evl/net: dev: send notice to console on input filter removal

Signed-off-by: Philippe Gerum <rpm@xenomai.org>

kernel/evl/net/dev.c

@@ -68,8 +68,9 @@ static LIST_HEAD(oob_port_list);
 
 static DEFINE_HARD_SPINLOCK(oob_port_lock);
 
-static void __set_rx_filter(struct evl_netdev_state *est,
-			struct evl_net_ebpf_filter *filter);
+static struct evl_net_ebpf_filter *
+__set_rx_filter(struct evl_netdev_state *est,
+		struct evl_net_ebpf_filter *filter);
 
 static struct evl_kthread *
 start_handler_thread(struct net_device *dev,
@@ -502,8 +503,9 @@ static void drop_rx_filter(struct rcu_head *rcu)
 	kfree(filter);
 }
 
-static void __set_rx_filter(struct evl_netdev_state *est,
-			struct evl_net_ebpf_filter *filter)
+static struct evl_net_ebpf_filter *
+__set_rx_filter(struct evl_netdev_state *est,
+		struct evl_net_ebpf_filter *filter)
 {
 	struct evl_net_ebpf_filter *old;
 
@@ -519,17 +521,19 @@ static void __set_rx_filter(struct evl_netdev_state *est,
 
 	if (old)
 		call_rcu(&old->rcu, drop_rx_filter);
+
+	return old;
 }
 
 /*
- * set_rx_filter - install an eBPF filter module to redirect ingress
+ * set_rx_filter - install an eBPF program module to redirect ingress
  * traffic to the proper network stack, inband or oob.  @dev is a
  * physical interface.
  */
 static int set_rx_filter(struct net_device *dev, unsigned long arg)
 {
 	struct oob_netdev_state *nds = &dev->oob_state;
-	struct evl_net_ebpf_filter *new = NULL;
+	struct evl_net_ebpf_filter *old, *new = NULL;
 	struct bpf_prog *prog;
 	int ret, fd;
 
@@ -540,17 +544,19 @@ static int set_rx_filter(struct net_device *dev, unsigned long arg)
 	if (fd != -1) {
 		prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
 		if (IS_ERR(prog)) {
-			netdev_warn(dev, "invalid out-of-band eBPF filter\n");
+			netdev_warn(dev, "invalid out-of-band eBPF program\n");
 			return PTR_ERR(prog);
 		}
 		new = kmalloc(sizeof(*new), GFP_KERNEL);
 		if (!new)
 			return -ENOMEM;
 		new->prog = prog;
-		netdev_notice(dev, "out-of-band eBPF filter installed\n");
+		netdev_notice(dev, "out-of-band eBPF program installed\n");
 	}
 
-	__set_rx_filter(nds->estate, new);
+	old = __set_rx_filter(nds->estate, new);
+	if (old && !new)
+		netdev_notice(dev, "out-of-band eBPF program removed\n");
 
 	return 0;
 }