chrome/common/content_settings_pattern_parser.cc

   1 // Copyright (c) 2012 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 "chrome/common/content_settings_pattern_parser.h"
   6
   7 #include "base/strings/string_util.h"
   8 #include "chrome/common/url_constants.h"
   9 #include "extensions/common/constants.h"
  10 #include "net/base/net_util.h"
  11 #include "url/gurl.h"
  12 #include "url/url_canon.h"
  13
  14 namespace {
  15
  16 const char* kUrlPathSeparator = "/";
  17 const char* kUrlPortSeparator = ":";
  18
  19 class Component {
  20  public:
  21   Component() : start(0), len(0) {}
  22   Component(size_t s, size_t l) : start(s), len(l) {}
  23
  24   bool IsNonEmpty() {
  25     return len > 0;
  26   }
  27
  28   size_t start;
  29   size_t len;
  30 };
  31
  32 }  // namespace
  33
  34 namespace content_settings {
  35
  36 const char* PatternParser::kDomainWildcard = "[*.]";
  37
  38 const size_t PatternParser::kDomainWildcardLength = 4;
  39
  40 const char* PatternParser::kSchemeWildcard = "*";
  41
  42 const char* PatternParser::kHostWildcard = "*";
  43
  44 const char* PatternParser::kPortWildcard = "*";
  45
  46 const char* PatternParser::kPathWildcard = "*";
  47
  48 // static
  49 void PatternParser::Parse(const std::string& pattern_spec,
  50                           ContentSettingsPattern::BuilderInterface* builder) {
  51   if (pattern_spec == "*") {
  52     builder->WithSchemeWildcard();
  53     builder->WithDomainWildcard();
  54     builder->WithPortWildcard();
  55     return;
  56   }
  57
  58   // Initialize components for the individual patterns parts to empty
  59   // sub-strings.
  60   Component scheme_component;
  61   Component host_component;
  62   Component port_component;
  63   Component path_component;
  64
  65   size_t start = 0;
  66   size_t current_pos = 0;
  67
  68   if (pattern_spec.empty())
  69     return;
  70
  71   // Test if a scheme pattern is in the spec.
  72   current_pos = pattern_spec.find(
  73       std::string(url::kStandardSchemeSeparator), start);
  74   if (current_pos != std::string::npos) {
  75     scheme_component = Component(start, current_pos);
  76     start = current_pos + strlen(url::kStandardSchemeSeparator);
  77     current_pos = start;
  78   } else {
  79     current_pos = start;
  80   }
  81
  82   if (start >= pattern_spec.size())
  83     return;  // Bad pattern spec.
  84
  85   // Jump to the end of domain wildcards or an IPv6 addresses. IPv6 addresses
  86   // contain ':'. So first move to the end of an IPv6 address befor searching
  87   // for the ':' that separates the port form the host.
  88   if (pattern_spec[current_pos] == '[')
  89     current_pos = pattern_spec.find("]", start);
  90
  91   if (current_pos == std::string::npos)
  92     return;  // Bad pattern spec.
  93
  94   current_pos = pattern_spec.find(std::string(kUrlPortSeparator), current_pos);
  95   if (current_pos == std::string::npos) {
  96     // No port spec found
  97     current_pos = pattern_spec.find(std::string(kUrlPathSeparator), start);
  98     if (current_pos == std::string::npos) {
  99       current_pos = pattern_spec.size();
 100       host_component = Component(start, current_pos - start);
 101     } else {
 102       // Pattern has a path spec.
 103       host_component = Component(start, current_pos - start);
 104     }
 105     start = current_pos;
 106   } else {
 107     // Port spec found.
 108     host_component = Component(start, current_pos - start);
 109     start = current_pos + 1;
 110     if (start < pattern_spec.size()) {
 111       current_pos = pattern_spec.find(std::string(kUrlPathSeparator), start);
 112       if (current_pos == std::string::npos) {
 113         current_pos = pattern_spec.size();
 114       }
 115       port_component = Component(start, current_pos - start);
 116       start = current_pos;
 117     }
 118   }
 119
 120   current_pos = pattern_spec.size();
 121   if (start < current_pos) {
 122     // Pattern has a path spec.
 123     path_component = Component(start, current_pos - start);
 124   }
 125
 126   // Set pattern parts.
 127   std::string scheme;
 128   if (scheme_component.IsNonEmpty()) {
 129     scheme = pattern_spec.substr(scheme_component.start, scheme_component.len);
 130     if (scheme == kSchemeWildcard) {
 131       builder->WithSchemeWildcard();
 132     } else {
 133       builder->WithScheme(scheme);
 134     }
 135   } else {
 136     builder->WithSchemeWildcard();
 137   }
 138
 139   if (host_component.IsNonEmpty()) {
 140     std::string host = pattern_spec.substr(host_component.start,
 141                                            host_component.len);
 142     if (host == kHostWildcard) {
 143       builder->WithDomainWildcard();
 144     } else if (StartsWithASCII(host, kDomainWildcard, true)) {
 145       host = host.substr(kDomainWildcardLength);
 146       builder->WithDomainWildcard();
 147       builder->WithHost(host);
 148     } else {
 149       // If the host contains a wildcard symbol then it is invalid.
 150       if (host.find(kHostWildcard) != std::string::npos) {
 151         builder->Invalid();
 152         return;
 153       }
 154       builder->WithHost(host);
 155     }
 156   }
 157
 158   if (port_component.IsNonEmpty()) {
 159     const std::string port = pattern_spec.substr(port_component.start,
 160                                                  port_component.len);
 161     if (port == kPortWildcard) {
 162       builder->WithPortWildcard();
 163     } else {
 164       // Check if the port string represents a valid port.
 165       for (size_t i = 0; i < port.size(); ++i) {
 166         if (!IsAsciiDigit(port[i])) {
 167           builder->Invalid();
 168           return;
 169         }
 170       }
 171       // TODO(markusheintz): Check port range.
 172       builder->WithPort(port);
 173     }
 174   } else {
 175     if (scheme != std::string(extensions::kExtensionScheme) &&
 176         scheme != std::string(url::kFileScheme))
 177       builder->WithPortWildcard();
 178   }
 179
 180   if (path_component.IsNonEmpty()) {
 181     const std::string path = pattern_spec.substr(path_component.start,
 182                                                  path_component.len);
 183     if (path.substr(1) == kPathWildcard)
 184       builder->WithPathWildcard();
 185     else
 186       builder->WithPath(path);
 187   }
 188 }
 189
 190 // static
 191 std::string PatternParser::ToString(
 192     const ContentSettingsPattern::PatternParts& parts) {
 193   // Return the most compact form to support legacy code and legacy pattern
 194   // strings.
 195   if (parts.is_scheme_wildcard &&
 196       parts.has_domain_wildcard &&
 197       parts.host.empty() &&
 198       parts.is_port_wildcard)
 199     return "*";
 200
 201   std::string str;
 202   if (!parts.is_scheme_wildcard)
 203     str += parts.scheme + url::kStandardSchemeSeparator;
 204
 205   if (parts.scheme == url::kFileScheme) {
 206     if (parts.is_path_wildcard)
 207       return str + kUrlPathSeparator + kPathWildcard;
 208     else
 209       return str + parts.path;
 210   }
 211
 212   if (parts.has_domain_wildcard) {
 213     if (parts.host.empty())
 214       str += kHostWildcard;
 215     else
 216       str += kDomainWildcard;
 217   }
 218   str += parts.host;
 219
 220   if (parts.scheme == std::string(extensions::kExtensionScheme)) {
 221     str += parts.path.empty() ? std::string(kUrlPathSeparator) : parts.path;
 222     return str;
 223   }
 224
 225   if (!parts.is_port_wildcard) {
 226     str += std::string(kUrlPortSeparator) + parts.port;
 227   }
 228
 229   return str;
 230 }
 231
 232 }  // namespace content_settings