igb: Add MAC address support for ethtool nftuple filters

This adds the capability of configuring the queue steering of arriving
packets based on their source and destination MAC addresses.

Source address steering (i.e. driving traffic to a specific queue),
for the i210, does not work, but filtering does (i.e. accepting
traffic based on the source address). So, trying to add a filter
specifying only a source address will be an error.

In practical terms this adds support for the following use cases,
characterized by these examples:

$ ethtool -N eth0 flow-type ether dst aa:aa:aa:aa:aa:aa action 0
(this will direct packets with destination address "aa:aa:aa:aa:aa:aa"
to the RX queue 0)

$ ethtool -N eth0 flow-type ether src 44:44:44:44:44:44 \
  	     	  	    	  proto 0x22f0 action 3
(this will direct packets with source address "44:44:44:44:44:44" and
ethertype 0x22f0 to the RX queue 3)
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -2495,6 +2495,23 @@ static int igb_get_ethtool_nfc_entry(struct igb_adapter *adapter,
 			fsp->h_ext.vlan_tci = rule->filter.vlan_tci;
 			fsp->m_ext.vlan_tci = htons(VLAN_PRIO_MASK);
 		}
+		if (rule->filter.match_flags & IGB_FILTER_FLAG_DST_MAC_ADDR) {
+			ether_addr_copy(fsp->h_u.ether_spec.h_dest,
+					rule->filter.dst_addr);
+			/* As we only support matching by the full
+			 * mask, return the mask to userspace
+			 */
+			eth_broadcast_addr(fsp->m_u.ether_spec.h_dest);
+		}
+		if (rule->filter.match_flags & IGB_FILTER_FLAG_SRC_MAC_ADDR) {
+			ether_addr_copy(fsp->h_u.ether_spec.h_source,
+					rule->filter.src_addr);
+			/* As we only support matching by the full
+			 * mask, return the mask to userspace
+			 */
+			eth_broadcast_addr(fsp->m_u.ether_spec.h_source);
+		}
+
 		return 0;
 	}
 	return -EINVAL;
@@ -2768,8 +2785,16 @@ static int igb_rxnfc_write_vlan_prio_filter(struct igb_adapter *adapter,
 
 int igb_add_filter(struct igb_adapter *adapter, struct igb_nfc_filter *input)
 {
+	struct e1000_hw *hw = &adapter->hw;
 	int err = -EINVAL;
 
+	if (hw->mac.type == e1000_i210 &&
+	    !(input->filter.match_flags & ~IGB_FILTER_FLAG_SRC_MAC_ADDR)) {
+		dev_err(&adapter->pdev->dev,
+			"i210 doesn't support flow classification rules specifying only source addresses.\n");
+		return -EOPNOTSUPP;
+	}
+
 	if (input->filter.match_flags & IGB_FILTER_FLAG_ETHER_TYPE) {
 		err = igb_rxnfc_write_etype_filter(adapter, input);
 		if (err)
@@ -2933,10 +2958,6 @@ static int igb_add_ethtool_nfc_entry(struct igb_adapter *adapter,
 	if ((fsp->flow_type & ~FLOW_EXT) != ETHER_FLOW)
 		return -EINVAL;
 
-	if (fsp->m_u.ether_spec.h_proto != ETHER_TYPE_FULL_MASK &&
-	    fsp->m_ext.vlan_tci != htons(VLAN_PRIO_MASK))
-		return -EINVAL;
-
 	input = kzalloc(sizeof(*input), GFP_KERNEL);
 	if (!input)
 		return -ENOMEM;
@@ -2946,6 +2967,20 @@ static int igb_add_ethtool_nfc_entry(struct igb_adapter *adapter,
 		input->filter.match_flags = IGB_FILTER_FLAG_ETHER_TYPE;
 	}
 
+	/* Only support matching addresses by the full mask */
+	if (is_broadcast_ether_addr(fsp->m_u.ether_spec.h_source)) {
+		input->filter.match_flags |= IGB_FILTER_FLAG_SRC_MAC_ADDR;
+		ether_addr_copy(input->filter.src_addr,
+				fsp->h_u.ether_spec.h_source);
+	}
+
+	/* Only support matching addresses by the full mask */
+	if (is_broadcast_ether_addr(fsp->m_u.ether_spec.h_dest)) {
+		input->filter.match_flags |= IGB_FILTER_FLAG_DST_MAC_ADDR;
+		ether_addr_copy(input->filter.dst_addr,
+				fsp->h_u.ether_spec.h_dest);
+	}
+
 	if ((fsp->flow_type & FLOW_EXT) && fsp->m_ext.vlan_tci) {
 		if (fsp->m_ext.vlan_tci != htons(VLAN_PRIO_MASK)) {
 			err = -EINVAL;