udptoaprs.c

#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 <ctype.h>
#include "sock.h"

// #define DEBUG 1

#define MAXLEN 16384

int checkcall(char*call) {
        char *p;
        if(strlen(call)<5) return 0;
        p=call;
	// 第3位必须是数字
        if(!isdigit(*(p+2))) return 0;
	// BA BD BG BH BI BL BM BR BV BX BY
	if(*p=='B') {
		if(*(p+1)=='A' ||
		  *(p+1)=='D' ||
		  *(p+1)=='G' ||
		  *(p+1)=='H' ||
		  *(p+1)=='I' ||
		  *(p+1)=='L' ||
		  *(p+1)=='M' ||
		  *(p+1)=='R' ||
		  *(p+1)=='V' ||
		  *(p+1)=='X' ||
		  *(p+1)=='Y')
			return 1;
	}
	// VR2
	if(*p=='V') {
		if(*(p+1)=='R' && *(p+2)=='2')
			return 1;
	}
	// XX9
	if(*p=='X') {
		if(*(p+1)=='X' && *(p+2)=='9')
			return 1;
	}

        return 0;
}


void Process(int u_fd, int r_fd) 
{	
	fd_set rset;
	char buff[MAXLEN];
	struct timeval tv;
	int m,n;
	int max_fd;
	char call[MAXLEN];

	while (1) {
		FD_ZERO(&rset);
		FD_SET(u_fd, &rset);
		FD_SET(r_fd, &rset);
		max_fd = max(u_fd,r_fd);
		tv.tv_sec = 300;
		tv.tv_usec = 0;

		m = Select (max_fd + 1, &rset, NULL, NULL, &tv);

		if (m == 0) 
			continue;
		
		if (FD_ISSET(r_fd, &rset)) {
			n = recv (r_fd, buff, MAXLEN,0);
			if((n<=0) &&(errno==EINTR)) continue;
			if(n<=0)   {
				err_sys("recv get %d from tcp server\n",n);
				exit(0);
			}
			buff[n]=0;
#ifdef DEBUG
			fprintf(stderr,"S: %s",buff);
#endif
		}	
		if (FD_ISSET(u_fd, &rset)) {
			n = recv (u_fd, buff, MAXLEN,0);
			if(n<0)   {
				err_sys("recv get %d from udp client\n",n);
				exit(0);		
			}
			if(n==0) continue;
			buff[n]=0;

#ifdef DEBUG
			fprintf(stderr,"C: %s",buff);
#endif
			strcpy(call,buff);
			char *p;
			p = strchr(call,'>');
			if(p) *p = 0;
#ifdef DEBUG
			if(checkcall(call) == 0) {
				fprintf(stderr,"!!  %s is not a china call!!!\n",call);
				continue;
			}
#else
			if(checkcall(call) == 0) continue;
#endif
			Write(r_fd, buff, n);
		}
	}
}


#include "passcode.c"

int main(int argc, char *argv[])
{
	int r_fd,u_fd;
	int llen;
	char buf[MAXLEN];

	signal(SIGCHLD,SIG_IGN);

	if(argc!=2) {
		fprintf(stderr,"usage:  udptoaprs your_call_sign\n");
		exit(0);
	}

#ifndef DEBUG
	daemon_init("udptoaprs",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
	err_msg("starting\n");
	u_fd = Udp_server("127.0.0.1","14581",(socklen_t *)&llen);

	r_fd = Tcp_connect("china.aprs2.net","14580");
	snprintf(buf,MAXLEN,"user %s pass %d vers udptoaprs 1.0 filter r/31.83/117.29/1\r\n",
		argv[1], passcode(argv[1]));
	Write(r_fd, buf, strlen(buf));
#ifdef DEBUG
	fprintf(stderr,"C: %s",buf);
	fprintf(stderr,"u_fd=%d, r_fd=%d\n",u_fd,r_fd);
#endif
	Process(u_fd,r_fd);
	return 0;
}