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// Copyright (c) 2012 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 "content/renderer/plugin_channel_host.h"
#include "base/metrics/histogram.h"
#include "base/time.h"
#include "content/common/child_process.h"
#include "content/common/npobject_base.h"
#include "content/common/plugin_messages.h"
#if defined(OS_POSIX)
#include "ipc/ipc_channel_posix.h"
#endif
#include "third_party/WebKit/Source/WebKit/chromium/public/WebBindings.h"
// TODO(shess): Debugging for http://crbug.com/97285
//
// The hypothesis at #55 requires that RemoveRoute() be called between
// sending ViewHostMsg_OpenChannelToPlugin to the browser, and calling
// GetPluginChannelHost() on the result. This code detects that case
// and stores the backtrace of the RemoveRoute() in a breakpad key.
// The specific RemoveRoute() is not tracked (there could be multiple,
// and which is the one can't be known until the open completes), but
// the backtrace from any such nested call should be sufficient to
// drive a repro.
#if defined(OS_MACOSX)
#include "base/debug/crash_logging.h"
#include "base/debug/stack_trace.h"
#include "base/strings/sys_string_conversions.h"
namespace {
// Breakpad key for the RemoveRoute() backtrace.
const char* kRemoveRouteTraceKey = "remove_route_bt";
// Breakpad key for the OnChannelError() backtrace.
const char* kChannelErrorTraceKey = "channel_error_bt";
// GetRemoveTrackingFlag() exposes this so that
// WebPluginDelegateProxy::Initialize() can do scoped set/reset. When
// true, RemoveRoute() knows WBDP::Initialize() is on the stack, and
// records the backtrace.
bool remove_tracking = false;
} // namespace
#endif
namespace content {
// A simple MessageFilter that will ignore all messages and respond to sync
// messages with an error when is_listening_ is false.
class IsListeningFilter : public IPC::ChannelProxy::MessageFilter {
public:
IsListeningFilter() : channel_(NULL) {}
// MessageFilter overrides
virtual void OnFilterRemoved() OVERRIDE {}
virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE {
channel_ = channel;
}
virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
static bool is_listening_;
protected:
virtual ~IsListeningFilter() {}
private:
IPC::Channel* channel_;
DISALLOW_COPY_AND_ASSIGN(IsListeningFilter);
};
bool IsListeningFilter::OnMessageReceived(const IPC::Message& message) {
if (IsListeningFilter::is_listening_) {
// Proceed with normal operation.
return false;
}
// Always process message reply to prevent renderer from hanging on sync
// messages.
if (message.is_reply() || message.is_reply_error()) {
return false;
}
// Reply to synchronous messages with an error (so they don't block while
// we're not listening).
if (message.is_sync()) {
IPC::Message* reply = IPC::SyncMessage::GenerateReply(&message);
reply->set_reply_error();
channel_->Send(reply);
}
return true;
}
// static
bool IsListeningFilter::is_listening_ = true;
// static
bool PluginChannelHost::IsListening() {
return IsListeningFilter::is_listening_;
}
// static
void PluginChannelHost::SetListening(bool flag) {
IsListeningFilter::is_listening_ = flag;
}
#if defined(OS_MACOSX)
// static
bool* PluginChannelHost::GetRemoveTrackingFlag() {
return &remove_tracking;
}
#endif
// static
PluginChannelHost* PluginChannelHost::GetPluginChannelHost(
const IPC::ChannelHandle& channel_handle,
base::MessageLoopProxy* ipc_message_loop) {
PluginChannelHost* result =
static_cast<PluginChannelHost*>(NPChannelBase::GetChannel(
channel_handle,
IPC::Channel::MODE_CLIENT,
ClassFactory,
ipc_message_loop,
true,
ChildProcess::current()->GetShutDownEvent()));
return result;
}
PluginChannelHost::PluginChannelHost() : expecting_shutdown_(false) {
}
PluginChannelHost::~PluginChannelHost() {
}
bool PluginChannelHost::Init(base::MessageLoopProxy* ipc_message_loop,
bool create_pipe_now,
base::WaitableEvent* shutdown_event) {
bool ret =
NPChannelBase::Init(ipc_message_loop, create_pipe_now, shutdown_event);
if (ret) {
is_listening_filter_ = new IsListeningFilter;
channel_->AddFilter(is_listening_filter_);
}
return ret;
}
int PluginChannelHost::GenerateRouteID() {
int route_id = MSG_ROUTING_NONE;
Send(new PluginMsg_GenerateRouteID(&route_id));
return route_id;
}
void PluginChannelHost::AddRoute(int route_id,
IPC::Listener* listener,
NPObjectBase* npobject) {
NPChannelBase::AddRoute(route_id, listener, npobject);
if (!npobject)
proxies_[route_id] = listener;
}
void PluginChannelHost::RemoveRoute(int route_id) {
#if defined(OS_MACOSX)
if (remove_tracking) {
base::debug::StackTrace trace;
size_t count = 0;
const void* const* addresses = trace.Addresses(&count);
base::debug::SetCrashKeyFromAddresses(
kRemoveRouteTraceKey, addresses, count);
}
#endif
proxies_.erase(route_id);
NPChannelBase::RemoveRoute(route_id);
}
bool PluginChannelHost::OnControlMessageReceived(const IPC::Message& message) {
bool handled = true;
IPC_BEGIN_MESSAGE_MAP(PluginChannelHost, message)
IPC_MESSAGE_HANDLER(PluginHostMsg_SetException, OnSetException)
IPC_MESSAGE_HANDLER(PluginHostMsg_PluginShuttingDown, OnPluginShuttingDown)
IPC_MESSAGE_UNHANDLED(handled = false)
IPC_END_MESSAGE_MAP()
DCHECK(handled);
return handled;
}
void PluginChannelHost::OnSetException(const std::string& message) {
WebKit::WebBindings::setException(NULL, message.c_str());
}
void PluginChannelHost::OnPluginShuttingDown() {
expecting_shutdown_ = true;
}
bool PluginChannelHost::Send(IPC::Message* msg) {
if (msg->is_sync()) {
base::TimeTicks start_time(base::TimeTicks::Now());
bool result = NPChannelBase::Send(msg);
UMA_HISTOGRAM_TIMES("Plugin.SyncMessageTime",
base::TimeTicks::Now() - start_time);
return result;
}
return NPChannelBase::Send(msg);
}
void PluginChannelHost::OnChannelError() {
#if defined(OS_MACOSX)
if (remove_tracking) {
base::debug::StackTrace trace;
size_t count = 0;
const void* const* addresses = trace.Addresses(&count);
base::debug::SetCrashKeyFromAddresses(
kChannelErrorTraceKey, addresses, count);
}
#endif
NPChannelBase::OnChannelError();
for (ProxyMap::iterator iter = proxies_.begin();
iter != proxies_.end(); iter++) {
iter->second->OnChannelError();
}
proxies_.clear();
}
} // namespace content
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