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 aix darwin dragonfly freebsd linux netbsd openbsd solaris
6
7package unix
8
9import (
10	"bytes"
11	"sort"
12	"sync"
13	"syscall"
14	"unsafe"
15
16	"golang.org/x/sys/internal/unsafeheader"
17)
18
19var (
20	Stdin  = 0
21	Stdout = 1
22	Stderr = 2
23)
24
25// Do the interface allocations only once for common
26// Errno values.
27var (
28	errEAGAIN error = syscall.EAGAIN
29	errEINVAL error = syscall.EINVAL
30	errENOENT error = syscall.ENOENT
31)
32
33var (
34	signalNameMapOnce sync.Once
35	signalNameMap     map[string]syscall.Signal
36)
37
38// errnoErr returns common boxed Errno values, to prevent
39// allocations at runtime.
40func errnoErr(e syscall.Errno) error {
41	switch e {
42	case 0:
43		return nil
44	case EAGAIN:
45		return errEAGAIN
46	case EINVAL:
47		return errEINVAL
48	case ENOENT:
49		return errENOENT
50	}
51	return e
52}
53
54// ErrnoName returns the error name for error number e.
55func ErrnoName(e syscall.Errno) string {
56	i := sort.Search(len(errorList), func(i int) bool {
57		return errorList[i].num >= e
58	})
59	if i < len(errorList) && errorList[i].num == e {
60		return errorList[i].name
61	}
62	return ""
63}
64
65// SignalName returns the signal name for signal number s.
66func SignalName(s syscall.Signal) string {
67	i := sort.Search(len(signalList), func(i int) bool {
68		return signalList[i].num >= s
69	})
70	if i < len(signalList) && signalList[i].num == s {
71		return signalList[i].name
72	}
73	return ""
74}
75
76// SignalNum returns the syscall.Signal for signal named s,
77// or 0 if a signal with such name is not found.
78// The signal name should start with "SIG".
79func SignalNum(s string) syscall.Signal {
80	signalNameMapOnce.Do(func() {
81		signalNameMap = make(map[string]syscall.Signal, len(signalList))
82		for _, signal := range signalList {
83			signalNameMap[signal.name] = signal.num
84		}
85	})
86	return signalNameMap[s]
87}
88
89// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
90func clen(n []byte) int {
91	i := bytes.IndexByte(n, 0)
92	if i == -1 {
93		i = len(n)
94	}
95	return i
96}
97
98// Mmap manager, for use by operating system-specific implementations.
99
100type mmapper struct {
101	sync.Mutex
102	active map[*byte][]byte // active mappings; key is last byte in mapping
103	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
104	munmap func(addr uintptr, length uintptr) error
105}
106
107func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
108	if length <= 0 {
109		return nil, EINVAL
110	}
111
112	// Map the requested memory.
113	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
114	if errno != nil {
115		return nil, errno
116	}
117
118	// Use unsafe to convert addr into a []byte.
119	var b []byte
120	hdr := (*unsafeheader.Slice)(unsafe.Pointer(&b))
121	hdr.Data = unsafe.Pointer(addr)
122	hdr.Cap = length
123	hdr.Len = length
124
125	// Register mapping in m and return it.
126	p := &b[cap(b)-1]
127	m.Lock()
128	defer m.Unlock()
129	m.active[p] = b
130	return b, nil
131}
132
133func (m *mmapper) Munmap(data []byte) (err error) {
134	if len(data) == 0 || len(data) != cap(data) {
135		return EINVAL
136	}
137
138	// Find the base of the mapping.
139	p := &data[cap(data)-1]
140	m.Lock()
141	defer m.Unlock()
142	b := m.active[p]
143	if b == nil || &b[0] != &data[0] {
144		return EINVAL
145	}
146
147	// Unmap the memory and update m.
148	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
149		return errno
150	}
151	delete(m.active, p)
152	return nil
153}
154
155func Read(fd int, p []byte) (n int, err error) {
156	n, err = read(fd, p)
157	if raceenabled {
158		if n > 0 {
159			raceWriteRange(unsafe.Pointer(&p[0]), n)
160		}
161		if err == nil {
162			raceAcquire(unsafe.Pointer(&ioSync))
163		}
164	}
165	return
166}
167
168func Write(fd int, p []byte) (n int, err error) {
169	if raceenabled {
170		raceReleaseMerge(unsafe.Pointer(&ioSync))
171	}
172	n, err = write(fd, p)
173	if raceenabled && n > 0 {
174		raceReadRange(unsafe.Pointer(&p[0]), n)
175	}
176	return
177}
178
179// For testing: clients can set this flag to force
180// creation of IPv6 sockets to return EAFNOSUPPORT.
181var SocketDisableIPv6 bool
182
183// Sockaddr represents a socket address.
184type Sockaddr interface {
185	sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
186}
187
188// SockaddrInet4 implements the Sockaddr interface for AF_INET type sockets.
189type SockaddrInet4 struct {
190	Port int
191	Addr [4]byte
192	raw  RawSockaddrInet4
193}
194
195// SockaddrInet6 implements the Sockaddr interface for AF_INET6 type sockets.
196type SockaddrInet6 struct {
197	Port   int
198	ZoneId uint32
199	Addr   [16]byte
200	raw    RawSockaddrInet6
201}
202
203// SockaddrUnix implements the Sockaddr interface for AF_UNIX type sockets.
204type SockaddrUnix struct {
205	Name string
206	raw  RawSockaddrUnix
207}
208
209func Bind(fd int, sa Sockaddr) (err error) {
210	ptr, n, err := sa.sockaddr()
211	if err != nil {
212		return err
213	}
214	return bind(fd, ptr, n)
215}
216
217func Connect(fd int, sa Sockaddr) (err error) {
218	ptr, n, err := sa.sockaddr()
219	if err != nil {
220		return err
221	}
222	return connect(fd, ptr, n)
223}
224
225func Getpeername(fd int) (sa Sockaddr, err error) {
226	var rsa RawSockaddrAny
227	var len _Socklen = SizeofSockaddrAny
228	if err = getpeername(fd, &rsa, &len); err != nil {
229		return
230	}
231	return anyToSockaddr(fd, &rsa)
232}
233
234func GetsockoptByte(fd, level, opt int) (value byte, err error) {
235	var n byte
236	vallen := _Socklen(1)
237	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
238	return n, err
239}
240
241func GetsockoptInt(fd, level, opt int) (value int, err error) {
242	var n int32
243	vallen := _Socklen(4)
244	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
245	return int(n), err
246}
247
248func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
249	vallen := _Socklen(4)
250	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
251	return value, err
252}
253
254func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
255	var value IPMreq
256	vallen := _Socklen(SizeofIPMreq)
257	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
258	return &value, err
259}
260
261func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
262	var value IPv6Mreq
263	vallen := _Socklen(SizeofIPv6Mreq)
264	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
265	return &value, err
266}
267
268func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
269	var value IPv6MTUInfo
270	vallen := _Socklen(SizeofIPv6MTUInfo)
271	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
272	return &value, err
273}
274
275func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
276	var value ICMPv6Filter
277	vallen := _Socklen(SizeofICMPv6Filter)
278	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
279	return &value, err
280}
281
282func GetsockoptLinger(fd, level, opt int) (*Linger, error) {
283	var linger Linger
284	vallen := _Socklen(SizeofLinger)
285	err := getsockopt(fd, level, opt, unsafe.Pointer(&linger), &vallen)
286	return &linger, err
287}
288
289func GetsockoptTimeval(fd, level, opt int) (*Timeval, error) {
290	var tv Timeval
291	vallen := _Socklen(unsafe.Sizeof(tv))
292	err := getsockopt(fd, level, opt, unsafe.Pointer(&tv), &vallen)
293	return &tv, err
294}
295
296func GetsockoptUint64(fd, level, opt int) (value uint64, err error) {
297	var n uint64
298	vallen := _Socklen(8)
299	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
300	return n, err
301}
302
303func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
304	var rsa RawSockaddrAny
305	var len _Socklen = SizeofSockaddrAny
306	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
307		return
308	}
309	if rsa.Addr.Family != AF_UNSPEC {
310		from, err = anyToSockaddr(fd, &rsa)
311	}
312	return
313}
314
315func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
316	ptr, n, err := to.sockaddr()
317	if err != nil {
318		return err
319	}
320	return sendto(fd, p, flags, ptr, n)
321}
322
323func SetsockoptByte(fd, level, opt int, value byte) (err error) {
324	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
325}
326
327func SetsockoptInt(fd, level, opt int, value int) (err error) {
328	var n = int32(value)
329	return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
330}
331
332func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
333	return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
334}
335
336func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
337	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
338}
339
340func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
341	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
342}
343
344func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
345	return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
346}
347
348func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
349	return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
350}
351
352func SetsockoptString(fd, level, opt int, s string) (err error) {
353	var p unsafe.Pointer
354	if len(s) > 0 {
355		p = unsafe.Pointer(&[]byte(s)[0])
356	}
357	return setsockopt(fd, level, opt, p, uintptr(len(s)))
358}
359
360func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
361	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
362}
363
364func SetsockoptUint64(fd, level, opt int, value uint64) (err error) {
365	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 8)
366}
367
368func Socket(domain, typ, proto int) (fd int, err error) {
369	if domain == AF_INET6 && SocketDisableIPv6 {
370		return -1, EAFNOSUPPORT
371	}
372	fd, err = socket(domain, typ, proto)
373	return
374}
375
376func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
377	var fdx [2]int32
378	err = socketpair(domain, typ, proto, &fdx)
379	if err == nil {
380		fd[0] = int(fdx[0])
381		fd[1] = int(fdx[1])
382	}
383	return
384}
385
386var ioSync int64
387
388func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
389
390func SetNonblock(fd int, nonblocking bool) (err error) {
391	flag, err := fcntl(fd, F_GETFL, 0)
392	if err != nil {
393		return err
394	}
395	if nonblocking {
396		flag |= O_NONBLOCK
397	} else {
398		flag &= ^O_NONBLOCK
399	}
400	_, err = fcntl(fd, F_SETFL, flag)
401	return err
402}
403
404// Exec calls execve(2), which replaces the calling executable in the process
405// tree. argv0 should be the full path to an executable ("/bin/ls") and the
406// executable name should also be the first argument in argv (["ls", "-l"]).
407// envv are the environment variables that should be passed to the new
408// process (["USER=go", "PWD=/tmp"]).
409func Exec(argv0 string, argv []string, envv []string) error {
410	return syscall.Exec(argv0, argv, envv)
411}
412
413// Lutimes sets the access and modification times tv on path. If path refers to
414// a symlink, it is not dereferenced and the timestamps are set on the symlink.
415// If tv is nil, the access and modification times are set to the current time.
416// Otherwise tv must contain exactly 2 elements, with access time as the first
417// element and modification time as the second element.
418func Lutimes(path string, tv []Timeval) error {
419	if tv == nil {
420		return UtimesNanoAt(AT_FDCWD, path, nil, AT_SYMLINK_NOFOLLOW)
421	}
422	if len(tv) != 2 {
423		return EINVAL
424	}
425	ts := []Timespec{
426		NsecToTimespec(TimevalToNsec(tv[0])),
427		NsecToTimespec(TimevalToNsec(tv[1])),
428	}
429	return UtimesNanoAt(AT_FDCWD, path, ts, AT_SYMLINK_NOFOLLOW)
430}
431