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Diffstat (limited to 'src/libbsc/system_information.c')
-rw-r--r-- | src/libbsc/system_information.c | 1169 |
1 files changed, 1169 insertions, 0 deletions
diff --git a/src/libbsc/system_information.c b/src/libbsc/system_information.c new file mode 100644 index 000000000..dcabbbdd1 --- /dev/null +++ b/src/libbsc/system_information.c @@ -0,0 +1,1169 @@ +/* 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) 2008-2010 by Harald Welte <laforge@gnumonks.org> + * (C) 2012 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 <errno.h> +#include <string.h> +#include <stdio.h> +#include <netinet/in.h> +#include <stdbool.h> + +#include <osmocom/core/bitvec.h> +#include <osmocom/core/utils.h> +#include <osmocom/gsm/sysinfo.h> + +#include <openbsc/debug.h> +#include <openbsc/gsm_04_08.h> +#include <openbsc/gsm_data.h> +#include <openbsc/abis_rsl.h> +#include <openbsc/rest_octets.h> +#include <openbsc/arfcn_range_encode.h> + +/* + * DCS1800 and PCS1900 have overlapping ARFCNs. We would need to set the + * ARFCN_PCS flag on the 1900 ARFCNs but this would increase cell_alloc + * and other arrays to make sure (ARFCN_PCS + 1024)/8 ARFCNs fit into the + * array. DCS1800 and PCS1900 can not be used at the same time so conserve + * memory and do the below. + */ +static int band_compatible(const struct gsm_bts *bts, int arfcn) +{ + enum gsm_band band = gsm_arfcn2band(arfcn); + + /* normal case */ + if (band == bts->band) + return 1; + /* deal with ARFCN_PCS not set */ + if (band == GSM_BAND_1800 && bts->band == GSM_BAND_1900) + return 1; + + return 0; +} + +static int is_dcs_net(const struct gsm_bts *bts) +{ + if (bts->band == GSM_BAND_850) + return 0; + if (bts->band == GSM_BAND_1900) + return 0; + return 1; +} + +/* Return p(n) for given NR_OF_TDD_CELLS - see Table 9.1.54.1a, 3GPP TS 44.018 */ +unsigned range1024_p(unsigned n) +{ + switch (n) { + case 0: return 0; + case 1: return 10; + case 2: return 19; + case 3: return 28; + case 4: return 36; + case 5: return 44; + case 6: return 52; + case 7: return 60; + case 8: return 67; + case 9: return 74; + case 10: return 81; + case 11: return 88; + case 12: return 95; + case 13: return 102; + case 14: return 109; + case 15: return 116; + case 16: return 122; + default: return 0; + } +} + +/* Return q(m) for given NR_OF_TDD_CELLS - see Table 9.1.54.1b, 3GPP TS 44.018 */ +unsigned range512_q(unsigned m) +{ + switch (m) { + case 0: return 0; + case 1: return 9; + case 2: return 17; + case 3: return 25; + case 4: return 32; + case 5: return 39; + case 6: return 46; + case 7: return 53; + case 8: return 59; + case 9: return 65; + case 10: return 71; + case 11: return 77; + case 12: return 83; + case 13: return 89; + case 14: return 95; + case 15: return 101; + case 16: return 106; + case 17: return 111; + case 18: return 116; + case 19: return 121; + case 20: return 126; + default: return 0; + } +} + +size_t si2q_earfcn_count(const struct osmo_earfcn_si2q *e) +{ + unsigned i, ret = 0; + + if (!e) + return 0; + + for (i = 0; i < e->length; i++) + if (e->arfcn[i] != OSMO_EARFCN_INVALID) + ret++; + + return ret; +} + +/* generate SI2quater messages, return rest octets length of last generated message or negative error code */ +static int make_si2quaters(struct gsm_bts *bts, bool counting) +{ + int rc; + bool memory_exceeded = true; + struct gsm48_system_information_type_2quater *si2q; + + for (bts->si2q_index = 0; bts->si2q_index < SI2Q_MAX_NUM; bts->si2q_index++) { + si2q = GSM_BTS_SI2Q(bts, bts->si2q_index); + if (counting) { /* that's legitimate if we're called for counting purpose: */ + if (bts->si2q_count < bts->si2q_index) + bts->si2q_count = bts->si2q_index; + } else { + memset(si2q, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si2q->header.l2_plen = GSM48_LEN2PLEN(22); + si2q->header.rr_protocol_discriminator = GSM48_PDISC_RR; + si2q->header.skip_indicator = 0; + si2q->header.system_information = GSM48_MT_RR_SYSINFO_2quater; + } + + rc = rest_octets_si2quater(si2q->rest_octets, bts); + if (rc < 0) + return rc; + + if (bts->u_offset >= bts->si_common.uarfcn_length && + bts->e_offset >= si2q_earfcn_count(&bts->si_common.si2quater_neigh_list)) { + memory_exceeded = false; + break; + } + } + + if (memory_exceeded) + return -ENOMEM; + + return rc; +} + +/* we generate SI2q rest octets twice to get proper estimation but it's one time cost anyway */ +uint8_t si2q_num(struct gsm_bts *bts) +{ + int rc = make_si2quaters(bts, true); + uint8_t num = bts->si2q_index + 1; /* number of SI2quater messages */ + + /* N. B: si2q_num() should NEVER be called during actualSI2q rest octets generation + we're not re-entrant because of the following code: */ + bts->u_offset = 0; + bts->e_offset = 0; + + if (rc < 0) + return 0xFF; /* return impossible index as an indicator of error in generating SI2quater */ + + return num; +} + +/* 3GPP TS 44.018, Table 9.1.54.1 - prepend diversity bit to scrambling code */ +static inline uint16_t encode_fdd(uint16_t scramble, bool diversity) +{ + if (diversity) + return scramble | (1 << 9); + return scramble; +} + +int bts_earfcn_add(struct gsm_bts *bts, uint16_t earfcn, uint8_t thresh_hi, uint8_t thresh_lo, uint8_t prio, + uint8_t qrx, uint8_t meas_bw) +{ + struct osmo_earfcn_si2q *e = &bts->si_common.si2quater_neigh_list; + int r = osmo_earfcn_add(e, earfcn, (meas_bw < EARFCN_MEAS_BW_INVALID) ? meas_bw : OSMO_EARFCN_MEAS_INVALID); + + if (r < 0) + return r; + + if (e->thresh_hi && thresh_hi != e->thresh_hi) + r = 1; + + e->thresh_hi = thresh_hi; + + if (thresh_lo != EARFCN_THRESH_LOW_INVALID) { + if (e->thresh_lo_valid && e->thresh_lo != thresh_lo) + r = EARFCN_THRESH_LOW_INVALID; + e->thresh_lo = thresh_lo; + e->thresh_lo_valid = true; + } + + if (qrx != EARFCN_QRXLV_INVALID) { + if (e->qrxlm_valid && e->qrxlm != qrx) + r = EARFCN_QRXLV_INVALID + 1; + e->qrxlm = qrx; + e->qrxlm_valid = true; + } + + if (prio != EARFCN_PRIO_INVALID) { + if (e->prio_valid && e->prio != prio) + r = EARFCN_PRIO_INVALID; + e->prio = prio; + e->prio_valid = true; + } + + return r; +} + +int bts_uarfcn_del(struct gsm_bts *bts, uint16_t arfcn, uint16_t scramble) +{ + uint16_t sc0 = encode_fdd(scramble, false), sc1 = encode_fdd(scramble, true), + *ual = bts->si_common.data.uarfcn_list, + *scl = bts->si_common.data.scramble_list; + size_t len = bts->si_common.uarfcn_length, i; + for (i = 0; i < len; i++) { + if (arfcn == ual[i] && (sc0 == scl[i] || sc1 == scl[i])) { + /* we rely on the assumption that (uarfcn, scramble) + tuple is unique in the lists */ + if (i != len - 1) { /* move the tail if necessary */ + memmove(ual + i, ual + i + 1, 2 * (len - i + 1)); + memmove(scl + i, scl + i + 1, 2 * (len - i + 1)); + } + break; + } + } + + if (i == len) + return -EINVAL; + + bts->si_common.uarfcn_length--; + return 0; +} + +int bts_uarfcn_add(struct gsm_bts *bts, uint16_t arfcn, uint16_t scramble, bool diversity) +{ + size_t len = bts->si_common.uarfcn_length, i, k = 0; + uint16_t scr, chk, + *ual = bts->si_common.data.uarfcn_list, + *scl = bts->si_common.data.scramble_list, + scramble1 = encode_fdd(scramble, true), + scramble0 = encode_fdd(scramble, false); + + scr = diversity ? scramble1 : scramble0; + chk = diversity ? scramble0 : scramble1; + + if (len == MAX_EARFCN_LIST) + return -ENOMEM; + + for (i = 0; i < len; i++) /* find the position of arfcn if any */ + if (arfcn == ual[i]) + break; + + for (k = 0; i < len; i++) { + if (arfcn == ual[i] && (scr == scl[i] || chk == scl[i])) + return -EADDRINUSE; + if (scr > scl[i]) + k = i + 1; + } + /* we keep lists sorted by scramble code: + insert into appropriate position and move the tail */ + if (len - k) { + memmove(ual + k + 1, ual + k, (len - k) * 2); + memmove(scl + k + 1, scl + k, (len - k) * 2); + } + + ual[k] = arfcn; + scl[k] = scr; + bts->si_common.uarfcn_length++; + + if (si2q_num(bts) <= SI2Q_MAX_NUM) { + bts->si2q_count = si2q_num(bts) - 1; + return 0; + } + + bts_uarfcn_del(bts, arfcn, scramble); + return -ENOSPC; +} + +static inline int use_arfcn(const struct gsm_bts *bts, const bool bis, const bool ter, + const bool pgsm, const int arfcn) +{ + if (bts->force_combined_si) + return !bis && !ter; + if (!bis && !ter && band_compatible(bts, arfcn)) + return 1; + /* Correct but somehow broken with either the nanoBTS or the iPhone5 */ + if (bis && pgsm && band_compatible(bts, arfcn) && (arfcn < 1 || arfcn > 124)) + return 1; + if (ter && !band_compatible(bts, arfcn)) + return 1; + return 0; +} + +/* Frequency Lists as per TS 04.08 10.5.2.13 */ + +/* 10.5.2.13.2: Bit map 0 format */ +static int freq_list_bm0_set_arfcn(uint8_t *chan_list, unsigned int arfcn) +{ + unsigned int byte, bit; + + if (arfcn > 124 || arfcn < 1) { + LOGP(DRR, LOGL_ERROR, "Bitmap 0 only supports ARFCN 1...124\n"); + return -EINVAL; + } + + /* the bitmask is from 1..124, not from 0..123 */ + arfcn--; + + byte = arfcn / 8; + bit = arfcn % 8; + + chan_list[GSM48_CELL_CHAN_DESC_SIZE-1-byte] |= (1 << bit); + + return 0; +} + +/* 10.5.2.13.7: Variable bit map format */ +static int freq_list_bmrel_set_arfcn(uint8_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) & 1023) > 111) { + LOGP(DRR, LOGL_ERROR, "arfcn(%u) > min(%u) + 111\n", arfcn, min_arfcn); + return -EINVAL; + } + + bitno = (arfcn - min_arfcn) & 1023; + byte = bitno / 8; + bit = bitno % 8; + + chan_list[2 + byte] |= 1 << (7 - bit); + + return 0; +} + +/* generate a variable bitmap */ +static inline int enc_freq_lst_var_bitmap(uint8_t *chan_list, + struct bitvec *bv, const struct gsm_bts *bts, + bool bis, bool ter, int min, bool pgsm) +{ + int i; + + /* set it to 'Variable bitmap format' */ + chan_list[0] = 0x8e; + + chan_list[0] |= (min >> 9) & 1; + chan_list[1] = (min >> 1); + chan_list[2] = (min & 1) << 7; + + for (i = 0; i < bv->data_len*8; i++) { + /* see notes in bitvec2freq_list */ + if (bitvec_get_bit_pos(bv, i) + && ((!bis && !ter && band_compatible(bts,i)) + || (bis && pgsm && band_compatible(bts,i) && (i < 1 || i > 124)) + || (ter && !band_compatible(bts, i)))) { + int rc = freq_list_bmrel_set_arfcn(chan_list, i); + if (rc < 0) + return rc; + } + } + + return 0; +} + +int range_encode(enum gsm48_range r, int *arfcns, int arfcns_used, int *w, + int f0, uint8_t *chan_list) +{ + /* + * Manipulate the ARFCN list according to the rules in J4 depending + * on the selected range. + */ + int rc, f0_included; + + range_enc_filter_arfcns(arfcns, arfcns_used, f0, &f0_included); + + rc = range_enc_arfcns(r, arfcns, arfcns_used, w, 0); + if (rc < 0) + return rc; + + /* Select the range and the amount of bits needed */ + switch (r) { + case ARFCN_RANGE_128: + return range_enc_range128(chan_list, f0, w); + case ARFCN_RANGE_256: + return range_enc_range256(chan_list, f0, w); + case ARFCN_RANGE_512: + return range_enc_range512(chan_list, f0, w); + case ARFCN_RANGE_1024: + return range_enc_range1024(chan_list, f0, f0_included, w); + default: + return -ERANGE; + }; + + return f0_included; +} + +/* generate a frequency list with the range 512 format */ +static inline int enc_freq_lst_range(uint8_t *chan_list, + struct bitvec *bv, const struct gsm_bts *bts, + bool bis, bool ter, bool pgsm) +{ + int arfcns[RANGE_ENC_MAX_ARFCNS]; + int w[RANGE_ENC_MAX_ARFCNS]; + int arfcns_used = 0; + int i, range, f0; + + /* + * Select ARFCNs according to the rules in bitvec2freq_list + */ + for (i = 0; i < bv->data_len * 8; ++i) { + /* More ARFCNs than the maximum */ + if (arfcns_used > ARRAY_SIZE(arfcns)) + return -1; + /* Check if we can select it? */ + if (bitvec_get_bit_pos(bv, i) && use_arfcn(bts, bis, ter, pgsm, i)) + arfcns[arfcns_used++] = i; + } + + /* + * Check if the given list of ARFCNs can be encoded. + */ + range = range_enc_determine_range(arfcns, arfcns_used, &f0); + if (range == ARFCN_RANGE_INVALID) + return -2; + + memset(w, 0, sizeof(w)); + return range_encode(range, arfcns, arfcns_used, w, f0, chan_list); +} + +/* generate a cell channel list as per Section 10.5.2.1b of 04.08 */ +static int bitvec2freq_list(uint8_t *chan_list, struct bitvec *bv, + const struct gsm_bts *bts, bool bis, bool ter) +{ + int i, rc, min = -1, max = -1, arfcns = 0; + bool pgsm = false; + memset(chan_list, 0, 16); + + if (bts->band == GSM_BAND_900 + && bts->c0->arfcn >= 1 && bts->c0->arfcn <= 124) + pgsm = true; + /* P-GSM-only handsets only support 'bit map 0 format' */ + if (!bis && !ter && pgsm) { + chan_list[0] = 0; + + for (i = 0; i < bv->data_len*8; i++) { + if (i >= 1 && i <= 124 + && bitvec_get_bit_pos(bv, i)) { + rc = freq_list_bm0_set_arfcn(chan_list, i); + if (rc < 0) + return rc; + } + } + return 0; + } + + for (i = 0; i < bv->data_len*8; i++) { + /* in case of SI2 or SI5 allow all neighbours in same band + * in case of SI*bis, allow neighbours in same band ouside pgsm + * in case of SI*ter, allow neighbours in different bands + */ + if (!bitvec_get_bit_pos(bv, i)) + continue; + if (!use_arfcn(bts, bis, ter, pgsm, i)) + continue; + /* count the arfcns we want to carry */ + arfcns += 1; + + /* 955..1023 < 0..885 */ + if (min < 0) + min = i; + if (i >= 955 && min < 955) + min = i; + if (i >= 955 && min >= 955 && i < min) + min = i; + if (i < 955 && min < 955 && i < min) + min = i; + if (max < 0) + max = i; + if (i < 955 && max >= 955) + max = i; + if (i >= 955 && max >= 955 && i > max) + max = i; + if (i < 955 && max < 955 && i > max) + max = i; + } + + if (max == -1) { + /* Empty set, use 'bit map 0 format' */ + chan_list[0] = 0; + return 0; + } + + /* Now find the best encoding */ + if (((max - min) & 1023) <= 111) + return enc_freq_lst_var_bitmap(chan_list, bv, bts, bis, + ter, min, pgsm); + + /* Attempt to do the range encoding */ + rc = enc_freq_lst_range(chan_list, bv, bts, bis, ter, pgsm); + if (rc >= 0) + return 0; + + LOGP(DRR, LOGL_ERROR, "min_arfcn=%u, max_arfcn=%u, arfcns=%d " + "can not generate ARFCN list", min, max, arfcns); + return -EINVAL; +} + +/* generate a cell channel list as per Section 10.5.2.1b of 04.08 */ +/* static*/ int generate_cell_chan_list(uint8_t *chan_list, struct gsm_bts *bts) +{ + struct gsm_bts_trx *trx; + struct bitvec *bv = &bts->si_common.cell_alloc; + + /* Zero-initialize the bit-vector */ + memset(bv->data, 0, bv->data_len); + + /* first we generate a bitvec of all TRX ARFCN's in our BTS */ + llist_for_each_entry(trx, &bts->trx_list, list) { + unsigned int i, j; + /* Always add the TRX's ARFCN */ + bitvec_set_bit_pos(bv, trx->arfcn, 1); + for (i = 0; i < ARRAY_SIZE(trx->ts); i++) { + struct gsm_bts_trx_ts *ts = &trx->ts[i]; + /* Add any ARFCNs present in hopping channels */ + for (j = 0; j < 1024; j++) { + if (bitvec_get_bit_pos(&ts->hopping.arfcns, j)) + bitvec_set_bit_pos(bv, j, 1); + } + } + } + + /* then we generate a GSM 04.08 frequency list from the bitvec */ + return bitvec2freq_list(chan_list, bv, bts, false, false); +} + +/* generate a cell channel list as per Section 10.5.2.1b of 04.08 */ +static int generate_bcch_chan_list(uint8_t *chan_list, struct gsm_bts *bts, + bool si5, bool bis, bool ter) +{ + struct gsm_bts *cur_bts; + struct bitvec *bv; + + if (si5 && bts->neigh_list_manual_mode == NL_MODE_MANUAL_SI5SEP) + bv = &bts->si_common.si5_neigh_list; + else + bv = &bts->si_common.neigh_list; + + /* Generate list of neighbor cells if we are in automatic mode */ + if (bts->neigh_list_manual_mode == NL_MODE_AUTOMATIC) { + /* Zero-initialize the bit-vector */ + memset(bv->data, 0, bv->data_len); + + /* first we generate a bitvec of the BCCH ARFCN's in our BSC */ + llist_for_each_entry(cur_bts, &bts->network->bts_list, list) { + if (cur_bts == bts) + continue; + bitvec_set_bit_pos(bv, cur_bts->c0->arfcn, 1); + } + } + + /* then we generate a GSM 04.08 frequency list from the bitvec */ + return bitvec2freq_list(chan_list, bv, bts, bis, ter); +} + +static int list_arfcn(uint8_t *chan_list, uint8_t mask, char *text) +{ + int n = 0, i; + struct gsm_sysinfo_freq freq[1024]; + + memset(freq, 0, sizeof(freq)); + gsm48_decode_freq_list(freq, chan_list, 16, 0xce, 1); + for (i = 0; i < 1024; i++) { + if (freq[i].mask) { + if (!n) + LOGP(DRR, LOGL_INFO, "%s", text); + LOGPC(DRR, LOGL_INFO, " %d", i); + n++; + } + } + if (n) + LOGPC(DRR, LOGL_INFO, "\n"); + + return n; +} + +static int generate_si1(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_1 *si1 = (struct gsm48_system_information_type_1 *) GSM_BTS_SI(bts, t); + + memset(si1, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si1->header.l2_plen = GSM48_LEN2PLEN(21); + 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; + list_arfcn(si1->cell_channel_description, 0xce, "Serving cell:"); + + si1->rach_control = bts->si_common.rach_control; + + /* + * SI1 Rest Octets (10.5.2.32), contains NCH position and band + * indicator but that is not in the 04.08. + */ + rc = rest_octets_si1(si1->rest_octets, NULL, is_dcs_net(bts)); + + return sizeof(*si1) + rc; +} + +static int generate_si2(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_2 *si2 = (struct gsm48_system_information_type_2 *) GSM_BTS_SI(bts, t); + + memset(si2, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si2->header.l2_plen = GSM48_LEN2PLEN(22); + 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, false, false, false); + if (rc < 0) + return rc; + list_arfcn(si2->bcch_frequency_list, 0xce, + "SI2 Neighbour cells in same band:"); + + si2->ncc_permitted = bts->si_common.ncc_permitted; + si2->rach_control = bts->si_common.rach_control; + + return sizeof(*si2); +} + +static int generate_si2bis(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_2bis *si2b = + (struct gsm48_system_information_type_2bis *) GSM_BTS_SI(bts, t); + int n; + + memset(si2b, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si2b->header.l2_plen = GSM48_LEN2PLEN(22); + si2b->header.rr_protocol_discriminator = GSM48_PDISC_RR; + si2b->header.skip_indicator = 0; + si2b->header.system_information = GSM48_MT_RR_SYSINFO_2bis; + + rc = generate_bcch_chan_list(si2b->bcch_frequency_list, bts, false, true, false); + if (rc < 0) + return rc; + n = list_arfcn(si2b->bcch_frequency_list, 0xce, + "Neighbour cells in same band, but outside P-GSM:"); + if (n) { + /* indicate in SI2 and SI2bis: there is an extension */ + struct gsm48_system_information_type_2 *si2 = + (struct gsm48_system_information_type_2 *) GSM_BTS_SI(bts, SYSINFO_TYPE_2); + si2->bcch_frequency_list[0] |= 0x20; + si2b->bcch_frequency_list[0] |= 0x20; + } else + bts->si_valid &= ~(1 << SYSINFO_TYPE_2bis); + + si2b->rach_control = bts->si_common.rach_control; + + return sizeof(*si2b); +} + +static int generate_si2ter(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_2ter *si2t = + (struct gsm48_system_information_type_2ter *) GSM_BTS_SI(bts, t); + int n; + + memset(si2t, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si2t->header.l2_plen = GSM48_LEN2PLEN(22); + si2t->header.rr_protocol_discriminator = GSM48_PDISC_RR; + si2t->header.skip_indicator = 0; + si2t->header.system_information = GSM48_MT_RR_SYSINFO_2ter; + + rc = generate_bcch_chan_list(si2t->ext_bcch_frequency_list, bts, false, false, true); + if (rc < 0) + return rc; + n = list_arfcn(si2t->ext_bcch_frequency_list, 0x8e, + "Neighbour cells in different band:"); + if (!n) + bts->si_valid &= ~(1 << SYSINFO_TYPE_2ter); + + return sizeof(*si2t); +} + +/* SI2quater messages are optional - we only generate them when neighbor UARFCNs or EARFCNs are configured */ +static inline bool si2quater_not_needed(struct gsm_bts *bts) +{ + unsigned i = MAX_EARFCN_LIST; + + if (bts->si_common.si2quater_neigh_list.arfcn) + for (i = 0; i < MAX_EARFCN_LIST; i++) + if (bts->si_common.si2quater_neigh_list.arfcn[i] != OSMO_EARFCN_INVALID) + break; + + if (!bts->si_common.uarfcn_length && i == MAX_EARFCN_LIST) { + bts->si_valid &= ~(1 << SYSINFO_TYPE_2quater); /* mark SI2q as invalid if no (E|U)ARFCNs are present */ + return true; + } + + return false; +} + +static int generate_si2quater(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_2quater *si2q; + + if (si2quater_not_needed(bts)) /* generate rest_octets for SI2q only when necessary */ + return GSM_MACBLOCK_LEN; + + bts->u_offset = 0; + bts->e_offset = 0; + bts->si2q_index = 0; + bts->si2q_count = si2q_num(bts) - 1; + + rc = make_si2quaters(bts, false); + if (rc < 0) + return rc; + + OSMO_ASSERT(bts->si2q_count == bts->si2q_index); + OSMO_ASSERT(bts->si2q_count <= SI2Q_MAX_NUM); + + return sizeof(*si2q) + rc; +} + +static 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 = 1, + }, + .si2quater_indicator = 0, + .lsa_params = { + .present = 0, + }, + .cell_id = 0, /* FIXME: doesn't the bts have this? */ + .break_ind = 0, +}; + +static int generate_si3(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_3 *si3 = (struct gsm48_system_information_type_3 *) GSM_BTS_SI(bts, t); + + memset(si3, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + si3->header.l2_plen = GSM48_LEN2PLEN(18); + 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); + gsm48_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; + + /* allow/disallow DTXu */ + gsm48_set_dtx(&si3->cell_options, bts->dtxu, bts->dtxu, true); + + if (GSM_BTS_HAS_SI(bts, SYSINFO_TYPE_2ter)) { + LOGP(DRR, LOGL_INFO, "SI 2ter is included.\n"); + si_info.si2ter_indicator = 1; + } else { + si_info.si2ter_indicator = 0; + } + if (GSM_BTS_HAS_SI(bts, SYSINFO_TYPE_2quater)) { + LOGP(DRR, LOGL_INFO, "SI 2quater is included, based on %zu EARFCNs and %zu UARFCNs.\n", + si2q_earfcn_count(&bts->si_common.si2quater_neigh_list), bts->si_common.uarfcn_length); + si_info.si2quater_indicator = 1; + } else { + si_info.si2quater_indicator = 0; + } + si_info.early_cm_ctrl = bts->early_classmark_allowed; + + /* 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 */ + rc = rest_octets_si3(si3->rest_octets, &si_info); + + return sizeof(*si3) + rc; +} + +static int generate_si4(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + int rc; + struct gsm48_system_information_type_4 *si4 = (struct gsm48_system_information_type_4 *) GSM_BTS_SI(bts, t); + struct gsm_lchan *cbch_lchan; + uint8_t *restoct = si4->data; + + /* 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; + + gsm48_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 */ + cbch_lchan = gsm_bts_get_cbch(bts); + if (cbch_lchan) { + struct gsm48_chan_desc cd; + gsm48_lchan2chan_desc(&cd, cbch_lchan); + tv_fixed_put(si4->data, GSM48_IE_CBCH_CHAN_DESC, 3, + (uint8_t *) &cd); + l2_plen += 3 + 1; + restoct += 3 + 1; + /* we don't use hopping and thus don't need a CBCH MA */ + } + + si4->header.l2_plen = GSM48_LEN2PLEN(l2_plen); + + /* SI4 Rest Octets (10.5.2.35), containing + Optional Power offset, GPRS Indicator, + Cell Identity, LSA ID, Selection Parameter */ + rc = rest_octets_si4(restoct, &si_info, (uint8_t *)GSM_BTS_SI(bts, t) + GSM_MACBLOCK_LEN - restoct); + + return l2_plen + 1 + rc; +} + +static int generate_si5(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + struct gsm48_system_information_type_5 *si5; + uint8_t *output = GSM_BTS_SI(bts, t); + int rc, l2_plen = 18; + + memset(output, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + /* ip.access nanoBTS needs l2_plen!! */ + switch (bts->type) { + case GSM_BTS_TYPE_NANOBTS: + case GSM_BTS_TYPE_OSMOBTS: + *output++ = GSM48_LEN2PLEN(l2_plen); + l2_plen++; + break; + default: + break; + } + + si5 = (struct gsm48_system_information_type_5 *) GSM_BTS_SI(bts, t); + + /* 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, true, false, false); + if (rc < 0) + return rc; + list_arfcn(si5->bcch_frequency_list, 0xce, + "SI5 Neighbour cells in same band:"); + + /* 04.08 9.1.37: L2 Pseudo Length of 18 */ + return l2_plen; +} + +static int generate_si5bis(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + struct gsm48_system_information_type_5bis *si5b; + uint8_t *output = GSM_BTS_SI(bts, t); + int rc, l2_plen = 18; + int n; + + memset(output, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + /* ip.access nanoBTS needs l2_plen!! */ + switch (bts->type) { + case GSM_BTS_TYPE_NANOBTS: + case GSM_BTS_TYPE_OSMOBTS: + *output++ = GSM48_LEN2PLEN(l2_plen); + l2_plen++; + break; + default: + break; + } + + si5b = (struct gsm48_system_information_type_5bis *) GSM_BTS_SI(bts, t); + + /* l2 pseudo length, not part of msg: 18 */ + si5b->rr_protocol_discriminator = GSM48_PDISC_RR; + si5b->skip_indicator = 0; + si5b->system_information = GSM48_MT_RR_SYSINFO_5bis; + rc = generate_bcch_chan_list(si5b->bcch_frequency_list, bts, true, true, false); + if (rc < 0) + return rc; + n = list_arfcn(si5b->bcch_frequency_list, 0xce, + "Neighbour cells in same band, but outside P-GSM:"); + if (n) { + /* indicate in SI5 and SI5bis: there is an extension */ + struct gsm48_system_information_type_5 *si5 = + (struct gsm48_system_information_type_5 *) GSM_BTS_SI(bts, SYSINFO_TYPE_5); + si5->bcch_frequency_list[0] |= 0x20; + si5b->bcch_frequency_list[0] |= 0x20; + } else + bts->si_valid &= ~(1 << SYSINFO_TYPE_5bis); + + /* 04.08 9.1.37: L2 Pseudo Length of 18 */ + return l2_plen; +} + +static int generate_si5ter(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + struct gsm48_system_information_type_5ter *si5t; + uint8_t *output = GSM_BTS_SI(bts, t); + int rc, l2_plen = 18; + int n; + + memset(output, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + /* ip.access nanoBTS needs l2_plen!! */ + switch (bts->type) { + case GSM_BTS_TYPE_NANOBTS: + case GSM_BTS_TYPE_OSMOBTS: + *output++ = GSM48_LEN2PLEN(l2_plen); + l2_plen++; + break; + default: + break; + } + + si5t = (struct gsm48_system_information_type_5ter *) GSM_BTS_SI(bts, t); + + /* l2 pseudo length, not part of msg: 18 */ + si5t->rr_protocol_discriminator = GSM48_PDISC_RR; + si5t->skip_indicator = 0; + si5t->system_information = GSM48_MT_RR_SYSINFO_5ter; + rc = generate_bcch_chan_list(si5t->bcch_frequency_list, bts, true, false, true); + if (rc < 0) + return rc; + n = list_arfcn(si5t->bcch_frequency_list, 0x8e, + "Neighbour cells in different band:"); + if (!n) + bts->si_valid &= ~(1 << SYSINFO_TYPE_5ter); + + /* 04.08 9.1.37: L2 Pseudo Length of 18 */ + return l2_plen; +} + +static int generate_si6(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + struct gsm48_system_information_type_6 *si6; + uint8_t *output = GSM_BTS_SI(bts, t); + int l2_plen = 11; + int rc; + + memset(output, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN); + + /* ip.access nanoBTS needs l2_plen!! */ + switch (bts->type) { + case GSM_BTS_TYPE_NANOBTS: + case GSM_BTS_TYPE_OSMOBTS: + *output++ = GSM48_LEN2PLEN(l2_plen); + l2_plen++; + break; + default: + break; + } + + si6 = (struct gsm48_system_information_type_6 *) GSM_BTS_SI(bts, t); + + /* 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); + gsm48_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; + /* allow/disallow DTXu */ + gsm48_set_dtx(&si6->cell_options, bts->dtxu, bts->dtxu, false); + + /* SI6 Rest Octets: 10.5.2.35a: PCH / NCH info, VBS/VGCS options */ + rc = rest_octets_si6(si6->rest_octets, is_dcs_net(bts)); + + return l2_plen + rc; +} + +static struct gsm48_si13_info si13_default = { + .cell_opts = { + .nmo = GPRS_NMO_II, + .t3168 = 2000, + .t3192 = 1500, + .drx_timer_max = 3, + .bs_cv_max = 15, + .ctrl_ack_type_use_block = true, + .ext_info_present = 0, + .supports_egprs_11bit_rach = 0, + .ext_info = { + /* The values below are just guesses ! */ + .egprs_supported = 0, + .use_egprs_p_ch_req = 1, + .bep_period = 5, + .pfc_supported = 0, + .dtm_supported = 0, + .bss_paging_coordination = 0, + }, + }, + .pwr_ctrl_pars = { + .alpha = 0, /* a = 0.0 */ + .t_avg_w = 16, + .t_avg_t = 16, + .pc_meas_chan = 0, /* downling measured on CCCH */ + .n_avg_i = 8, + }, + .bcch_change_mark = 1, + .si_change_field = 0, + .pbcch_present = 0, + { + .no_pbcch = { + .rac = 0, /* needs to be patched */ + .spgc_ccch_sup = 0, + .net_ctrl_ord = 0, + .prio_acc_thr = 6, + }, + }, +}; + +static int generate_si13(enum osmo_sysinfo_type t, struct gsm_bts *bts) +{ + struct gsm48_system_information_type_13 *si13 = + (struct gsm48_system_information_type_13 *) GSM_BTS_SI(bts, t); + 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; + + si13_default.no_pbcch.rac = bts->gprs.rac; + si13_default.no_pbcch.net_ctrl_ord = bts->gprs.net_ctrl_ord; + + si13_default.cell_opts.ctrl_ack_type_use_block = + bts->gprs.ctrl_ack_type_use_block; + + /* Information about the other SIs */ + si13_default.bcch_change_mark = bts->bcch_change_mark; + si13_default.cell_opts.supports_egprs_11bit_rach = + bts->gprs.supports_egprs_11bit_rach; + + ret = rest_octets_si13(si13->rest_octets, &si13_default); + if (ret < 0) + return ret; + + /* length is coded in bit 2 an up */ + si13->header.l2_plen = 0x01; + + return sizeof (*si13) + ret; +} + +typedef int (*gen_si_fn_t)(enum osmo_sysinfo_type t, struct gsm_bts *bts); + +static const gen_si_fn_t gen_si_fn[_MAX_SYSINFO_TYPE] = { + [SYSINFO_TYPE_1] = &generate_si1, + [SYSINFO_TYPE_2] = &generate_si2, + [SYSINFO_TYPE_2bis] = &generate_si2bis, + [SYSINFO_TYPE_2ter] = &generate_si2ter, + [SYSINFO_TYPE_2quater] = &generate_si2quater, + [SYSINFO_TYPE_3] = &generate_si3, + [SYSINFO_TYPE_4] = &generate_si4, + [SYSINFO_TYPE_5] = &generate_si5, + [SYSINFO_TYPE_5bis] = &generate_si5bis, + [SYSINFO_TYPE_5ter] = &generate_si5ter, + [SYSINFO_TYPE_6] = &generate_si6, + [SYSINFO_TYPE_13] = &generate_si13, +}; + +int gsm_generate_si(struct gsm_bts *bts, enum osmo_sysinfo_type si_type) +{ + gen_si_fn_t gen_si; + + switch (bts->gprs.mode) { + case BTS_GPRS_EGPRS: + si13_default.cell_opts.ext_info_present = 1; + si13_default.cell_opts.ext_info.egprs_supported = 1; + /* fallthrough */ + case BTS_GPRS_GPRS: + si_info.gprs_ind.present = 1; + break; + case BTS_GPRS_NONE: + si_info.gprs_ind.present = 0; + break; + } + + memcpy(&si_info.selection_params, + &bts->si_common.cell_ro_sel_par, + sizeof(struct gsm48_si_selection_params)); + + gen_si = gen_si_fn[si_type]; + if (!gen_si) + return -EINVAL; + + return gen_si(si_type, bts); +} |