1 // Copyright 2011 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.
12 // A PerHost directs connections to a default Dialer unless the host name
13 // requested matches one of a number of exceptions.
17 bypassNetworks []*net.IPNet
23 // NewPerHost returns a PerHost Dialer that directs connections to either
24 // defaultDialer or bypass, depending on whether the connection matches one of
25 // the configured rules.
26 func NewPerHost(defaultDialer, bypass Dialer) *PerHost {
33 // Dial connects to the address addr on the given network through either
34 // defaultDialer or bypass.
35 func (p *PerHost) Dial(network, addr string) (c net.Conn, err error) {
36 host, _, err := net.SplitHostPort(addr)
41 return p.dialerForRequest(host).Dial(network, addr)
44 func (p *PerHost) dialerForRequest(host string) Dialer {
45 if ip := net.ParseIP(host); ip != nil {
46 for _, net := range p.bypassNetworks {
51 for _, bypassIP := range p.bypassIPs {
52 if bypassIP.Equal(ip) {
59 for _, zone := range p.bypassZones {
60 if strings.HasSuffix(host, zone) {
64 // For a zone ".example.com", we match "example.com"
69 for _, bypassHost := range p.bypassHosts {
70 if bypassHost == host {
77 // AddFromString parses a string that contains comma-separated values
78 // specifying hosts that should use the bypass proxy. Each value is either an
79 // IP address, a CIDR range, a zone (*.example.com) or a host name
80 // (localhost). A best effort is made to parse the string and errors are
82 func (p *PerHost) AddFromString(s string) {
83 hosts := strings.Split(s, ",")
84 for _, host := range hosts {
85 host = strings.TrimSpace(host)
89 if strings.Contains(host, "/") {
90 // We assume that it's a CIDR address like 127.0.0.0/8
91 if _, net, err := net.ParseCIDR(host); err == nil {
96 if ip := net.ParseIP(host); ip != nil {
100 if strings.HasPrefix(host, "*.") {
108 // AddIP specifies an IP address that will use the bypass proxy. Note that
109 // this will only take effect if a literal IP address is dialed. A connection
110 // to a named host will never match an IP.
111 func (p *PerHost) AddIP(ip net.IP) {
112 p.bypassIPs = append(p.bypassIPs, ip)
115 // AddNetwork specifies an IP range that will use the bypass proxy. Note that
116 // this will only take effect if a literal IP address is dialed. A connection
117 // to a named host will never match.
118 func (p *PerHost) AddNetwork(net *net.IPNet) {
119 p.bypassNetworks = append(p.bypassNetworks, net)
122 // AddZone specifies a DNS suffix that will use the bypass proxy. A zone of
123 // "example.com" matches "example.com" and all of its subdomains.
124 func (p *PerHost) AddZone(zone string) {
125 if strings.HasSuffix(zone, ".") {
126 zone = zone[:len(zone)-1]
128 if !strings.HasPrefix(zone, ".") {
131 p.bypassZones = append(p.bypassZones, zone)
134 // AddHost specifies a host name that will use the bypass proxy.
135 func (p *PerHost) AddHost(host string) {
136 if strings.HasSuffix(host, ".") {
137 host = host[:len(host)-1]
139 p.bypassHosts = append(p.bypassHosts, host)