QUIC: separated path validation retransmit backoff.

Path validation packets containing PATH_CHALLENGE frames are sent separately
from regular frame queue, because of the need to use a decicated path and pad
the packets.  The packets are sent periodically, separately from the regular
probe/lost detection mechanism.  A path validation packet is resent up to 3
times, each time after PTO expiration, with increasing per-path PTO backoff.
This commit is contained in:
Sergey Kandaurov 2023-05-09 19:42:39 +04:00
parent f0537cf17c
commit f706744165
2 changed files with 10 additions and 7 deletions

View File

@ -736,7 +736,8 @@ ngx_quic_set_lost_timer(ngx_connection_t *c)
q = ngx_queue_last(&ctx->sent);
f = ngx_queue_data(q, ngx_quic_frame_t, queue);
w = (ngx_msec_int_t) (f->last + ngx_quic_pto(c, ctx) - now);
w = (ngx_msec_int_t) (f->last + (ngx_quic_pto(c, ctx) << qc->pto_count)
- now);
if (w < 0) {
w = 0;
@ -785,10 +786,9 @@ ngx_quic_pto(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx)
duration = qc->avg_rtt;
duration += ngx_max(4 * qc->rttvar, NGX_QUIC_TIME_GRANULARITY);
duration <<= qc->pto_count;
if (ctx->level == ssl_encryption_application && c->ssl->handshaked) {
duration += qc->ctp.max_ack_delay << qc->pto_count;
duration += qc->ctp.max_ack_delay;
}
return duration;
@ -846,7 +846,9 @@ ngx_quic_pto_handler(ngx_event_t *ev)
continue;
}
if ((ngx_msec_int_t) (f->last + ngx_quic_pto(c, ctx) - now) > 0) {
if ((ngx_msec_int_t) (f->last + (ngx_quic_pto(c, ctx) << qc->pto_count)
- now) > 0)
{
continue;
}

View File

@ -496,6 +496,7 @@ ngx_quic_validate_path(ngx_connection_t *c, ngx_quic_path_t *path)
"quic initiated validation of path seq:%uL", path->seqnum);
path->validating = 1;
path->tries = 0;
if (RAND_bytes(path->challenge1, 8) != 1) {
return NGX_ERROR;
@ -513,7 +514,6 @@ ngx_quic_validate_path(ngx_connection_t *c, ngx_quic_path_t *path)
pto = ngx_quic_pto(c, ctx);
path->expires = ngx_current_msec + pto;
path->tries = NGX_QUIC_PATH_RETRIES;
if (!qc->path_validation.timer_set) {
ngx_add_timer(&qc->path_validation, pto);
@ -578,7 +578,6 @@ ngx_quic_path_validation_handler(ngx_event_t *ev)
qc = ngx_quic_get_connection(c);
ctx = ngx_quic_get_send_ctx(qc, ssl_encryption_application);
pto = ngx_quic_pto(c, ctx);
next = -1;
now = ngx_current_msec;
@ -605,7 +604,9 @@ ngx_quic_path_validation_handler(ngx_event_t *ev)
continue;
}
if (--path->tries) {
if (++path->tries < NGX_QUIC_PATH_RETRIES) {
pto = ngx_quic_pto(c, ctx) << path->tries;
path->expires = ngx_current_msec + pto;
if (next == -1 || pto < next) {