bridge: implement rtnl_link_ops->changelink

Allow rtnetlink users to set bridge master info via IFLA_INFO_DATA attr
This initial part implements forward_delay, hello_time, max_age options.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_netlink.c

@@ -484,6 +484,42 @@ static size_t br_port_get_slave_size(const struct net_device *brdev,
 	return br_port_info_size();
 }
 
+static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = {
+	[IFLA_BR_FORWARD_DELAY]	= { .type = NLA_U32 },
+	[IFLA_BR_HELLO_TIME]	= { .type = NLA_U32 },
+	[IFLA_BR_MAX_AGE]	= { .type = NLA_U32 },
+};
+
+static int br_changelink(struct net_device *brdev, struct nlattr *tb[],
+			 struct nlattr *data[])
+{
+	struct net_bridge *br = netdev_priv(brdev);
+	int err;
+
+	if (!data)
+		return 0;
+
+	if (data[IFLA_BR_FORWARD_DELAY]) {
+		err = br_set_forward_delay(br, nla_get_u32(data[IFLA_BR_FORWARD_DELAY]));
+		if (err)
+			return err;
+	}
+
+	if (data[IFLA_BR_HELLO_TIME]) {
+		err = br_set_hello_time(br, nla_get_u32(data[IFLA_BR_HELLO_TIME]));
+		if (err)
+			return err;
+	}
+
+	if (data[IFLA_BR_MAX_AGE]) {
+		err = br_set_max_age(br, nla_get_u32(data[IFLA_BR_MAX_AGE]));
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static size_t br_get_size(const struct net_device *brdev)
 {
 	return nla_total_size(sizeof(u32)) +	/* IFLA_BR_FORWARD_DELAY  */
@@ -534,8 +570,11 @@ struct rtnl_link_ops br_link_ops __read_mostly = {
 	.kind			= "bridge",
 	.priv_size		= sizeof(struct net_bridge),
 	.setup			= br_dev_setup,
+	.maxtype		= IFLA_BRPORT_MAX,
+	.policy			= br_policy,
 	.validate		= br_validate,
 	.newlink		= br_dev_newlink,
+	.changelink		= br_changelink,
 	.dellink		= br_dev_delete,
 	.get_size		= br_get_size,
 	.fill_info		= br_fill_info,