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osmo-pcu/src/tbf_ul.cpp

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/* Copied from tbf.cpp
*
* Copyright (C) 2012 Ivan Klyuchnikov
* Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
* Copyright (C) 2013 by Holger Hans Peter Freyther
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <bts.h>
#include <tbf.h>
#include <rlc.h>
#include <encoding.h>
#include <gprs_rlcmac.h>
#include <gprs_debug.h>
#include <gprs_bssgp_pcu.h>
#include <decoding.h>
#include <pcu_l1_if.h>
extern "C" {
#include <osmocom/core/msgb.h>
#include <osmocom/core/talloc.h>
}
#include <errno.h>
#include <string.h>
/* After receiving these frames, we send ack/nack. */
#define SEND_ACK_AFTER_FRAMES 20
extern void *tall_pcu_ctx;
/*
* Store received block data in LLC message(s) and forward to SGSN
* if complete.
*/
int gprs_rlcmac_ul_tbf::assemble_forward_llc(const gprs_rlc_data *_data)
{
const uint8_t *data = _data->block;
uint8_t len = _data->len;
const struct gprs_rlc_ul_data_block_info *rdbi = &_data->block_info;
GprsCodingScheme cs = _data->cs;
Decoding::RlcData frames[16], *frame;
int i, num_frames = 0;
uint32_t dummy_tlli;
LOGP(DRLCMACUL, LOGL_DEBUG, "- Assembling frames: (len=%d)\n", len);
num_frames = Decoding::rlc_data_from_ul_data(
rdbi, cs, data, &(frames[0]), sizeof(frames),
&dummy_tlli);
/* create LLC frames */
for (i = 0; i < num_frames; i++) {
frame = frames + i;
LOGP(DRLCMACUL, LOGL_DEBUG, "-- Frame %d starts at offset %d, "
"length=%d, is_complete=%d\n",
i + 1, frame->offset, frame->length, frame->is_complete);
m_llc.append_frame(data + frame->offset, frame->length);
m_llc.consume(frame->length);
if (frame->is_complete) {
/* send frame to SGSN */
LOGP(DRLCMACUL, LOGL_INFO, "%s complete UL frame len=%d\n",
tbf_name(this) , m_llc.frame_length());
snd_ul_ud();
m_llc.reset();
}
}
return 0;
}
struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn)
{
int final = (state_is(GPRS_RLCMAC_FINISHED));
struct msgb *msg;
if (final) {
if (poll_state != GPRS_RLCMAC_POLL_NONE) {
LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
"sheduled for %s, so we must wait for "
"final uplink ack...\n", tbf_name(this));
return NULL;
}
if (bts->sba()->find(trx->trx_no, control_ts, (fn + 13) % 2715648)) {
LOGP(DRLCMACUL, LOGL_DEBUG, "Polling is already "
"scheduled for single block allocation...\n");
return NULL;
}
}
msg = msgb_alloc(23, "rlcmac_ul_ack");
if (!msg)
return NULL;
bitvec *ack_vec = bitvec_alloc(23);
if (!ack_vec) {
msgb_free(msg);
return NULL;
}
bitvec_unhex(ack_vec,
"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
Encoding::write_packet_uplink_ack(bts_data(), mac_control_block, this, final);
encode_gsm_rlcmac_downlink(ack_vec, mac_control_block);
bitvec_pack(ack_vec, msgb_put(msg, 23));
bitvec_free(ack_vec);
talloc_free(mac_control_block);
/* now we must set this flag, so we are allowed to assign downlink
* TBF on PACCH. it is only allowed when TLLI is acknowledged. */
m_contention_resolution_done = 1;
if (final) {
poll_state = GPRS_RLCMAC_POLL_SCHED;
poll_fn = (fn + 13) % 2715648;
/* waiting for final acknowledge */
ul_ack_state = GPRS_RLCMAC_UL_ACK_WAIT_ACK;
m_final_ack_sent = 1;
} else
ul_ack_state = GPRS_RLCMAC_UL_ACK_NONE;
return msg;
}
int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged(
const struct gprs_rlc_ul_header_egprs *rlc,
uint8_t *data, uint8_t len, struct pcu_l1_meas *meas)
{
int8_t rssi = meas->have_rssi ? meas->rssi : 0;
const uint16_t ws = m_window.ws();
this->state_flags |= (1 << GPRS_RLCMAC_FLAG_UL_DATA);
LOGP(DRLCMACUL, LOGL_DEBUG, "UL DATA TFI=%d received (V(Q)=%d .. "
"V(R)=%d)\n", rlc->tfi, this->m_window.v_q(),
this->m_window.v_r());
/* process RSSI */
gprs_rlcmac_rssi(this, rssi);
/* store measurement values */
if (ms())
ms()->update_l1_meas(meas);
uint32_t new_tlli = 0;
unsigned int block_idx;
/* restart T3169 */
tbf_timer_start(this, 3169, bts_data()->t3169, 0);
/* Increment RX-counter */
this->m_rx_counter++;
/* Loop over num_blocks */
for (block_idx = 0; block_idx < rlc->num_data_blocks; block_idx++) {
int num_chunks;
uint8_t *rlc_data;
const struct gprs_rlc_ul_data_block_info *rdbi =
&rlc->block_info[block_idx];
bool need_rlc_data = false;
struct gprs_rlc_data *block;
LOGP(DRLCMACUL, LOGL_DEBUG,
"%s: Got %s RLC data block: "
"CV=%d, BSN=%d, SPB=%d, "
"PI=%d, E=%d, TI=%d, bitoffs=%d\n",
name(), rlc->cs.name(),
rdbi->cv, rdbi->bsn, rdbi->spb,
rdbi->pi, rdbi->e, rdbi->ti,
rlc->data_offs_bits[block_idx]);
/* Check whether the block needs to be decoded */
if (!m_window.is_in_window(rdbi->bsn)) {
LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d out of window "
"%d..%d (it's normal)\n", rdbi->bsn,
m_window.v_q(),
m_window.mod_sns(m_window.v_q() + ws - 1));
} else if (m_window.is_received(rdbi->bsn)) {
LOGP(DRLCMACUL, LOGL_DEBUG,
"- BSN %d already received\n", rdbi->bsn);
} else {
need_rlc_data = true;
}
if (!is_tlli_valid()) {
if (!rdbi->ti) {
LOGP(DRLCMACUL, LOGL_NOTICE,
"%s: Missing TLLI within UL DATA.\n",
name());
continue;
}
need_rlc_data = true;
}
if (!need_rlc_data)
continue;
/* Store block and meta info to BSN buffer */
LOGP(DRLCMACUL, LOGL_DEBUG, "- BSN %d storing in window (%d..%d)\n",
rdbi->bsn, m_window.v_q(),
m_window.mod_sns(m_window.v_q() + ws - 1));
block = m_rlc.block(rdbi->bsn);
block->block_info = *rdbi;
block->cs = rlc->cs;
OSMO_ASSERT(rdbi->data_len < sizeof(block->block));
rlc_data = &(block->block[0]);
/* TODO: Handle SPB != 0 -> Set length to 2*len, add offset if
* 2nd part. Note that resegmentation is currently disabled
* within the UL assignment.
*/
if (rdbi->spb) {
LOGP(DRLCMACUL, LOGL_NOTICE,
"Got SPB != 0 but resegmentation has been "
"disabled, skipping %s data block with BSN %d, "
"TFI=%d.\n", rlc->cs.name(), rdbi->bsn,
rlc->tfi);
continue;
}
block->len =
Decoding::rlc_copy_to_aligned_buffer(rlc, block_idx, data,
rlc_data);
LOGP(DRLCMACUL, LOGL_DEBUG,
"%s: data_length=%d, data=%s\n",
name(), block->len, osmo_hexdump(rlc_data, block->len));
/* TODO: Handle SPB != 0 -> set state to partly received
* (upper/lower) and continue with the loop, unless the other
* part is already present.
*/
/* Get/Handle TLLI */
if (rdbi->ti) {
num_chunks = Decoding::rlc_data_from_ul_data(
rdbi, rlc->cs, rlc_data, NULL, 0, &new_tlli);
if (num_chunks < 0) {
bts->decode_error();
LOGP(DRLCMACUL, LOGL_NOTICE,
"Failed to decode TLLI of %s UL DATA "
"TFI=%d.\n", rlc->cs.name(), rlc->tfi);
m_window.invalidate_bsn(rdbi->bsn);
continue;
}
if (!this->is_tlli_valid()) {
if (!new_tlli) {
LOGP(DRLCMACUL, LOGL_NOTICE,
"%s: TLLI = 0 within UL DATA.\n",
name());
m_window.invalidate_bsn(rdbi->bsn);
continue;
}
LOGP(DRLCMACUL, LOGL_INFO,
"Decoded premier TLLI=0x%08x of "
"UL DATA TFI=%d.\n", tlli(), rlc->tfi);
set_tlli_from_ul(new_tlli);
} else if (new_tlli && new_tlli != tlli()) {
LOGP(DRLCMACUL, LOGL_NOTICE, "TLLI mismatch on UL "
"DATA TFI=%d. (Ignoring due to contention "
"resolution)\n", rlc->tfi);
m_window.invalidate_bsn(rdbi->bsn);
continue;
}
}
m_window.receive_bsn(rdbi->bsn);
}
/* Raise V(Q) if possible, and retrieve LLC frames from blocks.
* This is looped until there is a gap (non received block) or
* the window is empty.*/
const uint16_t v_q_beg = m_window.v_q();
const uint16_t count = m_window.raise_v_q();
/* Retrieve LLC frames from blocks that are ready */
for (uint16_t i = 0; i < count; ++i) {
uint16_t index = m_window.mod_sns(v_q_beg + i);
assemble_forward_llc(m_rlc.block(index));
}
/* Check CV of last frame in buffer */
if (this->state_is(GPRS_RLCMAC_FLOW) /* still in flow state */
&& this->m_window.v_q() == this->m_window.v_r()) { /* if complete */
struct gprs_rlc_data *block =
m_rlc.block(m_window.mod_sns(m_window.v_r() - 1));
const struct gprs_rlc_ul_data_block_info *rdbi =
&block->block_info;
LOGP(DRLCMACUL, LOGL_DEBUG, "- No gaps in received block, "
"last block: BSN=%d CV=%d\n", rdbi->bsn,
rdbi->cv);
if (rdbi->cv == 0) {
LOGP(DRLCMACUL, LOGL_DEBUG, "- Finished with UL "
"TBF\n");
set_state(GPRS_RLCMAC_FINISHED);
/* Reset N3103 counter. */
this->m_n3103 = 0;
}
}
/* If TLLI is included or if we received half of the window, we send
* an ack/nack */
maybe_schedule_uplink_acknack(rlc);
return 0;
}
void gprs_rlcmac_ul_tbf::maybe_schedule_uplink_acknack(
const gprs_rlc_ul_header_egprs *rlc)
{
bool have_ti = rlc->block_info[0].ti ||
(rlc->num_data_blocks > 1 && rlc->block_info[1].ti);
if (rlc->si || have_ti || state_is(GPRS_RLCMAC_FINISHED) ||
(m_rx_counter % SEND_ACK_AFTER_FRAMES) == 0)
{
if (rlc->si) {
LOGP(DRLCMACUL, LOGL_NOTICE, "- Scheduling Ack/Nack, "
"because MS is stalled.\n");
}
if (have_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;
}
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