Merge pull request #270 from Random-Liu/fix-checkpoint-recovery

Fix checkpoint recovery.

pkg/store/sandbox/netns.go

@@ -24,6 +24,7 @@ import (
 
 	cnins "github.com/containernetworking/plugins/pkg/ns"
 	"github.com/docker/docker/pkg/mount"
+	"github.com/docker/docker/pkg/symlink"
 	"golang.org/x/sys/unix"
 )
 
@@ -52,14 +53,16 @@ func NewNetNS() (*NetNS, error) {
 // LoadNetNS loads existing network namespace. It returns ErrClosedNetNS
 // if the network namespace has already been closed.
 func LoadNetNS(path string) (*NetNS, error) {
-	if err := cnins.IsNSorErr(path); err != nil {
+	ns, err := cnins.GetNS(path)
+	if err != nil {
 		if _, ok := err.(cnins.NSPathNotExistErr); ok {
 			return nil, ErrClosedNetNS
 		}
-		return nil, err
+		if _, ok := err.(cnins.NSPathNotNSErr); ok {
+			// Do best effort cleanup.
+			os.RemoveAll(path) // nolint: errcheck
+			return nil, ErrClosedNetNS
 		}
-	ns, err := cnins.GetNS(path)
-	if err != nil {
 		return nil, fmt.Errorf("failed to load network namespace %v", err)
 	}
 	return &NetNS{ns: ns, restored: true}, nil
@@ -87,6 +90,10 @@ func (n *NetNS) Remove() error {
 			}
 			return fmt.Errorf("failed to stat netns: %v", err)
 		}
+		path, err := symlink.FollowSymlinkInScope(path, "/")
+		if err != nil {
+			return fmt.Errorf("failed to follow symlink: %v", err)
+		}
 		mounted, err := mount.Mounted(path)
 		if err != nil {
 			return fmt.Errorf("failed to check netns mounted: %v", err)

vendor/github.com/docker/docker/pkg/symlink/LICENSE.APACHE

@@ -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.
+
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+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
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+
+      "Work" shall mean the work of authorship, whether in Source or
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+      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,
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+      (except as stated in this section) patent license to make, have made,
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+      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
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+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
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+      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
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+      (c) You must retain, in the Source form of any Derivative Works
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+      (d) If the Work includes a "NOTICE" text file as part of its
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+          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 2014-2017 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
+
+       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/docker/docker/pkg/symlink/LICENSE.BSD

@@ -0,0 +1,27 @@
+Copyright (c) 2014-2017 The Docker & Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * 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.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+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
+OWNER 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/docker/docker/pkg/symlink/README.md

@@ -0,0 +1,6 @@
+Package symlink implements EvalSymlinksInScope which is an extension of filepath.EvalSymlinks,
+as well as a Windows long-path aware version of filepath.EvalSymlinks
+from the [Go standard library](https://golang.org/pkg/path/filepath).
+
+The code from filepath.EvalSymlinks has been adapted in fs.go.
+Please read the LICENSE.BSD file that governs fs.go and LICENSE.APACHE for fs_test.go.

vendor/github.com/docker/docker/pkg/symlink/fs.go

@@ -0,0 +1,144 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE.BSD file.
+
+// This code is a modified version of path/filepath/symlink.go from the Go standard library.
+
+package symlink
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/docker/docker/pkg/system"
+)
+
+// FollowSymlinkInScope is a wrapper around evalSymlinksInScope that returns an
+// absolute path. This function handles paths in a platform-agnostic manner.
+func FollowSymlinkInScope(path, root string) (string, error) {
+	path, err := filepath.Abs(filepath.FromSlash(path))
+	if err != nil {
+		return "", err
+	}
+	root, err = filepath.Abs(filepath.FromSlash(root))
+	if err != nil {
+		return "", err
+	}
+	return evalSymlinksInScope(path, root)
+}
+
+// evalSymlinksInScope will evaluate symlinks in `path` within a scope `root` and return
+// a result guaranteed to be contained within the scope `root`, at the time of the call.
+// Symlinks in `root` are not evaluated and left as-is.
+// Errors encountered while attempting to evaluate symlinks in path will be returned.
+// Non-existing paths are valid and do not constitute an error.
+// `path` has to contain `root` as a prefix, or else an error will be returned.
+// Trying to break out from `root` does not constitute an error.
+//
+// Example:
+//   If /foo/bar -> /outside,
+//   FollowSymlinkInScope("/foo/bar", "/foo") == "/foo/outside" instead of "/outside"
+//
+// IMPORTANT: it is the caller's responsibility to call evalSymlinksInScope *after* relevant symlinks
+// are created and not to create subsequently, additional symlinks that could potentially make a
+// previously-safe path, unsafe. Example: if /foo/bar does not exist, evalSymlinksInScope("/foo/bar", "/foo")
+// would return "/foo/bar". If one makes /foo/bar a symlink to /baz subsequently, then "/foo/bar" should
+// no longer be considered safely contained in "/foo".
+func evalSymlinksInScope(path, root string) (string, error) {
+	root = filepath.Clean(root)
+	if path == root {
+		return path, nil
+	}
+	if !strings.HasPrefix(path, root) {
+		return "", errors.New("evalSymlinksInScope: " + path + " is not in " + root)
+	}
+	const maxIter = 255
+	originalPath := path
+	// given root of "/a" and path of "/a/b/../../c" we want path to be "/b/../../c"
+	path = path[len(root):]
+	if root == string(filepath.Separator) {
+		path = string(filepath.Separator) + path
+	}
+	if !strings.HasPrefix(path, string(filepath.Separator)) {
+		return "", errors.New("evalSymlinksInScope: " + path + " is not in " + root)
+	}
+	path = filepath.Clean(path)
+	// consume path by taking each frontmost path element,
+	// expanding it if it's a symlink, and appending it to b
+	var b bytes.Buffer
+	// b here will always be considered to be the "current absolute path inside
+	// root" when we append paths to it, we also append a slash and use
+	// filepath.Clean after the loop to trim the trailing slash
+	for n := 0; path != ""; n++ {
+		if n > maxIter {
+			return "", errors.New("evalSymlinksInScope: too many links in " + originalPath)
+		}
+
+		// find next path component, p
+		i := strings.IndexRune(path, filepath.Separator)
+		var p string
+		if i == -1 {
+			p, path = path, ""
+		} else {
+			p, path = path[:i], path[i+1:]
+		}
+
+		if p == "" {
+			continue
+		}
+
+		// this takes a b.String() like "b/../" and a p like "c" and turns it
+		// into "/b/../c" which then gets filepath.Cleaned into "/c" and then
+		// root gets prepended and we Clean again (to remove any trailing slash
+		// if the first Clean gave us just "/")
+		cleanP := filepath.Clean(string(filepath.Separator) + b.String() + p)
+		if isDriveOrRoot(cleanP) {
+			// never Lstat "/" itself, or drive letters on Windows
+			b.Reset()
+			continue
+		}
+		fullP := filepath.Clean(root + cleanP)
+
+		fi, err := os.Lstat(fullP)
+		if os.IsNotExist(err) {
+			// if p does not exist, accept it
+			b.WriteString(p)
+			b.WriteRune(filepath.Separator)
+			continue
+		}
+		if err != nil {
+			return "", err
+		}
+		if fi.Mode()&os.ModeSymlink == 0 {
+			b.WriteString(p)
+			b.WriteRune(filepath.Separator)
+			continue
+		}
+
+		// it's a symlink, put it at the front of path
+		dest, err := os.Readlink(fullP)
+		if err != nil {
+			return "", err
+		}
+		if system.IsAbs(dest) {
+			b.Reset()
+		}
+		path = dest + string(filepath.Separator) + path
+	}
+
+	// see note above on "fullP := ..." for why this is double-cleaned and
+	// what's happening here
+	return filepath.Clean(root + filepath.Clean(string(filepath.Separator)+b.String())), nil
+}
+
+// EvalSymlinks returns the path name after the evaluation of any symbolic
+// links.
+// If path is relative the result will be relative to the current directory,
+// unless one of the components is an absolute symbolic link.
+// This version has been updated to support long paths prepended with `\\?\`.
+func EvalSymlinks(path string) (string, error) {
+	return evalSymlinks(path)
+}

vendor/github.com/docker/docker/pkg/symlink/fs_unix.go

@@ -0,0 +1,15 @@
+// +build !windows
+
+package symlink
+
+import (
+	"path/filepath"
+)
+
+func evalSymlinks(path string) (string, error) {
+	return filepath.EvalSymlinks(path)
+}
+
+func isDriveOrRoot(p string) bool {
+	return p == string(filepath.Separator)
+}

vendor/github.com/docker/docker/pkg/symlink/fs_windows.go

@@ -0,0 +1,169 @@
+package symlink
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/docker/docker/pkg/longpath"
+	"golang.org/x/sys/windows"
+)
+
+func toShort(path string) (string, error) {
+	p, err := windows.UTF16FromString(path)
+	if err != nil {
+		return "", err
+	}
+	b := p // GetShortPathName says we can reuse buffer
+	n, err := windows.GetShortPathName(&p[0], &b[0], uint32(len(b)))
+	if err != nil {
+		return "", err
+	}
+	if n > uint32(len(b)) {
+		b = make([]uint16, n)
+		if _, err = windows.GetShortPathName(&p[0], &b[0], uint32(len(b))); err != nil {
+			return "", err
+		}
+	}
+	return windows.UTF16ToString(b), nil
+}
+
+func toLong(path string) (string, error) {
+	p, err := windows.UTF16FromString(path)
+	if err != nil {
+		return "", err
+	}
+	b := p // GetLongPathName says we can reuse buffer
+	n, err := windows.GetLongPathName(&p[0], &b[0], uint32(len(b)))
+	if err != nil {
+		return "", err
+	}
+	if n > uint32(len(b)) {
+		b = make([]uint16, n)
+		n, err = windows.GetLongPathName(&p[0], &b[0], uint32(len(b)))
+		if err != nil {
+			return "", err
+		}
+	}
+	b = b[:n]
+	return windows.UTF16ToString(b), nil
+}
+
+func evalSymlinks(path string) (string, error) {
+	path, err := walkSymlinks(path)
+	if err != nil {
+		return "", err
+	}
+
+	p, err := toShort(path)
+	if err != nil {
+		return "", err
+	}
+	p, err = toLong(p)
+	if err != nil {
+		return "", err
+	}
+	// windows.GetLongPathName does not change the case of the drive letter,
+	// but the result of EvalSymlinks must be unique, so we have
+	// EvalSymlinks(`c:\a`) == EvalSymlinks(`C:\a`).
+	// Make drive letter upper case.
+	if len(p) >= 2 && p[1] == ':' && 'a' <= p[0] && p[0] <= 'z' {
+		p = string(p[0]+'A'-'a') + p[1:]
+	} else if len(p) >= 6 && p[5] == ':' && 'a' <= p[4] && p[4] <= 'z' {
+		p = p[:3] + string(p[4]+'A'-'a') + p[5:]
+	}
+	return filepath.Clean(p), nil
+}
+
+const utf8RuneSelf = 0x80
+
+func walkSymlinks(path string) (string, error) {
+	const maxIter = 255
+	originalPath := path
+	// consume path by taking each frontmost path element,
+	// expanding it if it's a symlink, and appending it to b
+	var b bytes.Buffer
+	for n := 0; path != ""; n++ {
+		if n > maxIter {
+			return "", errors.New("EvalSymlinks: too many links in " + originalPath)
+		}
+
+		// A path beginning with `\\?\` represents the root, so automatically
+		// skip that part and begin processing the next segment.
+		if strings.HasPrefix(path, longpath.Prefix) {
+			b.WriteString(longpath.Prefix)
+			path = path[4:]
+			continue
+		}
+
+		// find next path component, p
+		var i = -1
+		for j, c := range path {
+			if c < utf8RuneSelf && os.IsPathSeparator(uint8(c)) {
+				i = j
+				break
+			}
+		}
+		var p string
+		if i == -1 {
+			p, path = path, ""
+		} else {
+			p, path = path[:i], path[i+1:]
+		}
+
+		if p == "" {
+			if b.Len() == 0 {
+				// must be absolute path
+				b.WriteRune(filepath.Separator)
+			}
+			continue
+		}
+
+		// If this is the first segment after the long path prefix, accept the
+		// current segment as a volume root or UNC share and move on to the next.
+		if b.String() == longpath.Prefix {
+			b.WriteString(p)
+			b.WriteRune(filepath.Separator)
+			continue
+		}
+
+		fi, err := os.Lstat(b.String() + p)
+		if err != nil {
+			return "", err
+		}
+		if fi.Mode()&os.ModeSymlink == 0 {
+			b.WriteString(p)
+			if path != "" || (b.Len() == 2 && len(p) == 2 && p[1] == ':') {
+				b.WriteRune(filepath.Separator)
+			}
+			continue
+		}
+
+		// it's a symlink, put it at the front of path
+		dest, err := os.Readlink(b.String() + p)
+		if err != nil {
+			return "", err
+		}
+		if filepath.IsAbs(dest) || os.IsPathSeparator(dest[0]) {
+			b.Reset()
+		}
+		path = dest + string(filepath.Separator) + path
+	}
+	return filepath.Clean(b.String()), nil
+}
+
+func isDriveOrRoot(p string) bool {
+	if p == string(filepath.Separator) {
+		return true
+	}
+
+	length := len(p)
+	if length >= 2 {
+		if p[length-1] == ':' && (('a' <= p[length-2] && p[length-2] <= 'z') || ('A' <= p[length-2] && p[length-2] <= 'Z')) {
+			return true
+		}
+	}
+	return false
+}