/*
  Copyright (C) 1995-2025 Free Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or (at
  your option) any later version.

  GNU Inetutils is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see `http://www.gnu.org/licenses/'. */

/*
 * Copyright (c) 1988, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#include <sys/types.h>

#include <stdlib.h>
#ifdef HAVE_LOCALE_H
# include <locale.h>
#endif

#include "ring.h"
#include "defines.h"
#include "externs.h"

#include <progname.h>
#include <error.h>
#include <argp.h>
#include <attribute.h>
#include <libinetutils.h>

#include <arpa/telnet.h>

#ifdef	AUTHENTICATION
# include <libtelnet/auth.h>
#endif
#ifdef	ENCRYPTION
# include <libtelnet/encrypt.h>
#endif

/* These values need to be the same as defined in libtelnet/kerberos5.c */
/* Either define them in both places, or put in some common header file. */
#define OPTS_FORWARD_CREDS           0x00000002
#define OPTS_FORWARDABLE_CREDS       0x00000001

#if 0
# define FORWARD
#endif

/*
 * Initialize variables.
 */
void
tninit (void)
{
  init_terminal ();

  init_network ();

  init_telnet ();

  init_sys ();

#if defined TN3270
  init_3270 ();
#endif
}

int family = 0;
char *user, *srcaddr;
#ifdef	FORWARD
extern int forward_flags;
#endif /* FORWARD */

enum
{
  OPTION_NOASYNCH = 256,
  OPTION_NOASYNCTTY,
  OPTION_NOASYNCNET
};

#if defined KERBEROS || defined SHISHI
extern char *dest_realm;
#endif

static struct argp_option argp_options[] = {
#define GRID 10
  {NULL, 0, NULL, 0,
   "General options:", GRID},

  {"ipv4", '4', NULL, 0,
   "use only IPv4", GRID + 1},
  {"ipv6", '6', NULL, 0,
   "use only IPv6", GRID + 1},
  /* FIXME: Called "8bit" in r* utils */
  {"binary", '8', NULL, 0,
   "use an 8-bit data transmission", GRID + 1},
  {"bind", 'b', "ADDRESS", 0,
   "bind to specific local ADDRESS", GRID + 1},
  {"login", 'a', NULL, 0,
   "attempt automatic login", GRID + 1},
  {"no-rc", 'c', NULL, 0,
   "do not read the user's .telnetrc file", GRID + 1},
  {"debug", 'd', NULL, 0,
   "turn on debugging", GRID + 1},
  {"escape", 'e', "CHAR", 0,
   "use CHAR as an escape character", GRID + 1},
  {"no-escape", 'E', NULL, 0,
   "use no escape character", GRID + 1},
  {"no-login", 'K', NULL, 0,
   "do not automatically login to the remote system", GRID + 1},
  {"user", 'l', "USER", 0,
   "attempt automatic login as USER", GRID + 1},
  {"binary-output", 'L', NULL, 0,	/* FIXME: Why L?? */
   "use an 8-bit data transmission for output only", GRID + 1},
  {"trace", 'n', "FILE", 0,
   "record trace information into FILE", GRID + 1},
  {"rlogin", 'r', NULL, 0,
   "use a user-interface similar to rlogin", GRID + 1},
#undef GRID

#ifdef ENCRYPTION
# define GRID 20
  {NULL, 0, NULL, 0,
   "Encryption control:", GRID},
  {"encrypt", 'x', NULL, 0,
   "encrypt the data stream, if possible", GRID + 1},
# undef GRID
#endif

#ifdef AUTHENTICATION
# define GRID 30
  {NULL, 0, NULL, 0,
   "Authentication and Kerberos options:", GRID},
  {"disable-auth", 'X', "ATYPE", 0,
   "disable type ATYPE authentication", GRID + 1},
# if defined KERBEROS || defined SHISHI
  {"realm", 'k', "REALM", 0,
   "obtain tickets for the remote host in REALM "
   "instead of the remote host's realm", GRID + 1},
# endif
# if defined KRB5 && defined FORWARD
  {"fwd-credentials", 'f', NULL, 0,
   "allow the local credentials to be forwarded", GRID + 1},
  {NULL, 'F', NULL, 0,
   "forward a forwardable copy of the local credentials "
   "to the remote system", GRID + 1},
# endif
# undef GRID
#endif

#if defined TN3270 && (defined unix || defined __unix || defined __unix__)
# define GRID 40
  {NULL, 0, NULL, 0,
   "TN3270 support:", GRID},
  /* FIXME: Do we need it? */
  {"transcom", 't', "ARG", 0, "", GRID + 1},
  {"noasynch", OPTION_NOASYNCH, NULL, 0, "", GRID + 1},
  {"noasynctty", OPTION_NOASYNCTTY, NULL, 0, "", GRID + 1},
  {"noasyncnet", OPTION_NOASYNCNET, NULL, 0, "", GRID + 1},
# undef GRID
#endif /* TN3270 && (unix || __unix || __unix__) */
  {NULL, 0, NULL, 0, NULL, 0}
};

static error_t
parse_opt (int key, char *arg, struct argp_state *state MAYBE_UNUSED)
{
  switch (key)
    {
    case '4':
      family = 4;
      break;

    case '6':
      family = 6;
      break;

    case '8':
      eight = 3;		/* binary output and input */
      break;

    case 'E':
      rlogin = escape = _POSIX_VDISABLE;
      break;

    case 'K':
#ifdef	AUTHENTICATION
      autologin = 0;
#endif
      break;

    case 'L':
      eight |= 2;		/* binary output only */
      break;

#ifdef	AUTHENTICATION
    case 'X':
      auth_disable_name (arg);
      break;
#endif

    case 'a':
      autologin = 1;
      break;

    case 'c':
      skiprc = 1;
      break;

    case 'd':
      debug = 1;
      break;

    case 'e':
      set_escape_char (arg);
      break;

#if defined AUTHENTICATION && defined KRB5 && defined FORWARD
    case 'f':
      if (forward_flags & OPTS_FORWARD_CREDS)
	argp_error (state, "Only one of -f and -F allowed.", prompt);
      forward_flags |= OPTS_FORWARD_CREDS;
      break;

    case 'F':
      if (forward_flags & OPTS_FORWARD_CREDS)
	argp_error (state, "Only one of -f and -F allowed");
      forward_flags |= OPTS_FORWARD_CREDS;
      forward_flags |= OPTS_FORWARDABLE_CREDS;
      break;
#endif

#if defined AUTHENTICATION && \
      ( defined KERBEROS || defined SHISHI )
    case 'k':
      dest_realm = arg;
      break;
#endif

    case 'l':
      autologin = 1;
      user = arg;
      break;

    case 'n':
      SetNetTrace (arg);
      break;

    case 'r':
      rlogin = '~';
      break;

#if defined TN3270 && (defined unix || defined __unix || defined __unix__)
    case 't':
      /* FIXME: Buffer!!! */
      transcom = tline;
      strcpy (transcom, arg);
      break;

    case OPTION_NOASYNCH:
      noasynchtty = noasynchtty = 1;
      break;

    case OPTION_NOASYNCTTY:
      noasynchtty = 1;
      break;

    case OPTION_NOASYNCNET:
      noasynchnet = 1;
      break;
#endif /* TN3270 && (unix || __unix || __unix__) */

#ifdef	ENCRYPTION
    case 'x':
      encrypt_auto (1);
      decrypt_auto (1);
      break;
#endif

    case 'b':
      srcaddr = arg;
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }

  return 0;
}


const char args_doc[] = "[HOST [PORT]]";
const char doc[] = "Login to remote system HOST "
  "(optionally, on service port PORT)";
static struct argp argp =
  { argp_options, parse_opt, args_doc, doc, NULL, NULL, NULL };



/*
 * main.  Parse arguments, invoke the protocol or command parser.
 */
int
main (int argc, char *argv[])
{
  int index;

  set_program_name (argv[0]);

#ifdef HAVE_SETLOCALE
  setlocale (LC_ALL, "");
#endif

  tninit ();			/* Clear out things */
#if defined CRAY && !defined __STDC__
  _setlist_init ();		/* Work around compiler bug */
#endif

  TerminalSaveState ();

  if ((prompt = strrchr (argv[0], '/')))
    ++prompt;
  else
    prompt = argv[0];

  user = NULL;

  rlogin = (strncmp (prompt, "rlog", 4) == 0) ? '~' : _POSIX_VDISABLE;
  autologin = -1;

  /* Parse command line */
  iu_argp_init ("telnet", default_program_authors);
  argp_parse (&argp, argc, argv, 0, &index, NULL);

  if (autologin == -1)
    autologin = (rlogin == _POSIX_VDISABLE) ? 0 : 1;

  argc -= index;
  argv += index;

  if (argc)
    {
      /* The command line contains at least one argument.
       */
      char *args[10], **argp = args;

      if (argc > 2)
	error (EXIT_FAILURE, 0, "too many arguments");
      *argp++ = prompt;
      if (user)
	{
	  *argp++ = "-l";
	  *argp++ = user;
	}
      if (srcaddr)
	{
	  *argp++ = "-b";
	  *argp++ = srcaddr;
	}
      if (family == 4)
	*argp++ = "-4";
      else if (family == 6)
	*argp++ = "-6";

      *argp++ = argv[0];	/* host */
      if (argc > 1)
	*argp++ = argv[1];	/* port */
      *argp = 0;

      if (setjmp (toplevel) != 0)
	Exit (0);
      if (tn (argp - args, args) == 1)	/* Returns only on error.  */
	return (0);
      else
	return (1);
      /* NOT REACHED */
    }

  /* Built-in parser loop; sub-commands jump to `toplevel' mark.  */
  setjmp (toplevel);
  for (;;)
    {
#ifdef TN3270
      if (shell_active)
	shell_continue ();
      else
#endif
	command (1, 0, 0);
    }
  /* NOT REACHED */
}