net/tools/balsa/balsa_frame.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_TOOLS_BALSA_BALSA_FRAME_H_
   6 #define NET_TOOLS_BALSA_BALSA_FRAME_H_
   7
   8 #include <utility>
   9 #include <vector>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/port.h"
  13 #include "net/tools/balsa/balsa_enums.h"
  14 #include "net/tools/balsa/balsa_headers.h"
  15 #include "net/tools/balsa/balsa_visitor_interface.h"
  16 #include "net/tools/balsa/buffer_interface.h"
  17 #include "net/tools/balsa/http_message_constants.h"
  18 #include "net/tools/balsa/simple_buffer.h"
  19
  20 // For additional debug output, uncomment the following:
  21 // #define DEBUGFRAMER 1
  22
  23 namespace net {
  24
  25 // BalsaFrame is a 'Model' of a framer (haha).
  26 // It exists as a proof of concept headers framer.
  27 class BalsaFrame {
  28  public:
  29   typedef std::vector<std::pair<size_t, size_t> > Lines;
  30
  31   typedef BalsaHeaders::HeaderLineDescription HeaderLineDescription;
  32   typedef BalsaHeaders::HeaderLines HeaderLines;
  33   typedef BalsaHeaders::HeaderTokenList HeaderTokenList;
  34
  35   // TODO(fenix): get rid of the 'kValidTerm*' stuff by using the 'since last
  36   // index' strategy.  Note that this implies getting rid of the HeaderFramed()
  37
  38   static const uint32 kValidTerm1  = '\n' << 16 |
  39                                      '\r' <<  8 |
  40                                      '\n';
  41   static const uint32 kValidTerm1Mask = 0xFF << 16 |
  42                                         0xFF <<  8 |
  43                                         0xFF;
  44   static const uint32 kValidTerm2      = '\n' << 8 |
  45                                          '\n';
  46   static const uint32 kValidTerm2Mask = 0xFF << 8 |
  47                                         0xFF;
  48   BalsaFrame();
  49   ~BalsaFrame();
  50
  51   // Reset reinitializes all the member variables of the framer and clears the
  52   // attached header object (but doesn't change the pointer value headers_).
  53   void Reset();
  54
  55   const BalsaHeaders* const_balsa_headers() const { return headers_; }
  56   BalsaHeaders* balsa_headers() { return headers_; }
  57   // The method set_balsa_headers clears the headers provided and attaches them
  58   // to the framer.  This is a required step before the framer will process any
  59   // input message data.
  60   // To detach the header object from the framer, use set_balsa_headers(NULL).
  61   void set_balsa_headers(BalsaHeaders* headers) {
  62     if (headers_ != headers) {
  63       headers_ = headers;
  64     }
  65     if (headers_) {
  66       // Clear the headers if they are non-null, even if the new headers are
  67       // the same as the old.
  68       headers_->Clear();
  69     }
  70   }
  71
  72   void set_balsa_visitor(BalsaVisitorInterface* visitor) {
  73     visitor_ = visitor;
  74     if (visitor_ == NULL) {
  75       visitor_ = &do_nothing_visitor_;
  76     }
  77   }
  78
  79   void set_is_request(bool is_request) { is_request_ = is_request; }
  80
  81   bool is_request() const {
  82     return is_request_;
  83   }
  84
  85   void set_request_was_head(bool request_was_head) {
  86     request_was_head_ = request_was_head;
  87   }
  88
  89   bool request_was_head() const {
  90     return request_was_head_;
  91   }
  92
  93   void set_max_header_length(size_t max_header_length) {
  94     max_header_length_ = max_header_length;
  95   }
  96
  97   size_t max_header_length() const {
  98     return max_header_length_;
  99   }
 100
 101   void set_max_request_uri_length(size_t max_request_uri_length) {
 102     max_request_uri_length_ = max_request_uri_length;
 103   }
 104
 105   size_t max_request_uri_length() const {
 106     return max_request_uri_length_;
 107   }
 108
 109
 110   bool MessageFullyRead() {
 111     return parse_state_ == BalsaFrameEnums::MESSAGE_FULLY_READ;
 112   }
 113
 114   BalsaFrameEnums::ParseState ParseState() const { return parse_state_; }
 115
 116
 117   bool Error() {
 118     return parse_state_ == BalsaFrameEnums::PARSE_ERROR;
 119   }
 120
 121   BalsaFrameEnums::ErrorCode ErrorCode() const { return last_error_; }
 122
 123   const BalsaHeaders* headers() const { return headers_; }
 124   BalsaHeaders* mutable_headers() { return headers_; }
 125
 126   size_t BytesSafeToSplice() const;
 127   void BytesSpliced(size_t bytes_spliced);
 128
 129   size_t ProcessInput(const char* input, size_t size);
 130
 131   // Parses input and puts the key, value chunk extensions into extensions.
 132   // TODO(phython): Find a better data structure to put the extensions into.
 133   static void ProcessChunkExtensions(const char* input, size_t size,
 134                                      BalsaHeaders* extensions);
 135
 136  protected:
 137   // The utils object needs access to the ParseTokenList in order to do its
 138   // job.
 139   friend class BalsaHeadersTokenUtils;
 140
 141   inline void ProcessContentLengthLine(
 142       size_t line_idx,
 143       BalsaHeadersEnums::ContentLengthStatus* status,
 144       size_t* length);
 145
 146   inline void ProcessTransferEncodingLine(size_t line_idx);
 147
 148   void ProcessFirstLine(const char* begin,
 149                         const char* end);
 150
 151   void CleanUpKeyValueWhitespace(
 152       const char* stream_begin,
 153       const char* line_begin,
 154       const char* current,
 155       const char* line_end,
 156       HeaderLineDescription* current_header_line);
 157
 158   void FindColonsAndParseIntoKeyValue();
 159
 160   void ProcessHeaderLines();
 161
 162   inline size_t ProcessHeaders(const char* message_start,
 163                                size_t message_length);
 164
 165   void AssignParseStateAfterHeadersHaveBeenParsed();
 166
 167   inline bool LineFramingFound(char current_char) {
 168     return current_char == '\n';
 169   }
 170
 171   // TODO(fenix): get rid of the following function and its uses (and
 172   // replace with something more efficient)
 173   inline bool HeaderFramingFound(char current_char) {
 174     // Note that the 'if (current_char == '\n' ...)' test exists to ensure that
 175     // the HeaderFramingMayBeFound test works properly. In benchmarking done on
 176     // 2/13/2008, the 'if' actually speeds up performance of the function
 177     // anyway..
 178     if (current_char == '\n' || current_char == '\r') {
 179       term_chars_ <<= 8;
 180       // This is necessary IFF architecture has > 8 bit char.  Alas, I'm
 181       // paranoid.
 182       term_chars_ |= current_char & 0xFF;
 183
 184       if ((term_chars_ & kValidTerm1Mask) == kValidTerm1) {
 185         term_chars_ = 0;
 186         return true;
 187       }
 188       if ((term_chars_ & kValidTerm2Mask) == kValidTerm2) {
 189         term_chars_ = 0;
 190         return true;
 191       }
 192     } else {
 193       term_chars_ = 0;
 194     }
 195     return false;
 196   }
 197
 198   inline bool HeaderFramingMayBeFound() const {
 199     return term_chars_ != 0;
 200   }
 201
 202  private:
 203   class DoNothingBalsaVisitor : public BalsaVisitorInterface {
 204     void ProcessBodyInput(const char* input, size_t size) override {}
 205     void ProcessBodyData(const char* input, size_t size) override {}
 206     void ProcessHeaderInput(const char* input, size_t size) override {}
 207     void ProcessTrailerInput(const char* input, size_t size) override {}
 208     void ProcessHeaders(const BalsaHeaders& headers) override {}
 209     void ProcessRequestFirstLine(const char* line_input,
 210                                  size_t line_length,
 211                                  const char* method_input,
 212                                  size_t method_length,
 213                                  const char* request_uri_input,
 214                                  size_t request_uri_length,
 215                                  const char* version_input,
 216                                  size_t version_length) override {}
 217     void ProcessResponseFirstLine(const char* line_input,
 218                                   size_t line_length,
 219                                   const char* version_input,
 220                                   size_t version_length,
 221                                   const char* status_input,
 222                                   size_t status_length,
 223                                   const char* reason_input,
 224                                   size_t reason_length) override {}
 225     void ProcessChunkLength(size_t chunk_length) override {}
 226     void ProcessChunkExtensions(const char* input, size_t size) override {}
 227     void HeaderDone() override {}
 228     void MessageDone() override {}
 229     void HandleHeaderError(BalsaFrame* framer) override {}
 230     void HandleHeaderWarning(BalsaFrame* framer) override {}
 231     void HandleChunkingError(BalsaFrame* framer) override {}
 232     void HandleBodyError(BalsaFrame* framer) override {}
 233   };
 234
 235   bool last_char_was_slash_r_;
 236   bool saw_non_newline_char_;
 237   bool start_was_space_;
 238   bool chunk_length_character_extracted_;
 239   bool is_request_;                // This is not reset in Reset()
 240   bool request_was_head_;          // This is not reset in Reset()
 241   size_t max_header_length_;       // This is not reset in Reset()
 242   size_t max_request_uri_length_;  // This is not reset in Reset()
 243   BalsaVisitorInterface* visitor_;
 244   size_t chunk_length_remaining_;
 245   size_t content_length_remaining_;
 246   const char* last_slash_n_loc_;
 247   const char* last_recorded_slash_n_loc_;
 248   size_t last_slash_n_idx_;
 249   uint32 term_chars_;
 250   BalsaFrameEnums::ParseState parse_state_;
 251   BalsaFrameEnums::ErrorCode last_error_;
 252
 253   Lines lines_;
 254
 255   BalsaHeaders* headers_;  // This is not reset to NULL in Reset().
 256   DoNothingBalsaVisitor do_nothing_visitor_;
 257 };
 258
 259 }  // namespace net
 260
 261 #endif  // NET_TOOLS_BALSA_BALSA_FRAME_H_
 262