Add tests for bitvec_write_field()

This function is actively used by OsmoPCU but have not been covered by
tests so far. The test code is based on
Minh-Quang Nguyen <minh-quang.nguyen@nutaq.com> submission with some
modifications.

The test's FIXME will be addressed in follow-up patches.

Change-Id: I2ee544256b8675bc62a42493aab66a8eeee54f90
Related: OS#1526

1 files changed, 164 insertions, 0 deletions

diff --git a/tests/bits/bitfield_test.c b/tests/bits/bitfield_test.c
new file mode 100644
index 00000000..d6653e32
--- /dev/null
+++ b/tests/bits/bitfield_test.c
@@ -0,0 +1,164 @@
+#include <inttypes.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <stdint.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/bits.h>
+#include <osmocom/core/bitvec.h>
+
+#define INTRO(p) printf("=== start %s(%u) ===\n", __func__, p)
+#define OUTRO(p) printf("=== end %s(%u) ===\n\n", __func__, p)
+
+static void test_bitvec_ia_octet_encode_pkt_dl_ass(struct bitvec *dest, uint32_t ttli,
+						   uint8_t tfi, uint8_t gamma, uint8_t ta_valid, uint8_t ws_enc,
+						   bool use_lh)
+{
+	unsigned wp = 0;
+
+	INTRO(use_lh);
+
+	/* 3GPP TS 44.018 §10.5.2.16 IA Rest Octets */
+	if (use_lh) /* FIXME: add function to encode LH properly */
+		bitvec_write_field(dest, &wp, 3, 2);		/* "HH" */
+	else
+		bitvec_write_field(dest, &wp, 3, 2);		/* "HH" */
+	bitvec_write_field(dest, &wp, 1, 2);			/* "01" Packet Downlink Assignment */
+	bitvec_write_field(dest, &wp, ttli, 32);		/* TLLI */
+	bitvec_write_field(dest, &wp, 1, 1);			/* switch TFI: on */
+	bitvec_write_field(dest, &wp, tfi, 5);			/* TFI */
+	bitvec_write_field(dest, &wp, 0x0, 1);			/* RLC acknowledged mode */
+	bitvec_write_field(dest, &wp, 0x0, 1);			/* ALPHA = not present */
+	bitvec_write_field(dest, &wp, gamma, 5);		/* GAMMA power control parameter */
+	bitvec_write_field(dest, &wp, 0,1);			/* Polling Bit: off */
+	bitvec_write_field(dest, &wp, ta_valid, 1);		/* N. B: NOT related to TAI! */
+	bitvec_write_field(dest, &wp, 0, 1);			/* No TIMING_ADVANCE_INDEX: */
+	bitvec_write_field(dest, &wp, 0, 1);			/* TBF Starting TIME present */
+	bitvec_write_field(dest, &wp, 0, 1);			/* P0 not present */
+	if (use_lh) { /* FIXME: add function to encode LH properly */
+		bitvec_write_field(dest, &wp, 1, 1);		/* "H" - additional for R99 */
+	} else
+		bitvec_write_field(dest, &wp, 1, 1);		/* "H" - additional for R99 */
+	bitvec_write_field(dest, &wp, ws_enc, 5);		/* EGPRS Window Size */
+	bitvec_write_field(dest, &wp, 0, 2);			/* LINK_QUALITY_MEASUREMENT_MODE */
+	bitvec_write_field(dest, &wp, 0, 1);			/* BEP_PERIOD2 not present */
+
+	printf("Encoded PKT DL ASS IA Rest Octets: %s\n", osmo_hexdump(dest->data, dest->data_len));
+
+	OUTRO(use_lh);
+}
+
+static void test_bitvec_ia_octet_encode_pkt_ul_ass(struct bitvec *dest, uint32_t fn,
+						   uint8_t tfi, uint8_t gamma, uint8_t usf, bool tbf, bool use_lh)
+{
+	unsigned wp = 0;
+
+	INTRO(use_lh);
+
+	/* 3GPP TS 44.018 §10.5.2.37b 10.5.2.16 */
+	if (use_lh) /* FIXME: add function to encode LH properly */
+		bitvec_write_field(dest, &wp, 3, 2);				/* "HH" */
+	else
+		bitvec_write_field(dest, &wp, 3, 2);				/* "HH" */
+	bitvec_write_field(dest, &wp, 0, 2);					/* "0" Packet Uplink Assignment */
+	if (!tbf) {
+		bitvec_write_field(dest, &wp, 0, 1);				/* Block Allocation: SBA */
+		bitvec_write_field(dest, &wp, 0, 1);				/* ALPHA = not present */
+		bitvec_write_field(dest, &wp, gamma, 5);			/* GAMMA power control parameter */
+		bitvec_write_field(dest, &wp, 0, 1);				/* No TIMING_ADVANCE_INDEX: */
+		bitvec_write_field(dest, &wp, 1, 1); 				/* TBF_STARTING_TIME_FLAG */
+		bitvec_write_field(dest, &wp, (fn / (26 * 51)) % 32, 5);	/* T1' */
+		bitvec_write_field(dest, &wp, fn % 51, 6);			/* T3 */
+		bitvec_write_field(dest, &wp, fn % 26, 5);			/* T2 */
+	} else {
+		bitvec_write_field(dest, &wp, 1, 1);				/* Block Allocation: Not SBA */
+		bitvec_write_field(dest, &wp, tfi, 5);				/* TFI_ASSIGNMENT */
+		bitvec_write_field(dest, &wp, 0, 1);				/* POLLING = none */
+		bitvec_write_field(dest, &wp, 0, 1);				/* ALLOCATION_TYPE: dynamic */
+		bitvec_write_field(dest, &wp, usf, 3);				/* USF */
+		bitvec_write_field(dest, &wp, 0, 1);				/* USF_GRANULARITY */
+		bitvec_write_field(dest, &wp, 0, 1);				/* "0" power control: Not Present */
+		bitvec_write_field(dest, &wp, 0, 2);				/* CHANNEL_CODING_COMMAND */
+		bitvec_write_field(dest, &wp, 1, 1);				/* TLLI_BLOCK_CHANNEL_CODING */
+		bitvec_write_field(dest, &wp, 0, 1);				/* ALPHA = not present */
+		bitvec_write_field(dest, &wp, gamma, 5);			/* GAMMA power control parameter */
+		/* note: there is no choise for TAI and no starting time */
+		bitvec_write_field(dest, &wp, 0, 1);				/* switch TIMING_ADVANCE_INDEX = off */
+		bitvec_write_field(dest, &wp, 0, 1);				/* TBF_STARTING_TIME_FLAG */
+	}
+
+	printf("Encoded PKT UL ASS IA Rest Octets: %s\n", osmo_hexdump(dest->data, dest->data_len));
+
+	OUTRO(use_lh);
+}
+
+static void test_bitdiff(const struct bitvec *src1, const struct bitvec *src2, unsigned len)
+{
+	unsigned int bit_err = 0, i, j;
+	uint8_t byte_err = 0;
+
+	INTRO(len);
+
+	for (i = 0; i < len; i++) {
+		/* byte compare */
+		byte_err = src1->data[i] ^ src2->data[i];
+		if (byte_err)
+			for (j = 0; j < 8; j++)
+				bit_err += (byte_err >> j) & 0x01; /* count bits which differ */
+	}
+
+
+	printf("=== total %u bits differ ===\n", bit_err);
+
+	OUTRO(len);
+}
+
+static inline void buf_init(struct bitvec *dest, struct bitvec *dest_lh)
+{
+	/* initialize buffer */
+	bitvec_unhex(dest, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	bitvec_unhex(dest_lh, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+}
+
+static inline void test_enc_ul_ass(struct bitvec *dest, struct bitvec *dest_lh, uint32_t fn,
+				   uint8_t tfi, uint8_t gamma, uint8_t usf, bool tbf)
+{
+	buf_init(dest, dest_lh);
+
+	test_bitvec_ia_octet_encode_pkt_ul_ass(dest, fn, tfi, gamma, usf, tbf, false);
+	test_bitvec_ia_octet_encode_pkt_ul_ass(dest_lh, fn, tfi, gamma, usf, tbf, true);
+
+	test_bitdiff(dest, dest_lh, 22);
+}
+
+int main(int argc, char **argv)
+{
+	void *tall_pcu_ctx;
+	struct bitvec *dest, *dest_lh;
+	uint8_t gamma = 0, ta_valid = 1, ws_enc = 3, usf = 1, tfi = 0; /* Temporary Flow Identity */
+	uint32_t ttli = 0xdeadbeef, fn = 1234;
+
+	tall_pcu_ctx = talloc_named_const(NULL, 1, "bitvecTest context");
+	if (!tall_pcu_ctx)
+		return EXIT_FAILURE;
+
+	dest = bitvec_alloc(22, tall_pcu_ctx);
+	dest_lh = bitvec_alloc(22, tall_pcu_ctx);
+
+	buf_init(dest, dest_lh);
+
+	test_bitvec_ia_octet_encode_pkt_dl_ass(dest, ttli, tfi, gamma, ta_valid, ws_enc, false);
+	test_bitvec_ia_octet_encode_pkt_dl_ass(dest_lh, ttli, tfi, gamma, ta_valid, ws_enc, true);
+
+	test_bitdiff(dest, dest_lh, 22);
+
+	test_enc_ul_ass(dest, dest_lh, fn, tfi, gamma, usf, false);
+	test_enc_ul_ass(dest, dest_lh, fn, tfi, gamma, usf, true);
+
+	bitvec_free(dest);
+	bitvec_free(dest_lh);
+
+	talloc_free(tall_pcu_ctx);
+
+	return EXIT_SUCCESS;
+}