Support for restarting initctl API socket on SIGHUP

This patch adds support for restarting the API socket on SIGHUP, similar
to how SysV init and systemd use SIGUSR1 to restart their FIFO or D-Bus.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/sig.c

@@ -27,6 +27,8 @@
  *
  * SIGHUP
  *      Same effect as init/telinit q, reloads *.conf in /etc/finit.d/
+ *      Also restarts API (initctl) socket, like SysV init and systemd
+ *      does on USR1 with their FIFO/D-Bus.
  *
  * SIGUSR1
  *      Calls shutdown hooks, including HOOK_SHUTDOWN, stops all running
@@ -236,6 +238,10 @@ static void sighup_cb(uev_t *w, void *arg, int events)
 		return;
 	}
 
+	/* Restart initctl API domain socket, similar to systemd/SysV init */
+	api_exit();
+	api_init(w->ctx);
+
 	/* INIT_CMD_RELOAD: 'init q', 'initctl reload', and SIGHUP */
 	service_reload_dynamic();
 }