/* encoding.cpp * * Copyright (C) 2012 Ivan Klyuchnikov * Copyright (C) 2012 Andreas Eversberg * Copyright (C) 2013 by Holger Hans Peter Freyther * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include extern "C" { #include #include #include } #include #include #include #define CHECK(rc) { if (rc < 0) return rc; } #define SET_X(bv, x) { if (bitvec_set_bit(bv, x) < 0) return -EOWNERDEAD; } #define SET_0(bv) SET_X(bv, ZERO) #define SET_1(bv) SET_X(bv, ONE) #define SET_L(bv) SET_X(bv, L) #define SET_H(bv) SET_X(bv, H) /* 3GPP TS 44.018 § 10.5.2.16: { 0 | 1 < ALPHA : bit (4) > } < GAMMA : bit (5) > */ static int write_alpha_gamma(bitvec *dest, uint8_t alpha, uint8_t gamma) { int rc; if (alpha) { SET_1(dest); rc = bitvec_set_u64(dest, alpha, 4, false); CHECK(rc); } else SET_0(dest); rc = bitvec_set_u64(dest, gamma, 5, false); CHECK(rc); return 0; } /* TBF_STARTING_TIME -- same as 3GPP TS 44.018 §10.5.2.38 Starting Time without tag: */ static int write_tbf_start_time(bitvec *dest, uint16_t rfn) { int rc; /* Set values according to 3GPP TS 44.018 Table 10.5.2.38.1 */ /* T1' */ rc = bitvec_set_u64(dest, (rfn / (26 * 51)) % 32, 5, false); CHECK(rc); /* T3 */ rc = bitvec_set_u64(dest, rfn % 51, 6, false); CHECK(rc); /* T2 */ rc = bitvec_set_u64(dest, rfn % 26, 5, false); CHECK(rc); return rc; } /* 3GPP TS 44.018 §10.5.2.16: < TFI_ASSIGNMENT : bit (5) > < POLLING : bit > 0 -- The value '1' was allocated in an earlier version of the protocol and shall not be used. < USF: bit (3) > < USF_GRANULARITY : bit > { 0 | 1 < P0 : bit (4) > < PR_MODE : bit (1) > } */ static int write_tfi_usf(bitvec *dest, const gprs_rlcmac_ul_tbf *tbf, uint8_t usf) { int rc = bitvec_set_u64(dest, tbf->tfi(), 5, false); /* TFI_ASSIGNMENT */ CHECK(rc); SET_0(dest); /* POLLING -- no action is required from MS */ SET_0(dest); rc = bitvec_set_u64(dest, usf, 3, false); /* USF */ CHECK(rc); SET_0(dest); /* USF_GRANULARITY -- the mobile station shall transmit one RLC/MAC block */ SET_0(dest); /* No P0 nor PR_MODE */ return 0; } /* { 0 | 1 < TIMING_ADVANCE_INDEX : bit (4) > } */ static int write_ta_index(bitvec *dest, int8_t tai) { int rc; if (tai < 0) { /* No TIMING_ADVANCE_INDEX: */ SET_0(dest); } else { /* TIMING_ADVANCE_INDEX: */ SET_1(dest); rc = bitvec_set_u64(dest, tai, 4, false); CHECK(rc); } return 0; } static inline bool write_tai(bitvec *dest, unsigned& wp, int8_t tai) { if (tai < 0) { /* No TIMING_ADVANCE_INDEX: */ bitvec_write_field(dest, &wp, 0, 1); return false; } /* TIMING_ADVANCE_INDEX: */ bitvec_write_field(dest, &wp, 1, 1); bitvec_write_field(dest, &wp, tai, 4); return true; } /* { 0 | 1 < TIMING_ADVANCE_VALUE : bit (6) > } */ static inline void write_ta(bitvec *dest, unsigned& wp, uint8_t ta) { if (ta > 63) /* No TIMING_ADVANCE_VALUE: */ bitvec_write_field(dest, &wp, 0, 1); else { /* TIMING_ADVANCE_VALUE: */ bitvec_write_field(dest, &wp, 1, 1); bitvec_write_field(dest, &wp, ta, 6); } } /* 3GPP TS 44.060 Table 12.5.2.1 */ static inline uint16_t enc_ws(uint16_t ws) { return (ws - 64) / 32; } static inline void write_ws(bitvec *dest, unsigned int *write_index, uint16_t ws) { dest->cur_bit = *write_index; int rc = bitvec_set_u64(dest, enc_ws(ws), 5, false); OSMO_ASSERT(rc == 0); *write_index += 5; } /* 3GPP TS 44.060 § 12.12: { 0 | 1 < TIMING_ADVANCE_VALUE : bit (6) > } { 0 | 1 < TIMING_ADVANCE_INDEX : bit (4) > < TIMING_ADVANCE_TIMESLOT_NUMBER : bit (3) > } */ static inline void write_ta_ie(bitvec *dest, unsigned& wp, uint8_t ta, int8_t tai, uint8_t ts) { write_ta(dest, wp, ta); if (write_tai(dest, wp, tai)) /* TIMING_ADVANCE_TIMESLOT_NUMBER: */ bitvec_write_field(dest, &wp, ts, 3); } static int write_ia_rest_downlink(const gprs_rlcmac_dl_tbf *tbf, bitvec * dest, bool polling, bool ta_valid, uint16_t rfn, uint8_t alpha, uint8_t gamma, int8_t ta_idx) { int rc = 0; SET_H(dest); SET_H(dest); SET_0(dest); SET_1(dest); /* 00 Packet Downlink Assignment */ rc = bitvec_set_u64(dest, tbf->tlli(), 32, false); /* TLLI */ CHECK(rc); SET_1(dest); rc = bitvec_set_u64(dest, tbf->tfi(), 5, false); /* TFI_ASSIGNMENT */ CHECK(rc); /* RLC acknowledged mode */ rc = bitvec_set_bit(dest, (bit_value) RLC_MODE_ACKNOWLEDGED); CHECK(rc); rc = write_alpha_gamma(dest, alpha, gamma); CHECK(rc); rc = bitvec_set_bit(dest, (bit_value) polling); /* POLLING */ CHECK(rc); /* N. B: NOT related to TAI! */ rc = bitvec_set_bit(dest, (bit_value) ta_valid); /* TA_VALID */ CHECK(rc); rc = write_ta_index(dest, ta_idx); CHECK(rc); if (polling) { SET_1(dest); rc = write_tbf_start_time(dest, rfn); CHECK(rc); } else SET_0(dest); SET_0(dest); /* No P0 nor PR_MODE */ if (tbf->is_egprs_enabled()) { SET_H(dest); rc = bitvec_set_u64(dest, enc_ws(tbf->window_size()), 5, false); /* EGPRS Window Size */ CHECK(rc); /* The mobile station shall not report measurements: (see 3GPP TS 44.060 Table 11.2.7.1) */ SET_0(dest); SET_0(dest); /* LINK_QUALITY_MEASUREMENT_MODE */ SET_1(dest); /* No BEP_PERIOD2 */ } else SET_L(dest); /* No Additions for Rel-6 */ return rc; } /* 3GPP TS 44.018 Table 10.5.2.16.1 < Packet Uplink Assignment > -- Single Block Allocation */ static int write_ia_rest_uplink_sba(bitvec *dest, uint32_t rfn, uint8_t alpha, uint8_t gamma) { int rc = 0; SET_0(dest); /* Single Block Allocation */ rc = write_alpha_gamma(dest, alpha, gamma); CHECK(rc); /* A 'Timing Advance index' shall not be allocated at a Single Block allocation. A 'TBF Starting Time' shall be allocated at a Single Block allocation. */ SET_0(dest); SET_1(dest); rc = write_tbf_start_time(dest, rfn); CHECK(rc); /* No P0 nor PR_MODE */ SET_L(dest); /* No Additions for R99 */ SET_L(dest); /* No Additions for Rel-6 */ SET_L(dest); return rc; } static int write_ia_rest_uplink_mba(const gprs_rlcmac_ul_tbf *tbf, bitvec *dest, uint8_t usf, uint8_t alpha, uint8_t gamma, int8_t ta_idx) { int rc = 0; SET_1(dest); /* Multi Block Allocation */ rc = write_tfi_usf(dest, tbf, usf); CHECK(rc); /* 3GPP TS 44.060 Table 11.2.28.2 Channel Coding Indicator */ rc = bitvec_set_u64(dest, mcs_chan_code(tbf->current_cs()), 2, false); /* CHANNEL_CODING_COMMAND */ CHECK(rc); /* TLLI_BLOCK_CHANNEL_CODING */ SET_1(dest); /* use coding scheme as specified by the corresponding CHANNEL CODING COMMAND */ rc = write_alpha_gamma(dest, alpha, gamma); CHECK(rc); rc = write_ta_index(dest, ta_idx); CHECK(rc); /* No TBF_STARTING_TIME */ SET_0(dest); return rc; } static int write_ia_rest_egprs_uplink_mba(bitvec * dest, uint32_t rfn, uint8_t alpha, uint8_t gamma) { int rc = 0; SET_0(dest); /* Multi Block Allocation */ rc = write_alpha_gamma(dest, alpha, gamma); CHECK(rc); rc = write_tbf_start_time(dest, rfn); CHECK(rc); SET_0(dest); /* NUMBER OF RADIO BLOCKS ALLOCATED: */ SET_0(dest); /* 1 radio block reserved for uplink transmission */ SET_0(dest); /* No P0 */ return rc; } static int write_ia_rest_egprs_uplink_sba(const gprs_rlcmac_ul_tbf *tbf, bitvec * dest, uint8_t usf, uint8_t alpha, uint8_t gamma, int8_t ta_idx) { int rc = 0; SET_1(dest); /* Single Block Allocation */ rc = write_tfi_usf(dest, tbf, usf); CHECK(rc); /* 3GPP TS 44.060 §12.10d EGPRS Modulation and coding Scheme description: */ rc = bitvec_set_u64(dest, mcs_chan_code(tbf->current_cs()), 4, false); /* EGPRS CHANNEL_CODING_COMMAND */ CHECK(rc); /* TLLI_BLOCK_CHANNEL_CODING */ rc = bitvec_set_bit(dest, (bit_value)tbf->tlli()); CHECK(rc); /* No BEP_PERIOD2 */ SET_0(dest); /* Retransmitted RLC data blocks shall not be re-segmented: (see 3GPP TS 44.060 §12.10e) */ SET_0(dest); /* RESEGMENT */ rc = bitvec_set_u64(dest, enc_ws(tbf->window_size()), 5, false); /* EGPRS Window Size */ CHECK(rc); rc = write_alpha_gamma(dest, alpha, gamma); CHECK(rc); rc = write_ta_index(dest, ta_idx); CHECK(rc); /* No TBF_STARTING_TIME */ SET_0(dest); /* No Additions for Rel-7 */ SET_0(dest); return rc; } /* * Immediate assignment reject, sent on the CCCH/AGCH * see GSM 44.018, 9.1.20 + 10.5.2.30 */ int Encoding::write_immediate_assignment_reject(bitvec *dest, uint16_t ra, uint16_t ref_rfn, enum ph_burst_type burst_type, uint8_t t3142) { unsigned wp = 0; int plen; int i; bitvec_write_field(dest, &wp, 0x0, 4); // Skip Indicator bitvec_write_field(dest, &wp, 0x6, 4); // Protocol Discriminator bitvec_write_field(dest, &wp, 0x3A, 8); // Immediate Assign Message Type // feature indicator bitvec_write_field(dest, &wp, 0x0, 1); // spare bitvec_write_field(dest, &wp, 0x0, 1); // spare bitvec_write_field(dest, &wp, 0x0, 1); // no cs bitvec_write_field(dest, &wp, 0x1, 1); // implicit detach for PS bitvec_write_field(dest, &wp, 0x0, 4); // Page Mode /* * 9.1.20.2 of 44.018 version 11.7.0 Release 11 * Filling of the message * If necessary the request reference information element and the * wait indication information element should be duplicated to * fill the message. * TODO: group rejection for multiple MS */ for (i = 0; i < 4; i++) { //10.5.2.30 Request Reference if (((burst_type == GSM_L1_BURST_TYPE_ACCESS_1) || (burst_type == GSM_L1_BURST_TYPE_ACCESS_2))) { //9.1.20.2a of 44.018 version 11.7.0 Release 11 bitvec_write_field(dest, &wp, 0x7f, 8); /* RACH value */ } else { bitvec_write_field(dest, &wp, ra, 8); /* RACH value */ } bitvec_write_field(dest, &wp, (ref_rfn / (26 * 51)) % 32, 5); // T1' bitvec_write_field(dest, &wp, ref_rfn % 51, 6); // T3 bitvec_write_field(dest, &wp, ref_rfn % 26, 5); // T2 /* 10.5.2.43 Wait Indication */ bitvec_write_field(dest, &wp, t3142, 8); } plen = wp / 8; if ((wp % 8)) { LOGP(DRLCMACUL, LOGL_ERROR, "Length of IMM.ASS.Rej without" "rest octets is not multiple of 8 bits, PLEASE FIX!\n"); return -1; } // Extended RA else if (((burst_type == GSM_L1_BURST_TYPE_ACCESS_1) || (burst_type == GSM_L1_BURST_TYPE_ACCESS_2))) { //9.1.20.2a of 44.018 version 11.7.0 Release 11 uint8_t extended_ra = 0; extended_ra = (ra & 0x1F); bitvec_write_field(dest, &wp, 0x1, 1); bitvec_write_field(dest, &wp, extended_ra, 5); /* Extended RA */ } else { bitvec_write_field(dest, &wp, 0x0, 1); } bitvec_write_field(dest, &wp, 0x0, 1); bitvec_write_field(dest, &wp, 0x0, 1); bitvec_write_field(dest, &wp, 0x0, 1); return plen; } /* * Immediate assignment, sent on the CCCH/AGCH * see GSM 04.08, 9.1.18 and GSM 44.018, 9.1.18 + 10.5.2.16 */ int Encoding::write_immediate_assignment( const struct gprs_rlcmac_pdch *pdch, const struct gprs_rlcmac_tbf *tbf, bitvec * dest, bool downlink, uint16_t ra, uint16_t ref_rfn, uint8_t ta, uint8_t usf, bool polling, uint16_t rfn, uint8_t alpha, uint8_t gamma, int8_t ta_idx, enum ph_burst_type burst_type) { unsigned wp = 0; int plen; int rc; bitvec_write_field(dest, &wp, 0x0, 4); // Skip Indicator bitvec_write_field(dest, &wp, 0x6, 4); // Protocol Discriminator bitvec_write_field(dest, &wp, GSM48_MT_RR_IMM_ASS, 8); // Immediate Assignment Message Type // 10.5.2.25b Dedicated mode or TBF bitvec_write_field(dest, &wp, 0x0, 1); // spare bitvec_write_field(dest, &wp, 0x0, 1); // TMA : Two-message assignment: No meaning bitvec_write_field(dest, &wp, downlink, 1); // Downlink : Downlink assignment to mobile in packet idle mode bitvec_write_field(dest, &wp, 0x1, 1); // T/D : TBF or dedicated mode: this message assigns a Temporary Block Flow (TBF). bitvec_write_field(dest, &wp, 0x0, 4); // Page Mode // GSM 04.08 10.5.2.25a Packet Channel Description bitvec_write_field(dest, &wp, 0x01, 5); // Channel type bitvec_write_field(dest, &wp, pdch->ts_no, 3); // TN bitvec_write_field(dest, &wp, pdch->tsc, 3); // TSC /* RF channel configuraion: hopping or non-hopping */ if (pdch->fh.enabled) { bitvec_write_field(dest, &wp, 0x01, 1); /* direct encoding */ bitvec_write_field(dest, &wp, pdch->fh.maio, 6); bitvec_write_field(dest, &wp, pdch->fh.hsn, 6); } else { bitvec_write_field(dest, &wp, 0x00, 3); bitvec_write_field(dest, &wp, pdch->trx->arfcn, 10); } //10.5.2.30 Request Reference if (((burst_type == GSM_L1_BURST_TYPE_ACCESS_1) || (burst_type == GSM_L1_BURST_TYPE_ACCESS_2))) { bitvec_write_field(dest, &wp, 0x7f, 8); /* RACH value */ } else { bitvec_write_field(dest, &wp, ra, 8); /* RACH value */ } bitvec_write_field(dest, &wp, (ref_rfn / (26 * 51)) % 32, 5); // T1' bitvec_write_field(dest, &wp, ref_rfn % 51, 6); // T3 bitvec_write_field(dest, &wp, ref_rfn % 26, 5); // T2 // 10.5.2.40 Timing Advance bitvec_write_field(dest, &wp, 0x0, 2); // spare bitvec_write_field(dest, &wp, ta, 6); // Timing Advance value /* 10.5.2.21 Mobile Allocation */ if (pdch->fh.enabled) { bitvec_write_field(dest, &wp, pdch->fh.ma_oct_len, 8); for (int i = 0; i < pdch->fh.ma_oct_len; i++) bitvec_write_field(dest, &wp, pdch->fh.ma[i], 8); } else { // No mobile allocation in non-hopping systems. // A zero-length LV. Just write L=0. bitvec_write_field(dest, &wp, 0x00, 8); } OSMO_ASSERT(wp % 8 == 0); plen = wp / 8; /* 3GPP TS 44.018 §10.5.2.16 IA Rest Octets */ dest->cur_bit = wp; if (downlink) { OSMO_ASSERT(tbf_as_dl_tbf_const(tbf) != NULL); rc = write_ia_rest_downlink(tbf_as_dl_tbf_const(tbf), dest, polling, gsm48_ta_is_valid(ta), rfn, alpha, gamma, ta_idx); } else if (((burst_type == GSM_L1_BURST_TYPE_ACCESS_1) || (burst_type == GSM_L1_BURST_TYPE_ACCESS_2))) { SET_L(dest); SET_H(dest); // "LH" SET_0(dest); SET_0(dest); // "00" < EGPRS Packet Uplink Assignment > rc = bitvec_set_u64(dest, ra & 0x1F, 5, false); // < Extended RA > CHECK(rc); SET_0(dest); // No < Access Technologies Request struct > if (tbf_as_ul_tbf_const(tbf) != NULL) rc = write_ia_rest_egprs_uplink_sba(tbf_as_ul_tbf_const(tbf), dest, usf, alpha, gamma, ta_idx); else rc = write_ia_rest_egprs_uplink_mba(dest, rfn, alpha, gamma); } else { OSMO_ASSERT(!tbf || !tbf->is_egprs_enabled()); SET_H(dest); SET_H(dest); // "HH" SET_0(dest); SET_0(dest); // "00" < Packet Uplink Assignment > if (tbf_as_ul_tbf_const(tbf) != NULL) rc = write_ia_rest_uplink_mba(tbf_as_ul_tbf_const(tbf), dest, usf, alpha, gamma, ta_idx); else rc = write_ia_rest_uplink_sba(dest, rfn, alpha, gamma); } if (rc < 0) { LOGP(DRLCMAC, LOGL_ERROR, "Failed to create IMMEDIATE ASSIGNMENT (%s) for %s\n", downlink ? "downlink" : "uplink", tbf ? tbf->name() : "single block allocation"); return rc; } return plen; } /* Prepare to be encoded Frequency Parameters IE (see Table 12.8.1) */ static void gen_freq_params(Frequency_Parameters_t *freq_params, const struct gprs_rlcmac_tbf *tbf) { const struct gprs_rlcmac_pdch *pdch; Direct_encoding_1_t fh_params; /* Check one PDCH, if it's hopping then all other should too */ pdch = tbf_get_first_ts_const(tbf); OSMO_ASSERT(pdch != NULL); /* Training Sequence Code */ freq_params->TSC = pdch->tsc; /* If frequency hopping is not in use, encode a single ARFCN */ if (!pdch->fh.enabled) { freq_params->UnionType = 0x00; freq_params->u.ARFCN = pdch->trx->arfcn; return; } /* Direct encoding 1 (see Table 12.8.1) */ freq_params->UnionType = 0x2; /* HSN / MAIO */ fh_params.MAIO = pdch->fh.maio; fh_params.GPRS_Mobile_Allocation.HSN = pdch->fh.hsn; fh_params.GPRS_Mobile_Allocation.ElementsOf_RFL_NUMBER = 0; memset(&fh_params.GPRS_Mobile_Allocation.RFL_NUMBER[0], 0x00, sizeof(fh_params.GPRS_Mobile_Allocation.RFL_NUMBER)); /* Mobile Allocation bitmap */ fh_params.GPRS_Mobile_Allocation.UnionType = 0; /* MA bitmap */ fh_params.GPRS_Mobile_Allocation.u.MA.MA_LENGTH = pdch->fh.ma_oct_len; /* in bytes */ fh_params.GPRS_Mobile_Allocation.u.MA.MA_BitLength = pdch->fh.ma_bit_len; /* in bits */ memcpy(fh_params.GPRS_Mobile_Allocation.u.MA.MA_BITMAP, pdch->fh.ma, pdch->fh.ma_oct_len); freq_params->u.Direct_encoding_1 = fh_params; } /* Generate Packet Uplink Assignment as per 3GPP TS 44.060, section 11.2.29. * NOTE: 'block' is expected to be zero-initialized by the caller. */ void write_packet_uplink_assignment(RlcMacDownlink_t *block, uint8_t old_tfi, uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli, const struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp, uint8_t alpha, uint8_t gamma, int8_t ta_idx, bool use_egprs) { Packet_Uplink_Assignment_t *pua; Packet_Timing_Advance_t *pta; Frequency_Parameters_t *fp; Dynamic_Allocation_t *da; /* RLC/MAC control block without the optional RLC/MAC control header */ block->PAYLOAD_TYPE = 0x01; // Payload Type block->RRBP = rrbp; // RRBP (e.g. N+13) block->SP = poll; // RRBP field is valid block->USF = 0x00; // Uplink state flag /* See 3GPP TS 44.060, section 11.2.29 */ pua = &block->u.Packet_Uplink_Assignment; pua->MESSAGE_TYPE = MT_PACKET_UPLINK_ASSIGNMENT; // Packet Uplink Assignment pua->PAGE_MODE = 0x00; // Normal Paging /* TLLI or Global (UL/DL) TFI */ if (use_tlli) { pua->ID.UnionType = 0x01; pua->ID.u.TLLI = tlli; } else { pua->ID.UnionType = 0x00; pua->ID.u.Global_TFI.UnionType = old_downlink; pua->ID.u.Global_TFI.u.UPLINK_TFI = old_tfi; } /* GPRS/EGPRS specific parameters */ pua->UnionType = use_egprs ? 0x01 : 0x00; if (!use_egprs) { PUA_GPRS_t *gprs = &pua->u.PUA_GPRS_Struct; /* Use the commanded CS/MCS value during the content resolution */ gprs->CHANNEL_CODING_COMMAND = mcs_chan_code(tbf->current_cs()); gprs->TLLI_BLOCK_CHANNEL_CODING = 0x01; // ^^^ /* Dynamic allocation */ gprs->UnionType = 0x01; /* Frequency Parameters IE is present */ gprs->Exist_Frequency_Parameters = 0x01; /* Common parameters to be set below */ pta = &gprs->Packet_Timing_Advance; fp = &gprs->Frequency_Parameters; da = &gprs->u.Dynamic_Allocation; } else { PUA_EGPRS_00_t *egprs = &pua->u.PUA_EGPRS_Struct.u.PUA_EGPRS_00; pua->u.PUA_EGPRS_Struct.UnionType = 0x00; // 'Normal' EGPRS, not EGPRS2 /* Use the commanded CS/MCS value during the content resolution */ egprs->EGPRS_CHANNEL_CODING_COMMAND = mcs_chan_code(tbf->current_cs()); egprs->TLLI_BLOCK_CHANNEL_CODING = 0x01; // ^^^ egprs->RESEGMENT = 0x01; // Enable segmentation egprs->EGPRS_WindowSize = tbf->window_size(); /* Dynamic allocation */ egprs->UnionType = 0x01; /* Frequency Parameters IE is present */ egprs->Exist_Frequency_Parameters = 0x01; /* Common parameters to be set below */ pta = &egprs->Packet_Timing_Advance; fp = &egprs->Frequency_Parameters; da = &egprs->u.Dynamic_Allocation; } /* Packet Timing Advance (if known) */ if (gsm48_ta_is_valid(tbf->ta())) { /* { 0 | 1 < TIMING_ADVANCE_VALUE : bit (6) > } */ pta->Exist_TIMING_ADVANCE_VALUE = 0x01; // Present pta->TIMING_ADVANCE_VALUE = tbf->ta(); } /* Continuous Timing Advance Control */ if (ta_idx >= 0 && ta_idx < 16) { pta->Exist_IndexAndtimeSlot = 0x01; // Present pta->TIMING_ADVANCE_TIMESLOT_NUMBER = 0; // FIXME! pta->TIMING_ADVANCE_INDEX = ta_idx; } /* Frequency Parameters IE */ gen_freq_params(fp, tbf); /* Dynamic allocation parameters */ da->USF_GRANULARITY = 0x00; /* Assign an Uplink TFI */ da->Exist_UPLINK_TFI_ASSIGNMENT = 0x01; da->UPLINK_TFI_ASSIGNMENT = tbf->tfi(); /* Timeslot Allocation with or without Power Control */ da->UnionType = (alpha || gamma) ? 0x01 : 0x00; if (da->UnionType == 0x01) da->u.Timeslot_Allocation_Power_Ctrl_Param.ALPHA = alpha; for (unsigned int tn = 0; tn < 8; tn++) { if (tbf->pdch[tn] == NULL) continue; if (da->UnionType == 0x01) { Timeslot_Allocation_Power_Ctrl_Param_t *params = \ &da->u.Timeslot_Allocation_Power_Ctrl_Param; params->Slot[tn].Exist = 0x01; // Enable this timeslot params->Slot[tn].USF_TN = tbf->m_usf[tn]; // USF_TN(i) params->Slot[tn].GAMMA_TN = gamma; } else { Timeslot_Allocation_t *slot = &da->u.Timeslot_Allocation[tn]; slot->Exist = 0x01; // Enable this timeslot slot->USF_TN = tbf->m_usf[tn]; // USF_TN(i) } } } /* Generate Packet Downlink Assignment as per 3GPP TS 44.060, section 11.2.7. * NOTE: 'block' is expected to be zero-initialized by the caller. */ void write_packet_downlink_assignment(RlcMacDownlink_t * block, bool old_tfi_is_valid, uint8_t old_tfi, uint8_t old_downlink, const struct gprs_rlcmac_dl_tbf *tbf, uint8_t poll, uint8_t rrbp, uint8_t alpha, uint8_t gamma, int8_t ta_idx, uint8_t ta_ts, bool use_egprs, uint8_t control_ack) { PDA_AdditionsR99_t *pda_r99; uint8_t tn; block->PAYLOAD_TYPE = 0x1; // RLC/MAC control block that does not include the optional octets of the RLC/MAC control header block->RRBP = rrbp; // 0: N+13 block->SP = poll; // RRBP field is valid block->USF = 0x0; // Uplink state flag block->u.Packet_Downlink_Assignment.MESSAGE_TYPE = 0x2; // Packet Downlink Assignment block->u.Packet_Downlink_Assignment.PAGE_MODE = 0x0; // Normal Paging block->u.Packet_Downlink_Assignment.Exist_PERSISTENCE_LEVEL = 0x0; // PERSISTENCE_LEVEL: off if (old_tfi_is_valid) { block->u.Packet_Downlink_Assignment.ID.UnionType = 0x0; // TFI = on block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.UnionType = old_downlink; // 0=UPLINK TFI, 1=DL TFI block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.u.UPLINK_TFI = old_tfi; // TFI } else { block->u.Packet_Downlink_Assignment.ID.UnionType = 0x1; // TLLI block->u.Packet_Downlink_Assignment.ID.u.TLLI = tbf->tlli(); } block->u.Packet_Downlink_Assignment.MAC_MODE = 0x0; // Dynamic Allocation block->u.Packet_Downlink_Assignment.RLC_MODE = RLC_MODE_ACKNOWLEDGED; block->u.Packet_Downlink_Assignment.CONTROL_ACK = control_ack; // NW establishes no new DL TBF for the MS with running timer T3192 block->u.Packet_Downlink_Assignment.TIMESLOT_ALLOCATION = 0; // timeslot(s) for (tn = 0; tn < 8; tn++) { if (tbf->pdch[tn]) block->u.Packet_Downlink_Assignment.TIMESLOT_ALLOCATION |= 0x80 >> tn; // timeslot(s) } if (tbf->ta() > 63) { /* { 0 | 1 < TIMING_ADVANCE_VALUE : bit (6) > } */ block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_TIMING_ADVANCE_VALUE = 0x0; // TIMING_ADVANCE_VALUE = off } else { block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_TIMING_ADVANCE_VALUE = 0x1; // TIMING_ADVANCE_VALUE = on block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.TIMING_ADVANCE_VALUE = tbf->ta(); // TIMING_ADVANCE_VALUE } if (ta_idx < 0) { block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_IndexAndtimeSlot = 0x0; // TIMING_ADVANCE_INDEX = off } else { block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_IndexAndtimeSlot = 0x1; // TIMING_ADVANCE_INDEX = on block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.TIMING_ADVANCE_INDEX = ta_idx; // TIMING_ADVANCE_INDEX block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.TIMING_ADVANCE_TIMESLOT_NUMBER = ta_ts; // TIMING_ADVANCE_TS } block->u.Packet_Downlink_Assignment.Exist_P0_and_BTS_PWR_CTRL_MODE = 0x0; // POWER CONTROL = off block->u.Packet_Downlink_Assignment.Exist_Frequency_Parameters = 0x1; // Frequency Parameters = on gen_freq_params(&block->u.Packet_Downlink_Assignment.Frequency_Parameters, tbf); block->u.Packet_Downlink_Assignment.Exist_DOWNLINK_TFI_ASSIGNMENT = 0x1; // DOWNLINK TFI ASSIGNMENT = on block->u.Packet_Downlink_Assignment.DOWNLINK_TFI_ASSIGNMENT = tbf->tfi(); // TFI block->u.Packet_Downlink_Assignment.Exist_Power_Control_Parameters = 0x1; // Power Control Parameters = on block->u.Packet_Downlink_Assignment.Power_Control_Parameters.ALPHA = alpha; // ALPHA for (tn = 0; tn < 8; tn++) { if (tbf->pdch[tn]) { block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].Exist = 0x1; // Slot[i] = on block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].GAMMA_TN = gamma; // GAMMA_TN } else { block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].Exist = 0x0; // Slot[i] = off } } block->u.Packet_Downlink_Assignment.Exist_TBF_Starting_Time = 0x0; // TBF Starting TIME = off block->u.Packet_Downlink_Assignment.Exist_Measurement_Mapping = 0x0; // Measurement_Mapping = off if (!use_egprs) { block->u.Packet_Downlink_Assignment.Exist_AdditionsR99 = 0x0; // AdditionsR99 = off return; } block->u.Packet_Downlink_Assignment.Exist_AdditionsR99 = 0x1; // AdditionsR99 = on pda_r99 = &block->u.Packet_Downlink_Assignment.AdditionsR99; pda_r99->Exist_EGPRS_Params = 1; pda_r99->EGPRS_WindowSize = enc_ws(tbf->window_size()); /* see TS 44.060, table 12.5.2.1 */ pda_r99->LINK_QUALITY_MEASUREMENT_MODE = 0x0; /* no meas, see TS 44.060, table 11.2.7.2 */ pda_r99->Exist_BEP_PERIOD2 = 0; /* No extra EGPRS BEP PERIOD */ pda_r99->Exist_Packet_Extended_Timing_Advance = 0; pda_r99->Exist_COMPACT_ReducedMA = 0; } /* Generate paging request. See 44.018, sections 10 and 9.1.22 */ int write_paging_request(struct bitvec *dest, const struct osmo_mobile_identity *mi) { uint8_t mi_buf[GSM48_MID_MAX_SIZE]; int mi_len; unsigned wp = 0; int plen; bitvec_write_field(dest, &wp,0x0,4); // Skip Indicator bitvec_write_field(dest, &wp,0x6,4); // Protocol Discriminator bitvec_write_field(dest, &wp,0x21,8); // Paging Request Message Type 1 bitvec_write_field(dest, &wp,0x0,4); // Page Mode bitvec_write_field(dest, &wp,0x0,4); // Channel Needed mi_len = osmo_mobile_identity_encode_buf(mi_buf, sizeof(mi_buf), mi, true); if (mi_len <= 0) return mi_len; bitvec_write_field(dest, &wp, mi_len, 8); // Mobile Identity length bitvec_set_bytes(dest, mi_buf, mi_len); // Mobile Identity wp += mi_len * 8; OSMO_ASSERT(wp % 8 == 0); plen = wp / 8; bitvec_write_field(dest, &wp,0x0,1); // "L" Notification List Number; NLN(PCH) = off bitvec_write_field(dest, &wp,0x0,1); // "L" Priority1 = off bitvec_write_field(dest, &wp,0x1,1); // "L" Priority2 = off bitvec_write_field(dest, &wp,0x0,1); // "L" Group Call information = off bitvec_write_field(dest, &wp,0x0,1); // "H" Packet Page Indication 1 = packet paging procedure bitvec_write_field(dest, &wp,0x1,1); // "H" Packet Page Indication 2 = packet paging procedure return plen; } /** * The index of the array show_rbb is the bit position inside the rbb * (show_rbb[63] relates to BSN ssn-1) */ void Encoding::encode_rbb(const char *show_rbb, bitvec *bv) { // RECEIVE_BLOCK_BITMAP for (int i = 0; i < 64; i++) { /* Set bit at the appropriate position (see 3GPP TS 44.060 9.1.8.1) */ bitvec_set_bit(bv, show_rbb[i] == 'R' ? ONE : ZERO); } } static void write_packet_ack_nack_desc_gprs( bitvec * dest, unsigned& wp, gprs_rlc_ul_window *window, bool is_final) { char rbb[65]; window->update_rbb(rbb); rbb[64] = 0; LOGP(DRLCMACUL, LOGL_DEBUG, "- V(N): \"%s\" R=Received " "I=Invalid\n", rbb); bitvec_write_field(dest, &wp, is_final, 1); // FINAL_ACK_INDICATION bitvec_write_field(dest, &wp, window->ssn(), 7); // STARTING_SEQUENCE_NUMBER for (int i = 0; i < 64; i++) { /* Set bit at the appropriate position (see 3GPP TS 44.060 9.1.8.1) */ bool is_ack = (rbb[i] == 'R'); bitvec_write_field(dest, &wp, is_ack, 1); } } static void write_packet_uplink_ack_gprs( bitvec * dest, unsigned& wp, struct gprs_rlcmac_ul_tbf *tbf, bool is_final) { gprs_rlc_ul_window *window = static_cast(tbf->window()); bitvec_write_field(dest, &wp, mcs_chan_code(tbf->current_cs()), 2); // CHANNEL_CODING_COMMAND write_packet_ack_nack_desc_gprs(dest, wp, window, is_final); if (tbf->is_tlli_valid()) { bitvec_write_field(dest, &wp, 1, 1); // 1: have CONTENTION_RESOLUTION_TLLI bitvec_write_field(dest, &wp, tbf->tlli(), 32); // CONTENTION_RESOLUTION_TLLI } else { bitvec_write_field(dest, &wp, 0, 1); // 0: don't have CONTENTION_RESOLUTION_TLLI } if (gsm48_ta_is_valid(tbf->ta())) { bitvec_write_field(dest, &wp, 1, 1); // 1: have Packet Timing Advance IE (TS 44.060 12.12) bitvec_write_field(dest, &wp, 1, 1); // 1: have TIMING_ADVANCE_VALUE bitvec_write_field(dest, &wp, tbf->ta(), 6); // TIMING_ADVANCE_VALUE bitvec_write_field(dest, &wp, 0, 1); // 0: don't have TIMING_ADVANCE_INDEX } else { bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Packet Timing Advance } bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Power Control Parameters bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Extension Bits bitvec_write_field(dest, &wp, 0, 1); // fixed 0 bitvec_write_field(dest, &wp, 1, 1); // 1: have Additions R99 bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Packet Extended Timing Advance bitvec_write_field(dest, &wp, 1, 1); // TBF_EST (enabled) bitvec_write_field(dest, &wp, 0, 1); // 0: don't have REL 5 }; /* Encode the Ack/Nack for EGPRS. 44.060 * The PCU encodes to receive block bitmap to the following rules: * - always encode the lenght field * - use compressed receive block bitmap if it's smaller than uncompressed * receive block bitmap * - use the remaining bits for an uncompressed receive block bitmap if needed * * Note: The spec also defines an Ack/Nack without length field, but the PCU's * doesn't support this in UL. It would require a lot more code complexity * and only saves 7 bit in lossy sitations. */ static void write_packet_ack_nack_desc_egprs( bitvec * dest, unsigned& wp, gprs_rlc_ul_window *window, bool is_final, unsigned rest_bits) { unsigned int urbb_len = 0; uint8_t crbb_len = 0; uint8_t len; bool bow = true; bool eow = true; uint16_t ssn = window->mod_sns(window->v_q() + 1); unsigned int num_blocks = window->mod_sns(window->v_r() - window->v_q()); uint16_t esn_crbb = window->mod_sns(ssn - 1); static uint8_t rbb[RLC_EGPRS_MAX_WS] = {'\0'}; uint8_t iter = 0; int is_compressed = 0; bool try_compression = false; uint16_t ucmp_bmplen; uint8_t crbb_bitmap[23] = {'\0'}; bitvec ucmp_vec; bitvec crbb_vec; uint8_t uclen_crbb = 0; uint8_t crbb_start_clr_code; uint8_t i; /* static size of 16 bits ..1. .... = ACKNACK: (Union) 0 0000 000 Length Desc ...0 .... = FINAL_ACK_INDICATION: False .... 1... = BEGINNING_OF_WINDOW: 1 .... .1.. = END_OF_WINDOW: 1 .... ..10 0101 0001 1... .... = STARTING_SEQUENCE_NUMBER: 1187 .0.. .... = CRBB Exist: 0 minimal size is 24 rest_bits */ rest_bits -= 24; if (num_blocks > 0) /* V(Q) is NACK and omitted -> SSN = V(Q) + 1 */ num_blocks -= 1; if (num_blocks > window->ws()) num_blocks = window->ws(); /* Try Compression as number of blocks does not fit */ if (num_blocks > rest_bits) { try_compression = true; } if (try_compression == true) { ucmp_bmplen = window->update_egprs_rbb(rbb); ucmp_vec.data = rbb; ucmp_vec.cur_bit = ucmp_bmplen; ucmp_vec.data_len = 127; crbb_vec.data = crbb_bitmap; crbb_vec.cur_bit = 0; crbb_vec.data_len = 127; LOGP(DRLCMACUL, LOGL_DEBUG, "rest_bits=%d uncompressed len %d and uncompressed bitmap = %s\n", rest_bits, ucmp_bmplen, osmo_hexdump(ucmp_vec.data, (ucmp_bmplen+7)/8)); is_compressed = egprs_compress::compress_rbb(&ucmp_vec, /* Uncompressed bitmap*/ &crbb_vec, /*Compressed bitmap vector */ &uclen_crbb, (rest_bits - 16));/* CRBBlength:7 colourcode:1 dissector length:8*/ LOGP(DRLCMACUL, LOGL_DEBUG, "the ucmp len=%d uclen_crbb=%d num_blocks=%d crbb length %d, " "and the CRBB bitmap = %s\n", ucmp_bmplen, uclen_crbb, num_blocks, crbb_vec.cur_bit, osmo_hexdump(crbb_bitmap, (crbb_vec.cur_bit+7)/8)); crbb_len = crbb_vec.cur_bit; } if (is_compressed) { /* 8 = 7 (CRBBlength) + 1 (CRBB starting color code) */ rest_bits -= 8; } else { uclen_crbb = 0; crbb_len = 0; } if (num_blocks > uclen_crbb + rest_bits) { eow = false; urbb_len = rest_bits - crbb_len; } else urbb_len = num_blocks - uclen_crbb; if (is_compressed) len = urbb_len + crbb_len + 23; else len = urbb_len + 15; /* EGPRS Ack/Nack Description IE * do not support Ack/Nack without length */ bitvec_write_field(dest, &wp, 1, 1); // 1: have length bitvec_write_field(dest, &wp, len, 8); // length bitvec_write_field(dest, &wp, is_final, 1); // FINAL_ACK_INDICATION bitvec_write_field(dest, &wp, bow, 1); // BEGINNING_OF_WINDOW bitvec_write_field(dest, &wp, eow, 1); // END_OF_WINDOW bitvec_write_field(dest, &wp, ssn, 11); // STARTING_SEQUENCE_NUMBER if (is_compressed) { bitvec_write_field(dest, &wp, 1, 1); // CRBB_Exist bitvec_write_field(dest, &wp, crbb_len, 7); // CRBB_LENGTH crbb_start_clr_code = (0x80 & ucmp_vec.data[0])>>7; bitvec_write_field(dest, &wp, crbb_start_clr_code, 1); // CRBB_clr_code LOGP(DRLCMACUL, LOGL_DEBUG, "EGPRS CRBB, crbb_len = %d, crbb_start_clr_code = %d\n", crbb_len, crbb_start_clr_code); while (crbb_len != 0) { if (crbb_len > 8) { bitvec_write_field(dest, &wp, crbb_bitmap[iter], 8); crbb_len = crbb_len - 8; iter++; } else { bitvec_write_field(dest, &wp, crbb_bitmap[iter] >> (8 - crbb_len), crbb_len); crbb_len = 0; } } esn_crbb = window->mod_sns(esn_crbb + uclen_crbb); } else { bitvec_write_field(dest, &wp, 0, 1); // CRBB_Exist } LOGP(DRLCMACUL, LOGL_DEBUG, "EGPRS URBB, urbb len = %d, SSN = %u, ESN_CRBB = %u, " "desc len = %d, " "SNS = %d, WS = %d, V(Q) = %d, V(R) = %d%s%s\n", urbb_len, ssn, esn_crbb, len, window->sns(), window->ws(), window->v_q(), window->v_r(), bow ? ", BOW" : "", eow ? ", EOW" : ""); for (i = urbb_len; i > 0; i--) { /* Set bit at the appropriate position (see 3GPP TS 44.060 12.3.1) */ bool is_ack = window->m_v_n.is_received(esn_crbb + i); bitvec_write_field(dest, &wp, is_ack, 1); } } static void write_packet_uplink_ack_egprs( bitvec * dest, unsigned& wp, struct gprs_rlcmac_ul_tbf *tbf, bool is_final) { gprs_rlc_ul_window *window = static_cast(tbf->window()); bitvec_write_field(dest, &wp, 0, 2); // fixed 00 /* CHANNEL_CODING_COMMAND */ bitvec_write_field(dest, &wp, mcs_chan_code(tbf->current_cs()), 4); /* 0: no RESEGMENT, 1: Segmentation*/ bitvec_write_field(dest, &wp, 1, 1); bitvec_write_field(dest, &wp, 1, 1); // PRE_EMPTIVE_TRANSMISSION, TODO: This resembles GPRS, change it? bitvec_write_field(dest, &wp, 0, 1); // 0: no PRR_RETRANSMISSION_REQUEST, TODO: clarify bitvec_write_field(dest, &wp, 0, 1); // 0: no ARAC_RETRANSMISSION_REQUEST, TODO: clarify if (tbf->is_tlli_valid()) { bitvec_write_field(dest, &wp, 1, 1); // 1: have CONTENTION_RESOLUTION_TLLI bitvec_write_field(dest, &wp, tbf->tlli(), 32); // CONTENTION_RESOLUTION_TLLI } else { bitvec_write_field(dest, &wp, 0, 1); // 0: don't have CONTENTION_RESOLUTION_TLLI } bitvec_write_field(dest, &wp, 1, 1); // TBF_EST (enabled) if (gsm48_ta_is_valid(tbf->ta())) { bitvec_write_field(dest, &wp, 1, 1); // 1: have Packet Timing Advance IE (TS 44.060 12.12) bitvec_write_field(dest, &wp, 1, 1); // 1: have TIMING_ADVANCE_VALUE bitvec_write_field(dest, &wp, tbf->ta(), 6); // TIMING_ADVANCE_VALUE bitvec_write_field(dest, &wp, 0, 1); // 0: don't have TIMING_ADVANCE_INDEX } else { bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Packet Timing Advance } bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Packet Extended Timing Advance bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Power Control Parameters bitvec_write_field(dest, &wp, 0, 1); // 0: don't have Extension Bits /* -2 for last bit 0 mandatory and REL5 not supported */ unsigned bits_ack_nack = dest->data_len * 8 - wp - 2; write_packet_ack_nack_desc_egprs(dest, wp, window, is_final, bits_ack_nack); bitvec_write_field(dest, &wp, 0, 1); // fixed 0 bitvec_write_field(dest, &wp, 0, 1); // 0: don't have REL 5 }; void write_packet_uplink_ack(struct bitvec *dest, struct gprs_rlcmac_ul_tbf *tbf, bool is_final, uint8_t rrbp) { unsigned wp = 0; LOGP(DRLCMACUL, LOGL_DEBUG, "Encoding Ack/Nack for %s " "(final=%d)\n", tbf_name(tbf), is_final); bitvec_write_field(dest, &wp, 0x1, 2); // Payload Type bitvec_write_field(dest, &wp, rrbp, 2); // Uplink block with TDMA framenumber bitvec_write_field(dest, &wp, is_final, 1); // Suppl/Polling Bit bitvec_write_field(dest, &wp, 0x0, 3); // Uplink state flag bitvec_write_field(dest, &wp, 0x9, 6); // MESSAGE TYPE Uplink Ack/Nack bitvec_write_field(dest, &wp, 0x0, 2); // Page Mode bitvec_write_field(dest, &wp, 0x0, 2); // fixed 00 bitvec_write_field(dest, &wp, tbf->tfi(), 5); // Uplink TFI if (tbf->is_egprs_enabled()) { /* PU_AckNack_EGPRS = on */ bitvec_write_field(dest, &wp, 1, 1); // 1: EGPRS write_packet_uplink_ack_egprs(dest, wp, tbf, is_final); } else { /* PU_AckNack_GPRS = on */ bitvec_write_field(dest, &wp, 0, 1); // 0: GPRS write_packet_uplink_ack_gprs(dest, wp, tbf, is_final); } LOGP(DRLCMACUL, LOGL_DEBUG, "Uplink Ack/Nack bit count %d, max %d, message = %s\n", wp, dest->data_len * 8, osmo_hexdump(dest->data, dest->data_len)); } unsigned Encoding::write_packet_paging_request(bitvec * dest) { unsigned wp = 0; bitvec_write_field(dest, &wp, 0x1, 2); // Payload Type bitvec_write_field(dest, &wp, 0x0, 3); // No polling bitvec_write_field(dest, &wp, 0x0, 3); // Uplink state flag bitvec_write_field(dest, &wp, 0x22, 6); // MESSAGE TYPE bitvec_write_field(dest, &wp, 0x0, 2); // Page Mode bitvec_write_field(dest, &wp, 0x0, 1); // No PERSISTENCE_LEVEL bitvec_write_field(dest, &wp, 0x0, 1); // No NLN return wp; } /* 3GPP TS 44.060 § 11.2.10: < Repeated Page info struct > ::= { 0 -- Page request for TBF establishment { 0 < PTMSI : bit (32) > | 1 < Length of Mobile Identity contents : bit (4) > < Mobile Identity : octet (val (Length of Mobile Identity contents)) > } | 1 -- Page request for RR conn. establishment { 0 < TMSI : bit (32) > | 1 < Length of Mobile Identity contents : bit (4) > < Mobile Identity : octet (val (Length of Mobile Identity contents)) > } < CHANNEL_NEEDED : bit (2) > { 0 | 1 < eMLPP_PRIORITY : bit (3) > } } */ unsigned Encoding::write_repeated_page_info(bitvec * dest, unsigned& wp, uint8_t len, uint8_t *identity, uint8_t chan_needed) { bitvec_write_field(dest, &wp,0x1,1); // Repeated Page info exists bitvec_write_field(dest, &wp,0x1,1); // RR connection paging if ((identity[0] & 0x07) == 4) { bitvec_write_field(dest, &wp,0x0,1); // TMSI identity++; len--; } else { bitvec_write_field(dest, &wp,0x1,1); // MI bitvec_write_field(dest, &wp,len,4); // MI len } while (len) { bitvec_write_field(dest, &wp,*identity++,8); // MI data len--; } bitvec_write_field(dest, &wp,chan_needed,2); // CHANNEL_NEEDED bitvec_write_field(dest, &wp,0x0,1); // No eMLPP_PRIORITY return wp; } int Encoding::rlc_write_dl_data_header(const struct gprs_rlc_data_info *rlc, uint8_t *data) { struct gprs_rlc_dl_header_egprs_1 *egprs1; struct gprs_rlc_dl_header_egprs_2 *egprs2; struct gprs_rlc_dl_header_egprs_3 *egprs3; struct rlc_dl_header *gprs; unsigned int e_fbi_header; enum CodingScheme cs = rlc->cs; unsigned int offs; unsigned int bsn_delta; switch(mcs_header_type(cs)) { case HEADER_GPRS_DATA: gprs = static_cast ((void *)data); gprs->usf = rlc->usf; gprs->s_p = rlc->es_p != 0 ? 1 : 0; gprs->rrbp = rlc->rrbp; gprs->pt = 0; gprs->tfi = rlc->tfi; gprs->pr = rlc->pr; gprs->fbi = rlc->block_info[0].cv == 0; gprs->e = rlc->block_info[0].e; gprs->bsn = rlc->block_info[0].bsn; break; case HEADER_EGPRS_DATA_TYPE_1: egprs1 = static_cast ((void *)data); egprs1->usf = rlc->usf; egprs1->es_p = rlc->es_p; egprs1->rrbp = rlc->rrbp; egprs1->tfi_hi = rlc->tfi >> 0; /* 1 bit LSB */ egprs1->tfi_lo = rlc->tfi >> 1; /* 4 bits */ egprs1->pr = rlc->pr; egprs1->cps = rlc->cps; egprs1->bsn1_hi = rlc->block_info[0].bsn >> 0; /* 2 bits LSB */ egprs1->bsn1_mid = rlc->block_info[0].bsn >> 2; /* 8 bits */ egprs1->bsn1_lo = rlc->block_info[0].bsn >> 10; /* 1 bit */ bsn_delta = (rlc->block_info[1].bsn - rlc->block_info[0].bsn) & (RLC_EGPRS_SNS - 1); egprs1->bsn2_hi = bsn_delta >> 0; /* 7 bits LSB */ egprs1->bsn2_lo = bsn_delta >> 7; /* 3 bits */ /* first FBI/E header */ e_fbi_header = rlc->block_info[0].e ? 0x01 : 0; e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */ offs = rlc->data_offs_bits[0] / 8; OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 2); e_fbi_header <<= 0; data[offs] = (data[offs] & 0b11111100) | e_fbi_header; /* second FBI/E header */ e_fbi_header = rlc->block_info[1].e ? 0x01 : 0; e_fbi_header |= rlc->block_info[1].cv == 0 ? 0x02 : 0; /* FBI */ offs = rlc->data_offs_bits[1] / 8; OSMO_ASSERT(rlc->data_offs_bits[1] % 8 == 4); e_fbi_header <<= 2; data[offs] = (data[offs] & 0b11110011) | e_fbi_header; break; case HEADER_EGPRS_DATA_TYPE_2: egprs2 = static_cast ((void *)data); egprs2->usf = rlc->usf; egprs2->es_p = rlc->es_p; egprs2->rrbp = rlc->rrbp; egprs2->tfi_hi = rlc->tfi >> 0; /* 1 bit LSB */ egprs2->tfi_lo = rlc->tfi >> 1; /* 4 bits */ egprs2->pr = rlc->pr; egprs2->cps = rlc->cps; egprs2->bsn1_hi = rlc->block_info[0].bsn >> 0; /* 2 bits LSB */ egprs2->bsn1_mid = rlc->block_info[0].bsn >> 2; /* 8 bits */ egprs2->bsn1_lo = rlc->block_info[0].bsn >> 10; /* 1 bit */ e_fbi_header = rlc->block_info[0].e ? 0x01 : 0; e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */ offs = rlc->data_offs_bits[0] / 8; OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 6); e_fbi_header <<= 4; data[offs] = (data[offs] & 0b11001111) | e_fbi_header; break; case HEADER_EGPRS_DATA_TYPE_3: egprs3 = static_cast ((void *)data); egprs3->usf = rlc->usf; egprs3->es_p = rlc->es_p; egprs3->rrbp = rlc->rrbp; egprs3->tfi_hi = rlc->tfi >> 0; /* 1 bit LSB */ egprs3->tfi_lo = rlc->tfi >> 1; /* 4 bits */ egprs3->pr = rlc->pr; egprs3->cps = rlc->cps; egprs3->bsn1_hi = rlc->block_info[0].bsn >> 0; /* 2 bits LSB */ egprs3->bsn1_mid = rlc->block_info[0].bsn >> 2; /* 8 bits */ egprs3->bsn1_lo = rlc->block_info[0].bsn >> 10; /* 1 bit */ egprs3->spb = rlc->block_info[0].spb; e_fbi_header = rlc->block_info[0].e ? 0x01 : 0; e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */ offs = rlc->data_offs_bits[0] / 8; OSMO_ASSERT(rlc->data_offs_bits[0] % 8 == 1); e_fbi_header <<= 7; data[offs-1] = (data[offs-1] & 0b01111111) | (e_fbi_header >> 0); data[offs] = (data[offs] & 0b11111110) | (e_fbi_header >> 8); break; default: LOGP(DRLCMACDL, LOGL_ERROR, "Encoding of uplink %s data blocks not yet supported.\n", mcs_name(cs)); return -ENOTSUP; }; return 0; } /** * \brief Copy LSB bitstream RLC data block from byte aligned buffer. * * Note that the bitstream is encoded in LSB first order, so the two octets * 654321xx xxxxxx87 contain the octet 87654321 starting at bit position 3 * (LSB has bit position 1). This is a different order than the one used by * CSN.1. * * \param data_block_idx The block index, 0..1 for header type 1, 0 otherwise * \param src A pointer to the start of the RLC block (incl. the header) * \param buffer A data area of a least the size of the RLC block * \returns the number of bytes copied */ unsigned int Encoding::rlc_copy_from_aligned_buffer( const struct gprs_rlc_data_info *rlc, unsigned int data_block_idx, uint8_t *dst, const uint8_t *buffer) { unsigned int hdr_bytes; unsigned int extra_bits; unsigned int i; uint8_t c, last_c; const uint8_t *src; const struct gprs_rlc_data_block_info *rdbi; OSMO_ASSERT(data_block_idx < rlc->num_data_blocks); rdbi = &rlc->block_info[data_block_idx]; hdr_bytes = rlc->data_offs_bits[data_block_idx] / 8; extra_bits = (rlc->data_offs_bits[data_block_idx] % 8); if (extra_bits == 0) { /* It is aligned already */ memmove(dst + hdr_bytes, buffer, rdbi->data_len); return rdbi->data_len; } src = buffer; dst = dst + hdr_bytes; last_c = *dst << (8 - extra_bits); for (i = 0; i < rdbi->data_len; i++) { c = src[i]; *(dst++) = (last_c >> (8 - extra_bits)) | (c << extra_bits); last_c = c; } /* overwrite the lower extra_bits */ *dst = (*dst & (0xff << extra_bits)) | (last_c >> (8 - extra_bits)); return rdbi->data_len; } /*! * \brief (GPRS) put llc pdu into an rlc/mac block. fragment the llc pdu if needed * \param rdbi rlc/mac block info * \param llc llc pdu * \param offset given offset within the rlc/mac block * \param num_chunks count the chunks (llc pdu data) within rlc/mac * \param data_block buffer holds rlc/mac data * \param is_final if this is the last rlc/mac within a TBF * \param count_payload if not NULL save the written size of payload in bytes into it * \return the state of the rlc/mac like if there is more space for another chunk */ static Encoding::AppendResult rlc_data_to_dl_append_gprs( struct gprs_rlc_data_block_info *rdbi, gprs_llc *llc, int *offset, int *num_chunks, uint8_t *data_block, bool is_final, int *count_payload) { int chunk; int space; struct rlc_li_field *li; uint8_t *delimiter, *data, *e_pointer; data = data_block + *offset; delimiter = data_block + *num_chunks; e_pointer = (*num_chunks ? delimiter - 1 : NULL); chunk = llc_chunk_size(llc); space = rdbi->data_len - *offset; /* if chunk will exceed block limit */ if (chunk > space) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "larger than space (%d) left in block: copy " "only remaining space, and we are done\n", chunk, space); if (e_pointer) { /* LLC frame not finished, so there is no extension octet */ *e_pointer |= 0x02; /* set previous M bit = 1 */ } /* fill only space */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; /* return data block as message */ *offset = rdbi->data_len; (*num_chunks)++; return Encoding::AR_NEED_MORE_BLOCKS; } /* if FINAL chunk would fit precisely in space left */ if (chunk == space && is_final) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "would exactly fit into space (%d): because " "this is a final block, we don't add length " "header, and we are done\n", chunk, space); /* block is filled, so there is no extension */ if (e_pointer) *e_pointer |= 0x01; /* fill space */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; *offset = rdbi->data_len; (*num_chunks)++; rdbi->cv = 0; return Encoding::AR_COMPLETED_BLOCK_FILLED; } /* if chunk would fit exactly in space left */ if (chunk == space) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "would exactly fit into space (%d): add length " "header with LI=0, to make frame extend to " "next block, and we are done\n", chunk, space); /* make space for delimiter */ if (delimiter != data) memmove(delimiter + 1, delimiter, data - delimiter); if (e_pointer) { *e_pointer &= 0xfe; /* set previous E bit = 0 */ *e_pointer |= 0x02; /* set previous M bit = 1 */ } data++; (*offset)++; space--; /* add LI with 0 length */ li = (struct rlc_li_field *)delimiter; li->e = 1; /* not more extension */ li->m = 0; /* shall be set to 0, in case of li = 0 */ li->li = 0; /* chunk fills the complete space */ rdbi->e = 0; /* 0: extensions present */ // no need to set e_pointer nor increase delimiter /* fill only space, which is 1 octet less than chunk */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; /* return data block as message */ *offset = rdbi->data_len; (*num_chunks)++; return Encoding::AR_NEED_MORE_BLOCKS; } LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d is less " "than remaining space (%d): add length header to " "delimit LLC frame\n", chunk, space); /* the LLC frame chunk ends in this block */ /* make space for delimiter */ if (delimiter != data) memmove(delimiter + 1, delimiter, data - delimiter); if (e_pointer) { *e_pointer &= 0xfe; /* set previous E bit = 0 */ *e_pointer |= 0x02; /* set previous M bit = 1 */ } data++; (*offset)++; space--; /* add LI to delimit frame */ li = (struct rlc_li_field *)delimiter; li->e = 1; /* not more extension, maybe set later */ li->m = 0; /* will be set later, if there is more LLC data */ li->li = chunk; /* length of chunk */ rdbi->e = 0; /* 0: extensions present */ (*num_chunks)++; /* copy (rest of) LLC frame to space and reset later */ llc_consume_data(llc, data, chunk); if (count_payload) *count_payload = chunk; data += chunk; space -= chunk; (*offset) += chunk; /* if we have more data and we have space left */ if (space > 0 && !is_final) return Encoding::AR_COMPLETED_SPACE_LEFT; /* if we don't have more LLC frames */ if (is_final) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we " "done.\n"); rdbi->cv = 0; return Encoding::AR_COMPLETED_BLOCK_FILLED; } /* we have no space left */ LOGP(DRLCMACDL, LOGL_DEBUG, "-- No space left, so we are " "done.\n"); return Encoding::AR_COMPLETED_BLOCK_FILLED; } /*! * \brief (EGPRS) put llc pdu into an rlc/mac block. fragment the llc pdu if needed * \param rdbi rlc/mac block info * \param llc llc pdu * \param offset given offset within the rlc/mac block * \param num_chunks count the chunks (llc pdu data) within rlc/mac * \param data_block buffer holds rlc/mac data * \param is_final if this is the last rlc/mac within a TBF * \param count_payload if not NULL save the written size of payload in bytes into it * \return the state of the rlc/mac like if there is more space for another chunk */ static Encoding::AppendResult rlc_data_to_dl_append_egprs( struct gprs_rlc_data_block_info *rdbi, gprs_llc *llc, int *offset, int *num_chunks, uint8_t *data_block, bool is_final, int *count_payload) { int chunk; int space; struct rlc_li_field_egprs *li; struct rlc_li_field_egprs *prev_li; uint8_t *delimiter, *data; data = data_block + *offset; delimiter = data_block + *num_chunks; prev_li = (struct rlc_li_field_egprs *) (*num_chunks ? delimiter - 1 : NULL); chunk = llc_chunk_size(llc); space = rdbi->data_len - *offset; /* if chunk will exceed block limit */ if (chunk > space) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "larger than space (%d) left in block: copy " "only remaining space, and we are done\n", chunk, space); /* fill only space */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; /* return data block as message */ *offset = rdbi->data_len; (*num_chunks)++; return Encoding::AR_NEED_MORE_BLOCKS; } /* if FINAL chunk would fit precisely in space left */ if (chunk == space && is_final) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "would exactly fit into space (%d): because " "this is a final block, we don't add length " "header, and we are done\n", chunk, space); /* fill space */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; *offset = rdbi->data_len; (*num_chunks)++; rdbi->cv = 0; return Encoding::AR_COMPLETED_BLOCK_FILLED; } /* if chunk would fit exactly in space left */ if (chunk == space) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d " "would exactly fit into space (%d): just copy " "it, and we are done. The next block will have " "to start with an empty chunk\n", chunk, space); /* fill space */ llc_consume_data(llc, data, space); if (count_payload) *count_payload = space; *offset = rdbi->data_len; (*num_chunks)++; return Encoding::AR_NEED_MORE_BLOCKS; } LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d is less " "than remaining space (%d): add length header to " "to delimit LLC frame\n", chunk, space); /* the LLC frame chunk ends in this block */ /* make space for delimiter */ if (delimiter != data) memmove(delimiter + 1, delimiter, data - delimiter); data += 1; (*offset) += 1; space -= 1; /* add LI to delimit frame */ li = (struct rlc_li_field_egprs *)delimiter; li->e = 1; /* not more extension, maybe set later */ li->li = chunk; /* length of chunk */ /* tell previous extension header about the new one */ if (prev_li) prev_li->e = 0; rdbi->e = 0; /* 0: extensions present */ delimiter++; prev_li = li; (*num_chunks)++; /* copy (rest of) LLC frame to space and reset later */ llc_consume_data(llc, data, chunk); if (count_payload) *count_payload = chunk; data += chunk; space -= chunk; (*offset) += chunk; /* if we have more data and we have space left */ if (!is_final) { if (space > 0) { return Encoding::AR_COMPLETED_SPACE_LEFT; } else { /* we have no space left */ LOGP(DRLCMACDL, LOGL_DEBUG, "-- No space left, so we are " "done.\n"); return Encoding::AR_COMPLETED_BLOCK_FILLED; } } else { /* we don't have more LLC frames */ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we are done.\n"); rdbi->cv = 0; if (space > 0) Encoding::rlc_data_to_dl_append_egprs_li_padding(rdbi, offset, num_chunks, data_block); return Encoding::AR_COMPLETED_BLOCK_FILLED; } } /*! * \brief Encoding::rlc_data_to_dl_append * \param rdbi rlc/mac block info * \param cs the coding scheme to use * \param llc llc pdu * \param offset given offset within the rlc/mac block * \param num_chunks count the chunks (llc pdu data) within rlc/mac * \param data_block buffer holds rlc/mac data * \param is_final if this is the last rlc/mac within a TBF * \param count_payload if not NULL save the written size of payload in bytes into it * \return the state of the rlc/mac like if there is more space for another chunk */ Encoding::AppendResult Encoding::rlc_data_to_dl_append( struct gprs_rlc_data_block_info *rdbi, enum CodingScheme cs, gprs_llc *llc, int *offset, int *num_chunks, uint8_t *data_block, bool is_final, int *count_payload) { if (mcs_is_gprs(cs)) return rlc_data_to_dl_append_gprs(rdbi, llc, offset, num_chunks, data_block, is_final, count_payload); if (mcs_is_edge(cs)) return rlc_data_to_dl_append_egprs(rdbi, llc, offset, num_chunks, data_block, is_final, count_payload); LOGP(DRLCMACDL, LOGL_ERROR, "%s data block encoding not implemented\n", mcs_name(cs)); OSMO_ASSERT(mcs_is_valid(cs)); return AR_NEED_MORE_BLOCKS; } void Encoding::rlc_data_to_dl_append_egprs_li_padding( const struct gprs_rlc_data_block_info *rdbi, int *offset, int *num_chunks, uint8_t *data_block) { struct rlc_li_field_egprs *li; struct rlc_li_field_egprs *prev_li; uint8_t *delimiter, *data; LOGP(DRLCMACDL, LOGL_DEBUG, "Adding LI=127 to signal padding\n"); data = data_block + *offset; delimiter = data_block + *num_chunks; prev_li = (struct rlc_li_field_egprs *)(*num_chunks ? delimiter - 1 : NULL); /* we don't have more LLC frames */ /* We will have to add another chunk with filling octets */ if (delimiter != data) memmove(delimiter + 1, delimiter, data - delimiter); /* set filling bytes extension */ li = (struct rlc_li_field_egprs *)delimiter; li->e = 1; li->li = 127; /* tell previous extension header about the new one */ if (prev_li) prev_li->e = 0; (*num_chunks)++; *offset = rdbi->data_len; } /* * Refer 44.060 version 7.27.0 Release 7 * section 7.1.3.2.1 On receipt of a PACKET RESOURCE REQUEST message * 8.1.2.5 Establishment of uplink TBF */ void write_packet_access_reject(struct bitvec *dest, uint32_t tlli, unsigned long t3172_ms) { unsigned wp = 0; bitvec_write_field(dest, &wp, 0x1, 2); // Payload Type bitvec_write_field(dest, &wp, 0x0, 2); // Uplink block with TDMA FN bitvec_write_field(dest, &wp, 0, 1); // No Polling Bit bitvec_write_field(dest, &wp, 0x0, 3); // Uplink state flag bitvec_write_field(dest, &wp, MT_PACKET_ACCESS_REJECT, 6); // MESSAGE TYPE bitvec_write_field(dest, &wp, 0, 2); // fixed 00 bitvec_write_field(dest, &wp, 0x0, 1); // TLLI / G-RNTI : bit (32) bitvec_write_field(dest, &wp, tlli, 32); // CONTENTION_RESOLUTION_TLLI bitvec_write_field(dest, &wp, 1, 1); // WAIT_INDICATION size in seconds /* WAIT_INDICATION, WAIT_INDICATION_SIZE */ if (t3172_ms / 20 <= 255) { /* In units of 20 milliseconds */ bitvec_write_field(dest, &wp, t3172_ms/20, 8); bitvec_write_field(dest, &wp, 1, 1); } else { /* value too big to fit in ms, do it in seconds */ bitvec_write_field(dest, &wp, t3172_ms/1000, 8); bitvec_write_field(dest, &wp, 0, 1); } } void write_packet_neighbour_cell_data(RlcMacDownlink_t *block, bool tfi_is_dl, uint8_t tfi, uint8_t container_id, uint8_t container_idx, PNCDContainer_t *container) { block->PAYLOAD_TYPE = 0x1; // RLC/MAC control block that does not include the optional octets of the RLC/MAC control header block->RRBP = 0; // 0: N+13 block->SP = 0; // RRBP field is not valid block->USF = 0x0; // Uplink state flag block->u.Packet_Neighbour_Cell_Data.MESSAGE_TYPE = MT_PACKET_NEIGHBOUR_CELL_DATA; block->u.Packet_Neighbour_Cell_Data.PAGE_MODE = 0x0; // Normal Paging block->u.Packet_Neighbour_Cell_Data.Global_TFI.UnionType = tfi_is_dl; // 0=UPLINK TFI, 1=DL TFI if (tfi_is_dl) { block->u.Packet_Neighbour_Cell_Data.Global_TFI.u.DOWNLINK_TFI = tfi; } else { block->u.Packet_Neighbour_Cell_Data.Global_TFI.u.UPLINK_TFI = tfi; } block->u.Packet_Neighbour_Cell_Data.CONTAINER_ID = container_id; block->u.Packet_Neighbour_Cell_Data.spare = 0; block->u.Packet_Neighbour_Cell_Data.CONTAINER_INDEX = container_idx; block->u.Packet_Neighbour_Cell_Data.Container = *container; } void write_packet_cell_change_continue(RlcMacDownlink_t *block, uint8_t poll, uint8_t rrbp, bool tfi_is_dl, uint8_t tfi, bool exist_id, uint16_t arfcn, uint8_t bsic, uint8_t container_id) { block->PAYLOAD_TYPE = 0x1; // RLC/MAC control block that does not include the optional octets of the RLC/MAC control header block->RRBP = rrbp; // RRBP (e.g. N+13) block->SP = poll; // RRBP field is valid? block->USF = 0x0; // Uplink state flag block->u.Packet_Cell_Change_Continue.MESSAGE_TYPE = MT_PACKET_CELL_CHANGE_CONTINUE; block->u.Packet_Cell_Change_Continue.PAGE_MODE = 0x0; // Normal Paging block->u.Packet_Cell_Change_Continue.Global_TFI.UnionType = tfi_is_dl; // 0=UPLINK TFI, 1=DL TFI if (tfi_is_dl) { block->u.Packet_Cell_Change_Continue.Global_TFI.u.DOWNLINK_TFI = tfi; } else { block->u.Packet_Cell_Change_Continue.Global_TFI.u.UPLINK_TFI = tfi; } block->u.Packet_Cell_Change_Continue.Exist_ID = exist_id; if (exist_id) { block->u.Packet_Cell_Change_Continue.ARFCN = arfcn; block->u.Packet_Cell_Change_Continue.BSIC = bsic; } block->u.Packet_Cell_Change_Continue.CONTAINER_ID = container_id; }