dccp ccid-2: use feature-negotiation to report Ack Ratio changes (31daf039) · Commits · 戴 / test

This uses the new feature-negotiation framework to signal Ack Ratio changes, as required by RFC 4341, sec. 6.1.2. That raises some problems with CCID-2, which at the moment can not cope gracefully with Ack Ratios > 1. Since these issues are not directly related to feature negotiation, they are marked by a FIXME. Signed-off-by:

Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by:

Samuel Jero <sj323707@ohio.edu> Acked-by:

Ian McDonald <ian.mcdonald@jandi.co.uk>

net/dccp/ccids/ccid2.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -494,8 +494,16 @@ static void ccid2_hc_tx_packet_recv(struct sock sk, struct sk_buff skb)
		if (hc->tx_rpdupack >= NUMDUPACK) {
		hc->tx_rpdupack = -1; /* XXX lame */
		hc->tx_rpseq = 0;

		#ifdef __CCID2_COPES_GRACEFULLY_WITH_ACK_CONGESTION_CONTROL__
		/*
		* FIXME: Ack Congestion Control is broken; in
		* the current state instabilities occurred with
		* Ack Ratios greater than 1; causing hang-ups
		* and long RTO timeouts. This needs to be fixed
		* before opening up dynamic changes. -- gerrit
		*/
		ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio);
		#endif
		}
		}
		}

net/dccp/proto.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -184,7 +184,6 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
		dp->dccps_rate_last = jiffies;
		dp->dccps_role = DCCP_ROLE_UNDEFINED;
		dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
		dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1;
		dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;

		dccp_init_xmit_timers(sk);

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