dccp: Limit feature negotiation to connection setup phase

This patch limits feature (capability) negotation to the connection setup phase:

 1. Although it is theoretically possible to perform feature negotiation at any
    time (and RFC 4340 supports this), in practice this is prohibitively complex,
    as it requires to put traffic on hold for each new negotiation.
 2. As a byproduct of restricting feature negotiation to connection setup, the
    feature-negotiation retransmit timer is no longer required. This part is now
    mapped onto the protocol-level retransmission.
    Details indicating why timers are no longer needed can be found on
    http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/feature_negotiation/\
	                                      implementation_notes.html

This patch disables anytime negotiation, subsequent patches work out full
feature negotiation support for connection setup.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 18 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
index 0809b63cb055..67a171a1268c 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -489,7 +489,6 @@ static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
 
 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
 {
-        struct dccp_sock *dp = dccp_sk(sk);
         struct dccp_minisock *dmsk = dccp_msk(sk);
         struct dccp_opt_pend *opt, *next;
         int change = 0;
@@ -530,23 +529,6 @@ static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
                 }
         }
 
-        /* Retransmit timer.
-         * If this is the master listening sock, we don't set a timer on it.  It
-         * should be fine because if the dude doesn't receive our RESPONSE
-         * [which will contain the CHANGE] he will send another REQUEST which
-         * will "retrnasmit" the change.
-         */
-        if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
-                dccp_pr_debug("reset feat negotiation timer %p\n", sk);
-
-                /* XXX don't reset the timer on re-transmissions.  I.e. reset it
-                 * only when sending new stuff i guess.  Currently the timer
-                 * never backs off because on re-transmission it just resets it!
-                 */
-                inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
-                                          inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
-        }
-
         return 0;
 }