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// +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 syscall
14
15import (
16	"runtime"
17	"unsafe"
18)
19
20/*
21 * Wrapped
22 */
23
24//sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)
25//sysnb	setgroups(ngid int, gid *_Gid_t) (err error)
26
27func Getgroups() (gids []int, err error) {
28	n, err := getgroups(0, nil)
29	if err != nil {
30		return nil, err
31	}
32	if n == 0 {
33		return nil, nil
34	}
35
36	// Sanity check group count. Max is 16 on BSD.
37	if n < 0 || n > 1000 {
38		return nil, EINVAL
39	}
40
41	a := make([]_Gid_t, n)
42	n, err = getgroups(n, &a[0])
43	if err != nil {
44		return nil, err
45	}
46	gids = make([]int, n)
47	for i, v := range a[0:n] {
48		gids[i] = int(v)
49	}
50	return
51}
52
53func Setgroups(gids []int) (err error) {
54	if len(gids) == 0 {
55		return setgroups(0, nil)
56	}
57
58	a := make([]_Gid_t, len(gids))
59	for i, v := range gids {
60		a[i] = _Gid_t(v)
61	}
62	return setgroups(len(a), &a[0])
63}
64
65func ReadDirent(fd int, buf []byte) (n int, err error) {
66	// Final argument is (basep *uintptr) and the syscall doesn't take nil.
67	// 64 bits should be enough. (32 bits isn't even on 386). Since the
68	// actual system call is getdirentries64, 64 is a good guess.
69	// TODO(rsc): Can we use a single global basep for all calls?
70	var base = (*uintptr)(unsafe.Pointer(new(uint64)))
71	return Getdirentries(fd, buf, base)
72}
73
74// Wait status is 7 bits at bottom, either 0 (exited),
75// 0x7F (stopped), or a signal number that caused an exit.
76// The 0x80 bit is whether there was a core dump.
77// An extra number (exit code, signal causing a stop)
78// is in the high bits.
79
80type WaitStatus uint32
81
82const (
83	mask  = 0x7F
84	core  = 0x80
85	shift = 8
86
87	exited  = 0
88	stopped = 0x7F
89)
90
91func (w WaitStatus) Exited() bool { return w&mask == exited }
92
93func (w WaitStatus) ExitStatus() int {
94	if w&mask != exited {
95		return -1
96	}
97	return int(w >> shift)
98}
99
100func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
101
102func (w WaitStatus) Signal() Signal {
103	sig := Signal(w & mask)
104	if sig == stopped || sig == 0 {
105		return -1
106	}
107	return sig
108}
109
110func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
111
112func (w WaitStatus) Stopped() bool { return w&mask == stopped && Signal(w>>shift) != SIGSTOP }
113
114func (w WaitStatus) Continued() bool { return w&mask == stopped && Signal(w>>shift) == SIGSTOP }
115
116func (w WaitStatus) StopSignal() Signal {
117	if !w.Stopped() {
118		return -1
119	}
120	return Signal(w>>shift) & 0xFF
121}
122
123func (w WaitStatus) TrapCause() int { return -1 }
124
125//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
126
127func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
128	var status _C_int
129	wpid, err = wait4(pid, &status, options, rusage)
130	if wstatus != nil {
131		*wstatus = WaitStatus(status)
132	}
133	return
134}
135
136//sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
137//sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
138//sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
139//sysnb	socket(domain int, typ int, proto int) (fd int, err error)
140//sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
141//sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
142//sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
143//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
144//sys	Shutdown(s int, how int) (err error)
145
146func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
147	if sa.Port < 0 || sa.Port > 0xFFFF {
148		return nil, 0, EINVAL
149	}
150	sa.raw.Len = SizeofSockaddrInet4
151	sa.raw.Family = AF_INET
152	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
153	p[0] = byte(sa.Port >> 8)
154	p[1] = byte(sa.Port)
155	for i := 0; i < len(sa.Addr); i++ {
156		sa.raw.Addr[i] = sa.Addr[i]
157	}
158	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
159}
160
161func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
162	if sa.Port < 0 || sa.Port > 0xFFFF {
163		return nil, 0, EINVAL
164	}
165	sa.raw.Len = SizeofSockaddrInet6
166	sa.raw.Family = AF_INET6
167	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
168	p[0] = byte(sa.Port >> 8)
169	p[1] = byte(sa.Port)
170	sa.raw.Scope_id = sa.ZoneId
171	for i := 0; i < len(sa.Addr); i++ {
172		sa.raw.Addr[i] = sa.Addr[i]
173	}
174	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
175}
176
177func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
178	name := sa.Name
179	n := len(name)
180	if n >= len(sa.raw.Path) || n == 0 {
181		return nil, 0, EINVAL
182	}
183	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
184	sa.raw.Family = AF_UNIX
185	for i := 0; i < n; i++ {
186		sa.raw.Path[i] = int8(name[i])
187	}
188	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
189}
190
191func (sa *SockaddrDatalink) sockaddr() (unsafe.Pointer, _Socklen, error) {
192	if sa.Index == 0 {
193		return nil, 0, EINVAL
194	}
195	sa.raw.Len = sa.Len
196	sa.raw.Family = AF_LINK
197	sa.raw.Index = sa.Index
198	sa.raw.Type = sa.Type
199	sa.raw.Nlen = sa.Nlen
200	sa.raw.Alen = sa.Alen
201	sa.raw.Slen = sa.Slen
202	for i := 0; i < len(sa.raw.Data); i++ {
203		sa.raw.Data[i] = sa.Data[i]
204	}
205	return unsafe.Pointer(&sa.raw), SizeofSockaddrDatalink, nil
206}
207
208func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
209	switch rsa.Addr.Family {
210	case AF_LINK:
211		pp := (*RawSockaddrDatalink)(unsafe.Pointer(rsa))
212		sa := new(SockaddrDatalink)
213		sa.Len = pp.Len
214		sa.Family = pp.Family
215		sa.Index = pp.Index
216		sa.Type = pp.Type
217		sa.Nlen = pp.Nlen
218		sa.Alen = pp.Alen
219		sa.Slen = pp.Slen
220		for i := 0; i < len(sa.Data); i++ {
221			sa.Data[i] = pp.Data[i]
222		}
223		return sa, nil
224
225	case AF_UNIX:
226		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
227		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {
228			return nil, EINVAL
229		}
230		sa := new(SockaddrUnix)
231
232		// Some BSDs include the trailing NUL in the length, whereas
233		// others do not. Work around this by subtracting the leading
234		// family and len. The path is then scanned to see if a NUL
235		// terminator still exists within the length.
236		n := int(pp.Len) - 2 // subtract leading Family, Len
237		for i := 0; i < n; i++ {
238			if pp.Path[i] == 0 {
239				// found early NUL; assume Len included the NUL
240				// or was overestimating.
241				n = i
242				break
243			}
244		}
245		bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
246		sa.Name = string(bytes)
247		return sa, nil
248
249	case AF_INET:
250		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
251		sa := new(SockaddrInet4)
252		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
253		sa.Port = int(p[0])<<8 + int(p[1])
254		for i := 0; i < len(sa.Addr); i++ {
255			sa.Addr[i] = pp.Addr[i]
256		}
257		return sa, nil
258
259	case AF_INET6:
260		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
261		sa := new(SockaddrInet6)
262		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
263		sa.Port = int(p[0])<<8 + int(p[1])
264		sa.ZoneId = pp.Scope_id
265		for i := 0; i < len(sa.Addr); i++ {
266			sa.Addr[i] = pp.Addr[i]
267		}
268		return sa, nil
269	}
270	return nil, EAFNOSUPPORT
271}
272
273func Accept(fd int) (nfd int, sa Sockaddr, err error) {
274	var rsa RawSockaddrAny
275	var len _Socklen = SizeofSockaddrAny
276	nfd, err = accept(fd, &rsa, &len)
277	if err != nil {
278		return
279	}
280	if runtime.GOOS == "darwin" && len == 0 {
281		// Accepted socket has no address.
282		// This is likely due to a bug in xnu kernels,
283		// where instead of ECONNABORTED error socket
284		// is accepted, but has no address.
285		Close(nfd)
286		return 0, nil, ECONNABORTED
287	}
288	sa, err = anyToSockaddr(&rsa)
289	if err != nil {
290		Close(nfd)
291		nfd = 0
292	}
293	return
294}
295
296func Getsockname(fd int) (sa Sockaddr, err error) {
297	var rsa RawSockaddrAny
298	var len _Socklen = SizeofSockaddrAny
299	if err = getsockname(fd, &rsa, &len); err != nil {
300		return
301	}
302	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be
303	// reported upstream.
304	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {
305		rsa.Addr.Family = AF_UNIX
306		rsa.Addr.Len = SizeofSockaddrUnix
307	}
308	return anyToSockaddr(&rsa)
309}
310
311//sysnb socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
312
313func GetsockoptByte(fd, level, opt int) (value byte, err error) {
314	var n byte
315	vallen := _Socklen(1)
316	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
317	return n, err
318}
319
320func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
321	vallen := _Socklen(4)
322	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
323	return value, err
324}
325
326func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
327	var value IPMreq
328	vallen := _Socklen(SizeofIPMreq)
329	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
330	return &value, err
331}
332
333func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
334	var value IPv6Mreq
335	vallen := _Socklen(SizeofIPv6Mreq)
336	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
337	return &value, err
338}
339
340func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
341	var value IPv6MTUInfo
342	vallen := _Socklen(SizeofIPv6MTUInfo)
343	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
344	return &value, err
345}
346
347func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
348	var value ICMPv6Filter
349	vallen := _Socklen(SizeofICMPv6Filter)
350	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
351	return &value, err
352}
353
354//sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
355//sys   sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
356//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
357
358func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
359	var msg Msghdr
360	var rsa RawSockaddrAny
361	msg.Name = (*byte)(unsafe.Pointer(&rsa))
362	msg.Namelen = uint32(SizeofSockaddrAny)
363	var iov Iovec
364	if len(p) > 0 {
365		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
366		iov.SetLen(len(p))
367	}
368	var dummy byte
369	if len(oob) > 0 {
370		// receive at least one normal byte
371		if len(p) == 0 {
372			iov.Base = &dummy
373			iov.SetLen(1)
374		}
375		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
376		msg.SetControllen(len(oob))
377	}
378	msg.Iov = &iov
379	msg.Iovlen = 1
380	if n, err = recvmsg(fd, &msg, flags); err != nil {
381		return
382	}
383	oobn = int(msg.Controllen)
384	recvflags = int(msg.Flags)
385	// source address is only specified if the socket is unconnected
386	if rsa.Addr.Family != AF_UNSPEC {
387		from, err = anyToSockaddr(&rsa)
388	}
389	return
390}
391
392//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
393
394func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
395	_, err = SendmsgN(fd, p, oob, to, flags)
396	return
397}
398
399func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
400	var ptr unsafe.Pointer
401	var salen _Socklen
402	if to != nil {
403		ptr, salen, err = to.sockaddr()
404		if err != nil {
405			return 0, err
406		}
407	}
408	var msg Msghdr
409	msg.Name = (*byte)(unsafe.Pointer(ptr))
410	msg.Namelen = uint32(salen)
411	var iov Iovec
412	if len(p) > 0 {
413		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
414		iov.SetLen(len(p))
415	}
416	var dummy byte
417	if len(oob) > 0 {
418		// send at least one normal byte
419		if len(p) == 0 {
420			iov.Base = &dummy
421			iov.SetLen(1)
422		}
423		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
424		msg.SetControllen(len(oob))
425	}
426	msg.Iov = &iov
427	msg.Iovlen = 1
428	if n, err = sendmsg(fd, &msg, flags); err != nil {
429		return 0, err
430	}
431	if len(oob) > 0 && len(p) == 0 {
432		n = 0
433	}
434	return n, nil
435}
436
437//sys	kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error)
438
439func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, err error) {
440	var change, event unsafe.Pointer
441	if len(changes) > 0 {
442		change = unsafe.Pointer(&changes[0])
443	}
444	if len(events) > 0 {
445		event = unsafe.Pointer(&events[0])
446	}
447	return kevent(kq, change, len(changes), event, len(events), timeout)
448}
449
450func Sysctl(name string) (value string, err error) {
451	// Translate name to mib number.
452	mib, err := nametomib(name)
453	if err != nil {
454		return "", err
455	}
456
457	// Find size.
458	n := uintptr(0)
459	if err = sysctl(mib, nil, &n, nil, 0); err != nil {
460		return "", err
461	}
462	if n == 0 {
463		return "", nil
464	}
465
466	// Read into buffer of that size.
467	buf := make([]byte, n)
468	if err = sysctl(mib, &buf[0], &n, nil, 0); err != nil {
469		return "", err
470	}
471
472	// Throw away terminating NUL.
473	if n > 0 && buf[n-1] == '\x00' {
474		n--
475	}
476	return string(buf[0:n]), nil
477}
478
479func SysctlUint32(name string) (value uint32, err error) {
480	// Translate name to mib number.
481	mib, err := nametomib(name)
482	if err != nil {
483		return 0, err
484	}
485
486	// Read into buffer of that size.
487	n := uintptr(4)
488	buf := make([]byte, 4)
489	if err = sysctl(mib, &buf[0], &n, nil, 0); err != nil {
490		return 0, err
491	}
492	if n != 4 {
493		return 0, EIO
494	}
495	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
496}
497
498//sys	utimes(path string, timeval *[2]Timeval) (err error)
499
500func Utimes(path string, tv []Timeval) (err error) {
501	if len(tv) != 2 {
502		return EINVAL
503	}
504	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
505}
506
507func UtimesNano(path string, ts []Timespec) error {
508	if len(ts) != 2 {
509		return EINVAL
510	}
511	// Darwin setattrlist can set nanosecond timestamps
512	err := setattrlistTimes(path, ts)
513	if err != ENOSYS {
514		return err
515	}
516	err = utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
517	if err != ENOSYS {
518		return err
519	}
520	// Not as efficient as it could be because Timespec and
521	// Timeval have different types in the different OSes
522	tv := [2]Timeval{
523		NsecToTimeval(TimespecToNsec(ts[0])),
524		NsecToTimeval(TimespecToNsec(ts[1])),
525	}
526	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
527}
528
529//sys	futimes(fd int, timeval *[2]Timeval) (err error)
530
531func Futimes(fd int, tv []Timeval) (err error) {
532	if len(tv) != 2 {
533		return EINVAL
534	}
535	return futimes(fd, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
536}
537
538//sys	fcntl(fd int, cmd int, arg int) (val int, err error)
539
540var mapper = &mmapper{
541	active: make(map[*byte][]byte),
542	mmap:   mmap,
543	munmap: munmap,
544}
545
546func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
547	return mapper.Mmap(fd, offset, length, prot, flags)
548}
549
550func Munmap(b []byte) (err error) {
551	return mapper.Munmap(b)
552}
553