@@ -9,6 +9,9 @@
 #include <net/dropreason.h>
 
 #define VXLAN_DROP_REASONS(R)			\
+	R(VXLAN_DROP_FLAGS)			\
+	R(VXLAN_DROP_VNI)			\
+	R(VXLAN_DROP_MAC)			\
 	/* deliberate comment for trailing \ */
 
 enum vxlan_drop_reason {

@@ -1668,6 +1668,7 @@ static bool vxlan_ecn_decapsulate(struct vxlan_sock *vs, void *oiph,
 /* Callback from net/ipv4/udp.c to receive packets */
 static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason = pskb_may_pull_reason(skb, VXLAN_HLEN);
 	struct vxlan_vni_node *vninode = NULL;
 	struct vxlan_dev *vxlan;
 	struct vxlan_sock *vs;

@@ -1681,7 +1682,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	int nh;
 
 	/* Need UDP and VXLAN header to be present */
-	if (!pskb_may_pull(skb, VXLAN_HLEN))
+	if (reason != SKB_NOT_DROPPED_YET)
 		goto drop;
 
 	unparsed = *vxlan_hdr(skb);

@@ -1690,6 +1691,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		netdev_dbg(skb->dev, "invalid vxlan flags=%#x vni=%#x\n",
 			   ntohl(vxlan_hdr(skb)->vx_flags),
 			   ntohl(vxlan_hdr(skb)->vx_vni));
+		reason = (u32)VXLAN_DROP_FLAGS;
 		/* Return non vxlan pkt */
 		goto drop;
 	}

@@ -1703,8 +1705,10 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	vni = vxlan_vni(vxlan_hdr(skb)->vx_vni);
 
 	vxlan = vxlan_vs_find_vni(vs, skb->dev->ifindex, vni, &vninode);
-	if (!vxlan)
+	if (!vxlan) {
+		reason = (u32)VXLAN_DROP_VNI;
 		goto drop;
+	}
 
 	/* For backwards compatibility, only allow reserved fields to be
 	 * used by VXLAN extensions if explicitly requested.

@@ -1717,12 +1721,16 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	}
 
 	if (__iptunnel_pull_header(skb, VXLAN_HLEN, protocol, raw_proto,
-				   !net_eq(vxlan->net, dev_net(vxlan->dev))))
+				   !net_eq(vxlan->net, dev_net(vxlan->dev)))) {
+		reason = SKB_DROP_REASON_NOMEM;
 		goto drop;
+	}
 
-	if (vs->flags & VXLAN_F_REMCSUM_RX)
-		if (unlikely(!vxlan_remcsum(&unparsed, skb, vs->flags)))
+	if (vs->flags & VXLAN_F_REMCSUM_RX) {
+		reason = vxlan_remcsum(&unparsed, skb, vs->flags);
+		if (unlikely(reason != SKB_NOT_DROPPED_YET))
 			goto drop;
+	}
 
 	if (vxlan_collect_metadata(vs)) {
 		IP_TUNNEL_DECLARE_FLAGS(flags) = { };

@@ -1732,8 +1740,10 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		tun_dst = udp_tun_rx_dst(skb, vxlan_get_sk_family(vs), flags,
 					 key32_to_tunnel_id(vni), sizeof(*md));
 
-		if (!tun_dst)
+		if (!tun_dst) {
+			reason = SKB_DROP_REASON_NOMEM;
 			goto drop;
+		}
 
 		md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
 

@@ -1757,12 +1767,15 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		 * is more robust and provides a little more security in
 		 * adding extensions to VXLAN.
 		 */
+		reason = (u32)VXLAN_DROP_FLAGS;
 		goto drop;
 	}
 
 	if (!raw_proto) {
-		if (!vxlan_set_mac(vxlan, vs, skb, vni))
+		if (!vxlan_set_mac(vxlan, vs, skb, vni)) {
+			reason = (u32)VXLAN_DROP_MAC;
 			goto drop;
+		}
 	} else {
 		skb_reset_mac_header(skb);
 		skb->dev = vxlan->dev;

@@ -1777,7 +1790,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 
 	skb_reset_network_header(skb);
 
-	if (!pskb_inet_may_pull(skb)) {
+	reason = pskb_inet_may_pull_reason(skb);
+	if (reason != SKB_NOT_DROPPED_YET) {
 		DEV_STATS_INC(vxlan->dev, rx_length_errors);
 		DEV_STATS_INC(vxlan->dev, rx_errors);
 		vxlan_vnifilter_count(vxlan, vni, vninode,

@@ -1789,6 +1803,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	oiph = skb->head + nh;
 
 	if (!vxlan_ecn_decapsulate(vs, oiph, skb)) {
+		reason = SKB_DROP_REASON_IP_TUNNEL_ECN;
 		DEV_STATS_INC(vxlan->dev, rx_frame_errors);
 		DEV_STATS_INC(vxlan->dev, rx_errors);
 		vxlan_vnifilter_count(vxlan, vni, vninode,

@@ -1803,6 +1818,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		dev_core_stats_rx_dropped_inc(vxlan->dev);
 		vxlan_vnifilter_count(vxlan, vni, vninode,
 				      VXLAN_VNI_STATS_RX_DROPS, 0);
+		reason = SKB_DROP_REASON_DEV_READY;
 		goto drop;
 	}
 

@@ -1815,8 +1831,9 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	return 0;
 
 drop:
+	SKB_DR_RESET(reason);
 	/* Consume bad packet */
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 	return 0;
 }
 

@@ -92,6 +92,7 @@
 	FN(PACKET_SOCK_ERROR)		\
 	FN(TC_CHAIN_NOTFOUND)		\
 	FN(TC_RECLASSIFY_LOOP)		\
+	FN(IP_TUNNEL_ECN)		\
 	FNe(MAX)
 
 /**

@@ -418,6 +419,11 @@ enum skb_drop_reason {
 	 * iterations.
 	 */
 	SKB_DROP_REASON_TC_RECLASSIFY_LOOP,
+	/**
+	 * @SKB_DROP_REASON_IP_TUNNEL_ECN: skb is dropped according to
+	 * RFC 6040 4.2, see __INET_ECN_decapsulate() for detail.
+	 */
+	SKB_DROP_REASON_IP_TUNNEL_ECN,
 	/**
 	 * @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which
 	 * shouldn't be used as a real 'reason' - only for tracing code gen