diff options
Diffstat (limited to 'libmisc/console.c')
| -rw-r--r-- | libmisc/console.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/libmisc/console.c b/libmisc/console.c new file mode 100644 index 0000000..cb74c2f --- /dev/null +++ b/libmisc/console.c @@ -0,0 +1,134 @@ +/* + * Copyright (c) 1991 , Julianne Frances Haugh + * Copyright (c) 1991 , Chip Rosenthal + * Copyright (c) 1996 - 1998, Marek Michałkiewicz + * Copyright (c) 2003 - 2005, Tomasz Kłoczko + * Copyright (c) 2007 - 2010, Nicolas François + * 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. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT + * HOLDERS 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 "prototypes.h" + +#ident "$Id$" + +/* local function prototypes */ +static bool is_listed (const char *cfgin, const char *tty, bool def); + +/* + * 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. + */ +static bool is_listed (const char *cfgin, const char *tty, bool def) +{ + FILE *fp; + char buf[1024], *s; + const char *cons; + + /* + * If the CONSOLE configuration definition isn't given, + * fallback to default. + */ + + cons = getdef_str (cfgin); + if (NULL == cons) { + 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 != '/') { + char *pbuf; + strncpy (buf, cons, sizeof (buf)); + buf[sizeof (buf) - 1] = '\0'; + pbuf = &buf[0]; + while ((s = strtok (pbuf, ":")) != NULL) { + if (strcmp (s, tty) == 0) { + return true; + } + + pbuf = NULL; + } + return false; + } + + /* + * If we can't open the console list, then call everything a + * console - otherwise root will never be allowed to login. + */ + + fp = fopen (cons, "r"); + if (NULL == fp) { + return def; + } + + /* + * See if this tty is listed in the console file. + */ + + while (fgets (buf, (int) sizeof (buf), fp) != NULL) { + buf[strlen (buf) - 1] = '\0'; + if (strcmp (buf, tty) == 0) { + (void) fclose (fp); + return true; + } + } + + /* + * This tty isn't a console. + */ + + (void) fclose (fp); + return false; +} + +/* + * 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. + */ + +bool console (const char *tty) +{ + if (strncmp (tty, "/dev/", 5) == 0) { + tty += 5; + } + + return is_listed ("CONSOLE", tty, true); +} + |