iavf: Fix ping is lost after untrusted VF had tried to change MAC

Make changes to MAC address dependent on the response of PF.
Disallow changes to HW MAC address and MAC filter from untrusted
VF, thanks to that ping is not lost if VF tries to change MAC.
Add a new field in iavf_mac_filter, to indicate whether there
was response from PF for given filter. Based on this field pass
or discard the filter.
If untrusted VF tried to change it's address, it's not changed.
Still filter was changed, because of that ping couldn't go through.

Fixes: c5c922b ("iavf: fix MAC address setting for VFs when filter is rejected")
Signed-off-by: Przemyslaw Patynowski <[email protected]>
Signed-off-by: Sylwester Dziedziuch <[email protected]>
Signed-off-by: Mateusz Palczewski <[email protected]>
Tested-by: Gurucharan G <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

Author: sylwesterdziedziuch

drivers/net/ethernet/intel/iavf/iavf.h

@@ -136,6 +136,7 @@ struct iavf_q_vector {
 struct iavf_mac_filter {
 	struct list_head list;
 	u8 macaddr[ETH_ALEN];
+	bool is_new_mac;	/* filter is new, wait for PF decision */
 	bool remove;		/* filter needs to be removed */
 	bool add;		/* filter needs to be added */
 };

drivers/net/ethernet/intel/iavf/iavf_main.c

@@ -751,6 +751,7 @@ struct iavf_mac_filter *iavf_add_filter(struct iavf_adapter *adapter,
 
 		list_add_tail(&f->list, &adapter->mac_filter_list);
 		f->add = true;
+		f->is_new_mac = true;
 		adapter->aq_required |= IAVF_FLAG_AQ_ADD_MAC_FILTER;
 	} else {
 		f->remove = false;

drivers/net/ethernet/intel/iavf/iavf_virtchnl.c

@@ -540,6 +540,47 @@ void iavf_del_ether_addrs(struct iavf_adapter *adapter)
 	kfree(veal);
 }
 
+/**
+ * iavf_mac_add_ok
+ * @adapter: adapter structure
+ *
+ * Submit list of filters based on PF response.
+ **/
+static void iavf_mac_add_ok(struct iavf_adapter *adapter)
+{
+	struct iavf_mac_filter *f, *ftmp;
+
+	spin_lock_bh(&adapter->mac_vlan_list_lock);
+	list_for_each_entry_safe(f, ftmp, &adapter->mac_filter_list, list) {
+		f->is_new_mac = false;
+	}
+	spin_unlock_bh(&adapter->mac_vlan_list_lock);
+}
+
+/**
+ * iavf_mac_add_reject
+ * @adapter: adapter structure
+ *
+ * Remove filters from list based on PF response.
+ **/
+static void iavf_mac_add_reject(struct iavf_adapter *adapter)
+{
+	struct net_device *netdev = adapter->netdev;
+	struct iavf_mac_filter *f, *ftmp;
+
+	spin_lock_bh(&adapter->mac_vlan_list_lock);
+	list_for_each_entry_safe(f, ftmp, &adapter->mac_filter_list, list) {
+		if (f->remove && ether_addr_equal(f->macaddr, netdev->dev_addr))
+			f->remove = false;
+
+		if (f->is_new_mac) {
+			list_del(&f->list);
+			kfree(f);
+		}
+	}
+	spin_unlock_bh(&adapter->mac_vlan_list_lock);
+}
+
 /**
  * iavf_add_vlans
  * @adapter: adapter structure
@@ -1492,6 +1533,7 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter,
 		case VIRTCHNL_OP_ADD_ETH_ADDR:
 			dev_err(&adapter->pdev->dev, "Failed to add MAC filter, error %s\n",
 				iavf_stat_str(&adapter->hw, v_retval));
+			iavf_mac_add_reject(adapter);
 			/* restore administratively set MAC address */
 			ether_addr_copy(adapter->hw.mac.addr, netdev->dev_addr);
 			break;
@@ -1639,10 +1681,11 @@ void iavf_virtchnl_completion(struct iavf_adapter *adapter,
 		}
 	}
 	switch (v_opcode) {
-	case VIRTCHNL_OP_ADD_ETH_ADDR: {
+	case VIRTCHNL_OP_ADD_ETH_ADDR:
+		if (!v_retval)
+			iavf_mac_add_ok(adapter);
 		if (!ether_addr_equal(netdev->dev_addr, adapter->hw.mac.addr))
 			ether_addr_copy(netdev->dev_addr, adapter->hw.mac.addr);
-		}
 		break;
 	case VIRTCHNL_OP_GET_STATS: {
 		struct iavf_eth_stats *stats =