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
TokenizeHeaderLine(const BalsaHeaders & headers,const BalsaHeaders::HeaderLineDescription & header_line,BalsaHeaders::HeaderTokenList * tokens)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
RemoveLastTokenFromHeaderValue(const base::StringPiece & key,BalsaHeaders * headers)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
CheckHeaderForLastToken(const BalsaHeaders & headers,const base::StringPiece & key,const base::StringPiece & token)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
TokenizeHeaderValue(const BalsaHeaders & headers,const base::StringPiece & key,BalsaHeaders::HeaderTokenList * tokens)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
ParseTokenList(const char * start,const char * end,BalsaHeaders::HeaderTokenList * tokens)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
143