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Commit b00d2bbc authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
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[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: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: default avatarIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e18d7a98

net/dccp/ccids/ccid2.c

+15 −5
Original line number Diff line number Diff line
@@ -741,15 +741,25 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) 
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;