mlxsw: spectrum: Register for IPIP_DECAP_ERROR trap

These traps are generated for packets that fail checks for source IP,
encapsulation type, or GRE key. Trap these packets to CPU for follow-up
handling by the kernel, which will send ICMP destination unreachable
responses.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -3400,6 +3400,7 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = {
 	MLXSW_SP_RXL_MARK(HOST_MISS_IPV6, TRAP_TO_CPU, HOST_MISS, false),
 	MLXSW_SP_RXL_MARK(ROUTER_ALERT_IPV4, TRAP_TO_CPU, ROUTER_EXP, false),
 	MLXSW_SP_RXL_MARK(ROUTER_ALERT_IPV6, TRAP_TO_CPU, ROUTER_EXP, false),
+	MLXSW_SP_RXL_MARK(IPIP_DECAP_ERROR, TRAP_TO_CPU, ROUTER_EXP, false),
 	/* PKT Sample trap */
 	MLXSW_RXL(mlxsw_sp_rx_listener_sample_func, PKT_SAMPLE, MIRROR_TO_CPU,
 		  false, SP_IP2ME, DISCARD),

drivers/net/ethernet/mellanox/mlxsw/trap.h

@@ -85,6 +85,7 @@ enum {
 	MLXSW_TRAP_ID_HOST_MISS_IPV4 = 0x90,
 	MLXSW_TRAP_ID_IPV6_MC_LINK_LOCAL_DEST = 0x91,
 	MLXSW_TRAP_ID_HOST_MISS_IPV6 = 0x92,
+	MLXSW_TRAP_ID_IPIP_DECAP_ERROR = 0xB1,
 	MLXSW_TRAP_ID_ROUTER_ALERT_IPV4 = 0xD6,
 	MLXSW_TRAP_ID_ROUTER_ALERT_IPV6 = 0xD7,
 	MLXSW_TRAP_ID_ACL0 = 0x1C0,