nacc_fsm: Move logic checking if SI is being waited for to a func helper

We already have a similar function for Neighbor Address Resolution.
This way we keep as much as possible internal state related logic into
the nacc_fsm.c file.

Change-Id: I7378939825cc3ec3280f76bc51233c0a172d8a27

src/gprs_bssgp_rim.c

@@ -158,13 +158,8 @@ static int handle_ran_info_response_nacc(const struct bssgp_ran_inf_app_cont_nac
 
 	llist_for_each(tmp, bts_ms_list(bts)) {
 		struct GprsMs *ms = llist_entry(tmp, typeof(*ms), list);
-		if (!ms->nacc)
-			continue;
-		if (ms->nacc->fi->state != NACC_ST_WAIT_REQUEST_SI)
-			continue;
-		if (osmo_cgi_ps_cmp(&nacc->reprt_cell, &ms->nacc->cgi_ps) != 0)
-			continue;
-		osmo_fsm_inst_dispatch(ms->nacc->fi, NACC_EV_RX_SI, entry);
+		if (ms->nacc && nacc_fsm_is_waiting_si_resolution(ms->nacc, &nacc->reprt_cell))
+			osmo_fsm_inst_dispatch(ms->nacc->fi, NACC_EV_RX_SI, entry);
 	}
 	return 0;
 }

src/nacc_fsm.c

@@ -887,3 +887,11 @@ bool nacc_fsm_is_waiting_addr_resolution(const struct nacc_fsm_ctx *ctx,
 		return false;
 	return neigh_cache_entry_key_eq(&ctx->neigh_key, neigh_key);
 }
+
+bool nacc_fsm_is_waiting_si_resolution(const struct nacc_fsm_ctx *ctx,
+				       const struct osmo_cell_global_id_ps *cgi_ps)
+{
+	if (ctx->fi->state != NACC_ST_WAIT_REQUEST_SI)
+		return false;
+	return !osmo_cgi_ps_cmp(&ctx->cgi_ps, cgi_ps);
+}

src/nacc_fsm.h

@@ -72,3 +72,6 @@ struct nacc_fsm_ctx *nacc_fsm_alloc(struct GprsMs* ms);
 
 bool nacc_fsm_is_waiting_addr_resolution(const struct nacc_fsm_ctx *ctx,
 					 const struct neigh_cache_entry_key *neigh_key);
+
+bool nacc_fsm_is_waiting_si_resolution(const struct nacc_fsm_ctx *ctx,
+				       const struct osmo_cell_global_id_ps *cgi_ps);