Patch "vxlan: fix test which detect duplicate vxlan iface" has been added to the 3.14-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 3.14-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-3.14 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
Content-Length: 2895
Lines: 75

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 ++++++++----
 include/net/vxlan.h |    5 +++++
 2 files changed, 13 insertions(+), 4 deletions(-)

@@ -2607,7 +2607,7 @@ static int vxlan_newlink(struct net *net
 			 struct nlattr *tb[], struct nlattr *data[])
 {
 	struct vxlan_net *vn = net_generic(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;
 	__u32 vni;
 	int err;

@@ -2715,9 +2715,13 @@ static int vxlan_newlink(struct net *net
 	if (data[IFLA_VXLAN_PORT])
 		vxlan->dst_port = nla_get_be16(data[IFLA_VXLAN_PORT]);
 
-	if (vxlan_find_vni(net, vni, use_ipv6 ? AF_INET6 : AF_INET,
-			   vxlan->dst_port)) {
-		pr_info("duplicate VNI %u\n", vni);
+	list_for_each_entry(tmp, &vn->vxlan_list, next) {
+		if (tmp->default_dst.remote_vni == vni &&
+		    (tmp->default_dst.remote_ip.sa.sa_family == AF_INET6 ||
+		     tmp->saddr.sa.sa_family == AF_INET6) == use_ipv6 &&
+		    tmp->dst_port == vxlan->dst_port &&
+		    (tmp->flags & VXLAN_F_RCV_FLAGS) ==
+		    (vxlan->flags & VXLAN_F_RCV_FLAGS))
 		return -EEXIST;
 	}
 

@@ -24,6 +24,11 @@ struct vxlan_sock {
 	struct udp_offload udp_offloads;
 };
 
+/* Flags that are used in the receive path. These flags must match in
+ * order for a socket to be shareable
+ */
+#define VXLAN_F_RCV_FLAGS		VXLAN_F_UDP_ZERO_CSUM6_RX
+
 struct vxlan_sock *vxlan_sock_add(struct net *net, __be16 port,
 				  vxlan_rcv_t *rcv, void *data,
 				  bool no_share, bool ipv6);

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

queue-3.14/vxlan-fix-test-which-detect-duplicate-vxlan-iface.patch queue-3.14/utf-8-q-veth-20don-e2-80-99t-20modify-20ip-5fsum-utf-8-q-med-20doing-20so-20treats-20packets-20with-20bad-20checksums-utf-8-q-20as-20good.patch