devlink: Add non-routable packet trap

Add packet trap that can report packets that reached the router, but are
non-routable. For example, IGMP queries can be flooded by the device in
layer 2 and reach the router. Such packets should not be routed and
instead dropped.

Signed-off-by: Amit Cohen <amitc@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/devlink-trap.rst

@@ -223,6 +223,12 @@ be added to the following table:
    * - ``ipv6_lpm_miss``
      - ``exception``
      - Traps unicast IPv6 packets that did not match any route
+   * - ``non_routable_packet``
+     - ``drop``
+     - Traps packets that the device decided to drop because they are not
+       supposed to be routed. For example, IGMP queries can be flooded by the
+       device in layer 2 and reach the router. Such packets should not be
+       routed and instead dropped
 
 Driver-specific Packet Traps
 ============================

include/net/devlink.h

@@ -591,6 +591,7 @@ enum devlink_trap_generic_id {
 	DEVLINK_TRAP_GENERIC_ID_REJECT_ROUTE,
 	DEVLINK_TRAP_GENERIC_ID_IPV4_LPM_UNICAST_MISS,
 	DEVLINK_TRAP_GENERIC_ID_IPV6_LPM_UNICAST_MISS,
+	DEVLINK_TRAP_GENERIC_ID_NON_ROUTABLE,
 
 	/* Add new generic trap IDs above */
 	__DEVLINK_TRAP_GENERIC_ID_MAX,
@@ -659,6 +660,8 @@ enum devlink_trap_group_generic_id {
 	"ipv4_lpm_miss"
 #define DEVLINK_TRAP_GENERIC_NAME_IPV6_LPM_UNICAST_MISS \
 	"ipv6_lpm_miss"
+#define DEVLINK_TRAP_GENERIC_NAME_NON_ROUTABLE \
+	"non_routable_packet"
 
 #define DEVLINK_TRAP_GROUP_GENERIC_NAME_L2_DROPS \
 	"l2_drops"

net/core/devlink.c

@@ -7706,6 +7706,7 @@ static const struct devlink_trap devlink_trap_generic[] = {
 	DEVLINK_TRAP(REJECT_ROUTE, EXCEPTION),
 	DEVLINK_TRAP(IPV4_LPM_UNICAST_MISS, EXCEPTION),
 	DEVLINK_TRAP(IPV6_LPM_UNICAST_MISS, EXCEPTION),
+	DEVLINK_TRAP(NON_ROUTABLE, DROP),
 };
 
 #define DEVLINK_TRAP_GROUP(_id)						      \