diff options
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 9297fca7868..4342caf5325 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -100,19 +100,24 @@ static void ccid3_hc_tx_set_state(struct sock *sk, hctx->ccid3hctx_state = state; } -/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */ -static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx) +/* + * Recalculate scheduled nominal send time t_nom, inter-packet interval + * t_ipi, and delta value. Should be called after each change to X. + */ +static inline void ccid3_update_send_time(struct ccid3_hc_tx_sock *hctx) { + timeval_sub_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); + + /* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */ hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_x); -} -/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ -static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx) -{ + /* Update nominal send time with regard to the new t_ipi */ + timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); + + /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, TFRC_OPSYS_HALF_TIME_GRAN); } - /* * Update X by * If (p > 0) @@ -126,6 +131,7 @@ static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx) static void ccid3_hc_tx_update_x(struct sock *sk) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + const __u32 old_x = hctx->ccid3hctx_x; /* To avoid large error in calcX */ if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) { @@ -149,6 +155,8 @@ static void ccid3_hc_tx_update_x(struct sock *sk) hctx->ccid3hctx_t_ld = now; } } + if (hctx->ccid3hctx_x != old_x) + ccid3_update_send_time(hctx); } static void ccid3_hc_tx_no_feedback_timer(unsigned long data) @@ -184,11 +192,7 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) /* The value of R is still undefined and so we can not recompute * the timout value. Keep initial value as per [RFC 4342, 5]. */ next_tmout = TFRC_INITIAL_TIMEOUT; - /* - * FIXME - not sure above calculation is correct. See section - * 5 of CCID3 11 should adjust tx_t_ipi and double that to - * achieve it really - */ + ccid3_update_send_time(hctx); break; case TFRC_SSTATE_FBACK: /* @@ -479,17 +483,9 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) /* unschedule no feedback timer */ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); - /* Update sending rate */ + /* Update sending rate (and likely t_ipi, t_nom, and delta) */ ccid3_hc_tx_update_x(sk); - /* Update next send time */ - timeval_sub_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - ccid3_calc_new_t_ipi(hctx); - timeval_add_usecs(&hctx->ccid3hctx_t_nom, - hctx->ccid3hctx_t_ipi); - ccid3_calc_new_delta(hctx); - /* remove all packets older than the one acked from history */ dccp_tx_hist_purge_older(ccid3_tx_hist, &hctx->ccid3hctx_hist, packet); |