libosmogsm 0.9.6-23.20170220git32ee5af8.fc42
Osmocom GSM library
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gsm_utils.h
1/* GSM utility functions, e.g. coding and decoding */
2/*
3 * (C) 2008 by Daniel Willmann <daniel@totalueberwachung.de>
4 * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
5 * (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
6 *
7 * All Rights Reserved
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 *
23 */
24
25#pragma once
26
27#include <stddef.h>
28#include <stdint.h>
29
30#include <osmocom/core/defs.h>
31#include <osmocom/core/utils.h>
32
33#define ADD_MODULO(sum, delta, modulo) do { \
34 if ((sum += delta) >= modulo) \
35 sum -= modulo; \
36 } while (0)
37
38#define GSM_MAX_FN (26*51*2048)
39
40struct gsm_time {
41 uint32_t fn; /* FN count */
42 uint16_t t1; /* FN div (26*51) */
43 uint8_t t2; /* FN modulo 26 */
44 uint8_t t3; /* FN modulo 51 */
45 uint8_t tc;
46};
47
48enum gsm_band {
49 GSM_BAND_850 = 1,
50 GSM_BAND_900 = 2,
51 GSM_BAND_1800 = 4,
52 GSM_BAND_1900 = 8,
53 GSM_BAND_450 = 0x10,
54 GSM_BAND_480 = 0x20,
55 GSM_BAND_750 = 0x40,
56 GSM_BAND_810 = 0x80,
57};
58
59const char *gsm_band_name(enum gsm_band band);
60enum gsm_band gsm_band_parse(const char *mhz);
61
76int gsm_7bit_decode_n(char *decoded, size_t n, const uint8_t *user_data, uint8_t length);
77
83int gsm_7bit_decode_n_ussd(char *decoded, size_t n, const uint8_t *user_data, uint8_t length);
84
97int gsm_7bit_encode_n(uint8_t *result, size_t n, const char *data, int *octets_written);
98
104int gsm_7bit_encode_n_ussd(uint8_t *result, size_t n, const char *data, int *octets_written);
105
106/* the four functions below are helper functions and here for the unit test */
107int gsm_septets2octets(uint8_t *result, const uint8_t *rdata, uint8_t septet_len, uint8_t padding);
108int gsm_septet_encode(uint8_t *result, const char *data);
109uint8_t gsm_get_octet_len(const uint8_t sept_len);
110int gsm_7bit_decode_n_hdr(char *decoded, size_t n, const uint8_t *user_data, uint8_t length, uint8_t ud_hdr_ind);
111
112unsigned int ms_class_gmsk_dbm(enum gsm_band band, int ms_class);
113
114int ms_pwr_ctl_lvl(enum gsm_band band, unsigned int dbm);
115int ms_pwr_dbm(enum gsm_band band, uint8_t lvl);
116
117/* According to TS 05.08 Chapter 8.1.4 */
118int rxlev2dbm(uint8_t rxlev);
119uint8_t dbm2rxlev(int dbm);
120
121/* According to GSM 04.08 Chapter 10.5.1.6 */
122static inline int ms_cm2_a5n_support(uint8_t *cm2, unsigned n) {
123 switch (n) {
124 case 0: return 1;
125 case 1: return (cm2[0] & (1<<3)) ? 0 : 1;
126 case 2: return (cm2[2] & (1<<0)) ? 1 : 0;
127 case 3: return (cm2[2] & (1<<1)) ? 1 : 0;
128 default:
129 return 0;
130 }
131}
132
133/* According to GSM 04.08 Chapter 10.5.1.7 */
134static inline int ms_cm3_a5n_support(uint8_t *cm3, unsigned n) {
135 switch (n) {
136 case 4: return (cm3[0] & (1<<0)) ? 1 : 0;
137 case 5: return (cm3[0] & (1<<1)) ? 1 : 0;
138 case 6: return (cm3[0] & (1<<2)) ? 1 : 0;
139 case 7: return (cm3[0] & (1<<3)) ? 1 : 0;
140 default:
141 return 0;
142 }
143}
144
145/* According to GSM 04.08 Chapter 10.5.2.29 */
146static inline int rach_max_trans_val2raw(int val) { return (val >> 1) & 3; }
147static inline int rach_max_trans_raw2val(int raw) {
148 const int tbl[4] = { 1, 2, 4, 7 };
149 return tbl[raw & 3];
150}
151
152#define ARFCN_PCS 0x8000
153#define ARFCN_UPLINK 0x4000
154#define ARFCN_FLAG_MASK 0xf000 /* Reserve the upper 5 bits for flags */
155
156enum gsm_band gsm_arfcn2band(uint16_t arfcn);
157
158/* Convert an ARFCN to the frequency in MHz * 10 */
159uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink);
160
161/* Convert a Frequency in MHz * 10 to ARFCN */
162uint16_t gsm_freq102arfcn(uint16_t freq10, int uplink);
163
164/* Convert from frame number to GSM time */
165void gsm_fn2gsmtime(struct gsm_time *time, uint32_t fn);
166
167/* Convert from GSM time to frame number */
168uint32_t gsm_gsmtime2fn(struct gsm_time *time);
169
170/* GSM TS 03.03 Chapter 2.6 */
171enum gprs_tlli_type {
172 TLLI_LOCAL,
173 TLLI_FOREIGN,
174 TLLI_RANDOM,
175 TLLI_AUXILIARY,
176 TLLI_RESERVED,
177 TLLI_G_RNTI,
178 TLLI_RAND_G_RNTI,
179};
180
181/* TS 03.03 Chapter 2.6 */
182int gprs_tlli_type(uint32_t tlli);
183
184uint32_t gprs_tmsi2tlli(uint32_t p_tmsi, enum gprs_tlli_type type);
185
186/* Osmocom internal, not part of any gsm spec */
187enum gsm_phys_chan_config {
188 GSM_PCHAN_NONE,
189 GSM_PCHAN_CCCH,
190 GSM_PCHAN_CCCH_SDCCH4,
191 GSM_PCHAN_TCH_F,
192 GSM_PCHAN_TCH_H,
193 GSM_PCHAN_SDCCH8_SACCH8C,
194 GSM_PCHAN_PDCH, /* GPRS PDCH */
195 GSM_PCHAN_TCH_F_PDCH, /* TCH/F if used, PDCH otherwise */
196 GSM_PCHAN_UNKNOWN,
197 GSM_PCHAN_CCCH_SDCCH4_CBCH,
198 GSM_PCHAN_SDCCH8_SACCH8C_CBCH,
199 GSM_PCHAN_TCH_F_TCH_H_PDCH,
200 _GSM_PCHAN_MAX
201};
202
203/* Osmocom internal, not part of any gsm spec */
204enum gsm_chan_t {
205 GSM_LCHAN_NONE,
206 GSM_LCHAN_SDCCH,
207 GSM_LCHAN_TCH_F,
208 GSM_LCHAN_TCH_H,
209 GSM_LCHAN_UNKNOWN,
210 GSM_LCHAN_CCCH,
211 GSM_LCHAN_PDTCH,
212 GSM_LCHAN_CBCH,
213 _GSM_LCHAN_MAX
214};
215
216extern const struct value_string gsm_chan_t_names[];
217
218/* Deprectated functions */
219/* Limit encoding and decoding to use no more than this amount of buffer bytes */
220#define GSM_7BIT_LEGACY_MAX_BUFFER_SIZE 0x10000
221
222int gsm_7bit_decode(char *decoded, const uint8_t *user_data, uint8_t length) OSMO_DEPRECATED("Use gsm_7bit_decode_n() instead");
223int gsm_7bit_decode_ussd(char *decoded, const uint8_t *user_data, uint8_t length) OSMO_DEPRECATED("Use gsm_7bit_decode_n_ussd() instead");
224int gsm_7bit_encode(uint8_t *result, const char *data) OSMO_DEPRECATED("Use gsm_7bit_encode_n() instead");
225int gsm_7bit_encode_ussd(uint8_t *result, const char *data, int *octets_written) OSMO_DEPRECATED("Use gsm_7bit_encode_n_ussd() instead");
226int gsm_7bit_encode_oct(uint8_t *result, const char *data, int *octets_written) OSMO_DEPRECATED("Use gsm_7bit_encode_n() instead");
Definition gsm_utils.h:40