105 lines
2.9 KiB
Go
105 lines
2.9 KiB
Go
// Copyright 2017 The Gorilla WebSocket 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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package websocket
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import (
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"bufio"
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"bytes"
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"context"
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"encoding/base64"
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"errors"
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"net"
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"net/http"
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"net/url"
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"strings"
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"golang.org/x/net/proxy"
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)
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type netDialerFunc func(ctx context.Context, network, addr string) (net.Conn, error)
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func (fn netDialerFunc) Dial(network, addr string) (net.Conn, error) {
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return fn(context.Background(), network, addr)
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}
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func (fn netDialerFunc) DialContext(ctx context.Context, network, addr string) (net.Conn, error) {
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return fn(ctx, network, addr)
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}
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func proxyFromURL(proxyURL *url.URL, forwardDial netDialerFunc) (netDialerFunc, error) {
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if proxyURL.Scheme == "http" {
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return (&httpProxyDialer{proxyURL: proxyURL, forwardDial: forwardDial}).DialContext, nil
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}
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dialer, err := proxy.FromURL(proxyURL, forwardDial)
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if err != nil {
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return nil, err
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}
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if d, ok := dialer.(proxy.ContextDialer); ok {
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return d.DialContext, nil
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}
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return func(ctx context.Context, net, addr string) (net.Conn, error) {
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return dialer.Dial(net, addr)
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}, nil
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}
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type httpProxyDialer struct {
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proxyURL *url.URL
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forwardDial netDialerFunc
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}
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func (hpd *httpProxyDialer) DialContext(ctx context.Context, network string, addr string) (net.Conn, error) {
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hostPort, _ := hostPortNoPort(hpd.proxyURL)
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conn, err := hpd.forwardDial(ctx, network, hostPort)
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if err != nil {
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return nil, err
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}
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connectHeader := make(http.Header)
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if user := hpd.proxyURL.User; user != nil {
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proxyUser := user.Username()
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if proxyPassword, passwordSet := user.Password(); passwordSet {
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credential := base64.StdEncoding.EncodeToString([]byte(proxyUser + ":" + proxyPassword))
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connectHeader.Set("Proxy-Authorization", "Basic "+credential)
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}
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}
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connectReq := &http.Request{
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Method: http.MethodConnect,
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URL: &url.URL{Opaque: addr},
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Host: addr,
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Header: connectHeader,
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}
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if err := connectReq.Write(conn); err != nil {
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conn.Close()
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return nil, err
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}
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// Read response. It's OK to use and discard buffered reader here because
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// the remote server does not speak until spoken to.
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br := bufio.NewReader(conn)
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resp, err := http.ReadResponse(br, connectReq)
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if err != nil {
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conn.Close()
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return nil, err
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}
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// Close the response body to silence false positives from linters. Reset
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// the buffered reader first to ensure that Close() does not read from
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// conn.
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// Note: Applications must call resp.Body.Close() on a response returned
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// http.ReadResponse to inspect trailers or read another response from the
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// buffered reader. The call to resp.Body.Close() does not release
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// resources.
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br.Reset(bytes.NewReader(nil))
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_ = resp.Body.Close()
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if resp.StatusCode != http.StatusOK {
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_ = conn.Close()
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f := strings.SplitN(resp.Status, " ", 2)
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return nil, errors.New(f[1])
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}
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return conn, nil
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}
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