From 31dcbb67e192f22a8f9de5b99a034eb1dcd4cbf0 Mon Sep 17 00:00:00 2001 From: Andreas Eversberg Date: Thu, 26 Jul 2012 13:18:48 +0200 Subject: Changes RLC/MAC code from C++ to C --- src/gprs_rlcmac_data.c | 1461 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1461 insertions(+) create mode 100644 src/gprs_rlcmac_data.c (limited to 'src/gprs_rlcmac_data.c') diff --git a/src/gprs_rlcmac_data.c b/src/gprs_rlcmac_data.c new file mode 100644 index 00000000..0efcb798 --- /dev/null +++ b/src/gprs_rlcmac_data.c @@ -0,0 +1,1461 @@ +/* Data block transfer + * + * Copyright (C) 2012 Ivan Klyuchnikov + * Copyright (C) 2012 Andreas Eversberg + * + * 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 + +extern void *tall_pcu_ctx; + +int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli, + uint8_t num_frames, uint32_t num_octets); + +/* 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 + +/* 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; +} + +int gprs_rlcmac_rcv_control_ack(uint8_t trx, uint8_t ts, uint32_t fn, + uint32_t tlli) +{ + struct gprs_rlcmac_tbf *tbf; + uint8_t tfi; + + 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); + return -EINVAL; + } + 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); + return 0; + } + 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; + if (tbf->direction == GPRS_RLCMAC_UL_TBF) + tbf = tbf_by_tlli(tbf->tlli, + GPRS_RLCMAC_DL_TBF); + if (!tbf) { + LOGP(DRLCMAC, LOGL_ERROR, "Got ACK, but DL " + "TBF is gone\n"); + return -EIO; + } + tbf_new_state(tbf, GPRS_RLCMAC_FLOW); + tbf_assign_control_ts(tbf); + return 0; + } + 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; + if (tbf->direction == GPRS_RLCMAC_DL_TBF) + tbf = tbf_by_tlli(tbf->tlli, + GPRS_RLCMAC_UL_TBF); + if (!tbf) { + LOGP(DRLCMAC, LOGL_ERROR, "Got ACK, but UL " + "TBF is gone\n"); + return -EIO; + } + tbf_new_state(tbf, GPRS_RLCMAC_FLOW); + tbf_assign_control_ts(tbf); + return 0; + } + LOGP(DRLCMAC, LOGL_ERROR, "Error: received PACET CONTROL ACK " + "at no request\n"); + return EINVAL; +} + +int gprs_rlcmac_rcv_downlink_ack(uint8_t trx, uint8_t ts, uint32_t fn, uint16_t tfi, uint8_t final, uint8_t ssn, uint8_t *rbb, uint8_t request) +{ + struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts; + struct gprs_rlcmac_tbf *tbf; + int rc; + + 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); + return -EINVAL; + } + /* reset N3105 */ + tbf->dir.dl.n3105 = 0; + /* stop timer T3191 */ + tbf_timer_stop(tbf); + 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, final, ssn, rbb); + if (rc == 1) { + tbf_free(tbf); + return 0; + } + /* check for channel request */ + if (request) { + 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"); + /* 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 */ + return -EIO; + } + /* 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 */ + return -EIO; + } + ul_tbf->tlli = tbf->tlli; + ul_tbf->tlli_valid = 1; /* no contention resolution */ + ul_tbf->dir.ul.contention_resolution_done = 1; + ul_tbf->ta = tbf->ta; /* use current TA */ + tbf_new_state(ul_tbf, GPRS_RLCMAC_ASSIGN); + tbf_timer_start(ul_tbf, 3169, bts->t3169, 0); + /* schedule uplink assignment */ + tbf->ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS; + } + + return 0; +} + +#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, NULL, 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 = write_packet_uplink_ack(tbf, final); + if (!msg) + return NULL; + + /* 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->dir.ul.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; + tbf->dir.ul.final_ack_sent = 1; + } 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) { + struct gprs_rlcmac_tbf *dl_tbf; + + /* 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); + if ((dl_tbf = tbf_by_tlli(tbf->tlli, GPRS_RLCMAC_DL_TBF))) { + LOGP(DRLCMACUL, LOGL_NOTICE, "Got RACH from " + "TLLI=0x%08x while DL TBF=%d still exists. " + "Killing pending DL TBF\n", tbf->tlli, + dl_tbf->tfi); + tbf_free(dl_tbf); + } + /* 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; + } + + LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Uplink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli); + + msg = write_packet_uplink_assignment(tbf->tfi, + (tbf->direction == GPRS_RLCMAC_DL_TBF), 0, 0, new_tbf, + POLLING_ASSIGNMENT); + if (!msg) + return NULL; + +#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; + tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW); + tbf_assign_control_ts(new_tbf); +#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 */ + uint8_t imm_ass[23]; + int rc; + + 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); + rc = write_immediate_assignment_uplink(imm_ass, ra, Fn, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, tbf->dir.ul.usf[tbf->first_ts], 0, 0); + if (rc < 0) + return rc; + + pcu_l1if_tx_agch(imm_ass); + return 0; +} + + +/* + * DL data block flow + */ + +static struct msgb *llc_dequeue(struct gprs_rlcmac_tbf *tbf) +{ + struct msgb *msg; + struct timeval *tv, tv_now; + uint32_t octets = 0, frames = 0; + + gettimeofday(&tv_now, NULL); + + while ((msg = msgb_dequeue(&tbf->llc_queue))) { + tv = (struct timeval *)msg->data; + msgb_pull(msg, sizeof(*tv)); + if (tv->tv_sec /* not infinite */ + && (tv_now.tv_sec > tv->tv_sec /* and secs expired */ + || (tv_now.tv_sec == tv->tv_sec /* .. or if secs equal .. */ + && tv_now.tv_usec > tv->tv_usec))) { /* .. usecs expired */ + LOGP(DRLCMACDL, LOGL_NOTICE, "Discarding LLC PDU of " + "DL TBF=%d, because lifetime limit reached\n", + tbf->tfi); + frames++; + octets += msg->len; + msgb_free(msg); + continue; + } + break; + } + + if (frames) { + if (frames > 0xff) + frames = 0xff; + if (octets > 0xffffff) + octets = 0xffffff; + bssgp_tx_llc_discarded(bctx, tbf->tlli, frames, octets); + } + + return msg; +} + +static int gprs_rlcmac_debug_bw(struct gprs_rlcmac_tbf *tbf, uint16_t octets) +{ + struct timeval now_tv, *bw_tv = &tbf->bw_tv; + uint32_t elapsed; + + tbf->bw_octets += octets; + + gettimeofday(&now_tv, NULL); + elapsed = ((now_tv.tv_sec - bw_tv->tv_sec) << 7) + + ((now_tv.tv_usec - bw_tv->tv_usec) << 7) / 1000000; + if (elapsed < 128) + return 0; + + LOGP(DRLCMACBW, LOGL_DEBUG, "DL Bandwitdh of TLLI=0x%08x: %d KBits/s\n", + tbf->tlli, tbf->bw_octets / elapsed); + + /* reset bandwidth values timestamp */ + memcpy(bw_tv, &now_tv, sizeof(struct timeval)); + tbf->bw_octets = 0; + + return 0; +} + +/* 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); + gprs_rlcmac_debug_bw(tbf, 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); + gprs_rlcmac_debug_bw(tbf, tbf->llc_length); + /* reset LLC frame */ + tbf->llc_index = tbf->llc_length = 0; + /* dequeue next LLC frame, if any */ + msg = llc_dequeue(tbf); + 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 = llc_dequeue(tbf); + 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, tbf, 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->dir.ul.contention_resolution_done) { + LOGP(DRLCMAC, LOGL_DEBUG, "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; + } + + LOGP(DRLCMAC, LOGL_INFO, "TBF: START TFI: %u TLLI: 0x%08x Packet Downlink Assignment (PACCH)\n", new_tbf->tfi, new_tbf->tlli); + msg = write_packet_downlink_assignment(tbf->tfi, + (tbf->direction == GPRS_RLCMAC_DL_TBF), new_tbf, + POLLING_ASSIGNMENT); + if (!msg) + return NULL; + +#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; + tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW); + tbf_assign_control_ts(new_tbf); +#endif + + return msg; +} + +static void gprs_rlcmac_downlink_assignment(struct gprs_rlcmac_tbf *tbf, + uint8_t poll, char *imsi) +{ + uint8_t imm_ass[23]; + int rc; + + LOGP(DRLCMAC, LOGL_INFO, "TX: START TFI: %u TLLI: 0x%08x Immediate Assignment Downlink (PCH)\n", tbf->tfi, tbf->tlli); + /* use request reference that has maximum distance to current time, + * so the assignment will not conflict with possible RACH requests. */ + rc = write_immediate_assignment_downlink(imm_ass, 125, (tbf->pdch[tbf->first_ts]->last_rts_fn + 21216) % 2715648, tbf->ta, tbf->arfcn, tbf->first_ts, tbf->tsc, tbf->tfi, tbf->tlli, poll, tbf->poll_fn); + if (rc < 0) + return; + + pcu_l1if_tx_pch(imm_ass, imsi); +} + +/* depending on the current TBF, we assign on PACCH or AGCH */ +void gprs_rlcmac_trigger_downlink_assignment(struct gprs_rlcmac_tbf *tbf, + struct gprs_rlcmac_tbf *old_tbf, char *imsi) +{ +#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_tbf) { +#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); +#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; + } + /* change state */ + tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN); + /* send immediate assignment */ + gprs_rlcmac_downlink_assignment(tbf, 0, imsi); + /* send immediate assignment */ + gprs_rlcmac_downlink_assignment(tbf, 0, imsi); + /* start timer */ + tbf_timer_start(tbf, 0, Tassign_agch); + } + } + -- cgit v1.2.3