From: Jiri Pirko <jiri@mellanox.com>
Date: Sat, 9 May 2020 23:06:07 +0300
Subject: mlxsw: spectrum_flower: Forbid to insert flower rules in collision
 with matchall rules
Patch-mainline: v5.8-rc1
Git-commit: 67ed68fc0c9aa4a456d03df216e571e0c6177097
References: bsc#1176774

On ingress, the matchall rules doing mirroring and sampling are offloaded
into hardware blocks that are processed before any flower rules.
On egress, the matchall mirroring rules are offloaded into hardware
block that is processed after all flower rules.

Therefore check the priorities of inserted flower rules against
existing matchall rules and ensure the correct ordering.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c |   32 ++++++++++++++++++
 1 file changed, 32 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
@@ -505,6 +505,34 @@ static int mlxsw_sp_flower_parse(struct
 					     f->common.extack);
 }
 
+static int mlxsw_sp_flower_mall_prio_check(struct mlxsw_sp_flow_block *block,
+					   struct flow_cls_offload *f)
+{
+	bool ingress = mlxsw_sp_flow_block_is_ingress_bound(block);
+	unsigned int mall_min_prio;
+	unsigned int mall_max_prio;
+	int err;
+
+	err = mlxsw_sp_mall_prio_get(block, f->common.chain_index,
+				     &mall_min_prio, &mall_max_prio);
+	if (err) {
+		if (err == -ENOENT)
+			/* No matchall filters installed on this chain. */
+			return 0;
+		NL_SET_ERR_MSG(f->common.extack, "Failed to get matchall priorities");
+		return err;
+	}
+	if (ingress && f->common.prio <= mall_min_prio) {
+		NL_SET_ERR_MSG(f->common.extack, "Failed to add in front of existing matchall rules");
+		return -EOPNOTSUPP;
+	}
+	if (!ingress && f->common.prio >= mall_max_prio) {
+		NL_SET_ERR_MSG(f->common.extack, "Failed to add behind of existing matchall rules");
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
 int mlxsw_sp_flower_replace(struct mlxsw_sp *mlxsw_sp,
 			    struct mlxsw_sp_flow_block *block,
 			    struct flow_cls_offload *f)
@@ -514,6 +542,10 @@ int mlxsw_sp_flower_replace(struct mlxsw
 	struct mlxsw_sp_acl_rule *rule;
 	int err;
 
+	err = mlxsw_sp_flower_mall_prio_check(block, f);
+	if (err)
+		return err;
+
 	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
 					   f->common.chain_index,
 					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);