Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 1 | /* GPRS utility functions */ |
| 2 | |
| 3 | /* (C) 2010 by Harald Welte <laforge@gnumonks.org> |
| 4 | * (C) 2010-2014 by On-Waves |
| 5 | * (C) 2013 by Holger Hans Peter Freyther |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU Affero General Public License as published by |
| 10 | * the Free Software Foundation; either version 3 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU Affero General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Affero General Public License |
| 19 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | * |
| 21 | */ |
| 22 | #include <openbsc/gprs_utils.h> |
| 23 | |
| 24 | #include <osmocom/core/msgb.h> |
| 25 | #include <osmocom/gprs/gprs_ns.h> |
| 26 | |
Harald Welte | 35ade5e | 2016-04-20 17:11:43 +0200 | [diff] [blame] | 27 | #include <osmocom/gsm/protocol/gsm_04_08_gprs.h> |
Jacob Erlbeck | cf11e93 | 2014-08-19 12:21:01 +0200 | [diff] [blame] | 28 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
Jacob Erlbeck | d6466c9 | 2016-01-04 18:43:34 +0100 | [diff] [blame] | 29 | #include <osmocom/gsm/gsm48.h> |
Jacob Erlbeck | cf11e93 | 2014-08-19 12:21:01 +0200 | [diff] [blame] | 30 | |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 31 | #include <string.h> |
| 32 | |
| 33 | /* FIXME: this needs to go to libosmocore/msgb.c */ |
| 34 | struct msgb *gprs_msgb_copy(const struct msgb *msg, const char *name) |
| 35 | { |
| 36 | struct libgb_msgb_cb *old_cb, *new_cb; |
| 37 | struct msgb *new_msg; |
| 38 | |
| 39 | new_msg = msgb_alloc(msg->data_len, name); |
| 40 | if (!new_msg) |
| 41 | return NULL; |
| 42 | |
| 43 | /* copy data */ |
| 44 | memcpy(new_msg->_data, msg->_data, new_msg->data_len); |
| 45 | |
| 46 | /* copy header */ |
| 47 | new_msg->len = msg->len; |
| 48 | new_msg->data += msg->data - msg->_data; |
| 49 | new_msg->head += msg->head - msg->_data; |
| 50 | new_msg->tail += msg->tail - msg->_data; |
| 51 | |
Jacob Erlbeck | 7557561 | 2014-09-22 18:50:08 +0200 | [diff] [blame] | 52 | if (msg->l1h) |
| 53 | new_msg->l1h = new_msg->_data + (msg->l1h - msg->_data); |
| 54 | if (msg->l2h) |
| 55 | new_msg->l2h = new_msg->_data + (msg->l2h - msg->_data); |
| 56 | if (msg->l3h) |
| 57 | new_msg->l3h = new_msg->_data + (msg->l3h - msg->_data); |
| 58 | if (msg->l4h) |
| 59 | new_msg->l4h = new_msg->_data + (msg->l4h - msg->_data); |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 60 | |
| 61 | /* copy GB specific data */ |
| 62 | old_cb = LIBGB_MSGB_CB(msg); |
| 63 | new_cb = LIBGB_MSGB_CB(new_msg); |
| 64 | |
Jacob Erlbeck | 7557561 | 2014-09-22 18:50:08 +0200 | [diff] [blame] | 65 | if (old_cb->bssgph) |
| 66 | new_cb->bssgph = new_msg->_data + (old_cb->bssgph - msg->_data); |
| 67 | if (old_cb->llch) |
| 68 | new_cb->llch = new_msg->_data + (old_cb->llch - msg->_data); |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 69 | |
| 70 | /* bssgp_cell_id is a pointer into the old msgb, so we need to make |
| 71 | * it a pointer into the new msgb */ |
Jacob Erlbeck | 7557561 | 2014-09-22 18:50:08 +0200 | [diff] [blame] | 72 | if (old_cb->bssgp_cell_id) |
| 73 | new_cb->bssgp_cell_id = new_msg->_data + |
| 74 | (old_cb->bssgp_cell_id - msg->_data); |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 75 | new_cb->nsei = old_cb->nsei; |
| 76 | new_cb->bvci = old_cb->bvci; |
| 77 | new_cb->tlli = old_cb->tlli; |
| 78 | |
| 79 | return new_msg; |
| 80 | } |
| 81 | |
| 82 | /* TODO: Move this to libosmocore/msgb.c */ |
| 83 | int gprs_msgb_resize_area(struct msgb *msg, uint8_t *area, |
| 84 | size_t old_size, size_t new_size) |
| 85 | { |
| 86 | int rc; |
| 87 | uint8_t *rest = area + old_size; |
| 88 | int rest_len = msg->len - old_size - (area - msg->data); |
| 89 | int delta_size = (int)new_size - (int)old_size; |
| 90 | |
| 91 | if (delta_size == 0) |
| 92 | return 0; |
| 93 | |
| 94 | if (delta_size > 0) { |
| 95 | rc = msgb_trim(msg, msg->len + delta_size); |
| 96 | if (rc < 0) |
| 97 | return rc; |
| 98 | } |
| 99 | |
| 100 | memmove(area + new_size, area + old_size, rest_len); |
| 101 | |
| 102 | if (msg->l1h >= rest) |
| 103 | msg->l1h += delta_size; |
| 104 | if (msg->l2h >= rest) |
| 105 | msg->l2h += delta_size; |
| 106 | if (msg->l3h >= rest) |
| 107 | msg->l3h += delta_size; |
| 108 | if (msg->l4h >= rest) |
| 109 | msg->l4h += delta_size; |
| 110 | |
| 111 | if (delta_size < 0) |
| 112 | msgb_trim(msg, msg->len + delta_size); |
| 113 | |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | /* TODO: Move these conversion functions to a utils file. */ |
Neels Hofmeyr | f16657a | 2015-11-08 20:34:47 +0100 | [diff] [blame] | 118 | /* TODO: consolidate with gprs_apn2str(). */ |
| 119 | /** memmove apn_enc to out_str, replacing the length octets in apn_enc with '.' |
| 120 | * (omitting the first one) and terminating with a '\0'. |
Holger Hans Peter Freyther | 2d10ad1 | 2014-08-04 14:22:13 +0200 | [diff] [blame] | 121 | * out_str needs to have rest_chars amount of bytes or 1 whatever is bigger. |
| 122 | */ |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 123 | char * gprs_apn_to_str(char *out_str, const uint8_t *apn_enc, size_t rest_chars) |
| 124 | { |
| 125 | char *str = out_str; |
| 126 | |
| 127 | while (rest_chars > 0 && apn_enc[0]) { |
| 128 | size_t label_size = apn_enc[0]; |
| 129 | if (label_size + 1 > rest_chars) |
| 130 | return NULL; |
| 131 | |
| 132 | memmove(str, apn_enc + 1, label_size); |
| 133 | str += label_size; |
| 134 | rest_chars -= label_size + 1; |
| 135 | apn_enc += label_size + 1; |
| 136 | |
| 137 | if (rest_chars) |
| 138 | *(str++) = '.'; |
| 139 | } |
| 140 | str[0] = '\0'; |
| 141 | |
| 142 | return out_str; |
| 143 | } |
| 144 | |
Holger Hans Peter Freyther | 2d10ad1 | 2014-08-04 14:22:13 +0200 | [diff] [blame] | 145 | int gprs_str_to_apn(uint8_t *apn_enc, size_t max_len, const char *str) |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 146 | { |
Holger Hans Peter Freyther | 2d10ad1 | 2014-08-04 14:22:13 +0200 | [diff] [blame] | 147 | uint8_t *last_len_field; |
| 148 | int len; |
| 149 | |
| 150 | /* Can we even write the length field to the output? */ |
| 151 | if (max_len == 0) |
| 152 | return -1; |
| 153 | |
| 154 | /* Remember where we need to put the length once we know it */ |
| 155 | last_len_field = apn_enc; |
| 156 | len = 1; |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 157 | apn_enc += 1; |
| 158 | |
| 159 | while (str[0]) { |
Holger Hans Peter Freyther | 2d10ad1 | 2014-08-04 14:22:13 +0200 | [diff] [blame] | 160 | if (len >= max_len) |
| 161 | return -1; |
| 162 | |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 163 | if (str[0] == '.') { |
| 164 | *last_len_field = (apn_enc - last_len_field) - 1; |
| 165 | last_len_field = apn_enc; |
| 166 | } else { |
| 167 | *apn_enc = str[0]; |
| 168 | } |
| 169 | apn_enc += 1; |
| 170 | str += 1; |
| 171 | len += 1; |
Holger Hans Peter Freyther | 8ac3a72 | 2014-08-04 11:52:52 +0200 | [diff] [blame] | 172 | } |
| 173 | |
| 174 | *last_len_field = (apn_enc - last_len_field) - 1; |
| 175 | |
| 176 | return len; |
| 177 | } |
| 178 | |
Jacob Erlbeck | c9a7ba3 | 2015-01-19 08:27:34 +0100 | [diff] [blame] | 179 | /* GSM 04.08, 10.5.7.3 GPRS Timer */ |
| 180 | int gprs_tmr_to_secs(uint8_t tmr) |
| 181 | { |
| 182 | switch (tmr & GPRS_TMR_UNIT_MASK) { |
| 183 | case GPRS_TMR_2SECONDS: |
| 184 | return 2 * (tmr & GPRS_TMR_FACT_MASK); |
| 185 | default: |
| 186 | case GPRS_TMR_MINUTE: |
| 187 | return 60 * (tmr & GPRS_TMR_FACT_MASK); |
| 188 | case GPRS_TMR_6MINUTE: |
| 189 | return 360 * (tmr & GPRS_TMR_FACT_MASK); |
| 190 | case GPRS_TMR_DEACTIVATED: |
| 191 | return -1; |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | /* This functions returns a tmr value such that |
| 196 | * - f is monotonic |
| 197 | * - f(s) <= s |
| 198 | * - f(s) == s if a tmr exists with s = gprs_tmr_to_secs(tmr) |
| 199 | * - the best possible resolution is used |
| 200 | * where |
| 201 | * f(s) = gprs_tmr_to_secs(gprs_secs_to_tmr_floor(s)) |
| 202 | */ |
| 203 | uint8_t gprs_secs_to_tmr_floor(int secs) |
| 204 | { |
| 205 | if (secs < 0) |
| 206 | return GPRS_TMR_DEACTIVATED; |
| 207 | if (secs < 2 * 32) |
| 208 | return GPRS_TMR_2SECONDS | (secs / 2); |
| 209 | if (secs < 60 * 2) |
| 210 | /* Ensure monotonicity */ |
| 211 | return GPRS_TMR_2SECONDS | GPRS_TMR_FACT_MASK; |
| 212 | if (secs < 60 * 32) |
| 213 | return GPRS_TMR_MINUTE | (secs / 60); |
| 214 | if (secs < 360 * 6) |
| 215 | /* Ensure monotonicity */ |
| 216 | return GPRS_TMR_MINUTE | GPRS_TMR_FACT_MASK; |
| 217 | if (secs < 360 * 32) |
| 218 | return GPRS_TMR_6MINUTE | (secs / 360); |
| 219 | |
| 220 | return GPRS_TMR_6MINUTE | GPRS_TMR_FACT_MASK; |
| 221 | } |
| 222 | |
Jacob Erlbeck | cf11e93 | 2014-08-19 12:21:01 +0200 | [diff] [blame] | 223 | /* GSM 04.08, 10.5.1.4 */ |
| 224 | int gprs_is_mi_tmsi(const uint8_t *value, size_t value_len) |
| 225 | { |
| 226 | if (value_len != GSM48_TMSI_LEN) |
| 227 | return 0; |
| 228 | |
| 229 | if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_TMSI) |
| 230 | return 0; |
| 231 | |
| 232 | return 1; |
| 233 | } |
| 234 | |
| 235 | /* GSM 04.08, 10.5.1.4 */ |
| 236 | int gprs_is_mi_imsi(const uint8_t *value, size_t value_len) |
| 237 | { |
| 238 | if (value_len == 0) |
| 239 | return 0; |
| 240 | |
| 241 | if (!value || (value[0] & GSM_MI_TYPE_MASK) != GSM_MI_TYPE_IMSI) |
| 242 | return 0; |
| 243 | |
| 244 | return 1; |
| 245 | } |
| 246 | |
| 247 | int gprs_parse_mi_tmsi(const uint8_t *value, size_t value_len, uint32_t *tmsi) |
| 248 | { |
| 249 | uint32_t tmsi_be; |
| 250 | |
| 251 | if (!gprs_is_mi_tmsi(value, value_len)) |
| 252 | return 0; |
| 253 | |
| 254 | memcpy(&tmsi_be, value + 1, sizeof(tmsi_be)); |
| 255 | |
| 256 | *tmsi = ntohl(tmsi_be); |
| 257 | return 1; |
| 258 | } |
| 259 | |
Jacob Erlbeck | 17608c6 | 2014-10-02 16:14:47 +0200 | [diff] [blame] | 260 | void gprs_parse_tmsi(const uint8_t *value, uint32_t *tmsi) |
| 261 | { |
| 262 | uint32_t tmsi_be; |
| 263 | |
| 264 | memcpy(&tmsi_be, value, sizeof(tmsi_be)); |
| 265 | |
| 266 | *tmsi = ntohl(tmsi_be); |
| 267 | } |
Jacob Erlbeck | dce4501 | 2014-12-11 11:01:46 +0100 | [diff] [blame] | 268 | |
Jacob Erlbeck | d6466c9 | 2016-01-04 18:43:34 +0100 | [diff] [blame] | 269 | int gprs_ra_id_equals(const struct gprs_ra_id *id1, |
| 270 | const struct gprs_ra_id *id2) |
| 271 | { |
| 272 | return (id1->mcc == id2->mcc && id1->mnc == id2->mnc && |
| 273 | id1->lac == id2->lac && id1->rac == id2->rac); |
| 274 | } |