hesiod: Always use thread-local resolver state [BZ #19573]

The Hesiod implementation imported into glibc was enhanced
to support caller-supplied resolver states.  But its only
consumer is nss_hesiod, and it supplies the thread-local
resolver state.  Therefore, this commit changes the Hesiod
implementation to use the thread-local resolver state (_res)
directly.  This fixes bug 19573 because the Hesiod
implementation no longer has to initialize and free any
resolver state.

To avoid any risk of interposition of ABI-incompatible Hesiod
function implementations, this commit marks the Hesiod functions
as hidden.  (They were already hidden using a linker version
script.)

6 files changed, 5 insertions, 76 deletions

diff --git a/hesiod/nss_hesiod/hesiod-grp.c b/hesiod/nss_hesiod/hesiod-grp.c
index 7e4ecb4..944e5e0 100644
--- a/hesiod/nss_hesiod/hesiod-grp.c
+++ b/hesiod/nss_hesiod/hesiod-grp.c
@@ -26,8 +26,6 @@
 #include <string.h>
 #include <sys/param.h>
 
-#include "nss_hesiod.h"
-
 /* Get the declaration of the parser function.  */
 #define ENTNAME grent
 #define STRUCTURE group
@@ -58,8 +56,7 @@ lookup (const char *name, const char *type, struct group *grp,
   size_t len;
   int olderr = errno;
 
-  context = _nss_hesiod_init ();
-  if (context == NULL)
+  if (hesiod_init (&context) < 0)
     return NSS_STATUS_UNAVAIL;
 
   list = hesiod_resolve (context, name, type);
@@ -179,8 +176,7 @@ _nss_hesiod_initgroups_dyn (const char *user, gid_t group, long int *start,
   gid_t *groups = *groupsp;
   int save_errno;
 
-  context = _nss_hesiod_init ();
-  if (context == NULL)
+  if (hesiod_init (&context) < 0)
     return NSS_STATUS_UNAVAIL;
 
   list = hesiod_resolve (context, user, "grplist");
diff --git a/hesiod/nss_hesiod/hesiod-init.c b/hesiod/nss_hesiod/hesiod-init.c
deleted file mode 100644
index 2315040..0000000
--- a/hesiod/nss_hesiod/hesiod-init.c
+++ /dev/null
@@ -1,38 +0,0 @@
-/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 2000.
-
-   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 <sys/cdefs.h>		/* Needs to come before <hesiod.h>.  */
-#include <hesiod.h>
-#include <resolv.h>
-#include <stddef.h>
-
-#include "nss_hesiod.h"
-
-void *
-_nss_hesiod_init (void)
-{
-  void *context;
-
-  if (hesiod_init (&context) == -1)
-    return NULL;
-
-  /* Use the default (per-thread) resolver state.  */
-  __hesiod_res_set (context, &_res, NULL);
-
-  return context;
-}
diff --git a/hesiod/nss_hesiod/hesiod-proto.c b/hesiod/nss_hesiod/hesiod-proto.c
index 3c59e73..8a13bba 100644
--- a/hesiod/nss_hesiod/hesiod-proto.c
+++ b/hesiod/nss_hesiod/hesiod-proto.c
@@ -25,8 +25,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "nss_hesiod.h"
-
 /* Declare a parser for Hesiod protocol entries.  Although the format
    of the entries is identical to those in /etc/protocols, here is no
    predefined parser for us to use.  */
@@ -68,8 +66,7 @@ lookup (const char *name, const char *type, struct protoent *proto,
   int found;
   int olderr = errno;
 
-  context = _nss_hesiod_init ();
-  if (context == NULL)
+  if (hesiod_init (&context) < 0)
     return NSS_STATUS_UNAVAIL;
 
   list = hesiod_resolve (context, name, type);
diff --git a/hesiod/nss_hesiod/hesiod-pwd.c b/hesiod/nss_hesiod/hesiod-pwd.c
index 1ddf3e3..c119167 100644
--- a/hesiod/nss_hesiod/hesiod-pwd.c
+++ b/hesiod/nss_hesiod/hesiod-pwd.c
@@ -24,8 +24,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "nss_hesiod.h"
-
 /* Get the declaration of the parser function.  */
 #define ENTNAME pwent
 #define STRUCTURE passwd
@@ -56,8 +54,7 @@ lookup (const char *name, const char *type, struct passwd *pwd,
   size_t len;
   int olderr = errno;
 
-  context = _nss_hesiod_init ();
-  if (context == NULL)
+  if (hesiod_init (&context) < 0)
     return NSS_STATUS_UNAVAIL;
 
   list = hesiod_resolve (context, name, type);
diff --git a/hesiod/nss_hesiod/hesiod-service.c b/hesiod/nss_hesiod/hesiod-service.c
index 756345f..2df9cbb 100644
--- a/hesiod/nss_hesiod/hesiod-service.c
+++ b/hesiod/nss_hesiod/hesiod-service.c
@@ -25,8 +25,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "nss_hesiod.h"
-
 /* Hesiod uses a format for service entries that differs from the
    traditional format.  We therefore declare our own parser.  */
 
@@ -69,8 +67,7 @@ lookup (const char *name, const char *type, const char *protocol,
   int found;
   int olderr = errno;
 
-  context = _nss_hesiod_init ();
-  if (context == NULL)
+  if (hesiod_init (&context) < 0)
     return NSS_STATUS_UNAVAIL;
 
   list = hesiod_resolve (context, name, type);
diff --git a/hesiod/nss_hesiod/nss_hesiod.h b/hesiod/nss_hesiod/nss_hesiod.h
deleted file mode 100644
index a6ed8ee..0000000
--- a/hesiod/nss_hesiod/nss_hesiod.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 2000.
-
-   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/>.  */
-
-/* Initialize a Hesiod context.  */
-extern void *_nss_hesiod_init (void);