[DCCP]: Check for unread data on close

This removes one FIXME with regard to close when there is still unread data.
The mechanism is implemented similar to TCP: with regard to DCCP-specifics,
a Reset with Code 2, "Aborted" is sent to the peer.

This corresponds in part to RFC 4340, 8.1.1 and 8.1.5.

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>

1 files changed, 8 insertions, 2 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index d48005f653c7..5f47b458ed8f 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -891,6 +891,7 @@ void dccp_close(struct sock *sk, long timeout)
 {
         struct dccp_sock *dp = dccp_sk(sk);
         struct sk_buff *skb;
+        u32 data_was_unread = 0;
         int state;
 
         lock_sock(sk);
@@ -913,12 +914,17 @@ void dccp_close(struct sock *sk, long timeout)
          * descriptor close, not protocol-sourced closes, because the
           *reader process may not have drained the data yet!
          */
-        /* FIXME: check for unread data */
         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+                data_was_unread += skb->len;
                 __kfree_skb(skb);
         }
 
-        if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
+        if (data_was_unread) {
+                /* Unread data was tossed, send an appropriate Reset Code */
+                DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
+                dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
+                dccp_set_state(sk, DCCP_CLOSED);
+        } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
                 /* Check zero linger _after_ checking for unread data. */
                 sk->sk_prot->disconnect(sk, 0);
         } else if (dccp_close_state(sk)) {