Add two new hook points: HOOK_SVC_RECONF and HOOK_RUNLEVEL_CHANGE.

These two new hooks run when SIGHUP is received and when changing
system runlevel.  The hooks are called when all services have been
stopped, just before starting up new/modified services.  Making it
the perfect hook for reconfiguring the system/hardware before new
services or modified services are started up again.

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

README.md

@@ -435,6 +435,8 @@ hook point in the boot process, useful to insert some pre-bootstrap
 mechanisms, like generating configuration files, restoring HW device
 state, etc.  Available hook points are:
 
+**Bootstrap Hooks**
+
 * `HOOK_ROOTFS_UP`: When `finit.conf` has been read and `/` has is
   mounted -- very early
 
@@ -449,6 +451,20 @@ state, etc.  Available hook points are:
 * `HOOK_SYSTEM_UP`: All services *and* everything in `/etc/finit.d`
   has been launched
 
+**Runtime Hooks**
+
+* `HOOK_SVC_RECONF`: Called when the user has changed something in the
+  `/etc/finit.d` directory and issued `SIGHUP`.  The hook is called when
+  all modified/removed services have been stopped.  When the hook has
+  completed, Finit continues to start all modified and new services.
+
+* `HOOK_RUNLEVEL_CHANGE`: Called when the user has issued a runlevel
+  change.  The hook is called when services not matching the new
+  runlevel have been been stopped.  When the hook has completed, Finit
+  continues to start all services in the new runlevel.
+
+**Shutdown Hooks**
+
 * `HOOK_SHUTDOWN`: Called at shutdown/reboot, right before all
   services are sent `SIGTERM`
 

plugin.h

@@ -41,11 +41,18 @@
  * Predefined hook points for easier plugin debugging 
  */
 typedef enum {
+	/* Bootstrap hooks */
 	HOOK_ROOTFS_UP = 0,
 	HOOK_BASEFS_UP,
 	HOOK_NETWORK_UP,
-	HOOK_SYSTEM_UP,
 	HOOK_SVC_UP,
+	HOOK_SYSTEM_UP,
+
+	/* Runtime hooks */
+	HOOK_SVC_RECONF,
+	HOOK_RUNLEVEL_CHANGE,
+
+	/* Shutdown hooks */
 	HOOK_SHUTDOWN,
 	HOOK_MAX_NUM
 } hook_point_t;

svc.c

@@ -286,17 +286,32 @@ void svc_runlevel(int newlevel)
 
 	prevlevel = runlevel;
 	runlevel  = newlevel;
-	utmp_save(prevlevel, newlevel);
 
 	_d("Setting new runlevel --> %d <-- previous %d", runlevel, prevlevel);
+	utmp_save(prevlevel, newlevel);
 
+	_d("Stopping services services not allowed in new runlevel ...");
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
-		/* Inetd services have slightly different semantics */
+		if (!ISSET(svc->runlevels, runlevel)) {
 #ifndef INETD_DISABLED
-		if (svc->type == SVC_TYPE_INETD) {
+			if (svc->type == SVC_TYPE_INETD)
-			if (!ISSET(svc->runlevels, runlevel))
 				inetd_stop(&svc->inetd);
 			else
+#endif
+				svc_stop(svc);
+		}
+	}
+
+	/* Prev runlevel services stopped, call hooks before starting new runlevel ... */
+	_d("All services have been stoppped, calling runlevel change hooks ...");
+	plugin_run_hooks(HOOK_RUNLEVEL_CHANGE);  /* Reconfigure HW/VLANs/etc here */
+
+	_d("Starting services services new to this runlevel ...");
+	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+#ifndef INETD_DISABLED
+		/* Inetd services have slightly different semantics */
+		if (svc->type == SVC_TYPE_INETD) {
+			if (ISSET(svc->runlevels, runlevel))
 				inetd_start(&svc->inetd);
 
 			continue;
@@ -901,13 +916,26 @@ int svc_reload(svc_t *svc)
  */
 void svc_reload_dynamic(void)
 {
+	int num = 0;
 	svc_t *svc;
 
-	_d("Checking if any dynamically loaded services need to be reloaded ...");
+	_d("Stopping disabled/removed services ...");
+	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+		if (svc->mtime && svc->dirty != 0) {
+			svc_stop(svc);
+			num++;
+		}
+	}
+
+	if (!num)
+		return;
+
+	_d("All disabled/removed services have been stoppped, calling reconf hooks ...");
+	plugin_run_hooks(HOOK_SVC_RECONF); /* Reconfigure HW/VLANs/etc here */
+
+	_d("Starting enabled/added services ...");
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
 		if (svc->mtime && svc->dirty > 0) {
-			_d("Service %s id %d modified, must stop-start for changes to take effect!", svc->cmd, svc->id);
-			svc_stop(svc); /* This will reset the restart_counter as well! */
 			svc_dance(svc);
 			svc->dirty = 0;
 		}