From: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> Date: Thu, 6 Nov 2008 06:40:14 +0100 > This provides a missing link in the code chain, as several features implicitly > depend and/or rely on the choice of CCID. Most notably, this is the Send Ack Vector > feature, but also Ack Ratio and Send Loss Event Rate (also taken care of). > > For Send Ack Vector, the situation is as follows: > * since CCID2 mandates the use of Ack Vectors, there is no point in allowing > endpoints which use CCID2 to disable Ack Vector features such a connection; > > * a peer with a TX CCID of CCID2 will always expect Ack Vectors, and a peer > with a RX CCID of CCID2 must always send Ack Vectors (RFC 4341, sec. 4); > > * for all other CCIDs, the use of (Send) Ack Vector is optional and thus > negotiable. However, this implies that the code negotiating the use of Ack > Vectors also supports it (i.e. is able to supply and to either parse or > ignore received Ack Vectors). Since this is not the case (CCID-3 has no Ack > Vector support), the use of Ack Vectors is here disabled, with a comment > in the source code. > > An analogous consideration arises for the Send Loss Event Rate feature, > since the CCID-3 implementation does not support the loss interval options > of RFC 4342. To make such use explicit, corresponding feature-negotiation > options are inserted which signal the use of the loss event rate option, > as it is used by the CCID3 code. > > Lastly, the values of the Ack Ratio feature are matched to the choice of CCID. > > The patch implements this as a function which is called after the user has > made all other registrations for changing default values of features. > > The table is variable-length, the reserved (and hence for feature-negotiation > invalid, confirmed by considering section 19.4 of RFC 4340) feature number `0' > is used to mark the end of the table. > > Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> > Acked-by: Ian McDonald <ian.mcdonald@xxxxxxxxxxx> Also applied, thanks. -- 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
