service: allow incremental changes to service properties

Support updating data and autostart without re-running the init script
or tearing down existing other service properties, e.g. validation or
triggers.
This can be used to allow services to manage their own data at runtime
without going through the init script.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 14 insertions, 17 deletions

diff --git a/service/service.c b/service/service.c
index de14aa3..25e2885 100644
--- a/service/service.c
+++ b/service/service.c
@@ -152,32 +152,28 @@ service_update_data(struct service *s, struct blob_attr *data)
 }
 
 static int
-service_update(struct service *s, struct blob_attr **tb, bool add)
+service_update(struct service *s, struct blob_attr **tb, bool add, bool init)
 {
 	struct blob_attr *cur;
 	int rem;
 
-	if (s->trigger) {
-		trigger_del(s);
-		free(s->trigger);
-		s->trigger = NULL;
-	}
-
-	service_validate_del(s);
-
-	if (tb[SERVICE_SET_AUTOSTART] && !blobmsg_get_bool(tb[SERVICE_SET_AUTOSTART]))
-		s->autostart = false;
-	else
+	if (tb[SERVICE_SET_AUTOSTART])
+		s->autostart = blobmsg_get_bool(tb[SERVICE_SET_AUTOSTART]);
+	else if (init)
 		s->autostart = true;
 
-	if (tb[SERVICE_SET_TRIGGER] && blobmsg_data_len(tb[SERVICE_SET_TRIGGER])) {
+	if (tb[SERVICE_SET_TRIGGER]) {
+		free(s->trigger);
 		s->trigger = blob_memdup(tb[SERVICE_SET_TRIGGER]);
 		if (!s->trigger)
 			return -1;
+
+		trigger_del(s);
 		trigger_add(s->trigger, s);
 	}
 
-	if (tb[SERVICE_SET_VALIDATE] && blobmsg_data_len(tb[SERVICE_SET_VALIDATE])) {
+	if (tb[SERVICE_SET_VALIDATE]) {
+		service_validate_del(s);
 		blobmsg_for_each_attr(cur, tb[SERVICE_SET_VALIDATE], rem)
 			service_validate_add(s, cur);
 	}
@@ -198,7 +194,8 @@ service_update(struct service *s, struct blob_attr **tb, bool add)
 
 	s->deleted = false;
 
-	rc(s->name, "running");
+	if (init || tb[SERVICE_SET_INSTANCES])
+		rc(s->name, "running");
 
 	return 0;
 }
@@ -441,7 +438,7 @@ service_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 
 	if (s) {
 		P_DEBUG(2, "Update service %s\n", name);
-		return service_update(s, tb, add);
+		return service_update(s, tb, add, false);
 	}
 
 	P_DEBUG(2, "Create service %s\n", name);
@@ -451,7 +448,7 @@ service_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 
 	s->container = container;
 
-	ret = service_update(s, tb, add);
+	ret = service_update(s, tb, add, true);
 	if (ret)
 		return ret;