Golang label.Validate函數代碼示例

//.........這裏部分代碼省略.........
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		// update the mount with the correct dest after symlinks are resolved.
		m.Destination = dest
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		// bind mount won't change mount options, we need remount to make mount options effective.
		// first check that we have non-default options required before attempting a remount
		if m.Flags&^(syscall.MS_REC|syscall.MS_REMOUNT|syscall.MS_BIND) != 0 {
			// only remount if unique mount options are set
			if err := remount(m, rootfs); err != nil {
				return err
			}
		}

		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
		var merged []string
		for _, b := range binds {
			ss := filepath.Base(b.Destination)
			if strings.Contains(ss, ",") {
				merged = append(merged, ss)
			}
		}
		tmpfs := &configs.Mount{
			Source:           "tmpfs",
			Device:           "tmpfs",
			Destination:      m.Destination,
			Flags:            defaultMountFlags,
			Data:             "mode=755",
			PropagationFlags: m.PropagationFlags,
		}
		if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil {
			return err
		}
		for _, b := range binds {
			if err := mountToRootfs(b, rootfs, mountLabel); err != nil {
				return err
			}
		}
		for _, mc := range merged {
			for _, ss := range strings.Split(mc, ",") {
				// symlink(2) is very dumb, it will just shove the path into
				// the link and doesn't do any checks or relative path
				// conversion. Also, don't error out if the cgroup already exists.
				if err := os.Symlink(mc, filepath.Join(rootfs, m.Destination, ss)); err != nil && !os.IsExist(err) {
					return err
				}
			}
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			// remount cgroup root as readonly
			mcgrouproot := &configs.Mount{
				Source:      m.Destination,
				Device:      "bind",
				Destination: m.Destination,
				Flags:       defaultMountFlags | syscall.MS_RDONLY | syscall.MS_BIND,
			}
			if err := remount(mcgrouproot, rootfs); err != nil {
				return err
			}
		}
	default:
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	}
	return nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		// Selinux kernels do not support labeling of /proc or /sys
		return mountPropagate(m, rootfs, "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			// older kernels do not support labeling of /dev/mqueue
			if err := mountPropagate(m, rootfs, ""); err != nil {
				return err
			}
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil {
				return err
			}
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	case "securityfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		// update the mount with the correct dest after symlinks are resolved.
		m.Destination = dest
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		// bind mount won't change mount options, we need remount to make mount options effective.
		// first check that we have non-default options required before attempting a remount
		if m.Flags&^(syscall.MS_REC|syscall.MS_REMOUNT|syscall.MS_BIND) != 0 {
			// only remount if unique mount options are set
			if err := remount(m, rootfs); err != nil {
				return err
			}
		}

		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
//.........這裏部分代碼省略.........

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), ""); err != nil {
			return err
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "securityfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
		var merged []string
		for _, b := range binds {
			ss := filepath.Base(b.Destination)
			if strings.Contains(ss, ",") {
//.........這裏部分代碼省略.........