gprs: Add expiry timeout for subscriber entries

Set the expiry delay after the subscriber has been deleted (e.g. by
freeing the MM context). If cancelled, the subscriber will be deleted
immediately and no timeout will be set. If the expiry time is set to
SGSN_TIMEOUT_NEVER, no timer will be started and the subscriber entry
will be kept until it is cancelled.

The following VTY command is added to the sgsn node:

  - subscriber-expiry-time <0-999999>    set expiry time in seconds
  - no subscriber-expiry-time            set to SGSN_TIMEOUT_NEVER

The default is an expiry time of 0 seconds, which means that the
subscriber entries are wiped out immediately after an MM context is
destroyed.

Note that unused MM contexts are not expired yet. Therefore the
subscriber will only be expired after a successful MM detach.

Sponsored-by: On-Waves ehf

1 files changed, 34 insertions, 1 deletions

diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index 78321ce0c..adaa32804 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -44,6 +44,7 @@ static struct sgsn_instance sgsn_inst = {
 	.cfg = {
 		.gtp_statedir = "./",
 		.auth_policy = SGSN_AUTH_POLICY_CLOSED,
+		.subscriber_expiry_timeout = SGSN_TIMEOUT_NEVER,
 	},
 };
 struct sgsn_instance *sgsn = &sgsn_inst;
@@ -200,9 +201,11 @@ static void assert_subscr(const struct gsm_subscriber *subscr, const char *imsi)
 
 static void test_subscriber(void)
 {
-	struct gsm_subscriber *s1, *s2, *sfound;
+	struct gsm_subscriber *s1, *s2, *s3, *sfound;
 	const char *imsi1 = "1234567890";
 	const char *imsi2 = "9876543210";
+	const char *imsi3 = "5656565656";
+	int saved_expiry_timeout = sgsn->cfg.subscriber_expiry_timeout;
 
 	update_subscriber_data_cb = my_dummy_sgsn_update_subscriber_data;
 
@@ -211,6 +214,7 @@ static void test_subscriber(void)
 	/* Check for emptiness */
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi2) == NULL);
+	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi3) == NULL);
 
 	/* Allocate entry 1 */
 	s1 = gprs_subscr_get_or_create(imsi1);
@@ -222,9 +226,13 @@ static void test_subscriber(void)
 	s2 = gprs_subscr_get_or_create(imsi2);
 	s2->flags |= GSM_SUBSCRIBER_FIRST_CONTACT;
 
+	/* Allocate entry 3 */
+	s3 = gprs_subscr_get_or_create(imsi3);
+
 	/* Check entries */
 	assert_subscr(s1, imsi1);
 	assert_subscr(s2, imsi2);
+	assert_subscr(s3, imsi3);
 
 	/* Update entry 1 */
 	last_updated_subscr = NULL;
@@ -251,12 +259,34 @@ static void test_subscriber(void)
 	s1 = NULL;
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
 	assert_subscr(s2, imsi2);
+	assert_subscr(s3, imsi3);
 
 	/* Free entry 2 (GSM_SUBSCRIBER_FIRST_CONTACT is set) */
 	gprs_subscr_delete(s2);
 	s2 = NULL;
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
 	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi2) == NULL);
+	assert_subscr(s3, imsi3);
+
+	/* Try to delete entry 3 */
+	OSMO_ASSERT(sgsn->cfg.subscriber_expiry_timeout == SGSN_TIMEOUT_NEVER);
+	gprs_subscr_delete(s3);
+	assert_subscr(s3, imsi3);
+	/* Process timeouts, this shouldn't delete s3 (SGSN_TIMEOUT_NEVER) */
+	osmo_timers_update();
+	assert_subscr(s3, imsi3);
+	s3 = subscr_get(s3);
+
+	/* Free entry 3 (TIMEOUT == 0) */
+	sgsn->cfg.subscriber_expiry_timeout = 0;
+	gprs_subscr_delete(s3);
+	assert_subscr(s3, imsi3);
+	/* Process timeouts, this should delete s3 */
+	osmo_timers_update();
+	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi1) == NULL);
+	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi2) == NULL);
+	OSMO_ASSERT(gprs_subscr_get_by_imsi(imsi3) == NULL);
+	sgsn->cfg.subscriber_expiry_timeout = saved_expiry_timeout;
 
 	OSMO_ASSERT(llist_empty(&active_subscribers));
 
@@ -862,6 +892,7 @@ static void test_gmm_attach_subscr(void)
 
 	subscr = gprs_subscr_get_or_create("123456789012345");
 	subscr->authorized = 1;
+	subscr->keep_in_ram = 1;
 	subscr_put(subscr);
 
 	printf("Auth policy 'remote': ");
@@ -895,6 +926,7 @@ static void test_gmm_attach_subscr_fake_auth(void)
 
 	subscr = gprs_subscr_get_or_create("123456789012345");
 	subscr->authorized = 1;
+	subscr->keep_in_ram = 1;
 	sgsn->cfg.require_authentication = 1;
 	sgsn->cfg.require_update_location = 1;
 	subscr_put(subscr);
@@ -936,6 +968,7 @@ static void test_gmm_attach_subscr_real_auth(void)
 
 	subscr = gprs_subscr_get_or_create("123456789012345");
 	subscr->authorized = 1;
+	subscr->keep_in_ram = 1;
 	sgsn->cfg.require_authentication = 1;
 	sgsn->cfg.require_update_location = 1;
 	subscr_put(subscr);