#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <string.h>

#define IPTABLES


#define STACKSIZE "200"

int main(int argc, char *argv[]) {
 char * theiraddr = getenv("REMOTE_ADDR");
 pid_t child = -1;
 extern int errno;
 int eflag;
 int try,i,s;
 int dotcount = 0;

 if(!theiraddr) {
   fprintf(stderr, "%s: No REMOTE_ADDR\n",argv[0]);
   exit(0);
 }
 /* How long is the string? */
 s = strlen(theiraddr);
 
 /* The first and last characters must be digits. */

 eflag = !(theiraddr[0] >= '0' && theiraddr[0] <= '9'
        && theiraddr[s-1] >= '0' && theiraddr[s-1] <= '9');

 /* Count the dots and make sure that the rest of the string is     dots and digits. */

 for(i = 1; i < (s-1); i ++) {
   if((theiraddr[i] == '.' && ++dotcount) ||
      (theiraddr[i] >= '0' && theiraddr[i] <= '9')) continue;
   eflag = 1;
   break;
 }
 if(eflag || dotcount != 3) {
   fprintf(stderr, "%s: %s is an invalid value for REMOTE_ADDR\n",
        argv[0],theiraddr);
   exit(1);
 }
 printf("Content-type: text/plain\n");
 printf("Pragma: no-cache\n\n");

 fflush(stdout);
 for(try = 0;
     try == 0 || (try < 20 && child == -1 && errno == EAGAIN);
     sleep(1),try++) {
      if(!(child = fork())) {
     int execrtn;
     
execrtn = execlp("/sbin/iptables","iptables","-I","FILTER80","-s",theiraddr,"-j","LOGDROP",(void*)NULL);

     perror("exec failed");
     exit(1);
   }
 }

 for(try = 0;
     try == 0 || (try < 20 && child == -1 && errno == EAGAIN);
     sleep(1),try++) {
      if(!(child = fork())) {
     int execrtn;
execrtn = execlp("/sbin/iptables","iptables","-D","FILTER80",STACKSIZE,NULL);
	
     perror("second exec failed");
     exit(1);
   }
 }

 /* Wait for our children to complete. */
 while(-1 != wait(NULL) && errno != ECHILD) {}  printf("bye bye LOOOOOOOOOOOSER!\nYou are now BLACKLISTED!\n");
 exit(0);
}


/* //Local Variables:--
//compile-command: "gcc ./blockme.c -O2 -Wall -o blockme.cgi"-- then chmod 7411 to setuid root
//End:--
*/