From 7918f84aeb65c4b833ccf86b9daa6ab76f06c031 Mon Sep 17 00:00:00 2001 From: Max Date: Mon, 10 Dec 2018 10:57:59 +0100 Subject: LCLS, TS 29.205: add GCR routines Add functions to encode and decode Global Call Reference as per 3GPP TS 29.205 Table B 2.1.9.1 add corresponding tests. Change-Id: Iee95aa4e5c056645b6cb5667e4a067097d52dfbf Related: OS#2487 --- src/gsm/Makefile.am | 2 +- src/gsm/gsm29205.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/gsm/libosmogsm.map | 3 ++ 3 files changed, 97 insertions(+), 1 deletion(-) create mode 100644 src/gsm/gsm29205.c (limited to 'src') diff --git a/src/gsm/Makefile.am b/src/gsm/Makefile.am index e28ea335..ccb38add 100644 --- a/src/gsm/Makefile.am +++ b/src/gsm/Makefile.am @@ -24,7 +24,7 @@ libgsmint_la_SOURCES = a5.c rxlev_stat.c tlv_parser.c comp128.c comp128v23.c \ gsm_utils.c rsl.c gsm48.c gsm48_ie.c gsm0808.c sysinfo.c \ gprs_cipher_core.c gprs_rlc.c gsm0480.c abis_nm.c gsm0502.c \ gsm0411_utils.c gsm0411_smc.c gsm0411_smr.c gsm0414.c \ - lapd_core.c lapdm.c kasumi.c gsm_04_08_gprs.c \ + lapd_core.c lapdm.c kasumi.c gsm29205.c gsm_04_08_gprs.c \ auth_core.c auth_comp128v1.c auth_comp128v23.c \ auth_milenage.c milenage/aes-encblock.c gea.c \ milenage/aes-internal.c milenage/aes-internal-enc.c \ diff --git a/src/gsm/gsm29205.c b/src/gsm/gsm29205.c new file mode 100644 index 00000000..0ef29b72 --- /dev/null +++ b/src/gsm/gsm29205.c @@ -0,0 +1,93 @@ +/* + * (C) 2018 by sysmocom - s.f.m.c. GmbH + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +#include +#include +#include +#include +#include + +#include + +/*! \addtogroup gsm29205 + * @{ + * \file gsm29205.c + * Functions related to 3GPP TS 29.205, primarily message generation/encoding. + */ + +/*! Create Global Call Reference. + * \param[out] msg Message Buffer for appending IE + * \param[in] g Global Call Reference, 3GPP TS 29.205 Table B 2.1.9.1 + * \returns number of bytes added to \a msg */ +uint8_t osmo_enc_gcr(struct msgb *msg, const struct osmo_gcr_parsed *g) +{ + uint8_t buf[2]; + + if (!g) + return 0; + + if (g->net_len < 3 || g->net_len > 5) + return 0; + + msgb_lv_put(msg, g->net_len, g->net); + + osmo_store16be(g->node, &buf); + msgb_lv_put(msg, 2, buf); + + msgb_lv_put(msg, 5, g->cr); + + /* Length: LV(Net) + LV(Node) + LV(CRef) - see 3GPP TS ยง3.2.2.115 */ + return (g->net_len + 1) + (2 + 1) + (5 + 1); +} + +/*! Decode Global Call Reference, 3GPP TS 29.205 Table B 2.1.9.1. + * \param[out] gcr Caller-provided memory to store Global Call Reference + * \param[in] elem IE value to be decoded + * \param[in] len Length of \a elem in bytes + * \returns number of bytes parsed; negative on error */ +int osmo_dec_gcr(struct osmo_gcr_parsed *gcr, const uint8_t *elem, uint8_t len) +{ + uint16_t parsed = 1; /* account for length byte right away */ + + if (len < 13) + return -EBADMSG; + + gcr->net_len = elem[0]; + if (gcr->net_len < 3 || gcr->net_len > 5) + return -EINVAL; + + memcpy(gcr->net, elem + parsed, gcr->net_len); + /* +1 for ignored Node ID length field */ + parsed += (gcr->net_len + 1); + + gcr->node = osmo_load16be(elem + parsed); + parsed += 2; + + if (elem[parsed] != 5) /* see Table B 2.1.9.2 */ + return -ENOENT; + + parsed++; + + memcpy(gcr->cr, elem + parsed, 5); + + return parsed + 5; +} diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index dc4e0a69..e85ed6d4 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -235,6 +235,9 @@ gsm29118_create_status; gsm29118_create_release_req; gsm29118_create_service_abort_req; +osmo_enc_gcr; +osmo_dec_gcr; + gsm0858_rsl_ul_meas_enc; gsm338_get_sms_alphabet; -- cgit v1.2.3