package syscallcompat import ( "log" "runtime" "syscall" "golang.org/x/sys/unix" "github.com/hanwen/go-fuse/fuse" "github.com/rfjakob/gocryptfs/internal/tlog" ) const ( // O_DIRECT means oncached I/O on Linux. No direct equivalent on MacOS and defined // to zero there. O_DIRECT = 0 // 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. func EnospcPrealloc(fd int, off int64, len int64) error { return nil } // See above. func Fallocate(fd int, mode uint32, off int64, len int64) error { return syscall.EOPNOTSUPP } // Dup3 is not available on Darwin, so we use Dup2 instead. func Dup3(oldfd int, newfd int, flags int) (err error) { if flags != 0 { log.Panic("darwin does not support dup3 flags") } return syscall.Dup2(oldfd, newfd) } //////////////////////////////////////////////////////// //// Emulated Syscalls (see emulate.go) //////////////// //////////////////////////////////////////////////////// func OpenatUser(dirfd int, path string, flags int, mode uint32, context *fuse.Context) (fd int, err error) { 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) } func Mknodat(dirfd int, path string, mode uint32, dev int) (err error) { return emulateMknodat(dirfd, path, mode, dev) } func MknodatUser(dirfd int, path string, mode uint32, dev int, context *fuse.Context) (err error) { 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) } func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) { // Why would we ever want to call this without AT_SYMLINK_NOFOLLOW? if flags&unix.AT_SYMLINK_NOFOLLOW == 0 { tlog.Warn.Printf("Fchmodat: adding missing AT_SYMLINK_NOFOLLOW flag") flags |= unix.AT_SYMLINK_NOFOLLOW } return unix.Fchmodat(dirfd, path, mode, flags) } func SymlinkatUser(oldpath string, newdirfd int, newpath string, context *fuse.Context) (err error) { 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) } func Mkdirat(dirfd int, path string, mode uint32) (err error) { return emulateMkdirat(dirfd, path, mode) } func MkdiratUser(dirfd int, path string, mode uint32, context *fuse.Context) (err error) { 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) } func Fstatat(dirfd int, path string, stat *unix.Stat_t, flags int) (err error) { return emulateFstatat(dirfd, path, stat, flags) } func Getdents(fd int) ([]fuse.DirEntry, error) { return emulateGetdents(fd) }