func (container *Container) networkMounts() []execdriver.Mount {
var mounts []execdriver.Mount
if container.ResolvConfPath != "" {
label.SetFileLabel(container.ResolvConfPath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.ResolvConfPath,
Destination: "/etc/resolv.conf",
Writable: !container.hostConfig.ReadonlyRootfs,
Private: true,
})
}
if container.HostnamePath != "" {
label.SetFileLabel(container.HostnamePath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.HostnamePath,
Destination: "/etc/hostname",
Writable: !container.hostConfig.ReadonlyRootfs,
Private: true,
})
}
if container.HostsPath != "" {
label.SetFileLabel(container.HostsPath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.HostsPath,
Destination: "/etc/hosts",
Writable: !container.hostConfig.ReadonlyRootfs,
Private: true,
})
}
return mounts
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {
if len(storageOpt) != 0 {
return fmt.Errorf("--storage-opt is not supported for vfs")
}
dir := d.dir(id)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(filepath.Dir(dir), 0700, rootUID, rootGID); err != nil {
return err
}
if err := idtools.MkdirAs(dir, 0755, rootUID, rootGID); err != nil {
return err
}
opts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(opts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent == "" {
return nil
}
parentDir, err := d.Get(parent, "")
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := CopyWithTar(parentDir, dir); err != nil {
return err
}
return nil
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent, mountLabel string) error {
dir := d.dir(id)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(filepath.Dir(dir), 0700, rootUID, rootGID); err != nil {
return err
}
if err := idtools.MkdirAs(dir, 0755, rootUID, rootGID); err != nil {
return err
}
opts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(opts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent == "" {
return nil
}
parentDir, err := d.Get(parent, "")
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := chrootarchive.CopyWithTar(parentDir, dir); err != nil {
return err
}
return nil
}
func (container *Container) ipcMounts() []execdriver.Mount {
var mounts []execdriver.Mount
label.SetFileLabel(container.ShmPath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.ShmPath,
Destination: "/dev/shm",
Writable: true,
Private: true,
})
label.SetFileLabel(container.MqueuePath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.MqueuePath,
Destination: "/dev/mqueue",
Writable: true,
Private: true,
})
return mounts
}
// IpcMounts returns the list of IPC mounts
func (container *Container) IpcMounts() []execdriver.Mount {
var mounts []execdriver.Mount
if !container.HasMountFor("/dev/shm") {
label.SetFileLabel(container.ShmPath, container.MountLabel)
mounts = append(mounts, execdriver.Mount{
Source: container.ShmPath,
Destination: "/dev/shm",
Writable: true,
Propagation: volume.DefaultPropagationMode,
})
}
return mounts
}
// mount initializes the console inside the rootfs mounting with the specified mount label
// and applying the correct ownership of the console.
func (c *linuxConsole) mount(rootfs, mountLabel string, uid, gid int) error {
oldMask := syscall.Umask(0000)
defer syscall.Umask(oldMask)
if err := label.SetFileLabel(c.slavePath, mountLabel); err != nil {
return err
}
dest := filepath.Join(rootfs, "/dev/console")
f, err := os.Create(dest)
if err != nil && !os.IsExist(err) {
return err
}
if f != nil {
f.Close()
}
return syscall.Mount(c.slavePath, dest, "bind", syscall.MS_BIND, "")
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent string) error {
dir := d.dir(id)
if err := system.MkdirAll(filepath.Dir(dir), 0700); err != nil {
return err
}
if err := os.Mkdir(dir, 0755); err != nil {
return err
}
opts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(opts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent == "" {
return nil
}
parentDir, err := d.Get(parent, "")
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := chrootarchive.CopyWithTar(parentDir, dir); err != nil {
return err
}
return nil
}
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 && !os.IsExist(err) {
return err
}
return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
case "mqueue":
if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
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 && !os.IsExist(err) {
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 && !os.IsExist(err) {
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.Relabel(m.Source, mountLabel, m.Relabel); 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, ",") {
merged = append(merged, ss)
}
}
tmpfs := &configs.Mount{
Source: "tmpfs",
Device: "tmpfs",
Destination: m.Destination,
Flags: defaultMountFlags,
}
if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil {
return err
}
for _, b := range binds {
if err := mountToRootfs(b, rootfs, mountLabel); err != nil {
return err
}
}
// create symlinks for merged cgroups
cwd, err := os.Getwd()
if err != nil {
return err
}
if err := os.Chdir(filepath.Join(rootfs, m.Destination)); err != nil {
return err
}
for _, mc := range merged {
for _, ss := range strings.Split(mc, ",") {
if err := os.Symlink(mc, ss); err != nil {
// if cgroup already exists, then okay(it could have been created before)
if os.IsExist(err) {
continue
}
os.Chdir(cwd)
return err
}
}
}
if err := os.Chdir(cwd); err != nil {
return err
}
default:
return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination)
}
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
}
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
}
}
// create symlinks for merged cgroups
cwd, err := os.Getwd()
if err != nil {
return err
}
if err := os.Chdir(filepath.Join(rootfs, m.Destination)); err != nil {
return err
}
for _, mc := range merged {
for _, ss := range strings.Split(mc, ",") {
if err := os.Symlink(mc, ss); err != nil {
// if cgroup already exists, then okay(it could have been created before)
if os.IsExist(err) {
continue
}
os.Chdir(cwd)
return err
}
}
}
if err := os.Chdir(cwd); err != nil {
return err
}
if m.Flags&syscall.MS_RDONLY != 0 {
// remount cgroup root as readonly
mcgrouproot := &configs.Mount{
Destination: m.Destination,
Flags: defaultMountFlags | syscall.MS_RDONLY,
}
if err := remount(mcgrouproot, rootfs); err != nil {
return err
}
}
default:
return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination)
}
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)
}
return nil
case "tmpfs":
copyUp := m.Extensions&configs.EXT_COPYUP == configs.EXT_COPYUP
tmpDir := ""
stat, err := os.Stat(dest)
if err != nil {
if err := os.MkdirAll(dest, 0755); err != nil {
return err
}
}
if copyUp {
tmpDir, err = ioutil.TempDir("/tmp", "runctmpdir")
if err != nil {
return newSystemErrorWithCause(err, "tmpcopyup: failed to create tmpdir")
}
defer os.RemoveAll(tmpDir)
m.Destination = tmpDir
}
if err := mountPropagate(m, rootfs, mountLabel); err != nil {
return err
}
if copyUp {
if err := fileutils.CopyDirectory(dest, tmpDir); err != nil {
errMsg := fmt.Errorf("tmpcopyup: failed to copy %s to %s: %v", dest, tmpDir, err)
if err1 := syscall.Unmount(tmpDir, syscall.MNT_DETACH); err1 != nil {
return newSystemErrorWithCausef(err1, "tmpcopyup: %v: failed to unmount", errMsg)
}
return errMsg
}
if err := syscall.Mount(tmpDir, dest, "", syscall.MS_MOVE, ""); err != nil {
errMsg := fmt.Errorf("tmpcopyup: failed to move mount %s to %s: %v", tmpDir, dest, err)
if err1 := syscall.Unmount(tmpDir, syscall.MNT_DETACH); err1 != nil {
return newSystemErrorWithCausef(err1, "tmpcopyup: %v: failed to unmount", errMsg)
}
return errMsg
}
}
if stat != nil {
if err = os.Chmod(dest, stat.Mode()); err != nil {
return err
}
}
return nil
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
}
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
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 && !os.IsExist(err) {
return err
}
return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
case "mqueue":
if err := os.MkdirAll(dest, 0755); err != nil && !os.IsExist(err) {
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 && !os.IsExist(err) {
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 && !os.IsExist(err) {
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.Relabel(m.Source, mountLabel, m.Relabel); 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":
mounts, err := cgroups.GetCgroupMounts()
if err != nil {
return err
}
var binds []*configs.Mount
for _, mm := range mounts {
dir, err := mm.GetThisCgroupDir()
if err != nil {
return err
}
binds = append(binds, &configs.Mount{
Device: "bind",
Source: filepath.Join(mm.Mountpoint, dir),
Destination: filepath.Join(m.Destination, strings.Join(mm.Subsystems, ",")),
Flags: syscall.MS_BIND | syscall.MS_REC | syscall.MS_RDONLY,
})
}
tmpfs := &configs.Mount{
Device: "tmpfs",
Source: "tmpfs",
Destination: m.Destination,
Flags: syscall.MS_NOEXEC | syscall.MS_NOSUID | syscall.MS_NODEV,
}
if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil {
return err
}
for _, b := range binds {
if err := mountToRootfs(b, rootfs, mountLabel); err != nil {
return err
}
}
default:
return fmt.Errorf("unknown mount device %q to %q", m.Device, m.Destination)
}
return nil
}
