gbproxy: Test invalid BVCI from SGSN

This adds a test with a UNITDATA SGSN message that is addressed to an
invalid (unknown) BVCI. The test shows, that the message is echoed to
the SGSN.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/gbproxy/gbproxy_test.c b/openbsc/tests/gbproxy/gbproxy_test.c
index 21ee723..e1e6587 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.c
+++ b/openbsc/tests/gbproxy/gbproxy_test.c
@@ -523,6 +523,8 @@
 	gprs_dump_nsi(nsi);
 	gbprox_dump_peers(stdout, 0, 1);
 
+	gbprox_dump_global(stdout, 0, 1);
+
 	send_bssgp_reset_ack(nsi, &sgsn_peer, 0x1002);
 
 	printf("--- Send message from BSS 1 to SGSN, BVCI 0x1002 ---\n\n");
@@ -533,6 +535,12 @@
 
 	send_ns_unitdata(nsi, NULL, &sgsn_peer, 0x1012, (uint8_t *)"", 0);
 
+	printf("--- Send message from SGSN to BSS 1, BVCI 0x10ff (invalid) ---\n\n");
+
+	send_ns_unitdata(nsi, NULL, &sgsn_peer, 0x10ff, (uint8_t *)"", 0);
+
+	gbprox_dump_global(stdout, 0, 1);
+
 	gprs_ns_destroy(nsi);
 	nsi = NULL;
 }