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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import NIO
import NIOHTTP1
import NIOWebSocket
let websocketResponse = """
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Swift NIO WebSocket Test Page</title>
<script>
var wsconnection = new WebSocket("ws://localhost:8888/websocket");
wsconnection.onmessage = function (msg) {
var element = document.createElement("p");
element.innerHTML = msg.data;
var textDiv = document.getElementById("websocket-stream");
textDiv.insertBefore(element, null);
};
</script>
</head>
<body>
<h1>WebSocket Stream</h1>
<div id="websocket-stream"></div>
</body>
</html>
"""
private final class HTTPHandler: ChannelInboundHandler, RemovableChannelHandler {
typealias InboundIn = HTTPServerRequestPart
typealias OutboundOut = HTTPServerResponsePart
private var responseBody: ByteBuffer!
func handlerAdded(context: ChannelHandlerContext) {
self.responseBody = context.channel.allocator.buffer(string: websocketResponse)
}
func handlerRemoved(context: ChannelHandlerContext) {
self.responseBody = nil
}
func channelRead(context: ChannelHandlerContext, data: NIOAny) {
let reqPart = self.unwrapInboundIn(data)
// We're not interested in request bodies here: we're just serving up GET responses
// to get the client to initiate a websocket request.
guard case .head(let head) = reqPart else {
return
}
// GETs only.
guard case .GET = head.method else {
self.respond405(context: context)
return
}
var headers = HTTPHeaders()
headers.add(name: "Content-Type", value: "text/html")
headers.add(name: "Content-Length", value: String(self.responseBody.readableBytes))
headers.add(name: "Connection", value: "close")
let responseHead = HTTPResponseHead(version: .init(major: 1, minor: 1),
status: .ok,
headers: headers)
context.write(self.wrapOutboundOut(.head(responseHead)), promise: nil)
context.write(self.wrapOutboundOut(.body(.byteBuffer(self.responseBody))), promise: nil)
context.write(self.wrapOutboundOut(.end(nil))).whenComplete { (_: Result<Void, Error>) in
context.close(promise: nil)
}
context.flush()
}
private func respond405(context: ChannelHandlerContext) {
var headers = HTTPHeaders()
headers.add(name: "Connection", value: "close")
headers.add(name: "Content-Length", value: "0")
let head = HTTPResponseHead(version: .http1_1,
status: .methodNotAllowed,
headers: headers)
context.write(self.wrapOutboundOut(.head(head)), promise: nil)
context.write(self.wrapOutboundOut(.end(nil))).whenComplete { (_: Result<Void, Error>) in
context.close(promise: nil)
}
context.flush()
}
}
private final class WebSocketTimeHandler: ChannelInboundHandler {
typealias InboundIn = WebSocketFrame
typealias OutboundOut = WebSocketFrame
private var awaitingClose: Bool = false
public func handlerAdded(context: ChannelHandlerContext) {
self.sendTime(context: context)
}
public func channelRead(context: ChannelHandlerContext, data: NIOAny) {
let frame = self.unwrapInboundIn(data)
switch frame.opcode {
case .connectionClose:
self.receivedClose(context: context, frame: frame)
case .ping:
self.pong(context: context, frame: frame)
case .text:
var data = frame.unmaskedData
let text = data.readString(length: data.readableBytes) ?? ""
print(text)
case .binary, .continuation, .pong:
// We ignore these frames.
break
default:
// Unknown frames are errors.
self.closeOnError(context: context)
}
}
public func channelReadComplete(context: ChannelHandlerContext) {
context.flush()
}
private func sendTime(context: ChannelHandlerContext) {
guard context.channel.isActive else { return }
// We can't send if we sent a close message.
guard !self.awaitingClose else { return }
// We can't really check for error here, but it's also not the purpose of the
// example so let's not worry about it.
let theTime = NIODeadline.now().uptimeNanoseconds
var buffer = context.channel.allocator.buffer(capacity: 12)
buffer.writeString("\(theTime)")
let frame = WebSocketFrame(fin: true, opcode: .text, data: buffer)
context.writeAndFlush(self.wrapOutboundOut(frame)).map {
context.eventLoop.scheduleTask(in: .seconds(1), { self.sendTime(context: context) })
}.whenFailure { (_: Error) in
context.close(promise: nil)
}
}
private func receivedClose(context: ChannelHandlerContext, frame: WebSocketFrame) {
// Handle a received close frame. In websockets, we're just going to send the close
// frame and then close, unless we already sent our own close frame.
if awaitingClose {
// Cool, we started the close and were waiting for the user. We're done.
context.close(promise: nil)
} else {
// This is an unsolicited close. We're going to send a response frame and
// then, when we've sent it, close up shop. We should send back the close code the remote
// peer sent us, unless they didn't send one at all.
var data = frame.unmaskedData
let closeDataCode = data.readSlice(length: 2) ?? ByteBuffer()
let closeFrame = WebSocketFrame(fin: true, opcode: .connectionClose, data: closeDataCode)
_ = context.write(self.wrapOutboundOut(closeFrame)).map { () in
context.close(promise: nil)
}
}
}
private func pong(context: ChannelHandlerContext, frame: WebSocketFrame) {
var frameData = frame.data
let maskingKey = frame.maskKey
if let maskingKey = maskingKey {
frameData.webSocketUnmask(maskingKey)
}
let responseFrame = WebSocketFrame(fin: true, opcode: .pong, data: frameData)
context.write(self.wrapOutboundOut(responseFrame), promise: nil)
}
private func closeOnError(context: ChannelHandlerContext) {
// We have hit an error, we want to close. We do that by sending a close frame and then
// shutting down the write side of the connection.
var data = context.channel.allocator.buffer(capacity: 2)
data.write(webSocketErrorCode: .protocolError)
let frame = WebSocketFrame(fin: true, opcode: .connectionClose, data: data)
context.write(self.wrapOutboundOut(frame)).whenComplete { (_: Result<Void, Error>) in
context.close(mode: .output, promise: nil)
}
awaitingClose = true
}
}
let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
let upgrader = NIOWebSocketServerUpgrader(shouldUpgrade: { (channel: Channel, head: HTTPRequestHead) in channel.eventLoop.makeSucceededFuture(HTTPHeaders()) },
upgradePipelineHandler: { (channel: Channel, _: HTTPRequestHead) in
channel.pipeline.addHandler(WebSocketTimeHandler())
})
let bootstrap = ServerBootstrap(group: group)
// Specify backlog and enable SO_REUSEADDR for the server itself
.serverChannelOption(ChannelOptions.backlog, value: 256)
.serverChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
// Set the handlers that are applied to the accepted Channels
.childChannelInitializer { channel in
let httpHandler = HTTPHandler()
let config: NIOHTTPServerUpgradeConfiguration = (
upgraders: [ upgrader ],
completionHandler: { _ in
channel.pipeline.removeHandler(httpHandler, promise: nil)
}
)
return channel.pipeline.configureHTTPServerPipeline(withServerUpgrade: config).flatMap {
channel.pipeline.addHandler(httpHandler)
}
}
// Enable SO_REUSEADDR for the accepted Channels
.childChannelOption(ChannelOptions.socketOption(.so_reuseaddr), value: 1)
defer {
try! group.syncShutdownGracefully()
}
// First argument is the program path
let arguments = CommandLine.arguments
let arg1 = arguments.dropFirst().first
let arg2 = arguments.dropFirst(2).first
let defaultHost = "localhost"
let defaultPort = 8888
enum BindTo {
case ip(host: String, port: Int)
case unixDomainSocket(path: String)
}
let bindTarget: BindTo
switch (arg1, arg1.flatMap(Int.init), arg2.flatMap(Int.init)) {
case (.some(let h), _ , .some(let p)):
/* we got two arguments, let's interpret that as host and port */
bindTarget = .ip(host: h, port: p)
case (let portString?, .none, _):
// Couldn't parse as number, expecting unix domain socket path.
bindTarget = .unixDomainSocket(path: portString)
case (_, let p?, _):
// Only one argument --> port.
bindTarget = .ip(host: defaultHost, port: p)
default:
bindTarget = .ip(host: defaultHost, port: defaultPort)
}
let channel = try { () -> Channel in
switch bindTarget {
case .ip(let host, let port):
return try bootstrap.bind(host: host, port: port).wait()
case .unixDomainSocket(let path):
return try bootstrap.bind(unixDomainSocketPath: path).wait()
}
}()
guard let localAddress = channel.localAddress else {
fatalError("Address was unable to bind. Please check that the socket was not closed or that the address family was understood.")
}
print("Server started and listening on \(localAddress)")
// This will never unblock as we don't close the ServerChannel
try channel.closeFuture.wait()
print("Server closed")
|
