Add a callback that notifies the QuicTransportClientSession visitor when the session is ready.

Also add a bit of extra defense in depth for ALPN checks.

gfe-relnote: n/a (not used in production)
PiperOrigin-RevId: 284658419
Change-Id: Ic665263a024821e529c564e7c8b86d362f9991a8

quic/quic_transport/quic_transport_client_session.cc

diff --git a/quic/quic_transport/quic_transport_client_session.cc b/quic/quic_transport/quic_transport_client_session.cc
index e9487ec..f316813 100644
--- a/quic/quic_transport/quic_transport_client_session.cc
+++ b/quic/quic_transport/quic_transport_client_session.cc
@@ -67,6 +67,19 @@
       proof_handler);
 }
 
+void QuicTransportClientSession::OnAlpnSelected(QuicStringPiece alpn) {
+  // Defense in-depth: ensure the ALPN selected is the desired one.
+  if (alpn != QuicTransportAlpn()) {
+    QUIC_BUG << "QuicTransport negotiated non-QuicTransport ALPN: " << alpn;
+    connection()->CloseConnection(
+        QUIC_INTERNAL_ERROR, "QuicTransport negotiated non-QuicTransport ALPN",
+        ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+    return;
+  }
+
+  alpn_received_ = true;
+}
+
 QuicStream* QuicTransportClientSession::CreateIncomingStream(QuicStreamId id) {
   QUIC_DVLOG(1) << "Creating incoming QuicTransport stream " << id;
   QuicTransportStream* stream = CreateStream(id);
@@ -222,12 +235,24 @@
                                        /*fin=*/true, nullptr);
   client_indication_sent_ = true;
 
+  // Defense in depth: never set the ready bit unless ALPN has been confirmed.
+  if (!alpn_received_) {
+    QUIC_BUG << "ALPN confirmation missing after handshake complete";
+    connection()->CloseConnection(
+        QUIC_INTERNAL_ERROR,
+        "ALPN confirmation missing after handshake complete",
+        ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+    return;
+  }
+
   // Don't set the ready bit if we closed the connection due to any error
   // beforehand.
   if (!connection()->connected()) {
     return;
   }
+
   ready_ = true;
+  visitor_->OnSessionReady();
 }
 
 }  // namespace quic

quic/quic_transport/quic_transport_client_session.h

diff --git a/quic/quic_transport/quic_transport_client_session.h b/quic/quic_transport/quic_transport_client_session.h
index b3d8f17..c09b076 100644
--- a/quic/quic_transport/quic_transport_client_session.h
+++ b/quic/quic_transport/quic_transport_client_session.h
@@ -37,6 +37,10 @@
    public:
     virtual ~ClientVisitor() {}
 
+    // Notifies the visitor when the client indication has been sent and the
+    // connection is ready to exchange application data.
+    virtual void OnSessionReady() = 0;
+
     // Notifies the visitor when a new stream has been received.  The stream in
     // question can be retrieved using AcceptIncomingBidirectionalStream() or
     // AcceptIncomingUnidirectionalStream().
@@ -56,6 +60,8 @@
   std::vector<std::string> GetAlpnsToOffer() const override {
     return std::vector<std::string>({QuicTransportAlpn()});
   }
+  void OnAlpnSelected(QuicStringPiece alpn) override;
+  bool alpn_received() const { return alpn_received_; }
 
   void CryptoConnect() { crypto_stream_->CryptoConnect(); }
 
@@ -121,6 +127,7 @@
   url::Origin origin_;
   ClientVisitor* visitor_;  // not owned
   bool client_indication_sent_ = false;
+  bool alpn_received_ = false;
   bool ready_ = false;
 
   // Contains all of the streams that has been received by the session but have

quic/quic_transport/quic_transport_client_session_test.cc

diff --git a/quic/quic_transport/quic_transport_client_session_test.cc b/quic/quic_transport/quic_transport_client_session_test.cc
index 51a0eb8..1225352 100644
--- a/quic/quic_transport/quic_transport_client_session_test.cc
+++ b/quic/quic_transport/quic_transport_client_session_test.cc
@@ -103,6 +103,7 @@
       "\0\x01"                    // length
       "/";                        // value
 
+  EXPECT_CALL(visitor_, OnSessionReady());
   Connect();
   EXPECT_TRUE(session_->IsSessionReady());
 

quic/quic_transport/quic_transport_integration_test.cc

diff --git a/quic/quic_transport/quic_transport_integration_test.cc b/quic/quic_transport/quic_transport_integration_test.cc
index 1695a19..f5c804d 100644
--- a/quic/quic_transport/quic_transport_integration_test.cc
+++ b/quic/quic_transport/quic_transport_integration_test.cc
@@ -205,6 +205,7 @@
 TEST_F(QuicTransportIntegrationTest, SuccessfulHandshake) {
   CreateDefaultEndpoints("/discard");
   WireUpEndpoints();
+  EXPECT_CALL(*client_->visitor(), OnSessionReady());
   RunHandshake();
   EXPECT_TRUE(client_->session()->IsSessionReady());
   EXPECT_TRUE(server_->session()->IsSessionReady());

quic/test_tools/quic_transport_test_tools.h

diff --git a/quic/test_tools/quic_transport_test_tools.h b/quic/test_tools/quic_transport_test_tools.h
index 9632d4c..9c5cef4 100644
--- a/quic/test_tools/quic_transport_test_tools.h
+++ b/quic/test_tools/quic_transport_test_tools.h
@@ -14,6 +14,7 @@
 
 class MockClientVisitor : public QuicTransportClientSession::ClientVisitor {
  public:
+  MOCK_METHOD0(OnSessionReady, void());
   MOCK_METHOD0(OnIncomingBidirectionalStreamAvailable, void());
   MOCK_METHOD0(OnIncomingUnidirectionalStreamAvailable, void());
 };