contrib/sendmail/test/t_seteuid.c

   1 /*
   2  * Copyright (c) 1999-2001 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 seteuid works.
  13 **  Compile it, make it set-user-ID root, and run it as yourself (NOT as
  14 **  root).  If it won't compile or outputs any MAYDAY messages, don't
  15 **  define USESETEUID in conf.h.
  16 **
  17 **      NOTE:  It is not sufficient to have seteuid in your library.
  18 **      You must also have saved uids that function properly.
  19 **
  20 **  Compilation is trivial -- just "cc t_seteuid.c".  Make it set-user-ID
  21 **  root and then execute it as a non-root user.
  22 */
  23
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <stdio.h>
  27
  28 #ifndef lint
  29 static char id[] = "@(#)$Id: t_seteuid.c,v 8.8 2001/09/23 03:35:41 ca Exp $";
  30 #endif /* ! lint */
  31
  32 #ifdef __hpux
  33 # define seteuid(e)     setresuid(-1, e, -1)
  34 #endif /* __hpux */
  35
  36 static void
  37 printuids(str, r, e)
  38         char *str;
  39         uid_t r, e;
  40 {
  41         printf("%s (should be %d/%d): r/euid=%d/%d\n", str, (int) r, (int) e,
  42                (int) getuid(), (int) geteuid());
  43 }
  44
  45 int
  46 main(argc, argv)
  47         int argc;
  48         char **argv;
  49 {
  50         int fail = 0;
  51         uid_t realuid = getuid();
  52
  53         printuids("initial uids", realuid, 0);
  54
  55         if (geteuid() != 0)
  56         {
  57                 printf("SETUP ERROR: re-run set-user-ID root\n");
  58                 exit(1);
  59         }
  60
  61         if (getuid() == 0)
  62         {
  63                 printf("SETUP ERROR: must be run by a non-root user\n");
  64                 exit(1);
  65         }
  66
  67         if (seteuid(1) < 0)
  68                 printf("seteuid(1) failure\n");
  69         printuids("after seteuid(1)", realuid, 1);
  70
  71         if (geteuid() != 1)
  72         {
  73                 fail++;
  74                 printf("MAYDAY!  Wrong effective uid\n");
  75         }
  76
  77         /* do activity here */
  78
  79         if (seteuid(0) < 0)
  80         {
  81                 fail++;
  82                 printf("seteuid(0) failure\n");
  83         }
  84         printuids("after seteuid(0)", realuid, 0);
  85
  86         if (geteuid() != 0)
  87         {
  88                 fail++;
  89                 printf("MAYDAY!  Wrong effective uid\n");
  90         }
  91         if (getuid() != realuid)
  92         {
  93                 fail++;
  94                 printf("MAYDAY!  Wrong real uid\n");
  95         }
  96         printf("\n");
  97
  98         if (seteuid(2) < 0)
  99         {
 100                 fail++;
 101                 printf("seteuid(2) failure\n");
 102         }
 103         printuids("after seteuid(2)", realuid, 2);
 104
 105         if (geteuid() != 2)
 106         {
 107                 fail++;
 108                 printf("MAYDAY!  Wrong effective uid\n");
 109         }
 110
 111         /* do activity here */
 112
 113         if (seteuid(0) < 0)
 114         {
 115                 fail++;
 116                 printf("seteuid(0) failure\n");
 117         }
 118         printuids("after seteuid(0)", realuid, 0);
 119
 120         if (geteuid() != 0)
 121         {
 122                 fail++;
 123                 printf("MAYDAY!  Wrong effective uid\n");
 124         }
 125         if (getuid() != realuid)
 126         {
 127                 fail++;
 128                 printf("MAYDAY!  Wrong real uid\n");
 129         }
 130
 131         if (fail)
 132         {
 133                 printf("\nThis system cannot use seteuid\n");
 134                 exit(1);
 135         }
 136
 137         printf("\nIt is safe to define USESETEUID on this system\n");
 138         exit(0);
 139 }