| /* Copied from tbf.cpp |
| * |
| * Copyright (C) 2012 Ivan Klyuchnikov |
| * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu> |
| * 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 <bts.h> |
| #include <tbf.h> |
| #include <rlc.h> |
| #include <gprs_rlcmac.h> |
| #include <gprs_debug.h> |
| #include <gprs_bssgp_pcu.h> |
| #include <decoding.h> |
| |
| #include "pcu_utils.h" |
| |
| extern "C" { |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/talloc.h> |
| } |
| |
| #include <errno.h> |
| #include <string.h> |
| |
| /* 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->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)); |
| 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(data, len); |
| } else if (!have_data()) { |
| m_llc.put_frame(data, len); |
| m_last_dl_drained_fn = -1; |
| bts->llc_frame_sched(); |
| /* it is no longer drained */ |
| m_last_dl_drained_fn = -1; |
| tbf_update_ms_class(this, ms_class); |
| start_llc_timer(); |
| } else { |
| /* TODO: put this path into an llc_enqueue method */ |
| /* the TBF exists, so we must write it in the queue |
| * we prepend lifetime in front of PDU */ |
| struct timeval *tv; |
| struct msgb *llc_msg = msgb_alloc(len + sizeof(*tv) * 2, |
| "llc_pdu_queue"); |
| if (!llc_msg) |
| return -ENOMEM; |
| tv = (struct timeval *)msgb_put(llc_msg, sizeof(*tv)); |
| gprs_llc::calc_pdu_lifetime(bts, pdu_delay_csec, tv); |
| tv = (struct timeval *)msgb_put(llc_msg, sizeof(*tv)); |
| gettimeofday(tv, NULL); |
| memcpy(msgb_put(llc_msg, len), data, len); |
| m_llc.enqueue(llc_msg); |
| tbf_update_ms_class(this, ms_class); |
| start_llc_timer(); |
| } |
| |
| return 0; |
| } |
| |
| static struct gprs_rlcmac_dl_tbf *tbf_lookup_dl(BTS *bts, |
| const uint32_t tlli, const char *imsi) |
| { |
| /* TODO: look up by IMSI first, then tlli, then old_tlli */ |
| return bts->dl_tbf_by_tlli(tlli); |
| } |
| |
| static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts, |
| const char *imsi, |
| const uint32_t tlli, const uint8_t ms_class, |
| const uint8_t *data, const uint16_t len) |
| { |
| uint8_t trx, ta, ss; |
| int8_t use_trx; |
| struct gprs_rlcmac_ul_tbf *ul_tbf, *old_ul_tbf; |
| struct gprs_rlcmac_dl_tbf *dl_tbf; |
| int8_t tfi; /* must be signed */ |
| int rc; |
| |
| /* 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" |
| ul_tbf = bts->bts->ul_tbf_by_tlli(tlli); |
| if (ul_tbf && ul_tbf->m_contention_resolution_done |
| && !ul_tbf->m_final_ack_sent) { |
| use_trx = ul_tbf->trx->trx_no; |
| ta = ul_tbf->ta; |
| ss = 0; |
| old_ul_tbf = ul_tbf; |
| } else { |
| use_trx = -1; |
| /* we already have an uplink TBF, so we use that TA */ |
| if (ul_tbf) |
| ta = ul_tbf->ta; |
| else { |
| /* recall TA */ |
| rc = bts->bts->timing_advance()->recall(tlli); |
| if (rc < 0) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "TA unknown" |
| ", assuming 0\n"); |
| ta = 0; |
| } else |
| ta = rc; |
| } |
| 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) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); |
| /* FIXME: send reject */ |
| return -EBUSY; |
| } |
| /* 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"); |
| /* FIXME: send reject */ |
| return -EBUSY; |
| } |
| dl_tbf->m_tlli = tlli; |
| dl_tbf->m_tlli_valid = 1; |
| dl_tbf->ta = ta; |
| |
| LOGP(DRLCMAC, LOGL_DEBUG, "%s [DOWNLINK] START\n", tbf_name(dl_tbf)); |
| |
| /* new TBF, so put first frame */ |
| dl_tbf->m_llc.put_frame(data, len); |
| dl_tbf->bts->llc_frame_sched(); |
| |
| /* 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, imsi); |
| 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 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; |
| |
| /* check for existing TBF */ |
| dl_tbf = tbf_lookup_dl(bts->bts, tlli, imsi); |
| if (dl_tbf) { |
| int rc = dl_tbf->append_data(ms_class, delay_csec, data, len); |
| if (rc >= 0) |
| dl_tbf->assign_imsi(imsi); |
| return rc; |
| } |
| |
| return tbf_new_dl_assignment(bts, imsi, tlli, ms_class, data, len); |
| } |
| |
| struct msgb *gprs_rlcmac_dl_tbf::llc_dequeue(bssgp_bvc_ctx *bctx) |
| { |
| struct msgb *msg; |
| struct timeval *tv, tv_now, tv_now2; |
| uint32_t octets = 0, frames = 0; |
| struct timeval hyst_delta = {0, 0}; |
| const unsigned keep_small_thresh = 60; |
| |
| 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 = m_llc.dequeue())) { |
| tv = (struct timeval *)msg->data; |
| msgb_pull(msg, sizeof(*tv)); |
| msgb_pull(msg, sizeof(*tv)); |
| |
| /* Is the age below the low water mark? */ |
| if (!gprs_llc::is_frame_expired(&tv_now2, tv)) |
| break; |
| |
| /* Is the age below the high water mark */ |
| if (!gprs_llc::is_frame_expired(&tv_now, tv)) { |
| /* 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); |
| 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, m_llc.m_queue_size); |
| if (frames > 0xff) |
| frames = 0xff; |
| if (octets > 0xffffff) |
| octets = 0xffffff; |
| bssgp_tx_llc_discarded(bctx, m_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; |
| } |
| |
| 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; |
| struct msgb *msg; |
| uint8_t *delimiter, *data, *e_pointer; |
| uint16_t space, chunk; |
| gprs_rlc_data *rlc_data; |
| const uint16_t bsn = m_window.v_s(); |
| |
| LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d\n", |
| m_window.v_s()); |
| |
| #warning "Selection of the CS doesn't belong here" |
| if (cs == 0) { |
| cs = bts_data()->initial_cs_dl; |
| if (cs < 1 || cs > 4) |
| cs = 1; |
| } |
| /* 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); |
| |
| 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 && llist_empty(&m_llc.queue) && !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 */ |
| msg = llc_dequeue(gprs_bssgp_pcu_current_bctx()); |
| if (msg) { |
| 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; |
| } |
| /* 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; |
| } |
| |
| 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(); |
| |
| 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 */ |
| } |
| |
| 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() |
| { |
| struct msgb *msg; |
| 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 */ |
| msg = llc_dequeue(gprs_bssgp_pcu_current_bctx()); |
| if (!msg) { |
| /* 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(msg->data, msg->len); |
| msgb_free(msg); |
| 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(const uint8_t *data, const uint16_t len) |
| { |
| uint8_t trx; |
| struct gprs_rlcmac_dl_tbf *new_tbf; |
| int8_t tfi; /* must be signed */ |
| struct msgb *msg; |
| |
| bts->tbf_reused(); |
| |
| tfi = bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, this->trx->trx_no); |
| if (tfi < 0) { |
| LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n"); |
| /* FIXME: send reject */ |
| return; |
| } |
| 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"); |
| /* FIXME: send reject */ |
| return; |
| } |
| |
| new_tbf->m_tlli = m_tlli; |
| new_tbf->m_tlli_valid = m_tlli_valid; |
| new_tbf->ta = ta; |
| new_tbf->assign_imsi(m_imsi); |
| |
| /* Copy over all data to the new TBF */ |
| new_tbf->m_llc.put_frame(data, len); |
| bts->llc_frame_sched(); |
| |
| while ((msg = m_llc.dequeue())) |
| new_tbf->m_llc.enqueue(msg); |
| |
| /* reset rlc states */ |
| m_tx_counter = 0; |
| m_wait_confirm = 0; |
| m_window.reset(); |
| |
| /* mark TLLI as invalid */ |
| m_tlli_valid = 0; |
| |
| /* 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, NULL); |
| } |
| |
| 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 || !llist_empty(&m_llc.queue); |
| } |
| |
| 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; |
| } |