int32       | INT32
+     uint32      | UINT32
+     int64       | INT64
+     uint64      | UINT64
+     float64     | DOUBLE
+     string      | STRING
+     ObjectPath  | OBJECT_PATH
+     Signature   | SIGNATURE
+     Variant     | VARIANT
+     interface{} | VARIANT
+     UnixFDIndex | UNIX_FD
+
+Slices and arrays encode as ARRAYs of their element type.
+
+Maps encode as DICTs, provided that their key type can be used as a key for
+a DICT.
+
+Structs other than Variant and Signature encode as a STRUCT containing their
+exported fields. Fields whose tags contain `dbus:"-"` and unexported fields will
+be skipped.
+
+Pointers encode as the value they're pointed to.
+
+Types convertible to one of the base types above will be mapped as the
+base type.
+
+Trying to encode any other type or a slice, map or struct containing an
+unsupported type will result in an InvalidTypeError.
+
+For incoming messages, the inverse of these rules are used, with the exception
+of STRUCTs. Incoming STRUCTS are represented as a slice of empty interfaces
+containing the struct fields in the correct order. The Store function can be
+used to convert such values to Go structs.
+
+Unix FD passing
+
+Handling Unix file descriptors deserves special mention. To use them, you should
+first check that they are supported on a connection by calling SupportsUnixFDs.
+If it returns true, all method of Connection will translate messages containing
+UnixFD's to messages that are accompanied by the given file descriptors with the
+UnixFD values being substituted by the correct indices. Similarily, the indices
+of incoming messages are automatically resolved. It shouldn't be necessary to use
+UnixFDIndex.
+
+*/
+package dbus

vendor/github.com/godbus/dbus/encoder.go

@@ -0,0 +1,210 @@
+package dbus
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"reflect"
+)
+
+// An encoder encodes values to the D-Bus wire format.
+type encoder struct {
+	out   io.Writer
+	order binary.ByteOrder
+	pos   int
+}
+
+// NewEncoder returns a new encoder that writes to out in the given byte order.
+func newEncoder(out io.Writer, order binary.ByteOrder) *encoder {
+	return newEncoderAtOffset(out, 0, order)
+}
+
+// newEncoderAtOffset returns a new encoder that writes to out in the given
+// byte order. Specify the offset to initialize pos for proper alignment
+// computation.
+func newEncoderAtOffset(out io.Writer, offset int, order binary.ByteOrder) *encoder {
+	enc := new(encoder)
+	enc.out = out
+	enc.order = order
+	enc.pos = offset
+	return enc
+}
+
+// Aligns the next output to be on a multiple of n. Panics on write errors.
+func (enc *encoder) align(n int) {
+	pad := enc.padding(0, n)
+	if pad > 0 {
+		empty := make([]byte, pad)
+		if _, err := enc.out.Write(empty); err != nil {
+			panic(err)
+		}
+		enc.pos += pad
+	}
+}
+
+// pad returns the number of bytes of padding, based on current position and additional offset.
+// and alignment.
+func (enc *encoder) padding(offset, algn int) int {
+	abs := enc.pos + offset
+	if abs%algn != 0 {
+		newabs := (abs + algn - 1) & ^(algn - 1)
+		return newabs - abs
+	}
+	return 0
+}
+
+// Calls binary.Write(enc.out, enc.order, v) and panics on write errors.
+func (enc *encoder) binwrite(v interface{}) {
+	if err := binary.Write(enc.out, enc.order, v); err != nil {
+		panic(err)
+	}
+}
+
+// Encode encodes the given values to the underyling reader. All written values
+// are aligned properly as required by the D-Bus spec.
+func (enc *encoder) Encode(vs ...interface{}) (err error) {
+	defer func() {
+		err, _ = recover().(error)
+	}()
+	for _, v := range vs {
+		enc.encode(reflect.ValueOf(v), 0)
+	}
+	return nil
+}
+
+// encode encodes the given value to the writer and panics on error. depth holds
+// the depth of the container nesting.
+func (enc *encoder) encode(v reflect.Value, depth int) {
+	enc.align(alignment(v.Type()))
+	switch v.Kind() {
+	case reflect.Uint8:
+		var b [1]byte
+		b[0] = byte(v.Uint())
+		if _, err := enc.out.Write(b[:]); err != nil {
+			panic(err)
+		}
+		enc.pos++
+	case reflect.Bool:
+		if v.Bool() {
+			enc.encode(reflect.ValueOf(uint32(1)), depth)
+		} else {
+			enc.encode(reflect.ValueOf(uint32(0)), depth)
+		}
+	case reflect.Int16:
+		enc.binwrite(int16(v.Int()))
+		enc.pos += 2
+	case reflect.Uint16:
+		enc.binwrite(uint16(v.Uint()))
+		enc.pos += 2
+	case reflect.Int, reflect.Int32:
+		enc.binwrite(int32(v.Int()))
+		enc.pos += 4
+	case reflect.Uint, reflect.Uint32:
+		enc.binwrite(uint32(v.Uint()))
+		enc.pos += 4
+	case reflect.Int64:
+		enc.binwrite(v.Int())
+		enc.pos += 8
+	case reflect.Uint64:
+		enc.binwrite(v.Uint())
+		enc.pos += 8
+	case reflect.Float64:
+		enc.binwrite(v.Float())
+		enc.pos += 8
+	case reflect.String:
+		enc.encode(reflect.ValueOf(uint32(len(v.String()))), depth)
+		b := make([]byte, v.Len()+1)
+		copy(b, v.String())
+		b[len(b)-1] = 0
+		n, err := enc.out.Write(b)
+		if err != nil {
+			panic(err)
+		}
+		enc.pos += n
+	case reflect.Ptr:
+		enc.encode(v.Elem(), depth)
+	case reflect.Slice, reflect.Array:
+		if depth >= 64 {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		// Lookahead offset: 4 bytes for uint32 length (with alignment),
+		// plus alignment for elements.
+		n := enc.padding(0, 4) + 4
+		offset := enc.pos + n + enc.padding(n, alignment(v.Type().Elem()))
+
+		var buf bytes.Buffer
+		bufenc := newEncoderAtOffset(&buf, offset, enc.order)
+
+		for i := 0; i < v.Len(); i++ {
+			bufenc.encode(v.Index(i), depth+1)
+		}
+		enc.encode(reflect.ValueOf(uint32(buf.Len())), depth)
+		length := buf.Len()
+		enc.align(alignment(v.Type().Elem()))
+		if _, err := buf.WriteTo(enc.out); err != nil {
+			panic(err)
+		}
+		enc.pos += length
+	case reflect.Struct:
+		if depth >= 64 && v.Type() != signatureType {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		switch t := v.Type(); t {
+		case signatureType:
+			str := v.Field(0)
+			enc.encode(reflect.ValueOf(byte(str.Len())), depth+1)
+			b := make([]byte, str.Len()+1)
+			copy(b, str.String())
+			b[len(b)-1] = 0
+			n, err := enc.out.Write(b)
+			if err != nil {
+				panic(err)
+			}
+			enc.pos += n
+		case variantType:
+			variant := v.Interface().(Variant)
+			enc.encode(reflect.ValueOf(variant.sig), depth+1)
+			enc.encode(reflect.ValueOf(variant.value), depth+1)
+		default:
+			for i := 0; i < v.Type().NumField(); i++ {
+				field := t.Field(i)
+				if field.PkgPath == "" && field.Tag.Get("dbus") != "-" {
+					enc.encode(v.Field(i), depth+1)
+				}
+			}
+		}
+	case reflect.Map:
+		// Maps are arrays of structures, so they actually increase the depth by
+		// 2.
+		if depth >= 63 {
+			panic(FormatError("input exceeds container depth limit"))
+		}
+		if !isKeyType(v.Type().Key()) {
+			panic(InvalidTypeError{v.Type()})
+		}
+		keys := v.MapKeys()
+		// Lookahead offset: 4 bytes for uint32 length (with alignment),
+		// plus 8-byte alignment
+		n := enc.padding(0, 4) + 4
+		offset := enc.pos + n + enc.padding(n, 8)
+
+		var buf bytes.Buffer
+		bufenc := newEncoderAtOffset(&buf, offset, enc.order)
+		for _, k := range keys {
+			bufenc.align(8)
+			bufenc.encode(k, depth+2)
+			bufenc.encode(v.MapIndex(k), depth+2)
+		}
+		enc.encode(reflect.ValueOf(uint32(buf.Len())), depth)
+		length := buf.Len()
+		enc.align(8)
+		if _, err := buf.WriteTo(enc.out); err != nil {
+			panic(err)
+		}
+		enc.pos += length
+	case reflect.Interface:
+		enc.encode(reflect.ValueOf(MakeVariant(v.Interface())), depth)
+	default:
+		panic(InvalidTypeError{v.Type()})
+	}
+}

vendor/github.com/godbus/dbus/export.go

@@ -0,0 +1,413 @@
+package dbus
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+var (
+	ErrMsgInvalidArg = Error{
+		"org.freedesktop.DBus.Error.InvalidArgs",
+		[]interface{}{"Invalid type / number of args"},
+	}
+	ErrMsgNoObject = Error{
+		"org.freedesktop.DBus.Error.NoSuchObject",
+		[]interface{}{"No such object"},
+	}
+	ErrMsgUnknownMethod = Error{
+		"org.freedesktop.DBus.Error.UnknownMethod",
+		[]interface{}{"Unknown / invalid method"},
+	}
+	ErrMsgUnknownInterface = Error{
+		"org.freedesktop.DBus.Error.UnknownInterface",
+		[]interface{}{"Object does not implement the interface"},
+	}
+)
+
+func MakeFailedError(err error) *Error {
+	return &Error{
+		"org.freedesktop.DBus.Error.Failed",
+		[]interface{}{err.Error()},
+	}
+}
+
+// Sender is a type which can be used in exported methods to receive the message
+// sender.
+type Sender string
+
+func computeMethodName(name string, mapping map[string]string) string {
+	newname, ok := mapping[name]
+	if ok {
+		name = newname
+	}
+	return name
+}
+
+func getMethods(in interface{}, mapping map[string]string) map[string]reflect.Value {
+	if in == nil {
+		return nil
+	}
+	methods := make(map[string]reflect.Value)
+	val := reflect.ValueOf(in)
+	typ := val.Type()
+	for i := 0; i < typ.NumMethod(); i++ {
+		methtype := typ.Method(i)
+		method := val.Method(i)
+		t := method.Type()
+		// only track valid methods must return *Error as last arg
+		// and must be exported
+		if t.NumOut() == 0 ||
+			t.Out(t.NumOut()-1) != reflect.TypeOf(&ErrMsgInvalidArg) ||
+			methtype.PkgPath != "" {
+			continue
+		}
+		// map names while building table
+		methods[computeMethodName(methtype.Name, mapping)] = method
+	}
+	return methods
+}
+
+func standardMethodArgumentDecode(m Method, sender string, msg *Message, body []interface{}) ([]interface{}, error) {
+	pointers := make([]interface{}, m.NumArguments())
+	decode := make([]interface{}, 0, len(body))
+
+	for i := 0; i < m.NumArguments(); i++ {
+		tp := reflect.TypeOf(m.ArgumentValue(i))
+		val := reflect.New(tp)
+		pointers[i] = val.Interface()
+		if tp == reflect.TypeOf((*Sender)(nil)).Elem() {
+			val.Elem().SetString(sender)
+		} else if tp == reflect.TypeOf((*Message)(nil)).Elem() {
+			val.Elem().Set(reflect.ValueOf(*msg))
+		} else {
+			decode = append(decode, pointers[i])
+		}
+	}
+
+	if len(decode) != len(body) {
+		return nil, ErrMsgInvalidArg
+	}
+
+	if err := Store(body, decode...); err != nil {
+		return nil, ErrMsgInvalidArg
+	}
+
+	return pointers, nil
+}
+
+func (conn *Conn) decodeArguments(m Method, sender string, msg *Message) ([]interface{}, error) {
+	if decoder, ok := m.(ArgumentDecoder); ok {
+		return decoder.DecodeArguments(conn, sender, msg, msg.Body)
+	}
+	return standardMethodArgumentDecode(m, sender, msg, msg.Body)
+}
+
+// handleCall handles the given method call (i.e. looks if it's one of the
+// pre-implemented ones and searches for a corresponding handler if not).
+func (conn *Conn) handleCall(msg *Message) {
+	name := msg.Headers[FieldMember].value.(string)
+	path := msg.Headers[FieldPath].value.(ObjectPath)
+	ifaceName, _ := msg.Headers[FieldInterface].value.(string)
+	sender, hasSender := msg.Headers[FieldSender].value.(string)
+	serial := msg.serial
+	if ifaceName == "org.freedesktop.DBus.Peer" {
+		switch name {
+		case "Ping":
+			conn.sendReply(sender, serial)
+		case "GetMachineId":
+			conn.sendReply(sender, serial, conn.uuid)
+		default:
+			conn.sendError(ErrMsgUnknownMethod, sender, serial)
+		}
+		return
+	}
+	if len(name) == 0 {
+		conn.sendError(ErrMsgUnknownMethod, sender, serial)
+	}
+
+	object, ok := conn.handler.LookupObject(path)
+	if !ok {
+		conn.sendError(ErrMsgNoObject, sender, serial)
+		return
+	}
+
+	iface, exists := object.LookupInterface(ifaceName)
+	if !exists {
+		conn.sendError(ErrMsgUnknownInterface, sender, serial)
+		return
+	}
+
+	m, exists := iface.LookupMethod(name)
+	if !exists {
+		conn.sendError(ErrMsgUnknownMethod, sender, serial)
+		return
+	}
+	args, err := conn.decodeArguments(m, sender, msg)
+	if err != nil {
+		conn.sendError(err, sender, serial)
+		return
+	}
+
+	ret, err := m.Call(args...)
+	if err != nil {
+		conn.sendError(err, sender, serial)
+		return
+	}
+
+	if msg.Flags&FlagNoReplyExpected == 0 {
+		reply := new(Message)
+		reply.Type = TypeMethodReply
+		reply.serial = conn.getSerial()
+		reply.Headers = make(map[HeaderField]Variant)
+		if hasSender {
+			reply.Headers[FieldDestination] = msg.Headers[FieldSender]
+		}
+		reply.Headers[FieldReplySerial] = MakeVariant(msg.serial)
+		reply.Body = make([]interface{}, len(ret))
+		for i := 0; i < len(ret); i++ {
+			reply.Body[i] = ret[i]
+		}
+		reply.Headers[FieldSignature] = MakeVariant(SignatureOf(reply.Body...))
+		conn.outLck.RLock()
+		if !conn.closed {
+			conn.out <- reply
+		}
+		conn.outLck.RUnlock()
+	}
+}
+
+// Emit emits the given signal on the message bus. The name parameter must be
+// formatted as "interface.member", e.g., "org.freedesktop.DBus.NameLost".
+func (conn *Conn) Emit(path ObjectPath, name string, values ...interface{}) error {
+	if !path.IsValid() {
+		return errors.New("dbus: invalid object path")
+	}
+	i := strings.LastIndex(name, ".")
+	if i == -1 {
+		return errors.New("dbus: invalid method name")
+	}
+	iface := name[:i]
+	member := name[i+1:]
+	if !isValidMember(member) {
+		return errors.New("dbus: invalid method name")
+	}
+	if !isValidInterface(iface) {
+		return errors.New("dbus: invalid interface name")
+	}
+	msg := new(Message)
+	msg.Type = TypeSignal
+	msg.serial = conn.getSerial()
+	msg.Headers = make(map[HeaderField]Variant)
+	msg.Headers[FieldInterface] = MakeVariant(iface)
+	msg.Headers[FieldMember] = MakeVariant(member)
+	msg.Headers[FieldPath] = MakeVariant(path)
+	msg.Body = values
+	if len(values) > 0 {
+		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(values...))
+	}
+	conn.outLck.RLock()
+	defer conn.outLck.RUnlock()
+	if conn.closed {
+		return ErrClosed
+	}
+	conn.out <- msg
+	return nil
+}
+
+// Export registers the given value to be exported as an object on the
+// message bus.
+//
+// If a method call on the given path and interface is received, an exported
+// method with the same name is called with v as the receiver if the
+// parameters match and the last return value is of type *Error. If this
+// *Error is not nil, it is sent back to the caller as an error.
+// Otherwise, a method reply is sent with the other return values as its body.
+//
+// Any parameters with the special type Sender are set to the sender of the
+// dbus message when the method is called. Parameters of this type do not
+// contribute to the dbus signature of the method (i.e. the method is exposed
+// as if the parameters of type Sender were not there).
+//
+// Similarly, any parameters with the type Message are set to the raw message
+// received on the bus. Again, parameters of this type do not contribute to the
+// dbus signature of the method.
+//
+// Every method call is executed in a new goroutine, so the method may be called
+// in multiple goroutines at once.
+//
+// Method calls on the interface org.freedesktop.DBus.Peer will be automatically
+// handled for every object.
+//
+// Passing nil as the first parameter will cause conn to cease handling calls on
+// the given combination of path and interface.
+//
+// Export returns an error if path is not a valid path name.
+func (conn *Conn) Export(v interface{}, path ObjectPath, iface string) error {
+	return conn.ExportWithMap(v, nil, path, iface)
+}
+
+// ExportWithMap works exactly like Export but provides the ability to remap
+// method names (e.g. export a lower-case method).
+//
+// The keys in the map are the real method names (exported on the struct), and
+// the values are the method names to be exported on DBus.
+func (conn *Conn) ExportWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error {
+	return conn.export(getMethods(v, mapping), path, iface, false)
+}
+
+// ExportSubtree works exactly like Export but registers the given value for
+// an entire subtree rather under the root path provided.
+//
+// In order to make this useful, one parameter in each of the value's exported
+// methods should be a Message, in which case it will contain the raw message
+// (allowing one to get access to the path that caused the method to be called).
+//
+// Note that more specific export paths take precedence over less specific. For
+// example, a method call using the ObjectPath /foo/bar/baz will call a method
+// exported on /foo/bar before a method exported on /foo.
+func (conn *Conn) ExportSubtree(v interface{}, path ObjectPath, iface string) error {
+	return conn.ExportSubtreeWithMap(v, nil, path, iface)
+}
+
+// ExportSubtreeWithMap works exactly like ExportSubtree but provides the
+// ability to remap method names (e.g. export a lower-case method).
+//
+// The keys in the map are the real method names (exported on the struct), and
+// the values are the method names to be exported on DBus.
+func (conn *Conn) ExportSubtreeWithMap(v interface{}, mapping map[string]string, path ObjectPath, iface string) error {
+	return conn.export(getMethods(v, mapping), path, iface, true)
+}
+
+// ExportMethodTable like Export registers the given methods as an object
+// on the message bus. Unlike Export the it uses a method table to define
+// the object instead of a native go object.
+//
+// The method table is a map from method name to function closure
+// representing the method. This allows an object exported on the bus to not
+// necessarily be a native go object. It can be useful for generating exposed
+// methods on the fly.
+//
+// Any non-function objects in the method table are ignored.
+func (conn *Conn) ExportMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error {
+	return conn.exportMethodTable(methods, path, iface, false)
+}
+
+// Like ExportSubtree, but with the same caveats as ExportMethodTable.
+func (conn *Conn) ExportSubtreeMethodTable(methods map[string]interface{}, path ObjectPath, iface string) error {
+	return conn.exportMethodTable(methods, path, iface, true)
+}
+
+func (conn *Conn) exportMethodTable(methods map[string]interface{}, path ObjectPath, iface string, includeSubtree bool) error {
+	out := make(map[string]reflect.Value)
+	for name, method := range methods {
+		rval := reflect.ValueOf(method)
+		if rval.Kind() != reflect.Func {
+			continue
+		}
+		t := rval.Type()
+		// only track valid methods must return *Error as last arg
+		if t.NumOut() == 0 ||
+			t.Out(t.NumOut()-1) != reflect.TypeOf(&ErrMsgInvalidArg) {
+			continue
+		}
+		out[name] = rval
+	}
+	return conn.export(out, path, iface, includeSubtree)
+}
+
+func (conn *Conn) unexport(h *defaultHandler, path ObjectPath, iface string) error {
+	if h.PathExists(path) {
+		obj := h.objects[path]
+		obj.DeleteInterface(iface)
+		if len(obj.interfaces) == 0 {
+			h.DeleteObject(path)
+		}
+	}
+	return nil
+}
+
+// exportWithMap is the worker function for all exports/registrations.
+func (conn *Conn) export(methods map[string]reflect.Value, path ObjectPath, iface string, includeSubtree bool) error {
+	h, ok := conn.handler.(*defaultHandler)
+	if !ok {
+		return fmt.Errorf(
+			`dbus: export only allowed on the default hander handler have %T"`,
+			conn.handler)
+	}
+
+	if !path.IsValid() {
+		return fmt.Errorf(`dbus: Invalid path name: "%s"`, path)
+	}
+
+	// Remove a previous export if the interface is nil
+	if methods == nil {
+		return conn.unexport(h, path, iface)
+	}
+
+	// If this is the first handler for this path, make a new map to hold all
+	// handlers for this path.
+	if !h.PathExists(path) {
+		h.AddObject(path, newExportedObject())
+	}
+
+	exportedMethods := make(map[string]Method)
+	for name, method := range methods {
+		exportedMethods[name] = exportedMethod{method}
+	}
+
+	// Finally, save this handler
+	obj := h.objects[path]
+	obj.AddInterface(iface, newExportedIntf(exportedMethods, includeSubtree))
+
+	return nil
+}
+
+// ReleaseName calls org.freedesktop.DBus.ReleaseName and awaits a response.
+func (conn *Conn) ReleaseName(name string) (ReleaseNameReply, error) {
+	var r uint32
+	err := conn.busObj.Call("org.freedesktop.DBus.ReleaseName", 0, name).Store(&r)
+	if err != nil {
+		return 0, err
+	}
+	return ReleaseNameReply(r), nil
+}
+
+// RequestName calls org.freedesktop.DBus.RequestName and awaits a response.
+func (conn *Conn) RequestName(name string, flags RequestNameFlags) (RequestNameReply, error) {
+	var r uint32
+	err := conn.busObj.Call("org.freedesktop.DBus.RequestName", 0, name, flags).Store(&r)
+	if err != nil {
+		return 0, err
+	}
+	return RequestNameReply(r), nil
+}
+
+// ReleaseNameReply is the reply to a ReleaseName call.
+type ReleaseNameReply uint32
+
+const (
+	ReleaseNameReplyReleased ReleaseNameReply = 1 + iota
+	ReleaseNameReplyNonExistent
+	ReleaseNameReplyNotOwner
+)
+
+// RequestNameFlags represents the possible flags for a RequestName call.
+type RequestNameFlags uint32
+
+const (
+	NameFlagAllowReplacement RequestNameFlags = 1 << iota
+	NameFlagReplaceExisting
+	NameFlagDoNotQueue
+)
+
+// RequestNameReply is the reply to a RequestName call.
+type RequestNameReply uint32
+
+const (
+	RequestNameReplyPrimaryOwner RequestNameReply = 1 + iota
+	RequestNameReplyInQueue
+	RequestNameReplyExists
+	RequestNameReplyAlreadyOwner
+)

vendor/github.com/godbus/dbus/homedir.go

@@ -0,0 +1,28 @@
+package dbus
+
+import (
+	"os"
+	"sync"
+)
+
+var (
+	homeDir     string
+	homeDirLock sync.Mutex
+)
+
+func getHomeDir() string {
+	homeDirLock.Lock()
+	defer homeDirLock.Unlock()
+
+	if homeDir != "" {
+		return homeDir
+	}
+
+	homeDir = os.Getenv("HOME")
+	if homeDir != "" {
+		return homeDir
+	}
+
+	homeDir = lookupHomeDir()
+	return homeDir
+}

vendor/github.com/godbus/dbus/homedir_dynamic.go

@@ -0,0 +1,15 @@
+// +build !static_build
+
+package dbus
+
+import (
+	"os/user"
+)
+
+func lookupHomeDir() string {
+	u, err := user.Current()
+	if err != nil {
+		return "/"
+	}
+	return u.HomeDir
+}

vendor/github.com/godbus/dbus/homedir_static.go

@@ -0,0 +1,45 @@
+// +build static_build
+
+package dbus
+
+import (
+	"bufio"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func lookupHomeDir() string {
+	myUid := os.Getuid()
+
+	f, err := os.Open("/etc/passwd")
+	if err != nil {
+		return "/"
+	}
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+
+	for s.Scan() {
+		if err := s.Err(); err != nil {
+			break
+		}
+
+		line := strings.TrimSpace(s.Text())
+		if line == "" {
+			continue
+		}
+
+		parts := strings.Split(line, ":")
+
+		if len(parts) >= 6 {
+			uid, err := strconv.Atoi(parts[2])
+			if err == nil && uid == myUid {
+				return parts[5]
+			}
+		}
+	}
+
+	// Default to / if we can't get a better value
+	return "/"
+}

vendor/github.com/godbus/dbus/message.go

@@ -0,0 +1,353 @@
+package dbus
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"io"
+	"reflect"
+	"strconv"
+)
+
+const protoVersion byte = 1
+
+// Flags represents the possible flags of a D-Bus message.
+type Flags byte
+
+const (
+	// FlagNoReplyExpected signals that the message is not expected to generate
+	// a reply. If this flag is set on outgoing messages, any possible reply
+	// will be discarded.
+	FlagNoReplyExpected Flags = 1 << iota
+	// FlagNoAutoStart signals that the message bus should not automatically
+	// start an application when handling this message.
+	FlagNoAutoStart
+	// FlagAllowInteractiveAuthorization may be set on a method call
+	// message to inform the receiving side that the caller is prepared
+	// to wait for interactive authorization, which might take a
+	// considerable time to complete. For instance, if this flag is set,
+	// it would be appropriate to query the user for passwords or
+	// confirmation via Polkit or a similar framework.
+	FlagAllowInteractiveAuthorization
+)
+
+// Type represents the possible types of a D-Bus message.
+type Type byte
+
+const (
+	TypeMethodCall Type = 1 + iota
+	TypeMethodReply
+	TypeError
+	TypeSignal
+	typeMax
+)
+
+func (t Type) String() string {
+	switch t {
+	case TypeMethodCall:
+		return "method call"
+	case TypeMethodReply:
+		return "reply"
+	case TypeError:
+		return "error"
+	case TypeSignal:
+		return "signal"
+	}
+	return "invalid"
+}
+
+// HeaderField represents the possible byte codes for the headers
+// of a D-Bus message.
+type HeaderField byte
+
+const (
+	FieldPath HeaderField = 1 + iota
+	FieldInterface
+	FieldMember
+	FieldErrorName
+	FieldReplySerial
+	FieldDestination
+	FieldSender
+	FieldSignature
+	FieldUnixFDs
+	fieldMax
+)
+
+// An InvalidMessageError describes the reason why a D-Bus message is regarded as
+// invalid.
+type InvalidMessageError string
+
+func (e InvalidMessageError) Error() string {
+	return "dbus: invalid message: " + string(e)
+}
+
+// fieldType are the types of the various header fields.
+var fieldTypes = [fieldMax]reflect.Type{
+	FieldPath:        objectPathType,
+	FieldInterface:   stringType,
+	FieldMember:      stringType,
+	FieldErrorName:   stringType,
+	FieldReplySerial: uint32Type,
+	FieldDestination: stringType,
+	FieldSender:      stringType,
+	FieldSignature:   signatureType,
+	FieldUnixFDs:     uint32Type,
+}
+
+// requiredFields lists the header fields that are required by the different
+// message types.
+var requiredFields = [typeMax][]HeaderField{
+	TypeMethodCall:  {FieldPath, FieldMember},
+	TypeMethodReply: {FieldReplySerial},
+	TypeError:       {FieldErrorName, FieldReplySerial},
+	TypeSignal:      {FieldPath, FieldInterface, FieldMember},
+}
+
+// Message represents a single D-Bus message.
+type Message struct {
+	Type
+	Flags
+	Headers map[HeaderField]Variant
+	Body    []interface{}
+
+	serial uint32
+}
+
+type header struct {
+	Field byte
+	Variant
+}
+
+// DecodeMessage tries to decode a single message in the D-Bus wire format
+// from the given reader. The byte order is figured out from the first byte.
+// The possibly returned error can be an error of the underlying reader, an
+// InvalidMessageError or a FormatError.
+func DecodeMessage(rd io.Reader) (msg *Message, err error) {
+	var order binary.ByteOrder
+	var hlength, length uint32
+	var typ, flags, proto byte
+	var headers []header
+
+	b := make([]byte, 1)
+	_, err = rd.Read(b)
+	if err != nil {
+		return
+	}
+	switch b[0] {
+	case 'l':
+		order = binary.LittleEndian
+	case 'B':
+		order = binary.BigEndian
+	default:
+		return nil, InvalidMessageError("invalid byte order")
+	}
+
+	dec := newDecoder(rd, order)
+	dec.pos = 1
+
+	msg = new(Message)
+	vs, err := dec.Decode(Signature{"yyyuu"})
+	if err != nil {
+		return nil, err
+	}
+	if err = Store(vs, &typ, &flags, &proto, &length, &msg.serial); err != nil {
+		return nil, err
+	}
+	msg.Type = Type(typ)
+	msg.Flags = Flags(flags)
+
+	// get the header length separately because we need it later
+	b = make([]byte, 4)
+	_, err = io.ReadFull(rd, b)
+	if err != nil {
+		return nil, err
+	}
+	binary.Read(bytes.NewBuffer(b), order, &hlength)
+	if hlength+length+16 > 1<<27 {
+		return nil, InvalidMessageError("message is too long")
+	}
+	dec = newDecoder(io.MultiReader(bytes.NewBuffer(b), rd), order)
+	dec.pos = 12
+	vs, err = dec.Decode(Signature{"a(yv)"})
+	if err != nil {
+		return nil, err
+	}
+	if err = Store(vs, &headers); err != nil {
+		return nil, err
+	}
+
+	msg.Headers = make(map[HeaderField]Variant)
+	for _, v := range headers {
+		msg.Headers[HeaderField(v.Field)] = v.Variant
+	}
+
+	dec.align(8)
+	body := make([]byte, int(length))
+	if length != 0 {
+		_, err := io.ReadFull(rd, body)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err = msg.IsValid(); err != nil {
+		return nil, err
+	}
+	sig, _ := msg.Headers[FieldSignature].value.(Signature)
+	if sig.str != "" {
+		buf := bytes.NewBuffer(body)
+		dec = newDecoder(buf, order)
+		vs, err := dec.Decode(sig)
+		if err != nil {
+			return nil, err
+		}
+		msg.Body = vs
+	}
+
+	return
+}
+
+// EncodeTo encodes and sends a message to the given writer. The byte order must
+// be either binary.LittleEndian or binary.BigEndian. If the message is not
+// valid or an error occurs when writing, an error is returned.
+func (msg *Message) EncodeTo(out io.Writer, order binary.ByteOrder) error {
+	if err := msg.IsValid(); err != nil {
+		return err
+	}
+	var vs [7]interface{}
+	switch order {
+	case binary.LittleEndian:
+		vs[0] = byte('l')
+	case binary.BigEndian:
+		vs[0] = byte('B')
+	default:
+		return errors.New("dbus: invalid byte order")
+	}
+	body := new(bytes.Buffer)
+	enc := newEncoder(body, order)
+	if len(msg.Body) != 0 {
+		enc.Encode(msg.Body...)
+	}
+	vs[1] = msg.Type
+	vs[2] = msg.Flags
+	vs[3] = protoVersion
+	vs[4] = uint32(len(body.Bytes()))
+	vs[5] = msg.serial
+	headers := make([]header, 0, len(msg.Headers))
+	for k, v := range msg.Headers {
+		headers = append(headers, header{byte(k), v})
+	}
+	vs[6] = headers
+	var buf bytes.Buffer
+	enc = newEncoder(&buf, order)
+	enc.Encode(vs[:]...)
+	enc.align(8)
+	body.WriteTo(&buf)
+	if buf.Len() > 1<<27 {
+		return InvalidMessageError("message is too long")
+	}
+	if _, err := buf.WriteTo(out); err != nil {
+		return err
+	}
+	return nil
+}
+
+// IsValid checks whether msg is a valid message and returns an
+// InvalidMessageError if it is not.
+func (msg *Message) IsValid() error {
+	if msg.Flags & ^(FlagNoAutoStart|FlagNoReplyExpected|FlagAllowInteractiveAuthorization) != 0 {
+		return InvalidMessageError("invalid flags")
+	}
+	if msg.Type == 0 || msg.Type >= typeMax {
+		return InvalidMessageError("invalid message type")
+	}
+	for k, v := range msg.Headers {
+		if k == 0 || k >= fieldMax {
+			return InvalidMessageError("invalid header")
+		}
+		if reflect.TypeOf(v.value) != fieldTypes[k] {
+			return InvalidMessageError("invalid type of header field")
+		}
+	}
+	for _, v := range requiredFields[msg.Type] {
+		if _, ok := msg.Headers[v]; !ok {
+			return InvalidMessageError("missing required header")
+		}
+	}
+	if path, ok := msg.Headers[FieldPath]; ok {
+		if !path.value.(ObjectPath).IsValid() {
+			return InvalidMessageError("invalid path name")
+		}
+	}
+	if iface, ok := msg.Headers[FieldInterface]; ok {
+		if !isValidInterface(iface.value.(string)) {
+			return InvalidMessageError("invalid interface name")
+		}
+	}
+	if member, ok := msg.Headers[FieldMember]; ok {
+		if !isValidMember(member.value.(string)) {
+			return InvalidMessageError("invalid member name")
+		}
+	}
+	if errname, ok := msg.Headers[FieldErrorName]; ok {
+		if !isValidInterface(errname.value.(string)) {
+			return InvalidMessageError("invalid error name")
+		}
+	}
+	if len(msg.Body) != 0 {
+		if _, ok := msg.Headers[FieldSignature]; !ok {
+			return InvalidMessageError("missing signature")
+		}
+	}
+	return nil
+}
+
+// Serial returns the message's serial number. The returned value is only valid
+// for messages received by eavesdropping.
+func (msg *Message) Serial() uint32 {
+	return msg.serial
+}
+
+// String returns a string representation of a message similar to the format of
+// dbus-monitor.
+func (msg *Message) String() string {
+	if err := msg.IsValid(); err != nil {
+		return "<invalid>"
+	}
+	s := msg.Type.String()
+	if v, ok := msg.Headers[FieldSender]; ok {
+		s += " from " + v.value.(string)
+	}
+	if v, ok := msg.Headers[FieldDestination]; ok {
+		s += " to " + v.value.(string)
+	}
+	s += " serial " + strconv.FormatUint(uint64(msg.serial), 10)
+	if v, ok := msg.Headers[FieldReplySerial]; ok {
+		s += " reply_serial " + strconv.FormatUint(uint64(v.value.(uint32)), 10)
+	}
+	if v, ok := msg.Headers[FieldUnixFDs]; ok {
+		s += " unixfds " + strconv.FormatUint(uint64(v.value.(uint32)), 10)
+	}
+	if v, ok := msg.Headers[FieldPath]; ok {
+		s += " path " + string(v.value.(ObjectPath))
+	}
+	if v, ok := msg.Headers[FieldInterface]; ok {
+		s += " interface " + v.value.(string)
+	}
+	if v, ok := msg.Headers[FieldErrorName]; ok {
+		s += " error " + v.value.(string)
+	}
+	if v, ok := msg.Headers[FieldMember]; ok {
+		s += " member " + v.value.(string)
+	}
+	if len(msg.Body) != 0 {
+		s += "\n"
+	}
+	for i, v := range msg.Body {
+		s += "  " + MakeVariant(v).String()
+		if i != len(msg.Body)-1 {
+			s += "\n"
+		}
+	}
+	return s
+}

vendor/github.com/godbus/dbus/object.go

@@ -0,0 +1,136 @@
+package dbus
+
+import (
+	"errors"
+	"strings"
+)
+
+// BusObject is the interface of a remote object on which methods can be
+// invoked.
+type BusObject interface {
+	Call(method string, flags Flags, args ...interface{}) *Call
+	Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call
+	GetProperty(p string) (Variant, error)
+	Destination() string
+	Path() ObjectPath
+}
+
+// Object represents a remote object on which methods can be invoked.
+type Object struct {
+	conn *Conn
+	dest string
+	path ObjectPath
+}
+
+// Call calls a method with (*Object).Go and waits for its reply.
+func (o *Object) Call(method string, flags Flags, args ...interface{}) *Call {
+	return <-o.Go(method, flags, make(chan *Call, 1), args...).Done
+}
+
+// AddMatchSignal subscribes BusObject to signals from specified interface and
+// method (member).
+func (o *Object) AddMatchSignal(iface, member string) *Call {
+	return o.Call(
+		"org.freedesktop.DBus.AddMatch",
+		0,
+		"type='signal',interface='"+iface+"',member='"+member+"'",
+	)
+}
+
+// Go calls a method with the given arguments asynchronously. It returns a
+// Call structure representing this method call. The passed channel will
+// return the same value once the call is done. If ch is nil, a new channel
+// will be allocated. Otherwise, ch has to be buffered or Go will panic.
+//
+// If the flags include FlagNoReplyExpected, ch is ignored and a Call structure
+// is returned of which only the Err member is valid.
+//
+// If the method parameter contains a dot ('.'), the part before the last dot
+// specifies the interface on which the method is called.
+func (o *Object) Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
+	iface := ""
+	i := strings.LastIndex(method, ".")
+	if i != -1 {
+		iface = method[:i]
+	}
+	method = method[i+1:]
+	msg := new(Message)
+	msg.Type = TypeMethodCall
+	msg.serial = o.conn.getSerial()
+	msg.Flags = flags & (FlagNoAutoStart | FlagNoReplyExpected)
+	msg.Headers = make(map[HeaderField]Variant)
+	msg.Headers[FieldPath] = MakeVariant(o.path)
+	msg.Headers[FieldDestination] = MakeVariant(o.dest)
+	msg.Headers[FieldMember] = MakeVariant(method)
+	if iface != "" {
+		msg.Headers[FieldInterface] = MakeVariant(iface)
+	}
+	msg.Body = args
+	if len(args) > 0 {
+		msg.Headers[FieldSignature] = MakeVariant(SignatureOf(args...))
+	}
+	if msg.Flags&FlagNoReplyExpected == 0 {
+		if ch == nil {
+			ch = make(chan *Call, 10)
+		} else if cap(ch) == 0 {
+			panic("dbus: unbuffered channel passed to (*Object).Go")
+		}
+		call := &Call{
+			Destination: o.dest,
+			Path:        o.path,
+			Method:      method,
+			Args:        args,
+			Done:        ch,
+		}
+		o.conn.callsLck.Lock()
+		o.conn.calls[msg.serial] = call
+		o.conn.callsLck.Unlock()
+		o.conn.outLck.RLock()
+		if o.conn.closed {
+			call.Err = ErrClosed
+			call.Done <- call
+		} else {
+			o.conn.out <- msg
+		}
+		o.conn.outLck.RUnlock()
+		return call
+	}
+	o.conn.outLck.RLock()
+	defer o.conn.outLck.RUnlock()
+	if o.conn.closed {
+		return &Call{Err: ErrClosed}
+	}
+	o.conn.out <- msg
+	return &Call{Err: nil}
+}
+
+// GetProperty calls org.freedesktop.DBus.Properties.GetProperty on the given
+// object. The property name must be given in interface.member notation.
+func (o *Object) GetProperty(p string) (Variant, error) {
+	idx := strings.LastIndex(p, ".")
+	if idx == -1 || idx+1 == len(p) {
+		return Variant{}, errors.New("dbus: invalid property " + p)
+	}
+
+	iface := p[:idx]
+	prop := p[idx+1:]
+
+	result := Variant{}
+	err := o.Call("org.freedesktop.DBus.Properties.Get", 0, iface, prop).Store(&result)
+
+	if err != nil {
+		return Variant{}, err
+	}
+
+	return result, nil
+}
+
+// Destination returns the destination that calls on (o *Object) are sent to.
+func (o *Object) Destination() string {
+	return o.dest
+}
+
+// Path returns the path that calls on (o *Object") are sent to.
+func (o *Object) Path() ObjectPath {
+	return o.path
+}

vendor/github.com/godbus/dbus/server_interfaces.go

@@ -0,0 +1,89 @@
+package dbus
+
+// Terminator allows a handler to implement a shutdown mechanism that
+// is called when the connection terminates.
+type Terminator interface {
+	Terminate()
+}
+
+// Handler is the representation of a D-Bus Application.
+//
+// The Handler must have a way to lookup objects given
+// an ObjectPath. The returned object must implement the
+// ServerObject interface.
+type Handler interface {
+	LookupObject(path ObjectPath) (ServerObject, bool)
+}
+
+// ServerObject is the representation of an D-Bus Object.
+//
+// Objects are registered at a path for a given Handler.
+// The Objects implement D-Bus interfaces. The semantics
+// of Interface lookup is up to the implementation of
+// the ServerObject. The ServerObject implementation may
+// choose to implement empty string as a valid interface
+// represeting all methods or not per the D-Bus specification.
+type ServerObject interface {
+	LookupInterface(name string) (Interface, bool)
+}
+
+// An Interface is the representation of a D-Bus Interface.
+//
+// Interfaces are a grouping of methods implemented by the Objects.
+// Interfaces are responsible for routing method calls.
+type Interface interface {
+	LookupMethod(name string) (Method, bool)
+}
+
+// A Method represents the exposed methods on D-Bus.
+type Method interface {
+	// Call requires that all arguments are decoded before being passed to it.
+	Call(args ...interface{}) ([]interface{}, error)
+	NumArguments() int
+	NumReturns() int
+	// ArgumentValue returns a representative value for the argument at position
+	// it should be of the proper type. reflect.Zero would be a good mechanism
+	// to use for this Value.
+	ArgumentValue(position int) interface{}
+	// ReturnValue returns a representative value for the return at position
+	// it should be of the proper type. reflect.Zero would be a good mechanism
+	// to use for this Value.
+	ReturnValue(position int) interface{}
+}
+
+// An Argument Decoder can decode arguments using the non-standard mechanism
+//
+// If a method implements this interface then the non-standard
+// decoder will be used.
+//
+// Method arguments must be decoded from the message.
+// The mechanism for doing this will vary based on the
+// implementation of the method. A normal approach is provided
+// as part of this library, but may be replaced with
+// any other decoding scheme.
+type ArgumentDecoder interface {
+	// To decode the arguments of a method the sender and message are
+	// provided incase the semantics of the implementer provides access
+	// to these as part of the method invocation.
+	DecodeArguments(conn *Conn, sender string, msg *Message, args []interface{}) ([]interface{}, error)
+}
+
+// A SignalHandler is responsible for delivering a signal.
+//
+// Signal delivery may be changed from the default channel
+// based approach by Handlers implementing the SignalHandler
+// interface.
+type SignalHandler interface {
+	DeliverSignal(iface, name string, signal *Signal)
+}
+
+// A DBusError is used to convert a generic object to a D-Bus error.
+//
+// Any custom error mechanism may implement this interface to provide
+// a custom encoding of the error on D-Bus. By default if a normal
+// error is returned, it will be encoded as the generic
+// "org.freedesktop.DBus.Error.Failed" error. By implementing this
+// interface as well a custom encoding may be provided.
+type DBusError interface {
+	DBusError() (string, []interface{})
+}

vendor/github.com/godbus/dbus/sig.go

@@ -0,0 +1,259 @@
+package dbus
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+var sigToType = map[byte]reflect.Type{
+	'y': byteType,
+	'b': boolType,
+	'n': int16Type,
+	'q': uint16Type,
+	'i': int32Type,
+	'u': uint32Type,
+	'x': int64Type,
+	't': uint64Type,
+	'd': float64Type,
+	's': stringType,
+	'g': signatureType,
+	'o': objectPathType,
+	'v': variantType,
+	'h': unixFDIndexType,
+}
+
+// Signature represents a correct type signature as specified by the D-Bus
+// specification. The zero value represents the empty signature, "".
+type Signature struct {
+	str string
+}
+
+// SignatureOf returns the concatenation of all the signatures of the given
+// values. It panics if one of them is not representable in D-Bus.
+func SignatureOf(vs ...interface{}) Signature {
+	var s string
+	for _, v := range vs {
+		s += getSignature(reflect.TypeOf(v))
+	}
+	return Signature{s}
+}
+
+// SignatureOfType returns the signature of the given type. It panics if the
+// type is not representable in D-Bus.
+func SignatureOfType(t reflect.Type) Signature {
+	return Signature{getSignature(t)}
+}
+
+// getSignature returns the signature of the given type and panics on unknown types.
+func getSignature(t reflect.Type) string {
+	// handle simple types first
+	switch t.Kind() {
+	case reflect.Uint8:
+		return "y"
+	case reflect.Bool:
+		return "b"
+	case reflect.Int16:
+		return "n"
+	case reflect.Uint16:
+		return "q"
+	case reflect.Int, reflect.Int32:
+		if t == unixFDType {
+			return "h"
+		}
+		return "i"
+	case reflect.Uint, reflect.Uint32:
+		if t == unixFDIndexType {
+			return "h"
+		}
+		return "u"
+	case reflect.Int64:
+		return "x"
+	case reflect.Uint64:
+		return "t"
+	case reflect.Float64:
+		return "d"
+	case reflect.Ptr:
+		return getSignature(t.Elem())
+	case reflect.String:
+		if t == objectPathType {
+			return "o"
+		}
+		return "s"
+	case reflect.Struct:
+		if t == variantType {
+			return "v"
+		} else if t == signatureType {
+			return "g"
+		}
+		var s string
+		for i := 0; i < t.NumField(); i++ {
+			field := t.Field(i)
+			if field.PkgPath == "" && field.Tag.Get("dbus") != "-" {
+				s += getSignature(t.Field(i).Type)
+			}
+		}
+		return "(" + s + ")"
+	case reflect.Array, reflect.Slice:
+		return "a" + getSignature(t.Elem())
+	case reflect.Map:
+		if !isKeyType(t.Key()) {
+			panic(InvalidTypeError{t})
+		}
+		return "a{" + getSignature(t.Key()) + getSignature(t.Elem()) + "}"
+	case reflect.Interface:
+		return "v"
+	}
+	panic(InvalidTypeError{t})
+}
+
+// ParseSignature returns the signature represented by this string, or a
+// SignatureError if the string is not a valid signature.
+func ParseSignature(s string) (sig Signature, err error) {
+	if len(s) == 0 {
+		return
+	}
+	if len(s) > 255 {
+		return Signature{""}, SignatureError{s, "too long"}
+	}
+	sig.str = s
+	for err == nil && len(s) != 0 {
+		err, s = validSingle(s, 0)
+	}
+	if err != nil {
+		sig = Signature{""}
+	}
+
+	return
+}
+
+// ParseSignatureMust behaves like ParseSignature, except that it panics if s
+// is not valid.
+func ParseSignatureMust(s string) Signature {
+	sig, err := ParseSignature(s)
+	if err != nil {
+		panic(err)
+	}
+	return sig
+}
+
+// Empty retruns whether the signature is the empty signature.
+func (s Signature) Empty() bool {
+	return s.str == ""
+}
+
+// Single returns whether the signature represents a single, complete type.
+func (s Signature) Single() bool {
+	err, r := validSingle(s.str, 0)
+	return err != nil && r == ""
+}
+
+// String returns the signature's string representation.
+func (s Signature) String() string {
+	return s.str
+}
+
+// A SignatureError indicates that a signature passed to a function or received
+// on a connection is not a valid signature.
+type SignatureError struct {
+	Sig    string
+	Reason string
+}
+
+func (e SignatureError) Error() string {
+	return fmt.Sprintf("dbus: invalid signature: %q (%s)", e.Sig, e.Reason)
+}
+
+// Try to read a single type from this string. If it was successful, err is nil
+// and rem is the remaining unparsed part. Otherwise, err is a non-nil
+// SignatureError and rem is "". depth is the current recursion depth which may
+// not be greater than 64 and should be given as 0 on the first call.
+func validSingle(s string, depth int) (err error, rem string) {
+	if s == "" {
+		return SignatureError{Sig: s, Reason: "empty signature"}, ""
+	}
+	if depth > 64 {
+		return SignatureError{Sig: s, Reason: "container nesting too deep"}, ""
+	}
+	switch s[0] {
+	case 'y', 'b', 'n', 'q', 'i', 'u', 'x', 't', 'd', 's', 'g', 'o', 'v', 'h':
+		return nil, s[1:]
+	case 'a':
+		if len(s) > 1 && s[1] == '{' {
+			i := findMatching(s[1:], '{', '}')
+			if i == -1 {
+				return SignatureError{Sig: s, Reason: "unmatched '{'"}, ""
+			}
+			i++
+			rem = s[i+1:]
+			s = s[2:i]
+			if err, _ = validSingle(s[:1], depth+1); err != nil {
+				return err, ""
+			}
+			err, nr := validSingle(s[1:], depth+1)
+			if err != nil {
+				return err, ""
+			}
+			if nr != "" {
+				return SignatureError{Sig: s, Reason: "too many types in dict"}, ""
+			}
+			return nil, rem
+		}
+		return validSingle(s[1:], depth+1)
+	case '(':
+		i := findMatching(s, '(', ')')
+		if i == -1 {
+			return SignatureError{Sig: s, Reason: "unmatched ')'"}, ""
+		}
+		rem = s[i+1:]
+		s = s[1:i]
+		for err == nil && s != "" {
+			err, s = validSingle(s, depth+1)
+		}
+		if err != nil {
+			rem = ""
+		}
+		return
+	}
+	return SignatureError{Sig: s, Reason: "invalid type character"}, ""
+}
+
+func findMatching(s string, left, right rune) int {
+	n := 0
+	for i, v := range s {
+		if v == left {
+			n++
+		} else if v == right {
+			n--
+		}
+		if n == 0 {
+			return i
+		}
+	}
+	return -1
+}
+
+// typeFor returns the type of the given signature. It ignores any left over
+// characters and panics if s doesn't start with a valid type signature.
+func typeFor(s string) (t reflect.Type) {
+	err, _ := validSingle(s, 0)
+	if err != nil {
+		panic(err)
+	}
+
+	if t, ok := sigToType[s[0]]; ok {
+		return t
+	}
+	switch s[0] {
+	case 'a':
+		if s[1] == '{' {
+			i := strings.LastIndex(s, "}")
+			t = reflect.MapOf(sigToType[s[2]], typeFor(s[3:i]))
+		} else {
+			t = reflect.SliceOf(typeFor(s[1:]))
+		}
+	case '(':
+		t = interfacesType
+	}
+	return
+}

vendor/github.com/godbus/dbus/transport_darwin.go

@@ -0,0 +1,6 @@
+package dbus
+
+func (t *unixTransport) SendNullByte() error {
+	_, err := t.Write([]byte{0})
+	return err
+}

vendor/github.com/godbus/dbus/transport_generic.go

@@ -0,0 +1,50 @@
+package dbus
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"unsafe"
+)
+
+var nativeEndian binary.ByteOrder
+
+func detectEndianness() binary.ByteOrder {
+	var x uint32 = 0x01020304
+		if *(*byte)(unsafe.Pointer(&x)) == 0x01 {
+		return binary.BigEndian
+	}
+	return binary.LittleEndian
+}
+
+func init() {
+	nativeEndian = detectEndianness()
+}
+
+type genericTransport struct {
+	io.ReadWriteCloser
+}
+
+func (t genericTransport) SendNullByte() error {
+	_, err := t.Write([]byte{0})
+	return err
+}
+
+func (t genericTransport) SupportsUnixFDs() bool {
+	return false
+}
+
+func (t genericTransport) EnableUnixFDs() {}
+
+func (t genericTransport) ReadMessage() (*Message, error) {
+	return DecodeMessage(t)
+}
+
+func (t genericTransport) SendMessage(msg *Message) error {
+	for _, v := range msg.Body {
+		if _, ok := v.(UnixFD); ok {
+			return errors.New("dbus: unix fd passing not enabled")
+		}
+	}
+	return msg.EncodeTo(t, nativeEndian)
+}

vendor/github.com/godbus/dbus/transport_tcp.go

@@ -0,0 +1,43 @@
+//+build !windows
+
+package dbus
+
+import (
+	"errors"
+	"net"
+)
+
+func init() {
+	transports["tcp"] = newTcpTransport
+}
+
+func tcpFamily(keys string) (string, error) {
+	switch getKey(keys, "family") {
+	case "":
+		return "tcp", nil
+	case "ipv4":
+		return "tcp4", nil
+	case "ipv6":
+		return "tcp6", nil
+	default:
+		return "", errors.New("dbus: invalid tcp family (must be ipv4 or ipv6)")
+	}
+}
+
+func newTcpTransport(keys string) (transport, error) {
+	host := getKey(keys, "host")
+	port := getKey(keys, "port")
+	if host == "" || port == "" {
+		return nil, errors.New("dbus: unsupported address (must set host and port)")
+	}
+
+	protocol, err := tcpFamily(keys)
+	if err != nil {
+		return nil, err
+	}
+	socket, err := net.Dial(protocol, net.JoinHostPort(host, port))
+	if err != nil {
+		return nil, err
+	}
+	return NewConn(socket)
+}

vendor/github.com/godbus/dbus/transport_unix.go

@@ -0,0 +1,196 @@
+//+build !windows,!solaris
+
+package dbus
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"syscall"
+)
+
+type oobReader struct {
+	conn *net.UnixConn
+	oob  []byte
+	buf  [4096]byte
+}
+
+func (o *oobReader) Read(b []byte) (n int, err error) {
+	n, oobn, flags, _, err := o.conn.ReadMsgUnix(b, o.buf[:])
+	if err != nil {
+		return n, err
+	}
+	if flags&syscall.MSG_CTRUNC != 0 {
+		return n, errors.New("dbus: control data truncated (too many fds received)")
+	}
+	o.oob = append(o.oob, o.buf[:oobn]...)
+	return n, nil
+}
+
+type unixTransport struct {
+	*net.UnixConn
+	hasUnixFDs bool
+}
+
+func newUnixTransport(keys string) (transport, error) {
+	var err error
+
+	t := new(unixTransport)
+	abstract := getKey(keys, "abstract")
+	path := getKey(keys, "path")
+	switch {
+	case abstract == "" && path == "":
+		return nil, errors.New("dbus: invalid address (neither path nor abstract set)")
+	case abstract != "" && path == "":
+		t.UnixConn, err = net.DialUnix("unix", nil, &net.UnixAddr{Name: "@" + abstract, Net: "unix"})
+		if err != nil {
+			return nil, err
+		}
+		return t, nil
+	case abstract == "" && path != "":
+		t.UnixConn, err = net.DialUnix("unix", nil, &net.UnixAddr{Name: path, Net: "unix"})
+		if err != nil {
+			return nil, err
+		}
+		return t, nil
+	default:
+		return nil, errors.New("dbus: invalid address (both path and abstract set)")
+	}
+}
+
+func init() {
+	transports["unix"] = newUnixTransport
+}
+
+func (t *unixTransport) EnableUnixFDs() {
+	t.hasUnixFDs = true
+}
+
+func (t *unixTransport) ReadMessage() (*Message, error) {
+	var (
+		blen, hlen uint32
+		csheader   [16]byte
+		headers    []header
+		order      binary.ByteOrder
+		unixfds    uint32
+	)
+	// To be sure that all bytes of out-of-band data are read, we use a special
+	// reader that uses ReadUnix on the underlying connection instead of Read
+	// and gathers the out-of-band data in a buffer.
+	rd := &oobReader{conn: t.UnixConn}
+	// read the first 16 bytes (the part of the header that has a constant size),
+	// from which we can figure out the length of the rest of the message
+	if _, err := io.ReadFull(rd, csheader[:]); err != nil {
+		return nil, err
+	}
+	switch csheader[0] {
+	case 'l':
+		order = binary.LittleEndian
+	case 'B':
+		order = binary.BigEndian
+	default:
+		return nil, InvalidMessageError("invalid byte order")
+	}
+	// csheader[4:8] -> length of message body, csheader[12:16] -> length of
+	// header fields (without alignment)
+	binary.Read(bytes.NewBuffer(csheader[4:8]), order, &blen)
+	binary.Read(bytes.NewBuffer(csheader[12:]), order, &hlen)
+	if hlen%8 != 0 {
+		hlen += 8 - (hlen % 8)
+	}
+
+	// decode headers and look for unix fds
+	headerdata := make([]byte, hlen+4)
+	copy(headerdata, csheader[12:])
+	if _, err := io.ReadFull(t, headerdata[4:]); err != nil {
+		return nil, err
+	}
+	dec := newDecoder(bytes.NewBuffer(headerdata), order)
+	dec.pos = 12
+	vs, err := dec.Decode(Signature{"a(yv)"})
+	if err != nil {
+		return nil, err
+	}
+	Store(vs, &headers)
+	for _, v := range headers {
+		if v.Field == byte(FieldUnixFDs) {
+			unixfds, _ = v.Variant.value.(uint32)
+		}
+	}
+	all := make([]byte, 16+hlen+blen)
+	copy(all, csheader[:])
+	copy(all[16:], headerdata[4:])
+	if _, err := io.ReadFull(rd, all[16+hlen:]); err != nil {
+		return nil, err
+	}
+	if unixfds != 0 {
+		if !t.hasUnixFDs {
+			return nil, errors.New("dbus: got unix fds on unsupported transport")
+		}
+		// read the fds from the OOB data
+		scms, err := syscall.ParseSocketControlMessage(rd.oob)
+		if err != nil {
+			return nil, err
+		}
+		if len(scms) != 1 {
+			return nil, errors.New("dbus: received more than one socket control message")
+		}
+		fds, err := syscall.ParseUnixRights(&scms[0])
+		if err != nil {
+			return nil, err
+		}
+		msg, err := DecodeMessage(bytes.NewBuffer(all))
+		if err != nil {
+			return nil, err
+		}
+		// substitute the values in the message body (which are indices for the
+		// array receiver via OOB) with the actual values
+		for i, v := range msg.Body {
+			if j, ok := v.(UnixFDIndex); ok {
+				if uint32(j) >= unixfds {
+					return nil, InvalidMessageError("invalid index for unix fd")
+				}
+				msg.Body[i] = UnixFD(fds[j])
+			}
+		}
+		return msg, nil
+	}
+	return DecodeMessage(bytes.NewBuffer(all))
+}
+
+func (t *unixTransport) SendMessage(msg *Message) error {
+	fds := make([]int, 0)
+	for i, v := range msg.Body {
+		if fd, ok := v.(UnixFD); ok {
+			msg.Body[i] = UnixFDIndex(len(fds))
+			fds = append(fds, int(fd))
+		}
+	}
+	if len(fds) != 0 {
+		if !t.hasUnixFDs {
+			return errors.New("dbus: unix fd passing not enabled")
+		}
+		msg.Headers[FieldUnixFDs] = MakeVariant(uint32(len(fds)))
+		oob := syscall.UnixRights(fds...)
+		buf := new(bytes.Buffer)
+		msg.EncodeTo(buf, nativeEndian)
+		n, oobn, err := t.UnixConn.WriteMsgUnix(buf.Bytes(), oob, nil)
+		if err != nil {
+			return err
+		}
+		if n != buf.Len() || oobn != len(oob) {
+			return io.ErrShortWrite
+		}
+	} else {
+		if err := msg.EncodeTo(t, nativeEndian); err != nil {
+			return nil
+		}
+	}
+	return nil
+}
+
+func (t *unixTransport) SupportsUnixFDs() bool {
+	return true
+}

vendor/github.com/godbus/dbus/transport_unixcred_dragonfly.go

@@ -0,0 +1,95 @@
+// The UnixCredentials system call is currently only implemented on Linux
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// https://golang.org/s/go1.4-syscall
+// http://code.google.com/p/go/source/browse/unix/sockcmsg_linux.go?repo=sys
+
+// Local implementation of the UnixCredentials system call for DragonFly BSD
+
+package dbus
+
+/*
+#include <sys/ucred.h>
+*/
+import "C"
+
+import (
+	"io"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// http://golang.org/src/pkg/syscall/ztypes_linux_amd64.go
+// http://golang.org/src/pkg/syscall/ztypes_dragonfly_amd64.go
+type Ucred struct {
+	Pid int32
+	Uid uint32
+	Gid uint32
+}
+
+// http://golang.org/src/pkg/syscall/types_linux.go
+// http://golang.org/src/pkg/syscall/types_dragonfly.go
+// https://github.com/DragonFlyBSD/DragonFlyBSD/blob/master/sys/sys/ucred.h
+const (
+	SizeofUcred = C.sizeof_struct_ucred
+)
+
+// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
+func cmsgAlignOf(salen int) int {
+	// From http://golang.org/src/pkg/syscall/sockcmsg_unix.go
+	//salign := sizeofPtr
+	// NOTE: It seems like 64-bit Darwin and DragonFly BSD kernels
+	// still require 32-bit aligned access to network subsystem.
+	//if darwin64Bit || dragonfly64Bit {
+	//	salign = 4
+	//}
+	salign := 4
+	return (salen + salign - 1) & ^(salign - 1)
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
+func cmsgData(h *syscall.Cmsghdr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(syscall.SizeofCmsghdr)))
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// UnixCredentials encodes credentials into a socket control message
+// for sending to another process. This can be used for
+// authentication.
+func UnixCredentials(ucred *Ucred) []byte {
+	b := make([]byte, syscall.CmsgSpace(SizeofUcred))
+	h := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	h.Level = syscall.SOL_SOCKET
+	h.Type = syscall.SCM_CREDS
+	h.SetLen(syscall.CmsgLen(SizeofUcred))
+	*((*Ucred)(cmsgData(h))) = *ucred
+	return b
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// ParseUnixCredentials decodes a socket control message that contains
+// credentials in a Ucred structure. To receive such a message, the
+// SO_PASSCRED option must be enabled on the socket.
+func ParseUnixCredentials(m *syscall.SocketControlMessage) (*Ucred, error) {
+	if m.Header.Level != syscall.SOL_SOCKET {
+		return nil, syscall.EINVAL
+	}
+	if m.Header.Type != syscall.SCM_CREDS {
+		return nil, syscall.EINVAL
+	}
+	ucred := *(*Ucred)(unsafe.Pointer(&m.Data[0]))
+	return &ucred, nil
+}
+
+func (t *unixTransport) SendNullByte() error {
+	ucred := &Ucred{Pid: int32(os.Getpid()), Uid: uint32(os.Getuid()), Gid: uint32(os.Getgid())}
+	b := UnixCredentials(ucred)
+	_, oobn, err := t.UnixConn.WriteMsgUnix([]byte{0}, b, nil)
+	if err != nil {
+		return err
+	}
+	if oobn != len(b) {
+		return io.ErrShortWrite
+	}
+	return nil
+}

vendor/github.com/godbus/dbus/transport_unixcred_freebsd.go

@@ -0,0 +1,91 @@
+// The UnixCredentials system call is currently only implemented on Linux
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// https://golang.org/s/go1.4-syscall
+// http://code.google.com/p/go/source/browse/unix/sockcmsg_linux.go?repo=sys
+
+// Local implementation of the UnixCredentials system call for FreeBSD
+
+package dbus
+
+/*
+const int sizeofPtr = sizeof(void*);
+#define _WANT_UCRED
+#include <sys/ucred.h>
+*/
+import "C"
+
+import (
+	"io"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// http://golang.org/src/pkg/syscall/ztypes_linux_amd64.go
+// https://golang.org/src/syscall/ztypes_freebsd_amd64.go
+type Ucred struct {
+	Pid int32
+	Uid uint32
+	Gid uint32
+}
+
+// http://golang.org/src/pkg/syscall/types_linux.go
+// https://golang.org/src/syscall/types_freebsd.go
+// https://github.com/freebsd/freebsd/blob/master/sys/sys/ucred.h
+const (
+	SizeofUcred = C.sizeof_struct_ucred
+)
+
+// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
+func cmsgAlignOf(salen int) int {
+	salign := C.sizeofPtr
+
+	return (salen + salign - 1) & ^(salign - 1)
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_unix.go
+func cmsgData(h *syscall.Cmsghdr) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(cmsgAlignOf(syscall.SizeofCmsghdr)))
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// UnixCredentials encodes credentials into a socket control message
+// for sending to another process. This can be used for
+// authentication.
+func UnixCredentials(ucred *Ucred) []byte {
+	b := make([]byte, syscall.CmsgSpace(SizeofUcred))
+	h := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
+	h.Level = syscall.SOL_SOCKET
+	h.Type = syscall.SCM_CREDS
+	h.SetLen(syscall.CmsgLen(SizeofUcred))
+	*((*Ucred)(cmsgData(h))) = *ucred
+	return b
+}
+
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// ParseUnixCredentials decodes a socket control message that contains
+// credentials in a Ucred structure. To receive such a message, the
+// SO_PASSCRED option must be enabled on the socket.
+func ParseUnixCredentials(m *syscall.SocketControlMessage) (*Ucred, error) {
+	if m.Header.Level != syscall.SOL_SOCKET {
+		return nil, syscall.EINVAL
+	}
+	if m.Header.Type != syscall.SCM_CREDS {
+		return nil, syscall.EINVAL
+	}
+	ucred := *(*Ucred)(unsafe.Pointer(&m.Data[0]))
+	return &ucred, nil
+}
+
+func (t *unixTransport) SendNullByte() error {
+	ucred := &Ucred{Pid: int32(os.Getpid()), Uid: uint32(os.Getuid()), Gid: uint32(os.Getgid())}
+	b := UnixCredentials(ucred)
+	_, oobn, err := t.UnixConn.WriteMsgUnix([]byte{0}, b, nil)
+	if err != nil {
+		return err
+	}
+	if oobn != len(b) {
+		return io.ErrShortWrite
+	}
+	return nil
+}

vendor/github.com/godbus/dbus/transport_unixcred_linux.go

@@ -0,0 +1,25 @@
+// The UnixCredentials system call is currently only implemented on Linux
+// http://golang.org/src/pkg/syscall/sockcmsg_linux.go
+// https://golang.org/s/go1.4-syscall
+// http://code.google.com/p/go/source/browse/unix/sockcmsg_linux.go?repo=sys
+
+package dbus
+
+import (
+	"io"
+	"os"
+	"syscall"
+)
+
+func (t *unixTransport) SendNullByte() error {
+	ucred := &syscall.Ucred{Pid: int32(os.Getpid()), Uid: uint32(os.Getuid()), Gid: uint32(os.Getgid())}
+	b := syscall.UnixCredentials(ucred)
+	_, oobn, err := t.UnixConn.WriteMsgUnix([]byte{0}, b, nil)
+	if err != nil {
+		return err
+	}
+	if oobn != len(b) {
+		return io.ErrShortWrite
+	}
+	return nil
+}

vendor/github.com/godbus/dbus/transport_unixcred_openbsd.go

@@ -0,0 +1,14 @@
+package dbus
+
+import "io"
+
+func (t *unixTransport) SendNullByte() error {
+	n, _, err := t.UnixConn.WriteMsgUnix([]byte{0}, nil, nil)
+	if err != nil {
+		return err
+	}
+	if n != 1 {
+		return io.ErrShortWrite
+	}
+	return nil
+}

vendor/github.com/godbus/dbus/variant.go

@@ -0,0 +1,144 @@
+package dbus
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"strconv"
+)
+
+// Variant represents the D-Bus variant type.
+type Variant struct {
+	sig   Signature
+	value interface{}
+}
+
+// MakeVariant converts the given value to a Variant. It panics if v cannot be
+// represented as a D-Bus type.
+func MakeVariant(v interface{}) Variant {
+	return MakeVariantWithSignature(v, SignatureOf(v))
+}
+
+// MakeVariantWithSignature converts the given value to a Variant.
+func MakeVariantWithSignature(v interface{}, s Signature) Variant {
+	return Variant{s, v}
+}
+
+// ParseVariant parses the given string as a variant as described at
+// https://developer.gnome.org/glib/unstable/gvariant-text.html. If sig is not
+// empty, it is taken to be the expected signature for the variant.
+func ParseVariant(s string, sig Signature) (Variant, error) {
+	tokens := varLex(s)
+	p := &varParser{tokens: tokens}
+	n, err := varMakeNode(p)
+	if err != nil {
+		return Variant{}, err
+	}
+	if sig.str == "" {
+		sig, err = varInfer(n)
+		if err != nil {
+			return Variant{}, err
+		}
+	}
+	v, err := n.Value(sig)
+	if err != nil {
+		return Variant{}, err
+	}
+	return MakeVariant(v), nil
+}
+
+// format returns a formatted version of v and whether this string can be parsed
+// unambigously.
+func (v Variant) format() (string, bool) {
+	switch v.sig.str[0] {
+	case 'b', 'i':
+		return fmt.Sprint(v.value), true
+	case 'n', 'q', 'u', 'x', 't', 'd', 'h':
+		return fmt.Sprint(v.value), false
+	case 's':
+		return strconv.Quote(v.value.(string)), true
+	case 'o':
+		return strconv.Quote(string(v.value.(ObjectPath))), false
+	case 'g':
+		return strconv.Quote(v.value.(Signature).str), false
+	case 'v':
+		s, unamb := v.value.(Variant).format()
+		if !unamb {
+			return "<@" + v.value.(Variant).sig.str + " " + s + ">", true
+		}
+		return "<" + s + ">", true
+	case 'y':
+		return fmt.Sprintf("%#x", v.value.(byte)), false
+	}
+	rv := reflect.ValueOf(v.value)
+	switch rv.Kind() {
+	case reflect.Slice:
+		if rv.Len() == 0 {
+			return "[]", false
+		}
+		unamb := true
+		buf := bytes.NewBuffer([]byte("["))
+		for i := 0; i < rv.Len(); i++ {
+			// TODO: slooow
+			s, b := MakeVariant(rv.Index(i).Interface()).format()
+			unamb = unamb && b
+			buf.WriteString(s)
+			if i != rv.Len()-1 {
+				buf.WriteString(", ")
+			}
+		}
+		buf.WriteByte(']')
+		return buf.String(), unamb
+	case reflect.Map:
+		if rv.Len() == 0 {
+			return "{}", false
+		}
+		unamb := true
+		var buf bytes.Buffer
+		kvs := make([]string, rv.Len())
+		for i, k := range rv.MapKeys() {
+			s, b := MakeVariant(k.Interface()).format()
+			unamb = unamb && b
+			buf.Reset()
+			buf.WriteString(s)
+			buf.WriteString(": ")
+			s, b = MakeVariant(rv.MapIndex(k).Interface()).format()
+			unamb = unamb && b
+			buf.WriteString(s)
+			kvs[i] = buf.String()
+		}
+		buf.Reset()
+		buf.WriteByte('{')
+		sort.Strings(kvs)
+		for i, kv := range kvs {
+			if i > 0 {
+				buf.WriteString(", ")
+			}
+			buf.WriteString(kv)
+		}
+		buf.WriteByte('}')
+		return buf.String(), unamb
+	}
+	return `"INVALID"`, true
+}
+
+// Signature returns the D-Bus signature of the underlying value of v.
+func (v Variant) Signature() Signature {
+	return v.sig
+}
+
+// String returns the string representation of the underlying value of v as
+// described at https://developer.gnome.org/glib/unstable/gvariant-text.html.
+func (v Variant) String() string {
+	s, unamb := v.format()
+	if !unamb {
+		return "@" + v.sig.str + " " + s
+	}
+	return s
+}
+
+// Value returns the underlying value of v.
+func (v Variant) Value() interface{} {
+	return v.value
+}

vendor/github.com/godbus/dbus/variant_lexer.go

@@ -0,0 +1,284 @@
+package dbus
+
+import (
+	"fmt"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// Heavily inspired by the lexer from text/template.
+
+type varToken struct {
+	typ varTokenType
+	val string
+}
+
+type varTokenType byte
+
+const (
+	tokEOF varTokenType = iota
+	tokError
+	tokNumber
+	tokString
+	tokBool
+	tokArrayStart
+	tokArrayEnd
+	tokDictStart
+	tokDictEnd
+	tokVariantStart
+	tokVariantEnd
+	tokComma
+	tokColon
+	tokType
+	tokByteString
+)
+
+type varLexer struct {
+	input  string
+	start  int
+	pos    int
+	width  int
+	tokens []varToken
+}
+
+type lexState func(*varLexer) lexState
+
+func varLex(s string) []varToken {
+	l := &varLexer{input: s}
+	l.run()
+	return l.tokens
+}
+
+func (l *varLexer) accept(valid string) bool {
+	if strings.IndexRune(valid, l.next()) >= 0 {
+		return true
+	}
+	l.backup()
+	return false
+}
+
+func (l *varLexer) backup() {
+	l.pos -= l.width
+}
+
+func (l *varLexer) emit(t varTokenType) {
+	l.tokens = append(l.tokens, varToken{t, l.input[l.start:l.pos]})
+	l.start = l.pos
+}
+
+func (l *varLexer) errorf(format string, v ...interface{}) lexState {
+	l.tokens = append(l.tokens, varToken{
+		tokError,
+		fmt.Sprintf(format, v...),
+	})
+	return nil
+}
+
+func (l *varLexer) ignore() {
+	l.start = l.pos
+}
+
+func (l *varLexer) next() rune {
+	var r rune
+
+	if l.pos >= len(l.input) {
+		l.width = 0
+		return -1
+	}
+	r, l.width = utf8.DecodeRuneInString(l.input[l.pos:])
+	l.pos += l.width
+	return r
+}
+
+func (l *varLexer) run() {
+	for state := varLexNormal; state != nil; {
+		state = state(l)
+	}
+}
+
+func (l *varLexer) peek() rune {
+	r := l.next()
+	l.backup()
+	return r
+}
+
+func varLexNormal(l *varLexer) lexState {
+	for {
+		r := l.next()
+		switch {
+		case r == -1:
+			l.emit(tokEOF)
+			return nil
+		case r == '[':
+			l.emit(tokArrayStart)
+		case r == ']':
+			l.emit(tokArrayEnd)
+		case r == '{':
+			l.emit(tokDictStart)
+		case r == '}':
+			l.emit(tokDictEnd)
+		case r == '<':
+			l.emit(tokVariantStart)
+		case r == '>':
+			l.emit(tokVariantEnd)
+		case r == ':':
+			l.emit(tokColon)
+		case r == ',':
+			l.emit(tokComma)
+		case r == '\'' || r == '"':
+			l.backup()
+			return varLexString
+		case r == '@':
+			l.backup()
+			return varLexType
+		case unicode.IsSpace(r):
+			l.ignore()
+		case unicode.IsNumber(r) || r == '+' || r == '-':
+			l.backup()
+			return varLexNumber
+		case r == 'b':
+			pos := l.start
+			if n := l.peek(); n == '"' || n == '\'' {
+				return varLexByteString
+			}
+			// not a byte string; try to parse it as a type or bool below
+			l.pos = pos + 1
+			l.width = 1
+			fallthrough
+		default:
+			// either a bool or a type. Try bools first.
+			l.backup()
+			if l.pos+4 <= len(l.input) {
+				if l.input[l.pos:l.pos+4] == "true" {
+					l.pos += 4
+					l.emit(tokBool)
+					continue
+				}
+			}
+			if l.pos+5 <= len(l.input) {
+				if l.input[l.pos:l.pos+5] == "false" {
+					l.pos += 5
+					l.emit(tokBool)
+					continue
+				}
+			}
+			// must be a type.
+			return varLexType
+		}
+	}
+}
+
+var varTypeMap = map[string]string{
+	"boolean":    "b",
+	"byte":       "y",
+	"int16":      "n",
+	"uint16":     "q",
+	"int32":      "i",
+	"uint32":     "u",
+	"int64":      "x",
+	"uint64":     "t",
+	"double":     "f",
+	"string":     "s",
+	"objectpath": "o",
+	"signature":  "g",
+}
+
+func varLexByteString(l *varLexer) lexState {
+	q := l.next()
+Loop:
+	for {
+		switch l.next() {
+		case '\\':
+			if r := l.next(); r != -1 {
+				break
+			}
+			fallthrough
+		case -1:
+			return l.errorf("unterminated bytestring")
+		case q:
+			break Loop
+		}
+	}
+	l.emit(tokByteString)
+	return varLexNormal
+}
+
+func varLexNumber(l *varLexer) lexState {
+	l.accept("+-")
+	digits := "0123456789"
+	if l.accept("0") {
+		if l.accept("x") {
+			digits = "0123456789abcdefABCDEF"
+		} else {
+			digits = "01234567"
+		}
+	}
+	for strings.IndexRune(digits, l.next()) >= 0 {
+	}
+	l.backup()
+	if l.accept(".") {
+		for strings.IndexRune(digits, l.next()) >= 0 {
+		}
+		l.backup()
+	}
+	if l.accept("eE") {
+		l.accept("+-")
+		for strings.IndexRune("0123456789", l.next()) >= 0 {
+		}
+		l.backup()
+	}
+	if r := l.peek(); unicode.IsLetter(r) {
+		l.next()
+		return l.errorf("bad number syntax: %q", l.input[l.start:l.pos])
+	}
+	l.emit(tokNumber)
+	return varLexNormal
+}
+
+func varLexString(l *varLexer) lexState {
+	q := l.next()
+Loop:
+	for {
+		switch l.next() {
+		case '\\':
+			if r := l.next(); r != -1 {
+				break
+			}
+			fallthrough
+		case -1:
+			return l.errorf("unterminated string")
+		case q:
+			break Loop
+		}
+	}
+	l.emit(tokString)
+	return varLexNormal
+}
+
+func varLexType(l *varLexer) lexState {
+	at := l.accept("@")
+	for {
+		r := l.next()
+		if r == -1 {
+			break
+		}
+		if unicode.IsSpace(r) {
+			l.backup()
+			break
+		}
+	}
+	if at {
+		if _, err := ParseSignature(l.input[l.start+1 : l.pos]); err != nil {
+			return l.errorf("%s", err)
+		}
+	} else {
+		if _, ok := varTypeMap[l.input[l.start:l.pos]]; ok {
+			l.emit(tokType)
+			return varLexNormal
+		}
+		return l.errorf("unrecognized type %q", l.input[l.start:l.pos])
+	}
+	l.emit(tokType)
+	return varLexNormal
+}

vendor/github.com/godbus/dbus/variant_parser.go

@@ -0,0 +1,817 @@
+package dbus
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+type varParser struct {
+	tokens []varToken
+	i      int
+}
+
+func (p *varParser) backup() {
+	p.i--
+}
+
+func (p *varParser) next() varToken {
+	if p.i < len(p.tokens) {
+		t := p.tokens[p.i]
+		p.i++
+		return t
+	}
+	return varToken{typ: tokEOF}
+}
+
+type varNode interface {
+	Infer() (Signature, error)
+	String() string
+	Sigs() sigSet
+	Value(Signature) (interface{}, error)
+}
+
+func varMakeNode(p *varParser) (varNode, error) {
+	var sig Signature
+
+	for {
+		t := p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		case tokNumber:
+			return varMakeNumNode(t, sig)
+		case tokString:
+			return varMakeStringNode(t, sig)
+		case tokBool:
+			if sig.str != "" && sig.str != "b" {
+				return nil, varTypeError{t.val, sig}
+			}
+			b, err := strconv.ParseBool(t.val)
+			if err != nil {
+				return nil, err
+			}
+			return boolNode(b), nil
+		case tokArrayStart:
+			return varMakeArrayNode(p, sig)
+		case tokVariantStart:
+			return varMakeVariantNode(p, sig)
+		case tokDictStart:
+			return varMakeDictNode(p, sig)
+		case tokType:
+			if sig.str != "" {
+				return nil, errors.New("unexpected type annotation")
+			}
+			if t.val[0] == '@' {
+				sig.str = t.val[1:]
+			} else {
+				sig.str = varTypeMap[t.val]
+			}
+		case tokByteString:
+			if sig.str != "" && sig.str != "ay" {
+				return nil, varTypeError{t.val, sig}
+			}
+			b, err := varParseByteString(t.val)
+			if err != nil {
+				return nil, err
+			}
+			return byteStringNode(b), nil
+		default:
+			return nil, fmt.Errorf("unexpected %q", t.val)
+		}
+	}
+}
+
+type varTypeError struct {
+	val string
+	sig Signature
+}
+
+func (e varTypeError) Error() string {
+	return fmt.Sprintf("dbus: can't parse %q as type %q", e.val, e.sig.str)
+}
+
+type sigSet map[Signature]bool
+
+func (s sigSet) Empty() bool {
+	return len(s) == 0
+}
+
+func (s sigSet) Intersect(s2 sigSet) sigSet {
+	r := make(sigSet)
+	for k := range s {
+		if s2[k] {
+			r[k] = true
+		}
+	}
+	return r
+}
+
+func (s sigSet) Single() (Signature, bool) {
+	if len(s) == 1 {
+		for k := range s {
+			return k, true
+		}
+	}
+	return Signature{}, false
+}
+
+func (s sigSet) ToArray() sigSet {
+	r := make(sigSet, len(s))
+	for k := range s {
+		r[Signature{"a" + k.str}] = true
+	}
+	return r
+}
+
+type numNode struct {
+	sig Signature
+	str string
+	val interface{}
+}
+
+var numSigSet = sigSet{
+	Signature{"y"}: true,
+	Signature{"n"}: true,
+	Signature{"q"}: true,
+	Signature{"i"}: true,
+	Signature{"u"}: true,
+	Signature{"x"}: true,
+	Signature{"t"}: true,
+	Signature{"d"}: true,
+}
+
+func (n numNode) Infer() (Signature, error) {
+	if strings.ContainsAny(n.str, ".e") {
+		return Signature{"d"}, nil
+	}
+	return Signature{"i"}, nil
+}
+
+func (n numNode) String() string {
+	return n.str
+}
+
+func (n numNode) Sigs() sigSet {
+	if n.sig.str != "" {
+		return sigSet{n.sig: true}
+	}
+	if strings.ContainsAny(n.str, ".e") {
+		return sigSet{Signature{"d"}: true}
+	}
+	return numSigSet
+}
+
+func (n numNode) Value(sig Signature) (interface{}, error) {
+	if n.sig.str != "" && n.sig != sig {
+		return nil, varTypeError{n.str, sig}
+	}
+	if n.val != nil {
+		return n.val, nil
+	}
+	return varNumAs(n.str, sig)
+}
+
+func varMakeNumNode(tok varToken, sig Signature) (varNode, error) {
+	if sig.str == "" {
+		return numNode{str: tok.val}, nil
+	}
+	num, err := varNumAs(tok.val, sig)
+	if err != nil {
+		return nil, err
+	}
+	return numNode{sig: sig, val: num}, nil
+}
+
+func varNumAs(s string, sig Signature) (interface{}, error) {
+	isUnsigned := false
+	size := 32
+	switch sig.str {
+	case "n":
+		size = 16
+	case "i":
+	case "x":
+		size = 64
+	case "y":
+		size = 8
+		isUnsigned = true
+	case "q":
+		size = 16
+		isUnsigned = true
+	case "u":
+		isUnsigned = true
+	case "t":
+		size = 64
+		isUnsigned = true
+	case "d":
+		d, err := strconv.ParseFloat(s, 64)
+		if err != nil {
+			return nil, err
+		}
+		return d, nil
+	default:
+		return nil, varTypeError{s, sig}
+	}
+	base := 10
+	if strings.HasPrefix(s, "0x") {
+		base = 16
+		s = s[2:]
+	}
+	if strings.HasPrefix(s, "0") && len(s) != 1 {
+		base = 8
+		s = s[1:]
+	}
+	if isUnsigned {
+		i, err := strconv.ParseUint(s, base, size)
+		if err != nil {
+			return nil, err
+		}
+		var v interface{} = i
+		switch sig.str {
+		case "y":
+			v = byte(i)
+		case "q":
+			v = uint16(i)
+		case "u":
+			v = uint32(i)
+		}
+		return v, nil
+	}
+	i, err := strconv.ParseInt(s, base, size)
+	if err != nil {
+		return nil, err
+	}
+	var v interface{} = i
+	switch sig.str {
+	case "n":
+		v = int16(i)
+	case "i":
+		v = int32(i)
+	}
+	return v, nil
+}
+
+type stringNode struct {
+	sig Signature
+	str string      // parsed
+	val interface{} // has correct type
+}
+
+var stringSigSet = sigSet{
+	Signature{"s"}: true,
+	Signature{"g"}: true,
+	Signature{"o"}: true,
+}
+
+func (n stringNode) Infer() (Signature, error) {
+	return Signature{"s"}, nil
+}
+
+func (n stringNode) String() string {
+	return n.str
+}
+
+func (n stringNode) Sigs() sigSet {
+	if n.sig.str != "" {
+		return sigSet{n.sig: true}
+	}
+	return stringSigSet
+}
+
+func (n stringNode) Value(sig Signature) (interface{}, error) {
+	if n.sig.str != "" && n.sig != sig {
+		return nil, varTypeError{n.str, sig}
+	}
+	if n.val != nil {
+		return n.val, nil
+	}
+	switch {
+	case sig.str == "g":
+		return Signature{n.str}, nil
+	case sig.str == "o":
+		return ObjectPath(n.str), nil
+	case sig.str == "s":
+		return n.str, nil
+	default:
+		return nil, varTypeError{n.str, sig}
+	}
+}
+
+func varMakeStringNode(tok varToken, sig Signature) (varNode, error) {
+	if sig.str != "" && sig.str != "s" && sig.str != "g" && sig.str != "o" {
+		return nil, fmt.Errorf("invalid type %q for string", sig.str)
+	}
+	s, err := varParseString(tok.val)
+	if err != nil {
+		return nil, err
+	}
+	n := stringNode{str: s}
+	if sig.str == "" {
+		return stringNode{str: s}, nil
+	}
+	n.sig = sig
+	switch sig.str {
+	case "o":
+		n.val = ObjectPath(s)
+	case "g":
+		n.val = Signature{s}
+	case "s":
+		n.val = s
+	}
+	return n, nil
+}
+
+func varParseString(s string) (string, error) {
+	// quotes are guaranteed to be there
+	s = s[1 : len(s)-1]
+	buf := new(bytes.Buffer)
+	for len(s) != 0 {
+		r, size := utf8.DecodeRuneInString(s)
+		if r == utf8.RuneError && size == 1 {
+			return "", errors.New("invalid UTF-8")
+		}
+		s = s[size:]
+		if r != '\\' {
+			buf.WriteRune(r)
+			continue
+		}
+		r, size = utf8.DecodeRuneInString(s)
+		if r == utf8.RuneError && size == 1 {
+			return "", errors.New("invalid UTF-8")
+		}
+		s = s[size:]
+		switch r {
+		case 'a':
+			buf.WriteRune(0x7)
+		case 'b':
+			buf.WriteRune(0x8)
+		case 'f':
+			buf.WriteRune(0xc)
+		case 'n':
+			buf.WriteRune('\n')
+		case 'r':
+			buf.WriteRune('\r')
+		case 't':
+			buf.WriteRune('\t')
+		case '\n':
+		case 'u':
+			if len(s) < 4 {
+				return "", errors.New("short unicode escape")
+			}
+			r, err := strconv.ParseUint(s[:4], 16, 32)
+			if err != nil {
+				return "", err
+			}
+			buf.WriteRune(rune(r))
+			s = s[4:]
+		case 'U':
+			if len(s) < 8 {
+				return "", errors.New("short unicode escape")
+			}
+			r, err := strconv.ParseUint(s[:8], 16, 32)
+			if err != nil {
+				return "", err
+			}
+			buf.WriteRune(rune(r))
+			s = s[8:]
+		default:
+			buf.WriteRune(r)
+		}
+	}
+	return buf.String(), nil
+}
+
+var boolSigSet = sigSet{Signature{"b"}: true}
+
+type boolNode bool
+
+func (boolNode) Infer() (Signature, error) {
+	return Signature{"b"}, nil
+}
+
+func (b boolNode) String() string {
+	if b {
+		return "true"
+	}
+	return "false"
+}
+
+func (boolNode) Sigs() sigSet {
+	return boolSigSet
+}
+
+func (b boolNode) Value(sig Signature) (interface{}, error) {
+	if sig.str != "b" {
+		return nil, varTypeError{b.String(), sig}
+	}
+	return bool(b), nil
+}
+
+type arrayNode struct {
+	set      sigSet
+	children []varNode
+	val      interface{}
+}
+
+func (n arrayNode) Infer() (Signature, error) {
+	for _, v := range n.children {
+		csig, err := varInfer(v)
+		if err != nil {
+			continue
+		}
+		return Signature{"a" + csig.str}, nil
+	}
+	return Signature{}, fmt.Errorf("can't infer type for %q", n.String())
+}
+
+func (n arrayNode) String() string {
+	s := "["
+	for i, v := range n.children {
+		s += v.String()
+		if i != len(n.children)-1 {
+			s += ", "
+		}
+	}
+	return s + "]"
+}
+
+func (n arrayNode) Sigs() sigSet {
+	return n.set
+}
+
+func (n arrayNode) Value(sig Signature) (interface{}, error) {
+	if n.set.Empty() {
+		// no type information whatsoever, so this must be an empty slice
+		return reflect.MakeSlice(typeFor(sig.str), 0, 0).Interface(), nil
+	}
+	if !n.set[sig] {
+		return nil, varTypeError{n.String(), sig}
+	}
+	s := reflect.MakeSlice(typeFor(sig.str), len(n.children), len(n.children))
+	for i, v := range n.children {
+		rv, err := v.Value(Signature{sig.str[1:]})
+		if err != nil {
+			return nil, err
+		}
+		s.Index(i).Set(reflect.ValueOf(rv))
+	}
+	return s.Interface(), nil
+}
+
+func varMakeArrayNode(p *varParser, sig Signature) (varNode, error) {
+	var n arrayNode
+	if sig.str != "" {
+		n.set = sigSet{sig: true}
+	}
+	if t := p.next(); t.typ == tokArrayEnd {
+		return n, nil
+	} else {
+		p.backup()
+	}
+Loop:
+	for {
+		t := p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		}
+		p.backup()
+		cn, err := varMakeNode(p)
+		if err != nil {
+			return nil, err
+		}
+		if cset := cn.Sigs(); !cset.Empty() {
+			if n.set.Empty() {
+				n.set = cset.ToArray()
+			} else {
+				nset := cset.ToArray().Intersect(n.set)
+				if nset.Empty() {
+					return nil, fmt.Errorf("can't parse %q with given type information", cn.String())
+				}
+				n.set = nset
+			}
+		}
+		n.children = append(n.children, cn)
+		switch t := p.next(); t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		case tokArrayEnd:
+			break Loop
+		case tokComma:
+			continue
+		default:
+			return nil, fmt.Errorf("unexpected %q", t.val)
+		}
+	}
+	return n, nil
+}
+
+type variantNode struct {
+	n varNode
+}
+
+var variantSet = sigSet{
+	Signature{"v"}: true,
+}
+
+func (variantNode) Infer() (Signature, error) {
+	return Signature{"v"}, nil
+}
+
+func (n variantNode) String() string {
+	return "<" + n.n.String() + ">"
+}
+
+func (variantNode) Sigs() sigSet {
+	return variantSet
+}
+
+func (n variantNode) Value(sig Signature) (interface{}, error) {
+	if sig.str != "v" {
+		return nil, varTypeError{n.String(), sig}
+	}
+	sig, err := varInfer(n.n)
+	if err != nil {
+		return nil, err
+	}
+	v, err := n.n.Value(sig)
+	if err != nil {
+		return nil, err
+	}
+	return MakeVariant(v), nil
+}
+
+func varMakeVariantNode(p *varParser, sig Signature) (varNode, error) {
+	n, err := varMakeNode(p)
+	if err != nil {
+		return nil, err
+	}
+	if t := p.next(); t.typ != tokVariantEnd {
+		return nil, fmt.Errorf("unexpected %q", t.val)
+	}
+	vn := variantNode{n}
+	if sig.str != "" && sig.str != "v" {
+		return nil, varTypeError{vn.String(), sig}
+	}
+	return variantNode{n}, nil
+}
+
+type dictEntry struct {
+	key, val varNode
+}
+
+type dictNode struct {
+	kset, vset sigSet
+	children   []dictEntry
+	val        interface{}
+}
+
+func (n dictNode) Infer() (Signature, error) {
+	for _, v := range n.children {
+		ksig, err := varInfer(v.key)
+		if err != nil {
+			continue
+		}
+		vsig, err := varInfer(v.val)
+		if err != nil {
+			continue
+		}
+		return Signature{"a{" + ksig.str + vsig.str + "}"}, nil
+	}
+	return Signature{}, fmt.Errorf("can't infer type for %q", n.String())
+}
+
+func (n dictNode) String() string {
+	s := "{"
+	for i, v := range n.children {
+		s += v.key.String() + ": " + v.val.String()
+		if i != len(n.children)-1 {
+			s += ", "
+		}
+	}
+	return s + "}"
+}
+
+func (n dictNode) Sigs() sigSet {
+	r := sigSet{}
+	for k := range n.kset {
+		for v := range n.vset {
+			sig := "a{" + k.str + v.str + "}"
+			r[Signature{sig}] = true
+		}
+	}
+	return r
+}
+
+func (n dictNode) Value(sig Signature) (interface{}, error) {
+	set := n.Sigs()
+	if set.Empty() {
+		// no type information -> empty dict
+		return reflect.MakeMap(typeFor(sig.str)).Interface(), nil
+	}
+	if !set[sig] {
+		return nil, varTypeError{n.String(), sig}
+	}
+	m := reflect.MakeMap(typeFor(sig.str))
+	ksig := Signature{sig.str[2:3]}
+	vsig := Signature{sig.str[3 : len(sig.str)-1]}
+	for _, v := range n.children {
+		kv, err := v.key.Value(ksig)
+		if err != nil {
+			return nil, err
+		}
+		vv, err := v.val.Value(vsig)
+		if err != nil {
+			return nil, err
+		}
+		m.SetMapIndex(reflect.ValueOf(kv), reflect.ValueOf(vv))
+	}
+	return m.Interface(), nil
+}
+
+func varMakeDictNode(p *varParser, sig Signature) (varNode, error) {
+	var n dictNode
+
+	if sig.str != "" {
+		if len(sig.str) < 5 {
+			return nil, fmt.Errorf("invalid signature %q for dict type", sig)
+		}
+		ksig := Signature{string(sig.str[2])}
+		vsig := Signature{sig.str[3 : len(sig.str)-1]}
+		n.kset = sigSet{ksig: true}
+		n.vset = sigSet{vsig: true}
+	}
+	if t := p.next(); t.typ == tokDictEnd {
+		return n, nil
+	} else {
+		p.backup()
+	}
+Loop:
+	for {
+		t := p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		}
+		p.backup()
+		kn, err := varMakeNode(p)
+		if err != nil {
+			return nil, err
+		}
+		if kset := kn.Sigs(); !kset.Empty() {
+			if n.kset.Empty() {
+				n.kset = kset
+			} else {
+				n.kset = kset.Intersect(n.kset)
+				if n.kset.Empty() {
+					return nil, fmt.Errorf("can't parse %q with given type information", kn.String())
+				}
+			}
+		}
+		t = p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		case tokColon:
+		default:
+			return nil, fmt.Errorf("unexpected %q", t.val)
+		}
+		t = p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		}
+		p.backup()
+		vn, err := varMakeNode(p)
+		if err != nil {
+			return nil, err
+		}
+		if vset := vn.Sigs(); !vset.Empty() {
+			if n.vset.Empty() {
+				n.vset = vset
+			} else {
+				n.vset = n.vset.Intersect(vset)
+				if n.vset.Empty() {
+					return nil, fmt.Errorf("can't parse %q with given type information", vn.String())
+				}
+			}
+		}
+		n.children = append(n.children, dictEntry{kn, vn})
+		t = p.next()
+		switch t.typ {
+		case tokEOF:
+			return nil, io.ErrUnexpectedEOF
+		case tokError:
+			return nil, errors.New(t.val)
+		case tokDictEnd:
+			break Loop
+		case tokComma:
+			continue
+		default:
+			return nil, fmt.Errorf("unexpected %q", t.val)
+		}
+	}
+	return n, nil
+}
+
+type byteStringNode []byte
+
+var byteStringSet = sigSet{
+	Signature{"ay"}: true,
+}
+
+func (byteStringNode) Infer() (Signature, error) {
+	return Signature{"ay"}, nil
+}
+
+func (b byteStringNode) String() string {
+	return string(b)
+}
+
+func (b byteStringNode) Sigs() sigSet {
+	return byteStringSet
+}
+
+func (b byteStringNode) Value(sig Signature) (interface{}, error) {
+	if sig.str != "ay" {
+		return nil, varTypeError{b.String(), sig}
+	}
+	return []byte(b), nil
+}
+
+func varParseByteString(s string) ([]byte, error) {
+	// quotes and b at start are guaranteed to be there
+	b := make([]byte, 0, 1)
+	s = s[2 : len(s)-1]
+	for len(s) != 0 {
+		c := s[0]
+		s = s[1:]
+		if c != '\\' {
+			b = append(b, c)
+			continue
+		}
+		c = s[0]
+		s = s[1:]
+		switch c {
+		case 'a':
+			b = append(b, 0x7)
+		case 'b':
+			b = append(b, 0x8)
+		case 'f':
+			b = append(b, 0xc)
+		case 'n':
+			b = append(b, '\n')
+		case 'r':
+			b = append(b, '\r')
+		case 't':
+			b = append(b, '\t')
+		case 'x':
+			if len(s) < 2 {
+				return nil, errors.New("short escape")
+			}
+			n, err := strconv.ParseUint(s[:2], 16, 8)
+			if err != nil {
+				return nil, err
+			}
+			b = append(b, byte(n))
+			s = s[2:]
+		case '0':
+			if len(s) < 3 {
+				return nil, errors.New("short escape")
+			}
+			n, err := strconv.ParseUint(s[:3], 8, 8)
+			if err != nil {
+				return nil, err
+			}
+			b = append(b, byte(n))
+			s = s[3:]
+		default:
+			b = append(b, c)
+		}
+	}
+	return append(b, 0), nil
+}
+
+func varInfer(n varNode) (Signature, error) {
+	if sig, ok := n.Sigs().Single(); ok {
+		return sig, nil
+	}
+	return n.Infer()
+}