Update.

	* nss/nss_db/db-XXX.c: Move internal_setent and internal_endent
	functions from here...
	* nss/db-alias.c: ...and here...
	* nss/db-netgrp.c: ...and here...
	* nss/nss_db/db-open.c: ...to here.  New file.
	* nss/nss_db/dummy-db.h: New file.
	* nss/nss_db/nss_db.h: New file.
	* nss/Depend: Depend in dlfcn, not db2.
	* nss/Makefile (libnss_db-routines): Add db-open.
	(distribute): Add nss_db.h dummy-db.h.
	(libnss_db.so): Replace libdb dependency by $(libdl).
	Based on a patch by Zack Weinberg.

8 files changed, 493 insertions, 261 deletions

diff --git a/nss/Depend b/nss/Depend
index c0c4073..d755539 100644
--- a/nss/Depend
+++ b/nss/Depend
@@ -1,2 +1,2 @@
-db2
+dlfcn
 resolv
diff --git a/nss/Makefile b/nss/Makefile
index 5615930..685047f 100644
--- a/nss/Makefile
+++ b/nss/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
+# Copyright (C) 1996, 1997, 1998, 2000 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
@@ -65,10 +65,11 @@ libnss_files-routines	:= $(addprefix files-,$(databases))
 distribute		+= files-XXX.c files-parse.c
 
 libnss_db-routines	:= $(addprefix db-,$(filter-out hosts network key,\
-							$(databases)))
+							$(databases))) \
+			   db-open
 generated		+= $(filter-out db-alias.c db-netgrp.c, \
 					$(addsuffix .c,$(libnss_db-routines)))
-distribute		+= db-XXX.c
+distribute		+= db-XXX.c nss_db.h dummy-db.h
 
 
 # Build static module if requested
@@ -80,7 +81,7 @@ libnss_db-inhibit-o	= $(filter-out .os,$(object-suffixes))
 include ../Rules
 
 
-$(objpfx)libnss_db.so: $(dbobjdir)/libdb.so $(objpfx)libnss_files.so
+$(objpfx)libnss_db.so: $(objpfx)libnss_files.so $(libdl)
 
 $(libnss_db-routines:%=$(objpfx)%.c): $(objpfx)db-%.c: nss_files/files-%.c
 	@rm -f $@.new
diff --git a/nss/nss_db/db-XXX.c b/nss/nss_db/db-XXX.c
index 1cbe8c2..9115000 100644
--- a/nss/nss_db/db-XXX.c
+++ b/nss/nss_db/db-XXX.c
@@ -1,5 +1,5 @@
 /* Common code for DB-based databases in nss_db module.
-   Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1998, 1999, 2000 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
@@ -17,10 +17,11 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-#include <db.h>
+#include <dlfcn.h>
 #include <fcntl.h>
 #include <bits/libc-lock.h>
 #include "nsswitch.h"
+#include "nss_db.h"
 
 /* These symbols are defined by the including source file:
 
@@ -51,68 +52,12 @@ __libc_lock_define_initialized (static, lock)
 
 /* Maintenance of the shared handle open on the database.  */
 
-static DB *db;
+static NSS_DB *db;
 static int keep_db;
-static unsigned int entidx;	/* Index for `getENTNAME'. */
+static int entidx;
 
-/* Open database file if not already opened.  */
-static enum nss_status
-internal_setent (int stayopen)
-{
-  enum nss_status status = NSS_STATUS_SUCCESS;
-  int err;
-
-  if (db == NULL)
-    {
-      err = __nss_db_open (DBFILE, DB_BTREE, DB_RDONLY, 0, NULL, NULL, &db);
 
-      if (err != 0)
-	{
-	  __set_errno (err);
-	  status = err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
-	}
-      else
-	{
-	  /* We have to make sure the file is `closed on exec'.  */
-	  int fd;
-	  int result;
-
-	  err = db->fd (db, &fd);
-	  if (err != 0)
-	    {
-	      __set_errno (err);
-	      result = -1;
-	    }
-	  else
-	    {
-	      int flags = result = fcntl (fd, F_GETFD, 0);
-
-	      if (result >= 0)
-		{
-		  flags |= FD_CLOEXEC;
-		  result = fcntl (fd, F_SETFD, flags);
-		}
-	    }
-	  if (result < 0)
-	    {
-	      /* Something went wrong.  Close the stream and return a
-		 failure.  */
-	      db->close (db, 0);
-	      db = NULL;
-	      status = NSS_STATUS_UNAVAIL;
-	    }
-	}
-    }
-
-  /* Remember STAYOPEN flag.  */
-  if (db != NULL)
-    keep_db |= stayopen;
-
-  return status;
-}
-
-
-/* Thread-safe, exported version of that.  */
+/* Open the database.  */
 enum nss_status
 CONCAT(_nss_db_set,ENTNAME) (int stayopen)
 {
@@ -120,8 +65,11 @@ CONCAT(_nss_db_set,ENTNAME) (int stayopen)
 
   __libc_lock_lock (lock);
 
-  status = internal_setent (stayopen);
+  status = internal_setent (DBFILE, &db);
 
+  /* Remember STAYOPEN flag.  */
+  if (db != NULL)
+    keep_db |= stayopen;
   /* Reset the sequential index.  */
   entidx = 0;
 
@@ -131,25 +79,13 @@ CONCAT(_nss_db_set,ENTNAME) (int stayopen)
 }
 
 
-/* Close the database file.  */
-static void
-internal_endent (void)
-{
-  if (db != NULL)
-    {
-      db->close (db, 0);
-      db = NULL;
-    }
-}
-
-
-/* Thread-safe, exported version of that.  */
+/* Close it again.  */
 enum nss_status
 CONCAT(_nss_db_end,ENTNAME) (void)
 {
   __libc_lock_lock (lock);
 
-  internal_endent ();
+  internal_endent (&db);
 
   /* Reset STAYOPEN flag.  */
   keep_db = 0;
@@ -170,17 +106,20 @@ lookup (DBT *key, struct STRUCTURE *result,
   DBT value;
 
   /* Open the database.  */
-  status = internal_setent (keep_db);
-  if (status != NSS_STATUS_SUCCESS)
+  if (db == NULL)
     {
-      *errnop = errno;
-      H_ERRNO_SET (NETDB_INTERNAL);
-      return status;
+      status = internal_setent (DBFILE, &db);
+      if (status != NSS_STATUS_SUCCESS)
+	{
+	  *errnop = errno;
+	  H_ERRNO_SET (NETDB_INTERNAL);
+	  return status;
+	}
     }
 
   /* Succeed iff it matches a value that parses correctly.  */
   value.flags = 0;
-  err = db->get (db, NULL, key, &value, 0);
+  err = DL_CALL_FCT (db->get, (db->db, NULL, key, &value, 0));
   if (err != 0)
     {
       if (err == DB_NOTFOUND)
@@ -240,7 +179,7 @@ lookup (DBT *key, struct STRUCTURE *result,
     }
 
   if (! keep_db)
-    internal_endent ();
+    internal_endent (&db);
 
   return status;
 }
diff --git a/nss/nss_db/db-alias.c b/nss/nss_db/db-alias.c
index bc9eea8..c5be8ba 100644
--- a/nss/nss_db/db-alias.c
+++ b/nss/nss_db/db-alias.c
@@ -1,5 +1,5 @@
 /* Mail alias file parser in nss_db module.
-   Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -21,81 +21,26 @@
 #include <aliases.h>
 #include <alloca.h>
 #include <ctype.h>
-#include <db.h>
+#include <dlfcn.h>
 #include <errno.h>
-#include <fcntl.h>
 #include <bits/libc-lock.h>
 #include <paths.h>
 #include <string.h>
 
 #include "nsswitch.h"
+#include "nss_db.h"
 
 /* Locks the static variables in this file.  */
 __libc_lock_define_initialized (static, lock)
 
 /* Maintenance of the shared handle open on the database.  */
 
-static DB *db;
+static NSS_DB *db;
 static int keep_db;
 static unsigned int entidx;	/* Index for `getaliasent_r'. */
 
-/* Open database file if not already opened.  */
-static enum nss_status
-internal_setent (int stayopen)
-{
-  enum nss_status status = NSS_STATUS_SUCCESS;
-  int err;
-
-  if (db == NULL)
-    {
-      err = __nss_db_open (_PATH_VARDB "aliases.db", DB_BTREE, DB_RDONLY, 0,
-			   NULL, NULL, &db);
-
-      if (err != 0)
-	{
-	  __set_errno (err);
-	  status = NSS_STATUS_UNAVAIL;
-	}
-      else
-	{
-	  /* We have to make sure the file is  `closed on exec'.  */
-	  int fd;
-	  int result;
-
-	  err = db->fd (db, &fd);
-	  if (err != 0)
-	    {
-	      __set_errno (err);
-	      result = -1;
-	    }
-	  else
-	    {
-	      result = fcntl (fd, F_GETFD, 0);
 
-	      if (result >= 0)
-		result = fcntl (fd, F_SETFD, result | FD_CLOEXEC);
-	    }
-
-	  if (result < 0)
-	    {
-	      /* Something went wrong.  Close the stream and return a
-		 failure.  */
-	      db->close (db, 0);
-	      db = NULL;
-	      status = NSS_STATUS_UNAVAIL;
-	    }
-	}
-    }
-
-  /* Remember STAYOPEN flag.  */
-  if (db != NULL)
-    keep_db |= stayopen;
-
-  return status;
-}
-
-
-/* Thread-safe, exported version of that.  */
+/* Open database.  */
 enum nss_status
 _nss_db_setaliasent (int stayopen)
 {
@@ -103,7 +48,11 @@ _nss_db_setaliasent (int stayopen)
 
   __libc_lock_lock (lock);
 
-  status = internal_setent (stayopen);
+  status = internal_setent (_PATH_VARDB "aliases.db", &db);
+
+  /* Remember STAYOPEN flag.  */
+  if (db != NULL)
+    keep_db |= stayopen;
 
   /* Reset the sequential index.  */
   entidx = 0;
@@ -114,25 +63,13 @@ _nss_db_setaliasent (int stayopen)
 }
 
 
-/* Close the database file.  */
-static void
-internal_endent (void)
-{
-  if (db != NULL)
-    {
-      db->close (db, 0);
-      db = NULL;
-    }
-}
-
-
-/* Thread-safe, exported version of that.  */
+/* Close it again.  */
 enum nss_status
 _nss_db_endaliasent (void)
 {
   __libc_lock_lock (lock);
 
-  internal_endent ();
+  internal_endent (&db);
 
   /* Reset STAYOPEN flag.  */
   keep_db = 0;
@@ -154,17 +91,22 @@ lookup (DBT *key, struct aliasent *result, char *buffer,
   DBT value;
 
   /* Open the database.  */
-  status = internal_setent (keep_db);
-  if (status != NSS_STATUS_SUCCESS)
+  if (db == NULL)
     {
-      *errnop = errno;
-      return status;
+      status = internal_setent (_PATH_VARDB "aliases.db", &db);
+      if (status != NSS_STATUS_SUCCESS)
+	{
+	  *errnop = errno;
+	  return status;
+	}
     }
 
   value.flags = 0;
-  if (db->get (db, NULL, key, &value, 0) == 0)
+  if (DL_CALL_FCT (db->get, (db->db, NULL, key, &value, 0)) == 0)
     {
       const char *src = value.data;
+      char *cp;
+      size_t cnt;
 
       result->alias_members_len = 0;
 
@@ -176,61 +118,55 @@ lookup (DBT *key, struct aliasent *result, char *buffer,
 	  return NSS_STATUS_TRYAGAIN;
 	}
 
-      if (status == NSS_STATUS_SUCCESS)
+      buffer = stpncpy (buffer, key->data, key->size) + 1;
+      buflen -= key->size + 1;
+
+      while (*src != '\0')
 	{
-	  char *cp;
-	  size_t cnt;
+	  const char *end, *upto;
+	  while (isspace (*src))
+	    ++src;
 
-	  buffer = stpncpy (buffer, key->data, key->size) + 1;
-	  buflen -= key->size + 1;
+	  end = strchr (src, ',');
+	  if (end == NULL)
+	    end = strchr (src, '\0');
+	  for (upto = end; upto > src && isspace (upto[-1]); --upto);
 
-	  while (*src != '\0')
+	  if (upto != src)
 	    {
-	      const char *end, *upto;
-	      while (isspace (*src))
-		++src;
-
-	      end = strchr (src, ',');
-	      if (end == NULL)
-		end = strchr (src, '\0');
-	      for (upto = end; upto > src && isspace (upto[-1]); --upto);
-
-	      if (upto != src)
-		{
-		  if ((upto - src) + __alignof__ (char *) > buflen)
-		    goto no_more_room;
-		  buffer = stpncpy (buffer, src, upto - src) + 1;
-		  buflen -= (upto - src) + __alignof (char *);
-		  ++result->alias_members_len;
-		}
-	      src = end + (*end != '\0');
+	      if ((upto - src) + __alignof__ (char *) > buflen)
+		goto no_more_room;
+	      buffer = stpncpy (buffer, src, upto - src) + 1;
+	      buflen -= (upto - src) + __alignof (char *);
+	      ++result->alias_members_len;
 	    }
+	  src = end + (*end != '\0');
+	}
 
-	  /* Now prepare the return.  Provide string pointers for the
-	     currently selected aliases.  */
-
-	  /* Adjust the pointer so it is aligned for storing pointers.  */
-	  buffer += __alignof__ (char *) - 1;
-	  buffer -= ((buffer - (char *) 0) % __alignof__ (char *));
-	  result->alias_members = (char **) buffer;
+      /* Now prepare the return.  Provide string pointers for the
+	 currently selected aliases.  */
 
-	  /* Compute addresses of alias entry strings.  */
-	  cp = result->alias_name;
-	  for (cnt = 0; cnt < result->alias_members_len; ++cnt)
-	    {
-	      cp = strchr (cp, '\0') + 1;
-	      result->alias_members[cnt] = cp;
-	    }
+      /* Adjust the pointer so it is aligned for storing pointers.  */
+      buffer += __alignof__ (char *) - 1;
+      buffer -= ((buffer - (char *) 0) % __alignof__ (char *));
+      result->alias_members = (char **) buffer;
 
-	  status = (result->alias_members_len == 0
-		    ? NSS_STATUS_RETURN : NSS_STATUS_SUCCESS);
+      /* Compute addresses of alias entry strings.  */
+      cp = result->alias_name;
+      for (cnt = 0; cnt < result->alias_members_len; ++cnt)
+	{
+	  cp = strchr (cp, '\0') + 1;
+	  result->alias_members[cnt] = cp;
 	}
+
+      status = (result->alias_members_len == 0
+		? NSS_STATUS_RETURN : NSS_STATUS_SUCCESS);
     }
   else
     status = NSS_STATUS_NOTFOUND;
 
   if (! keep_db)
-    internal_endent ();
+    internal_endent (&db);
 
   return status;
 }
diff --git a/nss/nss_db/db-netgrp.c b/nss/nss_db/db-netgrp.c
index 722281d..9538d27 100644
--- a/nss/nss_db/db-netgrp.c
+++ b/nss/nss_db/db-netgrp.c
@@ -1,5 +1,5 @@
 /* Netgroup file parser in nss_db modules.
-   Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1999, 2000 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -18,14 +18,16 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
-#include <db.h>
+#include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <netgroup.h>
 #include <string.h>
 #include <bits/libc-lock.h>
 #include <paths.h>
+
 #include "nsswitch.h"
-#include "netgroup.h"
+#include "nss_db.h"
 
 
 #define DBFILE		_PATH_VARDB "netgroup.db"
@@ -35,58 +37,18 @@
 __libc_lock_define_initialized (static, lock)
 
 /* Maintenance of the shared handle open on the database.  */
-static DB *db;
+static NSS_DB *db;
 static char *entry;
 static char *cursor;
 
 enum nss_status
 _nss_db_setnetgrent (const char *group)
 {
-  enum nss_status status = NSS_STATUS_SUCCESS;
-  int err;
+  enum nss_status status;
 
   __libc_lock_lock (lock);
 
-  /* Make sure the data base file is open.  */
-  if (db == NULL)
-    {
-      err = __nss_db_open (DBFILE, DB_BTREE, O_RDONLY, 0, NULL, NULL, &db);
-
-      if (err != 0)
-	{
-	  __set_errno (err);
-	  status = err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
-	}
-      else
-	{
-	  /* We have to make sure the file is  `closed on exec'.  */
-	  int fd;
-	  int result;
-
-	  err = db->fd (db, &fd);
-	  if (err != 0)
-	    {
-	      __set_errno (err);
-	      result = -1;
-	    }
-	  else
-	    {
-	      result = fcntl (fd, F_GETFD, 0);
-
-	      if (result >= 0)
-		result = fcntl (fd, F_SETFD, result | FD_CLOEXEC);
-	    }
-
-	  if (result < 0)
-	    {
-	      /* Something went wrong.  Close the stream and return a
-		 failure.  */
-	      db->close (db, 0);
-	      db = NULL;
-	      status = NSS_STATUS_UNAVAIL;
-	    }
-	}
-    }
+  status = internal_setent (DBFILE, &db);
 
   if (status == NSS_STATUS_SUCCESS)
     {
@@ -94,7 +56,7 @@ _nss_db_setnetgrent (const char *group)
       DBT value;
 
       value.flags = 0;
-      if (db->get (db, NULL, &key, &value, 0) != 0)
+      if (DL_CALL_FCT (db->get, (db->db, NULL, &key, &value, 0)) != 0)
 	status = NSS_STATUS_NOTFOUND;
       else
 	cursor = entry = value.data;
@@ -112,11 +74,7 @@ _nss_db_endnetgrent (void)
 {
   __libc_lock_lock (lock);
 
-  if (db != NULL)
-    {
-      db->close (db, 0);
-      db = NULL;
-    }
+  internal_endent (&db);
 
   __libc_lock_unlock (lock);
 
diff --git a/nss/nss_db/db-open.c b/nss/nss_db/db-open.c
new file mode 100644
index 0000000..2d96ffd
--- /dev/null
+++ b/nss/nss_db/db-open.c
@@ -0,0 +1,229 @@
+/* Common database open/close routines for nss_db.
+   Copyright (C) 1999, 2000 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <fcntl.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <bits/libc-lock.h>
+
+#include "dummy-db.h"
+#include "nsswitch.h"
+#include "nss_db.h"
+
+/* This file contains the functions used to open and close the databases
+   read by the rest of libnss_db.  They are not thread safe; the caller
+   must handle locking.
+
+   We dynamically load the database library, so that it does not have
+   to be present when glibc is compiled.  Once loaded, libdb is never
+   unloaded again unless this library is unloaded (from the free_mem
+   routine in nsswitch.c) - we catch the unload by providing a shlib
+   destructor.  (XXX Does it work?)  */
+
+static void *libdb_handle;
+enum {
+  nodb,
+  db24,
+  db27
+} libdb_version;
+static int (*libdb_db_open) (const char *, int,
+			     uint32_t, int, void *, void *, void **);
+
+/* Locks the static variables in this file.  */
+__libc_lock_define_initialized (static, lock)
+
+/* Dynamically load the database library.
+   We try libdb2.so.3, maybe others in the future.  */
+static int
+load_db (void)
+{
+  static const char *libnames[] = { "libdb.so.3" };
+  int x;
+
+  for(x = 0; x < 1; ++x)
+    {
+      libdb_handle = dlopen (libnames[x], RTLD_LAZY);
+      if (libdb_handle == NULL)
+	continue;
+
+      libdb_db_open = dlsym (libdb_handle, "db_open");
+      if (libdb_db_open)
+	{
+	  /* Alright, we got a library.  Now find out which version it is.  */
+	  const char *(*db_version) (int *, int *, int *);
+
+	  db_version = dlsym (libdb_handle, "db_version");
+	  if (db_version != NULL)
+	    {
+	      /* Call the function and get the information.  */
+	      int major, minor, subminor;
+
+	      DL_CALL_FCT (db_version, (&major, &minor, &subminor));
+	      if (major == 2)
+		{
+		  /* We currently cannot handle other versions than the
+		     2.x series.  */
+		  if (minor < 6 || (minor == 6 && subminor < 4))
+		    libdb_version = db24;
+		  else
+		    libdb_version = db27;
+		}
+	    }
+
+	  if (libdb_version != nodb)
+	    return 0;
+	}
+
+      dlclose (libdb_handle);
+    }
+
+  (void) dlerror ();
+  return 1;
+}
+
+
+/* Make sure we don't use the library anymore once we are shutting down.  */
+static void __attribute__ ((destructor))
+unload_db (void)
+{
+  if (libdb_handle != NULL)
+    {
+      libdb_db_open = NULL;
+      libdb_version = nodb;
+      dlclose (libdb_handle);
+    }
+}
+
+
+enum nss_status
+internal_setent (const char *file, NSS_DB **dbp)
+{
+  enum nss_status status = NSS_STATUS_SUCCESS;
+  int err;
+  void *db;
+
+  if (*dbp == NULL)
+    {
+      if (libdb_db_open == NULL)
+	{
+	  __libc_lock_lock (lock);
+
+	  err = load_db ();
+
+	  __libc_lock_unlock (lock);
+
+	  if (err != 0)
+	    return NSS_STATUS_UNAVAIL;
+	}
+
+      /* Open the database.  Fortunately this interface seems to be the
+	 same for all supported versions.  */
+      err = DL_CALL_FCT (libdb_db_open,
+			 (file, DB_BTREE, DB_RDONLY, 0, NULL, NULL, &db));
+
+      /* Construct the object we pass up.  */
+      *dbp = (NSS_DB *) malloc (sizeof (NSS_DB));
+      if (*dbp != NULL)
+	{
+	  (*dbp)->db = db;
+
+	  /* The functions are at different positions for the different
+	     versions.  Sigh.  */
+	  switch (libdb_version)
+	    {
+	    case db24:
+	      (*dbp)->close =
+		(int (*) (void *, uint32_t)) ((struct db24 *) db)->close;
+	      (*dbp)->fd =
+		(int (*) (void *, int *)) ((struct db24 *) db)->fd;
+	      (*dbp)->get =
+		(int (*) (void *, void *, void *, void *, uint32_t))
+		((struct db24 *) db)->get;
+	      break;
+	    case db27:
+	      (*dbp)->close =
+		(int (*) (void *, uint32_t)) ((struct db27 *) db)->close;
+	      (*dbp)->fd =
+		(int (*) (void *, int *)) ((struct db27 *) db)->fd;
+	      (*dbp)->get =
+		(int (*) (void *, void *, void *, void *, uint32_t))
+		((struct db27 *) db)->get;
+	      break;
+	    default:
+	      abort ();
+	    }
+	}
+
+      if (err != 0)
+	{
+	  __set_errno (err);
+	  *dbp = NULL;
+	  status = err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
+	}
+      else
+	{
+	  /* We have to make sure the file is `closed on exec'.  */
+	  int fd;
+	  int result;
+
+	  err = DL_CALL_FCT ((*dbp)->fd, (db, &fd));
+	  if (err != 0)
+	    {
+	      __set_errno (err);
+	      result = -1;
+	    }
+	  else
+	    {
+	      int flags = result = fcntl (fd, F_GETFD, 0);
+
+	      if (result >= 0)
+		{
+		  flags |= FD_CLOEXEC;
+		  result = fcntl (fd, F_SETFD, flags);
+		}
+	    }
+	  if (result < 0)
+	    {
+	      /* Something went wrong.  Close the stream and return a
+		 failure.  */
+	      DL_CALL_FCT ((*dbp)->close, (db, 0));
+	      status = NSS_STATUS_UNAVAIL;
+	    }
+
+	  if (result < 0)
+	    *dbp = NULL;
+	}
+    }
+
+  return status;
+}
+
+
+/* Close the database file.  */
+void
+internal_endent (NSS_DB **dbp)
+{
+  NSS_DB *db = *dbp;
+  if (db != NULL)
+    {
+      DL_CALL_FCT (db->close, (db->db, 0));
+      *dbp = NULL;
+    }
+}
diff --git a/nss/nss_db/dummy-db.h b/nss/nss_db/dummy-db.h
new file mode 100644
index 0000000..4414a1c
--- /dev/null
+++ b/nss/nss_db/dummy-db.h
@@ -0,0 +1,111 @@
+#include <stdint.h>
+
+#include "nss_db.h"
+
+/* This file contains dummy definitions of the DB structure of the
+   Berkeley DB.  We are only interested in the function pointers since
+   this is the interface to the database.  Unfortunately the structure
+   changed over time and we have to take this into account.  */
+
+/* The values to select the database type are unchanged over the version.
+   Define only what we really need.  */
+#define DB_BTREE	(1)
+
+/* Permission flags are also not changed.  */
+#define DB_RDONLY	0x010000
+
+
+/* This is for the db-2.x version up to 2.x.y.  We use the name `db24' since
+   this is the version which was shipped with glibc 2.1.  */
+struct db24
+{
+  void	*mutexp;
+  enum { dummy24 } type;
+  void *dbenv;
+  void *mp_dbenv;
+  void *master;
+  void *internal;
+  void *mp;
+  void *mpf;
+  struct
+  {
+    void *tqh_first;
+    void **tqh_last;
+  } curs_queue;
+  struct {
+    void *lh_first;
+  } handleq;
+  struct {
+    void *le_next;
+    void **le_prev;
+  } links;
+  uint32_t log_fileid;
+  void *txn;
+  uint32_t locker;
+  struct db24_dbt {
+    void *data;
+    uint32_t size;
+    uint32_t ulen;
+    uint32_t dlen;
+    uint32_t doff;
+    uint32_t flags;
+  } lock_dbt;
+  struct{
+    uint32_t pgno;
+    uint8_t fileid[20];
+  } lock;
+  size_t pgsize;
+  void *db_malloc;
+  /* Functions. */
+  int (*close) (void *, uint32_t);
+  int (*cursor) (void *, void *, void **);
+  int (*del) (void *, void *, DBT *, uint32_t);
+  int (*fd) (void *, int *);
+  int (*get) (void *, void *, DBT *, DBT *, uint32_t);
+  int (*put) (void *, void *, DBT *, DBT *, uint32_t);
+  int (*stat) (void *, void *, void *(*)(size_t), uint32_t);
+  int (*sync) (void *, uint32_t);
+};
+
+
+/* Version 2.7, slightly incompatible with version 2.4.  */
+struct db27
+{
+  void	*mutexp;
+  enum { dummy27 } type;
+  int byteswapped;
+  void *dbenv;
+  void *mp_dbenv;
+  void *internal;
+  void *mp;
+  void *mpf;
+  struct
+  {
+    void *tqh_first;
+    void **tqh_last;
+  } free_queue;
+  struct
+  {
+    void *tqh_first;
+    void **tqh_last;
+  } active_queue;
+  struct {
+    void *lh_first;
+  } handleq;
+  uint8_t fileid[20];
+  uint32_t log_fileid;
+  size_t pgsize;
+  void *db_malloc;
+  void *dup_compare;
+  void *h_hash;
+  /* Functions. */
+  int (*am_close) (void *);
+  int (*close) (void *, uint32_t);
+  int (*cursor) (void *, void *, void **, uint32_t);
+  int (*del) (void *, void *, DBT *, uint32_t);
+  int (*fd) (void *, int *);
+  int (*get) (void *, void *, DBT *, DBT *, uint32_t);
+  int (*put) (void *, void *, DBT *, DBT *, uint32_t);
+  int (*stat) (void *, void *, void *(*)(size_t), uint32_t);
+  int (*sync) (void *, uint32_t);
+};
diff --git a/nss/nss_db/nss_db.h b/nss/nss_db/nss_db.h
new file mode 100644
index 0000000..8dc2a36
--- /dev/null
+++ b/nss/nss_db/nss_db.h
@@ -0,0 +1,58 @@
+/* Common database open/close routines for nss_db.
+   Copyright (C) 1999, 2000 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _NSS_DB_H
+#define _NSS_DB_H	1
+
+#include <stdint.h>
+
+/* The error values kept the same values though new values were added.
+   Define only those which we need.  */
+#define DB_NOTFOUND	( -7)
+
+/* This is the wrapper we put around the `DB' structures to provide a
+   uniform interface to the higher-level functions.  */
+typedef struct
+{
+  void *db;
+  int (*close) (void *, uint32_t);
+  int (*fd) (void *, int *);
+  int (*get) (void *, void *, void *, void *, uint32_t);
+
+} NSS_DB;
+
+
+/* The `DBT' type is the same in all versions we support.  */
+typedef struct {
+  void *data;
+  uint32_t size;
+  uint32_t ulen;
+  uint32_t dlen;
+  uint32_t doff;
+  uint32_t flags;
+} DBT;
+
+
+/* Private routines to nss_db.
+   You must have included nsswitch.h and db.h before this file.  */
+
+extern enum nss_status internal_setent (const char *file, NSS_DB **dbp);
+extern void internal_endent (NSS_DB **dbp);
+
+#endif	/* nss_db.h */