1 /*
2  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 
12 #ifndef RTC_BASE_HTTPBASE_H_
13 #define RTC_BASE_HTTPBASE_H_
14 
15 #include "rtc_base/httpcommon.h"
16 
17 namespace rtc {
18 
19 class StreamInterface;
20 
21 ///////////////////////////////////////////////////////////////////////////////
22 // HttpParser - Parses an HTTP stream provided via Process and end_of_input, and
23 // generates events for:
24 //  Structural Elements: Leader, Headers, Document Data
25 //  Events: End of Headers, End of Document, Errors
26 ///////////////////////////////////////////////////////////////////////////////
27 
28 class HttpParser {
29 public:
30   enum ProcessResult { PR_CONTINUE, PR_BLOCK, PR_COMPLETE };
31   HttpParser();
32   virtual ~HttpParser();
33 
34   void reset();
35   ProcessResult Process(const char* buffer, size_t len, size_t* processed,
36                         HttpError* error);
37   bool is_valid_end_of_input() const;
38   void complete(HttpError err);
39 
GetDataRemaining()40   size_t GetDataRemaining() const { return data_size_; }
41 
42 protected:
43   ProcessResult ProcessLine(const char* line, size_t len, HttpError* error);
44 
45   // HttpParser Interface
46   virtual ProcessResult ProcessLeader(const char* line, size_t len,
47                                       HttpError* error) = 0;
48   virtual ProcessResult ProcessHeader(const char* name, size_t nlen,
49                                       const char* value, size_t vlen,
50                                       HttpError* error) = 0;
51   virtual ProcessResult ProcessHeaderComplete(bool chunked, size_t& data_size,
52                                               HttpError* error) = 0;
53   virtual ProcessResult ProcessData(const char* data, size_t len, size_t& read,
54                                     HttpError* error) = 0;
55   virtual void OnComplete(HttpError err) = 0;
56 
57 private:
58   enum State {
59     ST_LEADER, ST_HEADERS,
60     ST_CHUNKSIZE, ST_CHUNKTERM, ST_TRAILERS,
61     ST_DATA, ST_COMPLETE
62   } state_;
63   bool chunked_;
64   size_t data_size_;
65 };
66 
67 ///////////////////////////////////////////////////////////////////////////////
68 // IHttpNotify
69 ///////////////////////////////////////////////////////////////////////////////
70 
71 enum HttpMode { HM_NONE, HM_CONNECT, HM_RECV, HM_SEND };
72 
73 class IHttpNotify {
74 public:
~IHttpNotify()75   virtual ~IHttpNotify() {}
76   virtual HttpError onHttpHeaderComplete(bool chunked, size_t& data_size) = 0;
77   virtual void onHttpComplete(HttpMode mode, HttpError err) = 0;
78   virtual void onHttpClosed(HttpError err) = 0;
79 };
80 
81 ///////////////////////////////////////////////////////////////////////////////
82 // HttpBase - Provides a state machine for implementing HTTP-based components.
83 // Attach HttpBase to a StreamInterface which represents a bidirectional HTTP
84 // stream, and then call send() or recv() to initiate sending or receiving one
85 // side of an HTTP transaction.  By default, HttpBase operates as an I/O pump,
86 // moving data from the HTTP stream to the HttpData object and vice versa.
87 // However, it can also operate in stream mode, in which case the user of the
88 // stream interface drives I/O via calls to Read().
89 ///////////////////////////////////////////////////////////////////////////////
90 
91 class HttpBase
92 : private HttpParser,
93   public sigslot::has_slots<>
94 {
95 public:
96   HttpBase();
97   ~HttpBase() override;
98 
notify(IHttpNotify * notify)99   void notify(IHttpNotify* notify) { notify_ = notify; }
100   bool attach(StreamInterface* stream);
stream()101   StreamInterface* stream() { return http_stream_; }
102   StreamInterface* detach();
103   bool isConnected() const;
104 
105   void send(HttpData* data);
106   void recv(HttpData* data);
107   void abort(HttpError err);
108 
mode()109   HttpMode mode() const { return mode_; }
110 
set_ignore_data(bool ignore)111   void set_ignore_data(bool ignore) { ignore_data_ = ignore; }
ignore_data()112   bool ignore_data() const { return ignore_data_; }
113 
114   // Obtaining this stream puts HttpBase into stream mode until the stream
115   // is closed.  HttpBase can only expose one open stream interface at a time.
116   // Further calls will return null.
117   StreamInterface* GetDocumentStream();
118 
119 protected:
120   // Do cleanup when the http stream closes (error may be 0 for a clean
121   // shutdown), and return the error code to signal.
122   HttpError HandleStreamClose(int error);
123 
124   // DoReceiveLoop acts as a data pump, pulling data from the http stream,
125   // pushing it through the HttpParser, and then populating the HttpData object
126   // based on the callbacks from the parser.  One of the most interesting
127   // callbacks is ProcessData, which provides the actual http document body.
128   // This data is then written to the HttpData::document.  As a result, data
129   // flows from the network to the document, with some incidental protocol
130   // parsing in between.
131   // Ideally, we would pass in the document* to DoReceiveLoop, to more easily
132   // support GetDocumentStream().  However, since the HttpParser is callback
133   // driven, we are forced to store the pointer somewhere until the callback
134   // is triggered.
135   // Returns true if the received document has finished, and
136   // HttpParser::complete should be called.
137   bool DoReceiveLoop(HttpError* err);
138 
139   void read_and_process_data();
140   void flush_data();
141   bool queue_headers();
142   void do_complete(HttpError err = HE_NONE);
143 
144   void OnHttpStreamEvent(StreamInterface* stream, int events, int error);
145   void OnDocumentEvent(StreamInterface* stream, int events, int error);
146 
147   // HttpParser Interface
148   ProcessResult ProcessLeader(const char* line,
149                               size_t len,
150                               HttpError* error) override;
151   ProcessResult ProcessHeader(const char* name,
152                               size_t nlen,
153                               const char* value,
154                               size_t vlen,
155                               HttpError* error) override;
156   ProcessResult ProcessHeaderComplete(bool chunked,
157                                       size_t& data_size,
158                                       HttpError* error) override;
159   ProcessResult ProcessData(const char* data,
160                             size_t len,
161                             size_t& read,
162                             HttpError* error) override;
163   void OnComplete(HttpError err) override;
164 
165 private:
166   class DocumentStream;
167   friend class DocumentStream;
168 
169   enum { kBufferSize = 32 * 1024 };
170 
171   HttpMode mode_;
172   HttpData* data_;
173   IHttpNotify* notify_;
174   StreamInterface* http_stream_;
175   DocumentStream* doc_stream_;
176   char buffer_[kBufferSize];
177   size_t len_;
178 
179   bool ignore_data_, chunk_data_;
180   HttpData::const_iterator header_;
181 };
182 
183 ///////////////////////////////////////////////////////////////////////////////
184 
185 } // namespace rtc
186 
187 #endif // RTC_BASE_HTTPBASE_H_
188