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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 <string>
      8 
      9 #include "base/bind.h"
     10 #include "base/bind_helpers.h"
     11 #include "base/file_util.h"
     12 #include "base/files/file_path.h"
     13 #include "base/version.h"
     14 #include "chrome/browser/chrome_notification_types.h"
     15 #include "chrome/browser/extensions/extension_service.h"
     16 #include "chrome/browser/extensions/extension_util.h"
     17 #include "chrome/browser/profiles/profile.h"
     18 #include "chrome/common/extensions/api/i18n/default_locale_handler.h"
     19 #include "chrome/common/extensions/manifest_handlers/content_scripts_handler.h"
     20 #include "content/public/browser/notification_service.h"
     21 #include "content/public/browser/render_process_host.h"
     22 #include "extensions/browser/component_extension_resource_manager.h"
     23 #include "extensions/browser/content_verifier.h"
     24 #include "extensions/browser/extension_registry.h"
     25 #include "extensions/browser/extension_system.h"
     26 #include "extensions/browser/extensions_browser_client.h"
     27 #include "extensions/common/file_util.h"
     28 #include "extensions/common/message_bundle.h"
     29 #include "ui/base/resource/resource_bundle.h"
     30 
     31 using content::BrowserThread;
     32 using extensions::ExtensionsBrowserClient;
     33 
     34 namespace extensions {
     35 
     36 // Helper function to parse greasesmonkey headers
     37 static bool GetDeclarationValue(const base::StringPiece& line,
     38                                 const base::StringPiece& prefix,
     39                                 std::string* value) {
     40   base::StringPiece::size_type index = line.find(prefix);
     41   if (index == base::StringPiece::npos)
     42     return false;
     43 
     44   std::string temp(line.data() + index + prefix.length(),
     45                    line.length() - index - prefix.length());
     46 
     47   if (temp.empty() || !IsWhitespace(temp[0]))
     48     return false;
     49 
     50   base::TrimWhitespaceASCII(temp, base::TRIM_ALL, value);
     51   return true;
     52 }
     53 
     54 UserScriptMaster::ScriptReloader::ScriptReloader(UserScriptMaster* master)
     55     : master_(master) {
     56   CHECK(BrowserThread::GetCurrentThreadIdentifier(&master_thread_id_));
     57 }
     58 
     59 // static
     60 bool UserScriptMaster::ScriptReloader::ParseMetadataHeader(
     61       const base::StringPiece& script_text, UserScript* script) {
     62   // http://wiki.greasespot.net/Metadata_block
     63   base::StringPiece line;
     64   size_t line_start = 0;
     65   size_t line_end = line_start;
     66   bool in_metadata = false;
     67 
     68   static const base::StringPiece kUserScriptBegin("// ==UserScript==");
     69   static const base::StringPiece kUserScriptEng("// ==/UserScript==");
     70   static const base::StringPiece kNamespaceDeclaration("// @namespace");
     71   static const base::StringPiece kNameDeclaration("// @name");
     72   static const base::StringPiece kVersionDeclaration("// @version");
     73   static const base::StringPiece kDescriptionDeclaration("// @description");
     74   static const base::StringPiece kIncludeDeclaration("// @include");
     75   static const base::StringPiece kExcludeDeclaration("// @exclude");
     76   static const base::StringPiece kMatchDeclaration("// @match");
     77   static const base::StringPiece kExcludeMatchDeclaration("// @exclude_match");
     78   static const base::StringPiece kRunAtDeclaration("// @run-at");
     79   static const base::StringPiece kRunAtDocumentStartValue("document-start");
     80   static const base::StringPiece kRunAtDocumentEndValue("document-end");
     81   static const base::StringPiece kRunAtDocumentIdleValue("document-idle");
     82 
     83   while (line_start < script_text.length()) {
     84     line_end = script_text.find('\n', line_start);
     85 
     86     // Handle the case where there is no trailing newline in the file.
     87     if (line_end == std::string::npos)
     88       line_end = script_text.length() - 1;
     89 
     90     line.set(script_text.data() + line_start, line_end - line_start);
     91 
     92     if (!in_metadata) {
     93       if (line.starts_with(kUserScriptBegin))
     94         in_metadata = true;
     95     } else {
     96       if (line.starts_with(kUserScriptEng))
     97         break;
     98 
     99       std::string value;
    100       if (GetDeclarationValue(line, kIncludeDeclaration, &value)) {
    101         // We escape some characters that MatchPattern() considers special.
    102         ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
    103         ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
    104         script->add_glob(value);
    105       } else if (GetDeclarationValue(line, kExcludeDeclaration, &value)) {
    106         ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
    107         ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
    108         script->add_exclude_glob(value);
    109       } else if (GetDeclarationValue(line, kNamespaceDeclaration, &value)) {
    110         script->set_name_space(value);
    111       } else if (GetDeclarationValue(line, kNameDeclaration, &value)) {
    112         script->set_name(value);
    113       } else if (GetDeclarationValue(line, kVersionDeclaration, &value)) {
    114         Version version(value);
    115         if (version.IsValid())
    116           script->set_version(version.GetString());
    117       } else if (GetDeclarationValue(line, kDescriptionDeclaration, &value)) {
    118         script->set_description(value);
    119       } else if (GetDeclarationValue(line, kMatchDeclaration, &value)) {
    120         URLPattern pattern(UserScript::ValidUserScriptSchemes());
    121         if (URLPattern::PARSE_SUCCESS != pattern.Parse(value))
    122           return false;
    123         script->add_url_pattern(pattern);
    124       } else if (GetDeclarationValue(line, kExcludeMatchDeclaration, &value)) {
    125         URLPattern exclude(UserScript::ValidUserScriptSchemes());
    126         if (URLPattern::PARSE_SUCCESS != exclude.Parse(value))
    127           return false;
    128         script->add_exclude_url_pattern(exclude);
    129       } else if (GetDeclarationValue(line, kRunAtDeclaration, &value)) {
    130         if (value == kRunAtDocumentStartValue)
    131           script->set_run_location(UserScript::DOCUMENT_START);
    132         else if (value == kRunAtDocumentEndValue)
    133           script->set_run_location(UserScript::DOCUMENT_END);
    134         else if (value == kRunAtDocumentIdleValue)
    135           script->set_run_location(UserScript::DOCUMENT_IDLE);
    136         else
    137           return false;
    138       }
    139 
    140       // TODO(aa): Handle more types of metadata.
    141     }
    142 
    143     line_start = line_end + 1;
    144   }
    145 
    146   // If no patterns were specified, default to @include *. This is what
    147   // Greasemonkey does.
    148   if (script->globs().empty() && script->url_patterns().is_empty())
    149     script->add_glob("*");
    150 
    151   return true;
    152 }
    153 
    154 void UserScriptMaster::ScriptReloader::StartLoad(
    155     const UserScriptList& user_scripts,
    156     const ExtensionsInfo& extensions_info) {
    157   // Add a reference to ourselves to keep ourselves alive while we're running.
    158   // Balanced by NotifyMaster().
    159   AddRef();
    160 
    161   verifier_ = master_->content_verifier();
    162   this->extensions_info_ = extensions_info;
    163   BrowserThread::PostTask(
    164       BrowserThread::FILE, FROM_HERE,
    165       base::Bind(
    166           &UserScriptMaster::ScriptReloader::RunLoad, this, user_scripts));
    167 }
    168 
    169 UserScriptMaster::ScriptReloader::~ScriptReloader() {}
    170 
    171 void UserScriptMaster::ScriptReloader::NotifyMaster(
    172     scoped_ptr<base::SharedMemory> memory) {
    173   // The master could go away
    174   if (master_)
    175     master_->NewScriptsAvailable(memory.Pass());
    176 
    177   // Drop our self-reference.
    178   // Balances StartLoad().
    179   Release();
    180 }
    181 
    182 static void VerifyContent(ContentVerifier* verifier,
    183                           const std::string& extension_id,
    184                           const base::FilePath& extension_root,
    185                           const base::FilePath& relative_path,
    186                           const std::string& content) {
    187   scoped_refptr<ContentVerifyJob> job(
    188       verifier->CreateJobFor(extension_id, extension_root, relative_path));
    189   if (job.get()) {
    190     job->Start();
    191     job->BytesRead(content.size(), content.data());
    192     job->DoneReading();
    193   }
    194 }
    195 
    196 static bool LoadScriptContent(const std::string& extension_id,
    197                               UserScript::File* script_file,
    198                               const SubstitutionMap* localization_messages,
    199                               ContentVerifier* verifier) {
    200   std::string content;
    201   const base::FilePath& path = ExtensionResource::GetFilePath(
    202       script_file->extension_root(), script_file->relative_path(),
    203       ExtensionResource::SYMLINKS_MUST_RESOLVE_WITHIN_ROOT);
    204   if (path.empty()) {
    205     int resource_id;
    206     if (ExtensionsBrowserClient::Get()->GetComponentExtensionResourceManager()->
    207         IsComponentExtensionResource(
    208             script_file->extension_root(), script_file->relative_path(),
    209             &resource_id)) {
    210       const ResourceBundle& rb = ResourceBundle::GetSharedInstance();
    211       content = rb.GetRawDataResource(resource_id).as_string();
    212     } else {
    213       LOG(WARNING) << "Failed to get file path to "
    214                    << script_file->relative_path().value() << " from "
    215                    << script_file->extension_root().value();
    216       return false;
    217     }
    218   } else {
    219     if (!base::ReadFileToString(path, &content)) {
    220       LOG(WARNING) << "Failed to load user script file: " << path.value();
    221       return false;
    222     }
    223     if (verifier) {
    224       VerifyContent(verifier,
    225                     extension_id,
    226                     script_file->extension_root(),
    227                     script_file->relative_path(),
    228                     content);
    229     }
    230   }
    231 
    232   // Localize the content.
    233   if (localization_messages) {
    234     std::string error;
    235     MessageBundle::ReplaceMessagesWithExternalDictionary(
    236         *localization_messages, &content, &error);
    237     if (!error.empty()) {
    238       LOG(WARNING) << "Failed to replace messages in script: " << error;
    239     }
    240   }
    241 
    242   // Remove BOM from the content.
    243   std::string::size_type index = content.find(base::kUtf8ByteOrderMark);
    244   if (index == 0) {
    245     script_file->set_content(content.substr(strlen(base::kUtf8ByteOrderMark)));
    246   } else {
    247     script_file->set_content(content);
    248   }
    249 
    250   return true;
    251 }
    252 
    253 void UserScriptMaster::ScriptReloader::LoadUserScripts(
    254     UserScriptList* user_scripts) {
    255   for (size_t i = 0; i < user_scripts->size(); ++i) {
    256     UserScript& script = user_scripts->at(i);
    257     scoped_ptr<SubstitutionMap> localization_messages(
    258         GetLocalizationMessages(script.extension_id()));
    259     for (size_t k = 0; k < script.js_scripts().size(); ++k) {
    260       UserScript::File& script_file = script.js_scripts()[k];
    261       if (script_file.GetContent().empty())
    262         LoadScriptContent(
    263             script.extension_id(), &script_file, NULL, verifier_.get());
    264     }
    265     for (size_t k = 0; k < script.css_scripts().size(); ++k) {
    266       UserScript::File& script_file = script.css_scripts()[k];
    267       if (script_file.GetContent().empty())
    268         LoadScriptContent(script.extension_id(),
    269                           &script_file,
    270                           localization_messages.get(),
    271                           verifier_.get());
    272     }
    273   }
    274 }
    275 
    276 SubstitutionMap* UserScriptMaster::ScriptReloader::GetLocalizationMessages(
    277     const std::string& extension_id) {
    278   if (extensions_info_.find(extension_id) == extensions_info_.end()) {
    279     return NULL;
    280   }
    281 
    282   return file_util::LoadMessageBundleSubstitutionMap(
    283       extensions_info_[extension_id].first,
    284       extension_id,
    285       extensions_info_[extension_id].second);
    286 }
    287 
    288 // Pickle user scripts and return pointer to the shared memory.
    289 static scoped_ptr<base::SharedMemory> Serialize(const UserScriptList& scripts) {
    290   Pickle pickle;
    291   pickle.WriteUInt64(scripts.size());
    292   for (size_t i = 0; i < scripts.size(); i++) {
    293     const UserScript& script = scripts[i];
    294     // TODO(aa): This can be replaced by sending content script metadata to
    295     // renderers along with other extension data in ExtensionMsg_Loaded.
    296     // See crbug.com/70516.
    297     script.Pickle(&pickle);
    298     // Write scripts as 'data' so that we can read it out in the slave without
    299     // allocating a new string.
    300     for (size_t j = 0; j < script.js_scripts().size(); j++) {
    301       base::StringPiece contents = script.js_scripts()[j].GetContent();
    302       pickle.WriteData(contents.data(), contents.length());
    303     }
    304     for (size_t j = 0; j < script.css_scripts().size(); j++) {
    305       base::StringPiece contents = script.css_scripts()[j].GetContent();
    306       pickle.WriteData(contents.data(), contents.length());
    307     }
    308   }
    309 
    310   // Create the shared memory object.
    311   base::SharedMemory shared_memory;
    312 
    313   base::SharedMemoryCreateOptions options;
    314   options.size = pickle.size();
    315   options.share_read_only = true;
    316   if (!shared_memory.Create(options))
    317     return scoped_ptr<base::SharedMemory>();
    318 
    319   if (!shared_memory.Map(pickle.size()))
    320     return scoped_ptr<base::SharedMemory>();
    321 
    322   // Copy the pickle to shared memory.
    323   memcpy(shared_memory.memory(), pickle.data(), pickle.size());
    324 
    325   base::SharedMemoryHandle readonly_handle;
    326   if (!shared_memory.ShareReadOnlyToProcess(base::GetCurrentProcessHandle(),
    327                                             &readonly_handle))
    328     return scoped_ptr<base::SharedMemory>();
    329 
    330   return make_scoped_ptr(new base::SharedMemory(readonly_handle,
    331                                                 /*read_only=*/true));
    332 }
    333 
    334 // This method will be called on the file thread.
    335 void UserScriptMaster::ScriptReloader::RunLoad(
    336     const UserScriptList& user_scripts) {
    337   LoadUserScripts(const_cast<UserScriptList*>(&user_scripts));
    338 
    339   // Scripts now contains list of up-to-date scripts. Load the content in the
    340   // shared memory and let the master know it's ready. We need to post the task
    341   // back even if no scripts ware found to balance the AddRef/Release calls.
    342   BrowserThread::PostTask(master_thread_id_,
    343                           FROM_HERE,
    344                           base::Bind(&ScriptReloader::NotifyMaster,
    345                                      this,
    346                                      base::Passed(Serialize(user_scripts))));
    347 }
    348 
    349 UserScriptMaster::UserScriptMaster(Profile* profile)
    350     : extensions_service_ready_(false),
    351       pending_load_(false),
    352       profile_(profile),
    353       extension_registry_observer_(this) {
    354   extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
    355   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
    356                  content::Source<Profile>(profile_));
    357   registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CREATED,
    358                  content::NotificationService::AllBrowserContextsAndSources());
    359 }
    360 
    361 UserScriptMaster::~UserScriptMaster() {
    362   if (script_reloader_.get())
    363     script_reloader_->DisownMaster();
    364 }
    365 
    366 void UserScriptMaster::NewScriptsAvailable(
    367     scoped_ptr<base::SharedMemory> handle) {
    368   if (pending_load_) {
    369     // While we were loading, there were further changes.  Don't bother
    370     // notifying about these scripts and instead just immediately reload.
    371     pending_load_ = false;
    372     StartLoad();
    373   } else {
    374     // We're no longer loading.
    375     script_reloader_ = NULL;
    376 
    377     if (handle == NULL) {
    378       // This can happen if we run out of file descriptors.  In that case, we
    379       // have a choice between silently omitting all user scripts for new tabs,
    380       // by nulling out shared_memory_, or only silently omitting new ones by
    381       // leaving the existing object in place. The second seems less bad, even
    382       // though it removes the possibility that freeing the shared memory block
    383       // would open up enough FDs for long enough for a retry to succeed.
    384 
    385       // Pretend the extension change didn't happen.
    386       return;
    387     }
    388 
    389     // We've got scripts ready to go.
    390     shared_memory_ = handle.Pass();
    391 
    392     for (content::RenderProcessHost::iterator i(
    393             content::RenderProcessHost::AllHostsIterator());
    394          !i.IsAtEnd(); i.Advance()) {
    395       SendUpdate(i.GetCurrentValue(),
    396                  shared_memory_.get(),
    397                  changed_extensions_);
    398     }
    399     changed_extensions_.clear();
    400 
    401     content::NotificationService::current()->Notify(
    402         chrome::NOTIFICATION_USER_SCRIPTS_UPDATED,
    403         content::Source<Profile>(profile_),
    404         content::Details<base::SharedMemory>(shared_memory_.get()));
    405   }
    406 }
    407 
    408 ContentVerifier* UserScriptMaster::content_verifier() {
    409   ExtensionSystem* system = ExtensionSystem::Get(profile_);
    410   return system->content_verifier();
    411 }
    412 
    413 void UserScriptMaster::OnExtensionLoaded(
    414     content::BrowserContext* browser_context,
    415     const Extension* extension) {
    416   // Add any content scripts inside the extension.
    417   extensions_info_[extension->id()] =
    418       ExtensionSet::ExtensionPathAndDefaultLocale(
    419           extension->path(), LocaleInfo::GetDefaultLocale(extension));
    420   bool incognito_enabled = util::IsIncognitoEnabled(extension->id(), profile_);
    421   const UserScriptList& scripts =
    422       ContentScriptsInfo::GetContentScripts(extension);
    423   for (UserScriptList::const_iterator iter = scripts.begin();
    424        iter != scripts.end();
    425        ++iter) {
    426     user_scripts_.push_back(*iter);
    427     user_scripts_.back().set_incognito_enabled(incognito_enabled);
    428   }
    429   if (extensions_service_ready_) {
    430     changed_extensions_.insert(extension->id());
    431     if (script_reloader_.get()) {
    432       pending_load_ = true;
    433     } else {
    434       StartLoad();
    435     }
    436   }
    437 }
    438 
    439 void UserScriptMaster::OnExtensionUnloaded(
    440     content::BrowserContext* browser_context,
    441     const Extension* extension,
    442     UnloadedExtensionInfo::Reason reason) {
    443   // Remove any content scripts.
    444   extensions_info_.erase(extension->id());
    445   UserScriptList new_user_scripts;
    446   for (UserScriptList::iterator iter = user_scripts_.begin();
    447        iter != user_scripts_.end();
    448        ++iter) {
    449     if (iter->extension_id() != extension->id())
    450       new_user_scripts.push_back(*iter);
    451   }
    452   user_scripts_ = new_user_scripts;
    453   changed_extensions_.insert(extension->id());
    454   if (script_reloader_.get()) {
    455     pending_load_ = true;
    456   } else {
    457     StartLoad();
    458   }
    459 }
    460 
    461 void UserScriptMaster::Observe(int type,
    462                                const content::NotificationSource& source,
    463                                const content::NotificationDetails& details) {
    464   bool should_start_load = false;
    465   switch (type) {
    466     case chrome::NOTIFICATION_EXTENSIONS_READY:
    467       extensions_service_ready_ = true;
    468       should_start_load = true;
    469       break;
    470     case content::NOTIFICATION_RENDERER_PROCESS_CREATED: {
    471       content::RenderProcessHost* process =
    472           content::Source<content::RenderProcessHost>(source).ptr();
    473       Profile* profile = Profile::FromBrowserContext(
    474           process->GetBrowserContext());
    475       if (!profile_->IsSameProfile(profile))
    476         return;
    477       if (ScriptsReady()) {
    478         SendUpdate(process,
    479                    GetSharedMemory(),
    480                    std::set<std::string>());  // Include all extensions.
    481       }
    482       break;
    483     }
    484     default:
    485       DCHECK(false);
    486   }
    487 
    488   if (should_start_load) {
    489     if (script_reloader_.get()) {
    490       pending_load_ = true;
    491     } else {
    492       StartLoad();
    493     }
    494   }
    495 }
    496 
    497 void UserScriptMaster::StartLoad() {
    498   if (!script_reloader_.get())
    499     script_reloader_ = new ScriptReloader(this);
    500 
    501   script_reloader_->StartLoad(user_scripts_, extensions_info_);
    502 }
    503 
    504 void UserScriptMaster::SendUpdate(
    505     content::RenderProcessHost* process,
    506     base::SharedMemory* shared_memory,
    507     const std::set<std::string>& changed_extensions) {
    508   // Don't allow injection of content scripts into <webview>.
    509   if (process->IsIsolatedGuest())
    510     return;
    511 
    512   Profile* profile = Profile::FromBrowserContext(process->GetBrowserContext());
    513   // Make sure we only send user scripts to processes in our profile.
    514   if (!profile_->IsSameProfile(profile))
    515     return;
    516 
    517   // If the process is being started asynchronously, early return.  We'll end up
    518   // calling InitUserScripts when it's created which will call this again.
    519   base::ProcessHandle handle = process->GetHandle();
    520   if (!handle)
    521     return;
    522 
    523   base::SharedMemoryHandle handle_for_process;
    524   if (!shared_memory->ShareToProcess(handle, &handle_for_process))
    525     return;  // This can legitimately fail if the renderer asserts at startup.
    526 
    527   if (base::SharedMemory::IsHandleValid(handle_for_process)) {
    528     process->Send(new ExtensionMsg_UpdateUserScripts(handle_for_process,
    529                                                      changed_extensions));
    530   }
    531 }
    532 
    533 }  // namespace extensions
    534