372 lines
8.3 KiB
C
372 lines
8.3 KiB
C
/*
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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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* Copyright (C) 2024 Thomas Kolb
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*/
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#include <linux/if.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <arpa/inet.h>
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#include <liquid/liquid.h>
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#include <sys/poll.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <poll.h>
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#include <signal.h>
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#include <errno.h>
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#include "layer2/ham64.h"
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#include "utils.h"
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#define LOGGER_MODULE_NAME "main"
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#include "logger.h"
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#include "options.h"
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#include "jsonlogger.h"
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#include "debug_structs.h"
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#include "layer2/connection.h"
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#include "layer2/tundev.h"
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#include "config.h"
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#define RESULT_CHECK(stmt) { \
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result_t res = stmt; \
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if(res != OK) { \
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LOG(LVL_FATAL, "Error %d in %s:%d!", res, __FILE__, __LINE__); \
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exit(1); \
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} \
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}
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#define BROADCAST_PORT 3737
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static int m_tunfd = -1;
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static bool m_running = true;
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static int m_bcast_sock = -1;
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static double next_tx_switch_time = 0.0;
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static rx_stats_t m_rx_stats;
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static connection_ctx_t l2conn;
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static void signal_handler(int signal, siginfo_t *info, void *ctx)
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{
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(void)signal;
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(void)info;
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(void)ctx;
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LOG(LVL_INFO, "\nGracefully shutting down on signal %d.", signal);
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m_running = false;
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}
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static void block_tx_for(unsigned offset_ms)
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{
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next_tx_switch_time = get_hires_time() + (double)offset_ms * 0.001;
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}
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void handle_received_packet(uint8_t *packet_data, size_t packet_len)
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{
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block_tx_for(TX_SWITCH_BACKOFF_END_OF_PACKET_MS);
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result_t result = connection_handle_packet(&l2conn, packet_data, packet_len);
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switch(result) {
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case OK:
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m_rx_stats.successful_decodes++;
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break;
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case ERR_INTEGRITY:
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LOG(LVL_ERR, "Packet could not be decoded by Layer 2.");
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m_rx_stats.failed_decodes++;
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break;
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case ERR_SEQUENCE:
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LOG(LVL_ERR, "Packet not in the expected sequence.");
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break;
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default: // all other errors
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LOG(LVL_ERR, "layer2_rx_handle_packet() returned error code %u.", result);
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break;
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}
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}
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static result_t transmit(const uint8_t *data, size_t len)
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{
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result_t result = OK;
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struct sockaddr_in bcast_addr = {0};
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bcast_addr.sin_family = AF_INET;
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bcast_addr.sin_port = htons(BROADCAST_PORT);
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bcast_addr.sin_addr.s_addr = INADDR_BROADCAST;
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int ret = sendto(m_bcast_sock, data, len, 0, (struct sockaddr*)&bcast_addr, sizeof(bcast_addr));
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if(ret < 0) {
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LOG(LVL_ERR, "sendto: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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fprintf(stderr, "t");
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return result;
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}
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void rx_data_to_tun(struct connection_ctx_s *conn, const uint8_t *data, size_t len)
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{
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(void)conn;
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int ret = write(m_tunfd, data, len);
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if(ret < 0) {
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LOG(LVL_ERR, "write(tun): %s", strerror(errno));
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}
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}
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int main(int argc, char **argv)
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{
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// initialize the console logger
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logger_init();
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if(!jsonlogger_init("jsonlog.fifo")) {
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LOG(LVL_FATAL, "Could not initialize JSON logger.");
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return EXIT_FAILURE;
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}
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bool on_air = true;
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srand((int)(get_hires_time() * 1e6));
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// ** Initialize **
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char devname[IFNAMSIZ] = "hamnet70";
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m_tunfd = tundev_open(devname);
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if(m_tunfd < 0) {
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return 1;
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}
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ham64_t my_address, peer_address;
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ham64_encode(MY_CALL, &my_address);
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ham64_encode(PEER_CALL, &peer_address);
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RESULT_CHECK(connection_init(&l2conn, &my_address, &peer_address, rx_data_to_tun));
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// force connection into the established state
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l2conn.conn_state = CONN_STATE_ESTABLISHED;
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// ** Set up signal handling
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struct sigaction term_action = {0};
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term_action.sa_sigaction = signal_handler;
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if(sigaction(SIGTERM, &term_action, NULL) < 0) {
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LOG(LVL_ERR, "sigaction: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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if(sigaction(SIGINT, &term_action, NULL) < 0) {
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LOG(LVL_ERR, "sigaction: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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// ** Set up UDP socket
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m_bcast_sock = socket(AF_INET, SOCK_DGRAM, 0);
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if(m_bcast_sock < 0) {
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LOG(LVL_ERR, "socket: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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int broadcastEnable=1;
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int ret = setsockopt(m_bcast_sock, SOL_SOCKET, SO_BROADCAST, &broadcastEnable, sizeof(broadcastEnable));
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if(ret < 0) {
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LOG(LVL_ERR, "setsockopt: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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struct sockaddr_in bind_addr = {0};
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bind_addr.sin_family = AF_INET;
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bind_addr.sin_port = htons(BROADCAST_PORT);
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bind_addr.sin_addr.s_addr = INADDR_ANY;
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ret = bind(m_bcast_sock, (struct sockaddr*)&bind_addr, sizeof(bind_addr));
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if(ret < 0) {
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LOG(LVL_ERR, "bind: %s", strerror(errno));
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exit(EXIT_FAILURE);
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}
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// ** Process packets **
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struct pollfd pfd_tun;
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memset(&pfd_tun, 0, sizeof(pfd_tun));
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pfd_tun.fd = m_tunfd;
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pfd_tun.events = POLLIN;
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struct pollfd pfd_bcast;
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memset(&pfd_bcast, 0, sizeof(pfd_bcast));
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pfd_bcast.fd = m_bcast_sock;
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pfd_bcast.events = POLLIN;
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double old = get_hires_time();
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size_t total_bytes = 0;
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double next_stats_print_time = old + 0.5;
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double retransmit_time = 0.0;
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while(m_running) {
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double now = get_hires_time();
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if(retransmit_time != 0.0 && now >= retransmit_time) {
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LOG(LVL_INFO, "Retransmit triggered.");
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retransmit_time = 0.0;
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connection_restart_tx(&l2conn);
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}
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// fill the TX queue from the TUN device
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while(connection_can_enqueue_packet(&l2conn)) {
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int ret = poll(&pfd_tun, 1, 0 /* timeout */);
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if(ret < 0) {
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LOG(LVL_ERR, "poll: %s", strerror(errno));
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break;
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} else if(ret == 0) {
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// no more packets
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break;
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} else {
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// a packet is available -> move it to the queue
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static const size_t packetbuf_size = 2048;
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uint8_t packetbuf[packetbuf_size];
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ret = read(m_tunfd, packetbuf, packetbuf_size);
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if(ret < 0) {
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LOG(LVL_ERR, "read: %s", strerror(errno));
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return ERR_SYSCALL;
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} else if(ret == 0) {
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// no more data, should not happen
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break;
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}
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RESULT_CHECK(connection_enqueue_packet(&l2conn, packetbuf, ret));
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}
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}
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if((now > next_tx_switch_time)) {
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if(connection_can_transmit(&l2conn)) {
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// there is a packet to be (re)transmitted.
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LOG(LVL_DEBUG, "Starting new burst.");
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size_t burst_len = 0;
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// add packets to the burst until only 50000 samples remain free in the SDR buffer
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while(true) {
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uint8_t packet_buf[2048];
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size_t packet_size;
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packet_size = connection_encode_next_packet(&l2conn,
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connection_get_next_expected_seq(&l2conn),
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packet_buf, sizeof(packet_buf));
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if(packet_size == 0) {
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// no more packets available
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LOG(LVL_DEBUG, "Ending burst due to empty packet queue.");
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break;
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}
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LOG(LVL_DEBUG, "Adding packet with %d bytes to burst.", packet_size);
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burst_len++;
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RESULT_CHECK(transmit(packet_buf, packet_size));
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}
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connection_tx_clean_empty_packet(&l2conn);
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LOG(LVL_DEBUG, "Burst finished: %zd packets sent.", burst_len);
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if(!on_air) {
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LOG(LVL_INFO, "RX -> TX");
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}
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on_air = true;
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} else if(on_air) { // TX on, but no more bursts to send
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LOG(LVL_INFO, "TX -> RX");
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on_air = false;
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retransmit_time = get_hires_time() + 1.0 + 1.0 * rand() / RAND_MAX;
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block_tx_for(TX_SWITCH_BACKOFF_AFTER_RX_ON);
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}
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}
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if(!on_air) {
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// ** Receive signal **
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int ret = poll(&pfd_bcast, 1, 10);
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if(ret < 0) {
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LOG(LVL_ERR, "poll: %s", strerror(errno));
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break;
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}
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if(ret == 0) {
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continue;
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}
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uint8_t packetbuf[65536];
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ret = recv(m_bcast_sock, packetbuf, sizeof(packetbuf), 0);
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if(ret < 0) {
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LOG(LVL_ERR, "recv: %s", strerror(errno));
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}
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if(ret <= 0) {
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break;
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}
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handle_received_packet(packetbuf, ret);
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total_bytes += ret;
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double new = get_hires_time();
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if(new >= next_stats_print_time) {
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double rate = total_bytes / (new - old);
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LOG(LVL_INFO, "\nEstimated rate: %.3f kB/s", rate / 1e3);
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LOG(LVL_INFO, "Receiver statistics:");
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LOG(LVL_INFO, " Preambles found: %8zd", m_rx_stats.preambles_found);
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LOG(LVL_INFO, " Successful decodes: %8zd (%6.2f %%)",
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m_rx_stats.successful_decodes, m_rx_stats.successful_decodes * 100.0f / m_rx_stats.preambles_found);
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LOG(LVL_INFO, " Header errors: %8zd (%6.2f %%)",
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m_rx_stats.header_errors, m_rx_stats.header_errors * 100.0f / m_rx_stats.preambles_found);
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LOG(LVL_INFO, " Failed decodes: %8zd (%6.2f %%)",
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m_rx_stats.failed_decodes, m_rx_stats.failed_decodes * 100.0f / m_rx_stats.preambles_found);
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next_stats_print_time += 0.5;
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total_bytes = 0;
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old = new;
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}
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fprintf(stderr, "r");
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}
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}
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// ** Cleanup **
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close(m_bcast_sock);
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connection_destroy(&l2conn);
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jsonlogger_shutdown();
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LOG(LVL_INFO, "Done.");
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logger_shutdown();
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}
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