target/linux/generic/pending-5.15/779-net-vxlan-don-t-learn-non-unicast-L2-destinations.patch

   1 From 3f1a227cb071f65f6ecc4db9f399649869735a7c Mon Sep 17 00:00:00 2001
   2 From: David Bauer <mail@david-bauer.net>
   3 Date: Sat, 17 Feb 2024 22:34:59 +0100
   4 Subject: [PATCH] net vxlan: don't learn non-unicast L2 destinations
   5
   6 This patch avoids learning non-unicast targets in the vxlan FDB.
   7 They are non-unicast and thus should be sent to the broadcast-IPv6
   8 instead of a unicast address.
   9
  10 Link: https://lore.kernel.org/netdev/15ee0cc7-9252-466b-8ce7-5225d605dde8@david-bauer.net/
  11 Link: https://github.com/freifunk-gluon/gluon/issues/3191
  12
  13 Signed-off-by: David Bauer <mail@david-bauer.net>
  14 ---
  15  drivers/net/vxlan.c | 4 ++++
  16  1 file changed, 4 insertions(+)
  17
  18 --- a/drivers/net/vxlan/vxlan_core.c
  19 +++ b/drivers/net/vxlan/vxlan_core.c
  20 @@ -1493,6 +1493,10 @@ static bool vxlan_snoop(struct net_devic
  21         struct vxlan_fdb *f;
  22         u32 ifindex = 0;
  23
  24 +       /* Don't learn broadcast packets */
  25 +       if (is_multicast_ether_addr(src_mac) || is_zero_ether_addr(src_mac))
  26 +               return false;
  27 +
  28  #if IS_ENABLED(CONFIG_IPV6)
  29         if (src_ip->sa.sa_family == AF_INET6 &&
  30             (ipv6_addr_type(&src_ip->sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL))