1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
// Copyright 2009 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 websocket
import (
"bufio"
"context"
"io"
"net"
"net/http"
"net/url"
"time"
)
// DialError is an error that occurs while dialling a websocket server.
type DialError struct {
*Config
Err error
}
func (e *DialError) Error() string {
return "websocket.Dial " + e.Config.Location.String() + ": " + e.Err.Error()
}
// NewConfig creates a new WebSocket config for client connection.
func NewConfig(server, origin string) (config *Config, err error) {
config = new(Config)
config.Version = ProtocolVersionHybi13
config.Location, err = url.ParseRequestURI(server)
if err != nil {
return
}
config.Origin, err = url.ParseRequestURI(origin)
if err != nil {
return
}
config.Header = http.Header(make(map[string][]string))
return
}
// NewClient creates a new WebSocket client connection over rwc.
func NewClient(config *Config, rwc io.ReadWriteCloser) (ws *Conn, err error) {
br := bufio.NewReader(rwc)
bw := bufio.NewWriter(rwc)
err = hybiClientHandshake(config, br, bw)
if err != nil {
return
}
buf := bufio.NewReadWriter(br, bw)
ws = newHybiClientConn(config, buf, rwc)
return
}
// Dial opens a new client connection to a WebSocket.
func Dial(url_, protocol, origin string) (ws *Conn, err error) {
config, err := NewConfig(url_, origin)
if err != nil {
return nil, err
}
if protocol != "" {
config.Protocol = []string{protocol}
}
return DialConfig(config)
}
var portMap = map[string]string{
"ws": "80",
"wss": "443",
}
func parseAuthority(location *url.URL) string {
if _, ok := portMap[location.Scheme]; ok {
if _, _, err := net.SplitHostPort(location.Host); err != nil {
return net.JoinHostPort(location.Host, portMap[location.Scheme])
}
}
return location.Host
}
// DialConfig opens a new client connection to a WebSocket with a config.
func DialConfig(config *Config) (ws *Conn, err error) {
return config.DialContext(context.Background())
}
// DialContext opens a new client connection to a WebSocket, with context support for timeouts/cancellation.
func (config *Config) DialContext(ctx context.Context) (*Conn, error) {
if config.Location == nil {
return nil, &DialError{config, ErrBadWebSocketLocation}
}
if config.Origin == nil {
return nil, &DialError{config, ErrBadWebSocketOrigin}
}
dialer := config.Dialer
if dialer == nil {
dialer = &net.Dialer{}
}
client, err := dialWithDialer(ctx, dialer, config)
if err != nil {
return nil, &DialError{config, err}
}
// Cleanup the connection if we fail to create the websocket successfully
success := false
defer func() {
if !success {
_ = client.Close()
}
}()
var ws *Conn
var wsErr error
doneConnecting := make(chan struct{})
go func() {
defer close(doneConnecting)
ws, err = NewClient(config, client)
if err != nil {
wsErr = &DialError{config, err}
}
}()
// The websocket.NewClient() function can block indefinitely, make sure that we
// respect the deadlines specified by the context.
select {
case <-ctx.Done():
// Force the pending operations to fail, terminating the pending connection attempt
_ = client.SetDeadline(time.Now())
<-doneConnecting // Wait for the goroutine that tries to establish the connection to finish
return nil, &DialError{config, ctx.Err()}
case <-doneConnecting:
if wsErr == nil {
success = true // Disarm the deferred connection cleanup
}
return ws, wsErr
}
}
|
