[DCCP]: Initial feature negotiation implementation
Still needs more work, but boots and doesn't crashes, even
does some negotiation!
18:38:52.174934 127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2>
18:38:52.218526 127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2>
18:38:52.185398 127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212>
:-)
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index aa34b57..d7c7866 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -141,6 +141,17 @@
{
struct inet_connection_sock *icsk = inet_csk(sk);
+ /* retransmit timer is used for feature negotiation throughout
+ * connection. In this case, no packet is re-transmitted, but rather an
+ * ack is generated and pending changes are splaced into its options.
+ */
+ if (sk->sk_send_head == NULL) {
+ dccp_pr_debug("feat negotiation retransmit timeout %p\n", sk);
+ if (sk->sk_state == DCCP_OPEN)
+ dccp_send_ack(sk);
+ goto backoff;
+ }
+
/*
* sk->sk_send_head has to have one skb with
* DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
@@ -177,6 +188,7 @@
goto out;
}
+backoff:
icsk->icsk_backoff++;
icsk->icsk_retransmits++;