libgo/go/net/iprawsock_posix.go

   1 // Copyright 2010 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 aix darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
   6
   7 package net
   8
   9 import (
  10         "context"
  11         "syscall"
  12 )
  13
  14 func sockaddrToIP(sa syscall.Sockaddr) Addr {
  15         switch sa := sa.(type) {
  16         case *syscall.SockaddrInet4:
  17                 return &IPAddr{IP: sa.Addr[0:]}
  18         case *syscall.SockaddrInet6:
  19                 return &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
  20         }
  21         return nil
  22 }
  23
  24 func (a *IPAddr) 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 *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
  35         if a == nil {
  36                 return nil, nil
  37         }
  38         return ipToSockaddr(family, a.IP, 0, a.Zone)
  39 }
  40
  41 func (a *IPAddr) toLocal(net string) sockaddr {
  42         return &IPAddr{loopbackIP(net), a.Zone}
  43 }
  44
  45 func (c *IPConn) readFrom(b []byte) (int, *IPAddr, error) {
  46         // TODO(cw,rsc): consider using readv if we know the family
  47         // type to avoid the header trim/copy
  48         var addr *IPAddr
  49         n, sa, err := c.fd.readFrom(b)
  50         switch sa := sa.(type) {
  51         case *syscall.SockaddrInet4:
  52                 addr = &IPAddr{IP: sa.Addr[0:]}
  53                 n = stripIPv4Header(n, b)
  54         case *syscall.SockaddrInet6:
  55                 addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
  56         }
  57         return n, addr, err
  58 }
  59
  60 func stripIPv4Header(n int, b []byte) int {
  61         if len(b) < 20 {
  62                 return n
  63         }
  64         l := int(b[0]&0x0f) << 2
  65         if 20 > l || l > len(b) {
  66                 return n
  67         }
  68         if b[0]>>4 != 4 {
  69                 return n
  70         }
  71         copy(b, b[l:])
  72         return n - l
  73 }
  74
  75 func (c *IPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error) {
  76         var sa syscall.Sockaddr
  77         n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
  78         switch sa := sa.(type) {
  79         case *syscall.SockaddrInet4:
  80                 addr = &IPAddr{IP: sa.Addr[0:]}
  81         case *syscall.SockaddrInet6:
  82                 addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))}
  83         }
  84         return
  85 }
  86
  87 func (c *IPConn) writeTo(b []byte, addr *IPAddr) (int, error) {
  88         if c.fd.isConnected {
  89                 return 0, ErrWriteToConnected
  90         }
  91         if addr == nil {
  92                 return 0, errMissingAddress
  93         }
  94         sa, err := addr.sockaddr(c.fd.family)
  95         if err != nil {
  96                 return 0, err
  97         }
  98         return c.fd.writeTo(b, sa)
  99 }
 100
 101 func (c *IPConn) writeMsg(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
 102         if c.fd.isConnected {
 103                 return 0, 0, ErrWriteToConnected
 104         }
 105         if addr == nil {
 106                 return 0, 0, errMissingAddress
 107         }
 108         sa, err := addr.sockaddr(c.fd.family)
 109         if err != nil {
 110                 return 0, 0, err
 111         }
 112         return c.fd.writeMsg(b, oob, sa)
 113 }
 114
 115 func dialIP(ctx context.Context, netProto string, laddr, raddr *IPAddr) (*IPConn, error) {
 116         network, proto, err := parseNetwork(ctx, netProto)
 117         if err != nil {
 118                 return nil, err
 119         }
 120         switch network {
 121         case "ip", "ip4", "ip6":
 122         default:
 123                 return nil, UnknownNetworkError(netProto)
 124         }
 125         if raddr == nil {
 126                 return nil, errMissingAddress
 127         }
 128         fd, err := internetSocket(ctx, network, laddr, raddr, syscall.SOCK_RAW, proto, "dial")
 129         if err != nil {
 130                 return nil, err
 131         }
 132         return newIPConn(fd), nil
 133 }
 134
 135 func listenIP(ctx context.Context, netProto string, laddr *IPAddr) (*IPConn, error) {
 136         network, proto, err := parseNetwork(ctx, netProto)
 137         if err != nil {
 138                 return nil, err
 139         }
 140         switch network {
 141         case "ip", "ip4", "ip6":
 142         default:
 143                 return nil, UnknownNetworkError(netProto)
 144         }
 145         fd, err := internetSocket(ctx, network, laddr, nil, syscall.SOCK_RAW, proto, "listen")
 146         if err != nil {
 147                 return nil, err
 148         }
 149         return newIPConn(fd), nil
 150 }