xref: /openbmc/bmcweb/http/websocket.hpp (revision 1c79f93e)
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     Connection() = default;
31 
32     Connection(const Connection&) = delete;
33     Connection(Connection&&) = delete;
34     Connection& operator=(const Connection&) = delete;
35     Connection& operator=(const Connection&&) = delete;
36 
37     virtual void sendBinary(std::string_view msg) = 0;
38     virtual void sendBinary(std::string&& msg) = 0;
39     virtual void sendEx(MessageType type, std::string_view msg,
40                         std::function<void()>&& onDone) = 0;
41     virtual void sendText(std::string_view msg) = 0;
42     virtual void sendText(std::string&& msg) = 0;
43     virtual void close(std::string_view msg = "quit") = 0;
44     virtual void deferRead() = 0;
45     virtual void resumeRead() = 0;
46     virtual boost::asio::io_context& getIoContext() = 0;
47     virtual ~Connection() = default;
48     virtual boost::urls::url_view url() = 0;
49 };
50 
51 template <typename Adaptor>
52 class ConnectionImpl : public Connection
53 {
54     using self_t = ConnectionImpl<Adaptor>;
55 
56   public:
57     ConnectionImpl(
58         const boost::urls::url_view& urlViewIn,
59         const std::shared_ptr<persistent_data::UserSession>& sessionIn,
60         Adaptor adaptorIn, std::function<void(Connection&)> openHandlerIn,
61         std::function<void(Connection&, const std::string&, bool)>
62             messageHandlerIn,
63         std::function<void(crow::websocket::Connection&, std::string_view,
64                            crow::websocket::MessageType type,
65                            std::function<void()>&& whenComplete)>
66             messageExHandlerIn,
67         std::function<void(Connection&, const std::string&)> closeHandlerIn,
68         std::function<void(Connection&)> errorHandlerIn) :
69         uri(urlViewIn),
70         ws(std::move(adaptorIn)), inBuffer(inString, 131088),
71         openHandler(std::move(openHandlerIn)),
72         messageHandler(std::move(messageHandlerIn)),
73         messageExHandler(std::move(messageExHandlerIn)),
74         closeHandler(std::move(closeHandlerIn)),
75         errorHandler(std::move(errorHandlerIn)), session(sessionIn)
76     {
77         /* Turn on the timeouts on websocket stream to server role */
78         ws.set_option(boost::beast::websocket::stream_base::timeout::suggested(
79             boost::beast::role_type::server));
80         BMCWEB_LOG_DEBUG("Creating new connection {}", logPtr(this));
81     }
82 
83     boost::asio::io_context& getIoContext() override
84     {
85         return static_cast<boost::asio::io_context&>(
86             ws.get_executor().context());
87     }
88 
89     void start(const crow::Request& req)
90     {
91         BMCWEB_LOG_DEBUG("starting connection {}", logPtr(this));
92 
93         using bf = boost::beast::http::field;
94         std::string protocolHeader = req.req[bf::sec_websocket_protocol];
95 
96         ws.set_option(boost::beast::websocket::stream_base::decorator(
97             [session{session},
98              protocolHeader](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                         protocolHeader, 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 (!protocolHeader.empty())
115             {
116                 m.insert(bf::sec_websocket_protocol, protocolHeader);
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         // Make a pointer to keep the req alive while we accept it.
131         using Body = boost::beast::http::request<bmcweb::FileBody>;
132         std::unique_ptr<Body> mobile = std::make_unique<Body>(req.req);
133         Body* ptr = mobile.get();
134         // Perform the websocket upgrade
135         ws.async_accept(*ptr,
136                         std::bind_front(&self_t::acceptDone, this,
137                                         shared_from_this(), std::move(mobile)));
138     }
139 
140     void sendBinary(std::string_view msg) override
141     {
142         ws.binary(true);
143         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
144                                                   boost::asio::buffer(msg)));
145         doWrite();
146     }
147 
148     void sendEx(MessageType type, std::string_view msg,
149                 std::function<void()>&& onDone) override
150     {
151         if (doingWrite)
152         {
153             BMCWEB_LOG_CRITICAL(
154                 "Cannot mix sendEx usage with sendBinary or sendText");
155             onDone();
156             return;
157         }
158         ws.binary(type == MessageType::Binary);
159 
160         ws.async_write(boost::asio::buffer(msg),
161                        [weak(weak_from_this()), onDone{std::move(onDone)}](
162                            const boost::beast::error_code& ec, size_t) {
163             std::shared_ptr<Connection> self = weak.lock();
164             if (!self)
165             {
166                 BMCWEB_LOG_ERROR("Connection went away");
167                 return;
168             }
169 
170             // Call the done handler regardless of whether we
171             // errored, but before we close things out
172             onDone();
173 
174             if (ec)
175             {
176                 BMCWEB_LOG_ERROR("Error in ws.async_write {}", ec);
177                 self->close("write error");
178             }
179         });
180     }
181 
182     void sendBinary(std::string&& msg) override
183     {
184         ws.binary(true);
185         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
186                                                   boost::asio::buffer(msg)));
187         doWrite();
188     }
189 
190     void sendText(std::string_view msg) override
191     {
192         ws.text(true);
193         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
194                                                   boost::asio::buffer(msg)));
195         doWrite();
196     }
197 
198     void sendText(std::string&& msg) override
199     {
200         ws.text(true);
201         outBuffer.commit(boost::asio::buffer_copy(outBuffer.prepare(msg.size()),
202                                                   boost::asio::buffer(msg)));
203         doWrite();
204     }
205 
206     void close(std::string_view msg) override
207     {
208         ws.async_close(
209             {boost::beast::websocket::close_code::normal, msg},
210             [self(shared_from_this())](const boost::system::error_code& ec) {
211             if (ec == boost::asio::error::operation_aborted)
212             {
213                 return;
214             }
215             if (ec)
216             {
217                 BMCWEB_LOG_ERROR("Error closing websocket {}", ec);
218                 return;
219             }
220         });
221     }
222 
223     boost::urls::url_view url() override
224     {
225         return uri;
226     }
227 
228     void acceptDone(const std::shared_ptr<Connection>& /*self*/,
229                     const std::unique_ptr<
230                         boost::beast::http::request<bmcweb::FileBody>>& /*req*/,
231                     const boost::system::error_code& ec)
232     {
233         if (ec)
234         {
235             BMCWEB_LOG_ERROR("Error in ws.async_accept {}", ec);
236             return;
237         }
238         BMCWEB_LOG_DEBUG("Websocket accepted connection");
239 
240         if (openHandler)
241         {
242             openHandler(*this);
243         }
244         doRead();
245     }
246 
247     void deferRead() override
248     {
249         readingDefered = true;
250 
251         // If we're not actively reading, we need to take ownership of
252         // ourselves for a small portion of time, do that, and clear when we
253         // resume.
254         selfOwned = shared_from_this();
255     }
256 
257     void resumeRead() override
258     {
259         readingDefered = false;
260         doRead();
261 
262         // No longer need to keep ourselves alive now that read is active.
263         selfOwned.reset();
264     }
265 
266     void doRead()
267     {
268         if (readingDefered)
269         {
270             return;
271         }
272         ws.async_read(inBuffer, [this, self(shared_from_this())](
273                                     const boost::beast::error_code& ec,
274                                     size_t bytesRead) {
275             if (ec)
276             {
277                 if (ec != boost::beast::websocket::error::closed)
278                 {
279                     BMCWEB_LOG_ERROR("doRead error {}", ec);
280                 }
281                 if (closeHandler)
282                 {
283                     std::string reason{ws.reason().reason.c_str()};
284                     closeHandler(*this, reason);
285                 }
286                 return;
287             }
288 
289             handleMessage(bytesRead);
290         });
291     }
292     void doWrite()
293     {
294         // If we're already doing a write, ignore the request, it will be picked
295         // up when the current write is complete
296         if (doingWrite)
297         {
298             return;
299         }
300 
301         if (outBuffer.size() == 0)
302         {
303             // Done for now
304             return;
305         }
306         doingWrite = true;
307         ws.async_write(outBuffer.data(), [this, self(shared_from_this())](
308                                              const boost::beast::error_code& ec,
309                                              size_t bytesSent) {
310             doingWrite = false;
311             outBuffer.consume(bytesSent);
312             if (ec == boost::beast::websocket::error::closed)
313             {
314                 // Do nothing here.  doRead handler will call the
315                 // closeHandler.
316                 close("Write error");
317                 return;
318             }
319             if (ec)
320             {
321                 BMCWEB_LOG_ERROR("Error in ws.async_write {}", ec);
322                 return;
323             }
324             doWrite();
325         });
326     }
327 
328   private:
329     void handleMessage(size_t bytesRead)
330     {
331         if (messageExHandler)
332         {
333             // Note, because of the interactions with the read buffers,
334             // this message handler overrides the normal message handler
335             messageExHandler(*this, inString, MessageType::Binary,
336                              [this, self(shared_from_this()), bytesRead]() {
337                 if (self == nullptr)
338                 {
339                     return;
340                 }
341 
342                 inBuffer.consume(bytesRead);
343                 inString.clear();
344 
345                 doRead();
346             });
347             return;
348         }
349 
350         if (messageHandler)
351         {
352             messageHandler(*this, inString, ws.got_text());
353         }
354         inBuffer.consume(bytesRead);
355         inString.clear();
356         doRead();
357     }
358 
359     boost::urls::url uri;
360 
361     boost::beast::websocket::stream<Adaptor, false> ws;
362 
363     bool readingDefered = false;
364     std::string inString;
365     boost::asio::dynamic_string_buffer<std::string::value_type,
366                                        std::string::traits_type,
367                                        std::string::allocator_type>
368         inBuffer;
369 
370     boost::beast::multi_buffer outBuffer;
371     bool doingWrite = false;
372 
373     std::function<void(Connection&)> openHandler;
374     std::function<void(Connection&, const std::string&, bool)> messageHandler;
375     std::function<void(crow::websocket::Connection&, std::string_view,
376                        crow::websocket::MessageType type,
377                        std::function<void()>&& whenComplete)>
378         messageExHandler;
379     std::function<void(Connection&, const std::string&)> closeHandler;
380     std::function<void(Connection&)> errorHandler;
381     std::shared_ptr<persistent_data::UserSession> session;
382 
383     std::shared_ptr<Connection> selfOwned;
384 };
385 } // namespace websocket
386 } // namespace crow
387