| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // TCP sockets |
| |
| package net |
| |
| import ( |
| "os" |
| "syscall" |
| ) |
| |
| func sockaddrToTCP(sa syscall.Sockaddr) Addr { |
| switch sa := sa.(type) { |
| case *syscall.SockaddrInet4: |
| return &TCPAddr{sa.Addr[0:], sa.Port} |
| case *syscall.SockaddrInet6: |
| return &TCPAddr{sa.Addr[0:], sa.Port} |
| } |
| return nil |
| } |
| |
| // TCPAddr represents the address of a TCP end point. |
| type TCPAddr struct { |
| IP IP |
| Port int |
| } |
| |
| // Network returns the address's network name, "tcp". |
| func (a *TCPAddr) Network() string { return "tcp" } |
| |
| func (a *TCPAddr) String() string { |
| if a == nil { |
| return "<nil>" |
| } |
| return joinHostPort(a.IP.String(), itoa(a.Port)) |
| } |
| |
| func (a *TCPAddr) family() int { |
| if a == nil || len(a.IP) <= 4 { |
| return syscall.AF_INET |
| } |
| if ip := a.IP.To4(); ip != nil { |
| return syscall.AF_INET |
| } |
| return syscall.AF_INET6 |
| } |
| |
| func (a *TCPAddr) sockaddr(family int) (syscall.Sockaddr, os.Error) { |
| return ipToSockaddr(family, a.IP, a.Port) |
| } |
| |
| func (a *TCPAddr) toAddr() sockaddr { |
| if a == nil { // nil *TCPAddr |
| return nil // nil interface |
| } |
| return a |
| } |
| |
| // ResolveTCPAddr parses addr as a TCP address of the form |
| // host:port and resolves domain names or port names to |
| // numeric addresses. A literal IPv6 host address must be |
| // enclosed in square brackets, as in "[::]:80". |
| func ResolveTCPAddr(addr string) (*TCPAddr, os.Error) { |
| ip, port, err := hostPortToIP("tcp", addr) |
| if err != nil { |
| return nil, err |
| } |
| return &TCPAddr{ip, port}, nil |
| } |
| |
| // TCPConn is an implementation of the Conn interface |
| // for TCP network connections. |
| type TCPConn struct { |
| fd *netFD |
| } |
| |
| func newTCPConn(fd *netFD) *TCPConn { |
| c := &TCPConn{fd} |
| c.SetNoDelay(true) |
| return c |
| } |
| |
| func (c *TCPConn) ok() bool { return c != nil && c.fd != nil } |
| |
| // Implementation of the Conn interface - see Conn for documentation. |
| |
| // Read implements the net.Conn Read method. |
| func (c *TCPConn) Read(b []byte) (n int, err os.Error) { |
| if !c.ok() { |
| return 0, os.EINVAL |
| } |
| return c.fd.Read(b) |
| } |
| |
| // Write implements the net.Conn Write method. |
| func (c *TCPConn) Write(b []byte) (n int, err os.Error) { |
| if !c.ok() { |
| return 0, os.EINVAL |
| } |
| return c.fd.Write(b) |
| } |
| |
| // Close closes the TCP connection. |
| func (c *TCPConn) Close() os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| err := c.fd.Close() |
| c.fd = nil |
| return err |
| } |
| |
| // LocalAddr returns the local network address, a *TCPAddr. |
| func (c *TCPConn) LocalAddr() Addr { |
| if !c.ok() { |
| return nil |
| } |
| return c.fd.laddr |
| } |
| |
| // RemoteAddr returns the remote network address, a *TCPAddr. |
| func (c *TCPConn) RemoteAddr() Addr { |
| if !c.ok() { |
| return nil |
| } |
| return c.fd.raddr |
| } |
| |
| // SetTimeout implements the net.Conn SetTimeout method. |
| func (c *TCPConn) SetTimeout(nsec int64) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setTimeout(c.fd, nsec) |
| } |
| |
| // SetReadTimeout implements the net.Conn SetReadTimeout method. |
| func (c *TCPConn) SetReadTimeout(nsec int64) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setReadTimeout(c.fd, nsec) |
| } |
| |
| // SetWriteTimeout implements the net.Conn SetWriteTimeout method. |
| func (c *TCPConn) SetWriteTimeout(nsec int64) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setWriteTimeout(c.fd, nsec) |
| } |
| |
| // SetReadBuffer sets the size of the operating system's |
| // receive buffer associated with the connection. |
| func (c *TCPConn) SetReadBuffer(bytes int) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setReadBuffer(c.fd, bytes) |
| } |
| |
| // SetWriteBuffer sets the size of the operating system's |
| // transmit buffer associated with the connection. |
| func (c *TCPConn) SetWriteBuffer(bytes int) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setWriteBuffer(c.fd, bytes) |
| } |
| |
| // SetLinger sets the behavior of Close() on a connection |
| // which still has data waiting to be sent or to be acknowledged. |
| // |
| // If sec < 0 (the default), Close returns immediately and |
| // the operating system finishes sending the data in the background. |
| // |
| // If sec == 0, Close returns immediately and the operating system |
| // discards any unsent or unacknowledged data. |
| // |
| // If sec > 0, Close blocks for at most sec seconds waiting for |
| // data to be sent and acknowledged. |
| func (c *TCPConn) SetLinger(sec int) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setLinger(c.fd, sec) |
| } |
| |
| // SetKeepAlive sets whether the operating system should send |
| // keepalive messages on the connection. |
| func (c *TCPConn) SetKeepAlive(keepalive bool) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setKeepAlive(c.fd, keepalive) |
| } |
| |
| // SetNoDelay controls whether the operating system should delay |
| // packet transmission in hopes of sending fewer packets |
| // (Nagle's algorithm). The default is true (no delay), meaning |
| // that data is sent as soon as possible after a Write. |
| func (c *TCPConn) SetNoDelay(noDelay bool) os.Error { |
| if !c.ok() { |
| return os.EINVAL |
| } |
| return setNoDelay(c.fd, noDelay) |
| } |
| |
| // File returns a copy of the underlying os.File, set to blocking mode. |
| // It is the caller's responsibility to close f when finished. |
| // Closing c does not affect f, and closing f does not affect c. |
| func (c *TCPConn) File() (f *os.File, err os.Error) { return c.fd.dup() } |
| |
| // DialTCP is like Dial but can only connect to TCP networks |
| // and returns a TCPConn structure. |
| func DialTCP(net string, laddr, raddr *TCPAddr) (c *TCPConn, err os.Error) { |
| if raddr == nil { |
| return nil, &OpError{"dial", "tcp", nil, errMissingAddress} |
| } |
| fd, e := internetSocket(net, laddr.toAddr(), raddr.toAddr(), syscall.SOCK_STREAM, 0, "dial", sockaddrToTCP) |
| if e != nil { |
| return nil, e |
| } |
| return newTCPConn(fd), nil |
| } |
| |
| // TCPListener is a TCP network listener. |
| // Clients should typically use variables of type Listener |
| // instead of assuming TCP. |
| type TCPListener struct { |
| fd *netFD |
| } |
| |
| // ListenTCP announces on the TCP address laddr and returns a TCP listener. |
| // Net must be "tcp", "tcp4", or "tcp6". |
| // If laddr has a port of 0, it means to listen on some available port. |
| // The caller can use l.Addr() to retrieve the chosen address. |
| func ListenTCP(net string, laddr *TCPAddr) (l *TCPListener, err os.Error) { |
| fd, err := internetSocket(net, laddr.toAddr(), nil, syscall.SOCK_STREAM, 0, "listen", sockaddrToTCP) |
| if err != nil { |
| return nil, err |
| } |
| errno := syscall.Listen(fd.sysfd, listenBacklog()) |
| if errno != 0 { |
| closesocket(fd.sysfd) |
| return nil, &OpError{"listen", "tcp", laddr, os.Errno(errno)} |
| } |
| l = new(TCPListener) |
| l.fd = fd |
| return l, nil |
| } |
| |
| // AcceptTCP accepts the next incoming call and returns the new connection |
| // and the remote address. |
| func (l *TCPListener) AcceptTCP() (c *TCPConn, err os.Error) { |
| if l == nil || l.fd == nil || l.fd.sysfd < 0 { |
| return nil, os.EINVAL |
| } |
| fd, err := l.fd.accept(sockaddrToTCP) |
| if err != nil { |
| return nil, err |
| } |
| return newTCPConn(fd), nil |
| } |
| |
| // Accept implements the Accept method in the Listener interface; |
| // it waits for the next call and returns a generic Conn. |
| func (l *TCPListener) Accept() (c Conn, err os.Error) { |
| c1, err := l.AcceptTCP() |
| if err != nil { |
| return nil, err |
| } |
| return c1, nil |
| } |
| |
| // Close stops listening on the TCP address. |
| // Already Accepted connections are not closed. |
| func (l *TCPListener) Close() os.Error { |
| if l == nil || l.fd == nil { |
| return os.EINVAL |
| } |
| return l.fd.Close() |
| } |
| |
| // Addr returns the listener's network address, a *TCPAddr. |
| func (l *TCPListener) Addr() Addr { return l.fd.laddr } |
| |
| // File returns a copy of the underlying os.File, set to blocking mode. |
| // It is the caller's responsibility to close f when finished. |
| // Closing c does not affect f, and closing f does not affect c. |
| func (l *TCPListener) File() (f *os.File, err os.Error) { return l.fd.dup() } |