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libosmocore/src/gsm/gsm_utils.c

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/*! \file gsm_utils.c */
/*
* (C) 2008 by Daniel Willmann <daniel@totalueberwachung.de>
* (C) 2009,2013 by Holger Hans Peter Freyther <zecke@selfish.org>
* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
* (C) 2010-2012 by Nico Golde <nico@ngolde.de>
*
* 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.
*
*/
/*! \mainpage libosmogsm Documentation
*
* \section sec_intro Introduction
* This library is a collection of common code used in various
* GSM related sub-projects inside the Osmocom family of projects. It
* includes A5/1 and A5/2 ciphers, COMP128v1, a LAPDm implementation,
* a GSM TLV parser, SMS utility routines as well as
* protocol definitions for a series of protocols:
* * Um L2 (04.06)
* * Um L3 (04.08)
* * A-bis RSL (08.58)
* * A-bis OML (08.59, 12.21)
* * A (08.08)
* \n\n
* Please note that C language projects inside Osmocom are typically
* single-threaded event-loop state machine designs. As such,
* routines in libosmogsm are not thread-safe. If you must use them in
* a multi-threaded context, you have to add your own locking.
*
* libosmogsm is developed as part of the Osmocom (Open Source Mobile
* Communications) project, a community-based, collaborative development
* project to create Free and Open Source implementations of mobile
* communications systems. For more information about Osmocom, please
* see https://osmocom.org/
*
* \section sec_copyright Copyright and License
* Copyright © 2008-2011 - Harald Welte, Holger Freyther and contributors\n
* All rights reserved. \n\n
* The source code of libosmogsm is licensed 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.\n
* See <http://www.gnu.org/licenses/> or COPYING included in the source
* code package istelf.\n
* The information detailed here is provided AS IS with NO WARRANTY OF
* ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE.
* \n\n
*
* \section sec_tracker Homepage + Issue Tracker
* libosmogsm is distributed as part of libosmocore and shares its
* project page at http://osmocom.org/projects/libosmocore
*
* An Issue Tracker can be found at
* https://osmocom.org/projects/libosmocore/issues
*
* \section sec_contact Contact and Support
* Community-based support is available at the OpenBSC mailing list
* <http://lists.osmocom.org/mailman/listinfo/openbsc>\n
* Commercial support options available upon request from
* <http://sysmocom.de/>
*/
//#include <openbsc/gsm_data.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/bitvec.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/gsm/meas_rep.h>
#include <osmocom/gsm/protocol/gsm_04_08.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <inttypes.h>
#include <time.h>
#include <unistd.h>
#include "../../config.h"
/* FIXME: this can be removed once we bump glibc requirements to 2.25: */
#if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25)
#include <sys/random.h>
#elif HAVE_DECL_SYS_GETRANDOM
#include <sys/syscall.h>
#ifndef GRND_NONBLOCK
#define GRND_NONBLOCK 0x0001
#endif
#endif
#if (USE_GNUTLS)
#pragma message ("including GnuTLS for getrandom fallback.")
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
/* gnutls < 3.3.0 requires global init.
* gnutls >= 3.3.0 does it automatic.
* It doesn't hurt calling it twice,
* as long it's not done at the same time (threads).
*/
__attribute__((constructor))
static void on_dso_load_gnutls(void)
{
if (!gnutls_check_version("3.3.0"))
gnutls_global_init();
}
__attribute__((destructor))
static void on_dso_unload_gnutls(void)
{
if (!gnutls_check_version("3.3.0"))
gnutls_global_deinit();
}
#endif
/* ETSI GSM 03.38 6.2.1 and 6.2.1.1 default alphabet
* Greek symbols at hex positions 0x10 and 0x12-0x1a
* left out as they can't be handled with a char and
* since most phones don't display or write these
* characters this would only needlessly make the code
* more complex.
*
* Note that this table contains the latin1->7bit mapping _and_ has
* been merged with the reverse mapping (7bit->latin1) for the
* extended characters at offset 0x7f.
*/
static unsigned char gsm_7bit_alphabet[] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0a, 0xff, 0xff, 0x0d, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0x20, 0x21, 0x22, 0x23, 0x02, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c,
0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
0x3c, 0x3d, 0x3e, 0x3f, 0x00, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x3c, 0x2f, 0x3e, 0x14, 0x11, 0xff, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
0x78, 0x79, 0x7a, 0x28, 0x40, 0x29, 0x3d, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0x0c, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5e, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x40, 0xff, 0x01, 0xff,
0x03, 0xff, 0x7b, 0x7d, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5c, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5b, 0x7e, 0x5d, 0xff, 0x7c, 0xff, 0xff, 0xff,
0xff, 0x5b, 0x0e, 0x1c, 0x09, 0xff, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5d,
0xff, 0xff, 0xff, 0xff, 0x5c, 0xff, 0x0b, 0xff, 0xff, 0xff, 0x5e, 0xff, 0xff, 0x1e, 0x7f,
0xff, 0xff, 0xff, 0x7b, 0x0f, 0x1d, 0xff, 0x04, 0x05, 0xff, 0xff, 0x07, 0xff, 0xff, 0xff,
0xff, 0x7d, 0x08, 0xff, 0xff, 0xff, 0x7c, 0xff, 0x0c, 0x06, 0xff, 0xff, 0x7e, 0xff, 0xff
};
/* GSM 03.38 6.2.1 Character lookup for decoding */
static int gsm_septet_lookup(uint8_t ch)
{
int i = 0;
for (; i < sizeof(gsm_7bit_alphabet); i++) {
if (gsm_7bit_alphabet[i] == ch)
return i;
}
return -1;
}
/*! \brife Compute number of octets from number of septets,
* for instance: 47 septets needs 41,125 = 42 octets
* \param[in sept_len Number of Septets
* \returns Number of octets required */
uint8_t gsm_get_octet_len(const uint8_t sept_len){
int octet_len = (sept_len * 7) / 8;
if ((sept_len * 7) % 8 != 0)
octet_len++;
return octet_len;
}
/*! TS 03.38 7-bit Character unpacking (6.2.1)
* \param[out] text Caller-provided output text buffer
* \param[in] n Length of \a text
* \param[in] user_data Input Data (septets)
* \param[in] septet_l Number of septets in \a user_data
* \param[in] ud_hdr_ind User Data Header present in data
* \returns number of bytes written to \a text */
int gsm_7bit_decode_n_hdr(char *text, size_t n, const uint8_t *user_data, uint8_t septet_l, uint8_t ud_hdr_ind)
{
unsigned shift = 0;
uint8_t c7, c8, next_is_ext = 0, lu, ru;
const uint8_t maxlen = gsm_get_octet_len(septet_l);
const char *text_buf_begin = text;
const char *text_buf_end = text + n;
OSMO_ASSERT (n > 0);
/* skip the user data header */
if (ud_hdr_ind) {
/* get user data header length + 1 (for the 'user data header length'-field) */
shift = ((user_data[0] + 1) * 8) / 7;
if ((((user_data[0] + 1) * 8) % 7) != 0)
shift++;
septet_l = septet_l - shift;
}
unsigned i, l, r;
for (i = 0; i < septet_l && text != text_buf_end - 1; i++) {
l = ((i + shift) * 7 + 7) >> 3;
r = ((i + shift) * 7) >> 3;
/* the left side index is always >= right side index
sometimes it even gets beyond array boundary
check for that explicitly and force 0 instead
*/
if (l >= maxlen)
lu = 0;
else
lu = user_data[l] << (7 - (((i + shift) * 7 + 7) & 7));
ru = user_data[r] >> (((i + shift) * 7) & 7);
c7 = (lu | ru) & 0x7f;
if (next_is_ext) {
/* this is an extension character */
next_is_ext = 0;
c8 = gsm_7bit_alphabet[0x7f + c7];
} else if (c7 == 0x1b && i + 1 < septet_l) {
next_is_ext = 1;
continue;
} else {
c8 = gsm_septet_lookup(c7);
}
*(text++) = c8;
}
*text = '\0';
return text - text_buf_begin;
}
/*! Decode 7bit GSM Alphabet */
int gsm_7bit_decode_n(char *text, size_t n, const uint8_t *user_data, uint8_t septet_l)
{
return gsm_7bit_decode_n_hdr(text, n, user_data, septet_l, 0);
}
/*! Decode 7bit GSM Alphabet (USSD) */
int gsm_7bit_decode_n_ussd(char *text, size_t n, const uint8_t *user_data, uint8_t length)
{
int nchars;
nchars = gsm_7bit_decode_n_hdr(text, n, user_data, length, 0);
/* remove last <CR>, if it fits up to the end of last octet */
if (nchars && (user_data[gsm_get_octet_len(length) - 1] >> 1) == '\r')
text[--nchars] = '\0';
return nchars;
}
/*! Encode a ASCII characterrs as 7-bit GSM alphabet (TS 03.38)
*
* This function converts a zero-terminated input string \a data from
* ASCII into octet-aligned 7-bit GSM characters. No packing is
* performed.
*
* \param[out] result caller-allocated output buffer
* \param[in] data input data, ASCII
* \returns number of octets used in \a result */
int gsm_septet_encode(uint8_t *result, const char *data)
{
int i, y = 0;
uint8_t ch;
for (i = 0; i < strlen(data); i++) {
ch = data[i];
switch(ch){
/* fall-through for extension characters */
case 0x0c:
case 0x5e:
case 0x7b:
case 0x7d:
case 0x5c:
case 0x5b:
case 0x7e:
case 0x5d:
case 0x7c:
result[y++] = 0x1b;
default:
result[y] = gsm_7bit_alphabet[ch];
break;
}
y++;
}
return y;
}
/*! GSM Default Alphabet 7bit to octet packing
* \param[out] result Caller-provided output buffer
* \param[in] rdata Input data septets
* \param[in] septet_len Length of \a rdata
* \param[in] padding padding bits at start
* \returns number of bytes used in \a result */
int gsm_septets2octets(uint8_t *result, const uint8_t *rdata, uint8_t septet_len, uint8_t padding)
{
int i = 0, z = 0;
uint8_t cb, nb;
int shift = 0;
uint8_t *data = calloc(septet_len + 1, sizeof(uint8_t));
if (padding) {
shift = 7 - padding;
/* the first zero is needed for padding */
memcpy(data + 1, rdata, septet_len);
septet_len++;
} else
memcpy(data, rdata, septet_len);
for (i = 0; i < septet_len; i++) {
if (shift == 7) {
/*
* special end case with the. This is necessary if the
* last septet fits into the previous octet. E.g. 48
* non-extension characters:
* ....ag ( a = 1100001, g = 1100111)
* result[40] = 100001 XX, result[41] = 1100111 1 */
if (i + 1 < septet_len) {
shift = 0;
continue;
} else if (i + 1 == septet_len)
break;
}
cb = (data[i] & 0x7f) >> shift;
if (i + 1 < septet_len) {
nb = (data[i + 1] & 0x7f) << (7 - shift);
cb = cb | nb;
}
result[z++] = cb;
shift++;
}
free(data);
return z;
}
/*! GSM 7-bit alphabet TS 03.38 6.2.1 Character packing
* \param[out] result Caller-provided output buffer
* \param[in] n Maximum length of \a result in bytes
* \param[in] data octet-aligned string
* \param[out] octets Number of octets encoded
* \returns number of septets encoded */
int gsm_7bit_encode_n(uint8_t *result, size_t n, const char *data, int *octets)
{
int y = 0;
int o;
size_t max_septets = n * 8 / 7;
/* prepare for the worst case, every character expanding to two bytes */
uint8_t *rdata = calloc(strlen(data) * 2, sizeof(uint8_t));
y = gsm_septet_encode(rdata, data);
if (y > max_septets) {
/*
* Limit the number of septets to avoid the generation
* of more than n octets.
*/
y = max_septets;
}
o = gsm_septets2octets(result, rdata, y, 0);
if (octets)
*octets = o;
free(rdata);
/*
* We don't care about the number of octets, because they are not
* unique. E.g.:
* 1.) 46 non-extension characters + 1 extension character
* => (46 * 7 bit + (1 * (2 * 7 bit))) / 8 bit = 42 octets
* 2.) 47 non-extension characters
* => (47 * 7 bit) / 8 bit = 41,125 = 42 octets
* 3.) 48 non-extension characters
* => (48 * 7 bit) / 8 bit = 42 octects
*/
return y;
}
/*! Encode according to GSM 7-bit alphabet (TS 03.38 6.2.1) for USSD
* \param[out] result Caller-provided output buffer
* \param[in] n Maximum length of \a result in bytes
* \param[in] data octet-aligned string
* \param[out] octets Number of octets encoded
* \returns number of septets encoded */
int gsm_7bit_encode_n_ussd(uint8_t *result, size_t n, const char *data, int *octets)
{
int y;
y = gsm_7bit_encode_n(result, n, data, octets);
/* if last octet contains only one bit, add <CR> */
if (((y * 7) & 7) == 1)
result[(*octets) - 1] |= ('\r' << 1);
/* if last character is <CR> and completely fills last octet, add
* another <CR>. */
if (y && ((y * 7) & 7) == 0 && (result[(*octets) - 1] >> 1) == '\r' && *octets < n - 1) {
result[(*octets)++] = '\r';
y++;
}
return y;
}
/*! Generate random identifier
* We use /dev/urandom (default when GRND_RANDOM flag is not set).
* Both /dev/(u)random numbers are coming from the same CSPRNG anyway (at least on GNU/Linux >= 4.8).
* See also RFC4086.
* \param[out] out Buffer to be filled with random data
* \param[in] len Number of random bytes required
* \returns 0 on success, or a negative error code on error.
*/
int osmo_get_rand_id(uint8_t *out, size_t len)
{
int rc = -ENOTSUP;
/* this function is intended for generating short identifiers only, not arbitrary-length random data */
if (len > OSMO_MAX_RAND_ID_LEN)
return -E2BIG;
#if defined(__GLIBC__) && (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 25)
rc = getrandom(out, len, GRND_NONBLOCK);
#elif HAVE_DECL_SYS_GETRANDOM
#pragma message ("Using direct syscall access for getrandom(): consider upgrading to glibc >= 2.25")
/* FIXME: this can be removed once we bump glibc requirements to 2.25: */
rc = syscall(SYS_getrandom, out, len, GRND_NONBLOCK);
#endif
/* getrandom() failed entirely: */
if (rc < 0) {
#if (USE_GNUTLS)
#pragma message ("Secure random failed: using GnuTLS fallback.")
return gnutls_rnd(GNUTLS_RND_RANDOM, out, len);
#endif
return -errno;
}
/* getrandom() failed partially due to signal interruption:
this should never happen (according to getrandom(2)) as long as OSMO_MAX_RAND_ID_LEN < 256
because we do not set GRND_RANDOM but it's better to be paranoid and check anyway */
if (rc != len)
return -EAGAIN;
return 0;
}
/*! Build the RSL uplink measurement IE (3GPP TS 08.58 § 9.3.25)
* \param[in] mru Unidirectional measurement report structure
* \param[in] dtxd_used Indicates if DTXd was used during measurement report
* period
* \param[out] buf Pre-allocated bufer for storing IE
* \returns Number of bytes filled in buf
*/
size_t gsm0858_rsl_ul_meas_enc(struct gsm_meas_rep_unidir *mru, bool dtxd_used,
uint8_t *buf)
{
buf[0] = dtxd_used ? (1 << 6) : 0;
buf[0] |= (mru->full.rx_lev & 0x3f);
buf[1] = (mru->sub.rx_lev & 0x3f);
buf[2] = ((mru->full.rx_qual & 7) << 3) | (mru->sub.rx_qual & 7);
return 3;
}
/*! Convert power class to dBm according to GSM TS 05.05
* \param[in] band GSM frequency band
* \param[in] class GSM power class
* \returns maximum transmit power of power class in dBm */
unsigned int ms_class_gmsk_dbm(enum gsm_band band, int class)
{
switch (band) {
case GSM_BAND_450:
case GSM_BAND_480:
case GSM_BAND_750:
case GSM_BAND_900:
case GSM_BAND_810:
case GSM_BAND_850:
if (class == 1)
return 43; /* 20W */
if (class == 2)
return 39; /* 8W */
if (class == 3)
return 37; /* 5W */
if (class == 4)
return 33; /* 2W */
if (class == 5)
return 29; /* 0.8W */
break;
case GSM_BAND_1800:
if (class == 1)
return 30; /* 1W */
if (class == 2)
return 24; /* 0.25W */
if (class == 3)
return 36; /* 4W */
break;
case GSM_BAND_1900:
if (class == 1)
return 30; /* 1W */
if (class == 2)
return 24; /* 0.25W */
if (class == 3)
return 33; /* 2W */
break;
}
return -EINVAL;
}
/*! determine power control level for given dBm value, as indicated
* by the tables in chapter 4.1.1 of GSM TS 05.05
* \param[in] GSM frequency band
* \param[in] dbm RF power value in dBm
* \returns TS 05.05 power control level */
int ms_pwr_ctl_lvl(enum gsm_band band, unsigned int dbm)
{
switch (band) {
case GSM_BAND_450:
case GSM_BAND_480:
case GSM_BAND_750:
case GSM_BAND_900:
case GSM_BAND_810:
case GSM_BAND_850:
if (dbm >= 39)
return 0;
else if (dbm < 5)
return 19;
else {
/* we are guaranteed to have (5 <= dbm < 39) */
return 2 + ((39 - dbm) / 2);
}
break;
case GSM_BAND_1800:
if (dbm >= 36)
return 29;
else if (dbm >= 34)
return 30;
else if (dbm >= 32)
return 31;
else if (dbm == 31)
return 0;
else {
/* we are guaranteed to have (0 <= dbm < 31) */
return (30 - dbm) / 2;
}
break;
case GSM_BAND_1900:
if (dbm >= 33)
return 30;
else if (dbm >= 32)
return 31;
else if (dbm == 31)
return 0;
else {
/* we are guaranteed to have (0 <= dbm < 31) */
return (30 - dbm) / 2;
}
break;
}
return -EINVAL;
}
/*! Convert TS 05.05 power level to absolute dBm value
* \param[in] band GSM frequency band
* \param[in] lvl TS 05.05 power control level
* \returns RF power level in dBm */
int ms_pwr_dbm(enum gsm_band band, uint8_t lvl)
{
lvl &= 0x1f;
switch (band) {
case GSM_BAND_450:
case GSM_BAND_480:
case GSM_BAND_750:
case GSM_BAND_900:
case GSM_BAND_810:
case GSM_BAND_850:
if (lvl < 2)
return 39;
else if (lvl < 20)
return 39 - ((lvl - 2) * 2) ;
else
return 5;
break;
case GSM_BAND_1800:
if (lvl < 16)
return 30 - (lvl * 2);
else if (lvl < 29)
return 0;
else
return 36 - ((lvl - 29) * 2);
break;
case GSM_BAND_1900:
if (lvl < 16)
return 30 - (lvl * 2);
else if (lvl < 30)
return -EINVAL;
else
return 33 - (lvl - 30);
break;
}
return -EINVAL;
}
/*! Convert TS 05.08 RxLev to dBm (TS 05.08 Chapter 8.1.4)
* \param[in] rxlev TS 05.08 RxLev value
* \returns Received RF power in dBm */
int rxlev2dbm(uint8_t rxlev)
{
if (rxlev > 63)
rxlev = 63;
return -110 + rxlev;
}
/*! Convert RF signal level in dBm to TS 05.08 RxLev (TS 05.08 Chapter 8.1.4)
* \param[in] dbm RF signal level in dBm
* \returns TS 05.08 RxLev value */
uint8_t dbm2rxlev(int dbm)
{
int rxlev = dbm + 110;
if (rxlev > 63)
rxlev = 63;
else if (rxlev < 0)
rxlev = 0;
return rxlev;
}
/*! Return string name of a given GSM Band */
const char *gsm_band_name(enum gsm_band band)
{
switch (band) {
case GSM_BAND_450:
return "GSM450";
case GSM_BAND_480:
return "GSM480";
case GSM_BAND_750:
return "GSM750";
case GSM_BAND_810:
return "GSM810";
case GSM_BAND_850:
return "GSM850";
case GSM_BAND_900:
return "GSM900";
case GSM_BAND_1800:
return "DCS1800";
case GSM_BAND_1900:
return "PCS1900";
}
return "invalid";
}
/*! Parse string name of a GSM band */
enum gsm_band gsm_band_parse(const char* mhz)
{
while (*mhz && !isdigit((unsigned char)*mhz))
mhz++;
if (*mhz == '\0')
return -EINVAL;
switch (strtol(mhz, NULL, 10)) {
case 450:
return GSM_BAND_450;
case 480:
return GSM_BAND_480;
case 750:
return GSM_BAND_750;
case 810:
return GSM_BAND_810;
case 850:
return GSM_BAND_850;
case 900:
return GSM_BAND_900;
case 1800:
return GSM_BAND_1800;
case 1900:
return GSM_BAND_1900;
default:
return -EINVAL;
}
}
/*! Resolve GSM band from ARFCN.
* In Osmocom, we use the highest bit of the \a arfcn to indicate PCS
* \param[in] arfcn Osmocom ARFCN, highest bit determines PCS mode
* \param[out] band GSM Band containing \arfcn if arfcn is valid, undetermined otherwise
* \returns 0 if arfcn is valid and \a band was set, negative on error */
int gsm_arfcn2band_rc(uint16_t arfcn, enum gsm_band *band)
{
int is_pcs = arfcn & ARFCN_PCS;
arfcn &= ~ARFCN_FLAG_MASK;
if (is_pcs) {
*band = GSM_BAND_1900;
return 0;
} else if (arfcn <= 124) {
*band = GSM_BAND_900;
return 0;
} else if (arfcn >= 955 && arfcn <= 1023) {
*band = GSM_BAND_900;
return 0;
} else if (arfcn >= 128 && arfcn <= 251) {
*band = GSM_BAND_850;
return 0;
} else if (arfcn >= 512 && arfcn <= 885) {
*band = GSM_BAND_1800;
return 0;
} else if (arfcn >= 259 && arfcn <= 293) {
*band = GSM_BAND_450;
return 0;
} else if (arfcn >= 306 && arfcn <= 340) {
*band = GSM_BAND_480;
return 0;
} else if (arfcn >= 350 && arfcn <= 425) {
*band = GSM_BAND_810;
return 0;
} else if (arfcn >= 438 && arfcn <= 511) {
*band = GSM_BAND_750;
return 0;
}
return -1;
}
/*! Resolve GSM band from ARFCN, aborts process on invalid ARFCN.
* In Osmocom, we use the highest bit of the \a arfcn to indicate PCS.
* DEPRECATED: Use gsm_arfcn2band_rc instead.
* \param[in] arfcn Osmocom ARFCN, highest bit determines PCS mode
* \returns GSM Band if ARFCN is valid (part of any valid band), aborts otherwise */
enum gsm_band gsm_arfcn2band(uint16_t arfcn)
{
enum gsm_band band;
if (gsm_arfcn2band_rc(arfcn, &band) == 0)
return band;
osmo_panic("%s:%d Invalid arfcn %" PRIu16 " passed to gsm_arfcn2band\n",
__FILE__, __LINE__, arfcn);
}
struct gsm_freq_range {
uint16_t arfcn_first;
uint16_t arfcn_last;
uint16_t freq_ul_first;
uint16_t freq_dl_offset;
uint16_t flags;
};
static struct gsm_freq_range gsm_ranges[] = {
{ 512, 810, 18502, 800, ARFCN_PCS }, /* PCS 1900 */
{ 0, 124, 8900, 450, 0 }, /* P-GSM + E-GSM ARFCN 0 */
{ 955, 1023, 8762, 450, 0 }, /* E-GSM + R-GSM */
{ 128, 251, 8242, 450, 0 }, /* GSM 850 */
{ 512, 885, 17102, 950, 0 }, /* DCS 1800 */
{ 259, 293, 4506, 100, 0 }, /* GSM 450 */
{ 306, 340, 4790, 100, 0 }, /* GSM 480 */
{ 350, 425, 8060, 450, 0 }, /* GSM 810 */
{ 438, 511, 7472, 300, 0 }, /* GSM 750 */
{ /* Guard */ }
};
/*! Convert an ARFCN to the frequency in MHz * 10
* \param[in] arfcn GSM ARFCN to convert
* \param[in] uplink Uplink (1) or Downlink (0) frequency
* \returns Frequency in units of 1/10ths of MHz (100kHz) */
uint16_t gsm_arfcn2freq10(uint16_t arfcn, int uplink)
{
struct gsm_freq_range *r;
uint16_t flags = arfcn & ARFCN_FLAG_MASK;
uint16_t freq10_ul = 0xffff;
uint16_t freq10_dl = 0xffff;
arfcn &= ~ARFCN_FLAG_MASK;
for (r=gsm_ranges; r->freq_ul_first>0; r++) {
if ((flags == r->flags) &&
(arfcn >= r->arfcn_first) &&
(arfcn <= r->arfcn_last))
{
freq10_ul = r->freq_ul_first + 2 * (arfcn - r->arfcn_first);
freq10_dl = freq10_ul + r->freq_dl_offset;
break;
}
}
return uplink ? freq10_ul : freq10_dl;
}
/*! Convert a Frequency in MHz * 10 to ARFCN
* \param[in] freq10 Frequency in units of 1/10ths of MHz (100kHz)
* \param[in] uplink Frequency is Uplink (1) or Downlink (0)
* \returns ARFCN in case of success; 0xffff on error */
uint16_t gsm_freq102arfcn(uint16_t freq10, int uplink)
{
struct gsm_freq_range *r;
uint16_t freq10_lo, freq10_hi;
uint16_t arfcn = 0xffff;
for (r=gsm_ranges; r->freq_ul_first>0; r++) {
/* Generate frequency limits */
freq10_lo = r->freq_ul_first;
freq10_hi = freq10_lo + 2 * (r->arfcn_last - r->arfcn_first);
if (!uplink) {
freq10_lo += r->freq_dl_offset;
freq10_hi += r->freq_dl_offset;
}
/* Check if this fits */
if (freq10 >= freq10_lo && freq10 <= freq10_hi) {
arfcn = r->arfcn_first + ((freq10 - freq10_lo) >> 1);
arfcn |= r->flags;
break;
}
}
if (uplink)
arfcn |= ARFCN_UPLINK;
return arfcn;
}
/*! Parse GSM Frame Number into struct \ref gsm_time
* \param[out] time Caller-provided memory for \ref gsm_time
* \param[in] fn GSM Frame Number */
void gsm_fn2gsmtime(struct gsm_time *time, uint32_t fn)
{
time->fn = fn;
time->t1 = time->fn / (26*51);
time->t2 = time->fn % 26;
time->t3 = time->fn % 51;
time->tc = (time->fn / 51) % 8;
}
/*! Parse GSM Frame Number into printable string
* \param[in] fn GSM Frame Number
* \returns pointer to printable string */
char *gsm_fn_as_gsmtime_str(uint32_t fn)
{
struct gsm_time time;
gsm_fn2gsmtime(&time, fn);
return osmo_dump_gsmtime(&time);
}
/*! Encode decoded \ref gsm_time to Frame Number
* \param[in] time GSM Time in decoded structure
* \returns GSM Frame Number */
uint32_t gsm_gsmtime2fn(struct gsm_time *time)
{
/* TS 05.02 Chapter 4.3.3 TDMA frame number */
return (51 * ((time->t3 - time->t2 + 26) % 26) + time->t3 + (26 * 51 * time->t1));
}
char *osmo_dump_gsmtime(const struct gsm_time *tm)
{
static char buf[64];
snprintf(buf, sizeof(buf), "%06"PRIu32"/%02"PRIu16"/%02"PRIu8"/%02"PRIu8"/%02"PRIu8,
tm->fn, tm->t1, tm->t2, tm->t3, (uint8_t)tm->fn%52);
buf[sizeof(buf)-1] = '\0';
return buf;
}
/*! append range1024 encoded data to bit vector
* \param[out] bv Caller-provided output bit-vector
* \param[in] r Input Range1024 sructure */
void bitvec_add_range1024(struct bitvec *bv, const struct gsm48_range_1024 *r)
{
bitvec_set_uint(bv, r->w1_hi, 2);
bitvec_set_uint(bv, r->w1_lo, 8);
bitvec_set_uint(bv, r->w2_hi, 8);
bitvec_set_uint(bv, r->w2_lo, 1);
bitvec_set_uint(bv, r->w3_hi, 7);
bitvec_set_uint(bv, r->w3_lo, 2);
bitvec_set_uint(bv, r->w4_hi, 6);
bitvec_set_uint(bv, r->w4_lo, 2);
bitvec_set_uint(bv, r->w5_hi, 6);
bitvec_set_uint(bv, r->w5_lo, 2);
bitvec_set_uint(bv, r->w6_hi, 6);
bitvec_set_uint(bv, r->w6_lo, 2);
bitvec_set_uint(bv, r->w7_hi, 6);
bitvec_set_uint(bv, r->w7_lo, 2);
bitvec_set_uint(bv, r->w8_hi, 6);
bitvec_set_uint(bv, r->w8_lo, 1);
bitvec_set_uint(bv, r->w9, 7);
bitvec_set_uint(bv, r->w10, 7);
bitvec_set_uint(bv, r->w11_hi, 1);
bitvec_set_uint(bv, r->w11_lo, 6);
bitvec_set_uint(bv, r->w12_hi, 2);
bitvec_set_uint(bv, r->w12_lo, 5);
bitvec_set_uint(bv, r->w13_hi, 3);
bitvec_set_uint(bv, r->w13_lo, 4);
bitvec_set_uint(bv, r->w14_hi, 4);
bitvec_set_uint(bv, r->w14_lo, 3);
bitvec_set_uint(bv, r->w15_hi, 5);
bitvec_set_uint(bv, r->w15_lo, 2);
bitvec_set_uint(bv, r->w16, 6);
}
/*! Determine GPRS TLLI Type (TS 23.003 Chapter 2.6) */
int gprs_tlli_type(uint32_t tlli)
{
if ((tlli & 0xc0000000) == 0xc0000000)
return TLLI_LOCAL;
else if ((tlli & 0xc0000000) == 0x80000000)
return TLLI_FOREIGN;
else if ((tlli & 0xf8000000) == 0x78000000)
return TLLI_RANDOM;
else if ((tlli & 0xf8000000) == 0x70000000)
return TLLI_AUXILIARY;
else if ((tlli & 0xf0000000) == 0x00000000)
return TLLI_G_RNTI;
else if ((tlli & 0xf0000000) == 0x10000000)
return TLLI_RAND_G_RNTI;
return TLLI_RESERVED;
}
/*! Determine TLLI from P-TMSI
* \param[in] p_tmsi P-TMSI
* \param[in] type TLLI Type we want to derive from \a p_tmsi
* \returns TLLI of given type */
uint32_t gprs_tmsi2tlli(uint32_t p_tmsi, enum gprs_tlli_type type)
{
uint32_t tlli;
switch (type) {
case TLLI_LOCAL:
tlli = p_tmsi | 0xc0000000;
break;
case TLLI_FOREIGN:
tlli = (p_tmsi & 0x3fffffff) | 0x80000000;
break;
default:
tlli = 0;
break;
}
return tlli;
}
/* Wrappers for deprecated functions: */
int gsm_7bit_decode(char *text, const uint8_t *user_data, uint8_t septet_l)
{
gsm_7bit_decode_n(text, GSM_7BIT_LEGACY_MAX_BUFFER_SIZE,
user_data, septet_l);
/* Mimic the original behaviour. */
return septet_l;
}
int gsm_7bit_decode_ussd(char *text, const uint8_t *user_data, uint8_t length)
{
return gsm_7bit_decode_n_ussd(text, GSM_7BIT_LEGACY_MAX_BUFFER_SIZE,
user_data, length);
}
int gsm_7bit_encode(uint8_t *result, const char *data)
{
int out;
return gsm_7bit_encode_n(result, GSM_7BIT_LEGACY_MAX_BUFFER_SIZE,
data, &out);
}
int gsm_7bit_encode_ussd(uint8_t *result, const char *data, int *octets)
{
return gsm_7bit_encode_n_ussd(result, GSM_7BIT_LEGACY_MAX_BUFFER_SIZE,
data, octets);
}
int gsm_7bit_encode_oct(uint8_t *result, const char *data, int *octets)
{
return gsm_7bit_encode_n(result, GSM_7BIT_LEGACY_MAX_BUFFER_SIZE,
data, octets);
}
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