From 3f1a227cb071f65f6ecc4db9f399649869735a7c Mon Sep 17 00:00:00 2001 From: David Bauer Date: Sat, 17 Feb 2024 22:34:59 +0100 Subject: [PATCH] net vxlan: don't learn non-unicast L2 destinations This patch avoids learning non-unicast targets in the vxlan FDB. They are non-unicast and thus should be sent to the broadcast-IPv6 instead of a unicast address. Link: https://lore.kernel.org/netdev/15ee0cc7-9252-466b-8ce7-5225d605dde8@david-bauer.net/ Link: https://github.com/freifunk-gluon/gluon/issues/3191 Signed-off-by: David Bauer --- drivers/net/vxlan.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -1493,6 +1493,10 @@ static bool vxlan_snoop(struct net_devic struct vxlan_fdb *f; u32 ifindex = 0; + /* Don't learn broadcast packets */ + if (is_multicast_ether_addr(src_mac) || is_zero_ether_addr(src_mac)) + return false; + #if IS_ENABLED(CONFIG_IPV6) if (src_ip->sa.sa_family == AF_INET6 && (ipv6_addr_type(&src_ip->sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL))