Patch "vxlan: fix test which detect duplicate vxlan iface" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

vxlan: fix test which detect duplicate vxlan iface

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
vxlan-fix-test-which-detect-duplicate-vxlan-iface.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nicolas Dichtel <[email protected]>
Date: Thu, 7 Jan 2016 11:26:53 +0100
Subject: vxlan: fix test which detect duplicate vxlan iface

From: Nicolas Dichtel <[email protected]>

[ Upstream commit 07b9b37c227cb8d88d478b4a9c5634fee514ede1 ]

When a vxlan interface is created, the driver checks that there is not another vxlan interface with the same properties. To do this, it checks the existing vxlan udp socket. Since commit 1c51a9159dde, the creation of the vxlan socket is done only when the interface is set up, thus it breaks that test.

Example:

$ ip l a vxlan10 type vxlan id 10 group 239.0.0.10 dev eth0 dstport 0
$ ip l a vxlan11 type vxlan id 10 group 239.0.0.10 dev eth0 dstport 0
$ ip -br l | grep vxlan
vxlan10          DOWN           f2:55:1c:6a:fb:00 <BROADCAST,MULTICAST>
vxlan11          DOWN           7a:cb:b9:38:59:0d <BROADCAST,MULTICAST>

Instead of checking sockets, let's loop over the vxlan iface list.

---
 drivers/net/vxlan.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

@@ -2751,7 +2751,7 @@ static int vxlan_dev_configure(struct ne
 			       struct vxlan_config *conf)
 {
 	struct vxlan_net *vn = net_generic(src_net, vxlan_net_id);
-	struct vxlan_dev *vxlan = netdev_priv(dev);
+	struct vxlan_dev *vxlan = netdev_priv(dev), *tmp;
 	struct vxlan_rdst *dst = &vxlan->default_dst;
 	unsigned short needed_headroom = ETH_HLEN;
 	int err;

@@ -2817,9 +2817,15 @@ static int vxlan_dev_configure(struct ne
 	if (!vxlan->cfg.age_interval)
 		vxlan->cfg.age_interval = FDB_AGE_DEFAULT;
 
-	if (vxlan_find_vni(src_net, conf->vni, use_ipv6 ? AF_INET6 : AF_INET,
-			   vxlan->cfg.dst_port, vxlan->flags))
+	list_for_each_entry(tmp, &vn->vxlan_list, next) {
+		if (tmp->cfg.vni == conf->vni &&
+		    (tmp->default_dst.remote_ip.sa.sa_family == AF_INET6 ||
+		     tmp->cfg.saddr.sa.sa_family == AF_INET6) == use_ipv6 &&
+		    tmp->cfg.dst_port == vxlan->cfg.dst_port &&
+		    (tmp->flags & VXLAN_F_RCV_FLAGS) ==
+		    (vxlan->flags & VXLAN_F_RCV_FLAGS))
 		return -EEXIST;
+	}
 
 	dev->ethtool_ops = &vxlan_ethtool_ops;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/vxlan-fix-test-which-detect-duplicate-vxlan-iface.patch