tlv: Import osmo_shift_* and osmo_match_shift_* from openbsc

These routines have nothing to do with specifically the BSC, so import
them to the TLV parser we keep in libosmogsm.

7 files changed, 451 insertions, 2 deletions

diff --git a/include/osmocom/gsm/tlv.h b/include/osmocom/gsm/tlv.h
index c19034f0..cf09969d 100644
--- a/include/osmocom/gsm/tlv.h
+++ b/include/osmocom/gsm/tlv.h
@@ -436,4 +436,15 @@ static inline uint32_t tlvp_val32_unal(const struct tlv_parsed *tp, int pos)
 	return res;
 }
 
+int osmo_shift_v_fixed(uint8_t **data, size_t *data_len,
+		       size_t len, uint8_t **value);
+int osmo_match_shift_tv_fixed(uint8_t **data, size_t *data_len,
+			      uint8_t tag, size_t len, uint8_t **value);
+int osmo_shift_tlv(uint8_t **data, size_t *data_len,
+		   uint8_t *tag, uint8_t **value, size_t *value_len);
+int osmo_match_shift_tlv(uint8_t **data, size_t *data_len,
+		   uint8_t tag, uint8_t **value, size_t *value_len);
+int osmo_shift_lv(uint8_t **data, size_t *data_len,
+		  uint8_t **value, size_t *value_len);
+
 /*! @} */
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 21d3c293..8bd0dbfe 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -278,6 +278,12 @@ tlv_parse_one;
 tvlv_att_def;
 vtvlv_gan_att_def;
 
+osmo_shift_v_fixed;
+osmo_match_shift_tv_fixed;
+osmo_shift_tlv;
+osmo_match_shift_tlv;
+osmo_shift_lv;
+
 gan_msgt_vals;
 gan_pdisc_vals;
 
diff --git a/src/gsm/tlv_parser.c b/src/gsm/tlv_parser.c
index 19d0c84d..e84edd97 100644
--- a/src/gsm/tlv_parser.c
+++ b/src/gsm/tlv_parser.c
@@ -225,4 +225,175 @@ static __attribute__((constructor)) void on_dso_load_tlv(void)
 		vtvlv_gan_att_def.def[i].type = TLV_TYPE_vTvLV_GAN;
 }
 
+/*! Advance the data pointer, subtract length and assign value pointer
+ *  \param data pointer to the pointer to data
+ *  \param data_len pointer to size_t containing \arg data length
+ *  \param[in] len the length that we expect the fixed IE to hav
+ *  \param[out] value pointer to pointer of value part of IE
+ *  \returns length of IE value; negative in case of error
+ */
+int osmo_shift_v_fixed(uint8_t **data, size_t *data_len,
+			size_t len, uint8_t **value)
+{
+	if (len > *data_len)
+		goto fail;
+
+	if (value)
+		*value = *data;
+
+	*data += len;
+	*data_len -= len;
+
+	return len;
+
+fail:
+	*data += *data_len;
+	*data_len = 0;
+	return -1;
+}
+
+/*! Match tag, check length and assign value pointer
+ *  \param data pointer to the pointer to data
+ *  \param data_len pointer to size_t containing \arg data length
+ *  \param[in] tag the tag (IEI) that we expect at \arg data
+ *  \param[in] len the length that we expect the fixed IE to have
+ *  \param[out] value pointer to pointer of value part of IE
+ *  \returns length of IE value; negative in case of error
+ */
+int osmo_match_shift_tv_fixed(uint8_t **data, size_t *data_len,
+			      uint8_t tag, size_t len,
+			      uint8_t **value)
+{
+	size_t ie_len;
+
+	if (*data_len == 0)
+		goto fail;
+
+	if ((*data)[0] != tag)
+		return 0;
+
+	if (len > *data_len - 1)
+		goto fail;
+
+	if (value)
+		*value = *data + 1;
+
+	ie_len = len + 1;
+	*data += ie_len;
+	*data_len -= ie_len;
+
+	return ie_len;
+
+fail:
+	*data += *data_len;
+	*data_len = 0;
+	return -1;
+}
+
+/*! Verify TLV header and advance data / subtract length
+ *  \param data pointer to the pointer to data
+ *  \param data_len pointer to size_t containing \arg data length
+ *  \param[in] expected_tag the tag (IEI) that we expect at \arg data
+ *  \param[out] value pointer to pointer of value part of IE
+ *  \param[out] value_len pointer to length of \arg value
+ *  \returns length of IE value; negative in case of error
+ */
+int osmo_match_shift_tlv(uint8_t **data, size_t *data_len,
+			 uint8_t expected_tag, uint8_t **value,
+			 size_t *value_len)
+{
+	int rc;
+	uint8_t tag;
+	uint8_t *old_data = *data;
+	size_t old_data_len = *data_len;
+
+	rc = osmo_shift_tlv(data, data_len, &tag, value, value_len);
+
+	if (rc > 0 && tag != expected_tag) {
+		*data = old_data;
+		*data_len = old_data_len;
+		return 0;
+	}
+
+	return rc;
+}
+
+/*! Extract TLV and advance data pointer + subtract length
+ *  \param data pointer to the pointer to data
+ *  \param data_len  pointer to size_t containing \arg data lengt
+ *  \param[out] tag extract the tag (IEI) at start of \arg data
+ *  \param[out] value extracted pointer to value part of TLV
+ *  \param[out] value_len extracted length of \arg value
+ *  \returns number of bytes subtracted
+ */
+int osmo_shift_tlv(uint8_t **data, size_t *data_len,
+	      uint8_t *tag, uint8_t **value, size_t *value_len)
+{
+	size_t len;
+	size_t ie_len;
+
+	if (*data_len < 2)
+		goto fail;
+
+	len = (*data)[1];
+	if (len > *data_len - 2)
+		goto fail;
+
+	if (tag)
+		*tag = (*data)[0];
+	if (value)
+		*value = *data + 2;
+	if (value_len)
+		*value_len = len;
+
+	ie_len = len + 2;
+
+	*data += ie_len;
+	*data_len -= ie_len;
+
+	return ie_len;
+
+fail:
+	*data += *data_len;
+	*data_len = 0;
+	return -1;
+}
+
+/*! Extract LV and advance data pointer + subtract length
+ *  \param data pointer to the pointer to data
+ *  \param data_len  pointer to size_t containing \arg data lengt
+ *  \param[out] value extracted pointer to value part of TLV
+ *  \param[out] value_len extracted length of \arg value
+ *  \returns number of bytes subtracted
+ */
+int osmo_shift_lv(uint8_t **data, size_t *data_len,
+		  uint8_t **value, size_t *value_len)
+{
+	size_t len;
+	size_t ie_len;
+
+	if (*data_len < 1)
+		goto fail;
+
+	len = (*data)[0];
+	if (len > *data_len - 1)
+		goto fail;
+
+	if (value)
+		*value = *data + 1;
+	if (value_len)
+		*value_len = len;
+
+	ie_len = len + 1;
+	*data += ie_len;
+	*data_len -= ie_len;
+
+	return ie_len;
+
+fail:
+	*data += *data_len;
+	*data_len = 0;
+	return -1;
+}
+
 /*! @} */
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 3aaa99b5..fa814c72 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -13,7 +13,7 @@ check_PROGRAMS = timer/timer_test sms/sms_test ussd/ussd_test		\
 		 vty/vty_test comp128/comp128_test utils/utils_test	\
 		 smscb/gsm0341_test stats/stats_test			\
 		 bitvec/bitvec_test msgb/msgb_test bits/bitcomp_test	\
-		 sim/sim_test
+		 sim/sim_test tlv/tlv_test
 
 if ENABLE_MSGFILE
 check_PROGRAMS += msgfile/msgfile_test
@@ -109,6 +109,9 @@ vty_vty_test_LDADD = $(top_builddir)/src/vty/libosmovty.la $(top_builddir)/src/l
 sim_sim_test_SOURCES = sim/sim_test.c
 sim_sim_test_LDADD = $(top_builddir)/src/sim/libosmosim.la $(top_builddir)/src/libosmocore.la
 
+tlv_tlv_test_SOURCES = tlv/tlv_test.c
+tlv_tlv_test_LDADD = $(top_builddir)/src/gsm/libosmogsm.la $(top_builddir)/src/libosmocore.la
+
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac
 	:;{ \
@@ -143,7 +146,7 @@ EXTRA_DIST = testsuite.at $(srcdir)/package.m4 $(TESTSUITE)		\
 	     vty/vty_test.ok comp128/comp128_test.ok			\
 	     utils/utils_test.ok stats/stats_test.ok			\
 	     bitvec/bitvec_test.ok msgb/msgb_test.ok bits/bitcomp_test.ok \
-	     sim/sim_test.ok
+	     sim/sim_test.ok tlv/tlv_test.ok
 
 DISTCLEANFILES = atconfig
 
diff --git a/tests/testsuite.at b/tests/testsuite.at
index 902c1fcc..762b10a0 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -184,3 +184,9 @@ AT_KEYWORDS([timer])
 cat $abs_srcdir/timer/timer_test.ok > expout
 AT_CHECK([$abs_top_builddir/tests/timer/timer_test -s 5], [0], [expout], [ignore])
 AT_CLEANUP
+
+AT_SETUP([tlv])
+AT_KEYWORDS([tlv])
+cat $abs_srcdir/tlv/tlv_test.ok > expout
+AT_CHECK([$abs_top_builddir/tests/tlv/tlv_test], [0], [expout], [ignore])
+AT_CLEANUP
diff --git a/tests/tlv/tlv_test.c b/tests/tlv/tlv_test.c
new file mode 100644
index 00000000..c571c3bd
--- /dev/null
+++ b/tests/tlv/tlv_test.c
@@ -0,0 +1,250 @@
+#include <osmocom/gsm/tlv.h>
+
+static void check_tlv_parse(uint8_t **data, size_t *data_len,
+			    uint8_t exp_tag, size_t exp_len, const uint8_t *exp_val)
+{
+	uint8_t *value;
+	size_t value_len;
+	uint8_t tag;
+	int rc;
+	uint8_t *saved_data = *data;
+	size_t saved_data_len = *data_len;
+
+	rc = osmo_match_shift_tlv(data, data_len, exp_tag ^ 1, NULL, NULL);
+	OSMO_ASSERT(rc == 0);
+
+	rc = osmo_match_shift_tlv(data, data_len, exp_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);
+
+	/* restore data/data_len */
+	*data = saved_data;
+	*data_len = saved_data_len;
+
+	rc = osmo_shift_tlv(data, data_len, &tag, &value, &value_len);
+	OSMO_ASSERT(rc == (int)value_len + 2);
+	OSMO_ASSERT(tag == exp_tag);
+	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 = osmo_match_shift_tv_fixed(data, data_len, tag ^ 1, len, NULL);
+	OSMO_ASSERT(rc == 0);
+
+	rc = osmo_match_shift_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 = osmo_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 = osmo_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 == osmo_match_shift_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 <= osmo_match_shift_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 == osmo_match_shift_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 <= osmo_match_shift_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 == osmo_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 <= osmo_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 == osmo_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 <= osmo_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_parse(&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 == osmo_match_shift_tlv(&data, &data_len, tag, NULL, NULL));
+		OSMO_ASSERT(-1 == osmo_match_shift_tv_fixed(&data, &data_len, tag, len, NULL));
+		OSMO_ASSERT((len ? -1 : 0) == osmo_shift_v_fixed(&data, &data_len, len, NULL));
+		OSMO_ASSERT(-1 == osmo_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)
+{
+	//osmo_init_logging(&info);
+
+	test_tlv_shift_functions();
+
+	printf("Done.\n");
+	return EXIT_SUCCESS;
+}
diff --git a/tests/tlv/tlv_test.ok b/tests/tlv/tlv_test.ok
new file mode 100644
index 00000000..de159bfb
--- /dev/null
+++ b/tests/tlv/tlv_test.ok
@@ -0,0 +1,2 @@
+Test shift functions
+Done.