tbf: Split out UL/DL TBF methods into separate files
tbf_ul.cpp for UL TBF methods
tbf_dl.cpp for DL TBF methods
This commit contains no code changes.
Ticket: SYS#389
Sponsored by: On-Waves ehf
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
new file mode 100644
index 0000000..8abea20
--- /dev/null
+++ b/src/tbf_dl.cpp
@@ -0,0 +1,671 @@
+/* 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>
+
+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;
+}
+
+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 {
+ /* 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);
+ }
+
+ 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;
+ uint32_t octets = 0, frames = 0;
+
+ gettimeofday(&tv_now, NULL);
+
+ while ((msg = m_llc.dequeue())) {
+ tv = (struct timeval *)msg->data;
+ msgb_pull(msg, sizeof(*tv));
+ msgb_pull(msg, sizeof(*tv));
+
+ if (gprs_llc::is_frame_expired(&tv_now, tv)) {
+ LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU "
+ "because lifetime limit reached. Queue size %zu\n",
+ tbf_name(this), m_llc.m_queue_size);
+ bts->llc_timedout_frame();
+ 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, 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, false);
+ }
+
+ /* if the window has stalled, or transfer is complete,
+ * send an unacknowledged block */
+ if (state_is(GPRS_RLCMAC_FINISHED) || dl_window_stalled()) {
+ 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 {
+ LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, "
+ "because all window is stalled.\n",
+ m_window.v_a());
+ bts->rlc_stalled();
+ }
+ /* 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, false);
+ }
+
+ /* 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, false);
+ }
+ goto do_resend;
+ }
+
+ return create_new_bsn(fn, ts);
+}
+
+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;
+ bool first_fin_ack = false;
+ 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) {
+ 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)) {
+ 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 */
+ 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);
+ }
+ /* if we have more data and we have space left */
+ if (space > 0 && m_llc.frame_length()) {
+ li->m = 1; /* we indicate more frames to follow */
+ continue;
+ }
+ /* if we don't have more LLC frames */
+ if (!m_llc.frame_length()) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we "
+ "done.\n");
+ li->e = 1; /* we cannot extend */
+ rh->fbi = 1; /* we indicate final block */
+ first_fin_ack = true;
+ /* + 1 indicates: first final 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, first_fin_ack);
+}
+
+struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
+ const uint32_t fn, const uint8_t ts,
+ const int index, const bool first_fin_ack)
+{
+ uint8_t *data;
+ struct rlc_dl_header *rh;
+ struct msgb *dl_msg;
+ uint8_t len;
+
+ /* 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;
+
+ /* 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 || first_fin_ack) {
+ if (first_fin_ack) {
+ LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
+ "polling, because first final block sent.\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);
+#warning "What happens to the first_fin_ack in case something is already scheduled?"
+ 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;
+
+ /* set polling in header */
+ rh->rrbp = 0; /* N+13 */
+ rh->s_p = 1; /* Polling */
+ }
+ }
+
+ /* 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)
+{
+ bts->tbf_reused();
+ m_llc.put_frame(data, len);
+ bts->llc_frame_sched();
+
+ /* 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(this, this, NULL);
+}
+
+bool gprs_rlcmac_dl_tbf::dl_window_stalled() const
+{
+ return m_window.window_stalled();
+}
+