src/local.c

   1 /*
   2  * Copyright (c) 2003-2007 Andrea Luzzardi <scox@sig11.org>
   3  *
   4  * This file is part of the pam_usb project. pam_usb is free software;
   5  * you can redistribute it and/or modify it under the terms of the GNU General
   6  * Public License version 2, as published by the Free Software Foundation.
   7  *
   8  * pam_usb is distributed in the hope that it will be useful, but WITHOUT ANY
   9  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  10  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  11  * details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <utmp.h>
  22 #include "log.h"
  23 #include "conf.h"
  24
  25 int pusb_local_login(t_pusb_options *opts, const char *user)
  26 {
  27         struct utmp     utsearch;
  28         struct utmp     *utent;
  29         const char      *from;
  30         int                     i;
  31
  32         log_debug("Checking whether the caller is local or not...\n");
  33         from = ttyname(STDIN_FILENO);
  34         if (!from || !(*from))
  35         {
  36                 log_debug("Couldn't retrieve the tty name, aborting.\n");
  37                 return (1);
  38         }
  39         if (!strncmp(from, "/dev/", strlen("/dev/")))
  40                 from += strlen("/dev/");
  41         log_debug("Authentication request from tty %s\n", from);
  42         strncpy(utsearch.ut_line, from, sizeof(utsearch.ut_line) - 1);
  43         setutent();
  44         utent = getutline(&utsearch);
  45         endutent();
  46         if (!utent)
  47         {
  48                 log_debug("No utmp entry found for tty \"%s\"\n",
  49                                 from);
  50                 return (1);
  51         }
  52         for (i = 0; i < 4; ++i)
  53         {
  54                 if (utent->ut_addr_v6[i] != 0)
  55                 {
  56                         log_error("Remote authentication request: %s\n", utent->ut_host);
  57                         return (0);
  58                 }
  59         }
  60         log_debug("Caller is local (good)\n");
  61         return (1);
  62 }