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.
11 func parseDialNetwork(net string) (afnet string, proto int, err error) {
13 if i < 0 { // no colon
15 case "tcp", "tcp4", "tcp6":
16 case "udp", "udp4", "udp6":
17 case "unix", "unixgram", "unixpacket":
19 return "", 0, UnknownNetworkError(net)
25 case "ip", "ip4", "ip6":
27 proto, i, ok := dtoi(protostr, 0)
28 if !ok || i != len(protostr) {
29 proto, err = lookupProtocol(protostr)
34 return afnet, proto, nil
36 return "", 0, UnknownNetworkError(net)
39 func resolveNetAddr(op, net, addr string) (afnet string, a Addr, err error) {
40 afnet, _, err = parseDialNetwork(net)
42 return "", nil, &OpError{op, net, nil, err}
44 if op == "dial" && addr == "" {
45 return "", nil, &OpError{op, net, nil, errMissingAddress}
48 case "tcp", "tcp4", "tcp6":
50 a, err = ResolveTCPAddr(afnet, addr)
52 case "udp", "udp4", "udp6":
54 a, err = ResolveUDPAddr(afnet, addr)
56 case "ip", "ip4", "ip6":
58 a, err = ResolveIPAddr(afnet, addr)
60 case "unix", "unixgram", "unixpacket":
62 a, err = ResolveUnixAddr(afnet, addr)
68 // Dial connects to the address addr on the network net.
70 // Known networks are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only),
71 // "udp", "udp4" (IPv4-only), "udp6" (IPv6-only), "ip", "ip4"
72 // (IPv4-only), "ip6" (IPv6-only), "unix" and "unixpacket".
74 // For TCP and UDP networks, addresses have the form host:port.
75 // If host is a literal IPv6 address, it must be enclosed
76 // in square brackets. The functions JoinHostPort and SplitHostPort
77 // manipulate addresses in this form.
80 // Dial("tcp", "12.34.56.78:80")
81 // Dial("tcp", "google.com:80")
82 // Dial("tcp", "[de:ad:be:ef::ca:fe]:80")
84 // For IP networks, addr must be "ip", "ip4" or "ip6" followed
85 // by a colon and a protocol number or name.
88 // Dial("ip4:1", "127.0.0.1")
89 // Dial("ip6:ospf", "::1")
91 func Dial(net, addr string) (Conn, error) {
92 _, addri, err := resolveNetAddr("dial", net, addr)
96 return dialAddr(net, addr, addri)
99 func dialAddr(net, addr string, addri Addr) (c Conn, err error) {
100 switch ra := addri.(type) {
102 c, err = DialTCP(net, nil, ra)
104 c, err = DialUDP(net, nil, ra)
106 c, err = DialIP(net, nil, ra)
108 c, err = DialUnix(net, nil, ra)
110 err = &OpError{"dial", net + " " + addr, nil, UnknownNetworkError(net)}
118 // DialTimeout acts like Dial but takes a timeout.
119 // The timeout includes name resolution, if required.
120 func DialTimeout(net, addr string, timeout time.Duration) (Conn, error) {
121 // TODO(bradfitz): the timeout should be pushed down into the
122 // net package's event loop, so on timeout to dead hosts we
123 // don't have a goroutine sticking around for the default of
125 t := time.NewTimer(timeout)
131 ch := make(chan pair, 1)
132 resolvedAddr := make(chan Addr, 1)
134 _, addri, err := resolveNetAddr("dial", net, addr)
139 resolvedAddr <- addri // in case we need it for OpError
140 c, err := dialAddr(net, addr, addri)
145 // Try to use the real Addr in our OpError, if we resolved it
146 // before the timeout. Otherwise we just use stringAddr.
149 case a := <-resolvedAddr:
152 addri = &stringAddr{net, addr}
158 Err: &timeoutError{},
162 return p.Conn, p.error
167 type stringAddr struct {
171 func (a stringAddr) Network() string { return a.net }
172 func (a stringAddr) String() string { return a.addr }
174 // Listen announces on the local network address laddr.
175 // The network string net must be a stream-oriented network:
176 // "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
177 func Listen(net, laddr string) (Listener, error) {
178 afnet, a, err := resolveNetAddr("listen", net, laddr)
183 case "tcp", "tcp4", "tcp6":
188 return ListenTCP(net, la)
189 case "unix", "unixpacket":
194 return ListenUnix(net, la)
196 return nil, UnknownNetworkError(net)
199 // ListenPacket announces on the local network address laddr.
200 // The network string net must be a packet-oriented network:
201 // "udp", "udp4", "udp6", "ip", "ip4", "ip6" or "unixgram".
202 func ListenPacket(net, addr string) (PacketConn, error) {
203 afnet, a, err := resolveNetAddr("listen", net, addr)
208 case "udp", "udp4", "udp6":
213 return ListenUDP(net, la)
214 case "ip", "ip4", "ip6":
219 return ListenIP(net, la)
225 return DialUnix(net, la, nil)
227 return nil, UnknownNetworkError(net)