From: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> Date: Sat, 6 Dec 2008 17:40:57 +0100 > This removes the use of the sysctl and the minisock variable for the Send Ack > Vector feature, as it now is handled fully dynamically via feature negotiation > (i.e. when CCID-2 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. > > There was a FIXME to change the error code when dccp_ackvec_add() fails. > I removed this after finding out that: > * the check whether ackno < ISN is already made earlier, > * this Response is likely the 1st packet with an Ackno that the client gets, > * so when dccp_ackvec_add() fails, the reason is likely not a packet error. > > > Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> > Acked-by: Ian McDonald <ian.mcdonald@xxxxxxxxxxx> Also applied, thanks Gerrit. -- 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
