Do not migrate proxied connections for connectivity probing packets. Protected...

Do not migrate proxied connections for connectivity probing packets. Protected by existing flag FLAGS_quic_reloadable_flag_quic_enable_server_proxy.

Merge internal change: 191428948

R=rch@chromium.org

Change-Id: Ide8207871b8a31465cec09439e1f9e67a4366542
Reviewed-on: https://chromium-review.googlesource.com/995613Reviewed-by: Ryan Hamilton <rch@chromium.org>
Commit-Queue: Bin Wu <wub@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548098}

net/quic/core/quic_connection.cc

@@ -747,6 +747,7 @@ bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
 
   // Initialize the current packet content stats.
   current_packet_content_ = NO_FRAMES_RECEIVED;
+  is_current_packet_connectivity_probing_ = false;
 
   if (!enable_server_proxy_) {
     current_peer_migration_type_ = NO_CHANGE;
@@ -3022,6 +3023,10 @@ void QuicConnection::OnConnectionMigration(AddressChangeType addr_change_type) {
 }
 
 bool QuicConnection::IsCurrentPacketConnectivityProbing() const {
+  if (enable_server_proxy_) {
+    return is_current_packet_connectivity_probing_;
+  }
+
   if (current_packet_content_ != SECOND_FRAME_IS_PADDING) {
     return false;
   }
@@ -3133,6 +3138,16 @@ void QuicConnection::UpdatePacketContent(PacketContent type) {
   if (type == SECOND_FRAME_IS_PADDING) {
     if (current_packet_content_ == FIRST_FRAME_IS_PING) {
       current_packet_content_ = SECOND_FRAME_IS_PADDING;
+      if (enable_server_proxy_) {
+        if (perspective_ == Perspective::IS_SERVER) {
+          is_current_packet_connectivity_probing_ =
+              current_effective_peer_migration_type_ != NO_CHANGE;
+        } else {
+          is_current_packet_connectivity_probing_ =
+              (last_packet_source_address_ != peer_address_) ||
+              (last_packet_destination_address_ != self_address_);
+        }
+      }
       return;
     }
   }

net/quic/core/quic_connection.h

@@ -993,6 +993,11 @@ class QUIC_EXPORT_PRIVATE QuicConnection
   // Contents received in the current packet, especially used to identify
   // whether the current packet is a padded PING packet.
   PacketContent current_packet_content_;
+  // True if the packet currently being processed is a connectivity probing
+  // packet. Is set to false when a new packet is received, and will be set to
+  // true as soon as |current_packet_content_| is set to
+  // SECOND_FRAME_IS_PADDING.
+  bool is_current_packet_connectivity_probing_;
   // Caches the current peer migration type if a peer migration might be
   // initiated. As soon as the current packet is confirmed not a connectivity
   // probe, peer migration will start.

net/quic/core/quic_connection_test.cc

@@ -682,6 +682,7 @@ class TestConnection : public QuicConnection {
     next_effective_peer_addr_ = QuicMakeUnique<QuicSocketAddress>(addr);
   }
 
+  using QuicConnection::IsCurrentPacketConnectivityProbing;
   using QuicConnection::SelectMutualVersion;
   using QuicConnection::SendProbingRetransmissions;
   using QuicConnection::set_defer_send_in_response_to_packets;
@@ -1477,6 +1478,8 @@ TEST_P(QuicConnectionTest, ReceivePaddedPingAtServer) {
       clock_.Now()));
 
   ProcessReceivedPacket(kSelfAddress, kPeerAddress, *received);
+
+  EXPECT_FALSE(connection_.IsCurrentPacketConnectivityProbing());
   EXPECT_EQ(kPeerAddress, connection_.peer_address());
   if (GetQuicReloadableFlag(quic_enable_server_proxy)) {
     EXPECT_EQ(kPeerAddress, connection_.effective_peer_address());
@@ -1594,6 +1597,8 @@ TEST_P(QuicConnectionTest, ReceiveConnectivityProbingAtServer) {
       clock_.Now()));
 
   ProcessReceivedPacket(kSelfAddress, kNewPeerAddress, *received);
+
+  EXPECT_TRUE(connection_.IsCurrentPacketConnectivityProbing());
   EXPECT_EQ(kPeerAddress, connection_.peer_address());
   if (GetQuicReloadableFlag(quic_enable_server_proxy)) {
     EXPECT_EQ(kPeerAddress, connection_.effective_peer_address());
@@ -1714,6 +1719,7 @@ TEST_P(QuicConnectionTest, ReceivePaddedPingAtClient) {
       clock_.Now()));
   ProcessReceivedPacket(kSelfAddress, kPeerAddress, *received);
 
+  EXPECT_FALSE(connection_.IsCurrentPacketConnectivityProbing());
   EXPECT_EQ(kPeerAddress, connection_.peer_address());
   if (GetQuicReloadableFlag(quic_enable_server_proxy)) {
     EXPECT_EQ(kPeerAddress, connection_.effective_peer_address());
@@ -1765,6 +1771,7 @@ TEST_P(QuicConnectionTest, ReceiveConnectivityProbingAtClient) {
       clock_.Now()));
   ProcessReceivedPacket(kNewSelfAddress, kPeerAddress, *received);
 
+  EXPECT_TRUE(connection_.IsCurrentPacketConnectivityProbing());
   EXPECT_EQ(kPeerAddress, connection_.peer_address());
   if (GetQuicReloadableFlag(quic_enable_server_proxy)) {
     EXPECT_EQ(kPeerAddress, connection_.effective_peer_address());