dccp: Integrate feature-negotiation insertion code

The patch implements insertion of feature negotiation at the server (listening
and request socket) and the client (connecting socket).

In dccp_insert_options(), several statements have been grouped together now
to achieve (it is hoped) better efficiency by reducing the number of tests
each packet has to go through:
 - Ack Vectors are sent if the packet is neither a Data or a Request packet;
 - a previous issue is corrected - feature negotiation options are allowed
   on DataAck packets (5.8).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 12 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
index 20d5c72d1fdb..86c7a20d39b2 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -554,11 +554,25 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
             dccp_insert_option_ndp(sk, skb))
                 return -1;
 
-        if (!dccp_packet_without_ack(skb)) {
-                if (dmsk->dccpms_send_ack_vector &&
-                    dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
-                    dccp_insert_option_ackvec(sk, skb))
+        if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
+
+                /* Feature Negotiation */
+                if (dccp_feat_insert_opts(dp, NULL, skb))
                         return -1;
+
+                if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
+                        /*
+                         * Obtain RTT sample from Request/Response exchange.
+                         * This is currently used in CCID 3 initialisation.
+                         */
+                        if (dccp_insert_option_timestamp(sk, skb))
+                                return -1;
+
+                } else if (dmsk->dccpms_send_ack_vector &&
+                           dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
+                           dccp_insert_option_ackvec(sk, skb)) {
+                                return -1;
+                }
         }
 
         if (dp->dccps_hc_rx_insert_options) {
@@ -567,14 +581,6 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
                 dp->dccps_hc_rx_insert_options = 0;
         }
 
-        /*
-         * Obtain RTT sample from Request/Response exchange.
-         * This is currently used in CCID 3 initialisation.
-         */
-        if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
-            dccp_insert_option_timestamp(sk, skb))
-                return -1;
-
         if (dp->dccps_timestamp_echo != 0 &&
             dccp_insert_option_timestamp_echo(dp, NULL, skb))
                 return -1;
@@ -587,6 +593,9 @@ int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
 {
         DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 
+        if (dccp_feat_insert_opts(NULL, dreq, skb))
+                return -1;
+
         if (dreq->dreq_timestamp_echo != 0 &&
             dccp_insert_option_timestamp_echo(NULL, dreq, skb))
                 return -1;