/* gprs_rlcmac.cpp * * Copyright (C) 2012 Ivan Klyuchnikov * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include LLIST_HEAD(gprs_rlcmac_tbfs); void *rlcmac_tall_ctx; int tfi_alloc() { struct gprs_rlcmac_tbf *tbf; uint32_t tfi_map = 0; uint32_t tfi_ind = 0; uint32_t mask = 1; uint8_t i; llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) { tfi_ind = 1 << tbf->tfi; tfi_map = tfi_map|tfi_ind; } for (i = 0; i < 32; i++) { if(((tfi_map >> i) & mask) == 0) { return i; } } return -1; } /* lookup TBF Entity (by TFI) */ static struct gprs_rlcmac_tbf *tbf_by_tfi(uint8_t tfi) { struct gprs_rlcmac_tbf *tbf; llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) { if (tbf->tfi == tfi) return tbf; } return NULL; } static struct gprs_rlcmac_tbf *tbf_by_tlli(uint32_t tlli) { struct gprs_rlcmac_tbf *tbf; llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) { if ((tbf->tlli == tlli)&&(tbf->direction == GPRS_RLCMAC_UL_TBF)) return tbf; } return NULL; } struct gprs_rlcmac_tbf *tbf_alloc(uint8_t tfi) { struct gprs_rlcmac_tbf *tbf; tbf = talloc_zero(rlcmac_tall_ctx, struct gprs_rlcmac_tbf); if (!tbf) return NULL; tbf->tfi = tfi; llist_add(&tbf->list, &gprs_rlcmac_tbfs); return tbf; } static void tbf_free(struct gprs_rlcmac_tbf *tbf) { llist_del(&tbf->list); talloc_free(tbf); } static void tbf_timer_cb(void *_tbf) { struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf; tbf->num_T_exp++; switch (tbf->T) { case 1111: // TODO: We should add timers for TBF. break; default: COUT("Timer expired in unknown mode" << tbf->T); } } static void tbf_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int T, unsigned int seconds) { if (osmo_timer_pending(&tbf->timer)) COUT("Starting TBF timer %u while old timer %u pending" << T << tbf->T); tbf->T = T; tbf->num_T_exp = 0; /* FIXME: we should do this only once ? */ tbf->timer.data = tbf; tbf->timer.cb = &tbf_timer_cb; osmo_timer_schedule(&tbf->timer, seconds, 0); } static void tbf_gsm_timer_cb(void *_tbf) { struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf; tbf->num_fT_exp++; switch (tbf->fT) { case 0: // This is timer for delay RLC/MAC data sending after Downlink Immediate Assignment on CCCH. gprs_rlcmac_segment_llc_pdu(tbf); LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [DOWNLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); tbf_free(tbf); break; default: COUT("Timer expired in unknown mode" << tbf->fT); } } static void tbf_gsm_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int fT, int frames) { if (osmo_gsm_timer_pending(&tbf->gsm_timer)) COUT("Starting TBF timer %u while old timer %u pending" << fT << tbf->fT); tbf->fT = fT; tbf->num_fT_exp = 0; /* FIXME: we should do this only once ? */ tbf->gsm_timer.data = tbf; tbf->gsm_timer.cb = &tbf_gsm_timer_cb; osmo_gsm_timer_schedule(&tbf->gsm_timer, frames); } void write_packet_downlink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli, uint8_t tn, uint8_t ta, uint8_t tsc) { // TODO We should use our implementation of encode RLC/MAC Control messages. unsigned wp = 0; bitvec_write_field(dest, wp,0x1,2); // Payload Type bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit bitvec_write_field(dest, wp,0x1,3); // Uplink state flag bitvec_write_field(dest, wp,0x2,6); // MESSAGE TYPE bitvec_write_field(dest, wp,0x0,2); // Page Mode bitvec_write_field(dest, wp,0x0,1); // switch PERSIST_LEVEL: off bitvec_write_field(dest, wp,0x0,1); // switch TFI : on bitvec_write_field(dest, wp,0x0,1); // switch UPLINK TFI : on bitvec_write_field(dest, wp,tfi-1,5); // TFI bitvec_write_field(dest, wp,0x0,1); // Message escape bitvec_write_field(dest, wp,0x0,2); // Medium Access Method: Dynamic Allocation bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode bitvec_write_field(dest, wp,0x0,1); // the network establishes no new downlink TBF for the mobile station bitvec_write_field(dest, wp,0x1,8); // timeslot 7 bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on bitvec_write_field(dest, wp,ta,6); // TIMING_ADVANCE_VALUE bitvec_write_field(dest, wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off bitvec_write_field(dest, wp,0x0,1); // switch POWER CONTROL = off bitvec_write_field(dest, wp,0x1,1); // Frequency Parameters information elements = present bitvec_write_field(dest, wp,tsc,3); // Training Sequence Code (TSC) = 2 bitvec_write_field(dest, wp,0x0,2); // ARFCN = present bitvec_write_field(dest, wp,599,10); // ARFCN bitvec_write_field(dest, wp,0x1,1); // switch TFI : on bitvec_write_field(dest, wp,tfi,5);// TFI bitvec_write_field(dest, wp,0x1,1); // Power Control Parameters IE = present bitvec_write_field(dest, wp,0x0,4); // ALPHA power control parameter bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN0 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN1 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN2 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN3 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN4 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN5 = off bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN6 = off bitvec_write_field(dest, wp,0x1,1); // switch GAMMA_TN7 = on bitvec_write_field(dest, wp,0x0,5); // GAMMA_TN7 bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME IE not present bitvec_write_field(dest, wp,0x0,1); // Measurement Mapping struct not present bitvec_write_field(dest, wp,0x0,1); } void write_packet_uplink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli) { // TODO We should use our implementation of encode RLC/MAC Control messages. unsigned wp = 0; bitvec_write_field(dest, wp,0x1,2); // Payload Type bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit bitvec_write_field(dest, wp,0x1,3); // Uplink state flag bitvec_write_field(dest, wp,0xa,6); // MESSAGE TYPE bitvec_write_field(dest, wp,0x0,2); // Page Mode bitvec_write_field(dest, wp,0x0,1); // switch PERSIST_LEVEL: off bitvec_write_field(dest, wp,0x2,2); // switch TLLI : on bitvec_write_field(dest, wp,tlli,32); // TLLI bitvec_write_field(dest, wp,0x0,1); // Message escape bitvec_write_field(dest, wp,0x0,2); // CHANNEL_CODING_COMMAND bitvec_write_field(dest, wp,0x0,1); // TLLI_BLOCK_CHANNEL_CODING bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on bitvec_write_field(dest, wp,0x0,6); // TIMING_ADVANCE_VALUE bitvec_write_field(dest, wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off bitvec_write_field(dest, wp,0x0,1); // Frequency Parameters = off bitvec_write_field(dest, wp,0x1,2); // Dynamic Allocation = off bitvec_write_field(dest, wp,0x0,1); // Dynamic Allocation bitvec_write_field(dest, wp,0x0,1); // P0 = off bitvec_write_field(dest, wp,0x1,1); // USF_GRANULARITY bitvec_write_field(dest, wp,0x1,1); // switch TFI : on bitvec_write_field(dest, wp,tfi,5);// TFI bitvec_write_field(dest, wp,0x0,1); // bitvec_write_field(dest, wp,0x0,1); // TBF Starting Time = off bitvec_write_field(dest, wp,0x0,1); // Timeslot Allocation bitvec_write_field(dest, wp,0x0,5); // USF_TN 0 - 4 bitvec_write_field(dest, wp,0x1,1); // USF_TN 5 bitvec_write_field(dest, wp,0x1,3); // USF_TN 5 bitvec_write_field(dest, wp,0x0,2); // USF_TN 6 - 7 // bitvec_write_field(dest, wp,0x0,1); // Measurement Mapping struct not present } // GSM 04.08 9.1.18 Immediate assignment int write_immediate_assignment(bitvec * dest, uint8_t downlink, uint8_t ra, uint32_t fn, uint8_t ta, uint8_t tfi = 0, uint32_t tlli = 0) { unsigned wp = 0; bitvec_write_field(dest, wp,0x0,4); // Skip Indicator bitvec_write_field(dest, wp,0x6,4); // Protocol Discriminator bitvec_write_field(dest, wp,0x3F,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,0x1,5); // Channel type bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.tn,3); // TN bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.tsc,3); // TSC bitvec_write_field(dest, wp,0x0,3); // non-hopping RF channel configuraion bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.arfcn,10); // ARFCN //10.5.2.30 Request Reference bitvec_write_field(dest, wp,ra,8); // RA bitvec_write_field(dest, wp,(fn / (26 * 51)) % 32,5); // T1' bitvec_write_field(dest, wp,fn % 51,6); // T3 bitvec_write_field(dest, wp,fn % 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 // No mobile allocation in non-hopping systems. // A zero-length LV. Just write L=0. bitvec_write_field(dest, wp,0,8); if (downlink) { // GSM 04.08 10.5.2.16 IA Rest Octets bitvec_write_field(dest, wp, 3, 2); // "HH" bitvec_write_field(dest, wp, 1, 2); // "01" Packet Downlink Assignment bitvec_write_field(dest, wp,tlli,32); // TLLI bitvec_write_field(dest, wp,0x1,1); // switch TFI : on bitvec_write_field(dest, wp,tfi,5); // TFI bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode bitvec_write_field(dest, wp,0x0,1); // ALPHA = present bitvec_write_field(dest, wp,0x0,5); // GAMMA power control parameter bitvec_write_field(dest, wp,0x0,1); // Polling Bit bitvec_write_field(dest, wp,0x1,1); // TA_VALID ??? bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on bitvec_write_field(dest, wp,0x0,4); // TIMING_ADVANCE_INDEX bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME present bitvec_write_field(dest, wp,0x0,1); // P0 not present bitvec_write_field(dest, wp,0x1,1); // P0 not present bitvec_write_field(dest, wp,0xb,4); } else { // GMS 04.08 10.5.2.37b 10.5.2.16 bitvec_write_field(dest, wp, 3, 2); // "HH" bitvec_write_field(dest, wp, 0, 2); // "0" Packet Uplink Assignment bitvec_write_field(dest, wp, 1, 1); // Block Allocation : Not Single Block Allocation bitvec_write_field(dest, wp, tfi, 5); // TFI_ASSIGNMENT Temporary Flow Identity bitvec_write_field(dest, wp, 0, 1); // POLLING bitvec_write_field(dest, wp, 0, 1); // ALLOCATION_TYPE: dynamic bitvec_write_field(dest, wp, 1, 3); // USF bitvec_write_field(dest, wp, 1, 1); // USF_GRANULARITY bitvec_write_field(dest, wp, 0 , 1); // "0" power control: Not Present bitvec_write_field(dest, wp, 0, 2); // CHANNEL_CODING_COMMAND bitvec_write_field(dest, wp, 1, 1); // TLLI_BLOCK_CHANNEL_CODING bitvec_write_field(dest, wp, 1 , 1); // "1" Alpha : Present bitvec_write_field(dest, wp, 0, 4); // Alpha bitvec_write_field(dest, wp, 0, 5); // Gamma bitvec_write_field(dest, wp, 0, 1); // TIMING_ADVANCE_INDEX_FLAG bitvec_write_field(dest, wp, 0, 1); // TBF_STARTING_TIME_FLAG } if (wp%8) return wp/8+1; else return wp/8; } void write_ia_rest_octets_downlink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli) { // GSM 04.08 10.5.2.16 unsigned wp = 0; bitvec_write_field(dest, wp, 3, 2); // "HH" bitvec_write_field(dest, wp, 1, 2); // "01" Packet Downlink Assignment bitvec_write_field(dest, wp,tlli,32); // TLLI bitvec_write_field(dest, wp,0x1,1); // switch TFI : on bitvec_write_field(dest, wp,tfi,5); // TFI bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode bitvec_write_field(dest, wp,0x0,1); // ALPHA = present bitvec_write_field(dest, wp,0x0,5); // GAMMA power control parameter bitvec_write_field(dest, wp,0x0,1); // Polling Bit bitvec_write_field(dest, wp,0x1,1); // TA_VALID ??? bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on bitvec_write_field(dest, wp,0x0,4); // TIMING_ADVANCE_INDEX bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME present bitvec_write_field(dest, wp,0x0,1); // P0 not present bitvec_write_field(dest, wp,0x1,1); // P0 not present bitvec_write_field(dest, wp,0xb,4); } void write_packet_uplink_ack(bitvec * dest, uint8_t tfi, uint32_t tlli, unsigned cv, unsigned bsn) { // TODO We should use our implementation of encode RLC/MAC Control messages. unsigned wp = 0; bitvec_write_field(dest, wp,0x1,2); // payload bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber if (cv == 0) bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit else bitvec_write_field(dest, wp,0x0,1); //Suppl/Polling Bit bitvec_write_field(dest, wp,0x1,3); // Uplink state flag //bitvec_write_field(dest, wp,0x0,1); // Reduced block sequence number //bitvec_write_field(dest, wp,BSN+6,5); // Radio transaction identifier //bitvec_write_field(dest, wp,0x1,1); // Final segment //bitvec_write_field(dest, wp,0x1,1); // Address control //bitvec_write_field(dest, wp,0x0,2); // Power reduction: 0 //bitvec_write_field(dest, wp,TFI,5); // Temporary flow identifier //bitvec_write_field(dest, wp,0x1,1); // Direction bitvec_write_field(dest, wp,0x09,6); // MESSAGE TYPE bitvec_write_field(dest, wp,0x0,2); // Page Mode bitvec_write_field(dest, wp,0x0,2); bitvec_write_field(dest, wp,tfi,5); // Uplink TFI bitvec_write_field(dest, wp,0x0,1); bitvec_write_field(dest, wp,0x0,2); // CS1 if (cv == 0) bitvec_write_field(dest, wp,0x1,1); // FINAL_ACK_INDICATION else bitvec_write_field(dest, wp,0x0,1); // FINAL_ACK_INDICATION bitvec_write_field(dest, wp,bsn + 1,7); // STARTING_SEQUENCE_NUMBER // RECEIVE_BLOCK_BITMAP for (unsigned i=0; i<8; i++) { bitvec_write_field(dest, wp,0xff,8); } bitvec_write_field(dest, wp,0x1,1); // CONTENTION_RESOLUTION_TLLI = present bitvec_write_field(dest, wp,tlli,8*4); bitvec_write_field(dest, wp,0x00,4); //spare bitvec_write_field(dest, wp,0x5,4); //0101 } void gprs_rlcmac_tx_ul_ack(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * ul_data_block) { bitvec *packet_uplink_ack_vec = bitvec_alloc(23); bitvec_unhex(packet_uplink_ack_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); write_packet_uplink_ack(packet_uplink_ack_vec, tfi, tlli, ul_data_block->CV, ul_data_block->BSN); LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Packet Uplink Ack\n", tfi, tlli); RlcMacDownlink_t * packet_uplink_ack = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t)); LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Packet Uplink Ack +++++++++++++++++++++++++\n"); decode_gsm_rlcmac_downlink(packet_uplink_ack_vec, packet_uplink_ack); LOGPC(DRLCMAC, LOGL_NOTICE, "\n"); LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Packet Uplink Ack -------------------------\n"); free(packet_uplink_ack); pcu_l1if_tx(packet_uplink_ack_vec, GsmL1_Sapi_Pacch); bitvec_free(packet_uplink_ack_vec); } void gprs_rlcmac_data_block_parse(gprs_rlcmac_tbf* tbf, RlcMacUplinkDataBlock_t * ul_data_block) { // 1. Count the number of octets in header and number of LLC PDU in uplink data block. unsigned data_block_hdr_len = 3; // uplink data block header length: 3 mandatory octets unsigned llc_pdu_num = 0; // number of LLC PDU in data block if (ul_data_block->E_1 == 0) // Extension octet follows immediately { unsigned i = -1; do { i++; data_block_hdr_len += 1; llc_pdu_num++; // Singular case, TS 44.060 10.4.14 if (ul_data_block->LENGTH_INDICATOR[i] == 0) { break; } // New LLC PDU starts after the current LLC PDU and continues until // the end of the RLC information field, no more extension octets. if ((ul_data_block->M[i] == 1)&&(ul_data_block->E[i] == 1)) { llc_pdu_num++; } } while(ul_data_block->E[i] == 0); // there is another extension octet, which delimits the new LLC PDU } else { llc_pdu_num++; } if(ul_data_block->TI == 1) // TLLI field is present { tbf->tlli = ul_data_block->TLLI; data_block_hdr_len += 4; // TLLI length : 4 octets if (ul_data_block->PI == 1) // PFI is present if TI field indicates presence of TLLI { data_block_hdr_len += 1; // PFI length : 1 octet } } // 2. Extract all LLC PDU from uplink data block and send them to SGSN. unsigned llc_pdu_len = 0; unsigned data_octet_num = 0; for (unsigned num = 0; num < llc_pdu_num; num ++) { if (ul_data_block->E_1 == 0) // Extension octet follows immediately { // Singular case, TS 44.060 10.4.14 if (ul_data_block->LENGTH_INDICATOR[num] == 0) { llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len; } else { llc_pdu_len = ul_data_block->LENGTH_INDICATOR[num]; } } else { llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len; } for (unsigned i = tbf->data_index; i < tbf->data_index + llc_pdu_len; i++) { tbf->rlc_data[i] = ul_data_block->RLC_DATA[data_octet_num]; data_octet_num++; } tbf->data_index += llc_pdu_len; if (ul_data_block->E_1 == 0) // Extension octet follows immediately { // New LLC PDU starts after the current LLC PDU if (ul_data_block->M[num] == 1) { gsmtap_send_llc(tbf->rlc_data, tbf->data_index); gprs_rlcmac_tx_ul_ud(tbf); tbf->data_index = 0; // New LLC PDU continues until the end of the RLC information field, no more extension octets. if ((ul_data_block->E[num] == 1)) { llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len - data_octet_num; for (unsigned i = tbf->data_index; i < tbf->data_index + llc_pdu_len; i++) { tbf->rlc_data[i] = ul_data_block->RLC_DATA[data_octet_num]; data_octet_num++; } tbf->data_index += llc_pdu_len; num++; } } } } } /* Received Uplink RLC data block. */ int gprs_rlcmac_rcv_data_block(bitvec *rlc_block) { struct gprs_rlcmac_tbf *tbf; LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] Uplink Data Block\n"); RlcMacUplinkDataBlock_t * ul_data_block = (RlcMacUplinkDataBlock_t *)malloc(sizeof(RlcMacUplinkDataBlock_t)); LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ RX : Uplink Data Block +++++++++++++++++++++++++\n"); decode_gsm_rlcmac_uplink_data(rlc_block, ul_data_block); LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- RX : Uplink Data Block -------------------------\n"); tbf = tbf_by_tfi(ul_data_block->TFI); if (!tbf) { return 0; } if (ul_data_block->TI == 1) { tbf->tlli = ul_data_block->TLLI; } switch (tbf->state) { case GPRS_RLCMAC_WAIT_DATA_SEQ_START: if (ul_data_block->BSN == 0) { tbf->data_index = 0; gprs_rlcmac_data_block_parse(tbf, ul_data_block); gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block); if (ul_data_block->CV == 0) { // Recieved last Data Block in this sequence. gsmtap_send_llc(tbf->rlc_data, tbf->data_index); if (!((ul_data_block->E_1 == 0)&&(ul_data_block->M[0] == 0)&&(ul_data_block->E[0] == 1))) tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ; else tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START; gprs_rlcmac_tx_ul_ud(tbf); } else { tbf->bsn = ul_data_block->BSN; tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK; } } break; case GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK: if (tbf->bsn == (ul_data_block->BSN - 1)) { gprs_rlcmac_data_block_parse(tbf, ul_data_block); gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block); if (ul_data_block->CV == 0) { // Recieved last Data Block in this sequence. gsmtap_send_llc(tbf->rlc_data, tbf->data_index); if (!((ul_data_block->E_1 == 0)&&(ul_data_block->M[0] == 0)&&(ul_data_block->E[0] == 1))) tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ; else tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START; gprs_rlcmac_tx_ul_ud(tbf); } else { tbf->bsn = ul_data_block->BSN; tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK; } } else { // Recieved Data Block with unexpected BSN. // We should try to find nesessary Data Block. tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK; } break; case GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ: // Now we just ignore all Data Blocks and wait next Uplink TBF break; } free(ul_data_block); return 1; } /* Received Uplink RLC control block. */ int gprs_rlcmac_rcv_control_block(bitvec *rlc_block) { uint8_t tfi = 0; uint32_t tlli = 0; struct gprs_rlcmac_tbf *tbf; struct gprs_rlcmac_tbf *ul_tbf; RlcMacUplink_t * ul_control_block = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t)); LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++\n"); decode_gsm_rlcmac_uplink(rlc_block, ul_control_block); LOGPC(DRLCMAC, LOGL_NOTICE, "\n"); LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- RX : Uplink Control Block -------------------------\n"); switch (ul_control_block->u.MESSAGE_TYPE) { case MT_PACKET_CONTROL_ACK: tlli = ul_control_block->u.Packet_Control_Acknowledgement.TLLI; tbf = tbf_by_tlli(tlli); if (!tbf) { return 0; } LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Control Ack\n", tbf->tfi, tbf->tlli); LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [UPLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); tbf_free(tbf); break; case MT_PACKET_DOWNLINK_ACK_NACK: tfi = ul_control_block->u.Packet_Downlink_Ack_Nack.DOWNLINK_TFI; tbf = tbf_by_tfi(tfi); if (!tbf) { return 0; } LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Downlink Ack/Nack\n", tbf->tfi, tbf->tlli); tlli = tbf->tlli; LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [DOWNLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); tbf_free(tbf); break; } free(ul_control_block); return 1; } void gprs_rlcmac_rcv_block(bitvec *rlc_block) { unsigned readIndex = 0; unsigned payload = bitvec_read_field(rlc_block, readIndex, 2); switch (payload) { case GPRS_RLCMAC_DATA_BLOCK: gprs_rlcmac_rcv_data_block(rlc_block); break; case GPRS_RLCMAC_CONTROL_BLOCK: gprs_rlcmac_rcv_control_block(rlc_block); break; case GPRS_RLCMAC_CONTROL_BLOCK_OPT: COUT("GPRS_RLCMAC_CONTROL_BLOCK_OPT block payload is not supported.\n"); default: COUT("Unknown RLCMAC block payload.\n"); } } int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, uint16_t ta) { struct gprs_rlcmac_tbf *tbf; // Create new TBF int tfi = tfi_alloc(); if (tfi < 0) { return tfi; } tbf = tbf_alloc(tfi); tbf->direction = GPRS_RLCMAC_UL_TBF; tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START; LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [UPLINK] START TFI: %u\n", tbf->tfi); LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u RACH\n", tbf->tfi); LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u Packet Immidiate Assignment\n", tbf->tfi); bitvec *immediate_assignment = bitvec_alloc(23); bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); int len = write_immediate_assignment(immediate_assignment, 0, ra, Fn, ta, tbf->tfi); pcu_l1if_tx(immediate_assignment, GsmL1_Sapi_Agch, len); bitvec_free(immediate_assignment); } // Send RLC data to OpenBTS. void gprs_rlcmac_tx_dl_data_block(uint32_t tlli, uint8_t tfi, uint8_t *pdu, int start_index, int end_index, uint8_t bsn, uint8_t fbi) { int spare_len = 0; bitvec *data_block_vector = bitvec_alloc(BLOCK_LEN); bitvec_unhex(data_block_vector, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); RlcMacDownlinkDataBlock_t * data_block = (RlcMacDownlinkDataBlock_t *)malloc(sizeof(RlcMacDownlinkDataBlock_t)); data_block->PAYLOAD_TYPE = 0; data_block->RRBP = 0; data_block->SP = 1; data_block->USF = 1; data_block->PR = 0; data_block->TFI = tfi; data_block->FBI = fbi; data_block->BSN = bsn; // Last RLC data block of current LLC PDU if (fbi == 1) { data_block->E_1 = 0; data_block->M[0] = 0; data_block->E[0] = 1; // Singular case, TS 44.060 10.4.14 if ((end_index - start_index) == (BLOCK_LEN - 3)) { data_block->FBI = 0; data_block->LENGTH_INDICATOR[0] = 0; spare_len = 0; end_index--; } else { data_block->LENGTH_INDICATOR[0] = end_index-start_index; spare_len = BLOCK_LEN - 4 - data_block->LENGTH_INDICATOR[0]; } } else { data_block->E_1 = 1; } int data_oct_num = 0; int i = 0; // Pack LLC PDU into RLC data field for(i = start_index; i < end_index; i++) { data_block->RLC_DATA[data_oct_num] = pdu[i]; data_oct_num++; } // Fill spare bits for(i = data_oct_num; i < data_oct_num + spare_len; i++) { data_block->RLC_DATA[i] = 0x2b; } LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] Downlink Data Block\n"); LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Downlink Data Block +++++++++++++++++++++++++\n"); encode_gsm_rlcmac_downlink_data(data_block_vector, data_block); LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Downlink Data Block -------------------------\n"); free(data_block); pcu_l1if_tx(data_block_vector, GsmL1_Sapi_Pdtch); bitvec_free(data_block_vector); // Singular case, TS 44.060 10.4.14 if ((fbi == 1)&&((end_index + 1 - start_index) == (BLOCK_LEN - 3))) { gprs_rlcmac_tx_dl_data_block(tlli, tfi, pdu, end_index, end_index+1, bsn+1, fbi); } } int gprs_rlcmac_segment_llc_pdu(struct gprs_rlcmac_tbf *tbf) { int fbi = 0; int bsn = 0; int num_blocks = 0; // number of RLC data blocks necessary for LLC PDU transmission // LLC PDU fits into one RLC data block with optional LI field. if (tbf->data_index < BLOCK_LEN - 4) { fbi = 1; gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->tfi, tbf->rlc_data, 0, tbf->data_index, bsn, fbi); } // Necessary several RLC data blocks for transmit LLC PDU. else { // length of RLC data field in block (no optional octets) int block_data_len = BLOCK_LEN - 3; // number of blocks with 20 octets length RLC data field num_blocks = tbf->data_index/block_data_len; // rest of LLC PDU, which doesn't fit into data blocks with 20 octets RLC data field int rest_len = tbf->data_index%BLOCK_DATA_LEN; if (rest_len > 0) { // add one block for transmission rest of LLC PDU num_blocks++; } int start_index = 0; int end_index = 0; // Transmit all RLC data blocks of current LLC PDU to MS for (bsn = 0; bsn < num_blocks; bsn++) { if (bsn == num_blocks-1) { if (rest_len > 0) { block_data_len = rest_len; } fbi = 1; } end_index = start_index + block_data_len; gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->tfi, tbf->rlc_data, start_index, end_index, bsn, fbi); start_index += block_data_len; } } } /* Send Uplink unit-data to SGSN. */ void gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf) { const uint8_t qos_profile = QOS_PROFILE; struct msgb *llc_pdu; unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + tbf->data_index; LOGP(DBSSGP, LOGL_NOTICE, "TX: [PCU -> SGSN ] TFI: %u TLLI: 0x%08x DataLen: %u", tbf->tfi, tbf->tlli, tbf->data_index); //LOGP(DBSSGP, LOGL_NOTICE, " Data = "); //for (unsigned i = 0; i < tbf->data_index; i++) // LOGPC(DBSSGP, LOGL_NOTICE, "%02x ", tbf->rlc_data[i]); bctx->cell_id = CELL_ID; bctx->nsei = NSEI; bctx->ra_id.mnc = MNC; bctx->ra_id.mcc = MCC; bctx->ra_id.lac = PCU_LAC; bctx->ra_id.rac = PCU_RAC; bctx->bvci = BVCI; llc_pdu = msgb_alloc_headroom(msg_len, msg_len,"llc_pdu"); msgb_tvlv_push(llc_pdu, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*tbf->data_index, tbf->rlc_data); bssgp_tx_ul_ud(bctx, tbf->tlli, &qos_profile, llc_pdu); } void gprs_rlcmac_downlink_assignment(gprs_rlcmac_tbf *tbf) { LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Immidiate Assignment (CCCH)\n", tbf->tfi, tbf->tlli); bitvec *immediate_assignment = bitvec_alloc(23); bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); int len = write_immediate_assignment(immediate_assignment, 1, 125, get_current_fn(), (l1fh->fl1h)->channel_info.ta, tbf->tfi, tbf->tlli); pcu_l1if_tx(immediate_assignment, GsmL1_Sapi_Agch, len); bitvec_free(immediate_assignment); tbf_gsm_timer_start(tbf, 0, 120); } void gprs_rlcmac_packet_downlink_assignment(gprs_rlcmac_tbf *tbf) { LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Packet DL Assignment\n", tbf->tfi, tbf->tlli); bitvec *packet_downlink_assignment_vec = bitvec_alloc(23); bitvec_unhex(packet_downlink_assignment_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); write_packet_downlink_assignment(packet_downlink_assignment_vec, tbf->tfi, tbf->tlli, (l1fh->fl1h)->channel_info.tn, (l1fh->fl1h)->channel_info.ta, (l1fh->fl1h)->channel_info.tsc); RlcMacDownlink_t * packet_downlink_assignment = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t)); LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n"); decode_gsm_rlcmac_downlink(packet_downlink_assignment_vec, packet_downlink_assignment); LOGPC(DRLCMAC, LOGL_NOTICE, "\n"); LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Packet Downlink Assignment -------------------------\n"); free(packet_downlink_assignment); pcu_l1if_tx(packet_downlink_assignment_vec, GsmL1_Sapi_Pacch); bitvec_free(packet_downlink_assignment_vec); tbf_gsm_timer_start(tbf, 0, 120); }