vendor: update containers/storage

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
This commit is contained in:
Giuseppe Scrivano
2023-01-30 10:27:03 +01:00
parent 68bbdc283f
commit 427d69cc32
14 changed files with 117 additions and 68 deletions

View File

@@ -12,6 +12,7 @@ import (
"syscall"
"github.com/containers/storage/pkg/archive"
"github.com/containers/storage/pkg/idmap"
"github.com/containers/storage/pkg/idtools"
"github.com/containers/storage/pkg/ioutils"
"github.com/containers/storage/pkg/mount"
@@ -243,20 +244,20 @@ func supportsIdmappedLowerLayers(home string) (bool, error) {
_ = idtools.MkdirAs(upperDir, 0700, 0, 0)
_ = idtools.MkdirAs(workDir, 0700, 0, 0)
idmap := []idtools.IDMap{
mapping := []idtools.IDMap{
{
ContainerID: 0,
HostID: 0,
Size: 1,
},
}
pid, cleanupFunc, err := createUsernsProcess(idmap, idmap)
pid, cleanupFunc, err := idmap.CreateUsernsProcess(mapping, mapping)
if err != nil {
return false, err
}
defer cleanupFunc()
if err := createIDMappedMount(lowerDir, lowerMappedDir, int(pid)); err != nil {
if err := idmap.CreateIDMappedMount(lowerDir, lowerMappedDir, int(pid)); err != nil {
return false, fmt.Errorf("create mapped mount: %w", err)
}
defer unix.Unmount(lowerMappedDir, unix.MNT_DETACH)

View File

@@ -1,155 +0,0 @@
//go:build linux
// +build linux
package overlay
import (
"fmt"
"os"
"runtime"
"syscall"
"unsafe"
"github.com/containers/storage/pkg/idtools"
"golang.org/x/sys/unix"
)
type attr struct {
attrSet uint64
attrClr uint64
propagation uint64
userNs uint64
}
// openTree is a wrapper for the open_tree syscall
func openTree(path string, flags int) (fd int, err error) {
var _p0 *byte
if _p0, err = syscall.BytePtrFromString(path); err != nil {
return 0, err
}
r, _, e1 := syscall.Syscall6(uintptr(unix.SYS_OPEN_TREE), uintptr(0), uintptr(unsafe.Pointer(_p0)),
uintptr(flags), 0, 0, 0)
if e1 != 0 {
err = e1
}
return int(r), nil
}
// moveMount is a wrapper for the the move_mount syscall.
func moveMount(fdTree int, target string) (err error) {
var _p0, _p1 *byte
empty := ""
if _p0, err = syscall.BytePtrFromString(target); err != nil {
return err
}
if _p1, err = syscall.BytePtrFromString(empty); err != nil {
return err
}
flags := unix.MOVE_MOUNT_F_EMPTY_PATH
_, _, e1 := syscall.Syscall6(uintptr(unix.SYS_MOVE_MOUNT),
uintptr(fdTree), uintptr(unsafe.Pointer(_p1)),
0, uintptr(unsafe.Pointer(_p0)), uintptr(flags), 0)
if e1 != 0 {
err = e1
}
return
}
// mountSetAttr is a wrapper for the mount_setattr syscall
func mountSetAttr(dfd int, path string, flags uint, attr *attr, size uint) (err error) {
var _p0 *byte
if _p0, err = syscall.BytePtrFromString(path); err != nil {
return err
}
_, _, e1 := syscall.Syscall6(uintptr(unix.SYS_MOUNT_SETATTR), uintptr(dfd), uintptr(unsafe.Pointer(_p0)),
uintptr(flags), uintptr(unsafe.Pointer(attr)), uintptr(size), 0)
if e1 != 0 {
err = e1
}
return
}
// createIDMappedMount creates a IDMapped bind mount from SOURCE to TARGET using the user namespace
// for the PID process.
func createIDMappedMount(source, target string, pid int) error {
path := fmt.Sprintf("/proc/%d/ns/user", pid)
userNsFile, err := os.Open(path)
if err != nil {
return fmt.Errorf("unable to get user ns file descriptor for %q: %w", path, err)
}
var attr attr
attr.attrSet = unix.MOUNT_ATTR_IDMAP
attr.attrClr = 0
attr.propagation = 0
attr.userNs = uint64(userNsFile.Fd())
defer userNsFile.Close()
targetDirFd, err := openTree(source, unix.OPEN_TREE_CLONE)
if err != nil {
return err
}
defer unix.Close(targetDirFd)
if err := mountSetAttr(targetDirFd, "", unix.AT_EMPTY_PATH|unix.AT_RECURSIVE,
&attr, uint(unsafe.Sizeof(attr))); err != nil {
return err
}
if err := os.Mkdir(target, 0700); err != nil && !os.IsExist(err) {
return err
}
return moveMount(targetDirFd, target)
}
// createUsernsProcess forks the current process and creates a user namespace using the specified
// mappings. It returns the pid of the new process.
func createUsernsProcess(uidMaps []idtools.IDMap, gidMaps []idtools.IDMap) (int, func(), error) {
var pid uintptr
var err syscall.Errno
if runtime.GOARCH == "s390x" {
pid, _, err = syscall.Syscall6(uintptr(unix.SYS_CLONE), 0, unix.CLONE_NEWUSER|uintptr(unix.SIGCHLD), 0, 0, 0, 0)
} else {
pid, _, err = syscall.Syscall6(uintptr(unix.SYS_CLONE), unix.CLONE_NEWUSER|uintptr(unix.SIGCHLD), 0, 0, 0, 0, 0)
}
if err != 0 {
return -1, nil, err
}
if pid == 0 {
_ = unix.Prctl(unix.PR_SET_PDEATHSIG, uintptr(unix.SIGKILL), 0, 0, 0)
// just wait for the SIGKILL
for {
syscall.Pause()
}
}
cleanupFunc := func() {
unix.Kill(int(pid), unix.SIGKILL)
_, _ = unix.Wait4(int(pid), nil, 0, nil)
}
writeMappings := func(fname string, idmap []idtools.IDMap) error {
mappings := ""
for _, m := range idmap {
mappings = mappings + fmt.Sprintf("%d %d %d\n", m.ContainerID, m.HostID, m.Size)
}
return os.WriteFile(fmt.Sprintf("/proc/%d/%s", pid, fname), []byte(mappings), 0600)
}
if err := writeMappings("uid_map", uidMaps); err != nil {
cleanupFunc()
return -1, nil, err
}
if err := writeMappings("gid_map", gidMaps); err != nil {
cleanupFunc()
return -1, nil, err
}
return int(pid), cleanupFunc, nil
}

View File

@@ -26,6 +26,7 @@ import (
"github.com/containers/storage/pkg/chrootarchive"
"github.com/containers/storage/pkg/directory"
"github.com/containers/storage/pkg/fsutils"
"github.com/containers/storage/pkg/idmap"
"github.com/containers/storage/pkg/idtools"
"github.com/containers/storage/pkg/mount"
"github.com/containers/storage/pkg/parsers"
@@ -1511,7 +1512,7 @@ func (d *Driver) get(id string, disableShifting bool, options graphdriver.MountO
return "", err
}
pid, cleanupFunc, err := createUsernsProcess(options.UidMaps, options.GidMaps)
pid, cleanupFunc, err := idmap.CreateUsernsProcess(options.UidMaps, options.GidMaps)
if err != nil {
return "", err
}
@@ -1528,7 +1529,7 @@ func (d *Driver) get(id string, disableShifting bool, options graphdriver.MountO
if !found {
root = filepath.Join(mappedRoot, fmt.Sprintf("%d", c))
c++
if err := createIDMappedMount(mappedMountSrc, root, int(pid)); err != nil {
if err := idmap.CreateIDMappedMount(mappedMountSrc, root, int(pid)); err != nil {
return "", fmt.Errorf("create mapped mount for %q on %q: %w", mappedMountSrc, root, err)
}
idMappedMounts[mappedMountSrc] = root