vxlan: fix incorrect initializer in union vxlan_addr

The first initializer in the following

        union vxlan_addr ipa = {
            .sin.sin_addr.s_addr = tip,
            .sa.sa_family = AF_INET,
        };

is optimised away by the compiler, due to the second initializer,
therefore initialising .sin.sin_addr.s_addr always to 0.
This results in netlink messages indicating a L3 miss never contain the
missed IP address. This was observed with GCC 4.8 and 4.9. I do not know about previous versions.
The problem affects user space programs relying on an IP address being
sent as part of a netlink message indicating a L3 miss.

Changing
            .sa.sa_family = AF_INET,
to
            .sin.sin_family = AF_INET,
fixes the problem.

Signed-off-by: Gerhard Stenzel <gerhard.stenzel@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 1fb7b37d1402a447b84298829bab61d4f8b6d129..beb377b2d4b78e67e15fa2c7fe6404bef240eba0 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1327,7 +1327,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb)
        } else if (vxlan->flags & VXLAN_F_L3MISS) {
                union vxlan_addr ipa = {
                        .sin.sin_addr.s_addr = tip,
-                       .sa.sa_family = AF_INET,
+                       .sin.sin_family = AF_INET,
                };
 
                vxlan_ip_miss(dev, &ipa);
@@ -1488,7 +1488,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
        } else if (vxlan->flags & VXLAN_F_L3MISS) {
                union vxlan_addr ipa = {
                        .sin6.sin6_addr = msg->target,
-                       .sa.sa_family = AF_INET6,
+                       .sin6.sin6_family = AF_INET6,
                };
 
                vxlan_ip_miss(dev, &ipa);
@@ -1521,7 +1521,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
                if (!n && (vxlan->flags & VXLAN_F_L3MISS)) {
                        union vxlan_addr ipa = {
                                .sin.sin_addr.s_addr = pip->daddr,
-                               .sa.sa_family = AF_INET,
+                               .sin.sin_family = AF_INET,
                        };
 
                        vxlan_ip_miss(dev, &ipa);
@@ -1542,7 +1542,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
                if (!n && (vxlan->flags & VXLAN_F_L3MISS)) {
                        union vxlan_addr ipa = {
                                .sin6.sin6_addr = pip6->daddr,
-                               .sa.sa_family = AF_INET6,
+                               .sin6.sin6_family = AF_INET6,
                        };
 
                        vxlan_ip_miss(dev, &ipa);