Do not create multi-port path if the connection has active migration disabled.

PiperOrigin-RevId: 538268315

quiche/quic/core/quic_connection.cc

diff --git a/quiche/quic/core/quic_connection.cc b/quiche/quic/core/quic_connection.cc
index fc5e097..e1ec2d8 100644
--- a/quiche/quic/core/quic_connection.cc
+++ b/quiche/quic/core/quic_connection.cc
@@ -555,6 +555,10 @@
     OnNewConnectionIdFrameInner(frame);
   }
 
+  if (config.DisableConnectionMigration()) {
+    active_migration_disabled_ = true;
+  }
+
   sent_packet_manager_.SetFromConfig(config);
   if (perspective_ == Perspective::IS_SERVER &&
       config.HasClientSentConnectionOption(kAFF2, perspective_)) {
@@ -3992,6 +3996,14 @@
 
 void QuicConnection::MaybeCreateMultiPortPath() {
   QUICHE_DCHECK_EQ(Perspective::IS_CLIENT, perspective_);
+  QUIC_CLIENT_HISTOGRAM_BOOL(
+      "QuicConnection.ServerAllowsActiveMigrationForMultiPort",
+      !active_migration_disabled_,
+      "Whether the server allows active migration that's required for "
+      "multi-port");
+  if (active_migration_disabled_) {
+    return;
+  }
   if (path_validator_.HasPendingPathValidation()) {
     QUIC_CLIENT_HISTOGRAM_ENUM("QuicConnection.MultiPortPathCreationCancelled",
                                path_validator_.GetPathValidationReason(),

quiche/quic/core/quic_connection.h

diff --git a/quiche/quic/core/quic_connection.h b/quiche/quic/core/quic_connection.h
index e1832ab..a650978 100644
--- a/quiche/quic/core/quic_connection.h
+++ b/quiche/quic/core/quic_connection.h
@@ -2360,6 +2360,8 @@
 
   std::unique_ptr<MultiPortStats> multi_port_stats_;
 
+  bool active_migration_disabled_ = false;
+
   RetransmittableOnWireBehavior retransmittable_on_wire_behavior_ = DEFAULT;
 
   // Server addresses that are known to the client.

quiche/quic/core/quic_connection_test.cc

diff --git a/quiche/quic/core/quic_connection_test.cc b/quiche/quic/core/quic_connection_test.cc
index fae2512..c501347 100644
--- a/quiche/quic/core/quic_connection_test.cc
+++ b/quiche/quic/core/quic_connection_test.cc
@@ -13265,6 +13265,39 @@
   connection_.ProcessUdpPacket(kNewSelfAddress, kPeerAddress, *received);
 }
 
+// Test that if the client's active migration is disabled, multi-port will not
+// be attempted.
+TEST_P(QuicConnectionTest, MultiPortPathRespectsActiveMigrationConfig) {
+  set_perspective(Perspective::IS_CLIENT);
+  QuicConfig config;
+  QuicConfigPeer::SetReceivedStatelessResetToken(&config,
+                                                 kTestStatelessResetToken);
+  QuicConfigPeer::SetReceivedDisableConnectionMigration(&config);
+  config.SetClientConnectionOptions(QuicTagVector{kMPQC});
+  EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _));
+  connection_.SetFromConfig(config);
+  if (!connection_.connection_migration_use_new_cid()) {
+    return;
+  }
+  connection_.CreateConnectionIdManager();
+  connection_.SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
+  connection_.OnHandshakeComplete();
+
+  EXPECT_CALL(visitor_, OnPathDegrading());
+  connection_.OnPathDegradingDetected();
+
+  QuicNewConnectionIdFrame frame;
+  frame.connection_id = TestConnectionId(1234);
+  ASSERT_NE(frame.connection_id, connection_.connection_id());
+  frame.stateless_reset_token =
+      QuicUtils::GenerateStatelessResetToken(frame.connection_id);
+  frame.retire_prior_to = 0u;
+  frame.sequence_number = 1u;
+  EXPECT_CALL(visitor_, CreateContextForMultiPortPath).Times(0);
+  connection_.OnNewConnectionIdFrame(frame);
+  EXPECT_FALSE(connection_.HasPendingPathValidation());
+}
+
 // Verify that when multi-port is enabled and path degrading is triggered, if
 // the alt-path is not ready, nothing happens.
 TEST_P(QuicConnectionTest, PathDegradingWhenAltPathIsNotReady) {