ppapi/proxy/handle_converter.cc - platform/external/chromium_org - Git at Google

 // Copyright (c) 2013 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 "ppapi/proxy/handle_converter.h"

 #include <vector>
 #include "base/bind.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_message_macros.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_message_params.h"
 #include "ppapi/proxy/serialized_handle.h"
 #include "ppapi/proxy/serialized_var.h"

 class NaClDescImcShm;

 namespace IPC {
 class Message;
 }

 namespace {

 void WriteHandle(int handle_index,
                  const ppapi::proxy::SerializedHandle& handle,
                  IPC::Message* message) {
   ppapi::proxy::SerializedHandle::WriteHeader(handle.header(), message);

   // Now write the handle itself in POSIX style.
   message->WriteBool(true);  // valid == true
   message->WriteInt(handle_index);
 }

 typedef std::vector<ppapi::proxy::SerializedHandle> Handles;

 // We define overloads for catching SerializedHandles so that we can share
 // them correctly to the untrusted side.
 // See ConvertHandlesImpl for how these get used.
 void ConvertHandlesInParam(const ppapi::proxy::SerializedHandle& handle,
                            Handles* handles,
                            IPC::Message* msg,
                            int* handle_index) {
   handles->push_back(handle);
   if (msg)
     WriteHandle((*handle_index)++, handle, msg);
 }

 void HandleWriter(int* handle_index,
                   IPC::Message* m,
                   const ppapi::proxy::SerializedHandle& handle) {
   WriteHandle((*handle_index)++, handle, m);
 }

 void ConvertHandlesInParam(const ppapi::proxy::SerializedVar& var,
                            Handles* handles,
                            IPC::Message* msg,
                            int* handle_index) {
   std::vector<ppapi::proxy::SerializedHandle*> var_handles = var.GetHandles();
   if (var_handles.empty())
     return;

   for (size_t i = 0; i < var_handles.size(); ++i)
     handles->push_back(*var_handles[i]);
   if (msg)
     var.WriteDataToMessage(msg, base::Bind(&HandleWriter, handle_index));
 }

 // For PpapiMsg_ResourceReply and the reply to PpapiHostMsg_ResourceSyncCall,
 // the handles are carried inside the ResourceMessageReplyParams.
 // NOTE: We only translate handles from host->NaCl. The only kind of
 //       ResourceMessageParams that travels this direction is
 //       ResourceMessageReplyParams, so that's the only one we need to handle.
 void ConvertHandlesInParam(
     const ppapi::proxy::ResourceMessageReplyParams& params,
     Handles* handles,
     IPC::Message* msg,
     int* handle_index) {
   // First, if we need to rewrite the message parameters, write everything
   // before the handles (there's nothing after the handles).
   if (msg) {
     params.WriteReplyHeader(msg);
     // IPC writes the vector length as an int before the contents of the
     // vector.
     msg->WriteInt(static_cast<int>(params.handles().size()));
   }
   for (Handles::const_iterator iter = params.handles().begin();
        iter != params.handles().end();
        ++iter) {
     // ConvertHandle will write each handle to |msg|, if necessary.
     ConvertHandlesInParam(*iter, handles, msg, handle_index);
   }
   // Tell ResourceMessageReplyParams that we have taken the handles, so it
   // shouldn't close them. The NaCl runtime will take ownership of them.
   params.ConsumeHandles();
 }

 // This overload is to catch all types other than SerializedHandle or
 // ResourceMessageReplyParams. On Windows, |msg| will be a valid pointer, and we
 // must write |param| to it.
 template <class T>
 void ConvertHandlesInParam(const T& param,
                            Handles* /* handles */,
                            IPC::Message* msg,
                            int* /* handle_index */) {
   // It's not a handle, so just write to the output message, if necessary.
   if (msg)
     IPC::WriteParam(msg, param);
 }

 // These just break apart the given tuple and run ConvertHandle over each param.
 // The idea is to extract any handles in the tuple, while writing all data to
 // msg (if msg is valid). The msg will only be valid on Windows, where we need
 // to re-write all of the message parameters, writing the handles in POSIX style
 // for NaCl.
 template <class A>
 void ConvertHandlesImpl(const Tuple1<A>& t1, Handles* handles,
                         IPC::Message* msg) {
   int handle_index = 0;
   ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
 }
 template <class A, class B>
 void ConvertHandlesImpl(const Tuple2<A, B>& t1, Handles* handles,
                         IPC::Message* msg) {
   int handle_index = 0;
   ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
 }
 template <class A, class B, class C>
 void ConvertHandlesImpl(const Tuple3<A, B, C>& t1, Handles* handles,
                         IPC::Message* msg) {
   int handle_index = 0;
   ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.c, handles, msg, &handle_index);
 }
 template <class A, class B, class C, class D>
 void ConvertHandlesImpl(const Tuple4<A, B, C, D>& t1, Handles* handles,
                         IPC::Message* msg) {
   int handle_index = 0;
   ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.c, handles, msg, &handle_index);
   ConvertHandlesInParam(t1.d, handles, msg, &handle_index);
 }

 template <class MessageType>
 class HandleConverterImpl {
  public:
   explicit HandleConverterImpl(const IPC::Message* msg)
       : msg_(static_cast<const MessageType*>(msg)) {
   }
   bool ConvertMessage(Handles* handles, IPC::Message* out_msg) {
     typename TupleTypes<typename MessageType::Schema::Param>::ValueTuple params;
     if (!MessageType::Read(msg_, &params))
       return false;
     ConvertHandlesImpl(params, handles, out_msg);
     return true;
   }

   bool ConvertReply(Handles* handles, IPC::SyncMessage* out_msg) {
     typename TupleTypes<typename MessageType::Schema::ReplyParam>::ValueTuple
         params;
     if (!MessageType::ReadReplyParam(msg_, &params))
       return false;
     // If we need to rewrite the message (i.e., on Windows), we need to make
     // sure we write the message id first.
     if (out_msg) {
       out_msg->set_reply();
       int id = IPC::SyncMessage::GetMessageId(*msg_);
       out_msg->WriteInt(id);
     }
     ConvertHandlesImpl(params, handles, out_msg);
     return true;
   }
   // TODO(dmichael): Add ConvertSyncMessage for outgoing sync messages, if we
   //                 ever pass handles in one of those.

  private:
   const MessageType* msg_;
 };

 }  // namespace

 #define CASE_FOR_MESSAGE(MESSAGE_TYPE) \
       case MESSAGE_TYPE::ID: { \
         HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
         if (!extractor.ConvertMessage(handles, new_msg_ptr->get())) \
           return false; \
         break; \
       }
 #define CASE_FOR_REPLY(MESSAGE_TYPE) \
       case MESSAGE_TYPE::ID: { \
         HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
         if (!extractor.ConvertReply( \
                 handles, \
                 static_cast<IPC::SyncMessage*>(new_msg_ptr->get()))) \
           return false; \
         break; \
       }

 namespace ppapi {
 namespace proxy {

 class SerializedHandle;

 HandleConverter::HandleConverter() {
 }

 bool HandleConverter::ConvertNativeHandlesToPosix(
     const IPC::Message& msg,
     std::vector<SerializedHandle>* handles,
     scoped_ptr<IPC::Message>* new_msg_ptr) {
   DCHECK(handles);
   DCHECK(new_msg_ptr);
   DCHECK(!new_msg_ptr->get());

   // In Windows, we need to re-write the contents of the message. This is
   // because in Windows IPC code, native HANDLE values are serialized in the
   // body of the message.
   //
   // In POSIX, we only serialize an index in to a FileDescriptorSet, and the
   // actual file descriptors are sent out-of-band. So on Windows, to make a
   // message that's compatible with Windows, we need to write a new message that
   // has simple indices in the message body instead of the HANDLEs.
   //
   // NOTE: This means on Windows, new_msg_ptr's serialized contents are not
   // compatible with Windows IPC deserialization code; it is intended to be
   // passed to NaCl.
 #if defined(OS_WIN)
   new_msg_ptr->reset(
       new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
 #else
   // Even on POSIX, we have to rewrite messages to create channels, because
   // these contain a handle with an invalid (place holder) descriptor. The
   // message sending code sees this and doesn't pass the descriptor over
   // correctly.
   if (msg.type() == PpapiMsg_CreateNaClChannel::ID) {
     new_msg_ptr->reset(
         new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
   }
 #endif

   switch (msg.type()) {
     CASE_FOR_MESSAGE(PpapiMsg_CreateNaClChannel)
     CASE_FOR_MESSAGE(PpapiMsg_PPBAudio_NotifyAudioStreamCreated)
     CASE_FOR_MESSAGE(PpapiMsg_PPPMessaging_HandleMessage)
     CASE_FOR_MESSAGE(PpapiPluginMsg_ResourceReply)
     case IPC_REPLY_ID: {
       int id = IPC::SyncMessage::GetMessageId(msg);
       PendingSyncMsgMap::iterator iter(pending_sync_msgs_.find(id));
       if (iter == pending_sync_msgs_.end()) {
         NOTREACHED();
         return false;
       }
       uint32_t type = iter->second;
       pending_sync_msgs_.erase(iter);
       switch (type) {
         CASE_FOR_REPLY(PpapiHostMsg_PPBGraphics3D_GetTransferBuffer)
         CASE_FOR_REPLY(PpapiHostMsg_PPBImageData_CreateSimple)
         CASE_FOR_REPLY(PpapiHostMsg_ResourceSyncCall)
         CASE_FOR_REPLY(PpapiHostMsg_SharedMemory_CreateSharedMemory)
         default:
           // Do nothing for messages we don't know.
           break;
       }
       break;
     }
     default:
       // Do nothing for messages we don't know.
       break;
   }
   return true;
 }

 void HandleConverter::RegisterSyncMessageForReply(const IPC::Message& msg) {
   DCHECK(msg.is_sync());

   int msg_id = IPC::SyncMessage::GetMessageId(msg);
   DCHECK(pending_sync_msgs_.find(msg_id) == pending_sync_msgs_.end());

   pending_sync_msgs_[msg_id] = msg.type();
 }

 }  // namespace proxy
 }  // namespace ppapi
	// Copyright (c) 2013 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 "ppapi/proxy/handle_converter.h"

	#include <vector>
	#include "base/bind.h"
	#include "ipc/ipc_message.h"
	#include "ipc/ipc_message_macros.h"
	#include "ppapi/proxy/ppapi_messages.h"
	#include "ppapi/proxy/resource_message_params.h"
	#include "ppapi/proxy/serialized_handle.h"
	#include "ppapi/proxy/serialized_var.h"

	class NaClDescImcShm;

	namespace IPC {
	class Message;
	}

	namespace {

	void WriteHandle(int handle_index,
	const ppapi::proxy::SerializedHandle& handle,
	IPC::Message* message) {
	ppapi::proxy::SerializedHandle::WriteHeader(handle.header(), message);

	// Now write the handle itself in POSIX style.
	message->WriteBool(true); // valid == true
	message->WriteInt(handle_index);
	}

	typedef std::vector<ppapi::proxy::SerializedHandle> Handles;

	// We define overloads for catching SerializedHandles so that we can share
	// them correctly to the untrusted side.
	// See ConvertHandlesImpl for how these get used.
	void ConvertHandlesInParam(const ppapi::proxy::SerializedHandle& handle,
	Handles* handles,
	IPC::Message* msg,
	int* handle_index) {
	handles->push_back(handle);
	if (msg)
	WriteHandle((*handle_index)++, handle, msg);
	}

	void HandleWriter(int* handle_index,
	IPC::Message* m,
	const ppapi::proxy::SerializedHandle& handle) {
	WriteHandle((*handle_index)++, handle, m);
	}

	void ConvertHandlesInParam(const ppapi::proxy::SerializedVar& var,
	Handles* handles,
	IPC::Message* msg,
	int* handle_index) {
	std::vector<ppapi::proxy::SerializedHandle*> var_handles = var.GetHandles();
	if (var_handles.empty())
	return;

	for (size_t i = 0; i < var_handles.size(); ++i)
	handles->push_back(*var_handles[i]);
	if (msg)
	var.WriteDataToMessage(msg, base::Bind(&HandleWriter, handle_index));
	}

	// For PpapiMsg_ResourceReply and the reply to PpapiHostMsg_ResourceSyncCall,
	// the handles are carried inside the ResourceMessageReplyParams.
	// NOTE: We only translate handles from host->NaCl. The only kind of
	// ResourceMessageParams that travels this direction is
	// ResourceMessageReplyParams, so that's the only one we need to handle.
	void ConvertHandlesInParam(
	const ppapi::proxy::ResourceMessageReplyParams& params,
	Handles* handles,
	IPC::Message* msg,
	int* handle_index) {
	// First, if we need to rewrite the message parameters, write everything
	// before the handles (there's nothing after the handles).
	if (msg) {
	params.WriteReplyHeader(msg);
	// IPC writes the vector length as an int before the contents of the
	// vector.
	msg->WriteInt(static_cast<int>(params.handles().size()));
	}
	for (Handles::const_iterator iter = params.handles().begin();
	iter != params.handles().end();
	++iter) {
	// ConvertHandle will write each handle to \|msg\|, if necessary.
	ConvertHandlesInParam(*iter, handles, msg, handle_index);
	}
	// Tell ResourceMessageReplyParams that we have taken the handles, so it
	// shouldn't close them. The NaCl runtime will take ownership of them.
	params.ConsumeHandles();
	}

	// This overload is to catch all types other than SerializedHandle or
	// ResourceMessageReplyParams. On Windows, \|msg\| will be a valid pointer, and we
	// must write \|param\| to it.
	template <class T>
	void ConvertHandlesInParam(const T& param,
	Handles* /* handles */,
	IPC::Message* msg,
	int* /* handle_index */) {
	// It's not a handle, so just write to the output message, if necessary.
	if (msg)
	IPC::WriteParam(msg, param);
	}

	// These just break apart the given tuple and run ConvertHandle over each param.
	// The idea is to extract any handles in the tuple, while writing all data to
	// msg (if msg is valid). The msg will only be valid on Windows, where we need
	// to re-write all of the message parameters, writing the handles in POSIX style
	// for NaCl.
	template <class A>
	void ConvertHandlesImpl(const Tuple1<A>& t1, Handles* handles,
	IPC::Message* msg) {
	int handle_index = 0;
	ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
	}
	template <class A, class B>
	void ConvertHandlesImpl(const Tuple2<A, B>& t1, Handles* handles,
	IPC::Message* msg) {
	int handle_index = 0;
	ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
	}
	template <class A, class B, class C>
	void ConvertHandlesImpl(const Tuple3<A, B, C>& t1, Handles* handles,
	IPC::Message* msg) {
	int handle_index = 0;
	ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.c, handles, msg, &handle_index);
	}
	template <class A, class B, class C, class D>
	void ConvertHandlesImpl(const Tuple4<A, B, C, D>& t1, Handles* handles,
	IPC::Message* msg) {
	int handle_index = 0;
	ConvertHandlesInParam(t1.a, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.b, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.c, handles, msg, &handle_index);
	ConvertHandlesInParam(t1.d, handles, msg, &handle_index);
	}

	template <class MessageType>
	class HandleConverterImpl {
	public:
	explicit HandleConverterImpl(const IPC::Message* msg)
	: msg_(static_cast<const MessageType*>(msg)) {
	}
	bool ConvertMessage(Handles* handles, IPC::Message* out_msg) {
	typename TupleTypes<typename MessageType::Schema::Param>::ValueTuple params;
	if (!MessageType::Read(msg_, &params))
	return false;
	ConvertHandlesImpl(params, handles, out_msg);
	return true;
	}

	bool ConvertReply(Handles* handles, IPC::SyncMessage* out_msg) {
	typename TupleTypes<typename MessageType::Schema::ReplyParam>::ValueTuple
	params;
	if (!MessageType::ReadReplyParam(msg_, &params))
	return false;
	// If we need to rewrite the message (i.e., on Windows), we need to make
	// sure we write the message id first.
	if (out_msg) {
	out_msg->set_reply();
	int id = IPC::SyncMessage::GetMessageId(*msg_);
	out_msg->WriteInt(id);
	}
	ConvertHandlesImpl(params, handles, out_msg);
	return true;
	}
	// TODO(dmichael): Add ConvertSyncMessage for outgoing sync messages, if we
	// ever pass handles in one of those.

	private:
	const MessageType* msg_;
	};

	} // namespace

	#define CASE_FOR_MESSAGE(MESSAGE_TYPE) \
	case MESSAGE_TYPE::ID: { \
	HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
	if (!extractor.ConvertMessage(handles, new_msg_ptr->get())) \
	return false; \
	break; \
	}
	#define CASE_FOR_REPLY(MESSAGE_TYPE) \
	case MESSAGE_TYPE::ID: { \
	HandleConverterImpl<MESSAGE_TYPE> extractor(&msg); \
	if (!extractor.ConvertReply( \
	handles, \
	static_cast<IPC::SyncMessage*>(new_msg_ptr->get()))) \
	return false; \
	break; \
	}

	namespace ppapi {
	namespace proxy {

	class SerializedHandle;

	HandleConverter::HandleConverter() {
	}

	bool HandleConverter::ConvertNativeHandlesToPosix(
	const IPC::Message& msg,
	std::vector<SerializedHandle>* handles,
	scoped_ptr<IPC::Message>* new_msg_ptr) {
	DCHECK(handles);
	DCHECK(new_msg_ptr);
	DCHECK(!new_msg_ptr->get());

	// In Windows, we need to re-write the contents of the message. This is
	// because in Windows IPC code, native HANDLE values are serialized in the
	// body of the message.
	//
	// In POSIX, we only serialize an index in to a FileDescriptorSet, and the
	// actual file descriptors are sent out-of-band. So on Windows, to make a
	// message that's compatible with Windows, we need to write a new message that
	// has simple indices in the message body instead of the HANDLEs.
	//
	// NOTE: This means on Windows, new_msg_ptr's serialized contents are not
	// compatible with Windows IPC deserialization code; it is intended to be
	// passed to NaCl.
	#if defined(OS_WIN)
	new_msg_ptr->reset(
	new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
	#else
	// Even on POSIX, we have to rewrite messages to create channels, because
	// these contain a handle with an invalid (place holder) descriptor. The
	// message sending code sees this and doesn't pass the descriptor over
	// correctly.
	if (msg.type() == PpapiMsg_CreateNaClChannel::ID) {
	new_msg_ptr->reset(
	new IPC::Message(msg.routing_id(), msg.type(), msg.priority()));
	}
	#endif

	switch (msg.type()) {
	CASE_FOR_MESSAGE(PpapiMsg_CreateNaClChannel)
	CASE_FOR_MESSAGE(PpapiMsg_PPBAudio_NotifyAudioStreamCreated)
	CASE_FOR_MESSAGE(PpapiMsg_PPPMessaging_HandleMessage)
	CASE_FOR_MESSAGE(PpapiPluginMsg_ResourceReply)
	case IPC_REPLY_ID: {
	int id = IPC::SyncMessage::GetMessageId(msg);
	PendingSyncMsgMap::iterator iter(pending_sync_msgs_.find(id));
	if (iter == pending_sync_msgs_.end()) {
	NOTREACHED();
	return false;
	}
	uint32_t type = iter->second;
	pending_sync_msgs_.erase(iter);
	switch (type) {
	CASE_FOR_REPLY(PpapiHostMsg_PPBGraphics3D_GetTransferBuffer)
	CASE_FOR_REPLY(PpapiHostMsg_PPBImageData_CreateSimple)
	CASE_FOR_REPLY(PpapiHostMsg_ResourceSyncCall)
	CASE_FOR_REPLY(PpapiHostMsg_SharedMemory_CreateSharedMemory)
	default:
	// Do nothing for messages we don't know.
	break;
	}
	break;
	}
	default:
	// Do nothing for messages we don't know.
	break;
	}
	return true;
	}

	void HandleConverter::RegisterSyncMessageForReply(const IPC::Message& msg) {
	DCHECK(msg.is_sync());

	int msg_id = IPC::SyncMessage::GetMessageId(msg);
	DCHECK(pending_sync_msgs_.find(msg_id) == pending_sync_msgs_.end());

	pending_sync_msgs_[msg_id] = msg.type();
	}

	} // namespace proxy
	} // namespace ppapi