diff options
Diffstat (limited to 'kube2msb/src/vendor/github.com/opencontainers/runc/libcontainer/system/linux.go')
-rw-r--r-- | kube2msb/src/vendor/github.com/opencontainers/runc/libcontainer/system/linux.go | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/kube2msb/src/vendor/github.com/opencontainers/runc/libcontainer/system/linux.go b/kube2msb/src/vendor/github.com/opencontainers/runc/libcontainer/system/linux.go new file mode 100644 index 0000000..1afc52b --- /dev/null +++ b/kube2msb/src/vendor/github.com/opencontainers/runc/libcontainer/system/linux.go @@ -0,0 +1,143 @@ +// +build linux + +package system + +import ( + "bufio" + "fmt" + "os" + "os/exec" + "syscall" + "unsafe" +) + +// If arg2 is nonzero, set the "child subreaper" attribute of the +// calling process; if arg2 is zero, unset the attribute. When a +// process is marked as a child subreaper, all of the children +// that it creates, and their descendants, will be marked as +// having a subreaper. In effect, a subreaper fulfills the role +// of init(1) for its descendant processes. Upon termination of +// a process that is orphaned (i.e., its immediate parent has +// already terminated) and marked as having a subreaper, the +// nearest still living ancestor subreaper will receive a SIGCHLD +// signal and be able to wait(2) on the process to discover its +// termination status. +const PR_SET_CHILD_SUBREAPER = 36 + +type ParentDeathSignal int + +func (p ParentDeathSignal) Restore() error { + if p == 0 { + return nil + } + current, err := GetParentDeathSignal() + if err != nil { + return err + } + if p == current { + return nil + } + return p.Set() +} + +func (p ParentDeathSignal) Set() error { + return SetParentDeathSignal(uintptr(p)) +} + +func Execv(cmd string, args []string, env []string) error { + name, err := exec.LookPath(cmd) + if err != nil { + return err + } + + return syscall.Exec(name, args, env) +} + +func Prlimit(pid, resource int, limit syscall.Rlimit) error { + _, _, err := syscall.RawSyscall6(syscall.SYS_PRLIMIT64, uintptr(pid), uintptr(resource), uintptr(unsafe.Pointer(&limit)), uintptr(unsafe.Pointer(&limit)), 0, 0) + if err != 0 { + return err + } + return nil +} + +func SetParentDeathSignal(sig uintptr) error { + if _, _, err := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, sig, 0); err != 0 { + return err + } + return nil +} + +func GetParentDeathSignal() (ParentDeathSignal, error) { + var sig int + _, _, err := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_GET_PDEATHSIG, uintptr(unsafe.Pointer(&sig)), 0) + if err != 0 { + return -1, err + } + return ParentDeathSignal(sig), nil +} + +func SetKeepCaps() error { + if _, _, err := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_KEEPCAPS, 1, 0); err != 0 { + return err + } + + return nil +} + +func ClearKeepCaps() error { + if _, _, err := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_KEEPCAPS, 0, 0); err != 0 { + return err + } + + return nil +} + +func Setctty() error { + if _, _, err := syscall.RawSyscall(syscall.SYS_IOCTL, 0, uintptr(syscall.TIOCSCTTY), 0); err != 0 { + return err + } + return nil +} + +// 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 +} + +// SetSubreaper sets the value i as the subreaper setting for the calling process +func SetSubreaper(i int) error { + return Prctl(PR_SET_CHILD_SUBREAPER, uintptr(i), 0, 0, 0) +} + +func Prctl(option int, arg2, arg3, arg4, arg5 uintptr) (err error) { + _, _, e1 := syscall.Syscall6(syscall.SYS_PRCTL, uintptr(option), arg2, arg3, arg4, arg5, 0) + if e1 != 0 { + err = e1 + } + return +} |