diff options
Diffstat (limited to 'libmisc/chowntty.c')
| -rw-r--r-- | libmisc/chowntty.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/libmisc/chowntty.c b/libmisc/chowntty.c new file mode 100644 index 0000000..f6f5dbc --- /dev/null +++ b/libmisc/chowntty.c @@ -0,0 +1,99 @@ +/* + * Copyright (c) 1989 - 1994, Julianne Frances Haugh + * Copyright (c) 1996 - 2001, Marek Michałkiewicz + * Copyright (c) 2003 - 2005, Tomasz Kłoczko + * Copyright (c) 2007 - 2009, 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> + +#ident "$Id$" + +#include <sys/types.h> +#include <sys/stat.h> +#include <stdio.h> +#include <errno.h> +#include <grp.h> +#include "prototypes.h" +#include "defines.h" +#include <pwd.h> +#include "getdef.h" + +/* + * chown_tty() sets the login tty to be owned by the new user ID + * with TTYPERM modes + */ + +void chown_tty (const struct passwd *info) +{ + struct group *grent; + gid_t gid; + + /* + * See if login.defs has some value configured for the port group + * ID. Otherwise, use the user's primary group ID. + */ + + grent = getgr_nam_gid (getdef_str ("TTYGROUP")); + if (NULL != grent) { + gid = grent->gr_gid; + } else { + gid = info->pw_gid; + } + + /* + * Change the permissions on the TTY to be owned by the user with + * the group as determined above. + */ + + if ( (fchown (STDIN_FILENO, info->pw_uid, gid) != 0) + || (fchmod (STDIN_FILENO, (mode_t)getdef_num ("TTYPERM", 0600)) != 0)) { + int err = errno; + + fprintf (stderr, + _("Unable to change owner or mode of tty stdin: %s"), + strerror (err)); + SYSLOG ((LOG_WARN, + "unable to change owner or mode of tty stdin for user `%s': %s\n", + info->pw_name, strerror (err))); + if (EROFS != err) { + closelog (); + exit (EXIT_FAILURE); + } + } +#ifdef __linux__ + /* + * Please don't add code to chown /dev/vcs* to the user logging in - + * it's a potential security hole. I wouldn't like the previous user + * to hold the file descriptor open and watch my screen. We don't + * have the *BSD revoke() system call yet, and vhangup() only works + * for tty devices (which vcs* is not). --marekm + */ +#endif +} + |