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Diffstat (limited to 'pkg/sentry/syscalls/linux/sys_xattr.go')
-rw-r--r--pkg/sentry/syscalls/linux/sys_xattr.go152
1 files changed, 112 insertions, 40 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go
index 97d9a65ea..e35c077d6 100644
--- a/pkg/sentry/syscalls/linux/sys_xattr.go
+++ b/pkg/sentry/syscalls/linux/sys_xattr.go
@@ -25,12 +25,46 @@ import (
"gvisor.dev/gvisor/pkg/syserror"
)
-// Getxattr implements linux syscall getxattr(2).
-func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+// GetXattr implements linux syscall getxattr(2).
+func GetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getXattrFromPath(t, args, true)
+}
+
+// LGetXattr implements linux syscall lgetxattr(2).
+func LGetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getXattrFromPath(t, args, false)
+}
+
+// FGetXattr implements linux syscall fgetxattr(2).
+func FGetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := uint64(args[3].SizeT())
+
+ // TODO(b/113957122): Return EBADF if the fd was opened with O_PATH.
+ f := t.GetFile(fd)
+ if f == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer f.DecRef()
+
+ n, value, err := getXattr(t, f.Dirent, nameAddr, size)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ if _, err := t.CopyOutBytes(valueAddr, []byte(value)); err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+func getXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink bool) (uintptr, *kernel.SyscallControl, error) {
pathAddr := args[0].Pointer()
nameAddr := args[1].Pointer()
valueAddr := args[2].Pointer()
- size := args[3].SizeT()
+ size := uint64(args[3].SizeT())
path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */)
if err != nil {
@@ -38,21 +72,15 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
}
valueLen := 0
- err = fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
- value, err := getxattr(t, d, dirPath, nameAddr)
- if err != nil {
- return err
+ err = fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
+ if dirPath && !fs.IsDir(d.Inode.StableAttr) {
+ return syserror.ENOTDIR
}
- valueLen = len(value)
- if size == 0 {
- return nil
- }
- if size > linux.XATTR_SIZE_MAX {
- size = linux.XATTR_SIZE_MAX
- }
- if valueLen > int(size) {
- return syserror.ERANGE
+ n, value, err := getXattr(t, d, nameAddr, size)
+ valueLen = n
+ if err != nil {
+ return err
}
_, err = t.CopyOutBytes(valueAddr, []byte(value))
@@ -64,34 +92,78 @@ func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
return uintptr(valueLen), nil, nil
}
-// getxattr implements getxattr from the given *fs.Dirent.
-func getxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr usermem.Addr) (string, error) {
- if dirPath && !fs.IsDir(d.Inode.StableAttr) {
- return "", syserror.ENOTDIR
- }
-
+// getXattr implements getxattr(2) from the given *fs.Dirent.
+func getXattr(t *kernel.Task, d *fs.Dirent, nameAddr usermem.Addr, size uint64) (int, string, error) {
if err := checkXattrPermissions(t, d.Inode, fs.PermMask{Read: true}); err != nil {
- return "", err
+ return 0, "", err
}
name, err := copyInXattrName(t, nameAddr)
if err != nil {
- return "", err
+ return 0, "", err
}
if !strings.HasPrefix(name, linux.XATTR_USER_PREFIX) {
- return "", syserror.EOPNOTSUPP
+ return 0, "", syserror.EOPNOTSUPP
+ }
+
+ // If getxattr(2) is called with size 0, the size of the value will be
+ // returned successfully even if it is nonzero. In that case, we need to
+ // retrieve the entire attribute value so we can return the correct size.
+ requestedSize := size
+ if size == 0 || size > linux.XATTR_SIZE_MAX {
+ requestedSize = linux.XATTR_SIZE_MAX
+ }
+
+ value, err := d.Inode.GetXattr(t, name, requestedSize)
+ if err != nil {
+ return 0, "", err
}
+ n := len(value)
+ if uint64(n) > requestedSize {
+ return 0, "", syserror.ERANGE
+ }
+
+ // Don't copy out the attribute value if size is 0.
+ if size == 0 {
+ return n, "", nil
+ }
+ return n, value, nil
+}
+
+// SetXattr implements linux syscall setxattr(2).
+func SetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return setXattrFromPath(t, args, true)
+}
- return d.Inode.Getxattr(name)
+// LSetXattr implements linux syscall lsetxattr(2).
+func LSetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return setXattrFromPath(t, args, false)
}
-// Setxattr implements linux syscall setxattr(2).
-func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+// FSetXattr implements linux syscall fsetxattr(2).
+func FSetXattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := uint64(args[3].SizeT())
+ flags := args[4].Uint()
+
+ // TODO(b/113957122): Return EBADF if the fd was opened with O_PATH.
+ f := t.GetFile(fd)
+ if f == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer f.DecRef()
+
+ return 0, nil, setXattr(t, f.Dirent, nameAddr, valueAddr, uint64(size), flags)
+}
+
+func setXattrFromPath(t *kernel.Task, args arch.SyscallArguments, resolveSymlink bool) (uintptr, *kernel.SyscallControl, error) {
pathAddr := args[0].Pointer()
nameAddr := args[1].Pointer()
valueAddr := args[2].Pointer()
- size := args[3].SizeT()
+ size := uint64(args[3].SizeT())
flags := args[4].Uint()
path, dirPath, err := copyInPath(t, pathAddr, false /* allowEmpty */)
@@ -99,19 +171,19 @@ func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
return 0, nil, err
}
- if flags&^(linux.XATTR_CREATE|linux.XATTR_REPLACE) != 0 {
- return 0, nil, syserror.EINVAL
- }
+ return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, resolveSymlink, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
+ if dirPath && !fs.IsDir(d.Inode.StableAttr) {
+ return syserror.ENOTDIR
+ }
- return 0, nil, fileOpOn(t, linux.AT_FDCWD, path, true /* resolve */, func(root *fs.Dirent, d *fs.Dirent, _ uint) error {
- return setxattr(t, d, dirPath, nameAddr, valueAddr, size, flags)
+ return setXattr(t, d, nameAddr, valueAddr, uint64(size), flags)
})
}
-// setxattr implements setxattr from the given *fs.Dirent.
-func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr usermem.Addr, size uint, flags uint32) error {
- if dirPath && !fs.IsDir(d.Inode.StableAttr) {
- return syserror.ENOTDIR
+// setXattr implements setxattr(2) from the given *fs.Dirent.
+func setXattr(t *kernel.Task, d *fs.Dirent, nameAddr, valueAddr usermem.Addr, size uint64, flags uint32) error {
+ if flags&^(linux.XATTR_CREATE|linux.XATTR_REPLACE) != 0 {
+ return syserror.EINVAL
}
if err := checkXattrPermissions(t, d.Inode, fs.PermMask{Write: true}); err != nil {
@@ -127,7 +199,7 @@ func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr us
return syserror.E2BIG
}
buf := make([]byte, size)
- if _, err = t.CopyInBytes(valueAddr, buf); err != nil {
+ if _, err := t.CopyInBytes(valueAddr, buf); err != nil {
return err
}
value := string(buf)
@@ -136,7 +208,7 @@ func setxattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr us
return syserror.EOPNOTSUPP
}
- return d.Inode.Setxattr(name, value)
+ return d.Inode.SetXattr(t, d, name, value, flags)
}
func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 03:30:58 +0000