| /* GPRS utility functions */ |
| |
| /* (C) 2010 by Harald Welte <laforge@gnumonks.org> |
| * (C) 2010-2014 by On-Waves |
| * (C) 2013 by Holger Hans Peter Freyther |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as published by |
| * the Free Software Foundation; either version 3 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 Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| #include <osmocom/sgsn/gprs_utils.h> |
| |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/gprs/gprs_ns.h> |
| |
| #include <osmocom/gsm/protocol/gsm_04_08_gprs.h> |
| #include <osmocom/gsm/protocol/gsm_04_08.h> |
| #include <osmocom/gsm/gsm48.h> |
| |
| #include <string.h> |
| |
| int gprs_str_to_apn(uint8_t *apn_enc, size_t max_len, const char *str) |
| { |
| uint8_t *last_len_field; |
| int len; |
| |
| /* Can we even write the length field to the output? */ |
| if (max_len == 0) |
| return -1; |
| |
| /* Remember where we need to put the length once we know it */ |
| last_len_field = apn_enc; |
| len = 1; |
| apn_enc += 1; |
| |
| while (str[0]) { |
| if (len >= max_len) |
| return -1; |
| |
| if (str[0] == '.') { |
| *last_len_field = (apn_enc - last_len_field) - 1; |
| last_len_field = apn_enc; |
| } else { |
| *apn_enc = str[0]; |
| } |
| apn_enc += 1; |
| str += 1; |
| len += 1; |
| } |
| |
| *last_len_field = (apn_enc - last_len_field) - 1; |
| |
| return len; |
| } |
| |
| /* GSM 04.08, 10.5.7.3 GPRS Timer */ |
| int gprs_tmr_to_secs(uint8_t tmr) |
| { |
| switch (tmr & GPRS_TMR_UNIT_MASK) { |
| case GPRS_TMR_2SECONDS: |
| return 2 * (tmr & GPRS_TMR_FACT_MASK); |
| default: |
| case GPRS_TMR_MINUTE: |
| return 60 * (tmr & GPRS_TMR_FACT_MASK); |
| case GPRS_TMR_6MINUTE: |
| return 360 * (tmr & GPRS_TMR_FACT_MASK); |
| case GPRS_TMR_DEACTIVATED: |
| return -1; |
| } |
| } |
| |
| /* This functions returns a tmr value such that |
| * - f is monotonic |
| * - f(s) <= s |
| * - f(s) == s if a tmr exists with s = gprs_tmr_to_secs(tmr) |
| * - the best possible resolution is used |
| * where |
| * f(s) = gprs_tmr_to_secs(gprs_secs_to_tmr_floor(s)) |
| */ |
| uint8_t gprs_secs_to_tmr_floor(int secs) |
| { |
| if (secs < 0) |
| return GPRS_TMR_DEACTIVATED; |
| if (secs < 2 * 32) |
| return GPRS_TMR_2SECONDS | (secs / 2); |
| if (secs < 60 * 2) |
| /* Ensure monotonicity */ |
| return GPRS_TMR_2SECONDS | GPRS_TMR_FACT_MASK; |
| if (secs < 60 * 32) |
| return GPRS_TMR_MINUTE | (secs / 60); |
| if (secs < 360 * 6) |
| /* Ensure monotonicity */ |
| return GPRS_TMR_MINUTE | GPRS_TMR_FACT_MASK; |
| if (secs < 360 * 32) |
| return GPRS_TMR_6MINUTE | (secs / 360); |
| |
| return GPRS_TMR_6MINUTE | GPRS_TMR_FACT_MASK; |
| } |
| |
| /* GSM 04.08, 10.5.1.4 */ |
| int gprs_is_mi_tmsi(const uint8_t *value, size_t value_len) |
| { |
| if (value_len != GSM48_TMSI_LEN) |
| return 0; |
| |
| if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_TMSI) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* GSM 04.08, 10.5.1.4 */ |
| int gprs_is_mi_imsi(const uint8_t *value, size_t value_len) |
| { |
| if (value_len == 0) |
| return 0; |
| |
| if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI) |
| return 0; |
| |
| return 1; |
| } |
| |
| int gprs_parse_mi_tmsi(const uint8_t *value, size_t value_len, uint32_t *tmsi) |
| { |
| uint32_t tmsi_be; |
| |
| if (!gprs_is_mi_tmsi(value, value_len)) |
| return 0; |
| |
| memcpy(&tmsi_be, value + 1, sizeof(tmsi_be)); |
| |
| *tmsi = ntohl(tmsi_be); |
| return 1; |
| } |
| |
| void gprs_parse_tmsi(const uint8_t *value, uint32_t *tmsi) |
| { |
| uint32_t tmsi_be; |
| |
| memcpy(&tmsi_be, value, sizeof(tmsi_be)); |
| |
| *tmsi = ntohl(tmsi_be); |
| } |
| |
| int gprs_ra_id_equals(const struct gprs_ra_id *id1, |
| const struct gprs_ra_id *id2) |
| { |
| return (id1->mcc == id2->mcc |
| && !osmo_mnc_cmp(id1->mnc, id1->mnc_3_digits, |
| id2->mnc, id2->mnc_3_digits) |
| && id1->lac == id2->lac && id1->rac == id2->rac); |
| } |