mlxsw: Add layer 3 devlink-trap exceptions support

Add the trap IDs used to report layer 3 exceptions.

Trapped packets are first reported to devlink and then injected to the
kernel's receive path. All the packets have 'offload_fwd_mark' set in
order to prevent them from potentially being forwarded by the bridge
again.
Signed-off-by: Amit Cohen <amitc@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -4512,10 +4512,7 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = {
 	MLXSW_SP_RXL_NO_MARK(IPV6_MLDV2_LISTENER_REPORT, TRAP_TO_CPU, IPV6_MLD,
 			     false),
 	/* L3 traps */
-	MLXSW_SP_RXL_MARK(MTUERROR, TRAP_TO_CPU, ROUTER_EXP, false),
-	MLXSW_SP_RXL_MARK(TTLERROR, TRAP_TO_CPU, ROUTER_EXP, false),
 	MLXSW_SP_RXL_L3_MARK(LBERROR, MIRROR_TO_CPU, LBERROR, false),
-	MLXSW_SP_RXL_MARK(RTR_INGRESS1, TRAP_TO_CPU, REMOTE_ROUTE, false),
 	MLXSW_SP_RXL_MARK(IP2ME, TRAP_TO_CPU, IP2ME, false),
 	MLXSW_SP_RXL_MARK(IPV6_UNSPECIFIED_ADDRESS, TRAP_TO_CPU, ROUTER_EXP,
 			  false),
@@ -4528,8 +4525,6 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = {
 	MLXSW_SP_RXL_MARK(IPV6_OSPF, TRAP_TO_CPU, OSPF, false),
 	MLXSW_SP_RXL_MARK(IPV6_DHCP, TRAP_TO_CPU, DHCP, false),
 	MLXSW_SP_RXL_MARK(RTR_INGRESS0, TRAP_TO_CPU, REMOTE_ROUTE, false),
-	MLXSW_SP_RXL_MARK(DISCARD_ROUTER3, TRAP_EXCEPTION_TO_CPU, REMOTE_ROUTE,
-			  false),
 	MLXSW_SP_RXL_MARK(IPV4_BGP, TRAP_TO_CPU, BGP, false),
 	MLXSW_SP_RXL_MARK(IPV6_BGP, TRAP_TO_CPU, BGP, false),
 	MLXSW_SP_RXL_MARK(L3_IPV6_ROUTER_SOLICITATION, TRAP_TO_CPU, IPV6_ND,
@@ -4543,8 +4538,6 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = {
 	MLXSW_SP_RXL_MARK(L3_IPV6_REDIRECTION, TRAP_TO_CPU, IPV6_ND, false),
 	MLXSW_SP_RXL_MARK(IPV6_MC_LINK_LOCAL_DEST, TRAP_TO_CPU, ROUTER_EXP,
 			  false),
-	MLXSW_SP_RXL_MARK(HOST_MISS_IPV4, TRAP_TO_CPU, HOST_MISS, false),
-	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),
@@ -4559,7 +4552,6 @@ static const struct mlxsw_listener mlxsw_sp_listener[] = {
 	/* Multicast Router Traps */
 	MLXSW_SP_RXL_MARK(IPV4_PIM, TRAP_TO_CPU, PIM, false),
 	MLXSW_SP_RXL_MARK(IPV6_PIM, TRAP_TO_CPU, PIM, false),
-	MLXSW_SP_RXL_MARK(RPF, TRAP_TO_CPU, RPF, false),
 	MLXSW_SP_RXL_MARK(ACL1, TRAP_TO_CPU, MULTICAST, false),
 	MLXSW_SP_RXL_L3_MARK(ACL2, TRAP_TO_CPU, MULTICAST, false),
 	/* NVE traps */

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

@@ -13,16 +13,27 @@
 
 static void mlxsw_sp_rx_drop_listener(struct sk_buff *skb, u8 local_port,
 				      void *priv);
+static void mlxsw_sp_rx_exception_listener(struct sk_buff *skb, u8 local_port,
+					   void *trap_ctx);
 
 #define MLXSW_SP_TRAP_DROP(_id, _group_id)				      \
 	DEVLINK_TRAP_GENERIC(DROP, DROP, _id,				      \
 			     DEVLINK_TRAP_GROUP_GENERIC(_group_id),	      \
 			     MLXSW_SP_TRAP_METADATA)
 
+#define MLXSW_SP_TRAP_EXCEPTION(_id, _group_id)		      \
+	DEVLINK_TRAP_GENERIC(EXCEPTION, TRAP, _id,			      \
+			     DEVLINK_TRAP_GROUP_GENERIC(_group_id),	      \
+			     MLXSW_SP_TRAP_METADATA)
+
 #define MLXSW_SP_RXL_DISCARD(_id, _group_id)				      \
 	MLXSW_RXL(mlxsw_sp_rx_drop_listener, DISCARD_##_id, SET_FW_DEFAULT,   \
 		  false, SP_##_group_id, DISCARD)
 
+#define MLXSW_SP_RXL_EXCEPTION(_id, _group_id, _action)			      \
+	MLXSW_RXL(mlxsw_sp_rx_exception_listener, _id,			      \
+		   _action, false, SP_##_group_id, DISCARD)
+
 static struct devlink_trap mlxsw_sp_traps_arr[] = {
 	MLXSW_SP_TRAP_DROP(SMAC_MC, L2_DROPS),
 	MLXSW_SP_TRAP_DROP(VLAN_TAG_MISMATCH, L2_DROPS),
@@ -40,6 +51,13 @@ static struct devlink_trap mlxsw_sp_traps_arr[] = {
 	MLXSW_SP_TRAP_DROP(IPV4_SIP_BC, L3_DROPS),
 	MLXSW_SP_TRAP_DROP(IPV6_MC_DIP_RESERVED_SCOPE, L3_DROPS),
 	MLXSW_SP_TRAP_DROP(IPV6_MC_DIP_INTERFACE_LOCAL_SCOPE, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(MTU_ERROR, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(TTL_ERROR, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(RPF, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(REJECT_ROUTE, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(UNRESOLVED_NEIGH, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(IPV4_LPM_UNICAST_MISS, L3_DROPS),
+	MLXSW_SP_TRAP_EXCEPTION(IPV6_LPM_UNICAST_MISS, L3_DROPS),
 };
 
 static struct mlxsw_listener mlxsw_sp_listeners_arr[] = {
@@ -60,6 +78,18 @@ static struct mlxsw_listener mlxsw_sp_listeners_arr[] = {
 	MLXSW_SP_RXL_DISCARD(ING_ROUTER_IPV4_SIP_BC, L3_DISCARDS),
 	MLXSW_SP_RXL_DISCARD(IPV6_MC_DIP_RESERVED_SCOPE, L3_DISCARDS),
 	MLXSW_SP_RXL_DISCARD(IPV6_MC_DIP_INTERFACE_LOCAL_SCOPE, L3_DISCARDS),
+	MLXSW_SP_RXL_EXCEPTION(MTUERROR, ROUTER_EXP, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(TTLERROR, ROUTER_EXP, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(RPF, RPF, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(RTR_INGRESS1, REMOTE_ROUTE, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(HOST_MISS_IPV4, HOST_MISS, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(HOST_MISS_IPV6, HOST_MISS, TRAP_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(DISCARD_ROUTER3, REMOTE_ROUTE,
+			       TRAP_EXCEPTION_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(DISCARD_ROUTER_LPM4, ROUTER_EXP,
+			       TRAP_EXCEPTION_TO_CPU),
+	MLXSW_SP_RXL_EXCEPTION(DISCARD_ROUTER_LPM6, ROUTER_EXP,
+			       TRAP_EXCEPTION_TO_CPU),
 };
 
 /* Mapping between hardware trap and devlink trap. Multiple hardware traps can
@@ -84,6 +114,15 @@ static u16 mlxsw_sp_listener_devlink_map[] = {
 	DEVLINK_TRAP_GENERIC_ID_IPV4_SIP_BC,
 	DEVLINK_TRAP_GENERIC_ID_IPV6_MC_DIP_RESERVED_SCOPE,
 	DEVLINK_TRAP_GENERIC_ID_IPV6_MC_DIP_INTERFACE_LOCAL_SCOPE,
+	DEVLINK_TRAP_GENERIC_ID_MTU_ERROR,
+	DEVLINK_TRAP_GENERIC_ID_TTL_ERROR,
+	DEVLINK_TRAP_GENERIC_ID_RPF,
+	DEVLINK_TRAP_GENERIC_ID_REJECT_ROUTE,
+	DEVLINK_TRAP_GENERIC_ID_UNRESOLVED_NEIGH,
+	DEVLINK_TRAP_GENERIC_ID_UNRESOLVED_NEIGH,
+	DEVLINK_TRAP_GENERIC_ID_UNRESOLVED_NEIGH,
+	DEVLINK_TRAP_GENERIC_ID_IPV4_LPM_UNICAST_MISS,
+	DEVLINK_TRAP_GENERIC_ID_IPV6_LPM_UNICAST_MISS,
 };
 
 static int mlxsw_sp_rx_listener(struct mlxsw_sp *mlxsw_sp, struct sk_buff *skb,
@@ -134,6 +173,30 @@ static void mlxsw_sp_rx_drop_listener(struct sk_buff *skb, u8 local_port,
 	consume_skb(skb);
 }
 
+static void mlxsw_sp_rx_exception_listener(struct sk_buff *skb, u8 local_port,
+					   void *trap_ctx)
+{
+	struct devlink_port *in_devlink_port;
+	struct mlxsw_sp_port *mlxsw_sp_port;
+	struct mlxsw_sp *mlxsw_sp;
+	struct devlink *devlink;
+
+	mlxsw_sp = devlink_trap_ctx_priv(trap_ctx);
+	mlxsw_sp_port = mlxsw_sp->ports[local_port];
+
+	if (mlxsw_sp_rx_listener(mlxsw_sp, skb, local_port, mlxsw_sp_port))
+		return;
+
+	devlink = priv_to_devlink(mlxsw_sp->core);
+	in_devlink_port = mlxsw_core_port_devlink_port_get(mlxsw_sp->core,
+							   local_port);
+	skb_push(skb, ETH_HLEN);
+	devlink_trap_report(devlink, skb, trap_ctx, in_devlink_port);
+	skb_pull(skb, ETH_HLEN);
+	skb->offload_fwd_mark = 1;
+	netif_receive_skb(skb);
+}
+
 int mlxsw_sp_devlink_traps_init(struct mlxsw_sp *mlxsw_sp)
 {
 	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);

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

@@ -84,6 +84,8 @@ enum {
 	MLXSW_TRAP_ID_DISCARD_ING_ROUTER_CORRUPTED_IP_HDR = 0x167,
 	MLXSW_TRAP_ID_DISCARD_ING_ROUTER_IPV4_SIP_BC = 0x16A,
 	MLXSW_TRAP_ID_DISCARD_ING_ROUTER_IPV4_DIP_LOCAL_NET = 0x16B,
+	MLXSW_TRAP_ID_DISCARD_ROUTER_LPM4 = 0x17B,
+	MLXSW_TRAP_ID_DISCARD_ROUTER_LPM6 = 0x17C,
 	MLXSW_TRAP_ID_DISCARD_IPV6_MC_DIP_RESERVED_SCOPE = 0x1B0,
 	MLXSW_TRAP_ID_DISCARD_IPV6_MC_DIP_INTERFACE_LOCAL_SCOPE = 0x1B1,
 	MLXSW_TRAP_ID_ACL0 = 0x1C0,