diff options
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 84 |
1 files changed, 40 insertions, 44 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 8d33a09608e..35123c19a08 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -133,12 +133,23 @@ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; const __u64 old_x = hctx->ccid3hctx_x; + /* + * Handle IDLE periods: do not reduce below RFC3390 initial sending rate + * when idling [RFC 4342, 5.1]. See also draft-ietf-dccp-rfc3448bis. + * For consistency with X and X_recv, min_rate is also scaled by 2^6. + */ + if (unlikely(hctx->ccid3hctx_idle)) { + min_rate = rfc3390_initial_rate(sk); + min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); + } + if (hctx->ccid3hctx_p > 0) { hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, - hctx->ccid3hctx_x_recv * 2); + min_rate); hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, (((__u64)hctx->ccid3hctx_s) << 6) / TFRC_T_MBI); @@ -147,7 +158,7 @@ static void ccid3_hc_tx_update_x(struct sock *sk, struct timeval *now) (suseconds_t)hctx->ccid3hctx_rtt >= 0) { hctx->ccid3hctx_x = - max(2 * min(hctx->ccid3hctx_x, hctx->ccid3hctx_x_recv), + max(min(2 * hctx->ccid3hctx_x, min_rate), scaled_div(((__u64)hctx->ccid3hctx_s) << 6, hctx->ccid3hctx_rtt)); hctx->ccid3hctx_t_ld = *now; @@ -209,6 +220,7 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) { struct sock *sk = (struct sock *)data; struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + struct timeval now; unsigned long t_nfb = USEC_PER_SEC / 5; bh_lock_sock(sk); @@ -221,6 +233,8 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, ccid3_tx_state_name(hctx->ccid3hctx_state)); + hctx->ccid3hctx_idle = 1; + switch (hctx->ccid3hctx_state) { case TFRC_SSTATE_NO_FBACK: /* RFC 3448, 4.4: Halve send rate directly */ @@ -239,49 +253,33 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) break; case TFRC_SSTATE_FBACK: /* - * Check if IDLE since last timeout and recv rate is less than - * 4 packets (in units of 64*bytes/sec) per RTT + * Modify the cached value of X_recv [RFC 3448, 4.4] + * + * If (p == 0 || X_calc > 2 * X_recv) + * X_recv = max(X_recv / 2, s / (2 * t_mbi)); + * Else + * X_recv = X_calc / 4; + * + * Note that X_recv is scaled by 2^6 while X_calc is not */ - if (!hctx->ccid3hctx_idle || - (hctx->ccid3hctx_x_recv >= 4 * - scaled_div(((__u64)hctx->ccid3hctx_s) << 6, - hctx->ccid3hctx_rtt))) { - struct timeval now; + BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); - ccid3_pr_debug("%s(%p, state=%s), not idle\n", - dccp_role(sk), sk, - ccid3_tx_state_name(hctx->ccid3hctx_state)); + if (hctx->ccid3hctx_p == 0 || + (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5))) { - /* - * Modify the cached value of X_recv [RFC 3448, 4.4] - * - * If (p == 0 || X_calc > 2 * X_recv) - * X_recv = max(X_recv / 2, s / (2 * t_mbi)); - * Else - * X_recv = X_calc / 4; - * - * Note that X_recv is scaled by 2^6 while X_calc is not - */ - BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); - - if (hctx->ccid3hctx_p == 0 || - (hctx->ccid3hctx_x_calc > - (hctx->ccid3hctx_x_recv >> 5))) { - - hctx->ccid3hctx_x_recv = - max(hctx->ccid3hctx_x_recv / 2, - (((__u64)hctx->ccid3hctx_s) << 6) / - (2 * TFRC_T_MBI)); - - if (hctx->ccid3hctx_p == 0) - dccp_timestamp(sk, &now); - } else { - hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; - hctx->ccid3hctx_x_recv <<= 4; - } - /* Now recalculate X [RFC 3448, 4.3, step (4)] */ - ccid3_hc_tx_update_x(sk, &now); + hctx->ccid3hctx_x_recv = + max(hctx->ccid3hctx_x_recv / 2, + (((__u64)hctx->ccid3hctx_s) << 6) / + (2 * TFRC_T_MBI)); + + if (hctx->ccid3hctx_p == 0) + dccp_timestamp(sk, &now); + } else { + hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; + hctx->ccid3hctx_x_recv <<= 4; } + /* Now recalculate X [RFC 3448, 4.3, step (4)] */ + ccid3_hc_tx_update_x(sk, &now); /* * Schedule no feedback timer to expire in * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) @@ -296,8 +294,6 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) goto out; } - hctx->ccid3hctx_idle = 1; - restart_timer: sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, jiffies + usecs_to_jiffies(t_nfb)); @@ -377,6 +373,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) /* prepare to send now (add options etc.) */ dp->dccps_hc_tx_insert_options = 1; DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; + hctx->ccid3hctx_idle = 0; /* set the nominal send time for the next following packet */ timeval_add_usecs(&hctx->ccid3hctx_t_nom, hctx->ccid3hctx_t_ipi); @@ -407,7 +404,6 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, packet->dccphtx_seqno = dccp_sk(sk)->dccps_gss; packet->dccphtx_rtt = hctx->ccid3hctx_rtt; packet->dccphtx_sent = 1; - hctx->ccid3hctx_idle = 0; } static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |