mlxsw: spectrum: Trap loop-backed packets

One of the conditions to generate an ICMP Redirect Message is that "the
packet is being forwarded out the same physical interface that it was
received from" (RFC 1812).

Therefore, we need to be able to trap such packets and let the kernel
decide what to do with them.

For each RIF, enable the loop-back filter, which will raise the LBERROR
trap whenever the ingress RIF equals the egress RIF.

Fixes: 99724c18fc66 ("mlxsw: spectrum: Introduce support for router interfaces")
Reported-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/reg.h b/drivers/net/ethernet/mellanox/mlxsw/reg.h
index 7ca9201f7dcbf6de88e0cbf2d69393db13d0e57d..a1bd36cc9488ad8cccb9b402a78549c91ae68442 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/reg.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/reg.h
@@ -3383,6 +3383,15 @@ MLXSW_ITEM32(reg, ritr, ipv4_fe, 0x04, 29, 1);
  */
 MLXSW_ITEM32(reg, ritr, ipv6_fe, 0x04, 28, 1);
 
+/* reg_ritr_lb_en
+ * Loop-back filter enable for unicast packets.
+ * If the flag is set then loop-back filter for unicast packets is
+ * implemented on the RIF. Multicast packets are always subject to
+ * loop-back filtering.
+ * Access: RW
+ */
+MLXSW_ITEM32(reg, ritr, lb_en, 0x04, 24, 1);
+
 /* reg_ritr_virtual_router
  * Virtual router ID associated with the router interface.
  * Access: RW
@@ -3484,6 +3493,7 @@ static inline void mlxsw_reg_ritr_pack(char *payload, bool enable,
        mlxsw_reg_ritr_op_set(payload, op);
        mlxsw_reg_ritr_rif_set(payload, rif);
        mlxsw_reg_ritr_ipv4_fe_set(payload, 1);
+       mlxsw_reg_ritr_lb_en_set(payload, 1);
        mlxsw_reg_ritr_mtu_set(payload, mtu);
        mlxsw_reg_ritr_if_mac_memcpy_to(payload, mac);
 }

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 6b69c8ac7b881dd49fe70d63529bc9badf690d85..8137daadb25b5aa943976d4b182c630ca56cf665 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2658,6 +2658,11 @@ static const struct mlxsw_rx_listener mlxsw_sp_rx_listener[] = {
                .local_port = MLXSW_PORT_DONT_CARE,
                .trap_id = MLXSW_TRAP_ID_TTLERROR,
        },
+       {
+               .func = mlxsw_sp_rx_listener_func,
+               .local_port = MLXSW_PORT_DONT_CARE,
+               .trap_id = MLXSW_TRAP_ID_LBERROR,
+       },
        {
                .func = mlxsw_sp_rx_listener_func,
                .local_port = MLXSW_PORT_DONT_CARE,

diff --git a/drivers/net/ethernet/mellanox/mlxsw/trap.h b/drivers/net/ethernet/mellanox/mlxsw/trap.h
index 9508e0a49e885319ebe008a0f2b1e4dba184b85e..ed8e301864004f8092bcf82caf50edc730a4b7d4 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/trap.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/trap.h
@@ -58,6 +58,7 @@ enum {
        MLXSW_TRAP_ID_ARPUC = 0x51,
        MLXSW_TRAP_ID_MTUERROR = 0x52,
        MLXSW_TRAP_ID_TTLERROR = 0x53,
+       MLXSW_TRAP_ID_LBERROR = 0x54,
        MLXSW_TRAP_ID_OSPF = 0x55,
        MLXSW_TRAP_ID_IP2ME = 0x5F,
        MLXSW_TRAP_ID_RTR_INGRESS0 = 0x70,