dccp: Empty the write queue when disconnecting

dccp_disconnect() can be called due to several reasons:

 1. when the connection setup failed (inet_stream_connect());
 2. when shutting down (inet_shutdown(), inet_csk_listen_stop());
 3. when aborting the connection (dccp_close() with 0 linger time).

In case (1) the write queue is empty. This patch empties the write queue,
if in case (2) or (3) it was not yet empty.

This avoids triggering the write-queue BUG_TRAP in sk_stream_kill_queues()
later on.

It also seems natural to do: when breaking an association, to delete all
packets that were originally intended for the soon-disconnected end (compare
with call to tcp_write_queue_purge in tcp_disconnect()).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 1ca3b26eed0fb09c479d4e513efd2d185c69bcc0..ae66473b11fad5b8f3166b63fe82470d86ca5a20 100644 (file)
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -309,7 +309,9 @@ int dccp_disconnect(struct sock *sk, int flags)
                sk->sk_err = ECONNRESET;
 
        dccp_clear_xmit_timers(sk);
+
        __skb_queue_purge(&sk->sk_receive_queue);
+       __skb_queue_purge(&sk->sk_write_queue);
        if (sk->sk_send_head != NULL) {
                __kfree_skb(sk->sk_send_head);
                sk->sk_send_head = NULL;