From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: [PATCH net-next] vlan: allow changing VLAN id and protocol
Date: Sun, 8 Mar 2015 11:06:24 -0700
Message-ID: <20150308110624.5ab6f662@urahara>
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Cc: netdev@vger.kernel.org
To: David Miller <davem@davemloft.net>
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The VLAN netlink interface allows changing the ID and protocol of an existing
VLAN, but it was being ignored. Move the initialization of the proto and
id into the change function to fix that.

Example of the problem:
  # modprobe dummy
  # ip li set dev dummy0 up
  # ip li add link dummy0 name dummy0.10 type vlan id 100
  # ip li set dummy0.10 type vlan id 111
  # ip -d li show dev dummy0.10
19: dummy0.10@dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT 
    link/ether be:d3:7c:7f:86:18 brd ff:ff:ff:ff:ff:ff
    vlan id 100 <REORDER_HDR> 
            ^^^ should be 111

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

--- a/net/8021q/vlan_netlink.c	2015-03-08 09:38:48.519551748 -0700
+++ b/net/8021q/vlan_netlink.c	2015-03-08 09:42:16.332512289 -0700
@@ -89,10 +89,30 @@ static int vlan_validate(struct nlattr *
 static int vlan_changelink(struct net_device *dev,
 			   struct nlattr *tb[], struct nlattr *data[])
 {
+	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct ifla_vlan_flags *flags;
 	struct ifla_vlan_qos_mapping *m;
 	struct nlattr *attr;
-	int rem;
+	__be16 proto;
+	int err, rem;
+	u16 id;
+
+	if (data[IFLA_VLAN_PROTOCOL])
+		proto = nla_get_be16(data[IFLA_VLAN_PROTOCOL]);
+	else
+		proto = htons(ETH_P_8021Q);
+
+	if (data[IFLA_VLAN_ID])
+		id = nla_get_u16(data[IFLA_VLAN_ID]);
+	else
+		id = vlan->vlan_id;
+
+	err = vlan_check_real_dev(vlan->real_dev, proto, id);
+	if (err < 0)
+		return err;
+
+	vlan->vlan_id = id;
+	vlan->vlan_proto = proto;
 
 	if (data[IFLA_VLAN_FLAGS]) {
 		flags = nla_data(data[IFLA_VLAN_FLAGS]);
@@ -118,7 +138,6 @@ static int vlan_newlink(struct net *src_
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev;
-	__be16 proto;
 	int err;
 
 	if (!data[IFLA_VLAN_ID])
@@ -130,20 +149,9 @@ static int vlan_newlink(struct net *src_
 	if (!real_dev)
 		return -ENODEV;
 
-	if (data[IFLA_VLAN_PROTOCOL])
-		proto = nla_get_be16(data[IFLA_VLAN_PROTOCOL]);
-	else
-		proto = htons(ETH_P_8021Q);
-
-	vlan->vlan_proto = proto;
-	vlan->vlan_id	 = nla_get_u16(data[IFLA_VLAN_ID]);
 	vlan->real_dev	 = real_dev;
 	vlan->flags	 = VLAN_FLAG_REORDER_HDR;
 
-	err = vlan_check_real_dev(real_dev, vlan->vlan_proto, vlan->vlan_id);
-	if (err < 0)
-		return err;
-
 	if (!tb[IFLA_MTU])
 		dev->mtu = real_dev->mtu;
 	else if (dev->mtu > real_dev->mtu)