+static void *
+send_map_request_thread_fn (void * arg)
+{
+ map_request_args_t * a = arg;
+ lisp_cp_main_t * lcm = vnet_lisp_cp_get_main ();
+
+ lisp_pending_map_request_lock (lcm);
+
+ if (a->is_resend)
+ resend_encapsulated_map_request (lcm, &a->seid, &a->deid, a->smr_invoked);
+ else
+ send_encapsulated_map_request (lcm, &a->seid, &a->deid, a->smr_invoked);
+
+ lisp_pending_map_request_unlock (lcm);
+
+ return 0;
+}
+
+static int
+queue_map_request (gid_address_t * seid, gid_address_t * deid,
+ u8 smr_invoked, u8 is_resend)
+{
+ map_request_args_t a;
+
+ a.is_resend = is_resend;
+ gid_address_copy (&a.seid, seid);
+ gid_address_copy (&a.deid, deid);
+ a.smr_invoked = smr_invoked;
+
+ vl_api_rpc_call_main_thread (send_map_request_thread_fn,
+ (u8 *) &a, sizeof (a));
+ return 0;
+}
+
+/**
+ * Take an action with a pending map request depending on expiration time
+ * and re-try counters.
+ */
+static void
+update_pending_request (pending_map_request_t * r, f64 dt)
+{
+ lisp_cp_main_t * lcm = vnet_lisp_cp_get_main ();
+ map_resolver_t * mr;
+
+ if (r->time_to_expire - dt < 0)
+ /* it's time to decide what to do with this pending request */
+ {
+ if (r->retries_num >= NUMBER_OF_RETRIES)
+ /* too many retries -> assume current map resolver is not available */
+ {
+ mr = get_map_resolver (&lcm->active_map_resolver);
+ if (!mr)
+ {
+ clib_warning ("Map resolver %U not found - probably deleted "
+ "by the user recently.", format_ip_address,
+ &lcm->active_map_resolver);
+ }
+ else
+ {
+ clib_warning ("map resolver %U is unreachable, ignoring",
+ format_ip_address, &lcm->active_map_resolver);
+
+ /* mark current map resolver unavailable so it won't be
+ * selected next time */
+ mr->is_down = 1;
+ mr->last_update = vlib_time_now (lcm->vlib_main);
+ }
+
+ reset_pending_mr_counters (r);
+ elect_map_resolver (lcm);
+
+ /* try to find a next eligible map resolver and re-send */
+ queue_map_request (&r->src, &r->dst, r->is_smr_invoked,
+ 1 /* resend */);
+ }
+ else
+ {
+ /* try again */
+ queue_map_request (&r->src, &r->dst, r->is_smr_invoked,
+ 1 /* resend */);
+ r->retries_num++;
+ r->time_to_expire = PENDING_MREQ_EXPIRATION_TIME;
+ }
+ }
+ else
+ r->time_to_expire -= dt;
+}
+
+static void
+remove_dead_pending_map_requests (lisp_cp_main_t * lcm)
+{
+ u64 * nonce;
+ pending_map_request_t * pmr;
+ u32 * to_be_removed = 0, * pmr_index;
+
+ ASSERT (*lcm->pending_map_request_lock);
+
+ pool_foreach (pmr, lcm->pending_map_requests_pool,
+ ({
+ if (pmr->to_be_removed)
+ {
+ vec_foreach (nonce, pmr->nonces)
+ hash_unset (lcm->pending_map_requests_by_nonce, nonce[0]);
+
+ vec_add1 (to_be_removed, pmr - lcm->pending_map_requests_pool);
+ }
+ }));
+
+ vec_foreach (pmr_index, to_be_removed)
+ pool_put_index (lcm->pending_map_requests_by_nonce, pmr_index[0]);
+
+ vec_free (to_be_removed);
+}
+
+static uword
+send_map_resolver_service (vlib_main_t * vm,
+ vlib_node_runtime_t * rt,
+ vlib_frame_t * f)
+{
+ f64 period = 2.0;
+ pending_map_request_t * pmr;
+ lisp_cp_main_t * lcm = vnet_lisp_cp_get_main ();
+
+ while (1)
+ {
+ vlib_process_wait_for_event_or_clock (vm, period);
+
+ /* currently no signals are expected - just wait for clock */
+ (void) vlib_process_get_events (vm, 0);
+
+ lisp_pending_map_request_lock (lcm);
+ pool_foreach (pmr, lcm->pending_map_requests_pool,
+ ({
+ if (!pmr->to_be_removed)
+ update_pending_request (pmr, period);
+ }));
+
+ remove_dead_pending_map_requests (lcm);
+
+ lisp_pending_map_request_unlock (lcm);
+ }
+
+ /* unreachable */
+ return 0;
+}
+
+VLIB_REGISTER_NODE (lisp_retry_service_node,static) = {
+ .function = send_map_resolver_service,
+ .type = VLIB_NODE_TYPE_PROCESS,
+ .name = "lisp-retry-service",
+ .process_log2_n_stack_bytes = 16,
+};
+