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
17var (
18	Stdin  = 0
19	Stdout = 1
20	Stderr = 2
21)
22
23// Do the interface allocations only once for common
24// Errno values.
25var (
26	errEAGAIN error = syscall.EAGAIN
27	errEINVAL error = syscall.EINVAL
28	errENOENT error = syscall.ENOENT
29)
30
31var (
32	signalNameMapOnce sync.Once
33	signalNameMap     map[string]syscall.Signal
34)
35
36// errnoErr returns common boxed Errno values, to prevent
37// allocations at runtime.
38func errnoErr(e syscall.Errno) error {
39	switch e {
40	case 0:
41		return nil
42	case EAGAIN:
43		return errEAGAIN
44	case EINVAL:
45		return errEINVAL
46	case ENOENT:
47		return errENOENT
48	}
49	return e
50}
51
52// ErrnoName returns the error name for error number e.
53func ErrnoName(e syscall.Errno) string {
54	i := sort.Search(len(errorList), func(i int) bool {
55		return errorList[i].num >= e
56	})
57	if i < len(errorList) && errorList[i].num == e {
58		return errorList[i].name
59	}
60	return ""
61}
62
63// SignalName returns the signal name for signal number s.
64func SignalName(s syscall.Signal) string {
65	i := sort.Search(len(signalList), func(i int) bool {
66		return signalList[i].num >= s
67	})
68	if i < len(signalList) && signalList[i].num == s {
69		return signalList[i].name
70	}
71	return ""
72}
73
74// SignalNum returns the syscall.Signal for signal named s,
75// or 0 if a signal with such name is not found.
76// The signal name should start with "SIG".
77func SignalNum(s string) syscall.Signal {
78	signalNameMapOnce.Do(func() {
79		signalNameMap = make(map[string]syscall.Signal)
80		for _, signal := range signalList {
81			signalNameMap[signal.name] = signal.num
82		}
83	})
84	return signalNameMap[s]
85}
86
87// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
88func clen(n []byte) int {
89	i := bytes.IndexByte(n, 0)
90	if i == -1 {
91		i = len(n)
92	}
93	return i
94}
95
96// Mmap manager, for use by operating system-specific implementations.
97
98type mmapper struct {
99	sync.Mutex
100	active map[*byte][]byte // active mappings; key is last byte in mapping
101	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
102	munmap func(addr uintptr, length uintptr) error
103}
104
105func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
106	if length <= 0 {
107		return nil, EINVAL
108	}
109
110	// Map the requested memory.
111	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
112	if errno != nil {
113		return nil, errno
114	}
115
116	// Slice memory layout
117	var sl = struct {
118		addr uintptr
119		len  int
120		cap  int
121	}{addr, length, length}
122
123	// Use unsafe to turn sl into a []byte.
124	b := *(*[]byte)(unsafe.Pointer(&sl))
125
126	// Register mapping in m and return it.
127	p := &b[cap(b)-1]
128	m.Lock()
129	defer m.Unlock()
130	m.active[p] = b
131	return b, nil
132}
133
134func (m *mmapper) Munmap(data []byte) (err error) {
135	if len(data) == 0 || len(data) != cap(data) {
136		return EINVAL
137	}
138
139	// Find the base of the mapping.
140	p := &data[cap(data)-1]
141	m.Lock()
142	defer m.Unlock()
143	b := m.active[p]
144	if b == nil || &b[0] != &data[0] {
145		return EINVAL
146	}
147
148	// Unmap the memory and update m.
149	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
150		return errno
151	}
152	delete(m.active, p)
153	return nil
154}
155
156func Read(fd int, p []byte) (n int, err error) {
157	n, err = read(fd, p)
158	if raceenabled {
159		if n > 0 {
160			raceWriteRange(unsafe.Pointer(&p[0]), n)
161		}
162		if err == nil {
163			raceAcquire(unsafe.Pointer(&ioSync))
164		}
165	}
166	return
167}
168
169func Write(fd int, p []byte) (n int, err error) {
170	if raceenabled {
171		raceReleaseMerge(unsafe.Pointer(&ioSync))
172	}
173	n, err = write(fd, p)
174	if raceenabled && n > 0 {
175		raceReadRange(unsafe.Pointer(&p[0]), n)
176	}
177	return
178}
179
180// For testing: clients can set this flag to force
181// creation of IPv6 sockets to return EAFNOSUPPORT.
182var SocketDisableIPv6 bool
183
184// Sockaddr represents a socket address.
185type Sockaddr interface {
186	sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
187}
188
189// SockaddrInet4 implements the Sockaddr interface for AF_INET type sockets.
190type SockaddrInet4 struct {
191	Port int
192	Addr [4]byte
193	raw  RawSockaddrInet4
194}
195
196// SockaddrInet6 implements the Sockaddr interface for AF_INET6 type sockets.
197type SockaddrInet6 struct {
198	Port   int
199	ZoneId uint32
200	Addr   [16]byte
201	raw    RawSockaddrInet6
202}
203
204// SockaddrUnix implements the Sockaddr interface for AF_UNIX type sockets.
205type SockaddrUnix struct {
206	Name string
207	raw  RawSockaddrUnix
208}
209
210func Bind(fd int, sa Sockaddr) (err error) {
211	ptr, n, err := sa.sockaddr()
212	if err != nil {
213		return err
214	}
215	return bind(fd, ptr, n)
216}
217
218func Connect(fd int, sa Sockaddr) (err error) {
219	ptr, n, err := sa.sockaddr()
220	if err != nil {
221		return err
222	}
223	return connect(fd, ptr, n)
224}
225
226func Getpeername(fd int) (sa Sockaddr, err error) {
227	var rsa RawSockaddrAny
228	var len _Socklen = SizeofSockaddrAny
229	if err = getpeername(fd, &rsa, &len); err != nil {
230		return
231	}
232	return anyToSockaddr(fd, &rsa)
233}
234
235func GetsockoptByte(fd, level, opt int) (value byte, err error) {
236	var n byte
237	vallen := _Socklen(1)
238	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
239	return n, err
240}
241
242func GetsockoptInt(fd, level, opt int) (value int, err error) {
243	var n int32
244	vallen := _Socklen(4)
245	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
246	return int(n), err
247}
248
249func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
250	vallen := _Socklen(4)
251	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
252	return value, err
253}
254
255func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
256	var value IPMreq
257	vallen := _Socklen(SizeofIPMreq)
258	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
259	return &value, err
260}
261
262func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
263	var value IPv6Mreq
264	vallen := _Socklen(SizeofIPv6Mreq)
265	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
266	return &value, err
267}
268
269func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
270	var value IPv6MTUInfo
271	vallen := _Socklen(SizeofIPv6MTUInfo)
272	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
273	return &value, err
274}
275
276func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
277	var value ICMPv6Filter
278	vallen := _Socklen(SizeofICMPv6Filter)
279	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
280	return &value, err
281}
282
283func GetsockoptLinger(fd, level, opt int) (*Linger, error) {
284	var linger Linger
285	vallen := _Socklen(SizeofLinger)
286	err := getsockopt(fd, level, opt, unsafe.Pointer(&linger), &vallen)
287	return &linger, err
288}
289
290func GetsockoptTimeval(fd, level, opt int) (*Timeval, error) {
291	var tv Timeval
292	vallen := _Socklen(unsafe.Sizeof(tv))
293	err := getsockopt(fd, level, opt, unsafe.Pointer(&tv), &vallen)
294	return &tv, err
295}
296
297func GetsockoptUint64(fd, level, opt int) (value uint64, err error) {
298	var n uint64
299	vallen := _Socklen(8)
300	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
301	return n, err
302}
303
304func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
305	var rsa RawSockaddrAny
306	var len _Socklen = SizeofSockaddrAny
307	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
308		return
309	}
310	if rsa.Addr.Family != AF_UNSPEC {
311		from, err = anyToSockaddr(fd, &rsa)
312	}
313	return
314}
315
316func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
317	ptr, n, err := to.sockaddr()
318	if err != nil {
319		return err
320	}
321	return sendto(fd, p, flags, ptr, n)
322}
323
324func SetsockoptByte(fd, level, opt int, value byte) (err error) {
325	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
326}
327
328func SetsockoptInt(fd, level, opt int, value int) (err error) {
329	var n = int32(value)
330	return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
331}
332
333func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
334	return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
335}
336
337func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
338	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
339}
340
341func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
342	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
343}
344
345func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
346	return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
347}
348
349func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
350	return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
351}
352
353func SetsockoptString(fd, level, opt int, s string) (err error) {
354	var p unsafe.Pointer
355	if len(s) > 0 {
356		p = unsafe.Pointer(&[]byte(s)[0])
357	}
358	return setsockopt(fd, level, opt, p, uintptr(len(s)))
359}
360
361func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
362	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
363}
364
365func SetsockoptUint64(fd, level, opt int, value uint64) (err error) {
366	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 8)
367}
368
369func Socket(domain, typ, proto int) (fd int, err error) {
370	if domain == AF_INET6 && SocketDisableIPv6 {
371		return -1, EAFNOSUPPORT
372	}
373	fd, err = socket(domain, typ, proto)
374	return
375}
376
377func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
378	var fdx [2]int32
379	err = socketpair(domain, typ, proto, &fdx)
380	if err == nil {
381		fd[0] = int(fdx[0])
382		fd[1] = int(fdx[1])
383	}
384	return
385}
386
387var ioSync int64
388
389func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
390
391func SetNonblock(fd int, nonblocking bool) (err error) {
392	flag, err := fcntl(fd, F_GETFL, 0)
393	if err != nil {
394		return err
395	}
396	if nonblocking {
397		flag |= O_NONBLOCK
398	} else {
399		flag &= ^O_NONBLOCK
400	}
401	_, err = fcntl(fd, F_SETFL, flag)
402	return err
403}
404
405// Exec calls execve(2), which replaces the calling executable in the process
406// tree. argv0 should be the full path to an executable ("/bin/ls") and the
407// executable name should also be the first argument in argv (["ls", "-l"]).
408// envv are the environment variables that should be passed to the new
409// process (["USER=go", "PWD=/tmp"]).
410func Exec(argv0 string, argv []string, envv []string) error {
411	return syscall.Exec(argv0, argv, envv)
412}
413
414// Lutimes sets the access and modification times tv on path. If path refers to
415// a symlink, it is not dereferenced and the timestamps are set on the symlink.
416// If tv is nil, the access and modification times are set to the current time.
417// Otherwise tv must contain exactly 2 elements, with access time as the first
418// element and modification time as the second element.
419func Lutimes(path string, tv []Timeval) error {
420	if tv == nil {
421		return UtimesNanoAt(AT_FDCWD, path, nil, AT_SYMLINK_NOFOLLOW)
422	}
423	if len(tv) != 2 {
424		return EINVAL
425	}
426	ts := []Timespec{
427		NsecToTimespec(TimevalToNsec(tv[0])),
428		NsecToTimespec(TimevalToNsec(tv[1])),
429	}
430	return UtimesNanoAt(AT_FDCWD, path, ts, AT_SYMLINK_NOFOLLOW)
431}
432