libgo/go/net/tcpsock.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 // TCP sockets
   6
   7 package net
   8
   9 import (
  10         "os"
  11         "syscall"
  12 )
  13
  14 func sockaddrToTCP(sa syscall.Sockaddr) Addr {
  15         switch sa := sa.(type) {
  16         case *syscall.SockaddrInet4:
  17                 return &TCPAddr{sa.Addr[0:], sa.Port}
  18         case *syscall.SockaddrInet6:
  19                 return &TCPAddr{sa.Addr[0:], sa.Port}
  20         }
  21         return nil
  22 }
  23
  24 // TCPAddr represents the address of a TCP end point.
  25 type TCPAddr struct {
  26         IP   IP
  27         Port int
  28 }
  29
  30 // Network returns the address's network name, "tcp".
  31 func (a *TCPAddr) Network() string { return "tcp" }
  32
  33 func (a *TCPAddr) String() string {
  34         if a == nil {
  35                 return "<nil>"
  36         }
  37         return joinHostPort(a.IP.String(), itoa(a.Port))
  38 }
  39
  40 func (a *TCPAddr) family() int {
  41         if a == nil || len(a.IP) <= 4 {
  42                 return syscall.AF_INET
  43         }
  44         if ip := a.IP.To4(); ip != nil {
  45                 return syscall.AF_INET
  46         }
  47         return syscall.AF_INET6
  48 }
  49
  50 func (a *TCPAddr) sockaddr(family int) (syscall.Sockaddr, os.Error) {
  51         return ipToSockaddr(family, a.IP, a.Port)
  52 }
  53
  54 func (a *TCPAddr) toAddr() sockaddr {
  55         if a == nil { // nil *TCPAddr
  56                 return nil // nil interface
  57         }
  58         return a
  59 }
  60
  61 // ResolveTCPAddr parses addr as a TCP address of the form
  62 // host:port and resolves domain names or port names to
  63 // numeric addresses.  A literal IPv6 host address must be
  64 // enclosed in square brackets, as in "[::]:80".
  65 func ResolveTCPAddr(addr string) (*TCPAddr, os.Error) {
  66         ip, port, err := hostPortToIP("tcp", addr)
  67         if err != nil {
  68                 return nil, err
  69         }
  70         return &TCPAddr{ip, port}, nil
  71 }
  72
  73 // TCPConn is an implementation of the Conn interface
  74 // for TCP network connections.
  75 type TCPConn struct {
  76         fd *netFD
  77 }
  78
  79 func newTCPConn(fd *netFD) *TCPConn {
  80         c := &TCPConn{fd}
  81         c.SetNoDelay(true)
  82         return c
  83 }
  84
  85 func (c *TCPConn) ok() bool { return c != nil && c.fd != nil }
  86
  87 // Implementation of the Conn interface - see Conn for documentation.
  88
  89 // Read implements the net.Conn Read method.
  90 func (c *TCPConn) Read(b []byte) (n int, err os.Error) {
  91         if !c.ok() {
  92                 return 0, os.EINVAL
  93         }
  94         return c.fd.Read(b)
  95 }
  96
  97 // Write implements the net.Conn Write method.
  98 func (c *TCPConn) Write(b []byte) (n int, err os.Error) {
  99         if !c.ok() {
 100                 return 0, os.EINVAL
 101         }
 102         return c.fd.Write(b)
 103 }
 104
 105 // Close closes the TCP connection.
 106 func (c *TCPConn) Close() os.Error {
 107         if !c.ok() {
 108                 return os.EINVAL
 109         }
 110         err := c.fd.Close()
 111         c.fd = nil
 112         return err
 113 }
 114
 115 // LocalAddr returns the local network address, a *TCPAddr.
 116 func (c *TCPConn) LocalAddr() Addr {
 117         if !c.ok() {
 118                 return nil
 119         }
 120         return c.fd.laddr
 121 }
 122
 123 // RemoteAddr returns the remote network address, a *TCPAddr.
 124 func (c *TCPConn) RemoteAddr() Addr {
 125         if !c.ok() {
 126                 return nil
 127         }
 128         return c.fd.raddr
 129 }
 130
 131 // SetTimeout implements the net.Conn SetTimeout method.
 132 func (c *TCPConn) SetTimeout(nsec int64) os.Error {
 133         if !c.ok() {
 134                 return os.EINVAL
 135         }
 136         return setTimeout(c.fd, nsec)
 137 }
 138
 139 // SetReadTimeout implements the net.Conn SetReadTimeout method.
 140 func (c *TCPConn) SetReadTimeout(nsec int64) os.Error {
 141         if !c.ok() {
 142                 return os.EINVAL
 143         }
 144         return setReadTimeout(c.fd, nsec)
 145 }
 146
 147 // SetWriteTimeout implements the net.Conn SetWriteTimeout method.
 148 func (c *TCPConn) SetWriteTimeout(nsec int64) os.Error {
 149         if !c.ok() {
 150                 return os.EINVAL
 151         }
 152         return setWriteTimeout(c.fd, nsec)
 153 }
 154
 155 // SetReadBuffer sets the size of the operating system's
 156 // receive buffer associated with the connection.
 157 func (c *TCPConn) SetReadBuffer(bytes int) os.Error {
 158         if !c.ok() {
 159                 return os.EINVAL
 160         }
 161         return setReadBuffer(c.fd, bytes)
 162 }
 163
 164 // SetWriteBuffer sets the size of the operating system's
 165 // transmit buffer associated with the connection.
 166 func (c *TCPConn) SetWriteBuffer(bytes int) os.Error {
 167         if !c.ok() {
 168                 return os.EINVAL
 169         }
 170         return setWriteBuffer(c.fd, bytes)
 171 }
 172
 173 // SetLinger sets the behavior of Close() on a connection
 174 // which still has data waiting to be sent or to be acknowledged.
 175 //
 176 // If sec < 0 (the default), Close returns immediately and
 177 // the operating system finishes sending the data in the background.
 178 //
 179 // If sec == 0, Close returns immediately and the operating system
 180 // discards any unsent or unacknowledged data.
 181 //
 182 // If sec > 0, Close blocks for at most sec seconds waiting for
 183 // data to be sent and acknowledged.
 184 func (c *TCPConn) SetLinger(sec int) os.Error {
 185         if !c.ok() {
 186                 return os.EINVAL
 187         }
 188         return setLinger(c.fd, sec)
 189 }
 190
 191 // SetKeepAlive sets whether the operating system should send
 192 // keepalive messages on the connection.
 193 func (c *TCPConn) SetKeepAlive(keepalive bool) os.Error {
 194         if !c.ok() {
 195                 return os.EINVAL
 196         }
 197         return setKeepAlive(c.fd, keepalive)
 198 }
 199
 200 // SetNoDelay controls whether the operating system should delay
 201 // packet transmission in hopes of sending fewer packets
 202 // (Nagle's algorithm).  The default is true (no delay), meaning
 203 // that data is sent as soon as possible after a Write.
 204 func (c *TCPConn) SetNoDelay(noDelay bool) os.Error {
 205         if !c.ok() {
 206                 return os.EINVAL
 207         }
 208         return setNoDelay(c.fd, noDelay)
 209 }
 210
 211 // File returns a copy of the underlying os.File, set to blocking mode.
 212 // It is the caller's responsibility to close f when finished.
 213 // Closing c does not affect f, and closing f does not affect c.
 214 func (c *TCPConn) File() (f *os.File, err os.Error) { return c.fd.dup() }
 215
 216 // DialTCP is like Dial but can only connect to TCP networks
 217 // and returns a TCPConn structure.
 218 func DialTCP(net string, laddr, raddr *TCPAddr) (c *TCPConn, err os.Error) {
 219         if raddr == nil {
 220                 return nil, &OpError{"dial", "tcp", nil, errMissingAddress}
 221         }
 222         fd, e := internetSocket(net, laddr.toAddr(), raddr.toAddr(), syscall.SOCK_STREAM, 0, "dial", sockaddrToTCP)
 223         if e != nil {
 224                 return nil, e
 225         }
 226         return newTCPConn(fd), nil
 227 }
 228
 229 // TCPListener is a TCP network listener.
 230 // Clients should typically use variables of type Listener
 231 // instead of assuming TCP.
 232 type TCPListener struct {
 233         fd *netFD
 234 }
 235
 236 // ListenTCP announces on the TCP address laddr and returns a TCP listener.
 237 // Net must be "tcp", "tcp4", or "tcp6".
 238 // If laddr has a port of 0, it means to listen on some available port.
 239 // The caller can use l.Addr() to retrieve the chosen address.
 240 func ListenTCP(net string, laddr *TCPAddr) (l *TCPListener, err os.Error) {
 241         fd, err := internetSocket(net, laddr.toAddr(), nil, syscall.SOCK_STREAM, 0, "listen", sockaddrToTCP)
 242         if err != nil {
 243                 return nil, err
 244         }
 245         errno := syscall.Listen(fd.sysfd, listenBacklog())
 246         if errno != 0 {
 247                 syscall.Close(fd.sysfd)
 248                 return nil, &OpError{"listen", "tcp", laddr, os.Errno(errno)}
 249         }
 250         l = new(TCPListener)
 251         l.fd = fd
 252         return l, nil
 253 }
 254
 255 // AcceptTCP accepts the next incoming call and returns the new connection
 256 // and the remote address.
 257 func (l *TCPListener) AcceptTCP() (c *TCPConn, err os.Error) {
 258         if l == nil || l.fd == nil || l.fd.sysfd < 0 {
 259                 return nil, os.EINVAL
 260         }
 261         fd, err := l.fd.accept(sockaddrToTCP)
 262         if err != nil {
 263                 return nil, err
 264         }
 265         return newTCPConn(fd), nil
 266 }
 267
 268 // Accept implements the Accept method in the Listener interface;
 269 // it waits for the next call and returns a generic Conn.
 270 func (l *TCPListener) Accept() (c Conn, err os.Error) {
 271         c1, err := l.AcceptTCP()
 272         if err != nil {
 273                 return nil, err
 274         }
 275         return c1, nil
 276 }
 277
 278 // Close stops listening on the TCP address.
 279 // Already Accepted connections are not closed.
 280 func (l *TCPListener) Close() os.Error {
 281         if l == nil || l.fd == nil {
 282                 return os.EINVAL
 283         }
 284         return l.fd.Close()
 285 }
 286
 287 // Addr returns the listener's network address, a *TCPAddr.
 288 func (l *TCPListener) Addr() Addr { return l.fd.laddr }
 289
 290 // File returns a copy of the underlying os.File, set to blocking mode.
 291 // It is the caller's responsibility to close f when finished.
 292 // Closing c does not affect f, and closing f does not affect c.
 293 func (l *TCPListener) File() (f *os.File, err os.Error) { return l.fd.dup() }