nfp: flower: verify pre-tunnel rules

Pre-tunnel rules must direct packets to an internal port based on L2
information. Rules that egress to an internal port are already indicated
by a non-NULL device in its nfp_fl_payload struct. Verfiy the rest of the
match fields indicate that the rule is a pre-tunnel rule. This requires a
full match on the destination MAC address, an option VLAN field, and no
specific matches on other lower layer fields (with the exception of L4
proto and flags).

If a rule is identified as a pre-tunnel rule then mark it for offload to
the pre-tunnel table. Similarly, remove it from the pre-tunnel table on
rule deletion. The actual offloading of these commands is left to a
following patch.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/flower/main.h

@@ -283,6 +283,7 @@ struct nfp_fl_payload {
 	bool in_hw;
 	struct {
 		struct net_device *dev;
+		__be16 vlan_tci;
 	} pre_tun_rule;
 };
 
@@ -419,4 +420,8 @@ void
 nfp_flower_non_repr_priv_put(struct nfp_app *app, struct net_device *netdev);
 u32 nfp_flower_get_port_id_from_netdev(struct nfp_app *app,
 				       struct net_device *netdev);
+int nfp_flower_xmit_pre_tun_flow(struct nfp_app *app,
+				 struct nfp_fl_payload *flow);
+int nfp_flower_xmit_pre_tun_del_flow(struct nfp_app *app,
+				     struct nfp_fl_payload *flow);
 #endif

drivers/net/ethernet/netronome/nfp/flower/offload.c

@@ -61,6 +61,11 @@
 	 NFP_FLOWER_LAYER_IPV4 | \
 	 NFP_FLOWER_LAYER_IPV6)
 
+#define NFP_FLOWER_PRE_TUN_RULE_FIELDS \
+	(NFP_FLOWER_LAYER_PORT | \
+	 NFP_FLOWER_LAYER_MAC | \
+	 NFP_FLOWER_LAYER_IPV4)
+
 struct nfp_flower_merge_check {
 	union {
 		struct {
@@ -1012,7 +1017,89 @@ nfp_flower_validate_pre_tun_rule(struct nfp_app *app,
 				 struct nfp_fl_payload *flow,
 				 struct netlink_ext_ack *extack)
 {
-	return -EOPNOTSUPP;
+	struct nfp_flower_meta_tci *meta_tci;
+	struct nfp_flower_mac_mpls *mac;
+	struct nfp_fl_act_head *act;
+	u8 *mask = flow->mask_data;
+	bool vlan = false;
+	int act_offset;
+	u8 key_layer;
+
+	meta_tci = (struct nfp_flower_meta_tci *)flow->unmasked_data;
+	if (meta_tci->tci & cpu_to_be16(NFP_FLOWER_MASK_VLAN_PRESENT)) {
+		u16 vlan_tci = be16_to_cpu(meta_tci->tci);
+
+		vlan_tci &= ~NFP_FLOWER_MASK_VLAN_PRESENT;
+		flow->pre_tun_rule.vlan_tci = cpu_to_be16(vlan_tci);
+		vlan = true;
+	} else {
+		flow->pre_tun_rule.vlan_tci = cpu_to_be16(0xffff);
+	}
+
+	key_layer = meta_tci->nfp_flow_key_layer;
+	if (key_layer & ~NFP_FLOWER_PRE_TUN_RULE_FIELDS) {
+		NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: too many match fields");
+		return -EOPNOTSUPP;
+	}
+
+	if (!(key_layer & NFP_FLOWER_LAYER_MAC)) {
+		NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: MAC fields match required");
+		return -EOPNOTSUPP;
+	}
+
+	/* Skip fields known to exist. */
+	mask += sizeof(struct nfp_flower_meta_tci);
+	mask += sizeof(struct nfp_flower_in_port);
+
+	/* Ensure destination MAC address is fully matched. */
+	mac = (struct nfp_flower_mac_mpls *)mask;
+	if (!is_broadcast_ether_addr(&mac->mac_dst[0])) {
+		NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: dest MAC field must not be masked");
+		return -EOPNOTSUPP;
+	}
+
+	if (key_layer & NFP_FLOWER_LAYER_IPV4) {
+		int ip_flags = offsetof(struct nfp_flower_ipv4, ip_ext.flags);
+		int ip_proto = offsetof(struct nfp_flower_ipv4, ip_ext.proto);
+		int i;
+
+		mask += sizeof(struct nfp_flower_mac_mpls);
+
+		/* Ensure proto and flags are the only IP layer fields. */
+		for (i = 0; i < sizeof(struct nfp_flower_ipv4); i++)
+			if (mask[i] && i != ip_flags && i != ip_proto) {
+				NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: only flags and proto can be matched in ip header");
+				return -EOPNOTSUPP;
+			}
+	}
+
+	/* Action must be a single egress or pop_vlan and egress. */
+	act_offset = 0;
+	act = (struct nfp_fl_act_head *)&flow->action_data[act_offset];
+	if (vlan) {
+		if (act->jump_id != NFP_FL_ACTION_OPCODE_POP_VLAN) {
+			NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: match on VLAN must have VLAN pop as first action");
+			return -EOPNOTSUPP;
+		}
+
+		act_offset += act->len_lw << NFP_FL_LW_SIZ;
+		act = (struct nfp_fl_act_head *)&flow->action_data[act_offset];
+	}
+
+	if (act->jump_id != NFP_FL_ACTION_OPCODE_OUTPUT) {
+		NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: non egress action detected where egress was expected");
+		return -EOPNOTSUPP;
+	}
+
+	act_offset += act->len_lw << NFP_FL_LW_SIZ;
+
+	/* Ensure there are no more actions after egress. */
+	if (act_offset != flow->meta.act_len) {
+		NL_SET_ERR_MSG_MOD(extack, "unsupported pre-tunnel rule: egress is not the last action");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
 }
 
 /**
@@ -1083,8 +1170,11 @@ nfp_flower_add_offload(struct nfp_app *app, struct net_device *netdev,
 		goto err_release_metadata;
 	}
 
-	err = nfp_flower_xmit_flow(app, flow_pay,
-				   NFP_FLOWER_CMSG_TYPE_FLOW_ADD);
+	if (flow_pay->pre_tun_rule.dev)
+		err = nfp_flower_xmit_pre_tun_flow(app, flow_pay);
+	else
+		err = nfp_flower_xmit_flow(app, flow_pay,
+					   NFP_FLOWER_CMSG_TYPE_FLOW_ADD);
 	if (err)
 		goto err_remove_rhash;
 
@@ -1226,8 +1316,11 @@ nfp_flower_del_offload(struct nfp_app *app, struct net_device *netdev,
 		goto err_free_merge_flow;
 	}
 
-	err = nfp_flower_xmit_flow(app, nfp_flow,
-				   NFP_FLOWER_CMSG_TYPE_FLOW_DEL);
+	if (nfp_flow->pre_tun_rule.dev)
+		err = nfp_flower_xmit_pre_tun_del_flow(app, nfp_flow);
+	else
+		err = nfp_flower_xmit_flow(app, nfp_flow,
+					   NFP_FLOWER_CMSG_TYPE_FLOW_DEL);
 	/* Fall through on error. */
 
 err_free_merge_flow:

drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c

@@ -832,6 +832,18 @@ int nfp_tunnel_mac_event_handler(struct nfp_app *app,
 	return NOTIFY_OK;
 }
 
+int nfp_flower_xmit_pre_tun_flow(struct nfp_app *app,
+				 struct nfp_fl_payload *flow)
+{
+	return -EOPNOTSUPP;
+}
+
+int nfp_flower_xmit_pre_tun_del_flow(struct nfp_app *app,
+				     struct nfp_fl_payload *flow)
+{
+	return -EOPNOTSUPP;
+}
+
 int nfp_tunnel_config_start(struct nfp_app *app)
 {
 	struct nfp_flower_priv *priv = app->priv;