[DCCP]: Send Reset upon Sync in state REQUEST

This fixes the code to correspond to RFC 4340, 7.5.4, which states the
exception that a Sync received in state REQUEST generates a Reset (not
a SyncAck).

To achieve this, only a small change is required. Since
dccp_rcv_request_sent_state_process() already uses the correct Reset Code
number 4 ("Packet Error"), we only need to shift the if-statement a few
lines further down.

(To test this case: replace DCCP_PKT_RESPONSE with DCCP_PKT_SYNC
                    in dccp_make_response.)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>

1 files changed, 3 insertions, 5 deletions

diff --git a/net/dccp/input.c b/net/dccp/input.c
index cde0e704dfce..86ad3ba0649a 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -540,11 +540,6 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                 return 0;
         }
 
-        if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
-                dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
-                goto discard;
-        }
-
         switch (sk->sk_state) {
         case DCCP_CLOSED:
                 dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
@@ -575,6 +570,9 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                         sk_wake_async(sk, 0, POLL_OUT);
                         break;
                 }
+        } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
+                dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
+                goto discard;
         }
 
         if (!queued) {