Send connection close packet for QUIC_INVALID_VERSION, behind client_connection_option INVC.

PiperOrigin-RevId: 437343247

quic/core/crypto/crypto_protocol.h

diff --git a/quic/core/crypto/crypto_protocol.h b/quic/core/crypto/crypto_protocol.h
index 32fd192..ea05d35 100644
--- a/quic/core/crypto/crypto_protocol.h
+++ b/quic/core/crypto/crypto_protocol.h
@@ -430,6 +430,9 @@
                                                  // server side.
 const QuicTag kGSR0 = TAG('G', 'S', 'R', '0');   // Selective Resumption
 
+const QuicTag kINVC = TAG('I', 'N', 'V', 'C');   // Send connection close for
+                                                 // INVALID_VERSION
+
 // Client Hints triggers.
 const QuicTag kGWCH = TAG('G', 'W', 'C', 'H');
 const QuicTag kYTCH = TAG('Y', 'T', 'C', 'H');

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 6edaa8f..0cc3296 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -619,6 +619,10 @@
   if (config.HasClientSentConnectionOption(kDFER, perspective_)) {
     defer_send_in_response_to_packets_ = false;
   }
+
+  if (config.HasClientRequestedIndependentOption(kINVC, perspective_)) {
+    send_connection_close_for_invalid_version_ = true;
+  }
   const bool remove_connection_migration_connection_option =
       GetQuicReloadableFlag(quic_remove_connection_migration_connection_option);
   if (remove_connection_migration_connection_option) {
@@ -882,7 +886,9 @@
           ParsedQuicVersionVectorToString(framer_.supported_versions()),
           "}, peer supported versions: {",
           ParsedQuicVersionVectorToString(packet.versions), "}"),
-      ConnectionCloseBehavior::SILENT_CLOSE);
+      send_connection_close_for_invalid_version_
+          ? ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET
+          : ConnectionCloseBehavior::SILENT_CLOSE);
 }
 
 // Handles retry for client connection.

quic/core/quic_connection.h

diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index a38f2c0..17c0830 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -2276,6 +2276,9 @@
   // TODO(b/180103273): remove this after the bug gets fixed.
   absl::optional<QuicConnectionCloseFrame> connection_close_frame_sent_;
 
+  // If true, send connection close packet on INVALID_VERSION.
+  bool send_connection_close_for_invalid_version_ = false;
+
   // TODO(b/205023946) Debug-only fields, to be deprecated after the bug is
   // fixed.
   absl::optional<QuicWallTime> quic_bug_10511_43_timestamp_;

quic/core/quic_connection_test.cc

diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 5effe44..fb16c11 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -7049,6 +7049,41 @@
               IsError(QUIC_INVALID_VERSION));
 }
 
+TEST_P(QuicConnectionTest, ClientHandlesVersionNegotiationWithConnectionClose) {
+  EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+  QuicConfig config;
+  QuicTagVector connection_options;
+  connection_options.push_back(kINVC);
+  config.SetClientConnectionOptions(connection_options);
+  connection_.SetFromConfig(config);
+
+  // All supported versions except the one the connection supports.
+  ParsedQuicVersionVector versions;
+  for (auto version : AllSupportedVersions()) {
+    if (version != connection_.version()) {
+      versions.push_back(version);
+    }
+  }
+
+  // Send a version negotiation packet.
+  std::unique_ptr<QuicEncryptedPacket> encrypted(
+      QuicFramer::BuildVersionNegotiationPacket(
+          connection_id_, EmptyQuicConnectionId(),
+          connection_.version().HasIetfInvariantHeader(),
+          connection_.version().HasLengthPrefixedConnectionIds(), versions));
+  std::unique_ptr<QuicReceivedPacket> received(
+      ConstructReceivedPacket(*encrypted, QuicTime::Zero()));
+  EXPECT_CALL(visitor_, OnConnectionClosed(_, ConnectionCloseSource::FROM_SELF))
+      .WillOnce(Invoke(this, &QuicConnectionTest::SaveConnectionCloseFrame));
+  // Verify connection close packet gets sent.
+  EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(AtLeast(1u));
+  connection_.ProcessUdpPacket(kSelfAddress, kPeerAddress, *received);
+  EXPECT_FALSE(connection_.connected());
+  EXPECT_EQ(1, connection_close_frame_count_);
+  EXPECT_THAT(saved_connection_close_frame_.quic_error_code,
+              IsError(QUIC_INVALID_VERSION));
+}
+
 TEST_P(QuicConnectionTest, BadVersionNegotiation) {
   // Send a version negotiation packet with the version the client started with.
   // It should be rejected.