QUIC: removed check for in-flight packets in computing PTO.

The check is needed for clients in order to unblock a server due to
anti-amplification limits, and it seems to make no sense for servers.
See RFC 9002, A.6 and A.8 for a further explanation.

This makes max_ack_delay to now always account, notably including
PATH_CHALLENGE timers as noted in the last paragraph of 9000, 9.4,
unlike when it was only used when there are packets in flight.

While here, fixed nearby style.
This commit is contained in:
Sergey Kandaurov 2023-05-09 19:42:38 +04:00
parent 1465a34067
commit f0537cf17c

View File

@ -782,15 +782,11 @@ ngx_quic_pto(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx)
qc = ngx_quic_get_connection(c); qc = ngx_quic_get_connection(c);
/* RFC 9002, Appendix A.8. Setting the Loss Detection Timer */ /* RFC 9002, Appendix A.8. Setting the Loss Detection Timer */
duration = qc->avg_rtt;
duration = qc->avg_rtt;
duration += ngx_max(4 * qc->rttvar, NGX_QUIC_TIME_GRANULARITY); duration += ngx_max(4 * qc->rttvar, NGX_QUIC_TIME_GRANULARITY);
duration <<= qc->pto_count; duration <<= qc->pto_count;
if (qc->congestion.in_flight == 0) { /* no in-flight packets */
return duration;
}
if (ctx->level == ssl_encryption_application && c->ssl->handshaked) { if (ctx->level == ssl_encryption_application && c->ssl->handshaked) {
duration += qc->ctp.max_ack_delay << qc->pto_count; duration += qc->ctp.max_ack_delay << qc->pto_count;
} }