--- /dev/null
+/*
+ * Copyright (C) 2011 Free Software Foundation, Inc.
+ * Written by Ben Walton.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+#include <unistd.h>
+
+#include "signature.h"
+SIGNATURE_CHECK (sethostname, int, (const char *, size_t));
+
+/* for HOST_NAME_MAX */
+#include <limits.h>
+/* for uid_t */
+#include <sys/types.h>
+/* for strlen */
+#include <string.h>
+
+#include <errno.h>
+#include <stdio.h>
+
+#include "macros.h"
+
+#define TESTHOSTNAME "gnulib-hostname"
+
+/* mingw and MSVC 9 lack geteuid, so setup a value that will indicate
+ we don't have root privilege since we wouldn't know whether to
+ expect success or failure when setting a name anyway*/
+#if !HAVE_GETEUID
+# define geteuid() ((uid_t) -1)
+#endif
+
+int
+main (int argc, char *argv[] _GL_UNUSED)
+{
+ char origname[HOST_NAME_MAX];
+ char newname[HOST_NAME_MAX];
+ char longname[HOST_NAME_MAX + 2];
+ int rcg, rcs, i;
+
+ /* skip the tests if we don't have root privilege. this does not
+ consider things like CAP_SYS_ADMIN (linux) or PRIV_SYS_ADMIN
+ (solaris), etc. systems without a working geteuid (mingw, MSVC
+ 9) will always skip this test. */
+ if (geteuid() != 0)
+ return 0;
+
+ /* we want to ensure we can do a get/set/get check to ensure the
+ change is accepted. record the current name so it can be restored
+ later */
+ ASSERT(gethostname (origname, sizeof (origname)) == 0);
+
+ /* try setting a valid hostname. if it fails -1/ENOSYS, we will
+ skip the test for long names as this is an indication we're using
+ the stub function that doesn't do anything on this platform. */
+ rcs = sethostname (TESTHOSTNAME, strlen (TESTHOSTNAME));
+
+ if (rcs != 0)
+ {
+ if (rcs == -1 && errno == ENOSYS)
+ return 0;
+ else
+ {
+ printf ("error setting valid hostname.\n");
+ return 1;
+ }
+ }
+ else
+ {
+ ASSERT (gethostname (newname, sizeof (newname)) == 0);
+
+ /* if we don't get back what we put in, there is no need to
+ restore the original name as we will assume it was not
+ properly changed. */
+ if (strcmp (newname, TESTHOSTNAME) != 0)
+ {
+ printf ("set/get comparison failed.\n");
+ return 1;
+ }
+ }
+
+ /* glibc does allow setting a zero length name, so the lower bound
+ needs no test. validate that we are constrained by
+ HOST_NAME_MAX */
+ for (i = 0; i < (HOST_NAME_MAX + 1); i++)
+ longname[i] = 'a';
+
+ longname[i] = '\0';
+
+ rcs = sethostname ((const char *) longname, (HOST_NAME_MAX + 1));
+
+ if (rcs != -1)
+ {
+ /* attempt to restore the original name. */
+ sethostname (origname, strlen (origname));
+ printf ("expected failure when setting very long hostname.\n");
+ return 1;
+ }
+
+ /* restore the original name. */
+ sethostname (origname, strlen (origname));
+
+ return 0;
+}