libgo/syscalls/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 type RawSockaddrAny struct {
  16         Addr RawSockaddr;
  17         Pad [12]int8;
  18 }
  19
  20 const SizeofSockaddrAny = 0x1c;
  21
  22 // For testing: clients can set this flag to force
  23 // creation of IPv6 sockets to return EAFNOSUPPORT.
  24 var SocketDisableIPv6 bool
  25
  26 type Sockaddr interface {
  27         sockaddr() (ptr *RawSockaddrAny, len Socklen_t, errno int);     // lowercase; only we can define Sockaddrs
  28 }
  29
  30 type SockaddrInet4 struct {
  31         Port int;
  32         Addr [4]byte;
  33         raw RawSockaddrInet4;
  34 }
  35
  36 type SockaddrInet6 struct {
  37         Port int;
  38         Addr [16]byte;
  39         raw RawSockaddrInet6;
  40 }
  41
  42 type SockaddrUnix struct {
  43         Name string;
  44         raw RawSockaddrUnix;
  45 }
  46
  47 type Linger struct {
  48         Onoff int32;
  49         Linger int32;
  50 }
  51
  52 func (sa *SockaddrInet4) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
  53         if sa.Port < 0 || sa.Port > 0xFFFF {
  54                 return nil, 0, EINVAL;
  55         }
  56         sa.raw.Family = AF_INET;
  57         n := sa.raw.setLen()
  58         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port));
  59         p[0] = byte(sa.Port>>8);
  60         p[1] = byte(sa.Port);
  61         for i := 0; i < len(sa.Addr); i++ {
  62                 sa.raw.Addr[i] = sa.Addr[i];
  63         }
  64         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, 0;
  65 }
  66
  67 func (sa *SockaddrInet6) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
  68         if sa.Port < 0 || sa.Port > 0xFFFF {
  69                 return nil, 0, EINVAL;
  70         }
  71         sa.raw.Family = AF_INET6;
  72         n := sa.raw.setLen()
  73         p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port));
  74         p[0] = byte(sa.Port>>8);
  75         p[1] = byte(sa.Port);
  76         for i := 0; i < len(sa.Addr); i++ {
  77                 sa.raw.Addr[i] = sa.Addr[i];
  78         }
  79         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), n, 0;
  80 }
  81
  82 func (sa *SockaddrUnix) sockaddr() (*RawSockaddrAny, Socklen_t, int) {
  83         name := sa.Name;
  84         n := len(name);
  85         if n >= len(sa.raw.Path) || n == 0 {
  86                 return nil, 0, EINVAL;
  87         }
  88         sa.raw.Family = AF_UNIX;
  89         sa.raw.setLen(n)
  90         for i := 0; i < n; i++ {
  91                 sa.raw.Path[i] = int8(name[i]);
  92         }
  93         if sa.raw.Path[0] == '@' {
  94                 sa.raw.Path[0] = 0;
  95         }
  96
  97         // length is family (uint16), name, NUL.
  98         return (*RawSockaddrAny)(unsafe.Pointer(&sa.raw)), 2 + Socklen_t(n) + 1, 0;
  99 }
 100
 101 func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, int) {
 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 != 0 {
 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, 0;
 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, 0;
 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, 0;
 133         }
 134         return nil, EAFNOSUPPORT;
 135 }
 136
 137 func libc_accept(fd int, sa *RawSockaddrAny, len *Socklen_t) int __asm__ ("accept");
 138 func libc_bind(fd int, sa *RawSockaddrAny, len Socklen_t) int __asm__ ("bind");
 139 func libc_connect(fd int, sa *RawSockaddrAny, len Socklen_t) int __asm__ ("connect");
 140 func libc_socket(domain, typ, protocol int) int __asm__ ("socket");
 141 func libc_setsockopt(fd, level, optname int, optval *byte, optlen Socklen_t) int __asm__ ("setsockopt");
 142 func libc_listen(fd, backlog int) int __asm__ ("listen");
 143 func libc_getsockopt(fd, level, optname int, optval *byte, optlen *Socklen_t) int __asm__ ("getsockopt");
 144 func libc_getsockname(fd int, sa *RawSockaddrAny, len *Socklen_t) int __asm__ ("getsockname");
 145 func libc_getpeername(fd int, sa *RawSockaddrAny, len *Socklen_t) int __asm__ ("getpeername");
 146 func libc_recv(fd int, buf *byte, len Size_t, flags int) Ssize_t __asm__ ("recv");
 147 func libc_recvfrom(fd int, buf *byte, len Size_t, flags int,
 148         from *RawSockaddrAny, fromlen *Socklen_t) Ssize_t __asm__("recvfrom");
 149 func libc_recvmsg(fd int, msg *Msghdr, flags int) Ssize_t __asm__("recvmsg")
 150 func libc_send(fd int, buf *byte, len Size_t, flags int) Ssize_t __asm__("send");
 151 func libc_sendto(fd int, buf *byte, len Size_t, flags int,
 152         to *RawSockaddrAny, tolen Socklen_t) Ssize_t __asm__("sendto");
 153 func libc_sendmsg(fd int, msg *Msghdr, flags int) Ssize_t __asm__("sendmsg")
 154 func libc_shutdown(fd int, how int) int __asm__ ("shutdown");
 155
 156 func Accept(fd int) (nfd int, sa Sockaddr, errno int) {
 157         var rsa RawSockaddrAny;
 158         var len Socklen_t = SizeofSockaddrAny;
 159         nfd = libc_accept(fd, &rsa, &len);
 160         if nfd < 0 {
 161                 errno = GetErrno();
 162                 return;
 163         }
 164         sa, errno = anyToSockaddr(&rsa);
 165         if errno != 0 {
 166                 Close(nfd);
 167                 nfd = 0;
 168         }
 169         return;
 170 }
 171
 172 func Bind(fd int, sa Sockaddr) (errno int) {
 173         ptr, n, err := sa.sockaddr();
 174         if err != 0 {
 175                 return err;
 176         }
 177         if libc_bind(fd, ptr, n) < 0 {
 178                 errno = GetErrno();
 179         }
 180         return;
 181 }
 182
 183 func Connect(fd int, sa Sockaddr) (errno int) {
 184         ptr, n, err := sa.sockaddr();
 185         if err != 0 {
 186                 return err;
 187         }
 188         if libc_connect(fd, ptr, n) < 0 {
 189                 errno = GetErrno();
 190         }
 191         return;
 192 }
 193
 194 func Socket(domain, typ, proto int) (fd, errno int) {
 195   if domain == AF_INET6 && SocketDisableIPv6 {
 196     return -1, EAFNOSUPPORT
 197   }
 198   fd = libc_socket(int(domain), int(typ), int(proto));
 199   if fd < 0 {
 200     errno = GetErrno();
 201   }
 202   return;
 203 }
 204
 205 func Listen(fd int, n int) (errno int) {
 206   r := libc_listen(int(fd), int(n));
 207   if r < 0 { errno = GetErrno() }
 208   return;
 209 }
 210
 211 func GetsockoptInt(fd, level, opt int) (value, errno int) {
 212         var n int32
 213         vallen := Socklen_t(4)
 214         errno = libc_getsockopt(fd, level, opt, (*byte)(unsafe.Pointer(&n)), &vallen)
 215         return int(n), errno
 216 }
 217
 218 func setsockopt(fd, level, opt int, valueptr uintptr, length Socklen_t) (errno int) {
 219   r := libc_setsockopt(fd, level, opt, (*byte)(unsafe.Pointer(valueptr)),
 220                        length);
 221   if r < 0 { errno = GetErrno() }
 222   return;
 223 }
 224
 225 func SetsockoptInt(fd, level, opt int, value int) (errno int) {
 226         var n = int32(value);
 227         return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&n)), 4);
 228 }
 229
 230 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (errno int) {
 231         return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(tv)), Socklen_t(unsafe.Sizeof(*tv)));
 232 }
 233
 234 func SetsockoptLinger(fd, level, opt int, l *Linger) (errno int) {
 235         return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(l)), Socklen_t(unsafe.Sizeof(*l)));
 236 }
 237
 238 func SetsockoptString(fd, level, opt int, s string) (errno int) {
 239         return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(&[]byte(s)[0])), Socklen_t(len(s)))
 240 }
 241
 242 func SetsockoptIpMreq(fd, level, opt int, mreq *IpMreq) (errno int) {
 243         return setsockopt(fd, level, opt, uintptr(unsafe.Pointer(mreq)), unsafe.Sizeof(*mreq))
 244 }
 245
 246 func Getsockname(fd int) (sa Sockaddr, errno int) {
 247         var rsa RawSockaddrAny;
 248         var len Socklen_t = SizeofSockaddrAny;
 249         if libc_getsockname(fd, &rsa, &len) != 0 {
 250                 errno = GetErrno();
 251                 return;
 252         }
 253         return anyToSockaddr(&rsa);
 254 }
 255
 256 func Getpeername(fd int) (sa Sockaddr, errno int) {
 257         var rsa RawSockaddrAny;
 258         var len Socklen_t = SizeofSockaddrAny;
 259         if libc_getpeername(fd, &rsa, &len) != 0 {
 260                 errno = GetErrno();
 261                 return;
 262         }
 263         return anyToSockaddr(&rsa);
 264 }
 265
 266 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, errno int) {
 267         var rsa RawSockaddrAny;
 268         var slen Socklen_t = SizeofSockaddrAny;
 269         var _p0 *byte;
 270         if len(p) > 0 { _p0 = &p[0]; }
 271         r := libc_recvfrom(fd, _p0, Size_t(len(p)), flags, &rsa, &slen);
 272         n = int(r);
 273         if r == -1 {
 274                 errno = GetErrno();
 275         } else {
 276                 from, errno = anyToSockaddr(&rsa);
 277         }
 278         return;
 279 }
 280
 281 func (iov *Iovec) SetLen(length int) {
 282         iov.Len = Iovec_len_t(length)
 283 }
 284
 285 func (msghdr *Msghdr) SetControllen(length int) {
 286         msghdr.Controllen = Msghdr_controllen_t(length)
 287 }
 288
 289 func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, errno int) {
 290         var msg Msghdr
 291         var rsa RawSockaddrAny
 292         msg.Name = (*byte)(unsafe.Pointer(&rsa))
 293         msg.Namelen = uint32(SizeofSockaddrAny)
 294         var iov Iovec
 295         if len(p) > 0 {
 296                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 297                 iov.SetLen(len(p))
 298         }
 299         var dummy byte
 300         if len(oob) > 0 {
 301                 // receive at least one normal byte
 302                 if len(p) == 0 {
 303                         iov.Base = &dummy
 304                         iov.SetLen(1)
 305                 }
 306                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 307                 msg.SetControllen(len(oob))
 308         }
 309         msg.Iov = &iov
 310         msg.Iovlen = 1
 311         if n, errno = recvmsg(fd, &msg, flags); errno != 0 {
 312                 return
 313         }
 314         oobn = int(msg.Controllen)
 315         recvflags = int(msg.Flags)
 316         // source address is only specified if the socket is unconnected
 317         if rsa.Addr.Family != 0 {
 318                 from, errno = anyToSockaddr(&rsa)
 319         }
 320         return
 321 }
 322
 323 func recvmsg(s int, msg *Msghdr, flags int) (n int, errno int) {
 324         r := libc_recvmsg(s, msg, flags)
 325         if r < 0 {
 326                 errno = GetErrno()
 327         } else {
 328                 n = int(r)
 329         }
 330         return
 331 }
 332
 333 func Sendto(fd int, p []byte, flags int, to Sockaddr) (errno int) {
 334         ptr, n, err := to.sockaddr();
 335         if err != 0 {
 336                 return err;
 337         }
 338         var _p0 *byte;
 339         if len(p) > 0 { _p0 = &p[0]; }
 340         r := libc_sendto(fd, _p0, Size_t(len(p)), flags, ptr, n);
 341         if r == -1 { errno = GetErrno(); }
 342         return;
 343 }
 344
 345 func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (errno int) {
 346         var ptr *RawSockaddrAny
 347         var nsock Socklen_t
 348         if to != nil {
 349                 var err int
 350                 ptr, nsock, err = to.sockaddr()
 351                 if err != 0 {
 352                         return err
 353                 }
 354         }
 355         var msg Msghdr
 356         msg.Name = (*byte)(unsafe.Pointer(ptr))
 357         msg.Namelen = uint32(nsock)
 358         var iov Iovec
 359         if len(p) > 0 {
 360                 iov.Base = (*byte)(unsafe.Pointer(&p[0]))
 361                 iov.SetLen(len(p))
 362         }
 363         var dummy byte
 364         if len(oob) > 0 {
 365                 // send at least one normal byte
 366                 if len(p) == 0 {
 367                         iov.Base = &dummy
 368                         iov.SetLen(1)
 369                 }
 370                 msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 371                 msg.SetControllen(len(oob))
 372         }
 373         msg.Iov = &iov
 374         msg.Iovlen = 1
 375         if errno = sendmsg(fd, &msg, flags); errno != 0 {
 376                 return
 377         }
 378         return
 379 }
 380
 381 func sendmsg(s int, msg *Msghdr, flags int) (errno int) {
 382         if libc_sendmsg(s, msg, flags) < 0 {
 383                 errno = GetErrno()
 384         }
 385         return
 386 }
 387
 388 func Shutdown(fd int, how int) (errno int) {
 389         r := libc_shutdown(fd, how);
 390         if r < 0 { errno = GetErrno() }
 391         return;
 392 }