well-goknown/vendor/github.com/fasthttp/websocket/proxy.go
2024-09-25 21:59:44 -04:00

105 lines
2.9 KiB
Go

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