1 files changed, 72 insertions, 6 deletions

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index f8d711a84763..259d5cbacf2c 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -1310,6 +1310,61 @@ static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
 	skb_dst_set(skb, &rt6->dst);
 }
 
+static int vrf_prepare_mac_header(struct sk_buff *skb,
+				  struct net_device *vrf_dev, u16 proto)
+{
+	struct ethhdr *eth;
+	int err;
+
+	/* in general, we do not know if there is enough space in the head of
+	 * the packet for hosting the mac header.
+	 */
+	err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
+	if (unlikely(err))
+		/* no space in the skb head */
+		return -ENOBUFS;
+
+	__skb_push(skb, ETH_HLEN);
+	eth = (struct ethhdr *)skb->data;
+
+	skb_reset_mac_header(skb);
+
+	/* we set the ethernet destination and the source addresses to the
+	 * address of the VRF device.
+	 */
+	ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
+	ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
+	eth->h_proto = htons(proto);
+
+	/* the destination address of the Ethernet frame corresponds to the
+	 * address set on the VRF interface; therefore, the packet is intended
+	 * to be processed locally.
+	 */
+	skb->protocol = eth->h_proto;
+	skb->pkt_type = PACKET_HOST;
+
+	skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
+
+	skb_pull_inline(skb, ETH_HLEN);
+
+	return 0;
+}
+
+/* prepare and add the mac header to the packet if it was not set previously.
+ * In this way, packet sniffers such as tcpdump can parse the packet correctly.
+ * If the mac header was already set, the original mac header is left
+ * untouched and the function returns immediately.
+ */
+static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
+				       struct net_device *vrf_dev,
+				       u16 proto)
+{
+	if (skb_mac_header_was_set(skb))
+		return 0;
+
+	return vrf_prepare_mac_header(skb, vrf_dev, proto);
+}
+
 static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
 				   struct sk_buff *skb)
 {
@@ -1336,9 +1391,15 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
 		skb->skb_iif = vrf_dev->ifindex;
 
 		if (!list_empty(&vrf_dev->ptype_all)) {
-			skb_push(skb, skb->mac_len);
-			dev_queue_xmit_nit(skb, vrf_dev);
-			skb_pull(skb, skb->mac_len);
+			int err;
+
+			err = vrf_add_mac_header_if_unset(skb, vrf_dev,
+							  ETH_P_IPV6);
+			if (likely(!err)) {
+				skb_push(skb, skb->mac_len);
+				dev_queue_xmit_nit(skb, vrf_dev);
+				skb_pull(skb, skb->mac_len);
+			}
 		}
 
 		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
@@ -1381,9 +1442,14 @@ static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
 	vrf_rx_stats(vrf_dev, skb->len);
 
 	if (!list_empty(&vrf_dev->ptype_all)) {
-		skb_push(skb, skb->mac_len);
-		dev_queue_xmit_nit(skb, vrf_dev);
-		skb_pull(skb, skb->mac_len);
+		int err;
+
+		err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP);
+		if (likely(!err)) {
+			skb_push(skb, skb->mac_len);
+			dev_queue_xmit_nit(skb, vrf_dev);
+			skb_pull(skb, skb->mac_len);
+		}
 	}
 
 	skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);