libgo/go/net/iprawsock.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 package net
   6
   7 import (
   8         "context"
   9         "syscall"
  10 )
  11
  12 // BUG(mikio): On every POSIX platform, reads from the "ip4" network
  13 // using the ReadFrom or ReadFromIP method might not return a complete
  14 // IPv4 packet, including its header, even if there is space
  15 // available. This can occur even in cases where Read or ReadMsgIP
  16 // could return a complete packet. For this reason, it is recommended
  17 // that you do not use these methods if it is important to receive a
  18 // full packet.
  19 //
  20 // The Go 1 compatibility guidelines make it impossible for us to
  21 // change the behavior of these methods; use Read or ReadMsgIP
  22 // instead.
  23
  24 // BUG(mikio): On JS, NaCl and Plan 9, methods and functions related
  25 // to IPConn are not implemented.
  26
  27 // BUG(mikio): On Windows, the File method of IPConn is not
  28 // implemented.
  29
  30 // IPAddr represents the address of an IP end point.
  31 type IPAddr struct {
  32         IP   IP
  33         Zone string // IPv6 scoped addressing zone
  34 }
  35
  36 // Network returns the address's network name, "ip".
  37 func (a *IPAddr) Network() string { return "ip" }
  38
  39 func (a *IPAddr) String() string {
  40         if a == nil {
  41                 return "<nil>"
  42         }
  43         ip := ipEmptyString(a.IP)
  44         if a.Zone != "" {
  45                 return ip + "%" + a.Zone
  46         }
  47         return ip
  48 }
  49
  50 func (a *IPAddr) isWildcard() bool {
  51         if a == nil || a.IP == nil {
  52                 return true
  53         }
  54         return a.IP.IsUnspecified()
  55 }
  56
  57 func (a *IPAddr) opAddr() Addr {
  58         if a == nil {
  59                 return nil
  60         }
  61         return a
  62 }
  63
  64 // ResolveIPAddr returns an address of IP end point.
  65 //
  66 // The network must be an IP network name.
  67 //
  68 // If the host in the address parameter is not a literal IP address,
  69 // ResolveIPAddr resolves the address to an address of IP end point.
  70 // Otherwise, it parses the address as a literal IP address.
  71 // The address parameter can use a host name, but this is not
  72 // recommended, because it will return at most one of the host name's
  73 // IP addresses.
  74 //
  75 // See func Dial for a description of the network and address
  76 // parameters.
  77 func ResolveIPAddr(network, address string) (*IPAddr, error) {
  78         if network == "" { // a hint wildcard for Go 1.0 undocumented behavior
  79                 network = "ip"
  80         }
  81         afnet, _, err := parseNetwork(context.Background(), network, false)
  82         if err != nil {
  83                 return nil, err
  84         }
  85         switch afnet {
  86         case "ip", "ip4", "ip6":
  87         default:
  88                 return nil, UnknownNetworkError(network)
  89         }
  90         addrs, err := DefaultResolver.internetAddrList(context.Background(), afnet, address)
  91         if err != nil {
  92                 return nil, err
  93         }
  94         return addrs.forResolve(network, address).(*IPAddr), nil
  95 }
  96
  97 // IPConn is the implementation of the Conn and PacketConn interfaces
  98 // for IP network connections.
  99 type IPConn struct {
 100         conn
 101 }
 102
 103 // SyscallConn returns a raw network connection.
 104 // This implements the syscall.Conn interface.
 105 func (c *IPConn) SyscallConn() (syscall.RawConn, error) {
 106         if !c.ok() {
 107                 return nil, syscall.EINVAL
 108         }
 109         return newRawConn(c.fd)
 110 }
 111
 112 // ReadFromIP acts like ReadFrom but returns an IPAddr.
 113 func (c *IPConn) ReadFromIP(b []byte) (int, *IPAddr, error) {
 114         if !c.ok() {
 115                 return 0, nil, syscall.EINVAL
 116         }
 117         n, addr, err := c.readFrom(b)
 118         if err != nil {
 119                 err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
 120         }
 121         return n, addr, err
 122 }
 123
 124 // ReadFrom implements the PacketConn ReadFrom method.
 125 func (c *IPConn) ReadFrom(b []byte) (int, Addr, error) {
 126         if !c.ok() {
 127                 return 0, nil, syscall.EINVAL
 128         }
 129         n, addr, err := c.readFrom(b)
 130         if err != nil {
 131                 err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
 132         }
 133         if addr == nil {
 134                 return n, nil, err
 135         }
 136         return n, addr, err
 137 }
 138
 139 // ReadMsgIP reads a message from c, copying the payload into b and
 140 // the associated out-of-band data into oob. It returns the number of
 141 // bytes copied into b, the number of bytes copied into oob, the flags
 142 // that were set on the message and the source address of the message.
 143 //
 144 // The packages golang.org/x/net/ipv4 and golang.org/x/net/ipv6 can be
 145 // used to manipulate IP-level socket options in oob.
 146 func (c *IPConn) ReadMsgIP(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error) {
 147         if !c.ok() {
 148                 return 0, 0, 0, nil, syscall.EINVAL
 149         }
 150         n, oobn, flags, addr, err = c.readMsg(b, oob)
 151         if err != nil {
 152                 err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
 153         }
 154         return
 155 }
 156
 157 // WriteToIP acts like WriteTo but takes an IPAddr.
 158 func (c *IPConn) WriteToIP(b []byte, addr *IPAddr) (int, error) {
 159         if !c.ok() {
 160                 return 0, syscall.EINVAL
 161         }
 162         n, err := c.writeTo(b, addr)
 163         if err != nil {
 164                 err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
 165         }
 166         return n, err
 167 }
 168
 169 // WriteTo implements the PacketConn WriteTo method.
 170 func (c *IPConn) WriteTo(b []byte, addr Addr) (int, error) {
 171         if !c.ok() {
 172                 return 0, syscall.EINVAL
 173         }
 174         a, ok := addr.(*IPAddr)
 175         if !ok {
 176                 return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr, Err: syscall.EINVAL}
 177         }
 178         n, err := c.writeTo(b, a)
 179         if err != nil {
 180                 err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: a.opAddr(), Err: err}
 181         }
 182         return n, err
 183 }
 184
 185 // WriteMsgIP writes a message to addr via c, copying the payload from
 186 // b and the associated out-of-band data from oob. It returns the
 187 // number of payload and out-of-band bytes written.
 188 //
 189 // The packages golang.org/x/net/ipv4 and golang.org/x/net/ipv6 can be
 190 // used to manipulate IP-level socket options in oob.
 191 func (c *IPConn) WriteMsgIP(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
 192         if !c.ok() {
 193                 return 0, 0, syscall.EINVAL
 194         }
 195         n, oobn, err = c.writeMsg(b, oob, addr)
 196         if err != nil {
 197                 err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
 198         }
 199         return
 200 }
 201
 202 func newIPConn(fd *netFD) *IPConn { return &IPConn{conn{fd}} }
 203
 204 // DialIP acts like Dial for IP networks.
 205 //
 206 // The network must be an IP network name; see func Dial for details.
 207 //
 208 // If laddr is nil, a local address is automatically chosen.
 209 // If the IP field of raddr is nil or an unspecified IP address, the
 210 // local system is assumed.
 211 func DialIP(network string, laddr, raddr *IPAddr) (*IPConn, error) {
 212         if raddr == nil {
 213                 return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: nil, Err: errMissingAddress}
 214         }
 215         sd := &sysDialer{network: network, address: raddr.String()}
 216         c, err := sd.dialIP(context.Background(), laddr, raddr)
 217         if err != nil {
 218                 return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: err}
 219         }
 220         return c, nil
 221 }
 222
 223 // ListenIP acts like ListenPacket for IP networks.
 224 //
 225 // The network must be an IP network name; see func Dial for details.
 226 //
 227 // If the IP field of laddr is nil or an unspecified IP address,
 228 // ListenIP listens on all available IP addresses of the local system
 229 // except multicast IP addresses.
 230 func ListenIP(network string, laddr *IPAddr) (*IPConn, error) {
 231         if laddr == nil {
 232                 laddr = &IPAddr{}
 233         }
 234         sl := &sysListener{network: network, address: laddr.String()}
 235         c, err := sl.listenIP(context.Background(), laddr)
 236         if err != nil {
 237                 return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: err}
 238         }
 239         return c, nil
 240 }