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 = 0x1c
  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
  97         // length is family (uint16), name, NUL.
  98         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), sl, nil
  99 }
 100
 101 func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
 102         switch rsa.Addr.Family {
 103         case AF_UNIX:
 104                 pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
 105                 sa := new(SockaddrUnix)
 106                 n, err := pp.getLen()
 107                 if err != nil {
 108                         return nil, err
 109                 }
 110                 bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))
 111                 sa.Name = string(bytes[0:n])
 112                 return sa, nil
 113
 114         case AF_INET:
 115                 pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
 116                 sa := new(SockaddrInet4)
 117                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 118                 sa.Port = int(p[0])<<8 + int(p[1])
 119                 for i := 0; i < len(sa.Addr); i++ {
 120                         sa.Addr[i] = pp.Addr[i]
 121                 }
 122                 return sa, nil
 123
 124         case AF_INET6:
 125                 pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
 126                 sa := new(SockaddrInet6)
 127                 p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 128                 sa.Port = int(p[0])<<8 + int(p[1])
 129                 for i := 0; i < len(sa.Addr); i++ {
 130                         sa.Addr[i] = pp.Addr[i]
 131                 }
 132                 return sa, nil
 133         }
 134         return anyToSockaddrOS(rsa)
 135 }
 136
 137 //sys   accept(fd int, sa *RawSockaddrAny, len *Socklen_t) (nfd int, err error)
 138 //accept(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 139
 140 func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 141         var rsa RawSockaddrAny
 142         var len Socklen_t = SizeofSockaddrAny
 143         nfd, err = accept(fd, &rsa, &len)
 144         if err != nil {
 145                 return
 146         }
 147         sa, err = anyToSockaddr(&rsa)
 148         if err != nil {
 149                 Close(nfd)
 150                 nfd = 0
 151         }
 152         return
 153 }
 154
 155 //sysnb getsockname(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 156 //getsockname(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 157
 158 func Getsockname(fd int) (sa Sockaddr, err error) {
 159         var rsa RawSockaddrAny
 160         var len Socklen_t = SizeofSockaddrAny
 161         if err = getsockname(fd, &rsa, &len); err != nil {
 162                 return
 163         }
 164         return anyToSockaddr(&rsa)
 165 }
 166
 167 //sysnb getpeername(fd int, sa *RawSockaddrAny, len *Socklen_t) (err error)
 168 //getpeername(fd _C_int, sa *RawSockaddrAny, len *Socklen_t) _C_int
 169
 170 func Getpeername(fd int) (sa Sockaddr, err error) {
 171         var rsa RawSockaddrAny
 172         var len Socklen_t = SizeofSockaddrAny
 173         if err = getpeername(fd, &rsa, &len); err != nil {
 174                 return
 175         }
 176         return anyToSockaddr(&rsa)
 177 }
 178
 179 func Bind(fd int, sa Sockaddr) (err error) {
 180         ptr, n, err := sa.sockaddr()
 181         if err != nil {
 182                 return err
 183         }
 184         return bind(fd, ptr, n)
 185 }
 186
 187 func Connect(fd int, sa Sockaddr) (err error) {
 188         ptr, n, err := sa.sockaddr()
 189         if err != nil {
 190                 return err
 191         }
 192         return connect(fd, ptr, n)
 193 }
 194
 195 func Socket(domain, typ, proto int) (fd int, err error) {
 196         if domain == AF_INET6 && SocketDisableIPv6 {
 197                 return -1, EAFNOSUPPORT
 198         }
 199         fd, err = socket(domain, typ, proto)
 200         return
 201 }
 202
 203 func Socketpair(domain, typ, proto int) (fd [2]int, err error) {
 204         var fdx [2]_C_int
 205         err = socketpair(domain, typ, proto, &fdx)
 206         if err == nil {
 207                 fd[0] = int(fdx[0])
 208                 fd[1] = int(fdx[1])
 209         }
 210         return
 211 }
 212
 213 func GetsockoptByte(fd, level, opt int) (value byte, err error) {
 214         var n byte
 215         vallen := Socklen_t(1)
 216         err = getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), &vallen)
 217         return n, err
 218 }
 219
 220 func GetsockoptInt(fd, level, opt int) (value int, err error) {
 221         var n int32
 222         vallen := Socklen_t(4)
 223         err = getsockopt(fd, level, opt, (uintptr)(unsafe.Pointer(&n)), &vallen)
 224         return int(n), err
 225 }
 226
 227 func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
 228         vallen := Socklen_t(4)
 229         err = getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value[0])), &vallen)
 230         return value, err
 231 }
 232
 233 func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
 234         var value IPMreq
 235         vallen := Socklen_t(SizeofIPMreq)
 236         err := getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), &vallen)
 237         return &value, err
 238 }
 239
 240 func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
 241         var value IPMreqn
 242         vallen := Socklen_t(SizeofIPMreqn)
 243         err := getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), &vallen)
 244         return &value, err
 245 }
 246
 247 func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
 248         var value IPv6Mreq
 249         vallen := Socklen_t(SizeofIPv6Mreq)
 250         err := getsockopt(fd, level, opt, uintptr(unsafe.Pointer(&value)), &vallen)
 251         return &value, err
 252 }
 253
 254 //sys   setsockopt(s int, level int, name int, val *byte, vallen Socklen_t) (err error)
 255 //setsockopt(s _C_int, level _C_int, optname _C_int, val *byte, vallen Socklen_t) _C_int
 256
 257 func SetsockoptByte(fd, level, opt int, value byte) (err error) {
 258         var n = byte(value)
 259         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(&n)), 1)
 260 }
 261
 262 func SetsockoptInt(fd, level, opt int, value int) (err error) {
 263         var n = int32(value)
 264         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(&n)), 4)
 265 }
 266
 267 func SetsockoptInet4Addr(fd, level, opt int, value [4]byte) (err error) {
 268         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(&value[0])), 4)
 269 }
 270
 271 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
 272         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(tv)), Socklen_t(unsafe.Sizeof(*tv)))
 273 }
 274
 275 func SetsockoptICMPv6Filter(fd, level, opt int, filter *ICMPv6Filter) error {
 276         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(filter)), SizeofICMPv6Filter)
 277 }
 278
 279 type Linger struct {
 280         Onoff  int32
 281         Linger int32
 282 }
 283
 284 func SetsockoptLinger(fd, level, opt int, l *Linger) (err error) {
 285         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(l)), Socklen_t(unsafe.Sizeof(*l)))
 286 }
 287
 288 func SetsockoptIPMreq(fd, level, opt int, mreq *IPMreq) (err error) {
 289         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(mreq)), Socklen_t(unsafe.Sizeof(*mreq)))
 290 }
 291
 292 func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
 293         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(mreq)), Socklen_t(unsafe.Sizeof(*mreq)))
 294 }
 295
 296 func SetsockoptIPv6Mreq(fd, level, opt int, mreq *IPv6Mreq) (err error) {
 297         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(mreq)), Socklen_t(unsafe.Sizeof(*mreq)))
 298 }
 299
 300 func SetsockoptString(fd, level, opt int, s string) (err error) {
 301         return setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(&[]byte(s)[0])), Socklen_t(len(s)))
 302 }
 303
 304 //sys   recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *Socklen_t) (n int, err error)
 305 //recvfrom(fd _C_int, buf *byte, len Size_t, flags _C_int, from *RawSockaddrAny, fromlen *Socklen_t) Ssize_t
 306
 307 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 308         var rsa RawSockaddrAny
 309         var len Socklen_t = SizeofSockaddrAny
 310         if n, err = recvfrom(fd, p, flags, &rsa, &len); err != nil {
 311                 return
 312         }
 313         if rsa.Addr.Family != AF_UNSPEC {
 314                 from, err = anyToSockaddr(&rsa)
 315         }
 316         return
 317 }
 318
 319 func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 320         ptr, n, err := to.sockaddr()
 321         if err != nil {
 322                 return err
 323         }
 324         return sendto(fd, p, flags, ptr, n)
 325 }
 326
 327 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
 328         var msg Msghdr
 329         var rsa RawSockaddrAny
 330         msg.Name = (*byte)(unsafe.Pointer(&rsa))
 331         msg.Namelen = uint32(SizeofSockaddrAny)
 332         var iov Iovec
 333         if len(p) > 0 {
 334                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 335                 iov.SetLen(len(p))
 336         }
 337         var dummy byte
 338         if len(oob) > 0 {
 339                 // receive at least one normal byte
 340                 if len(p) == 0 {
 341                         iov.Base = &dummy
 342                         iov.SetLen(1)
 343                 }
 344                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 345                 msg.SetControllen(len(oob))
 346         }
 347         msg.Iov = &iov
 348         msg.Iovlen = 1
 349         if n, err = recvmsg(fd, &msg, flags); err != nil {
 350                 return
 351         }
 352         oobn = int(msg.Controllen)
 353         recvflags = int(msg.Flags)
 354         // source address is only specified if the socket is unconnected
 355         if rsa.Addr.Family != AF_UNSPEC {
 356                 from, err = anyToSockaddr(&rsa)
 357         }
 358         return
 359 }
 360
 361 func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
 362         var ptr *RawSockaddrAny
 363         var salen Socklen_t
 364         if to != nil {
 365                 var err error
 366                 ptr, salen, err = to.sockaddr()
 367                 if err != nil {
 368                         return err
 369                 }
 370         }
 371         var msg Msghdr
 372         msg.Name = (*byte)(unsafe.Pointer(ptr))
 373         msg.Namelen = uint32(salen)
 374         var iov Iovec
 375         if len(p) > 0 {
 376                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 377                 iov.SetLen(len(p))
 378         }
 379         var dummy byte
 380         if len(oob) > 0 {
 381                 // send at least one normal byte
 382                 if len(p) == 0 {
 383                         iov.Base = &dummy
 384                         iov.SetLen(1)
 385                 }
 386                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 387                 msg.SetControllen(len(oob))
 388         }
 389         msg.Iov = &iov
 390         msg.Iovlen = 1
 391         if err = sendmsg(fd, &msg, flags); err != nil {
 392                 return
 393         }
 394         return
 395 }
 396
 397 //sys   Listen(fd int, n int) (err error)
 398 //listen(fd _C_int, n _C_int) _C_int
 399
 400 //sys   Shutdown(fd int, how int) (err error)
 401 //shutdown(fd _C_int, how _C_int) _C_int
 402
 403 func (iov *Iovec) SetLen(length int) {
 404         iov.Len = Iovec_len_t(length)
 405 }
 406
 407 func (msghdr *Msghdr) SetControllen(length int) {
 408         msghdr.Controllen = Msghdr_controllen_t(length)
 409 }
 410
 411 func (cmsg *Cmsghdr) SetLen(length int) {
 412         cmsg.Len = Cmsghdr_len_t(length)
 413 }