diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/event/ngx_event_quic.c | 102 | ||||
| -rw-r--r-- | src/event/ngx_event_quic.h | 3 |
2 files changed, 96 insertions, 9 deletions
diff --git a/src/event/ngx_event_quic.c b/src/event/ngx_event_quic.c index 526427c2e..4f380658d 100644 --- a/src/event/ngx_event_quic.c +++ b/src/event/ngx_event_quic.c @@ -99,6 +99,11 @@ struct ngx_quic_connection_s { ngx_queue_t free_frames; ngx_msec_t last_cc; + ngx_msec_t latest_rtt; + ngx_msec_t avg_rtt; + ngx_msec_t min_rtt; + ngx_msec_t rttvar; + #if (NGX_DEBUG) ngx_uint_t nframes; #endif @@ -189,7 +194,10 @@ static ngx_int_t ngx_quic_send_new_token(ngx_connection_t *c); static ngx_int_t ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, ngx_quic_ack_frame_t *f); static ngx_int_t ngx_quic_handle_ack_frame_range(ngx_connection_t *c, - ngx_quic_send_ctx_t *ctx, uint64_t min, uint64_t max); + ngx_quic_send_ctx_t *ctx, uint64_t min, uint64_t max, + ngx_msec_t *send_time); +static void ngx_quic_rtt_sample(ngx_connection_t *c, ngx_quic_ack_frame_t *ack, + enum ssl_encryption_level_t level, ngx_msec_t send_time); static void ngx_quic_handle_stream_ack(ngx_connection_t *c, ngx_quic_frame_t *f); @@ -665,6 +673,14 @@ ngx_quic_new_connection(ngx_connection_t *c, ngx_ssl_t *ssl, ngx_quic_tp_t *tp, ngx_queue_init(&qc->free_frames); + qc->avg_rtt = NGX_QUIC_INITIAL_RTT; + qc->rttvar = NGX_QUIC_INITIAL_RTT / 2; + qc->min_rtt = NGX_TIMER_INFINITE; + + /* + * qc->latest_rtt = 0 + */ + qc->retransmit.log = c->log; qc->retransmit.data = c; qc->retransmit.handler = ngx_quic_retransmit_handler; @@ -2210,6 +2226,7 @@ ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, ssize_t n; u_char *pos, *end; uint64_t gap, range; + ngx_msec_t send_time; ngx_uint_t i, min, max; ngx_quic_send_ctx_t *ctx; @@ -2234,7 +2251,9 @@ ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, min = ack->largest - ack->first_range; max = ack->largest; - if (ngx_quic_handle_ack_frame_range(c, ctx, min, max) != NGX_OK) { + if (ngx_quic_handle_ack_frame_range(c, ctx, min, max, &send_time) + != NGX_OK) + { return NGX_ERROR; } @@ -2243,6 +2262,18 @@ ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, ctx->largest_ack = max; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "quic updated largest received ack: %ui", max); + + /* + * An endpoint generates an RTT sample on receiving an + * ACK frame that meets the following two conditions: + * + * - the largest acknowledged packet number is newly acknowledged + * - at least one of the newly acknowledged packets was ack-eliciting. + */ + + if (send_time != NGX_TIMER_INFINITE) { + ngx_quic_rtt_sample(c, ack, pkt->level, send_time); + } } pos = ack->ranges_start; @@ -2274,7 +2305,9 @@ ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, min = max - range + 1; - if (ngx_quic_handle_ack_frame_range(c, ctx, min, max) != NGX_OK) { + if (ngx_quic_handle_ack_frame_range(c, ctx, min, max, &send_time) + != NGX_OK) + { return NGX_ERROR; } } @@ -2285,8 +2318,9 @@ ngx_quic_handle_ack_frame(ngx_connection_t *c, ngx_quic_header_t *pkt, static ngx_int_t ngx_quic_handle_ack_frame_range(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx, - uint64_t min, uint64_t max) + uint64_t min, uint64_t max, ngx_msec_t *send_time) { + uint64_t found_num; ngx_uint_t found; ngx_queue_t *q; ngx_quic_frame_t *f; @@ -2294,26 +2328,30 @@ ngx_quic_handle_ack_frame_range(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx, qc = c->quic; + *send_time = NGX_TIMER_INFINITE; found = 0; + found_num = 0; - q = ngx_queue_head(&ctx->sent); + q = ngx_queue_last(&ctx->sent); while (q != ngx_queue_sentinel(&ctx->sent)) { f = ngx_queue_data(q, ngx_quic_frame_t, queue); + q = ngx_queue_prev(q); if (f->pnum >= min && f->pnum <= max) { ngx_quic_congestion_ack(c, f); ngx_quic_handle_stream_ack(c, f); - q = ngx_queue_next(q); + if (f->pnum > found_num || !found) { + *send_time = f->last; + found_num = f->pnum; + } + ngx_queue_remove(&f->queue); ngx_quic_free_frame(c, f); found = 1; - - } else { - q = ngx_queue_next(q); } } @@ -2343,6 +2381,52 @@ ngx_quic_handle_ack_frame_range(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx, static void +ngx_quic_rtt_sample(ngx_connection_t *c, ngx_quic_ack_frame_t *ack, + enum ssl_encryption_level_t level, ngx_msec_t send_time) +{ + ngx_msec_t latest_rtt, ack_delay, adjusted_rtt, rttvar_sample; + ngx_quic_connection_t *qc; + + qc = c->quic; + + latest_rtt = ngx_current_msec - send_time; + qc->latest_rtt = latest_rtt; + + if (qc->min_rtt == NGX_TIMER_INFINITE) { + qc->min_rtt = latest_rtt; + qc->avg_rtt = latest_rtt; + qc->rttvar = latest_rtt / 2; + + } else { + qc->min_rtt = ngx_min(qc->min_rtt, latest_rtt); + + + if (level == ssl_encryption_application) { + ack_delay = ack->delay * (1 << qc->ctp.ack_delay_exponent) / 1000; + ack_delay = ngx_min(ack_delay, qc->ctp.max_ack_delay); + + } else { + ack_delay = 0; + } + + adjusted_rtt = latest_rtt; + + if (qc->min_rtt + ack_delay < latest_rtt) { + adjusted_rtt -= ack_delay; + } + + qc->avg_rtt = 0.875 * qc->avg_rtt + 0.125 * adjusted_rtt; + rttvar_sample = ngx_abs((ngx_msec_int_t) (qc->avg_rtt - adjusted_rtt)); + qc->rttvar = 0.75 * qc->rttvar + 0.25 * rttvar_sample; + } + + ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, + "quic rtt sample: latest %M, min %M, avg %M, var %M", + latest_rtt, qc->min_rtt, qc->avg_rtt, qc->rttvar); +} + + +static void ngx_quic_handle_stream_ack(ngx_connection_t *c, ngx_quic_frame_t *f) { uint64_t sent, unacked; diff --git a/src/event/ngx_event_quic.h b/src/event/ngx_event_quic.h index 02ee03869..3ff54b2d4 100644 --- a/src/event/ngx_event_quic.h +++ b/src/event/ngx_event_quic.h @@ -41,6 +41,9 @@ #define NGX_QUIC_MAX_TOKEN_SIZE 32 /* sizeof(struct in6_addr) + sizeof(ngx_msec_t) up to AES-256 block size */ +/* quic-recovery, section 6.2.2, kInitialRtt */ +#define NGX_QUIC_INITIAL_RTT 333 /* ms */ + #define NGX_QUIC_HARDCODED_PTO 1000 /* 1s, TODO: collect */ #define NGX_QUIC_CC_MIN_INTERVAL 1000 /* 1s */ |