net: ip6_gre: initialize erspan_ver just for erspan tunnels

After commit c706863 ("net: ip6_gre: always reports o_key to
userspace"), ip6gre and ip6gretap tunnels started reporting TUNNEL_KEY
output flag even if it is not configured.
ip6gre_fill_info checks erspan_ver value to add TUNNEL_KEY for
erspan tunnels, however in commit 84581bd ("erspan: set
erspan_ver to 1 by default when adding an erspan dev")
erspan_ver is initialized to 1 even for ip6gre or ip6gretap
Fix the issue moving erspan_ver initialization in a dedicated routine

Fixes: c706863 ("net: ip6_gre: always reports o_key to userspace")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: LorenzoBianconi

net/ipv6/ip6_gre.c

@@ -1719,6 +1719,24 @@ static int ip6erspan_tap_validate(struct nlattr *tb[], struct nlattr *data[],
 	return 0;
 }
 
+static void ip6erspan_set_version(struct nlattr *data[],
+				  struct __ip6_tnl_parm *parms)
+{
+	parms->erspan_ver = 1;
+	if (data[IFLA_GRE_ERSPAN_VER])
+		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
+
+	if (parms->erspan_ver == 1) {
+		if (data[IFLA_GRE_ERSPAN_INDEX])
+			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
+	} else if (parms->erspan_ver == 2) {
+		if (data[IFLA_GRE_ERSPAN_DIR])
+			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
+		if (data[IFLA_GRE_ERSPAN_HWID])
+			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
+	}
+}
+
 static void ip6gre_netlink_parms(struct nlattr *data[],
 				struct __ip6_tnl_parm *parms)
 {
@@ -1767,20 +1785,6 @@ static void ip6gre_netlink_parms(struct nlattr *data[],
 
 	if (data[IFLA_GRE_COLLECT_METADATA])
 		parms->collect_md = true;
-
-	parms->erspan_ver = 1;
-	if (data[IFLA_GRE_ERSPAN_VER])
-		parms->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
-
-	if (parms->erspan_ver == 1) {
-		if (data[IFLA_GRE_ERSPAN_INDEX])
-			parms->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
-	} else if (parms->erspan_ver == 2) {
-		if (data[IFLA_GRE_ERSPAN_DIR])
-			parms->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
-		if (data[IFLA_GRE_ERSPAN_HWID])
-			parms->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
-	}
 }
 
 static int ip6gre_tap_init(struct net_device *dev)
@@ -2203,6 +2207,7 @@ static int ip6erspan_newlink(struct net *src_net, struct net_device *dev,
 	int err;
 
 	ip6gre_netlink_parms(data, &nt->parms);
+	ip6erspan_set_version(data, &nt->parms);
 	ign = net_generic(net, ip6gre_net_id);
 
 	if (nt->parms.collect_md) {
@@ -2248,6 +2253,7 @@ static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (IS_ERR(t))
 		return PTR_ERR(t);
 
+	ip6erspan_set_version(data, &p);
 	ip6gre_tunnel_unlink_md(ign, t);
 	ip6gre_tunnel_unlink(ign, t);
 	ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);