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_ul.cpp b/src/tbf_ul.cpp
new file mode 100644
index 0000000..3ab71f0
--- /dev/null
+++ b/src/tbf_ul.cpp
@@ -0,0 +1,418 @@
+/* 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 <encoding.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 receiving these frames, we send ack/nack. */
+#define SEND_ACK_AFTER_FRAMES 20
+
+extern void *tall_pcu_ctx;
+
+
+/*
+ * Store received block data in LLC message(s) and forward to SGSN
+ * if complete.
+ */
+int gprs_rlcmac_ul_tbf::assemble_forward_llc(const gprs_rlc_data *_data)
+{
+ const uint8_t *data = _data->block;
+ uint8_t len = _data->len;
+ const struct rlc_ul_header *rh = (const 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, "%s too many frames in "
+ "block\n", tbf_name(this));
+ 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, "%s UL DATA "
+ "ignored, because M='0' and E='0'.\n",
+ tbf_name(this));
+ 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, "%s UL DATA TLLI out of "
+ "frame border\n", tbf_name(this));
+ 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, "%s UL DATA PFI out of "
+ "frame border\n", tbf_name(this));
+ 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, "%s UL DATA ignored, "
+ "because LI delimits data that exceeds block size.\n",
+ tbf_name(this));
+ 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];
+ }
+ if (!m_llc.fits_in_current_frame(chunk)) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "%s LLC frame exceeds "
+ "maximum size %u.\n", tbf_name(this),
+ m_llc.remaining_space());
+ chunk = m_llc.remaining_space();
+ }
+ m_llc.append_frame(data + frame_offset[i], chunk);
+ m_llc.consume(chunk);
+ /* not last frame. */
+ if (i != frames - 1) {
+ /* send frame to SGSN */
+ LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame len=%d\n",
+ tbf_name(this) , m_llc.frame_length());
+ snd_ul_ud();
+ m_llc.reset();
+ /* 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, "%s complete UL frame "
+ "that fits precisely in last block: "
+ "len=%d\n", tbf_name(this), m_llc.frame_length());
+ snd_ul_ud();
+ m_llc.reset();
+ }
+ }
+
+ return 0;
+}
+
+
+struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn)
+{
+ int final = (state_is(GPRS_RLCMAC_FINISHED));
+ struct msgb *msg;
+
+ if (final) {
+ if (poll_state != GPRS_RLCMAC_POLL_NONE) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
+ "sheduled for %s, so we must wait for "
+ "final uplink ack...\n", tbf_name(this));
+ return NULL;
+ }
+ if (bts->sba()->find(trx->trx_no, control_ts, (fn + 13) % 2715648)) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
+ "scheduled for single block allocation...\n");
+ return NULL;
+ }
+ }
+
+ msg = msgb_alloc(23, "rlcmac_ul_ack");
+ if (!msg)
+ return NULL;
+ bitvec *ack_vec = bitvec_alloc(23);
+ if (!ack_vec) {
+ msgb_free(msg);
+ return NULL;
+ }
+ bitvec_unhex(ack_vec,
+ "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+ RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
+ Encoding::write_packet_uplink_ack(bts_data(), mac_control_block, this, final);
+ encode_gsm_rlcmac_downlink(ack_vec, mac_control_block);
+ bitvec_pack(ack_vec, msgb_put(msg, 23));
+ bitvec_free(ack_vec);
+ talloc_free(mac_control_block);
+
+ /* now we must set this flag, so we are allowed to assign downlink
+ * TBF on PACCH. it is only allowed when TLLI is acknowledged. */
+ m_contention_resolution_done = 1;
+
+ if (final) {
+ poll_state = GPRS_RLCMAC_POLL_SCHED;
+ poll_fn = (fn + 13) % 2715648;
+ /* waiting for final acknowledge */
+ ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK;
+ m_final_ack_sent = 1;
+ } else
+ ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
+
+ return msg;
+}
+
+int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged(const uint8_t *data, size_t len, int8_t rssi)
+{
+ struct rlc_ul_header *rh = (struct rlc_ul_header *)data;
+ int rc;
+
+ const uint16_t mod_sns = m_window.mod_sns();
+ const uint16_t ws = m_window.ws();
+
+ this->state_flags |= (1 << GPRS_RLCMAC_FLAG_UL_DATA);
+
+ LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TFI=%d received (V(Q)=%d .. "
+ "V(R)=%d)\n", rh->tfi, this->m_window.v_q(),
+ this->m_window.v_r());
+
+ /* process RSSI */
+ gprs_rlcmac_rssi(this, rssi);
+
+ /* get TLLI */
+ if (!this->is_tlli_valid()) {
+ if (!extract_tlli(data, len))
+ return 0;
+ /* already have TLLI, but we stille get another one */
+ } else if (rh->ti) {
+ uint32_t tlli;
+ rc = Decoding::tlli_from_ul_data(data, len, &tlli);
+ if (rc) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI "
+ "of UL DATA TFI=%d.\n", rh->tfi);
+ return 0;
+ }
+ if (tlli != this->tlli()) {
+ LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL "
+ "DATA TFI=%d. (Ignoring due to contention "
+ "resolution)\n", rh->tfi);
+ return 0;
+ }
+ }
+
+ /* restart T3169 */
+ tbf_timer_start(this, 3169, bts_data()->t3169, 0);
+
+ /* Increment RX-counter */
+ this->m_rx_counter++;
+
+ if (!m_window.is_in_window(rh->bsn)) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window "
+ "%d..%d (it's normal)\n", rh->bsn,
+ m_window.v_q(),
+ (m_window.v_q() + ws - 1) & mod_sns);
+ maybe_schedule_uplink_acknack(rh);
+ return 0;
+ }
+
+ /* Write block to buffer and set receive state array. */
+ m_rlc.block(rh->bsn)->put_data(data, len);
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n",
+ rh->bsn, m_window.v_q(),
+ (m_window.v_q() + ws - 1) & mod_sns);
+
+ /* 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.*/
+ const uint16_t v_q_beg = m_window.v_q();
+
+ const uint16_t count = m_window.receive_bsn(rh->bsn);
+
+ /* Retrieve LLC frames from blocks that are ready */
+ for (uint16_t i = 0; i < count; ++i) {
+ uint16_t index = (v_q_beg + i) & mod_sns;
+ assemble_forward_llc(m_rlc.block(index));
+ }
+
+ /* Check CV of last frame in buffer */
+ if (this->state_is(GPRS_RLCMAC_FLOW) /* still in flow state */
+ && this->m_window.v_q() == this->m_window.v_r()) { /* if complete */
+ struct rlc_ul_header *last_rh = (struct rlc_ul_header *)
+ m_rlc.block((m_window.v_r() - 1) & mod_sns)->block;
+ 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");
+ set_state(GPRS_RLCMAC_FINISHED);
+ /* Reset N3103 counter. */
+ this->m_n3103 = 0;
+ }
+ }
+
+ /* If TLLI is included or if we received half of the window, we send
+ * an ack/nack */
+ maybe_schedule_uplink_acknack(rh);
+
+ return 0;
+}
+
+void gprs_rlcmac_ul_tbf::maybe_schedule_uplink_acknack(const rlc_ul_header *rh)
+{
+ if (rh->si || rh->ti || state_is(GPRS_RLCMAC_FINISHED)
+ || (m_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 (state_is(GPRS_RLCMAC_FINISHED)) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
+ "because last block has CV==0.\n");
+ }
+ if ((m_rx_counter % SEND_ACK_AFTER_FRAMES) == 0) {
+ LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
+ "because %d frames received.\n",
+ SEND_ACK_AFTER_FRAMES);
+ }
+ if (ul_ack_state == GPRS_RLCMAC_UL_ACK_NONE) {
+ /* trigger sending at next RTS */
+ 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");
+ }
+ }
+}
+
+/* Send Uplink unit-data to SGSN. */
+int gprs_rlcmac_ul_tbf::snd_ul_ud()
+{
+ uint8_t qos_profile[3];
+ struct msgb *llc_pdu;
+ unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + m_llc.frame_length();
+ struct bssgp_bvc_ctx *bctx = gprs_bssgp_pcu_current_bctx();
+
+ LOGP(DBSSGP, LOGL_INFO, "LLC [PCU -> SGSN] %s len=%d\n", tbf_name(this), m_llc.frame_length());
+ if (!bctx) {
+ LOGP(DBSSGP, LOGL_ERROR, "No bctx\n");
+ m_llc.reset_frame_space();
+ return -EIO;
+ }
+
+ llc_pdu = msgb_alloc_headroom(msg_len, msg_len,"llc_pdu");
+ uint8_t *buf = msgb_push(llc_pdu, TL16V_GROSS_LEN(sizeof(uint8_t)*m_llc.frame_length()));
+ tl16v_put(buf, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*m_llc.frame_length(), m_llc.frame);
+ qos_profile[0] = QOS_PROFILE >> 16;
+ qos_profile[1] = QOS_PROFILE >> 8;
+ qos_profile[2] = QOS_PROFILE;
+ bssgp_tx_ul_ud(bctx, tlli(), qos_profile, llc_pdu);
+
+ m_llc.reset_frame_space();
+ return 0;
+}
+