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/*GPRSSocket.cpp
*
* Copyright (C) 2011 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 <Sockets.h>
#include <Threads.h>
#include <BitVector.h>
#include "GPRSSocket.h"
#include "gsm_rlcmac.h"
#include "bssgp.h"
#define MAX_UDP_LENGTH 1500
#define RLCMAC_DATA_BLOCK 0
#define RLCMAC_CONTROL_BLOCK 1
// TODO: We should take ports and IP from config.
UDPSocket GPRSRLCMACSocket(5070, "127.0.0.1", 5934);
void sendToOpenBTS(BitVector * vector)
{
char buffer[MAX_UDP_LENGTH];
int ofs = 0;
vector->pack((unsigned char*)&buffer[ofs]);
ofs += vector->size() >> 3;
COUT("Send to OpenBTS: " << *vector);
GPRSRLCMACSocket.write(buffer, ofs);
}
void writePDassignment(BitVector * dest, uint8_t TFI, uint32_t TLLI)
{
// TODO We should use our implementation of encode RLC/MAC Control messages.
unsigned wp = 0;
dest->writeField(wp,0x1,2); // Payload Type
dest->writeField(wp,0x0,2); // Uplink block with TDMA framenumber
dest->writeField(wp,0x1,1); // Suppl/Polling Bit
dest->writeField(wp,0x1,3); // Uplink state flag
dest->writeField(wp,0x2,6); // MESSAGE TYPE
dest->writeField(wp,0x0,2); // Page Mode
dest->writeField(wp,0x0,1); // switch PERSIST_LEVEL: off
dest->writeField(wp,0x2,2); // switch TLLI : on
dest->writeField(wp,TLLI,32); // TLLI
dest->writeField(wp,0x0,1); // Message escape
dest->writeField(wp,0x0,2); // Medium Access Method: Dynamic Allocation
dest->writeField(wp,0x0,1); // RLC acknowledged mode
dest->writeField(wp,0x0,1); // the network establishes no new downlink TBF for the mobile station
dest->writeField(wp,0x1,8); // timeslot 7
dest->writeField(wp,0x1,8); // TIMING_ADVANCE_INDEX
dest->writeField(wp,0x0,1); // switch TIMING_ADVANCE_VALUE = off
dest->writeField(wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on
dest->writeField(wp,0xC,4); // TIMING_ADVANCE_INDEX
dest->writeField(wp,0x7,3); // TIMING_ADVANCE_TIMESLOT_NUMBER
dest->writeField(wp,0x0,1); // switch POWER CONTROL = off
dest->writeField(wp,0x1,1); // Frequency Parameters information elements = present
dest->writeField(wp,0x2,3); // Training Sequence Code (TSC) = 2
dest->writeField(wp,0x1,2); // Indirect encoding struct = present
dest->writeField(wp,0x0,6); // MAIO
dest->writeField(wp,0xE,4); // MA_Number
dest->writeField(wp,0x8,4); // CHANGE_MARK_1 CHANGE_MARK_2
dest->writeField(wp,0x1,1); // switch TFI : on
dest->writeField(wp,0x14,5);// TFI
dest->writeField(wp,0x1,1); // Power Control Parameters IE = present
dest->writeField(wp,0x0,4); // ALPHA power control parameter
dest->writeField(wp,0x0,1); // switch GAMMA_TN0 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN1 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN2 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN3 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN4 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN5 = off
dest->writeField(wp,0x0,1); // switch GAMMA_TN6 = off
dest->writeField(wp,0x1,1); // switch GAMMA_TN7 = on
dest->writeField(wp,0x0,5); // GAMMA_TN7
dest->writeField(wp,0x0,1); // TBF Starting TIME IE not present
dest->writeField(wp,0x0,1); // Measurement Mapping struct not present
}
void writePUack(BitVector * 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;
dest->writeField(wp,0x1,2); // payload
dest->writeField(wp,0x0,2); // Uplink block with TDMA framenumber
if (CV == 0) dest->writeField(wp,0x1,1); // Suppl/Polling Bit
else dest->writeField(wp,0x0,1); //Suppl/Polling Bit
dest->writeField(wp,0x1,3); // Uplink state flag
//dest->writeField(wp,0x0,1); // Reduced block sequence number
//dest->writeField(wp,BSN+6,5); // Radio transaction identifier
//dest->writeField(wp,0x1,1); // Final segment
//dest->writeField(wp,0x1,1); // Address control
//dest->writeField(wp,0x0,2); // Power reduction: 0
//dest->writeField(wp,TFI,5); // Temporary flow identifier
//dest->writeField(wp,0x1,1); // Direction
dest->writeField(wp,0x09,6); // MESSAGE TYPE
dest->writeField(wp,0x0,2); // Page Mode
dest->writeField(wp,0x0,2);
dest->writeField(wp,TFI,5); // Uplink TFI
dest->writeField(wp,0x0,1);
dest->writeField(wp,0x0,2); // CS1
if (CV == 0) dest->writeField(wp,0x1,1); // FINAL_ACK_INDICATION
else dest->writeField(wp,0x0,1); // FINAL_ACK_INDICATION
dest->writeField(wp,BSN+1,7); // STARTING_SEQUENCE_NUMBER
// RECEIVE_BLOCK_BITMAP
for (unsigned i=0; i<8; i++) {
dest->writeField(wp,0xff,8);
}
dest->writeField(wp,0x1,1); // CONTENTION_RESOLUTION_TLLI = present
dest->writeField(wp,TLLI,8*4);
dest->writeField(wp,0x00,4); //spare
}
void RLCMACDispatchMessage(BitVector *vector)
{
static uint8_t rlc_data[60];
static uint8_t tfi = 0;
static uint32_t tlli = 0;
static unsigned dataIndex = 0;
static unsigned startDispatch = 0;
unsigned blockDataLen = 0;
unsigned readIndex = 0;
unsigned payload = vector->readField(readIndex, 2);
switch (payload) {
case RLCMAC_DATA_BLOCK:
{
COUT("RLCMAC_DATA_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
RlcMacUplinkDataBlock_t * dataBlock = (RlcMacUplinkDataBlock_t *)malloc(sizeof(RlcMacUplinkDataBlock_t));
decode_gsm_rlcmac_uplink_data(vector, dataBlock);
COUT("RLCMAC_DATA_BLOCK_END------------------------------");
//TODO Implement other cases.
if (dataBlock->BSN == 0)
{
startDispatch = 1;
}
if (startDispatch)
{
tfi = dataBlock->TFI;
if (dataBlock->E_1 == 0) // Extension octet follows immediately
{
blockDataLen = dataBlock->LENGTH_INDICATOR[0];
}
else
{
blockDataLen = 20;
if(dataBlock->TI == 1) // TLLI field is present
{
tlli = dataBlock->TLLI;
blockDataLen -= 4;
if (dataBlock->PI == 1) // PFI is present if TI field indicates presence of TLLI
{
blockDataLen -= 1;
}
}
}
unsigned dataOctetNum = 0;
for (unsigned i = dataIndex; i < dataIndex + blockDataLen; i++)
{
rlc_data[i] = dataBlock->RLC_DATA[dataOctetNum];
dataOctetNum++;
}
dataIndex += blockDataLen;
BitVector packetUplinkAck(23*8);
packetUplinkAck.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
writePUack(&packetUplinkAck, tfi, tlli, dataBlock->CV, dataBlock->BSN);
COUT("RLCMAC_CONTROL_BLOCK>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
RlcMacDownlink_t * pUA = (RlcMacDownlink_t *)malloc(sizeof(RlcMacUplink_t));
decode_gsm_rlcmac_downlink(&packetUplinkAck, pUA);
free(pUA);
COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
sendToOpenBTS(&packetUplinkAck);
}
if (dataBlock->CV == 0)
{
sendToSGSN(tfi, tlli, rlc_data, dataIndex);
dataIndex = 0;
startDispatch = 0;
}
free(dataBlock);
}
break;
case RLCMAC_CONTROL_BLOCK:
{
COUT("RLCMAC_CONTROL_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
RlcMacUplink_t * controlBlock = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t));
decode_gsm_rlcmac_uplink(vector, controlBlock);
free(controlBlock);
COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
}
break;
default:
COUT("Unknown RLCMAC block payload\n");
}
}
void *RLCMACSocket(void *)
{
BitVector *vector = new BitVector(23*8);
GPRSRLCMACSocket.nonblocking();
while (1) {
char buf[MAX_UDP_LENGTH];
int count = GPRSRLCMACSocket.read(buf, 3000);
if (count>0) {
vector->unpack((const unsigned char*)buf);
COUT("Recieve from OpenBTS (MS): " << *vector);
RLCMACDispatchMessage(vector);
}
}
}
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