102 lines
2.7 KiB
C
102 lines
2.7 KiB
C
/* GPRS utility functions */
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/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
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* (C) 2010-2014 by On-Waves
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* (C) 2013 by Holger Hans Peter Freyther
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <osmocom/sgsn/gprs_utils.h>
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#include <osmocom/core/msgb.h>
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#include <osmocom/gprs/gprs_ns2.h>
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#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
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#include <osmocom/gsm/protocol/gsm_04_08.h>
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#include <osmocom/gsm/gsm48.h>
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#include <string.h>
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/* This functions returns a tmr value such that
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* - f is monotonic
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* - f(s) <= s
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* - f(s) == s if a tmr exists with s = gprs_tmr_to_secs(tmr)
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* - the best possible resolution is used
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* where
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* f(s) = gprs_tmr_to_secs(gprs_secs_to_tmr_floor(s))
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*/
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uint8_t gprs_secs_to_tmr_floor(int secs)
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{
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if (secs < 0)
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return GPRS_TMR_DEACTIVATED;
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if (secs < 2 * 32)
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return GPRS_TMR_2SECONDS | (secs / 2);
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if (secs < 60 * 2)
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/* Ensure monotonicity */
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return GPRS_TMR_2SECONDS | GPRS_TMR_FACT_MASK;
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if (secs < 60 * 32)
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return GPRS_TMR_MINUTE | (secs / 60);
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if (secs < 360 * 6)
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/* Ensure monotonicity */
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return GPRS_TMR_MINUTE | GPRS_TMR_FACT_MASK;
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if (secs < 360 * 32)
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return GPRS_TMR_6MINUTE | (secs / 360);
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return GPRS_TMR_6MINUTE | GPRS_TMR_FACT_MASK;
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}
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/* GSM 04.08, 10.5.1.4 */
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int gprs_is_mi_tmsi(const uint8_t *value, size_t value_len)
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{
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if (value_len != GSM48_TMSI_LEN)
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return 0;
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if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_TMSI)
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return 0;
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return 1;
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}
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/* GSM 04.08, 10.5.1.4 */
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int gprs_is_mi_imsi(const uint8_t *value, size_t value_len)
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{
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if (value_len == 0)
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return 0;
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if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI)
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return 0;
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return 1;
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}
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void gprs_parse_tmsi(const uint8_t *value, uint32_t *tmsi)
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{
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uint32_t tmsi_be;
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memcpy(&tmsi_be, value, sizeof(tmsi_be));
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*tmsi = ntohl(tmsi_be);
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}
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int gprs_ra_id_equals(const struct gprs_ra_id *id1,
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const struct gprs_ra_id *id2)
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{
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return (id1->mcc == id2->mcc
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&& !osmo_mnc_cmp(id1->mnc, id1->mnc_3_digits,
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id2->mnc, id2->mnc_3_digits)
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&& id1->lac == id2->lac && id1->rac == id2->rac);
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}
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