Bump dependency opencontainers/runc@v1.0.0-rc10

This commit is contained in:
Odin Ugedal
2020-01-24 13:11:01 +01:00
parent 90da466221
commit 088ee920e0
116 changed files with 9182 additions and 1047 deletions

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load("@io_bazel_rules_go//go:def.bzl", "go_library")
go_library(
name = "go_default_library",
srcs = ["ebpf.go"],
importmap = "k8s.io/kubernetes/vendor/github.com/opencontainers/runc/libcontainer/cgroups/ebpf",
importpath = "github.com/opencontainers/runc/libcontainer/cgroups/ebpf",
visibility = ["//visibility:public"],
deps = [
"//vendor/github.com/cilium/ebpf:go_default_library",
"//vendor/github.com/cilium/ebpf/asm:go_default_library",
"//vendor/github.com/pkg/errors:go_default_library",
"//vendor/golang.org/x/sys/unix:go_default_library",
],
)
filegroup(
name = "package-srcs",
srcs = glob(["**"]),
tags = ["automanaged"],
visibility = ["//visibility:private"],
)
filegroup(
name = "all-srcs",
srcs = [
":package-srcs",
"//vendor/github.com/opencontainers/runc/libcontainer/cgroups/ebpf/devicefilter:all-srcs",
],
tags = ["automanaged"],
visibility = ["//visibility:public"],
)

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load("@io_bazel_rules_go//go:def.bzl", "go_library")
go_library(
name = "go_default_library",
srcs = ["devicefilter.go"],
importmap = "k8s.io/kubernetes/vendor/github.com/opencontainers/runc/libcontainer/cgroups/ebpf/devicefilter",
importpath = "github.com/opencontainers/runc/libcontainer/cgroups/ebpf/devicefilter",
visibility = ["//visibility:public"],
deps = [
"//vendor/github.com/cilium/ebpf/asm:go_default_library",
"//vendor/github.com/opencontainers/runc/libcontainer/configs:go_default_library",
"//vendor/github.com/pkg/errors:go_default_library",
"//vendor/golang.org/x/sys/unix:go_default_library",
],
)
filegroup(
name = "package-srcs",
srcs = glob(["**"]),
tags = ["automanaged"],
visibility = ["//visibility:private"],
)
filegroup(
name = "all-srcs",
srcs = [":package-srcs"],
tags = ["automanaged"],
visibility = ["//visibility:public"],
)

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// Package devicefilter containes eBPF device filter program
//
// The implementation is based on https://github.com/containers/crun/blob/0.10.2/src/libcrun/ebpf.c
//
// Although ebpf.c is originally licensed under LGPL-3.0-or-later, the author (Giuseppe Scrivano)
// agreed to relicense the file in Apache License 2.0: https://github.com/opencontainers/runc/issues/2144#issuecomment-543116397
package devicefilter
import (
"fmt"
"math"
"github.com/cilium/ebpf/asm"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
const (
// license string format is same as kernel MODULE_LICENSE macro
license = "Apache"
)
// DeviceFilter returns eBPF device filter program and its license string
func DeviceFilter(devices []*configs.Device) (asm.Instructions, string, error) {
p := &program{}
p.init()
for i := len(devices) - 1; i >= 0; i-- {
if err := p.appendDevice(devices[i]); err != nil {
return nil, "", err
}
}
insts, err := p.finalize()
return insts, license, err
}
type program struct {
insts asm.Instructions
hasWildCard bool
blockID int
}
func (p *program) init() {
// struct bpf_cgroup_dev_ctx: https://elixir.bootlin.com/linux/v5.3.6/source/include/uapi/linux/bpf.h#L3423
/*
u32 access_type
u32 major
u32 minor
*/
// R2 <- type (lower 16 bit of u32 access_type at R1[0])
p.insts = append(p.insts,
asm.LoadMem(asm.R2, asm.R1, 0, asm.Half))
// R3 <- access (upper 16 bit of u32 access_type at R1[0])
p.insts = append(p.insts,
asm.LoadMem(asm.R3, asm.R1, 0, asm.Word),
// RSh: bitwise shift right
asm.RSh.Imm32(asm.R3, 16))
// R4 <- major (u32 major at R1[4])
p.insts = append(p.insts,
asm.LoadMem(asm.R4, asm.R1, 4, asm.Word))
// R5 <- minor (u32 minor at R1[8])
p.insts = append(p.insts,
asm.LoadMem(asm.R5, asm.R1, 8, asm.Word))
}
// appendDevice needs to be called from the last element of OCI linux.resources.devices to the head element.
func (p *program) appendDevice(dev *configs.Device) error {
if p.blockID < 0 {
return errors.New("the program is finalized")
}
if p.hasWildCard {
// All entries after wildcard entry are ignored
return nil
}
bpfType := int32(-1)
hasType := true
switch dev.Type {
case 'c':
bpfType = int32(unix.BPF_DEVCG_DEV_CHAR)
case 'b':
bpfType = int32(unix.BPF_DEVCG_DEV_BLOCK)
case 'a':
hasType = false
default:
// if not specified in OCI json, typ is set to DeviceTypeAll
return errors.Errorf("invalid DeviceType %q", string(dev.Type))
}
if dev.Major > math.MaxUint32 {
return errors.Errorf("invalid major %d", dev.Major)
}
if dev.Minor > math.MaxUint32 {
return errors.Errorf("invalid minor %d", dev.Major)
}
hasMajor := dev.Major >= 0 // if not specified in OCI json, major is set to -1
hasMinor := dev.Minor >= 0
bpfAccess := int32(0)
for _, r := range dev.Permissions {
switch r {
case 'r':
bpfAccess |= unix.BPF_DEVCG_ACC_READ
case 'w':
bpfAccess |= unix.BPF_DEVCG_ACC_WRITE
case 'm':
bpfAccess |= unix.BPF_DEVCG_ACC_MKNOD
default:
return errors.Errorf("unknown device access %v", r)
}
}
// If the access is rwm, skip the check.
hasAccess := bpfAccess != (unix.BPF_DEVCG_ACC_READ | unix.BPF_DEVCG_ACC_WRITE | unix.BPF_DEVCG_ACC_MKNOD)
blockSym := fmt.Sprintf("block-%d", p.blockID)
nextBlockSym := fmt.Sprintf("block-%d", p.blockID+1)
prevBlockLastIdx := len(p.insts) - 1
if hasType {
p.insts = append(p.insts,
// if (R2 != bpfType) goto next
asm.JNE.Imm(asm.R2, bpfType, nextBlockSym),
)
}
if hasAccess {
p.insts = append(p.insts,
// if (R3 & bpfAccess == 0 /* use R1 as a temp var */) goto next
asm.Mov.Reg32(asm.R1, asm.R3),
asm.And.Imm32(asm.R1, bpfAccess),
asm.JEq.Imm(asm.R1, 0, nextBlockSym),
)
}
if hasMajor {
p.insts = append(p.insts,
// if (R4 != major) goto next
asm.JNE.Imm(asm.R4, int32(dev.Major), nextBlockSym),
)
}
if hasMinor {
p.insts = append(p.insts,
// if (R5 != minor) goto next
asm.JNE.Imm(asm.R5, int32(dev.Minor), nextBlockSym),
)
}
if !hasType && !hasAccess && !hasMajor && !hasMinor {
p.hasWildCard = true
}
p.insts = append(p.insts, acceptBlock(dev.Allow)...)
// set blockSym to the first instruction we added in this iteration
p.insts[prevBlockLastIdx+1] = p.insts[prevBlockLastIdx+1].Sym(blockSym)
p.blockID++
return nil
}
func (p *program) finalize() (asm.Instructions, error) {
if p.hasWildCard {
// acceptBlock with asm.Return() is already inserted
return p.insts, nil
}
blockSym := fmt.Sprintf("block-%d", p.blockID)
p.insts = append(p.insts,
// R0 <- 0
asm.Mov.Imm32(asm.R0, 0).Sym(blockSym),
asm.Return(),
)
p.blockID = -1
return p.insts, nil
}
func acceptBlock(accept bool) asm.Instructions {
v := int32(0)
if accept {
v = 1
}
return []asm.Instruction{
// R0 <- v
asm.Mov.Imm32(asm.R0, v),
asm.Return(),
}
}

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package ebpf
import (
"github.com/cilium/ebpf"
"github.com/cilium/ebpf/asm"
"github.com/pkg/errors"
"golang.org/x/sys/unix"
)
// LoadAttachCgroupDeviceFilter installs eBPF device filter program to /sys/fs/cgroup/<foo> directory.
//
// Requires the system to be running in cgroup2 unified-mode with kernel >= 4.15 .
//
// https://github.com/torvalds/linux/commit/ebc614f687369f9df99828572b1d85a7c2de3d92
func LoadAttachCgroupDeviceFilter(insts asm.Instructions, license string, dirFD int) (func() error, error) {
nilCloser := func() error {
return nil
}
// Increase `ulimit -l` limit to avoid BPF_PROG_LOAD error (#2167).
// This limit is not inherited into the container.
memlockLimit := &unix.Rlimit{
Cur: unix.RLIM_INFINITY,
Max: unix.RLIM_INFINITY,
}
_ = unix.Setrlimit(unix.RLIMIT_MEMLOCK, memlockLimit)
spec := &ebpf.ProgramSpec{
Type: ebpf.CGroupDevice,
Instructions: insts,
License: license,
}
prog, err := ebpf.NewProgram(spec)
if err != nil {
return nilCloser, err
}
if err := prog.Attach(dirFD, ebpf.AttachCGroupDevice, unix.BPF_F_ALLOW_MULTI); err != nil {
return nilCloser, errors.Wrap(err, "failed to call BPF_PROG_ATTACH (BPF_CGROUP_DEVICE, BPF_F_ALLOW_MULTI)")
}
closer := func() error {
if err := prog.Detach(dirFD, ebpf.AttachCGroupDevice, unix.BPF_F_ALLOW_MULTI); err != nil {
return errors.Wrap(err, "failed to call BPF_PROG_DETACH (BPF_CGROUP_DEVICE, BPF_F_ALLOW_MULTI)")
}
return nil
}
return closer, nil
}