/* compare.c - ldbm backend compare routine */
/* $OpenLDAP: pkg/ldap/servers/slapd/back-ldbm/compare.c,v 1.36 2002/02/09 04:14:18 kurt Exp $ */
/*
 * Copyright 1998-2002 The OpenLDAP Foundation, All Rights Reserved.
 * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
 */

#include "portable.h"

#include <stdio.h>

#include <ac/socket.h>
#include <ac/string.h>

#include "slap.h"
#include "back-ldbm.h"
#include "proto-back-ldbm.h"

int
ldbm_back_compare(
    Backend	*be,
    Connection	*conn,
    Operation	*op,
    struct berval	*dn,
    struct berval	*ndn,
	AttributeAssertion *ava
)
{
	struct ldbminfo	*li = (struct ldbminfo *) be->be_private;
	Entry		*matched;
	Entry		*e;
	Attribute	*a;
	int		rc;
	int		manageDSAit = get_manageDSAit( op );

	/* grab giant lock for reading */
	ldap_pvt_thread_rdwr_rlock(&li->li_giant_rwlock);

	/* get entry with reader lock */
	if ( (e = dn2entry_r( be, ndn, &matched )) == NULL ) {
		char *matched_dn = NULL;
		BerVarray refs = NULL;

		if ( matched != NULL ) {
			matched_dn = ch_strdup( matched->e_dn );
			refs = is_entry_referral( matched )
				? get_entry_referrals( be, conn, op, matched )
				: NULL;
			cache_return_entry_r( &li->li_cache, matched );
		} else {
			refs = referral_rewrite( default_referral,
				NULL, dn, LDAP_SCOPE_DEFAULT );
		}

		ldap_pvt_thread_rdwr_runlock(&li->li_giant_rwlock);

		send_ldap_result( conn, op, LDAP_REFERRAL,
			matched_dn, NULL, refs, NULL );

		if ( refs ) ber_bvarray_free( refs );
		free( matched_dn );

		return( 1 );
	}

	if (!manageDSAit && is_entry_referral( e ) ) {
		/* entry is a referral, don't allow add */
		BerVarray refs = get_entry_referrals( be,
			conn, op, e );

#ifdef NEW_LOGGING
		LDAP_LOG(( "backend", LDAP_LEVEL_INFO,
			"ldbm_back_compare: entry (%s) is a referral.\n", e->e_dn ));
#else
		Debug( LDAP_DEBUG_TRACE, "entry is referral\n", 0,
		    0, 0 );
#endif


		send_ldap_result( conn, op, LDAP_REFERRAL,
		    e->e_dn, NULL, refs, NULL );

		if (refs ) ber_bvarray_free( refs );

		rc = 1;
		goto return_results;
	}

	if ( ! access_allowed( be, conn, op, e,
		ava->aa_desc, &ava->aa_value, ACL_COMPARE, NULL ) )
	{
		send_ldap_result( conn, op, LDAP_INSUFFICIENT_ACCESS,
			NULL, NULL, NULL, NULL );
		rc = 1;
		goto return_results;
	}

	rc = LDAP_NO_SUCH_ATTRIBUTE;

	for(a = attrs_find( e->e_attrs, ava->aa_desc );
		a != NULL;
		a = attrs_find( a->a_next, ava->aa_desc ))
	{
		rc = LDAP_COMPARE_FALSE;

		if ( value_find( ava->aa_desc, a->a_vals, &ava->aa_value ) == 0 ) {
			rc = LDAP_COMPARE_TRUE;
			break;
		}
	}

	send_ldap_result( conn, op, rc,
		NULL, NULL, NULL, NULL );

	if( rc != LDAP_NO_SUCH_ATTRIBUTE ) {
		rc = 0;
	}


return_results:;
	cache_return_entry_r( &li->li_cache, e );
	ldap_pvt_thread_rdwr_runlock(&li->li_giant_rwlock);
	return( rc );
}
