Synchronize support/ infrastructure with master

This commit updates the support/ subdirectory to
commit 84d0e6f05212cabe786cdf00bf3ba5d166d077c0
on the master branch.

6 files changed, 134 insertions, 16 deletions

diff --git a/support/Makefile b/support/Makefile
index 2ace3fa8cc..027a663000 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -65,6 +65,7 @@ libsupport-routines = \
   xchroot \
   xclose \
   xconnect \
+  xdlfcn \
   xdup2 \
   xfclose \
   xfopen \
diff --git a/support/namespace.h b/support/namespace.h
index 859c2fda3f..9eddb1a0e9 100644
--- a/support/namespace.h
+++ b/support/namespace.h
@@ -66,7 +66,9 @@ struct support_chroot_configuration
 {
   /* File contents.  The files are not created if the field is
      NULL.  */
-  const char *resolv_conf;
+  const char *resolv_conf;      /* /etc/resolv.conf.  */
+  const char *hosts;            /* /etc/hosts.  */
+  const char *host_conf;        /* /etc/host.conf.  */
 };
 
 /* The result of the creation of a chroot.  */
@@ -78,8 +80,11 @@ struct support_chroot
   /* Path to the chroot directory.  */
   char *path_chroot;
 
-  /* Path to the /etc/resolv.conf file.  */
-  char *path_resolv_conf;
+  /* Paths to files in the chroot.  These are absolute and outside of
+     the chroot.  */
+  char *path_resolv_conf;       /* /etc/resolv.conf.  */
+  char *path_hosts;             /* /etc/hosts.  */
+  char *path_host_conf;         /* /etc/host.conf.  */
 };
 
 /* Create a chroot environment.  The returned data should be freed
diff --git a/support/support_chroot.c b/support/support_chroot.c
index c0807b313a..f3ef551b05 100644
--- a/support/support_chroot.c
+++ b/support/support_chroot.c
@@ -24,6 +24,23 @@
 #include <support/test-driver.h>
 #include <support/xunistd.h>
 
+/* If CONTENTS is not NULL, write it to the file at DIRECTORY/RELPATH,
+   and store the name in *ABSPATH.  If CONTENTS is NULL, store NULL in
+   *ABSPATH.  */
+static void
+write_file (const char *directory, const char *relpath, const char *contents,
+            char **abspath)
+{
+  if (contents != NULL)
+    {
+      *abspath = xasprintf ("%s/%s", directory, relpath);
+      add_temp_file (*abspath);
+      support_write_file_string (*abspath, contents);
+    }
+  else
+    *abspath = NULL;
+}
+
 struct support_chroot *
 support_chroot_create (struct support_chroot_configuration conf)
 {
@@ -39,15 +56,10 @@ support_chroot_create (struct support_chroot_configuration conf)
   xmkdir (path_etc, 0777);
   add_temp_file (path_etc);
 
-  if (conf.resolv_conf != NULL)
-    {
-      /* Create an empty resolv.conf file.  */
-      chroot->path_resolv_conf = xasprintf ("%s/resolv.conf", path_etc);
-      add_temp_file (chroot->path_resolv_conf);
-      support_write_file_string (chroot->path_resolv_conf, conf.resolv_conf);
-    }
-  else
-    chroot->path_resolv_conf = NULL;
+  write_file (path_etc, "resolv.conf", conf.resolv_conf,
+              &chroot->path_resolv_conf);
+  write_file (path_etc, "hosts", conf.hosts, &chroot->path_hosts);
+  write_file (path_etc, "host.conf", conf.host_conf, &chroot->path_host_conf);
 
   free (path_etc);
 
@@ -67,5 +79,7 @@ support_chroot_free (struct support_chroot *chroot)
 {
   free (chroot->path_chroot);
   free (chroot->path_resolv_conf);
+  free (chroot->path_hosts);
+  free (chroot->path_host_conf);
   free (chroot);
 }
diff --git a/support/support_format_hostent.c b/support/support_format_hostent.c
index 5b5f26082e..88c85ec1f1 100644
--- a/support/support_format_hostent.c
+++ b/support/support_format_hostent.c
@@ -19,6 +19,7 @@
 #include <support/format_nss.h>
 
 #include <arpa/inet.h>
+#include <errno.h>
 #include <stdio.h>
 #include <support/support.h>
 #include <support/xmemstream.h>
@@ -41,10 +42,15 @@ support_format_hostent (struct hostent *h)
 {
   if (h == NULL)
     {
-      char *value = support_format_herrno (h_errno);
-      char *result = xasprintf ("error: %s\n", value);
-      free (value);
-      return result;
+      if (h_errno == NETDB_INTERNAL)
+        return xasprintf ("error: NETDB_INTERNAL (errno %d, %m)\n", errno);
+      else
+        {
+          char *value = support_format_herrno (h_errno);
+          char *result = xasprintf ("error: %s\n", value);
+          free (value);
+          return result;
+        }
     }
 
   struct xmemstream mem;
diff --git a/support/xdlfcn.c b/support/xdlfcn.c
new file mode 100644
index 0000000000..6e3979983d
--- /dev/null
+++ b/support/xdlfcn.c
@@ -0,0 +1,58 @@
+/* Support functionality for using dlopen/dlclose/dlsym.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+void *
+xdlopen (const char *filename, int flags)
+{
+  void *dso = dlopen (filename, flags);
+
+  if (dso == NULL)
+    FAIL_EXIT1 ("error: dlopen: %s\n", dlerror ());
+
+  /* Clear any errors.  */
+  dlerror ();
+
+  return dso;
+}
+
+void *
+xdlsym (void *handle, const char *symbol)
+{
+  void *sym = dlsym (handle, symbol);
+
+  if (sym == NULL)
+    FAIL_EXIT1 ("error: dlsym: %s\n", dlerror ());
+
+  /* Clear any errors.  */
+  dlerror ();
+
+  return sym;
+}
+
+void
+xdlclose (void *handle)
+{
+  if (dlclose (handle) != 0)
+    FAIL_EXIT1 ("error: dlclose: %s\n", dlerror ());
+
+  /* Clear any errors.  */
+  dlerror ();
+}
diff --git a/support/xdlfcn.h b/support/xdlfcn.h
new file mode 100644
index 0000000000..9bdcb38d3e
--- /dev/null
+++ b/support/xdlfcn.h
@@ -0,0 +1,34 @@
+/* Support functionality for using dlopen/dlclose/dlsym.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef SUPPORT_DLOPEN_H
+#define SUPPORT_DLOPEN_H
+
+#include <dlfcn.h>
+
+__BEGIN_DECLS
+
+/* Each of these terminates process on failure with relevant error message.  */
+void *xdlopen (const char *filename, int flags);
+void *xdlsym (void *handle, const char *symbol);
+void xdlclose (void *handle);
+
+
+__END_DECLS
+
+#endif /* SUPPORT_DLOPEN_H */