Adding LLC-XID encoder / decoder and unit test

The lle-xid encoder/decoder is needed to encode and decode llc
xid parameter messages. We need this to exchange sndcp-parameters
(SNDCP-XID) and also simple parameters such as encryption IOVs

Change-Id: Ia06e4cb08bf9b48c2a4682606d1b1a91d19a9d37
changes/88/3188/1
Philipp Maier 7 years ago committed by Harald Welte
parent d5d39ae2b6
commit a536fc644b
  1. 1
      openbsc/.gitignore
  2. 1
      openbsc/configure.ac
  3. 2
      openbsc/include/openbsc/Makefile.am
  4. 57
      openbsc/include/openbsc/gprs_llc_xid.h
  5. 2
      openbsc/src/gprs/Makefile.am
  6. 262
      openbsc/src/gprs/gprs_llc_xid.c
  7. 2
      openbsc/tests/Makefile.am
  8. 5
      openbsc/tests/testsuite.at
  9. 21
      openbsc/tests/xid/Makefile.am
  10. 164
      openbsc/tests/xid/xid_test.c
  11. 12
      openbsc/tests/xid/xid_test.ok

@ -81,6 +81,7 @@ tests/subscr/subscr_test
tests/oap/oap_test
tests/gtphub/gtphub_test
tests/mm_auth/mm_auth_test
tests/xid/xid_test
tests/atconfig
tests/atlocal

@ -229,6 +229,7 @@ AC_OUTPUT(
tests/oap/Makefile
tests/gtphub/Makefile
tests/mm_auth/Makefile
tests/xid/Makefile
doc/Makefile
doc/examples/Makefile
Makefile)

@ -18,7 +18,7 @@ noinst_HEADERS = abis_nm.h abis_rsl.h db.h gsm_04_08.h gsm_data.h \
gprs_gb_parse.h smpp.h meas_feed.h \
gprs_gsup_client.h bsc_msg_filter.h \
oap.h oap_messages.h \
gtphub.h
gtphub.h gprs_llc_xid.h
openbsc_HEADERS = gsm_04_08.h meas_rep.h bsc_api.h
openbscdir = $(includedir)/openbsc

@ -0,0 +1,57 @@
/* GPRS LLC XID field encoding/decoding as per 3GPP TS 44.064 */
/* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Philipp Maier
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <stdint.h>
#include <osmocom/core/linuxlist.h>
/* 3GPP TS 44.064 6.4.1.6 Exchange Identification (XID)
command/response parameter field */
struct gprs_llc_xid_field {
struct llist_head list;
uint8_t type; /* See also Table 6: LLC layer parameter
negotiation */
uint8_t *data; /* Payload data (memory is owned by the
* creator of the struct) */
unsigned int data_len; /* Payload length */
};
/* Transform a list with XID fields into a XID message (dst) */
int gprs_llc_compile_xid(uint8_t *dst, int dst_maxlen,
const struct llist_head *xid_fields);
/* Transform a XID message (dst) into a list of XID fields */
struct llist_head *gprs_llc_parse_xid(const void *ctx, const uint8_t *src,
int src_len);
/* Create a duplicate of an XID-Field */
struct gprs_llc_xid_field *gprs_llc_dup_xid_field(const void *ctx,
const struct gprs_llc_xid_field *xid_field);
/* Copy an llist with xid fields */
struct llist_head *gprs_llc_copy_xid(const void *ctx,
const struct llist_head *xid_fields);
/* Dump a list with XID fields (Debug) */
void gprs_llc_dump_xid_fields(const struct llist_head *xid_fields,
unsigned int logl);

@ -28,7 +28,7 @@ osmo_sgsn_SOURCES = gprs_gmm.c gprs_sgsn.c gprs_sndcp.c gprs_sndcp_vty.c \
sgsn_ctrl.c sgsn_auth.c gprs_subscriber.c \
gprs_utils.c gprs_gsup_client.c \
sgsn_cdr.c sgsn_ares.c \
oap.c oap_messages.c
oap.c oap_messages.c gprs_llc_xid.c
osmo_sgsn_LDADD = \
$(top_builddir)/src/libcommon/libcommon.a \
-lgtp $(OSMO_LIBS) $(LIBOSMOABIS_LIBS) $(LIBCARES_LIBS) \

@ -0,0 +1,262 @@
/* GPRS LLC XID field encoding/decoding as per 3GPP TS 44.064 */
/* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Philipp Maier
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
#include <openbsc/debug.h>
#include <openbsc/gprs_llc.h>
#include <openbsc/sgsn.h>
#include <openbsc/gprs_llc_xid.h>
/* Parse XID parameter field */
static int decode_xid_field(struct gprs_llc_xid_field *xid_field,
const uint8_t *src, uint8_t src_len)
{
uint8_t xl;
uint8_t type;
uint8_t len;
int src_counter = 0;
/* Exit immediately if it is clear that no
* parseable data is present */
if (src_len < 1 || !src)
return -EINVAL;
/* Extract header info */
xl = (*src >> 7) & 1;
type = (*src >> 2) & 0x1F;
/* Extract length field */
len = (*src) & 0x3;
src++;
src_counter++;
if (xl) {
if (src_len < 2)
return -EINVAL;
len = (len << 6) & 0xC0;
len |= ((*src) >> 2) & 0x3F;
src++;
src_counter++;
}
/* Fill out struct */
xid_field->type = type;
xid_field->data_len = len;
if (len > 0) {
if (src_len < src_counter + len)
return -EINVAL;
xid_field->data =
talloc_memdup(xid_field,src,xid_field->data_len);
} else
xid_field->data = NULL;
/* Return consumed length */
return src_counter + len;
}
/* Encode XID parameter field */
static int encode_xid_field(uint8_t *dst, int dst_maxlen,
const struct gprs_llc_xid_field *xid_field)
{
int xl = 0;
/* When the length does not fit into 2 bits,
* we need extended length fields */
if (xid_field->data_len > 3)
xl = 1;
/* Exit immediately if it is clear that no
* encoding result can be stored */
if (dst_maxlen < xid_field->data_len + 1 + xl)
return -EINVAL;
/* There are only 5 bits reserved for the type, exit on exceed */
if (xid_field->type > 31)
return -EINVAL;
/* Encode header */
memset(dst, 0, dst_maxlen);
if (xl)
dst[0] |= 0x80;
dst[0] |= (((xid_field->type) & 0x1F) << 2);
if (xl) {
dst[0] |= (((xid_field->data_len) >> 6) & 0x03);
dst[1] = ((xid_field->data_len) << 2) & 0xFC;
} else
dst[0] |= ((xid_field->data_len) & 0x03);
/* Append payload data */
if (xid_field->data && xid_field->data_len)
memcpy(dst + 1 + xl, xid_field->data, xid_field->data_len);
/* Return generated length */
return xid_field->data_len + 1 + xl;
}
/* Transform a list with XID fields into a XID message (dst) */
int gprs_llc_compile_xid(uint8_t *dst, int dst_maxlen,
const struct llist_head *xid_fields)
{
struct gprs_llc_xid_field *xid_field;
int rc;
int byte_counter = 0;
OSMO_ASSERT(xid_fields);
OSMO_ASSERT(dst);
llist_for_each_entry_reverse(xid_field, xid_fields, list) {
/* Encode XID-Field */
rc = encode_xid_field(dst, dst_maxlen, xid_field);
if (rc < 0)
return -EINVAL;
/* Advance pointer and lower maxlen for the
* next encoding round */
dst += rc;
byte_counter += rc;
dst_maxlen -= rc;
}
/* Return generated length */
return byte_counter;
}
/* Transform a XID message (dst) into a list of XID fields */
struct llist_head *gprs_llc_parse_xid(const void *ctx, const uint8_t *src,
int src_len)
{
struct gprs_llc_xid_field *xid_field;
struct llist_head *xid_fields;
int rc;
int max_loops = src_len;
OSMO_ASSERT(src);
xid_fields = talloc_zero(ctx, struct llist_head);
INIT_LLIST_HEAD(xid_fields);
while (1) {
/* Bail in case decode_xid_field() constantly returns zero */
if (max_loops <= 0) {
talloc_free(xid_fields);
return NULL;
}
/* Decode XID field */
xid_field = talloc_zero(xid_fields, struct gprs_llc_xid_field);
rc = decode_xid_field(xid_field, src, src_len);
/* Immediately stop on error */
if (rc < 0) {
talloc_free(xid_fields);
return NULL;
}
/* Add parsed XID field to list */
llist_add(&xid_field->list, xid_fields);
/* Advance pointer and lower dst_len for the next
* decoding round */
src += rc;
src_len -= rc;
/* We are (scuccessfully) done when no further byes are left */
if (src_len == 0)
return xid_fields;
max_loops--;
}
}
/* Create a duplicate of an XID-Field */
struct gprs_llc_xid_field *gprs_llc_dup_xid_field(const void *ctx, const struct
gprs_llc_xid_field
*xid_field)
{
struct gprs_llc_xid_field *dup;
OSMO_ASSERT(xid_field);
/* Create a copy of the XID field in memory */
dup = talloc_memdup(ctx, xid_field, sizeof(*xid_field));
dup->data = talloc_memdup(ctx, xid_field->data, xid_field->data_len);
/* Unlink duplicate from source list */
INIT_LLIST_HEAD(&dup->list);
return dup;
}
/* Copy an llist with xid fields */
struct llist_head *gprs_llc_copy_xid(const void *ctx,
const struct llist_head *xid_fields)
{
struct gprs_llc_xid_field *xid_field;
struct llist_head *xid_fields_copy;
OSMO_ASSERT(xid_fields);
xid_fields_copy = talloc_zero(ctx, struct llist_head);
INIT_LLIST_HEAD(xid_fields_copy);
/* Create duplicates and add them to the target list */
llist_for_each_entry(xid_field, xid_fields, list) {
llist_add(&gprs_llc_dup_xid_field(ctx, xid_field)->list,
xid_fields_copy);
}
return xid_fields_copy;
}
/* Dump a list with XID fields (Debug) */
void gprs_llc_dump_xid_fields(const struct llist_head *xid_fields,
unsigned int logl)
{
struct gprs_llc_xid_field *xid_field;
OSMO_ASSERT(xid_fields);
llist_for_each_entry(xid_field, xid_fields, list) {
if (xid_field->data_len) {
OSMO_ASSERT(xid_field->data);
LOGP(DLLC, logl,
"XID: type=%d, data_len=%d, data=%s\n",
xid_field->type, xid_field->data_len,
osmo_hexdump_nospc(xid_field->data,
xid_field->data_len));
} else {
LOGP(DLLC, logl,
"XID: type=%d, data_len=%d, data=NULL\n",
xid_field->type, xid_field->data_len);
}
}
}

@ -1,4 +1,4 @@
SUBDIRS = gsm0408 db channel mgcp gprs abis gbproxy trau subscr mm_auth
SUBDIRS = gsm0408 db channel mgcp gprs abis gbproxy trau subscr mm_auth xid
if BUILD_NAT
SUBDIRS += bsc-nat bsc-nat-trie

@ -124,3 +124,8 @@ cat $abs_srcdir/mm_auth/mm_auth_test.ok > expout
AT_CHECK([$abs_top_builddir/tests/mm_auth/mm_auth_test], [], [expout], [ignore])
AT_CLEANUP
AT_SETUP([xid])
AT_KEYWORDS([xid])
cat $abs_srcdir/xid/xid_test.ok > expout
AT_CHECK([$abs_top_builddir/tests/xid/xid_test], [], [expout], [ignore])
AT_CLEANUP

@ -0,0 +1,21 @@
AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include
AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBCARES_CFLAGS)
EXTRA_DIST = xid_test.ok
noinst_PROGRAMS = xid_test
xid_test_SOURCES = xid_test.c
xid_test_LDADD = \
$(top_builddir)/src/gprs/gprs_llc_xid.o \
$(top_builddir)/src/libcommon/libcommon.a \
$(LIBOSMOABIS_LIBS) \
$(LIBOSMOCORE_LIBS) \
$(LIBOSMOGSM_LIBS) \
$(LIBOSMOGB_LIBS) \
$(LIBCARES_LIBS) \
$(LIBCRYPTO_LIBS) \
-lgtp -lrt -lm

@ -0,0 +1,164 @@
/* Test LLC-XID Encoding/Decoding */
/* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
* All Rights Reserved
*
* Author: Philipp Maier
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <openbsc/gprs_llc_xid.h>
#include <openbsc/debug.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/application.h>
#include <stdio.h>
#include <string.h>
/* Test XID encoding */
static void test_xid_encode(const void *ctx)
{
struct gprs_llc_xid_field xid_field_1;
struct gprs_llc_xid_field xid_field_2;
struct gprs_llc_xid_field xid_field_3;
struct gprs_llc_xid_field xid_field_4;
LLIST_HEAD(xid_fields);
uint8_t xid[255];
uint8_t xid_expected[] =
{ 0x10, 0x8c, 0x14, 0x43, 0x43, 0x43, 0x43, 0x43, 0x0b, 0x42, 0x42,
0x42, 0x05, 0x41 };
int rc;
printf("Testing LLC XID-Encoder\n");
/* Setup some simple XID data */
xid_field_1.type = 1;
xid_field_2.type = 2;
xid_field_3.type = 3;
xid_field_4.type = 4;
xid_field_1.data = (uint8_t *) "A";
xid_field_2.data = (uint8_t *) "BBB";
xid_field_3.data = (uint8_t *) "CCCCC";
xid_field_4.data = NULL;
xid_field_1.data_len = 1;
xid_field_2.data_len = 3;
xid_field_3.data_len = 5;
xid_field_4.data_len = 0;
llist_add(&xid_field_4.list, &xid_fields);
llist_add(&xid_field_3.list, &xid_fields);
llist_add(&xid_field_2.list, &xid_fields);
llist_add(&xid_field_1.list, &xid_fields);
printf("Data to encode:\n");
gprs_llc_dump_xid_fields(&xid_fields, DSNDCP);
/* Encode data */
rc = gprs_llc_compile_xid(xid, sizeof(xid), &xid_fields);
OSMO_ASSERT(rc == 14);
printf("Encoded: %s (%i bytes)\n", osmo_hexdump_nospc(xid, rc), rc);
printf("Expected: %s (%i bytes)\n",
osmo_hexdump_nospc(xid_expected, sizeof(xid_expected)),
(int)sizeof(xid_expected));
OSMO_ASSERT(memcmp(xid_expected, xid, sizeof(xid_expected)) == 0);
printf("\n");
}
/* Test XID decoding */
static void test_xid_decode(const void *ctx)
{
struct llist_head *xid_fields;
int rc;
printf("Testing LLC XID-Decoder/Encoder\n");
/* Example of a real world LLC-XID message */
uint8_t xid[] =
{ 0x01, 0x00, 0x16, 0x05, 0xf0, 0x1a, 0x05, 0xf0, 0xac, 0xd8, 0x00,
0x01, 0x00, 0x02, 0x31, 0x82, 0x02, 0x27, 0x89, 0xff, 0xe0, 0x00, 0x0f,
0x00, 0xa8, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x00, 0x02, 0x01, 0x02,
0x00, 0x03, 0x01, 0x03, 0x00, 0x04, 0x01, 0x04, 0x00, 0x05, 0x01, 0x05,
0x00, 0x06, 0x00, 0x07, 0x01, 0x07, 0x00, 0x08, 0x01, 0x08, 0x80, 0x00,
0x04, 0x12, 0x00, 0x40, 0x07 };
uint8_t xid_r[512];
/* Decode and display XID fields */
xid_fields = gprs_llc_parse_xid(ctx, xid, sizeof(xid));
OSMO_ASSERT(xid_fields);
printf("Decoded:\n");
gprs_llc_dump_xid_fields(xid_fields, DSNDCP);
/* Encode xid-fields again */
rc = gprs_llc_compile_xid(xid_r, sizeof(xid_r), xid_fields);
printf("Result length=%i\n",rc);
printf("Encoded: %s\n", osmo_hexdump_nospc(xid, sizeof(xid)));
printf("Rencoded: %s\n", osmo_hexdump_nospc(xid_r, rc));
OSMO_ASSERT(rc == 64);
OSMO_ASSERT(memcmp(xid, xid_r, sizeof(xid)) == 0);
/* Free xid fields */
talloc_free(xid_fields);
printf("\n");
}
static struct log_info_cat gprs_categories[] = {
[DSNDCP] = {
.name = "DSNDCP",
.description =
"GPRS Sub-Network Dependent Control Protocol (SNDCP)",
.enabled = 1,.loglevel = LOGL_DEBUG,
}
};
static struct log_info info = {
.cat = gprs_categories,
.num_cat = ARRAY_SIZE(gprs_categories),
};
int main(int argc, char **argv)
{
void *xid_ctx;
osmo_init_logging(&info);
xid_ctx = talloc_named_const(NULL, 0, "xid_ctx");
test_xid_decode(xid_ctx);
test_xid_encode(xid_ctx);
printf("Done\n");
talloc_report_full(xid_ctx, stderr);
OSMO_ASSERT(talloc_total_blocks(xid_ctx) == 1);
return 0;
}
/* stubs */
struct osmo_prim_hdr;
int bssgp_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
{
abort();
}

@ -0,0 +1,12 @@
Testing LLC XID-Decoder/Encoder
Decoded:
Result length=64
Encoded: 01001605f01a05f0acd8000100023182022789ffe0000f00a8000000010101000201020003010300040104000501050006000701070008010880000412004007
Rencoded: 01001605f01a05f0acd8000100023182022789ffe0000f00a8000000010101000201020003010300040104000501050006000701070008010880000412004007
Testing LLC XID-Encoder
Data to encode:
Encoded: 108c1443434343430b4242420541 (14 bytes)
Expected: 108c1443434343430b4242420541 (14 bytes)
Done
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