Source file src/pkg/net/dial.go

// Copyright 2010 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.

package net

import "os"

// Dial connects to the remote address raddr on the network net.
// If the string laddr is not empty, it is used as the local address
// for the connection.
//
// Known networks are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only),
// "udp", "udp4" (IPv4-only), "udp6" (IPv6-only), "ip", "ip4"
// (IPv4-only) and "ip6" IPv6-only).
//
// For IP networks, addresses have the form host:port.  If host is
// a literal IPv6 address, it must be enclosed in square brackets.
//
// Examples:
//	Dial("tcp", "", "12.34.56.78:80")
//	Dial("tcp", "", "google.com:80")
//	Dial("tcp", "", "[de:ad:be:ef::ca:fe]:80")
//	Dial("tcp", "127.0.0.1:123", "127.0.0.1:88")
//
func Dial(net, laddr, raddr string) (c Conn, err os.Error) {
    switch prefixBefore(net, ':') {
    case "tcp", "tcp4", "tcp6":
        var la, ra *TCPAddr
        if laddr != "" {
            if la, err = ResolveTCPAddr(laddr); err != nil {
                goto Error
            }
        }
        if raddr != "" {
            if ra, err = ResolveTCPAddr(raddr); err != nil {
                goto Error
            }
        }
        c, err := DialTCP(net, la, ra)
        if err != nil {
            return nil, err
        }
        return c, nil
    case "udp", "udp4", "udp6":
        var la, ra *UDPAddr
        if laddr != "" {
            if la, err = ResolveUDPAddr(laddr); err != nil {
                goto Error
            }
        }
        if raddr != "" {
            if ra, err = ResolveUDPAddr(raddr); err != nil {
                goto Error
            }
        }
        c, err := DialUDP(net, la, ra)
        if err != nil {
            return nil, err
        }
        return c, nil
    case "unix", "unixgram":
        var la, ra *UnixAddr
        if raddr != "" {
            if ra, err = ResolveUnixAddr(net, raddr); err != nil {
                goto Error
            }
        }
        if laddr != "" {
            if la, err = ResolveUnixAddr(net, laddr); err != nil {
                goto Error
            }
        }
        c, err = DialUnix(net, la, ra)
        if err != nil {
            return nil, err
        }
        return c, nil
    case "ip", "ip4", "ip6":
        var la, ra *IPAddr
        if laddr != "" {
            if la, err = ResolveIPAddr(laddr); err != nil {
                goto Error
            }
        }
        if raddr != "" {
            if ra, err = ResolveIPAddr(raddr); err != nil {
                goto Error
            }
        }
        c, err := DialIP(net, la, ra)
        if err != nil {
            return nil, err
        }
        return c, nil

    }
    err = UnknownNetworkError(net)
Error:
    return nil, &OpError{"dial", net + " " + raddr, nil, err}
}

// Listen announces on the local network address laddr.
// The network string net must be a stream-oriented
// network: "tcp", "tcp4", "tcp6", or "unix".
func Listen(net, laddr string) (l Listener, err os.Error) {
    switch net {
    case "tcp", "tcp4", "tcp6":
        var la *TCPAddr
        if laddr != "" {
            if la, err = ResolveTCPAddr(laddr); err != nil {
                return nil, err
            }
        }
        l, err := ListenTCP(net, la)
        if err != nil {
            return nil, err
        }
        return l, nil
    case "unix":
        var la *UnixAddr
        if laddr != "" {
            if la, err = ResolveUnixAddr(net, laddr); err != nil {
                return nil, err
            }
        }
        l, err := ListenUnix(net, la)
        if err != nil {
            return nil, err
        }
        return l, nil
    }
    return nil, UnknownNetworkError(net)
}

// ListenPacket announces on the local network address laddr.
// The network string net must be a packet-oriented network:
// "udp", "udp4", "udp6", or "unixgram".
func ListenPacket(net, laddr string) (c PacketConn, err os.Error) {
    switch prefixBefore(net, ':') {
    case "udp", "udp4", "udp6":
        var la *UDPAddr
        if laddr != "" {
            if la, err = ResolveUDPAddr(laddr); err != nil {
                return nil, err
            }
        }
        c, err := ListenUDP(net, la)
        if err != nil {
            return nil, err
        }
        return c, nil
    case "unixgram":
        var la *UnixAddr
        if laddr != "" {
            if la, err = ResolveUnixAddr(net, laddr); err != nil {
                return nil, err
            }
        }
        c, err := DialUnix(net, la, nil)
        if err != nil {
            return nil, err
        }
        return c, nil
    case "ip", "ip4", "ip6":
        var la *IPAddr
        if laddr != "" {
            if la, err = ResolveIPAddr(laddr); err != nil {
                return nil, err
            }
        }
        c, err := ListenIP(net, la)
        if err != nil {
            return nil, err
        }
        return c, nil
    }
    return nil, UnknownNetworkError(net)
}