IPC::ChannelMojo: Make IPC handling robust against bad messages.

ipc/mojo/ipc_mojo_bootstrap.cc

Index: ipc/mojo/ipc_mojo_bootstrap.cc
diff --git a/ipc/mojo/ipc_mojo_bootstrap.cc b/ipc/mojo/ipc_mojo_bootstrap.cc
index 4af4e503a9d27b04efc732b5c6faf935046693a5..7f19bb43051e741ed686ba7bae80c1ed7e5e6782 100644
--- a/ipc/mojo/ipc_mojo_bootstrap.cc
+++ b/ipc/mojo/ipc_mojo_bootstrap.cc
@@ -100,9 +100,13 @@ void MojoServerBootstrap::OnChannelConnected(int32 peer_pid) {
 }
 
 bool MojoServerBootstrap::OnMessageReceived(const Message&) {
-  DCHECK_EQ(state(), STATE_WAITING_ACK);
-  set_state(STATE_READY);
+  if (state() != STATE_WAITING_ACK) {

[viettrungluu, 2014/11/13 20:27:57]

You should probably document in the header what the valid state transitions are.

[Hajime Morrita, 2014/11/13 21:01:18]

Done.

+    DLOG(WARNING) << "Got inconsistent message from client.";

[viettrungluu, 2014/11/13 20:27:57]

LOG(ERROR)?

This seems pretty serious.

[Hajime Morrita, 2014/11/13 21:01:18]

Done.

+    return false;
+  }
 
+  set_state(STATE_READY);
+  DCHECK(server_pipe_.is_valid());

[viettrungluu, 2014/11/13 20:27:57]

CHECK?

[Hajime Morrita, 2014/11/13 21:01:18]

Done.

   delegate()->OnPipeAvailable(
       mojo::embedder::ScopedPlatformHandle(server_pipe_.release()));
 
@@ -129,6 +133,11 @@ MojoClientBootstrap::MojoClientBootstrap() {
 }
 
 bool MojoClientBootstrap::OnMessageReceived(const Message& message) {
+  if (STATE_INITIALIZED != state()) {

[viettrungluu, 2014/11/13 20:27:57]

state() != STATE_INITIALIZED

[Hajime Morrita, 2014/11/13 21:01:18]

Done.

+    DLOG(WARNING) << "Got inconsistent message from server.";

[viettrungluu, 2014/11/13 20:27:57]

LOG(ERROR)?

[Hajime Morrita, 2014/11/13 21:01:18]

Done.

+    return false;
+  }
+
   PlatformFileForTransit pipe;
   PickleIterator iter(message);
   if (!ParamTraits<PlatformFileForTransit>::Read(&message, &iter, &pipe)) {