libgo/go/net/sock_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 freebsd linux netbsd openbsd windows
   6
   7 package net
   8
   9 import (
  10         "syscall"
  11         "time"
  12 )
  13
  14 var listenerBacklog = maxListenerBacklog()
  15
  16 // Generic POSIX socket creation.
  17 func socket(net string, f, t, p int, ipv6only bool, ulsa, ursa syscall.Sockaddr, deadline time.Time, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err error) {
  18         s, err := sysSocket(f, t, p)
  19         if err != nil {
  20                 return nil, err
  21         }
  22
  23         if err = setDefaultSockopts(s, f, t, ipv6only); err != nil {
  24                 closesocket(s)
  25                 return nil, err
  26         }
  27
  28         // This socket is used by a listener.
  29         if ulsa != nil && ursa == nil {
  30                 // We provide a socket that listens to a wildcard
  31                 // address with reusable UDP port when the given ulsa
  32                 // is an appropriate UDP multicast address prefix.
  33                 // This makes it possible for a single UDP listener
  34                 // to join multiple different group addresses, for
  35                 // multiple UDP listeners that listen on the same UDP
  36                 // port to join the same group address.
  37                 if ulsa, err = listenerSockaddr(s, f, ulsa, toAddr); err != nil {
  38                         closesocket(s)
  39                         return nil, err
  40                 }
  41         }
  42
  43         if ulsa != nil {
  44                 if err = syscall.Bind(s, ulsa); err != nil {
  45                         closesocket(s)
  46                         return nil, err
  47                 }
  48         }
  49
  50         if fd, err = newFD(s, f, t, net); err != nil {
  51                 closesocket(s)
  52                 return nil, err
  53         }
  54
  55         // This socket is used by a dialer.
  56         if ursa != nil {
  57                 if !deadline.IsZero() {
  58                         setWriteDeadline(fd, deadline)
  59                 }
  60                 if err = fd.connect(ulsa, ursa); err != nil {
  61                         fd.Close()
  62                         return nil, err
  63                 }
  64                 fd.isConnected = true
  65                 if !deadline.IsZero() {
  66                         setWriteDeadline(fd, time.Time{})
  67                 }
  68         }
  69
  70         lsa, _ := syscall.Getsockname(s)
  71         laddr := toAddr(lsa)
  72         rsa, _ := syscall.Getpeername(s)
  73         if rsa == nil {
  74                 rsa = ursa
  75         }
  76         raddr := toAddr(rsa)
  77         fd.setAddr(laddr, raddr)
  78         return fd, nil
  79 }