/* Copied from tbf.cpp * * Copyright (C) 2012 Ivan Klyuchnikov * Copyright (C) 2012 Andreas Eversberg * Copyright (C) 2013 by Holger Hans Peter Freyther * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include #include #include #include "pcu_utils.h" extern "C" { #include #include } #include #include /* After sending these frames, we poll for ack/nack. */ #define POLL_ACK_AFTER_FRAMES 20 static const struct gprs_rlcmac_cs gprs_rlcmac_cs[] = { /* frame length data block max payload */ { 0, 0, 0 }, { 23, 23, 20 }, /* CS-1 */ { 34, 33, 30 }, /* CS-2 */ { 40, 39, 36 }, /* CS-3 */ { 54, 53, 50 }, /* CS-4 */ }; extern "C" { int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli, uint8_t num_frames, uint32_t num_octets); } static inline void tbf_update_ms_class(struct gprs_rlcmac_tbf *tbf, const uint8_t ms_class) { if (!tbf->ms_class() && ms_class) tbf->set_ms_class(ms_class); } static void llc_timer_cb(void *_tbf) { struct gprs_rlcmac_dl_tbf *tbf = (struct gprs_rlcmac_dl_tbf *)_tbf; if (tbf->state_is_not(GPRS_RLCMAC_FLOW)) return; LOGP(DRLCMAC, LOGL_DEBUG, "%s LLC receive timeout, requesting DL ACK\n", tbf_name(tbf)); tbf->request_dl_ack(); } void gprs_rlcmac_dl_tbf::cleanup() { osmo_timer_del(&m_llc_timer); } void gprs_rlcmac_dl_tbf::start_llc_timer() { if (bts_data()->llc_idle_ack_csec > 0) { struct timeval tv; /* TODO: this ought to be within a constructor */ m_llc_timer.data = this; m_llc_timer.cb = &llc_timer_cb; csecs_to_timeval(bts_data()->llc_idle_ack_csec, &tv); osmo_timer_schedule(&m_llc_timer, tv.tv_sec, tv.tv_usec); } } int gprs_rlcmac_dl_tbf::append_data(const uint8_t ms_class, const uint16_t pdu_delay_csec, const uint8_t *data, const uint16_t len) { LOGP(DRLCMAC, LOGL_INFO, "%s append\n", tbf_name(this)); gprs_llc_queue::MetaInfo info; struct msgb *llc_msg = msgb_alloc(len, "llc_pdu_queue"); if (!llc_msg) return -ENOMEM; gprs_llc_queue::calc_pdu_lifetime(bts, pdu_delay_csec, &info.expire_time); gettimeofday(&info.recv_time, NULL); memcpy(msgb_put(llc_msg, len), data, len); llc_queue()->enqueue(llc_msg, &info); tbf_update_ms_class(this, ms_class); start_llc_timer(); if (state_is(GPRS_RLCMAC_WAIT_RELEASE)) { LOGP(DRLCMAC, LOGL_DEBUG, "%s in WAIT RELEASE state " "(T3193), so reuse TBF\n", tbf_name(this)); tbf_update_ms_class(this, ms_class); reuse_tbf(); } return 0; } static struct gprs_rlcmac_dl_tbf *tbf_lookup_dl(BTS *bts, const uint32_t tlli, const uint32_t tlli_old, const char *imsi) { GprsMs *ms = bts->ms_store().get_ms(tlli, tlli_old, imsi); if (!ms) return NULL; return ms->dl_tbf(); } static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts, const char *imsi, const uint32_t tlli, const uint32_t tlli_old, const uint8_t ms_class, struct gprs_rlcmac_dl_tbf **tbf) { uint8_t trx, ss; int8_t use_trx; uint16_t ta = 0; struct gprs_rlcmac_ul_tbf *ul_tbf = NULL, *old_ul_tbf; struct gprs_rlcmac_dl_tbf *dl_tbf = NULL; int8_t tfi; /* must be signed */ GprsMs *ms; /* check for uplink data, so we copy our informations */ #warning "Do the same look up for IMSI, TLLI and OLD_TLLI" #warning "Refactor the below lines... into a new method" ms = bts->bts->ms_store().get_ms(tlli, tlli_old, imsi); if (ms) { ul_tbf = ms->ul_tbf(); ta = ms->ta(); } if (ul_tbf && ul_tbf->m_contention_resolution_done && !ul_tbf->m_final_ack_sent) { use_trx = ul_tbf->trx->trx_no; ss = 0; old_ul_tbf = ul_tbf; } else { use_trx = -1; ss = 1; /* PCH assignment only allows one timeslot */ old_ul_tbf = NULL; } // Create new TBF (any TRX) #warning "Copy and paste with alloc_ul_tbf" tfi = bts->bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, use_trx); if (tfi >= 0) /* set number of downlink slots according to multislot class */ dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf, tfi, trx, ms_class, ss); if (!dl_tbf) { LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); return -EBUSY; } dl_tbf->update_ms(tlli, GPRS_RLCMAC_DL_TBF); dl_tbf->ms()->set_ta(ta); LOGP(DRLCMAC, LOGL_DEBUG, "%s [DOWNLINK] START\n", tbf_name(dl_tbf)); /* Store IMSI for later look-up and PCH retransmission */ dl_tbf->assign_imsi(imsi); /* trigger downlink assignment and set state to ASSIGN. * we don't use old_downlink, so the possible uplink is used * to trigger downlink assignment. if there is no uplink, * AGCH is used. */ dl_tbf->bts->trigger_dl_ass(dl_tbf, old_ul_tbf); *tbf = dl_tbf; return 0; } /** * TODO: split into unit test-able parts... */ int gprs_rlcmac_dl_tbf::handle(struct gprs_rlcmac_bts *bts, const uint32_t tlli, const uint32_t tlli_old, const char *imsi, const uint8_t ms_class, const uint16_t delay_csec, const uint8_t *data, const uint16_t len) { struct gprs_rlcmac_dl_tbf *dl_tbf; int rc; GprsMs *ms; /* check for existing TBF */ dl_tbf = tbf_lookup_dl(bts->bts, tlli, tlli_old, imsi); if (!dl_tbf) { rc = tbf_new_dl_assignment(bts, imsi, tlli, tlli_old, ms_class, &dl_tbf); if (rc < 0) return rc; } OSMO_ASSERT(dl_tbf->ms() != NULL); ms = dl_tbf->ms(); GprsMs::Guard guard(ms); rc = dl_tbf->append_data(ms_class, delay_csec, data, len); dl_tbf = ms->dl_tbf(); dl_tbf->assign_imsi(imsi); ms->confirm_tlli(tlli); return rc; } struct msgb *gprs_rlcmac_dl_tbf::llc_dequeue(bssgp_bvc_ctx *bctx) { struct msgb *msg; struct timeval tv_now, tv_now2; uint32_t octets = 0, frames = 0; struct timeval hyst_delta = {0, 0}; const unsigned keep_small_thresh = 60; const gprs_llc_queue::MetaInfo *info; if (bts_data()->llc_discard_csec) csecs_to_timeval(bts_data()->llc_discard_csec, &hyst_delta); gettimeofday(&tv_now, NULL); timeradd(&tv_now, &hyst_delta, &tv_now2); while ((msg = llc_queue()->dequeue(&info))) { const struct timeval *tv_disc = &info->expire_time; const struct timeval *tv_recv = &info->recv_time; gprs_bssgp_update_queue_delay(tv_recv, &tv_now); /* Is the age below the low water mark? */ if (!gprs_llc_queue::is_frame_expired(&tv_now2, tv_disc)) break; /* Is the age below the high water mark */ if (!gprs_llc_queue::is_frame_expired(&tv_now, tv_disc)) { /* Has the previous message not been dropped? */ if (frames == 0) break; /* Hysteresis mode, try to discard LLC messages until * the low water mark has been reached */ /* Check whether to abort the hysteresis mode */ /* Is the frame small, perhaps only a TCP ACK? */ if (msg->len <= keep_small_thresh) break; /* Is it a GMM message? */ if (!gprs_llc::is_user_data_frame(msg->data, msg->len)) break; } bts->llc_timedout_frame(); frames++; octets += msg->len; msgb_free(msg); bts->llc_dropped_frame(); continue; } if (frames) { LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU " "because lifetime limit reached, " "count=%u new_queue_size=%zu\n", tbf_name(this), frames, llc_queue()->size()); if (frames > 0xff) frames = 0xff; if (octets > 0xffffff) octets = 0xffffff; bssgp_tx_llc_discarded(bctx, tlli(), frames, octets); } return msg; } /* * Create DL data block * The messages are fragmented and forwarded as data blocks. */ struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(uint32_t fn, uint8_t ts) { LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink (V(A)==%d .. " "V(S)==%d)\n", tbf_name(this), m_window.v_a(), m_window.v_s()); do_resend: /* check if there is a block with negative acknowledgement */ int resend_bsn = m_window.resend_needed(); if (resend_bsn >= 0) { LOGP(DRLCMACDL, LOGL_DEBUG, "- Resending BSN %d\n", resend_bsn); /* re-send block with negative aknowlegement */ m_window.m_v_b.mark_unacked(resend_bsn); bts->rlc_resent(); return create_dl_acked_block(fn, ts, resend_bsn); } /* if the window has stalled, or transfer is complete, * send an unacknowledged block */ if (state_is(GPRS_RLCMAC_FINISHED)) { LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, " "because all blocks have been transmitted.\n", m_window.v_a()); bts->rlc_restarted(); } else if (dl_window_stalled()) { LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, " "because all window is stalled.\n", m_window.v_a()); bts->rlc_stalled(); } else if (have_data()) { /* New blocks may be send */ return create_new_bsn(fn, ts); } else if (!m_window.window_empty()) { LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, " "because all blocks have been transmitted (FLOW).\n", m_window.v_a()); bts->rlc_restarted(); } else { /* Nothing left to send, create dummy LLC commands */ return create_new_bsn(fn, ts); } /* 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 (m_window.window_empty()) { LOGP(DRLCMACDL, LOGL_DEBUG, "- MS acked all blocks, " "so we re-transmit final block!\n"); /* we just send final block again */ int16_t index = m_window.v_s_mod(-1); bts->rlc_resent(); return create_dl_acked_block(fn, ts, index); } /* cycle through all unacked blocks */ int resend = m_window.mark_for_resend(); /* At this point there should be at least 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 */ int16_t index = m_window.v_s_mod(-1); return create_dl_acked_block(fn, ts, index); } goto do_resend; } void gprs_rlcmac_dl_tbf::schedule_next_frame() { struct msgb *msg; if (m_llc.frame_length() != 0) return; /* dequeue next LLC frame, if any */ msg = llc_dequeue(gprs_bssgp_pcu_current_bctx()); if (!msg) return; LOGP(DRLCMACDL, LOGL_INFO, "- Dequeue next LLC for %s (len=%d)\n", tbf_name(this), msg->len); m_llc.put_frame(msg->data, msg->len); bts->llc_frame_sched(); msgb_free(msg); m_last_dl_drained_fn = -1; } struct msgb *gprs_rlcmac_dl_tbf::create_new_bsn(const uint32_t fn, const uint8_t ts) { struct rlc_dl_header *rh; struct rlc_li_field *li; uint8_t *delimiter, *data, *e_pointer; uint16_t space, chunk; gprs_rlc_data *rlc_data; const uint16_t bsn = m_window.v_s(); uint8_t cs = 1; if (m_llc.frame_length() == 0) schedule_next_frame(); cs = current_cs(); LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d, CS=%d\n", m_window.v_s(), cs); OSMO_ASSERT(cs >= 1); OSMO_ASSERT(cs <= 4); /* total length of block, including spare bits */ const uint8_t block_length = gprs_rlcmac_cs[cs].block_length; /* length of usable data of block, w/o spare bits, inc. MAC */ const uint8_t block_data_len = gprs_rlcmac_cs[cs].block_data; /* now we still have untransmitted LLC data, so we fill mac block */ rlc_data = m_rlc.block(bsn); data = rlc_data->prepare(block_data_len); rlc_data->cs = cs; 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 = m_tfi; /* TFI */ rh->fbi = 0; /* Final Block Indicator, set late, if true */ rh->bsn = bsn; /* Block Sequence Number */ rh->e = 0; /* Extension bit, maybe set later */ e_pointer = data + 2; /* points to E of current chunk */ data += sizeof(*rh); delimiter = data; /* where next length header would be stored */ space = block_data_len - sizeof(*rh); while (1) { if (m_llc.frame_length() == 0) { /* A header will need to by added, so we just need * space-1 octets */ m_llc.put_dummy_frame(space - 1); /* The data just drained, store the current fn */ if (m_last_dl_drained_fn < 0) m_last_dl_drained_fn = fn; /* It is not clear, when the next real data will * arrive, so request a DL ack/nack now */ request_dl_ack(); LOGP(DRLCMACDL, LOGL_DEBUG, "-- Empty chunk, " "added LLC dummy command of size %d, " "drained_since=%d\n", m_llc.frame_length(), frames_since_last_drain(fn)); } chunk = m_llc.chunk_size(); /* 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 */ m_llc.consume(data, space); /* return data block as message */ break; } /* if FINAL chunk would fit precisely in space left */ if (chunk == space && llc_queue()->size() == 0 && !keep_open(fn)) { 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 " "%s that fits precisely in last block: " "len=%d\n", tbf_name(this), m_llc.frame_length()); gprs_rlcmac_dl_bw(this, m_llc.frame_length()); /* block is filled, so there is no extension */ *e_pointer |= 0x01; /* fill space */ m_llc.consume(data, space); m_llc.reset(); /* final block */ rh->fbi = 1; /* we indicate final block */ request_dl_ack(); set_state(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) memmove(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 */ m_llc.consume(data, 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) memmove(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 and reset later */ m_llc.consume(data, chunk); data += chunk; space -= chunk; LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for %s" "len=%d\n", tbf_name(this), m_llc.frame_length()); gprs_rlcmac_dl_bw(this, m_llc.frame_length()); m_llc.reset(); /* dequeue next LLC frame, if any */ schedule_next_frame(); /* if we have more data and we have space left */ if (space > 0 && (m_llc.frame_length() || keep_open(fn))) { li->m = 1; /* we indicate more frames to follow */ continue; } /* if we don't have more LLC frames */ if (!m_llc.frame_length() && !keep_open(fn)) { LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we " "done.\n"); li->e = 1; /* we cannot extend */ rh->fbi = 1; /* we indicate final block */ request_dl_ack(); set_state(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(rlc_data->block, block_length)); #warning "move this up?" rlc_data->len = block_length; /* raise send state and set ack state array */ m_window.m_v_b.mark_unacked(bsn); m_window.increment_send(); return create_dl_acked_block(fn, ts, bsn); } struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block( const uint32_t fn, const uint8_t ts, const int index) { uint8_t *data; struct rlc_dl_header *rh; struct msgb *dl_msg; uint8_t len; bool need_poll; /* get data and header from current block */ data = m_rlc.block(index)->block; len = m_rlc.block(index)->len; rh = (struct rlc_dl_header *)data; /* If the TBF has just started, relate frames_since_last_poll to the * current fn */ if (m_last_dl_poll_fn < 0) m_last_dl_poll_fn = fn; need_poll = state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK); /* 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 (m_tx_counter >= POLL_ACK_AFTER_FRAMES || m_dl_ack_requested || need_poll) { if (m_dl_ack_requested) { LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack " "polling, because is was requested explicitly " "(e.g. first final block sent).\n"); } else if (need_poll) { LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack " "polling, because polling timed out.\n"); } else { LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack " "polling, because %d blocks sent.\n", POLL_ACK_AFTER_FRAMES); } /* scheduling not possible, because: */ if (poll_state != GPRS_RLCMAC_POLL_NONE) LOGP(DRLCMACDL, LOGL_DEBUG, "Polling is already " "sheduled for %s, so we must wait for " "requesting downlink ack\n", tbf_name(this)); else if (control_ts != ts) LOGP(DRLCMACDL, LOGL_DEBUG, "Polling cannot be " "sheduled in this TS %d, waiting for " "TS %d\n", ts, control_ts); else if (bts->sba()->find(trx->trx_no, ts, (fn + 13) % 2715648)) LOGP(DRLCMACDL, LOGL_DEBUG, "Polling cannot be " "sheduled, because single block alllocation " "already exists\n"); else { LOGP(DRLCMACDL, LOGL_DEBUG, "Polling sheduled in this " "TS %d\n", ts); m_tx_counter = 0; /* start timer whenever we send the final block */ if (rh->fbi == 1) tbf_timer_start(this, 3191, bts_data()->t3191, 0); /* schedule polling */ poll_state = GPRS_RLCMAC_POLL_SCHED; poll_fn = (fn + 13) % 2715648; /* Clear poll timeout flag */ state_flags &= ~(1 << GPRS_RLCMAC_FLAG_TO_DL_ACK); /* Clear request flag */ m_dl_ack_requested = false; /* set polling in header */ rh->rrbp = 0; /* N+13 */ rh->s_p = 1; /* Polling */ m_last_dl_poll_fn = poll_fn; } } /* return data block as message */ dl_msg = msgb_alloc(len, "rlcmac_dl_data"); if (!dl_msg) return NULL; /* Increment TX-counter */ m_tx_counter++; memcpy(msgb_put(dl_msg, len), data, len); bts->rlc_sent(); return dl_msg; } static uint16_t bitnum_to_bsn(int bitnum, uint16_t ssn, uint16_t mod_sns) { return (ssn - 1 - bitnum) & mod_sns; } int gprs_rlcmac_dl_tbf::analyse_errors(char *show_rbb, uint8_t ssn) { gprs_rlc_data *rlc_data; uint16_t lost = 0, received = 0, skipped = 0; char info[65]; memset(info, '.', sizeof(info)); info[64] = 0; uint16_t bsn = 0; /* SSN - 1 is in range V(A)..V(S)-1 */ for (int bitpos = 0; bitpos < m_window.ws(); bitpos++) { bsn = bitnum_to_bsn(bitpos, ssn, m_window.mod_sns()); if (bsn == ((m_window.v_a() - 1) & m_window.mod_sns())) { info[bitpos] = '$'; break; } rlc_data = m_rlc.block(bsn); if (!rlc_data) { info[bitpos] = '0'; continue; } if (rlc_data->cs != current_cs()) { /* This block has already been encoded with a different * CS, so it doesn't help us to decide, whether the * current CS is ok. Ignore it. */ info[bitpos] = 'x'; skipped += 1; continue; } if (show_rbb[m_window.ws() - 1 - bitpos] == 'R') { if (!m_window.m_v_b.is_acked(bsn)) { received += 1; info[bitpos] = 'R'; } else { info[bitpos] = 'r'; } } else { info[bitpos] = 'L'; lost += 1; } } LOGP(DRLCMACDL, LOGL_DEBUG, "%s DL analysis, range=%d:%d, lost=%d, recv=%d, " "skipped=%d, bsn=%d, info='%s'\n", name(), m_window.v_a(), m_window.v_s(), lost, received, skipped, bsn, info); if (lost + received <= 1) return -1; return lost * 100 / (lost + received); } int gprs_rlcmac_dl_tbf::update_window(const uint8_t ssn, const uint8_t *rbb) { int16_t dist; /* must be signed */ uint16_t lost = 0, received = 0; char show_rbb[65]; char show_v_b[RLC_MAX_SNS + 1]; const uint16_t mod_sns = m_window.mod_sns(); int error_rate; Decoding::extract_rbb(rbb, show_rbb); /* show received array in debug (bit 64..1) */ LOGP(DRLCMACDL, LOGL_DEBUG, "- ack: (BSN=%d)\"%s\"" "(BSN=%d) R=ACK I=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 = (m_window.v_s() - ssn) & mod_sns; /* check if distance is less than distance V(A)..V(S) */ if (dist >= m_window.distance()) { /* 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 %s Free TBF!\n", tbf_name(this)); return 1; /* indicate to free TBF */ } if (bts_data()->cs_adj_enabled && ms()) { error_rate = analyse_errors(show_rbb, ssn); ms()->update_error_rate(this, error_rate); } m_window.update(bts, show_rbb, ssn, &lost, &received); /* report lost and received packets */ gprs_rlcmac_received_lost(this, received, lost); /* raise V(A), if possible */ m_window.raise(m_window.move_window()); /* show receive state array in debug (V(A)..V(S)-1) */ m_window.show_state(show_v_b); LOGP(DRLCMACDL, LOGL_DEBUG, "- V(B): (V(A)=%d)\"%s\"" "(V(S)-1=%d) A=Acked N=Nacked U=Unacked " "X=Resend-Unacked I=Invalid\n", m_window.v_a(), show_v_b, m_window.v_s_mod(-1)); if (state_is(GPRS_RLCMAC_FINISHED) && m_window.window_empty()) { LOGP(DRLCMACDL, LOGL_NOTICE, "Received acknowledge of " "all blocks, but without final ack " "inidcation (don't worry)\n"); } return 0; } int gprs_rlcmac_dl_tbf::maybe_start_new_window() { uint16_t received; LOGP(DRLCMACDL, LOGL_DEBUG, "- Final ACK received.\n"); /* range V(A)..V(S)-1 */ received = m_window.count_unacked(); /* report all outstanding packets as received */ gprs_rlcmac_received_lost(this, received, 0); set_state(GPRS_RLCMAC_WAIT_RELEASE); /* check for LLC PDU in the LLC Queue */ if (!have_data()) { /* no message, start T3193, change state to RELEASE */ LOGP(DRLCMACDL, LOGL_DEBUG, "- No new message, so we release.\n"); /* start T3193 */ tbf_timer_start(this, 3193, bts_data()->t3193_msec / 1000, (bts_data()->t3193_msec % 1000) * 1000); return 0; } /* we have more data so we will re-use this tbf */ reuse_tbf(); return 0; } int gprs_rlcmac_dl_tbf::rcvd_dl_ack(uint8_t final_ack, uint8_t ssn, uint8_t *rbb) { LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink acknowledge\n", tbf_name(this)); if (!final_ack) return update_window(ssn, rbb); return maybe_start_new_window(); } void gprs_rlcmac_dl_tbf::reuse_tbf() { uint8_t trx; struct gprs_rlcmac_dl_tbf *new_tbf = NULL; int8_t tfi; /* must be signed */ bts->tbf_reused(); tfi = bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, this->trx->trx_no); if (tfi >= 0) new_tbf = tbf_alloc_dl_tbf(bts->bts_data(), NULL, tfi, trx, ms_class(), 0); if (!new_tbf) { LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); return; } new_tbf->set_ms(ms()); /* reset rlc states */ m_tx_counter = 0; m_wait_confirm = 0; m_window.reset(); /* keep to flags */ state_flags &= GPRS_RLCMAC_FLAG_TO_MASK; state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH); update(); LOGP(DRLCMAC, LOGL_DEBUG, "%s Trigger dowlink assignment on PACCH, " "because another LLC PDU has arrived in between\n", tbf_name(this)); bts->trigger_dl_ass(new_tbf, this); } bool gprs_rlcmac_dl_tbf::dl_window_stalled() const { return m_window.window_stalled(); } void gprs_rlcmac_dl_tbf::request_dl_ack() { m_dl_ack_requested = true; } bool gprs_rlcmac_dl_tbf::need_control_ts() const { if (poll_state != GPRS_RLCMAC_POLL_NONE) return false; return state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK) || m_tx_counter >= POLL_ACK_AFTER_FRAMES || m_dl_ack_requested; } bool gprs_rlcmac_dl_tbf::have_data() const { return m_llc.chunk_size() > 0 || (llc_queue() && llc_queue()->size() > 0); } int gprs_rlcmac_dl_tbf::frames_since_last_poll(unsigned fn) const { unsigned wrapped; if (m_last_dl_poll_fn < 0) return -1; wrapped = (fn + 2715648 - m_last_dl_poll_fn) % 2715648; if (wrapped < 2715648/2) return wrapped; else return wrapped - 2715648; } int gprs_rlcmac_dl_tbf::frames_since_last_drain(unsigned fn) const { unsigned wrapped; if (m_last_dl_drained_fn < 0) return -1; wrapped = (fn + 2715648 - m_last_dl_drained_fn) % 2715648; if (wrapped < 2715648/2) return wrapped; else return wrapped - 2715648; } bool gprs_rlcmac_dl_tbf::keep_open(unsigned fn) const { int keep_time_frames; if (bts_data()->dl_tbf_idle_msec <= 0) return false; keep_time_frames = msecs_to_frames(bts_data()->dl_tbf_idle_msec); return frames_since_last_drain(fn) <= keep_time_frames; }