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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 unix
14
15import (
16	"runtime"
17	"syscall"
18	"unsafe"
19)
20
21/*
22 * Wrapped
23 */
24
25//sysnb	getgroups(ngid int, gid *_Gid_t) (n int, err error)
26//sysnb	setgroups(ngid int, gid *_Gid_t) (err error)
27
28func Getgroups() (gids []int, err error) {
29	n, err := getgroups(0, nil)
30	if err != nil {
31		return nil, err
32	}
33	if n == 0 {
34		return nil, nil
35	}
36
37	// Sanity check group count. Max is 16 on BSD.
38	if n < 0 || n > 1000 {
39		return nil, EINVAL
40	}
41
42	a := make([]_Gid_t, n)
43	n, err = getgroups(n, &a[0])
44	if err != nil {
45		return nil, err
46	}
47	gids = make([]int, n)
48	for i, v := range a[0:n] {
49		gids[i] = int(v)
50	}
51	return
52}
53
54func Setgroups(gids []int) (err error) {
55	if len(gids) == 0 {
56		return setgroups(0, nil)
57	}
58
59	a := make([]_Gid_t, len(gids))
60	for i, v := range gids {
61		a[i] = _Gid_t(v)
62	}
63	return setgroups(len(a), &a[0])
64}
65
66func ReadDirent(fd int, buf []byte) (n int, err error) {
67	// Final argument is (basep *uintptr) and the syscall doesn't take nil.
68	// 64 bits should be enough. (32 bits isn't even on 386). Since the
69	// actual system call is getdirentries64, 64 is a good guess.
70	// TODO(rsc): Can we use a single global basep for all calls?
71	var base = (*uintptr)(unsafe.Pointer(new(uint64)))
72	return Getdirentries(fd, buf, base)
73}
74
75// Wait status is 7 bits at bottom, either 0 (exited),
76// 0x7F (stopped), or a signal number that caused an exit.
77// The 0x80 bit is whether there was a core dump.
78// An extra number (exit code, signal causing a stop)
79// is in the high bits.
80
81type WaitStatus uint32
82
83const (
84	mask  = 0x7F
85	core  = 0x80
86	shift = 8
87
88	exited  = 0
89	stopped = 0x7F
90)
91
92func (w WaitStatus) Exited() bool { return w&mask == exited }
93
94func (w WaitStatus) ExitStatus() int {
95	if w&mask != exited {
96		return -1
97	}
98	return int(w >> shift)
99}
100
101func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != 0 }
102
103func (w WaitStatus) Signal() syscall.Signal {
104	sig := syscall.Signal(w & mask)
105	if sig == stopped || sig == 0 {
106		return -1
107	}
108	return sig
109}
110
111func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
112
113func (w WaitStatus) Stopped() bool { return w&mask == stopped && syscall.Signal(w>>shift) != SIGSTOP }
114
115func (w WaitStatus) Continued() bool { return w&mask == stopped && syscall.Signal(w>>shift) == SIGSTOP }
116
117func (w WaitStatus) StopSignal() syscall.Signal {
118	if !w.Stopped() {
119		return -1
120	}
121	return syscall.Signal(w>>shift) & 0xFF
122}
123
124func (w WaitStatus) TrapCause() int { return -1 }
125
126//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
127
128func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
129	var status _C_int
130	wpid, err = wait4(pid, &status, options, rusage)
131	if wstatus != nil {
132		*wstatus = WaitStatus(status)
133	}
134	return
135}
136
137//sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
138//sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
139//sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
140//sysnb	socket(domain int, typ int, proto int) (fd int, err error)
141//sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
142//sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
143//sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
144//sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
145//sys	Shutdown(s int, how int) (err error)
146
147func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
148	if sa.Port < 0 || sa.Port > 0xFFFF {
149		return nil, 0, EINVAL
150	}
151	sa.raw.Len = SizeofSockaddrInet4
152	sa.raw.Family = AF_INET
153	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
154	p[0] = byte(sa.Port >> 8)
155	p[1] = byte(sa.Port)
156	for i := 0; i < len(sa.Addr); i++ {
157		sa.raw.Addr[i] = sa.Addr[i]
158	}
159	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
160}
161
162func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
163	if sa.Port < 0 || sa.Port > 0xFFFF {
164		return nil, 0, EINVAL
165	}
166	sa.raw.Len = SizeofSockaddrInet6
167	sa.raw.Family = AF_INET6
168	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
169	p[0] = byte(sa.Port >> 8)
170	p[1] = byte(sa.Port)
171	sa.raw.Scope_id = sa.ZoneId
172	for i := 0; i < len(sa.Addr); i++ {
173		sa.raw.Addr[i] = sa.Addr[i]
174	}
175	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
176}
177
178func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
179	name := sa.Name
180	n := len(name)
181	if n >= len(sa.raw.Path) || n == 0 {
182		return nil, 0, EINVAL
183	}
184	sa.raw.Len = byte(3 + n) // 2 for Family, Len; 1 for NUL
185	sa.raw.Family = AF_UNIX
186	for i := 0; i < n; i++ {
187		sa.raw.Path[i] = int8(name[i])
188	}
189	return unsafe.Pointer(&sa.raw), _Socklen(sa.raw.Len), nil
190}
191
192func (sa *SockaddrDatalink) sockaddr() (unsafe.Pointer, _Socklen, error) {
193	if sa.Index == 0 {
194		return nil, 0, EINVAL
195	}
196	sa.raw.Len = sa.Len
197	sa.raw.Family = AF_LINK
198	sa.raw.Index = sa.Index
199	sa.raw.Type = sa.Type
200	sa.raw.Nlen = sa.Nlen
201	sa.raw.Alen = sa.Alen
202	sa.raw.Slen = sa.Slen
203	for i := 0; i < len(sa.raw.Data); i++ {
204		sa.raw.Data[i] = sa.Data[i]
205	}
206	return unsafe.Pointer(&sa.raw), SizeofSockaddrDatalink, nil
207}
208
209func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
210	switch rsa.Addr.Family {
211	case AF_LINK:
212		pp := (*RawSockaddrDatalink)(unsafe.Pointer(rsa))
213		sa := new(SockaddrDatalink)
214		sa.Len = pp.Len
215		sa.Family = pp.Family
216		sa.Index = pp.Index
217		sa.Type = pp.Type
218		sa.Nlen = pp.Nlen
219		sa.Alen = pp.Alen
220		sa.Slen = pp.Slen
221		for i := 0; i < len(sa.Data); i++ {
222			sa.Data[i] = pp.Data[i]
223		}
224		return sa, nil
225
226	case AF_UNIX:
227		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
228		if pp.Len < 2 || pp.Len > SizeofSockaddrUnix {
229			return nil, EINVAL
230		}
231		sa := new(SockaddrUnix)
232
233		// Some BSDs include the trailing NUL in the length, whereas
234		// others do not. Work around this by subtracting the leading
235		// family and len. The path is then scanned to see if a NUL
236		// terminator still exists within the length.
237		n := int(pp.Len) - 2 // subtract leading Family, Len
238		for i := 0; i < n; i++ {
239			if pp.Path[i] == 0 {
240				// found early NUL; assume Len included the NUL
241				// or was overestimating.
242				n = i
243				break
244			}
245		}
246		bytes := (*[10000]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
247		sa.Name = string(bytes)
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		for i := 0; i < len(sa.Addr); i++ {
256			sa.Addr[i] = pp.Addr[i]
257		}
258		return sa, nil
259
260	case AF_INET6:
261		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
262		sa := new(SockaddrInet6)
263		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
264		sa.Port = int(p[0])<<8 + int(p[1])
265		sa.ZoneId = pp.Scope_id
266		for i := 0; i < len(sa.Addr); i++ {
267			sa.Addr[i] = pp.Addr[i]
268		}
269		return sa, nil
270	}
271	return nil, EAFNOSUPPORT
272}
273
274func Accept(fd int) (nfd int, sa Sockaddr, err error) {
275	var rsa RawSockaddrAny
276	var len _Socklen = SizeofSockaddrAny
277	nfd, err = accept(fd, &rsa, &len)
278	if err != nil {
279		return
280	}
281	if runtime.GOOS == "darwin" && len == 0 {
282		// Accepted socket has no address.
283		// This is likely due to a bug in xnu kernels,
284		// where instead of ECONNABORTED error socket
285		// is accepted, but has no address.
286		Close(nfd)
287		return 0, nil, ECONNABORTED
288	}
289	sa, err = anyToSockaddr(&rsa)
290	if err != nil {
291		Close(nfd)
292		nfd = 0
293	}
294	return
295}
296
297func Getsockname(fd int) (sa Sockaddr, err error) {
298	var rsa RawSockaddrAny
299	var len _Socklen = SizeofSockaddrAny
300	if err = getsockname(fd, &rsa, &len); err != nil {
301		return
302	}
303	// TODO(jsing): DragonFly has a "bug" (see issue 3349), which should be
304	// reported upstream.
305	if runtime.GOOS == "dragonfly" && rsa.Addr.Family == AF_UNSPEC && rsa.Addr.Len == 0 {
306		rsa.Addr.Family = AF_UNIX
307		rsa.Addr.Len = SizeofSockaddrUnix
308	}
309	return anyToSockaddr(&rsa)
310}
311
312//sysnb socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
313
314// GetsockoptString returns the string value of the socket option opt for the
315// socket associated with fd at the given socket level.
316func GetsockoptString(fd, level, opt int) (string, error) {
317	buf := make([]byte, 256)
318	vallen := _Socklen(len(buf))
319	err := getsockopt(fd, level, opt, unsafe.Pointer(&buf[0]), &vallen)
320	if err != nil {
321		return "", err
322	}
323	return string(buf[:vallen-1]), nil
324}
325
326//sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
327//sys   sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
328//sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error)
329
330func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
331	var msg Msghdr
332	var rsa RawSockaddrAny
333	msg.Name = (*byte)(unsafe.Pointer(&rsa))
334	msg.Namelen = uint32(SizeofSockaddrAny)
335	var iov Iovec
336	if len(p) > 0 {
337		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
338		iov.SetLen(len(p))
339	}
340	var dummy byte
341	if len(oob) > 0 {
342		// receive at least one normal byte
343		if len(p) == 0 {
344			iov.Base = &dummy
345			iov.SetLen(1)
346		}
347		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
348		msg.SetControllen(len(oob))
349	}
350	msg.Iov = &iov
351	msg.Iovlen = 1
352	if n, err = recvmsg(fd, &msg, flags); err != nil {
353		return
354	}
355	oobn = int(msg.Controllen)
356	recvflags = int(msg.Flags)
357	// source address is only specified if the socket is unconnected
358	if rsa.Addr.Family != AF_UNSPEC {
359		from, err = anyToSockaddr(&rsa)
360	}
361	return
362}
363
364//sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
365
366func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
367	_, err = SendmsgN(fd, p, oob, to, flags)
368	return
369}
370
371func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
372	var ptr unsafe.Pointer
373	var salen _Socklen
374	if to != nil {
375		ptr, salen, err = to.sockaddr()
376		if err != nil {
377			return 0, err
378		}
379	}
380	var msg Msghdr
381	msg.Name = (*byte)(unsafe.Pointer(ptr))
382	msg.Namelen = uint32(salen)
383	var iov Iovec
384	if len(p) > 0 {
385		iov.Base = (*byte)(unsafe.Pointer(&p[0]))
386		iov.SetLen(len(p))
387	}
388	var dummy byte
389	if len(oob) > 0 {
390		// send at least one normal byte
391		if len(p) == 0 {
392			iov.Base = &dummy
393			iov.SetLen(1)
394		}
395		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
396		msg.SetControllen(len(oob))
397	}
398	msg.Iov = &iov
399	msg.Iovlen = 1
400	if n, err = sendmsg(fd, &msg, flags); err != nil {
401		return 0, err
402	}
403	if len(oob) > 0 && len(p) == 0 {
404		n = 0
405	}
406	return n, nil
407}
408
409//sys	kevent(kq int, change unsafe.Pointer, nchange int, event unsafe.Pointer, nevent int, timeout *Timespec) (n int, err error)
410
411func Kevent(kq int, changes, events []Kevent_t, timeout *Timespec) (n int, err error) {
412	var change, event unsafe.Pointer
413	if len(changes) > 0 {
414		change = unsafe.Pointer(&changes[0])
415	}
416	if len(events) > 0 {
417		event = unsafe.Pointer(&events[0])
418	}
419	return kevent(kq, change, len(changes), event, len(events), timeout)
420}
421
422//sys	sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) = SYS___SYSCTL
423
424// sysctlmib translates name to mib number and appends any additional args.
425func sysctlmib(name string, args ...int) ([]_C_int, error) {
426	// Translate name to mib number.
427	mib, err := nametomib(name)
428	if err != nil {
429		return nil, err
430	}
431
432	for _, a := range args {
433		mib = append(mib, _C_int(a))
434	}
435
436	return mib, nil
437}
438
439func Sysctl(name string) (string, error) {
440	return SysctlArgs(name)
441}
442
443func SysctlArgs(name string, args ...int) (string, error) {
444	buf, err := SysctlRaw(name, args...)
445	if err != nil {
446		return "", err
447	}
448	n := len(buf)
449
450	// Throw away terminating NUL.
451	if n > 0 && buf[n-1] == '\x00' {
452		n--
453	}
454	return string(buf[0:n]), nil
455}
456
457func SysctlUint32(name string) (uint32, error) {
458	return SysctlUint32Args(name)
459}
460
461func SysctlUint32Args(name string, args ...int) (uint32, error) {
462	mib, err := sysctlmib(name, args...)
463	if err != nil {
464		return 0, err
465	}
466
467	n := uintptr(4)
468	buf := make([]byte, 4)
469	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
470		return 0, err
471	}
472	if n != 4 {
473		return 0, EIO
474	}
475	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
476}
477
478func SysctlUint64(name string, args ...int) (uint64, error) {
479	mib, err := sysctlmib(name, args...)
480	if err != nil {
481		return 0, err
482	}
483
484	n := uintptr(8)
485	buf := make([]byte, 8)
486	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
487		return 0, err
488	}
489	if n != 8 {
490		return 0, EIO
491	}
492	return *(*uint64)(unsafe.Pointer(&buf[0])), nil
493}
494
495func SysctlRaw(name string, args ...int) ([]byte, error) {
496	mib, err := sysctlmib(name, args...)
497	if err != nil {
498		return nil, err
499	}
500
501	// Find size.
502	n := uintptr(0)
503	if err := sysctl(mib, nil, &n, nil, 0); err != nil {
504		return nil, err
505	}
506	if n == 0 {
507		return nil, nil
508	}
509
510	// Read into buffer of that size.
511	buf := make([]byte, n)
512	if err := sysctl(mib, &buf[0], &n, nil, 0); err != nil {
513		return nil, err
514	}
515
516	// The actual call may return less than the original reported required
517	// size so ensure we deal with that.
518	return buf[:n], nil
519}
520
521//sys	utimes(path string, timeval *[2]Timeval) (err error)
522
523func Utimes(path string, tv []Timeval) error {
524	if tv == nil {
525		return utimes(path, nil)
526	}
527	if len(tv) != 2 {
528		return EINVAL
529	}
530	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
531}
532
533func UtimesNano(path string, ts []Timespec) error {
534	if ts == nil {
535		err := utimensat(AT_FDCWD, path, nil, 0)
536		if err != ENOSYS {
537			return err
538		}
539		return utimes(path, nil)
540	}
541	if len(ts) != 2 {
542		return EINVAL
543	}
544	// Darwin setattrlist can set nanosecond timestamps
545	err := setattrlistTimes(path, ts, 0)
546	if err != ENOSYS {
547		return err
548	}
549	err = utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
550	if err != ENOSYS {
551		return err
552	}
553	// Not as efficient as it could be because Timespec and
554	// Timeval have different types in the different OSes
555	tv := [2]Timeval{
556		NsecToTimeval(TimespecToNsec(ts[0])),
557		NsecToTimeval(TimespecToNsec(ts[1])),
558	}
559	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
560}
561
562func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
563	if ts == nil {
564		return utimensat(dirfd, path, nil, flags)
565	}
566	if len(ts) != 2 {
567		return EINVAL
568	}
569	err := setattrlistTimes(path, ts, flags)
570	if err != ENOSYS {
571		return err
572	}
573	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
574}
575
576//sys	futimes(fd int, timeval *[2]Timeval) (err error)
577
578func Futimes(fd int, tv []Timeval) error {
579	if tv == nil {
580		return futimes(fd, nil)
581	}
582	if len(tv) != 2 {
583		return EINVAL
584	}
585	return futimes(fd, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
586}
587
588//sys	fcntl(fd int, cmd int, arg int) (val int, err error)
589
590//sys   poll(fds *PollFd, nfds int, timeout int) (n int, err error)
591
592func Poll(fds []PollFd, timeout int) (n int, err error) {
593	if len(fds) == 0 {
594		return poll(nil, 0, timeout)
595	}
596	return poll(&fds[0], len(fds), timeout)
597}
598
599// TODO: wrap
600//	Acct(name nil-string) (err error)
601//	Gethostuuid(uuid *byte, timeout *Timespec) (err error)
602//	Ptrace(req int, pid int, addr uintptr, data int) (ret uintptr, err error)
603
604var mapper = &mmapper{
605	active: make(map[*byte][]byte),
606	mmap:   mmap,
607	munmap: munmap,
608}
609
610func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
611	return mapper.Mmap(fd, offset, length, prot, flags)
612}
613
614func Munmap(b []byte) (err error) {
615	return mapper.Munmap(b)
616}
617
618//sys	Madvise(b []byte, behav int) (err error)
619//sys	Mlock(b []byte) (err error)
620//sys	Mlockall(flags int) (err error)
621//sys	Mprotect(b []byte, prot int) (err error)
622//sys	Msync(b []byte, flags int) (err error)
623//sys	Munlock(b []byte) (err error)
624//sys	Munlockall() (err error)
625