Max | 7918f84 | 2018-12-10 10:57:59 +0100 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2018 by sysmocom - s.f.m.c. GmbH |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * SPDX-License-Identifier: GPL-2.0+ |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
Max | 7918f84 | 2018-12-10 10:57:59 +0100 | [diff] [blame] | 17 | */ |
| 18 | |
Max | 5ec0cf5 | 2019-01-15 16:37:09 +0100 | [diff] [blame] | 19 | #include "config.h" |
| 20 | |
Max | 7918f84 | 2018-12-10 10:57:59 +0100 | [diff] [blame] | 21 | #include <osmocom/gsm/protocol/gsm_08_08.h> |
| 22 | #include <osmocom/gsm/gsm29205.h> |
| 23 | #include <osmocom/gsm/gsm0808.h> |
Max | 5ec0cf5 | 2019-01-15 16:37:09 +0100 | [diff] [blame] | 24 | #include <osmocom/core/utils.h> |
Max | 7918f84 | 2018-12-10 10:57:59 +0100 | [diff] [blame] | 25 | #include <osmocom/core/msgb.h> |
| 26 | #include <osmocom/gsm/tlv.h> |
| 27 | |
| 28 | #include <errno.h> |
| 29 | |
| 30 | /*! \addtogroup gsm29205 |
| 31 | * @{ |
| 32 | * \file gsm29205.c |
| 33 | * Functions related to 3GPP TS 29.205, primarily message generation/encoding. |
| 34 | */ |
| 35 | |
| 36 | /*! Create Global Call Reference. |
| 37 | * \param[out] msg Message Buffer for appending IE |
| 38 | * \param[in] g Global Call Reference, 3GPP TS 29.205 Table B 2.1.9.1 |
| 39 | * \returns number of bytes added to \a msg */ |
| 40 | uint8_t osmo_enc_gcr(struct msgb *msg, const struct osmo_gcr_parsed *g) |
| 41 | { |
| 42 | uint8_t buf[2]; |
| 43 | |
| 44 | if (!g) |
| 45 | return 0; |
| 46 | |
| 47 | if (g->net_len < 3 || g->net_len > 5) |
| 48 | return 0; |
| 49 | |
| 50 | msgb_lv_put(msg, g->net_len, g->net); |
| 51 | |
| 52 | osmo_store16be(g->node, &buf); |
| 53 | msgb_lv_put(msg, 2, buf); |
| 54 | |
| 55 | msgb_lv_put(msg, 5, g->cr); |
| 56 | |
| 57 | /* Length: LV(Net) + LV(Node) + LV(CRef) - see 3GPP TS ยง3.2.2.115 */ |
| 58 | return (g->net_len + 1) + (2 + 1) + (5 + 1); |
| 59 | } |
| 60 | |
| 61 | /*! Decode Global Call Reference, 3GPP TS 29.205 Table B 2.1.9.1. |
| 62 | * \param[out] gcr Caller-provided memory to store Global Call Reference |
| 63 | * \param[in] elem IE value to be decoded |
| 64 | * \param[in] len Length of \a elem in bytes |
| 65 | * \returns number of bytes parsed; negative on error */ |
| 66 | int osmo_dec_gcr(struct osmo_gcr_parsed *gcr, const uint8_t *elem, uint8_t len) |
| 67 | { |
| 68 | uint16_t parsed = 1; /* account for length byte right away */ |
| 69 | |
| 70 | if (len < 13) |
| 71 | return -EBADMSG; |
| 72 | |
| 73 | gcr->net_len = elem[0]; |
| 74 | if (gcr->net_len < 3 || gcr->net_len > 5) |
| 75 | return -EINVAL; |
| 76 | |
| 77 | memcpy(gcr->net, elem + parsed, gcr->net_len); |
| 78 | /* +1 for ignored Node ID length field */ |
| 79 | parsed += (gcr->net_len + 1); |
| 80 | |
| 81 | gcr->node = osmo_load16be(elem + parsed); |
| 82 | parsed += 2; |
| 83 | |
| 84 | if (elem[parsed] != 5) /* see Table B 2.1.9.2 */ |
| 85 | return -ENOENT; |
| 86 | |
| 87 | parsed++; |
| 88 | |
| 89 | memcpy(gcr->cr, elem + parsed, 5); |
| 90 | |
| 91 | return parsed + 5; |
| 92 | } |
Max | 1bec390 | 2019-01-14 19:31:42 +0100 | [diff] [blame] | 93 | |
| 94 | /*! Compare two GCR structs. |
| 95 | * \param[in] gcr1 pointer to the GCR struct |
| 96 | * \param[in] gcr2 pointer to the GCR struct |
| 97 | * \returns true if GCRs are equal, false otherwise */ |
| 98 | bool osmo_gcr_eq(const struct osmo_gcr_parsed *gcr1, const struct osmo_gcr_parsed *gcr2) |
| 99 | { |
| 100 | if (gcr1->net_len != gcr2->net_len) |
| 101 | return false; |
| 102 | |
| 103 | if (gcr1->node != gcr2->node) |
| 104 | return false; |
| 105 | |
| 106 | if (memcmp(gcr1->cr, gcr2->cr, 5) != 0) |
| 107 | return false; |
| 108 | |
| 109 | if (memcmp(gcr1->net, gcr2->net, gcr2->net_len) != 0) |
| 110 | return false; |
| 111 | |
| 112 | return true; |
| 113 | } |