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 // For testing: clients can set this flag to force
  16 // creation of IPv6 sockets to return EAFNOSUPPORT.
  17 var SocketDisableIPv6 bool
  18
  19 type Sockaddr interface {
  20         sockaddr() (ptr *RawSockaddrAny, len Socklen_t, err error) // lowercase; only we can define Sockaddrs
  21 }
  22
  23 type RawSockaddrAny struct {
  24         Addr RawSockaddr
  25         Pad  [96]int8
  26 }
  27
  28 const SizeofSockaddrAny = 0x6c
  29
  30 type SockaddrInet4 struct {
  31         Port int
  32         Addr [4]byte
  33         raw  RawSockaddrInet4
  34 }
  35
  36 func (sa *SockaddrInet4) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  37         if sa.Port < 0 || sa.Port > 0xFFFF {
  38                 return nil, 0, EINVAL
  39         }
  40         sa.raw.Family = AF_INET
  41         n := sa.raw.setLen()
  42         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  43         p[0] = byte(sa.Port >> 8)
  44         p[1] = byte(sa.Port)
  45         for i := 0; i < len(sa.Addr); i++ {
  46                 sa.raw.Addr[i] = sa.Addr[i]
  47         }
  48         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
  49 }
  50
  51 type SockaddrInet6 struct {
  52         Port   int
  53         ZoneId uint32
  54         Addr   [16]byte
  55         raw    RawSockaddrInet6
  56 }
  57
  58 func (sa *SockaddrInet6) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  59         if sa.Port < 0 || sa.Port > 0xFFFF {
  60                 return nil, 0, EINVAL
  61         }
  62         sa.raw.Family = AF_INET6
  63         n := sa.raw.setLen()
  64         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  65         p[0] = byte(sa.Port >> 8)
  66         p[1] = byte(sa.Port)
  67         sa.raw.Scope_id = sa.ZoneId
  68         for i := 0; i < len(sa.Addr); i++ {
  69                 sa.raw.Addr[i] = sa.Addr[i]
  70         }
  71         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, nil
  72 }
  73
  74 type SockaddrUnix struct {
  75         Name string
  76         raw  RawSockaddrUnix
  77 }
  78
  79 func (sa *SockaddrUnix) sockaddr() (*RawSockaddrAny, Socklen_t, error) {
  80         name := sa.Name
  81         n := len(name)
  82         if n > len(sa.raw.Path) {
  83                 return nil, 0, EINVAL
  84         }
  85         sa.raw.Family = AF_UNIX
  86         sa.raw.setLen(n)
  87         for i := 0; i < n; i++ {
  88                 sa.raw.Path[i] = int8(name[i])
  89         }
  90         // length is family (uint16), name, NUL.
  91         sl := Socklen_t(2)
  92         if n > 0 {
  93                 sl += Socklen_t(n) + 1
  94         }
  95         sl = sa.raw.adjustAbstract(sl)
  96         // Check again after adjustAbstract adjusts the length.
  97         // This is testing whether the +1 for NUL puts us out of range.
  98         if sl-2 > Socklen_t(len(sa.raw.Path)) {
  99                 return nil, 0, EINVAL
 100         }
 101
 102         // length is family (uint16), name, NUL.
 103         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), sl, nil
 104 }
 105
 106 func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
 107         switch rsa.Addr.Family {
 108         case AF_UNIX:
 109                 pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
 110                 sa := new(SockaddrUnix)
 111                 n, err := pp.getLen()
 112                 if err != nil {
 113                         return nil, err
 114                 }
 115                 bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))
 116                 sa.Name = string(bytes[0:n])
 117                 return sa, nil
 118
 119         case AF_INET:
 120                 pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
 121                 sa := new(SockaddrInet4)
 122                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 123                 sa.Port = int(p[0])<<8 + int(p[1])
 124                 for i := 0; i < len(sa.Addr); i++ {
 125                         sa.Addr[i] = pp.Addr[i]
 126                 }
 127                 return sa, nil
 128
 129         case AF_INET6:
 130                 pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
 131                 sa := new(SockaddrInet6)
 132                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 133                 sa.Port = int(p[0])<<8 + int(p[1])
 134                 for i := 0; i < len(sa.Addr); i++ {
 135                         sa.Addr[i] = pp.Addr[i]
 136                 }
 137                 return sa, nil
 138         }
 139         return anyToSockaddrOS(rsa)
 140 }
 141
 142 //sys   accept(fd int, sa *RawSockaddrAny, len *Socklen_t) (nfd int, err error)
 143 //accept(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 144
 145 func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 146         var rsa RawSockaddrAny
 147         var len Socklen_t = SizeofSockaddrAny
 148         nfd, err = accept(fd, &rsa, &len)
 149         if err != nil {
 150                 return
 151         }
 152         sa, err = anyToSockaddr(&rsa)
 153         if err != nil {
 154                 Close(nfd)
 155                 nfd = 0
 156         }
 157         return
 158 }
 159
 160 //sysnb getsockname(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 161 //getsockname(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 162
 163 func Getsockname(fd int) (sa Sockaddr, err error) {
 164         var rsa RawSockaddrAny
 165         var len Socklen_t = SizeofSockaddrAny
 166         if err = getsockname(fd, &rsa, &len); err != nil {
 167                 return
 168         }
 169         return anyToSockaddr(&rsa)
 170 }
 171
 172 //sysnb getpeername(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 173 //getpeername(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 174
 175 func Getpeername(fd int) (sa Sockaddr, err error) {
 176         var rsa RawSockaddrAny
 177         var len Socklen_t = SizeofSockaddrAny
 178         if err = getpeername(fd, &rsa, &len); err != nil {
 179                 return
 180         }
 181         return anyToSockaddr(&rsa)
 182 }
 183
 184 func Bind(fd int, sa Sockaddr) (err error) {
 185         ptr, n, err := sa.sockaddr()
 186         if err != nil {
 187                 return err
 188         }
 189         return bind(fd, ptr, n)
 190 }
 191
 192 func Connect(fd int, sa Sockaddr) (err error) {
 193         ptr, n, err := sa.sockaddr()
 194         if err != nil {
 195                 return err
 196         }
 197         return connect(fd, ptr, n)
 198 }
 199
 200 func Socket(domain, typ, proto int) (fd int, err error) {
 201         if domain == AF_INET6 && SocketDisableIPv6 {
 202                 return -1, EAFNOSUPPORT
 203         }
 204         fd, err = socket(domain, typ, proto)
 205         return
 206 }
 207
 208 func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
 209         var fdx [2]_C_int
 210         err = socketpair(domain, typ, proto, &fdx)
 211         if err == nil {
 212                 fd[0] = int(fdx[0])
 213                 fd[1] = int(fdx[1])
 214         }
 215         return
 216 }
 217
 218 func GetsockoptByte(fd, level, opt int) (value byte, err error) {
 219         var n byte
 220         vallen := Socklen_t(1)
 221         err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
 222         return n, err
 223 }
 224
 225 func GetsockoptInt(fd, level, opt int) (value int, err error) {
 226         var n int32
 227         vallen := Socklen_t(4)
 228         err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
 229         return int(n), err
 230 }
 231
 232 func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
 233         vallen := Socklen_t(4)
 234         err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
 235         return value, err
 236 }
 237
 238 func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
 239         var value IPMreq
 240         vallen := Socklen_t(SizeofIPMreq)
 241         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 242         return &value, err
 243 }
 244
 245 func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
 246         var value IPMreqn
 247         vallen := Socklen_t(SizeofIPMreqn)
 248         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 249         return &value, err
 250 }
 251
 252 func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
 253         var value IPv6Mreq
 254         vallen := Socklen_t(SizeofIPv6Mreq)
 255         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 256         return &value, err
 257 }
 258
 259 func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
 260         var value ICMPv6Filter
 261         vallen := Socklen_t(SizeofICMPv6Filter)
 262         err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
 263         return &value, err
 264 }
 265
 266 //sys   setsockopt(s int, level int, name int, val unsafe.Pointer, vallen Socklen_t) (err error)
 267 //setsockopt(s _C_int, level _C_int, optname _C_int, val *byte, vallen Socklen_t) _C_int
 268
 269 func SetsockoptByte(fd, level, opt int, value byte) (err error) {
 270         var n = byte(value)
 271         return setsockopt(fd, level, opt, unsafe.Pointer(&n), 1)
 272 }
 273
 274 func SetsockoptInt(fd, level, opt int, value int) (err error) {
 275         var n = int32(value)
 276         return setsockopt(fd, level, opt, unsafe.Pointer(&n), 4)
 277 }
 278
 279 func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
 280         return setsockopt(fd, level, opt, unsafe.Pointer(&value[0]), 4)
 281 }
 282
 283 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
 284         return setsockopt(fd, level, opt, unsafe.Pointer(tv), Socklen_t(unsafe.Sizeof(*tv)))
 285 }
 286
 287 func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
 288         return setsockopt(fd, level, opt, unsafe.Pointer(filter), SizeofICMPv6Filter)
 289 }
 290
 291 type Linger struct {
 292         Onoff  int32
 293         Linger int32
 294 }
 295
 296 func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
 297         return setsockopt(fd, level, opt, unsafe.Pointer(l), Socklen_t(unsafe.Sizeof(*l)))
 298 }
 299
 300 func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
 301         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 302 }
 303
 304 func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
 305         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 306 }
 307
 308 func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
 309         return setsockopt(fd, level, opt, unsafe.Pointer(mreq), Socklen_t(unsafe.Sizeof(*mreq)))
 310 }
 311
 312 func SetsockoptString(fd, level, opt int, s string) (err error) {
 313         var p unsafe.Pointer
 314         if len(s) > 0 {
 315                 p = unsafe.Pointer(&[]byte(s)[0])
 316         }
 317         return setsockopt(fd, level, opt, p, Socklen_t(len(s)))
 318 }
 319
 320 //sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *Socklen_t) (n int, err error)
 321 //recvfrom(fd _C_int, buf *byte, len Size_t, flags _C_int, from *RawSockaddrAny, fromlen *Socklen_t) Ssize_t
 322
 323 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 324         var rsa RawSockaddrAny
 325         var len Socklen_t = SizeofSockaddrAny
 326         if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
 327                 return
 328         }
 329         if rsa.Addr.Family != AF_UNSPEC {
 330                 from, err = anyToSockaddr(&rsa)
 331         }
 332         return
 333 }
 334
 335 func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 336         ptr, n, err := to.sockaddr()
 337         if err != nil {
 338                 return err
 339         }
 340         return sendto(fd, p, flags, ptr, n)
 341 }
 342
 343 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
 344         var msg Msghdr
 345         var rsa RawSockaddrAny
 346         msg.Name = (*byte)(unsafe.Pointer(&rsa))
 347         msg.Namelen = uint32(SizeofSockaddrAny)
 348         var iov Iovec
 349         if len(p) > 0 {
 350                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 351                 iov.SetLen(len(p))
 352         }
 353         var dummy byte
 354         if len(oob) > 0 {
 355                 var sockType int
 356                 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
 357                 if err != nil {
 358                         return
 359                 }
 360                 // receive at least one normal byte
 361                 if sockType != SOCK_DGRAM && len(p) == 0 {
 362                         iov.Base = &dummy
 363                         iov.SetLen(1)
 364                 }
 365                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 366                 msg.SetControllen(len(oob))
 367         }
 368         msg.Iov = &iov
 369         msg.Iovlen = 1
 370         if n, err = recvmsg(fd, &msg, flags); err != nil {
 371                 return
 372         }
 373         oobn = int(msg.Controllen)
 374         recvflags = int(msg.Flags)
 375         // source address is only specified if the socket is unconnected
 376         if rsa.Addr.Family != AF_UNSPEC {
 377                 from, err = anyToSockaddr(&rsa)
 378         }
 379         return
 380 }
 381
 382 func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
 383         _, err = SendmsgN(fd, p, oob, to, flags)
 384         return
 385 }
 386
 387 func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
 388         var ptr *RawSockaddrAny
 389         var salen Socklen_t
 390         if to != nil {
 391                 var err error
 392                 ptr, salen, err = to.sockaddr()
 393                 if err != nil {
 394                         return 0, err
 395                 }
 396         }
 397         var msg Msghdr
 398         msg.Name = (*byte)(unsafe.Pointer(ptr))
 399         msg.Namelen = uint32(salen)
 400         var iov Iovec
 401         if len(p) > 0 {
 402                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 403                 iov.SetLen(len(p))
 404         }
 405         var dummy byte
 406         if len(oob) > 0 {
 407                 var sockType int
 408                 sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
 409                 if err != nil {
 410                         return 0, err
 411                 }
 412                 // send at least one normal byte
 413                 if sockType != SOCK_DGRAM && len(p) == 0 {
 414                         iov.Base = &dummy
 415                         iov.SetLen(1)
 416                 }
 417                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 418                 msg.SetControllen(len(oob))
 419         }
 420         msg.Iov = &iov
 421         msg.Iovlen = 1
 422         if n, err = sendmsg(fd, &msg, flags); err != nil {
 423                 return 0, err
 424         }
 425         if len(oob) > 0 && len(p) == 0 {
 426                 n = 0
 427         }
 428         return n, nil
 429 }
 430
 431 //sys   Listen(fd int, n int) (err error)
 432 //listen(fd _C_int, n _C_int) _C_int
 433
 434 //sys   Shutdown(fd int, how int) (err error)
 435 //shutdown(fd _C_int, how _C_int) _C_int
 436
 437 func (iov *Iovec) SetLen(length int) {
 438         iov.Len = Iovec_len_t(length)
 439 }
 440
 441 func (msghdr *Msghdr) SetControllen(length int) {
 442         msghdr.Controllen = Msghdr_controllen_t(length)
 443 }
 444
 445 func (cmsg *Cmsghdr) SetLen(length int) {
 446         cmsg.Len = Cmsghdr_len_t(length)
 447 }