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Diffstat (limited to 'vendor/golang.org/x/net/proxy/proxy.go')
-rw-r--r--vendor/golang.org/x/net/proxy/proxy.go149
1 files changed, 149 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/proxy/proxy.go b/vendor/golang.org/x/net/proxy/proxy.go
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+++ b/vendor/golang.org/x/net/proxy/proxy.go
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+// 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 provides support for a variety of protocols to proxy network
+// data.
+package proxy // import "golang.org/x/net/proxy"
+
+import (
+ "errors"
+ "net"
+ "net/url"
+ "os"
+ "sync"
+)
+
+// A Dialer is a means to establish a connection.
+// Custom dialers should also implement ContextDialer.
+type Dialer interface {
+ // Dial connects to the given address via the proxy.
+ Dial(network, addr string) (c net.Conn, err error)
+}
+
+// Auth contains authentication parameters that specific Dialers may require.
+type Auth struct {
+ User, Password string
+}
+
+// FromEnvironment returns the dialer specified by the proxy-related
+// variables in the environment and makes underlying connections
+// directly.
+func FromEnvironment() Dialer {
+ return FromEnvironmentUsing(Direct)
+}
+
+// FromEnvironmentUsing returns the dialer specify by the proxy-related
+// variables in the environment and makes underlying connections
+// using the provided forwarding Dialer (for instance, a *net.Dialer
+// with desired configuration).
+func FromEnvironmentUsing(forward Dialer) Dialer {
+ allProxy := allProxyEnv.Get()
+ if len(allProxy) == 0 {
+ return forward
+ }
+
+ proxyURL, err := url.Parse(allProxy)
+ if err != nil {
+ return forward
+ }
+ proxy, err := FromURL(proxyURL, forward)
+ if err != nil {
+ return forward
+ }
+
+ noProxy := noProxyEnv.Get()
+ if len(noProxy) == 0 {
+ return proxy
+ }
+
+ perHost := NewPerHost(proxy, forward)
+ perHost.AddFromString(noProxy)
+ return perHost
+}
+
+// proxySchemes is a map from URL schemes to a function that creates a Dialer
+// from a URL with such a scheme.
+var proxySchemes map[string]func(*url.URL, Dialer) (Dialer, error)
+
+// RegisterDialerType takes a URL scheme and a function to generate Dialers from
+// a URL with that scheme and a forwarding Dialer. Registered schemes are used
+// by FromURL.
+func RegisterDialerType(scheme string, f func(*url.URL, Dialer) (Dialer, error)) {
+ if proxySchemes == nil {
+ proxySchemes = make(map[string]func(*url.URL, Dialer) (Dialer, error))
+ }
+ proxySchemes[scheme] = f
+}
+
+// FromURL returns a Dialer given a URL specification and an underlying
+// Dialer for it to make network requests.
+func FromURL(u *url.URL, forward Dialer) (Dialer, error) {
+ var auth *Auth
+ if u.User != nil {
+ auth = new(Auth)
+ auth.User = u.User.Username()
+ if p, ok := u.User.Password(); ok {
+ auth.Password = p
+ }
+ }
+
+ switch u.Scheme {
+ case "socks5", "socks5h":
+ addr := u.Hostname()
+ port := u.Port()
+ if port == "" {
+ port = "1080"
+ }
+ return SOCKS5("tcp", net.JoinHostPort(addr, port), auth, forward)
+ }
+
+ // If the scheme doesn't match any of the built-in schemes, see if it
+ // was registered by another package.
+ if proxySchemes != nil {
+ if f, ok := proxySchemes[u.Scheme]; ok {
+ return f(u, forward)
+ }
+ }
+
+ return nil, errors.New("proxy: unknown scheme: " + u.Scheme)
+}
+
+var (
+ allProxyEnv = &envOnce{
+ names: []string{"ALL_PROXY", "all_proxy"},
+ }
+ noProxyEnv = &envOnce{
+ names: []string{"NO_PROXY", "no_proxy"},
+ }
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+// (Borrowed from net/http/transport.go)
+type envOnce struct {
+ names []string
+ once sync.Once
+ val string
+}
+
+func (e *envOnce) Get() string {
+ e.once.Do(e.init)
+ return e.val
+}
+
+func (e *envOnce) init() {
+ for _, n := range e.names {
+ e.val = os.Getenv(n)
+ if e.val != "" {
+ return
+ }
+ }
+}
+
+// reset is used by tests
+func (e *envOnce) reset() {
+ e.once = sync.Once{}
+ e.val = ""
+}