James Robinson | 646469d | 2014-10-03 15:33:28 -0700 | [diff] [blame] | 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/websockets/websocket_extension_parser.h" |
| 6 | |
| 7 | #include "base/strings/string_util.h" |
| 8 | |
| 9 | namespace net { |
| 10 | |
| 11 | WebSocketExtensionParser::WebSocketExtensionParser() {} |
| 12 | |
| 13 | WebSocketExtensionParser::~WebSocketExtensionParser() {} |
| 14 | |
| 15 | void WebSocketExtensionParser::Parse(const char* data, size_t size) { |
| 16 | current_ = data; |
| 17 | end_ = data + size; |
| 18 | has_error_ = false; |
| 19 | |
| 20 | ConsumeExtension(&extension_); |
| 21 | if (has_error_) return; |
| 22 | ConsumeSpaces(); |
| 23 | has_error_ = has_error_ || (current_ != end_); |
| 24 | } |
| 25 | |
| 26 | void WebSocketExtensionParser::Consume(char c) { |
| 27 | DCHECK(!has_error_); |
| 28 | ConsumeSpaces(); |
| 29 | DCHECK(!has_error_); |
| 30 | if (current_ == end_ || c != current_[0]) { |
| 31 | has_error_ = true; |
| 32 | return; |
| 33 | } |
| 34 | ++current_; |
| 35 | } |
| 36 | |
| 37 | void WebSocketExtensionParser::ConsumeExtension(WebSocketExtension* extension) { |
| 38 | DCHECK(!has_error_); |
| 39 | base::StringPiece name; |
| 40 | ConsumeToken(&name); |
| 41 | if (has_error_) return; |
| 42 | *extension = WebSocketExtension(name.as_string()); |
| 43 | |
| 44 | while (ConsumeIfMatch(';')) { |
| 45 | WebSocketExtension::Parameter parameter((std::string())); |
| 46 | ConsumeExtensionParameter(¶meter); |
| 47 | if (has_error_) return; |
| 48 | extension->Add(parameter); |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | void WebSocketExtensionParser::ConsumeExtensionParameter( |
| 53 | WebSocketExtension::Parameter* parameter) { |
| 54 | DCHECK(!has_error_); |
| 55 | base::StringPiece name, value; |
| 56 | std::string value_string; |
| 57 | |
| 58 | ConsumeToken(&name); |
| 59 | if (has_error_) return; |
| 60 | if (!ConsumeIfMatch('=')) { |
| 61 | *parameter = WebSocketExtension::Parameter(name.as_string()); |
| 62 | return; |
| 63 | } |
| 64 | |
| 65 | if (Lookahead('\"')) { |
| 66 | ConsumeQuotedToken(&value_string); |
| 67 | } else { |
| 68 | ConsumeToken(&value); |
| 69 | value_string = value.as_string(); |
| 70 | } |
| 71 | if (has_error_) return; |
| 72 | *parameter = WebSocketExtension::Parameter(name.as_string(), value_string); |
| 73 | } |
| 74 | |
| 75 | void WebSocketExtensionParser::ConsumeToken(base::StringPiece* token) { |
| 76 | DCHECK(!has_error_); |
| 77 | ConsumeSpaces(); |
| 78 | DCHECK(!has_error_); |
| 79 | const char* head = current_; |
| 80 | while (current_ < end_ && |
| 81 | !IsControl(current_[0]) && !IsSeparator(current_[0])) |
| 82 | ++current_; |
| 83 | if (current_ == head) { |
| 84 | has_error_ = true; |
| 85 | return; |
| 86 | } |
| 87 | *token = base::StringPiece(head, current_ - head); |
| 88 | } |
| 89 | |
| 90 | void WebSocketExtensionParser::ConsumeQuotedToken(std::string* token) { |
| 91 | DCHECK(!has_error_); |
| 92 | Consume('"'); |
| 93 | if (has_error_) return; |
| 94 | *token = ""; |
| 95 | while (current_ < end_ && !IsControl(current_[0])) { |
| 96 | if (UnconsumedBytes() >= 2 && current_[0] == '\\') { |
| 97 | char next = current_[1]; |
| 98 | if (IsControl(next) || IsSeparator(next)) break; |
| 99 | *token += next; |
| 100 | current_ += 2; |
| 101 | } else if (IsSeparator(current_[0])) { |
| 102 | break; |
| 103 | } else { |
| 104 | *token += current_[0]; |
| 105 | ++current_; |
| 106 | } |
| 107 | } |
| 108 | // We can't use Consume here because we don't want to consume spaces. |
| 109 | if (current_ < end_ && current_[0] == '"') |
| 110 | ++current_; |
| 111 | else |
| 112 | has_error_ = true; |
| 113 | has_error_ = has_error_ || token->empty(); |
| 114 | } |
| 115 | |
| 116 | void WebSocketExtensionParser::ConsumeSpaces() { |
| 117 | DCHECK(!has_error_); |
| 118 | while (current_ < end_ && (current_[0] == ' ' || current_[0] == '\t')) |
| 119 | ++current_; |
| 120 | return; |
| 121 | } |
| 122 | |
| 123 | bool WebSocketExtensionParser::Lookahead(char c) { |
| 124 | DCHECK(!has_error_); |
| 125 | const char* head = current_; |
| 126 | |
| 127 | Consume(c); |
| 128 | bool result = !has_error_; |
| 129 | current_ = head; |
| 130 | has_error_ = false; |
| 131 | return result; |
| 132 | } |
| 133 | |
| 134 | bool WebSocketExtensionParser::ConsumeIfMatch(char c) { |
| 135 | DCHECK(!has_error_); |
| 136 | const char* head = current_; |
| 137 | |
| 138 | Consume(c); |
| 139 | if (has_error_) { |
| 140 | current_ = head; |
| 141 | has_error_ = false; |
| 142 | return false; |
| 143 | } |
| 144 | return true; |
| 145 | } |
| 146 | |
| 147 | // static |
| 148 | bool WebSocketExtensionParser::IsControl(char c) { |
| 149 | return (0 <= c && c <= 31) || c == 127; |
| 150 | } |
| 151 | |
| 152 | // static |
| 153 | bool WebSocketExtensionParser::IsSeparator(char c) { |
| 154 | const char separators[] = "()<>@,;:\\\"/[]?={} \t"; |
| 155 | return strchr(separators, c) != NULL; |
| 156 | } |
| 157 | |
| 158 | } // namespace net |