| /* |
| * (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 "config.h" |
| |
| #include <osmocom/gsm/protocol/gsm_08_08.h> |
| #include <osmocom/gsm/gsm29205.h> |
| #include <osmocom/gsm/gsm0808.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/gsm/tlv.h> |
| |
| #include <errno.h> |
| |
| /*! \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; |
| } |
| |
| /*! Compare two GCR structs. |
| * \param[in] gcr1 pointer to the GCR struct |
| * \param[in] gcr2 pointer to the GCR struct |
| * \returns true if GCRs are equal, false otherwise */ |
| bool osmo_gcr_eq(const struct osmo_gcr_parsed *gcr1, const struct osmo_gcr_parsed *gcr2) |
| { |
| if (gcr1->net_len != gcr2->net_len) |
| return false; |
| |
| if (gcr1->node != gcr2->node) |
| return false; |
| |
| if (memcmp(gcr1->cr, gcr2->cr, 5) != 0) |
| return false; |
| |
| if (memcmp(gcr1->net, gcr2->net, gcr2->net_len) != 0) |
| return false; |
| |
| return true; |
| } |