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
31// errnoErr returns common boxed Errno values, to prevent
32// allocations at runtime.
33func errnoErr(e syscall.Errno) error {
34	switch e {
35	case 0:
36		return nil
37	case EAGAIN:
38		return errEAGAIN
39	case EINVAL:
40		return errEINVAL
41	case ENOENT:
42		return errENOENT
43	}
44	return e
45}
46
47// ErrnoName returns the error name for error number e.
48func ErrnoName(e syscall.Errno) string {
49	i := sort.Search(len(errorList), func(i int) bool {
50		return errorList[i].num >= e
51	})
52	if i < len(errorList) && errorList[i].num == e {
53		return errorList[i].name
54	}
55	return ""
56}
57
58// SignalName returns the signal name for signal number s.
59func SignalName(s syscall.Signal) string {
60	i := sort.Search(len(signalList), func(i int) bool {
61		return signalList[i].num >= s
62	})
63	if i < len(signalList) && signalList[i].num == s {
64		return signalList[i].name
65	}
66	return ""
67}
68
69// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
70func clen(n []byte) int {
71	i := bytes.IndexByte(n, 0)
72	if i == -1 {
73		i = len(n)
74	}
75	return i
76}
77
78// Mmap manager, for use by operating system-specific implementations.
79
80type mmapper struct {
81	sync.Mutex
82	active map[*byte][]byte // active mappings; key is last byte in mapping
83	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
84	munmap func(addr uintptr, length uintptr) error
85}
86
87func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
88	if length <= 0 {
89		return nil, EINVAL
90	}
91
92	// Map the requested memory.
93	addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
94	if errno != nil {
95		return nil, errno
96	}
97
98	// Slice memory layout
99	var sl = struct {
100		addr uintptr
101		len  int
102		cap  int
103	}{addr, length, length}
104
105	// Use unsafe to turn sl into a []byte.
106	b := *(*[]byte)(unsafe.Pointer(&sl))
107
108	// Register mapping in m and return it.
109	p := &b[cap(b)-1]
110	m.Lock()
111	defer m.Unlock()
112	m.active[p] = b
113	return b, nil
114}
115
116func (m *mmapper) Munmap(data []byte) (err error) {
117	if len(data) == 0 || len(data) != cap(data) {
118		return EINVAL
119	}
120
121	// Find the base of the mapping.
122	p := &data[cap(data)-1]
123	m.Lock()
124	defer m.Unlock()
125	b := m.active[p]
126	if b == nil || &b[0] != &data[0] {
127		return EINVAL
128	}
129
130	// Unmap the memory and update m.
131	if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
132		return errno
133	}
134	delete(m.active, p)
135	return nil
136}
137
138func Read(fd int, p []byte) (n int, err error) {
139	n, err = read(fd, p)
140	if raceenabled {
141		if n > 0 {
142			raceWriteRange(unsafe.Pointer(&p[0]), n)
143		}
144		if err == nil {
145			raceAcquire(unsafe.Pointer(&ioSync))
146		}
147	}
148	return
149}
150
151func Write(fd int, p []byte) (n int, err error) {
152	if raceenabled {
153		raceReleaseMerge(unsafe.Pointer(&ioSync))
154	}
155	n, err = write(fd, p)
156	if raceenabled && n > 0 {
157		raceReadRange(unsafe.Pointer(&p[0]), n)
158	}
159	return
160}
161
162// For testing: clients can set this flag to force
163// creation of IPv6 sockets to return EAFNOSUPPORT.
164var SocketDisableIPv6 bool
165
166// Sockaddr represents a socket address.
167type Sockaddr interface {
168	sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // lowercase; only we can define Sockaddrs
169}
170
171// SockaddrInet4 implements the Sockaddr interface for AF_INET type sockets.
172type SockaddrInet4 struct {
173	Port int
174	Addr [4]byte
175	raw  RawSockaddrInet4
176}
177
178// SockaddrInet6 implements the Sockaddr interface for AF_INET6 type sockets.
179type SockaddrInet6 struct {
180	Port   int
181	ZoneId uint32
182	Addr   [16]byte
183	raw    RawSockaddrInet6
184}
185
186// SockaddrUnix implements the Sockaddr interface for AF_UNIX type sockets.
187type SockaddrUnix struct {
188	Name string
189	raw  RawSockaddrUnix
190}
191
192func Bind(fd int, sa Sockaddr) (err error) {
193	ptr, n, err := sa.sockaddr()
194	if err != nil {
195		return err
196	}
197	return bind(fd, ptr, n)
198}
199
200func Connect(fd int, sa Sockaddr) (err error) {
201	ptr, n, err := sa.sockaddr()
202	if err != nil {
203		return err
204	}
205	return connect(fd, ptr, n)
206}
207
208func Getpeername(fd int) (sa Sockaddr, err error) {
209	var rsa RawSockaddrAny
210	var len _Socklen = SizeofSockaddrAny
211	if err = getpeername(fd, &rsa, &len); err != nil {
212		return
213	}
214	return anyToSockaddr(fd, &rsa)
215}
216
217func GetsockoptByte(fd, level, opt int) (value byte, err error) {
218	var n byte
219	vallen := _Socklen(1)
220	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
221	return n, err
222}
223
224func GetsockoptInt(fd, level, opt int) (value int, err error) {
225	var n int32
226	vallen := _Socklen(4)
227	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
228	return int(n), err
229}
230
231func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
232	vallen := _Socklen(4)
233	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
234	return value, err
235}
236
237func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
238	var value IPMreq
239	vallen := _Socklen(SizeofIPMreq)
240	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
241	return &value, err
242}
243
244func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
245	var value IPv6Mreq
246	vallen := _Socklen(SizeofIPv6Mreq)
247	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
248	return &value, err
249}
250
251func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
252	var value IPv6MTUInfo
253	vallen := _Socklen(SizeofIPv6MTUInfo)
254	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
255	return &value, err
256}
257
258func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
259	var value ICMPv6Filter
260	vallen := _Socklen(SizeofICMPv6Filter)
261	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
262	return &value, err
263}
264
265func GetsockoptLinger(fd, level, opt int) (*Linger, error) {
266	var linger Linger
267	vallen := _Socklen(SizeofLinger)
268	err := getsockopt(fd, level, opt, unsafe.Pointer(&linger), &vallen)
269	return &linger, err
270}
271
272func GetsockoptTimeval(fd, level, opt int) (*Timeval, error) {
273	var tv Timeval
274	vallen := _Socklen(unsafe.Sizeof(tv))
275	err := getsockopt(fd, level, opt, unsafe.Pointer(&tv), &vallen)
276	return &tv, err
277}
278
279func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
280	var rsa RawSockaddrAny
281	var len _Socklen = SizeofSockaddrAny
282	if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
283		return
284	}
285	if rsa.Addr.Family != AF_UNSPEC {
286		from, err = anyToSockaddr(fd, &rsa)
287	}
288	return
289}
290
291func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
292	ptr, n, err := to.sockaddr()
293	if err != nil {
294		return err
295	}
296	return sendto(fd, p, flags, ptr, n)
297}
298
299func SetsockoptByte(fd, level, opt int, value byte) (err error) {
300	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1)
301}
302
303func SetsockoptInt(fd, level, opt int, value int) (err error) {
304	var n = int32(value)
305	return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
306}
307
308func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
309	return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
310}
311
312func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
313	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq)
314}
315
316func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
317	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq)
318}
319
320func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
321	return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
322}
323
324func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
325	return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger)
326}
327
328func SetsockoptString(fd, level, opt int, s string) (err error) {
329	return setsockopt(fd, level, opt, unsafe.Pointer(&[]byte(s)[0]), uintptr(len(s)))
330}
331
332func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
333	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
334}
335
336func Socket(domain, typ, proto int) (fd int, err error) {
337	if domain == AF_INET6 && SocketDisableIPv6 {
338		return -1, EAFNOSUPPORT
339	}
340	fd, err = socket(domain, typ, proto)
341	return
342}
343
344func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
345	var fdx [2]int32
346	err = socketpair(domain, typ, proto, &fdx)
347	if err == nil {
348		fd[0] = int(fdx[0])
349		fd[1] = int(fdx[1])
350	}
351	return
352}
353
354var ioSync int64
355
356func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) }
357
358func SetNonblock(fd int, nonblocking bool) (err error) {
359	flag, err := fcntl(fd, F_GETFL, 0)
360	if err != nil {
361		return err
362	}
363	if nonblocking {
364		flag |= O_NONBLOCK
365	} else {
366		flag &= ^O_NONBLOCK
367	}
368	_, err = fcntl(fd, F_SETFL, flag)
369	return err
370}
371
372// Exec calls execve(2), which replaces the calling executable in the process
373// tree. argv0 should be the full path to an executable ("/bin/ls") and the
374// executable name should also be the first argument in argv (["ls", "-l"]).
375// envv are the environment variables that should be passed to the new
376// process (["USER=go", "PWD=/tmp"]).
377func Exec(argv0 string, argv []string, envv []string) error {
378	return syscall.Exec(argv0, argv, envv)
379}
380