res_pjsip_pubsub: Postpone destruction of old subscriptions on RLS update

Set termination state to old subscriptions to prevent queueing and sending
NOTIFY messages on exten/device state changes.

Postpone destruction of old subscriptions until all already queued tasks
that may be using old subscriptions have completed.

ASTERISK-29906

Change-Id: I96582aad3a26515ca73a8460ee6756f56f6ba23b

diff --git a/res/res_pjsip_exten_state.c b/res/res_pjsip_exten_state.c
index b51df87b622287a2c12607d4933e33c7b8191c09..3c7baeeaa910b93d16bf426b7d8f530139c650c0 100644 (file)
--- a/res/res_pjsip_exten_state.c
+++ b/res/res_pjsip_exten_state.c
@@ -296,7 +296,8 @@ static int notify_task(void *obj)
                .body_data = &task_data->exten_state_data,
        };
 
-       /* Terminated subscriptions are no longer associated with a valid tree, and sending
+       /* The subscription was terminated while notify_task was in queue.
+          Terminated subscriptions are no longer associated with a valid tree, and sending
         * NOTIFY messages on a subscription which has already been terminated won't work.
         */
        if (ast_sip_subscription_is_terminated(task_data->exten_state_sub->sip_sub)) {
@@ -339,6 +340,13 @@ static int state_changed(const char *context, const char *exten,
        struct notify_task_data *task_data;
        struct exten_state_subscription *exten_state_sub = data;
 
+       /* Terminated subscriptions are no longer associated with a valid tree.
+        * Do not queue notify_task.
+        */
+       if (ast_sip_subscription_is_terminated(exten_state_sub->sip_sub)) {
+               return 0;
+       }
+
        if (!(task_data = alloc_notify_task_data(exten, exten_state_sub, info))) {
                return -1;
        }

diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index d0f3717dbded9c60cfb1bc9d3a60a75ed4c0b32b..4086445353b79f434cf9e5ba69437020dcc6e086 100644 (file)
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -3994,6 +3994,15 @@ static int cmp_subscription_childrens(struct ast_sip_subscription *s1, struct as
        return 0;
 }
 
+static int destroy_subscriptions_task(void *obj)
+{
+       struct ast_sip_subscription *sub = (struct ast_sip_subscription *) obj;
+
+       destroy_subscriptions(sub);
+
+       return 0;
+}
+
 /*!
  * \brief Called whenever an in-dialog SUBSCRIBE is received
  *
@@ -4067,8 +4076,19 @@ static void pubsub_on_rx_refresh(pjsip_evsub *evsub, pjsip_rx_data *rdata,
                                                        AST_SCHED_DEL_UNREF(sched, sub_tree->notify_sched_id, ao2_ref(sub_tree, -1));
                                                        sub_tree->send_scheduled_notify = 0;
                                                }
+
+                                               /* Terminate old subscriptions to stop sending NOTIFY messages on exten/device state changes */
+                                               set_state_terminated(old_root);
+
+                                               /* Shutdown old subscriptions to remove exten/device state change callbacks
+                                                that can queue tasks for old subscriptions */
                                                shutdown_subscriptions(old_root);
-                                               destroy_subscriptions(old_root);
+
+                                               /* Postpone destruction until all already queued tasks that may be using old subscriptions have completed */
+                                               if (ast_sip_push_task(sub_tree->serializer, destroy_subscriptions_task, old_root)) {
+                                                       ast_log(LOG_ERROR, "Failed to push task to destroy old subscriptions for RLS '%s->%s'.\n",
+                                                               ast_sorcery_object_get_id(endpoint), old_root->resource);
+                                               }
                                        } else {
                                                destroy_subscriptions(new_root);
                                        }