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
   7 namespace net {
   8
   9 inline void BalsaHeadersTokenUtils::TokenizeHeaderLine(
  10     const BalsaHeaders& headers,
  11     const BalsaHeaders::HeaderLineDescription& header_line,
  12     BalsaHeaders::HeaderTokenList* tokens) {
  13   CHECK(tokens);
  14
  15   // Find where this line is stored
  16   const char* stream_begin = headers.GetPtr(header_line.buffer_base_idx);
  17
  18   // Determine the boundaries of the value
  19   const char* value_begin = stream_begin + header_line.value_begin_idx;
  20   const char* line_end = stream_begin + header_line.last_char_idx;
  21
  22   // Tokenize
  23   ParseTokenList(value_begin, line_end, tokens);
  24 }
  25
  26 void BalsaHeadersTokenUtils::RemoveLastTokenFromHeaderValue(
  27     const base::StringPiece& key, BalsaHeaders* headers) {
  28   BalsaHeaders::HeaderLines::iterator it =
  29       headers->GetHeaderLinesIterator(key, headers->header_lines_.begin());
  30   if (it == headers->header_lines_.end()) {
  31     DLOG(WARNING) << "Attempting to remove last token from a non-existent "
  32                   << "header \"" << key << "\"";
  33     return;
  34   }
  35
  36   // Find the last line with that key.
  37   BalsaHeaders::HeaderLines::iterator header_line;
  38   do {
  39     header_line = it;
  40     it = headers->GetHeaderLinesIterator(key, it + 1);
  41   }
  42   while (it != headers->header_lines_.end());
  43
  44   // Tokenize just that line.
  45   BalsaHeaders::HeaderTokenList tokens;
  46   TokenizeHeaderLine(*headers, *header_line, &tokens);
  47
  48   if (tokens.empty()) {
  49     DLOG(WARNING) << "Attempting to remove a token from an empty header value "
  50                   << "for header \"" << key << "\"";
  51     header_line->skip = true;  // remove the whole line
  52   } else if (tokens.size() == 1) {
  53     header_line->skip = true;  // remove the whole line
  54   } else {
  55     // Shrink the line size and leave the extra data in the buffer.
  56     const base::StringPiece& new_last_token = tokens[tokens.size() - 2];
  57     const char* last_char_address =
  58         new_last_token.data() + new_last_token.size() - 1;
  59     const char* stream_begin = headers->GetPtr(header_line->buffer_base_idx);
  60
  61     header_line->last_char_idx = last_char_address - stream_begin + 1;
  62   }
  63 }
  64
  65 bool BalsaHeadersTokenUtils::CheckHeaderForLastToken(
  66     const BalsaHeaders& headers,
  67     const base::StringPiece& key,
  68     const base::StringPiece& token) {
  69   BalsaHeaders::const_header_lines_key_iterator it =
  70       headers.GetIteratorForKey(key);
  71   if (it == headers.header_lines_key_end())
  72     return false;
  73
  74   // Find the last line
  75   BalsaHeaders::const_header_lines_key_iterator header_line = it;
  76   do {
  77     header_line = it;
  78     ++it;
  79   }
  80   while (it != headers.header_lines_key_end());
  81
  82   // Tokenize just that line
  83   BalsaHeaders::HeaderTokenList tokens;
  84   ParseTokenList(header_line->second.begin(), header_line->second.end(),
  85                  &tokens);
  86
  87   return !tokens.empty() &&
  88          base::StartsWith(tokens.back(), token,
  89                           base::CompareCase::INSENSITIVE_ASCII);
  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