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osmo-pcu
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osmo-pcu/src/tbf.cpp

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/* Copied from gprs_bssgp_pcu.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 sending these frames, we poll for ack/nack. */
#define POLL_ACK_AFTER_FRAMES 20
/* After receiving these frames, we send ack/nack. */
#define SEND_ACK_AFTER_FRAMES 20
/* If acknowledgement to downlink assignment should be polled */
#define POLLING_ASSIGNMENT_DL 1
#define POLLING_ASSIGNMENT_UL 1
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);
}
extern void *tall_pcu_ctx;
static void tbf_timer_cb(void *_tbf);
inline gprs_rlcmac_bts *gprs_rlcmac_tbf::bts_data() const
{
return bts->bts_data();
}
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;
}
void gprs_rlcmac_tbf::assign_imsi(const char *imsi)
{
strncpy(m_imsi, imsi, sizeof(m_imsi));
m_imsi[sizeof(m_imsi) - 1] = '\0';
}
static struct gprs_rlcmac_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->tbf_by_tlli(tlli, GPRS_RLCMAC_DL_TBF);
}
int gprs_rlcmac_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));
#warning "verify that m_llc.index/length is 0... check the state change"
bts->tbf_reused();
m_llc.put_frame(data, len);
/* reset rlc states */
memset(&dir.dl, 0, sizeof(dir.dl));
/* keep to flags */
state_flags &= GPRS_RLCMAC_FLAG_TO_MASK;
state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH);
tbf_update_ms_class(this, ms_class);
update();
bts->trigger_dl_ass(this, this, NULL);
} 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),
"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);
memcpy(msgb_put(llc_msg, len), data, len);
m_llc.enqueue(llc_msg);
tbf_update_ms_class(this, ms_class);
}
return 0;
}
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_tbf *old_tbf, *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"
tbf = bts->bts->tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF);
if (tbf && tbf->dir.ul.contention_resolution_done
&& !tbf->dir.ul.final_ack_sent) {
use_trx = tbf->trx->trx_no;
ta = tbf->ta;
ss = 0;
old_tbf = tbf;
} else {
use_trx = -1;
/* we already have an uplink TBF, so we use that TA */
if (tbf)
ta = 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_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 */
tbf = tbf_alloc(bts, tbf, GPRS_RLCMAC_DL_TBF, tfi, trx, ms_class, ss);
if (!tbf) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
/* FIXME: send reject */
return -EBUSY;
}
tbf->m_tlli = tlli;
tbf->m_tlli_valid = 1;
tbf->ta = ta;
LOGP(DRLCMAC, LOGL_DEBUG, "%s [DOWNLINK] START\n", tbf_name(tbf));
/* new TBF, so put first frame */
tbf->m_llc.put_frame(data, len);
/* Store IMSI for later look-up and PCH retransmission */
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. */
tbf->bts->trigger_dl_ass(tbf, old_tbf, imsi);
return 0;
}
/**
* TODO: split into unit test-able parts...
*/
int gprs_rlcmac_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_tbf *tbf;
/* check for existing TBF */
tbf = tbf_lookup_dl(bts->bts, tlli, imsi);
if (tbf) {
int rc = tbf->append_data(ms_class, delay_csec, data, len);
if (rc >= 0)
tbf->assign_imsi(imsi);
return rc;
}
return tbf_new_dl_assignment(bts, imsi, tlli, ms_class, data, len);
}
struct gprs_rlcmac_tbf *tbf_alloc_ul(struct gprs_rlcmac_bts *bts,
int8_t use_trx, uint8_t ms_class,
uint32_t tlli, uint8_t ta, struct gprs_rlcmac_tbf *dl_tbf)
{
uint8_t trx;
struct gprs_rlcmac_tbf *tbf;
int8_t tfi; /* must be signed */
#warning "Copy and paste with tbf_new_dl_assignment"
/* create new TBF, use sme TRX as DL TBF */
tfi = bts->bts->tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx, use_trx);
if (tfi < 0) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
/* FIXME: send reject */
return NULL;
}
/* use multislot class of downlink TBF */
tbf = tbf_alloc(bts, dl_tbf, GPRS_RLCMAC_UL_TBF, tfi, trx, ms_class, 0);
if (!tbf) {
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
/* FIXME: send reject */
return NULL;
}
tbf->m_tlli = tlli;
tbf->m_tlli_valid = 1; /* no contention resolution */
tbf->dir.ul.contention_resolution_done = 1;
tbf->ta = ta; /* use current TA */
tbf_new_state(tbf, GPRS_RLCMAC_ASSIGN);
tbf->state_flags |= (1 << GPRS_RLCMAC_FLAG_PACCH);
tbf_timer_start(tbf, 3169, bts->t3169, 0);
return tbf;
}
static void tbf_unlink_pdch(struct gprs_rlcmac_tbf *tbf)
{
struct gprs_rlcmac_pdch *pdch;
int ts;
if (tbf->direction == GPRS_RLCMAC_UL_TBF) {
tbf->trx->ul_tbf[tbf->tfi()] = NULL;
for (ts = 0; ts < 8; ts++) {
pdch = tbf->pdch[ts];
if (pdch)
pdch->ul_tbf[tbf->tfi()] = NULL;
tbf->pdch[ts] = NULL;
}
} else {
tbf->trx->dl_tbf[tbf->tfi()] = NULL;
for (ts = 0; ts < 8; ts++) {
pdch = tbf->pdch[ts];
if (pdch)
pdch->dl_tbf[tbf->tfi()] = NULL;
tbf->pdch[ts] = NULL;
}
}
}
void tbf_free(struct gprs_rlcmac_tbf *tbf)
{
/* Give final measurement report */
gprs_rlcmac_rssi_rep(tbf);
gprs_rlcmac_lost_rep(tbf);
debug_diagram(tbf->bts, tbf->diag, "+---------------+");
debug_diagram(tbf->bts, tbf->diag, "| THE END |");
debug_diagram(tbf->bts, tbf->diag, "+---------------+");
LOGP(DRLCMAC, LOGL_INFO, "%s free\n", tbf_name(tbf));
if (tbf->ul_ass_state != GPRS_RLCMAC_UL_ASS_NONE)
LOGP(DRLCMAC, LOGL_ERROR, "%s Software error: Pending uplink "
"assignment. This may not happen, because the "
"assignment message never gets transmitted. Please "
"be sure not to free in this state. PLEASE FIX!\n",
tbf_name(tbf));
if (tbf->dl_ass_state != GPRS_RLCMAC_DL_ASS_NONE)
LOGP(DRLCMAC, LOGL_ERROR, "%s Software error: Pending downlink "
"assignment. This may not happen, because the "
"assignment message never gets transmitted. Please "
"be sure not to free in this state. PLEASE FIX!\n",
tbf_name(tbf));
tbf->stop_timer();
#warning "TODO: Could/Should generate bssgp_tx_llc_discarded"
tbf->m_llc.clear(tbf->bts);
tbf_unlink_pdch(tbf);
llist_del(&tbf->list);
if (tbf->direction == GPRS_RLCMAC_UL_TBF)
tbf->bts->tbf_ul_freed();
else
tbf->bts->tbf_dl_freed();
LOGP(DRLCMAC, LOGL_DEBUG, "********** TBF ends here **********\n");
talloc_free(tbf);
}
int gprs_rlcmac_tbf::update()
{
struct gprs_rlcmac_tbf *ul_tbf = NULL;
struct gprs_rlcmac_bts *bts_data = bts->bts_data();
int rc;
LOGP(DRLCMAC, LOGL_DEBUG, "********** TBF update **********\n");
if (direction != GPRS_RLCMAC_DL_TBF)
return -EINVAL;
if (!ms_class) {
LOGP(DRLCMAC, LOGL_DEBUG, "- Cannot update, no class\n");
return -EINVAL;
}
ul_tbf = bts->tbf_by_tlli(m_tlli, GPRS_RLCMAC_UL_TBF);
tbf_unlink_pdch(this);
rc = bts_data->alloc_algorithm(bts_data, ul_tbf, this, bts_data->alloc_algorithm_curst, 0);
/* if no resource */
if (rc < 0) {
LOGP(DRLCMAC, LOGL_ERROR, "No resource after update???\n");
return -rc;
}
return 0;
}
int tbf_assign_control_ts(struct gprs_rlcmac_tbf *tbf)
{
if (tbf->control_ts == 0xff)
LOGP(DRLCMAC, LOGL_INFO, "- Setting Control TS %d\n",
tbf->first_common_ts);
else if (tbf->control_ts != tbf->first_common_ts)
LOGP(DRLCMAC, LOGL_INFO, "- Changing Control TS %d\n",
tbf->first_common_ts);
tbf->control_ts = tbf->first_common_ts;
return 0;
}
static const char *tbf_state_name[] = {
"NULL",
"ASSIGN",
"FLOW",
"FINISHED",
"WAIT RELEASE",
"RELEASING",
};
void tbf_new_state(struct gprs_rlcmac_tbf *tbf,
enum gprs_rlcmac_tbf_state state)
{
debug_diagram(tbf->bts, tbf->diag, "->%s", tbf_state_name[state]);
LOGP(DRLCMAC, LOGL_DEBUG, "%s changes state from %s to %s\n",
tbf_name(tbf),
tbf_state_name[tbf->state], tbf_state_name[state]);
tbf->set_state(state);
}
void tbf_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int T,
unsigned int seconds, unsigned int microseconds)
{
if (!osmo_timer_pending(&tbf->timer))
LOGP(DRLCMAC, LOGL_DEBUG, "%s starting timer %u.\n",
tbf_name(tbf), T);
else
LOGP(DRLCMAC, LOGL_DEBUG, "%s restarting timer %u "
"while old timer %u pending \n",
tbf_name(tbf), T, tbf->T);
tbf->T = T;
tbf->num_T_exp = 0;
/* Tunning timers can be safely re-scheduled. */
tbf->timer.data = tbf;
tbf->timer.cb = &tbf_timer_cb;
osmo_timer_schedule(&tbf->timer, seconds, microseconds);
}
void gprs_rlcmac_tbf::stop_t3191()
{
return stop_timer();
}
void gprs_rlcmac_tbf::stop_timer()
{
if (osmo_timer_pending(&timer)) {
LOGP(DRLCMAC, LOGL_DEBUG, "%s stopping timer %u.\n",
tbf_name(this), T);
osmo_timer_del(&timer);
}
}
void gprs_rlcmac_tbf::poll_timeout()
{
LOGP(DRLCMAC, LOGL_NOTICE, "%s poll timeout\n",
tbf_name(this));
poll_state = GPRS_RLCMAC_POLL_NONE;
if (ul_ack_state == GPRS_RLCMAC_UL_ACK_WAIT_ACK) {
if (!(state_flags & (1 << GPRS_RLCMAC_FLAG_TO_UL_ACK))) {
LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling "
"PACKET CONTROL ACK for PACKET UPLINK ACK\n");
rlcmac_diag();
state_flags |= (1 << GPRS_RLCMAC_FLAG_TO_UL_ACK);
}
ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
debug_diagram(bts, this->diag, "timeout UL-ACK");
if (state_is(GPRS_RLCMAC_FINISHED)) {
dir.ul.n3103++;
if (dir.ul.n3103 == bts->bts_data()->n3103) {
LOGP(DRLCMAC, LOGL_NOTICE,
"- N3103 exceeded\n");
debug_diagram(bts, diag, "N3103 exceeded");
tbf_new_state(this, GPRS_RLCMAC_RELEASING);
tbf_timer_start(this, 3169, bts->bts_data()->t3169, 0);
return;
}
/* reschedule UL ack */
ul_ack_state = GPRS_RLCMAC_UL_ACK_SEND_ACK;
}
} else if (ul_ass_state == GPRS_RLCMAC_UL_ASS_WAIT_ACK) {
if (!(state_flags & (1 << GPRS_RLCMAC_FLAG_TO_UL_ASS))) {
LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling "
"PACKET CONTROL ACK for PACKET UPLINK "
"ASSIGNMENT.\n");
rlcmac_diag();
state_flags |= (1 << GPRS_RLCMAC_FLAG_TO_UL_ASS);
}
ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
debug_diagram(bts, diag, "timeout UL-ASS");
n3105++;
if (n3105 == bts_data()->n3105) {
LOGP(DRLCMAC, LOGL_NOTICE, "- N3105 exceeded\n");
debug_diagram(bts, diag, "N3105 exceeded");
tbf_new_state(this, GPRS_RLCMAC_RELEASING);
tbf_timer_start(this, 3195, bts_data()->t3195, 0);
return;
}
/* reschedule UL assignment */
ul_ass_state = GPRS_RLCMAC_UL_ASS_SEND_ASS;
} else if (dl_ass_state == GPRS_RLCMAC_DL_ASS_WAIT_ACK) {
if (!(state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ASS))) {
LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling "
"PACKET CONTROL ACK for PACKET DOWNLINK "
"ASSIGNMENT.\n");
rlcmac_diag();
state_flags |= (1 << GPRS_RLCMAC_FLAG_TO_DL_ASS);
}
dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
debug_diagram(bts, diag, "timeout DL-ASS");
n3105++;
if (n3105 == bts->bts_data()->n3105) {
LOGP(DRLCMAC, LOGL_NOTICE, "- N3105 exceeded\n");
debug_diagram(bts, diag, "N3105 exceeded");
tbf_new_state(this, GPRS_RLCMAC_RELEASING);
tbf_timer_start(this, 3195, bts_data()->t3195, 0);
return;
}
/* reschedule DL assignment */
dl_ass_state = GPRS_RLCMAC_DL_ASS_SEND_ASS;
} else if (direction == GPRS_RLCMAC_DL_TBF) {
if (!(state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK))) {
LOGP(DRLCMAC, LOGL_NOTICE, "- Timeout for polling "
"PACKET DOWNLINK ACK.\n");
rlcmac_diag();
state_flags |= (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
}
debug_diagram(bts, diag, "timeout DL-ACK");
n3105++;
if (n3105 == bts->bts_data()->n3105) {
LOGP(DRLCMAC, LOGL_NOTICE, "- N3105 exceeded\n");
debug_diagram(bts, diag, "N3105 exceeded");
tbf_new_state(this, GPRS_RLCMAC_RELEASING);
tbf_timer_start(this, 3195, bts_data()->t3195, 0);
return;
}
/* resend IMM.ASS on CCCH on timeout */
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH))
&& !(state_flags & (1 << GPRS_RLCMAC_FLAG_DL_ACK))) {
LOGP(DRLCMAC, LOGL_DEBUG, "Re-send dowlink assignment "
"for %s on PCH (IMSI=%s)\n",
tbf_name(this),
m_imsi);
/* send immediate assignment */
bts->snd_dl_ass(this, 0, m_imsi);
dir.dl.wait_confirm = 1;
}
} else
LOGP(DRLCMAC, LOGL_ERROR, "- Poll Timeout, but no event!\n");
}
struct gprs_rlcmac_tbf *tbf_alloc(struct gprs_rlcmac_bts *bts,
struct gprs_rlcmac_tbf *old_tbf, enum gprs_rlcmac_tbf_direction dir,
uint8_t tfi, uint8_t trx,
uint8_t ms_class, uint8_t single_slot)
{
struct gprs_rlcmac_tbf *tbf;
int rc;
#ifdef DEBUG_DIAGRAM
/* hunt for first free number in diagram */
int diagram_num;
for (diagram_num = 0; ; diagram_num++) {
llist_for_each_entry(tbf, &bts->ul_tbfs, list) {
if (tbf->diag == diagram_num)
goto next_diagram;
}
llist_for_each_entry(tbf, &bts->dl_tbfs, list) {
if (tbf->diag == diagram_num)
goto next_diagram;
}
break;
next_diagram:
continue;
}
#endif
LOGP(DRLCMAC, LOGL_DEBUG, "********** TBF starts here **********\n");
LOGP(DRLCMAC, LOGL_INFO, "Allocating %s TBF: TFI=%d TRX=%d "
"MS_CLASS=%d\n", (dir == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL",
tfi, trx, ms_class);
if (trx >= 8 || tfi >= 32)
return NULL;
tbf = talloc_zero(tall_pcu_ctx, struct gprs_rlcmac_tbf);
if (!tbf)
return NULL;
tbf->bts = bts->bts;
#ifdef DEBUG_DIAGRAM
tbf->diag = diagram_num;
#endif
tbf->direction = dir;
tbf->m_tfi = tfi;
tbf->trx = &bts->trx[trx];
tbf->ms_class = ms_class;
tbf->ws = 64;
tbf->sns = 128;
/* select algorithm */
rc = bts->alloc_algorithm(bts, old_tbf, tbf, bts->alloc_algorithm_curst,
single_slot);
/* if no resource */
if (rc < 0) {
talloc_free(tbf);
return NULL;
}
/* assign control ts */
tbf->control_ts = 0xff;
rc = tbf_assign_control_ts(tbf);
/* if no resource */
if (rc < 0) {
talloc_free(tbf);
return NULL;
}
/* set timestamp */
gettimeofday(&tbf->meas.dl_bw_tv, NULL);
gettimeofday(&tbf->meas.rssi_tv, NULL);
gettimeofday(&tbf->meas.dl_loss_tv, NULL);
tbf->m_llc.init();
if (dir == GPRS_RLCMAC_UL_TBF) {
llist_add(&tbf->list, &bts->ul_tbfs);
tbf->bts->tbf_ul_created();
} else {
llist_add(&tbf->list, &bts->dl_tbfs);
tbf->bts->tbf_dl_created();
}
debug_diagram(bts->bts, tbf->diag, "+-----------------+");
debug_diagram(bts->bts, tbf->diag, "|NEW %s TBF TFI=%2d|",
(dir == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tfi);
debug_diagram(bts->bts, tbf->diag, "+-----------------+");
return tbf;
}
static void tbf_timer_cb(void *_tbf)
{
struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf;
tbf->handle_timeout();
}
void gprs_rlcmac_tbf::handle_timeout()
{
LOGP(DRLCMAC, LOGL_DEBUG, "%s timer %u expired.\n",
tbf_name(this), T);
num_T_exp++;
switch (T) {
case 0: /* assignment */
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_PACCH))) {
if (state_is(GPRS_RLCMAC_ASSIGN)) {
LOGP(DRLCMAC, LOGL_NOTICE, "%s releasing due to "
"PACCH assignment timeout.\n", tbf_name(this));
tbf_free(this);
} else
LOGP(DRLCMAC, LOGL_ERROR, "Error: %s is not "
"in assign state\n", tbf_name(this));
}
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH))) {
/* change state to FLOW, so scheduler will start transmission */
dir.dl.wait_confirm = 0;
if (state_is(GPRS_RLCMAC_ASSIGN)) {
tbf_new_state(this, GPRS_RLCMAC_FLOW);
tbf_assign_control_ts(this);
} else
LOGP(DRLCMAC, LOGL_NOTICE, "%s Continue flow after "
"IMM.ASS confirm\n", tbf_name(this));
}
break;
case 3169:
case 3191:
case 3195:
LOGP(DRLCMAC, LOGL_NOTICE, "%s T%d timeout during "
"transsmission\n", tbf_name(this), T);
rlcmac_diag();
/* fall through */
case 3193:
if (T == 3193)
debug_diagram(bts, diag, "T3193 timeout");
LOGP(DRLCMAC, LOGL_DEBUG,
"%s will be freed due to timeout\n", tbf_name(this));
/* free TBF */
tbf_free(this);
break;
default:
LOGP(DRLCMAC, LOGL_ERROR,
"%s timer expired in unknown mode: %u\n", tbf_name(this), T);
}
}
int gprs_rlcmac_tbf::rlcmac_diag()
{
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_CCCH)))
LOGP(DRLCMAC, LOGL_NOTICE, "- Assignment was on CCCH\n");
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_PACCH)))
LOGP(DRLCMAC, LOGL_NOTICE, "- Assignment was on PACCH\n");
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_UL_DATA)))
LOGP(DRLCMAC, LOGL_NOTICE, "- Uplink data was received\n");
else if (direction == GPRS_RLCMAC_UL_TBF)
LOGP(DRLCMAC, LOGL_NOTICE, "- No uplink data received yet\n");
if ((state_flags & (1 << GPRS_RLCMAC_FLAG_DL_ACK)))
LOGP(DRLCMAC, LOGL_NOTICE, "- Downlink ACK was received\n");
else if (direction == GPRS_RLCMAC_DL_TBF)
LOGP(DRLCMAC, LOGL_NOTICE, "- No downlink ACK received yet\n");
return 0;
}
struct msgb *gprs_rlcmac_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));
/* Timeout is infinite */
if (tv->tv_sec == 0 && tv->tv_usec == 0)
break;
if (timercmp(&tv_now, tv, >)) {
LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU "
"because lifetime limit reached\n",
tbf_name(this));
bts->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;
}
/*
* Store received block data in LLC message(s) and forward to SGSN
* if complete.
*/
int gprs_rlcmac_tbf::assemble_forward_llc(uint8_t *data, uint8_t len)
{
struct rlc_ul_header *rh = (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];
}
LOGP(DRLCMACUL, LOGL_DEBUG, "-- Appending chunk (len=%d) to "
"frame at %d.\n", chunk, m_llc.index);
if (m_llc.index + chunk > LLC_MAX_LEN) {
LOGP(DRLCMACUL, LOGL_NOTICE, "%s LLC frame exceeds "
"maximum size.\n", tbf_name(this));
chunk = LLC_MAX_LEN - m_llc.index;
}
memcpy(m_llc.frame + m_llc.index, data + frame_offset[i], chunk);
m_llc.index += 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.index);
snd_ul_ud();
/* 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.index);
snd_ul_ud();
}
}
return 0;
}
/*
* Create DL data block
* The messages are fragmented and forwarded as data blocks.
*/
struct msgb *gprs_rlcmac_tbf::create_dl_acked_block(uint32_t fn, uint8_t ts)
{
struct rlc_dl_header *rh;
struct rlc_li_field *li;
uint8_t block_length; /* total length of block, including spare bits */
uint8_t block_data; /* usable data of block, w/o spare bits, inc. MAC */
struct msgb *msg;
uint8_t bsn;
uint16_t mod_sns = sns - 1;
uint16_t mod_sns_half = (sns >> 1) - 1;
uint16_t index;
uint8_t *delimiter, *data, *e_pointer;
uint16_t space, chunk;
bool first_fin_ack = false;
LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink (V(A)==%d .. "
"V(S)==%d)\n", tbf_name(this), dir.dl.v_a, dir.dl.v_s);
do_resend:
/* check if there is a block with negative acknowledgement */
for (bsn = dir.dl.v_a; bsn != dir.dl.v_s;
bsn = (bsn + 1) & mod_sns) {
index = (bsn & mod_sns_half);
if (dir.dl.v_b[index] == 'N'
|| dir.dl.v_b[index] == 'X') {
LOGP(DRLCMACDL, LOGL_DEBUG, "- Resending BSN %d\n",
bsn);
/* re-send block with negative aknowlegement */
dir.dl.v_b[index] = 'U'; /* unacked */
return create_dl_acked_block(fn, ts, index, first_fin_ack);
}
}
/* if the window has stalled, or transfer is complete,
* send an unacknowledged block */
if (state_is(GPRS_RLCMAC_FINISHED)
|| ((dir.dl.v_s - dir.dl.v_a) & mod_sns) == ws) {
int resend = 0;
if (state_is(GPRS_RLCMAC_FINISHED))
LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, "
"because all blocks have been transmitted.\n",
dir.dl.v_a);
else
LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, "
"because all window is stalled.\n",
dir.dl.v_a);
/* 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 (dir.dl.v_s == dir.dl.v_a) {
LOGP(DRLCMACDL, LOGL_DEBUG, "- MS acked all blocks, "
"so we re-transmit final block!\n");
/* we just send final block again */
index = ((dir.dl.v_s - 1) & mod_sns_half);
return create_dl_acked_block(fn, ts, index, first_fin_ack);
}
/* cycle through all unacked blocks */
for (bsn = dir.dl.v_a; bsn != dir.dl.v_s;
bsn = (bsn + 1) & mod_sns) {
index = (bsn & mod_sns_half);
if (dir.dl.v_b[index] == 'U') {
/* mark to be re-send */
dir.dl.v_b[index] = 'X';
resend++;
}
}
/* At this point there should be at leasst 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 */
index = ((dir.dl.v_s - 1) & mod_sns_half);
return create_dl_acked_block(fn, ts, index, first_fin_ack);
}
goto do_resend;
}
LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d\n",
dir.dl.v_s);
/* now we still have untransmitted LLC data, so we fill mac block */
index = dir.dl.v_s & mod_sns_half;
data = rlc_block[index];
#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;
}
block_length = gprs_rlcmac_cs[cs].block_length;
block_data = gprs_rlcmac_cs[cs].block_data;
memset(data, 0x2b, block_data); /* spare bits will be left 0 */
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 = dir.dl.v_s; /* Block Sequence Number */
rh->e = 0; /* Extension bit, maybe set later */
e_pointer = data + 2; /* points to E of current chunk */
data += 3;
delimiter = data; /* where next length header would be stored */
space = block_data - 3;
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.length);
gprs_rlcmac_dl_bw(this, m_llc.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 */
tbf_new_state(this, 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)
memcpy(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)
memcpy(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.length);
gprs_rlcmac_dl_bw(this, m_llc.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);
msgb_free(msg);
}
/* if we have more data and we have space left */
if (space > 0 && m_llc.length) {
li->m = 1; /* we indicate more frames to follow */
continue;
}
/* if we don't have more LLC frames */
if (!m_llc.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 */
tbf_new_state(this, 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_block[index], block_length));
rlc_block_len[index] = block_length;
/* raise send state and set ack state array */
dir.dl.v_b[index] = 'U'; /* unacked */
dir.dl.v_s = (dir.dl.v_s + 1) & mod_sns; /* inc send state */
return create_dl_acked_block(fn, ts, index, first_fin_ack);
}
struct msgb *gprs_rlcmac_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 = rlc_block[index];
len = rlc_block_len[index];
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 (dir.dl.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(DRLCMAC, 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(DRLCMAC, 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(DRLCMAC, LOGL_DEBUG, "Polling cannot be "
"sheduled, because single block alllocation "
"already exists\n");
else {
LOGP(DRLCMAC, LOGL_DEBUG, "Polling sheduled in this "
"TS %d\n", ts);
dir.dl.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;
#ifdef DEBUG_DIAGRAM
debug_diagram(bts, diag, "poll DL-ACK");
if (first_fin_ack)
debug_diagram(bts, diag, "(is first FINAL)");
if (rh->fbi)
debug_diagram(bts, diag, "(FBI is set)");
#endif
/* set polling in header */
rh->rrbp = 0; /* N+13 */
rh->s_p = 1; /* Polling */
/* Increment TX-counter */
dir.dl.tx_counter++;
}
} else {
/* Increment TX-counter */
dir.dl.tx_counter++;
}
/* return data block as message */
dl_msg = msgb_alloc(len, "rlcmac_dl_data");
if (!dl_msg)
return NULL;
memcpy(msgb_put(dl_msg, len), data, len);
return dl_msg;
}
struct msgb *gprs_rlcmac_tbf::create_dl_ass(uint32_t fn)
{
struct msgb *msg;
struct gprs_rlcmac_tbf *new_tbf;
int poll_ass_dl = POLLING_ASSIGNMENT_DL;
if (poll_ass_dl && direction == GPRS_RLCMAC_DL_TBF
&& control_ts != first_common_ts) {
LOGP(DRLCMAC, LOGL_NOTICE, "Cannot poll for downlink "
"assigment, because MS cannot reply. (control TS=%d, "
"first common TS=%d)\n", control_ts,
first_common_ts);
poll_ass_dl = 0;
}
if (poll_ass_dl) {
if (poll_state != GPRS_RLCMAC_POLL_NONE) {
LOGP(DRLCMAC, LOGL_DEBUG, "Polling is already sheduled "
"for %s, so we must wait for downlink "
"assignment...\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;
}
}
/* on uplink TBF we get the downlink TBF to be assigned. */
if (direction == GPRS_RLCMAC_UL_TBF) {
/* be sure to check first, if contention resolution is done,
* otherwise we cannot send the assignment yet */
if (!dir.ul.contention_resolution_done) {
LOGP(DRLCMAC, LOGL_DEBUG, "Cannot assign DL TBF now, "
"because contention resolution is not "
"finished.\n");
return NULL;
}
#warning "THIS should probably go over the IMSI too"
new_tbf = bts->tbf_by_tlli(m_tlli, GPRS_RLCMAC_DL_TBF);
} else
new_tbf = this;
if (!new_tbf) {
LOGP(DRLCMACDL, LOGL_ERROR, "We have a schedule for downlink "
"assignment at uplink %s, but there is no downlink "
"TBF\n", tbf_name(this));
dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
return NULL;
}
msg = msgb_alloc(23, "rlcmac_dl_ass");
if (!msg)
return NULL;
bitvec *ass_vec = bitvec_alloc(23);
if (!ass_vec) {
msgb_free(msg);
return NULL;
}
bitvec_unhex(ass_vec,
"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
LOGP(DRLCMAC, LOGL_INFO, "%s start Packet Downlink Assignment (PACCH)\n", tbf_name(new_tbf));
RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
Encoding::write_packet_downlink_assignment(mac_control_block, m_tfi,
(direction == GPRS_RLCMAC_DL_TBF), new_tbf,
poll_ass_dl, bts_data()->alpha, bts_data()->gamma, -1, 0);
LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n");
encode_gsm_rlcmac_downlink(ass_vec, mac_control_block);
LOGPC(DCSN1, LOGL_NOTICE, "\n");
LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Downlink Assignment -------------------------\n");
bitvec_pack(ass_vec, msgb_put(msg, 23));
bitvec_free(ass_vec);
talloc_free(mac_control_block);
if (poll_ass_dl) {
poll_state = GPRS_RLCMAC_POLL_SCHED;
poll_fn = (fn + 13) % 2715648;
dl_ass_state = GPRS_RLCMAC_DL_ASS_WAIT_ACK;
} else {
dl_ass_state = GPRS_RLCMAC_DL_ASS_NONE;
tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW);
tbf_assign_control_ts(new_tbf);
/* stop pending assignment timer */
new_tbf->stop_timer();
}
debug_diagram(bts, diag, "send DL-ASS");
return msg;
}
struct msgb *gprs_rlcmac_tbf::create_ul_ass(uint32_t fn)
{
struct msgb *msg;
struct gprs_rlcmac_tbf *new_tbf;
#if POLLING_ASSIGNMENT_UL == 1
if (poll_state != GPRS_RLCMAC_POLL_NONE) {
LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
"sheduled for %s, so we must wait for uplink "
"assignment...\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;
}
#endif
/* on down TBF we get the uplink TBF to be assigned. */
#warning "Probably want to find by IMSI too"
if (direction == GPRS_RLCMAC_DL_TBF)
new_tbf = bts->tbf_by_tlli(m_tlli, GPRS_RLCMAC_UL_TBF);
else
new_tbf = this;
if (!new_tbf) {
LOGP(DRLCMACUL, LOGL_ERROR, "We have a schedule for uplink "
"assignment at downlink %s, but there is no uplink "
"TBF\n", tbf_name(this));
ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
return NULL;
}
msg = msgb_alloc(23, "rlcmac_ul_ass");
if (!msg)
return NULL;
LOGP(DRLCMAC, LOGL_INFO, "%ss start Packet Uplink Assignment (PACCH)\n", tbf_name(new_tbf));
bitvec *ass_vec = bitvec_alloc(23);
if (!ass_vec) {
msgb_free(msg);
return NULL;
}
bitvec_unhex(ass_vec,
"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
Encoding::write_packet_uplink_assignment(bts_data(), ass_vec, m_tfi,
(direction == GPRS_RLCMAC_DL_TBF), m_tlli,
m_tlli_valid, new_tbf, POLLING_ASSIGNMENT_UL, bts_data()->alpha,
bts_data()->gamma, -1);
bitvec_pack(ass_vec, msgb_put(msg, 23));
RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Assignment +++++++++++++++++++++++++\n");
decode_gsm_rlcmac_downlink(ass_vec, mac_control_block);
LOGPC(DCSN1, LOGL_NOTICE, "\n");
LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Uplink Assignment -------------------------\n");
bitvec_free(ass_vec);
talloc_free(mac_control_block);
#if POLLING_ASSIGNMENT_UL == 1
poll_state = GPRS_RLCMAC_POLL_SCHED;
poll_fn = (fn + 13) % 2715648;
ul_ass_state = GPRS_RLCMAC_UL_ASS_WAIT_ACK;
#else
ul_ass_state = GPRS_RLCMAC_UL_ASS_NONE;
tbf_new_state(new_tbf, GPRS_RLCMAC_FLOW);
tbf_assign_control_ts(new_tbf);
#endif
debug_diagram(bts, diag, "send UL-ASS");
return msg;
}
struct msgb *gprs_rlcmac_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. */
dir.ul.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;
dir.ul.final_ack_sent = 1;
} else
ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
debug_diagram(bts->bts, diag, "send UL-ACK");
return msg;
}
int gprs_rlcmac_tbf::snd_dl_ack(uint8_t final, uint8_t ssn, uint8_t *rbb)
{
char show_rbb[65], show_v_b[RLC_MAX_SNS + 1];
uint16_t mod_sns = sns - 1;
uint16_t mod_sns_half = (sns >> 1) - 1;
int i; /* must be signed */
int16_t dist; /* must be signed */
uint8_t bit;
uint16_t bsn;
struct msgb *msg;
uint16_t lost = 0, received = 0;
LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink acknowledge\n", tbf_name(this));
if (!final) {
/* show received array in debug (bit 64..1) */
for (i = 63; i >= 0; i--) {
bit = (rbb[i >> 3] >> (7 - (i&7))) & 1;
show_rbb[i] = (bit) ? '1' : 'o';
}
show_rbb[64] = '\0';
LOGP(DRLCMACDL, LOGL_DEBUG, "- ack: (BSN=%d)\"%s\""
"(BSN=%d) 1=ACK o=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 = (dir.dl.v_s - ssn) & mod_sns;
/* check if distance is less than distance V(A)..V(S) */
if (dist >= ((dir.dl.v_s - dir.dl.v_a) & mod_sns)) {
/* 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 */
}
/* SSN - 1 is in range V(A)..V(S)-1 */
for (i = 63, bsn = (ssn - 1) & mod_sns;
i >= 0 && bsn != ((dir.dl.v_a - 1) & mod_sns);
i--, bsn = (bsn - 1) & mod_sns) {
bit = (rbb[i >> 3] >> (7 - (i&7))) & 1;
if (bit) {
LOGP(DRLCMACDL, LOGL_DEBUG, "- got "
"ack for BSN=%d\n", bsn);
if (dir.dl.v_b[bsn & mod_sns_half]
!= 'A')
received++;
dir.dl.v_b[bsn & mod_sns_half] = 'A';
} else {
LOGP(DRLCMACDL, LOGL_DEBUG, "- got "
"NACK for BSN=%d\n", bsn);
dir.dl.v_b[bsn & mod_sns_half] = 'N';
lost++;
}
}
/* report lost and received packets */
gprs_rlcmac_received_lost(this, received, lost);
/* raise V(A), if possible */
for (i = 0, bsn = dir.dl.v_a; bsn != dir.dl.v_s;
i++, bsn = (bsn + 1) & mod_sns) {
if (dir.dl.v_b[bsn & mod_sns_half] == 'A') {
dir.dl.v_b[bsn & mod_sns_half] = 'I';
/* mark invalid */
dir.dl.v_a = (dir.dl.v_a + 1)
& mod_sns;
} else
break;
}
/* show receive state array in debug (V(A)..V(S)-1) */
for (i = 0, bsn = dir.dl.v_a; bsn != dir.dl.v_s;
i++, bsn = (bsn + 1) & mod_sns) {
show_v_b[i] = dir.dl.v_b[bsn & mod_sns_half];
if (show_v_b[i] == 0)
show_v_b[i] = ' ';
}
show_v_b[i] = '\0';
LOGP(DRLCMACDL, LOGL_DEBUG, "- V(B): (V(A)=%d)\"%s\""
"(V(S)-1=%d) A=Acked N=Nacked U=Unacked "
"X=Resend-Unacked\n", dir.dl.v_a, show_v_b,
(dir.dl.v_s - 1) & mod_sns);
if (state_is(GPRS_RLCMAC_FINISHED)
&& dir.dl.v_s == dir.dl.v_a) {
LOGP(DRLCMACDL, LOGL_NOTICE, "Received acknowledge of "
"all blocks, but without final ack "
"inidcation (don't worry)\n");
}
return 0;
}
LOGP(DRLCMACDL, LOGL_DEBUG, "- Final ACK received.\n");
debug_diagram(ts, diag, "got Final ACK");
/* range V(A)..V(S)-1 */
for (bsn = dir.dl.v_a; bsn != dir.dl.v_s;
bsn = (bsn + 1) & mod_sns) {
if (dir.dl.v_b[bsn & mod_sns_half] != 'A')
received++;
}
/* report all outstanding packets as received */
gprs_rlcmac_received_lost(this, received, lost);
/* 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 */
debug_diagram(bts, diag, "start T3193");
tbf_timer_start(this, 3193,
bts_data()->t3193_msec / 1000,
(bts_data()->t3193_msec % 1000) * 1000);
tbf_new_state(this, GPRS_RLCMAC_WAIT_RELEASE);
return 0;
}
#warning "Copy and paste on the sender path"
m_llc.put_frame(msg->data, msg->len);
msgb_free(msg);
/* we have a message, so we trigger downlink assignment, and there
* set the state to ASSIGN. also we set old_downlink, because we
* re-use this tbf. */
LOGP(DRLCMAC, LOGL_DEBUG, "Trigger dowlink assignment on PACCH, "
"because another LLC PDU has arrived in between\n");
memset(&dir.dl, 0, sizeof(dir.dl)); /* reset RLC states */
state_flags &= GPRS_RLCMAC_FLAG_TO_MASK; /* keep TO flags */
state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH);
update();
bts->trigger_dl_ass(this, this, NULL);
return 0;
}
void gprs_rlcmac_tbf::free_all(struct gprs_rlcmac_trx *trx)
{
for (uint8_t tfi = 0; tfi < 32; tfi++) {
struct gprs_rlcmac_tbf *tbf;
tbf = trx->ul_tbf[tfi];
if (tbf)
tbf_free(tbf);
tbf = trx->dl_tbf[tfi];
if (tbf)
tbf_free(tbf);
}
}
void gprs_rlcmac_tbf::free_all(struct gprs_rlcmac_pdch *pdch)
{
for (uint8_t tfi = 0; tfi < 32; tfi++) {
struct gprs_rlcmac_tbf *tbf;
tbf = pdch->ul_tbf[tfi];
if (tbf)
tbf_free(tbf);
tbf = pdch->dl_tbf[tfi];
if (tbf)
tbf_free(tbf);
}
}
void gprs_rlcmac_tbf::tlli_mark_valid()
{
m_tlli_valid = true;
}
void gprs_rlcmac_tbf::update_tlli(uint32_t tlli)
{
if (tlli == m_tlli)
return;
bool changedUl = false;
/*
* During a Routing Area Update (due the assignment of a new
* P-TMSI) the tlli can change. We notice this when receiving
* a PACKET CONTROL ACK.
* When we get a TLLI change on the DL we will look if there
* is a UL TBF and change the tlli there as well.
*
* TODO: There could be multiple DL and UL TBFs and we should
* have a proper way to link all the related TBFs so we can do
* a group update.
*/
if (m_tlli_valid && direction == GPRS_RLCMAC_DL_TBF) {
gprs_rlcmac_tbf *ul_tbf;
ul_tbf = bts->tbf_by_tlli(m_tlli, GPRS_RLCMAC_UL_TBF);
if (ul_tbf) {
ul_tbf->m_tlli = tlli;
changedUl = true;
}
}
/* update the timing advance for the new tlli */
bts->timing_advance()->update(m_tlli, tlli, ta);
LOGP(DRLCMAC, LOGL_NOTICE,
"%s changing tlli from TLLI=0x%08x TLLI=0x%08x ul_changed=%d\n",
tbf_name(this), m_tlli, tlli, changedUl);
m_tlli = tlli;
}
int gprs_rlcmac_tbf::rcv_data_block_acknowledged(const uint8_t *data, size_t len, int8_t rssi)
{
uint16_t mod_sns, mod_sns_half, offset_v_q, offset_v_r, index;
struct rlc_ul_header *rh = (struct rlc_ul_header *)data;
int rc;
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->dir.ul.v_q, this->dir.ul.v_r);
/* process RSSI */
gprs_rlcmac_rssi(this, rssi);
/* get TLLI */
if (!this->is_tlli_valid()) {
struct gprs_rlcmac_tbf *dl_tbf, *ul_tbf;
uint32_t tlli;
/* no TLLI yet */
if (!rh->ti) {
LOGP(DRLCMACUL, LOGL_NOTICE, "UL DATA TFI=%d without "
"TLLI, but no TLLI received yet\n", rh->tfi);
return 0;
}
rc = Decoding::tlli_from_ul_data(data, len, &tlli);
if (rc) {
bts->decode_error();
LOGP(DRLCMACUL, LOGL_NOTICE, "Failed to decode TLLI "
"of UL DATA TFI=%d.\n", rh->tfi);
return 0;
}
this->update_tlli(tlli);
LOGP(DRLCMACUL, LOGL_INFO, "Decoded premier TLLI=0x%08x of "
"UL DATA TFI=%d.\n", this->tlli(), rh->tfi);
if ((dl_tbf = bts->tbf_by_tlli(this->tlli(), GPRS_RLCMAC_DL_TBF))) {
LOGP(DRLCMACUL, LOGL_NOTICE, "Got RACH from "
"TLLI=0x%08x while %s still exists. "
"Killing pending DL TBF\n", this->tlli(),
tbf_name(dl_tbf));
tbf_free(dl_tbf);
}
/* tbf_by_tlli will not find your TLLI, because it is not
* yet marked valid */
if ((ul_tbf = bts->tbf_by_tlli(this->tlli(), GPRS_RLCMAC_UL_TBF))) {
LOGP(DRLCMACUL, LOGL_NOTICE, "Got RACH from "
"TLLI=0x%08x while %s still exists. "
"Killing pending UL TBF\n", this->tlli(),
tbf_name(ul_tbf));
tbf_free(ul_tbf);
}
/* mark TLLI valid now */
this->tlli_mark_valid();
/* store current timing advance */
bts->timing_advance()->remember(this->tlli(), this->ta);
/* 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;
}
}
mod_sns = this->sns - 1;
mod_sns_half = (this->sns >> 1) - 1;
/* restart T3169 */
tbf_timer_start(this, 3169, bts_data()->t3169, 0);
/* Increment RX-counter */
this->dir.ul.rx_counter++;
/* current block relative to lowest unreceived block */
offset_v_q = (rh->bsn - this->dir.ul.v_q) & mod_sns;
/* If out of window (may happen if blocks below V(Q) are received
* again. */
if (offset_v_q >= this->ws) {
LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window "
"%d..%d (it's normal)\n", rh->bsn, this->dir.ul.v_q,
(this->dir.ul.v_q + this->ws - 1) & mod_sns);
return 0;
}
/* Write block to buffer and set receive state array. */
index = rh->bsn & mod_sns_half; /* memory index of block */
memcpy(this->rlc_block[index], data, len); /* Copy block. */
this->rlc_block_len[index] = len;
this->dir.ul.v_n[index] = 'R'; /* Mark received block. */
LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n",
rh->bsn, this->dir.ul.v_q,
(this->dir.ul.v_q + this->ws - 1) & mod_sns);
/* Raise V(R) to highest received sequence number not received. */
offset_v_r = (rh->bsn + 1 - this->dir.ul.v_r) & mod_sns;
if (offset_v_r < (this->sns >> 1)) { /* Positive offset, so raise. */
while (offset_v_r--) {
if (offset_v_r) /* all except the received block */
this->dir.ul.v_n[this->dir.ul.v_r & mod_sns_half]
= 'N'; /* Mark block as not received */
this->dir.ul.v_r = (this->dir.ul.v_r + 1) & mod_sns;
/* Inc V(R). */
}
LOGP(DRLCMACUL, LOGL_DEBUG, "- Raising V(R) to %d\n",
this->dir.ul.v_r);
}
#warning "Move to TBF and remove the index side effect.."
/* 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.*/
while (this->dir.ul.v_q != this->dir.ul.v_r && this->dir.ul.v_n[
(index = this->dir.ul.v_q & mod_sns_half)] == 'R') {
LOGP(DRLCMACUL, LOGL_DEBUG, "- Taking block %d out, raising "
"V(Q) to %d\n", this->dir.ul.v_q,
(this->dir.ul.v_q + 1) & mod_sns);
/* get LLC data from block */
this->assemble_forward_llc(this->rlc_block[index], this->rlc_block_len[index]);
/* raise V(Q), because block already received */
this->dir.ul.v_q = (this->dir.ul.v_q + 1) & mod_sns;
}
/* Check CV of last frame in buffer */
if (this->state_is(GPRS_RLCMAC_FLOW) /* still in flow state */
&& this->dir.ul.v_q == this->dir.ul.v_r) { /* if complete */
struct rlc_ul_header *last_rh = (struct rlc_ul_header *)
this->rlc_block[(this->dir.ul.v_r - 1) & mod_sns_half];
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");
tbf_new_state(this, GPRS_RLCMAC_FINISHED);
/* Reset N3103 counter. */
this->dir.ul.n3103 = 0;
}
}
/* If TLLI is included or if we received half of the window, we send
* an ack/nack */
if (rh->si || rh->ti || this->state_is(GPRS_RLCMAC_FINISHED)
|| (this->dir.ul.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 (this->state_is(GPRS_RLCMAC_FINISHED)) {
LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
"because last block has CV==0.\n");
}
if ((this->dir.ul.rx_counter % SEND_ACK_AFTER_FRAMES) == 0) {
LOGP(DRLCMACUL, LOGL_DEBUG, "- Scheduling Ack/Nack, "
"because %d frames received.\n",
SEND_ACK_AFTER_FRAMES);
}
if (this->ul_ack_state == GPRS_RLCMAC_UL_ACK_NONE) {
#ifdef DEBUG_DIAGRAM
if (rh->si)
debug_diagram(bts->bts, this->diag, "sched UL-ACK stall");
if (rh->ti)
debug_diagram(bts->bts, this->diag, "sched UL-ACK TLLI");
if (this->state_is(GPRS_RLCMAC_FINISHED))
debug_diagram(bts->bts, this->diag, "sched UL-ACK CV==0");
if ((this->dir.ul.rx_counter % SEND_ACK_AFTER_FRAMES) == 0)
debug_diagram(bts->bts, this->diag, "sched UL-ACK n=%d",
this->dir.ul.rx_counter);
#endif
/* trigger sending at next RTS */
this->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");
}
}
return 0;
}
/* Send Uplink unit-data to SGSN. */
int gprs_rlcmac_tbf::snd_ul_ud()
{
uint8_t qos_profile[3];
struct msgb *llc_pdu;
unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + m_llc.index;
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.index);
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.index));
tl16v_put(buf, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*m_llc.index, 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;
}
const char *tbf_name(gprs_rlcmac_tbf *tbf)
{
static char buf[40];
snprintf(buf, sizeof(buf), "TBF(TFI=%d TLLI=0x%08x DIR=%s)",
tbf->m_tfi, tbf->m_tlli,
tbf->direction == GPRS_RLCMAC_UL_TBF ? "UL" : "DL");
buf[sizeof(buf) - 1] = '\0';
return buf;
}
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