src/extensions/renderer/user_script_injector.cc

   1 // Copyright 2014 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 "extensions/renderer/user_script_injector.h"
   6
   7 #include <vector>
   8
   9 #include "base/lazy_instance.h"
  10 #include "content/public/common/url_constants.h"
  11 #include "extensions/common/extension.h"
  12 #include "extensions/common/permissions/permissions_data.h"
  13 #include "extensions/renderer/script_context.h"
  14 #include "extensions/renderer/scripts_run_info.h"
  15 #include "grit/extensions_renderer_resources.h"
  16 #include "third_party/WebKit/public/web/WebDocument.h"
  17 #include "third_party/WebKit/public/web/WebFrame.h"
  18 #include "third_party/WebKit/public/web/WebScriptSource.h"
  19 #include "ui/base/resource/resource_bundle.h"
  20 #include "url/gurl.h"
  21
  22 namespace extensions {
  23
  24 namespace {
  25
  26 // These two strings are injected before and after the Greasemonkey API and
  27 // user script to wrap it in an anonymous scope.
  28 const char kUserScriptHead[] = "(function (unsafeWindow) {\n";
  29 const char kUserScriptTail[] = "\n})(window);";
  30
  31 // Greasemonkey API source that is injected with the scripts.
  32 struct GreasemonkeyApiJsString {
  33   GreasemonkeyApiJsString();
  34   blink::WebScriptSource GetSource() const;
  35
  36  private:
  37   std::string source_;
  38 };
  39
  40 // The below constructor, monstrous as it is, just makes a WebScriptSource from
  41 // the GreasemonkeyApiJs resource.
  42 GreasemonkeyApiJsString::GreasemonkeyApiJsString()
  43     : source_(ResourceBundle::GetSharedInstance()
  44                   .GetRawDataResource(IDR_GREASEMONKEY_API_JS)
  45                   .as_string()) {
  46 }
  47
  48 blink::WebScriptSource GreasemonkeyApiJsString::GetSource() const {
  49   return blink::WebScriptSource(blink::WebString::fromUTF8(source_));
  50 }
  51
  52 base::LazyInstance<GreasemonkeyApiJsString> g_greasemonkey_api =
  53     LAZY_INSTANCE_INITIALIZER;
  54
  55 }  // namespace
  56
  57 UserScriptInjector::UserScriptInjector(
  58     const UserScript* script,
  59     UserScriptSet* script_list,
  60     bool is_declarative)
  61     : script_(script),
  62       script_id_(script_->id()),
  63       extension_id_(script_->extension_id()),
  64       is_declarative_(is_declarative),
  65       user_script_set_observer_(this) {
  66   user_script_set_observer_.Add(script_list);
  67 }
  68
  69 UserScriptInjector::~UserScriptInjector() {
  70 }
  71
  72 void UserScriptInjector::OnUserScriptsUpdated(
  73     const std::set<std::string>& changed_extensions,
  74     const std::vector<UserScript*>& scripts) {
  75   // If the extension causing this injection changed, then this injection
  76   // will be removed, and there's no guarantee the backing script still exists.
  77   if (changed_extensions.count(extension_id_) > 0)
  78     return;
  79
  80   for (std::vector<UserScript*>::const_iterator iter = scripts.begin();
  81        iter != scripts.end();
  82        ++iter) {
  83     // We need to compare to |script_id_| (and not to script_->id()) because the
  84     // old |script_| may be deleted by now.
  85     if ((*iter)->id() == script_id_) {
  86       script_ = *iter;
  87       break;
  88     }
  89   }
  90 }
  91
  92 UserScript::InjectionType UserScriptInjector::script_type() const {
  93   return UserScript::CONTENT_SCRIPT;
  94 }
  95
  96 bool UserScriptInjector::ShouldExecuteInChildFrames() const {
  97   return false;
  98 }
  99
 100 bool UserScriptInjector::ShouldExecuteInMainWorld() const {
 101   return false;
 102 }
 103
 104 bool UserScriptInjector::IsUserGesture() const {
 105   return false;
 106 }
 107
 108 bool UserScriptInjector::ExpectsResults() const {
 109   return false;
 110 }
 111
 112 bool UserScriptInjector::ShouldInjectJs(
 113     UserScript::RunLocation run_location) const {
 114   return script_->run_location() == run_location &&
 115          !script_->js_scripts().empty();
 116 }
 117
 118 bool UserScriptInjector::ShouldInjectCss(
 119     UserScript::RunLocation run_location) const {
 120   return run_location == UserScript::DOCUMENT_START &&
 121          !script_->css_scripts().empty();
 122 }
 123
 124 PermissionsData::AccessType UserScriptInjector::CanExecuteOnFrame(
 125     const Extension* extension,
 126     blink::WebFrame* web_frame,
 127     int tab_id,
 128     const GURL& top_url) const {
 129   // If we don't have a tab id, we have no UI surface to ask for user consent.
 130   // For now, we treat this as an automatic allow.
 131   if (tab_id == -1)
 132     return PermissionsData::ACCESS_ALLOWED;
 133
 134   GURL effective_document_url = ScriptContext::GetEffectiveDocumentURL(
 135       web_frame, web_frame->document().url(), script_->match_about_blank());
 136
 137   // Declarative user scripts use "page access" (from "permissions" section in
 138   // manifest) whereas non-declarative user scripts use custom
 139   // "content script access" logic.
 140   if (is_declarative_) {
 141     return extension->permissions_data()->GetPageAccess(
 142         extension,
 143         effective_document_url,
 144         top_url,
 145         tab_id,
 146         -1,  // no process id
 147         NULL /* ignore error */);
 148   } else {
 149     return extension->permissions_data()->GetContentScriptAccess(
 150         extension,
 151         effective_document_url,
 152         top_url,
 153         tab_id,
 154         -1,  // no process id
 155         NULL /* ignore error */);
 156   }
 157 }
 158
 159 std::vector<blink::WebScriptSource> UserScriptInjector::GetJsSources(
 160     UserScript::RunLocation run_location) const {
 161   DCHECK_EQ(script_->run_location(), run_location);
 162
 163   std::vector<blink::WebScriptSource> sources;
 164   const UserScript::FileList& js_scripts = script_->js_scripts();
 165   bool is_standalone_or_emulate_greasemonkey =
 166       script_->is_standalone() || script_->emulate_greasemonkey();
 167
 168   for (UserScript::FileList::const_iterator iter = js_scripts.begin();
 169        iter != js_scripts.end();
 170        ++iter) {
 171     std::string content = iter->GetContent().as_string();
 172
 173     // We add this dumb function wrapper for standalone user script to
 174     // emulate what Greasemonkey does.
 175     // TODO(aa): I think that maybe "is_standalone" scripts don't exist
 176     // anymore. Investigate.
 177     if (is_standalone_or_emulate_greasemonkey) {
 178       content.insert(0, kUserScriptHead);
 179       content += kUserScriptTail;
 180     }
 181     sources.push_back(blink::WebScriptSource(
 182         blink::WebString::fromUTF8(content), iter->url()));
 183   }
 184
 185   // Emulate Greasemonkey API for scripts that were converted to extensions
 186   // and "standalone" user scripts.
 187   if (is_standalone_or_emulate_greasemonkey)
 188     sources.insert(sources.begin(), g_greasemonkey_api.Get().GetSource());
 189
 190   return sources;
 191 }
 192
 193 std::vector<std::string> UserScriptInjector::GetCssSources(
 194     UserScript::RunLocation run_location) const {
 195   DCHECK_EQ(UserScript::DOCUMENT_START, run_location);
 196
 197   std::vector<std::string> sources;
 198   const UserScript::FileList& css_scripts = script_->css_scripts();
 199   for (UserScript::FileList::const_iterator iter = css_scripts.begin();
 200        iter != css_scripts.end();
 201        ++iter) {
 202     sources.push_back(iter->GetContent().as_string());
 203   }
 204   return sources;
 205 }
 206
 207 void UserScriptInjector::OnInjectionComplete(
 208     scoped_ptr<base::ListValue> execution_results,
 209     ScriptsRunInfo* scripts_run_info,
 210     UserScript::RunLocation run_location) {
 211   if (ShouldInjectJs(run_location)) {
 212     const UserScript::FileList& js_scripts = script_->js_scripts();
 213     scripts_run_info->num_js += js_scripts.size();
 214     for (UserScript::FileList::const_iterator iter = js_scripts.begin();
 215          iter != js_scripts.end();
 216          ++iter) {
 217       scripts_run_info->executing_scripts[extension_id_].insert(
 218           iter->url().path());
 219     }
 220   }
 221
 222   if (ShouldInjectCss(run_location))
 223     scripts_run_info->num_css += script_->css_scripts().size();
 224 }
 225
 226 void UserScriptInjector::OnWillNotInject(InjectFailureReason reason) {
 227 }
 228
 229 }  // namespace extensions