102 lines
2.2 KiB
Go
102 lines
2.2 KiB
Go
// +build linux freebsd
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package devices
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import (
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"errors"
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"syscall"
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"github.com/opencontainers/runc/libcontainer/configs"
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)
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var (
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ErrNotADevice = errors.New("not a device node")
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)
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// Testing dependencies
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var (
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osLstat = os.Lstat
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ioutilReadDir = ioutil.ReadDir
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)
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// Given the path to a device and it's cgroup_permissions(which cannot be easily queried) look up the information about a linux device and return that information as a Device struct.
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func DeviceFromPath(path, permissions string) (*configs.Device, error) {
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fileInfo, err := osLstat(path)
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if err != nil {
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return nil, err
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}
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var (
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devType rune
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mode = fileInfo.Mode()
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fileModePermissionBits = os.FileMode.Perm(mode)
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)
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switch {
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case mode&os.ModeDevice == 0:
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return nil, ErrNotADevice
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case mode&os.ModeCharDevice != 0:
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fileModePermissionBits |= syscall.S_IFCHR
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devType = 'c'
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default:
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fileModePermissionBits |= syscall.S_IFBLK
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devType = 'b'
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}
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stat_t, ok := fileInfo.Sys().(*syscall.Stat_t)
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if !ok {
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return nil, fmt.Errorf("cannot determine the device number for device %s", path)
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}
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devNumber := int(stat_t.Rdev)
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return &configs.Device{
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Type: devType,
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Path: path,
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Major: Major(devNumber),
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Minor: Minor(devNumber),
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Permissions: permissions,
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FileMode: fileModePermissionBits,
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Uid: stat_t.Uid,
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Gid: stat_t.Gid,
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}, nil
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}
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func HostDevices() ([]*configs.Device, error) {
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return getDevices("/dev")
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}
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func getDevices(path string) ([]*configs.Device, error) {
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files, err := ioutilReadDir(path)
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if err != nil {
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return nil, err
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}
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out := []*configs.Device{}
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for _, f := range files {
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switch {
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case f.IsDir():
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switch f.Name() {
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case "pts", "shm", "fd", "mqueue":
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continue
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default:
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sub, err := getDevices(filepath.Join(path, f.Name()))
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if err != nil {
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return nil, err
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}
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out = append(out, sub...)
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continue
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}
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case f.Name() == "console":
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continue
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}
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device, err := DeviceFromPath(filepath.Join(path, f.Name()), "rwm")
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if err != nil {
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if err == ErrNotADevice {
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continue
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}
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return nil, err
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}
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out = append(out, device)
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}
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return out, nil
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}
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