sgsn: Don't allow mmctx == NULL in sgsn_update_subscriber_data

Currently, sgsn_update_subscriber_data can be called with mmctx ==
NULL and will find and associate the right context (if present) based
on the subscriber's IMSI. This will not happen in regular use
any more, since sgsn_update_subscriber_data will only be called when
subscribers are used (auth mode 'remote') and in this case
gprs_subscr_get_or_create_by_mmctx will already be called by
sgsn_auth_request. Therefore, MM context and subscriber are always
associated except for some test cases and experimental VTY usage.
The current implementation of sgsn_update_subscriber_data also causes
additional complexity for the deletion on MM contexts to avoid a
ipossible double-free MM contexts.

This commit removes the MM context <-> subscriber association code
from sgsn_update_subscriber_data. That function must always be called
with mmctx != NULL, now. To avoid problems with VTY and test usage,
the calling subscriber function now only call
sgsn_update_subscriber_data when mmctx != NULL, since the purpose of
that function is to update that state of an existing MM context after
subscriber data has been changed.

Sponsored-by: On-Waves ehf

1 files changed, 11 insertions, 10 deletions

diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index 5d142da90..da7da855f 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -61,14 +61,13 @@ int bssgp_tx_dl_ud(struct msgb *msg, uint16_t pdu_lifetime,
 }
 
 /* override, requires '-Wl,--wrap=sgsn_update_subscriber_data' */
-void __real_sgsn_update_subscriber_data(struct sgsn_mm_ctx *, struct gsm_subscriber *);
-void (*update_subscriber_data_cb)(struct sgsn_mm_ctx *, struct gsm_subscriber *) =
+void __real_sgsn_update_subscriber_data(struct sgsn_mm_ctx *);
+void (*update_subscriber_data_cb)(struct sgsn_mm_ctx *) =
     &__real_sgsn_update_subscriber_data;
 
-void __wrap_sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx,
-					struct gsm_subscriber *subscr)
+void __wrap_sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx)
 {
-	(*update_subscriber_data_cb)(mmctx, subscr);
+	(*update_subscriber_data_cb)(mmctx);
 }
 
 /* override, requires '-Wl,--wrap=gprs_subscr_request_update_location' */
@@ -191,12 +190,12 @@ static void test_llme(void)
 }
 
 struct gsm_subscriber *last_updated_subscr = NULL;
-void my_dummy_sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx,
-					  struct gsm_subscriber *subscr)
+void my_dummy_sgsn_update_subscriber_data(struct sgsn_mm_ctx *mmctx)
 {
+	OSMO_ASSERT(mmctx);
 	fprintf(stderr, "Called %s, mmctx = %p, subscr = %p\n",
-		__func__, mmctx, subscr);
-	last_updated_subscr = subscr;
+		__func__, mmctx, mmctx->subscr);
+	last_updated_subscr = mmctx->subscr;
 }
 
 static void assert_subscr(const struct gsm_subscriber *subscr, const char *imsi)
@@ -266,7 +265,9 @@ static void test_subscriber(void)
 	/* Update entry 1 */
 	last_updated_subscr = NULL;
 	gprs_subscr_update(s1);
-	OSMO_ASSERT(last_updated_subscr == s1);
+	OSMO_ASSERT(last_updated_subscr == NULL);
+	OSMO_ASSERT(s1->sgsn_data->mm == NULL);
+	OSMO_ASSERT((s1->flags & GSM_SUBSCRIBER_FIRST_CONTACT) == 0);
 
 	/* There is no subscriber cache. Verify it */
 	gprs_subscr_cleanup(s1);