gprs: Move TLV parser functions to gprs_utils.c and rename them

Currently the parser functions for single information elements are
defined within gprs_gb_parse.c and not exported explicitely. In
addition they are named like libosmocore's TLV parser functions and
do not have a proper name prefix. Since it is planned to use them for
other protocols, they need to be globally accessible.

This patch moves them to gprs_utils.c and renames them.

The new names are:
    lv_shift             -> gprs_shift_lv
    v_fixed_shift        -> gprs_shift_v_fixed
    lv_shift             -> gprs_shift_lv
    v_fixed_shift        -> gprs_shift_v_fixed

In the long term, these functions should be moved to libosmocore (and
renamed again).

Sponsored-by: On-Waves ehf

2 files changed, 229 insertions, 0 deletions

diff --git a/openbsc/tests/gprs/gprs_test.c b/openbsc/tests/gprs/gprs_test.c
index 30e900f61..5bc207343 100644
--- a/openbsc/tests/gprs/gprs_test.c
+++ b/openbsc/tests/gprs/gprs_test.c
@@ -138,10 +138,238 @@ static void test_gsm_03_03_apn(void)
 	}
 }
 
+/* TODO: Move tlv testing to libosmocore */
+static void check_tlv_match(uint8_t **data, size_t *data_len,
+			    uint8_t tag, size_t exp_len, const uint8_t *exp_val)
+{
+	uint8_t *value;
+	size_t value_len;
+	int rc;
+
+	rc = gprs_match_tlv(data, data_len, tag ^ 1, NULL, NULL);
+	OSMO_ASSERT(rc == 0);
+
+	rc = gprs_match_tlv(data, data_len, tag, &value, &value_len);
+	OSMO_ASSERT(rc == (int)value_len + 2);
+	OSMO_ASSERT(value_len == exp_len);
+	OSMO_ASSERT(memcmp(value, exp_val, exp_len) == 0);
+}
+
+static void check_tv_fixed_match(uint8_t **data, size_t *data_len,
+				 uint8_t tag, size_t len, const uint8_t *exp_val)
+{
+	uint8_t *value;
+	int rc;
+
+	rc = gprs_match_tv_fixed(data, data_len, tag ^ 1, len, NULL);
+	OSMO_ASSERT(rc == 0);
+
+	rc = gprs_match_tv_fixed(data, data_len, tag, len, &value);
+	OSMO_ASSERT(rc == (int)len + 1);
+	OSMO_ASSERT(memcmp(value, exp_val, len) == 0);
+}
+
+static void check_v_fixed_shift(uint8_t **data, size_t *data_len,
+				size_t len, const uint8_t *exp_val)
+{
+	uint8_t *value;
+	int rc;
+
+	rc = gprs_shift_v_fixed(data, data_len, len, &value);
+	OSMO_ASSERT(rc == (int)len);
+	OSMO_ASSERT(memcmp(value, exp_val, len) == 0);
+}
+
+static void check_lv_shift(uint8_t **data, size_t *data_len,
+			   size_t exp_len, const uint8_t *exp_val)
+{
+	uint8_t *value;
+	size_t value_len;
+	int rc;
+
+	rc = gprs_shift_lv(data, data_len, &value, &value_len);
+	OSMO_ASSERT(rc == (int)value_len + 1);
+	OSMO_ASSERT(value_len == exp_len);
+	OSMO_ASSERT(memcmp(value, exp_val, exp_len) == 0);
+}
+
+static void check_tlv_match_data_len(size_t data_len, uint8_t tag, size_t len,
+				     const uint8_t *test_data)
+{
+	uint8_t buf[300] = {0};
+
+	uint8_t *unchanged_ptr = buf - 1;
+	size_t unchanged_len = 0xdead;
+	size_t tmp_data_len = data_len;
+	uint8_t *value = unchanged_ptr;
+	size_t value_len = unchanged_len;
+	uint8_t *data = buf;
+
+	OSMO_ASSERT(data_len <= sizeof(buf));
+
+	tlv_put(data, tag, len, test_data);
+	if (data_len < len + 2) {
+		OSMO_ASSERT(-1 == gprs_match_tlv(&data, &tmp_data_len,
+					    tag, &value, &value_len));
+		OSMO_ASSERT(tmp_data_len == 0);
+		OSMO_ASSERT(data == buf + data_len);
+		OSMO_ASSERT(value == unchanged_ptr);
+		OSMO_ASSERT(value_len == unchanged_len);
+	} else {
+		OSMO_ASSERT(0 <= gprs_match_tlv(&data, &tmp_data_len,
+					   tag, &value, &value_len));
+		OSMO_ASSERT(value != unchanged_ptr);
+		OSMO_ASSERT(value_len != unchanged_len);
+	}
+}
+
+static void check_tv_fixed_match_data_len(size_t data_len,
+					  uint8_t tag, size_t len,
+					  const uint8_t *test_data)
+{
+	uint8_t buf[300] = {0};
+
+	uint8_t *unchanged_ptr = buf - 1;
+	size_t tmp_data_len = data_len;
+	uint8_t *value = unchanged_ptr;
+	uint8_t *data = buf;
+
+	OSMO_ASSERT(data_len <= sizeof(buf));
+
+	tv_fixed_put(data, tag, len, test_data);
+
+	if (data_len < len + 1) {
+		OSMO_ASSERT(-1 == gprs_match_tv_fixed(&data, &tmp_data_len,
+						 tag, len, &value));
+		OSMO_ASSERT(tmp_data_len == 0);
+		OSMO_ASSERT(data == buf + data_len);
+		OSMO_ASSERT(value == unchanged_ptr);
+	} else {
+		OSMO_ASSERT(0 <= gprs_match_tv_fixed(&data, &tmp_data_len,
+						tag, len, &value));
+		OSMO_ASSERT(value != unchanged_ptr);
+	}
+}
+
+static void check_v_fixed_shift_data_len(size_t data_len,
+					 size_t len, const uint8_t *test_data)
+{
+	uint8_t buf[300] = {0};
+
+	uint8_t *unchanged_ptr = buf - 1;
+	size_t tmp_data_len = data_len;
+	uint8_t *value = unchanged_ptr;
+	uint8_t *data = buf;
+
+	OSMO_ASSERT(data_len <= sizeof(buf));
+
+	memcpy(data, test_data, len);
+
+	if (data_len < len) {
+		OSMO_ASSERT(-1 == gprs_shift_v_fixed(&data, &tmp_data_len,
+						len, &value));
+		OSMO_ASSERT(tmp_data_len == 0);
+		OSMO_ASSERT(data == buf + data_len);
+		OSMO_ASSERT(value == unchanged_ptr);
+	} else {
+		OSMO_ASSERT(0 <= gprs_shift_v_fixed(&data, &tmp_data_len,
+					       len, &value));
+		OSMO_ASSERT(value != unchanged_ptr);
+	}
+}
+
+static void check_lv_shift_data_len(size_t data_len,
+				    size_t len, const uint8_t *test_data)
+{
+	uint8_t buf[300] = {0};
+
+	uint8_t *unchanged_ptr = buf - 1;
+	size_t unchanged_len = 0xdead;
+	size_t tmp_data_len = data_len;
+	uint8_t *value = unchanged_ptr;
+	size_t value_len = unchanged_len;
+	uint8_t *data = buf;
+
+	lv_put(data, len, test_data);
+	if (data_len < len + 1) {
+		OSMO_ASSERT(-1 == gprs_shift_lv(&data, &tmp_data_len,
+					   &value, &value_len));
+		OSMO_ASSERT(tmp_data_len == 0);
+		OSMO_ASSERT(data == buf + data_len);
+		OSMO_ASSERT(value == unchanged_ptr);
+		OSMO_ASSERT(value_len == unchanged_len);
+	} else {
+		OSMO_ASSERT(0 <= gprs_shift_lv(&data, &tmp_data_len,
+					  &value, &value_len));
+		OSMO_ASSERT(value != unchanged_ptr);
+		OSMO_ASSERT(value_len != unchanged_len);
+	}
+}
+
+static void test_tlv_shift_functions()
+{
+	uint8_t test_data[1024];
+	uint8_t buf[1024];
+	uint8_t *data_end;
+	unsigned i, len;
+	uint8_t *data;
+	size_t data_len;
+	const uint8_t tag = 0x1a;
+
+	printf("Test shift functions\n");
+
+	for (i = 0; i < ARRAY_SIZE(test_data); i++)
+		test_data[i] = (uint8_t)i;
+
+	for (len = 0; len < 256; len++) {
+		const unsigned iterations = sizeof(buf) / (len + 2) / 4;
+
+		memset(buf, 0xee, sizeof(buf));
+		data_end = data = buf;
+
+		for (i = 0; i < iterations; i++) {
+			data_end = tlv_put(data_end, tag, len, test_data);
+			data_end = tv_fixed_put(data_end, tag, len, test_data);
+			/* v_fixed_put */
+			memcpy(data_end, test_data, len);
+			data_end += len;
+			data_end = lv_put(data_end, len, test_data);
+		}
+
+		data_len = data_end - data;
+		OSMO_ASSERT(data_len <= sizeof(buf));
+
+		for (i = 0; i < iterations; i++) {
+			check_tlv_match(&data, &data_len, tag, len, test_data);
+			check_tv_fixed_match(&data, &data_len, tag, len, test_data);
+			check_v_fixed_shift(&data, &data_len, len, test_data);
+			check_lv_shift(&data, &data_len, len, test_data);
+		}
+
+		OSMO_ASSERT(data == data_end);
+
+		/* Test at end of data */
+
+		OSMO_ASSERT(-1 == gprs_match_tlv(&data, &data_len, tag, NULL, NULL));
+		OSMO_ASSERT(-1 == gprs_match_tv_fixed(&data, &data_len, tag, len, NULL));
+		OSMO_ASSERT((len ? -1 : 0) == gprs_shift_v_fixed(&data, &data_len, len, NULL));
+		OSMO_ASSERT(-1 == gprs_shift_lv(&data, &data_len, NULL, NULL));
+
+		/* Test invalid data_len */
+		for (data_len = 0; data_len <= len + 2 + 1; data_len += 1) {
+			check_tlv_match_data_len(data_len, tag, len, test_data);
+			check_tv_fixed_match_data_len(data_len, tag, len, test_data);
+			check_v_fixed_shift_data_len(data_len, len, test_data);
+			check_lv_shift_data_len(data_len, len, test_data);
+		}
+	}
+}
+
 int main(int argc, char **argv)
 {
 	test_8_4_2();
 	test_gsm_03_03_apn();
+	test_tlv_shift_functions();
 
 	printf("Done.\n");
 	return EXIT_SUCCESS;
diff --git a/openbsc/tests/gprs/gprs_test.ok b/openbsc/tests/gprs/gprs_test.ok
index 39d37c120..56d4b6543 100644
--- a/openbsc/tests/gprs/gprs_test.ok
+++ b/openbsc/tests/gprs/gprs_test.ok
@@ -13,4 +13,5 @@ N(U) = 511, V(UR) = 511 => new
 N(U) = 510, V(UR) = 511 => retransmit
 N(U) = 481, V(UR) = 511 => retransmit
 N(U) = 479, V(UR) = 511 => new
+Test shift functions
 Done.