161 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			161 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
Subject: NET: skip GRO for foreign MAC addresses
 | 
						|
 | 
						|
For network drivers using napi_gro_receive, packets are run through GRO,
 | 
						|
even when the destination MAC address does not match, and they're supposed
 | 
						|
to be delivered to another host behind a different bridge port.
 | 
						|
 | 
						|
This can be very expensive, because for drivers without TSO or scatter-
 | 
						|
gather, this can only be undone by copying the skb and checksumming it
 | 
						|
again.
 | 
						|
 | 
						|
To be able to track foreign MAC addresses in an inexpensive way, create
 | 
						|
a mask of changed bits in MAC addresses of upper devices. This allows
 | 
						|
handling VLANs and bridge devices with different addresses (as long as
 | 
						|
they are not too different).
 | 
						|
 | 
						|
Signed-off-by: Felix Fietkau <nbd@nbd.name>
 | 
						|
 | 
						|
--- a/net/core/dev.c
 | 
						|
+++ b/net/core/dev.c
 | 
						|
@@ -4002,6 +4002,9 @@ static enum gro_result dev_gro_receive(s
 | 
						|
 	enum gro_result ret;
 | 
						|
 	int grow;
 | 
						|
 
 | 
						|
+	if (skb->gro_skip)
 | 
						|
+		goto normal;
 | 
						|
+
 | 
						|
 	if (!(skb->dev->features & NETIF_F_GRO))
 | 
						|
 		goto normal;
 | 
						|
 
 | 
						|
@@ -5067,6 +5070,48 @@ static void __netdev_adjacent_dev_unlink
 | 
						|
 					   &upper_dev->adj_list.lower);
 | 
						|
 }
 | 
						|
 
 | 
						|
+static void __netdev_addr_mask(unsigned char *mask, const unsigned char *addr,
 | 
						|
+			       struct net_device *dev)
 | 
						|
+{
 | 
						|
+	int i;
 | 
						|
+
 | 
						|
+	for (i = 0; i < dev->addr_len; i++)
 | 
						|
+		mask[i] |= addr[i] ^ dev->dev_addr[i];
 | 
						|
+}
 | 
						|
+
 | 
						|
+static void __netdev_upper_mask(unsigned char *mask, struct net_device *dev,
 | 
						|
+				struct net_device *lower)
 | 
						|
+{
 | 
						|
+	struct net_device *cur;
 | 
						|
+	struct list_head *iter;
 | 
						|
+
 | 
						|
+	netdev_for_each_upper_dev_rcu(dev, cur, iter) {
 | 
						|
+		__netdev_addr_mask(mask, cur->dev_addr, lower);
 | 
						|
+		__netdev_upper_mask(mask, cur, lower);
 | 
						|
+	}
 | 
						|
+}
 | 
						|
+
 | 
						|
+static void __netdev_update_addr_mask(struct net_device *dev)
 | 
						|
+{
 | 
						|
+	unsigned char mask[MAX_ADDR_LEN];
 | 
						|
+	struct net_device *cur;
 | 
						|
+	struct list_head *iter;
 | 
						|
+
 | 
						|
+	memset(mask, 0, sizeof(mask));
 | 
						|
+	__netdev_upper_mask(mask, dev, dev);
 | 
						|
+	memcpy(dev->local_addr_mask, mask, dev->addr_len);
 | 
						|
+
 | 
						|
+	netdev_for_each_lower_dev(dev, cur, iter)
 | 
						|
+		__netdev_update_addr_mask(cur);
 | 
						|
+}
 | 
						|
+
 | 
						|
+static void netdev_update_addr_mask(struct net_device *dev)
 | 
						|
+{
 | 
						|
+	rcu_read_lock();
 | 
						|
+	__netdev_update_addr_mask(dev);
 | 
						|
+	rcu_read_unlock();
 | 
						|
+}
 | 
						|
+
 | 
						|
 static int __netdev_upper_dev_link(struct net_device *dev,
 | 
						|
 				   struct net_device *upper_dev, bool master,
 | 
						|
 				   void *private)
 | 
						|
@@ -5127,6 +5172,7 @@ static int __netdev_upper_dev_link(struc
 | 
						|
 			goto rollback_lower_mesh;
 | 
						|
 	}
 | 
						|
 
 | 
						|
+	netdev_update_addr_mask(dev);
 | 
						|
 	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
 | 
						|
 	return 0;
 | 
						|
 
 | 
						|
@@ -5244,6 +5290,7 @@ void netdev_upper_dev_unlink(struct net_
 | 
						|
 	list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
 | 
						|
 		__netdev_adjacent_dev_unlink(dev, i->dev);
 | 
						|
 
 | 
						|
+	netdev_update_addr_mask(dev);
 | 
						|
 	call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
 | 
						|
 }
 | 
						|
 EXPORT_SYMBOL(netdev_upper_dev_unlink);
 | 
						|
@@ -5763,6 +5810,7 @@ int dev_set_mac_address(struct net_devic
 | 
						|
 	if (err)
 | 
						|
 		return err;
 | 
						|
 	dev->addr_assign_type = NET_ADDR_SET;
 | 
						|
+	netdev_update_addr_mask(dev);
 | 
						|
 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
 | 
						|
 	add_device_randomness(dev->dev_addr, dev->addr_len);
 | 
						|
 	return 0;
 | 
						|
--- a/include/linux/netdevice.h
 | 
						|
+++ b/include/linux/netdevice.h
 | 
						|
@@ -1556,6 +1556,8 @@ struct net_device {
 | 
						|
 	struct netdev_hw_addr_list	mc;
 | 
						|
 	struct netdev_hw_addr_list	dev_addrs;
 | 
						|
 
 | 
						|
+	unsigned char		local_addr_mask[MAX_ADDR_LEN];
 | 
						|
+
 | 
						|
 #ifdef CONFIG_SYSFS
 | 
						|
 	struct kset		*queues_kset;
 | 
						|
 #endif
 | 
						|
--- a/include/linux/skbuff.h
 | 
						|
+++ b/include/linux/skbuff.h
 | 
						|
@@ -597,7 +597,8 @@ struct sk_buff {
 | 
						|
 #endif
 | 
						|
 	__u8			ipvs_property:1;
 | 
						|
 	__u8			inner_protocol_type:1;
 | 
						|
-	/* 4 or 6 bit hole */
 | 
						|
+	__u8			gro_skip:1;
 | 
						|
+	/* 3 or 5 bit hole */
 | 
						|
 
 | 
						|
 #ifdef CONFIG_NET_SCHED
 | 
						|
 	__u16			tc_index;	/* traffic control index */
 | 
						|
--- a/net/ethernet/eth.c
 | 
						|
+++ b/net/ethernet/eth.c
 | 
						|
@@ -172,6 +172,18 @@ u32 eth_get_headlen(void *data, unsigned
 | 
						|
 }
 | 
						|
 EXPORT_SYMBOL(eth_get_headlen);
 | 
						|
 
 | 
						|
+static inline bool
 | 
						|
+eth_check_local_mask(const void *addr1, const void *addr2, const void *mask)
 | 
						|
+{
 | 
						|
+	const u16 *a1 = addr1;
 | 
						|
+	const u16 *a2 = addr2;
 | 
						|
+	const u16 *m = mask;
 | 
						|
+
 | 
						|
+	return (((a1[0] ^ a2[0]) & ~m[0]) |
 | 
						|
+		((a1[1] ^ a2[1]) & ~m[1]) |
 | 
						|
+		((a1[2] ^ a2[2]) & ~m[2]));
 | 
						|
+}
 | 
						|
+
 | 
						|
 /**
 | 
						|
  * eth_type_trans - determine the packet's protocol ID.
 | 
						|
  * @skb: received socket data
 | 
						|
@@ -199,8 +211,12 @@ __be16 eth_type_trans(struct sk_buff *sk
 | 
						|
 			skb->pkt_type = PACKET_MULTICAST;
 | 
						|
 	}
 | 
						|
 	else if (unlikely(!ether_addr_equal_64bits(eth->h_dest,
 | 
						|
-						   dev->dev_addr)))
 | 
						|
+						   dev->dev_addr))) {
 | 
						|
 		skb->pkt_type = PACKET_OTHERHOST;
 | 
						|
+		if (eth_check_local_mask(eth->h_dest, dev->dev_addr,
 | 
						|
+					 dev->local_addr_mask))
 | 
						|
+			skb->gro_skip = 1;
 | 
						|
+	}
 | 
						|
 
 | 
						|
 	/*
 | 
						|
 	 * Some variants of DSA tagging don't have an ethertype field
 |