local.toudp.c

/* local.toudp.c v1.0 by  james@ustc.edu.cn 2015.12.19

   connect to 127.0.0.1 tcp 14580 port, login 
   send all packets to udp
	127.0.0.1 14583

*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include "sock.h"
#include <ctype.h>

#define MAXLEN 16384

#define PORT 14580

int debug = 0;

int r_fd;

#include "sendudp.c"

void relayaprs(char *buf, int len)
{
	FILE *fp;
	fp = fopen("/usr/src/aprs/local.udpdest", "r");
	if (fp == NULL) {
		fprintf(stderr, "open host error\n");
		return;
	}
	char hbuf[MAXLEN];
	while (fgets(hbuf, MAXLEN, fp)) {
		char *p;
		if (strlen(hbuf) < 5)
			continue;
		if (hbuf[strlen(hbuf) - 1] == '\n')
			hbuf[strlen(hbuf) - 1] = 0;
		p = strchr(hbuf, ':');
		if (p) {
			*p = 0;
			p++;
			sendudp(buf, len, hbuf, atoi(p));
		} else
			sendudp(buf, len, hbuf, PORT);
	}
	fclose(fp);
}

#include "passcode.c"

void Process(char *server, char *call)
{
	char buffer[MAXLEN];
	int n;
	int optval;
	socklen_t optlen = sizeof(optval);
	r_fd = Tcp_connect(server, "14580");
	optval = 1;
	Setsockopt(r_fd, SOL_SOCKET, SO_KEEPALIVE, &optval, optlen);
	optval = 3;
	Setsockopt(r_fd, SOL_TCP, TCP_KEEPCNT, &optval, optlen);
	optval = 2;
	Setsockopt(r_fd, SOL_TCP, TCP_KEEPIDLE, &optval, optlen);
	optval = 2;
	Setsockopt(r_fd, SOL_TCP, TCP_KEEPINTVL, &optval, optlen);

	snprintf(buffer, MAXLEN, "user %s pass %d vers aprsfwd 1.5 filter b/B*/VR2*/XX9*\r\n", call, passcode(call));
	Write(r_fd, buffer, strlen(buffer));

	while (1) {
		n = Readline(r_fd, buffer, MAXLEN);
		if (n <= 0) {
			exit(0);
		}
		if (buffer[0] == '#')
			continue;
		buffer[n] = 0;
		relayaprs(buffer, n);
	}
}

void usage()
{
	printf("\nlocal.toudp v1.0 - aprs relay by james@ustc.edu.cn\n");
	printf("\nlocal.toudp x.x.x.x CALL\n\n");
	exit(0);
}

int main(int argc, char *argv[])
{
	char *call = "CNGD-1";
	char *server = "127.0.0.1";
	signal(SIGCHLD, SIG_IGN);
	if (argc == 3) {
		server = argv[1];
		call = argv[2];
	} else if (argc != 1) {
		printf("local.toudp server call\n");
		exit(0);
	}
#ifndef DEBUG
	daemon_init("local.toudp", LOG_DAEMON);
	while (1) {
		int pid;
		pid = fork();
		if (pid == 0)	// i am child, will do the job
			break;
		else if (pid == -1)	// error
			exit(0);
		else
			wait(NULL);	// i am parent, wait for child
		sleep(2);	// if child exit, wait 2 second, and rerun
	}
#endif

	Process(server, call);
	return (0);
}