419 lines
12 KiB
C++
419 lines
12 KiB
C++
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/* Copied from tbf.cpp
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*
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* Copyright (C) 2012 Ivan Klyuchnikov
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* Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
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* Copyright (C) 2013 by Holger Hans Peter Freyther
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <bts.h>
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#include <tbf.h>
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#include <rlc.h>
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#include <encoding.h>
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#include <gprs_rlcmac.h>
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#include <gprs_debug.h>
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#include <gprs_bssgp_pcu.h>
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#include <decoding.h>
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extern "C" {
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#include <osmocom/core/msgb.h>
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#include <osmocom/core/talloc.h>
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}
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#include <errno.h>
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#include <string.h>
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/* After receiving these frames, we send ack/nack. */
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#define SEND_ACK_AFTER_FRAMES 20
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extern void *tall_pcu_ctx;
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/*
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* Store received block data in LLC message(s) and forward to SGSN
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* if complete.
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*/
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int gprs_rlcmac_ul_tbf::assemble_forward_llc(const gprs_rlc_data *_data)
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{
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const uint8_t *data = _data->block;
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uint8_t len = _data->len;
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const struct rlc_ul_header *rh = (const struct rlc_ul_header *) data;
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uint8_t e, m;
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struct rlc_li_field *li;
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uint8_t frame_offset[16], offset = 0, chunk;
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int i, frames = 0;
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Assembling frames: (len=%d)\n", len);
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data += 3;
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len -= 3;
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e = rh->e; /* if extended */
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m = 1; /* more frames, that means: the first frame */
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/* Parse frame offsets from length indicator(s), if any. */
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while (1) {
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if (frames == (int)sizeof(frame_offset)) {
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LOGP(DRLCMACUL, LOGL_ERROR, "%s too many frames in "
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"block\n", tbf_name(this));
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return -EINVAL;
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}
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frame_offset[frames++] = offset;
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LOGP(DRLCMACUL, LOGL_DEBUG, "-- Frame %d starts at offset "
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"%d\n", frames, offset);
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if (!len)
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break;
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/* M == 0 and E == 0 is not allowed in this version. */
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if (!m && !e) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA "
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"ignored, because M='0' and E='0'.\n",
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tbf_name(this));
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return 0;
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}
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/* no more frames in this segment */
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if (e) {
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break;
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}
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/* There is a new frame and an LI that delimits it. */
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if (m) {
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li = (struct rlc_li_field *)data;
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LOGP(DRLCMACUL, LOGL_DEBUG, "-- Delimiter len=%d\n",
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li->li);
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/* Special case: LI == 0
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* If the last segment would fit precisely into the
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* rest of the RLC MAC block, there would be no way
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* to delimit that this segment ends and is not
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* continued in the next block.
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* The special LI (0) is used to force the segment to
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* extend into the next block, so it is delimited there.
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* This LI must be skipped. Also it is the last LI.
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*/
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if (li->li == 0) {
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data++;
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len--;
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m = 1; /* M is ignored, we know there is more */
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break; /* handle E as '1', so we break! */
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}
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e = li->e;
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m = li->m;
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offset += li->li;
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data++;
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len--;
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continue;
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}
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}
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if (!m) {
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Last frame carries spare "
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"data\n");
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}
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Data length after length fields: %d\n",
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len);
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/* TLLI */
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if (rh->ti) {
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if (len < 4) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA TLLI out of "
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"frame border\n", tbf_name(this));
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return -EINVAL;
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}
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data += 4;
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len -= 4;
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping TLLI: "
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"%d\n", len);
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}
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/* PFI */
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if (rh->pi) {
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LOGP(DRLCMACUL, LOGL_ERROR, "ERROR: PFI not supported, "
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"please disable in SYSTEM INFORMATION\n");
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if (len < 1) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA PFI out of "
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"frame border\n", tbf_name(this));
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return -EINVAL;
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}
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data++;
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len--;
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Length after skipping PFI: "
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"%d\n", len);
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}
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/* Now we have:
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* - a list of frames offsets: frame_offset[]
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* - number of frames: i
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* - m == 0: Last frame carries spare data (end of TBF).
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*/
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/* Check if last offset would exceed frame. */
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if (offset > len) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "%s UL DATA ignored, "
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"because LI delimits data that exceeds block size.\n",
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tbf_name(this));
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return -EINVAL;
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}
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/* create LLC frames */
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for (i = 0; i < frames; i++) {
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/* last frame ? */
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if (i == frames - 1) {
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/* no more data in last frame */
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if (!m)
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break;
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/* data until end of frame */
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chunk = len - frame_offset[i];
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} else {
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/* data until next frame */
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chunk = frame_offset[i + 1] - frame_offset[i];
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}
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if (!m_llc.fits_in_current_frame(chunk)) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "%s LLC frame exceeds "
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"maximum size %u.\n", tbf_name(this),
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m_llc.remaining_space());
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chunk = m_llc.remaining_space();
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}
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m_llc.append_frame(data + frame_offset[i], chunk);
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m_llc.consume(chunk);
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/* not last frame. */
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if (i != frames - 1) {
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/* send frame to SGSN */
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LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame len=%d\n",
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tbf_name(this) , m_llc.frame_length());
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snd_ul_ud();
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m_llc.reset();
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/* also check if CV==0, because the frame may fill up the
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* block precisely, then it is also complete. normally the
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* frame would be extended into the next block with a 0-length
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* delimiter added to this block. */
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} else if (rh->cv == 0) {
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/* send frame to SGSN */
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LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame "
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"that fits precisely in last block: "
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"len=%d\n", tbf_name(this), m_llc.frame_length());
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snd_ul_ud();
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m_llc.reset();
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}
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}
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return 0;
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}
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struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn)
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{
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int final = (state_is(GPRS_RLCMAC_FINISHED));
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struct msgb *msg;
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if (final) {
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if (poll_state != GPRS_RLCMAC_POLL_NONE) {
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LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
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"sheduled for %s, so we must wait for "
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"final uplink ack...\n", tbf_name(this));
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return NULL;
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}
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if (bts->sba()->find(trx->trx_no, control_ts, (fn + 13) % 2715648)) {
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LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
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"scheduled for single block allocation...\n");
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return NULL;
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}
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}
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msg = msgb_alloc(23, "rlcmac_ul_ack");
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if (!msg)
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return NULL;
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bitvec *ack_vec = bitvec_alloc(23);
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if (!ack_vec) {
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msgb_free(msg);
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return NULL;
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}
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bitvec_unhex(ack_vec,
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"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
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RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
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Encoding::write_packet_uplink_ack(bts_data(), mac_control_block, this, final);
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encode_gsm_rlcmac_downlink(ack_vec, mac_control_block);
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bitvec_pack(ack_vec, msgb_put(msg, 23));
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bitvec_free(ack_vec);
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talloc_free(mac_control_block);
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/* now we must set this flag, so we are allowed to assign downlink
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* TBF on PACCH. it is only allowed when TLLI is acknowledged. */
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m_contention_resolution_done = 1;
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if (final) {
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poll_state = GPRS_RLCMAC_POLL_SCHED;
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poll_fn = (fn + 13) % 2715648;
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/* waiting for final acknowledge */
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ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK;
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m_final_ack_sent = 1;
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} else
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ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
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return msg;
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}
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int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged(const uint8_t *data, size_t len, int8_t rssi)
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{
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struct rlc_ul_header *rh = (struct rlc_ul_header *)data;
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int rc;
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const uint16_t mod_sns = m_window.mod_sns();
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const uint16_t ws = m_window.ws();
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this->state_flags |= (1 << GPRS_RLCMAC_FLAG_UL_DATA);
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LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TFI=%d received (V(Q)=%d .. "
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"V(R)=%d)\n", rh->tfi, this->m_window.v_q(),
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this->m_window.v_r());
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/* process RSSI */
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gprs_rlcmac_rssi(this, rssi);
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/* get TLLI */
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if (!this->is_tlli_valid()) {
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if (!extract_tlli(data, len))
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return 0;
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/* already have TLLI, but we stille get another one */
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} else if (rh->ti) {
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uint32_t tlli;
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rc = Decoding::tlli_from_ul_data(data, len, &tlli);
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if (rc) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI "
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"of UL DATA TFI=%d.\n", rh->tfi);
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return 0;
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}
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if (tlli != this->tlli()) {
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LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL "
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"DATA TFI=%d. (Ignoring due to contention "
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"resolution)\n", rh->tfi);
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return 0;
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}
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}
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/* restart T3169 */
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tbf_timer_start(this, 3169, bts_data()->t3169, 0);
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/* Increment RX-counter */
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this->m_rx_counter++;
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if (!m_window.is_in_window(rh->bsn)) {
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LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window "
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"%d..%d (it's normal)\n", rh->bsn,
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m_window.v_q(),
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(m_window.v_q() + ws - 1) & mod_sns);
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maybe_schedule_uplink_acknack(rh);
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return 0;
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}
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/* Write block to buffer and set receive state array. */
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m_rlc.block(rh->bsn)->put_data(data, len);
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LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n",
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rh->bsn, m_window.v_q(),
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(m_window.v_q() + ws - 1) & mod_sns);
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/* Raise V(Q) if possible, and retrieve LLC frames from blocks.
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* This is looped until there is a gap (non received block) or
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* the window is empty.*/
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const uint16_t v_q_beg = m_window.v_q();
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const uint16_t count = m_window.receive_bsn(rh->bsn);
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/* Retrieve LLC frames from blocks that are ready */
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for (uint16_t i = 0; i < count; ++i) {
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uint16_t index = (v_q_beg + i) & mod_sns;
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assemble_forward_llc(m_rlc.block(index));
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}
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/* Check CV of last frame in buffer */
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if (this->state_is(GPRS_RLCMAC_FLOW) /* still in flow state */
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&& this->m_window.v_q() == this->m_window.v_r()) { /* if complete */
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struct rlc_ul_header *last_rh = (struct rlc_ul_header *)
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m_rlc.block((m_window.v_r() - 1) & mod_sns)->block;
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LOGP(DRLCMACUL, LOGL_DEBUG, "- No gaps in received block, "
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"last block: BSN=%d CV=%d\n", last_rh->bsn,
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last_rh->cv);
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if (last_rh->cv == 0) {
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LOGP(DRLCMACUL, LOGL_DEBUG, "- Finished with UL "
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"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;
|
||
|
|
}
|
||
|
|
|