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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
'use strict'
const { kReadyState, kController, kResponse, kBinaryType, kWebSocketURL } = require('./symbols')
const { states, opcodes } = require('./constants')
const { MessageEvent, ErrorEvent } = require('./events')
/* globals Blob */
/**
* @param {import('./websocket').WebSocket} ws
*/
function isEstablished (ws) {
// If the server's response is validated as provided for above, it is
// said that _The WebSocket Connection is Established_ and that the
// WebSocket Connection is in the OPEN state.
return ws[kReadyState] === states.OPEN
}
/**
* @param {import('./websocket').WebSocket} ws
*/
function isClosing (ws) {
// Upon either sending or receiving a Close control frame, it is said
// that _The WebSocket Closing Handshake is Started_ and that the
// WebSocket connection is in the CLOSING state.
return ws[kReadyState] === states.CLOSING
}
/**
* @param {import('./websocket').WebSocket} ws
*/
function isClosed (ws) {
return ws[kReadyState] === states.CLOSED
}
/**
* @see https://dom.spec.whatwg.org/#concept-event-fire
* @param {string} e
* @param {EventTarget} target
* @param {EventInit | undefined} eventInitDict
*/
function fireEvent (e, target, eventConstructor = Event, eventInitDict) {
// 1. If eventConstructor is not given, then let eventConstructor be Event.
// 2. Let event be the result of creating an event given eventConstructor,
// in the relevant realm of target.
// 3. Initialize event’s type attribute to e.
const event = new eventConstructor(e, eventInitDict) // eslint-disable-line new-cap
// 4. Initialize any other IDL attributes of event as described in the
// invocation of this algorithm.
// 5. Return the result of dispatching event at target, with legacy target
// override flag set if set.
target.dispatchEvent(event)
}
/**
* @see https://websockets.spec.whatwg.org/#feedback-from-the-protocol
* @param {import('./websocket').WebSocket} ws
* @param {number} type Opcode
* @param {Buffer} data application data
*/
function websocketMessageReceived (ws, type, data) {
// 1. If ready state is not OPEN (1), then return.
if (ws[kReadyState] !== states.OPEN) {
return
}
// 2. Let dataForEvent be determined by switching on type and binary type:
let dataForEvent
if (type === opcodes.TEXT) {
// -> type indicates that the data is Text
// a new DOMString containing data
try {
dataForEvent = new TextDecoder('utf-8', { fatal: true }).decode(data)
} catch {
failWebsocketConnection(ws, 'Received invalid UTF-8 in text frame.')
return
}
} else if (type === opcodes.BINARY) {
if (ws[kBinaryType] === 'blob') {
// -> type indicates that the data is Binary and binary type is "blob"
// a new Blob object, created in the relevant Realm of the WebSocket
// object, that represents data as its raw data
dataForEvent = new Blob([data])
} else {
// -> type indicates that the data is Binary and binary type is "arraybuffer"
// a new ArrayBuffer object, created in the relevant Realm of the
// WebSocket object, whose contents are data
dataForEvent = new Uint8Array(data).buffer
}
}
// 3. Fire an event named message at the WebSocket object, using MessageEvent,
// with the origin attribute initialized to the serialization of the WebSocket
// object’s url's origin, and the data attribute initialized to dataForEvent.
fireEvent('message', ws, MessageEvent, {
origin: ws[kWebSocketURL].origin,
data: dataForEvent
})
}
/**
* @see https://datatracker.ietf.org/doc/html/rfc6455
* @see https://datatracker.ietf.org/doc/html/rfc2616
* @see https://bugs.chromium.org/p/chromium/issues/detail?id=398407
* @param {string} protocol
*/
function isValidSubprotocol (protocol) {
// If present, this value indicates one
// or more comma-separated subprotocol the client wishes to speak,
// ordered by preference. The elements that comprise this value
// MUST be non-empty strings with characters in the range U+0021 to
// U+007E not including separator characters as defined in
// [RFC2616] and MUST all be unique strings.
if (protocol.length === 0) {
return false
}
for (const char of protocol) {
const code = char.charCodeAt(0)
if (
code < 0x21 ||
code > 0x7E ||
char === '(' ||
char === ')' ||
char === '<' ||
char === '>' ||
char === '@' ||
char === ',' ||
char === ';' ||
char === ':' ||
char === '\\' ||
char === '"' ||
char === '/' ||
char === '[' ||
char === ']' ||
char === '?' ||
char === '=' ||
char === '{' ||
char === '}' ||
code === 32 || // SP
code === 9 // HT
) {
return false
}
}
return true
}
/**
* @see https://datatracker.ietf.org/doc/html/rfc6455#section-7-4
* @param {number} code
*/
function isValidStatusCode (code) {
if (code >= 1000 && code < 1015) {
return (
code !== 1004 && // reserved
code !== 1005 && // "MUST NOT be set as a status code"
code !== 1006 // "MUST NOT be set as a status code"
)
}
return code >= 3000 && code <= 4999
}
/**
* @param {import('./websocket').WebSocket} ws
* @param {string|undefined} reason
*/
function failWebsocketConnection (ws, reason) {
const { [kController]: controller, [kResponse]: response } = ws
controller.abort()
if (response?.socket && !response.socket.destroyed) {
response.socket.destroy()
}
if (reason) {
fireEvent('error', ws, ErrorEvent, {
error: new Error(reason)
})
}
}
module.exports = {
isEstablished,
isClosing,
isClosed,
fireEvent,
isValidSubprotocol,
isValidStatusCode,
failWebsocketConnection,
websocketMessageReceived
}
|
