vendor/golang.org/x/sys/unix/syscall_unix.go

   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 }