[CCID2]: Larger initial windows also for CCID2
RFC 4341, sec. 5 states that "The cwnd parameter is initialized to at most
four packets for new connections, following the rules from [RFC3390]", which
is implemented by this patch.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
net/dccp/ccids/ccid2.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -741,15 +741,25 @@ static void ccid2_hc_tx_packet_recv(stru
static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
+ struct dccp_sock *dp = dccp_sk(sk);
+ u32 max_ratio;
- ccid2_change_cwnd(hctx, 1);
- /* Initialize ssthresh to infinity. This means that we will exit the
- * initial slow-start after the first packet loss. This is what we
- * want.
- */
+ /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */
hctx->ccid2hctx_ssthresh = ~0;
hctx->ccid2hctx_numdupack = 3;
+ /*
+ * RFC 4341, 5: "The cwnd parameter is initialized to at most four
+ * packets for new connections, following the rules from [RFC3390]".
+ * We need to convert the bytes of RFC3390 into the packets of RFC 4341.
+ */
+ hctx->ccid2hctx_cwnd = min(4U, max(2U, 4380U / dp->dccps_mss_cache));
+
+ /* Make sure that Ack Ratio is enabled and within bounds. */
+ max_ratio = DIV_ROUND_UP(hctx->ccid2hctx_cwnd, 2);
+ if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio)
+ dp->dccps_l_ack_ratio = max_ratio;
+
/* XXX init ~ to window size... */
if (ccid2_hc_tx_alloc_seq(hctx))
return -ENOMEM;
-
To unsubscribe from this list: send the line "unsubscribe dccp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
