156 lines
4.1 KiB
Go
156 lines
4.1 KiB
Go
// Copyright 2011 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 proxy
|
|
|
|
import (
|
|
"context"
|
|
"net"
|
|
"strings"
|
|
)
|
|
|
|
// A PerHost directs connections to a default Dialer unless the host name
|
|
// requested matches one of a number of exceptions.
|
|
type PerHost struct {
|
|
def, bypass Dialer
|
|
|
|
bypassNetworks []*net.IPNet
|
|
bypassIPs []net.IP
|
|
bypassZones []string
|
|
bypassHosts []string
|
|
}
|
|
|
|
// NewPerHost returns a PerHost Dialer that directs connections to either
|
|
// defaultDialer or bypass, depending on whether the connection matches one of
|
|
// the configured rules.
|
|
func NewPerHost(defaultDialer, bypass Dialer) *PerHost {
|
|
return &PerHost{
|
|
def: defaultDialer,
|
|
bypass: bypass,
|
|
}
|
|
}
|
|
|
|
// Dial connects to the address addr on the given network through either
|
|
// defaultDialer or bypass.
|
|
func (p *PerHost) Dial(network, addr string) (c net.Conn, err error) {
|
|
host, _, err := net.SplitHostPort(addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return p.dialerForRequest(host).Dial(network, addr)
|
|
}
|
|
|
|
// DialContext connects to the address addr on the given network through either
|
|
// defaultDialer or bypass.
|
|
func (p *PerHost) DialContext(ctx context.Context, network, addr string) (c net.Conn, err error) {
|
|
host, _, err := net.SplitHostPort(addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
d := p.dialerForRequest(host)
|
|
if x, ok := d.(ContextDialer); ok {
|
|
return x.DialContext(ctx, network, addr)
|
|
}
|
|
return dialContext(ctx, d, network, addr)
|
|
}
|
|
|
|
func (p *PerHost) dialerForRequest(host string) Dialer {
|
|
if ip := net.ParseIP(host); ip != nil {
|
|
for _, net := range p.bypassNetworks {
|
|
if net.Contains(ip) {
|
|
return p.bypass
|
|
}
|
|
}
|
|
for _, bypassIP := range p.bypassIPs {
|
|
if bypassIP.Equal(ip) {
|
|
return p.bypass
|
|
}
|
|
}
|
|
return p.def
|
|
}
|
|
|
|
for _, zone := range p.bypassZones {
|
|
if strings.HasSuffix(host, zone) {
|
|
return p.bypass
|
|
}
|
|
if host == zone[1:] {
|
|
// For a zone ".example.com", we match "example.com"
|
|
// too.
|
|
return p.bypass
|
|
}
|
|
}
|
|
for _, bypassHost := range p.bypassHosts {
|
|
if bypassHost == host {
|
|
return p.bypass
|
|
}
|
|
}
|
|
return p.def
|
|
}
|
|
|
|
// AddFromString parses a string that contains comma-separated values
|
|
// specifying hosts that should use the bypass proxy. Each value is either an
|
|
// IP address, a CIDR range, a zone (*.example.com) or a host name
|
|
// (localhost). A best effort is made to parse the string and errors are
|
|
// ignored.
|
|
func (p *PerHost) AddFromString(s string) {
|
|
hosts := strings.Split(s, ",")
|
|
for _, host := range hosts {
|
|
host = strings.TrimSpace(host)
|
|
if len(host) == 0 {
|
|
continue
|
|
}
|
|
if strings.Contains(host, "/") {
|
|
// We assume that it's a CIDR address like 127.0.0.0/8
|
|
if _, net, err := net.ParseCIDR(host); err == nil {
|
|
p.AddNetwork(net)
|
|
}
|
|
continue
|
|
}
|
|
if ip := net.ParseIP(host); ip != nil {
|
|
p.AddIP(ip)
|
|
continue
|
|
}
|
|
if strings.HasPrefix(host, "*.") {
|
|
p.AddZone(host[1:])
|
|
continue
|
|
}
|
|
p.AddHost(host)
|
|
}
|
|
}
|
|
|
|
// AddIP specifies an IP address that will use the bypass proxy. Note that
|
|
// this will only take effect if a literal IP address is dialed. A connection
|
|
// to a named host will never match an IP.
|
|
func (p *PerHost) AddIP(ip net.IP) {
|
|
p.bypassIPs = append(p.bypassIPs, ip)
|
|
}
|
|
|
|
// AddNetwork specifies an IP range that will use the bypass proxy. Note that
|
|
// this will only take effect if a literal IP address is dialed. A connection
|
|
// to a named host will never match.
|
|
func (p *PerHost) AddNetwork(net *net.IPNet) {
|
|
p.bypassNetworks = append(p.bypassNetworks, net)
|
|
}
|
|
|
|
// AddZone specifies a DNS suffix that will use the bypass proxy. A zone of
|
|
// "example.com" matches "example.com" and all of its subdomains.
|
|
func (p *PerHost) AddZone(zone string) {
|
|
if strings.HasSuffix(zone, ".") {
|
|
zone = zone[:len(zone)-1]
|
|
}
|
|
if !strings.HasPrefix(zone, ".") {
|
|
zone = "." + zone
|
|
}
|
|
p.bypassZones = append(p.bypassZones, zone)
|
|
}
|
|
|
|
// AddHost specifies a host name that will use the bypass proxy.
|
|
func (p *PerHost) AddHost(host string) {
|
|
if strings.HasSuffix(host, ".") {
|
|
host = host[:len(host)-1]
|
|
}
|
|
p.bypassHosts = append(p.bypassHosts, host)
|
|
}
|