xref: /openbmc/bmcweb/http/websocket.hpp (revision 863c1c2e78a8cce2e6b5cf0e80b8cf75fbc801b3)
1 #pragma once
2 #include "async_resp.hpp"
3 #include "http_request.hpp"
4 
5 #include <boost/asio/buffer.hpp>
6 #include <boost/beast/core/multi_buffer.hpp>
7 #include <boost/beast/websocket.hpp>
8 
9 #include <array>
10 #include <functional>
11 
12 #ifdef BMCWEB_ENABLE_SSL
13 #include <boost/beast/websocket/ssl.hpp>
14 #endif
15 
16 namespace crow
17 {
18 namespace websocket
19 {
20 
21 enum class MessageType
22 {
23     Binary,
24     Text,
25 };
26 
27 struct Connection : std::enable_shared_from_this<Connection>
28 {
29   public:
30     explicit Connection(const crow::Request& reqIn) : req(reqIn.req)
31     {}
32 
33     Connection(const Connection&) = delete;
34     Connection(Connection&&) = delete;
35     Connection& operator=(const Connection&) = delete;
36     Connection& operator=(const Connection&&) = delete;
37 
38     virtual void sendBinary(std::string_view msg) = 0;
39     virtual void sendBinary(std::string&& msg) = 0;
40     virtual void sendEx(MessageType type, std::string_view msg,
41                         std::function<void()>&& onDone) = 0;
42     virtual void sendText(std::string_view msg) = 0;
43     virtual void sendText(std::string&& msg) = 0;
44     virtual void close(std::string_view msg = "quit") = 0;
45     virtual void deferRead() = 0;
46     virtual void resumeRead() = 0;
47     virtual boost::asio::io_context& getIoContext() = 0;
48     virtual ~Connection() = default;
49 
50     boost::beast::http::request<boost::beast::http::string_body> req;
51 };
52 
53 template <typename Adaptor>
54 class ConnectionImpl : public Connection
55 {
56   public:
57     ConnectionImpl(
58         const crow::Request& reqIn, Adaptor adaptorIn,
59         std::function<void(Connection&)> openHandlerIn,
60         std::function<void(Connection&, const std::string&, bool)>
61             messageHandlerIn,
62         std::function<void(crow::websocket::Connection&, std::string_view,
63                            crow::websocket::MessageType type,
64                            std::function<void()>&& whenComplete)>
65             messageExHandlerIn,
66         std::function<void(Connection&, const std::string&)> closeHandlerIn,
67         std::function<void(Connection&)> errorHandlerIn) :
68         Connection(reqIn),
69         ws(std::move(adaptorIn)), inBuffer(inString, 131088),
70         openHandler(std::move(openHandlerIn)),
71         messageHandler(std::move(messageHandlerIn)),
72         messageExHandler(std::move(messageExHandlerIn)),
73         closeHandler(std::move(closeHandlerIn)),
74         errorHandler(std::move(errorHandlerIn)), session(reqIn.session)
75     {
76         /* Turn on the timeouts on websocket stream to server role */
77         ws.set_option(boost::beast::websocket::stream_base::timeout::suggested(
78             boost::beast::role_type::server));
79         BMCWEB_LOG_DEBUG << "Creating new connection " << this;
80     }
81 
82     boost::asio::io_context& getIoContext() override
83     {
84         return static_cast<boost::asio::io_context&>(
85             ws.get_executor().context());
86     }
87 
88     void start()
89     {
90         BMCWEB_LOG_DEBUG << "starting connection " << this;
91 
92         using bf = boost::beast::http::field;
93 
94         std::string_view protocol = req[bf::sec_websocket_protocol];
95 
96         ws.set_option(boost::beast::websocket::stream_base::decorator(
97             [session{session}, protocol{std::string(protocol)}](
98                 boost::beast::websocket::response_type& m) {
99 
100 #ifndef BMCWEB_INSECURE_DISABLE_CSRF_PREVENTION
101             if (session != nullptr)
102             {
103                 // use protocol for csrf checking
104                 if (session->cookieAuth &&
105                     !crow::utility::constantTimeStringCompare(
106                         protocol, session->csrfToken))
107                 {
108                     BMCWEB_LOG_ERROR << "Websocket CSRF error";
109                     m.result(boost::beast::http::status::unauthorized);
110                     return;
111                 }
112             }
113 #endif
114             if (!protocol.empty())
115             {
116                 m.insert(bf::sec_websocket_protocol, protocol);
117             }
118 
119             m.insert(bf::strict_transport_security, "max-age=31536000; "
120                                                     "includeSubdomains; "
121                                                     "preload");
122             m.insert(bf::pragma, "no-cache");
123             m.insert(bf::cache_control, "no-Store,no-Cache");
124             m.insert("Content-Security-Policy", "default-src 'self'");
125             m.insert("X-XSS-Protection", "1; "
126                                          "mode=block");
127             m.insert("X-Content-Type-Options", "nosniff");
128         }));
129 
130         // Perform the websocket upgrade
131         ws.async_accept(req, [this, self(shared_from_this())](
132                                  const boost::system::error_code& ec) {
133             if (ec)
134             {
135                 BMCWEB_LOG_ERROR << "Error in ws.async_accept " << ec;
136                 return;
137             }
138             acceptDone();
139         });
140     }
141 
142     void sendBinary(std::string_view msg) override
143     {
144         ws.binary(true);
145         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
146                                                   boost::asio::buffer(msg)));
147         doWrite();
148     }
149 
150     void sendEx(MessageType type, std::string_view msg,
151                 std::function<void()>&& onDone) override
152     {
153         if (doingWrite)
154         {
155             BMCWEB_LOG_CRITICAL
156                 << "Cannot mix sendEx usage with sendBinary or sendText";
157             onDone();
158             return;
159         }
160         ws.binary(type == MessageType::Binary);
161 
162         ws.async_write(boost::asio::buffer(msg),
163                        [weak(weak_from_this()), onDone{std::move(onDone)}](
164                            const boost::beast::error_code& ec, size_t) {
165             std::shared_ptr<Connection> self = weak.lock();
166 
167             // Call the done handler regardless of whether we
168             // errored, but before we close things out
169             onDone();
170 
171             if (ec)
172             {
173                 BMCWEB_LOG_ERROR << "Error in ws.async_write " << ec;
174                 self->close("write error");
175             }
176         });
177     }
178 
179     void sendBinary(std::string&& msg) override
180     {
181         ws.binary(true);
182         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
183                                                   boost::asio::buffer(msg)));
184         doWrite();
185     }
186 
187     void sendText(std::string_view msg) override
188     {
189         ws.text(true);
190         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
191                                                   boost::asio::buffer(msg)));
192         doWrite();
193     }
194 
195     void sendText(std::string&& msg) override
196     {
197         ws.text(true);
198         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
199                                                   boost::asio::buffer(msg)));
200         doWrite();
201     }
202 
203     void close(std::string_view msg) override
204     {
205         ws.async_close(
206             {boost::beast::websocket::close_code::normal, msg},
207             [self(shared_from_this())](const boost::system::error_code& ec) {
208             if (ec == boost::asio::error::operation_aborted)
209             {
210                 return;
211             }
212             if (ec)
213             {
214                 BMCWEB_LOG_ERROR << "Error closing websocket " << ec;
215                 return;
216             }
217             });
218     }
219 
220     void acceptDone()
221     {
222         BMCWEB_LOG_DEBUG << "Websocket accepted connection";
223 
224         if (openHandler)
225         {
226             openHandler(*this);
227         }
228         doRead();
229     }
230 
231     void deferRead() override
232     {
233         readingDefered = true;
234 
235         // If we're not actively reading, we need to take ownership of
236         // ourselves for a small portion of time, do that, and clear when we
237         // resume.
238         selfOwned = shared_from_this();
239     }
240 
241     void resumeRead() override
242     {
243         readingDefered = false;
244         doRead();
245 
246         // No longer need to keep ourselves alive now that read is active.
247         selfOwned.reset();
248     }
249 
250     void doRead()
251     {
252         if (readingDefered)
253         {
254             return;
255         }
256         ws.async_read(inBuffer, [this, self(shared_from_this())](
257                                     const boost::beast::error_code& ec,
258                                     size_t bytesRead) {
259             if (ec)
260             {
261                 if (ec != boost::beast::websocket::error::closed)
262                 {
263                     BMCWEB_LOG_ERROR << "doRead error " << ec;
264                 }
265                 if (closeHandler)
266                 {
267                     std::string reason{ws.reason().reason.c_str()};
268                     closeHandler(*this, reason);
269                 }
270                 return;
271             }
272 
273             handleMessage(bytesRead);
274         });
275     }
276     void doWrite()
277     {
278         // If we're already doing a write, ignore the request, it will be picked
279         // up when the current write is complete
280         if (doingWrite)
281         {
282             return;
283         }
284 
285         if (outBuffer.size() == 0)
286         {
287             // Done for now
288             return;
289         }
290         doingWrite = true;
291         ws.async_write(outBuffer.data(), [this, self(shared_from_this())](
292                                              const boost::beast::error_code& ec,
293                                              size_t bytesSent) {
294             doingWrite = false;
295             outBuffer.consume(bytesSent);
296             if (ec == boost::beast::websocket::error::closed)
297             {
298                 // Do nothing here.  doRead handler will call the
299                 // closeHandler.
300                 close("Write error");
301                 return;
302             }
303             if (ec)
304             {
305                 BMCWEB_LOG_ERROR << "Error in ws.async_write " << ec;
306                 return;
307             }
308             doWrite();
309         });
310     }
311 
312   private:
313     void handleMessage(size_t bytesRead)
314     {
315         if (messageExHandler)
316         {
317             // Note, because of the interactions with the read buffers,
318             // this message handler overrides the normal message handler
319             messageExHandler(*this, inString, MessageType::Binary,
320                              [this, self(shared_from_this()), bytesRead]() {
321                 if (self == nullptr)
322                 {
323                     return;
324                 }
325 
326                 inBuffer.consume(bytesRead);
327                 inString.clear();
328 
329                 doRead();
330             });
331             return;
332         }
333 
334         if (messageHandler)
335         {
336             messageHandler(*this, inString, ws.got_text());
337         }
338         inBuffer.consume(bytesRead);
339         inString.clear();
340         doRead();
341     }
342 
343     boost::beast::websocket::stream<Adaptor, false> ws;
344 
345     bool readingDefered = false;
346     std::string inString;
347     boost::asio::dynamic_string_buffer<std::string::value_type,
348                                        std::string::traits_type,
349                                        std::string::allocator_type>
350         inBuffer;
351 
352     boost::beast::multi_buffer outBuffer;
353     bool doingWrite = false;
354 
355     std::function<void(Connection&)> openHandler;
356     std::function<void(Connection&, const std::string&, bool)> messageHandler;
357     std::function<void(crow::websocket::Connection&, std::string_view,
358                        crow::websocket::MessageType type,
359                        std::function<void()>&& whenComplete)>
360         messageExHandler;
361     std::function<void(Connection&, const std::string&)> closeHandler;
362     std::function<void(Connection&)> errorHandler;
363     std::shared_ptr<persistent_data::UserSession> session;
364 
365     std::shared_ptr<Connection> selfOwned;
366 };
367 } // namespace websocket
368 } // namespace crow
369