/*! \file gsm_utils.h
* GSM utility functions, e.g. coding and decoding. */
/*
* (C) 2008 by Daniel Willmann <daniel@totalueberwachung.de>
* (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* 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.
*
*/
#pragma once
#include <stddef.h>
#include <stdint.h>
#include <osmocom/core/defs.h>
#include <osmocom/core/utils.h>
#define ADD_MODULO(sum, delta, modulo) do { \
if ((sum += delta) >= modulo) \
sum -= modulo; \
} while (0)
#define GSM_MAX_FN (26*51*2048)
#define GSM_FN_UNSET 0xFFFFFFFF
/* Max length of random identifier which can be requested via osmo_get_rand_id() */
#define OSMO_MAX_RAND_ID_LEN 16
struct gsm_time {
uint32_t fn; /* FN count */
uint16_t t1; /* FN div (26*51) */
uint8_t t2; /* FN modulo 26 */
uint8_t t3; /* FN modulo 51 */
uint8_t tc;
};
enum gsm_band {
GSM_BAND_850 = 1,
GSM_BAND_900 = 2,
GSM_BAND_1800 = 4,
GSM_BAND_1900 = 8,
GSM_BAND_450 = 0x10,
GSM_BAND_480 = 0x20,
GSM_BAND_750 = 0x40,
GSM_BAND_810 = 0x80,
};
const char *gsm_band_name(enum gsm_band band);
enum gsm_band gsm_band_parse(const char *mhz);
int osmo_get_rand_id(uint8_t *out, size_t len);
/*!
* Decode a sequence of GSM 03.38 encoded 7 bit characters.
*
* \param decoded The destination buffer for the decoded characters.
* \param n A maximum of n chars is written (incl. terminating \0).
* Requires n >= 1.
* \param user_data A pointer to the start of the packed 7bit character
* sequence.
* \param length The length of the input sequence in septets, for
* example pass octet_length*8/7.
*
* \returns the number of (8 bit) chars written excluding the terminating \0.
* This is the same like strlen(decoded).
*/
int gsm_7bit_decode_n(char *decoded, size_t n, const uint8_t *user_data, uint8_t length);
/*!
* Decode a sequence of 7 bit characters (USSD encoding).
*
* \see gsm_7bit_encode_n()
*/
int gsm_7bit_decode_n_ussd(char *decoded, size_t n, const uint8_t *user_data, uint8_t length);
/*!
* Encode a text string into GSM 03.38 encoded 7 bit characters.
*
* \param result The destination buffer for the packed 7 bit sequence.
* \param n A maximum of n octets is written.
* \param data A pointer to the start of the \0 terminated 8 bit character
* string.
* \param octets_written Iff not NULL, *octets_written will be set to the
* number of octets written to the result buffer.
*
* \returns the number of septets that have been created.
*/
int gsm_7bit_encode_n(uint8_t *result, size_t n, const char *data, int *octets_written);
/*!
* Encode a text string into GSM 03.38 encoded 7 bit characters (USSD encoding).
*
* \see gsm_7bit_decode_n()
*/
int gsm_7bit_encode_n_ussd(uint8_t *result, size_t n, const char *data, int *octets_written);
/* the four functions below are helper functions and here for the unit test */
int gsm_septets2octets(uint8_t *result, const uint8_t *rdata, uint8_t septet_len, uint8_t padding)
OSMO_DEPRECATED("This function is unable to handle more than 255 septets, "
"use gsm_septet_pack() instead.");
int gsm_septet_pack(uint8_t *result, const uint8_t *rdata, size_t septet_len, uint8_t padding);
int gsm_septet_encode(uint8_t *result, const char *data);
uint8_t gsm_get_octet_len(const uint8_t sept_len);
int gsm_7bit_decode_n_hdr(char *decoded, size_t n, const uint8_t *user_data, uint8_t length, uint8_t ud_hdr_ind);
int ms_class_gmsk_dbm(enum gsm_band band, int ms_class);
int ms_pwr_ctl_lvl(enum gsm_band band, unsigned int dbm);
int ms_pwr_dbm(enum gsm_band band, uint8_t lvl);
/* According to TS 05.08 Chapter 8.1.4 */
int rxlev2dbm(uint8_t rxlev);
uint8_t dbm2rxlev(int dbm);
/* According to GSM 04.08 Chapter 10.5.1.6 */
static inline int ms_cm2_a5n_support(uint8_t *cm2, unsigned n) {
switch (n) {
case 0: return 1;
case 1: return (cm2[0] & (1<<3)) ? 0 : 1;
case 2: return (cm2[2] & (1<<0)) ? 1 : 0;
case 3: return (cm2[2] & (1<<1)) ? 1 : 0;
default:
return 0;
}
}
/* According to GSM 04.08 Chapter 10.5.1.7 */
static inline int ms_cm3_a5n_support(uint8_t *cm3, unsigned n) {
switch (n) {
case 4: return (cm3[0] & (1<<0)) ? 1 : 0;
case 5: return (cm3[0] & (1<<1)) ? 1 : 0;
case 6: return (cm3[0] & (1<<2)) ? 1 : 0;
case 7: return (cm3[0] & (1<<3)) ? 1 : 0;
default:
return 0;
}
}
/* According to GSM 04.08 Chapter 10.5.2.29 */
static inline int rach_max_trans_val2raw(int val) { return (val >> 1) & 3; }
static inline int rach_max_trans_raw2val(int raw) {
const int tbl[4] = { 1, 2, 4, 7 };
return tbl[raw & 3];
}
static inline uint8_t rach_tx_integer_raw2val(uint8_t raw) {
const int tbl[6] = { 14, 16, 20, 25, 32, 50 };
raw &= 0x0f;
if (raw <= 9)
return raw + 3;
return tbl[raw - 10];
}
#define ARFCN_PCS 0x8000
#define ARFCN_UPLINK 0x4000
#define ARFCN_FLAG_MASK 0xf000 /* Reserve the upper 5 bits for flags */
int gsm_arfcn2band_rc(uint16_t arfcn, enum gsm_band *band);
enum gsm_band gsm_arfcn2band(uint16_t arfcn) OSMO_DEPRECATED("Use gsm_arfcn2band_rc() instead");
/* Convert an ARFCN to the frequency in MHz * 10 */
uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink);
/* Convert a Frequency in MHz * 10 to ARFCN */
uint16_t gsm_freq102arfcn(uint16_t freq10, int uplink);
/* Convert from frame number to GSM time */
void gsm_fn2gsmtime(struct gsm_time *time, uint32_t fn);
/* Parse GSM Frame Number into printable string */
char *gsm_fn_as_gsmtime_str(uint32_t fn);
/* Convert from GSM time to frame number */
uint32_t gsm_gsmtime2fn(const struct gsm_time *time);
/* Returns static buffer with string representation of a GSM Time */
char *osmo_dump_gsmtime(const struct gsm_time *tm);
char *osmo_dump_gsmtime_buf(char *buf, size_t buf_len, const struct gsm_time *tm);
char *osmo_dump_gsmtime_c(const void *ctx, const struct gsm_time *tm);
/* Reduced Frame Number (3GPP TS 44.018 §10.5.2.38) */
#define GSM_RFN_MODULUS 42432
uint32_t gsm_rfn2fn(uint16_t rfn, uint32_t curr_fn);
static inline uint16_t gsm_fn2rfn(uint32_t fn)
{
return fn % GSM_RFN_MODULUS;
}
/* GSM TS 03.03 Chapter 2.6 */
enum gprs_tlli_type {
TLLI_LOCAL,
TLLI_FOREIGN,
TLLI_RANDOM,
TLLI_AUXILIARY,
TLLI_RESERVED,
TLLI_G_RNTI,
TLLI_RAND_G_RNTI,
};
/* TS 03.03 Chapter 2.6 */
int gprs_tlli_type(uint32_t tlli);
uint32_t gprs_tmsi2tlli(uint32_t p_tmsi, enum gprs_tlli_type type);
uint32_t gprs_tlli2tmsi(uint32_t tlli);
/* Osmocom internal, not part of any gsm spec */
enum gsm_phys_chan_config {
GSM_PCHAN_NONE,
GSM_PCHAN_CCCH,
GSM_PCHAN_CCCH_SDCCH4,
GSM_PCHAN_TCH_F,
GSM_PCHAN_TCH_H,
GSM_PCHAN_SDCCH8_SACCH8C,
GSM_PCHAN_PDCH, /* GPRS PDCH */
GSM_PCHAN_TCH_F_PDCH, /* TCH/F if used, PDCH otherwise */
GSM_PCHAN_UNKNOWN,
GSM_PCHAN_CCCH_SDCCH4_CBCH,
GSM_PCHAN_SDCCH8_SACCH8C_CBCH,
GSM_PCHAN_OSMO_DYN,
_GSM_PCHAN_MAX
};
/* Backward compatibility with older naming: */
#define GSM_PCHAN_TCH_F_TCH_H_PDCH GSM_PCHAN_OSMO_DYN
/* Osmocom internal, not part of any gsm spec */
enum gsm_chan_t {
GSM_LCHAN_NONE,
GSM_LCHAN_SDCCH,
GSM_LCHAN_TCH_F,
GSM_LCHAN_TCH_H,
GSM_LCHAN_UNKNOWN,
GSM_LCHAN_CCCH,
GSM_LCHAN_PDTCH,
GSM_LCHAN_CBCH,
_GSM_LCHAN_MAX
};
extern const struct value_string gsm_chan_t_names[];
static inline const char *gsm_chan_t_name(enum gsm_chan_t val)
{ return get_value_string(gsm_chan_t_names, val); }
/* Deprectated functions */
/* Limit encoding and decoding to use no more than this amount of buffer bytes */
#define GSM_7BIT_LEGACY_MAX_BUFFER_SIZE 0x10000
int gsm_7bit_decode(char *decoded, const uint8_t *user_data, uint8_t length) OSMO_DEPRECATED("Use gsm_7bit_decode_n() instead");
int gsm_7bit_decode_ussd(char *decoded, const uint8_t *user_data, uint8_t length) OSMO_DEPRECATED("Use gsm_7bit_decode_n_ussd() instead");
int gsm_7bit_encode(uint8_t *result, const char *data) OSMO_DEPRECATED("Use gsm_7bit_encode_n() instead");
int gsm_7bit_encode_ussd(uint8_t *result, const char *data, int *octets_written) OSMO_DEPRECATED("Use gsm_7bit_encode_n_ussd() instead");
int gsm_7bit_encode_oct(uint8_t *result, const char *data, int *octets_written) OSMO_DEPRECATED("Use gsm_7bit_encode_n() instead");
enum osmo_rat_type {
OSMO_RAT_UNKNOWN = 0,
OSMO_RAT_GERAN_A,
OSMO_RAT_UTRAN_IU,
OSMO_RAT_EUTRAN_SGS,
/* keep this last */
OSMO_RAT_COUNT
};
extern const struct value_string osmo_rat_type_names[];
inline static const char *osmo_rat_type_name(enum osmo_rat_type val)
{ return get_value_string(osmo_rat_type_names, val); }