gprs: Add TLV parse functions
This adds a set of function that parse a single tlv, lv, tv, or v
encoded information element. They are complementary to the *_put
functions defined in libosmocore's tlv.h file. The functions update
the data and data_len fields unless they are a 'match' function and
the tag field doesn't match.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index bc2e119..bf79444 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -403,6 +403,122 @@
return len;
}
+/* TODO: Move shift functions to libosmocore */
+
+int v_fixed_shift(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;
+}
+
+int tv_fixed_match(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;
+}
+
+int tlv_match(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;
+
+ if ((*data)[0] != tag)
+ return 0;
+
+ len = (*data)[1];
+ if (len > *data_len - 2)
+ goto fail;
+
+ 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;
+}
+
+int lv_shift(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;
+}
+
struct gbprox_tlli_info {
struct llist_head list;
diff --git a/openbsc/tests/gbproxy/gbproxy_test.c b/openbsc/tests/gbproxy/gbproxy_test.c
index 1598c72..d5675d8 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.c
+++ b/openbsc/tests/gbproxy/gbproxy_test.c
@@ -23,6 +23,7 @@
#include <osmocom/core/talloc.h>
#include <osmocom/core/signal.h>
#include <osmocom/core/rate_ctr.h>
+#include <osmocom/gsm/tlv.h>
#include <osmocom/gprs/gprs_msgb.h>
#include <osmocom/gprs/gprs_ns.h>
#include <osmocom/gprs/gprs_bssgp.h>
@@ -967,6 +968,240 @@
nsi = NULL;
}
+/* TODO: Move tlv testing to libosmocore */
+int v_fixed_shift(uint8_t **data, size_t *data_len, size_t len, uint8_t **value);
+int tv_fixed_match(uint8_t **data, size_t *data_len, uint8_t tag, size_t len,
+ uint8_t **value);
+int tlv_match(uint8_t **data, size_t *data_len, uint8_t tag, uint8_t **value,
+ size_t *value_len);
+int lv_shift(uint8_t **data, size_t *data_len,
+ uint8_t **value, size_t *value_len);
+
+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 = tlv_match(data, data_len, tag ^ 1, NULL, NULL);
+ OSMO_ASSERT(rc == 0);
+
+ rc = tlv_match(data, data_len, tag, &value, &value_len);
+ OSMO_ASSERT(rc == 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 = tv_fixed_match(data, data_len, tag ^ 1, len, NULL);
+ OSMO_ASSERT(rc == 0);
+
+ rc = tv_fixed_match(data, data_len, tag, len, &value);
+ OSMO_ASSERT(rc == 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 = v_fixed_shift(data, data_len, len, &value);
+ OSMO_ASSERT(rc == 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 = lv_shift(data, data_len, &value, &value_len);
+ OSMO_ASSERT(rc == 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 == tlv_match(&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 <= tlv_match(&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 == tv_fixed_match(&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 <= tv_fixed_match(&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 == v_fixed_shift(&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 <= v_fixed_shift(&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 == lv_shift(&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 <= lv_shift(&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;
+ int 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 int 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 == tlv_match(&data, &data_len, tag, NULL, NULL));
+ OSMO_ASSERT(-1 == tv_fixed_match(&data, &data_len, tag, len, NULL));
+ OSMO_ASSERT((len ? -1 : 0) == v_fixed_shift(&data, &data_len, len, NULL));
+ OSMO_ASSERT(-1 == lv_shift(&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);
+ }
+ }
+}
static struct log_info_cat gprs_categories[] = {
[DGPRS] = {
.name = "DGPRS",
@@ -1006,6 +1241,7 @@
setlinebuf(stdout);
printf("===== GbProxy test START\n");
+ test_tlv_shift_functions();
test_gbproxy();
test_gbproxy_ident_changes();
test_gbproxy_ra_patching();
diff --git a/openbsc/tests/gbproxy/gbproxy_test.ok b/openbsc/tests/gbproxy/gbproxy_test.ok
index 5f2d81e..f99087d 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.ok
+++ b/openbsc/tests/gbproxy/gbproxy_test.ok
@@ -1,4 +1,5 @@
===== GbProxy test START
+Test shift functions
=== test_gbproxy ===
--- Initialise SGSN ---