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From: Ido Schimmel <idosch@mellanox.com>
Date: Wed, 29 Jul 2020 12:26:44 +0300
Subject: mlxsw: spectrum: Use different trap group for externally routed
 packets
Patch-mainline: v5.8
Git-commit: ec4f5b3617049d474b3263792785b638640f2dbe
References: bsc#1176774

Cited commit mistakenly removed the trap group for externally routed
packets (e.g., via the management interface) and grouped locally routed
and externally routed packet traps under the same group, thereby
subjecting them to the same policer.

This can result in problems, for example, when FRR is restarted and
suddenly all transient traffic is trapped to the CPU because of a
default route through the management interface. Locally routed packets
required to re-establish a BGP connection will never reach the CPU and
the routing tables will not be re-populated.

Fix this by using a different trap group for externally routed packets.

Fixes: 8110668ecd9a ("mlxsw: spectrum_trap: Register layer 3 control traps")
Reported-by: Alex Veber <alexve@mellanox.com>
Tested-by: Alex Veber <alexve@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 Documentation/networking/devlink/devlink-trap.rst   |    4 ++++
 drivers/net/ethernet/mellanox/mlxsw/reg.h           |    1 +
 drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c |   14 +++++++++++---
 include/net/devlink.h                               |    3 +++
 net/core/devlink.c                                  |    1 +
 5 files changed, 20 insertions(+), 3 deletions(-)

--- a/Documentation/networking/devlink/devlink-trap.rst
+++ b/Documentation/networking/devlink/devlink-trap.rst
@@ -484,6 +484,10 @@ narrow. The description of these groups
      - Contains packet traps for packets that should be locally delivered after
        routing, but do not match more specific packet traps (e.g.,
        ``ipv4_bgp``)
+   * - ``external_delivery``
+     - Contains packet traps for packets that should be routed through an
+       external interface (e.g., management interface) that does not belong to
+       the same device (e.g., switch ASIC) as the ingress interface
    * - ``ipv6``
      - Contains packet traps for various IPv6 control packets (e.g., Router
        Advertisements)
--- a/drivers/net/ethernet/mellanox/mlxsw/reg.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/reg.h
@@ -5536,6 +5536,7 @@ enum mlxsw_reg_htgt_trap_group {
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_MULTICAST,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_NEIGH_DISCOVERY,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_ROUTER_EXP,
+	MLXSW_REG_HTGT_TRAP_GROUP_SP_EXTERNAL_ROUTE,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_IP2ME,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_DHCP,
 	MLXSW_REG_HTGT_TRAP_GROUP_SP_EVENT,
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_trap.c
@@ -328,6 +328,9 @@ mlxsw_sp_trap_policer_items_arr[] = {
 	{
 		.policer = MLXSW_SP_TRAP_POLICER(18, 1024, 128),
 	},
+	{
+		.policer = MLXSW_SP_TRAP_POLICER(19, 1024, 512),
+	},
 };
 
 static const struct mlxsw_sp_trap_group_item mlxsw_sp_trap_group_items_arr[] = {
@@ -422,6 +425,11 @@ static const struct mlxsw_sp_trap_group_
 		.priority = 2,
 	},
 	{
+		.group = DEVLINK_TRAP_GROUP_GENERIC(EXTERNAL_DELIVERY, 19),
+		.hw_group_id = MLXSW_REG_HTGT_TRAP_GROUP_SP_EXTERNAL_ROUTE,
+		.priority = 1,
+	},
+	{
 		.group = DEVLINK_TRAP_GROUP_GENERIC(IPV6, 15),
 		.hw_group_id = MLXSW_REG_HTGT_TRAP_GROUP_SP_IPV6,
 		.priority = 2,
@@ -882,11 +890,11 @@ static const struct mlxsw_sp_trap_item m
 		},
 	},
 	{
-		.trap = MLXSW_SP_TRAP_CONTROL(EXTERNAL_ROUTE, LOCAL_DELIVERY,
+		.trap = MLXSW_SP_TRAP_CONTROL(EXTERNAL_ROUTE, EXTERNAL_DELIVERY,
 					      TRAP),
 		.listeners_arr = {
-			MLXSW_SP_RXL_MARK(RTR_INGRESS0, IP2ME, TRAP_TO_CPU,
-					  false),
+			MLXSW_SP_RXL_MARK(RTR_INGRESS0, EXTERNAL_ROUTE,
+					  TRAP_TO_CPU, false),
 		},
 	},
 	{
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -718,6 +718,7 @@ enum devlink_trap_group_generic_id {
 	DEVLINK_TRAP_GROUP_GENERIC_ID_PIM,
 	DEVLINK_TRAP_GROUP_GENERIC_ID_UC_LB,
 	DEVLINK_TRAP_GROUP_GENERIC_ID_LOCAL_DELIVERY,
+	DEVLINK_TRAP_GROUP_GENERIC_ID_EXTERNAL_DELIVERY,
 	DEVLINK_TRAP_GROUP_GENERIC_ID_IPV6,
 	DEVLINK_TRAP_GROUP_GENERIC_ID_PTP_EVENT,
 	DEVLINK_TRAP_GROUP_GENERIC_ID_PTP_GENERAL,
@@ -915,6 +916,8 @@ enum devlink_trap_group_generic_id {
 	"uc_loopback"
 #define DEVLINK_TRAP_GROUP_GENERIC_NAME_LOCAL_DELIVERY \
 	"local_delivery"
+#define DEVLINK_TRAP_GROUP_GENERIC_NAME_EXTERNAL_DELIVERY \
+	"external_delivery"
 #define DEVLINK_TRAP_GROUP_GENERIC_NAME_IPV6 \
 	"ipv6"
 #define DEVLINK_TRAP_GROUP_GENERIC_NAME_PTP_EVENT \
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -8516,6 +8516,7 @@ static const struct devlink_trap_group d
 	DEVLINK_TRAP_GROUP(PIM),
 	DEVLINK_TRAP_GROUP(UC_LB),
 	DEVLINK_TRAP_GROUP(LOCAL_DELIVERY),
+	DEVLINK_TRAP_GROUP(EXTERNAL_DELIVERY),
 	DEVLINK_TRAP_GROUP(IPV6),
 	DEVLINK_TRAP_GROUP(PTP_EVENT),
 	DEVLINK_TRAP_GROUP(PTP_GENERAL),