channels/chan_sip: Fix registration leak during reload

When the SIP registrations were migrated to using ao2 in what was then trunk,
the explicit destruction of the registrations on module reload was removed and
not replaced with an ao2 equivalent. Debugging done by Stefan Engström, the
issue reporter, on ASTERISK-24673 confirmed that the reference in the
registry_list container was being leaked.

Since the purpose of cleanup_all_regs is to prep a registration for
destruction, this function now calls an ao2_callback function callback with the
OBJ_MULTIPLE | OBJ_NODATA | OBJ_UNLINK flags used to remove the registrations.
This cleans up each registration, and also removes it from the registration
container registry_list.

Review: https://reviewboard.asterisk.org/r/4355/

ASTERISK-24640 #close
Reported by: Max Man

ASTERISK-24673 #close
Reported by: Stefan Engström
Tested by: Stefan Engström



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@430864 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -31075,38 +31075,37 @@ static void display_nat_warning(const char *cat, int reason, struct ast_flags *f
 	}
 }
 
-static void cleanup_all_regs(void)
+static int cleanup_registration(void *obj, void *arg, int flags)
 {
-	struct ao2_iterator iter;
-	struct sip_registry *iterator;
-	/* First, destroy all outstanding registry calls */
-	/* This is needed, since otherwise active registry entries will not be destroyed */
-	iter = ao2_iterator_init(registry_list, 0);
-	while ((iterator = ao2_t_iterator_next(&iter, "cleanup_all_regs iter"))) {
-		ao2_lock(iterator);
-
-		if (iterator->call) {
-			ast_debug(3, "Destroying active SIP dialog for registry %s@%s\n", iterator->username, iterator->hostname);
-			/* This will also remove references to the registry */
-			dialog_unlink_all(iterator->call);
-			iterator->call = dialog_unref(iterator->call, "remove iterator->call from registry traversal");
-		}
-		if (iterator->expire > -1) {
-			AST_SCHED_DEL_UNREF(sched, iterator->expire, ao2_t_ref(iterator, -1, "reg ptr unref from reload config"));
-		}
-		if (iterator->timeout > -1) {
-			AST_SCHED_DEL_UNREF(sched, iterator->timeout, ao2_t_ref(iterator, -1, "reg ptr unref from reload config"));
-		}
-		if (iterator->dnsmgr) {
-			ast_dnsmgr_release(iterator->dnsmgr);
-			iterator->dnsmgr = NULL;
-			ao2_t_ref(iterator, -1, "reg ptr unref from dnsmgr");
-		}
+	struct sip_registry *reg = obj;
+	ao2_lock(reg);
 
-		ao2_unlock(iterator);
-		ao2_t_ref(iterator, -1, "cleanup_all_regs iter");
+	if (reg->call) {
+		ast_debug(3, "Destroying active SIP dialog for registry %s@%s\n", reg->username, reg->hostname);
+		/* This will also remove references to the registry */
+		dialog_unlink_all(reg->call);
+		reg->call = dialog_unref(reg->call, "remove iterator->call from registry traversal");
 	}
-	ao2_iterator_destroy(&iter);
+	if (reg->expire > -1) {
+		AST_SCHED_DEL_UNREF(sched, reg->expire, ao2_t_ref(reg, -1, "reg ptr unref from reload config"));
+	}
+	if (reg->timeout > -1) {
+		AST_SCHED_DEL_UNREF(sched, reg->timeout, ao2_t_ref(reg, -1, "reg ptr unref from reload config"));
+	}
+	if (reg->dnsmgr) {
+		ast_dnsmgr_release(reg->dnsmgr);
+		reg->dnsmgr = NULL;
+		ao2_t_ref(reg, -1, "reg ptr unref from dnsmgr");
+	}
+
+	ao2_unlock(reg);
+	return CMP_MATCH;
+}
+
+static void cleanup_all_regs(void)
+{
+	ao2_t_callback(registry_list, OBJ_NODATA | OBJ_UNLINK | OBJ_MULTIPLE,
+		cleanup_registration, NULL, "remove all SIP registry items");
 }
 
 /*! \brief Re-read SIP.conf config file