net/mlx5e: CT: Make mlx5_ct_fs_smfs_ct_validate_flow_rule reusable

This function checks whether a flow_rule has the right flow dissector
keys and masks used for a connection tracking flow offload. It is
currently used locally by the tc_ct smfs module, but is about to be used
from another place, so this commit moves it to a better place, renames
it to mlx5e_tc_ct_is_valid_flow_rule and drops the unused fs argument.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Jianbo Liu <jianbol@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20250114130646.1937192-4-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Cosmin Ratiu

drivers/net/ethernet/mellanox/mlx5/core/en/tc/ct_fs_smfs.c

@@ -13,7 +13,6 @@
 #define INIT_ERR_PREFIX "ct_fs_smfs init failed"
 #define ct_dbg(fmt, args...)\
 	netdev_dbg(fs->netdev, "ct_fs_smfs debug: " fmt "\n", ##args)
-#define MLX5_CT_TCP_FLAGS_MASK cpu_to_be16(be32_to_cpu(TCP_FLAG_RST | TCP_FLAG_FIN) >> 16)
 
 struct mlx5_ct_fs_smfs_matcher {
 	struct mlx5dr_matcher *dr_matcher;
@@ -220,78 +219,6 @@ mlx5_ct_fs_smfs_destroy(struct mlx5_ct_fs *fs)
 	mlx5_smfs_action_destroy(fs_smfs->fwd_action);
 }
 
-static inline bool
-mlx5_tc_ct_valid_used_dissector_keys(const u64 used_keys)
-{
-#define DISS_BIT(name) BIT_ULL(FLOW_DISSECTOR_KEY_ ## name)
-	const u64 basic_keys = DISS_BIT(BASIC) | DISS_BIT(CONTROL) |
-				DISS_BIT(META);
-	const u64 ipv4_tcp = basic_keys | DISS_BIT(IPV4_ADDRS) |
-				DISS_BIT(PORTS) | DISS_BIT(TCP);
-	const u64 ipv6_tcp = basic_keys | DISS_BIT(IPV6_ADDRS) |
-				DISS_BIT(PORTS) | DISS_BIT(TCP);
-	const u64 ipv4_udp = basic_keys | DISS_BIT(IPV4_ADDRS) |
-				DISS_BIT(PORTS);
-	const u64 ipv6_udp = basic_keys | DISS_BIT(IPV6_ADDRS) |
-				 DISS_BIT(PORTS);
-	const u64 ipv4_gre = basic_keys | DISS_BIT(IPV4_ADDRS);
-	const u64 ipv6_gre = basic_keys | DISS_BIT(IPV6_ADDRS);
-
-	return (used_keys == ipv4_tcp || used_keys == ipv4_udp || used_keys == ipv6_tcp ||
-		used_keys == ipv6_udp || used_keys == ipv4_gre || used_keys == ipv6_gre);
-}
-
-static bool
-mlx5_ct_fs_smfs_ct_validate_flow_rule(struct mlx5_ct_fs *fs, struct flow_rule *flow_rule)
-{
-	struct flow_match_ipv4_addrs ipv4_addrs;
-	struct flow_match_ipv6_addrs ipv6_addrs;
-	struct flow_match_control control;
-	struct flow_match_basic basic;
-	struct flow_match_ports ports;
-	struct flow_match_tcp tcp;
-
-	if (!mlx5_tc_ct_valid_used_dissector_keys(flow_rule->match.dissector->used_keys)) {
-		ct_dbg("rule uses unexpected dissectors (0x%016llx)",
-		       flow_rule->match.dissector->used_keys);
-		return false;
-	}
-
-	flow_rule_match_basic(flow_rule, &basic);
-	flow_rule_match_control(flow_rule, &control);
-	flow_rule_match_ipv4_addrs(flow_rule, &ipv4_addrs);
-	flow_rule_match_ipv6_addrs(flow_rule, &ipv6_addrs);
-	if (basic.key->ip_proto != IPPROTO_GRE)
-		flow_rule_match_ports(flow_rule, &ports);
-	if (basic.key->ip_proto == IPPROTO_TCP)
-		flow_rule_match_tcp(flow_rule, &tcp);
-
-	if (basic.mask->n_proto != htons(0xFFFF) ||
-	    (basic.key->n_proto != htons(ETH_P_IP) && basic.key->n_proto != htons(ETH_P_IPV6)) ||
-	    basic.mask->ip_proto != 0xFF ||
-	    (basic.key->ip_proto != IPPROTO_UDP && basic.key->ip_proto != IPPROTO_TCP &&
-	     basic.key->ip_proto != IPPROTO_GRE)) {
-		ct_dbg("rule uses unexpected basic match (n_proto 0x%04x/0x%04x, ip_proto 0x%02x/0x%02x)",
-		       ntohs(basic.key->n_proto), ntohs(basic.mask->n_proto),
-		       basic.key->ip_proto, basic.mask->ip_proto);
-		return false;
-	}
-
-	if (basic.key->ip_proto != IPPROTO_GRE &&
-	    (ports.mask->src != htons(0xFFFF) || ports.mask->dst != htons(0xFFFF))) {
-		ct_dbg("rule uses ports match (src 0x%04x, dst 0x%04x)",
-		       ports.mask->src, ports.mask->dst);
-		return false;
-	}
-
-	if (basic.key->ip_proto == IPPROTO_TCP && tcp.mask->flags != MLX5_CT_TCP_FLAGS_MASK) {
-		ct_dbg("rule uses unexpected tcp match (flags 0x%02x)", tcp.mask->flags);
-		return false;
-	}
-
-	return true;
-}
-
 static struct mlx5_ct_fs_rule *
 mlx5_ct_fs_smfs_ct_rule_add(struct mlx5_ct_fs *fs, struct mlx5_flow_spec *spec,
 			    struct mlx5_flow_attr *attr, struct flow_rule *flow_rule)
@@ -304,7 +231,7 @@ mlx5_ct_fs_smfs_ct_rule_add(struct mlx5_ct_fs *fs, struct mlx5_flow_spec *spec,
 	int num_actions = 0, err;
 	bool nat, tcp, ipv4, gre;
 
-	if (!mlx5_ct_fs_smfs_ct_validate_flow_rule(fs, flow_rule))
+	if (!mlx5e_tc_ct_is_valid_flow_rule(fs->netdev, flow_rule))
 		return ERR_PTR(-EOPNOTSUPP);
 
 	smfs_rule = kzalloc(sizeof(*smfs_rule), GFP_KERNEL);

drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c

@@ -2430,3 +2430,74 @@ mlx5e_tc_ct_restore_flow(struct mlx5_tc_ct_priv *ct_priv,
 	atomic_inc(&ct_priv->debugfs.stats.rx_dropped);
 	return false;
 }
+
+static bool mlx5e_tc_ct_valid_used_dissector_keys(const u64 used_keys)
+{
+#define DISS_BIT(name) BIT_ULL(FLOW_DISSECTOR_KEY_ ## name)
+	const u64 basic_keys = DISS_BIT(BASIC) | DISS_BIT(CONTROL) |
+				DISS_BIT(META);
+	const u64 ipv4_tcp = basic_keys | DISS_BIT(IPV4_ADDRS) |
+				DISS_BIT(PORTS) | DISS_BIT(TCP);
+	const u64 ipv6_tcp = basic_keys | DISS_BIT(IPV6_ADDRS) |
+				DISS_BIT(PORTS) | DISS_BIT(TCP);
+	const u64 ipv4_udp = basic_keys | DISS_BIT(IPV4_ADDRS) |
+				DISS_BIT(PORTS);
+	const u64 ipv6_udp = basic_keys | DISS_BIT(IPV6_ADDRS) |
+				 DISS_BIT(PORTS);
+	const u64 ipv4_gre = basic_keys | DISS_BIT(IPV4_ADDRS);
+	const u64 ipv6_gre = basic_keys | DISS_BIT(IPV6_ADDRS);
+
+	return (used_keys == ipv4_tcp || used_keys == ipv4_udp || used_keys == ipv6_tcp ||
+		used_keys == ipv6_udp || used_keys == ipv4_gre || used_keys == ipv6_gre);
+}
+
+bool mlx5e_tc_ct_is_valid_flow_rule(const struct net_device *dev, struct flow_rule *flow_rule)
+{
+	struct flow_match_ipv4_addrs ipv4_addrs;
+	struct flow_match_ipv6_addrs ipv6_addrs;
+	struct flow_match_control control;
+	struct flow_match_basic basic;
+	struct flow_match_ports ports;
+	struct flow_match_tcp tcp;
+
+	if (!mlx5e_tc_ct_valid_used_dissector_keys(flow_rule->match.dissector->used_keys)) {
+		netdev_dbg(dev, "ct_debug: rule uses unexpected dissectors (0x%016llx)",
+			   flow_rule->match.dissector->used_keys);
+		return false;
+	}
+
+	flow_rule_match_basic(flow_rule, &basic);
+	flow_rule_match_control(flow_rule, &control);
+	flow_rule_match_ipv4_addrs(flow_rule, &ipv4_addrs);
+	flow_rule_match_ipv6_addrs(flow_rule, &ipv6_addrs);
+	if (basic.key->ip_proto != IPPROTO_GRE)
+		flow_rule_match_ports(flow_rule, &ports);
+	if (basic.key->ip_proto == IPPROTO_TCP)
+		flow_rule_match_tcp(flow_rule, &tcp);
+
+	if (basic.mask->n_proto != htons(0xFFFF) ||
+	    (basic.key->n_proto != htons(ETH_P_IP) && basic.key->n_proto != htons(ETH_P_IPV6)) ||
+	    basic.mask->ip_proto != 0xFF ||
+	    (basic.key->ip_proto != IPPROTO_UDP && basic.key->ip_proto != IPPROTO_TCP &&
+	     basic.key->ip_proto != IPPROTO_GRE)) {
+		netdev_dbg(dev, "ct_debug: rule uses unexpected basic match (n_proto 0x%04x/0x%04x, ip_proto 0x%02x/0x%02x)",
+			   ntohs(basic.key->n_proto), ntohs(basic.mask->n_proto),
+			   basic.key->ip_proto, basic.mask->ip_proto);
+		return false;
+	}
+
+	if (basic.key->ip_proto != IPPROTO_GRE &&
+	    (ports.mask->src != htons(0xFFFF) || ports.mask->dst != htons(0xFFFF))) {
+		netdev_dbg(dev, "ct_debug: rule uses ports match (src 0x%04x, dst 0x%04x)",
+			   ports.mask->src, ports.mask->dst);
+		return false;
+	}
+
+	if (basic.key->ip_proto == IPPROTO_TCP && tcp.mask->flags != MLX5_CT_TCP_FLAGS_MASK) {
+		netdev_dbg(dev, "ct_debug: rule uses unexpected tcp match (flags 0x%02x)",
+			   tcp.mask->flags);
+		return false;
+	}
+
+	return true;
+}

drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h

@@ -128,6 +128,9 @@ bool
 mlx5e_tc_ct_restore_flow(struct mlx5_tc_ct_priv *ct_priv,
 			 struct sk_buff *skb, u8 zone_restore_id);
 
+#define MLX5_CT_TCP_FLAGS_MASK cpu_to_be16(be32_to_cpu(TCP_FLAG_RST | TCP_FLAG_FIN) >> 16)
+bool mlx5e_tc_ct_is_valid_flow_rule(const struct net_device *dev, struct flow_rule *flow_rule);
+
 #else /* CONFIG_MLX5_TC_CT */
 
 static inline struct mlx5_tc_ct_priv *
@@ -202,5 +205,12 @@ mlx5e_tc_ct_restore_flow(struct mlx5_tc_ct_priv *ct_priv,
 	return false;
 }
 
+static inline bool
+mlx5e_tc_ct_is_valid_flow_rule(const struct net_device *dev,
+			       struct flow_rule *flow_rule)
+{
+	return false;
+}
+
 #endif /* !IS_ENABLED(CONFIG_MLX5_TC_CT) */
 #endif /* __MLX5_EN_TC_CT_H__ */