hamnet70/impl/src/main.c

190 lines
4 KiB
C

#include <linux/if.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#include <ctype.h>
#include <liquid/liquid.h>
#include <unistd.h>
#include "utils.h"
#include "layer1/tx.h"
#include "layer1/rx.h"
#include "layer2/tundev.h"
#define RESULT_CHECK(stmt) { \
result_t res = stmt; \
if(res != OK) { \
fprintf(stderr, "Error %d in %s:%d!", res, __FILE__, __LINE__); \
exit(1); \
} \
}
static int m_tunfd = -1;
static bool m_running = true;
void print_complex_array(const char *varname, float complex const *array, size_t len)
{
fprintf(stderr, "%s=np.array([%f%+fj", varname, crealf(array[0]), cimagf(array[0]));
for(size_t k = 1; k < len; k++) {
fprintf(stderr, ", %f%+fj", crealf(array[k]), cimagf(array[k]));
}
fprintf(stderr, "])\n");
}
void hexdump(const uint8_t *data, size_t len)
{
static const char lut[16] = "0123456789ABCDEF";
static const size_t BYTES_PER_LINE = 16;
size_t pos = 0;
while(pos < len) {
size_t bytes_in_line = len - pos;
if(bytes_in_line > BYTES_PER_LINE) {
bytes_in_line = BYTES_PER_LINE;
}
for(size_t i = 0; i < BYTES_PER_LINE; i++) {
if(i >= bytes_in_line) {
fputs(" ", stderr);
} else {
uint8_t byte = data[pos+i];
fprintf(stderr, "%c%c ", lut[byte >> 4], lut[byte & 0x0F]);
}
}
fputs(" ", stderr);
for(size_t i = 0; i < bytes_in_line; i++) {
uint8_t byte = data[pos+i];
if(isprint(byte)) {
putc(byte, stderr);
} else {
putc('.', stderr);
}
}
putc('\n', stderr);
pos += bytes_in_line;
}
}
void cb_rx(rx_evt_t evt, uint8_t *packet_data, size_t packet_len)
{
int ret;
switch(evt)
{
case RX_EVT_CHECKSUM_ERROR:
fprintf(stderr, "Received a message of %zu bytes, but decoding failed.\n", packet_len);
//fprintf(stderr, "=== FAILED PAYLOAD ===\n");
//hexdump(packet_data, packet_len);
//fprintf(stderr, "=======================\n");
break;
case RX_EVT_PACKET_RECEIVED:
fprintf(stderr, "=== DECODED PAYLOAD (%4zu bytes) ===\n", packet_len);
hexdump(packet_data, packet_len);
fprintf(stderr, "====================================\n");
ret = write(m_tunfd, packet_data, packet_len);
if(ret < 0) {
perror("write");
}
break;
case RX_EVT_PREAMBLE_FOUND:
fprintf(stderr, "Found preamble!\n");
break;
}
}
int main(void)
{
layer1_tx_t tx;
layer1_rx_t rx;
// ** Initialize **
char devname[IFNAMSIZ] = "hamnet70";
m_tunfd = tundev_open(devname);
if(m_tunfd < 0) {
return 1;
}
RESULT_CHECK(layer1_tx_init(&tx));
RESULT_CHECK(layer1_rx_init(&rx, cb_rx));
// channel emulation
channel_cccf channel = channel_cccf_create();
float snr = 15.0f;
channel_cccf_add_awgn(channel, -snr, snr);
channel_cccf_add_carrier_offset(channel, 0.20f, 1.00f);
//channel_cccf_add_shadowing(channel, 1.00f, 0.1f);
// ** Process packets **
uint8_t packetbuf[2048];
while(m_running) {
int ret = read(m_tunfd, packetbuf, sizeof(packetbuf));
if(ret < 0) {
perror("read");
break;
} else if(ret == 0) {
// no more data
break;
}
fprintf(stderr, "Transmitting packet with %d bytes.\n", ret);
RESULT_CHECK(layer1_tx_reset(&tx));
// ** Modulate packet **
RESULT_CHECK(layer1_tx_add_packet_to_burst(&tx, packetbuf, ret));
RESULT_CHECK(layer1_tx_finalize_burst(&tx));
size_t burst_len = layer1_tx_get_sample_count(&tx);
const float complex *whole_burst = layer1_tx_get_sample_data(&tx);
dump_array_cf(whole_burst, burst_len, 1.0f, "/tmp/tx.cpx");
// ** Apply channel distortions **
float complex msg_received[burst_len];
channel_cccf_execute_block(channel, whole_burst, burst_len, msg_received);
// scale the entire signal to give the AGC something to do
for(size_t i = 0; i < burst_len; i++) {
msg_received[i] *= 0.02f;
}
dump_array_cf(msg_received, burst_len, 1.0f, "/tmp/rx.cpx");
// ** Receive signal **
RESULT_CHECK(layer1_rx_process(&rx, msg_received, burst_len));
}
// ** Cleanup **
channel_cccf_destroy(channel);
layer1_tx_shutdown(&tx);
layer1_rx_shutdown(&rx);
fprintf(stderr, "Done.\n");
}