Mercurial > hg > nginx
changeset 9143:48691bab4474
QUIC: fixed probe-congestion deadlock.
When probe timeout expired while congestion window was exhausted, probe PINGs
could not be sent. As a result, lost packets could not be declared lost and
congestion window could not be freed for new packets. This deadlock
continued until connection idle timeout expiration.
Now PINGs are sent separately from the frame queue without congestion control,
as specified by RFC 9002, Section 7:
An endpoint MUST NOT send a packet if it would cause bytes_in_flight
(see Appendix B.2) to be larger than the congestion window, unless the
packet is sent on a PTO timer expiration (see Section 6.2) or when entering
recovery (see Section 7.3.2).
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 14 Aug 2023 08:28:30 +0400 |
parents | 7e8ee4b7cbf4 |
children | bba136612fe4 |
files | src/event/quic/ngx_event_quic_ack.c src/event/quic/ngx_event_quic_output.c src/event/quic/ngx_event_quic_transport.h |
diffstat | 3 files changed, 12 insertions(+), 57 deletions(-) [+] |
line wrap: on
line diff
--- a/src/event/quic/ngx_event_quic_ack.c Tue Aug 01 11:21:59 2023 +0400 +++ b/src/event/quic/ngx_event_quic_ack.c Mon Aug 14 08:28:30 2023 +0400 @@ -820,9 +820,9 @@ { ngx_uint_t i; ngx_msec_t now; - ngx_queue_t *q, *next; + ngx_queue_t *q; ngx_connection_t *c; - ngx_quic_frame_t *f; + ngx_quic_frame_t *f, frame; ngx_quic_send_ctx_t *ctx; ngx_quic_connection_t *qc; @@ -859,63 +859,23 @@ "quic pto %s pto_count:%ui", ngx_quic_level_name(ctx->level), qc->pto_count); - for (q = ngx_queue_head(&ctx->frames); - q != ngx_queue_sentinel(&ctx->frames); - /* void */) - { - next = ngx_queue_next(q); - f = ngx_queue_data(q, ngx_quic_frame_t, queue); + ngx_memzero(&frame, sizeof(ngx_quic_frame_t)); - if (f->type == NGX_QUIC_FT_PING) { - ngx_queue_remove(q); - ngx_quic_free_frame(c, f); - } - - q = next; - } - - for (q = ngx_queue_head(&ctx->sent); - q != ngx_queue_sentinel(&ctx->sent); - /* void */) - { - next = ngx_queue_next(q); - f = ngx_queue_data(q, ngx_quic_frame_t, queue); + frame.level = ctx->level; + frame.type = NGX_QUIC_FT_PING; - if (f->type == NGX_QUIC_FT_PING) { - ngx_quic_congestion_lost(c, f); - ngx_queue_remove(q); - ngx_quic_free_frame(c, f); - } - - q = next; - } - - /* enforce 2 udp datagrams */ - - f = ngx_quic_alloc_frame(c); - if (f == NULL) { - break; + if (ngx_quic_frame_sendto(c, &frame, 0, qc->path) != NGX_OK + || ngx_quic_frame_sendto(c, &frame, 0, qc->path) != NGX_OK) + { + ngx_quic_close_connection(c, NGX_ERROR); + return; } - - f->level = ctx->level; - f->type = NGX_QUIC_FT_PING; - f->flush = 1; - - ngx_quic_queue_frame(qc, f); - - f = ngx_quic_alloc_frame(c); - if (f == NULL) { - break; - } - - f->level = ctx->level; - f->type = NGX_QUIC_FT_PING; - - ngx_quic_queue_frame(qc, f); } qc->pto_count++; + ngx_quic_set_lost_timer(c); + ngx_quic_connstate_dbg(c); }