Dinesh Belwalkar | e63f7f9 | 2019-11-22 23:11:16 +0000 | [diff] [blame^] | 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 | |
| 7 | package unix |
| 8 | |
| 9 | import ( |
| 10 | "bytes" |
| 11 | "sort" |
| 12 | "sync" |
| 13 | "syscall" |
| 14 | "unsafe" |
| 15 | ) |
| 16 | |
| 17 | var ( |
| 18 | Stdin = 0 |
| 19 | Stdout = 1 |
| 20 | Stderr = 2 |
| 21 | ) |
| 22 | |
| 23 | // Do the interface allocations only once for common |
| 24 | // Errno values. |
| 25 | var ( |
| 26 | errEAGAIN error = syscall.EAGAIN |
| 27 | errEINVAL error = syscall.EINVAL |
| 28 | errENOENT error = syscall.ENOENT |
| 29 | ) |
| 30 | |
| 31 | var ( |
| 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. |
| 38 | func 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. |
| 53 | func 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. |
| 64 | func 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". |
| 77 | func 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. |
| 88 | func 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 | |
| 98 | type 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 | |
| 105 | func (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 | |
| 134 | func (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 | |
| 156 | func 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 | |
| 169 | func 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. |
| 182 | var SocketDisableIPv6 bool |
| 183 | |
| 184 | // Sockaddr represents a socket address. |
| 185 | type 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. |
| 190 | type 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. |
| 197 | type 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. |
| 205 | type SockaddrUnix struct { |
| 206 | Name string |
| 207 | raw RawSockaddrUnix |
| 208 | } |
| 209 | |
| 210 | func 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 | |
| 218 | func 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 | |
| 226 | func 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 | |
| 235 | func 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 | |
| 242 | func 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 | |
| 249 | func 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 | |
| 255 | func 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 | |
| 262 | func 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 | |
| 269 | func 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 | |
| 276 | func 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 | |
| 283 | func 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 | |
| 290 | func 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 | |
| 297 | func 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 | |
| 304 | func 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 | |
| 316 | func 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 | |
| 324 | func SetsockoptByte(fd, level, opt int, value byte) (err error) { |
| 325 | return setsockopt(fd, level, opt, unsafe.Pointer(&value), 1) |
| 326 | } |
| 327 | |
| 328 | func 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 | |
| 333 | func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) { |
| 334 | return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4) |
| 335 | } |
| 336 | |
| 337 | func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) { |
| 338 | return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPMreq) |
| 339 | } |
| 340 | |
| 341 | func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) { |
| 342 | return setsockopt(fd, level, opt, unsafe.Pointer(mreq), SizeofIPv6Mreq) |
| 343 | } |
| 344 | |
| 345 | func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error { |
| 346 | return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter) |
| 347 | } |
| 348 | |
| 349 | func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) { |
| 350 | return setsockopt(fd, level, opt, unsafe.Pointer(l), SizeofLinger) |
| 351 | } |
| 352 | |
| 353 | func 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 | |
| 361 | func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) { |
| 362 | return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv)) |
| 363 | } |
| 364 | |
| 365 | func SetsockoptUint64(fd, level, opt int, value uint64) (err error) { |
| 366 | return setsockopt(fd, level, opt, unsafe.Pointer(&value), 8) |
| 367 | } |
| 368 | |
| 369 | func 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 | |
| 377 | func 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 | |
| 387 | var ioSync int64 |
| 388 | |
| 389 | func CloseOnExec(fd int) { fcntl(fd, F_SETFD, FD_CLOEXEC) } |
| 390 | |
| 391 | func 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"]). |
| 410 | func 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. |
| 419 | func 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 | } |