gprs: Block other GSUP procedures during PURGE_MS

GSM 09.02, 19.4.1.4 mandates that no other MAP procedures shall be
started until the PURGE_MS procedure has been completed.

This patch implements this by adding corresponding state and checks
to gprs_subscr_purge, gprs_subscr_location_update, and
gprs_subscr_update_auth_info. If an Update Location or a Send Auth
Info Req procedure is not started because of blocking, the retry
mechanism is aborted to shorten the blocking time. The outstanding
Purge MS procedure itself is not aborted.

Sponsored-by: On-Waves ehf

2 files changed, 93 insertions, 0 deletions

diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index 818106190..d419f0a92 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -546,6 +546,97 @@ static void test_subscriber_gsup(void)
 	update_subscriber_data_cb = __real_sgsn_update_subscriber_data;
 }
 
+int my_gprs_gsup_client_send_dummy(struct gprs_gsup_client *gsupc, struct msgb *msg)
+{
+	msgb_free(msg);
+	return 0;
+};
+
+
+static void test_subscriber_blocking(void)
+{
+	struct gsm_subscriber *s1;
+	const char *imsi1 = "1234567890";
+	struct sgsn_mm_ctx *ctx;
+	struct gprs_ra_id raid = { 0, };
+	uint32_t local_tlli = 0xffeeddcc;
+	struct gprs_llc_llme *llme;
+	int rc;
+
+	printf("Testing subcriber procedure blocking\n");
+
+	gprs_gsup_client_send_cb = my_gprs_gsup_client_send_dummy;
+	sgsn->gsup_client = talloc_zero(tall_bsc_ctx, struct gprs_gsup_client);
+
+	/* Check for emptiness */
+	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
+
+	/* Create a context */
+	OSMO_ASSERT(count(gprs_llme_list()) == 0);
+	ctx = alloc_mm_ctx(local_tlli, &raid);
+	llme = ctx->llme;
+	strncpy(ctx->imsi, imsi1, sizeof(ctx->imsi) - 1);
+
+	/* Allocate and attach a subscriber */
+	s1 = gprs_subscr_get_or_create_by_mmctx(ctx);
+	assert_subscr(s1, imsi1);
+
+	/* Start SendAuthInfoRequest procedure */
+	rc = gprs_subscr_query_auth_info(s1);
+	/* Not blocking */
+	OSMO_ASSERT(rc == 0);
+
+	/* Start UpdateLocation procedure */
+	rc = gprs_subscr_location_update(s1);
+	/* Blocking */
+	OSMO_ASSERT(rc == 0);
+
+	/* Start PurgeMS procedure */
+	rc = gprs_subscr_purge(s1);
+	/* Not blocking */
+	OSMO_ASSERT(rc == 0);
+	OSMO_ASSERT(s1->sgsn_data->blocked_by == SGSN_SUBSCR_PROC_PURGE);
+
+	/* Start PurgeMS procedure (retry) */
+	rc = gprs_subscr_purge(s1);
+	/* Not blocking */
+	OSMO_ASSERT(rc == 0);
+
+	/* Start SendAuthInfoRequest procedure */
+	rc = gprs_subscr_query_auth_info(s1);
+	/* Blocking */
+	OSMO_ASSERT(rc == -EAGAIN);
+
+	/* Start UpdateLocation procedure */
+	rc = gprs_subscr_location_update(s1);
+	/* Blocking */
+	OSMO_ASSERT(rc == -EAGAIN);
+
+	/* Unblock manually (normally done by the caller of gprs_subscr_purge) */
+	s1->sgsn_data->blocked_by = SGSN_SUBSCR_PROC_NONE;
+
+	/* Start SendAuthInfoRequest procedure */
+	rc = gprs_subscr_query_auth_info(s1);
+	/* Not blocking */
+	OSMO_ASSERT(rc == 0);
+
+	/* Start UpdateLocation procedure */
+	rc = gprs_subscr_location_update(s1);
+	/* Blocking */
+	OSMO_ASSERT(rc == 0);
+
+	subscr_put(s1);
+	sgsn_mm_ctx_free(ctx);
+	gprs_llgmm_assign(llme, local_tlli, 0xffffffff, GPRS_ALGO_GEA0, NULL);
+
+	assert_no_subscrs();
+
+	gprs_gsup_client_send_cb = __real_gprs_gsup_client_send;
+	talloc_free(sgsn->gsup_client);
+	sgsn->gsup_client = NULL;
+}
+
+
 /*
  * Test that a GMM Detach will remove the MMCTX and the
  * associated LLME.
@@ -1710,6 +1801,7 @@ int main(int argc, char **argv)
 	test_subscriber();
 	test_auth_triplets();
 	test_subscriber_gsup();
+	test_subscriber_blocking();
 	test_gmm_detach();
 	test_gmm_detach_power_off();
 	test_gmm_detach_no_mmctx();
diff --git a/openbsc/tests/sgsn/sgsn_test.ok b/openbsc/tests/sgsn/sgsn_test.ok
index cff29205d..e5df50482 100644
--- a/openbsc/tests/sgsn/sgsn_test.ok
+++ b/openbsc/tests/sgsn/sgsn_test.ok
@@ -2,6 +2,7 @@ Testing LLME allocations
 Testing core subscriber data API
 Testing authentication triplet handling
 Testing subcriber GSUP handling
+Testing subcriber procedure blocking
 Testing GMM detach
 Testing GMM detach (power off)
 Testing GMM detach (no MMCTX)