[Dnsmasq-discuss] [PATCH] Eliminate redundant UBus `notify` variable.

[Etan Kissling]

There was a `notify` variable to keep track whether a subscriber is
observing our UBus object. However, it was not properly cleaned up in
`ubus_destroy`, potentially becoming stale over UBus reconnections.
The variable was removed and the current state is examined when sending
notifications, similarly as is done in other existing OpenWrt code.

Signed-off-by: Etan Kissling <etan.kissling at gmail.com>
---
 src/ubus.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/ubus.c b/src/ubus.c
index 296a496..37e36fa 100644
--- a/src/ubus.c
+++ b/src/ubus.c
@@ -21,7 +21,6 @@
 #include <libubus.h>
 
 static struct blob_buf b;
-static int notify;
 static int error_logged = 0;
 
 static int ubus_handle_metrics(struct ubus_context *ctx, struct ubus_object *obj,
@@ -78,7 +77,6 @@ static void ubus_subscribe_cb(struct ubus_context *ctx, struct ubus_object *obj)
   (void)ctx;
 
   my_syslog(LOG_DEBUG, _("UBus subscription callback: %s subscriber(s)"), obj->has_subscribers ? "1" : "0");
-  notify = obj->has_subscribers;
 }
 
 static void ubus_destroy(struct ubus_context *ubus)
@@ -334,7 +332,7 @@ void ubus_event_bcast(const char *type, const char *mac, const char *ip, const c
 {
   struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 
-  if (!ubus || !notify)
+  if (!ubus || !ubus_object.has_subscribers)
     return;
 
   CHECK(blob_buf_init(&b, BLOBMSG_TYPE_TABLE));
@@ -355,7 +353,7 @@ void ubus_event_bcast_connmark_allowlist_refused(u32 mark, const char *name)
 {
   struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 
-  if (!ubus || !notify)
+  if (!ubus || !ubus_object.has_subscribers)
     return;
 
   CHECK(blob_buf_init(&b, 0));
@@ -369,7 +367,7 @@ void ubus_event_bcast_connmark_allowlist_resolved(u32 mark, const char *name, co
 {
   struct ubus_context *ubus = (struct ubus_context *)daemon->ubus;
 
-  if (!ubus || !notify)
+  if (!ubus || !ubus_object.has_subscribers)
     return;
 
   CHECK(blob_buf_init(&b, 0));
-- 
2.30.1 (Apple Git-130)