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      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/browser/extensions/user_script_master.h"
      6 
      7 #include <map>
      8 #include <string>
      9 #include <vector>
     10 
     11 #include "base/bind.h"
     12 #include "base/file_util.h"
     13 #include "base/files/file_path.h"
     14 #include "base/pickle.h"
     15 #include "base/stl_util.h"
     16 #include "base/strings/string_util.h"
     17 #include "base/threading/thread.h"
     18 #include "base/version.h"
     19 #include "chrome/browser/chrome_notification_types.h"
     20 #include "chrome/browser/extensions/extension_service.h"
     21 #include "chrome/browser/extensions/extension_system.h"
     22 #include "chrome/browser/extensions/extension_util.h"
     23 #include "chrome/browser/extensions/image_loader.h"
     24 #include "chrome/browser/profiles/profile.h"
     25 #include "chrome/common/extensions/api/i18n/default_locale_handler.h"
     26 #include "chrome/common/extensions/extension_file_util.h"
     27 #include "chrome/common/extensions/extension_set.h"
     28 #include "chrome/common/extensions/manifest_handlers/content_scripts_handler.h"
     29 #include "chrome/common/extensions/message_bundle.h"
     30 #include "content/public/browser/notification_service.h"
     31 #include "content/public/browser/render_process_host.h"
     32 #include "extensions/common/extension.h"
     33 #include "extensions/common/extension_resource.h"
     34 #include "ui/base/resource/resource_bundle.h"
     35 
     36 using content::BrowserThread;
     37 
     38 namespace extensions {
     39 
     40 // Helper function to parse greasesmonkey headers
     41 static bool GetDeclarationValue(const base::StringPiece& line,
     42                                 const base::StringPiece& prefix,
     43                                 std::string* value) {
     44   base::StringPiece::size_type index = line.find(prefix);
     45   if (index == base::StringPiece::npos)
     46     return false;
     47 
     48   std::string temp(line.data() + index + prefix.length(),
     49                    line.length() - index - prefix.length());
     50 
     51   if (temp.empty() || !IsWhitespace(temp[0]))
     52     return false;
     53 
     54   TrimWhitespaceASCII(temp, TRIM_ALL, value);
     55   return true;
     56 }
     57 
     58 UserScriptMaster::ScriptReloader::ScriptReloader(UserScriptMaster* master)
     59     : master_(master) {
     60   CHECK(BrowserThread::GetCurrentThreadIdentifier(&master_thread_id_));
     61 }
     62 
     63 // static
     64 bool UserScriptMaster::ScriptReloader::ParseMetadataHeader(
     65       const base::StringPiece& script_text, UserScript* script) {
     66   // http://wiki.greasespot.net/Metadata_block
     67   base::StringPiece line;
     68   size_t line_start = 0;
     69   size_t line_end = line_start;
     70   bool in_metadata = false;
     71 
     72   static const base::StringPiece kUserScriptBegin("// ==UserScript==");
     73   static const base::StringPiece kUserScriptEng("// ==/UserScript==");
     74   static const base::StringPiece kNamespaceDeclaration("// @namespace");
     75   static const base::StringPiece kNameDeclaration("// @name");
     76   static const base::StringPiece kVersionDeclaration("// @version");
     77   static const base::StringPiece kDescriptionDeclaration("// @description");
     78   static const base::StringPiece kIncludeDeclaration("// @include");
     79   static const base::StringPiece kExcludeDeclaration("// @exclude");
     80   static const base::StringPiece kMatchDeclaration("// @match");
     81   static const base::StringPiece kExcludeMatchDeclaration("// @exclude_match");
     82   static const base::StringPiece kRunAtDeclaration("// @run-at");
     83   static const base::StringPiece kRunAtDocumentStartValue("document-start");
     84   static const base::StringPiece kRunAtDocumentEndValue("document-end");
     85   static const base::StringPiece kRunAtDocumentIdleValue("document-idle");
     86 
     87   while (line_start < script_text.length()) {
     88     line_end = script_text.find('\n', line_start);
     89 
     90     // Handle the case where there is no trailing newline in the file.
     91     if (line_end == std::string::npos)
     92       line_end = script_text.length() - 1;
     93 
     94     line.set(script_text.data() + line_start, line_end - line_start);
     95 
     96     if (!in_metadata) {
     97       if (line.starts_with(kUserScriptBegin))
     98         in_metadata = true;
     99     } else {
    100       if (line.starts_with(kUserScriptEng))
    101         break;
    102 
    103       std::string value;
    104       if (GetDeclarationValue(line, kIncludeDeclaration, &value)) {
    105         // We escape some characters that MatchPattern() considers special.
    106         ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
    107         ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
    108         script->add_glob(value);
    109       } else if (GetDeclarationValue(line, kExcludeDeclaration, &value)) {
    110         ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
    111         ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
    112         script->add_exclude_glob(value);
    113       } else if (GetDeclarationValue(line, kNamespaceDeclaration, &value)) {
    114         script->set_name_space(value);
    115       } else if (GetDeclarationValue(line, kNameDeclaration, &value)) {
    116         script->set_name(value);
    117       } else if (GetDeclarationValue(line, kVersionDeclaration, &value)) {
    118         Version version(value);
    119         if (version.IsValid())
    120           script->set_version(version.GetString());
    121       } else if (GetDeclarationValue(line, kDescriptionDeclaration, &value)) {
    122         script->set_description(value);
    123       } else if (GetDeclarationValue(line, kMatchDeclaration, &value)) {
    124         URLPattern pattern(UserScript::ValidUserScriptSchemes());
    125         if (URLPattern::PARSE_SUCCESS != pattern.Parse(value))
    126           return false;
    127         script->add_url_pattern(pattern);
    128       } else if (GetDeclarationValue(line, kExcludeMatchDeclaration, &value)) {
    129         URLPattern exclude(UserScript::ValidUserScriptSchemes());
    130         if (URLPattern::PARSE_SUCCESS != exclude.Parse(value))
    131           return false;
    132         script->add_exclude_url_pattern(exclude);
    133       } else if (GetDeclarationValue(line, kRunAtDeclaration, &value)) {
    134         if (value == kRunAtDocumentStartValue)
    135           script->set_run_location(UserScript::DOCUMENT_START);
    136         else if (value == kRunAtDocumentEndValue)
    137           script->set_run_location(UserScript::DOCUMENT_END);
    138         else if (value == kRunAtDocumentIdleValue)
    139           script->set_run_location(UserScript::DOCUMENT_IDLE);
    140         else
    141           return false;
    142       }
    143 
    144       // TODO(aa): Handle more types of metadata.
    145     }
    146 
    147     line_start = line_end + 1;
    148   }
    149 
    150   // If no patterns were specified, default to @include *. This is what
    151   // Greasemonkey does.
    152   if (script->globs().empty() && script->url_patterns().is_empty())
    153     script->add_glob("*");
    154 
    155   return true;
    156 }
    157 
    158 void UserScriptMaster::ScriptReloader::StartLoad(
    159     const UserScriptList& user_scripts,
    160     const ExtensionsInfo& extensions_info_) {
    161   // Add a reference to ourselves to keep ourselves alive while we're running.
    162   // Balanced by NotifyMaster().
    163   AddRef();
    164 
    165   this->extensions_info_ = extensions_info_;
    166   BrowserThread::PostTask(
    167       BrowserThread::FILE, FROM_HERE,
    168       base::Bind(
    169           &UserScriptMaster::ScriptReloader::RunLoad, this, user_scripts));
    170 }
    171 
    172 UserScriptMaster::ScriptReloader::~ScriptReloader() {}
    173 
    174 void UserScriptMaster::ScriptReloader::NotifyMaster(
    175     base::SharedMemory* memory) {
    176   // The master went away, so these new scripts aren't useful anymore.
    177   if (!master_)
    178     delete memory;
    179   else
    180     master_->NewScriptsAvailable(memory);
    181 
    182   // Drop our self-reference.
    183   // Balances StartLoad().
    184   Release();
    185 }
    186 
    187 static bool LoadScriptContent(UserScript::File* script_file,
    188                               const SubstitutionMap* localization_messages) {
    189   std::string content;
    190   const base::FilePath& path = ExtensionResource::GetFilePath(
    191       script_file->extension_root(), script_file->relative_path(),
    192       ExtensionResource::SYMLINKS_MUST_RESOLVE_WITHIN_ROOT);
    193   if (path.empty()) {
    194     int resource_id;
    195     if (extensions::ImageLoader::IsComponentExtensionResource(
    196             script_file->extension_root(), script_file->relative_path(),
    197             &resource_id)) {
    198       const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
    199       content = rb.GetRawDataResource(resource_id).as_string();
    200     } else {
    201       LOG(WARNING) << "Failed to get file path to "
    202                    << script_file->relative_path().value() << " from "
    203                    << script_file->extension_root().value();
    204       return false;
    205     }
    206   } else {
    207     if (!base::ReadFileToString(path, &content)) {
    208       LOG(WARNING) << "Failed to load user script file: " << path.value();
    209       return false;
    210     }
    211   }
    212 
    213   // Localize the content.
    214   if (localization_messages) {
    215     std::string error;
    216     MessageBundle::ReplaceMessagesWithExternalDictionary(
    217         *localization_messages, &content, &error);
    218     if (!error.empty()) {
    219       LOG(WARNING) << "Failed to replace messages in script: " << error;
    220     }
    221   }
    222 
    223   // Remove BOM from the content.
    224   std::string::size_type index = content.find(base::kUtf8ByteOrderMark);
    225   if (index == 0) {
    226     script_file->set_content(content.substr(strlen(base::kUtf8ByteOrderMark)));
    227   } else {
    228     script_file->set_content(content);
    229   }
    230 
    231   return true;
    232 }
    233 
    234 void UserScriptMaster::ScriptReloader::LoadUserScripts(
    235     UserScriptList* user_scripts) {
    236   for (size_t i = 0; i < user_scripts->size(); ++i) {
    237     UserScript& script = user_scripts->at(i);
    238     scoped_ptr<SubstitutionMap> localization_messages(
    239         GetLocalizationMessages(script.extension_id()));
    240     for (size_t k = 0; k < script.js_scripts().size(); ++k) {
    241       UserScript::File& script_file = script.js_scripts()[k];
    242       if (script_file.GetContent().empty())
    243         LoadScriptContent(&script_file, NULL);
    244     }
    245     for (size_t k = 0; k < script.css_scripts().size(); ++k) {
    246       UserScript::File& script_file = script.css_scripts()[k];
    247       if (script_file.GetContent().empty())
    248         LoadScriptContent(&script_file, localization_messages.get());
    249     }
    250   }
    251 }
    252 
    253 SubstitutionMap* UserScriptMaster::ScriptReloader::GetLocalizationMessages(
    254     std::string extension_id) {
    255   if (extensions_info_.find(extension_id) == extensions_info_.end()) {
    256     return NULL;
    257   }
    258 
    259   return extension_file_util::LoadMessageBundleSubstitutionMap(
    260       extensions_info_[extension_id].first,
    261       extension_id,
    262       extensions_info_[extension_id].second);
    263 }
    264 
    265 // Pickle user scripts and return pointer to the shared memory.
    266 static base::SharedMemory* Serialize(const UserScriptList& scripts) {
    267   Pickle pickle;
    268   pickle.WriteUInt64(scripts.size());
    269   for (size_t i = 0; i < scripts.size(); i++) {
    270     const UserScript& script = scripts[i];
    271     // TODO(aa): This can be replaced by sending content script metadata to
    272     // renderers along with other extension data in ExtensionMsg_Loaded.
    273     // See crbug.com/70516.
    274     script.Pickle(&pickle);
    275     // Write scripts as 'data' so that we can read it out in the slave without
    276     // allocating a new string.
    277     for (size_t j = 0; j < script.js_scripts().size(); j++) {
    278       base::StringPiece contents = script.js_scripts()[j].GetContent();
    279       pickle.WriteData(contents.data(), contents.length());
    280     }
    281     for (size_t j = 0; j < script.css_scripts().size(); j++) {
    282       base::StringPiece contents = script.css_scripts()[j].GetContent();
    283       pickle.WriteData(contents.data(), contents.length());
    284     }
    285   }
    286 
    287   // Create the shared memory object.
    288   base::SharedMemory shared_memory;
    289 
    290   if (!shared_memory.CreateAndMapAnonymous(pickle.size()))
    291     return NULL;
    292 
    293   // Copy the pickle to shared memory.
    294   memcpy(shared_memory.memory(), pickle.data(), pickle.size());
    295 
    296   base::SharedMemoryHandle readonly_handle;
    297   if (!shared_memory.ShareReadOnlyToProcess(base::GetCurrentProcessHandle(),
    298                                             &readonly_handle))
    299     return NULL;
    300 
    301   return new base::SharedMemory(readonly_handle, /*read_only=*/true);
    302 }
    303 
    304 // This method will be called on the file thread.
    305 void UserScriptMaster::ScriptReloader::RunLoad(
    306     const UserScriptList& user_scripts) {
    307   LoadUserScripts(const_cast<UserScriptList*>(&user_scripts));
    308 
    309   // Scripts now contains list of up-to-date scripts. Load the content in the
    310   // shared memory and let the master know it's ready. We need to post the task
    311   // back even if no scripts ware found to balance the AddRef/Release calls.
    312   BrowserThread::PostTask(
    313       master_thread_id_, FROM_HERE,
    314       base::Bind(
    315           &ScriptReloader::NotifyMaster, this, Serialize(user_scripts)));
    316 }
    317 
    318 
    319 UserScriptMaster::UserScriptMaster(Profile* profile)
    320     : extensions_service_ready_(false),
    321       pending_load_(false),
    322       profile_(profile) {
    323   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
    324                  content::Source<Profile>(profile_));
    325   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
    326                  content::Source<Profile>(profile_));
    327   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
    328                  content::Source<Profile>(profile_));
    329   registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CREATED,
    330                  content::NotificationService::AllBrowserContextsAndSources());
    331 }
    332 
    333 UserScriptMaster::~UserScriptMaster() {
    334   if (script_reloader_.get())
    335     script_reloader_->DisownMaster();
    336 }
    337 
    338 void UserScriptMaster::NewScriptsAvailable(base::SharedMemory* handle) {
    339   // Ensure handle is deleted or released.
    340   scoped_ptr<base::SharedMemory> handle_deleter(handle);
    341 
    342   if (pending_load_) {
    343     // While we were loading, there were further changes.  Don't bother
    344     // notifying about these scripts and instead just immediately reload.
    345     pending_load_ = false;
    346     StartLoad();
    347   } else {
    348     // We're no longer loading.
    349     script_reloader_ = NULL;
    350     // We've got scripts ready to go.
    351     shared_memory_.swap(handle_deleter);
    352 
    353     for (content::RenderProcessHost::iterator i(
    354             content::RenderProcessHost::AllHostsIterator());
    355          !i.IsAtEnd(); i.Advance()) {
    356       SendUpdate(i.GetCurrentValue(), handle);
    357     }
    358 
    359     content::NotificationService::current()->Notify(
    360         chrome::NOTIFICATION_USER_SCRIPTS_UPDATED,
    361         content::Source<Profile>(profile_),
    362         content::Details<base::SharedMemory>(handle));
    363   }
    364 }
    365 
    366 void UserScriptMaster::Observe(int type,
    367                                const content::NotificationSource& source,
    368                                const content::NotificationDetails& details) {
    369   bool should_start_load = false;
    370   switch (type) {
    371     case chrome::NOTIFICATION_EXTENSIONS_READY:
    372       extensions_service_ready_ = true;
    373       should_start_load = true;
    374       break;
    375     case chrome::NOTIFICATION_EXTENSION_LOADED: {
    376       // Add any content scripts inside the extension.
    377       const Extension* extension =
    378           content::Details<const Extension>(details).ptr();
    379       extensions_info_[extension->id()] =
    380           ExtensionSet::ExtensionPathAndDefaultLocale(
    381               extension->path(), LocaleInfo::GetDefaultLocale(extension));
    382       bool incognito_enabled = extension_util::IsIncognitoEnabled(
    383           extension->id(),
    384           extensions::ExtensionSystem::Get(profile_)->extension_service());
    385       const UserScriptList& scripts =
    386           ContentScriptsInfo::GetContentScripts(extension);
    387       for (UserScriptList::const_iterator iter = scripts.begin();
    388            iter != scripts.end(); ++iter) {
    389         user_scripts_.push_back(*iter);
    390         user_scripts_.back().set_incognito_enabled(incognito_enabled);
    391       }
    392       if (extensions_service_ready_)
    393         should_start_load = true;
    394       break;
    395     }
    396     case chrome::NOTIFICATION_EXTENSION_UNLOADED: {
    397       // Remove any content scripts.
    398       const Extension* extension =
    399           content::Details<UnloadedExtensionInfo>(details)->extension;
    400       extensions_info_.erase(extension->id());
    401       UserScriptList new_user_scripts;
    402       for (UserScriptList::iterator iter = user_scripts_.begin();
    403            iter != user_scripts_.end(); ++iter) {
    404         if (iter->extension_id() != extension->id())
    405           new_user_scripts.push_back(*iter);
    406       }
    407       user_scripts_ = new_user_scripts;
    408       should_start_load = true;
    409       break;
    410     }
    411     case content::NOTIFICATION_RENDERER_PROCESS_CREATED: {
    412       content::RenderProcessHost* process =
    413           content::Source<content::RenderProcessHost>(source).ptr();
    414       Profile* profile = Profile::FromBrowserContext(
    415           process->GetBrowserContext());
    416       if (!profile_->IsSameProfile(profile))
    417         return;
    418       if (ScriptsReady())
    419         SendUpdate(process, GetSharedMemory());
    420       break;
    421     }
    422     default:
    423       DCHECK(false);
    424   }
    425 
    426   if (should_start_load) {
    427     if (script_reloader_.get()) {
    428       pending_load_ = true;
    429     } else {
    430       StartLoad();
    431     }
    432   }
    433 }
    434 
    435 void UserScriptMaster::StartLoad() {
    436   if (!script_reloader_.get())
    437     script_reloader_ = new ScriptReloader(this);
    438 
    439   script_reloader_->StartLoad(user_scripts_, extensions_info_);
    440 }
    441 
    442 void UserScriptMaster::SendUpdate(content::RenderProcessHost* process,
    443                                   base::SharedMemory* shared_memory) {
    444   // Don't allow injection of content scripts into <webview>.
    445   if (process->IsGuest())
    446     return;
    447 
    448   Profile* profile = Profile::FromBrowserContext(process->GetBrowserContext());
    449   // Make sure we only send user scripts to processes in our profile.
    450   if (!profile_->IsSameProfile(profile))
    451     return;
    452 
    453   // If the process is being started asynchronously, early return.  We'll end up
    454   // calling InitUserScripts when it's created which will call this again.
    455   base::ProcessHandle handle = process->GetHandle();
    456   if (!handle)
    457     return;
    458 
    459   base::SharedMemoryHandle handle_for_process;
    460   if (!shared_memory->ShareToProcess(handle, &handle_for_process))
    461     return;  // This can legitimately fail if the renderer asserts at startup.
    462 
    463   if (base::SharedMemory::IsHandleValid(handle_for_process))
    464     process->Send(new ExtensionMsg_UpdateUserScripts(handle_for_process));
    465 }
    466 
    467 }  // namespace extensions
    468