941 lines
26 KiB
C++
941 lines
26 KiB
C++
/* Copied from tbf.cpp
|
|
*
|
|
* Copyright (C) 2012 Ivan Klyuchnikov
|
|
* Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
|
|
* Copyright (C) 2013 by Holger Hans Peter Freyther
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#include <bts.h>
|
|
#include <tbf.h>
|
|
#include <rlc.h>
|
|
#include <gprs_rlcmac.h>
|
|
#include <gprs_debug.h>
|
|
#include <gprs_bssgp_pcu.h>
|
|
#include <decoding.h>
|
|
|
|
#include "pcu_utils.h"
|
|
|
|
extern "C" {
|
|
#include <osmocom/core/msgb.h>
|
|
#include <osmocom/core/talloc.h>
|
|
}
|
|
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
|
|
/* After sending these frames, we poll for ack/nack. */
|
|
#define POLL_ACK_AFTER_FRAMES 20
|
|
|
|
|
|
static const struct gprs_rlcmac_cs gprs_rlcmac_cs[] = {
|
|
/* frame length data block max payload */
|
|
{ 0, 0, 0 },
|
|
{ 23, 23, 20 }, /* CS-1 */
|
|
{ 34, 33, 30 }, /* CS-2 */
|
|
{ 40, 39, 36 }, /* CS-3 */
|
|
{ 54, 53, 50 }, /* CS-4 */
|
|
};
|
|
|
|
extern "C" {
|
|
int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
|
|
uint8_t num_frames, uint32_t num_octets);
|
|
}
|
|
|
|
static inline void tbf_update_ms_class(struct gprs_rlcmac_tbf *tbf,
|
|
const uint8_t ms_class)
|
|
{
|
|
if (!tbf->ms_class() && ms_class)
|
|
tbf->set_ms_class(ms_class);
|
|
}
|
|
|
|
static void llc_timer_cb(void *_tbf)
|
|
{
|
|
struct gprs_rlcmac_dl_tbf *tbf = (struct gprs_rlcmac_dl_tbf *)_tbf;
|
|
|
|
if (tbf->state_is_not(GPRS_RLCMAC_FLOW))
|
|
return;
|
|
|
|
LOGP(DRLCMAC, LOGL_DEBUG,
|
|
"%s LLC receive timeout, requesting DL ACK\n", tbf_name(tbf));
|
|
|
|
tbf->request_dl_ack();
|
|
}
|
|
|
|
void gprs_rlcmac_dl_tbf::cleanup()
|
|
{
|
|
osmo_timer_del(&m_llc_timer);
|
|
}
|
|
|
|
void gprs_rlcmac_dl_tbf::start_llc_timer()
|
|
{
|
|
if (bts_data()->llc_idle_ack_csec > 0) {
|
|
struct timeval tv;
|
|
|
|
/* TODO: this ought to be within a constructor */
|
|
m_llc_timer.data = this;
|
|
m_llc_timer.cb = &llc_timer_cb;
|
|
|
|
csecs_to_timeval(bts_data()->llc_idle_ack_csec, &tv);
|
|
osmo_timer_schedule(&m_llc_timer, tv.tv_sec, tv.tv_usec);
|
|
}
|
|
}
|
|
|
|
int gprs_rlcmac_dl_tbf::append_data(const uint8_t ms_class,
|
|
const uint16_t pdu_delay_csec,
|
|
const uint8_t *data, const uint16_t len)
|
|
{
|
|
LOGP(DRLCMAC, LOGL_INFO, "%s append\n", tbf_name(this));
|
|
gprs_llc_queue::MetaInfo info;
|
|
struct msgb *llc_msg = msgb_alloc(len, "llc_pdu_queue");
|
|
if (!llc_msg)
|
|
return -ENOMEM;
|
|
|
|
gprs_llc_queue::calc_pdu_lifetime(bts, pdu_delay_csec, &info.expire_time);
|
|
gettimeofday(&info.recv_time, NULL);
|
|
memcpy(msgb_put(llc_msg, len), data, len);
|
|
llc_queue()->enqueue(llc_msg, &info);
|
|
tbf_update_ms_class(this, ms_class);
|
|
start_llc_timer();
|
|
|
|
if (state_is(GPRS_RLCMAC_WAIT_RELEASE)) {
|
|
LOGP(DRLCMAC, LOGL_DEBUG,
|
|
"%s in WAIT RELEASE state "
|
|
"(T3193), so reuse TBF\n", tbf_name(this));
|
|
tbf_update_ms_class(this, ms_class);
|
|
reuse_tbf();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct gprs_rlcmac_dl_tbf *tbf_lookup_dl(BTS *bts,
|
|
const uint32_t tlli, const uint32_t tlli_old,
|
|
const char *imsi)
|
|
{
|
|
GprsMs *ms = bts->ms_store().get_ms(tlli, tlli_old, imsi);
|
|
if (!ms)
|
|
return NULL;
|
|
|
|
return ms->dl_tbf();
|
|
}
|
|
|
|
static int tbf_new_dl_assignment(struct gprs_rlcmac_bts *bts,
|
|
const char *imsi,
|
|
const uint32_t tlli, const uint32_t tlli_old,
|
|
const uint8_t ms_class,
|
|
struct gprs_rlcmac_dl_tbf **tbf)
|
|
{
|
|
uint8_t trx, ss;
|
|
int8_t use_trx;
|
|
uint16_t ta = 0;
|
|
struct gprs_rlcmac_ul_tbf *ul_tbf = NULL, *old_ul_tbf;
|
|
struct gprs_rlcmac_dl_tbf *dl_tbf = NULL;
|
|
int8_t tfi; /* must be signed */
|
|
GprsMs *ms;
|
|
|
|
/* 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"
|
|
ms = bts->bts->ms_store().get_ms(tlli, tlli_old, imsi);
|
|
if (ms) {
|
|
ul_tbf = ms->ul_tbf();
|
|
ta = ms->ta();
|
|
}
|
|
|
|
if (ul_tbf && ul_tbf->m_contention_resolution_done
|
|
&& !ul_tbf->m_final_ack_sent) {
|
|
use_trx = ul_tbf->trx->trx_no;
|
|
ss = 0;
|
|
old_ul_tbf = ul_tbf;
|
|
} else {
|
|
use_trx = -1;
|
|
ss = 1; /* PCH assignment only allows one timeslot */
|
|
old_ul_tbf = NULL;
|
|
}
|
|
|
|
// Create new TBF (any TRX)
|
|
#warning "Copy and paste with alloc_ul_tbf"
|
|
tfi = bts->bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, use_trx);
|
|
if (tfi >= 0)
|
|
/* set number of downlink slots according to multislot class */
|
|
dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf, tfi, trx, ms_class, ss);
|
|
|
|
if (!dl_tbf) {
|
|
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
|
|
return -EBUSY;
|
|
}
|
|
dl_tbf->update_ms(tlli, GPRS_RLCMAC_DL_TBF);
|
|
dl_tbf->ms()->set_ta(ta);
|
|
|
|
LOGP(DRLCMAC, LOGL_DEBUG, "%s [DOWNLINK] START\n", tbf_name(dl_tbf));
|
|
|
|
/* Store IMSI for later look-up and PCH retransmission */
|
|
dl_tbf->assign_imsi(imsi);
|
|
|
|
/* trigger downlink assignment and set state to ASSIGN.
|
|
* we don't use old_downlink, so the possible uplink is used
|
|
* to trigger downlink assignment. if there is no uplink,
|
|
* AGCH is used. */
|
|
dl_tbf->bts->trigger_dl_ass(dl_tbf, old_ul_tbf);
|
|
*tbf = dl_tbf;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* TODO: split into unit test-able parts...
|
|
*/
|
|
int gprs_rlcmac_dl_tbf::handle(struct gprs_rlcmac_bts *bts,
|
|
const uint32_t tlli, const uint32_t tlli_old, const char *imsi,
|
|
const uint8_t ms_class, const uint16_t delay_csec,
|
|
const uint8_t *data, const uint16_t len)
|
|
{
|
|
struct gprs_rlcmac_dl_tbf *dl_tbf;
|
|
int rc;
|
|
GprsMs *ms;
|
|
|
|
/* check for existing TBF */
|
|
dl_tbf = tbf_lookup_dl(bts->bts, tlli, tlli_old, imsi);
|
|
if (!dl_tbf) {
|
|
rc = tbf_new_dl_assignment(bts, imsi, tlli, tlli_old, ms_class,
|
|
&dl_tbf);
|
|
if (rc < 0)
|
|
return rc;
|
|
}
|
|
|
|
OSMO_ASSERT(dl_tbf->ms() != NULL);
|
|
ms = dl_tbf->ms();
|
|
GprsMs::Guard guard(ms);
|
|
|
|
rc = dl_tbf->append_data(ms_class, delay_csec, data, len);
|
|
|
|
dl_tbf = ms->dl_tbf();
|
|
|
|
dl_tbf->assign_imsi(imsi);
|
|
ms->confirm_tlli(tlli);
|
|
|
|
return rc;
|
|
}
|
|
|
|
struct msgb *gprs_rlcmac_dl_tbf::llc_dequeue(bssgp_bvc_ctx *bctx)
|
|
{
|
|
struct msgb *msg;
|
|
struct timeval tv_now, tv_now2;
|
|
uint32_t octets = 0, frames = 0;
|
|
struct timeval hyst_delta = {0, 0};
|
|
const unsigned keep_small_thresh = 60;
|
|
const gprs_llc_queue::MetaInfo *info;
|
|
|
|
if (bts_data()->llc_discard_csec)
|
|
csecs_to_timeval(bts_data()->llc_discard_csec, &hyst_delta);
|
|
|
|
gettimeofday(&tv_now, NULL);
|
|
timeradd(&tv_now, &hyst_delta, &tv_now2);
|
|
|
|
while ((msg = llc_queue()->dequeue(&info))) {
|
|
const struct timeval *tv_disc = &info->expire_time;
|
|
const struct timeval *tv_recv = &info->recv_time;
|
|
|
|
gprs_bssgp_update_queue_delay(tv_recv, &tv_now);
|
|
|
|
/* Is the age below the low water mark? */
|
|
if (!gprs_llc_queue::is_frame_expired(&tv_now2, tv_disc))
|
|
break;
|
|
|
|
/* Is the age below the high water mark */
|
|
if (!gprs_llc_queue::is_frame_expired(&tv_now, tv_disc)) {
|
|
/* Has the previous message not been dropped? */
|
|
if (frames == 0)
|
|
break;
|
|
|
|
/* Hysteresis mode, try to discard LLC messages until
|
|
* the low water mark has been reached */
|
|
|
|
/* Check whether to abort the hysteresis mode */
|
|
|
|
/* Is the frame small, perhaps only a TCP ACK? */
|
|
if (msg->len <= keep_small_thresh)
|
|
break;
|
|
|
|
/* Is it a GMM message? */
|
|
if (!gprs_llc::is_user_data_frame(msg->data, msg->len))
|
|
break;
|
|
}
|
|
|
|
bts->llc_timedout_frame();
|
|
frames++;
|
|
octets += msg->len;
|
|
msgb_free(msg);
|
|
bts->llc_dropped_frame();
|
|
continue;
|
|
}
|
|
|
|
if (frames) {
|
|
LOGP(DRLCMACDL, LOGL_NOTICE, "%s Discarding LLC PDU "
|
|
"because lifetime limit reached, "
|
|
"count=%u new_queue_size=%zu\n",
|
|
tbf_name(this), frames, llc_queue()->size());
|
|
if (frames > 0xff)
|
|
frames = 0xff;
|
|
if (octets > 0xffffff)
|
|
octets = 0xffffff;
|
|
bssgp_tx_llc_discarded(bctx, tlli(), frames, octets);
|
|
}
|
|
|
|
return msg;
|
|
}
|
|
|
|
/*
|
|
* Create DL data block
|
|
* The messages are fragmented and forwarded as data blocks.
|
|
*/
|
|
struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(uint32_t fn, uint8_t ts)
|
|
{
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink (V(A)==%d .. "
|
|
"V(S)==%d)\n", tbf_name(this),
|
|
m_window.v_a(), m_window.v_s());
|
|
|
|
do_resend:
|
|
/* check if there is a block with negative acknowledgement */
|
|
int resend_bsn = m_window.resend_needed();
|
|
if (resend_bsn >= 0) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Resending BSN %d\n", resend_bsn);
|
|
/* re-send block with negative aknowlegement */
|
|
m_window.m_v_b.mark_unacked(resend_bsn);
|
|
bts->rlc_resent();
|
|
return create_dl_acked_block(fn, ts, resend_bsn);
|
|
}
|
|
|
|
/* if the window has stalled, or transfer is complete,
|
|
* send an unacknowledged block */
|
|
if (state_is(GPRS_RLCMAC_FINISHED)) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, "
|
|
"because all blocks have been transmitted.\n",
|
|
m_window.v_a());
|
|
bts->rlc_restarted();
|
|
} else if (dl_window_stalled()) {
|
|
LOGP(DRLCMACDL, LOGL_NOTICE, "- Restarting at BSN %d, "
|
|
"because all window is stalled.\n",
|
|
m_window.v_a());
|
|
bts->rlc_stalled();
|
|
} else if (have_data()) {
|
|
/* New blocks may be send */
|
|
return create_new_bsn(fn, ts);
|
|
} else if (!m_window.window_empty()) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Restarting at BSN %d, "
|
|
"because all blocks have been transmitted (FLOW).\n",
|
|
m_window.v_a());
|
|
bts->rlc_restarted();
|
|
} else {
|
|
/* Nothing left to send, create dummy LLC commands */
|
|
return create_new_bsn(fn, ts);
|
|
}
|
|
|
|
/* If V(S) == V(A) and finished state, we would have received
|
|
* acknowledgement of all transmitted block. In this case we
|
|
* would have transmitted the final block, and received ack
|
|
* from MS. But in this case we did not receive the final ack
|
|
* indication from MS. This should never happen if MS works
|
|
* correctly. */
|
|
if (m_window.window_empty()) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- MS acked all blocks, "
|
|
"so we re-transmit final block!\n");
|
|
/* we just send final block again */
|
|
int16_t index = m_window.v_s_mod(-1);
|
|
bts->rlc_resent();
|
|
return create_dl_acked_block(fn, ts, index);
|
|
}
|
|
|
|
/* cycle through all unacked blocks */
|
|
int resend = m_window.mark_for_resend();
|
|
|
|
/* At this point there should be at least one unacked block
|
|
* to be resent. If not, this is an software error. */
|
|
if (resend == 0) {
|
|
LOGP(DRLCMACDL, LOGL_ERROR, "Software error: "
|
|
"There are no unacknowledged blocks, but V(A) "
|
|
" != V(S). PLEASE FIX!\n");
|
|
/* we just send final block again */
|
|
int16_t index = m_window.v_s_mod(-1);
|
|
return create_dl_acked_block(fn, ts, index);
|
|
}
|
|
goto do_resend;
|
|
}
|
|
|
|
void gprs_rlcmac_dl_tbf::schedule_next_frame()
|
|
{
|
|
struct msgb *msg;
|
|
|
|
if (m_llc.frame_length() != 0)
|
|
return;
|
|
|
|
/* dequeue next LLC frame, if any */
|
|
msg = llc_dequeue(gprs_bssgp_pcu_current_bctx());
|
|
if (!msg)
|
|
return;
|
|
|
|
LOGP(DRLCMACDL, LOGL_INFO,
|
|
"- Dequeue next LLC for %s (len=%d)\n",
|
|
tbf_name(this), msg->len);
|
|
|
|
m_llc.put_frame(msg->data, msg->len);
|
|
bts->llc_frame_sched();
|
|
msgb_free(msg);
|
|
m_last_dl_drained_fn = -1;
|
|
}
|
|
|
|
struct msgb *gprs_rlcmac_dl_tbf::create_new_bsn(const uint32_t fn, const uint8_t ts)
|
|
{
|
|
struct rlc_dl_header *rh;
|
|
struct rlc_li_field *li;
|
|
uint8_t *delimiter, *data, *e_pointer;
|
|
uint16_t space, chunk;
|
|
gprs_rlc_data *rlc_data;
|
|
const uint16_t bsn = m_window.v_s();
|
|
uint8_t cs = 1;
|
|
|
|
if (m_llc.frame_length() == 0)
|
|
schedule_next_frame();
|
|
|
|
cs = current_cs();
|
|
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d, CS=%d\n",
|
|
m_window.v_s(), cs);
|
|
|
|
OSMO_ASSERT(cs >= 1);
|
|
OSMO_ASSERT(cs <= 4);
|
|
|
|
/* total length of block, including spare bits */
|
|
const uint8_t block_length = gprs_rlcmac_cs[cs].block_length;
|
|
/* length of usable data of block, w/o spare bits, inc. MAC */
|
|
const uint8_t block_data_len = gprs_rlcmac_cs[cs].block_data;
|
|
|
|
/* now we still have untransmitted LLC data, so we fill mac block */
|
|
rlc_data = m_rlc.block(bsn);
|
|
data = rlc_data->prepare(block_data_len);
|
|
rlc_data->cs = cs;
|
|
|
|
rh = (struct rlc_dl_header *)data;
|
|
rh->pt = 0; /* Data Block */
|
|
rh->rrbp = rh->s_p = 0; /* Polling, set later, if required */
|
|
rh->usf = 7; /* will be set at scheduler */
|
|
rh->pr = 0; /* FIXME: power reduction */
|
|
rh->tfi = m_tfi; /* TFI */
|
|
rh->fbi = 0; /* Final Block Indicator, set late, if true */
|
|
rh->bsn = bsn; /* Block Sequence Number */
|
|
rh->e = 0; /* Extension bit, maybe set later */
|
|
e_pointer = data + 2; /* points to E of current chunk */
|
|
data += sizeof(*rh);
|
|
delimiter = data; /* where next length header would be stored */
|
|
space = block_data_len - sizeof(*rh);
|
|
while (1) {
|
|
if (m_llc.frame_length() == 0) {
|
|
/* A header will need to by added, so we just need
|
|
* space-1 octets */
|
|
m_llc.put_dummy_frame(space - 1);
|
|
|
|
/* The data just drained, store the current fn */
|
|
if (m_last_dl_drained_fn < 0)
|
|
m_last_dl_drained_fn = fn;
|
|
|
|
/* It is not clear, when the next real data will
|
|
* arrive, so request a DL ack/nack now */
|
|
request_dl_ack();
|
|
|
|
LOGP(DRLCMACDL, LOGL_DEBUG,
|
|
"-- Empty chunk, "
|
|
"added LLC dummy command of size %d, "
|
|
"drained_since=%d\n",
|
|
m_llc.frame_length(), frames_since_last_drain(fn));
|
|
}
|
|
|
|
chunk = m_llc.chunk_size();
|
|
|
|
/* if chunk will exceed block limit */
|
|
if (chunk > space) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
|
|
"larger than space (%d) left in block: copy "
|
|
"only remaining space, and we are done\n",
|
|
chunk, space);
|
|
/* block is filled, so there is no extension */
|
|
*e_pointer |= 0x01;
|
|
/* fill only space */
|
|
m_llc.consume(data, space);
|
|
/* return data block as message */
|
|
break;
|
|
}
|
|
/* if FINAL chunk would fit precisely in space left */
|
|
if (chunk == space && llc_queue()->size() == 0 && !keep_open(fn))
|
|
{
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
|
|
"would exactly fit into space (%d): because "
|
|
"this is a final block, we don't add length "
|
|
"header, and we are done\n", chunk, space);
|
|
LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for "
|
|
"%s that fits precisely in last block: "
|
|
"len=%d\n", tbf_name(this), m_llc.frame_length());
|
|
gprs_rlcmac_dl_bw(this, m_llc.frame_length());
|
|
/* block is filled, so there is no extension */
|
|
*e_pointer |= 0x01;
|
|
/* fill space */
|
|
m_llc.consume(data, space);
|
|
m_llc.reset();
|
|
/* final block */
|
|
rh->fbi = 1; /* we indicate final block */
|
|
request_dl_ack();
|
|
set_state(GPRS_RLCMAC_FINISHED);
|
|
/* return data block as message */
|
|
break;
|
|
}
|
|
/* if chunk would fit exactly in space left */
|
|
if (chunk == space) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d "
|
|
"would exactly fit into space (%d): add length "
|
|
"header with LI=0, to make frame extend to "
|
|
"next block, and we are done\n", chunk, space);
|
|
/* make space for delimiter */
|
|
if (delimiter != data)
|
|
memmove(delimiter + 1, delimiter,
|
|
data - delimiter);
|
|
data++;
|
|
space--;
|
|
/* add LI with 0 length */
|
|
li = (struct rlc_li_field *)delimiter;
|
|
li->e = 1; /* not more extension */
|
|
li->m = 0; /* shall be set to 0, in case of li = 0 */
|
|
li->li = 0; /* chunk fills the complete space */
|
|
// no need to set e_pointer nor increase delimiter
|
|
/* fill only space, which is 1 octet less than chunk */
|
|
m_llc.consume(data, space);
|
|
/* return data block as message */
|
|
break;
|
|
}
|
|
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- Chunk with length %d is less "
|
|
"than remaining space (%d): add length header to "
|
|
"to delimit LLC frame\n", chunk, space);
|
|
/* the LLC frame chunk ends in this block */
|
|
/* make space for delimiter */
|
|
if (delimiter != data)
|
|
memmove(delimiter + 1, delimiter, data - delimiter);
|
|
data++;
|
|
space--;
|
|
/* add LI to delimit frame */
|
|
li = (struct rlc_li_field *)delimiter;
|
|
li->e = 0; /* Extension bit, maybe set later */
|
|
li->m = 0; /* will be set later, if there is more LLC data */
|
|
li->li = chunk; /* length of chunk */
|
|
e_pointer = delimiter; /* points to E of current delimiter */
|
|
delimiter++;
|
|
/* copy (rest of) LLC frame to space and reset later */
|
|
m_llc.consume(data, chunk);
|
|
data += chunk;
|
|
space -= chunk;
|
|
LOGP(DRLCMACDL, LOGL_INFO, "Complete DL frame for %s"
|
|
"len=%d\n", tbf_name(this), m_llc.frame_length());
|
|
gprs_rlcmac_dl_bw(this, m_llc.frame_length());
|
|
m_llc.reset();
|
|
/* dequeue next LLC frame, if any */
|
|
schedule_next_frame();
|
|
/* if we have more data and we have space left */
|
|
if (space > 0 && (m_llc.frame_length() || keep_open(fn))) {
|
|
li->m = 1; /* we indicate more frames to follow */
|
|
continue;
|
|
}
|
|
/* if we don't have more LLC frames */
|
|
if (!m_llc.frame_length() && !keep_open(fn)) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- Final block, so we "
|
|
"done.\n");
|
|
li->e = 1; /* we cannot extend */
|
|
|
|
rh->fbi = 1; /* we indicate final block */
|
|
request_dl_ack();
|
|
set_state(GPRS_RLCMAC_FINISHED);
|
|
break;
|
|
}
|
|
/* we have no space left */
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "-- No space left, so we are "
|
|
"done.\n");
|
|
li->e = 1; /* we cannot extend */
|
|
break;
|
|
}
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "data block: %s\n",
|
|
osmo_hexdump(rlc_data->block, block_length));
|
|
#warning "move this up?"
|
|
rlc_data->len = block_length;
|
|
/* raise send state and set ack state array */
|
|
m_window.m_v_b.mark_unacked(bsn);
|
|
m_window.increment_send();
|
|
|
|
return create_dl_acked_block(fn, ts, bsn);
|
|
}
|
|
|
|
struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
|
|
const uint32_t fn, const uint8_t ts,
|
|
const int index)
|
|
{
|
|
uint8_t *data;
|
|
struct rlc_dl_header *rh;
|
|
struct msgb *dl_msg;
|
|
uint8_t len;
|
|
bool need_poll;
|
|
|
|
/* get data and header from current block */
|
|
data = m_rlc.block(index)->block;
|
|
len = m_rlc.block(index)->len;
|
|
rh = (struct rlc_dl_header *)data;
|
|
|
|
/* If the TBF has just started, relate frames_since_last_poll to the
|
|
* current fn */
|
|
if (m_last_dl_poll_fn < 0)
|
|
m_last_dl_poll_fn = fn;
|
|
|
|
need_poll = state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
|
|
/* Clear Polling, if still set in history buffer */
|
|
rh->s_p = 0;
|
|
|
|
/* poll after POLL_ACK_AFTER_FRAMES frames, or when final block is tx.
|
|
*/
|
|
if (m_tx_counter >= POLL_ACK_AFTER_FRAMES || m_dl_ack_requested ||
|
|
need_poll) {
|
|
if (m_dl_ack_requested) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
|
|
"polling, because is was requested explicitly "
|
|
"(e.g. first final block sent).\n");
|
|
} else if (need_poll) {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
|
|
"polling, because polling timed out.\n");
|
|
} else {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Scheduling Ack/Nack "
|
|
"polling, because %d blocks sent.\n",
|
|
POLL_ACK_AFTER_FRAMES);
|
|
}
|
|
/* scheduling not possible, because: */
|
|
if (poll_state != GPRS_RLCMAC_POLL_NONE)
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "Polling is already "
|
|
"sheduled for %s, so we must wait for "
|
|
"requesting downlink ack\n", tbf_name(this));
|
|
else if (control_ts != ts)
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "Polling cannot be "
|
|
"sheduled in this TS %d, waiting for "
|
|
"TS %d\n", ts, control_ts);
|
|
else if (bts->sba()->find(trx->trx_no, ts, (fn + 13) % 2715648))
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "Polling cannot be "
|
|
"sheduled, because single block alllocation "
|
|
"already exists\n");
|
|
else {
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "Polling sheduled in this "
|
|
"TS %d\n", ts);
|
|
m_tx_counter = 0;
|
|
/* start timer whenever we send the final block */
|
|
if (rh->fbi == 1)
|
|
tbf_timer_start(this, 3191, bts_data()->t3191, 0);
|
|
|
|
/* schedule polling */
|
|
poll_state = GPRS_RLCMAC_POLL_SCHED;
|
|
poll_fn = (fn + 13) % 2715648;
|
|
|
|
/* Clear poll timeout flag */
|
|
state_flags &= ~(1 << GPRS_RLCMAC_FLAG_TO_DL_ACK);
|
|
|
|
/* Clear request flag */
|
|
m_dl_ack_requested = false;
|
|
|
|
/* set polling in header */
|
|
rh->rrbp = 0; /* N+13 */
|
|
rh->s_p = 1; /* Polling */
|
|
|
|
m_last_dl_poll_fn = poll_fn;
|
|
}
|
|
}
|
|
|
|
/* return data block as message */
|
|
dl_msg = msgb_alloc(len, "rlcmac_dl_data");
|
|
if (!dl_msg)
|
|
return NULL;
|
|
|
|
/* Increment TX-counter */
|
|
m_tx_counter++;
|
|
|
|
memcpy(msgb_put(dl_msg, len), data, len);
|
|
bts->rlc_sent();
|
|
|
|
return dl_msg;
|
|
}
|
|
|
|
static uint16_t bitnum_to_bsn(int bitnum, uint16_t ssn, uint16_t mod_sns)
|
|
{
|
|
return (ssn - 1 - bitnum) & mod_sns;
|
|
}
|
|
|
|
int gprs_rlcmac_dl_tbf::analyse_errors(char *show_rbb, uint8_t ssn)
|
|
{
|
|
gprs_rlc_data *rlc_data;
|
|
uint16_t lost = 0, received = 0, skipped = 0;
|
|
char info[65];
|
|
memset(info, '.', sizeof(info));
|
|
info[64] = 0;
|
|
uint16_t bsn = 0;
|
|
|
|
/* SSN - 1 is in range V(A)..V(S)-1 */
|
|
for (int bitpos = 0; bitpos < m_window.ws(); bitpos++) {
|
|
bsn = bitnum_to_bsn(bitpos, ssn, m_window.mod_sns());
|
|
|
|
if (bsn == ((m_window.v_a() - 1) & m_window.mod_sns())) {
|
|
info[bitpos] = '$';
|
|
break;
|
|
}
|
|
|
|
rlc_data = m_rlc.block(bsn);
|
|
if (!rlc_data) {
|
|
info[bitpos] = '0';
|
|
continue;
|
|
}
|
|
|
|
if (rlc_data->cs != current_cs()) {
|
|
/* This block has already been encoded with a different
|
|
* CS, so it doesn't help us to decide, whether the
|
|
* current CS is ok. Ignore it. */
|
|
info[bitpos] = 'x';
|
|
skipped += 1;
|
|
continue;
|
|
}
|
|
|
|
if (show_rbb[m_window.ws() - 1 - bitpos] == 'R') {
|
|
if (!m_window.m_v_b.is_acked(bsn)) {
|
|
received += 1;
|
|
info[bitpos] = 'R';
|
|
} else {
|
|
info[bitpos] = 'r';
|
|
}
|
|
} else {
|
|
info[bitpos] = 'L';
|
|
lost += 1;
|
|
}
|
|
}
|
|
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "%s DL analysis, range=%d:%d, lost=%d, recv=%d, "
|
|
"skipped=%d, bsn=%d, info='%s'\n",
|
|
name(), m_window.v_a(), m_window.v_s(), lost, received,
|
|
skipped, bsn, info);
|
|
|
|
if (lost + received <= 1)
|
|
return -1;
|
|
|
|
return lost * 100 / (lost + received);
|
|
}
|
|
|
|
|
|
int gprs_rlcmac_dl_tbf::update_window(const uint8_t ssn, const uint8_t *rbb)
|
|
{
|
|
int16_t dist; /* must be signed */
|
|
uint16_t lost = 0, received = 0;
|
|
char show_rbb[65];
|
|
char show_v_b[RLC_MAX_SNS + 1];
|
|
const uint16_t mod_sns = m_window.mod_sns();
|
|
int error_rate;
|
|
|
|
Decoding::extract_rbb(rbb, show_rbb);
|
|
/* show received array in debug (bit 64..1) */
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- ack: (BSN=%d)\"%s\""
|
|
"(BSN=%d) R=ACK I=NACK\n", (ssn - 64) & mod_sns,
|
|
show_rbb, (ssn - 1) & mod_sns);
|
|
|
|
/* apply received array to receive state (SSN-64..SSN-1) */
|
|
/* calculate distance of ssn from V(S) */
|
|
dist = (m_window.v_s() - ssn) & mod_sns;
|
|
/* check if distance is less than distance V(A)..V(S) */
|
|
if (dist >= m_window.distance()) {
|
|
/* this might happpen, if the downlink assignment
|
|
* was not received by ms and the ack refers
|
|
* to previous TBF
|
|
* FIXME: we should implement polling for
|
|
* control ack!*/
|
|
LOGP(DRLCMACDL, LOGL_NOTICE, "- ack range is out of "
|
|
"V(A)..V(S) range %s Free TBF!\n", tbf_name(this));
|
|
return 1; /* indicate to free TBF */
|
|
}
|
|
|
|
if (bts_data()->cs_adj_enabled && ms()) {
|
|
error_rate = analyse_errors(show_rbb, ssn);
|
|
ms()->update_error_rate(this, error_rate);
|
|
}
|
|
|
|
m_window.update(bts, show_rbb, ssn,
|
|
&lost, &received);
|
|
|
|
/* report lost and received packets */
|
|
gprs_rlcmac_received_lost(this, received, lost);
|
|
|
|
/* raise V(A), if possible */
|
|
m_window.raise(m_window.move_window());
|
|
|
|
/* show receive state array in debug (V(A)..V(S)-1) */
|
|
m_window.show_state(show_v_b);
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- V(B): (V(A)=%d)\"%s\""
|
|
"(V(S)-1=%d) A=Acked N=Nacked U=Unacked "
|
|
"X=Resend-Unacked I=Invalid\n",
|
|
m_window.v_a(), show_v_b,
|
|
m_window.v_s_mod(-1));
|
|
|
|
if (state_is(GPRS_RLCMAC_FINISHED) && m_window.window_empty()) {
|
|
LOGP(DRLCMACDL, LOGL_NOTICE, "Received acknowledge of "
|
|
"all blocks, but without final ack "
|
|
"inidcation (don't worry)\n");
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
int gprs_rlcmac_dl_tbf::maybe_start_new_window()
|
|
{
|
|
uint16_t received;
|
|
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- Final ACK received.\n");
|
|
/* range V(A)..V(S)-1 */
|
|
received = m_window.count_unacked();
|
|
|
|
/* report all outstanding packets as received */
|
|
gprs_rlcmac_received_lost(this, received, 0);
|
|
|
|
set_state(GPRS_RLCMAC_WAIT_RELEASE);
|
|
|
|
/* check for LLC PDU in the LLC Queue */
|
|
if (!have_data()) {
|
|
/* no message, start T3193, change state to RELEASE */
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "- No new message, so we release.\n");
|
|
/* start T3193 */
|
|
tbf_timer_start(this, 3193,
|
|
bts_data()->t3193_msec / 1000,
|
|
(bts_data()->t3193_msec % 1000) * 1000);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* we have more data so we will re-use this tbf */
|
|
reuse_tbf();
|
|
return 0;
|
|
}
|
|
|
|
int gprs_rlcmac_dl_tbf::rcvd_dl_ack(uint8_t final_ack, uint8_t ssn, uint8_t *rbb)
|
|
{
|
|
LOGP(DRLCMACDL, LOGL_DEBUG, "%s downlink acknowledge\n", tbf_name(this));
|
|
|
|
if (!final_ack)
|
|
return update_window(ssn, rbb);
|
|
return maybe_start_new_window();
|
|
}
|
|
|
|
void gprs_rlcmac_dl_tbf::reuse_tbf()
|
|
{
|
|
uint8_t trx;
|
|
struct gprs_rlcmac_dl_tbf *new_tbf = NULL;
|
|
int8_t tfi; /* must be signed */
|
|
|
|
bts->tbf_reused();
|
|
|
|
tfi = bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx, this->trx->trx_no);
|
|
if (tfi >= 0)
|
|
new_tbf = tbf_alloc_dl_tbf(bts->bts_data(), NULL, tfi, trx,
|
|
ms_class(), 0);
|
|
|
|
if (!new_tbf) {
|
|
LOGP(DRLCMAC, LOGL_NOTICE, "No PDCH resource\n");
|
|
return;
|
|
}
|
|
|
|
new_tbf->set_ms(ms());
|
|
|
|
/* reset rlc states */
|
|
m_tx_counter = 0;
|
|
m_wait_confirm = 0;
|
|
m_window.reset();
|
|
|
|
/* keep to flags */
|
|
state_flags &= GPRS_RLCMAC_FLAG_TO_MASK;
|
|
state_flags &= ~(1 << GPRS_RLCMAC_FLAG_CCCH);
|
|
|
|
update();
|
|
|
|
LOGP(DRLCMAC, LOGL_DEBUG, "%s Trigger dowlink assignment on PACCH, "
|
|
"because another LLC PDU has arrived in between\n",
|
|
tbf_name(this));
|
|
bts->trigger_dl_ass(new_tbf, this);
|
|
}
|
|
|
|
bool gprs_rlcmac_dl_tbf::dl_window_stalled() const
|
|
{
|
|
return m_window.window_stalled();
|
|
}
|
|
|
|
void gprs_rlcmac_dl_tbf::request_dl_ack()
|
|
{
|
|
m_dl_ack_requested = true;
|
|
}
|
|
|
|
bool gprs_rlcmac_dl_tbf::need_control_ts() const
|
|
{
|
|
if (poll_state != GPRS_RLCMAC_POLL_NONE)
|
|
return false;
|
|
|
|
return state_flags & (1 << GPRS_RLCMAC_FLAG_TO_DL_ACK) ||
|
|
m_tx_counter >= POLL_ACK_AFTER_FRAMES ||
|
|
m_dl_ack_requested;
|
|
}
|
|
|
|
bool gprs_rlcmac_dl_tbf::have_data() const
|
|
{
|
|
return m_llc.chunk_size() > 0 ||
|
|
(llc_queue() && llc_queue()->size() > 0);
|
|
}
|
|
|
|
int gprs_rlcmac_dl_tbf::frames_since_last_poll(unsigned fn) const
|
|
{
|
|
unsigned wrapped;
|
|
if (m_last_dl_poll_fn < 0)
|
|
return -1;
|
|
|
|
wrapped = (fn + 2715648 - m_last_dl_poll_fn) % 2715648;
|
|
if (wrapped < 2715648/2)
|
|
return wrapped;
|
|
else
|
|
return wrapped - 2715648;
|
|
}
|
|
|
|
int gprs_rlcmac_dl_tbf::frames_since_last_drain(unsigned fn) const
|
|
{
|
|
unsigned wrapped;
|
|
if (m_last_dl_drained_fn < 0)
|
|
return -1;
|
|
|
|
wrapped = (fn + 2715648 - m_last_dl_drained_fn) % 2715648;
|
|
if (wrapped < 2715648/2)
|
|
return wrapped;
|
|
else
|
|
return wrapped - 2715648;
|
|
}
|
|
|
|
bool gprs_rlcmac_dl_tbf::keep_open(unsigned fn) const
|
|
{
|
|
int keep_time_frames;
|
|
|
|
if (bts_data()->dl_tbf_idle_msec <= 0)
|
|
return false;
|
|
|
|
keep_time_frames = msecs_to_frames(bts_data()->dl_tbf_idle_msec);
|
|
return frames_since_last_drain(fn) <= keep_time_frames;
|
|
}
|