tests/test-sethostname2.c

   1 /*
   2  * Copyright (C) 2011-2024 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, _GL_UNUSED char *argv[])
  45 {
  46   char origname[HOST_NAME_MAX];
  47   char newname[HOST_NAME_MAX];
  48   int rcs, i;
  49
  50   /* skip the tests if we don't have root privilege.  this does not
  51      consider things like CAP_SYS_ADMIN (linux) or PRIV_SYS_ADMIN
  52      (solaris), etc.  systems without a working geteuid (mingw, MSVC
  53      9) will always skip this test. */
  54   if (geteuid () != ROOT_UID)
  55     {
  56       fprintf (stderr, "Skipping test: insufficient permissions.\n");
  57       return 77;
  58     }
  59
  60   /* we want to ensure we can do a get/set/get check to ensure the
  61      change is accepted. record the current name so it can be restored
  62      later */
  63   ASSERT (gethostname (origname, sizeof (origname)) == 0);
  64
  65   /* try setting a valid hostname.  if it fails -1/ENOSYS, we will
  66      skip the test for long names as this is an indication we're using
  67      the stub function that doesn't do anything on this platform. */
  68   rcs = sethostname (TESTHOSTNAME, strlen (TESTHOSTNAME));
  69
  70   if (rcs != 0)
  71     {
  72       if (rcs == -1 && errno == ENOSYS)
  73         {
  74           fprintf (stderr,
  75                    "Skipping test: sethostname is not really implemented.\n");
  76           return 77;
  77         }
  78       else if (rcs == -1
  79                && (errno == EPERM
  80                    || errno == EACCES)) /* Cygwin */
  81         {
  82           fprintf (stderr, "Skipping test: insufficient permissions.\n");
  83           return 77;
  84         }
  85       else
  86         {
  87           fprintf (stderr, "error setting valid hostname.\n");
  88           return 1;
  89         }
  90     }
  91   else
  92     {
  93       ASSERT (gethostname (newname, sizeof (newname)) == 0);
  94
  95       /* On Windows, a hostname change becomes effective only after
  96          a reboot.  */
  97 #if !(defined _WIN32 || defined __CYGWIN__)
  98
  99       /* if we don't get back what we put in, there is no need to
 100          restore the original name as we will assume it was not
 101          properly changed. */
 102       if (strcmp (newname, TESTHOSTNAME) != 0)
 103         {
 104           fprintf (stderr, "set/get comparison failed.\n");
 105           return 1;
 106         }
 107 #endif
 108     }
 109
 110   /* Known Cygwin bug:
 111      <https://cygwin.com/pipermail/cygwin/2024-May/255986.html>  */
 112 #if !defined __CYGWIN__
 113   {
 114     char longname[HOST_NAME_MAX + 2];
 115
 116     /* glibc does allow setting a zero length name, so the lower bound
 117        needs no test. validate that we are constrained by
 118        HOST_NAME_MAX */
 119     for (i = 0; i < (HOST_NAME_MAX + 1); i++)
 120       longname[i] = 'a';
 121
 122     longname[i] = '\0';
 123
 124     rcs = sethostname (longname, (HOST_NAME_MAX + 1));
 125
 126     if (rcs != -1)
 127       {
 128         /* attempt to restore the original name. */
 129         ASSERT (sethostname (origname, strlen (origname)) == 0);
 130         fprintf (stderr, "setting a too long hostname succeeded.\n");
 131         return 1;
 132       }
 133   }
 134 #endif
 135
 136   /* restore the original name. */
 137   ASSERT (sethostname (origname, strlen (origname)) == 0);
 138
 139   return test_exit_status;
 140 }