Commit 92d31920 authored by Gerrit Renker's avatar Gerrit Renker Committed by David S. Miller
Browse files

[DCCP]: Shift the retransmit timer for active-close into output.c 



When performing active close, RFC 4340, 8.3. requires to retransmit the
Close/CloseReq with a backoff-retransmit timer starting at intially 2 RTTs.

This patch shifts the existing code for active-close retransmit timer
into output.c, so that the retransmit timer is started when the first
Close/CloseReq is sent. Previously, the timer was started when, after
releasing the socket in dccp_close(), the actively-closing side had not yet
reached the CLOSED/TIMEWAIT state.

The patch further reduces the initial timeout from 3 seconds to the required
2 RTTs, where - in absence of a known RTT - the fallback value specified in
RFC 4340, 3.4 is used.

Signed-off-by: default avatarGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-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 09f7709f

net/dccp/output.c

+12 −1
Original line number Diff line number Diff line
@@ -574,7 +574,18 @@ void dccp_send_close(struct sock *sk, const int active) 
		dccp_write_xmit(sk, 1);

		dccp_skb_entail(sk, skb);

		dccp_transmit_skb(sk, skb_clone(skb, prio));

		/* FIXME do we need a retransmit timer here? */

		/*

		 * Retransmission timer for active-close: RFC 4340, 8.3 requires

		 * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ

		 * state can be left. The initial timeout is 2 RTTs.

		 * Since RTT measurement is done by the CCIDs, there is no easy

		 * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4

		 * is too low (200ms); we use a high value to avoid unnecessary

		 * retransmissions when the link RTT is > 0.2 seconds.

		 * FIXME: Let main module sample RTTs and use that instead.

		 */

		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

					  DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);

	} else

		dccp_transmit_skb(sk, skb);

}

net/dccp/proto.c

+0 −18
Original line number Diff line number Diff line
@@ -996,24 +996,6 @@ adjudge_to_death: 
	if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)

		goto out;



	/*

	 * The last release_sock may have processed the CLOSE or RESET

	 * packet moving sock to CLOSED state, if not we have to fire

	 * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination"

	 * in draft-ietf-dccp-spec-11. -acme

	 */

	if (sk->sk_state == DCCP_CLOSING) {

		/* FIXME: should start at 2 * RTT */

		/* Timer for repeating the CLOSE/CLOSEREQ until an answer. */

		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

					  inet_csk(sk)->icsk_rto,

					  DCCP_RTO_MAX);

#if 0

		/* Yeah, we should use sk->sk_prot->orphan_count, etc */

		dccp_set_state(sk, DCCP_CLOSED);

#endif

	}



	if (sk->sk_state == DCCP_CLOSED)

		inet_csk_destroy_sock(sk);

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