tests/test-sethostname2.c

   1 /*
   2  * Copyright (C) 2011-2020 Free Software Foundation, Inc.
   3  * Written by Ben Walton.
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 #include <unistd.h>
  21
  22 /* for HOST_NAME_MAX */
  23 #include <limits.h>
  24 /* for strlen */
  25 #include <string.h>
  26
  27 #include <errno.h>
  28 #include <stdio.h>
  29
  30 #include "root-uid.h"
  31
  32 #include "macros.h"
  33
  34 #define TESTHOSTNAME "gnulib-hostname"
  35
  36 /* mingw and MSVC 9 lack geteuid, so setup a dummy value.
  37    On Cygwin, geteuid() may return non-zero even for user accounts with
  38    administrator privileges, so use a dummy value as well.  */
  39 #if !HAVE_GETEUID || defined __CYGWIN__
  40 # define geteuid() ROOT_UID
  41 #endif
  42
  43 int
  44 main (int argc, char *argv[] _GL_UNUSED)
  45 {
  46   char origname[HOST_NAME_MAX];
  47   char newname[HOST_NAME_MAX];
  48   char longname[HOST_NAME_MAX + 2];
  49   int rcs, i;
  50
  51   /* skip the tests if we don't have root privilege.  this does not
  52      consider things like CAP_SYS_ADMIN (linux) or PRIV_SYS_ADMIN
  53      (solaris), etc.  systems without a working geteuid (mingw, MSVC
  54      9) will always skip this test. */
  55   if (geteuid () != ROOT_UID)
  56     {
  57       fprintf (stderr, "Skipping test: insufficient permissions.\n");
  58       return 77;
  59     }
  60
  61   /* we want to ensure we can do a get/set/get check to ensure the
  62      change is accepted. record the current name so it can be restored
  63      later */
  64   ASSERT (gethostname (origname, sizeof (origname)) == 0);
  65
  66   /* try setting a valid hostname.  if it fails -1/ENOSYS, we will
  67      skip the test for long names as this is an indication we're using
  68      the stub function that doesn't do anything on this platform. */
  69   rcs = sethostname (TESTHOSTNAME, strlen (TESTHOSTNAME));
  70
  71   if (rcs != 0)
  72     {
  73       if (rcs == -1 && errno == ENOSYS)
  74         {
  75           fprintf (stderr,
  76                    "Skipping test: sethostname is not really implemented.\n");
  77           return 77;
  78         }
  79       else if (rcs == -1 && errno == EPERM)
  80         {
  81           fprintf (stderr, "Skipping test: insufficient permissions.\n");
  82           return 77;
  83         }
  84       else
  85         {
  86           fprintf (stderr, "error setting valid hostname.\n");
  87           return 1;
  88         }
  89     }
  90   else
  91     {
  92       ASSERT (gethostname (newname, sizeof (newname)) == 0);
  93
  94       /* On Windows, a hostname change becomes effective only after
  95          a reboot.  */
  96 #if !(defined _WIN32 || defined __CYGWIN__)
  97
  98       /* if we don't get back what we put in, there is no need to
  99          restore the original name as we will assume it was not
 100          properly changed. */
 101       if (strcmp (newname, TESTHOSTNAME) != 0)
 102         {
 103           fprintf (stderr, "set/get comparison failed.\n");
 104           return 1;
 105         }
 106 #endif
 107     }
 108
 109   /* glibc does allow setting a zero length name, so the lower bound
 110      needs no test. validate that we are constrained by
 111      HOST_NAME_MAX */
 112   for (i = 0; i < (HOST_NAME_MAX + 1); i++)
 113     longname[i] = 'a';
 114
 115   longname[i] = '\0';
 116
 117   rcs = sethostname (longname, (HOST_NAME_MAX + 1));
 118
 119   if (rcs != -1)
 120     {
 121       /* attempt to restore the original name. */
 122       ASSERT (sethostname (origname, strlen (origname)) == 0);
 123       fprintf (stderr, "setting a too long hostname succeeded.\n");
 124       return 1;
 125     }
 126
 127   /* restore the original name. */
 128   ASSERT (sethostname (origname, strlen (origname)) == 0);
 129
 130   return 0;
 131 }