text: /* bind.c - mdb backend bind routine */
  /* $OpenLDAP$ */
  /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   *
   * Copyright 2000-2018 The OpenLDAP Foundation.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted only as authorized by the OpenLDAP
   * Public License.
   *
   * A copy of this license is available in the file LICENSE in the
   * top-level directory of the distribution or, alternatively, at
   * <http://www.OpenLDAP.org/license.html>.
   */
  
  #include "portable.h"
  
  #include <stdio.h>
  #include <ac/string.h>
  #include <ac/unistd.h>
  
  #include "back-mdb.h"
  
  int
  mdb_bind( Operation *op, SlapReply *rs )
  {
  	struct mdb_info *mdb = (struct mdb_info *) op->o_bd->be_private;
  	Entry		*e;
  	Attribute	*a;
  
  	AttributeDescription *password = slap_schema.si_ad_userPassword;
  
  	MDB_txn		*rtxn;
  	mdb_op_info	opinfo = {{{0}}}, *moi = &opinfo;
  
  	Debug( LDAP_DEBUG_ARGS,
  		"==> " LDAP_XSTRING(mdb_bind) ": dn: %s\n",
  		op->o_req_dn.bv_val, 0, 0);
  
  	/* allow noauth binds */
  	switch ( be_rootdn_bind( op, NULL ) ) {
  	case LDAP_SUCCESS:
  		/* frontend will send result */
  		return rs->sr_err = LDAP_SUCCESS;
  
  	default:
  		/* give the database a chance */
  		/* NOTE: this behavior departs from that of other backends,
  		 * since the others, in case of password checking failure
  		 * do not give the database a chance.  If an entry with
  		 * rootdn's name does not exist in the database the result
  		 * will be the same.  See ITS#4962 for discussion. */
  		break;
  	}
  
  	rs->sr_err = mdb_opinfo_get(op, mdb, 1, &moi);
  	switch(rs->sr_err) {
  	case 0:
  		break;
  	default:
  		rs->sr_text = "internal error";
  		send_ldap_result( op, rs );
  		return rs->sr_err;
  	}
  
  	rtxn = moi->moi_txn;
  
  	/* get entry with reader lock */
  	rs->sr_err = mdb_dn2entry( op, rtxn, NULL, &op->o_req_ndn, &e, NULL, 0 );
  
  	switch(rs->sr_err) {
  	case MDB_NOTFOUND:
  		rs->sr_err = LDAP_INVALID_CREDENTIALS;
  		goto done;
  	case 0:
  		break;
  	case LDAP_BUSY:
  		rs->sr_text = "ldap_server_busy";
  		goto done;
  	default:
  		rs->sr_err = LDAP_OTHER;
  		rs->sr_text = "internal error";
  		goto done;
  	}
  
  	ber_dupbv( &op->oq_bind.rb_edn, &e->e_name );
  
  	/* check for deleted */
  	if ( is_entry_subentry( e ) ) {
  		/* entry is an subentry, don't allow bind */
  		Debug( LDAP_DEBUG_TRACE, "entry is subentry\n", 0,
  			0, 0 );
  		rs->sr_err = LDAP_INVALID_CREDENTIALS;
  		goto done;
  	}
  
  	if ( is_entry_alias( e ) ) {
  		/* entry is an alias, don't allow bind */
  		Debug( LDAP_DEBUG_TRACE, "entry is alias\n", 0, 0, 0 );
  		rs->sr_err = LDAP_INVALID_CREDENTIALS;
  		goto done;
  	}
  
  	if ( is_entry_referral( e ) ) {
  		Debug( LDAP_DEBUG_TRACE, "entry is referral\n", 0,
  			0, 0 );
  		rs->sr_err = LDAP_INVALID_CREDENTIALS;
  		goto done;
  	}
  
  	switch ( op->oq_bind.rb_method ) {
  	case LDAP_AUTH_SIMPLE:
  		a = attr_find( e->e_attrs, password );
  		if ( a == NULL ) {
  			rs->sr_err = LDAP_INVALID_CREDENTIALS;
  			goto done;
  		}
  
  		if ( slap_passwd_check( op, e, a, &op->oq_bind.rb_cred,
  					&rs->sr_text ) != 0 )
  		{
  			/* failure; stop front end from sending result */
  			rs->sr_err = LDAP_INVALID_CREDENTIALS;
  			goto done;
  		}
  			
  		rs->sr_err = 0;
  		break;
  
  	default:
  		assert( 0 ); /* should not be reachable */
  		rs->sr_err = LDAP_STRONG_AUTH_NOT_SUPPORTED;
  		rs->sr_text = "authentication method not supported";
  	}
  
  done:
  	if ( moi == &opinfo ) {
  		mdb_txn_reset( moi->moi_txn );
  		LDAP_SLIST_REMOVE( &op->o_extra, &moi->moi_oe, OpExtra, oe_next );
  	} else {
  		moi->moi_ref--;
  	}
  	/* free entry and reader lock */
  	if( e != NULL ) {
  		mdb_entry_return( op, e );
  	}
  
  	if ( rs->sr_err ) {
  		send_ldap_result( op, rs );
  		if ( rs->sr_ref ) {
  			ber_bvarray_free( rs->sr_ref );
  			rs->sr_ref = NULL;
  		}
  	}
  	/* front end will send result on success (rs->sr_err==0) */
  	return rs->sr_err;
  }
  