Handle Immediate assignment reject

When RACH is received, PCU will generate the Immediate assignment reject
message if no resources are present. The encoding is done based on section
9.1.20 of 44.018 version 11.7.0 Release 11. This patch also includes the
test case to validate the generated Immediate assignment reject message.

This patch is integration tested on Osmo-trx setup with Ettus B210 board
and LG F70 MS with some simulation code changes in Osmo-pcu.

Change-Id: I3d33e2b9746fa4f338fad0e6b63b1c5f07de6f9b

1 files changed, 83 insertions, 0 deletions

diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index cc48392..339390b 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -1372,6 +1372,88 @@ static void test_tbf_single_phase()
 	printf("=== end %s ===\n", __func__);
 }
 
+/*
+ * Trigger rach for single block
+ */
+static void test_immediate_assign_rej_single_block()
+{
+	BTS the_bts;
+	uint32_t fn = 2654218;
+	uint16_t qta = 31;
+	int ts_no = 7;
+
+	printf("=== start %s ===\n", __func__);
+
+	setup_bts(&the_bts, ts_no, 4);
+
+	the_bts.bts_data()->trx[0].pdch[ts_no].disable();
+
+	uint32_t rach_fn = fn - 51;
+
+	int rc = 0;
+
+	/*
+	 * simulate RACH, sends an Immediate Assignment
+	 * Uplink reject on the AGCH
+	 */
+	rc = the_bts.rcv_rach(0x70, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+
+	OSMO_ASSERT(rc == -EINVAL);
+
+	printf("=== end %s ===\n", __func__);
+}
+
+/*
+ * Trigger rach till resources(USF) exhaust
+ */
+static void test_immediate_assign_rej_multi_block()
+{
+	BTS the_bts;
+	uint32_t fn = 2654218;
+	uint16_t qta = 31;
+	int ts_no = 7;
+
+	printf("=== start %s ===\n", __func__);
+
+	setup_bts(&the_bts, ts_no, 4);
+
+	uint32_t rach_fn = fn - 51;
+
+	int rc = 0;
+
+	/*
+	 * simulate RACH, sends an Immediate Assignment Uplink
+	 * reject on the AGCH
+	 */
+	rc = the_bts.rcv_rach(0x78, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x79, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7a, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7b, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7c, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7d, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7e, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+	rc = the_bts.rcv_rach(0x7f, rach_fn, qta, 0,
+				GSM_L1_BURST_TYPE_ACCESS_0);
+
+	OSMO_ASSERT(rc == -EBUSY);
+
+	printf("=== end %s ===\n", __func__);
+}
+
+static void test_immediate_assign_rej()
+{
+	test_immediate_assign_rej_multi_block();
+	test_immediate_assign_rej_single_block();
+}
+
 static void test_tbf_two_phase()
 {
 	BTS the_bts;
@@ -2791,6 +2873,7 @@ int main(int argc, char **argv)
 	test_tbf_update_ws();
 	test_tbf_li_decoding();
 	test_tbf_epdan_out_of_rx_window();
+	test_immediate_assign_rej();
 
 	if (getenv("TALLOC_REPORT_FULL"))
 		talloc_report_full(tall_pcu_ctx, stderr);