xref: /openbmc/bmcweb/http/http_client.hpp (revision 262d7d4b) 
1 /*
2 // Copyright (c) 2020 Intel Corporation
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 //      http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 */
16 #pragma once
17 #include <boost/asio/steady_timer.hpp>
18 #include <boost/beast/core/flat_buffer.hpp>
19 #include <boost/beast/core/tcp_stream.hpp>
20 #include <boost/beast/http/message.hpp>
21 #include <boost/beast/version.hpp>
22 
23 #include <cstdlib>
24 #include <functional>
25 #include <iostream>
26 #include <memory>
27 #include <queue>
28 #include <string>
29 
30 namespace crow
31 {
32 
33 static constexpr uint8_t maxRequestQueueSize = 50;
34 
35 enum class ConnState
36 {
37     initialized,
38     connectInProgress,
39     connectFailed,
40     connected,
41     sendInProgress,
42     sendFailed,
43     recvFailed,
44     idle,
45     suspended,
46     closed,
47     terminated
48 };
49 
50 class HttpClient : public std::enable_shared_from_this<HttpClient>
51 {
52   private:
53     boost::beast::tcp_stream conn;
54     boost::asio::steady_timer timer;
55     boost::beast::flat_buffer buffer;
56     boost::beast::http::request<boost::beast::http::string_body> req;
57     boost::beast::http::response<boost::beast::http::string_body> res;
58     boost::asio::ip::tcp::resolver::results_type endpoint;
59     std::vector<std::pair<std::string, std::string>> headers;
60     std::queue<std::string> requestDataQueue;
61     ConnState state;
62     std::string subId;
63     std::string host;
64     std::string port;
65     std::string uri;
66     uint32_t retryCount;
67     uint32_t maxRetryAttempts;
68     uint32_t retryIntervalSecs;
69     std::string retryPolicyAction;
70     bool runningTimer;
71 
72     void doConnect()
73     {
74         if (state == ConnState::connectInProgress)
75         {
76             return;
77         }
78         state = ConnState::connectInProgress;
79 
80         BMCWEB_LOG_DEBUG << "Trying to connect to: " << host << ":" << port;
81         // Set a timeout on the operation
82         conn.expires_after(std::chrono::seconds(30));
83         conn.async_connect(endpoint, [self(shared_from_this())](
84                                          const boost::beast::error_code& ec,
85                                          const boost::asio::ip::tcp::resolver::
86                                              results_type::endpoint_type& ep) {
87             if (ec)
88             {
89                 BMCWEB_LOG_ERROR << "Connect " << ep
90                                  << " failed: " << ec.message();
91                 self->state = ConnState::connectFailed;
92                 self->checkQueue();
93                 return;
94             }
95             self->state = ConnState::connected;
96             BMCWEB_LOG_DEBUG << "Connected to: " << ep;
97 
98             self->checkQueue();
99         });
100     }
101 
102     void sendMessage(const std::string& data)
103     {
104         if (state == ConnState::sendInProgress)
105         {
106             return;
107         }
108         state = ConnState::sendInProgress;
109 
110         BMCWEB_LOG_DEBUG << __FUNCTION__ << "(): " << host << ":" << port;
111 
112         req.version(static_cast<int>(11)); // HTTP 1.1
113         req.target(uri);
114         req.method(boost::beast::http::verb::post);
115 
116         // Set headers
117         for (const auto& [key, value] : headers)
118         {
119             req.set(key, value);
120         }
121         req.set(boost::beast::http::field::host, host);
122         req.keep_alive(true);
123 
124         req.body() = data;
125         req.prepare_payload();
126 
127         // Set a timeout on the operation
128         conn.expires_after(std::chrono::seconds(30));
129 
130         // Send the HTTP request to the remote host
131         boost::beast::http::async_write(
132             conn, req,
133             [self(shared_from_this())](const boost::beast::error_code& ec,
134                                        const std::size_t& bytesTransferred) {
135                 if (ec)
136                 {
137                     BMCWEB_LOG_ERROR << "sendMessage() failed: "
138                                      << ec.message();
139                     self->state = ConnState::sendFailed;
140                     self->checkQueue();
141                     return;
142                 }
143                 BMCWEB_LOG_DEBUG << "sendMessage() bytes transferred: "
144                                  << bytesTransferred;
145                 boost::ignore_unused(bytesTransferred);
146 
147                 self->recvMessage();
148             });
149     }
150 
151     void recvMessage()
152     {
153         // Receive the HTTP response
154         boost::beast::http::async_read(
155             conn, buffer, res,
156             [self(shared_from_this())](const boost::beast::error_code& ec,
157                                        const std::size_t& bytesTransferred) {
158                 if (ec)
159                 {
160                     BMCWEB_LOG_ERROR << "recvMessage() failed: "
161                                      << ec.message();
162                     self->state = ConnState::recvFailed;
163                     self->checkQueue();
164                     return;
165                 }
166                 BMCWEB_LOG_DEBUG << "recvMessage() bytes transferred: "
167                                  << bytesTransferred;
168                 boost::ignore_unused(bytesTransferred);
169 
170                 // Discard received data. We are not interested.
171                 BMCWEB_LOG_DEBUG << "recvMessage() data: " << self->res;
172 
173                 // Send is successful, Lets remove data from queue
174                 // check for next request data in queue.
175                 self->requestDataQueue.pop();
176                 self->state = ConnState::idle;
177                 self->checkQueue();
178             });
179     }
180 
181     void doClose()
182     {
183         boost::beast::error_code ec;
184         conn.socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
185 
186         state = ConnState::closed;
187         // not_connected happens sometimes so don't bother reporting it.
188         if (ec && ec != boost::beast::errc::not_connected)
189         {
190             BMCWEB_LOG_ERROR << "shutdown failed: " << ec.message();
191             return;
192         }
193         BMCWEB_LOG_DEBUG << "Connection closed gracefully";
194     }
195 
196     void checkQueue(const bool newRecord = false)
197     {
198         if (requestDataQueue.empty())
199         {
200             // TODO: Having issue in keeping connection alive. So lets close if
201             // nothing to be transferred.
202             doClose();
203 
204             BMCWEB_LOG_DEBUG << "requestDataQueue is empty\n";
205             return;
206         }
207 
208         if (retryCount >= maxRetryAttempts)
209         {
210             BMCWEB_LOG_ERROR << "Maximum number of retries is reached.";
211 
212             // Clear queue.
213             while (!requestDataQueue.empty())
214             {
215                 requestDataQueue.pop();
216             }
217 
218             BMCWEB_LOG_DEBUG << "Retry policy is set to " << retryPolicyAction;
219             if (retryPolicyAction == "TerminateAfterRetries")
220             {
221                 // TODO: delete subscription
222                 state = ConnState::terminated;
223                 return;
224             }
225             if (retryPolicyAction == "SuspendRetries")
226             {
227                 state = ConnState::suspended;
228                 return;
229             }
230             // keep retrying, reset count and continue.
231             retryCount = 0;
232         }
233 
234         if ((state == ConnState::connectFailed) ||
235             (state == ConnState::sendFailed) ||
236             (state == ConnState::recvFailed))
237         {
238             if (newRecord)
239             {
240                 // We are already running async wait and retry.
241                 // Since record is added to queue, it gets the
242                 // turn in FIFO.
243                 return;
244             }
245 
246             if (runningTimer)
247             {
248                 BMCWEB_LOG_DEBUG << "Retry timer is already running.";
249                 return;
250             }
251             runningTimer = true;
252 
253             retryCount++;
254 
255             BMCWEB_LOG_DEBUG << "Attempt retry after " << retryIntervalSecs
256                              << " seconds. RetryCount = " << retryCount;
257             timer.expires_after(std::chrono::seconds(retryIntervalSecs));
258             timer.async_wait(
259                 [self = shared_from_this()](const boost::system::error_code&) {
260                     self->runningTimer = false;
261                     self->connStateCheck();
262                 });
263             return;
264         }
265         // reset retry count.
266         retryCount = 0;
267         connStateCheck();
268 
269         return;
270     }
271 
272     void connStateCheck()
273     {
274         switch (state)
275         {
276             case ConnState::connectInProgress:
277             case ConnState::sendInProgress:
278             case ConnState::suspended:
279             case ConnState::terminated:
280                 // do nothing
281                 break;
282             case ConnState::initialized:
283             case ConnState::closed:
284             case ConnState::connectFailed:
285             case ConnState::sendFailed:
286             case ConnState::recvFailed:
287             {
288                 // After establishing the connection, checkQueue() will
289                 // get called and it will attempt to send data.
290                 doConnect();
291                 break;
292             }
293             case ConnState::connected:
294             case ConnState::idle:
295             {
296                 std::string data = requestDataQueue.front();
297                 sendMessage(data);
298                 break;
299             }
300         }
301     }
302 
303   public:
304     explicit HttpClient(boost::asio::io_context& ioc, const std::string& id,
305                         const std::string& destIP, const std::string& destPort,
306                         const std::string& destUri) :
307         conn(ioc),
308         timer(ioc), subId(id), host(destIP), port(destPort), uri(destUri),
309         retryCount(0), maxRetryAttempts(5), retryIntervalSecs(0),
310         retryPolicyAction("TerminateAfterRetries"), runningTimer(false)
311     {
312         boost::asio::ip::tcp::resolver resolver(ioc);
313         endpoint = resolver.resolve(host, port);
314         state = ConnState::initialized;
315     }
316 
317     void sendData(const std::string& data)
318     {
319         if (state == ConnState::suspended)
320         {
321             return;
322         }
323 
324         if (requestDataQueue.size() <= maxRequestQueueSize)
325         {
326             requestDataQueue.push(data);
327             checkQueue(true);
328         }
329         else
330         {
331             BMCWEB_LOG_ERROR << "Request queue is full. So ignoring data.";
332         }
333 
334         return;
335     }
336 
337     void setHeaders(
338         const std::vector<std::pair<std::string, std::string>>& httpHeaders)
339     {
340         headers = httpHeaders;
341     }
342 
343     void setRetryConfig(const uint32_t retryAttempts,
344                         const uint32_t retryTimeoutInterval)
345     {
346         maxRetryAttempts = retryAttempts;
347         retryIntervalSecs = retryTimeoutInterval;
348     }
349 
350     void setRetryPolicy(const std::string& retryPolicy)
351     {
352         retryPolicyAction = retryPolicy;
353     }
354 };
355 
356 } // namespace crow
357