diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2007-12-17 14:48:47 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-01-28 22:58:22 (GMT) |
| commit | d8d1252f744cb7cebd6ba3a4b7feec31ff23ccde (patch) | |
| tree | acb47c9a5e654a6b5ca3ebf60c8c60d783fb3a65 /net/dccp | |
| parent | 5bd370a63daf62bb5520c258f04e91a4d9d274dd (diff) | |
| download | linux-d8d1252f744cb7cebd6ba3a4b7feec31ff23ccde.tar.xz | |
[CCID3]: Implement rfc3448bis changes to feedback reception
This implements the algorithm to update the allowed sending rate X upon
receiving feedback packets, as described in draft rfc3448bis, 4.2/4.3.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 47 |
1 files changed, 26 insertions, 21 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index a93a556..1156fef 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -429,40 +429,46 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ hctx->ccid3hctx_p = 0; else /* can not exceed 100% */ - hctx->ccid3hctx_p = 1000000 / pinv; + hctx->ccid3hctx_p = scaled_div(1, pinv); /* * Validate new RTT sample and update moving average */ r_sample = dccp_sample_rtt(sk, r_sample); hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); - + /* + * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 + */ if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { - /* - * Larger Initial Windows [RFC 4342, sec. 5] - */ - hctx->ccid3hctx_x = rfc3390_initial_rate(sk); - hctx->ccid3hctx_t_ld = now; + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - ccid3_update_send_interval(hctx); + if (hctx->ccid3hctx_t_rto == 0) { + /* + * Initial feedback packet: Larger Initial Windows (4.2) + */ + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); + hctx->ccid3hctx_t_ld = now; - ccid3_pr_debug("%s(%p), s=%u, MSS=%u, " - "R_sample=%uus, X=%u\n", dccp_role(sk), - sk, hctx->ccid3hctx_s, - dccp_sk(sk)->dccps_mss_cache, r_sample, - (unsigned)(hctx->ccid3hctx_x >> 6)); + ccid3_update_send_interval(hctx); - ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - } else { + goto done_computing_x; + } else if (hctx->ccid3hctx_p == 0) { + /* + * First feedback after nofeedback timer expiry (4.3) + */ + goto done_computing_x; + } + } - /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ - if (hctx->ccid3hctx_p > 0) - hctx->ccid3hctx_x_calc = + /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ + if (hctx->ccid3hctx_p > 0) + hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt, hctx->ccid3hctx_p); - ccid3_hc_tx_update_x(sk, &now); + ccid3_hc_tx_update_x(sk, &now); - ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " +done_computing_x: + ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " "p=%u, X_calc=%u, X_recv=%u, X=%u\n", dccp_role(sk), sk, hctx->ccid3hctx_rtt, r_sample, @@ -470,7 +476,6 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) hctx->ccid3hctx_x_calc, (unsigned)(hctx->ccid3hctx_x_recv >> 6), (unsigned)(hctx->ccid3hctx_x >> 6)); - } /* unschedule no feedback timer */ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); |