diff options
| -rw-r--r-- | internal/syscallcompat/sys_darwin.go | 71 |
1 files changed, 56 insertions, 15 deletions
diff --git a/internal/syscallcompat/sys_darwin.go b/internal/syscallcompat/sys_darwin.go index 5c855d8..a260db6 100644 --- a/internal/syscallcompat/sys_darwin.go +++ b/internal/syscallcompat/sys_darwin.go @@ -2,6 +2,7 @@ package syscallcompat import ( "log" + "runtime" "syscall" "golang.org/x/sys/unix" @@ -16,8 +17,22 @@ const ( // O_PATH is only defined on Linux O_PATH = 0 + + // KAUTH_UID_NONE and KAUTH_GID_NONE are special values to + // revert permissions to the process credentials. + KAUTH_UID_NONE = ^uint32(0) - 100 + KAUTH_GID_NONE = ^uint32(0) - 100 ) +// Unfortunately pthread_setugid_np does not have a syscall wrapper yet. +func pthread_setugid_np(uid uint32, gid uint32) (err error) { + _, _, e1 := syscall.RawSyscall(syscall.SYS_SETTID, uintptr(uid), uintptr(gid), 0) + if e1 != 0 { + err = e1 + } + return +} + // Sorry, fallocate is not available on OSX at all and // fcntl F_PREALLOCATE is not accessible from Go. // See https://github.com/rfjakob/gocryptfs/issues/18 if you want to help. @@ -47,9 +62,16 @@ func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) } func OpenatUser(dirfd int, path string, flags int, mode uint32, context *fuse.Context) (fd int, err error) { - // FIXME: take into account context.Owner - // Until we have that, filter SUID and SGID bits: - mode = filterSuidSgid(mode) + if context != nil { + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + err = pthread_setugid_np(context.Owner.Uid, context.Owner.Gid) + if err != nil { + return -1, err + } + defer pthread_setugid_np(KAUTH_UID_NONE, KAUTH_GID_NONE) + } return Openat(dirfd, path, flags, mode) } @@ -67,9 +89,16 @@ func Mknodat(dirfd int, path string, mode uint32, dev int) (err error) { } func MknodatUser(dirfd int, path string, mode uint32, dev int, context *fuse.Context) (err error) { - // FIXME: take into account context.Owner - // Until we have that, filter SUID and SGID bits: - mode = filterSuidSgid(mode) + if context != nil { + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + err = pthread_setugid_np(context.Owner.Uid, context.Owner.Gid) + if err != nil { + return err + } + defer pthread_setugid_np(KAUTH_UID_NONE, KAUTH_GID_NONE) + } return Mknodat(dirfd, path, mode, dev) } @@ -87,7 +116,17 @@ func Symlinkat(oldpath string, newdirfd int, newpath string) (err error) { } func SymlinkatUser(oldpath string, newdirfd int, newpath string, context *fuse.Context) (err error) { - // FIXME: take into account context.Owner + if context != nil { + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + err = pthread_setugid_np(context.Owner.Uid, context.Owner.Gid) + if err != nil { + return err + } + defer pthread_setugid_np(KAUTH_UID_NONE, KAUTH_GID_NONE) + } + return Symlinkat(oldpath, newdirfd, newpath) } @@ -96,9 +135,16 @@ func Mkdirat(dirfd int, path string, mode uint32) (err error) { } func MkdiratUser(dirfd int, path string, mode uint32, context *fuse.Context) (err error) { - // FIXME: take into account context.Owner - // Until we have that, filter SUID and SGID bits: - mode = filterSuidSgid(mode) + if context != nil { + runtime.LockOSThread() + defer runtime.UnlockOSThread() + + err = pthread_setugid_np(context.Owner.Uid, context.Owner.Gid) + if err != nil { + return err + } + defer pthread_setugid_np(KAUTH_UID_NONE, KAUTH_GID_NONE) + } return Mkdirat(dirfd, path, mode) } @@ -110,8 +156,3 @@ func Fstatat(dirfd int, path string, stat *unix.Stat_t, flags int) (err error) { func Getdents(fd int) ([]fuse.DirEntry, error) { return emulateGetdents(fd) } - -// filterSuidSgid removes SUID and SGID bits from "mode". -func filterSuidSgid(mode uint32) uint32 { - return mode & ^uint32(syscall.S_ISGID|syscall.S_ISUID) -} |