From b235dc4abbc1356284bd0dc730efa711f394e0e2 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: dccp ccid-2: Phase out the use of boolean Ack Vector sysctl This removes the use of the sysctl and the minisock variable for the Send Ack Vector feature, which is now handled fully dynamically via feature negotiation; i.e. when CCID2 is enabled, Ack Vectors are automatically enabled (as per RFC 4341, 4.). Using a sysctl in parallel to this implementation would open the door to crashes, since much of the code relies on tests of the boolean minisock / sysctl variable. Thus, this patch replaces all tests of type if (dccp_msk(sk)->dccpms_send_ack_vector) /* ... */ with if (dp->dccps_hc_rx_ackvec != NULL) /* ... */ The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature negotiation concluded that Ack Vectors are to be used on the half-connection. Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child), so that the test is a valid one. The activation handler for Ack Vectors is called as soon as the feature negotiation has concluded at the * server when the Ack marking the transition RESPOND => OPEN arrives; * client after it has sent its ACK, marking the transition REQUEST => PARTOPEN. Adding the sequence number of the Response packet to the Ack Vector has been removed, since (a) connection establishment implies that the Response has been received; (b) the CCIDs only look at packets received in the (PART)OPEN state, i.e. this entry will always be ignored; (c) it can not be used for anything useful - to detect loss for instance, only packets received after the loss can serve as pseudo-dupacks. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald --- Documentation/networking/dccp.txt | 3 --- 1 file changed, 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt index 1403745ab40..7a3bb1abb83 100644 --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -133,9 +133,6 @@ retries2 importance for retransmitted acknowledgments and feature negotiation, data packets are never retransmitted. Analogue of tcp_retries2. -send_ackvec = 1 - Whether or not to send Ack Vector options (sec. 11.5). - tx_ccid = 2 Default CCID for the sender-receiver half-connection. Depending on the choice of CCID, the Send Ack Vector feature is enabled automatically. -- cgit v1.2.3-18-g5258