In QuicReceivedPacketManager, only record receive timestamps for packets received in order for IETF QUIC.

PiperOrigin-RevId: 424344189

quic/core/quic_received_packet_manager.cc

diff --git a/quic/core/quic_received_packet_manager.cc b/quic/core/quic_received_packet_manager.cc
index 079778c..d0f1578 100644
--- a/quic/core/quic_received_packet_manager.cc
+++ b/quic/core/quic_received_packet_manager.cc
@@ -38,6 +38,7 @@
       max_ack_ranges_(0),
       time_largest_observed_(QuicTime::Zero()),
       save_timestamps_(false),
+      save_timestamps_for_in_order_packets_(false),
       stats_(stats),
       num_retransmittable_packets_received_since_last_ack_sent_(0),
       min_received_before_ack_decimation_(kMinReceivedBeforeAckDecimation),
@@ -80,9 +81,12 @@
   }
   ack_frame_updated_ = true;
 
+  // Whether |packet_number| is received out of order.
+  bool packet_reordered = false;
   if (LargestAcked(ack_frame_).IsInitialized() &&
       LargestAcked(ack_frame_) > packet_number) {
     // Record how out of order stats.
+    packet_reordered = true;
     ++stats_->packets_reordered;
     stats_->max_sequence_reordering =
         std::max(stats_->max_sequence_reordering,
@@ -101,8 +105,11 @@
 
   if (save_timestamps_) {
     // The timestamp format only handles packets in time order.
-    if (!ack_frame_.received_packet_times.empty() &&
-        ack_frame_.received_packet_times.back().second > receipt_time) {
+    if (save_timestamps_for_in_order_packets_ && packet_reordered) {
+      QUIC_DLOG(WARNING) << "Not saving receive timestamp for packet "
+                         << packet_number;
+    } else if (!ack_frame_.received_packet_times.empty() &&
+               ack_frame_.received_packet_times.back().second > receipt_time) {
       QUIC_LOG(WARNING)
           << "Receive time went backwards from: "
           << ack_frame_.received_packet_times.back().second.ToDebuggingValue()

quic/core/quic_received_packet_manager.h

diff --git a/quic/core/quic_received_packet_manager.h b/quic/core/quic_received_packet_manager.h
index 822725d..21f7f04 100644
--- a/quic/core/quic_received_packet_manager.h
+++ b/quic/core/quic_received_packet_manager.h
@@ -103,8 +103,9 @@
     max_ack_ranges_ = max_ack_ranges;
   }
 
-  void set_save_timestamps(bool save_timestamps) {
+  void set_save_timestamps(bool save_timestamps, bool in_order_packets_only) {
     save_timestamps_ = save_timestamps;
+    save_timestamps_for_in_order_packets_ = in_order_packets_only;
   }
 
   size_t min_received_before_ack_decimation() const {
@@ -167,6 +168,10 @@
   // If true, save timestamps in the ack_frame_.
   bool save_timestamps_;
 
+  // If true and |save_timestamps_|, only save timestamps for packets that are
+  // received in order.
+  bool save_timestamps_for_in_order_packets_;
+
   // Least packet number received from peer.
   QuicPacketNumber least_received_packet_number_;
 

quic/core/quic_received_packet_manager_test.cc

diff --git a/quic/core/quic_received_packet_manager_test.cc b/quic/core/quic_received_packet_manager_test.cc
index 9d6b664..cc04381 100644
--- a/quic/core/quic_received_packet_manager_test.cc
+++ b/quic/core/quic_received_packet_manager_test.cc
@@ -46,7 +46,7 @@
   QuicReceivedPacketManagerTest() : received_manager_(&stats_) {
     clock_.AdvanceTime(QuicTime::Delta::FromSeconds(1));
     rtt_stats_.UpdateRtt(kMinRttMs, QuicTime::Delta::Zero(), QuicTime::Zero());
-    received_manager_.set_save_timestamps(true);
+    received_manager_.set_save_timestamps(true, false);
   }
 
   void RecordPacketReceipt(uint64_t packet_number) {
@@ -189,6 +189,21 @@
   EXPECT_EQ(2u, received_manager_.ack_frame().received_packet_times.size());
 }
 
+TEST_F(QuicReceivedPacketManagerTest, IgnoreOutOfOrderPackets) {
+  received_manager_.set_save_timestamps(true, true);
+  EXPECT_FALSE(received_manager_.ack_frame_updated());
+  RecordPacketReceipt(1, QuicTime::Zero());
+  EXPECT_TRUE(received_manager_.ack_frame_updated());
+  EXPECT_EQ(1u, received_manager_.ack_frame().received_packet_times.size());
+  RecordPacketReceipt(4,
+                      QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(1));
+  EXPECT_EQ(2u, received_manager_.ack_frame().received_packet_times.size());
+
+  RecordPacketReceipt(3,
+                      QuicTime::Zero() + QuicTime::Delta::FromMilliseconds(3));
+  EXPECT_EQ(2u, received_manager_.ack_frame().received_packet_times.size());
+}
+
 TEST_F(QuicReceivedPacketManagerTest, HasMissingPackets) {
   EXPECT_QUIC_BUG(received_manager_.PeerFirstSendingPacketNumber(),
                   "No packets have been received yet");

quic/core/uber_received_packet_manager.cc

diff --git a/quic/core/uber_received_packet_manager.cc b/quic/core/uber_received_packet_manager.cc
index 8f20b33..c25329c 100644
--- a/quic/core/uber_received_packet_manager.cc
+++ b/quic/core/uber_received_packet_manager.cc
@@ -228,7 +228,8 @@
 
 void UberReceivedPacketManager::set_save_timestamps(bool save_timestamps) {
   for (auto& received_packet_manager : received_packet_managers_) {
-    received_packet_manager.set_save_timestamps(save_timestamps);
+    received_packet_manager.set_save_timestamps(
+        save_timestamps, supports_multiple_packet_number_spaces_);
   }
 }