l2tp: fix userspace reception on plain L2TP sockets

As pppol2tp_recv() never queues up packets to plain L2TP sockets,
pppol2tp_recvmsg() never returns data to userspace, thus making
the recv*() system calls unusable.

Instead of dropping packets when the L2TP socket isn't bound to a PPP
channel, this patch adds them to its reception queue.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 6bfeaa7..5990919 100644 (file)
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -254,12 +254,14 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int
                po = pppox_sk(sk);
                ppp_input(&po->chan, skb);
        } else {
-               l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: socket not bound\n",
-                         session->name);
+               l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+                        "%s: recv %d byte data frame, passing to L2TP socket\n",
+                        session->name, data_len);
 
-               /* Not bound. Nothing we can do, so discard. */
-               atomic_long_inc(&session->stats.rx_errors);
-               kfree_skb(skb);
+               if (sock_queue_rcv_skb(sk, skb) < 0) {
+                       atomic_long_inc(&session->stats.rx_errors);
+                       kfree_skb(skb);
+               }
        }
 
        return;