diff options
| -rw-r--r-- | net/dccp/ccids/ccid3.c | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 122a716eb877..1a2ffa1d8794 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -161,6 +161,33 @@ static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) */ } +/* + * Update Window Counter using the algorithm from [RFC 4342, 8.1]. + * The algorithm is not applicable if RTT < 4 microseconds. + */ +static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, + struct timeval *now) +{ + suseconds_t delta; + u32 quarter_rtts; + + if (unlikely(hctx->ccid3hctx_rtt < 4)) /* avoid divide-by-zero */ + return; + + delta = timeval_delta(now, &hctx->ccid3hctx_t_last_win_count); + DCCP_BUG_ON(delta < 0); + + quarter_rtts = (u32)delta / (hctx->ccid3hctx_rtt / 4); + + if (quarter_rtts > 0) { + hctx->ccid3hctx_t_last_win_count = *now; + hctx->ccid3hctx_last_win_count += min_t(u32, quarter_rtts, 5); + hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ + + ccid3_pr_debug("now at %#X\n", hctx->ccid3hctx_last_win_count); + } +} + static void ccid3_hc_tx_no_feedback_timer(unsigned long data) { struct sock *sk = (struct sock *)data; @@ -333,6 +360,8 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) */ if (delay - (suseconds_t)hctx->ccid3hctx_delta >= 0) return delay / 1000L; + + ccid3_hc_tx_update_win_count(hctx, &now); break; case TFRC_SSTATE_TERM: DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk); @@ -353,7 +382,6 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) const struct dccp_sock *dp = dccp_sk(sk); struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); struct timeval now; - suseconds_t quarter_rtt; struct dccp_tx_hist_entry *packet; BUG_ON(hctx == NULL); @@ -373,25 +401,6 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) } packet->dccphtx_tstamp = now; packet->dccphtx_seqno = dp->dccps_gss; - /* - * Check if win_count have changed - * Algorithm in "8.1. Window Counter Value" in RFC 4342. - */ - quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count); - if (likely(hctx->ccid3hctx_rtt > 8)) - quarter_rtt /= hctx->ccid3hctx_rtt / 4; - - if (quarter_rtt > 0) { - hctx->ccid3hctx_t_last_win_count = now; - hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count + - min_t(unsigned long, quarter_rtt, 5)) % 16; - ccid3_pr_debug("%s, sk=%p, window changed from " - "%u to %u!\n", - dccp_role(sk), sk, - packet->dccphtx_ccval, - hctx->ccid3hctx_last_win_count); - } - hctx->ccid3hctx_idle = 0; packet->dccphtx_rtt = hctx->ccid3hctx_rtt; packet->dccphtx_sent = 1; |