Logo Search packages:      
Sourcecode: shadow version File versions

console.c

/*
 * Copyright 1991, Julianne Frances Haugh and Chip Rosenthal
 * 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 Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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 "defines.h"
#include <stdio.h>
#include "getdef.h"

#include "rcsid.h"
RCSID("$Id: console.c 6 2005-03-20 15:34:28Z bubulle $")

/*
 * This is now rather generic function which decides if "tty" is listed
 * under "cfgin" in config (directly or indirectly). Fallback to default if
 * something is bad.
 */
int
is_listed(const char *cfgin, const char *tty, int def)
{
      FILE *fp;
      char buf[200], *cons, *s;

      /*
       * If the CONSOLE configuration definition isn't given,
       * fallback to default.
       */

      if ((cons = getdef_str(cfgin)) == NULL)
            return def;

      /*
       * If this isn't a filename, then it is a ":" delimited list of
       * console devices upon which root logins are allowed.
       */

      if (*cons != '/') {
            cons = strcpy(buf, cons);
            while ((s = strtok(cons, ":")) != NULL) {
                  if (strcmp(s, tty) == 0)
                        return 1;

                  cons = NULL;
            }
            return 0;
      }

      /*
       * If we can't open the console list, then call everything a
       * console - otherwise root will never be allowed to login.
       */

      if ((fp = fopen(cons, "r")) == NULL)
            return def;

      /*
       * See if this tty is listed in the console file.
       */

      while (fgets(buf, sizeof(buf), fp) != NULL) {
            buf[strlen(buf) - 1] = '\0';
            if (strcmp(buf, tty) == 0) {
                  (void) fclose(fp);
                  return 1;
            }
      }

      /*
       * This tty isn't a console.
       */

      (void) fclose(fp);
      return 0;
}

/*
 * console - return 1 if the "tty" is a console device, else 0.
 *
 * Note - we need to take extreme care here to avoid locking out root logins
 * if something goes awry.  That's why we do things like call everything a
 * console if the consoles file can't be opened.  Because of this, we must
 * warn the user to protect against the remove of the consoles file since
 * that would allow an unauthorized root login.
 */

int
console(const char *tty)
{
      return is_listed("CONSOLE", tty, 1);
}

Generated by  Doxygen 1.6.0   Back to index