node: save created time for node

Save the timestamp of the node creation. This is required to optimize
the selection of most-roamed to neighbors relative to their creation
time.

Signed-off-by: David Bauer <mail@david-bauer.net>

local_node.c

@@ -409,6 +409,7 @@ usteer_get_node(struct ubus_context *ctx, const char *name)
 	ln = calloc_a(sizeof(*ln), &str, strlen(name) + 1);
 	node = &ln->node;
 	node->type = NODE_TYPE_LOCAL;
+	node->created = current_time;
 	node->avl.key = strcpy(str, name);
 	ln->ev.remove_cb = usteer_handle_remove;
 	ln->ev.cb = usteer_handle_event;

remote.c

@@ -257,6 +257,7 @@ interface_get_node(struct usteer_remote_host *host, const char *name)
 
 	node = calloc_a(sizeof(*node), &buf, addr_len + 1 + strlen(name) + 1);
 	node->node.type = NODE_TYPE_REMOTE;
+	node->node.created = current_time;
 
 	sprintf(buf, "%s#%s", host->addr, name);
 	node->node.avl.key = buf;

usteer.h

@@ -90,6 +90,8 @@ struct usteer_node {
 
 	int roam_source;
 	int roam_destination;
+
+	uint64_t created;
 };
 
 struct usteer_scan_request {