BBR2 - Fixes and updates

quiche/include/quiche.h

@@ -216,6 +216,7 @@ enum quiche_cc_algorithm {
     QUICHE_CC_RENO = 0,
     QUICHE_CC_CUBIC = 1,
     QUICHE_CC_BBR = 2,
+    QUICHE_CC_BBR2 = 3,
 };
 
 // Sets the congestion control algorithm used.

quiche/src/lib.rs

@@ -4256,6 +4256,8 @@ impl Connection {
             delivered_time: now,
             first_sent_time: now,
             is_app_limited: false,
+            tx_in_flight: 0,
+            lost: 0,
             has_data,
         };
 

quiche/src/recovery/bbr/mod.rs

@@ -323,13 +323,13 @@ fn on_packets_acked(
 }
 
 fn congestion_event(
-    r: &mut Recovery, lost_bytes: usize, time_sent: Instant,
+    r: &mut Recovery, lost_bytes: usize, largest_lost_pkt: &Sent,
     _epoch: packet::Epoch, now: Instant,
 ) {
     r.bbr_state.newly_lost_bytes = lost_bytes;
 
     // Upon entering Fast Recovery.
-    if !r.in_congestion_recovery(time_sent) {
+    if !r.in_congestion_recovery(largest_lost_pkt.time_sent) {
         // Upon entering Fast Recovery.
         bbr_enter_recovery(r, now);
     }
@@ -426,6 +426,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -494,6 +496,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -561,6 +565,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -610,6 +616,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -680,6 +688,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -749,6 +759,8 @@ mod tests {
                 delivered_time: now,
                 first_sent_time: now,
                 is_app_limited: false,
+                tx_in_flight: 0,
+                lost: 0,
                 has_data: false,
             };
 
@@ -801,6 +813,8 @@ mod tests {
             delivered_time: now,
             first_sent_time: now,
             is_app_limited: false,
+            tx_in_flight: 0,
+            lost: 0,
             has_data: false,
         };
 

quiche/src/recovery/bbr2/init.rs

@@ -0,0 +1,90 @@
+// Copyright (C) 2022, Cloudflare, Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright notice,
+//       this list of conditions and the following disclaimer.
+//
+//     * Redistributions in binary form must reproduce the above copyright
+//       notice, this list of conditions and the following disclaimer in the
+//       documentation and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+use super::*;
+use crate::recovery::Recovery;
+
+use std::time::Instant;
+
+// BBR2 Functions at Initialization.
+//
+
+// 4.2.1.  Initialization
+pub fn bbr2_init(r: &mut Recovery) {
+    let rtt = r.rtt();
+    let now = Instant::now();
+
+    let bbr = &mut r.bbr2_state;
+    bbr.min_rtt = rtt;
+    bbr.min_rtt_stamp = now;
+    bbr.probe_rtt_done_stamp = None;
+    bbr.probe_rtt_round_done = false;
+    bbr.prior_cwnd = 0;
+    bbr.idle_restart = false;
+    bbr.extra_acked_interval_start = now;
+    bbr.extra_acked_delivered = 0;
+    bbr.bw_lo = u64::MAX;
+    bbr.bw_hi = u64::MAX;
+    bbr.inflight_lo = usize::MAX;
+    bbr.inflight_hi = usize::MAX;
+    bbr.probe_up_cnt = usize::MAX;
+
+    r.send_quantum = r.max_datagram_size;
+
+    per_loss::bbr2_reset_congestion_signals(r);
+    per_loss::bbr2_reset_lower_bounds(r);
+    bbr2_init_round_counting(r);
+    bbr2_init_full_pipe(r);
+    pacing::bbr2_init_pacing_rate(r);
+    bbr2_enter_startup(r);
+}
+
+// 4.5.1.  BBR.round_count: Tracking Packet-Timed Round Trips
+fn bbr2_init_round_counting(r: &mut Recovery) {
+    let bbr = &mut r.bbr2_state;
+
+    bbr.next_round_delivered = 0;
+    bbr.round_start = false;
+    bbr.round_count = 0;
+}
+
+// 4.3.1.1.  Startup Dynamics
+pub fn bbr2_enter_startup(r: &mut Recovery) {
+    let bbr = &mut r.bbr2_state;
+
+    bbr.state = BBR2StateMachine::Startup;
+    bbr.pacing_gain = STARTUP_PACING_GAIN;
+    bbr.cwnd_gain = STARTUP_CWND_GAIN;
+}
+
+// 4.3.1.2.  Exiting Startup Based on Bandwidth Plateau
+fn bbr2_init_full_pipe(r: &mut Recovery) {
+    let bbr = &mut r.bbr2_state;
+
+    bbr.filled_pipe = false;
+    bbr.full_bw = 0;
+    bbr.full_bw_count = 0;
+}