From 386329d3cf207e0a52056d195fefb4e85dfc8c26 Mon Sep 17 00:00:00 2001 From: Sergey Kandaurov Date: Tue, 12 Dec 2023 20:21:12 +0400 Subject: [PATCH] QUIC: path aware in-flight bytes accounting. On-packet acknowledgement is made path aware, as per RFC 9000, Section 9.4: Packets sent on the old path MUST NOT contribute to congestion control or RTT estimation for the new path. To make this possible in a single congestion control context, the first packet to be sent after the new path has been validated, which includes resetting the congestion controller and RTT estimator, is now remembered in the connection. Packets sent previously, such as on the old path, are not taken into account. Note that although the packet number is saved per-connection, the added checks affect application level packets only. For non-application level packets, which are only processed prior to the handshake is complete, the remembered packet number remains set to zero. --- src/event/quic/ngx_event_quic_ack.c | 8 ++++++++ src/event/quic/ngx_event_quic_connection.h | 2 ++ src/event/quic/ngx_event_quic_migration.c | 6 ++++++ 3 files changed, 16 insertions(+) diff --git a/src/event/quic/ngx_event_quic_ack.c b/src/event/quic/ngx_event_quic_ack.c index deeaae1e3..c7ffd44dd 100644 --- a/src/event/quic/ngx_event_quic_ack.c +++ b/src/event/quic/ngx_event_quic_ack.c @@ -325,6 +325,10 @@ ngx_quic_congestion_ack(ngx_connection_t *c, ngx_quic_frame_t *f) qc = ngx_quic_get_connection(c); cg = &qc->congestion; + if (f->pnum < qc->rst_pnum) { + return; + } + blocked = (cg->in_flight >= cg->window) ? 1 : 0; cg->in_flight -= f->plen; @@ -667,6 +671,10 @@ ngx_quic_congestion_lost(ngx_connection_t *c, ngx_quic_frame_t *f) qc = ngx_quic_get_connection(c); cg = &qc->congestion; + if (f->pnum < qc->rst_pnum) { + return; + } + blocked = (cg->in_flight >= cg->window) ? 1 : 0; cg->in_flight -= f->plen; diff --git a/src/event/quic/ngx_event_quic_connection.h b/src/event/quic/ngx_event_quic_connection.h index ae771bcc5..824c92b57 100644 --- a/src/event/quic/ngx_event_quic_connection.h +++ b/src/event/quic/ngx_event_quic_connection.h @@ -266,6 +266,8 @@ struct ngx_quic_connection_s { ngx_quic_streams_t streams; ngx_quic_congestion_t congestion; + uint64_t rst_pnum; /* first on validated path */ + off_t received; ngx_uint_t error; diff --git a/src/event/quic/ngx_event_quic_migration.c b/src/event/quic/ngx_event_quic_migration.c index 58f3fc545..3c1bbaf43 100644 --- a/src/event/quic/ngx_event_quic_migration.c +++ b/src/event/quic/ngx_event_quic_migration.c @@ -110,6 +110,7 @@ ngx_quic_handle_path_response_frame(ngx_connection_t *c, ngx_uint_t rst; ngx_queue_t *q; ngx_quic_path_t *path, *prev; + ngx_quic_send_ctx_t *ctx; ngx_quic_connection_t *qc; qc = ngx_quic_get_connection(c); @@ -174,6 +175,11 @@ valid: } if (rst) { + /* prevent old path packets contribution to congestion control */ + + ctx = ngx_quic_get_send_ctx(qc, ssl_encryption_application); + qc->rst_pnum = ctx->pnum; + ngx_memzero(&qc->congestion, sizeof(ngx_quic_congestion_t)); qc->congestion.window = ngx_min(10 * qc->tp.max_udp_payload_size,