sgsn/test: Don't rely on the actual PRNG sequence
Currently the expected P-TMSI generated by the SGSN is hard-coded
into the test. This adds a dependency on the implementation of rand()
and thus the libc used. This breaks the test e.g. on FreeBSD.
This patch modifies test_gmm_attach() to srand(1) first, generate the
P-TMSI, and finally srand(1) again before starting the test.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index d6091fd..464f4d7 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -297,6 +297,7 @@
struct gprs_ra_id raid = { 0, };
struct sgsn_mm_ctx *ctx = NULL;
struct sgsn_mm_ctx *ictx;
+ uint32_t ptmsi1;
uint32_t foreign_tlli;
uint32_t local_tlli = 0;
struct gprs_llc_lle *lle;
@@ -340,6 +341,13 @@
/* reset the PRNG used by sgsn_alloc_ptmsi */
srand(1);
+ ptmsi1 = sgsn_alloc_ptmsi();
+ OSMO_ASSERT(ptmsi1 != GSM_RESERVED_TMSI);
+
+ /* reset the PRNG, so that the same P-TMSI sequence will be generated
+ * again */
+ srand(1);
+
sgsn_acl_add("123456789012345", &sgsn->cfg);
foreign_tlli = gprs_tmsi2tlli(0xc0000023, TLLI_FOREIGN);
@@ -381,7 +389,7 @@
OSMO_ASSERT(sgsn_tx_counter == 1);
/* this has been randomly assigned by the SGSN */
- local_tlli = gprs_tmsi2tlli(0xeb8b4567, TLLI_LOCAL);
+ local_tlli = gprs_tmsi2tlli(ptmsi1, TLLI_LOCAL);
/* inject the attach complete */
send_0408_message(ctx->llme, local_tlli,