Example #1
0
// setupNewMountNamespace is used to initialize a new mount namespace for an new
// container in the rootfs that is specified.
//
// There is no need to unmount the new mounts because as soon as the mount namespace
// is no longer in use, the mounts will be removed automatically
func setupNewMountNamespace(rootfs, console string, readonly bool) error {
	// mount as slave so that the new mounts do not propagate to the host
	if err := system.Mount("", "/", "", syscall.MS_SLAVE|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mounting / as slave %s", err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if readonly {
		if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_REC, ""); err != nil {
			return fmt.Errorf("mounting %s as readonly %s", rootfs, err)
		}
	}
	if err := mountSystem(rootfs); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := copyDevNodes(rootfs); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	// In non-privileged mode, this fails. Discard the error.
	setupLoopbackDevices(rootfs)
	if err := setupDev(rootfs); err != nil {
		return err
	}
	if console != "" {
		if err := setupPtmx(rootfs, console); err != nil {
			return err
		}
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	pivotDir, err := ioutil.TempDir(rootfs, ".pivot_root")
	if err != nil {
		return fmt.Errorf("can't create pivot_root dir %s", pivotDir, err)
	}
	if err := system.Pivotroot(rootfs, pivotDir); err != nil {
		return fmt.Errorf("pivot_root %s", err)
	}
	if err := system.Chdir("/"); err != nil {
		return fmt.Errorf("chdir / %s", err)
	}

	// path to pivot dir now changed, update
	pivotDir = filepath.Join("/", filepath.Base(pivotDir))

	if err := system.Unmount(pivotDir, syscall.MNT_DETACH); err != nil {
		return fmt.Errorf("unmount pivot_root dir %s", err)
	}

	if err := os.Remove(pivotDir); err != nil {
		return fmt.Errorf("remove pivot_root dir %s", err)
	}

	system.Umask(0022)

	return nil
}
Example #2
0
// FinalizeNamespace drops the caps, sets the correct user
// and working dir, and closes any leaky file descriptors
// before execing the command inside the namespace
func FinalizeNamespace(container *libcontainer.Container) error {
	if err := system.CloseFdsFrom(3); err != nil {
		return fmt.Errorf("close open file descriptors %s", err)
	}

	// drop capabilities in bounding set before changing user
	if err := capabilities.DropBoundingSet(container); err != nil {
		return fmt.Errorf("drop bounding set %s", err)
	}

	// preserve existing capabilities while we change users
	if err := system.SetKeepCaps(); err != nil {
		return fmt.Errorf("set keep caps %s", err)
	}

	if err := SetupUser(container.User); err != nil {
		return fmt.Errorf("setup user %s", err)
	}

	if err := system.ClearKeepCaps(); err != nil {
		return fmt.Errorf("clear keep caps %s", err)
	}

	// drop all other capabilities
	if err := capabilities.DropCapabilities(container); err != nil {
		return fmt.Errorf("drop capabilities %s", err)
	}

	if container.WorkingDir != "" {
		if err := system.Chdir(container.WorkingDir); err != nil {
			return fmt.Errorf("chdir to %s %s", container.WorkingDir, err)
		}
	}
	return nil
}
Example #3
0
// setupNewMountNamespace is used to initialize a new mount namespace for an new
// container in the rootfs that is specified.
//
// There is no need to unmount the new mounts because as soon as the mount namespace
// is no longer in use, the mounts will be removed automatically
func setupNewMountNamespace(rootfs, console string, readonly bool) error {
	// mount as slave so that the new mounts do not propagate to the host
	if err := system.Mount("", "/", "", syscall.MS_SLAVE|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mounting / as slave %s", err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if readonly {
		if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_REC, ""); err != nil {
			return fmt.Errorf("mounting %s as readonly %s", rootfs, err)
		}
	}
	if err := mountSystem(rootfs); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := copyDevNodes(rootfs); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	// In non-privileged mode, this fails. Discard the error.
	setupLoopbackDevices(rootfs)
	if err := setupDev(rootfs); err != nil {
		return err
	}
	if console != "" {
		if err := setupPtmx(rootfs, console); err != nil {
			return err
		}
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}
	if err := system.Mount(rootfs, "/", "", syscall.MS_MOVE, ""); err != nil {
		return fmt.Errorf("mount move %s into / %s", rootfs, err)
	}
	if err := system.Chroot("."); err != nil {
		return fmt.Errorf("chroot . %s", err)
	}
	if err := system.Chdir("/"); err != nil {
		return fmt.Errorf("chdir / %s", err)
	}

	system.Umask(0022)

	return nil
}
Example #4
0
func MsMoveRoot(rootfs string) error {
	if err := system.Mount(rootfs, "/", "", syscall.MS_MOVE, ""); err != nil {
		return fmt.Errorf("mount move %s into / %s", rootfs, err)
	}
	if err := system.Chroot("."); err != nil {
		return fmt.Errorf("chroot . %s", err)
	}
	return system.Chdir("/")
}
Example #5
0
// InitializeMountNamespace setups up the devices, mount points, and filesystems for use inside a
// new mount namepsace
func InitializeMountNamespace(rootfs, console string, container *libcontainer.Container) error {
	var (
		err  error
		flag = syscall.MS_PRIVATE
	)
	if container.NoPivotRoot {
		flag = syscall.MS_SLAVE
	}
	if err := system.Mount("", "/", "", uintptr(flag|syscall.MS_REC), ""); err != nil {
		return fmt.Errorf("mounting / with flags %X %s", (flag | syscall.MS_REC), err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if err := mountSystem(rootfs, container); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := setupBindmounts(rootfs, container.Mounts); err != nil {
		return fmt.Errorf("bind mounts %s", err)
	}
	if err := nodes.CopyN(rootfs, nodes.DefaultNodes, true); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	if err := nodes.CopyN(rootfs, nodes.AdditionalNodes, false); err != nil {
		return fmt.Errorf("copy additional dev nodes %s", err)
	}
	if err := SetupPtmx(rootfs, console, container.Context["mount_label"]); err != nil {
		return err
	}
	if err := setupDevSymlinks(rootfs); err != nil {
		return fmt.Errorf("dev symlinks %s", err)
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	if container.NoPivotRoot {
		err = MsMoveRoot(rootfs)
	} else {
		err = PivotRoot(rootfs)
	}
	if err != nil {
		return err
	}

	if container.ReadonlyFs {
		if err := SetReadonly(); err != nil {
			return fmt.Errorf("set readonly %s", err)
		}
	}

	system.Umask(0022)

	return nil
}
Example #6
0
// InitializeMountNamespace setups up the devices, mount points, and filesystems for use inside a
// new mount namepsace
func InitializeMountNamespace(rootfs, console string, container *libcontainer.Container) error {
	var (
		err  error
		flag = syscall.MS_PRIVATE
	)
	if container.NoPivotRoot {
		flag = syscall.MS_SLAVE
	}
	if err := system.Mount("", "/", "", uintptr(flag|syscall.MS_REC), ""); err != nil {
		return fmt.Errorf("mounting / as slave %s", err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if err := mountSystem(rootfs, container); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := setupBindmounts(rootfs, container.Mounts); err != nil {
		return fmt.Errorf("bind mounts %s", err)
	}
	if err := nodes.CopyN(rootfs, nodes.DefaultNodes); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	if restrictionPath := container.Context["restriction_path"]; restrictionPath != "" {
		if err := restrict.Restrict(rootfs, restrictionPath); err != nil {
			return fmt.Errorf("restrict %s", err)
		}
	}
	if err := SetupPtmx(rootfs, console, container.Context["mount_label"]); err != nil {
		return err
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	if container.NoPivotRoot {
		err = MsMoveRoot(rootfs)
	} else {
		err = PivotRoot(rootfs)
	}
	if err != nil {
		return err
	}

	if container.ReadonlyFs {
		if err := SetReadonly(); err != nil {
			return fmt.Errorf("set readonly %s", err)
		}
	}

	system.Umask(0022)

	return nil
}
Example #7
0
// InitializeMountNamespace sets up the devices, mount points, and filesystems for use inside a
// new mount namespace.
func InitializeMountNamespace(rootfs, console string, mountConfig *MountConfig) error {
	var (
		err  error
		flag = syscall.MS_PRIVATE
	)
	if mountConfig.NoPivotRoot {
		flag = syscall.MS_SLAVE
	}
	if err := system.Mount("", "/", "", uintptr(flag|syscall.MS_REC), ""); err != nil {
		return fmt.Errorf("mounting / with flags %X %s", (flag | syscall.MS_REC), err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if err := mountSystem(rootfs, mountConfig); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := setupBindmounts(rootfs, mountConfig); err != nil {
		return fmt.Errorf("bind mounts %s", err)
	}
	if err := nodes.CreateDeviceNodes(rootfs, mountConfig.DeviceNodes); err != nil {
		return fmt.Errorf("create device nodes %s", err)
	}
	if err := SetupPtmx(rootfs, console, mountConfig.MountLabel); err != nil {
		return err
	}
	if err := setupDevSymlinks(rootfs); err != nil {
		return fmt.Errorf("dev symlinks %s", err)
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	if mountConfig.NoPivotRoot {
		err = MsMoveRoot(rootfs)
	} else {
		err = PivotRoot(rootfs)
	}
	if err != nil {
		return err
	}

	if mountConfig.ReadonlyFs {
		if err := SetReadonly(); err != nil {
			return fmt.Errorf("set readonly %s", err)
		}
	}

	system.Umask(0022)

	return nil
}
Example #8
0
// finalizeNamespace drops the caps and sets the correct user
// and working dir before execing the command inside the namespace
func finalizeNamespace(container *libcontainer.Container) error {
	if err := capabilities.DropCapabilities(container); err != nil {
		return fmt.Errorf("drop capabilities %s", err)
	}
	if err := setupUser(container); err != nil {
		return fmt.Errorf("setup user %s", err)
	}
	if container.WorkingDir != "" {
		if err := system.Chdir(container.WorkingDir); err != nil {
			return fmt.Errorf("chdir to %s %s", container.WorkingDir, err)
		}
	}
	return nil
}
Example #9
0
// setupNewMountNamespace is used to initialize a new mount namespace for an new
// container in the rootfs that is specified.
//
// There is no need to unmount the new mounts because as soon as the mount namespace
// is no longer in use, the mounts will be removed automatically
func setupNewMountNamespace(rootfs, console string, readonly, noPivotRoot bool) error {
	flag := syscall.MS_PRIVATE
	if noPivotRoot {
		flag = syscall.MS_SLAVE
	}
	if err := system.Mount("", "/", "", uintptr(flag|syscall.MS_REC), ""); err != nil {
		return fmt.Errorf("mounting / as slave %s", err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if readonly {
		if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_REC, ""); err != nil {
			return fmt.Errorf("mounting %s as readonly %s", rootfs, err)
		}
	}
	if err := mountSystem(rootfs); err != nil {
		return fmt.Errorf("mount system %s", err)
	}
	if err := copyDevNodes(rootfs); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	// In non-privileged mode, this fails. Discard the error.
	setupLoopbackDevices(rootfs)
	if err := setupDev(rootfs); err != nil {
		return err
	}
	if console != "" {
		if err := setupPtmx(rootfs, console); err != nil {
			return err
		}
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	if noPivotRoot {
		if err := rootMsMove(rootfs); err != nil {
			return err
		}
	} else {
		if err := rootPivot(rootfs); err != nil {
			return err
		}
	}

	system.Umask(0022)

	return nil
}
Example #10
0
// FinalizeNamespace drops the caps, sets the correct user
// and working dir, and closes any leaky file descriptors
// before execing the command inside the namespace
func FinalizeNamespace(container *libcontainer.Container) error {
	if err := capabilities.DropCapabilities(container); err != nil {
		return fmt.Errorf("drop capabilities %s", err)
	}
	if err := system.CloseFdsFrom(3); err != nil {
		return fmt.Errorf("close open file descriptors %s", err)
	}
	if err := SetupUser(container.User); err != nil {
		return fmt.Errorf("setup user %s", err)
	}
	if container.WorkingDir != "" {
		if err := system.Chdir(container.WorkingDir); err != nil {
			return fmt.Errorf("chdir to %s %s", container.WorkingDir, err)
		}
	}
	return nil
}
Example #11
0
func PivotRoot(rootfs string) error {
	pivotDir, err := ioutil.TempDir(rootfs, ".pivot_root")
	if err != nil {
		return fmt.Errorf("can't create pivot_root dir %s", pivotDir, err)
	}
	if err := system.Pivotroot(rootfs, pivotDir); err != nil {
		return fmt.Errorf("pivot_root %s", err)
	}
	if err := system.Chdir("/"); err != nil {
		return fmt.Errorf("chdir / %s", err)
	}
	// path to pivot dir now changed, update
	pivotDir = filepath.Join("/", filepath.Base(pivotDir))
	if err := system.Unmount(pivotDir, syscall.MNT_DETACH); err != nil {
		return fmt.Errorf("unmount pivot_root dir %s", err)
	}
	return os.Remove(pivotDir)
}
Example #12
0
// FinalizeNamespace drops the caps, sets the correct user
// and working dir, and closes any leaky file descriptors
// before execing the command inside the namespace
func FinalizeNamespace(container *libcontainer.Config) error {
	// Ensure that all non-standard fds we may have accidentally
	// inherited are marked close-on-exec so they stay out of the
	// container
	if err := utils.CloseExecFrom(3); err != nil {
		return fmt.Errorf("close open file descriptors %s", err)
	}

	// drop capabilities in bounding set before changing user
	if err := capabilities.DropBoundingSet(container.Capabilities); err != nil {
		return fmt.Errorf("drop bounding set %s", err)
	}

	// preserve existing capabilities while we change users
	if err := system.SetKeepCaps(); err != nil {
		return fmt.Errorf("set keep caps %s", err)
	}

	if err := SetupUser(container.User); err != nil {
		return fmt.Errorf("setup user %s", err)
	}

	if err := system.ClearKeepCaps(); err != nil {
		return fmt.Errorf("clear keep caps %s", err)
	}

	// drop all other capabilities
	if err := capabilities.DropCapabilities(container.Capabilities); err != nil {
		return fmt.Errorf("drop capabilities %s", err)
	}

	if container.WorkingDir != "" {
		if err := system.Chdir(container.WorkingDir); err != nil {
			return fmt.Errorf("chdir to %s %s", container.WorkingDir, err)
		}
	}

	return nil
}
Example #13
0
// setupNewMountNamespace is used to initialize a new mount namespace for an new
// container in the rootfs that is specified.
//
// There is no need to unmount the new mounts because as soon as the mount namespace
// is no longer in use, the mounts will be removed automatically
func setupNewMountNamespace(rootfs string, bindMounts []libcontainer.Mount, console string, readonly, noPivotRoot bool, mountLabel string) error {
	flag := syscall.MS_PRIVATE
	if noPivotRoot {
		flag = syscall.MS_SLAVE
	}
	if err := system.Mount("", "/", "", uintptr(flag|syscall.MS_REC), ""); err != nil {
		return fmt.Errorf("mounting / as slave %s", err)
	}
	if err := system.Mount(rootfs, rootfs, "bind", syscall.MS_BIND|syscall.MS_REC, ""); err != nil {
		return fmt.Errorf("mouting %s as bind %s", rootfs, err)
	}
	if err := mountSystem(rootfs, mountLabel); err != nil {
		return fmt.Errorf("mount system %s", err)
	}

	for _, m := range bindMounts {
		flags := syscall.MS_BIND | syscall.MS_REC
		if !m.Writable {
			flags = flags | syscall.MS_RDONLY
		}
		dest := filepath.Join(rootfs, m.Destination)
		if err := system.Mount(m.Source, dest, "bind", uintptr(flags), ""); err != nil {
			return fmt.Errorf("mounting %s into %s %s", m.Source, dest, err)
		}
		if m.Private {
			if err := system.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return fmt.Errorf("mounting %s private %s", dest, err)
			}
		}
	}

	if err := copyDevNodes(rootfs); err != nil {
		return fmt.Errorf("copy dev nodes %s", err)
	}
	// In non-privileged mode, this fails. Discard the error.
	setupLoopbackDevices(rootfs)
	if err := setupPtmx(rootfs, console, mountLabel); err != nil {
		return err
	}
	if err := system.Chdir(rootfs); err != nil {
		return fmt.Errorf("chdir into %s %s", rootfs, err)
	}

	if noPivotRoot {
		if err := rootMsMove(rootfs); err != nil {
			return err
		}
	} else {
		if err := rootPivot(rootfs); err != nil {
			return err
		}
	}

	if readonly {
		if err := system.Mount("/", "/", "bind", syscall.MS_BIND|syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_REC, ""); err != nil {
			return fmt.Errorf("mounting %s as readonly %s", rootfs, err)
		}
	}

	system.Umask(0022)

	return nil
}