tipc: add net set to new netlink api

Add TIPC_NL_NET_SET command to the new tipc netlink API.

This command can set the network id and network (tipc) address.

Netlink logical layout of network set message:
-> net
     [ -> id ]
     [ -> address ]

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/net.c b/net/tipc/net.c
index d9e666a..cf13df3 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -197,3 +197,50 @@
 
 	return skb->len;
 }
+
+int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
+
+	if (!info->attrs[TIPC_NLA_NET])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
+			       info->attrs[TIPC_NLA_NET],
+			       tipc_nl_net_policy);
+	if (err)
+		return err;
+
+	if (attrs[TIPC_NLA_NET_ID]) {
+		u32 val;
+
+		/* Can't change net id once TIPC has joined a network */
+		if (tipc_own_addr)
+			return -EPERM;
+
+		val = nla_get_u32(attrs[TIPC_NLA_NET_ID]);
+		if (val < 1 || val > 9999)
+			return -EINVAL;
+
+		tipc_net_id = val;
+	}
+
+	if (attrs[TIPC_NLA_NET_ADDR]) {
+		u32 addr;
+
+		/* Can't change net addr once TIPC has joined a network */
+		if (tipc_own_addr)
+			return -EPERM;
+
+		addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
+		if (!tipc_addr_node_valid(addr))
+			return -EINVAL;
+
+		rtnl_lock();
+		tipc_net_start(addr);
+		rtnl_unlock();
+	}
+
+	return 0;
+}
diff --git a/net/tipc/net.h b/net/tipc/net.h
index 60dc22f..a81c1b9 100644
--- a/net/tipc/net.h
+++ b/net/tipc/net.h
@@ -44,5 +44,6 @@
 void tipc_net_stop(void);
 
 int tipc_nl_net_dump(struct sk_buff *skb, struct netlink_callback *cb);
+int tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info);
 
 #endif
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index c143f9c..cb37d30 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -180,6 +180,11 @@
 		.cmd	= TIPC_NL_NET_GET,
 		.dumpit	= tipc_nl_net_dump,
 		.policy = tipc_nl_policy,
+	},
+	{
+		.cmd	= TIPC_NL_NET_SET,
+		.doit	= tipc_nl_net_set,
+		.policy = tipc_nl_policy,
 	}
 };