contrib/sendmail-8.14/test/t_setgid.c

   1 /*
   2  * Copyright (c) 2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  *
   9  */
  10
  11 /*
  12 **  This program checks to see if your version of setgid works.
  13 **  Compile it, make it set-group-ID guest, and run it as yourself (NOT as
  14 **  root and not as member of the group guest).
  15 **
  16 **  Compilation is trivial -- just "cc t_setgid.c".  Make it set-group-ID,
  17 **  guest and then execute it as a non-root user.
  18 */
  19
  20 #include <sys/types.h>
  21 #include <unistd.h>
  22 #include <stdio.h>
  23
  24 #ifndef lint
  25 static char id[] = "@(#)$Id: t_setgid.c,v 1.6 2001/09/23 03:35:41 ca Exp $";
  26 #endif /* ! lint */
  27
  28 static void
  29 printgids(str, r, e)
  30         char *str;
  31         gid_t r, e;
  32 {
  33         printf("%s (should be %d/%d): r/egid=%d/%d\n", str, (int) r, (int) e,
  34                (int) getgid(), (int) getegid());
  35 }
  36
  37 int
  38 main(argc, argv)
  39         int argc;
  40         char **argv;
  41 {
  42         int fail = 0;
  43         int res;
  44         gid_t realgid = getgid();
  45         gid_t effgid = getegid();
  46
  47         printgids("initial gids", realgid, effgid);
  48
  49         if (effgid == realgid)
  50         {
  51                 printf("SETUP ERROR: re-run set-group-ID guest\n");
  52                 exit(1);
  53         }
  54
  55 #if SM_CONF_SETREGID
  56         res = setregid(effgid, effgid);
  57 #else /* SM_CONF_SETREGID */
  58         res = setgid(effgid);
  59 #endif /* SM_CONF_SETREGID */
  60
  61         printf("setgid(%d)=%d %s\n", (int) effgid, res,
  62                 res < 0 ? "failure" : "ok");
  63 #if SM_CONF_SETREGID
  64         printgids("after setregid()", effgid, effgid);
  65 #else /* SM_CONF_SETREGID */
  66         printgids("after setgid()", effgid, effgid);
  67 #endif /* SM_CONF_SETREGID */
  68
  69         if (getegid() != effgid)
  70         {
  71                 fail++;
  72                 printf("MAYDAY!  Wrong effective gid\n");
  73         }
  74
  75         if (getgid() != effgid)
  76         {
  77                 fail++;
  78                 printf("MAYDAY!  Wrong real gid\n");
  79         }
  80
  81         /* do activity here */
  82         if (setgid(0) == 0)
  83         {
  84                 fail++;
  85                 printf("MAYDAY!  setgid(0) succeeded (should have failed)\n");
  86         }
  87         else
  88         {
  89                 printf("setgid(0) failed (this is correct)\n");
  90         }
  91         printgids("after setgid(0)", effgid, effgid);
  92
  93         if (getegid() != effgid)
  94         {
  95                 fail++;
  96                 printf("MAYDAY!  Wrong effective gid\n");
  97         }
  98         if (getgid() != effgid)
  99         {
 100                 fail++;
 101                 printf("MAYDAY!  Wrong real gid\n");
 102         }
 103         printf("\n");
 104
 105         if (fail > 0)
 106         {
 107                 printf("\nThis system cannot use %s to set the real gid to the effective gid\nand clear the saved gid.\n",
 108 #if SM_CONF_SETREGID
 109                         "setregid"
 110 #else /* SM_CONF_SETREGID */
 111                         "setgid"
 112 #endif /* SM_CONF_SETREGID */
 113                         );
 114                 exit(1);
 115         }
 116
 117         printf("\nIt is possible to use setgid on this system\n");
 118         exit(0);
 119 }