drop_monitor: Add support for packet alert mode for hardware drops

In a similar fashion to software drops, extend drop monitor to send
netlink events when packets are dropped by the underlying hardware.

The main difference is that instead of encoding the program counter (PC)
from which kfree_skb() was called in the netlink message, we encode the
hardware trap name. The two are mostly equivalent since they should both
help the user understand why the packet was dropped.

Signed-off-by: Ido Schimmel <[email protected]>
Acked-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: idosch

include/uapi/linux/net_dropmon.h

@@ -83,6 +83,10 @@ enum net_dm_attr {
 	NET_DM_ATTR_ORIG_LEN,			/* u32 */
 	NET_DM_ATTR_QUEUE_LEN,			/* u32 */
 	NET_DM_ATTR_STATS,			/* nested */
+	NET_DM_ATTR_HW_STATS,			/* nested */
+	NET_DM_ATTR_ORIGIN,			/* u16 */
+	NET_DM_ATTR_HW_TRAP_GROUP_NAME,		/* string */
+	NET_DM_ATTR_HW_TRAP_NAME,		/* string */
 
 	__NET_DM_ATTR_MAX,
 	NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1
@@ -101,6 +105,7 @@ enum net_dm_alert_mode {
 
 enum {
 	NET_DM_ATTR_PORT_NETDEV_IFINDEX,	/* u32 */
+	NET_DM_ATTR_PORT_NETDEV_NAME,		/* string */
 
 	__NET_DM_ATTR_PORT_MAX,
 	NET_DM_ATTR_PORT_MAX = __NET_DM_ATTR_PORT_MAX - 1
@@ -113,4 +118,9 @@ enum {
 	NET_DM_ATTR_STATS_MAX = __NET_DM_ATTR_STATS_MAX - 1
 };
 
+enum net_dm_origin {
+	NET_DM_ORIGIN_SW,
+	NET_DM_ORIGIN_HW,
+};
+
 #endif