| /* Data block transfer |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * |
| * 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 <gprs_bssgp_pcu.h> |
| #include <gprs_rlcmac.h> |
| #include <pcu_l1_if.h> |
| |
| /* After receiving these frames, we send ack/nack. */ |
| #define SEND_ACK_AFTER_FRAMES 20 |
| |
| /* After sending these frames, we poll for ack/nack. */ |
| #define POLL_ACK_AFTER_FRAMES 10 |
| |
| /* If acknowledgement to uplink/downlin assignmentshould be polled */ |
| #define POLLING_ASSIGNMENT 0 |
| |
| extern "C" { |
| /* TS 04.60 10.2.2 */ |
| struct rlc_ul_header { |
| uint8_t r:1, |
| si:1, |
| cv:4, |
| pt:2; |
| uint8_t ti:1, |
| tfi:5, |
| pi:1, |
| spare:1; |
| uint8_t e:1, |
| bsn:7; |
| } __attribute__ ((packed)); |
| |
| struct rlc_dl_header { |
| uint8_t usf:3, |
| s_p:1, |
| rrbp:2, |
| pt:2; |
| uint8_t fbi:1, |
| tfi:5, |
| pr:2; |
| uint8_t e:1, |
| bsn:7; |
| } __attribute__ ((packed)); |
| |
| struct rlc_li_field { |
| uint8_t e:1, |
| m:1, |
| li:6; |
| } __attribute__ ((packed)); |
| } |
| |
| int gprs_rlcmac_poll_timeout(struct gprs_rlcmac_tbf *tbf) |
| { |
| LOGP(DRLCMAC, LOGL_NOTICE, "Poll timeout for %s TBF=%d\n", |
| (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi); |
| |
| tbf->poll_state = GPRS_RLCMAC_POLL_NONE; |
| |
| if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET " |
| "CONTROL ACK for PACKET UPLINK ACK\n"); |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE; |
| if (tbf->state == GPRS_RLCMAC_FINISHED) { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| |
| tbf->dir.ul.n3103++; |
| if (tbf->dir.ul.n3103 == bts->n3103) { |
| LOGP(DRLCMAC, LOGL_NOTICE, |
| "- N3103 exceeded\n"); |
| tbf_new_state(tbf, GPRS_RLCMAC_RELEASING); |
| tbf_timer_start(tbf, 3169, bts->t3169, 0); |
| return 0; |
| } |
| /* reschedule UL ack */ |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_SEND_ACK; |
| } |
| } else |
| if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET " |
| "CONTROL ACK for PACKET UPLINK ASSIGNMENT.\n"); |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE; |
| } else |
| if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET " |
| "CONTROL ACK for PACKET DOWNLINK ASSIGNMENT.\n"); |
| tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE; |
| /* in case out downlink assigment failed: */ |
| if (tbf->state == GPRS_RLCMAC_ASSIGN) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "- Assignment failed\n"); |
| tbf_free(tbf); |
| } |
| } else |
| if (tbf->direction == GPRS_RLCMAC_DL_TBF) |
| { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| |
| LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling PACKET " |
| " DOWNLINK ACK.\n"); |
| tbf->dir.dl.n3105++; |
| if (tbf->dir.dl.n3105 == bts->n3105) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "- N3105 exceeded\n"); |
| tbf_new_state(tbf, GPRS_RLCMAC_RELEASING); |
| tbf_timer_start(tbf, 3195, bts->t3195, 0); |
| return 0; |
| } |
| } else |
| LOGP(DRLCMAC, LOGL_ERROR, "- Poll Timeout, but no event!\n"); |
| |
| return 0; |
| } |
| |
| /* Received Uplink RLC control block. */ |
| int gprs_rlcmac_rcv_control_block(bitvec *rlc_block, uint8_t trx, uint8_t ts, |
| uint32_t fn) |
| { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| int8_t tfi = 0; /* must be signed */ |
| uint32_t tlli = 0; |
| struct gprs_rlcmac_tbf *tbf; |
| int rc; |
| |
| RlcMacUplink_t * ul_control_block = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t)); |
| LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++\n"); |
| decode_gsm_rlcmac_uplink(rlc_block, ul_control_block); |
| LOGPC(DCSN1, LOGL_NOTICE, "\n"); |
| LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- 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_poll_fn(fn, trx, ts); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "PACKET CONTROL ACK with " |
| "unknown FN=%u TLL=0x%08x (TRX %d TS %d)\n", |
| fn, tlli, trx, ts); |
| break; |
| } |
| tfi = tbf->tfi; |
| if (tlli != tbf->tlli) { |
| LOGP(DRLCMAC, LOGL_INFO, "Phone changed TLLI to " |
| "0x%08x\n", tlli); |
| tbf->tlli = tlli; |
| } |
| LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Control Ack\n", tbf->tfi, tbf->tlli); |
| tbf->poll_state = GPRS_RLCMAC_POLL_NONE; |
| |
| /* check if this control ack belongs to packet uplink ack */ |
| if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE; |
| tbf_free(tbf); |
| break; |
| } |
| if (tbf->dl_ass_state == GPRS_RLCMAC_DL_ASS_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] DOWNLINK ASSIGNED TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); |
| tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE; |
| break; |
| } |
| if (tbf->ul_ass_state == GPRS_RLCMAC_UL_ASS_WAIT_ACK) { |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [DOWNLINK] UPLINK ASSIGNED TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli); |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE; |
| break; |
| } |
| LOGP(DRLCMAC, LOGL_ERROR, "Error: received PACET CONTROL ACK " |
| "at no request\n"); |
| break; |
| case MT_PACKET_DOWNLINK_ACK_NACK: |
| tfi = ul_control_block->u.Packet_Downlink_Ack_Nack.DOWNLINK_TFI; |
| tbf = tbf_by_poll_fn(fn, trx, ts); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "PACKET DOWNLINK ACK with " |
| "unknown FN=%u TBF=%d (TRX %d TS %d)\n", |
| fn, tfi, trx, ts); |
| break; |
| } |
| /* reset N3105 */ |
| tbf->dir.dl.n3105 = 0; |
| /* stop timer T3191 */ |
| tbf_timer_stop(tbf); |
| tlli = tbf->tlli; |
| LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Downlink Ack/Nack\n", tbf->tfi, tbf->tlli); |
| tbf->poll_state = GPRS_RLCMAC_POLL_NONE; |
| |
| rc = gprs_rlcmac_downlink_ack(tbf, |
| ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.FINAL_ACK_INDICATION, |
| ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.STARTING_SEQUENCE_NUMBER, |
| ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.RECEIVED_BLOCK_BITMAP); |
| if (rc == 1) { |
| tbf_free(tbf); |
| break; |
| } |
| /* check for channel request */ |
| if (ul_control_block->u.Packet_Downlink_Ack_Nack.Exist_Channel_Request_Description) { |
| uint8_t trx, ts; |
| struct gprs_rlcmac_tbf *ul_tbf; |
| |
| LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF in ack " |
| "message, so we provide one:\n"); |
| uplink_request: |
| /* create new TBF, use sme TRX as DL TBF */ |
| tfi = tfi_alloc(GPRS_RLCMAC_UL_TBF, &trx, &ts, tbf->trx, tbf->first_ts); |
| if (tfi < 0) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); |
| /* FIXME: send reject */ |
| break; |
| } |
| /* use multislot class of downlink TBF */ |
| ul_tbf = tbf_alloc(tbf, GPRS_RLCMAC_UL_TBF, tfi, trx, |
| ts, tbf->ms_class, 0); |
| if (!ul_tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); |
| /* FIXME: send reject */ |
| break; |
| } |
| ul_tbf->tlli = tbf->tlli; |
| ul_tbf->tlli_valid = 1; /* no contention resolution */ |
| ul_tbf->contention_resolution_done = 1; |
| ul_tbf->ta = tbf->ta; /* use current TA */ |
| tbf_new_state(ul_tbf, GPRS_RLCMAC_FLOW); |
| tbf_timer_start(ul_tbf, 3169, bts->t3169, 0); |
| /* schedule uplink assignment */ |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS; |
| } |
| break; |
| case MT_PACKET_RESOURCE_REQUEST: |
| if (ul_control_block->u.Packet_Resource_Request.ID.UnionType) { |
| tlli = ul_control_block->u.Packet_Resource_Request.ID.u.TLLI; |
| tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown uplink TLLI=0x%08x\n", tlli); |
| break; |
| } |
| tfi = tbf->tfi; |
| } else { |
| if (ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.UnionType) { |
| tfi = ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.u.DOWNLINK_TFI; |
| tbf = tbf_by_tfi(tfi, trx, ts, GPRS_RLCMAC_DL_TBF); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown downlink TBF=%d\n", tlli); |
| break; |
| } |
| } else { |
| tfi = ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.u.UPLINK_TFI; |
| tbf = tbf_by_tfi(tfi, trx, ts, GPRS_RLCMAC_UL_TBF); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown uplink TBF=%d\n", tlli); |
| break; |
| } |
| } |
| tlli = tbf->tlli; |
| } |
| LOGP(DRLCMAC, LOGL_ERROR, "RX: [PCU <- BTS] %s TFI: %u TLLI: 0x%08x FIXME: Packet ressource request\n", (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi, tbf->tlli); |
| break; |
| default: |
| LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] unknown control block received\n"); |
| } |
| free(ul_control_block); |
| return 1; |
| } |
| |
| #ifdef DEBUG_DL_ASS_IDLE |
| char debug_imsi[16]; |
| #endif |
| |
| void tbf_timer_cb(void *_tbf) |
| { |
| struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf; |
| |
| LOGP(DRLCMAC, LOGL_DEBUG, "%s TBF=%d timer %u expired.\n", |
| (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi, |
| tbf->T); |
| |
| tbf->num_T_exp++; |
| |
| switch (tbf->T) { |
| #ifdef DEBUG_DL_ASS_IDLE |
| case 1234: |
| gprs_rlcmac_trigger_downlink_assignment(tbf, 0, debug_imsi); |
| break; |
| #endif |
| case 0: /* assignment */ |
| /* change state to FLOW, so scheduler will start transmission */ |
| if (tbf->state == GPRS_RLCMAC_ASSIGN) { |
| tbf_new_state(tbf, GPRS_RLCMAC_FLOW); |
| tbf_assign_control_ts(tbf); |
| } else |
| LOGP(DRLCMAC, LOGL_ERROR, "Error: TBF is not in assign " |
| "state\n"); |
| break; |
| case 3169: |
| case 3191: |
| case 3195: |
| LOGP(DRLCMAC, LOGL_NOTICE, "TBF T%d timeout during " |
| "transsmission\n", tbf->T); |
| /* fall through */ |
| case 3193: |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF will be freed due to timeout\n"); |
| /* free TBF */ |
| tbf_free(tbf); |
| break; |
| default: |
| LOGP(DRLCMAC, LOGL_ERROR, "Timer expired in unknown mode: %u\n", |
| tbf->T); |
| } |
| } |
| |
| /* |
| * UL data block flow |
| */ |
| |
| /* get TLLI from received UL data block */ |
| static int tlli_from_ul_data(uint8_t *data, uint8_t len, uint32_t *tlli) |
| { |
| struct rlc_ul_header *rh = (struct rlc_ul_header *)data; |
| struct rlc_li_field *li; |
| uint8_t e; |
| |
| if (!rh->ti) |
| return -EINVAL; |
| |
| data += 3; |
| len -= 3; |
| e = rh->e; |
| /* if E is not set (LI follows) */ |
| while (!e) { |
| if (!len) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA LI extended, " |
| "but no more data\n"); |
| return -EINVAL; |
| } |
| /* get new E */ |
| li = (struct rlc_li_field *)data; |
| if (li->e == 0) /* if LI==0, E is interpreted as '1' */ |
| e = 1; |
| else |
| e = li->e; |
| data++; |
| len--; |
| } |
| if (len < 4) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TLLI out of frame " |
| "border\n"); |
| return -EINVAL; |
| } |
| *tlli = ntohl(*((uint32_t *)data)); |
| |
| return 0; |
| } |
| |
| /* Store received block data in LLC message(s) and forward to SGSN if complete. |
| */ |
| static int gprs_rlcmac_assemble_llc(struct gprs_rlcmac_tbf *tbf, uint8_t *data, |
| uint8_t len) |
| { |
| struct rlc_ul_header *rh = (struct rlc_ul_header *)data; |
| uint8_t e, m; |
| struct rlc_li_field *li; |
| uint8_t frame_offset[16], offset = 0, chunk; |
| int i, frames = 0; |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Assembling frames: (len=%d)\n", len); |
| |
| data += 3; |
| len -= 3; |
| e = rh->e; /* if extended */ |
| m = 1; /* more frames, that means: the first frame */ |
| |
| /* Parse frame offsets from length indicator(s), if any. */ |
| while (1) { |
| if (frames == (int)sizeof(frame_offset)) { |
| LOGP(DRLCMACUL, LOGL_ERROR, "Too many frames in " |
| "block\n"); |
| return -EINVAL; |
| } |
| frame_offset[frames++] = offset; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "-- Frame %d starts at offset " |
| "%d\n", frames, offset); |
| if (!len) |
| break; |
| /* M == 0 and E == 0 is not allowed in this version. */ |
| if (!m && !e) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TBF=%d " |
| "ignored, because M='0' and E='0'.\n", |
| tbf->tfi); |
| return 0; |
| } |
| /* no more frames in this segment */ |
| if (e) { |
| break; |
| } |
| /* There is a new frame and an LI that delimits it. */ |
| if (m) { |
| li = (struct rlc_li_field *)data; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "-- Delimiter len=%d\n", |
| li->li); |
| /* Special case: LI == 0 |
| * If the last segment would fit precisely into the |
| * rest of the RLC MAC block, there would be no way |
| * to delimit that this segment ends and is not |
| * continued in the next block. |
| * The special LI (0) is used to force the segment to |
| * extend into the next block, so it is delimited there. |
| * This LI must be skipped. Also it is the last LI. |
| */ |
| if (li->li == 0) { |
| data++; |
| len--; |
| m = 1; /* M is ignored, we know there is more */ |
| break; /* handle E as '1', so we break! */ |
| } |
| e = li->e; |
| m = li->m; |
| offset += li->li; |
| data++; |
| len--; |
| continue; |
| } |
| } |
| if (!m) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Last frame carries spare " |
| "data\n"); |
| } |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Data length after length fields: %d\n", |
| len); |
| /* TLLI */ |
| if (rh->ti) { |
| if (len < 4) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TLLI out of " |
| "frame border\n"); |
| return -EINVAL; |
| } |
| data += 4; |
| len -= 4; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping TLLI: " |
| "%d\n", len); |
| } |
| |
| /* PFI */ |
| if (rh->pi) { |
| LOGP(DRLCMACUL, LOGL_ERROR, "ERROR: PFI not supported, " |
| "please disable in SYSTEM INFORMATION\n"); |
| if (len < 1) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA PFI out of " |
| "frame border\n"); |
| return -EINVAL; |
| } |
| data++; |
| len--; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping PFI: " |
| "%d\n", len); |
| } |
| |
| /* Now we have: |
| * - a list of frames offsets: frame_offset[] |
| * - number of frames: i |
| * - m == 0: Last frame carries spare data (end of TBF). |
| */ |
| |
| /* Check if last offset would exceed frame. */ |
| if (offset > len) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TBF=%d ignored, " |
| "because LI delimits data that exceeds block size.\n", |
| tbf->tfi); |
| return -EINVAL; |
| } |
| |
| /* create LLC frames */ |
| for (i = 0; i < frames; i++) { |
| /* last frame ? */ |
| if (i == frames - 1) { |
| /* no more data in last frame */ |
| if (!m) |
| break; |
| /* data until end of frame */ |
| chunk = len - frame_offset[i]; |
| } else { |
| /* data until next frame */ |
| chunk = frame_offset[i + 1] - frame_offset[i]; |
| } |
| LOGP(DRLCMACUL, LOGL_DEBUG, "-- Appending chunk (len=%d) to " |
| "frame at %d.\n", chunk, tbf->llc_index); |
| if (tbf->llc_index + chunk > LLC_MAX_LEN) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "LLC frame exceeds " |
| "maximum size.\n"); |
| chunk = LLC_MAX_LEN - tbf->llc_index; |
| } |
| memcpy(tbf->llc_frame + tbf->llc_index, data + frame_offset[i], |
| chunk); |
| tbf->llc_index += chunk; |
| /* not last frame. */ |
| if (i != frames - 1) { |
| /* send frame to SGSN */ |
| LOGP(DRLCMACUL, LOGL_INFO, "Complete UL frame for " |
| "TBF=%d: len=%d\n", tbf->tfi, tbf->llc_index); |
| gprs_rlcmac_tx_ul_ud(tbf); |
| tbf->llc_index = 0; /* reset frame space */ |
| /* also check if CV==0, because the frame may fill up the |
| * block precisely, then it is also complete. normally the |
| * frame would be extended into the next block with a 0-length |
| * delimiter added to this block. */ |
| } else if (rh->cv == 0) { |
| /* send frame to SGSN */ |
| LOGP(DRLCMACUL, LOGL_INFO, "Complete UL frame for " |
| "TBF=%d that fits precisely in last block: " |
| "len=%d\n", tbf->tfi, tbf->llc_index); |
| gprs_rlcmac_tx_ul_ud(tbf); |
| tbf->llc_index = 0; /* reset frame space */ |
| } |
| } |
| |
| return 0; |
| } |
| |
| struct msgb *gprs_rlcmac_send_uplink_ack(struct gprs_rlcmac_tbf *tbf, |
| uint32_t fn) |
| { |
| int final = (tbf->state == GPRS_RLCMAC_FINISHED); |
| struct msgb *msg; |
| |
| if (final && tbf->poll_state != GPRS_RLCMAC_POLL_NONE) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already " |
| "sheduled for TBF=%d, so we must wait for final uplink " |
| "ack...\n", tbf->tfi); |
| return NULL; |
| } |
| |
| msg = msgb_alloc(23, "rlcmac_ul_ack"); |
| if (!msg) |
| return NULL; |
| bitvec *ack_vec = bitvec_alloc(23); |
| if (!ack_vec) { |
| msgb_free(msg); |
| return NULL; |
| } |
| bitvec_unhex(ack_vec, |
| "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t)); |
| write_packet_uplink_ack(mac_control_block, tbf, final); |
| encode_gsm_rlcmac_downlink(ack_vec, mac_control_block); |
| bitvec_pack(ack_vec, msgb_put(msg, 23)); |
| bitvec_free(ack_vec); |
| free(mac_control_block); |
| |
| /* now we must set this flag, so we are allowed to assign downlink |
| * TBF on PACCH. it is only allowed when TLLI is aknowledged. */ |
| tbf->contention_resolution_done = 1; |
| |
| if (final) { |
| tbf->poll_state = GPRS_RLCMAC_POLL_SCHED; |
| tbf->poll_fn = (fn + 13) % 2715648; |
| /* waiting for final acknowledge */ |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK; |
| } else |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE; |
| |
| return msg; |
| } |
| |
| /* receive UL data block |
| * |
| * The blocks are defragmented and forwarded as LLC frames, if complete. |
| */ |
| int gprs_rlcmac_rcv_data_block_acknowledged(uint8_t trx, uint8_t ts, |
| uint8_t *data, uint8_t len) |
| { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| struct gprs_rlcmac_tbf *tbf; |
| struct rlc_ul_header *rh = (struct rlc_ul_header *)data; |
| uint16_t mod_sns, mod_sns_half, offset_v_q, offset_v_r, index; |
| int rc; |
| |
| switch (len) { |
| case 54: |
| /* omitting spare bits */ |
| len = 53; |
| break; |
| case 40: |
| /* omitting spare bits */ |
| len = 39; |
| break; |
| case 34: |
| /* omitting spare bits */ |
| len = 33; |
| break; |
| case 23: |
| break; |
| default: |
| LOGP(DRLCMACUL, LOGL_ERROR, "Dropping data block with invalid" |
| "length: %d)\n", len); |
| return -EINVAL; |
| } |
| |
| /* find TBF inst from given TFI */ |
| tbf = tbf_by_tfi(rh->tfi, trx, ts, GPRS_RLCMAC_UL_TBF); |
| if (!tbf) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA unknown TBF=%d\n", |
| rh->tfi); |
| return 0; |
| } |
| |
| LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TBF=%d received (V(Q)=%d .. " |
| "V(R)=%d)\n", rh->tfi, tbf->dir.ul.v_q, tbf->dir.ul.v_r); |
| |
| /* get TLLI */ |
| if (!tbf->tlli_valid) { |
| /* no TLLI yet */ |
| if (!rh->ti) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TBF=%d without " |
| "TLLI, but no TLLI received yet\n", rh->tfi); |
| return 0; |
| } |
| rc = tlli_from_ul_data(data, len, &tbf->tlli); |
| if (rc) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI " |
| "of UL DATA TBF=%d.\n", rh->tfi); |
| return 0; |
| } |
| tbf->tlli_valid = 1; |
| LOGP(DRLCMACUL, LOGL_INFO, "Decoded premier TLLI=0x%08x of " |
| "UL DATA TBF=%d.\n", tbf->tlli, rh->tfi); |
| /* already have TLLI, but we stille get another one */ |
| } else if (rh->ti) { |
| uint32_t tlli; |
| rc = tlli_from_ul_data(data, len, &tlli); |
| if (rc) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI " |
| "of UL DATA TBF=%d.\n", rh->tfi); |
| return 0; |
| } |
| if (tlli != tbf->tlli) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL " |
| "DATA TBF=%d. (Ignoring due to contention " |
| "resolution)\n", rh->tfi); |
| return 0; |
| } |
| } |
| |
| mod_sns = tbf->sns - 1; |
| mod_sns_half = (tbf->sns >> 1) - 1; |
| |
| /* restart T3169 */ |
| tbf_timer_start(tbf, 3169, bts->t3169, 0); |
| |
| /* Increment RX-counter */ |
| tbf->dir.ul.rx_counter++; |
| |
| /* current block relative to lowest unreceived block */ |
| offset_v_q = (rh->bsn - tbf->dir.ul.v_q) & mod_sns; |
| /* If out of window (may happen if blocks below V(Q) are received |
| * again. */ |
| if (offset_v_q >= tbf->ws) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window " |
| "%d..%d (it's normal)\n", rh->bsn, tbf->dir.ul.v_q, |
| (tbf->dir.ul.v_q + tbf->ws - 1) & mod_sns); |
| return 0; |
| } |
| /* Write block to buffer and set receive state array. */ |
| index = rh->bsn & mod_sns_half; /* memory index of block */ |
| memcpy(tbf->rlc_block[index], data, len); /* Copy block. */ |
| tbf->rlc_block_len[index] = len; |
| tbf->dir.ul.v_n[index] = 'R'; /* Mark received block. */ |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n", |
| rh->bsn, tbf->dir.ul.v_q, |
| (tbf->dir.ul.v_q + tbf->ws - 1) & mod_sns); |
| /* Raise V(R) to highest received sequence number not received. */ |
| offset_v_r = (rh->bsn + 1 - tbf->dir.ul.v_r) & mod_sns; |
| if (offset_v_r < (tbf->sns >> 1)) { /* Positive offset, so raise. */ |
| while (offset_v_r--) { |
| if (offset_v_r) /* all except the received block */ |
| tbf->dir.ul.v_n[tbf->dir.ul.v_r & mod_sns_half] |
| = 'N'; /* Mark block as not received */ |
| tbf->dir.ul.v_r = (tbf->dir.ul.v_r + 1) & mod_sns; |
| /* Inc V(R). */ |
| } |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Raising V(R) to %d\n", |
| tbf->dir.ul.v_r); |
| } |
| |
| /* Raise V(Q) if possible, and retrieve LLC frames from blocks. |
| * This is looped until there is a gap (non received block) or |
| * the window is empty.*/ |
| while (tbf->dir.ul.v_q != tbf->dir.ul.v_r && tbf->dir.ul.v_n[ |
| (index = tbf->dir.ul.v_q & mod_sns_half)] == 'R') { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Taking block %d out, raising " |
| "V(Q) to %d\n", tbf->dir.ul.v_q, |
| (tbf->dir.ul.v_q + 1) & mod_sns); |
| /* get LLC data from block */ |
| gprs_rlcmac_assemble_llc(tbf, tbf->rlc_block[index], |
| tbf->rlc_block_len[index]); |
| /* raise V(Q), because block already received */ |
| tbf->dir.ul.v_q = (tbf->dir.ul.v_q + 1) & mod_sns; |
| } |
| |
| /* Check CV of last frame in buffer */ |
| if (tbf->state == GPRS_RLCMAC_FLOW /* still in flow state */ |
| && tbf->dir.ul.v_q == tbf->dir.ul.v_r) { /* if complete */ |
| struct rlc_ul_header *last_rh = (struct rlc_ul_header *) |
| tbf->rlc_block[(tbf->dir.ul.v_r - 1) & mod_sns_half]; |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- No gaps in received block, " |
| "last block: BSN=%d CV=%d\n", last_rh->bsn, |
| last_rh->cv); |
| if (last_rh->cv == 0) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Finished with UL " |
| "TBF\n"); |
| tbf_new_state(tbf, GPRS_RLCMAC_FINISHED); |
| /* Reset N3103 counter. */ |
| tbf->dir.ul.n3103 = 0; |
| } |
| } |
| |
| /* If TLLI is included or if we received half of the window, we send |
| * an ack/nack */ |
| if (rh->si || rh->ti || tbf->state == GPRS_RLCMAC_FINISHED |
| || (tbf->dir.ul.rx_counter % SEND_ACK_AFTER_FRAMES) == 0) { |
| if (rh->si) { |
| LOGP(DRLCMACUL, LOGL_NOTICE, "- Scheduling Ack/Nack, " |
| "because MS is stalled.\n"); |
| } |
| if (rh->ti) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because TLLI is included.\n"); |
| } |
| if (tbf->state == GPRS_RLCMAC_FINISHED) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because last block has CV==0.\n"); |
| } |
| if ((tbf->dir.ul.rx_counter % SEND_ACK_AFTER_FRAMES) == 0) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, " |
| "because %d frames received.\n", |
| SEND_ACK_AFTER_FRAMES); |
| } |
| if (tbf->ul_ack_state == GPRS_RLCMAC_UL_ACK_NONE) { |
| /* trigger sending at next RTS */ |
| tbf->ul_ack_state = GPRS_RLCMAC_UL_ACK_SEND_ACK; |
| } else { |
| /* already triggered */ |
| LOGP(DRLCMACUL, LOGL_DEBUG, "- Sending Ack/Nack is " |
| "already triggered, don't schedule!\n"); |
| } |
| } |
| |
| return 0; |
| } |
| |
| struct msgb *gprs_rlcmac_send_packet_uplink_assignment( |
| struct gprs_rlcmac_tbf *tbf, uint32_t fn) |
| { |
| struct msgb *msg; |
| struct gprs_rlcmac_tbf *new_tbf; |
| |
| #if POLLING_ASSIGNMENT == 1 |
| if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE) { |
| LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already " |
| "sheduled for TBF=%d, so we must wait for uplink " |
| "assignment...\n", tbf->tfi); |
| return NULL; |
| } |
| #endif |
| |
| /* on down TBF we get the uplink TBF to be assigned. */ |
| if (tbf->direction == GPRS_RLCMAC_DL_TBF) |
| new_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_UL_TBF); |
| else |
| new_tbf = tbf; |
| |
| if (!new_tbf) { |
| LOGP(DRLCMACUL, LOGL_ERROR, "We have a schedule for uplink " |
| "assignment at downlink TBF=%d, but there is no uplink " |
| "TBF\n", tbf->tfi); |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE; |
| return NULL; |
| } |
| |
| msg = msgb_alloc(23, "rlcmac_ul_ass"); |
| if (!msg) |
| return NULL; |
| LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Uplink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli); |
| bitvec *ass_vec = bitvec_alloc(23); |
| if (!ass_vec) { |
| msgb_free(msg); |
| return NULL; |
| } |
| bitvec_unhex(ass_vec, |
| "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| write_packet_uplink_assignment(ass_vec, tbf->tfi, |
| (tbf->direction == GPRS_RLCMAC_DL_TBF), 0, 0, new_tbf, |
| POLLING_ASSIGNMENT); |
| bitvec_pack(ass_vec, msgb_put(msg, 23)); |
| RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t)); |
| LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Assignment +++++++++++++++++++++++++\n"); |
| decode_gsm_rlcmac_downlink(ass_vec, mac_control_block); |
| LOGPC(DCSN1, LOGL_NOTICE, "\n"); |
| LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Uplink Assignment -------------------------\n"); |
| bitvec_free(ass_vec); |
| |
| #if POLLING_ASSIGNMENT == 1 |
| FIXME process does not work, also the acknowledgement is not checked. |
| tbf->poll_state = GPRS_RLCMAC_POLL_SCHED; |
| tbf->poll_fn = (fn + 13) % 2715648; |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_WAIT_ACK; |
| #else |
| tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE; |
| #endif |
| |
| return msg; |
| } |
| |
| int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta) |
| { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| struct gprs_rlcmac_tbf *tbf; |
| uint8_t trx, ts; |
| int8_t tfi; /* must be signed */ |
| |
| LOGP(DRLCMAC, LOGL_DEBUG, "MS requests UL TBF on RACH, so we provide " |
| "one:\n"); |
| // Create new TBF |
| tfi = tfi_alloc(GPRS_RLCMAC_UL_TBF, &trx, &ts, -1, -1); |
| if (tfi < 0) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); |
| /* FIXME: send reject */ |
| return -EBUSY; |
| } |
| /* set class to 0, since we don't know the multislot class yet */ |
| tbf = tbf_alloc(NULL, GPRS_RLCMAC_UL_TBF, tfi, trx, ts, 0, 1); |
| if (!tbf) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH ressource\n"); |
| /* FIXME: send reject */ |
| return -EBUSY; |
| } |
| if (qta < 0) |
| qta = 0; |
| if (qta > 252) |
| qta = 252; |
| tbf->ta = qta >> 2; |
| tbf_new_state(tbf, GPRS_RLCMAC_FLOW); |
| tbf_timer_start(tbf, 3169, bts->t3169, 0); |
| LOGP(DRLCMAC, LOGL_DEBUG, "TBF: [UPLINK] START TFI: %u\n", tbf->tfi); |
| LOGP(DRLCMAC, LOGL_DEBUG, "RX: [PCU <- BTS] TFI: %u RACH qbit-ta=%d ra=%d, Fn=%d (%d,%d,%d)\n", tbf->tfi, qta, ra, Fn, (Fn / (26 * 51)) % 32, Fn % 51, Fn % 26); |
| LOGP(DRLCMAC, LOGL_INFO, "TX: START TFI: %u Immediate Assignment Uplink (AGCH)\n", tbf->tfi); |
| bitvec *immediate_assignment = bitvec_alloc(22) /* without plen */; |
| bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| int plen = write_immediate_assignment(immediate_assignment, 0, ra, Fn, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, tbf->dir.ul.usf[tbf->first_ts], 0, 0, 0); |
| pcu_l1if_tx_agch(immediate_assignment, plen); |
| bitvec_free(immediate_assignment); |
| |
| return 0; |
| } |
| |
| |
| /* |
| * DL data block flow |
| */ |
| |
| /* send DL data block |
| * |
| * The messages are fragmented and forwarded as data blocks. |
| */ |
| struct msgb *gprs_rlcmac_send_data_block_acknowledged( |
| struct gprs_rlcmac_tbf *tbf, uint32_t fn, uint8_t ts) |
| { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| struct rlc_dl_header *rh; |
| struct rlc_li_field *li; |
| uint8_t block_length; /* total length of block, including spare bits */ |
| uint8_t block_data; /* usable data of block, w/o spare bits, inc. MAC */ |
| struct msgb *msg, *dl_msg; |
| uint8_t bsn; |
| uint16_t mod_sns = tbf->sns - 1; |
| uint16_t mod_sns_half = (tbf->sns >> 1) - 1; |
| uint16_t index; |
| uint8_t *delimiter, *data, *e_pointer; |
| uint8_t len; |
| uint16_t space, chunk; |
| |
| LOGP(DRLCMACDL, LOGL_DEBUG, "DL DATA TBF=%d downlink (V(A)==%d .. " |
| "V(S)==%d)\n", tbf->tfi, tbf->dir.dl.v_a, tbf->dir.dl.v_s); |
| |
| do_resend: |
| /* check if there is a block with negative acknowledgement */ |
| for (bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s; |
| bsn = (bsn + 1) & mod_sns) { |
| index = (bsn & mod_sns_half); |
| if (tbf->dir.dl.v_b[index] == 'N' |
| || tbf->dir.dl.v_b[index] == 'X') { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Resending BSN %d\n", |
| bsn); |
| /* re-send block with negative aknowlegement */ |
| tbf->dir.dl.v_b[index] = 'U'; /* unacked */ |
| goto tx_block; |
| } |
| } |
| |
| /* if the window has stalled, or transfer is complete, |
| * send an unacknowledged block */ |
| if (tbf->state == GPRS_RLCMAC_FINISHED |
| || ((tbf->dir.dl.v_s - tbf->dir.dl.v_a) & mod_sns) == tbf->ws) { |
| int resend = 0; |
| |
| if (tbf->state == GPRS_RLCMAC_FINISHED) |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, " |
| "because all blocks have been transmitted.\n", |
| tbf->dir.dl.v_a); |
| else |
| LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, " |
| "because all window is stalled.\n", |
| tbf->dir.dl.v_a); |
| /* If V(S) == V(A) and finished state, we would have received |
| * acknowledgement of all transmitted block. In this case we |
| * would have transmitted the final block, and received ack |
| * from MS. But in this case we did not receive the final ack |
| * indication from MS. This should never happen if MS works |
| * correctly. */ |
| if (tbf->dir.dl.v_s == tbf->dir.dl.v_a) { |
| LOGP(DRLCMACDL, LOGL_ERROR, "- MS acked all block, " |
| "but we still transmitting!\n"); |
| /* we just send final block again */ |
| index = ((tbf->dir.dl.v_s - 1) & mod_sns_half); |
| goto tx_block; |
| } |
| |
| /* cycle through all unacked blocks */ |
| for (bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s; |
| bsn = (bsn + 1) & mod_sns) { |
| index = (bsn & mod_sns_half); |
| if (tbf->dir.dl.v_b[index] == 'U') { |
| /* mark to be re-send */ |
| tbf->dir.dl.v_b[index] = 'X'; |
| resend++; |
| } |
| } |
| /* At this point there should be at leasst one unacked block |
| * to be resent. If not, this is an software error. */ |
| if (resend == 0) { |
| LOGP(DRLCMACDL, LOGL_ERROR, "Software error: " |
| "There are no unacknowledged blocks, but V(A) " |
| " != V(S). PLEASE FIX!\n"); |
| /* we just send final block again */ |
| index = ((tbf->dir.dl.v_s - 1) & mod_sns_half); |
| goto tx_block; |
| } |
| goto do_resend; |
| } |
| |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d\n", |
| tbf->dir.dl.v_s); |
| |
| /* now we still have untransmitted LLC data, so we fill mac block */ |
| index = tbf->dir.dl.v_s & mod_sns_half; |
| data = tbf->rlc_block[index]; |
| switch (bts->initial_cs) { |
| case 2: /* CS-2 */ |
| block_length = 34; |
| block_data = 33; |
| break; |
| case 3: /* CS-3 */ |
| block_length = 40; |
| block_data = 39; |
| break; |
| case 4: /* CS-4 */ |
| block_length = 54; |
| block_data = 53; |
| break; |
| default: /* CS-1 */ |
| block_length = 23; |
| block_data = 23; |
| } |
| memset(data, 0x2b, block_data); /* spare bits will be left 0 */ |
| rh = (struct rlc_dl_header *)data; |
| rh->pt = 0; /* Data Block */ |
| rh->rrbp = rh->s_p = 0; /* Polling, set later, if required */ |
| rh->usf = 7; /* will be set at scheduler */ |
| rh->pr = 0; /* FIXME: power reduction */ |
| rh->tfi = tbf->tfi; /* TFI */ |
| rh->fbi = 0; /* Final Block Indicator, set late, if true */ |
| rh->bsn = tbf->dir.dl.v_s; /* Block Sequence Number */ |
| rh->e = 0; /* Extension bit, maybe set later */ |
| e_pointer = data + 2; /* points to E of current chunk */ |
| data += 3; |
| delimiter = data; /* where next length header would be stored */ |
| space = block_data - 3; |
| while (1) { |
| chunk = tbf->llc_length - tbf->llc_index; |
| /* 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); |
| /* block is filled, so there is no extension */ |
| *e_pointer |= 0x01; |
| /* fill only space */ |
| memcpy(data, tbf->llc_frame + tbf->llc_index, space); |
| /* incement index */ |
| tbf->llc_index += space; |
| /* return data block as message */ |
| break; |
| } |
| /* if FINAL chunk would fit precisely in space left */ |
| if (chunk == space && llist_empty(&tbf->llc_queue)) { |
| 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); |
| LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for " |
| "TBF=%d that fits precisely in last block: " |
| "len=%d\n", tbf->tfi, tbf->llc_length); |
| /* block is filled, so there is no extension */ |
| *e_pointer |= 0x01; |
| /* fill space */ |
| memcpy(data, tbf->llc_frame + tbf->llc_index, space); |
| /* reset LLC frame */ |
| tbf->llc_index = tbf->llc_length = 0; |
| /* final block */ |
| rh->fbi = 1; /* we indicate final block */ |
| tbf_new_state(tbf, GPRS_RLCMAC_FINISHED); |
| /* return data block as message */ |
| break; |
| } |
| /* 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) |
| memcpy(delimiter + 1, delimiter, |
| data - delimiter); |
| data++; |
| 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 */ |
| // no need to set e_pointer nor increase delimiter |
| /* fill only space, which is 1 octet less than chunk */ |
| memcpy(data, tbf->llc_frame + tbf->llc_index, space); |
| /* incement index */ |
| tbf->llc_index += space; |
| /* return data block as message */ |
| break; |
| } |
| 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) |
| memcpy(delimiter + 1, delimiter, data - delimiter); |
| data++; |
| space--; |
| /* add LI to delimit frame */ |
| li = (struct rlc_li_field *)delimiter; |
| li->e = 0; /* Extension bit, maybe set later */ |
| li->m = 0; /* will be set later, if there is more LLC data */ |
| li->li = chunk; /* length of chunk */ |
| e_pointer = delimiter; /* points to E of current delimiter */ |
| delimiter++; |
| /* copy (rest of) LLC frame to space */ |
| memcpy(data, tbf->llc_frame + tbf->llc_index, chunk); |
| data += chunk; |
| space -= chunk; |
| LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for TBF=%d: " |
| "len=%d\n", tbf->tfi, tbf->llc_length); |
| /* reset LLC frame */ |
| tbf->llc_index = tbf->llc_length = 0; |
| /* dequeue next LLC frame, if any */ |
| msg = msgb_dequeue(&tbf->llc_queue); |
| if (msg) { |
| LOGP(DRLCMACDL, LOGL_INFO, "- Dequeue next LLC for " |
| "TBF=%d (len=%d)\n", tbf->tfi, msg->len); |
| memcpy(tbf->llc_frame, msg->data, msg->len); |
| tbf->llc_length = msg->len; |
| msgb_free(msg); |
| } |
| /* if we have more data and we have space left */ |
| if (space > 0 && tbf->llc_length) { |
| li->m = 1; /* we indicate more frames to follow */ |
| continue; |
| } |
| /* if we don't have more LLC frames */ |
| if (!tbf->llc_length) { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we " |
| "done.\n"); |
| li->e = 1; /* we cannot extend */ |
| rh->fbi = 1; /* we indicate final block */ |
| tbf->dir.dl.tx_counter = POLL_ACK_AFTER_FRAMES + 1; |
| /* + 1 indicates: first final ack */ |
| tbf_new_state(tbf, GPRS_RLCMAC_FINISHED); |
| break; |
| } |
| /* we have no space left */ |
| LOGP(DRLCMACDL, LOGL_DEBUG, "-- No space left, so we are " |
| "done.\n"); |
| li->e = 1; /* we cannot extend */ |
| break; |
| } |
| LOGP(DRLCMACDL, LOGL_DEBUG, "data block: %s\n", |
| osmo_hexdump(tbf->rlc_block[index], block_length)); |
| tbf->rlc_block_len[index] = block_length; |
| /* raise send state and set ack state array */ |
| tbf->dir.dl.v_b[index] = 'U'; /* unacked */ |
| tbf->dir.dl.v_s = (tbf->dir.dl.v_s + 1) & mod_sns; /* inc send state */ |
| |
| tx_block: |
| /* from this point on, new block is sent or old block is resent */ |
| |
| /* get data and header from current block */ |
| data = tbf->rlc_block[index]; |
| len = tbf->rlc_block_len[index]; |
| rh = (struct rlc_dl_header *)data; |
| |
| /* Clear Polling, if still set in history buffer */ |
| rh->s_p = 0; |
| |
| /* poll after POLL_ACK_AFTER_FRAMES frames, or when final block is tx. |
| */ |
| if (tbf->dir.dl.tx_counter >= POLL_ACK_AFTER_FRAMES) { |
| if (tbf->dir.dl.tx_counter > POLL_ACK_AFTER_FRAMES) { |
| /* if rx_counter is POLL_ACK_AFTER_FRAMES + 1, this |
| * indicates: poll caused by final ack. */ |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack " |
| "polling, because final block sent.\n"); |
| } else { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack " |
| "polling, because %d blocks sent.\n", |
| POLL_ACK_AFTER_FRAMES); |
| } |
| tbf->dir.dl.tx_counter = 0; |
| /* scheduling not possible, because: */ |
| if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE) |
| LOGP(DRLCMAC, LOGL_DEBUG, "Polling is already " |
| "sheduled for TBF=%d, so we must wait for " |
| "requesting downlink ack\n", tbf->tfi); |
| else if (tbf->control_ts != ts) |
| LOGP(DRLCMAC, LOGL_DEBUG, "Polling cannot be " |
| "sheduled in this TS %d, waiting for " |
| "TS %d\n", ts, tbf->control_ts); |
| else { |
| LOGP(DRLCMAC, LOGL_DEBUG, "Polling sheduled in this " |
| "TS %d\n", ts); |
| /* start timer whenever we send the final block */ |
| if (rh->fbi == 1) |
| tbf_timer_start(tbf, 3191, bts->t3191, 0); |
| |
| /* schedule polling */ |
| tbf->poll_state = GPRS_RLCMAC_POLL_SCHED; |
| tbf->poll_fn = (fn + 13) % 2715648; |
| |
| /* set polling in header */ |
| rh->rrbp = 0; /* N+13 */ |
| rh->s_p = 1; /* Polling */ |
| |
| /* Increment TX-counter */ |
| tbf->dir.dl.tx_counter++; |
| } |
| } else { |
| /* Increment TX-counter */ |
| tbf->dir.dl.tx_counter++; |
| } |
| |
| /* return data block as message */ |
| dl_msg = msgb_alloc(len, "rlcmac_dl_data"); |
| if (!dl_msg) |
| return NULL; |
| memcpy(msgb_put(dl_msg, len), data, len); |
| |
| return dl_msg; |
| } |
| |
| int gprs_rlcmac_downlink_ack(struct gprs_rlcmac_tbf *tbf, uint8_t final, |
| uint8_t ssn, uint8_t *rbb) |
| { |
| char show_rbb[65], show_v_b[RLC_MAX_SNS + 1]; |
| uint16_t mod_sns = tbf->sns - 1; |
| uint16_t mod_sns_half = (tbf->sns >> 1) - 1; |
| int i; /* must be signed */ |
| int16_t dist; /* must be signed */ |
| uint8_t bit; |
| uint16_t bsn; |
| struct msgb *msg; |
| |
| LOGP(DRLCMACDL, LOGL_DEBUG, "TBF=%d downlink acknowledge\n", |
| tbf->tfi); |
| |
| if (!final) { |
| /* show received array in debug (bit 64..1) */ |
| for (i = 63; i >= 0; i--) { |
| bit = (rbb[i >> 3] >> (7 - (i&7))) & 1; |
| show_rbb[i] = (bit) ? '1' : 'o'; |
| } |
| show_rbb[64] = '\0'; |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- ack: (BSN=%d)\"%s\"" |
| "(BSN=%d) 1=ACK o=NACK\n", (ssn - 64) & mod_sns, |
| show_rbb, (ssn - 1) & mod_sns); |
| |
| /* apply received array to receive state (SSN-64..SSN-1) */ |
| /* calculate distance of ssn from V(S) */ |
| dist = (tbf->dir.dl.v_s - ssn) & mod_sns; |
| /* check if distance is less than distance V(A)..V(S) */ |
| if (dist < ((tbf->dir.dl.v_s - tbf->dir.dl.v_a) & mod_sns)) { |
| /* SSN - 1 is in range V(A)..V(S)-1 */ |
| for (i = 63, bsn = (ssn - 1) & mod_sns; |
| i >= 0 && bsn != ((tbf->dir.dl.v_a - 1) & mod_sns); |
| i--, bsn = (bsn - 1) & mod_sns) { |
| bit = (rbb[i >> 3] >> (7 - (i&7))) & 1; |
| if (bit) { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got " |
| "ack for BSN=%d\n", bsn); |
| tbf->dir.dl.v_b[bsn & mod_sns_half] |
| = 'A'; |
| } else { |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- got " |
| "NACK for BSN=%d\n", bsn); |
| tbf->dir.dl.v_b[bsn & mod_sns_half] |
| = 'N'; |
| } |
| } |
| } else { |
| /* this might happpen, if the downlink assignment |
| * was not received by ms and the ack refers |
| * to previous TBF |
| * FIXME: we should implement polling for |
| * control ack!*/ |
| LOGP(DRLCMACDL, LOGL_NOTICE, "- ack range is out of " |
| "V(A)..V(S) range (DL TBF=%d) Free TFB!\n", |
| tbf->tfi); |
| return 1; /* indicate to free TBF */ |
| } |
| |
| /* raise V(A), if possible */ |
| for (i = 0, bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s; |
| i++, bsn = (bsn + 1) & mod_sns) { |
| if (tbf->dir.dl.v_b[bsn & mod_sns_half] == 'A') { |
| tbf->dir.dl.v_b[bsn & mod_sns_half] = 'I'; |
| /* mark invalid */ |
| tbf->dir.dl.v_a = (tbf->dir.dl.v_a + 1) |
| & mod_sns; |
| } else |
| break; |
| } |
| |
| /* show receive state array in debug (V(A)..V(S)-1) */ |
| for (i = 0, bsn = tbf->dir.dl.v_a; bsn != tbf->dir.dl.v_s; |
| i++, bsn = (bsn + 1) & mod_sns) { |
| show_v_b[i] = tbf->dir.dl.v_b[bsn & mod_sns_half]; |
| if (show_v_b[i] == 0) |
| show_v_b[i] = ' '; |
| } |
| show_v_b[i] = '\0'; |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- V(B): (V(A)=%d)\"%s\"" |
| "(V(S)-1=%d) A=Acked N=Nacked U=Unacked " |
| "X=Resend-Unacked\n", tbf->dir.dl.v_a, show_v_b, |
| (tbf->dir.dl.v_s - 1) & mod_sns); |
| |
| if (tbf->state == GPRS_RLCMAC_FINISHED |
| && tbf->dir.dl.v_s == tbf->dir.dl.v_a) { |
| LOGP(DRLCMACDL, LOGL_NOTICE, "Received final block, " |
| "but without final ack inidcation\n"); |
| } else |
| return 0; |
| } else |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Final ACK received.\n"); |
| |
| /* check for LLC PDU in the LLC Queue */ |
| msg = msgb_dequeue(&tbf->llc_queue); |
| if (!msg) { |
| struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; |
| |
| /* no message, start T3193, change state to RELEASE */ |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- No new message, so we " |
| "release.\n"); |
| /* start T3193 */ |
| tbf_timer_start(tbf, 3193, bts->t3193_msec / 1000, |
| bts->t3193_msec & 1000); |
| tbf_new_state(tbf, GPRS_RLCMAC_WAIT_RELEASE); |
| |
| return 0; |
| } |
| memcpy(tbf->llc_frame, msg->data, msg->len); |
| tbf->llc_length = msg->len; |
| msgb_free(msg); |
| |
| /* we have a message, so we trigger downlink assignment, and there |
| * set the state to ASSIGN. also we set old_downlink, because we |
| * re-use this tbf. */ |
| LOGP(DRLCMAC, LOGL_DEBUG, "Trigger dowlink assignment on PACCH, " |
| "because another LLC PDU has arrived in between\n"); |
| memset(&tbf->dir.dl, 0, sizeof(tbf->dir.dl)); /* reset RLC states */ |
| tbf_update(tbf); |
| gprs_rlcmac_trigger_downlink_assignment(tbf, 1, NULL); |
| |
| return 0; |
| } |
| |
| |
| struct msgb *gprs_rlcmac_send_packet_downlink_assignment( |
| struct gprs_rlcmac_tbf *tbf, uint32_t fn) |
| { |
| struct msgb *msg; |
| struct gprs_rlcmac_tbf *new_tbf; |
| |
| #if POLLING_ASSIGNMENT == 1 |
| if (tbf->poll_state != GPRS_RLCMAC_POLL_NONE) { |
| LOGP(DRLCMAC, LOGL_DEBUG, "Polling is already " |
| "sheduled for TBF=%d, so we must wait for downlink " |
| "assignment...\n", tbf->tfi); |
| return NULL; |
| } |
| #endif |
| |
| /* on uplink TBF we get the downlink TBF to be assigned. */ |
| if (tbf->direction == GPRS_RLCMAC_UL_TBF) { |
| /* be sure to check first, if contention resolution is done, |
| * otherwise we cannot send the assignment yet */ |
| if (!tbf->contention_resolution_done) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "Cannot assign DL TBF now, " |
| "because contention resolution is not " |
| "finished.\n"); |
| return NULL; |
| } |
| new_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_DL_TBF); |
| } else |
| new_tbf = tbf; |
| if (!new_tbf) { |
| LOGP(DRLCMACDL, LOGL_ERROR, "We have a schedule for downlink " |
| "assignment at uplink TBF=%d, but there is no downlink " |
| "TBF\n", tbf->tfi); |
| tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE; |
| return NULL; |
| } |
| |
| msg = msgb_alloc(23, "rlcmac_dl_ass"); |
| if (!msg) |
| return NULL; |
| bitvec *ass_vec = bitvec_alloc(23); |
| if (!ass_vec) { |
| msgb_free(msg); |
| return NULL; |
| } |
| bitvec_unhex(ass_vec, |
| "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Downlink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli); |
| RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t)); |
| write_packet_downlink_assignment(mac_control_block, tbf->tfi, |
| (tbf->direction == GPRS_RLCMAC_DL_TBF), new_tbf, |
| POLLING_ASSIGNMENT); |
| LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n"); |
| encode_gsm_rlcmac_downlink(ass_vec, mac_control_block); |
| LOGPC(DCSN1, LOGL_NOTICE, "\n"); |
| LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Downlink Assignment -------------------------\n"); |
| bitvec_pack(ass_vec, msgb_put(msg, 23)); |
| bitvec_free(ass_vec); |
| free(mac_control_block); |
| |
| #if POLLING_ASSIGNMENT == 1 |
| tbf->poll_state = GPRS_RLCMAC_POLL_SCHED; |
| tbf->poll_fn = (fn + 13) % 2715648; |
| tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_WAIT_ACK; |
| #else |
| tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE; |
| #endif |
| |
| return msg; |
| } |
| |
| static void gprs_rlcmac_downlink_assignment(gprs_rlcmac_tbf *tbf, uint8_t poll, |
| char *imsi) |
| { |
| LOGP(DRLCMAC, LOGL_INFO, "TX: START TFI: %u TLLI: 0x%08x Immediate Assignment Downlink (PCH)\n", tbf->tfi, tbf->tlli); |
| bitvec *immediate_assignment = bitvec_alloc(22); /* without plen */ |
| bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b"); |
| /* use request reference that has maximum distance to current time, |
| * so the assignment will not conflict with possible RACH requests. */ |
| int plen = write_immediate_assignment(immediate_assignment, 1, 125, (tbf->pdch[tbf->first_ts]->last_rts_fn + 21216) % 2715648, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, 0, tbf->tlli, poll, tbf->poll_fn); |
| pcu_l1if_tx_pch(immediate_assignment, plen, imsi); |
| bitvec_free(immediate_assignment); |
| } |
| |
| /* depending on the current TBF, we assign on PACCH or AGCH */ |
| void gprs_rlcmac_trigger_downlink_assignment(gprs_rlcmac_tbf *tbf, |
| uint8_t old_downlink, char *imsi) |
| { |
| gprs_rlcmac_tbf *old_tbf; |
| |
| #ifdef DEBUG_DL_ASS_IDLE |
| strncpy(debug_imsi, imsi); |
| LOGP(DRLCMAC, LOGL_ERROR, "**** DEBUGGING DOWNLINK ASSIGNMENT ****\n"); |
| #endif |
| |
| /* stop pending timer */ |
| tbf_timer_stop(tbf); |
| |
| /* check for downlink tbf: */ |
| if (old_downlink) |
| old_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_DL_TBF); |
| else |
| old_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_UL_TBF); |
| if (old_tbf && (old_tbf->state != GPRS_RLCMAC_FINISHED || |
| old_tbf->ul_ack_state != GPRS_RLCMAC_UL_ACK_WAIT_ACK)) { |
| #ifdef DEBUG_DL_ASS_IDLE |
| LOGP(DRLCMAC, LOGL_ERROR, "We must wait for current TBF to be " |
| "released.\n"); |
| /* wait one second until assignment */ |
| tbf_timer_start(tbf, 1234, 1,0); |
| #else |
| LOGP(DRLCMAC, LOGL_DEBUG, "Send dowlink assignment on " |
| "PACCH, because %s TBF=%d exists for TLLI=0x%08x\n", |
| (old_tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", |
| old_tbf->tfi, old_tbf->tlli); |
| old_tbf->dl_ass_state = GPRS_RLCMAC_DL_ASS_SEND_ASS; |
| /* use TA from old TBF */ |
| tbf->ta = old_tbf->ta; |
| /* change state */ |
| tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN); |
| /* start timer */ |
| tbf_timer_start(tbf, 0, Tassign_pacch); |
| #endif |
| } else { |
| LOGP(DRLCMAC, LOGL_DEBUG, "Send dowlink assignment for TBF=%d on PCH, no TBF exist (IMSI=%s)\n", tbf->tfi, imsi); |
| if (!imsi || strlen(imsi) < 3) { |
| LOGP(DRLCMAC, LOGL_ERROR, "No valid IMSI!\n"); |
| return; |
| } |
| /* send immediate assignment */ |
| gprs_rlcmac_downlink_assignment(tbf, 0, imsi); |
| /* change state */ |
| tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN); |
| /* start timer */ |
| tbf_timer_start(tbf, 0, Tassign_agch); |
| } |
| } |
| |