/*
 *    announce - sits listening on a port, and whenever anyone connects
 *                 announces a message and disconnects them
 *
 *      Usage:  announce [port] < message_file
 *
 *      Author: Lawrence Brown <lpb@cs.adfa.oz.au>      Aug 90
 *
 *      Bits of code are adapted from the Berkeley telnetd sources
 */

#define PORT	4201

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <netinet/in.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <ctype.h>

extern char **environ;
extern int errno;
char *Name;			/* name of this program for error messages */
char msg[2048];

int
main(argc, argv)
    int argc;
    char **argv;
{
  int s, ns, foo;
  static struct sockaddr_in sin =
  {AF_INET};
  char *host, *inet_ntoa( /* ??? */ );
  char tmp[80];
  long ct;
  int opt;

  Name = argv[0];		/* save name of program for error messages  */
  sin.sin_port = htons((u_short) PORT);		/* Assume PORT */
  argc--, argv++;
  if (argc > 0) {		/*   unless specified on command-line       */
    sin.sin_port = atoi(*argv);
    sin.sin_port = htons((u_short) sin.sin_port);
  }
  strcpy(msg, "");
  strcpy(tmp, "");
  while (1) {
    if ((gets(tmp)) == NULL)
      break;
    strcat(tmp, "\r\n");
    strcat(msg, tmp);
  }
  msg[2048] = '\0';
  signal(SIGHUP, SIG_IGN);	/* get socket, bind port to it      */
  s = socket(AF_INET, SOCK_STREAM, 0);
  if (s < 0) {
    perror("announce: socket");;
    exit(1);
  }
  opt = 1;
  if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
		 (char *) &opt, sizeof(opt)) < 0) {
    perror("setsockopt");
    exit(1);
  }
  if (bind(s, &sin, sizeof sin) < 0) {
    perror("bind");
    exit(1);
  }
  if ((foo = fork()) != 0) {
    fprintf(stderr, "announce: pid %d running on port %d\n", foo,
	    ntohs((u_short) sin.sin_port));
    exit(0);
  } else {
    setpriority(PRIO_PROCESS, getpid(), 10);
  }
  if (listen(s, 1) < 0) {	/* start listening on port */
    perror("announce: listen");
    exit(1);
  }
  foo = sizeof sin;
  for (;;) {			/* loop forever, accepting requests & printing msg */
    ns = accept(s, &sin, &foo);
    if (ns < 0) {
      perror("announce: accept");
      exit(1);
    }
    host = inet_ntoa(sin.sin_addr.s_addr);
    ct = time(0L);
    fprintf(stderr, "CONNECTION made from %s at %s",
	    host, ctime(&ct));
    write(ns, msg, strlen(msg));
    sleep(5);
    close(ns);
  }
}				/* main */