From 26a41ae604381c5cc0caf1c3261ca6b298b5fe69 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Mon, 17 Jun 2013 12:09:58 -0700 Subject: [PATCH] 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. This patch applies only to -net, a different patch would be needed for earlier kernels since the NTF_SELF flag was introduced with 3.10. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 577a069a6dde..15a73ec42c64 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -565,8 +565,9 @@ 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, +static bool vxlan_snoop(struct net_device *dev, __be32 src_ip, const u8 *src_mac) { struct vxlan_dev *vxlan = netdev_priv(dev); @@ -575,7 +576,11 @@ static void vxlan_snoop(struct net_device *dev, 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, @@ -598,6 +603,8 @@ static void vxlan_snoop(struct net_device *dev, 0, NTF_SELF); spin_unlock(&vxlan->hash_lock); } + + return false; } @@ -729,8 +736,9 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb) 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); -- 2.20.1