libgo/go/syscall/socket.go

   1 // socket.go -- Socket handling.
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 // Low-level socket interface.
   8 // Only for implementing net package.
   9 // DO NOT USE DIRECTLY.
  10
  11 package syscall
  12
  13 import "unsafe"
  14
  15 // These functions are called from the internal/syscall/unix package.
  16 // Use go:linkname to export them.
  17 //
  18 //go:linkname recvfromInet4
  19 //go:linkname recvfromInet6
  20 //go:linkname sendtoInet4
  21 //go:linkname sendtoInet6
  22 //go:linkname sendmsgNInet4
  23 //go:linkname sendmsgNInet6
  24 //go:linkname recvmsgInet4
  25 //go:linkname recvmsgInet6
  26
  27 // For testing: clients can set this flag to force
  28 // creation of IPv6 sockets to return EAFNOSUPPORT.
  29 var SocketDisableIPv6 bool
  30
  31 type Sockaddr interface {
  32         sockaddr() (ptr *RawSockaddrAny, len Socklen_t, err error) // lowercase; only we can define Sockaddrs
  33 }
  34
  35 type RawSockaddrAny struct {
  36         Addr RawSockaddr
  37         Pad  [96]int8
  38 }
  39
  40 const SizeofSockaddrAny = 0x6c
  41
  42 type SockaddrInet4 struct {
  43         Port int
  44         Addr [4]byte
  45         raw  RawSockaddrInet4
  46 }
  47
  48 func (sa *SockaddrInet4) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  49         if sa.Port < 0 || sa.Port > 0xFFFF {
  50                 return nil, 0, EINVAL
  51         }
  52         sa.raw.Family = AF_INET
  53         n := sa.raw.setLen()
  54         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  55         p[0] = byte(sa.Port >> 8)
  56         p[1] = byte(sa.Port)
  57         for i := 0; i < len(sa.Addr); i++ {
  58                 sa.raw.Addr[i] = sa.Addr[i]
  59         }
  60         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
  61 }
  62
  63 type SockaddrInet6 struct {
  64         Port   int
  65         ZoneId uint32
  66         Addr   [16]byte
  67         raw    RawSockaddrInet6
  68 }
  69
  70 func (sa *SockaddrInet6) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  71         if sa.Port < 0 || sa.Port > 0xFFFF {
  72                 return nil, 0, EINVAL
  73         }
  74         sa.raw.Family = AF_INET6
  75         n := sa.raw.setLen()
  76         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  77         p[0] = byte(sa.Port >> 8)
  78         p[1] = byte(sa.Port)
  79         sa.raw.Scope_id = sa.ZoneId
  80         for i := 0; i < len(sa.Addr); i++ {
  81                 sa.raw.Addr[i] = sa.Addr[i]
  82         }
  83         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
  84 }
  85
  86 type SockaddrUnix struct {
  87         Name string
  88         raw  RawSockaddrUnix
  89 }
  90
  91 func (sa *SockaddrUnix) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  92         name := sa.Name
  93         n := len(name)
  94         if n > len(sa.raw.Path) {
  95                 return nil, 0, EINVAL
  96         }
  97         sa.raw.Family = AF_UNIX
  98         sa.raw.setLen(n)
  99         for i := 0; i < n; i++ {
 100                 sa.raw.Path[i] = int8(name[i])
 101         }
 102         // length is family (uint16), name, NUL.
 103         sl := Socklen_t(2)
 104         if n > 0 {
 105                 sl += Socklen_t(n) + 1
 106         }
 107         sl = sa.raw.adjustAbstract(sl)
 108         // Check again after adjustAbstract adjusts the length.
 109         // This is testing whether the +1 for NUL puts us out of range.
 110         if sl-2 > Socklen_t(len(sa.raw.Path)) {
 111                 return nil, 0, EINVAL
 112         }
 113
 114         // length is family (uint16), name, NUL.
 115         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), sl, nil
 116 }
 117
 118 func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
 119         switch rsa.Addr.Family {
 120         case AF_UNIX:
 121                 pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
 122                 sa := new(SockaddrUnix)
 123                 n, err := pp.getLen()
 124                 if err != nil {
 125                         return nil, err
 126                 }
 127                 bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))
 128                 sa.Name = string(bytes[0:n])
 129                 return sa, nil
 130
 131         case AF_INET:
 132                 pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
 133                 sa := new(SockaddrInet4)
 134                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 135                 sa.Port = int(p[0])<<8 + int(p[1])
 136                 for i := 0; i < len(sa.Addr); i++ {
 137                         sa.Addr[i] = pp.Addr[i]
 138                 }
 139                 return sa, nil
 140
 141         case AF_INET6:
 142                 pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
 143                 sa := new(SockaddrInet6)
 144                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 145                 sa.Port = int(p[0])<<8 + int(p[1])
 146                 for i := 0; i < len(sa.Addr); i++ {
 147                         sa.Addr[i] = pp.Addr[i]
 148                 }
 149                 return sa, nil
 150         }
 151         return anyToSockaddrOS(rsa)
 152 }
 153
 154 //sys   accept(fd int, sa *RawSockaddrAny, len *Socklen_t) (nfd int, err error)
 155 //accept(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 156
 157 func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 158         var rsa RawSockaddrAny
 159         var len Socklen_t = SizeofSockaddrAny
 160         nfd, err = accept(fd, &rsa, &len)
 161         if err != nil {
 162                 return
 163         }
 164         sa, err = anyToSockaddr(&rsa)
 165         if err != nil {
 166                 Close(nfd)
 167                 nfd = 0
 168         }
 169         return
 170 }
 171
 172 //sysnb getsockname(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 173 //getsockname(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 174
 175 func Getsockname(fd int) (sa Sockaddr, err error) {
 176         var rsa RawSockaddrAny
 177         var len Socklen_t = SizeofSockaddrAny
 178         if err = getsockname(fd, &rsa, &len); err != nil {
 179                 return
 180         }
 181         return anyToSockaddr(&rsa)
 182 }
 183
 184 //sysnb getpeername(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 185 //getpeername(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 186
 187 func Getpeername(fd int) (sa Sockaddr, err error) {
 188         var rsa RawSockaddrAny
 189         var len Socklen_t = SizeofSockaddrAny
 190         if err = getpeername(fd, &rsa, &len); err != nil {
 191                 return
 192         }
 193         return anyToSockaddr(&rsa)
 194 }
 195
 196 func Bind(fd int, sa Sockaddr) (err error) {
 197         ptr, n, err := sa.sockaddr()
 198         if err != nil {
 199                 return err
 200         }
 201         return bind(fd, ptr, n)
 202 }
 203
 204 func Connect(fd int, sa Sockaddr) (err error) {
 205         ptr, n, err := sa.sockaddr()
 206         if err != nil {
 207                 return err
 208         }
 209         return connect(fd, ptr, n)
 210 }
 211
 212 func Socket(domain, typ, proto int) (fd int, err error) {
 213         if domain == AF_INET6 && SocketDisableIPv6 {
 214                 return -1, EAFNOSUPPORT
 215         }
 216         fd, err = socket(domain, typ, proto)
 217         return
 218 }
 219
 220 func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
 221         var fdx [2]_C_int
 222         err = socketpair(domain, typ, proto, &fdx)
 223         if err == nil {
 224                 fd[0] = int(fdx[0])
 225                 fd[1] = int(fdx[1])
 226         }
 227         return
 228 }
 229
 230 func GetsockoptByte(fd, level, opt int) (value byte, err error) {
 231         var n byte
 232         vallen := Socklen_t(1)
 233         err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
 234         return n, err
 235 }
 236
 237 func GetsockoptInt(fd, level, opt int) (value int, err error) {
 238         var n int32
 239         vallen := Socklen_t(4)
 240         err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
 241         return int(n), err
 242 }
 243
 244 func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
 245         vallen := Socklen_t(4)
 246         err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
 247         return value, err
 248 }
 249
 250 func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
 251         var value IPMreq
 252         vallen := Socklen_t(SizeofIPMreq)
 253         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 254         return &value, err
 255 }
 256
 257 func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
 258         var value IPMreqn
 259         vallen := Socklen_t(SizeofIPMreqn)
 260         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 261         return &value, err
 262 }
 263
 264 func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
 265         var value IPv6Mreq
 266         vallen := Socklen_t(SizeofIPv6Mreq)
 267         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 268         return &value, err
 269 }
 270
 271 func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
 272         var value ICMPv6Filter
 273         vallen := Socklen_t(SizeofICMPv6Filter)
 274         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 275         return &value, err
 276 }
 277
 278 //sys   setsockopt(s int, level int, name int, val unsafe.Pointer, vallen Socklen_t) (err error)
 279 //setsockopt(s _C_int, level _C_int, optname _C_int, val *byte, vallen Socklen_t) _C_int
 280
 281 func SetsockoptByte(fd, level, opt int, value byte) (err error) {
 282         var n = byte(value)
 283         return setsockopt(fd, level, opt, unsafe.Pointer(&n), 1)
 284 }
 285
 286 func SetsockoptInt(fd, level, opt int, value int) (err error) {
 287         var n = int32(value)
 288         return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
 289 }
 290
 291 func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
 292         return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
 293 }
 294
 295 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
 296         return setsockopt(fd, level, opt, unsafe.Pointer(tv), Socklen_t(unsafe.Sizeof(*tv)))
 297 }
 298
 299 func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
 300         return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
 301 }
 302
 303 type Linger struct {
 304         Onoff  int32
 305         Linger int32
 306 }
 307
 308 func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
 309         return setsockopt(fd, level, opt, unsafe.Pointer(l), Socklen_t(unsafe.Sizeof(*l)))
 310 }
 311
 312 func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
 313         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 314 }
 315
 316 func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
 317         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 318 }
 319
 320 func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
 321         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 322 }
 323
 324 func SetsockoptString(fd, level, opt int, s string) (err error) {
 325         var p unsafe.Pointer
 326         if len(s) > 0 {
 327                 p = unsafe.Pointer(&[]byte(s)[0])
 328         }
 329         return setsockopt(fd, level, opt, p, Socklen_t(len(s)))
 330 }
 331
 332 //sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *Socklen_t) (n int, err error)
 333 //recvfrom(fd _C_int, buf *byte, len Size_t, flags _C_int, from *RawSockaddrAny, fromlen *Socklen_t) Ssize_t
 334
 335 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 336         var rsa RawSockaddrAny
 337         var len Socklen_t = SizeofSockaddrAny
 338         if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
 339                 return
 340         }
 341         if rsa.Addr.Family != AF_UNSPEC {
 342                 from, err = anyToSockaddr(&rsa)
 343         }
 344         return
 345 }
 346
 347 func recvfromInet4(fd int, p []byte, flags int, from *SockaddrInet4) (n int, err error) {
 348         var rsa RawSockaddrAny
 349         var socklen Socklen_t = SizeofSockaddrAny
 350         if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
 351                 return
 352         }
 353         pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
 354         port := (*[2]byte)(unsafe.Pointer(&pp.Port))
 355         from.Port = int(port[0])<<8 + int(port[1])
 356         from.Addr = pp.Addr
 357         return
 358 }
 359
 360 func recvfromInet6(fd int, p []byte, flags int, from *SockaddrInet6) (n int, err error) {
 361         var rsa RawSockaddrAny
 362         var socklen Socklen_t = SizeofSockaddrAny
 363         if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
 364                 return
 365         }
 366         pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
 367         port := (*[2]byte)(unsafe.Pointer(&pp.Port))
 368         from.Port = int(port[0])<<8 + int(port[1])
 369         from.ZoneId = pp.Scope_id
 370         from.Addr = pp.Addr
 371         return
 372 }
 373
 374 func recvmsgInet4(fd int, p, oob []byte, flags int, from *SockaddrInet4) (n, oobn int, recvflags int, err error) {
 375         var rsa RawSockaddrAny
 376         n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
 377         if err != nil {
 378                 return
 379         }
 380         pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
 381         port := (*[2]byte)(unsafe.Pointer(&pp.Port))
 382         from.Port = int(port[0])<<8 + int(port[1])
 383         from.Addr = pp.Addr
 384         return
 385 }
 386
 387 func recvmsgInet6(fd int, p, oob []byte, flags int, from *SockaddrInet6) (n, oobn int, recvflags int, err error) {
 388         var rsa RawSockaddrAny
 389         n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
 390         if err != nil {
 391                 return
 392         }
 393         pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
 394         port := (*[2]byte)(unsafe.Pointer(&pp.Port))
 395         from.Port = int(port[0])<<8 + int(port[1])
 396         from.ZoneId = pp.Scope_id
 397         from.Addr = pp.Addr
 398         return
 399 }
 400
 401 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
 402         var rsa RawSockaddrAny
 403         n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
 404         // source address is only specified if the socket is unconnected
 405         if rsa.Addr.Family != AF_UNSPEC {
 406                 from, err = anyToSockaddr(&rsa)
 407         }
 408         return
 409 }
 410
 411 func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
 412         _, err = SendmsgN(fd, p, oob, to, flags)
 413         return
 414 }
 415
 416 func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
 417         var ptr *RawSockaddrAny
 418         var salen Socklen_t
 419         if to != nil {
 420                 ptr, salen, err = to.sockaddr()
 421                 if err != nil {
 422                         return 0, err
 423                 }
 424         }
 425         return sendmsgN(fd, p, oob, ptr, salen, flags)
 426 }
 427
 428 func sendmsgNInet4(fd int, p, oob []byte, to *SockaddrInet4, flags int) (n int, err error) {
 429         ptr, salen, err := to.sockaddr()
 430         if err != nil {
 431                 return 0, err
 432         }
 433         return sendmsgN(fd, p, oob, ptr, salen, flags)
 434 }
 435
 436 func sendmsgNInet6(fd int, p, oob []byte, to *SockaddrInet6, flags int) (n int, err error) {
 437         ptr, salen, err := to.sockaddr()
 438         if err != nil {
 439                 return 0, err
 440         }
 441         return sendmsgN(fd, p, oob, ptr, salen, flags)
 442 }
 443
 444 func sendtoInet4(fd int, p []byte, flags int, to *SockaddrInet4) (err error) {
 445         ptr, n, err := to.sockaddr()
 446         if err != nil {
 447                 return err
 448         }
 449         return sendto(fd, p, flags, ptr, n)
 450 }
 451
 452 func sendtoInet6(fd int, p []byte, flags int, to *SockaddrInet6) (err error) {
 453         ptr, n, err := to.sockaddr()
 454         if err != nil {
 455                 return err
 456         }
 457         return sendto(fd, p, flags, ptr, n)
 458 }
 459
 460 func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 461         ptr, n, err := to.sockaddr()
 462         if err != nil {
 463                 return err
 464         }
 465         return sendto(fd, p, flags, ptr, n)
 466 }
 467
 468 func recvmsgRaw(fd int, p, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
 469         var msg Msghdr
 470         msg.Name = (*byte)(unsafe.Pointer(&rsa))
 471         msg.Namelen = uint32(SizeofSockaddrAny)
 472         var iov Iovec
 473         if len(p) > 0 {
 474                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 475                 iov.SetLen(len(p))
 476         }
 477         var dummy byte
 478         if len(oob) > 0 {
 479                 var sockType int
 480                 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
 481                 if err != nil {
 482                         return
 483                 }
 484                 // receive at least one normal byte
 485                 if sockType != SOCK_DGRAM && len(p) == 0 {
 486                         iov.Base = &dummy
 487                         iov.SetLen(1)
 488                 }
 489                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 490                 msg.SetControllen(len(oob))
 491         }
 492         msg.Iov = &iov
 493         msg.Iovlen = 1
 494         if n, err = recvmsg(fd, &msg, flags); err != nil {
 495                 return
 496         }
 497         oobn = int(msg.Controllen)
 498         recvflags = int(msg.Flags)
 499         return
 500 }
 501
 502 func sendmsgN(fd int, p, oob []byte, to *RawSockaddrAny, salen Socklen_t, flags int) (n int, err error) {
 503         var msg Msghdr
 504         msg.Name = (*byte)(unsafe.Pointer(to))
 505         msg.Namelen = uint32(salen)
 506         var iov Iovec
 507         if len(p) > 0 {
 508                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 509                 iov.SetLen(len(p))
 510         }
 511         var dummy byte
 512         if len(oob) > 0 {
 513                 var sockType int
 514                 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
 515                 if err != nil {
 516                         return 0, err
 517                 }
 518                 // send at least one normal byte
 519                 if sockType != SOCK_DGRAM && len(p) == 0 {
 520                         iov.Base = &dummy
 521                         iov.SetLen(1)
 522                 }
 523                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 524                 msg.SetControllen(len(oob))
 525         }
 526         msg.Iov = &iov
 527         msg.Iovlen = 1
 528         if n, err = sendmsg(fd, &msg, flags); err != nil {
 529                 return 0, err
 530         }
 531         if len(oob) > 0 && len(p) == 0 {
 532                 n = 0
 533         }
 534         return n, nil
 535 }
 536
 537 //sys   Listen(fd int, n int) (err error)
 538 //listen(fd _C_int, n _C_int) _C_int
 539
 540 //sys   Shutdown(fd int, how int) (err error)
 541 //shutdown(fd _C_int, how _C_int) _C_int
 542
 543 func (iov *Iovec) SetLen(length int) {
 544         iov.Len = Iovec_len_t(length)
 545 }
 546
 547 func (msghdr *Msghdr) SetControllen(length int) {
 548         msghdr.Controllen = Msghdr_controllen_t(length)
 549 }
 550
 551 func (cmsg *Cmsghdr) SetLen(length int) {
 552         cmsg.Len = Cmsghdr_len_t(length)
 553 }