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      1 //* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* ***** BEGIN LICENSE BLOCK *****
      3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
      4  *
      5  * The contents of this file are subject to the Mozilla Public License Version
      6  * 1.1 (the "License"); you may not use this file except in compliance with
      7  * the License. You may obtain a copy of the License at
      8  * http://www.mozilla.org/MPL/
      9  *
     10  * Software distributed under the License is distributed on an "AS IS" basis,
     11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
     12  * for the specific language governing rights and limitations under the
     13  * License.
     14  *
     15  * The Original Code is Mozilla Effective-TLD Service
     16  *
     17  * The Initial Developer of the Original Code is
     18  * Google Inc.
     19  * Portions created by the Initial Developer are Copyright (C) 2006
     20  * the Initial Developer. All Rights Reserved.
     21  *
     22  * Contributor(s):
     23  *   Pamela Greene <pamg.bugs (at) gmail.com> (original author)
     24  *   Daniel Witte <dwitte (at) stanford.edu>
     25  *
     26  * Alternatively, the contents of this file may be used under the terms of
     27  * either the GNU General Public License Version 2 or later (the "GPL"), or
     28  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
     29  * in which case the provisions of the GPL or the LGPL are applicable instead
     30  * of those above. If you wish to allow use of your version of this file only
     31  * under the terms of either the GPL or the LGPL, and not to allow others to
     32  * use your version of this file under the terms of the MPL, indicate your
     33  * decision by deleting the provisions above and replace them with the notice
     34  * and other provisions required by the GPL or the LGPL. If you do not delete
     35  * the provisions above, a recipient may use your version of this file under
     36  * the terms of any one of the MPL, the GPL or the LGPL.
     37  *
     38  * ***** END LICENSE BLOCK ***** */
     39 
     40 #include "net/base/registry_controlled_domain.h"
     41 
     42 #include "base/logging.h"
     43 #include "base/memory/singleton.h"
     44 #include "base/string_util.h"
     45 #include "googleurl/src/gurl.h"
     46 #include "googleurl/src/url_parse.h"
     47 #include "net/base/net_module.h"
     48 #include "net/base/net_util.h"
     49 
     50 #include "effective_tld_names.cc"
     51 
     52 namespace net {
     53 
     54 namespace {
     55 
     56 const int kExceptionRule = 1;
     57 const int kWildcardRule = 2;
     58 
     59 RegistryControlledDomainService* test_instance_;
     60 
     61 }  // namespace
     62 
     63 // static
     64 std::string RegistryControlledDomainService::GetDomainAndRegistry(
     65     const GURL& gurl) {
     66   const url_parse::Component host =
     67       gurl.parsed_for_possibly_invalid_spec().host;
     68   if ((host.len <= 0) || gurl.HostIsIPAddress())
     69     return std::string();
     70   return GetDomainAndRegistryImpl(std::string(
     71       gurl.possibly_invalid_spec().data() + host.begin, host.len));
     72 }
     73 
     74 // static
     75 std::string RegistryControlledDomainService::GetDomainAndRegistry(
     76     const std::string& host) {
     77   url_canon::CanonHostInfo host_info;
     78   const std::string canon_host(CanonicalizeHost(host, &host_info));
     79   if (canon_host.empty() || host_info.IsIPAddress())
     80     return std::string();
     81   return GetDomainAndRegistryImpl(canon_host);
     82 }
     83 
     84 // static
     85 std::string RegistryControlledDomainService::GetDomainAndRegistry(
     86     const std::wstring& host) {
     87   url_canon::CanonHostInfo host_info;
     88   const std::string canon_host(CanonicalizeHost(host, &host_info));
     89   if (canon_host.empty() || host_info.IsIPAddress())
     90     return std::string();
     91   return GetDomainAndRegistryImpl(canon_host);
     92 }
     93 
     94 // static
     95 bool RegistryControlledDomainService::SameDomainOrHost(const GURL& gurl1,
     96                                                        const GURL& gurl2) {
     97   // See if both URLs have a known domain + registry, and those values are the
     98   // same.
     99   const std::string domain1(GetDomainAndRegistry(gurl1));
    100   const std::string domain2(GetDomainAndRegistry(gurl2));
    101   if (!domain1.empty() || !domain2.empty())
    102     return domain1 == domain2;
    103 
    104   // No domains.  See if the hosts are identical.
    105   const url_parse::Component host1 =
    106       gurl1.parsed_for_possibly_invalid_spec().host;
    107   const url_parse::Component host2 =
    108       gurl2.parsed_for_possibly_invalid_spec().host;
    109   if ((host1.len <= 0) || (host1.len != host2.len))
    110     return false;
    111   return !strncmp(gurl1.possibly_invalid_spec().data() + host1.begin,
    112                   gurl2.possibly_invalid_spec().data() + host2.begin,
    113                   host1.len);
    114 }
    115 
    116 // static
    117 size_t RegistryControlledDomainService::GetRegistryLength(
    118     const GURL& gurl,
    119     bool allow_unknown_registries) {
    120   const url_parse::Component host =
    121       gurl.parsed_for_possibly_invalid_spec().host;
    122   if (host.len <= 0)
    123     return std::string::npos;
    124   if (gurl.HostIsIPAddress())
    125     return 0;
    126   return GetInstance()->GetRegistryLengthImpl(
    127       std::string(gurl.possibly_invalid_spec().data() + host.begin, host.len),
    128       allow_unknown_registries);
    129 }
    130 
    131 // static
    132 size_t RegistryControlledDomainService::GetRegistryLength(
    133     const std::string& host,
    134     bool allow_unknown_registries) {
    135   url_canon::CanonHostInfo host_info;
    136   const std::string canon_host(CanonicalizeHost(host, &host_info));
    137   if (canon_host.empty())
    138     return std::string::npos;
    139   if (host_info.IsIPAddress())
    140     return 0;
    141   return GetInstance()->GetRegistryLengthImpl(canon_host,
    142                                               allow_unknown_registries);
    143 }
    144 
    145 // static
    146 size_t RegistryControlledDomainService::GetRegistryLength(
    147     const std::wstring& host,
    148     bool allow_unknown_registries) {
    149   url_canon::CanonHostInfo host_info;
    150   const std::string canon_host(CanonicalizeHost(host, &host_info));
    151   if (canon_host.empty())
    152     return std::string::npos;
    153   if (host_info.IsIPAddress())
    154     return 0;
    155   return GetInstance()->GetRegistryLengthImpl(canon_host,
    156                                               allow_unknown_registries);
    157 }
    158 
    159 // static
    160 RegistryControlledDomainService* RegistryControlledDomainService::GetInstance()
    161 {
    162   if (test_instance_)
    163     return test_instance_;
    164 
    165   return Singleton<RegistryControlledDomainService>::get();
    166 }
    167 
    168 RegistryControlledDomainService::RegistryControlledDomainService()
    169     : find_domain_function_(Perfect_Hash::FindDomain) {
    170 }
    171 
    172 // static
    173 RegistryControlledDomainService* RegistryControlledDomainService::SetInstance(
    174     RegistryControlledDomainService* instance) {
    175   RegistryControlledDomainService* old_instance = test_instance_;
    176   test_instance_ = instance;
    177   return old_instance;
    178 }
    179 
    180 // static
    181 void RegistryControlledDomainService::UseFindDomainFunction(
    182     FindDomainPtr function) {
    183   RegistryControlledDomainService* instance = GetInstance();
    184   instance->find_domain_function_ = function;
    185 }
    186 
    187 // static
    188 std::string RegistryControlledDomainService::GetDomainAndRegistryImpl(
    189     const std::string& host) {
    190   DCHECK(!host.empty());
    191 
    192   // Find the length of the registry for this host.
    193   const size_t registry_length =
    194       GetInstance()->GetRegistryLengthImpl(host, true);
    195   if ((registry_length == std::string::npos) || (registry_length == 0))
    196     return std::string();  // No registry.
    197   // The "2" in this next line is 1 for the dot, plus a 1-char minimum preceding
    198   // subcomponent length.
    199   DCHECK(host.length() >= 2);
    200   if (registry_length > (host.length() - 2)) {
    201     NOTREACHED() <<
    202         "Host does not have at least one subcomponent before registry!";
    203     return std::string();
    204   }
    205 
    206   // Move past the dot preceding the registry, and search for the next previous
    207   // dot.  Return the host from after that dot, or the whole host when there is
    208   // no dot.
    209   const size_t dot = host.rfind('.', host.length() - registry_length - 2);
    210   if (dot == std::string::npos)
    211     return host;
    212   return host.substr(dot + 1);
    213 }
    214 
    215 size_t RegistryControlledDomainService::GetRegistryLengthImpl(
    216     const std::string& host,
    217     bool allow_unknown_registries) {
    218   DCHECK(!host.empty());
    219 
    220   // Skip leading dots.
    221   const size_t host_check_begin = host.find_first_not_of('.');
    222   if (host_check_begin == std::string::npos)
    223     return 0;  // Host is only dots.
    224 
    225   // A single trailing dot isn't relevant in this determination, but does need
    226   // to be included in the final returned length.
    227   size_t host_check_len = host.length();
    228   if (host[host_check_len - 1] == '.') {
    229     --host_check_len;
    230     DCHECK(host_check_len > 0);  // If this weren't true, the host would be ".",
    231                                  // and we'd have already returned above.
    232     if (host[host_check_len - 1] == '.')
    233       return 0;  // Multiple trailing dots.
    234   }
    235 
    236   // Walk up the domain tree, most specific to least specific,
    237   // looking for matches at each level.
    238   size_t prev_start = std::string::npos;
    239   size_t curr_start = host_check_begin;
    240   size_t next_dot = host.find('.', curr_start);
    241   if (next_dot >= host_check_len)  // Catches std::string::npos as well.
    242     return 0;  // This can't have a registry + domain.
    243   while (1) {
    244     const char* domain_str = host.data() + curr_start;
    245     int domain_length = host_check_len - curr_start;
    246     const DomainRule* rule = find_domain_function_(domain_str, domain_length);
    247 
    248     // We need to compare the string after finding a match because the
    249     // no-collisions of perfect hashing only refers to items in the set.  Since
    250     // we're searching for arbitrary domains, there could be collisions.
    251     if (rule &&
    252         base::strncasecmp(domain_str, rule->name, domain_length) == 0) {
    253       // Exception rules override wildcard rules when the domain is an exact
    254       // match, but wildcards take precedence when there's a subdomain.
    255       if (rule->type == kWildcardRule && (prev_start != std::string::npos)) {
    256         // If prev_start == host_check_begin, then the host is the registry
    257         // itself, so return 0.
    258         return (prev_start == host_check_begin) ?
    259             0 : (host.length() - prev_start);
    260       }
    261 
    262       if (rule->type == kExceptionRule) {
    263         if (next_dot == std::string::npos) {
    264           // If we get here, we had an exception rule with no dots (e.g.
    265           // "!foo").  This would only be valid if we had a corresponding
    266           // wildcard rule, which would have to be "*".  But we explicitly
    267           // disallow that case, so this kind of rule is invalid.
    268           NOTREACHED() << "Invalid exception rule";
    269           return 0;
    270         }
    271         return host.length() - next_dot - 1;
    272       }
    273 
    274       // If curr_start == host_check_begin, then the host is the registry
    275       // itself, so return 0.
    276       return (curr_start == host_check_begin) ?
    277           0 : (host.length() - curr_start);
    278     }
    279 
    280     if (next_dot >= host_check_len)  // Catches std::string::npos as well.
    281       break;
    282 
    283     prev_start = curr_start;
    284     curr_start = next_dot + 1;
    285     next_dot = host.find('.', curr_start);
    286   }
    287 
    288   // No rule found in the registry.  curr_start now points to the first
    289   // character of the last subcomponent of the host, so if we allow unknown
    290   // registries, return the length of this subcomponent.
    291   return allow_unknown_registries ? (host.length() - curr_start) : 0;
    292 }
    293 
    294 }  // namespace net
    295