l2tp: use standard API for warning log messages

The l2tp_* log wrappers only emit messages of a given category if the
tunnel or session structure has the appropriate flag set in its debug
field. Flags default to being unset.

For warning messages, this doesn't make a lot of sense since an
administrator is likely to want to know about datapath warnings without
needing to tweak the debug flags setting for a given tunnel or session
instance.

Modify l2tp_warn callsites to use pr_warn_ratelimited instead for
unconditional output of warning messages.

Signed-off-by: Tom Parkin <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/l2tp/l2tp_core.c

···
 	/* Parse and check optional cookie */
 	if (session->peer_cookie_len > 0) {
 		if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) {
-			l2tp_warn(tunnel, L2TP_MSG_DATA,
-				  "%s: cookie mismatch (%u/%u). Discarding.\n",
-				  tunnel->name, tunnel->tunnel_id,
-				  session->session_id);
+			pr_warn_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n",
+					    tunnel->name, tunnel->tunnel_id,
+					    session->session_id);
 			atomic_long_inc(&session->stats.rx_cookie_discards);
 			goto discard;
 		}
···
 		 * If user has configured mandatory sequence numbers, discard.
 		 */
 		if (session->recv_seq) {
-			l2tp_warn(session, L2TP_MSG_SEQ,
-				  "%s: recv data has no seq numbers when required. Discarding.\n",
-				  session->name);
+			pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n",
+					    session->name);
 			atomic_long_inc(&session->stats.rx_seq_discards);
 			goto discard;
 		}
···
 			session->send_seq = 0;
 			l2tp_session_set_header_len(session, tunnel->version);
 		} else if (session->send_seq) {
-			l2tp_warn(session, L2TP_MSG_SEQ,
-				  "%s: recv data has no seq numbers when required. Discarding.\n",
-				  session->name);
+			pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n",
+					    session->name);
 			atomic_long_inc(&session->stats.rx_seq_discards);
 			goto discard;
 		}
···
 
 	/* Short packet? */
 	if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) {
-		l2tp_warn(tunnel, L2TP_MSG_DATA,
-			  "%s: recv short packet (len=%d)\n",
-			  tunnel->name, skb->len);
+		pr_warn_ratelimited("%s: recv short packet (len=%d)\n",
+				    tunnel->name, skb->len);
 		goto error;
 	}
 
···
 	/* Check protocol version */
 	version = hdrflags & L2TP_HDR_VER_MASK;
 	if (version != tunnel->version) {
-		l2tp_warn(tunnel, L2TP_MSG_DATA,
-			  "%s: recv protocol version mismatch: got %d expected %d\n",
-			  tunnel->name, version, tunnel->version);
+		pr_warn_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n",
+				    tunnel->name, version, tunnel->version);
 		goto error;
 	}
 
···
 			l2tp_session_dec_refcount(session);
 
 		/* Not found? Pass to userspace to deal with */
-		l2tp_warn(tunnel, L2TP_MSG_DATA,
-			  "%s: no session found (%u/%u). Passing up.\n",
-			  tunnel->name, tunnel_id, session_id);
+		pr_warn_ratelimited("%s: no session found (%u/%u). Passing up.\n",
+				    tunnel->name, tunnel_id, session_id);
 		goto error;
 	}
 

net/l2tp/l2tp_ppp.c

···
 
 no_sock:
 	rcu_read_unlock();
-	l2tp_warn(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
+	pr_warn_ratelimited("%s: no socket in recv\n", session->name);
 	kfree_skb(skb);
 }