Technical Reference: Communications, Volume 1

DL_DISCONNECT_REQ Primitive

Purpose

Requests that an active data link be disconnected.

Structure

The primitive consists of one M_PROTO message block, which contains the following structure:
typedef struct { ulong dl_primitive; ulong dl_reason; ulong dl_correlation; } dl_disconnect_req_t;

The DL_DISCONNECT_REQ primitive requests the data link service (DLS) provider to disconnect an active data link connection or one that was in the process of activation. The DL_DISCONNECT_REQ primitive can be sent in response to a previously issued DL_CONNECT_IND or DL_CONNECT_REQ primitive. If an incoming DL_CONNECT_IND primitive is being refused, the correlation number associated with that connect indication must be supplied. The message indicates the reason for the disconnect.

Note: This primitive applies to connection mode.

Parameters

dl_primitive	Specifies the DL_DISCONNECT_REQ primitive.
dl_reason	Indicates one of the following reasons for the disconnect: DL_DISC_NORMAL_CONDITION Indicates normal release of a data link connection. DL_DISC_ABNORMAL_CONDITION Indicates abnormal release of a data link connection. DL_CONREJ_PERMANENT_COND Indicates a permanent condition caused the rejection of a connect request. DL_CONREJ_TRANSIENT_COND Indicates a transient condition caused the rejection of a connect request. DL_DISC_UNSPECIFIED Indicates the connection was closed for an unspecified reason.
dl_correlation	Specifies one of the following values: 0 Indicates either the disconnect request is releasing an established connection or is cancelling a previously sent DL_CONNECT_REQ primitive. >0 Specifies the correlation number that was contained in the DL_CONNECT_IND primitive being rejected. This value permits the DLS provider to associate the primitive with the proper DL_CONNECT_IND primitive when rejecting an incoming connection.

States

Valid

The primitive is valid in any of the following states:

DL_DATAXFER
DL_INCON_PENDING
DL_OUTCON_PENDING
DL_PROV_RESET_PENDING
DL_USER_RESET_PENDING

New

DL_DISCON11_PENDING

Acknowledgments

Successful	The DL_OK_ACK primitive is sent to the DLS user resulting in the DL_IDLE state.
Unsuccessful	The DL_ERROR_ACK primitive is returned, and the resulting state is unchanged.

Error Codes

DL_BADCORR	Indicates the correlation number specified in this primitive does not correspond to a pending connect indication.
DL_OUTSTATE	Indicates the primitive was issued from an invalid state.
DL_SYSERR	Indicates a system error occurred. The system error is indicated in the DL_ERROR_ACK primitive.

Implementation Specifics

This primitive is part of Base Operating System (BOS) Runtime.

Related Information

The DL_CONNECT_IND primitive, DL_OK_ACK primitive, DL_ERROR_ACK primitive, DL_CONNECT_REQ primitive.