| /* GSM 04.08 System Information (SI) encoding and decoding |
| * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */ |
| |
| /* (C) 2008-2009 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. |
| * |
| * 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. |
| * |
| */ |
| |
| #include <errno.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <netinet/in.h> |
| |
| #include <openbsc/gsm_04_08.h> |
| #include <openbsc/gsm_data.h> |
| #include <openbsc/abis_rsl.h> |
| #include <openbsc/rest_octets.h> |
| |
| #define GSM48_CELL_CHAN_DESC_SIZE 16 |
| #define GSM_MACBLOCK_LEN 23 |
| #define GSM_MACBLOCK_PADDING 0x2b |
| |
| static int cchan_list_bm0_set_arfcn(u_int8_t *chan_list, unsigned int arfcn) |
| { |
| unsigned int byte, bit; |
| |
| if (arfcn > 124) |
| return -EINVAL; |
| |
| byte = arfcn / 8; |
| bit = arfcn % 8; |
| |
| chan_list[GSM48_CELL_CHAN_DESC_SIZE-byte] |= (1 << bit); |
| |
| return 0; |
| } |
| |
| static int cchan_list_bmrel_set_arfcn(u_int8_t *chan_list, unsigned int arfcn) |
| { |
| unsigned int byte, bit; |
| unsigned int min_arfcn; |
| unsigned int bitno; |
| |
| min_arfcn = (chan_list[0] & 1) << 9; |
| min_arfcn |= chan_list[1] << 1; |
| min_arfcn |= (chan_list[2] >> 7) & 1; |
| |
| /* The lower end of our bitmaks is always implicitly included */ |
| if (arfcn == min_arfcn) |
| return 0; |
| |
| if (arfcn < min_arfcn) |
| return -EINVAL; |
| if (arfcn > min_arfcn + 111) |
| return -EINVAL; |
| |
| bitno = (arfcn - min_arfcn); |
| byte = bitno / 8; |
| bit = bitno % 8; |
| |
| chan_list[2 + byte] |= 1 << (7 - bit); |
| |
| return 0; |
| } |
| |
| /* generate a cell channel list as per Section 10.5.2.1b of 04.08 */ |
| static int generate_cell_chan_list(u_int8_t *chan_list, const struct gsm_bts *bts) |
| { |
| struct gsm_bts_trx *trx; |
| int rc, min = 1024, max = 0; |
| |
| memset(chan_list, 0, 16); |
| |
| /* GSM900-only handsets only support 'bit map 0 format' */ |
| if (bts->band == GSM_BAND_900) { |
| chan_list[0] = 0; |
| llist_for_each_entry(trx, &bts->trx_list, list) { |
| rc = cchan_list_bm0_set_arfcn(chan_list, trx->arfcn); |
| if (rc < 0) |
| return rc; |
| } |
| return 0; |
| } |
| |
| /* We currently only support the 'Variable bitmap format' */ |
| chan_list[0] = 0x8e; |
| |
| llist_for_each_entry(trx, &bts->trx_list, list) { |
| if (trx->arfcn < min) |
| min = trx->arfcn; |
| if (trx->arfcn > max) |
| max = trx->arfcn; |
| } |
| |
| if ((max - min) > 111) |
| return -EINVAL; |
| |
| chan_list[0] |= (min >> 9) & 1; |
| chan_list[1] = (min >> 1); |
| chan_list[2] = (min & 1) << 7; |
| |
| llist_for_each_entry(trx, &bts->trx_list, list) { |
| rc = cchan_list_bmrel_set_arfcn(chan_list, trx->arfcn); |
| if (rc < 0) |
| return rc; |
| } |
| |
| return 0; |
| } |
| |
| /* generate a cell channel list as per Section 10.5.2.1b of 04.08 */ |
| static int generate_bcch_chan_list(u_int8_t *chan_list, const struct gsm_bts *bts) |
| { |
| struct gsm_bts *cur_bts; |
| struct gsm_bts_trx *trx; |
| int rc, min = 1024, max = 0; |
| |
| memset(chan_list, 0, 16); |
| |
| /* GSM900-only handsets only support 'bit map 0 format' */ |
| if (bts->band == GSM_BAND_900) { |
| chan_list[0] = 0; |
| llist_for_each_entry(cur_bts, &bts->list, list) { |
| if (&cur_bts->list == &bts->network->bts_list) |
| continue; |
| trx = cur_bts->c0; |
| rc = cchan_list_bm0_set_arfcn(chan_list, trx->arfcn); |
| if (rc < 0) |
| return rc; |
| } |
| return 0; |
| } |
| |
| /* We currently only support the 'Variable bitmap format' */ |
| chan_list[0] = 0x8e; |
| |
| llist_for_each_entry(cur_bts, &bts->list, list) { |
| if (&cur_bts->list == &bts->network->bts_list) |
| continue; |
| trx = cur_bts->c0; |
| if (trx->arfcn < min) |
| min = trx->arfcn; |
| if (trx->arfcn > max) |
| max = trx->arfcn; |
| } |
| |
| if ((max - min) > 111) |
| return -EINVAL; |
| |
| chan_list[0] |= (min >> 9) & 1; |
| chan_list[1] = (min >> 1); |
| chan_list[2] = (min & 1) << 7; |
| |
| llist_for_each_entry(cur_bts, &bts->list, list) { |
| if (&cur_bts->list == &bts->network->bts_list) |
| continue; |
| trx = cur_bts->c0; |
| rc = cchan_list_bmrel_set_arfcn(chan_list, trx->arfcn); |
| if (rc < 0) |
| return rc; |
| } |
| |
| return 0; |
| } |
| |
| static int generate_si1(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| int rc; |
| struct gsm48_system_information_type_1 *si1 = |
| (struct gsm48_system_information_type_1 *) output; |
| |
| memset(si1, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| si1->header.l2_plen = (21 << 2) | 1; |
| si1->header.rr_protocol_discriminator = GSM48_PDISC_RR; |
| si1->header.skip_indicator = 0; |
| si1->header.system_information = GSM48_MT_RR_SYSINFO_1; |
| |
| rc = generate_cell_chan_list(si1->cell_channel_description, bts); |
| if (rc < 0) |
| return rc; |
| |
| si1->rach_control = bts->si_common.rach_control; |
| |
| /* SI1 Rest Octets (10.5.2.32), contains NCH position */ |
| rest_octets_si1(si1->rest_octets, NULL); |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| static int generate_si2(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| int rc; |
| struct gsm48_system_information_type_2 *si2 = |
| (struct gsm48_system_information_type_2 *) output; |
| |
| memset(si2, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| si2->header.l2_plen = (22 << 2) | 1; |
| si2->header.rr_protocol_discriminator = GSM48_PDISC_RR; |
| si2->header.skip_indicator = 0; |
| si2->header.system_information = GSM48_MT_RR_SYSINFO_2; |
| |
| rc = generate_bcch_chan_list(si2->bcch_frequency_list, bts); |
| if (rc < 0) |
| return rc; |
| |
| si2->ncc_permitted = bts->si_common.ncc_permitted; |
| si2->rach_control = bts->si_common.rach_control; |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| struct gsm48_si_ro_info si_info = { |
| .selection_params = { |
| .present = 0, |
| }, |
| .power_offset = { |
| .present = 0, |
| }, |
| .si2ter_indicator = 0, |
| .early_cm_ctrl = 1, |
| .scheduling = { |
| .present = 0, |
| }, |
| .gprs_ind = { |
| .si13_position = 0, |
| .ra_colour = 0, |
| .present = 0, |
| }, |
| .lsa_params = { |
| .present = 0, |
| }, |
| .cell_id = 0, /* FIXME: doesn't the bts have this? */ |
| .break_ind = 0, |
| }; |
| |
| static int generate_si3(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| struct gsm48_system_information_type_3 *si3 = |
| (struct gsm48_system_information_type_3 *) output; |
| |
| memset(si3, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| si3->header.l2_plen = (18 << 2) | 1; |
| si3->header.rr_protocol_discriminator = GSM48_PDISC_RR; |
| si3->header.skip_indicator = 0; |
| si3->header.system_information = GSM48_MT_RR_SYSINFO_3; |
| |
| si3->cell_identity = htons(bts->cell_identity); |
| gsm0408_generate_lai(&si3->lai, bts->network->country_code, |
| bts->network->network_code, |
| bts->location_area_code); |
| si3->control_channel_desc = bts->si_common.chan_desc; |
| si3->cell_options = bts->si_common.cell_options; |
| si3->cell_sel_par = bts->si_common.cell_sel_par; |
| si3->rach_control = bts->si_common.rach_control; |
| |
| /* SI3 Rest Octets (10.5.2.34), containing |
| CBQ, CELL_RESELECT_OFFSET, TEMPORARY_OFFSET, PENALTY_TIME |
| Power Offset, 2ter Indicator, Early Classmark Sending, |
| Scheduling if and WHERE, GPRS Indicator, SI13 position */ |
| rest_octets_si3(si3->rest_octets, &si_info); |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| static int generate_si4(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| struct gsm48_system_information_type_4 *si4 = |
| (struct gsm48_system_information_type_4 *) output; |
| |
| /* length of all IEs present except SI4 rest octets and l2_plen */ |
| int l2_plen = sizeof(*si4) - 1; |
| |
| memset(si4, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| si4->header.rr_protocol_discriminator = GSM48_PDISC_RR; |
| si4->header.skip_indicator = 0; |
| si4->header.system_information = GSM48_MT_RR_SYSINFO_4; |
| |
| gsm0408_generate_lai(&si4->lai, bts->network->country_code, |
| bts->network->network_code, |
| bts->location_area_code); |
| si4->cell_sel_par = bts->si_common.cell_sel_par; |
| si4->rach_control = bts->si_common.rach_control; |
| |
| /* Optional: CBCH Channel Description + CBCH Mobile Allocation */ |
| |
| si4->header.l2_plen = (l2_plen << 2) | 1; |
| |
| /* SI4 Rest Octets (10.5.2.35), containing |
| Optional Power offset, GPRS Indicator, |
| Cell Identity, LSA ID, Selection Parameter */ |
| rest_octets_si4(si4->data, &si_info); |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| static int generate_si5(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| struct gsm48_system_information_type_5 *si5 = |
| (struct gsm48_system_information_type_5 *) output; |
| int rc; |
| |
| memset(si5, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| /* l2 pseudo length, not part of msg: 18 */ |
| si5->rr_protocol_discriminator = GSM48_PDISC_RR; |
| si5->skip_indicator = 0; |
| si5->system_information = GSM48_MT_RR_SYSINFO_5; |
| rc = generate_bcch_chan_list(si5->bcch_frequency_list, bts); |
| if (rc < 0) |
| return rc; |
| |
| /* 04.08 9.1.37: L2 Pseudo Length of 18 */ |
| return 18; |
| } |
| |
| static int generate_si6(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| struct gsm48_system_information_type_6 *si6 = |
| (struct gsm48_system_information_type_6 *) output; |
| |
| memset(si6, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| /* l2 pseudo length, not part of msg: 11 */ |
| si6->rr_protocol_discriminator = GSM48_PDISC_RR; |
| si6->skip_indicator = 0; |
| si6->system_information = GSM48_MT_RR_SYSINFO_6; |
| si6->cell_identity = htons(bts->cell_identity); |
| gsm0408_generate_lai(&si6->lai, bts->network->country_code, |
| bts->network->network_code, |
| bts->location_area_code); |
| si6->cell_options = bts->si_common.cell_options; |
| si6->ncc_permitted = bts->si_common.ncc_permitted; |
| |
| /* SI6 Rest Octets: 10.5.2.35a: PCH / NCH info, VBS/VGCS options */ |
| |
| return 18; |
| } |
| |
| static struct gsm48_si13_info si13_default = { |
| .cell_opts = { |
| .nmo = GPRS_NMO_III, |
| .t3168 = 1000, |
| .t3192 = 1000, |
| .drx_timer_max = 1, |
| .bs_cv_max = 15, |
| }, |
| .pwr_ctrl_pars = { |
| .alpha = 10, /* a = 1.0 */ |
| .t_avg_w = 25, |
| .t_avg_t = 25, |
| .pc_meas_chan = 0, /* downling measured on CCCH */ |
| .n_avg_i = 15, |
| }, |
| .bcch_change_mark = 0, |
| .si_change_field = 0, |
| .pbcch_present = 0, |
| { |
| .no_pbcch = { |
| .rac = 0, |
| .spgc_ccch_sup = 0, |
| .net_ctrl_ord = 0, |
| .prio_acc_thr = 0, |
| }, |
| }, |
| }; |
| |
| static int generate_si13(u_int8_t *output, const struct gsm_bts *bts) |
| { |
| struct gsm48_system_information_type_13 *si13 = |
| (struct gsm48_system_information_type_13 *) output; |
| int ret; |
| |
| memset(si13, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); |
| |
| si13->header.rr_protocol_discriminator = GSM48_PDISC_RR; |
| si13->header.skip_indicator = 0; |
| si13->header.system_information = GSM48_MT_RR_SYSINFO_13; |
| |
| ret = rest_octets_si13(si13->rest_octets, &si13_default); |
| if (ret < 0) |
| return ret; |
| |
| si13->header.l2_plen = ret & 0xff; |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| int gsm_generate_si(u_int8_t *output, struct gsm_bts *bts, int type) |
| { |
| switch (type) { |
| case RSL_SYSTEM_INFO_1: |
| return generate_si1(output, bts); |
| case RSL_SYSTEM_INFO_2: |
| return generate_si2(output, bts); |
| case RSL_SYSTEM_INFO_3: |
| return generate_si3(output, bts); |
| case RSL_SYSTEM_INFO_4: |
| return generate_si4(output, bts); |
| case RSL_SYSTEM_INFO_5: |
| return generate_si5(output, bts); |
| case RSL_SYSTEM_INFO_6: |
| return generate_si6(output, bts); |
| case RSL_SYSTEM_INFO_13: |
| return generate_si13(output, bts); |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |