diff options
Diffstat (limited to 'internal')
| -rw-r--r-- | internal/syscallcompat/sys_freebsd.go | 31 |
1 files changed, 1 insertions, 30 deletions
diff --git a/internal/syscallcompat/sys_freebsd.go b/internal/syscallcompat/sys_freebsd.go index 874e920..51884a9 100644 --- a/internal/syscallcompat/sys_freebsd.go +++ b/internal/syscallcompat/sys_freebsd.go @@ -63,37 +63,8 @@ func Dup3(oldfd int, newfd int, flags int) (err error) { } // FchmodatNofollow is like Fchmodat but never follows symlinks. -// -// This should be handled by the AT_SYMLINK_NOFOLLOW flag, but Linux -// does not implement it, so we have to perform an elaborate dance -// with O_PATH and /proc/self/fd. -// -// See also: Qemu implemented the same logic as fchmodat_nofollow(): -// https://git.qemu.org/?p=qemu.git;a=blob;f=hw/9pfs/9p-local.c#l335 func FchmodatNofollow(dirfd int, path string, mode uint32) (err error) { - // Open handle to the filename (but without opening the actual file). - // This succeeds even when we don't have read permissions to the file. - fd, err := unix.Openat(dirfd, path, unix.O_NOFOLLOW|O_PATH, 0) - if err != nil { - return err - } - defer unix.Close(fd) - - // Now we can check the type without the risk of race-conditions. - // Return syscall.ELOOP if it is a symlink. - var st unix.Stat_t - err = unix.Fstat(fd, &st) - if err != nil { - return err - } - if st.Mode&unix.S_IFMT == unix.S_IFLNK { - return unix.ELOOP - } - - // Change mode of the actual file. Fchmod does not work with O_PATH, - // but Chmod via /proc/self/fd works. - procPath := fmt.Sprintf("/proc/self/fd/%d", fd) - return unix.Chmod(procPath, mode) + return unix.Fchmodat(dirfd, path, mode, unix.AT_SYMLINK_NOFOLLOW); } // LsetxattrUser runs the Lsetxattr syscall in the context of a different user. |