| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "extensions/renderer/event_bindings.h" |
| |
| #include <stdint.h> |
| |
| #include <map> |
| #include <memory> |
| #include <utility> |
| |
| #include "base/bind.h" |
| #include "base/lazy_instance.h" |
| #include "base/memory/ptr_util.h" |
| #include "components/crx_file/id_util.h" |
| #include "content/public/child/v8_value_converter.h" |
| #include "content/public/renderer/render_frame.h" |
| #include "content/public/renderer/render_thread.h" |
| #include "content/public/renderer/render_view.h" |
| #include "extensions/common/event_filter.h" |
| #include "extensions/common/extension.h" |
| #include "extensions/common/extension_messages.h" |
| #include "extensions/common/value_counter.h" |
| #include "extensions/renderer/extension_frame_helper.h" |
| #include "extensions/renderer/script_context.h" |
| #include "url/gurl.h" |
| |
| namespace extensions { |
| |
| namespace { |
| |
| // A map of event names to the number of contexts listening to that event. |
| // We notify the browser about event listeners when we transition between 0 |
| // and 1. |
| typedef std::map<std::string, int> EventListenerCounts; |
| |
| // A map of extension IDs to listener counts for that extension. |
| base::LazyInstance<std::map<std::string, EventListenerCounts>> |
| g_listener_counts = LAZY_INSTANCE_INITIALIZER; |
| |
| // A map of (extension ID, event name) pairs to the filtered listener counts |
| // for that pair. The map is used to keep track of which filters are in effect |
| // for which events. We notify the browser about filtered event listeners when |
| // we transition between 0 and 1. |
| using FilteredEventListenerKey = std::pair<std::string, std::string>; |
| using FilteredEventListenerCounts = |
| std::map<FilteredEventListenerKey, std::unique_ptr<ValueCounter>>; |
| base::LazyInstance<FilteredEventListenerCounts> g_filtered_listener_counts = |
| LAZY_INSTANCE_INITIALIZER; |
| |
| base::LazyInstance<EventFilter> g_event_filter = LAZY_INSTANCE_INITIALIZER; |
| |
| // Gets a unique string key identifier for a ScriptContext. |
| // TODO(kalman): Just use pointer equality...? |
| std::string GetKeyForScriptContext(ScriptContext* script_context) { |
| const std::string& extension_id = script_context->GetExtensionID(); |
| CHECK(crx_file::id_util::IdIsValid(extension_id) || |
| script_context->url().is_valid()); |
| return crx_file::id_util::IdIsValid(extension_id) |
| ? extension_id |
| : script_context->url().spec(); |
| } |
| |
| // Increments the number of event-listeners for the given |event_name| and |
| // ScriptContext. Returns the count after the increment. |
| int IncrementEventListenerCount(ScriptContext* script_context, |
| const std::string& event_name) { |
| return ++g_listener_counts |
| .Get()[GetKeyForScriptContext(script_context)][event_name]; |
| } |
| |
| // Decrements the number of event-listeners for the given |event_name| and |
| // ScriptContext. Returns the count after the increment. |
| int DecrementEventListenerCount(ScriptContext* script_context, |
| const std::string& event_name) { |
| return --g_listener_counts |
| .Get()[GetKeyForScriptContext(script_context)][event_name]; |
| } |
| |
| EventFilteringInfo ParseFromObject(v8::Local<v8::Object> object, |
| v8::Isolate* isolate) { |
| EventFilteringInfo info; |
| v8::Local<v8::String> url(v8::String::NewFromUtf8(isolate, "url")); |
| if (object->Has(url)) { |
| v8::Local<v8::Value> url_value(object->Get(url)); |
| info.SetURL(GURL(*v8::String::Utf8Value(url_value))); |
| } |
| v8::Local<v8::String> instance_id( |
| v8::String::NewFromUtf8(isolate, "instanceId")); |
| if (object->Has(instance_id)) { |
| v8::Local<v8::Value> instance_id_value(object->Get(instance_id)); |
| info.SetInstanceID(instance_id_value->IntegerValue()); |
| } |
| v8::Local<v8::String> service_type( |
| v8::String::NewFromUtf8(isolate, "serviceType")); |
| if (object->Has(service_type)) { |
| v8::Local<v8::Value> service_type_value(object->Get(service_type)); |
| info.SetServiceType(*v8::String::Utf8Value(service_type_value)); |
| } |
| v8::Local<v8::String> window_types( |
| v8::String::NewFromUtf8(isolate, "windowType")); |
| if (object->Has(window_types)) { |
| v8::Local<v8::Value> window_types_value(object->Get(window_types)); |
| info.SetWindowType(*v8::String::Utf8Value(window_types_value)); |
| } |
| |
| v8::Local<v8::String> window_exposed( |
| v8::String::NewFromUtf8(isolate, "windowExposedByDefault")); |
| if (object->Has(window_exposed)) { |
| v8::Local<v8::Value> window_exposed_value(object->Get(window_exposed)); |
| info.SetWindowExposedByDefault( |
| window_exposed_value.As<v8::Boolean>()->Value()); |
| } |
| |
| return info; |
| } |
| |
| // Add a filter to |event_name| in |extension_id|, returning true if it |
| // was the first filter for that event in that extension. |
| bool AddFilter(const std::string& event_name, |
| const std::string& extension_id, |
| const base::DictionaryValue& filter) { |
| FilteredEventListenerKey key(extension_id, event_name); |
| FilteredEventListenerCounts& all_counts = g_filtered_listener_counts.Get(); |
| FilteredEventListenerCounts::const_iterator counts = all_counts.find(key); |
| if (counts == all_counts.end()) { |
| counts = |
| all_counts |
| .insert(std::make_pair(key, base::WrapUnique(new ValueCounter()))) |
| .first; |
| } |
| return counts->second->Add(filter); |
| } |
| |
| // Remove a filter from |event_name| in |extension_id|, returning true if it |
| // was the last filter for that event in that extension. |
| bool RemoveFilter(const std::string& event_name, |
| const std::string& extension_id, |
| base::DictionaryValue* filter) { |
| FilteredEventListenerKey key(extension_id, event_name); |
| FilteredEventListenerCounts& all_counts = g_filtered_listener_counts.Get(); |
| FilteredEventListenerCounts::const_iterator counts = all_counts.find(key); |
| if (counts == all_counts.end()) |
| return false; |
| // Note: Remove() returns true if it removed the last filter equivalent to |
| // |filter|. If there are more equivalent filters, or if there weren't any in |
| // the first place, it returns false. |
| if (counts->second->Remove(*filter)) { |
| if (counts->second->is_empty()) |
| all_counts.erase(counts); // Clean up if there are no more filters. |
| return true; |
| } |
| return false; |
| } |
| |
| } // namespace |
| |
| EventBindings::EventBindings(ScriptContext* context) |
| : ObjectBackedNativeHandler(context) { |
| RouteFunction("AttachEvent", base::Bind(&EventBindings::AttachEventHandler, |
| base::Unretained(this))); |
| RouteFunction("DetachEvent", base::Bind(&EventBindings::DetachEventHandler, |
| base::Unretained(this))); |
| RouteFunction( |
| "AttachFilteredEvent", |
| base::Bind(&EventBindings::AttachFilteredEvent, base::Unretained(this))); |
| RouteFunction("DetachFilteredEvent", |
| base::Bind(&EventBindings::DetachFilteredEventHandler, |
| base::Unretained(this))); |
| RouteFunction("MatchAgainstEventFilter", |
| base::Bind(&EventBindings::MatchAgainstEventFilter, |
| base::Unretained(this))); |
| |
| // It's safe to use base::Unretained here because |context| will always |
| // outlive us. |
| context->AddInvalidationObserver( |
| base::Bind(&EventBindings::OnInvalidated, base::Unretained(this))); |
| } |
| |
| EventBindings::~EventBindings() {} |
| |
| void EventBindings::AttachEventHandler( |
| const v8::FunctionCallbackInfo<v8::Value>& args) { |
| CHECK_EQ(1, args.Length()); |
| CHECK(args[0]->IsString()); |
| AttachEvent(*v8::String::Utf8Value(args[0])); |
| } |
| |
| void EventBindings::AttachEvent(const std::string& event_name) { |
| if (!context()->HasAccessOrThrowError(event_name)) |
| return; |
| |
| // Record the attachment for this context so that events can be detached when |
| // the context is destroyed. |
| // |
| // Ideally we'd CHECK that it's not already attached, however that's not |
| // possible because extensions can create and attach events themselves. Very |
| // silly, but that's the way it is. For an example of this, see |
| // chrome/test/data/extensions/api_test/events/background.js. |
| attached_event_names_.insert(event_name); |
| |
| const std::string& extension_id = context()->GetExtensionID(); |
| if (IncrementEventListenerCount(context(), event_name) == 1) { |
| content::RenderThread::Get()->Send(new ExtensionHostMsg_AddListener( |
| extension_id, context()->url(), event_name)); |
| } |
| |
| // This is called the first time the page has added a listener. Since |
| // the background page is the only lazy page, we know this is the first |
| // time this listener has been registered. |
| if (ExtensionFrameHelper::IsContextForEventPage(context())) { |
| content::RenderThread::Get()->Send( |
| new ExtensionHostMsg_AddLazyListener(extension_id, event_name)); |
| } |
| } |
| |
| void EventBindings::DetachEventHandler( |
| const v8::FunctionCallbackInfo<v8::Value>& args) { |
| CHECK_EQ(2, args.Length()); |
| CHECK(args[0]->IsString()); |
| CHECK(args[1]->IsBoolean()); |
| DetachEvent(*v8::String::Utf8Value(args[0]), args[1]->BooleanValue()); |
| } |
| |
| void EventBindings::DetachEvent(const std::string& event_name, bool is_manual) { |
| // See comment in AttachEvent(). |
| attached_event_names_.erase(event_name); |
| |
| const std::string& extension_id = context()->GetExtensionID(); |
| |
| if (DecrementEventListenerCount(context(), event_name) == 0) { |
| content::RenderThread::Get()->Send(new ExtensionHostMsg_RemoveListener( |
| extension_id, context()->url(), event_name)); |
| } |
| |
| // DetachEvent is called when the last listener for the context is |
| // removed. If the context is the background page, and it removes the |
| // last listener manually, then we assume that it is no longer interested |
| // in being awakened for this event. |
| if (is_manual && ExtensionFrameHelper::IsContextForEventPage(context())) { |
| content::RenderThread::Get()->Send( |
| new ExtensionHostMsg_RemoveLazyListener(extension_id, event_name)); |
| } |
| } |
| |
| // MatcherID AttachFilteredEvent(string event_name, object filter) |
| // event_name - Name of the event to attach. |
| // filter - Which instances of the named event are we interested in. |
| // returns the id assigned to the listener, which will be returned from calls |
| // to MatchAgainstEventFilter where this listener matches. |
| void EventBindings::AttachFilteredEvent( |
| const v8::FunctionCallbackInfo<v8::Value>& args) { |
| CHECK_EQ(2, args.Length()); |
| CHECK(args[0]->IsString()); |
| CHECK(args[1]->IsObject()); |
| |
| std::string event_name = *v8::String::Utf8Value(args[0]); |
| if (!context()->HasAccessOrThrowError(event_name)) |
| return; |
| |
| std::unique_ptr<base::DictionaryValue> filter; |
| { |
| std::unique_ptr<content::V8ValueConverter> converter( |
| content::V8ValueConverter::create()); |
| std::unique_ptr<base::Value> filter_value(converter->FromV8Value( |
| v8::Local<v8::Object>::Cast(args[1]), context()->v8_context())); |
| if (!filter_value || !filter_value->IsType(base::Value::TYPE_DICTIONARY)) { |
| args.GetReturnValue().Set(static_cast<int32_t>(-1)); |
| return; |
| } |
| filter = base::DictionaryValue::From(std::move(filter_value)); |
| } |
| |
| int id = g_event_filter.Get().AddEventMatcher( |
| event_name, ParseEventMatcher(std::move(filter))); |
| if (id == -1) { |
| args.GetReturnValue().Set(static_cast<int32_t>(-1)); |
| return; |
| } |
| attached_matcher_ids_.insert(id); |
| |
| // Only send IPCs the first time a filter gets added. |
| const EventMatcher* matcher = g_event_filter.Get().GetEventMatcher(id); |
| DCHECK(matcher); |
| base::DictionaryValue* filter_weak = matcher->value(); |
| std::string extension_id = context()->GetExtensionID(); |
| if (AddFilter(event_name, extension_id, *filter_weak)) { |
| bool lazy = ExtensionFrameHelper::IsContextForEventPage(context()); |
| content::RenderThread::Get()->Send(new ExtensionHostMsg_AddFilteredListener( |
| extension_id, event_name, *filter_weak, lazy)); |
| } |
| |
| args.GetReturnValue().Set(static_cast<int32_t>(id)); |
| } |
| |
| void EventBindings::DetachFilteredEventHandler( |
| const v8::FunctionCallbackInfo<v8::Value>& args) { |
| CHECK_EQ(2, args.Length()); |
| CHECK(args[0]->IsInt32()); |
| CHECK(args[1]->IsBoolean()); |
| DetachFilteredEvent(args[0]->Int32Value(), args[1]->BooleanValue()); |
| } |
| |
| void EventBindings::DetachFilteredEvent(int matcher_id, bool is_manual) { |
| EventFilter& event_filter = g_event_filter.Get(); |
| EventMatcher* event_matcher = event_filter.GetEventMatcher(matcher_id); |
| |
| const std::string& event_name = event_filter.GetEventName(matcher_id); |
| |
| // Only send IPCs the last time a filter gets removed. |
| std::string extension_id = context()->GetExtensionID(); |
| if (RemoveFilter(event_name, extension_id, event_matcher->value())) { |
| bool remove_lazy = |
| is_manual && ExtensionFrameHelper::IsContextForEventPage(context()); |
| content::RenderThread::Get()->Send( |
| new ExtensionHostMsg_RemoveFilteredListener( |
| extension_id, event_name, *event_matcher->value(), remove_lazy)); |
| } |
| |
| event_filter.RemoveEventMatcher(matcher_id); |
| attached_matcher_ids_.erase(matcher_id); |
| } |
| |
| void EventBindings::MatchAgainstEventFilter( |
| const v8::FunctionCallbackInfo<v8::Value>& args) { |
| v8::Isolate* isolate = args.GetIsolate(); |
| typedef std::set<EventFilter::MatcherID> MatcherIDs; |
| EventFilter& event_filter = g_event_filter.Get(); |
| std::string event_name = *v8::String::Utf8Value(args[0]); |
| EventFilteringInfo info = |
| ParseFromObject(args[1]->ToObject(isolate), isolate); |
| // Only match events routed to this context's RenderFrame or ones that don't |
| // have a routingId in their filter. |
| MatcherIDs matched_event_filters = event_filter.MatchEvent( |
| event_name, info, context()->GetRenderFrame()->GetRoutingID()); |
| v8::Local<v8::Array> array( |
| v8::Array::New(isolate, matched_event_filters.size())); |
| int i = 0; |
| for (MatcherIDs::iterator it = matched_event_filters.begin(); |
| it != matched_event_filters.end(); |
| ++it) { |
| array->Set(v8::Integer::New(isolate, i++), v8::Integer::New(isolate, *it)); |
| } |
| args.GetReturnValue().Set(array); |
| } |
| |
| std::unique_ptr<EventMatcher> EventBindings::ParseEventMatcher( |
| std::unique_ptr<base::DictionaryValue> filter) { |
| return base::WrapUnique(new EventMatcher( |
| std::move(filter), context()->GetRenderFrame()->GetRoutingID())); |
| } |
| |
| void EventBindings::OnInvalidated() { |
| // Detach all attached events that weren't attached. Iterate over a copy |
| // because it will be mutated. |
| std::set<std::string> attached_event_names_safe = attached_event_names_; |
| for (const std::string& event_name : attached_event_names_safe) { |
| DetachEvent(event_name, false /* is_manual */); |
| } |
| DCHECK(attached_event_names_.empty()) |
| << "Events cannot be attached during invalidation"; |
| |
| // Same for filtered events. |
| std::set<int> attached_matcher_ids_safe = attached_matcher_ids_; |
| for (int matcher_id : attached_matcher_ids_safe) { |
| DetachFilteredEvent(matcher_id, false /* is_manual */); |
| } |
| DCHECK(attached_matcher_ids_.empty()) |
| << "Filtered events cannot be attached during invalidation"; |
| } |
| |
| } // namespace extensions |