rate-limit complaints for injected packets

when we open a new connected UDP socket, the main socket might
still have some packets in the inbound kernel queue.  We normally
read those, and push them to the connected socket.  But if the
connected socket / message queue is full, then we complain loudly.

Author: alandekok

src/lib/io/master.c

@@ -49,6 +49,7 @@ typedef struct {
 	uint64_t			client_id;			//!< Unique client identifier.
 	fr_rate_limit_t			unknown_client;
 	fr_rate_limit_t			repeat_nak;
+	fr_rate_limit_t			queue_full;
 } fr_io_thread_t;
 
 /** A saved packet
@@ -1345,7 +1346,7 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 		 */
 		if (fr_time_neq(pending->recv_time, track->timestamp)) {
 			DEBUG3("Discarding old packet");
-			talloc_free(pending);
+			TALLOC_FREE(pending);
 			goto redo;
 		}
 
@@ -1365,7 +1366,7 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 		 *	Shouldn't be necessary, but what the heck...
 		 */
 		memcpy(&address, track->address, sizeof(address));
-		talloc_free(pending);
+		TALLOC_FREE(pending);
 
 		/*
 		 *	Skip over all kinds of logic to find /
@@ -1719,7 +1720,7 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 				DEBUG("Too many pending packets for dynamic client %pV - discarding packet",
 				      fr_box_ipaddr(client->src_ipaddr));
 
-			done:
+			discard:
 				talloc_free(to_free);
 				return 0;
 			}
@@ -1732,7 +1733,7 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 			if (!pending) {
 				INFO("proto_%s - Failed allocating space for dynamic client %pV - discarding packet",
 				     inst->app_io->common.name, fr_box_ipaddr(client->src_ipaddr));
-				goto done;
+				goto discard;
 			}
 
 			if (fr_heap_num_elements(client->pending) > 1) {
@@ -1769,6 +1770,11 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 		return packet_len;
 	}
 
+	/*
+	 *
+	 */
+	fr_assert(!pending);
+
 	/*
 	 *	This must be the main UDP socket which creates
 	 *	connections.
@@ -1834,8 +1840,15 @@ static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time
 	 *	We don't need "to_free" after this, as it will be
 	 *	tracked in the connected socket.
 	 */
-	(void) fr_network_listen_inject(connection->nr, connection->listen,
-					buffer, packet_len, recv_time);
+	if (fr_network_listen_inject(connection->nr, connection->listen,
+				     buffer, packet_len, recv_time) < 0) {
+		RATE_LIMIT_LOCAL(&thread->queue_full, ERROR, "proto_%s - Discarding packet from dynamic client %pV - cannot push packet to connected socket due to %s",
+				 inst->app_io->common.name, fr_box_ipaddr(address.socket.inet.src_ipaddr), fr_strerror());
+		/*
+		 *	Don't return an error, because that will cause the listener to close its socket.
+		 */
+	}
+
 	return 0;
 }