Update.

2000-05-07  Mark Kettenis  <kettenis@gnu.org>

	* nss/nss_db/db-open.c: Cleanup and add comments.  Pretty print.
	Remove duplicate <errno.h> include.  Remove inclusion of
	<libintl.h> and "nsswitch.h".
	(set_cloexec_flag): New function, broken out of dbopen.
	(dbopen): Changed return type to `enum
	nss_status'.  Mostly rewritten to make sure that we do not report
	NSS_STATUS_SUCCESS if something went wrong.  Remove unnecessary casts.
	(internal_setent): Change return type to nss_status.
	Document, and make sure that the function
	behaves accordingly.  Make dynamically loading the database
	library really thread-safe and return NSS_STATUS_UNAVAIL if it
	failed.
	(db_cursor): Return ENOMEM is memory allocation failed.  Remove
	unecessary casts.
	* nss/nss_db/dummy-db.h: Add copyright notice.  Improve
	documentation.
	(struct dbc24, struct dbc27): Use DBT type in parameter lists for
	c_get function member.
	* nss/nss_db/nss_db.h: Add and tweak some comments.
	(DBT): Move typedef before NSS_DBC typedef.
	(NSS_DBC, NSS_DB): Use DBT in function member parameter lists.

3 files changed, 253 insertions, 230 deletions

diff --git a/nss/nss_db/db-open.c b/nss/nss_db/db-open.c
index 470af043a6..6a21a0af58 100644
--- a/nss/nss_db/db-open.c
+++ b/nss/nss_db/db-open.c
@@ -20,35 +20,42 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <dlfcn.h>
-#include <errno.h>
 #include <stdlib.h>
-#include <libintl.h>
+#include <string.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.
+   read by the rest of libnss_db.  Not all of them are thread safe;
+   make sure the caller does the appropriate 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?)  */
-
+   to be present when glibc is compiled.  Once loaded, the database
+   library is never never unloaded again until the libnss_db module is
+   unloaded (from the free_mem routine in nsswitch.c) -- we catch the
+   unload by providing a shlib destructor.  (XXX Does that actually
+   work?)  */
+
+/* Handle for the shared Berkeley DB library.  If non-null, the
+   database library is completely loaded and ready to be used by
+   multithreaded code.  */
 static void *libdb_handle;
+
+/* The version of the Berkeley DB library we are using.  */
 enum {
   nodb,
   db24,
   db27,
   db30
 } libdb_version;
+
+/* Pointer to the db_open function.  For use with DB 2.x.  */
 static int (*libdb_db_open) (const char *, int,
 			     uint32_t, int, void *, void *, void **);
 
+/* Pointer to the db_create function.  For use with DB 3.x.  */
 static int (*libdb_db_create) (void *, void *, uint32_t);
 
 /* Constants which vary from version to version are actually variables
@@ -65,13 +72,17 @@ int db_notfound;
 /* Locks the static variables in this file.  */
 __libc_lock_define_initialized (static, lock)
 
-/* Dynamically load the database library.
+/* Dynamically load the database library.  Return zero if successful,
+   non-zero if no suitable version of the library could be loaded.
+   Must be called with the above lock held if it might run in a
+   multithreaded context.
+
    We try currently:
    - libdb.so.3: the name used by glibc 2.1
    - libdb-3.0.so: the name used by db-3.0.x
    and maybe others in the future.  */
-   
-int
+
+enum nss_status
 load_db (void)
 {
   static const char *libnames[] = { "libdb.so.3", "libdb-3.0.so" };
@@ -83,11 +94,11 @@ load_db (void)
       if (libdb_handle == NULL)
 	continue;
 
-      /* db 3.0 has db_create instead of db_open.  */
+      /* DB 3.0 has db_create instead of db_open.  */
       libdb_db_create = dlsym (libdb_handle, "db_create");
 
       if (libdb_db_create == NULL)
-	/* db 2.x uses db_open.  */
+	/* DB 2.x uses db_open.  */
 	libdb_db_open = dlsym (libdb_handle, "db_open");
 
       if (libdb_db_open != NULL || libdb_db_create != NULL)
@@ -129,6 +140,7 @@ load_db (void)
 		      db_rdonly = DB2x_RDONLY;
 		    }
 		  break;
+
 		case 3:
 		  /* Sanity check: Do we have db_create?  */
 		  if (libdb_db_create != NULL)
@@ -141,12 +153,14 @@ load_db (void)
 		      db_rdonly = DB30_RDONLY;
 		    }
 		  break;
+
 		default:
 		  break;
 		}
 	    }
+
 	  if (libdb_version != nodb)
-	    return 0;
+	    return NSS_STATUS_SUCCESS;
 
 	  /* Clear variables.  */
 	  libdb_db_open = NULL;
@@ -157,7 +171,22 @@ load_db (void)
     }
 
   (void) dlerror ();
-  return 1;
+  return NSS_STATUS_UNAVAIL;
+}
+
+/* Set the `FD_CLOEXEC' flag of FD.  Return 0 on success, or -1 on
+   error with `errno' set. */
+static int
+set_cloexec_flag (int fd)
+{
+  int oldflags = fcntl (fd, F_GETFD, 0);
+
+  if (oldflags < 0)
+    return oldflags;
+
+  oldflags |= FD_CLOEXEC;
+
+  return fcntl (fd, F_SETFD, oldflags);
 }
 
 /* Make sure we don't use the library anymore once we are shutting down.  */
@@ -173,6 +202,9 @@ unload_db (void)
     }
 }
 
+/* Open the database stored in FILE.  If succesful, store the database
+   handle in *DBP and return NSS_STATUS_SUCCESS.  On failure, return
+   the appropriate lookup status.  */
 enum nss_status
 internal_setent (const char *file, NSS_DB **dbp)
 {
@@ -184,26 +216,26 @@ internal_setent (const char *file, NSS_DB **dbp)
 	{
 	  __libc_lock_lock (lock);
 
-	  status = load_db ();
+	  if (libdb_db_open == NULL && libdb_db_create == NULL)
+	    status = load_db ();
 
 	  __libc_lock_unlock (lock);
-
-	  if (status != 0)
-	    return status;
 	}
 
-      status = dbopen (file, db_rdonly, 0, dbp);
+      if (status == NSS_STATUS_SUCCESS)
+	status = dbopen (file, db_rdonly, 0, dbp);
     }
 
   return status;
 }
 
 
-/* Close the database file.  */
+/* Close the database *DBP.  */
 void
 internal_endent (NSS_DB **dbp)
 {
   NSS_DB *db = *dbp;
+
   if (db != NULL)
     {
       DL_CALL_FCT (db->close, (db->db, 0));
@@ -211,188 +243,147 @@ internal_endent (NSS_DB **dbp)
     }
 }
 
+/* Allocate a cursor for database DB and transaction TXN.  On success,
+   store the cursor in *DBCP and return zero.  Otherwise return an
+   error value.  */
 int
 db_cursor (void *db, void *txn, NSS_DBC **dbcp)
 {
-  void *ptr;
-  NSS_DBC *dbc = NULL;
+  NSS_DBC *dbc;
   int ret;
 
+  dbc = (NSS_DBC *) malloc (sizeof (NSS_DBC));
+  if (dbc == NULL)
+    return ENOMEM;
+
   switch (libdb_version)
     {
     case db24:
-      ret = ((struct db24 *) db)->cursor (db, txn, &ptr);
+      ret = ((struct db24 *) db)->cursor (db, txn, &dbc->cursor);
+
+      if (ret == 0)
+	dbc->c_get = ((struct dbc24 *) dbc->cursor)->c_get;
       break;
+
     case db27:
-      ret = ((struct db27 *) db)->cursor (db, txn, &ptr, 0);
+      ret = ((struct db27 *) db)->cursor (db, txn, &dbc->cursor, 0);
+
+      if (ret == 0)
+	dbc->c_get = ((struct dbc27 *) dbc->cursor)->c_get;
       break;
+
     case db30:
-      ret = ((struct db30 *) db)->cursor (db, txn, &ptr, 0);
+      ret = ((struct db30 *) db)->cursor (db, txn, &dbc->cursor, 0);
+
+      if (ret == 0)
+	dbc->c_get = ((struct dbc30 *) dbc->cursor)->c_get;
       break;
+
     default:
       abort ();
     }
 
-  if (ret == 0)
+  if (ret != 0)
     {
-      dbc = (NSS_DBC *) malloc (sizeof (NSS_DBC));
-      if (dbc == NULL)
-	return 1;
-      dbc->cursor = ptr;
-
-      switch (libdb_version)
-	{
-	case db24:
-	  dbc->c_get =
-	    (int (*) (void *, void *, void *, uint32_t))
-	    ((struct dbc24 *) ptr)->c_get;
-	  break;
-	case db27:
-	  dbc->c_get =
-	    (int (*) (void *, void *, void *, uint32_t))
-	    ((struct dbc27 *) ptr)->c_get;
-	  break;
-	case db30:
-	  dbc->c_get =
-	    (int (*) (void *, void *, void *, uint32_t))
-	    ((struct dbc30 *) ptr)->c_get;
-	default:
-	  abort ();
-	}
+      free (dbc);
+      return ret;
     }
 
   *dbcp = dbc;
 
-  return ret;
+  return 0;
 }
 
 
+/* Open the database in FNAME, for access specified by FLAGS.  If
+   opening the database causes the file FNAME to be created, it is
+   created with MODE.  If succesful, store the database handle in *DBP
+   and return NSS_STATUS_SUCCESS.  On failure, return the appropriate
+   lookup status.  */
 int
 dbopen (const char *fname, int oper, int mode, NSS_DB **dbp)
 {
   int err;
-  int result;
   int fd;
-  void *odb;
-  enum nss_status status = NSS_STATUS_SUCCESS;
   NSS_DB *db;
 
+  /* Construct the object we pass up.  */
+  db = (NSS_DB *) calloc (1, sizeof (NSS_DB));
+  if (db == NULL)
+    return NSS_STATUS_UNAVAIL;
+
+  /* Initialize the object.  */
+  db->cursor = db_cursor;
+
   /* Actually open the database.  */
   switch (libdb_version)
     {
     case db24:
     case db27:
       err = DL_CALL_FCT (libdb_db_open,
-			 (fname, DB_BTREE, oper, mode, NULL, NULL, &odb));
+			 (fname, DB_BTREE, oper, mode, NULL, NULL, &db->db));
       if (err != 0)
+	goto fail;
+
+      if (libdb_version)
 	{
-	  __set_errno (err);
-	  *dbp = NULL;
-	  return err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
+	  db->close = ((struct db24 *) db->db)->close;
+	  db->fd = ((struct db24 *) db->db)->fd;
+	  db->get = ((struct db24 *) db->db)->get;
+	  db->put = ((struct db24 *) db->db)->put;
+	}
+      else
+	{
+	  db->close = ((struct db27 *) db->db)->close;
+	  db->fd = ((struct db27 *) db->db)->fd;
+	  db->get = ((struct db27 *) db->db)->get;
+	  db->put = ((struct db27 *) db->db)->put;
 	}
       break;
+
     case db30:
-      err = DL_CALL_FCT (libdb_db_create, (&odb, NULL, 0));
+      err = DL_CALL_FCT (libdb_db_create, (db->db, NULL, 0));
       if (err != 0)
-	{
-	  __set_errno (err);
-	  *dbp = NULL;
-	  return err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
-	}
-      err = ((struct db30 *) odb)->open (odb, fname, NULL, DB_BTREE,
-					oper, mode);
+	goto fail;
+
+      db->close = ((struct db30 *) db->db)->close;
+      db->fd = ((struct db30 *) db->db)->fd;
+      db->get = ((struct db30 *) db->db)->get;
+      db->put = ((struct db30 *) db->db)->put;
+
+      err = ((struct db30 *) db->db)->open (db->db, fname, NULL, DB_BTREE,
+					    oper, mode);
       if (err != 0)
-	{
-	  __set_errno (err);
-	  /* Free all resources.  */
-	  ((struct db30 *) odb)->close (odb, 0);
-	  *dbp = NULL;
-	  return NSS_STATUS_UNAVAIL;
-	}
+	goto fail;
       break;
+
     default:
       abort ();
     }
-      
-  /* Construct the object we pass up.  */
-  db = (NSS_DB *) malloc (sizeof (NSS_DB));
-  if (db != NULL)
-    {
-      db->db = odb;
 
-      /* The functions are at different positions for the different
-	 versions.  Sigh.  */
-      switch (libdb_version)
-	{
-	case db24:
-	  db->close =
-	    (int (*) (void *, uint32_t)) ((struct db24 *) odb)->close;
-	  db->fd =
-	    (int (*) (void *, int *)) ((struct db24 *) odb)->fd;
-	  db->get =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db24 *) odb)->get;
-	  db->put =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db24 *) odb)->put;
-	  break;
-	case db27:
-	  db->close =
-	    (int (*) (void *, uint32_t)) ((struct db27 *) odb)->close;
-	  db->fd =
-	    (int (*) (void *, int *)) ((struct db27 *) odb)->fd;
-	  db->get =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db27 *) odb)->get;
-	  db->put =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db27 *) odb)->put;
-	  break;
-	case db30:
-	  db->close =
-	    (int (*) (void *, uint32_t)) ((struct db30 *) odb)->close;
-	  db->fd =
-	    (int (*) (void *, int *)) ((struct db30 *) odb)->fd;
-	  db->get =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db30 *) odb)->get;
-	  db->put =
-	    (int (*) (void *, void *, void *, void *, uint32_t))
-	    ((struct db30 *) odb)->put;
-	  break;
-	default:
-	  abort ();
-	}
-      db->cursor = db_cursor;
+  /* We have to make sure the file is `closed on exec'.  */
+  err = DL_CALL_FCT (db->fd, (db->db, &fd));
+  if (err != 0)
+    goto fail;
+  if (set_cloexec_flag (fd) < 0)
+    goto fail;
 
-      /* We have to make sure the file is `closed on exec'.  */
-      err = DL_CALL_FCT (db->fd, (odb, &fd));
-      if (err != 0)
-	{
-	  __set_errno (err);
-	  result = -1;
-	}
-      else
-	{
-	  int flags = result = fcntl (fd, F_GETFD, 0);
+  *dbp = db;
 
-	  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 (db->close, (odb, 0));
-	  free (db);
-	  status = NSS_STATUS_UNAVAIL;
-	  db = NULL;
-	}
+  return NSS_STATUS_UNAVAIL;
+
+ fail:
+  /* Something went wrong.  Close the database if necessary.  */
+  if (db)
+    {
+      if (db->db && db->close)
+	DL_CALL_FCT (db->close, (db->db, 0));
+      free (db);
     }
-  *dbp = db;
-  
-  return status;
+
+  /* Make sure `errno' is set.  */
+  if (err)
+    __set_errno (err);
+
+  return err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
 }
diff --git a/nss/nss_db/dummy-db.h b/nss/nss_db/dummy-db.h
index 66b5416189..75d7bac6df 100644
--- a/nss/nss_db/dummy-db.h
+++ b/nss/nss_db/dummy-db.h
@@ -1,31 +1,56 @@
+/* Constants and structures from the various Berkeley DB releases.
+   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 <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.  */
+/* This file contains dummy definitions for various constants and
+   structures from the Berkeley release.  We only provide those
+   definitions that are actually needed.  In case of the structures,
+   we're only interested in the function pointers, since that's the
+   interface to the database.  Unfortunately the structures have been
+   changed several times.  */
 
-/* The values to select the database type are unchanged over the version.
-   Define only what we really need.  */
+/* The value for the btree database type has not been changed (yet?).  */
 #define DB_BTREE	(1)
 
-/* Permission flags.  */
+/* Permission flags for all 2.x releases.  */
 #define DB2x_RDONLY	0x010000
 
-/* Access methods.  */
+/* The error values for all 2.x releases.  */
+#define DB2x_KEYEXIST	( -3)
+#define DB2x_NOTFOUND	( -7)
+
+/* For all 2.x releases up to 2.6.3 we can use the same definitions.
+   We'll refer to them as 2.4 since that's the version distributed
+   with glibc 2.1.  */
+
+/* Access methods from version 2.4.  */
 #define DB24_FIRST		0x000020
 #define DB24_NEXT		0x000800
 #define DB24_NOOVERWRITE	0x001000
 
-/* The error values that are needed.  */
-#define DB2x_KEYEXIST	( -3)
-#define DB2x_NOTFOUND	( -7)
-
+/* Permission flags from version 2.4.  */
+#define DB24_TRUNCATE	0x080000
 
-/* 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.  */
+/* The DB structure from version 2.4.  */
 struct db24
 {
   void	*mutexp;
@@ -77,7 +102,7 @@ struct db24
   uint32_t flags;
 };
 
-
+/* The DBC structure for the 2.4 release.  */
 struct dbc24
 {
   void *dbp;
@@ -90,15 +115,21 @@ struct dbc24
   void *internal;
   void *c_close;
   void *c_del;
-  int (*c_get) (void *, void *, void *, uint32_t);
+  int (*c_get) (void *, DBT *, DBT *, uint32_t);
   void *c_put;
 };
 
-/* Flags which changed.  */
-#define DB24_TRUNCATE	0x080000
+/* The 2.7 release is slighty different.  */
 
+/* Access methods from version 2.7.  */
+#define DB27_FIRST		7
+#define DB27_NEXT		15
+#define DB27_NOOVERWRITE	17
+
+/* Permission flags from version 2.7.  */
+#define DB27_TRUNCATE	0x020000
 
-/* Versions for 2.7, slightly incompatible with version 2.4.  */
+/* The DB structure from version 2.7.  */
 struct db27
 {
   void	*mutexp;
@@ -133,14 +164,14 @@ struct db27
   int (*del) (void *, void *, DBT *, uint32_t);
   int (*fd) (void *, int *);
   int (*get) (void *, void *, DBT *, DBT *, uint32_t);
-  int (*join) (void *, void **, uint32_t, void **);  
+  int (*join) (void *, void **, uint32_t, void **);
   int (*put) (void *, void *, DBT *, DBT *, uint32_t);
   int (*stat) (void *, void *, void *(*)(size_t), uint32_t);
   int (*sync) (void *, uint32_t);
   uint32_t flags;
 };
 
-
+/* The DBC structure for version 2.7.  */
 struct dbc27
 {
   void *dbp;
@@ -164,21 +195,28 @@ struct dbc27
   void *c_am_destroy;
   void *c_close;
   void *c_del;
-  int (*c_get) (void *, void *, void *, uint32_t);
+  int (*c_get) (void *, DBT *, DBT *, uint32_t);
   void *c_put;
   void *internal;
   uint32_t flags;
 };
 
-/* Flags which changed.  */
-#define DB27_TRUNCATE	0x020000
+/* Version 3.0 is mostly incompatible with 2.x.  */
 
-/* Access methods.  */
-#define DB27_FIRST		7
-#define DB27_NEXT		15
-#define DB27_NOOVERWRITE	17
+/* Access methods from version 3.0.  */
+#define DB30_FIRST		9
+#define DB30_NEXT		17
+#define DB30_NOOVERWRITE	20
 
-/* Versions for 3.0, incompatible with version 2.x.  */
+/* Error values from version 3.0.  */
+#define DB30_KEYEXIST	(-30997)
+#define DB30_NOTFOUND	(-30994)
+
+/* Permission flags from version 3.0.  */
+#define DB30_RDONLY	0x000010
+#define DB30_TRUNCATE	0x020000
+
+/* The DB structure from version 3.0.  */
 struct db30
 {
   size_t pgsize;
@@ -238,16 +276,16 @@ struct db30
   int  (*stat) (void *, void *, void *(*)(size_t), uint32_t);
   int  (*sync) (void *, uint32_t);
   int  (*upgrade) (void *, const char *, uint32_t);
-  
+
   int  (*set_bt_compare) (void *, int (*)(const DBT *, const DBT *));
   int  (*set_bt_maxkey) (void *, uint32_t);
   int  (*set_bt_minkey) (void *, uint32_t);
   int  (*set_bt_prefix) (void *, size_t (*)(const DBT *, const DBT *));
-  
+
   int  (*set_h_ffactor) (void *, uint32_t);
   int  (*set_h_hash) (void *, uint32_t (*)(const void *, uint32_t));
   int  (*set_h_nelem) (void *, uint32_t);
-  
+
   int  (*set_re_delim) (void *, int);
   int  (*set_re_len) (void *, uint32_t);
   int  (*set_re_pad) (void *, int);
@@ -257,7 +295,7 @@ struct db30
   uint32_t flags;
 };
 
-
+/* The DBC structure from version 3.0.  */
 struct dbc30
 {
   void *dbp;
@@ -293,19 +331,3 @@ struct dbc30
   void *internal;
   uint32_t flags;
 };
-
-/* Flags which changed.  */
-#define DB30_TRUNCATE	0x020000
-
-/* Access methods.  */
-#define DB30_FIRST		9
-#define DB30_NEXT		17
-#define DB30_NOOVERWRITE	20
-
-/* Permission flags are changed.  */
-#define DB30_RDONLY	0x000010
-
-
-/* The error values that are needed.  */
-#define DB30_KEYEXIST	(-30997)
-#define DB30_NOTFOUND	(-30994)
diff --git a/nss/nss_db/nss_db.h b/nss/nss_db/nss_db.h
index 8abec2d8de..4ace9ed846 100644
--- a/nss/nss_db/nss_db.h
+++ b/nss/nss_db/nss_db.h
@@ -20,32 +20,44 @@
 #ifndef _NSS_DB_H
 #define _NSS_DB_H	1
 
+#include <nss.h>
 #include <stdint.h>
 
 /* Variables which keep track of the error values.  */
 extern int db_keyexist;
 extern int db_notfound;
 
-/* Constants which vary from version to version are actually variables
-   here.  */
+/* This flag is the same for all versions of the Berkeley DB library.  */
+#define DB_CREATE	0x000001
+
+/* But constants which vary from version to version are actually
+   variables here.  */
 extern int db_first;
 extern int db_next;
 extern int db_nooverwrite;
 extern int db_truncate;
 extern int db_rdonly;
 
-/* Flags are also unchanged.  */
-#define DB_CREATE	0x000001
-
+/* 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;
 
-/* Similarly we have to handle the cursor object.  It is also very
-   different from version to version.  */
+/* But the cursor object is very different from version to version.  */
 typedef struct
 {
   void *cursor;
-  int (*c_get) (void *, void *, void *, uint32_t);
+  int (*c_get) (void *, DBT *, DBT *, uint32_t);
 } NSS_DBC;
 
+/* We need a helper function for it.  */
+extern int db_cursor (void *db, void *txn, NSS_DBC **dbcp);
 
 /* This is the wrapper we put around the `DB' structures to provide a
    uniform interface to the higher-level functions.  */
@@ -55,30 +67,28 @@ typedef struct
   int (*close) (void *, uint32_t);
   int (*cursor) (void *, void *, NSS_DBC **);
   int (*fd) (void *, int *);
-  int (*get) (void *, void *, void *, void *, uint32_t);
-  int (*put) (void *, void *, void *, void *, uint32_t);
+  int (*get) (void *, void *, DBT *, DBT *, uint32_t);
+  int (*put) (void *, void *, DBT *, DBT *, uint32_t);
 } NSS_DB;
 
+/* Open the database stored in FILE.  If succesful, store the database
+   handle in *DBP and return NSS_STATUS_SUCCESS.  On failure, return
+   the appropriate lookup status.  */
+extern enum nss_status internal_setent (const char *file, NSS_DB **dbp);
 
-/* 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;
-
+/* Close the database *DBP.  */
+extern void internal_endent (NSS_DB **dbp);
 
-/* Private routines to nss_db.
-   You must have included nsswitch.h and db.h before this file.  */
+/* Dynamically load the Berkeley DB library.  Return zero if
+   successful, non-zero if no suitable version of the library could be
+   loaded.  */
+extern enum nss_status load_db (void);
 
-extern enum nss_status internal_setent (const char *file, NSS_DB **dbp);
-extern void internal_endent (NSS_DB **dbp);
-extern int db_cursor (void *db, void *txn, NSS_DBC **dbcp);
-extern int load_db (void);
+/* Open the database in FNAME, for access specified by FLAGS.  If
+   opening the database causes the file FNAME to be created, it is
+   created with MODE.  If succesful, store the database handle in *DBP
+   and return NSS_STATUS_SUCCESS.  On failure, return the appropriate
+   lookup status.  */
 extern int dbopen (const char *fname, int oper, int mode, NSS_DB **dbp);
 
-
 #endif	/* nss_db.h */