diff options
Diffstat (limited to 'src/osmo-bts-trx/gsm0503_coding.c')
| -rw-r--r-- | src/osmo-bts-trx/gsm0503_coding.c | 2698 |
1 files changed, 0 insertions, 2698 deletions
diff --git a/src/osmo-bts-trx/gsm0503_coding.c b/src/osmo-bts-trx/gsm0503_coding.c deleted file mode 100644 index 4c4f7f1e..00000000 --- a/src/osmo-bts-trx/gsm0503_coding.c +++ /dev/null @@ -1,2698 +0,0 @@ -/* (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> - * (C) 2015 by Alexander Chemeris <Alexander.Chemeris@fairwaves.co> - * (C) 2016 by Tom Tsou <tom.tsou@ettus.com> - * - * 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 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 <stdio.h> -#include <stdint.h> -#include <string.h> -#include <stdlib.h> - -#include <osmocom/core/utils.h> -#include <osmocom/core/bits.h> -#include <osmocom/core/conv.h> -#include <osmocom/core/crcgen.h> -#include <osmocom/core/endian.h> -#include <osmocom/codec/codec.h> -#include <osmocom/gprs/gprs_rlc.h> -#include <osmocom/gprs/protocol/gsm_04_60.h> - -#include <osmo-bts/logging.h> -#include <osmo-bts/gsm_data.h> - -#include "gsm0503_conv.h" -#include "gsm0503_parity.h" -#include "gsm0503_mapping.h" -#include "gsm0503_interleaving.h" -#include "gsm0503_tables.h" -#include "gsm0503_coding.h" - -/* - * EGPRS coding limits - */ - -/* Max header size with parity bits */ -#define EGPRS_HDR_UPP_MAX 54 - -/* Max encoded header size */ -#define EGPRS_HDR_C_MAX 162 - -/* Max punctured header size */ -#define EGPRS_HDR_HC_MAX 160 - -/* Max data block size with parity bits */ -#define EGPRS_DATA_U_MAX 612 - -/* Max encoded data block size */ -#define EGPRS_DATA_C_MAX 1836 - -/* Max single block punctured data size */ -#define EGPRS_DATA_DC_MAX 1248 - -/* Dual block punctured data size */ -#define EGPRS_DATA_C1 612 -#define EGPRS_DATA_C2 EGPRS_DATA_C1 - -struct gsm0503_mcs_code { - uint8_t mcs; - uint8_t usf_len; - - /* Header coding */ - uint8_t hdr_len; - uint8_t hdr_code_len; - uint8_t hdr_punc_len; - const struct osmo_conv_code *hdr_conv; - const uint8_t *hdr_punc; - - /* Data coding */ - uint16_t data_len; - uint16_t data_code_len; - uint16_t data_punc_len; - const struct osmo_conv_code *data_conv; - const uint8_t *data_punc[3]; -}; - -/* - * EGPRS UL coding parameters - */ -struct gsm0503_mcs_code gsm0503_mcs_ul_codes[EGPRS_NUM_MCS] = { - { - .mcs = EGPRS_MCS0, - }, - { - .mcs = EGPRS_MCS1, - .hdr_len = 31, - .hdr_code_len = 117, - .hdr_punc_len = 80, - .hdr_conv = &gsm0503_conv_mcs1_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, - - .data_len = 178, - .data_code_len = 588, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs1, - .data_punc = { - gsm0503_puncture_mcs1_p1, - gsm0503_puncture_mcs1_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS2, - .hdr_len = 31, - .hdr_code_len = 117, - .hdr_punc_len = 80, - .hdr_conv = &gsm0503_conv_mcs1_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, - - .data_len = 226, - .data_code_len = 732, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs2, - .data_punc = { - gsm0503_puncture_mcs2_p1, - gsm0503_puncture_mcs2_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS3, - .hdr_len = 31, - .hdr_code_len = 117, - .hdr_punc_len = 80, - .hdr_conv = &gsm0503_conv_mcs1_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, - - .data_len = 298, - .data_code_len = 948, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs3, - .data_punc = { - gsm0503_puncture_mcs3_p1, - gsm0503_puncture_mcs3_p2, - gsm0503_puncture_mcs3_p3, - }, - }, - { - .mcs = EGPRS_MCS4, - .hdr_len = 31, - .hdr_code_len = 117, - .hdr_punc_len = 80, - .hdr_conv = &gsm0503_conv_mcs1_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, - - .data_len = 354, - .data_code_len = 1116, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs4, - .data_punc = { - gsm0503_puncture_mcs4_p1, - gsm0503_puncture_mcs4_p2, - gsm0503_puncture_mcs4_p3, - }, - }, - { - .mcs = EGPRS_MCS5, - .hdr_len = 37, - .hdr_code_len = 135, - .hdr_punc_len = 136, - .hdr_conv = &gsm0503_conv_mcs5_ul_hdr, - .hdr_punc = NULL, - - .data_len = 450, - .data_code_len = 1404, - .data_punc_len = 1248, - .data_conv = &gsm0503_conv_mcs5, - .data_punc = { - gsm0503_puncture_mcs5_p1, - gsm0503_puncture_mcs5_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS6, - .hdr_len = 37, - .hdr_code_len = 135, - .hdr_punc_len = 136, - .hdr_conv = &gsm0503_conv_mcs5_ul_hdr, - .hdr_punc = NULL, - - .data_len = 594, - .data_code_len = 1836, - .data_punc_len = 1248, - .data_conv = &gsm0503_conv_mcs6, - .data_punc = { - gsm0503_puncture_mcs6_p1, - gsm0503_puncture_mcs6_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS7, - .hdr_len = 46, - .hdr_code_len = 162, - .hdr_punc_len = 160, - .hdr_conv = &gsm0503_conv_mcs7_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, - .hdr_len = 46, - - .data_len = 900, - .data_code_len = 1404, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs7, - .data_punc = { - gsm0503_puncture_mcs7_p1, - gsm0503_puncture_mcs7_p2, - gsm0503_puncture_mcs7_p3, - } - }, - { - .mcs = EGPRS_MCS8, - .hdr_len = 46, - .hdr_code_len = 162, - .hdr_punc_len = 160, - .hdr_conv = &gsm0503_conv_mcs7_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, - .hdr_len = 46, - - .data_len = 1092, - .data_code_len = 1692, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs8, - .data_punc = { - gsm0503_puncture_mcs8_p1, - gsm0503_puncture_mcs8_p2, - gsm0503_puncture_mcs8_p3, - } - }, - { - .mcs = EGPRS_MCS9, - .hdr_len = 46, - .hdr_code_len = 162, - .hdr_punc_len = 160, - .hdr_conv = &gsm0503_conv_mcs7_ul_hdr, - .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, - .hdr_len = 46, - - .data_len = 1188, - .data_code_len = 1836, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs9, - .data_punc = { - gsm0503_puncture_mcs9_p1, - gsm0503_puncture_mcs9_p2, - gsm0503_puncture_mcs9_p3, - } - }, -}; - -/* - * EGPRS DL coding parameters - */ -struct gsm0503_mcs_code gsm0503_mcs_dl_codes[EGPRS_NUM_MCS] = { - { - .mcs = EGPRS_MCS0, - }, - { - .mcs = EGPRS_MCS1, - .usf_len = 3, - .hdr_len = 28, - .hdr_code_len = 108, - .hdr_punc_len = 68, - .hdr_conv = &gsm0503_conv_mcs1_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, - - .data_len = 178, - .data_code_len = 588, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs1, - .data_punc = { - gsm0503_puncture_mcs1_p1, - gsm0503_puncture_mcs1_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS2, - .usf_len = 3, - .hdr_len = 28, - .hdr_code_len = 108, - .hdr_punc_len = 68, - .hdr_conv = &gsm0503_conv_mcs1_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, - - .data_len = 226, - .data_code_len = 732, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs2, - .data_punc = { - gsm0503_puncture_mcs2_p1, - gsm0503_puncture_mcs2_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS3, - .usf_len = 3, - .hdr_len = 28, - .hdr_code_len = 108, - .hdr_punc_len = 68, - .hdr_conv = &gsm0503_conv_mcs1_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, - - .data_len = 298, - .data_code_len = 948, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs3, - .data_punc = { - gsm0503_puncture_mcs3_p1, - gsm0503_puncture_mcs3_p2, - gsm0503_puncture_mcs3_p3, - }, - }, - { - .mcs = EGPRS_MCS4, - .usf_len = 3, - .hdr_len = 28, - .hdr_code_len = 108, - .hdr_punc_len = 68, - .hdr_conv = &gsm0503_conv_mcs1_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, - - .data_len = 354, - .data_code_len = 1116, - .data_punc_len = 372, - .data_conv = &gsm0503_conv_mcs4, - .data_punc = { - gsm0503_puncture_mcs4_p1, - gsm0503_puncture_mcs4_p2, - gsm0503_puncture_mcs4_p3, - }, - }, - { - .mcs = EGPRS_MCS5, - .usf_len = 3, - .hdr_len = 25, - .hdr_code_len = 99, - .hdr_punc_len = 100, - .hdr_conv = &gsm0503_conv_mcs5_dl_hdr, - .hdr_punc = NULL, - - .data_len = 450, - .data_code_len = 1404, - .data_punc_len = 1248, - .data_conv = &gsm0503_conv_mcs5, - .data_punc = { - gsm0503_puncture_mcs5_p1, - gsm0503_puncture_mcs5_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS6, - .usf_len = 3, - .hdr_len = 25, - .hdr_code_len = 99, - .hdr_punc_len = 100, - .hdr_conv = &gsm0503_conv_mcs5_dl_hdr, - .hdr_punc = NULL, - - .data_len = 594, - .data_code_len = 1836, - .data_punc_len = 1248, - .data_conv = &gsm0503_conv_mcs6, - .data_punc = { - gsm0503_puncture_mcs6_p1, - gsm0503_puncture_mcs6_p2, - NULL, - }, - }, - { - .mcs = EGPRS_MCS7, - .usf_len = 3, - .hdr_len = 37, - .hdr_code_len = 135, - .hdr_punc_len = 124, - .hdr_conv = &gsm0503_conv_mcs7_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, - - .data_len = 900, - .data_code_len = 1404, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs7, - .data_punc = { - gsm0503_puncture_mcs7_p1, - gsm0503_puncture_mcs7_p2, - gsm0503_puncture_mcs7_p3, - } - }, - { - .mcs = EGPRS_MCS8, - .usf_len = 3, - .hdr_len = 37, - .hdr_code_len = 135, - .hdr_punc_len = 124, - .hdr_conv = &gsm0503_conv_mcs7_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, - - .data_len = 1092, - .data_code_len = 1692, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs8, - .data_punc = { - gsm0503_puncture_mcs8_p1, - gsm0503_puncture_mcs8_p2, - gsm0503_puncture_mcs8_p3, - } - }, - { - .mcs = EGPRS_MCS9, - .usf_len = 3, - .hdr_len = 37, - .hdr_code_len = 135, - .hdr_punc_len = 124, - .hdr_conv = &gsm0503_conv_mcs7_dl_hdr, - .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, - - .data_len = 1188, - .data_code_len = 1836, - .data_punc_len = 612, - .data_conv = &gsm0503_conv_mcs9, - .data_punc = { - gsm0503_puncture_mcs9_p1, - gsm0503_puncture_mcs9_p2, - gsm0503_puncture_mcs9_p3, - } - }, -}; - -static int osmo_conv_decode_ber(const struct osmo_conv_code *code, - const sbit_t *input, ubit_t *output, - int *n_errors, int *n_bits_total) -{ - int res, i, coded_len; - ubit_t recoded[EGPRS_DATA_C_MAX]; - - res = osmo_conv_decode(code, input, output); - - if (n_bits_total || n_errors) { - coded_len = osmo_conv_encode(code, output, recoded); - OSMO_ASSERT(sizeof(recoded)/sizeof(recoded[0]) >= coded_len); - } - - /* Count bit errors */ - if (n_errors) { - *n_errors = 0; - for (i = 0; i < coded_len; i++) { - if (! ((recoded[i] && input[i]<0) || - (!recoded[i] && input[i]>0)) ) - *n_errors += 1; - } - } - - if (n_bits_total) - *n_bits_total = coded_len; - - return res; -} - - -static int _xcch_decode_cB(uint8_t *l2_data, sbit_t *cB, - int *n_errors, int *n_bits_total) -{ - ubit_t conv[224]; - int rv; - - osmo_conv_decode_ber(&gsm0503_conv_xcch, cB, conv, n_errors, n_bits_total); - - rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, conv, 184, conv+184); - if (rv) - return -1; - - osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); - - return 0; -} - -static int _xcch_encode_cB(ubit_t *cB, uint8_t *l2_data) -{ - ubit_t conv[224]; - - osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); - - osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv+184); - - osmo_conv_encode(&gsm0503_conv_xcch, conv, cB); - - return 0; -} - - -/* - * GSM xCCH block transcoding - */ - -int xcch_decode(uint8_t *l2_data, sbit_t *bursts, - int *n_errors, int *n_bits_total) -{ - sbit_t iB[456], cB[456]; - int i; - - for (i=0; i<4; i++) - gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, - NULL); - - gsm0503_xcch_deinterleave(cB, iB); - - return _xcch_decode_cB(l2_data, cB, n_errors, n_bits_total); -} - -int xcch_encode(ubit_t *bursts, uint8_t *l2_data) -{ - ubit_t iB[456], cB[456], hl = 1, hn = 1; - int i; - - _xcch_encode_cB(cB, l2_data); - - gsm0503_xcch_interleave(cB, iB); - - for (i=0; i<4; i++) - gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], &hl, - &hn); - - return 0; -} - -/* - * EGPRS PDTCH UL block decoding - */ - -/* - * Type 3 - MCS-1,2,3,4 - * Unmapping and deinterleaving - */ -static int egprs_type3_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc) -{ - int i; - sbit_t iB[456], q[8]; - - for (i=0; i<4; i++) - gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], - q + i*2, q + i*2 + 1); - - gsm0503_mcs1_ul_deinterleave(hc, dc, iB); - - return 0; -} - -/* - * Type 2 - MCS-5,6 - * Unmapping and deinterleaving - */ -static int egprs_type2_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc) -{ - int i; - sbit_t burst[348]; - sbit_t hi[EGPRS_HDR_HC_MAX]; - sbit_t di[EGPRS_DATA_DC_MAX]; - - for (i=0; i<4; i++) { - memcpy(burst, &bursts[i * 348], 348); - - gsm0503_mcs5_burst_swap(burst); - gsm0503_mcs5_ul_burst_unmap(di, burst, hi, i); - } - - gsm0503_mcs5_ul_deinterleave(hc, dc, hi, di); - - return 0; -} - -/* - * Type 1 - MCS-7,8,9 - * Unmapping and deinterleaving - Note that MCS-7 interleaver is unique - */ -static int egprs_type1_unmap(const sbit_t *bursts, sbit_t *hc, - sbit_t *c1, sbit_t *c2, int msc) -{ - int i; - sbit_t burst[348]; - sbit_t hi[EGPRS_HDR_HC_MAX]; - sbit_t di[EGPRS_DATA_C1 * 2]; - - for (i = 0; i < 4; i++) { - memcpy(burst, &bursts[i * 348], 348); - - gsm0503_mcs5_burst_swap(burst); - gsm0503_mcs7_ul_burst_unmap(di, burst, hi, i); - } - - if (msc == EGPRS_MCS7) - gsm0503_mcs7_ul_deinterleave(hc, c1, c2, hi, di); - else - gsm0503_mcs8_ul_deinterleave(hc, c1, c2, hi, di); - - return 0; -} - -union gprs_rlc_ul_hdr_egprs { - struct gprs_rlc_ul_header_egprs_1 type1; - struct gprs_rlc_ul_header_egprs_2 type2; - struct gprs_rlc_ul_header_egprs_3 type3; -}; - -/* - * Decode EGPRS UL header section - * - * 1. Depuncture - * 2. Convolutional decoding - * 3. CRC check - */ -static int _egprs_decode_hdr(const sbit_t *hc, int mcs, - union gprs_rlc_ul_hdr_egprs *hdr) -{ - sbit_t C[EGPRS_HDR_C_MAX]; - ubit_t upp[EGPRS_HDR_UPP_MAX]; - int i, j, rc; - struct gsm0503_mcs_code *code; - - code = &gsm0503_mcs_ul_codes[mcs]; - - /* Skip depuncturing on MCS-5,6 header */ - if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) { - memcpy(C, hc, code->hdr_code_len); - goto hdr_conv_decode; - } - - if (!code->hdr_punc) { - LOGP(DL1C, LOGL_ERROR, - "Invalid MCS-%u header puncture matrix\n", mcs); - return -1; - } - - i = code->hdr_code_len - 1; - j = code->hdr_punc_len - 1; - - for (; i >= 0; i--) { - if (!code->hdr_punc[i]) - C[i] = hc[j--]; - else - C[i] = 0; - } - -hdr_conv_decode: - osmo_conv_decode_ber(code->hdr_conv, C, upp, NULL, NULL); - rc = osmo_crc8gen_check_bits(&gsm0503_mcs_crc8_hdr, upp, - code->hdr_len, upp + code->hdr_len); - if (rc) - return -1; - - osmo_ubit2pbit_ext((pbit_t *) hdr, 0, upp, 0, code->hdr_len, 1); - - return 0; -} - -/* - * Blind MCS header decoding based on burst length and CRC validation. - * Ignore 'q' value coding indentification. This approach provides - * the strongest chance of header recovery. - */ -static int egprs_decode_hdr(union gprs_rlc_ul_hdr_egprs *hdr, - const sbit_t *bursts, uint16_t nbits) -{ - int rc; - sbit_t hc[EGPRS_HDR_HC_MAX]; - - if (nbits == GSM0503_GPRS_BURSTS_NBITS) { - /* MCS-1,2,3,4 */ - egprs_type3_unmap(bursts, hc, NULL); - rc = _egprs_decode_hdr(hc, EGPRS_MCS1, hdr); - if (!rc) - return EGPRS_HDR_TYPE3; - } else if (nbits == GSM0503_EGPRS_BURSTS_NBITS) { - /* MCS-5,6 */ - egprs_type2_unmap(bursts, hc, NULL); - rc = _egprs_decode_hdr(hc, EGPRS_MCS5, hdr); - if (!rc) - return EGPRS_HDR_TYPE2; - - /* MCS-7,8,9 */ - egprs_type1_unmap(bursts, hc, NULL, NULL, EGPRS_MCS7); - rc = _egprs_decode_hdr(hc, EGPRS_MCS7, hdr); - if (!rc) - return EGPRS_HDR_TYPE1; - } - - return -1; -} - -/* - * Parse EGPRS UL header for coding and puncturing scheme (CPS) - * - * Type 1 - MCS-7,8,9 - * Type 2 - MCS-5,6 - * Type 3 - MCS-1,2,3,4 - */ -static int egprs_parse_ul_cps(struct egprs_cps *cps, - union gprs_rlc_ul_hdr_egprs *hdr, int type) -{ - uint8_t bits; - - switch (type) { - case EGPRS_HDR_TYPE1: - bits = hdr->type1.cps; - break; - case EGPRS_HDR_TYPE2: - bits = (hdr->type2.cps_lo << 2) | hdr->type2.cps_hi; - break; - case EGPRS_HDR_TYPE3: - bits = (hdr->type3.cps_lo << 2) | hdr->type3.cps_hi; - break; - default: - return -1; - } - - return egprs_get_cps(cps, type, bits); -} - -#define NUM_BYTES(N) ((N + 8 - 1) / 8) - -/* - * Decode EGPRS UL data section - * - * 1. Depuncture - * 2. Convolutional decoding - * 3. CRC check - * 4. Block combining (MCS-7,8,9 only) - */ -static int egprs_decode_data(uint8_t *l2_data, sbit_t *c, - int mcs, int p, int blk, - int *n_errors, int *n_bits_total) -{ - ubit_t u[EGPRS_DATA_U_MAX]; - sbit_t C[EGPRS_DATA_C_MAX]; - - int i, j, rc, data_len; - struct gsm0503_mcs_code *code; - - if (blk && mcs < EGPRS_MCS7) { - LOGP(DL1C, LOGL_ERROR, "Invalid MCS-%u block state\n", mcs); - return -1; - } - - code = &gsm0503_mcs_ul_codes[mcs]; - if (!code->data_punc[p]) { - LOGP(DL1C, LOGL_ERROR, - "Invalid MCS-%u data puncture matrix %i\n", mcs, p); - return -1; - } - - /* - * MCS-1,6 - single block processing - * MCS-7,9 - dual block processing - */ - if (mcs >= EGPRS_MCS7) - data_len = code->data_len / 2; - else - data_len = code->data_len; - - i = code->data_code_len - 1; - j = code->data_punc_len - 1; - - for (; i >= 0; i--) { - if (!code->data_punc[p][i]) - C[i] = c[j--]; - else - C[i] = 0; - } - - osmo_conv_decode_ber(code->data_conv, C, u, n_errors, n_bits_total); - rc = osmo_crc16gen_check_bits(&gsm0503_mcs_crc12, u, - data_len, u + data_len); - if (rc) - return -1; - - /* Offsets output pointer on the second block of Type 1 MCS */ - osmo_ubit2pbit_ext(l2_data, code->hdr_len + blk * data_len, - u, 0, data_len, 1); - - /* Return the number of bytes required for the bit message */ - return NUM_BYTES(code->hdr_len + code->data_len); -} - -/* - * Decode EGPRS UL message - * - * 1. Header section decoding - * 2. Extract CPS settings - * 3. Burst unmapping and deinterleaving - * 4. Data section decoding - */ -int pdtch_egprs_decode(uint8_t *l2_data, sbit_t *bursts, uint16_t nbits, - uint8_t *usf_p, int *n_errors, int *n_bits_total) -{ - sbit_t dc[EGPRS_DATA_DC_MAX]; - sbit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2]; - int type, rc; - struct egprs_cps cps; - union gprs_rlc_ul_hdr_egprs *hdr; - - if ((nbits != GSM0503_GPRS_BURSTS_NBITS) && - (nbits != GSM0503_EGPRS_BURSTS_NBITS)) { - LOGP(DL1C, LOGL_ERROR, "Invalid EGPRS bit length %u\n", nbits); - return -1; - } - - hdr = (union gprs_rlc_ul_hdr_egprs *) l2_data; - type = egprs_decode_hdr(hdr, bursts, nbits); - if (egprs_parse_ul_cps(&cps, hdr, type) < 0) - return -1; - - switch (cps.mcs) { - case EGPRS_MCS1: - case EGPRS_MCS2: - case EGPRS_MCS3: - case EGPRS_MCS4: - egprs_type3_unmap(bursts, NULL, dc); - break; - case EGPRS_MCS5: - case EGPRS_MCS6: - egprs_type2_unmap(bursts, NULL, dc); - break; - case EGPRS_MCS7: - case EGPRS_MCS8: - case EGPRS_MCS9: - egprs_type1_unmap(bursts, NULL, c1, c2, cps.mcs); - break; - default: - LOGP(DL1C, LOGL_ERROR, "Invalid MCS-%u\n", cps.mcs); - return -1; - } - - LOGP(DL1C, LOGL_DEBUG, "Decoding MCS-%i block\n", cps.mcs); - - if (cps.mcs < EGPRS_MCS7) { - rc = egprs_decode_data(l2_data, dc, cps.mcs, cps.p[0], - 0, n_errors, n_bits_total); - if (rc < 0) - return -1; - } else { - /* MCS-7,8,9 block 1 */ - rc = egprs_decode_data(l2_data, c1, cps.mcs, cps.p[0], - 0, n_errors, n_bits_total); - if (rc < 0) - return -1; - - /* MCS-7,8,9 block 2 */ - rc = egprs_decode_data(l2_data, c2, cps.mcs, cps.p[1], - 1, n_errors, n_bits_total); - if (rc < 0) - return -1; - } - - return rc; -} - -/* - * GSM PDTCH block transcoding - */ - -int pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, - int *n_errors, int *n_bits_total) -{ - sbit_t iB[456], cB[676], hl_hn[8]; - ubit_t conv[456]; - int i, j, k, rv, best = 0, cs = 0, usf = 0; /* make GCC happy */ - - for (i=0; i<4; i++) - gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], - hl_hn + i*2, hl_hn + i*2 + 1); - - for (i=0; i<4; i++) { - for (j=0, k=0; j<8; j++) - k += abs(((int)gsm0503_pdtch_hl_hn_sbit[i][j]) - - ((int)hl_hn[j])); - if (i == 0 || k < best) { - best = k; - cs = i+1; - } - } - - gsm0503_xcch_deinterleave(cB, iB); - - switch (cs) { - case 1: - osmo_conv_decode_ber(&gsm0503_conv_xcch, cB, conv, n_errors, n_bits_total); - - rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, conv, 184, - conv+184); - if (rv) - return -1; - - osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); - - return 23; - case 2: - for (i=587, j=455; i>=0; i--) - if (!gsm0503_puncture_cs2[i]) - cB[i] = cB[j--]; - else - cB[i] = 0; - - osmo_conv_decode_ber(&gsm0503_conv_cs2, cB, conv, n_errors, n_bits_total); - - for (i=0; i<8; i++) { - for (j=0, k=0; j<6; j++) - k += abs(((int)gsm0503_usf2six[i][j]) - - ((int)conv[j])); - if (i == 0 || k < best) { - best = k; - usf = i; - } - } - - conv[3] = usf & 1; - conv[4] = (usf >> 1) & 1; - conv[5] = (usf >> 2) & 1; - if (usf_p) - *usf_p = usf; - - rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, conv+3, 271, - conv+3+271); - if (rv) - return -1; - - osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 271, 1); - - return 34; - case 3: - for (i=675, j=455; i>=0; i--) - if (!gsm0503_puncture_cs3[i]) - cB[i] = cB[j--]; - else - cB[i] = 0; - - osmo_conv_decode_ber(&gsm0503_conv_cs3, cB, conv, n_errors, n_bits_total); - - for (i=0; i<8; i++) { - for (j=0, k=0; j<6; j++) - k += abs(((int)gsm0503_usf2six[i][j]) - - ((int)conv[j])); - if (i == 0 || k < best) { - best = k; - usf = i; - } - } - - conv[3] = usf & 1; - conv[4] = (usf >> 1) & 1; - conv[5] = (usf >> 2) & 1; - if (usf_p) - *usf_p = usf; - - rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, conv+3, 315, - conv+3+315); - if (rv) - return -1; - - osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 315, 1); - - return 40; - case 4: - for (i=12; i<456;i++) - conv[i] = (cB[i] < 0) ? 1:0; - - for (i=0; i<8; i++) { - for (j=0, k=0; j<12; j++) - k += abs(((int)gsm0503_usf2twelve_sbit[i][j]) - - ((int)cB[j])); - if (i == 0 || k < best) { - best = k; - usf = i; - } - } - - conv[9] = usf & 1; - conv[10] = (usf >> 1) & 1; - conv[11] = (usf >> 2) & 1; - if (usf_p) - *usf_p = usf; - - rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, conv+9, 431, - conv+9+431); - if (rv) { - *n_bits_total = 456-12; - *n_errors = *n_bits_total; - return -1; - } - - *n_bits_total = 456-12; - *n_errors = 0; - - osmo_ubit2pbit_ext(l2_data, 0, conv, 9, 431, 1); - - return 54; - default: - *n_bits_total = 0; - *n_errors = 0; - break; - } - - return -1; -} - -/* - * EGPRS PDTCH UL block encoding - */ -static int egprs_type3_map(ubit_t *bursts, ubit_t *hc, ubit_t *dc, int usf) -{ - int i; - ubit_t iB[456]; - const ubit_t *hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; - - gsm0503_mcs1_dl_interleave(gsm0503_usf2six[usf], hc, dc, iB); - - for (i=0; i<4; i++) - gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], - hl_hn + i * 2, hl_hn + i * 2 + 1); - - return 0; -} - -static int egprs_type2_map(ubit_t *bursts, ubit_t *hc, ubit_t *dc, int usf) -{ - int i; - const ubit_t *up; - ubit_t hi[EGPRS_HDR_HC_MAX]; - ubit_t di[EGPRS_DATA_DC_MAX]; - - gsm0503_mcs5_dl_interleave(hc, dc, hi, di); - up = gsm0503_mcs5_usf_precode_table[usf]; - - for (i = 0; i < 4; i++) { - gsm0503_mcs5_dl_burst_map(di, &bursts[i * 348], hi, up, i); - gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]); - } - - return 0; -} - -static int egprs_type1_map(ubit_t *bursts, ubit_t *hc, - ubit_t *c1, ubit_t *c2, int usf, int mcs) -{ - int i; - const ubit_t *up; - ubit_t hi[EGPRS_HDR_HC_MAX]; - ubit_t di[EGPRS_DATA_C1 * 2]; - - if (mcs == EGPRS_MCS7) - gsm0503_mcs7_dl_interleave(hc, c1, c2, hi, di); - else - gsm0503_mcs8_dl_interleave(hc, c1, c2, hi, di); - - up = gsm0503_mcs5_usf_precode_table[usf]; - - for (i = 0; i < 4; i++) { - gsm0503_mcs7_dl_burst_map(di, &bursts[i * 348], hi, up, i); - gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]); - } - - return 0; -} - -static int egprs_encode_hdr(ubit_t *hc, uint8_t *l2_data, int mcs) -{ - int i, j; - ubit_t upp[EGPRS_HDR_UPP_MAX], C[EGPRS_HDR_C_MAX]; - struct gsm0503_mcs_code *code; - - code = &gsm0503_mcs_dl_codes[mcs]; - - osmo_pbit2ubit_ext(upp, 0, l2_data, code->usf_len, code->hdr_len, 1); - osmo_crc8gen_set_bits(&gsm0503_mcs_crc8_hdr, upp, - code->hdr_len, upp + code->hdr_len); - - osmo_conv_encode(code->hdr_conv, upp, C); - - /* MCS-5,6 header direct puncture instead of table */ - if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) { - memcpy(hc, C, code->hdr_code_len); - hc[99] = hc[98]; - return 0; - } - - if (!code->hdr_punc) { - LOGP(DL1C, LOGL_ERROR, - "Invalid MCS-%u header puncture matrix\n", mcs); - return -1; - } - - for (i = 0, j = 0; i < code->hdr_code_len; i++) { - if (!code->hdr_punc[i]) - hc[j++] = C[i]; - } - - return 0; -} - -static int egprs_encode_data(ubit_t *c, uint8_t *l2_data, - int mcs, int p, int blk) -{ - int i, j, data_len; - ubit_t u[EGPRS_DATA_U_MAX], C[EGPRS_DATA_C_MAX]; - struct gsm0503_mcs_code *code; - - code = &gsm0503_mcs_dl_codes[mcs]; - - /* - * Dual block - MCS-7,8,9 - * Single block - MCS-1,2,3,4,5,6 - */ - if (mcs >= EGPRS_MCS7) - data_len = code->data_len / 2; - else - data_len = code->data_len; - - osmo_pbit2ubit_ext(u, 0, l2_data, - code->usf_len + code->hdr_len + blk * data_len, - data_len, 1); - osmo_crc16gen_set_bits(&gsm0503_mcs_crc12, u, data_len, u + data_len); - - osmo_conv_encode(code->data_conv, u, C); - - if (!code->data_punc[p]) { - LOGP(DL1C, LOGL_ERROR, - "Invalid MCS-%u data puncture matrix %i\n", mcs, p); - return -1; - } - - for (i = 0, j = 0; i < code->data_code_len; i++) { - if (!code->data_punc[p][i]) - c[j++] = C[i]; - } - - return 0; -} - -union gprs_rlc_dl_hdr_egprs { - struct gprs_rlc_dl_header_egprs_1 type1; - struct gprs_rlc_dl_header_egprs_2 type2; - struct gprs_rlc_dl_header_egprs_3 type3; -}; - -/* - * Parse EGPRS DL header for coding and puncturing scheme (CPS) - * - * Type 1 - MCS-7,8,9 - * Type 2 - MCS-5,6 - * Type 3 - MCS-1,2,3,4 - */ -static int egprs_parse_dl_cps(struct egprs_cps *cps, - union gprs_rlc_dl_hdr_egprs *hdr, int type) -{ - uint8_t bits; - - switch (type) { - case EGPRS_HDR_TYPE1: - bits = hdr->type1.cps; - break; - case EGPRS_HDR_TYPE2: - bits = hdr->type2.cps; - break; - case EGPRS_HDR_TYPE3: - bits = hdr->type3.cps; - break; - default: - return -1; - } - - return egprs_get_cps(cps, type, bits); -} - -/* - * EGPRS DL message encoding - */ -int pdtch_egprs_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) -{ - ubit_t hc[EGPRS_DATA_C_MAX], dc[EGPRS_DATA_DC_MAX]; - ubit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2]; - uint8_t mcs; - struct egprs_cps cps; - union gprs_rlc_dl_hdr_egprs *hdr; - - switch (l2_len) { - case 27: - mcs = EGPRS_MCS1; - break; - case 33: - mcs = EGPRS_MCS2; - break; - case 42: - mcs = EGPRS_MCS3; - break; - case 49: - mcs = EGPRS_MCS4; - break; - case 60: - mcs = EGPRS_MCS5; - break; - case 78: - mcs = EGPRS_MCS6; - break; - case 118: - mcs = EGPRS_MCS7; - break; - case 142: - mcs = EGPRS_MCS8; - break; - case 154: - mcs = EGPRS_MCS9; - break; - default: - return -1; - } - - /* Read header for USF and puncturing matrix selection. */ - hdr = (union gprs_rlc_dl_hdr_egprs *) l2_data; - - switch (mcs) { - case EGPRS_MCS1: - case EGPRS_MCS2: - case EGPRS_MCS3: - case EGPRS_MCS4: - /* Check for valid CPS and matching MCS to message size */ - if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE3) < 0) || - (cps.mcs != mcs)) - goto bad_header; - - egprs_encode_hdr(hc, l2_data, mcs); - egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0); - egprs_type3_map(bursts, hc, dc, hdr->type3.usf); - break; - case EGPRS_MCS5: - case EGPRS_MCS6: - if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE2) < 0) || - (cps.mcs != mcs)) - goto bad_header; - - egprs_encode_hdr(hc, l2_data, mcs); - egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0); - egprs_type2_map(bursts, hc, dc, hdr->type2.usf); - break; - case EGPRS_MCS7: - case EGPRS_MCS8: - case EGPRS_MCS9: - if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE1) < 0) || - (cps.mcs != mcs)) - goto bad_header; - - egprs_encode_hdr(hc, l2_data, mcs); - egprs_encode_data(c1, l2_data, mcs, cps.p[0], 0); - egprs_encode_data(c2, l2_data, mcs, cps.p[1], 1); - egprs_type1_map(bursts, hc, c1, c2, hdr->type1.usf, mcs); - break; - } - - LOGP(DL1C, LOGL_DEBUG, "Encoded PDTCH mcs=%i, len=%u\n", mcs, l2_len); - - return mcs >= EGPRS_MCS5 ? GSM0503_EGPRS_BURSTS_NBITS : - GSM0503_GPRS_BURSTS_NBITS; - -bad_header: - LOGP(DL1C, LOGL_ERROR, "Invalid EGPRS MCS-%i header\n", mcs); - return -1; -} - -int pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) -{ - ubit_t iB[456], cB[676]; - const ubit_t *hl_hn; - ubit_t conv[334]; - int i, j, usf; - - switch (l2_len) { - case 23: - osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); - - osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, - conv+184); - - osmo_conv_encode(&gsm0503_conv_xcch, conv, cB); - - hl_hn = gsm0503_pdtch_hl_hn_ubit[0]; - - break; - case 34: - osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 271, 1); - usf = l2_data[0] & 0x7; - - osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv+3, 271, - conv+3+271); - - memcpy(conv, gsm0503_usf2six[usf], 6); - - osmo_conv_encode(&gsm0503_conv_cs2, conv, cB); - - for (i=0, j=0; i<588; i++) - if (!gsm0503_puncture_cs2[i]) - cB[j++] = cB[i]; - - hl_hn = gsm0503_pdtch_hl_hn_ubit[1]; - - break; - case 40: - osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 315, 1); - usf = l2_data[0] & 0x7; - - osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv+3, 315, - conv+3+315); - - memcpy(conv, gsm0503_usf2six[usf], 6); - - osmo_conv_encode(&gsm0503_conv_cs3, conv, cB); - - for (i=0, j=0; i<676; i++) - if (!gsm0503_puncture_cs3[i]) - cB[j++] = cB[i]; - - hl_hn = gsm0503_pdtch_hl_hn_ubit[2]; - - break; - case 54: - osmo_pbit2ubit_ext(cB, 9, l2_data, 0, 431, 1); - usf = l2_data[0] & 0x7; - - osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, cB+9, 431, - cB+9+431); - - memcpy(cB, gsm0503_usf2twelve_ubit[usf], 12); - - hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; - - break; - default: - return -1; - } - - gsm0503_xcch_interleave(cB, iB); - - for (i=0; i<4; i++) - gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], - hl_hn + i*2, hl_hn + i*2 + 1); - - return GSM0503_GPRS_BURSTS_NBITS; -} - - -/* - * GSM TCH/F FR/EFR transcoding - */ - -static void tch_fr_reassemble(uint8_t *tch_data, ubit_t *b_bits, int net_order) -{ - int i, j, k, l, o; - - tch_data[0] = 0xd << 4; - memset(tch_data + 1, 0, 32); - - if (net_order) { - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - while (i < 260) { - tch_data[j>>3] |= (b_bits[i] << (7-(j&7))); - i++; - j++; - } - return; - } - - /* reassemble d-bits */ - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - k = gsm0503_gsm_fr_map[0]-1; /* current number bit in element */ - l = 0; /* counts element bits */ - o = 0; /* offset input bits */ - while (i < 260) { - tch_data[j>>3] |= (b_bits[k+o] << (7-(j&7))); - if (--k < 0) { - o += gsm0503_gsm_fr_map[l]; - k = gsm0503_gsm_fr_map[++l]-1; - } - i++; - j++; - } -} - -static void tch_fr_disassemble(ubit_t *b_bits, uint8_t *tch_data, int net_order) -{ - int i, j, k, l, o; - - if (net_order) { - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - while (i < 260) { - b_bits[i] = (tch_data[j>>3] >> (7-(j&7))) & 1; - i++; - j++; - } - return; - } - - i = 0; /* counts bits */ - j = 4; /* counts input bits */ - k = gsm0503_gsm_fr_map[0]-1; /* current number bit in element */ - l = 0; /* counts element bits */ - o = 0; /* offset output bits */ - while (i < 260) { - b_bits[k+o] = (tch_data[j>>3] >> (7-(j&7))) & 1; - if (--k < 0) { - o += gsm0503_gsm_fr_map[l]; - k = gsm0503_gsm_fr_map[++l]-1; - } - i++; - j++; - } -} - -static void tch_hr_reassemble(uint8_t *tch_data, ubit_t *b_bits) -{ - int i, j; - - tch_data[0] = 0x00; /* F = 0, FT = 000 */ - memset(tch_data + 1, 0, 14); - - i = 0; /* counts bits */ - j = 8; /* counts output bits */ - while (i < 112) { - tch_data[j>>3] |= (b_bits[i] << (7-(j&7))); - i++; - j++; - } -} - -static void tch_hr_disassemble(ubit_t *b_bits, uint8_t *tch_data) -{ - int i, j; - - i = 0; /* counts bits */ - j = 8; /* counts output bits */ - while (i < 112) { - b_bits[i] = (tch_data[j>>3] >> (7-(j&7))) & 1; - i++; - j++; - } -} - -static void tch_efr_reassemble(uint8_t *tch_data, ubit_t *b_bits) -{ - int i, j; - - tch_data[0] = 0xc << 4; - memset(tch_data + 1, 0, 30); - - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - while (i < 244) { - tch_data[j>>3] |= (b_bits[i] << (7-(j&7))); - i++; - j++; - } -} - -static void tch_efr_disassemble(ubit_t *b_bits, uint8_t *tch_data) -{ - int i, j; - - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - while (i < 244) { - b_bits[i] = (tch_data[j>>3] >> (7-(j&7))) & 1; - i++; - j++; - } -} - -static void tch_amr_reassemble(uint8_t *tch_data, ubit_t *d_bits, int len) -{ - int i, j; - - memset(tch_data, 0, (len + 7) >> 3); - - i = 0; /* counts bits */ - j = 0; /* counts output bits */ - while (i < len) { - tch_data[j>>3] |= (d_bits[i] << (7-(j&7))); - i++; - j++; - } -} - -static void tch_amr_disassemble(ubit_t *d_bits, uint8_t *tch_data, int len) -{ - int i, j; - - i = 0; /* counts bits */ - j = 0; /* counts output bits */ - while (i < len) { - d_bits[i] = (tch_data[j>>3] >> (7-(j&7))) & 1; - i++; - j++; - } -} - -static void tch_fr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) -{ - int i; - - for (i = 0; i < 260; i++) - b_bits[gsm610_bitorder[i]] = d_bits[i]; -} - -static void tch_fr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) -{ - int i; - - for (i = 0; i < 260; i++) - d_bits[i] = b_bits[gsm610_bitorder[i]]; -} - -static void tch_hr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) -{ - int i; - - const uint16_t *map; - - if (!d_bits[93] && !d_bits[94]) - map = gsm620_unvoiced_bitorder; - else - map = gsm620_voiced_bitorder; - - for (i = 0; i < 112; i++) - b_bits[map[i]] = d_bits[i]; -} - -static void tch_hr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) -{ - int i; - const uint16_t *map; - - if (!b_bits[34] && !b_bits[35]) - map = gsm620_unvoiced_bitorder; - else - map = gsm620_voiced_bitorder; - - for (i = 0; i < 112; i++) - d_bits[i] = b_bits[map[i]]; -} - -static void tch_efr_d_to_w(ubit_t *b_bits, ubit_t *d_bits) -{ - int i; - - for (i = 0; i < 260; i++) - b_bits[gsm660_bitorder[i]] = d_bits[i]; -} - -static void tch_efr_w_to_d(ubit_t *d_bits, ubit_t *b_bits) -{ - int i; - - for (i = 0; i < 260; i++) - d_bits[i] = b_bits[gsm660_bitorder[i]]; -} - -static void tch_efr_protected(ubit_t *s_bits, ubit_t *b_bits) -{ - int i; - - for (i = 0; i < 65; i++) - b_bits[i] = s_bits[gsm0503_gsm_efr_protected_bits[i]-1]; -} - -static void tch_fr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) -{ - int i; - - for (i=0; i<91; i++) { - d[i<<1] = u[i]; - d[(i<<1)+1] = u[184-i]; - } - for (i=0; i<3; i++) - p[i] = u[91+i]; -} - -static void tch_fr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) -{ - int i; - - for (i=0; i<91; i++) { - u[i] = d[i<<1]; - u[184-i] = d[(i<<1)+1]; - } - for (i=0; i<3; i++) - u[91+i] = p[i]; -} - -static void tch_hr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) -{ - memcpy(d, u, 95); - memcpy(p, u+95, 3); -} - -static void tch_hr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) -{ - memcpy(u, d, 95); - memcpy(u+95, p, 3); -} - -static void tch_efr_reorder(ubit_t *w, ubit_t *s, ubit_t *p) -{ - memcpy(w, s, 71); - w[71] = w[72] = s[69]; - memcpy(w+73, s+71, 50); - w[123] = w[124] = s[119]; - memcpy(w+125, s+121, 53); - w[178] = w[179] = s[172]; - memcpy(w+180, s+174, 50); - w[230] = w[231] = s[222]; - memcpy(w+232, s+224, 20); - memcpy(w+252, p, 8); -} - -static void tch_efr_unreorder(ubit_t *s, ubit_t *p, ubit_t *w) -{ - int sum; - - memcpy(s, w, 71); - sum = s[69] + w[71] + w[72]; - s[69] = (sum > 2); - memcpy(s+71, w+73, 50); - sum = s[119] + w[123] + w[124]; - s[119] = (sum > 2); - memcpy(s+121, w+125, 53); - sum = s[172] + w[178] + w[179]; - s[172] = (sum > 2); - memcpy(s+174, w+180, 50); - sum = s[220] + w[230] + w[231]; - s[222] = (sum > 2); - memcpy(s+224, w+232, 20); - memcpy(p, w+252, 8); -} - -static void tch_amr_merge(ubit_t *u, ubit_t *d, ubit_t *p, int len, int prot) -{ - memcpy(u, d, prot); - memcpy(u+prot, p, 6); - memcpy(u+prot+6, d+prot, len-prot); -} - -static void tch_amr_unmerge(ubit_t *d, ubit_t *p, ubit_t *u, int len, int prot) -{ - memcpy(d, u, prot); - memcpy(p, u+prot, 6); - memcpy(d+prot, u+prot+6, len-prot); -} - -int tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, int net_order, int efr, - int *n_errors, int *n_bits_total) -{ - sbit_t iB[912], cB[456], h; - ubit_t conv[185], s[244], w[260], b[65], d[260], p[8]; - int i, rv, len, steal = 0; - - for (i=0; i<8; i++) { - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, - i>>2); - steal -= h; - } - - gsm0503_tch_fr_deinterleave(cB, iB); - - if (steal > 0) { - rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_fr_decode(): error decoding FACCH frame (%d/%d bits)\n", *n_errors, *n_bits_total); - return -1; - } - - return 23; - } - - osmo_conv_decode_ber(&gsm0503_conv_tch_fr, cB, conv, n_errors, n_bits_total); - - tch_fr_unreorder(d, p, conv); - - for (i=0; i<78; i++) - d[i+182] = (cB[i+378] < 0) ? 1:0; - - rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d, 50, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_fr_decode(): error checking CRC8 for the FR part of an %s frame\n", efr?"EFR":"FR"); - return -1; - } - - - if (efr) { - tch_efr_d_to_w(w, d); - - tch_efr_unreorder(s, p, w); - - tch_efr_protected(s, b); - - rv = osmo_crc8gen_check_bits(&gsm0503_tch_efr_crc8, b, - 65, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_fr_decode(): error checking CRC8 for the EFR part of an EFR frame\n"); - return -1; - } - - tch_efr_reassemble(tch_data, s); - - len = GSM_EFR_BYTES; - } else { - tch_fr_d_to_b(w, d); - - tch_fr_reassemble(tch_data, w, net_order); - - len = GSM_FR_BYTES; - } - - return len; -} - -int tch_fr_encode(ubit_t *bursts, uint8_t *tch_data, int len, int net_order) -{ - ubit_t iB[912], cB[456], h; - ubit_t conv[185], w[260], b[65], s[244], d[260], p[8]; - int i; - - switch (len) { - case GSM_EFR_BYTES: /* TCH EFR */ - - tch_efr_disassemble(s, tch_data); - - tch_efr_protected(s, b); - - osmo_crc8gen_set_bits(&gsm0503_tch_efr_crc8, b, 65, p); - - tch_efr_reorder(w, s, p); - - tch_efr_w_to_d(d, w); - - goto coding_efr_fr; - case GSM_FR_BYTES: /* TCH FR */ - tch_fr_disassemble(w, tch_data, net_order); - - tch_fr_b_to_d(d, w); - -coding_efr_fr: - osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d, 50, p); - - tch_fr_reorder(conv, d, p); - - memcpy(cB+378, d+182, 78); - - osmo_conv_encode(&gsm0503_conv_tch_fr, conv, cB); - - h = 0; - - break; - case GSM_MACBLOCK_LEN: /* FACCH */ - _xcch_encode_cB(cB, tch_data); - - h = 1; - - break; - default: - return -1; - } - - gsm0503_tch_fr_interleave(cB, iB); - - for (i=0; i<8; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i>>2); - - return 0; -} - -int tch_hr_decode(uint8_t *tch_data, sbit_t *bursts, int odd, - int *n_errors, int *n_bits_total) -{ - sbit_t iB[912], cB[456], h; - ubit_t conv[98], b[112], d[112], p[3]; - int i, rv, steal = 0; - - /* only unmap the stealing bits */ - if (!odd) { - for (i=0; i<4; i++) { - gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); - steal -= h; - } - for (i=2; i<5; i++) { - gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); - steal -= h; - } - } - - /* if we found a stole FACCH, but only at correct alignment */ - if (steal > 0) { - for (i=0; i<6; i++) - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], - NULL, i>>2); - for (i=2; i<4; i++) - gsm0503_tch_burst_unmap(&iB[i * 114 + 456], - &bursts[i * 116], NULL, 1); - - gsm0503_tch_fr_deinterleave(cB, iB); - - rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_hr_decode(): error decoding FACCH frame (%d/%d bits)\n", *n_errors, *n_bits_total); - return -1; - } - - return GSM_MACBLOCK_LEN; - } - - for (i=0; i<4; i++) - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, - i>>1); - - gsm0503_tch_hr_deinterleave(cB, iB); - - osmo_conv_decode_ber(&gsm0503_conv_tch_hr, cB, conv, n_errors, n_bits_total); - - tch_hr_unreorder(d, p, conv); - - for (i=0; i<17; i++) - d[i+95] = (cB[i+211] < 0) ? 1:0; - - rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_fr_decode(): error checking CRC8 for an HR frame\n"); - return -1; - } - - tch_hr_d_to_b(b, d); - - tch_hr_reassemble(tch_data, b); - - return 15; -} - -int tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len) -{ - ubit_t iB[912], cB[456], h; - ubit_t conv[98], b[112], d[112], p[3]; - int i; - - switch (len) { - case 15: /* TCH HR */ - tch_hr_disassemble(b, tch_data); - - tch_hr_b_to_d(d, b); - - osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); - - tch_hr_reorder(conv, d, p); - - osmo_conv_encode(&gsm0503_conv_tch_hr, conv, cB); - - memcpy(cB+211, d+95, 17); - - h = 0; - - gsm0503_tch_hr_interleave(cB, iB); - - for (i=0; i<4; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], - &h, i>>1); - - break; - case GSM_MACBLOCK_LEN: /* FACCH */ - _xcch_encode_cB(cB, tch_data); - - h = 1; - - gsm0503_tch_fr_interleave(cB, iB); - - for (i=0; i<6; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], - &h, i>>2); - for (i=2; i<4; i++) - gsm0503_tch_burst_map(&iB[i * 114 + 456], - &bursts[i * 116], &h, 1); - - break; - default: - return -1; - } - - return 0; -} - -int tch_afs_decode(uint8_t *tch_data, sbit_t *bursts, int codec_mode_req, - uint8_t *codec, int codecs, uint8_t *ft, uint8_t *cmr, - int *n_errors, int *n_bits_total) -{ - sbit_t iB[912], cB[456], h; - ubit_t d[244], p[6], conv[250]; - int i, j, k, best = 0, rv, len, steal = 0, id = 0; - *n_errors = 0; *n_bits_total = 0; - - for (i=0; i<8; i++) { - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, - i>>2); - steal -= h; - } - - gsm0503_tch_fr_deinterleave(cB, iB); - - if (steal > 0) { - rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error decoding FACCH frame (%d/%d bits)\n", *n_errors, *n_bits_total); - return -1; - } - - return GSM_MACBLOCK_LEN; - } - - for (i=0; i<4; i++) { - for (j=0, k=0; j<8; j++) - k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - - ((int)cB[j])); - if (i == 0 || k < best) { - best = k; - id = i; - } - } - - /* check if indicated codec fits into range of codecs */ - if (id >= codecs) { - /* codec mode out of range, return id */ - return id; - } - - switch ((codec_mode_req) ? codec[*ft] : codec[id]) { - case 7: /* TCH/AFS12.2 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_12_2, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 244, 81); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 81, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 12.2 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 244); - - len = 31; - - break; - case 6: /* TCH/AFS10.2 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_10_2, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 204, 65); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 65, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 10.2 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 204); - - len = 26; - - break; - case 5: /* TCH/AFS7.95 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_7_95, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 159, 75); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 75, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 7.95 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 159); - - len = 20; - - break; - case 4: /* TCH/AFS7.4 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_7_4, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 148, 61); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 7.4 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 148); - - len = 19; - - break; - case 3: /* TCH/AFS6.7 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_6_7, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 134, 55); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 6.7 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 134); - - len = 17; - - break; - case 2: /* TCH/AFS5.9 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_5_9, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 118, 55); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 5.9 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 118); - - len = 15; - - break; - case 1: /* TCH/AFS5.15 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_5_15, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 103, 49); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 5.15 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 103); - - len = 13; - - break; - case 0: /* TCH/AFS4.75 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_afs_4_75, cB+8, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 95, 39); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_afs_decode(): error checking CRC8 for an AMR 4.75 frame\n"); - return -1; - } - - tch_amr_reassemble(tch_data, d, 95); - - len = 12; - - break; - default: - LOGP(DL1C, LOGL_ERROR, "tch_afs_decode(): Unknown frame type\n"); - fprintf(stderr, "FIXME: FT %d not supported!\n", *ft); - *n_bits_total = 448; - *n_errors = *n_bits_total; - return -1; - } - - /* change codec request / indication, if frame is valid */ - if (codec_mode_req) - *cmr = id; - else - *ft = id; - - return len; -} - -int tch_afs_encode(ubit_t *bursts, uint8_t *tch_data, int len, - int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, - uint8_t cmr) -{ - ubit_t iB[912], cB[456], h; - ubit_t d[244], p[6], conv[250]; - int i; - uint8_t id; - - if (len == GSM_MACBLOCK_LEN) { /* FACCH */ - _xcch_encode_cB(cB, tch_data); - - h = 1; - - goto facch; - } - - h = 0; - - if (codec_mode_req) { - if (cmr >= codecs) { - fprintf(stderr, "FIXME: CMR ID %d not in codec list!\n", - cmr); - return -1; - } - id = cmr; - } else { - if (ft >= codecs) { - fprintf(stderr, "FIXME: FT ID %d not in codec list!\n", - ft); - return -1; - } - id = ft; - } - - switch (codec[ft]) { - case 7: /* TCH/AFS12.2 */ - if (len != 31) { -invalid_length: - fprintf(stderr, "FIXME: payload length %d does not " - "comply with codec type %d!\n", len, ft); - return -1; - } - - tch_amr_disassemble(d, tch_data, 244); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 81, p); - - tch_amr_merge(conv, d, p, 244, 81); - - osmo_conv_encode(&gsm0503_conv_tch_afs_12_2, conv, cB+8); - - break; - case 6: /* TCH/AFS10.2 */ - if (len != 26) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 204); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 65, p); - - tch_amr_merge(conv, d, p, 204, 65); - - osmo_conv_encode(&gsm0503_conv_tch_afs_10_2, conv, cB+8); - - break; - case 5: /* TCH/AFS7.95 */ - if (len != 20) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 159); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 75, p); - - tch_amr_merge(conv, d, p, 159, 75); - - osmo_conv_encode(&gsm0503_conv_tch_afs_7_95, conv, cB+8); - - break; - case 4: /* TCH/AFS7.4 */ - if (len != 19) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 148); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); - - tch_amr_merge(conv, d, p, 148, 61); - - osmo_conv_encode(&gsm0503_conv_tch_afs_7_4, conv, cB+8); - - break; - case 3: /* TCH/AFS6.7 */ - if (len != 17) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 134); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); - - tch_amr_merge(conv, d, p, 134, 55); - - osmo_conv_encode(&gsm0503_conv_tch_afs_6_7, conv, cB+8); - - break; - case 2: /* TCH/AFS5.9 */ - if (len != 15) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 118); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); - - tch_amr_merge(conv, d, p, 118, 55); - - osmo_conv_encode(&gsm0503_conv_tch_afs_5_9, conv, cB+8); - - break; - case 1: /* TCH/AFS5.15 */ - if (len != 13) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 103); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); - - tch_amr_merge(conv, d, p, 103, 49); - - osmo_conv_encode(&gsm0503_conv_tch_afs_5_15, conv, cB+8); - - break; - case 0: /* TCH/AFS4.75 */ - if (len != 12) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 95); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); - - tch_amr_merge(conv, d, p, 95, 39); - - osmo_conv_encode(&gsm0503_conv_tch_afs_4_75, conv, cB+8); - - break; - default: - fprintf(stderr, "FIXME: FT %d not supported!\n", ft); - - return -1; - } - - memcpy(cB, gsm0503_afs_ic_ubit[id], 8); - -facch: - gsm0503_tch_fr_interleave(cB, iB); - - for (i=0; i<8; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i>>2); - - return 0; -} - -int tch_ahs_decode(uint8_t *tch_data, sbit_t *bursts, int odd, - int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, - uint8_t *cmr, int *n_errors, int *n_bits_total) -{ - sbit_t iB[912], cB[456], h; - ubit_t d[244], p[6], conv[135]; - int i, j, k, best = 0, rv, len, steal = 0, id = 0; - - /* only unmap the stealing bits */ - if (!odd) { - for (i=0; i<4; i++) { - gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); - steal -= h; - } - for (i=2; i<5; i++) { - gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); - steal -= h; - } - } - - /* if we found a stole FACCH, but only at correct alignment */ - if (steal > 0) { - for (i=0; i<6; i++) - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], - NULL, i>>2); - for (i=2; i<4; i++) - gsm0503_tch_burst_unmap(&iB[i * 114 + 456], - &bursts[i * 116], NULL, 1); - - gsm0503_tch_fr_deinterleave(cB, iB); - - rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error decoding FACCH frame (%d/%d bits)\n", *n_errors, *n_bits_total); - return -1; - } - - return GSM_MACBLOCK_LEN; - } - - for (i=0; i<4; i++) - gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, - i>>1); - - gsm0503_tch_hr_deinterleave(cB, iB); - - for (i=0; i<4; i++) { - for (j=0, k=0; j<4; j++) - k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - - ((int)cB[j])); - if (i == 0 || k < best) { - best = k; - id = i; - } - } - - /* check if indicated codec fits into range of codecs */ - if (id >= codecs) { - /* codec mode out of range, return id */ - return id; - } - - switch ((codec_mode_req) ? codec[*ft] : codec[id]) { - case 5: /* TCH/AHS7.95 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_7_95, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 123, 67); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 67, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 7.95 frame\n"); - return -1; - } - - for (i=0; i<36;i++) - d[i+123] = (cB[i+192] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 159); - - len = 20; - - break; - case 4: /* TCH/AHS7.4 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_7_4, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 120, 61); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 7.4 frame\n"); - return -1; - } - - for (i=0; i<28;i++) - d[i+120] = (cB[i+200] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 148); - - len = 19; - - break; - case 3: /* TCH/AHS6.7 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_6_7, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 110, 55); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 6.7 frame\n"); - return -1; - } - - for (i=0; i<24;i++) - d[i+110] = (cB[i+204] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 134); - - len = 17; - - break; - case 2: /* TCH/AHS5.9 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_5_9, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 102, 55); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 5.9 frame\n"); - return -1; - } - - for (i=0; i<16;i++) - d[i+102] = (cB[i+212] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 118); - - len = 15; - - break; - case 1: /* TCH/AHS5.15 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_5_15, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 91, 49); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 5.15 frame\n"); - return -1; - } - - for (i=0; i<12;i++) - d[i+91] = (cB[i+216] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 103); - - len = 13; - - break; - case 0: /* TCH/AHS4.75 */ - osmo_conv_decode_ber(&gsm0503_conv_tch_ahs_4_75, cB+4, conv, n_errors, n_bits_total); - - tch_amr_unmerge(d, p, conv, 83, 39); - - rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); - if (rv) { - LOGP(DL1C, LOGL_NOTICE, "tch_ahs_decode(): error checking CRC8 for an AMR 4.75 frame\n"); - return -1; - } - - for (i=0; i<12;i++) - d[i+83] = (cB[i+216] < 0) ? 1:0; - - tch_amr_reassemble(tch_data, d, 95); - - len = 12; - - break; - default: - LOGP(DL1C, LOGL_ERROR, "tch_afs_decode(): Unknown frame type\n"); - fprintf(stderr, "FIXME: FT %d not supported!\n", *ft); - *n_bits_total = 159; - *n_errors = *n_bits_total; - return -1; - } - - /* change codec request / indication, if frame is valid */ - if (codec_mode_req) - *cmr = id; - else - *ft = id; - - return len; -} - -int tch_ahs_encode(ubit_t *bursts, uint8_t *tch_data, int len, - int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, - uint8_t cmr) -{ - ubit_t iB[912], cB[456], h; - ubit_t d[244], p[6], conv[135]; - int i; - uint8_t id; - - if (len == GSM_MACBLOCK_LEN) { /* FACCH */ - _xcch_encode_cB(cB, tch_data); - - h = 1; - - gsm0503_tch_fr_interleave(cB, iB); - - for (i=0; i<6; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], - &h, i>>2); - for (i=2; i<4; i++) - gsm0503_tch_burst_map(&iB[i * 114 + 456], - &bursts[i * 116], &h, 1); - - return 0; - } - - h = 0; - - if (codec_mode_req) { - if (cmr >= codecs) { - fprintf(stderr, "FIXME: CMR ID %d not in codec list!\n", - cmr); - return -1; - } - id = cmr; - } else { - if (ft >= codecs) { - fprintf(stderr, "FIXME: FT ID %d not in codec list!\n", - ft); - return -1; - } - id = ft; - } - - switch (codec[ft]) { - case 5: /* TCH/AHS7.95 */ - if (len != 20) { -invalid_length: - fprintf(stderr, "FIXME: payload length %d does not " - "comply with codec type %d!\n", len, ft); - return -1; - } - - tch_amr_disassemble(d, tch_data, 159); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 67, p); - - tch_amr_merge(conv, d, p, 123, 67); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_7_95, conv, cB+4); - - memcpy(cB+192, d+123, 36); - - break; - case 4: /* TCH/AHS7.4 */ - if (len != 19) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 148); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); - - tch_amr_merge(conv, d, p, 120, 61); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_7_4, conv, cB+4); - - memcpy(cB+200, d+120, 28); - - break; - case 3: /* TCH/AHS6.7 */ - if (len != 17) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 134); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); - - tch_amr_merge(conv, d, p, 110, 55); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_6_7, conv, cB+4); - - memcpy(cB+204, d+110, 24); - - break; - case 2: /* TCH/AHS5.9 */ - if (len != 15) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 118); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); - - tch_amr_merge(conv, d, p, 102, 55); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_5_9, conv, cB+4); - - memcpy(cB+212, d+102, 16); - - break; - case 1: /* TCH/AHS5.15 */ - if (len != 13) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 103); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); - - tch_amr_merge(conv, d, p, 91, 49); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_5_15, conv, cB+4); - - memcpy(cB+216, d+91, 12); - - break; - case 0: /* TCH/AHS4.75 */ - if (len != 12) - goto invalid_length; - - tch_amr_disassemble(d, tch_data, 95); - - osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); - - tch_amr_merge(conv, d, p, 83, 39); - - osmo_conv_encode(&gsm0503_conv_tch_ahs_4_75, conv, cB+4); - - memcpy(cB+216, d+83, 12); - - break; - default: - fprintf(stderr, "FIXME: FT %d not supported!\n", ft); - - return -1; - } - - memcpy(cB, gsm0503_afs_ic_ubit[id], 4); - - gsm0503_tch_hr_interleave(cB, iB); - - for (i=0; i<4; i++) - gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i>>1); - - return 0; -} - -/* - * GSM RACH transcoding - */ - -/* - * GSM RACH apply BSIC to parity - * - * p(j) = p(j) xor b(j) j = 0, ..., 5 - * b(0) = MSB of PLMN colour code - * b(5) = LSB of BS colour code - */ - -static int rach_apply_bsic(ubit_t *d, uint8_t bsic) -{ - int i; - - /* Apply it */ - for (i=0; i<6; i++) - d[8+i] ^= ((bsic >> (5-i)) & 1); - - return 0; -} - -int rach_decode(uint8_t *ra, sbit_t *burst, uint8_t bsic) -{ - ubit_t conv[14]; - int rv; - - osmo_conv_decode(&gsm0503_conv_rach, burst, conv); - - rach_apply_bsic(conv, bsic); - - rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, 8, conv+8); - if (rv) - return -1; - - osmo_ubit2pbit_ext(ra, 0, conv, 0, 8, 1); - - return 0; -} - -int rach_encode(ubit_t *burst, uint8_t *ra, uint8_t bsic) -{ - ubit_t conv[14]; - - osmo_pbit2ubit_ext(conv, 0, ra, 0, 8, 1); - - osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, 8, conv+8); - - rach_apply_bsic(conv, bsic); - - osmo_conv_encode(&gsm0503_conv_rach, conv, burst); - - return 0; -} - - -/* - * GSM SCH transcoding - */ - -int sch_decode(uint8_t *sb_info, sbit_t *burst) -{ - ubit_t conv[35]; - int rv; - - osmo_conv_decode(&gsm0503_conv_sch, burst, conv); - - rv = osmo_crc16gen_check_bits(&gsm0503_sch_crc10, conv, 25, conv+25); - if (rv) - return -1; - - osmo_ubit2pbit_ext(sb_info, 0, conv, 0, 25, 1); - - return 0; -} - -int sch_encode(ubit_t *burst, uint8_t *sb_info) -{ - ubit_t conv[35]; - - osmo_pbit2ubit_ext(conv, 0, sb_info, 0, 25, 1); - - osmo_crc16gen_set_bits(&gsm0503_sch_crc10, conv, 25, conv+25); - - osmo_conv_encode(&gsm0503_conv_sch, conv, burst); - - return 0; -} - |