Notice of disconnection

["Lars Hesel Christensen XX \(AH/LMD\)" <lars.hesel.xx.christensen@ericsson.com>]

Hi all

I've been looking at the Notice of disconnection handling in OpenLDAP
and there is a thing that is confusing me a bit.

in result.c, the function try_read1msg reads data from socket and
creates a new message from that. If we receive an unsolicited message,
e.g, notice of disconnection, then the msgId will be zero, and we will
go through the following code(taken from /* $OpenLDAP:
/libraries/libldap/result.c,v 1.144 2006/12/17 21:04:25 ando Exp $ */):

	/* message id */
	if ( ber_get_int( ber, &id ) == LBER_ERROR ) {
		ber_free( ber, 1 );
		ld->ld_errno = LDAP_DECODING_ERROR;
		return( -1 );
	}

	/* if it's been abandoned, toss it */
	if ( ldap_abandoned( ld, id, &idx ) ) {

 <REMOVED since the msgId is not abandoned>

retry_ber:
		ber_free( ber, 1 );
		if ( ber_sockbuf_ctrl( lc->lconn_sb,
LBER_SB_OPT_DATA_READY, NULL ) ) {
			goto retry;
		}
-->     	return( LDAP_MSG_X_KEEP_LOOKING );	/* continue
looking */
	}

	lr = ldap_find_request_by_msgid( ld, id );
	if ( lr == NULL ) {
		const char	*msg = "unknown";

		/* the message type */
		tag = ber_peek_tag( ber, &len );
		switch ( tag ) {
		case LBER_ERROR:
			break;

		default:
			msg = ldap_int_msgtype2str( tag );
			break;
		}

		Debug( LDAP_DEBUG_ANY,
			"no request for response on ld %p msgid %ld
message type %s (tossing)\n",
			(void *)ld, (long)id, msg );

		goto retry_ber;
	}

Assuming there is no more data to be read from the socket we will return
in the line marked with the arrow '-->' since
ldap_find_request_by_msgid() returns NULL.

What confuses me is that later on in try_read1msg we get to (after
constructing the message:

	/* is this the one we're looking for? */
	if ( msgid == LDAP_RES_ANY || id == msgid ) {
		if ( all == LDAP_MSG_ONE
			|| ( newmsg->lm_msgtype !=
LDAP_RES_SEARCH_RESULT
			    	&& newmsg->lm_msgtype !=
LDAP_RES_SEARCH_ENTRY
			  	&& newmsg->lm_msgtype !=
LDAP_RES_SEARCH_REFERENCE ) )
		{
			*result = newmsg;
			ld->ld_errno = LDAP_SUCCESS;
			return( tag );

		} else if ( newmsg->lm_msgtype ==
LDAP_RES_SEARCH_RESULT) {
			foundit = 1;	/* return the chain later */
		}
	}

Do we have a test case testing notice of disconnection? I tried to grep
the 'tests' directory for 'notice', 'disconnection' and 'unsolicited'
but nothing came up.

Perhaps I'm misunderstanding something here, so if I am I would very
much appreciate a hint.

Happy newyear everyone,

Lars Hesel Christensen

--
Lars Hesel Christensen
Ericsson Denmark A/S, Telebit
lars.hesel.xx.christensen@ericsson.com