1// Copyright 2009 The Go Authors. All rights reserved.
  2// Use of this source code is governed by a BSD-style
  3// license that can be found in the LICENSE file.
  4
  5//go:build darwin || dragonfly || freebsd || netbsd || openbsd
  6
  7// BSD system call wrappers shared by *BSD based systems
  8// including OS X (Darwin) and FreeBSD.  Like the other
  9// syscall_*.go files it is compiled as Go code but also
 10// used as input to mksyscall which parses the //sys
 11// lines and generates system call stubs.
 12
 13package unix
 14
 15import (
 16	"runtime"
 17	"syscall"
 18	"unsafe"
 19)
 20
 21const ImplementsGetwd = true
 22
 23func Getwd() (string, error) {
 24	var buf [PathMax]byte
 25	_, err := Getcwd(buf[0:])
 26	if err != nil {
 27		return "", err
 28	}
 29	n := clen(buf[:])
 30	if n < 1 {
 31		return "", EINVAL
 32	}
 33	return string(buf[:n]), nil
 34}
 35
 36/*
 37 * Wrapped
 38 */
 39
 40//sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)
 41//sysnb	setgroups(ngid int, gid *_Gid_t) (err error)
 42
 43func Getgroups() (gids []int, err error) {
 44	n, err := getgroups(0, nil)
 45	if err != nil {
 46		return nil, err
 47	}
 48	if n == 0 {
 49		return nil, nil
 50	}
 51
 52	// Sanity check group count. Max is 16 on BSD.
 53	if n < 0 || n > 1000 {
 54		return nil, EINVAL
 55	}
 56
 57	a := make([]_Gid_t, n)
 58	n, err = getgroups(n, &a[0])
 59	if err != nil {
 60		return nil, err
 61	}
 62	gids = make([]int, n)
 63	for i, v := range a[0:n] {
 64		gids[i] = int(v)
 65	}
 66	return
 67}
 68
 69func Setgroups(gids []int) (err error) {
 70	if len(gids) == 0 {
 71		return setgroups(0, nil)
 72	}
 73
 74	a := make([]_Gid_t, len(gids))
 75	for i, v := range gids {
 76		a[i] = _Gid_t(v)
 77	}
 78	return setgroups(len(a), &a[0])
 79}
 80
 81// Wait status is 7 bits at bottom, either 0 (exited),
 82// 0x7F (stopped), or a signal number that caused an exit.
 83// The 0x80 bit is whether there was a core dump.
 84// An extra number (exit code, signal causing a stop)
 85// is in the high bits.
 86
 87type WaitStatus uint32
 88
 89const (
 90	mask  = 0x7F
 91	core  = 0x80
 92	shift = 8
 93
 94	exited  = 0
 95	killed  = 9
 96	stopped = 0x7F
 97)
 98
 99func (w WaitStatus) Exited() bool { return w&mask == exited }
100
101func (w WaitStatus) ExitStatus() int {
102	if w&mask != exited {
103		return -1
104	}
105	return int(w >> shift)
106}
107
108func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
109
110func (w WaitStatus) Signal() syscall.Signal {
111	sig := syscall.Signal(w & mask)
112	if sig == stopped || sig == 0 {
113		return -1
114	}
115	return sig
116}
117
118func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
119
120func (w WaitStatus) Stopped() bool { return w&mask == stopped && syscall.Signal(w>>shift) != SIGSTOP }
121
122func (w WaitStatus) Killed() bool { return w&mask == killed && syscall.Signal(w>>shift) != SIGKILL }
123
124func (w WaitStatus) Continued() bool { return w&mask == stopped && syscall.Signal(w>>shift) == SIGSTOP }
125
126func (w WaitStatus) StopSignal() syscall.Signal {
127	if !w.Stopped() {
128		return -1
129	}
130	return syscall.Signal(w>>shift) & 0xFF
131}
132
133func (w WaitStatus) TrapCause() int { return -1 }
134
135//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
136
137func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
138	var status _C_int
139	wpid, err = wait4(pid, &status, options, rusage)
140	if wstatus != nil {
141		*wstatus = WaitStatus(status)
142	}
143	return
144}
145
146//sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
147//sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
148//sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
149//sysnb	socket(domain int, typ int, proto int) (fd int, err error)
150//sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
151//sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
152//sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
153//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
154//sys	Shutdown(s int, how int) (err error)
155
156func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
157	if sa.Port < 0 || sa.Port > 0xFFFF {
158		return nil, 0, EINVAL
159	}
160	sa.raw.Len = SizeofSockaddrInet4
161	sa.raw.Family = AF_INET
162	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
163	p[0] = byte(sa.Port >> 8)
164	p[1] = byte(sa.Port)
165	sa.raw.Addr = sa.Addr
166	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
167}
168
169func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
170	if sa.Port < 0 || sa.Port > 0xFFFF {
171		return nil, 0, EINVAL
172	}
173	sa.raw.Len = SizeofSockaddrInet6
174	sa.raw.Family = AF_INET6
175	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
176	p[0] = byte(sa.Port >> 8)
177	p[1] = byte(sa.Port)
178	sa.raw.Scope_id = sa.ZoneId
179	sa.raw.Addr = sa.Addr
180	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
181}
182
183func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
184	name := sa.Name
185	n := len(name)
186	if n >= len(sa.raw.Path) || n == 0 {
187		return nil, 0, EINVAL
188	}
189	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
190	sa.raw.Family = AF_UNIX
191	for i := 0; i < n; i++ {
192		sa.raw.Path[i] = int8(name[i])
193	}
194	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
195}
196
197func (sa *SockaddrDatalink) sockaddr() (unsafe.Pointer, _Socklen, error) {
198	if sa.Index == 0 {
199		return nil, 0, EINVAL
200	}
201	sa.raw.Len = sa.Len
202	sa.raw.Family = AF_LINK
203	sa.raw.Index = sa.Index
204	sa.raw.Type = sa.Type
205	sa.raw.Nlen = sa.Nlen
206	sa.raw.Alen = sa.Alen
207	sa.raw.Slen = sa.Slen
208	sa.raw.Data = sa.Data
209	return unsafe.Pointer(&sa.raw), SizeofSockaddrDatalink, nil
210}
211
212func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {
213	switch rsa.Addr.Family {
214	case AF_LINK:
215		pp := (*RawSockaddrDatalink)(unsafe.Pointer(rsa))
216		sa := new(SockaddrDatalink)
217		sa.Len = pp.Len
218		sa.Family = pp.Family
219		sa.Index = pp.Index
220		sa.Type = pp.Type
221		sa.Nlen = pp.Nlen
222		sa.Alen = pp.Alen
223		sa.Slen = pp.Slen
224		sa.Data = pp.Data
225		return sa, nil
226
227	case AF_UNIX:
228		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
229		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {
230			return nil, EINVAL
231		}
232		sa := new(SockaddrUnix)
233
234		// Some BSDs include the trailing NUL in the length, whereas
235		// others do not. Work around this by subtracting the leading
236		// family and len. The path is then scanned to see if a NUL
237		// terminator still exists within the length.
238		n := int(pp.Len) - 2 // subtract leading Family, Len
239		for i := 0; i < n; i++ {
240			if pp.Path[i] == 0 {
241				// found early NUL; assume Len included the NUL
242				// or was overestimating.
243				n = i
244				break
245			}
246		}
247		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
248		return sa, nil
249
250	case AF_INET:
251		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
252		sa := new(SockaddrInet4)
253		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
254		sa.Port = int(p[0])<<8 + int(p[1])
255		sa.Addr = pp.Addr
256		return sa, nil
257
258	case AF_INET6:
259		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
260		sa := new(SockaddrInet6)
261		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
262		sa.Port = int(p[0])<<8 + int(p[1])
263		sa.ZoneId = pp.Scope_id
264		sa.Addr = pp.Addr
265		return sa, nil
266	}
267	return anyToSockaddrGOOS(fd, rsa)
268}
269
270func Accept(fd int) (nfd int, sa Sockaddr, err error) {
271	var rsa RawSockaddrAny
272	var len _Socklen = SizeofSockaddrAny
273	nfd, err = accept(fd, &rsa, &len)
274	if err != nil {
275		return
276	}
277	if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && len == 0 {
278		// Accepted socket has no address.
279		// This is likely due to a bug in xnu kernels,
280		// where instead of ECONNABORTED error socket
281		// is accepted, but has no address.
282		Close(nfd)
283		return 0, nil, ECONNABORTED
284	}
285	sa, err = anyToSockaddr(fd, &rsa)
286	if err != nil {
287		Close(nfd)
288		nfd = 0
289	}
290	return
291}
292
293func Getsockname(fd int) (sa Sockaddr, err error) {
294	var rsa RawSockaddrAny
295	var len _Socklen = SizeofSockaddrAny
296	if err = getsockname(fd, &rsa, &len); err != nil {
297		return
298	}
299	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be
300	// reported upstream.
301	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {
302		rsa.Addr.Family = AF_UNIX
303		rsa.Addr.Len = SizeofSockaddrUnix
304	}
305	return anyToSockaddr(fd, &rsa)
306}
307
308//sysnb	socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
309
310// GetsockoptString returns the string value of the socket option opt for the
311// socket associated with fd at the given socket level.
312func GetsockoptString(fd, level, opt int) (string, error) {
313	buf := make([]byte, 256)
314	vallen := _Socklen(len(buf))
315	err := getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)
316	if err != nil {
317		return "", err
318	}
319	return ByteSliceToString(buf[:vallen]), nil
320}
321
322//sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
323//sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
324//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
325
326func recvmsgRaw(fd int, iov []Iovec, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
327	var msg Msghdr
328	msg.Name = (*byte)(unsafe.Pointer(rsa))
329	msg.Namelen = uint32(SizeofSockaddrAny)
330	var dummy byte
331	if len(oob) > 0 {
332		// receive at least one normal byte
333		if emptyIovecs(iov) {
334			var iova [1]Iovec
335			iova[0].Base = &dummy
336			iova[0].SetLen(1)
337			iov = iova[:]
338		}
339		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
340		msg.SetControllen(len(oob))
341	}
342	if len(iov) > 0 {
343		msg.Iov = &iov[0]
344		msg.SetIovlen(len(iov))
345	}
346	if n, err = recvmsg(fd, &msg, flags); err != nil {
347		return
348	}
349	oobn = int(msg.Controllen)
350	recvflags = int(msg.Flags)
351	return
352}
353
354//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
355
356func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {
357	var msg Msghdr
358	msg.Name = (*byte)(unsafe.Pointer(ptr))
359	msg.Namelen = uint32(salen)
360	var dummy byte
361	var empty bool
362	if len(oob) > 0 {
363		// send at least one normal byte
364		empty = emptyIovecs(iov)
365		if empty {
366			var iova [1]Iovec
367			iova[0].Base = &dummy
368			iova[0].SetLen(1)
369			iov = iova[:]
370		}
371		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
372		msg.SetControllen(len(oob))
373	}
374	if len(iov) > 0 {
375		msg.Iov = &iov[0]
376		msg.SetIovlen(len(iov))
377	}
378	if n, err = sendmsg(fd, &msg, flags); err != nil {
379		return 0, err
380	}
381	if len(oob) > 0 && empty {
382		n = 0
383	}
384	return n, nil
385}
386
387//sys	kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error)
388
389func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, err error) {
390	var change, event unsafe.Pointer
391	if len(changes) > 0 {
392		change = unsafe.Pointer(&changes[0])
393	}
394	if len(events) > 0 {
395		event = unsafe.Pointer(&events[0])
396	}
397	return kevent(kq, change, len(changes), event, len(events), timeout)
398}
399
400// sysctlmib translates name to mib number and appends any additional args.
401func sysctlmib(name string, args ...int) ([]_C_int, error) {
402	// Translate name to mib number.
403	mib, err := nametomib(name)
404	if err != nil {
405		return nil, err
406	}
407
408	for _, a := range args {
409		mib = append(mib, _C_int(a))
410	}
411
412	return mib, nil
413}
414
415func Sysctl(name string) (string, error) {
416	return SysctlArgs(name)
417}
418
419func SysctlArgs(name string, args ...int) (string, error) {
420	buf, err := SysctlRaw(name, args...)
421	if err != nil {
422		return "", err
423	}
424	n := len(buf)
425
426	// Throw away terminating NUL.
427	if n > 0 && buf[n-1] == '\x00' {
428		n--
429	}
430	return string(buf[0:n]), nil
431}
432
433func SysctlUint32(name string) (uint32, error) {
434	return SysctlUint32Args(name)
435}
436
437func SysctlUint32Args(name string, args ...int) (uint32, error) {
438	mib, err := sysctlmib(name, args...)
439	if err != nil {
440		return 0, err
441	}
442
443	n := uintptr(4)
444	buf := make([]byte, 4)
445	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
446		return 0, err
447	}
448	if n != 4 {
449		return 0, EIO
450	}
451	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
452}
453
454func SysctlUint64(name string, args ...int) (uint64, error) {
455	mib, err := sysctlmib(name, args...)
456	if err != nil {
457		return 0, err
458	}
459
460	n := uintptr(8)
461	buf := make([]byte, 8)
462	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
463		return 0, err
464	}
465	if n != 8 {
466		return 0, EIO
467	}
468	return *(*uint64)(unsafe.Pointer(&buf[0])), nil
469}
470
471func SysctlRaw(name string, args ...int) ([]byte, error) {
472	mib, err := sysctlmib(name, args...)
473	if err != nil {
474		return nil, err
475	}
476
477	// Find size.
478	n := uintptr(0)
479	if err := sysctl(mib, nil, &n, nil, 0); err != nil {
480		return nil, err
481	}
482	if n == 0 {
483		return nil, nil
484	}
485
486	// Read into buffer of that size.
487	buf := make([]byte, n)
488	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
489		return nil, err
490	}
491
492	// The actual call may return less than the original reported required
493	// size so ensure we deal with that.
494	return buf[:n], nil
495}
496
497func SysctlClockinfo(name string) (*Clockinfo, error) {
498	mib, err := sysctlmib(name)
499	if err != nil {
500		return nil, err
501	}
502
503	n := uintptr(SizeofClockinfo)
504	var ci Clockinfo
505	if err := sysctl(mib, (*byte)(unsafe.Pointer(&ci)), &n, nil, 0); err != nil {
506		return nil, err
507	}
508	if n != SizeofClockinfo {
509		return nil, EIO
510	}
511	return &ci, nil
512}
513
514func SysctlTimeval(name string) (*Timeval, error) {
515	mib, err := sysctlmib(name)
516	if err != nil {
517		return nil, err
518	}
519
520	var tv Timeval
521	n := uintptr(unsafe.Sizeof(tv))
522	if err := sysctl(mib, (*byte)(unsafe.Pointer(&tv)), &n, nil, 0); err != nil {
523		return nil, err
524	}
525	if n != unsafe.Sizeof(tv) {
526		return nil, EIO
527	}
528	return &tv, nil
529}
530
531//sys	utimes(path string, timeval *[2]Timeval) (err error)
532
533func Utimes(path string, tv []Timeval) error {
534	if tv == nil {
535		return utimes(path, nil)
536	}
537	if len(tv) != 2 {
538		return EINVAL
539	}
540	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
541}
542
543func UtimesNano(path string, ts []Timespec) error {
544	if ts == nil {
545		err := utimensat(AT_FDCWD, path, nil, 0)
546		if err != ENOSYS {
547			return err
548		}
549		return utimes(path, nil)
550	}
551	if len(ts) != 2 {
552		return EINVAL
553	}
554	err := utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
555	if err != ENOSYS {
556		return err
557	}
558	// Not as efficient as it could be because Timespec and
559	// Timeval have different types in the different OSes
560	tv := [2]Timeval{
561		NsecToTimeval(TimespecToNsec(ts[0])),
562		NsecToTimeval(TimespecToNsec(ts[1])),
563	}
564	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
565}
566
567func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
568	if ts == nil {
569		return utimensat(dirfd, path, nil, flags)
570	}
571	if len(ts) != 2 {
572		return EINVAL
573	}
574	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
575}
576
577//sys	futimes(fd int, timeval *[2]Timeval) (err error)
578
579func Futimes(fd int, tv []Timeval) error {
580	if tv == nil {
581		return futimes(fd, nil)
582	}
583	if len(tv) != 2 {
584		return EINVAL
585	}
586	return futimes(fd, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
587}
588
589//sys	poll(fds *PollFd, nfds int, timeout int) (n int, err error)
590
591func Poll(fds []PollFd, timeout int) (n int, err error) {
592	if len(fds) == 0 {
593		return poll(nil, 0, timeout)
594	}
595	return poll(&fds[0], len(fds), timeout)
596}
597
598// TODO: wrap
599//	Acct(name nil-string) (err error)
600//	Gethostuuid(uuid *byte, timeout *Timespec) (err error)
601//	Ptrace(req int, pid int, addr uintptr, data int) (ret uintptr, err error)
602
603//sys	Madvise(b []byte, behav int) (err error)
604//sys	Mlock(b []byte) (err error)
605//sys	Mlockall(flags int) (err error)
606//sys	Mprotect(b []byte, prot int) (err error)
607//sys	Msync(b []byte, flags int) (err error)
608//sys	Munlock(b []byte) (err error)
609//sys	Munlockall() (err error)