network: Make it possible to set the mode of IPVLAN to L2

src/lxc/network.c

@@ -582,24 +582,21 @@ static int lxc_ipvlan_create(const char *master, const char *name, int mode, int
 	if (nla_put_string(nlmsg, IFLA_INFO_KIND, "ipvlan"))
 		return ret_errno(EPROTO);
 
-	if (mode) {
-		nest2 = nla_begin_nested(nlmsg, IFLA_INFO_DATA);
-		if (!nest2)
-			return ret_errno(EPROTO);
-
-		if (nla_put_u32(nlmsg, IFLA_IPVLAN_MODE, mode))
-			return ret_errno(EPROTO);
+	nest2 = nla_begin_nested(nlmsg, IFLA_INFO_DATA);
+	if (!nest2)
+		return ret_errno(EPROTO);
 
-		/* if_link.h does not define the isolation flag value for bridge mode so we define it as 0
-		 * and only send mode if mode >0 as default mode is bridge anyway according to ipvlan docs.
-		 */
-		if (isolation > 0 &&
-		    nla_put_u16(nlmsg, IFLA_IPVLAN_ISOLATION, isolation))
-			return ret_errno(EPROTO);
+	if (nla_put_u32(nlmsg, IFLA_IPVLAN_MODE, mode))
+		return ret_errno(EPROTO);
 
-		nla_end_nested(nlmsg, nest2);
-	}
+	/* if_link.h does not define the isolation flag value for bridge mode so we define it as 0
+	 * and only send mode if mode >0 as default mode is bridge anyway according to ipvlan docs.
+	 */
+	if (isolation > 0 &&
+	    nla_put_u16(nlmsg, IFLA_IPVLAN_ISOLATION, isolation))
+		return ret_errno(EPROTO);
 
+	nla_end_nested(nlmsg, nest2);
 	nla_end_nested(nlmsg, nest);
 
 	if (nla_put_u32(nlmsg, IFLA_LINK, index))