[DCCP]: Add support for abortive release

This continues from the previous patch and adds support for actively aborting
a DCCP connection, using a Reset Code 2, "Aborted" to inform the peer of an
abortive release.

I have tried this in various client/server settings and it works as expected.

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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 5f47b458ed8fb3b57e432daca1f8c8b60835c245..73006b74767854bcb7b00bbcb9b8498ce69fa3bb 100644 (file)
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -276,6 +276,12 @@ static inline int dccp_listen_start(struct sock *sk, int backlog)
        return inet_csk_listen_start(sk, backlog);
 }
 
+static inline int dccp_need_reset(int state)
+{
+       return state != DCCP_CLOSED && state != DCCP_LISTEN &&
+              state != DCCP_REQUESTING;
+}
+
 int dccp_disconnect(struct sock *sk, int flags)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
@@ -286,10 +292,15 @@ int dccp_disconnect(struct sock *sk, int flags)
        if (old_state != DCCP_CLOSED)
                dccp_set_state(sk, DCCP_CLOSED);
 
-       /* ABORT function of RFC793 */
+       /*
+        * This corresponds to the ABORT function of RFC793, sec. 3.8
+        * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
+        */
        if (old_state == DCCP_LISTEN) {
                inet_csk_listen_stop(sk);
-       /* FIXME: do the active reset thing */
+       } else if (dccp_need_reset(old_state)) {
+               dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
+               sk->sk_err = ECONNRESET;
        } else if (old_state == DCCP_REQUESTING)
                sk->sk_err = ECONNRESET;