1//
2// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
3//
4// Distributed under the Boost Software License, Version 1.0. (See accompanying
5// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6//
7// Official repository: https://github.com/boostorg/beast
8//
9
10//------------------------------------------------------------------------------
11//
12// Example: WebSocket SSL server, asynchronous
13//
14//------------------------------------------------------------------------------
15
16#include "example/common/server_certificate.hpp"
17
18#include <boost/beast/core.hpp>
19#include <boost/beast/ssl.hpp>
20#include <boost/beast/websocket.hpp>
21#include <boost/beast/websocket/ssl.hpp>
22#include <boost/asio/strand.hpp>
23#include <boost/asio/dispatch.hpp>
24#include <algorithm>
25#include <cstdlib>
26#include <functional>
27#include <iostream>
28#include <memory>
29#include <string>
30#include <thread>
31#include <vector>
32
33namespace beast = boost::beast; // from <boost/beast.hpp>
34namespace http = beast::http; // from <boost/beast/http.hpp>
35namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
36namespace net = boost::asio; // from <boost/asio.hpp>
37namespace ssl = boost::asio::ssl; // from <boost/asio/ssl.hpp>
38using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
39
40//------------------------------------------------------------------------------
41
42// Report a failure
43void
44fail(beast::error_code ec, char const* what)
45{
46 std::cerr << what << ": " << ec.message() << "\n";
47}
48
49// Echoes back all received WebSocket messages
50class session : public std::enable_shared_from_this<session>
51{
52 websocket::stream<
53 beast::ssl_stream<beast::tcp_stream>> ws_;
54 beast::flat_buffer buffer_;
55
56public:
57 // Take ownership of the socket
58 session(tcp::socket&& socket, ssl::context& ctx)
59 : ws_(std::move(socket), ctx)
60 {
61 }
62
63 // Get on the correct executor
64 void
65 run()
66 {
67 // We need to be executing within a strand to perform async operations
68 // on the I/O objects in this session. Although not strictly necessary
69 // for single-threaded contexts, this example code is written to be
70 // thread-safe by default.
71 net::dispatch(ex: ws_.get_executor(),
72 token: beast::bind_front_handler(
73 handler: &session::on_run,
74 args: shared_from_this()));
75 }
76
77 // Start the asynchronous operation
78 void
79 on_run()
80 {
81 // Set the timeout.
82 beast::get_lowest_layer(t&: ws_).expires_after(expiry_time: std::chrono::seconds(30));
83
84 // Perform the SSL handshake
85 ws_.next_layer().async_handshake(
86 type: ssl::stream_base::server,
87 handler: beast::bind_front_handler(
88 handler: &session::on_handshake,
89 args: shared_from_this()));
90 }
91
92 void
93 on_handshake(beast::error_code ec)
94 {
95 if(ec)
96 return fail(ec, what: "handshake");
97
98 // Turn off the timeout on the tcp_stream, because
99 // the websocket stream has its own timeout system.
100 beast::get_lowest_layer(t&: ws_).expires_never();
101
102 // Set suggested timeout settings for the websocket
103 ws_.set_option(
104 websocket::stream_base::timeout::suggested(
105 role: beast::role_type::server));
106
107 // Set a decorator to change the Server of the handshake
108 ws_.set_option(websocket::stream_base::decorator(
109 [](websocket::response_type& res)
110 {
111 res.set(name: http::field::server,
112 value: std::string(BOOST_BEAST_VERSION_STRING) +
113 " websocket-server-async-ssl");
114 }));
115
116 // Accept the websocket handshake
117 ws_.async_accept(
118 handler: beast::bind_front_handler(
119 handler: &session::on_accept,
120 args: shared_from_this()));
121 }
122
123 void
124 on_accept(beast::error_code ec)
125 {
126 if(ec)
127 return fail(ec, what: "accept");
128
129 // Read a message
130 do_read();
131 }
132
133 void
134 do_read()
135 {
136 // Read a message into our buffer
137 ws_.async_read(
138 buffer&: buffer_,
139 handler: beast::bind_front_handler(
140 handler: &session::on_read,
141 args: shared_from_this()));
142 }
143
144 void
145 on_read(
146 beast::error_code ec,
147 std::size_t bytes_transferred)
148 {
149 boost::ignore_unused(bytes_transferred);
150
151 // This indicates that the session was closed
152 if(ec == websocket::error::closed)
153 return;
154
155 if(ec)
156 fail(ec, what: "read");
157
158 // Echo the message
159 ws_.text(value: ws_.got_text());
160 ws_.async_write(
161 bs: buffer_.data(),
162 handler: beast::bind_front_handler(
163 handler: &session::on_write,
164 args: shared_from_this()));
165 }
166
167 void
168 on_write(
169 beast::error_code ec,
170 std::size_t bytes_transferred)
171 {
172 boost::ignore_unused(bytes_transferred);
173
174 if(ec)
175 return fail(ec, what: "write");
176
177 // Clear the buffer
178 buffer_.consume(n: buffer_.size());
179
180 // Do another read
181 do_read();
182 }
183};
184
185//------------------------------------------------------------------------------
186
187// Accepts incoming connections and launches the sessions
188class listener : public std::enable_shared_from_this<listener>
189{
190 net::io_context& ioc_;
191 ssl::context& ctx_;
192 tcp::acceptor acceptor_;
193
194public:
195 listener(
196 net::io_context& ioc,
197 ssl::context& ctx,
198 tcp::endpoint endpoint)
199 : ioc_(ioc)
200 , ctx_(ctx)
201 , acceptor_(net::make_strand(ctx&: ioc))
202 {
203 beast::error_code ec;
204
205 // Open the acceptor
206 acceptor_.open(protocol: endpoint.protocol(), ec);
207 if(ec)
208 {
209 fail(ec, what: "open");
210 return;
211 }
212
213 // Allow address reuse
214 acceptor_.set_option(option: net::socket_base::reuse_address(true), ec);
215 if(ec)
216 {
217 fail(ec, what: "set_option");
218 return;
219 }
220
221 // Bind to the server address
222 acceptor_.bind(endpoint, ec);
223 if(ec)
224 {
225 fail(ec, what: "bind");
226 return;
227 }
228
229 // Start listening for connections
230 acceptor_.listen(
231 backlog: net::socket_base::max_listen_connections, ec);
232 if(ec)
233 {
234 fail(ec, what: "listen");
235 return;
236 }
237 }
238
239 // Start accepting incoming connections
240 void
241 run()
242 {
243 do_accept();
244 }
245
246private:
247 void
248 do_accept()
249 {
250 // The new connection gets its own strand
251 acceptor_.async_accept(
252 ex: net::make_strand(ctx&: ioc_),
253 token: beast::bind_front_handler(
254 handler: &listener::on_accept,
255 args: shared_from_this()));
256 }
257
258 void
259 on_accept(beast::error_code ec, tcp::socket socket)
260 {
261 if(ec)
262 {
263 fail(ec, what: "accept");
264 }
265 else
266 {
267 // Create the session and run it
268 std::make_shared<session>(args: std::move(socket), args&: ctx_)->run();
269 }
270
271 // Accept another connection
272 do_accept();
273 }
274};
275
276//------------------------------------------------------------------------------
277
278int main(int argc, char* argv[])
279{
280 // Check command line arguments.
281 if (argc != 4)
282 {
283 std::cerr <<
284 "Usage: websocket-server-async-ssl <address> <port> <threads>\n" <<
285 "Example:\n" <<
286 " websocket-server-async-ssl 0.0.0.0 8080 1\n";
287 return EXIT_FAILURE;
288 }
289 auto const address = net::ip::make_address(str: argv[1]);
290 auto const port = static_cast<unsigned short>(std::atoi(nptr: argv[2]));
291 auto const threads = std::max<int>(a: 1, b: std::atoi(nptr: argv[3]));
292
293 // The io_context is required for all I/O
294 net::io_context ioc{threads};
295
296 // The SSL context is required, and holds certificates
297 ssl::context ctx{ssl::context::tlsv12};
298
299 // This holds the self-signed certificate used by the server
300 load_server_certificate(ctx);
301
302 // Create and launch a listening port
303 std::make_shared<listener>(args&: ioc, args&: ctx, args: tcp::endpoint{address, port})->run();
304
305 // Run the I/O service on the requested number of threads
306 std::vector<std::thread> v;
307 v.reserve(n: threads - 1);
308 for(auto i = threads - 1; i > 0; --i)
309 v.emplace_back(
310 args: [&ioc]
311 {
312 ioc.run();
313 });
314 ioc.run();
315
316 return EXIT_SUCCESS;
317}
318

source code of boost/libs/beast/example/websocket/server/async-ssl/websocket_server_async_ssl.cpp