This is a Re-sent after discusssion with Ian. I have renamed
the variable also, as the term got too long for the 80 columns fixed
linelength - hope `t_nfb' is ok as mnemonic for the nofeedback timeout.
-----------------------> Commit Message <----------------------------
[CCID 3]: Set NoFeedback Timeout according to RFC 3448
This corrects the setting of the nofeedback timer with
regard to RFC 3448 - previously it was not set to
max(4*R, 2*s/X) as specified. Using the maximum of 1 second
as upper bound (as it was done before) can have detrimental
effects, especially if R is small.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/ccids/ccid3.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -183,7 +183,7 @@ static void ccid3_hc_tx_no_feedback_time
{
struct sock *sk = (struct sock *)data;
struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
- unsigned long next_tmout = USEC_PER_SEC / 5;
+ unsigned long t_nfb = USEC_PER_SEC / 5;
bh_lock_sock(sk);
if (sock_owned_by_user(sk)) {
@@ -208,7 +208,7 @@ static void ccid3_hc_tx_no_feedback_time
hctx->ccid3hctx_x);
/* 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;
+ t_nfb = TFRC_INITIAL_TIMEOUT;
ccid3_update_send_time(hctx);
break;
case TFRC_SSTATE_FBACK:
@@ -246,10 +246,9 @@ static void ccid3_hc_tx_no_feedback_time
}
/*
* Schedule no feedback timer to expire in
- * max(4 * t_RTO, 2 * s/X) = max(4 * t_RTO, 2 * t_ipi)
- * XXX This is non-standard, RFC 3448, 4.3 uses 4 * R
+ * max(4 * R, 2 * s/X) = max(4 * R, 2 * t_ipi)
*/
- next_tmout = max(hctx->ccid3hctx_t_rto, 2*hctx->ccid3hctx_t_ipi);
+ t_nfb = max(4 * hctx->ccid3hctx_rtt, 2 * hctx->ccid3hctx_t_ipi);
break;
case TFRC_SSTATE_NO_SENT:
DCCP_BUG("Illegal %s state NO_SENT, sk=%p", dccp_role(sk), sk);
@@ -262,7 +261,7 @@ static void ccid3_hc_tx_no_feedback_time
restart_timer:
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + usecs_to_jiffies(next_tmout));
+ jiffies + usecs_to_jiffies(t_nfb));
out:
bh_unlock_sock(sk);
sock_put(sk);
@@ -420,7 +419,7 @@ static void ccid3_hc_tx_packet_recv(stru
struct ccid3_options_received *opt_recv;
struct dccp_tx_hist_entry *packet;
struct timeval now;
- unsigned long next_tmout;
+ unsigned long t_nfb;
u32 t_elapsed;
u32 pinv;
u32 r_sample;
@@ -523,18 +522,17 @@ static void ccid3_hc_tx_packet_recv(stru
USEC_PER_SEC );
/*
* Schedule no feedback timer to expire in
- * max(4 * t_RTO, 2 * s/X) = max(4 * t_RTO, 2 * t_ipi)
- * XXX This is non-standard, RFC 3448, 4.3 uses 4 * R
+ * max(4 * R, 2 * s/X) = max(4 * R, 2 * t_ipi)
*/
- next_tmout = max(hctx->ccid3hctx_t_rto, 2*hctx->ccid3hctx_t_ipi);
+ t_nfb = max(4 * hctx->ccid3hctx_rtt, 2 * hctx->ccid3hctx_t_ipi);
ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
"expire in %lu jiffies (%luus)\n",
dccp_role(sk), sk,
- usecs_to_jiffies(next_tmout), next_tmout);
+ usecs_to_jiffies(t_nfb), t_nfb);
sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
- jiffies + usecs_to_jiffies(next_tmout));
+ jiffies + usecs_to_jiffies(t_nfb));
/* set idle flag */
hctx->ccid3hctx_idle = 1;
-
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