bnxt_en: Implement .ndo_features_check().

For UDP encapsultions, we only support the offloaded Vxlan port and
Geneve port.  All other ports included FOU and GUE are not supported so
we need to turn off TSO and checksum features.

v2: Reverse the check for supported UDP ports to be more straight forward.

Reviewed-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -10781,6 +10781,40 @@ static int bnxt_set_features(struct net_device *dev, netdev_features_t features)
 	return rc;
 }
 
+static netdev_features_t bnxt_features_check(struct sk_buff *skb,
+					     struct net_device *dev,
+					     netdev_features_t features)
+{
+	struct bnxt *bp;
+	__be16 udp_port;
+	u8 l4_proto = 0;
+
+	features = vlan_features_check(skb, features);
+	if (!skb->encapsulation)
+		return features;
+
+	switch (vlan_get_protocol(skb)) {
+	case htons(ETH_P_IP):
+		l4_proto = ip_hdr(skb)->protocol;
+		break;
+	case htons(ETH_P_IPV6):
+		l4_proto = ipv6_hdr(skb)->nexthdr;
+		break;
+	default:
+		return features;
+	}
+
+	if (l4_proto != IPPROTO_UDP)
+		return features;
+
+	bp = netdev_priv(dev);
+	/* For UDP, we can only handle 1 Vxlan port and 1 Geneve port. */
+	udp_port = udp_hdr(skb)->dest;
+	if (udp_port == bp->vxlan_port || udp_port == bp->nge_port)
+		return features;
+	return features & ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
+}
+
 int bnxt_dbg_hwrm_rd_reg(struct bnxt *bp, u32 reg_off, u16 num_words,
 			 u32 *reg_buf)
 {
@@ -12288,10 +12322,13 @@ static int bnxt_udp_tunnel_sync(struct net_device *netdev, unsigned int table)
 	unsigned int cmd;
 
 	udp_tunnel_nic_get_port(netdev, table, 0, &ti);
-	if (ti.type == UDP_TUNNEL_TYPE_VXLAN)
+	if (ti.type == UDP_TUNNEL_TYPE_VXLAN) {
+		bp->vxlan_port = ti.port;
 		cmd = TUNNEL_DST_PORT_FREE_REQ_TUNNEL_TYPE_VXLAN;
-	else
+	} else {
+		bp->nge_port = ti.port;
 		cmd = TUNNEL_DST_PORT_FREE_REQ_TUNNEL_TYPE_GENEVE;
+	}
 
 	if (ti.port)
 		return bnxt_hwrm_tunnel_dst_port_alloc(bp, ti.port, cmd);
@@ -12391,6 +12428,7 @@ static const struct net_device_ops bnxt_netdev_ops = {
 	.ndo_change_mtu		= bnxt_change_mtu,
 	.ndo_fix_features	= bnxt_fix_features,
 	.ndo_set_features	= bnxt_set_features,
+	.ndo_features_check	= bnxt_features_check,
 	.ndo_tx_timeout		= bnxt_tx_timeout,
 #ifdef CONFIG_BNXT_SRIOV
 	.ndo_get_vf_config	= bnxt_get_vf_config,

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1914,6 +1914,8 @@ struct bnxt {
 
 	u16			vxlan_fw_dst_port_id;
 	u16			nge_fw_dst_port_id;
+	__be16			vxlan_port;
+	__be16			nge_port;
 	u8			port_partition_type;
 	u8			port_count;
 	u16			br_mode;