/* (C) 2013 by Andreas Eversberg * (C) 2015 by Alexander Chemeris * (C) 2016 by Tom Tsou * * 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 . * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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, } }, }; 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; ubit_t recoded[EGPRS_DATA_C_MAX]; res = osmo_conv_decode(code, input, output); if (n_bits_total) { *n_bits_total = osmo_conv_encode(code, output, recoded); OSMO_ASSERT(sizeof(recoded)/sizeof(recoded[0]) >= *n_bits_total); } /* Count bit errors */ if (n_errors) { *n_errors = 0; for (i=0; i< *n_bits_total; i++) { if (! ((recoded[i] && input[i]<0) || (!recoded[i] && input[i]>0)) ) *n_errors += 1; } } 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 0; } /* * 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; }