netdev - [PATCH net v2 01/03] vxlan: only migrate dynamic FDB entries

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Message-ID: <20130610131317.0c17ed0d@nehalam.linuxnetplumber.net>
Date:	Mon, 10 Jun 2013 13:13:17 -0700
From:	Stephen Hemminger <stephen@...workplumber.org>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org,
	Stephen Hemminger <stephen@...workplumber.org>
Subject: [PATCH net v2 01/03] vxlan: only migrate dynamic FDB entries

Only migrate dynamic forwarding table entries, don't modify
static entries. If packet received from incorrect source IP address
assume it is an imposter and drop it.

Signed-off-by: Stephen Hemminger <stephen@...workplumber.org>

---
Should go to -stable as well.

--- a/drivers/net/vxlan.c	2013-06-06 08:27:07.499595174 -0700
+++ b/drivers/net/vxlan.c	2013-06-06 09:38:54.291654035 -0700
@@ -603,9 +603,10 @@ skip:
 
 /* Watch incoming packets to learn mapping between Ethernet address
  * and Tunnel endpoint.
+ * Return true if packet is bogus and should be droppped.
  */
-static void vxlan_snoop(struct net_device *dev,
-			__be32 src_ip, const u8 *src_mac)
+static bool vxlan_snoop(struct net_device *dev,
+		       __be32 src_ip, const u8 *src_mac)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_fdb *f;
@@ -614,7 +615,11 @@ static void vxlan_snoop(struct net_devic
 	f = vxlan_find_mac(vxlan, src_mac);
 	if (likely(f)) {
 		if (likely(f->remote.remote_ip == src_ip))
-			return;
+			return false;
+
+		/* Don't migrate static entries, drop packets */
+		if (!(f->flags & NTF_SELF))
+			return true;
 
 		if (net_ratelimit())
 			netdev_info(dev,
@@ -634,6 +639,8 @@ static void vxlan_snoop(struct net_devic
 				       0, NTF_SELF);
 		spin_unlock(&vxlan->hash_lock);
 	}
+
+	return false;
 }
 
 
@@ -766,8 +773,9 @@ static int vxlan_udp_encap_recv(struct s
 			       vxlan->dev->dev_addr) == 0)
 		goto drop;
 
-	if (vxlan->flags & VXLAN_F_LEARN)
-		vxlan_snoop(skb->dev, oip->saddr, eth_hdr(skb)->h_source);
+	if ((vxlan->flags & VXLAN_F_LEARN) &&
+	    vxlan_snoop(skb->dev, oip->saddr, eth_hdr(skb)->h_source))
+		goto drop;
 
 	__skb_tunnel_rx(skb, vxlan->dev);
 	skb_reset_network_header(skb);

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