rsh.c

inetutils 1.5的rsh源代码

/*-
 * Copyright (c) 1983, 1990, 1993, 1994, 2002
 *	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.
 * 4. 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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif
#include <sys/file.h>
#ifdef TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# ifdef HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif

#include <netinet/in.h>
#include <netdb.h>

#include <error.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if defined(HAVE_STDARG_H) && defined(__STDC__) && __STDC__
# include <stdarg.h>
#else
# include <varargs.h>
#endif
#include <getopt.h>
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h>
#endif

#ifdef SHISHI
#define REALM_SZ 1040
#endif

#if defined(KERBEROS) || defined(SHISHI)
int use_kerberos = 1, doencrypt;
#ifdef KERBEROS
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>
char dest_realm_buf[REALM_SZ], *dest_realm = NULL;
CREDENTIALS cred;
Key_schedule schedule;
extern char *krb_realmofhost();

# elif defined(SHISHI)
# include <shishi.h>
# include "shishi_def.h"
char dest_realm_buf[REALM_SZ], *dest_realm = NULL;

Shishi * h;
Shishi_key * enckey;
shishi_ivector iv1, iv2, iv3, iv4;
shishi_ivector * ivtab[4];

int keytype;
int keylen;
int rc;
int wlen;
#endif
#endif /* KERBEROS */

/*
 * rsh - remote shell
 */
int	rfd2;

char *copyargs (char **);
RETSIGTYPE sendsig   (int);
void talk      (int, sigset_t *, pid_t, int);
void usage     (void);
void warning   (const char *, ...);

char *program_name;

#ifdef KERBEROS
#ifdef ENCRYPTION
#define	OPTIONS	"8Kdek:l:nxVh"
#else
#define	OPTIONS	"8Kdek:l:nVh"
#endif
#else
#define	OPTIONS	"8KLdel:nVh"
#endif
static const char *short_options = "+" OPTIONS;
static struct option long_options[] =
{
  { "debug", no_argument, 0, 'd' },
  { "user", required_argument, 0, 'l' },
  { "escape", required_argument, 0, 'e' },
  { "8-bit", no_argument, 0, '8' },
  { "kerberos", no_argument, 0, 'K' },
  { "no-input", no_argument, 0, 'n' },
#if defined(KERBEROS) || defined(SHISHI)
  { "realm", required_argument, 0, 'k' },
  { "encrypt", no_argument, 0, 'x' },
#endif
  { "help", no_argument, 0, 'h' },
  { "version", no_argument, 0, 'V' },
  { 0, 0, 0, 0 }
};

static void
pusage (FILE *stream)
{
  fprintf (stream,
	  "Usage: %s [-nd%s]%s[-l USER] [USER@]HOST [COMMAND [ARG...]]\n",
	   program_name,
#if defined(KERBEROS) || defined(SHISHI)
#ifdef ENCRYPTION
	    "x", " [-k REALM] "
#else
	    "", " [-k REALM] "
#endif
#else
	    "", " "
#endif
	   );
}

/* Print a help message describing all options to STDOUT and exit with a
   status of 0.  */
static void
help (void)
{
  pusage (stdout);
  puts ("Execute COMMAND on remote system HOST");
  puts ("When use as rlogin:");
  puts ("\
  -8, --8-bit       allows an eight-bit input data path at all times");
  puts ("\
  -E, --no-escape   stops any character from being recognized as an escape\n\
                    character");
  puts ("\
  -d, --debug       turns on socket debugging (see setsockopt(2))");
  puts ("\
  -e, --escape=CHAR allows user specification of the escape character,\n\
                    which is ``~'' by default");
  puts ("\
  -l, --user USER   run as USER on the remote system");
#if defined(KERBEROS) || defined(SHISHI)
  puts ("\
  -K, --kerberos    turns off all Kerberos authentication");
  puts ("\
  -k, --realm REALM Obtain tickets for the remote host in REALM\n\
                    instead of the remote host's realm");
# ifdef ENCRYPTION
  puts ("\
  -x, --encrypt     encrypt all data using DES");
# endif
#endif
  puts ("\
  -n, --no-input    use /dev/null as input");
  puts ("\
      --help        give this help list");
  puts ("\
  -V, --version     print program version");
  fprintf (stdout, "\nSubmit bug reports to %s.\n", PACKAGE_BUGREPORT);
  exit (0);
}

/* Print a message saying to use --help to STDERR, and exit with a status of
   1.  */
static void
try_help (void)
{
  fprintf (stderr, "Try `%s --help' for more information.\n", program_name);
  exit (1);
}

void
usage()
{
  pusage (stderr);
  try_help ();
}


int
main (int argc, char **argv)
{
  struct passwd *pw;
  struct servent *sp;
  sigset_t sigs, osigs;
  int asrsh, ch, dflag, nflag, rem;
  pid_t pid = 0;
  uid_t uid;
  char *args, *host, *user;

  program_name = argv[0];

  asrsh = dflag = nflag = 0;
  host = user = NULL;

  /* If called as something other than "rsh", use it as the host name */
  {
    char *p = strrchr(argv[0], '/');
    if (p)
      ++p;
    else
      p = argv[0];
    if (strcmp (p, "rsh"))
      host = p;
    else
      asrsh = 1;
  }

  while ((ch = getopt_long (argc, argv, short_options, long_options, 0))
	 != EOF)
    {
      switch (ch)
	{
	case 'L':	/* -8Lew are ignored to allow rlogin aliases */
	case 'e':
	case 'w':
	case '8':
	  break;

	case 'd':
	  dflag = 1;
	  break;

	case 'l':
	  user = optarg;
	  break;

	case 'K':
#if defined(KERBEROS) || defined(SHISHI)
	  use_kerberos = 0;
#endif
	  break;

#if defined(KERBEROS) || defined(SHISHI)
	case 'k':
	  strncpy (dest_realm_buf, optarg, sizeof dest_realm_buf);
	  dest_realm_buf [REALM_SZ - 1] = '\0';
	  dest_realm = dest_realm_buf;
	  break;

# ifdef ENCRYPTION
	case 'x':
	  doencrypt = 1;
#ifdef KERBEROS
	  des_set_key (cred.session, schedule);
#endif
	  break;
# endif
#endif

	case 'n':
	  nflag = 1;
	  break;

	case 'h':
	  help ();

	case 'V':
	  printf ("rsh (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION);
	  exit (0);

	case '?':
	  try_help ();

	default:
	  usage();
	}
    }

  if (optind < argc)
    host = argv[optind++];

  /* To few args.  */
  if (!host)
    usage ();

  /* If no further arguments, must have been called as rlogin. */
  if (!argv[optind])
    {
      if (asrsh)
	*argv = (char *)"rlogin";
      seteuid (getuid ());
      setuid (getuid ());
      execv (PATH_RLOGIN, argv);
      error (1, errno, "can't exec %s", PATH_RLOGIN);
    }

  argc -= optind;
  argv += optind;

  /* We must be setuid root.  */
  if (geteuid ())
    error (1, 0, "must be setuid root.\n");

  if (!(pw = getpwuid (uid = getuid ())))
    error (1, 0, "unknown user id");

  /* Accept user1@host format, though "-l user2" overrides user1 */
  {
    char *p = strchr (host, '@');
    if (p)
      {
	*p = '\0';
	if (!user && p > host)
	  user = host;
	host = p + 1;
	if (*host == '\0')
	  usage ();
      }
  }

#if defined(KERBEROS) || defined(SHISHI)
#ifdef ENCRYPTION
  /* -x turns off -n */
  if (doencrypt)
    nflag = 0;
#endif
#endif

  args = copyargs (argv);

  sp = NULL;
#ifdef KERBEROS
  if (use_kerberos)
    {
      sp = getservbyname ((doencrypt ? "ekshell" : "kshell"), "tcp");
      if (sp == NULL)
	{
	  use_kerberos = 0;
	  warning ("can't get entry for %s/tcp service",
		   doencrypt ? "ekshell" : "kshell");
	}
    }
#elif defined(SHISHI)
  if (use_kerberos)
    {
      sp = getservbyname ("kshell", "tcp");
      if (sp == NULL)
	{
	  use_kerberos = 0;
	  warning ("can't get entry for %s/tcp service",
		   "kshell");
	}
    }
#endif
  if (sp == NULL)
    sp = getservbyname("shell", "tcp");
  if (sp == NULL)