Line data    Source code

       1             : // Copyright (c) 2015-2020 The Bitcoin Core developers
       2             : // Distributed under the MIT software license, see the accompanying
       3             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4             : 
       5             : #ifndef BITCOIN_HTTPSERVER_H
       6             : #define BITCOIN_HTTPSERVER_H
       7             : 
       8             : #include <string>
       9             : #include <functional>
      10             : 
      11             : static const int DEFAULT_HTTP_THREADS=4;
      12             : static const int DEFAULT_HTTP_WORKQUEUE=16;
      13             : static const int DEFAULT_HTTP_SERVER_TIMEOUT=30;
      14             : 
      15             : struct evhttp_request;
      16             : struct event_base;
      17             : class CService;
      18             : class HTTPRequest;
      19             : 
      20             : /** Initialize HTTP server.
      21             :  * Call this before RegisterHTTPHandler or EventBase().
      22             :  */
      23             : bool InitHTTPServer();
      24             : /** Start HTTP server.
      25             :  * This is separate from InitHTTPServer to give users race-condition-free time
      26             :  * to register their handlers between InitHTTPServer and StartHTTPServer.
      27             :  */
      28             : void StartHTTPServer();
      29             : /** Interrupt HTTP server threads */
      30             : void InterruptHTTPServer();
      31             : /** Stop HTTP server */
      32             : void StopHTTPServer();
      33             : 
      34             : /** Change logging level for libevent. Removes BCLog::LIBEVENT from log categories if
      35             :  * libevent doesn't support debug logging.*/
      36             : bool UpdateHTTPServerLogging(bool enable);
      37             : 
      38             : /** Handler for requests to a certain HTTP path */
      39             : typedef std::function<bool(HTTPRequest* req, const std::string &)> HTTPRequestHandler;
      40             : /** Register handler for prefix.
      41             :  * If multiple handlers match a prefix, the first-registered one will
      42             :  * be invoked.
      43             :  */
      44             : void RegisterHTTPHandler(const std::string &prefix, bool exactMatch, const HTTPRequestHandler &handler);
      45             : /** Unregister handler for prefix */
      46             : void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch);
      47             : 
      48             : /** Return evhttp event base. This can be used by submodules to
      49             :  * queue timers or custom events.
      50             :  */
      51             : struct event_base* EventBase();
      52             : 
      53             : /** In-flight HTTP request.
      54             :  * Thin C++ wrapper around evhttp_request.
      55             :  */
      56             : class HTTPRequest
      57             : {
      58             : private:
      59             :     struct evhttp_request* req;
      60             :     bool replySent;
      61             : 
      62             : public:
      63             :     explicit HTTPRequest(struct evhttp_request* req, bool replySent = false);
      64             :     ~HTTPRequest();
      65             : 
      66             :     enum RequestMethod {
      67             :         UNKNOWN,
      68             :         GET,
      69             :         POST,
      70             :         HEAD,
      71             :         PUT
      72             :     };
      73             : 
      74             :     /** Get requested URI.
      75             :      */
      76             :     std::string GetURI() const;
      77             : 
      78             :     /** Get CService (address:ip) for the origin of the http request.
      79             :      */
      80             :     CService GetPeer() const;
      81             : 
      82             :     /** Get request method.
      83             :      */
      84             :     RequestMethod GetRequestMethod() const;
      85             : 
      86             :     /**
      87             :      * Get the request header specified by hdr, or an empty string.
      88             :      * Return a pair (isPresent,string).
      89             :      */
      90             :     std::pair<bool, std::string> GetHeader(const std::string& hdr) const;
      91             : 
      92             :     /**
      93             :      * Read request body.
      94             :      *
      95             :      * @note As this consumes the underlying buffer, call this only once.
      96             :      * Repeated calls will return an empty string.
      97             :      */
      98             :     std::string ReadBody();
      99             : 
     100             :     /**
     101             :      * Write output header.
     102             :      *
     103             :      * @note call this before calling WriteErrorReply or Reply.
     104             :      */
     105             :     void WriteHeader(const std::string& hdr, const std::string& value);
     106             : 
     107             :     /**
     108             :      * Write HTTP reply.
     109             :      * nStatus is the HTTP status code to send.
     110             :      * strReply is the body of the reply. Keep it empty to send a standard message.
     111             :      *
     112             :      * @note Can be called only once. As this will give the request back to the
     113             :      * main thread, do not call any other HTTPRequest methods after calling this.
     114             :      */
     115             :     void WriteReply(int nStatus, const std::string& strReply = "");
     116             : };
     117             : 
     118             : /** Event handler closure.
     119             :  */
     120       79065 : class HTTPClosure
     121             : {
     122             : public:
     123             :     virtual void operator()() = 0;
     124       79065 :     virtual ~HTTPClosure() {}
     125             : };
     126             : 
     127             : /** Event class. This can be used either as a cross-thread trigger or as a timer.
     128             :  */
     129             : class HTTPEvent
     130             : {
     131             : public:
     132             :     /** Create a new event.
     133             :      * deleteWhenTriggered deletes this event object after the event is triggered (and the handler called)
     134             :      * handler is the handler to call when the event is triggered.
     135             :      */
     136             :     HTTPEvent(struct event_base* base, bool deleteWhenTriggered, const std::function<void()>& handler);
     137             :     ~HTTPEvent();
     138             : 
     139             :     /** Trigger the event. If tv is 0, trigger it immediately. Otherwise trigger it after
     140             :      * the given time has elapsed.
     141             :      */
     142             :     void trigger(struct timeval* tv);
     143             : 
     144             :     bool deleteWhenTriggered;
     145             :     std::function<void()> handler;
     146             : private:
     147             :     struct event* ev;
     148             : };
     149             : 
     150             : #endif // BITCOIN_HTTPSERVER_H