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osmo-pcu/src/gprs_rlcmac.cpp

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/* gprs_rlcmac.cpp
*
* Copyright (C) 2012 Ivan Klyuchnikov
*
* 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 <gprs_bssgp_pcu.h>
#include <pcu_l1_if.h>
#include <gprs_rlcmac.h>
#include <gsmL1prim.h>
LLIST_HEAD(gprs_rlcmac_tbfs);
void *rlcmac_tall_ctx;
int tfi_alloc()
{
struct gprs_rlcmac_tbf *tbf;
uint32_t tfi_map = 0;
uint32_t tfi_ind = 0;
uint32_t mask = 1;
uint8_t i;
llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
tfi_ind = 1 << tbf->tfi;
tfi_map = tfi_map|tfi_ind;
}
for (i = 0; i < 32; i++) {
if(((tfi_map >> i) & mask) == 0) {
return i;
}
}
return -1;
}
/* lookup TBF Entity (by TFI) */
static struct gprs_rlcmac_tbf *tbf_by_tfi(uint8_t tfi)
{
struct gprs_rlcmac_tbf *tbf;
llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
if (tbf->tfi == tfi)
return tbf;
}
return NULL;
}
static struct gprs_rlcmac_tbf *tbf_by_tlli(uint32_t tlli)
{
struct gprs_rlcmac_tbf *tbf;
llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
if ((tbf->tlli == tlli)&&(tbf->direction == GPRS_RLCMAC_UL_TBF))
return tbf;
}
return NULL;
}
struct gprs_rlcmac_tbf *tbf_alloc(uint8_t tfi)
{
struct gprs_rlcmac_tbf *tbf;
tbf = talloc_zero(rlcmac_tall_ctx, struct gprs_rlcmac_tbf);
if (!tbf)
return NULL;
tbf->tfi = tfi;
llist_add(&tbf->list, &gprs_rlcmac_tbfs);
return tbf;
}
static void tbf_free(struct gprs_rlcmac_tbf *tbf)
{
llist_del(&tbf->list);
talloc_free(tbf);
}
static void tbf_timer_cb(void *_tbf)
{
struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf;
tbf->num_T_exp++;
switch (tbf->T) {
case 1111:
// TODO: We should add timers for TBF.
break;
default:
LOGP(DRLCMAC, LOGL_NOTICE, "Timer expired in unknown mode: %u \n", tbf->T);
}
}
static void tbf_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int T,
unsigned int seconds)
{
if (osmo_timer_pending(&tbf->timer))
LOGP(DRLCMAC, LOGL_NOTICE, "Starting TBF timer %u while old timer %u pending \n", T, tbf->T);
tbf->T = T;
tbf->num_T_exp = 0;
/* FIXME: we should do this only once ? */
tbf->timer.data = tbf;
tbf->timer.cb = &tbf_timer_cb;
osmo_timer_schedule(&tbf->timer, seconds, 0);
}
static void tbf_gsm_timer_cb(void *_tbf)
{
struct gprs_rlcmac_tbf *tbf = (struct gprs_rlcmac_tbf *)_tbf;
tbf->num_fT_exp++;
switch (tbf->fT) {
case 0:
// This is timer for delay RLC/MAC data sending after Downlink Immediate Assignment on CCCH.
gprs_rlcmac_segment_llc_pdu(tbf);
LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [DOWNLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
tbf_free(tbf);
break;
default:
LOGP(DRLCMAC, LOGL_NOTICE, "Timer expired in unknown mode: %u \n", tbf->fT);
}
}
static void tbf_gsm_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int fT,
int frames)
{
if (osmo_gsm_timer_pending(&tbf->gsm_timer))
LOGP(DRLCMAC, LOGL_NOTICE, "Starting TBF timer %u while old timer %u pending \n", fT, tbf->fT);
tbf->fT = fT;
tbf->num_fT_exp = 0;
/* FIXME: we should do this only once ? */
tbf->gsm_timer.data = tbf;
tbf->gsm_timer.cb = &tbf_gsm_timer_cb;
osmo_gsm_timer_schedule(&tbf->gsm_timer, frames);
}
void write_packet_downlink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli, uint8_t tn, uint8_t ta, uint8_t tsc)
{
// TODO We should use our implementation of encode RLC/MAC Control messages.
unsigned wp = 0;
bitvec_write_field(dest, wp,0x1,2); // Payload Type
bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber
bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit
bitvec_write_field(dest, wp,0x1,3); // Uplink state flag
bitvec_write_field(dest, wp,0x2,6); // MESSAGE TYPE
bitvec_write_field(dest, wp,0x0,2); // Page Mode
bitvec_write_field(dest, wp,0x0,1); // switch PERSIST_LEVEL: off
bitvec_write_field(dest, wp,0x0,1); // switch TFI : on
bitvec_write_field(dest, wp,0x0,1); // switch UPLINK TFI : on
bitvec_write_field(dest, wp,tfi-1,5); // TFI
bitvec_write_field(dest, wp,0x0,1); // Message escape
bitvec_write_field(dest, wp,0x0,2); // Medium Access Method: Dynamic Allocation
bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode
bitvec_write_field(dest, wp,0x0,1); // the network establishes no new downlink TBF for the mobile station
bitvec_write_field(dest, wp,0x1,8); // timeslot 7
bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
bitvec_write_field(dest, wp,ta,6); // TIMING_ADVANCE_VALUE
bitvec_write_field(dest, wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off
bitvec_write_field(dest, wp,0x0,1); // switch POWER CONTROL = off
bitvec_write_field(dest, wp,0x1,1); // Frequency Parameters information elements = present
bitvec_write_field(dest, wp,tsc,3); // Training Sequence Code (TSC) = 2
bitvec_write_field(dest, wp,0x0,2); // ARFCN = present
bitvec_write_field(dest, wp,599,10); // ARFCN
bitvec_write_field(dest, wp,0x1,1); // switch TFI : on
bitvec_write_field(dest, wp,tfi,5);// TFI
bitvec_write_field(dest, wp,0x1,1); // Power Control Parameters IE = present
bitvec_write_field(dest, wp,0x0,4); // ALPHA power control parameter
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN0 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN1 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN2 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN3 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN4 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN5 = off
bitvec_write_field(dest, wp,0x0,1); // switch GAMMA_TN6 = off
bitvec_write_field(dest, wp,0x1,1); // switch GAMMA_TN7 = on
bitvec_write_field(dest, wp,0x0,5); // GAMMA_TN7
bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME IE not present
bitvec_write_field(dest, wp,0x0,1); // Measurement Mapping struct not present
bitvec_write_field(dest, wp,0x0,1);
}
void write_packet_uplink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli)
{
// TODO We should use our implementation of encode RLC/MAC Control messages.
unsigned wp = 0;
bitvec_write_field(dest, wp,0x1,2); // Payload Type
bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber
bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit
bitvec_write_field(dest, wp,0x1,3); // Uplink state flag
bitvec_write_field(dest, wp,0xa,6); // MESSAGE TYPE
bitvec_write_field(dest, wp,0x0,2); // Page Mode
bitvec_write_field(dest, wp,0x0,1); // switch PERSIST_LEVEL: off
bitvec_write_field(dest, wp,0x2,2); // switch TLLI : on
bitvec_write_field(dest, wp,tlli,32); // TLLI
bitvec_write_field(dest, wp,0x0,1); // Message escape
bitvec_write_field(dest, wp,0x0,2); // CHANNEL_CODING_COMMAND
bitvec_write_field(dest, wp,0x0,1); // TLLI_BLOCK_CHANNEL_CODING
bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
bitvec_write_field(dest, wp,0x0,6); // TIMING_ADVANCE_VALUE
bitvec_write_field(dest, wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off
bitvec_write_field(dest, wp,0x0,1); // Frequency Parameters = off
bitvec_write_field(dest, wp,0x1,2); // Dynamic Allocation = off
bitvec_write_field(dest, wp,0x0,1); // Dynamic Allocation
bitvec_write_field(dest, wp,0x0,1); // P0 = off
bitvec_write_field(dest, wp,0x1,1); // USF_GRANULARITY
bitvec_write_field(dest, wp,0x1,1); // switch TFI : on
bitvec_write_field(dest, wp,tfi,5);// TFI
bitvec_write_field(dest, wp,0x0,1); //
bitvec_write_field(dest, wp,0x0,1); // TBF Starting Time = off
bitvec_write_field(dest, wp,0x0,1); // Timeslot Allocation
bitvec_write_field(dest, wp,0x0,5); // USF_TN 0 - 4
bitvec_write_field(dest, wp,0x1,1); // USF_TN 5
bitvec_write_field(dest, wp,0x1,3); // USF_TN 5
bitvec_write_field(dest, wp,0x0,2); // USF_TN 6 - 7
// bitvec_write_field(dest, wp,0x0,1); // Measurement Mapping struct not present
}
// GSM 04.08 9.1.18 Immediate assignment
int write_immediate_assignment(bitvec * dest, uint8_t downlink, uint8_t ra, uint32_t fn,
uint8_t ta, uint8_t tfi = 0, uint32_t tlli = 0)
{
unsigned wp = 0;
bitvec_write_field(dest, wp,0x0,4); // Skip Indicator
bitvec_write_field(dest, wp,0x6,4); // Protocol Discriminator
bitvec_write_field(dest, wp,0x3F,8); // Immediate Assignment Message Type
// 10.5.2.25b Dedicated mode or TBF
bitvec_write_field(dest, wp,0x0,1); // spare
bitvec_write_field(dest, wp,0x0,1); // TMA : Two-message assignment: No meaning
bitvec_write_field(dest, wp,downlink,1); // Downlink : Downlink assignment to mobile in packet idle mode
bitvec_write_field(dest, wp,0x1,1); // T/D : TBF or dedicated mode: this message assigns a Temporary Block Flow (TBF).
bitvec_write_field(dest, wp,0x0,4); // Page Mode
// GSM 04.08 10.5.2.25a Packet Channel Description
bitvec_write_field(dest, wp,0x1,5); // Channel type
bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.tn,3); // TN
bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.tsc,3); // TSC
bitvec_write_field(dest, wp,0x0,3); // non-hopping RF channel configuraion
bitvec_write_field(dest, wp,(l1fh->fl1h)->channel_info.arfcn,10); // ARFCN
//10.5.2.30 Request Reference
bitvec_write_field(dest, wp,ra,8); // RA
bitvec_write_field(dest, wp,(fn / (26 * 51)) % 32,5); // T1'
bitvec_write_field(dest, wp,fn % 51,6); // T3
bitvec_write_field(dest, wp,fn % 26,5); // T2
// 10.5.2.40 Timing Advance
bitvec_write_field(dest, wp,0x0,2); // spare
bitvec_write_field(dest, wp,ta,6); // Timing Advance value
// No mobile allocation in non-hopping systems.
// A zero-length LV. Just write L=0.
bitvec_write_field(dest, wp,0,8);
if (downlink)
{
// GSM 04.08 10.5.2.16 IA Rest Octets
bitvec_write_field(dest, wp, 3, 2); // "HH"
bitvec_write_field(dest, wp, 1, 2); // "01" Packet Downlink Assignment
bitvec_write_field(dest, wp,tlli,32); // TLLI
bitvec_write_field(dest, wp,0x1,1); // switch TFI : on
bitvec_write_field(dest, wp,tfi,5); // TFI
bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode
bitvec_write_field(dest, wp,0x0,1); // ALPHA = present
bitvec_write_field(dest, wp,0x0,5); // GAMMA power control parameter
bitvec_write_field(dest, wp,0x0,1); // Polling Bit
bitvec_write_field(dest, wp,0x1,1); // TA_VALID ???
bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on
bitvec_write_field(dest, wp,0x0,4); // TIMING_ADVANCE_INDEX
bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME present
bitvec_write_field(dest, wp,0x0,1); // P0 not present
bitvec_write_field(dest, wp,0x1,1); // P0 not present
bitvec_write_field(dest, wp,0xb,4);
}
else
{
// GMS 04.08 10.5.2.37b 10.5.2.16
bitvec_write_field(dest, wp, 3, 2); // "HH"
bitvec_write_field(dest, wp, 0, 2); // "0" Packet Uplink Assignment
bitvec_write_field(dest, wp, 1, 1); // Block Allocation : Not Single Block Allocation
bitvec_write_field(dest, wp, tfi, 5); // TFI_ASSIGNMENT Temporary Flow Identity
bitvec_write_field(dest, wp, 0, 1); // POLLING
bitvec_write_field(dest, wp, 0, 1); // ALLOCATION_TYPE: dynamic
bitvec_write_field(dest, wp, 1, 3); // USF
bitvec_write_field(dest, wp, 1, 1); // USF_GRANULARITY
bitvec_write_field(dest, wp, 0 , 1); // "0" power control: Not Present
bitvec_write_field(dest, wp, 0, 2); // CHANNEL_CODING_COMMAND
bitvec_write_field(dest, wp, 1, 1); // TLLI_BLOCK_CHANNEL_CODING
bitvec_write_field(dest, wp, 1 , 1); // "1" Alpha : Present
bitvec_write_field(dest, wp, 0, 4); // Alpha
bitvec_write_field(dest, wp, 0, 5); // Gamma
bitvec_write_field(dest, wp, 0, 1); // TIMING_ADVANCE_INDEX_FLAG
bitvec_write_field(dest, wp, 0, 1); // TBF_STARTING_TIME_FLAG
}
if (wp%8)
return wp/8+1;
else
return wp/8;
}
void write_ia_rest_octets_downlink_assignment(bitvec * dest, uint8_t tfi, uint32_t tlli)
{
// GSM 04.08 10.5.2.16
unsigned wp = 0;
bitvec_write_field(dest, wp, 3, 2); // "HH"
bitvec_write_field(dest, wp, 1, 2); // "01" Packet Downlink Assignment
bitvec_write_field(dest, wp,tlli,32); // TLLI
bitvec_write_field(dest, wp,0x1,1); // switch TFI : on
bitvec_write_field(dest, wp,tfi,5); // TFI
bitvec_write_field(dest, wp,0x0,1); // RLC acknowledged mode
bitvec_write_field(dest, wp,0x0,1); // ALPHA = present
bitvec_write_field(dest, wp,0x0,5); // GAMMA power control parameter
bitvec_write_field(dest, wp,0x0,1); // Polling Bit
bitvec_write_field(dest, wp,0x1,1); // TA_VALID ???
bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on
bitvec_write_field(dest, wp,0x0,4); // TIMING_ADVANCE_INDEX
bitvec_write_field(dest, wp,0x0,1); // TBF Starting TIME present
bitvec_write_field(dest, wp,0x0,1); // P0 not present
bitvec_write_field(dest, wp,0x1,1); // P0 not present
bitvec_write_field(dest, wp,0xb,4);
}
void write_packet_uplink_ack(bitvec * dest, uint8_t tfi, uint32_t tlli, unsigned cv, unsigned bsn)
{
// TODO We should use our implementation of encode RLC/MAC Control messages.
unsigned wp = 0;
bitvec_write_field(dest, wp,0x1,2); // payload
bitvec_write_field(dest, wp,0x0,2); // Uplink block with TDMA framenumber
if (cv == 0) bitvec_write_field(dest, wp,0x1,1); // Suppl/Polling Bit
else bitvec_write_field(dest, wp,0x0,1); //Suppl/Polling Bit
bitvec_write_field(dest, wp,0x1,3); // Uplink state flag
//bitvec_write_field(dest, wp,0x0,1); // Reduced block sequence number
//bitvec_write_field(dest, wp,BSN+6,5); // Radio transaction identifier
//bitvec_write_field(dest, wp,0x1,1); // Final segment
//bitvec_write_field(dest, wp,0x1,1); // Address control
//bitvec_write_field(dest, wp,0x0,2); // Power reduction: 0
//bitvec_write_field(dest, wp,TFI,5); // Temporary flow identifier
//bitvec_write_field(dest, wp,0x1,1); // Direction
bitvec_write_field(dest, wp,0x09,6); // MESSAGE TYPE
bitvec_write_field(dest, wp,0x0,2); // Page Mode
bitvec_write_field(dest, wp,0x0,2);
bitvec_write_field(dest, wp,tfi,5); // Uplink TFI
bitvec_write_field(dest, wp,0x0,1);
bitvec_write_field(dest, wp,0x0,2); // CS1
if (cv == 0) bitvec_write_field(dest, wp,0x1,1); // FINAL_ACK_INDICATION
else bitvec_write_field(dest, wp,0x0,1); // FINAL_ACK_INDICATION
bitvec_write_field(dest, wp,bsn + 1,7); // STARTING_SEQUENCE_NUMBER
// RECEIVE_BLOCK_BITMAP
for (unsigned i=0; i<8; i++) {
bitvec_write_field(dest, wp,0xff,8);
}
bitvec_write_field(dest, wp,0x1,1); // CONTENTION_RESOLUTION_TLLI = present
bitvec_write_field(dest, wp,tlli,8*4);
bitvec_write_field(dest, wp,0x00,4); //spare
bitvec_write_field(dest, wp,0x5,4); //0101
}
void gprs_rlcmac_tx_ul_ack(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * ul_data_block)
{
bitvec *packet_uplink_ack_vec = bitvec_alloc(23);
bitvec_unhex(packet_uplink_ack_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
write_packet_uplink_ack(packet_uplink_ack_vec, tfi, tlli, ul_data_block->CV, ul_data_block->BSN);
LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Packet Uplink Ack\n", tfi, tlli);
RlcMacDownlink_t * packet_uplink_ack = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t));
LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Packet Uplink Ack +++++++++++++++++++++++++\n");
decode_gsm_rlcmac_downlink(packet_uplink_ack_vec, packet_uplink_ack);
LOGPC(DRLCMAC, LOGL_NOTICE, "\n");
LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Packet Uplink Ack -------------------------\n");
free(packet_uplink_ack);
pcu_l1if_tx(packet_uplink_ack_vec, GsmL1_Sapi_Pacch);
bitvec_free(packet_uplink_ack_vec);
}
void gprs_rlcmac_data_block_parse(gprs_rlcmac_tbf* tbf, RlcMacUplinkDataBlock_t * ul_data_block)
{
// 1. Count the number of octets in header and number of LLC PDU in uplink data block.
unsigned data_block_hdr_len = 3; // uplink data block header length: 3 mandatory octets
unsigned llc_pdu_num = 0; // number of LLC PDU in data block
if (ul_data_block->E_1 == 0) // Extension octet follows immediately
{
unsigned i = -1;
do
{
i++;
data_block_hdr_len += 1;
llc_pdu_num++;
// Singular case, TS 44.060 10.4.14
if (ul_data_block->LENGTH_INDICATOR[i] == 0)
{
break;
}
// New LLC PDU starts after the current LLC PDU and continues until
// the end of the RLC information field, no more extension octets.
if ((ul_data_block->M[i] == 1)&&(ul_data_block->E[i] == 1))
{
llc_pdu_num++;
}
} while(ul_data_block->E[i] == 0); // there is another extension octet, which delimits the new LLC PDU
}
else
{
llc_pdu_num++;
}
if(ul_data_block->TI == 1) // TLLI field is present
{
tbf->tlli = ul_data_block->TLLI;
data_block_hdr_len += 4; // TLLI length : 4 octets
if (ul_data_block->PI == 1) // PFI is present if TI field indicates presence of TLLI
{
data_block_hdr_len += 1; // PFI length : 1 octet
}
}
// 2. Extract all LLC PDU from uplink data block and send them to SGSN.
unsigned llc_pdu_len = 0;
unsigned data_octet_num = 0;
for (unsigned num = 0; num < llc_pdu_num; num ++)
{
if (ul_data_block->E_1 == 0) // Extension octet follows immediately
{
// Singular case, TS 44.060 10.4.14
if (ul_data_block->LENGTH_INDICATOR[num] == 0)
{
llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len;
}
else
{
llc_pdu_len = ul_data_block->LENGTH_INDICATOR[num];
}
}
else
{
llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len;
}
for (unsigned i = tbf->data_index; i < tbf->data_index + llc_pdu_len; i++)
{
tbf->rlc_data[i] = ul_data_block->RLC_DATA[data_octet_num];
data_octet_num++;
}
tbf->data_index += llc_pdu_len;
if (ul_data_block->E_1 == 0) // Extension octet follows immediately
{
// New LLC PDU starts after the current LLC PDU
if (ul_data_block->M[num] == 1)
{
gprs_rlcmac_tx_ul_ud(tbf);
tbf->data_index = 0;
// New LLC PDU continues until the end of the RLC information field, no more extension octets.
if ((ul_data_block->E[num] == 1))
{
llc_pdu_len = UL_RLC_DATA_BLOCK_LEN - data_block_hdr_len - data_octet_num;
for (unsigned i = tbf->data_index; i < tbf->data_index + llc_pdu_len; i++)
{
tbf->rlc_data[i] = ul_data_block->RLC_DATA[data_octet_num];
data_octet_num++;
}
tbf->data_index += llc_pdu_len;
num++;
}
}
}
}
}
/* Received Uplink RLC data block. */
int gprs_rlcmac_rcv_data_block(bitvec *rlc_block)
{
struct gprs_rlcmac_tbf *tbf;
LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] Uplink Data Block\n");
RlcMacUplinkDataBlock_t * ul_data_block = (RlcMacUplinkDataBlock_t *)malloc(sizeof(RlcMacUplinkDataBlock_t));
LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ RX : Uplink Data Block +++++++++++++++++++++++++\n");
decode_gsm_rlcmac_uplink_data(rlc_block, ul_data_block);
LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- RX : Uplink Data Block -------------------------\n");
tbf = tbf_by_tfi(ul_data_block->TFI);
if (!tbf) {
return 0;
}
if (ul_data_block->TI == 1)
{
tbf->tlli = ul_data_block->TLLI;
}
switch (tbf->state) {
case GPRS_RLCMAC_WAIT_DATA_SEQ_START:
if (ul_data_block->BSN == 0) {
tbf->data_index = 0;
gprs_rlcmac_data_block_parse(tbf, ul_data_block);
gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block);
if (ul_data_block->CV == 0) {
// Recieved last Data Block in this sequence.
tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ;
gprs_rlcmac_tx_ul_ud(tbf);
} else {
tbf->bsn = ul_data_block->BSN;
tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
}
}
break;
case GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK:
if (tbf->bsn == (ul_data_block->BSN - 1)) {
gprs_rlcmac_data_block_parse(tbf, ul_data_block);
gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block);
if (ul_data_block->CV == 0) {
// Recieved last Data Block in this sequence.
tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ;
gprs_rlcmac_tx_ul_ud(tbf);
} else {
tbf->bsn = ul_data_block->BSN;
tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
}
} else {
// Recieved Data Block with unexpected BSN.
// We should try to find nesessary Data Block.
tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
}
break;
case GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ:
// Now we just ignore all Data Blocks and wait next Uplink TBF
break;
}
free(ul_data_block);
return 1;
}
/* Received Uplink RLC control block. */
int gprs_rlcmac_rcv_control_block(bitvec *rlc_block)
{
uint8_t tfi = 0;
uint32_t tlli = 0;
struct gprs_rlcmac_tbf *tbf;
struct gprs_rlcmac_tbf *ul_tbf;
RlcMacUplink_t * ul_control_block = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t));
LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++\n");
decode_gsm_rlcmac_uplink(rlc_block, ul_control_block);
LOGPC(DRLCMAC, LOGL_NOTICE, "\n");
LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- RX : Uplink Control Block -------------------------\n");
switch (ul_control_block->u.MESSAGE_TYPE) {
case MT_PACKET_CONTROL_ACK:
tlli = ul_control_block->u.Packet_Control_Acknowledgement.TLLI;
tbf = tbf_by_tlli(tlli);
if (!tbf) {
return 0;
}
LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Control Ack\n", tbf->tfi, tbf->tlli);
LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [UPLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
tbf_free(tbf);
break;
case MT_PACKET_DOWNLINK_ACK_NACK:
tfi = ul_control_block->u.Packet_Downlink_Ack_Nack.DOWNLINK_TFI;
tbf = tbf_by_tfi(tfi);
if (!tbf) {
return 0;
}
LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u TLLI: 0x%08x Packet Downlink Ack/Nack\n", tbf->tfi, tbf->tlli);
tlli = tbf->tlli;
LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [DOWNLINK] END TFI: %u TLLI: 0x%08x \n", tbf->tfi, tbf->tlli);
tbf_free(tbf);
break;
}
free(ul_control_block);
return 1;
}
void gprs_rlcmac_rcv_block(bitvec *rlc_block)
{
unsigned readIndex = 0;
unsigned payload = bitvec_read_field(rlc_block, readIndex, 2);
switch (payload) {
case GPRS_RLCMAC_DATA_BLOCK:
gprs_rlcmac_rcv_data_block(rlc_block);
break;
case GPRS_RLCMAC_CONTROL_BLOCK:
gprs_rlcmac_rcv_control_block(rlc_block);
break;
case GPRS_RLCMAC_CONTROL_BLOCK_OPT:
LOGP(DRLCMAC, LOGL_NOTICE, "GPRS_RLCMAC_CONTROL_BLOCK_OPT block payload is not supported.\n");
default:
LOGP(DRLCMAC, LOGL_NOTICE, "Unknown RLCMAC block payload.\n");
}
}
int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, uint16_t ta)
{
struct gprs_rlcmac_tbf *tbf;
// Create new TBF
int tfi = tfi_alloc();
if (tfi < 0) {
return tfi;
}
tbf = tbf_alloc(tfi);
tbf->direction = GPRS_RLCMAC_UL_TBF;
tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START;
LOGP(DRLCMAC, LOGL_NOTICE, "TBF: [UPLINK] START TFI: %u\n", tbf->tfi);
LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] TFI: %u RACH\n", tbf->tfi);
LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u Packet Immidiate Assignment\n", tbf->tfi);
bitvec *immediate_assignment = bitvec_alloc(23);
bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
int len = write_immediate_assignment(immediate_assignment, 0, ra, Fn, ta, tbf->tfi);
pcu_l1if_tx(immediate_assignment, GsmL1_Sapi_Agch, len);
bitvec_free(immediate_assignment);
}
// Send RLC data to OpenBTS.
void gprs_rlcmac_tx_dl_data_block(uint32_t tlli, uint8_t tfi, uint8_t *pdu, int start_index, int end_index, uint8_t bsn, uint8_t fbi)
{
int spare_len = 0;
bitvec *data_block_vector = bitvec_alloc(BLOCK_LEN);
bitvec_unhex(data_block_vector, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
RlcMacDownlinkDataBlock_t * data_block = (RlcMacDownlinkDataBlock_t *)malloc(sizeof(RlcMacDownlinkDataBlock_t));
data_block->PAYLOAD_TYPE = 0;
data_block->RRBP = 0;
data_block->SP = 1;
data_block->USF = 1;
data_block->PR = 0;
data_block->TFI = tfi;
data_block->FBI = fbi;
data_block->BSN = bsn;
// Last RLC data block of current LLC PDU
if (fbi == 1)
{
data_block->E_1 = 0;
data_block->M[0] = 0;
data_block->E[0] = 1;
// Singular case, TS 44.060 10.4.14
if ((end_index - start_index) == (BLOCK_LEN - 3))
{
data_block->FBI = 0;
data_block->LENGTH_INDICATOR[0] = 0;
spare_len = 0;
end_index--;
}
else
{
data_block->LENGTH_INDICATOR[0] = end_index-start_index;
spare_len = BLOCK_LEN - 4 - data_block->LENGTH_INDICATOR[0];
}
}
else
{
data_block->E_1 = 1;
}
int data_oct_num = 0;
int i = 0;
// Pack LLC PDU into RLC data field
for(i = start_index; i < end_index; i++) {
data_block->RLC_DATA[data_oct_num] = pdu[i];
data_oct_num++;
}
// Fill spare bits
for(i = data_oct_num; i < data_oct_num + spare_len; i++) {
data_block->RLC_DATA[i] = 0x2b;
}
LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] Downlink Data Block\n");
LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Downlink Data Block +++++++++++++++++++++++++\n");
encode_gsm_rlcmac_downlink_data(data_block_vector, data_block);
LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Downlink Data Block -------------------------\n");
free(data_block);
pcu_l1if_tx(data_block_vector, GsmL1_Sapi_Pdtch);
bitvec_free(data_block_vector);
// Singular case, TS 44.060 10.4.14
if ((fbi == 1)&&((end_index + 1 - start_index) == (BLOCK_LEN - 3)))
{
gprs_rlcmac_tx_dl_data_block(tlli, tfi, pdu, end_index, end_index+1, bsn+1, fbi);
}
}
int gprs_rlcmac_segment_llc_pdu(struct gprs_rlcmac_tbf *tbf)
{
int fbi = 0;
int bsn = 0;
int num_blocks = 0; // number of RLC data blocks necessary for LLC PDU transmission
// LLC PDU fits into one RLC data block with optional LI field.
if (tbf->data_index < BLOCK_LEN - 4)
{
fbi = 1;
gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->tfi, tbf->rlc_data, 0, tbf->data_index, bsn, fbi);
}
// Necessary several RLC data blocks for transmit LLC PDU.
else
{
// length of RLC data field in block (no optional octets)
int block_data_len = BLOCK_LEN - 3;
// number of blocks with 20 octets length RLC data field
num_blocks = tbf->data_index/block_data_len;
// rest of LLC PDU, which doesn't fit into data blocks with 20 octets RLC data field
int rest_len = tbf->data_index%BLOCK_DATA_LEN;
if (rest_len > 0)
{
// add one block for transmission rest of LLC PDU
num_blocks++;
}
int start_index = 0;
int end_index = 0;
// Transmit all RLC data blocks of current LLC PDU to MS
for (bsn = 0; bsn < num_blocks; bsn++)
{
if (bsn == num_blocks-1)
{
if (rest_len > 0)
{
block_data_len = rest_len;
}
fbi = 1;
}
end_index = start_index + block_data_len;
gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->tfi, tbf->rlc_data, start_index, end_index, bsn, fbi);
start_index += block_data_len;
}
}
}
/* Send Uplink unit-data to SGSN. */
void gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf)
{
const uint8_t qos_profile = QOS_PROFILE;
struct msgb *llc_pdu;
unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + tbf->data_index;
LOGP(DBSSGP, LOGL_NOTICE, "TX: [PCU -> SGSN ] TFI: %u TLLI: 0x%08x DataLen: %u", tbf->tfi, tbf->tlli, tbf->data_index);
//LOGP(DBSSGP, LOGL_NOTICE, " Data = ");
//for (unsigned i = 0; i < tbf->data_index; i++)
// LOGPC(DBSSGP, LOGL_NOTICE, "%02x ", tbf->rlc_data[i]);
bctx->cell_id = CELL_ID;
bctx->nsei = NSEI;
bctx->ra_id.mnc = MNC;
bctx->ra_id.mcc = MCC;
bctx->ra_id.lac = PCU_LAC;
bctx->ra_id.rac = PCU_RAC;
bctx->bvci = BVCI;
llc_pdu = msgb_alloc_headroom(msg_len, msg_len,"llc_pdu");
msgb_tvlv_push(llc_pdu, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*tbf->data_index, tbf->rlc_data);
bssgp_tx_ul_ud(bctx, tbf->tlli, &qos_profile, llc_pdu);
}
void gprs_rlcmac_downlink_assignment(gprs_rlcmac_tbf *tbf)
{
LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Immidiate Assignment (CCCH)\n", tbf->tfi, tbf->tlli);
bitvec *immediate_assignment = bitvec_alloc(23);
bitvec_unhex(immediate_assignment, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
int len = write_immediate_assignment(immediate_assignment, 1, 125, get_current_fn(), (l1fh->fl1h)->channel_info.ta, tbf->tfi, tbf->tlli);
pcu_l1if_tx(immediate_assignment, GsmL1_Sapi_Agch, len);
bitvec_free(immediate_assignment);
tbf_gsm_timer_start(tbf, 0, 120);
}
void gprs_rlcmac_packet_downlink_assignment(gprs_rlcmac_tbf *tbf)
{
LOGP(DRLCMAC, LOGL_NOTICE, "TX: [PCU -> BTS] TFI: %u TLLI: 0x%08x Packet DL Assignment\n", tbf->tfi, tbf->tlli);
bitvec *packet_downlink_assignment_vec = bitvec_alloc(23);
bitvec_unhex(packet_downlink_assignment_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
write_packet_downlink_assignment(packet_downlink_assignment_vec, tbf->tfi, tbf->tlli, (l1fh->fl1h)->channel_info.tn,
(l1fh->fl1h)->channel_info.ta, (l1fh->fl1h)->channel_info.tsc);
RlcMacDownlink_t * packet_downlink_assignment = (RlcMacDownlink_t *)malloc(sizeof(RlcMacDownlink_t));
LOGP(DRLCMAC, LOGL_NOTICE, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n");
decode_gsm_rlcmac_downlink(packet_downlink_assignment_vec, packet_downlink_assignment);
LOGPC(DRLCMAC, LOGL_NOTICE, "\n");
LOGP(DRLCMAC, LOGL_NOTICE, "------------------------- TX : Packet Downlink Assignment -------------------------\n");
free(packet_downlink_assignment);
pcu_l1if_tx(packet_downlink_assignment_vec, GsmL1_Sapi_Pacch);
bitvec_free(packet_downlink_assignment_vec);
tbf_gsm_timer_start(tbf, 0, 120);
}
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