generic 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/[email protected]/
Link: https://github.com/freifunk-gluon/gluon/issues/3191

Signed-off-by: David Bauer <[email protected]>

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

@@ -0,0 +1,30 @@
+From 3f1a227cb071f65f6ecc4db9f399649869735a7c Mon Sep 17 00:00:00 2001
+From: David Bauer <[email protected]>
+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/[email protected]/
+Link: https://github.com/freifunk-gluon/gluon/issues/3191
+
+Signed-off-by: David Bauer <[email protected]>
+---
+ 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))

target/linux/generic/pending-6.1/779-net-vxlan-don-t-learn-non-unicast-L2-destinations.patch

@@ -0,0 +1,30 @@
+From 3f1a227cb071f65f6ecc4db9f399649869735a7c Mon Sep 17 00:00:00 2001
+From: David Bauer <[email protected]>
+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/[email protected]/
+Link: https://github.com/freifunk-gluon/gluon/issues/3191
+
+Signed-off-by: David Bauer <[email protected]>
+---
+ 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))