66 lines
1.5 KiB
Go
66 lines
1.5 KiB
Go
// Copyright 2010 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// (Raw) IP sockets
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package net
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// IPAddr represents the address of a IP end point.
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type IPAddr struct {
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IP IP
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}
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// Network returns the address's network name, "ip".
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func (a *IPAddr) Network() string { return "ip" }
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func (a *IPAddr) String() string {
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if a == nil {
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return "<nil>"
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}
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return a.IP.String()
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}
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// ResolveIPAddr parses addr as a IP address and resolves domain
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// names to numeric addresses on the network net, which must be
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// "ip", "ip4" or "ip6". A literal IPv6 host address must be
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// enclosed in square brackets, as in "[::]".
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func ResolveIPAddr(net, addr string) (*IPAddr, error) {
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ip, err := hostToIP(net, addr)
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if err != nil {
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return nil, err
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}
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return &IPAddr{ip}, nil
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}
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// Convert "host" into IP address.
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func hostToIP(net, host string) (ip IP, err error) {
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var addr IP
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// Try as an IP address.
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addr = ParseIP(host)
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if addr == nil {
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filter := anyaddr
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if net != "" && net[len(net)-1] == '4' {
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filter = ipv4only
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}
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if net != "" && net[len(net)-1] == '6' {
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filter = ipv6only
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}
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// Not an IP address. Try as a DNS name.
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addrs, err1 := LookupHost(host)
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if err1 != nil {
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err = err1
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goto Error
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}
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addr = firstFavoriteAddr(filter, addrs)
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if addr == nil {
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// should not happen
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err = &AddrError{"LookupHost returned no suitable address", addrs[0]}
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goto Error
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}
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}
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return addr, nil
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Error:
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return nil, err
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}
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