/*
        Written 2005 by chrak <chrak@b4b0.org> <http://www.chrakworld.com>

  shoutoutz to #b4b0 and #c1zc0 @ EFNet

 ircclient -> ciscoBNC -> router -> ircserver

/server ciscoBNCserv 7777
/quote doitup 1.1.1.1 mypass irc.LOL.com 6667


this is version 0.9, next will have more bug fixes, error checking, password protection,
ability to disconnect and resume irc sessions, lists of DOITUPs stored!

 can someone email me if they know how to turn off IOS> shell echoing?


  This code is distributed under the GNU Public Licence (GPL) version 2.
   See http://www.gnu.org/ for further details of the GPL.  If you do not
   have a web browser you can read the LICENSE file in this directory.
**/



#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <signal.h>
#include <time.h>


#define D_VER "0.9"
#define D_PORT "7777"
#define D_REALNAME "ciscoBNC user"


int create_server (unsigned int port);
int server_notice (int sock, char *msg);
int server_notice_from (int sock, char *msg, char *from);
int serve_client (int sock);
int relay_client_and_router (int sock, int r_sock);

int rnd1toN (int max);


void
startdaemon (void)
{
  switch (fork ())
    {
    case -1:
      perror ("fork()");
      exit (1);
    case 0:      /* child */
      break;
    default:      /* parent */
      exit (0);
    }

  if (setsid () == -1)
    {
      perror ("setsid()");
      exit (1);
    }
  //fclose(stdin);
  //fclose(stdout);
}


// vhost = NULL for no bind()
int
connect_to_tcphost (const char *hostname, unsigned int port,
        const char *vhost)
{
  int sock;
  struct hostent *he, *hel;
  struct sockaddr_in saddr;
  struct sockaddr_in localaddr;

  if ((sock = socket (AF_INET, SOCK_STREAM, 0)) == -1)
    {
      perror ("socket()");
      return -1;
    }


  if (vhost)
    {
      if ((hel = gethostbyname (vhost)) == NULL)
  {
    herror ("gethostbyname()");
    close (sock);
    return -1;
  }

      memset (&localaddr, 0, sizeof (struct sockaddr_in));

      localaddr.sin_family = AF_INET;
      localaddr.sin_port = 0;
      localaddr.sin_addr = *((struct in_addr *) hel->h_addr);

/* this is to use VHOST */

      if (bind (sock, (struct sockaddr *) &localaddr, sizeof (localaddr)))
  {
    perror ("bind()");
    close (sock);
    return -1;
  }
    }


  if ((he = gethostbyname (hostname)) == NULL)
    {
      herror ("gethostbyname()");
      close (sock);
      return -1;
    }


  saddr.sin_family = AF_INET;
  saddr.sin_port = htons (port);
  saddr.sin_addr = *((struct in_addr *) he->h_addr);
  if (connect
      (sock, (struct sockaddr *) &saddr, sizeof (struct sockaddr)) == -1)
    {
      perror ("connect()");
      close (sock);
      return -1;
    }
  return sock;
}

int
readline_from_sock (int sock, char *line, int max_read)
{
  int i = 0, retval = 0;
  bzero (line, max_read);
  retval = recv (sock, line, max_read, MSG_PEEK);
  while (line[i] != '\n' && i != max_read && i != retval)
    ++i;
  retval = read (sock, line, ++i);
  line[i] = '\0';    /* terminate the string */

// sloppy but to kill it
  if (strlen (line) == 0)
    {
      fprintf (stderr, "KILLING THIS CONNECTION\n");
      exit (0);
    }
  return retval;

}




int
main (int argc, char *argv[])
{
  int sock, csock, l;
  struct sockaddr_in caddr;



  fprintf (stderr,
     "ciscoBNC V%s\nrun with additional arg to make daemon (%s -)\n(chrak@b4b0.org) (http://www.chrakworld.com)\non port %s\n",
     D_VER, argv[0], D_PORT);

  if ((sock = create_server (atoi (D_PORT))) == -1)
    {
// change to stdout so we can see it from PHP!!@!@
      fprintf (stderr, "create_server FAIL\n");
      exit (-1);
    }
  if (argc > 1)
    startdaemon ();

// stop zombies
  signal (SIGCHLD, SIG_IGN);

  while (1)
    {
      l = sizeof (struct sockaddr_in);
      if ((csock = accept (sock, (struct sockaddr *) &caddr, &l)) == -1)
  {
    perror ("accept()");
    exit (-1);
  }
      fprintf (stderr, "connection from: %s\n", inet_ntoa (caddr.sin_addr));


      switch (fork ())
  {
  case -1:
    perror ("fork()");
    //write(csock,"fork():ERROR\r\n",strlen("fork():ERROR\r\n"));
    exit (1);
  case 0:    /* child */
    server_notice (csock, "connected to ciscoBNC!");
    {
      serve_client (csock);
    }
    close (csock);
    exit (0);
  default:    /* parent */
    close (csock);
  }

    }



}




int
create_server (unsigned int port)
{
  int sock, l = 1;
  struct sockaddr_in saddr;

  if ((sock = socket (AF_INET, SOCK_STREAM, 0)) == -1)
    {
      perror ("socket()");
      return -1;
    }
  setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &l, sizeof (int));

  saddr.sin_family = AF_INET;
  saddr.sin_port = htons (port);
  saddr.sin_addr.s_addr = INADDR_ANY;

  if (bind (sock, (struct sockaddr *) &saddr, sizeof (struct sockaddr)) == -1)
    {
      perror ("bind()");
      return -1;
    }
  /* only 5 connection at a time heh!@ */
  if (listen (sock, 5) == -1)
    {
      perror ("listen()");
      return -1;
    }
  return sock;
}


int
serve_client (int sock)
{
  char buf[1024];
  char doitup[250];
  char mbuf[1024];
  int connected_to_router = 0;
  int connecting_to_irc = 0;
  int sent_pass_once = 0;
  int r_sock;
  char *routername;
  char *routerpass;
  char *ircservname;
  char *ircport;
  char myuser[20], mynick[20];


  srand (time (NULL));    // seed random # generator

  snprintf (myuser, sizeof (myuser), "user%d", rnd1toN (99));
  snprintf (mynick, sizeof (mynick), "d0ud%d", rnd1toN (99));


repeatdoitup:
  routername = NULL;
  routerpass = NULL;
  ircservname = NULL;
  ircport = NULL;

  server_notice (sock, "**************TO CONTINUE*******************");
  server_notice (sock,
     "HELP ME OUT CLICK ADS AT http://www.chrakworld.com !!");
  server_notice (sock,
     "/QUOTE DOITUP router routerpass ircserver ircserverport");
  server_notice (sock,
     "EXAMPLE /quote doitup 1.1.1.1 mypass irc.LOL.com 6667");


  while (1)
    {
      if (readline_from_sock (sock, buf, sizeof (buf)) == -1)
  {
    perror ("readline_from_sock()");  //change.
    return -1;
  }
      if (!strncasecmp (buf, "DOITUP", strlen ("DOITUP")))
  {
    char *p;

    strncpy (doitup, buf, sizeof (doitup));
    if ((p = strtok (doitup, " \r\n")))
      {
        while ((p = strtok (NULL, " \r\n"))
         && (!routername || !routerpass || !ircservname
       || !ircport))
    {
      if (!routername)
        routername = p;
      else if (!routerpass)
        routerpass = p;
      else if (!ircservname)
        ircservname = p;
      else if (!ircport)
        ircport = p;
    }
        if (!routername || !routerpass || !ircservname || !ircport)
    goto repeatdoitup;  // fuck you
        snprintf (buf, sizeof (buf),
      "OK.. connecting to router %s with pass %s,ircserver %s:%s\n\nQUOTE something else if nothing happens\n",
      routername, routerpass, ircservname, ircport);
        server_notice (sock, buf);
        goto doitup_done;  // goto
      }
    else
      {
        goto repeatdoitup;  //LOL
      }
  }
    }
doitup_done:

  while (1)
    {
      if (readline_from_sock (sock, buf, sizeof (buf)) == -1)
  {
    perror ("readline_from_sock()");  //change.
    return -1;
  }

      if ((r_sock = connect_to_tcphost (routername, 23, NULL)) != -1)
  {
    connected_to_router = 1;
    snprintf (mbuf, sizeof (mbuf), "connected to %s", routername);
    server_notice (sock, mbuf);
    while (1)
      {
        if (readline_from_sock (r_sock, buf, sizeof (buf)) == -1)
    {
      perror ("readline_from_sock()");  //change.
      // do something
    }
        else
    {
      //        buf[strlen (buf) - 1] = '\0';
      if (strstr (buf, "assword:"))  // send router passwd
        {
          if (sent_pass_once)  // failed already. reprompted
      {
        // test this
        server_notice (sock, "ROUTER PASSWORD FAILED!!!");
        return -1;
      }
          sent_pass_once = 1;
          server_notice_from (sock, "Logging into router...",
            "ciscoBNC");
          write (r_sock, "cisco\r\n", strlen ("cisco\r\n"));
        }
      else if (buf[strlen (buf) - 1] == '>')  // got cmd prompt
        {
          if (connecting_to_irc)  // failed. back at prompt.
      {
        server_notice (sock, "connect irc port FAILED!!");
        return -1;
      }
          server_notice_from (sock, "trying connect irc server",
            routername);

//                    write (r_sock,
//                           "telnet Sterling.VA.US.UnderNet.org 6667\r\n",
//                           strlen
//                           ("telnet Sterling.VA.US.UnderNet.org 6667\r\n"));
          snprintf (buf, sizeof (buf), "connect %s %s\r\n",
        ircservname, ircport);
          write (r_sock, buf, strlen (buf));
          connecting_to_irc = 1;

        }
      else if (strstr (buf, "Open"))  // connection opened!
        {

          snprintf (buf, sizeof (buf), "USER %s %s %s %s\r\n",
        myuser, routername, ircservname, D_REALNAME);
          write (r_sock, buf, strlen (buf));
          snprintf (buf, sizeof (buf), "NICK %s\r\n", mynick);
          write (r_sock, buf, strlen (buf));

          relay_client_and_router (sock, r_sock);
          return 0;
        }

    }
      }
  }
      else
  {
    // fail!
    return -1;
  }

    }

}


int
server_notice (int sock, char *msg)
{
  char buf[1024];
  snprintf (buf, sizeof (buf), "NOTICE * :%s\r\n", msg);
  return write (sock, buf, strlen (buf));
}


int
server_notice_from (int sock, char *msg, char *from)
{
  char buf[1024];

  snprintf (buf, sizeof (buf), "%s: %s", from, msg);
  return server_notice (sock, buf);
}


// assumes we are connected to irc server from router already.
int
relay_client_and_router (int sock, int r_sock)
{
  char buf[1024];
  char buf1[1024];
  fd_set rfds;
  int retval;



  while (1)
    {
      FD_ZERO (&rfds);
      FD_SET (sock, &rfds);
      FD_SET (r_sock, &rfds);

      retval = select (1023, &rfds, NULL, NULL, 0);
      if (retval)
  {

    if (FD_ISSET (sock, &rfds))
      {
        if (readline_from_sock (sock, buf, sizeof (buf)) > 0)
    {
      write (r_sock, buf, strlen (buf));
      strncpy (buf1, buf, sizeof (buf1));  // save last thing sent. we will need this to stop shell echo from IOS.
    }    // else..
      }
    if (FD_ISSET (r_sock, &rfds))
      {
        if (readline_from_sock (r_sock, buf, sizeof (buf)) > 0)
    {
      if (strcmp (buf, buf1))
        write (sock, buf, strlen (buf));
      else
        {
//                  printf ("IGNORING IOS ECHO\n");
        }    // else
    }

      }
  }

    }
}

int
rnd1toN (int max)
{
  return (rand () % max) + 1;
}