net/tools/balsa/balsa_headers_token_utils.cc

   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 #include "net/tools/balsa/balsa_headers_token_utils.h"
   6 #include "net/tools/balsa/string_piece_utils.h"
   7
   8 namespace net {
   9
  10 inline void BalsaHeadersTokenUtils::TokenizeHeaderLine(
  11     const BalsaHeaders& headers,
  12     const BalsaHeaders::HeaderLineDescription& header_line,
  13     BalsaHeaders::HeaderTokenList* tokens) {
  14   CHECK(tokens);
  15
  16   // Find where this line is stored
  17   const char* stream_begin = headers.GetPtr(header_line.buffer_base_idx);
  18
  19   // Determine the boundaries of the value
  20   const char* value_begin = stream_begin + header_line.value_begin_idx;
  21   const char* line_end = stream_begin + header_line.last_char_idx;
  22
  23   // Tokenize
  24   ParseTokenList(value_begin, line_end, tokens);
  25 }
  26
  27 void BalsaHeadersTokenUtils::RemoveLastTokenFromHeaderValue(
  28     const base::StringPiece& key, BalsaHeaders* headers) {
  29   BalsaHeaders::HeaderLines::iterator it =
  30       headers->GetHeaderLinesIterator(key, headers->header_lines_.begin());
  31   if (it == headers->header_lines_.end()) {
  32     DLOG(WARNING) << "Attempting to remove last token from a non-existent "
  33                   << "header \"" << key << "\"";
  34     return;
  35   }
  36
  37   // Find the last line with that key.
  38   BalsaHeaders::HeaderLines::iterator header_line;
  39   do {
  40     header_line = it;
  41     it = headers->GetHeaderLinesIterator(key, it + 1);
  42   }
  43   while (it != headers->header_lines_.end());
  44
  45   // Tokenize just that line.
  46   BalsaHeaders::HeaderTokenList tokens;
  47   TokenizeHeaderLine(*headers, *header_line, &tokens);
  48
  49   if (tokens.empty()) {
  50     DLOG(WARNING) << "Attempting to remove a token from an empty header value "
  51                   << "for header \"" << key << "\"";
  52     header_line->skip = true;  // remove the whole line
  53   } else if (tokens.size() == 1) {
  54     header_line->skip = true;  // remove the whole line
  55   } else {
  56     // Shrink the line size and leave the extra data in the buffer.
  57     const base::StringPiece& new_last_token = tokens[tokens.size() - 2];
  58     const char* last_char_address =
  59         new_last_token.data() + new_last_token.size() - 1;
  60     const char* stream_begin = headers->GetPtr(header_line->buffer_base_idx);
  61
  62     header_line->last_char_idx = last_char_address - stream_begin + 1;
  63   }
  64 }
  65
  66 bool BalsaHeadersTokenUtils::CheckHeaderForLastToken(
  67     const BalsaHeaders& headers,
  68     const base::StringPiece& key,
  69     const base::StringPiece& token) {
  70   BalsaHeaders::const_header_lines_key_iterator it =
  71       headers.GetIteratorForKey(key);
  72   if (it == headers.header_lines_key_end())
  73     return false;
  74
  75   // Find the last line
  76   BalsaHeaders::const_header_lines_key_iterator header_line = it;
  77   do {
  78     header_line = it;
  79     ++it;
  80   }
  81   while (it != headers.header_lines_key_end());
  82
  83   // Tokenize just that line
  84   BalsaHeaders::HeaderTokenList tokens;
  85   ParseTokenList(header_line->second.begin(), header_line->second.end(),
  86                  &tokens);
  87
  88   return !tokens.empty() &&
  89       StringPieceUtils::StartsWithIgnoreCase(tokens.back(), token);
  90 }
  91
  92 void BalsaHeadersTokenUtils::TokenizeHeaderValue(
  93     const BalsaHeaders& headers,
  94     const base::StringPiece& key,
  95     BalsaHeaders::HeaderTokenList* tokens) {
  96   CHECK(tokens);
  97   tokens->clear();
  98
  99   // We may have more then 1 line with the same header key. Tokenize them all
 100   // and stick all the tokens into the same list.
 101   for (BalsaHeaders::const_header_lines_key_iterator header_line =
 102            headers.GetIteratorForKey(key);
 103        header_line != headers.header_lines_key_end(); ++header_line) {
 104     ParseTokenList(header_line->second.begin(), header_line->second.end(),
 105                    tokens);
 106   }
 107 }
 108
 109 void BalsaHeadersTokenUtils::ParseTokenList(
 110     const char* start,
 111     const char* end,
 112     BalsaHeaders::HeaderTokenList* tokens) {
 113   if (start == end) {
 114     return;
 115   }
 116   while (true) {
 117     // search for first nonwhitespace, non separator char.
 118     while (*start == ',' || *start <= ' ') {
 119       ++start;
 120       if (start == end) {
 121         return;
 122       }
 123     }
 124     // found. marked.
 125     const char* nws = start;
 126
 127     // search for next whitspace or separator char.
 128     while (*start != ',' && *start > ' ') {
 129       ++start;
 130       if (start == end) {
 131         if (nws != start) {
 132           tokens->push_back(base::StringPiece(nws, start - nws));
 133         }
 134         return;
 135       }
 136     }
 137     tokens->push_back(base::StringPiece(nws, start - nws));
 138   }
 139 }
 140
 141 }  // namespace net
 142