libgo/go/net/udpsock_posix.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 darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
   6
   7 package net
   8
   9 import (
  10         "syscall"
  11         "time"
  12 )
  13
  14 func sockaddrToUDP(sa syscall.Sockaddr) Addr {
  15         switch sa := sa.(type) {
  16         case *syscall.SockaddrInet4:
  17                 return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
  18         case *syscall.SockaddrInet6:
  19                 return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
  20         }
  21         return nil
  22 }
  23
  24 func (a *UDPAddr) family() int {
  25         if a == nil || len(a.IP) <= IPv4len {
  26                 return syscall.AF_INET
  27         }
  28         if a.IP.To4() != nil {
  29                 return syscall.AF_INET
  30         }
  31         return syscall.AF_INET6
  32 }
  33
  34 func (a *UDPAddr) isWildcard() bool {
  35         if a == nil || a.IP == nil {
  36                 return true
  37         }
  38         return a.IP.IsUnspecified()
  39 }
  40
  41 func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
  42         if a == nil {
  43                 return nil, nil
  44         }
  45         return ipToSockaddr(family, a.IP, a.Port, a.Zone)
  46 }
  47
  48 // UDPConn is the implementation of the Conn and PacketConn interfaces
  49 // for UDP network connections.
  50 type UDPConn struct {
  51         conn
  52 }
  53
  54 func newUDPConn(fd *netFD) *UDPConn { return &UDPConn{conn{fd}} }
  55
  56 // ReadFromUDP reads a UDP packet from c, copying the payload into b.
  57 // It returns the number of bytes copied into b and the return address
  58 // that was on the packet.
  59 //
  60 // ReadFromUDP can be made to time out and return an error with
  61 // Timeout() == true after a fixed time limit; see SetDeadline and
  62 // SetReadDeadline.
  63 func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err error) {
  64         if !c.ok() {
  65                 return 0, nil, syscall.EINVAL
  66         }
  67         n, sa, err := c.fd.readFrom(b)
  68         switch sa := sa.(type) {
  69         case *syscall.SockaddrInet4:
  70                 addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
  71         case *syscall.SockaddrInet6:
  72                 addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
  73         }
  74         return
  75 }
  76
  77 // ReadFrom implements the PacketConn ReadFrom method.
  78 func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
  79         if !c.ok() {
  80                 return 0, nil, syscall.EINVAL
  81         }
  82         n, addr, err := c.ReadFromUDP(b)
  83         return n, addr.toAddr(), err
  84 }
  85
  86 // ReadMsgUDP reads a packet from c, copying the payload into b and
  87 // the associated out-of-band data into oob.  It returns the number
  88 // of bytes copied into b, the number of bytes copied into oob, the
  89 // flags that were set on the packet and the source address of the
  90 // packet.
  91 func (c *UDPConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
  92         if !c.ok() {
  93                 return 0, 0, 0, nil, syscall.EINVAL
  94         }
  95         var sa syscall.Sockaddr
  96         n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
  97         switch sa := sa.(type) {
  98         case *syscall.SockaddrInet4:
  99                 addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
 100         case *syscall.SockaddrInet6:
 101                 addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
 102         }
 103         return
 104 }
 105
 106 // WriteToUDP writes a UDP packet to addr via c, copying the payload
 107 // from b.
 108 //
 109 // WriteToUDP can be made to time out and return an error with
 110 // Timeout() == true after a fixed time limit; see SetDeadline and
 111 // SetWriteDeadline.  On packet-oriented connections, write timeouts
 112 // are rare.
 113 func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error) {
 114         if !c.ok() {
 115                 return 0, syscall.EINVAL
 116         }
 117         if c.fd.isConnected {
 118                 return 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
 119         }
 120         if addr == nil {
 121                 return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
 122         }
 123         sa, err := addr.sockaddr(c.fd.family)
 124         if err != nil {
 125                 return 0, &OpError{"write", c.fd.net, addr, err}
 126         }
 127         return c.fd.writeTo(b, sa)
 128 }
 129
 130 // WriteTo implements the PacketConn WriteTo method.
 131 func (c *UDPConn) WriteTo(b []byte, addr Addr) (int, error) {
 132         if !c.ok() {
 133                 return 0, syscall.EINVAL
 134         }
 135         a, ok := addr.(*UDPAddr)
 136         if !ok {
 137                 return 0, &OpError{"write", c.fd.net, addr, syscall.EINVAL}
 138         }
 139         return c.WriteToUDP(b, a)
 140 }
 141
 142 // WriteMsgUDP writes a packet to addr via c, copying the payload from
 143 // b and the associated out-of-band data from oob.  It returns the
 144 // number of payload and out-of-band bytes written.
 145 func (c *UDPConn) WriteMsgUDP(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
 146         if !c.ok() {
 147                 return 0, 0, syscall.EINVAL
 148         }
 149         if c.fd.isConnected {
 150                 return 0, 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
 151         }
 152         if addr == nil {
 153                 return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
 154         }
 155         sa, err := addr.sockaddr(c.fd.family)
 156         if err != nil {
 157                 return 0, 0, &OpError{"write", c.fd.net, addr, err}
 158         }
 159         return c.fd.writeMsg(b, oob, sa)
 160 }
 161
 162 // DialUDP connects to the remote address raddr on the network net,
 163 // which must be "udp", "udp4", or "udp6".  If laddr is not nil, it is
 164 // used as the local address for the connection.
 165 func DialUDP(net string, laddr, raddr *UDPAddr) (*UDPConn, error) {
 166         switch net {
 167         case "udp", "udp4", "udp6":
 168         default:
 169                 return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: UnknownNetworkError(net)}
 170         }
 171         if raddr == nil {
 172                 return nil, &OpError{Op: "dial", Net: net, Addr: nil, Err: errMissingAddress}
 173         }
 174         return dialUDP(net, laddr, raddr, noDeadline)
 175 }
 176
 177 func dialUDP(net string, laddr, raddr *UDPAddr, deadline time.Time) (*UDPConn, error) {
 178         fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_DGRAM, 0, "dial", sockaddrToUDP)
 179         if err != nil {
 180                 return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: err}
 181         }
 182         return newUDPConn(fd), nil
 183 }
 184
 185 // ListenUDP listens for incoming UDP packets addressed to the local
 186 // address laddr.  Net must be "udp", "udp4", or "udp6".  If laddr has
 187 // a port of 0, ListenUDP will choose an available port.
 188 // The LocalAddr method of the returned UDPConn can be used to
 189 // discover the port.  The returned connection's ReadFrom and WriteTo
 190 // methods can be used to receive and send UDP packets with per-packet
 191 // addressing.
 192 func ListenUDP(net string, laddr *UDPAddr) (*UDPConn, error) {
 193         switch net {
 194         case "udp", "udp4", "udp6":
 195         default:
 196                 return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
 197         }
 198         if laddr == nil {
 199                 laddr = &UDPAddr{}
 200         }
 201         fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
 202         if err != nil {
 203                 return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
 204         }
 205         return newUDPConn(fd), nil
 206 }
 207
 208 // ListenMulticastUDP listens for incoming multicast UDP packets
 209 // addressed to the group address gaddr on ifi, which specifies the
 210 // interface to join.  ListenMulticastUDP uses default multicast
 211 // interface if ifi is nil.
 212 func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
 213         switch net {
 214         case "udp", "udp4", "udp6":
 215         default:
 216                 return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: UnknownNetworkError(net)}
 217         }
 218         if gaddr == nil || gaddr.IP == nil {
 219                 return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
 220         }
 221         fd, err := internetSocket(net, gaddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
 222         if err != nil {
 223                 return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: err}
 224         }
 225         c := newUDPConn(fd)
 226         if ip4 := gaddr.IP.To4(); ip4 != nil {
 227                 if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
 228                         c.Close()
 229                         return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: ip4}, Err: err}
 230                 }
 231         } else {
 232                 if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
 233                         c.Close()
 234                         return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: gaddr.IP}, Err: err}
 235                 }
 236         }
 237         return c, nil
 238 }
 239
 240 func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
 241         if ifi != nil {
 242                 if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
 243                         return err
 244                 }
 245         }
 246         if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
 247                 return err
 248         }
 249         if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
 250                 return err
 251         }
 252         return nil
 253 }
 254
 255 func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
 256         if ifi != nil {
 257                 if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
 258                         return err
 259                 }
 260         }
 261         if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
 262                 return err
 263         }
 264         if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
 265                 return err
 266         }
 267         return nil
 268 }