WIP CLI packet encoder

pull/6/head
Wojciech Kaczmarski 2023-09-06 20:43:53 +02:00 zatwierdzone przez GitHub
rodzic 463b2eae8c
commit b8f4f852b0
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m17-packet-encode: m17-packet-encode.c crc.c
gcc -O2 -w -lm m17-packet-encode.c crc.c -o m17-packet-encode
clean:
rm m17-packet-encode

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#include <string.h>
#include <stdint.h>
#include "crc.h"
const uint16_t M17_CRC_POLY = 0x5935;
uint16_t CRC_M17(const uint8_t *in, const uint16_t len)
{
uint32_t crc=0xFFFF; //init val
for(uint16_t i=0; i<len; i++)
{
crc^=in[i]<<8;
for(uint8_t j=0; j<8; j++)
{
crc<<=1;
if(crc&0x10000)
crc=(crc^M17_CRC_POLY)&0xFFFF;
}
}
return crc&(0xFFFF);
}

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#ifndef CRC_H
#define CRC_H
#ifdef __cplusplus
extern "C" {
#endif
uint16_t CRC_M17(const uint8_t *in, const uint16_t len);
#ifdef __cplusplus
}
#endif
#endif

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#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include "../inc/m17.h"
#include "crc.h"
struct LSF
{
uint8_t dst[6];
uint8_t src[6];
uint8_t type[2];
uint8_t meta[112/8];
uint8_t crc[2];
} lsf;
uint8_t enc_bits[SYM_PER_PLD*2]; //type-2 bits, unpacked
uint8_t rf_bits[SYM_PER_PLD*2]; //type-4 bits, unpacked
uint8_t dst_raw[10]={'A', 'L', 'L', '\0'}; //raw, unencoded destination address
uint8_t src_raw[10]={'N', '0', 'C', 'A', 'L', 'L', '\0'}; //raw, unencoded source address
uint8_t can=0; //Channel Access Number, default: 0
uint16_t num_bytes=0; //number of bytes in packet, max 800-2=798
uint8_t data[25]; //raw payload, packed bits
uint8_t got_lsf=0; //have we filled the LSF struct yet?
void send_Preamble(const uint8_t type)
{
float symb;
if(type) //pre-BERT
{
for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
{
symb=-3.0;
write(STDOUT_FILENO, (uint8_t*)&symb, sizeof(float));
symb=+3.0;
write(STDOUT_FILENO, (uint8_t*)&symb, sizeof(float));
}
}
else //pre-LSF
{
for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
{
symb=+3.0;
write(STDOUT_FILENO, (uint8_t*)&symb, sizeof(float));
symb=-3.0;
write(STDOUT_FILENO, (uint8_t*)&symb, sizeof(float));
}
}
}
void send_Syncword(const uint16_t sword)
{
float symb;
for(uint8_t i=0; i<16; i+=2)
{
symb=symbol_map[(sword>>(14-i))&3];
write(STDOUT_FILENO, (uint8_t*)&symb, sizeof(float));
}
}
//send the data (can be used for both LSF and frames)
void send_data(uint8_t* in)
{
float s=0.0;
for(uint16_t i=0; i<SYM_PER_PLD; i++) //40ms * 4800 - 8 (syncword)
{
s=symbol_map[in[2*i]*2+in[2*i+1]];
write(STDOUT_FILENO, (uint8_t*)&s, sizeof(float));
}
}
//out - unpacked bits
//in - packed raw bits
//fn - frame number
void conv_Encode_Frame(uint8_t* out, uint8_t* in, uint16_t fn)
{
uint8_t pp_len = sizeof(P_2);
uint8_t p=0; //puncturing pattern index
uint16_t pb=0; //pushed punctured bits
uint8_t ud[144+4+4]; //unpacked data
memset(ud, 0, 144+4+4);
//unpack frame number
for(uint8_t i=0; i<16; i++)
{
ud[4+i]=(fn>>(15-i))&1;
}
//unpack data
for(uint8_t i=0; i<16; i++)
{
for(uint8_t j=0; j<8; j++)
{
ud[4+16+i*8+j]=(in[i]>>(7-j))&1;
}
}
//encode
for(uint8_t i=0; i<144+4; i++)
{
uint8_t G1=(ud[i+4] +ud[i+1]+ud[i+0])%2;
uint8_t G2=(ud[i+4]+ud[i+3]+ud[i+2] +ud[i+0])%2;
//printf("%d%d", G1, G2);
if(P_2[p])
{
out[pb]=G1;
pb++;
}
p++;
p%=pp_len;
if(P_2[p])
{
out[pb]=G2;
pb++;
}
p++;
p%=pp_len;
}
//printf("pb=%d\n", pb);
}
//out - unpacked bits
//in - packed raw bits (LSF struct)
void conv_Encode_LSF(uint8_t* out, struct LSF *in)
{
uint8_t pp_len = sizeof(P_1);
uint8_t p=0; //puncturing pattern index
uint16_t pb=0; //pushed punctured bits
uint8_t ud[240+4+4]; //unpacked data
memset(ud, 0, 240+4+4);
//unpack DST
for(uint8_t i=0; i<8; i++)
{
ud[4+i] =((in->dst[0])>>(7-i))&1;
ud[4+i+8] =((in->dst[1])>>(7-i))&1;
ud[4+i+16]=((in->dst[2])>>(7-i))&1;
ud[4+i+24]=((in->dst[3])>>(7-i))&1;
ud[4+i+32]=((in->dst[4])>>(7-i))&1;
ud[4+i+40]=((in->dst[5])>>(7-i))&1;
}
//unpack SRC
for(uint8_t i=0; i<8; i++)
{
ud[4+i+48]=((in->src[0])>>(7-i))&1;
ud[4+i+56]=((in->src[1])>>(7-i))&1;
ud[4+i+64]=((in->src[2])>>(7-i))&1;
ud[4+i+72]=((in->src[3])>>(7-i))&1;
ud[4+i+80]=((in->src[4])>>(7-i))&1;
ud[4+i+88]=((in->src[5])>>(7-i))&1;
}
//unpack TYPE
for(uint8_t i=0; i<8; i++)
{
ud[4+i+96] =((in->type[0])>>(7-i))&1;
ud[4+i+104]=((in->type[1])>>(7-i))&1;
}
//unpack META
for(uint8_t i=0; i<8; i++)
{
ud[4+i+112]=((in->meta[0])>>(7-i))&1;
ud[4+i+120]=((in->meta[1])>>(7-i))&1;
ud[4+i+128]=((in->meta[2])>>(7-i))&1;
ud[4+i+136]=((in->meta[3])>>(7-i))&1;
ud[4+i+144]=((in->meta[4])>>(7-i))&1;
ud[4+i+152]=((in->meta[5])>>(7-i))&1;
ud[4+i+160]=((in->meta[6])>>(7-i))&1;
ud[4+i+168]=((in->meta[7])>>(7-i))&1;
ud[4+i+176]=((in->meta[8])>>(7-i))&1;
ud[4+i+184]=((in->meta[9])>>(7-i))&1;
ud[4+i+192]=((in->meta[10])>>(7-i))&1;
ud[4+i+200]=((in->meta[11])>>(7-i))&1;
ud[4+i+208]=((in->meta[12])>>(7-i))&1;
ud[4+i+216]=((in->meta[13])>>(7-i))&1;
}
//unpack CRC
for(uint8_t i=0; i<8; i++)
{
ud[4+i+224]=((in->crc[0])>>(7-i))&1;
ud[4+i+232]=((in->crc[1])>>(7-i))&1;
}
//encode
for(uint8_t i=0; i<240+4; i++)
{
uint8_t G1=(ud[i+4] +ud[i+1]+ud[i+0])%2;
uint8_t G2=(ud[i+4]+ud[i+3]+ud[i+2] +ud[i+0])%2;
//printf("%d%d", G1, G2);
if(P_1[p])
{
out[pb]=G1;
pb++;
}
p++;
p%=pp_len;
if(P_1[p])
{
out[pb]=G2;
pb++;
}
p++;
p%=pp_len;
}
//printf("pb=%d\n", pb);
}
uint16_t LSF_CRC(struct LSF *in)
{
uint8_t d[28];
memcpy(&d[0], in->dst, 6);
memcpy(&d[6], in->src, 6);
memcpy(&d[12], in->type, 2);
memcpy(&d[14], in->meta, 14);
return CRC_M17(d, 28);
}
//encode callsign
uint8_t encode_callsign(uint64_t* out, const uint8_t* inp)
{
//assert inp length
if(strlen(inp)>9)
{
return -1;
}
const uint8_t charMap[40]=" ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-/.";
uint64_t tmp=0;
if(strcmp(inp, "ALL")==0)
{
*out=0xFFFFFFFFFFFF;
return 0;
}
for(int8_t i=strlen(inp)-1; i>=0; i--)
{
for(uint8_t j=0; j<40; j++)
{
if(inp[i]==charMap[j])
{
tmp=tmp*40+j;
break;
}
}
}
*out=tmp;
return 0;
}
//main routine
int main(int argc, char* argv[])
{
//scan command line options for input data
//TODO: support for strings with spaces
if(argc>=2)
{
for(uint8_t i=1; i<argc-1; i++)
{
if(argv[i][0]=='-')
{
if(argv[i][1]=='d') //-d - destination
{
if(strlen(argv[i+1])<=9)
memcpy(dst_raw, &argv[i+1][0], strlen(&argv[i+1][0]));
else
{
fprintf(stderr, "Too long destination callsign.\n");
return -1;
}
}
else if(argv[i][1]=='s') //-s - source
{
if(strlen(argv[i+1])<=9)
memcpy(src_raw, &argv[i+1][0], strlen(&argv[i+1][0]));
else
{
fprintf(stderr, "Too long source callsign.\n");
return -1;
}
}
else if(argv[i][1]=='c') //-c - CAN
{
if(atoi(argv[i+1])<=15)
can=atoi(&argv[i+1]);
else
{
fprintf(stderr, "CAN out of range: 0..15.\n");
return -1;
}
}
else if(argv[i][1]=='n') //-n - number of bytes in packet
{
if(atoi(argv[i+1])>0 && atoi(argv[i+1])<=798)
num_bytes=atoi(argv[i+1]);
else
{
fprintf(stderr, "Number of bytes 0 or exceeding the maximum of 798. Exiting...\n");
return -1;
}
}
else
{
fprintf(stderr, "Unknown param. Exiting...\n");
return -1; //unknown option
}
}
}
}
else
{
fprintf(stderr, "Not enough params. Exiting...\n");
return -1;
}
//assert number of bytes
if(num_bytes==0)
{
fprintf(stderr, "Number of bytes not set. Exiting...\n");
return -1;
}
//encode dst, src for the lsf struct
uint64_t dst_encoded=0, src_encoded=0;
uint16_t type=0;
encode_callsign(&dst_encoded, dst_raw);
encode_callsign(&src_encoded, src_raw);
for(int8_t i=5; i>=0; i--)
{
lsf.dst[5-i]=(dst_encoded>>(i*8))&0xFF;
lsf.src[5-i]=(src_encoded>>(i*8))&0xFF;
}
printf("DST: %s\t%012lX\nSRC: %s\t%012lX\n", dst_raw, dst_encoded, src_raw, src_encoded);
//printf("DST: %02X %02X %02X %02X %02X %02X\n", lsf.dst[0], lsf.dst[1], lsf.dst[2], lsf.dst[3], lsf.dst[4], lsf.dst[5]);
//printf("SRC: %02X %02X %02X %02X %02X %02X\n", lsf.src[0], lsf.src[1], lsf.src[2], lsf.src[3], lsf.src[4], lsf.src[5]);
type=((uint16_t)0b01<<1)|((uint16_t)can<<7); //packet mode, content: data
lsf.type[0]=(uint16_t)type>>8;
lsf.type[1]=(uint16_t)type&0xFF;
memset(&lsf.meta, 0, 112/8);
//encode LSF data
conv_Encode_LSF(enc_bits, &lsf);
/*
//send preamble
send_Preamble(0);
//send LSF syncword
send_Syncword(SYNC_LSF);
//reorder bits
for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
rf_bits[i]=enc_bits[intrl_seq[i]];
//randomize
for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
{
if((rand_seq[i/8]>>(7-(i%8)))&1) //flip bit if '1'
{
if(rf_bits[i])
rf_bits[i]=0;
else
rf_bits[i]=1;
}
}
//send LSF
send_data(rf_bits);
//encode the packet frame
conv_Encode_Frame();
//send packet frame syncword
send_Syncword(SYNC_PKT);
//reorder bits
for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
rf_bits[i]=enc_bits[intrl_seq[i]];
//randomize
for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
{
if((rand_seq[i/8]>>(7-(i%8)))&1) //flip bit if '1'
{
if(rf_bits[i])
rf_bits[i]=0;
else
rf_bits[i]=1;
}
}
//send packet frame data
send_data(rf_bits);
*/
return 0;
}