Patch: back-passwd needs pwent mutex  (ITS#1794)

			================
Written by Hallvard B. Furuseth and placed into the public domain.
This software is not subject to any license of the University of Oslo.
			================

back-passwd uses getpwent() and setpwfile(), which use static data.
It needs a mutex to make sure these operations can complete without
interference from another back-passwd call.  Here is a patch.

Hallvard B. Furuseth <h.b.furuseth@usit.uio.no>, May 2002.


diff -N -u2 -r servers/slapd/back-passwd/back-passwd.h~ servers/slapd/back-passwd/back-passwd.h
--- servers/slapd/back-passwd/back-passwd.h~	Thu Jan  1 01:00:00 1970
+++ servers/slapd/back-passwd/back-passwd.h	Fri May  3 15:38:57 2002
@@ -0,0 +1,13 @@
+/* $OpenLDAP$ */
+#ifndef _BACK_PASSWD_H
+#define _BACK_PASSWD_H
+
+#include "external.h"
+
+LDAP_BEGIN_DECL
+
+extern ldap_pvt_thread_mutex_t passwd_mutex;
+
+LDAP_END_DECL
+
+#endif /* _BACK_PASSWD_H */
diff -N -u2 -r servers/slapd/back-passwd/external.h~ servers/slapd/back-passwd/external.h
--- servers/slapd/back-passwd/external.h~	Wed Dec 26 08:47:04 2001
+++ servers/slapd/back-passwd/external.h	Fri May  3 15:31:08 2002
@@ -6,4 +6,5 @@
 
 extern BI_init	passwd_back_initialize;
+extern BI_destroy	passwd_back_destroy;
 
 extern BI_op_search	passwd_back_search;
diff -N -u2 -r servers/slapd/back-passwd/init.c~ servers/slapd/back-passwd/init.c
--- servers/slapd/back-passwd/init.c~	Wed Dec 26 08:32:08 2001
+++ servers/slapd/back-passwd/init.c	Fri May  3 15:39:14 2002
@@ -9,5 +9,7 @@
 
 #include "slap.h"
-#include "external.h"
+#include "back-passwd.h"
+
+ldap_pvt_thread_mutex_t passwd_mutex;
 
 #ifdef SLAPD_PASSWD_DYNAMIC
@@ -31,8 +33,10 @@
 )
 {
+	ldap_pvt_thread_mutex_init( &passwd_mutex );
+
 	bi->bi_open = 0;
 	bi->bi_config = 0;
 	bi->bi_close = 0;
-	bi->bi_destroy = 0;
+	bi->bi_destroy = passwd_back_destroy;
 
 	bi->bi_db_init = 0;
@@ -61,4 +65,13 @@
 	bi->bi_connection_destroy = 0;
 
+	return 0;
+}
+
+int
+passwd_back_destroy(
+	BackendInfo *bi
+)
+{
+	ldap_pvt_thread_mutex_destroy( &passwd_mutex );
 	return 0;
 }
diff -N -u2 -r servers/slapd/back-passwd/search.c~ servers/slapd/back-passwd/search.c
--- servers/slapd/back-passwd/search.c~	Thu May  2 10:36:36 2002
+++ servers/slapd/back-passwd/search.c	Fri May  3 15:39:23 2002
@@ -14,7 +14,9 @@
 
 #include "slap.h"
-#include "external.h"
+#include "back-passwd.h"
 #include <ldap_pvt.h>
 
+stativ void pw_start( Backend *be );
+
 static Entry *pw2entry(
 	Backend *be,
@@ -60,12 +62,4 @@
 	    : slimit;
 
-	endpwent();
-
-#ifdef HAVE_SETPWFILE
-	if ( be->be_private != NULL ) {
-		(void) setpwfile( (char *) be->be_private );
-	}
-#endif /* HAVE_SETPWFILE */
-
 	/* Handle a query for the base of this backend */
 	if ( be_issuffix( be, nbase ) ) {
@@ -131,8 +125,11 @@
 			/* check all our "children" */
 
+			ldap_pvt_thread_mutex_lock( &passwd_mutex );
+			pw_start( be );
 			for ( pw = getpwent(); pw != NULL; pw = getpwent() ) {
 				/* check for abandon */
 				if ( op->o_abandon ) {
 					endpwent();
+					ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 					return( -1 );
 				}
@@ -143,4 +140,5 @@
 			    		NULL, NULL, NULL, NULL );
 					endpwent();
+					ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 					return( 0 );
 				}
@@ -149,4 +147,5 @@
 					err = LDAP_OPERATIONS_ERROR;
 					endpwent();
+					ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 					goto done;
 				}
@@ -158,4 +157,5 @@
 				    		NULL, NULL, NULL, NULL );
 						endpwent();
+						ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 						return( 0 );
 					}
@@ -169,4 +169,5 @@
 			}
 			endpwent();
+			ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 		}
 
@@ -202,11 +203,16 @@
 		}
 
+		ldap_pvt_thread_mutex_lock( &passwd_mutex );
+		pw_start( be );
 		if ( (pw = getpwnam( rdn[0][0]->la_value.bv_val )) == NULL ) {
 			matched = parent.bv_val;
 			err = LDAP_NO_SUCH_OBJECT;
+			ldap_pvt_thread_mutex_unlock( &passwd_mutex );
 			goto done;
 		}
 
-		if ( !(e = pw2entry( be, pw, &text )) ) {
+		e = pw2entry( be, pw, &text );
+		ldap_pvt_thread_mutex_unlock( &passwd_mutex );
+		if ( !e ) {
 			err = LDAP_OPERATIONS_ERROR;
 			goto done;
@@ -230,4 +236,18 @@
 
 	return( 0 );
+}
+
+static void
+pw_start(
+	Backend *be
+)
+{
+	endpwent();
+
+#ifdef HAVE_SETPWFILE
+	if ( be->be_private != NULL ) {
+		(void) setpwfile( (char *) be->be_private );
+	}
+#endif /* HAVE_SETPWFILE */
 }