proxy.go

Documentation: github.com/gorilla/websocket

     1  // Copyright 2017 The Gorilla WebSocket 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.
     4  
     5  package websocket
     6  
     7  import (
     8  	"bufio"
     9  	"encoding/base64"
    10  	"errors"
    11  	"net"
    12  	"net/http"
    13  	"net/url"
    14  	"strings"
    15  )
    16  
    17  type netDialerFunc func(network, addr string) (net.Conn, error)
    18  
    19  func (fn netDialerFunc) Dial(network, addr string) (net.Conn, error) {
    20  	return fn(network, addr)
    21  }
    22  
    23  func init() {
    24  	proxy_RegisterDialerType("http", func(proxyURL *url.URL, forwardDialer proxy_Dialer) (proxy_Dialer, error) {
    25  		return &httpProxyDialer{proxyURL: proxyURL, forwardDial: forwardDialer.Dial}, nil
    26  	})
    27  }
    28  
    29  type httpProxyDialer struct {
    30  	proxyURL    *url.URL
    31  	forwardDial func(network, addr string) (net.Conn, error)
    32  }
    33  
    34  func (hpd *httpProxyDialer) Dial(network string, addr string) (net.Conn, error) {
    35  	hostPort, _ := hostPortNoPort(hpd.proxyURL)
    36  	conn, err := hpd.forwardDial(network, hostPort)
    37  	if err != nil {
    38  		return nil, err
    39  	}
    40  
    41  	connectHeader := make(http.Header)
    42  	if user := hpd.proxyURL.User; user != nil {
    43  		proxyUser := user.Username()
    44  		if proxyPassword, passwordSet := user.Password(); passwordSet {
    45  			credential := base64.StdEncoding.EncodeToString([]byte(proxyUser + ":" + proxyPassword))
    46  			connectHeader.Set("Proxy-Authorization", "Basic "+credential)
    47  		}
    48  	}
    49  
    50  	connectReq := &http.Request{
    51  		Method: http.MethodConnect,
    52  		URL:    &url.URL{Opaque: addr},
    53  		Host:   addr,
    54  		Header: connectHeader,
    55  	}
    56  
    57  	if err := connectReq.Write(conn); err != nil {
    58  		conn.Close()
    59  		return nil, err
    60  	}
    61  
    62  	// Read response. It's OK to use and discard buffered reader here becaue
    63  	// the remote server does not speak until spoken to.
    64  	br := bufio.NewReader(conn)
    65  	resp, err := http.ReadResponse(br, connectReq)
    66  	if err != nil {
    67  		conn.Close()
    68  		return nil, err
    69  	}
    70  
    71  	if resp.StatusCode != 200 {
    72  		conn.Close()
    73  		f := strings.SplitN(resp.Status, " ", 2)
    74  		return nil, errors.New(f[1])
    75  	}
    76  	return conn, nil
    77  }
    78
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