cippd_protocol.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

 *
 *   IPL_SCS			- Interrupt processor level
 *   cippdbp			- Address of CI PPD header in datagram
 *   pb				- Path Block pointer
 *   pccb			- Port Command and Control Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   pb				- Path Block pointer
 *	sb			- Address of formative System Block
 *	pinfo.protocol		- Remote systems CI PPD protocol version
 *   pccb			- Port Command and Control Block pointer
 *      ppd.cippd               -  CI PPD specific PCCB fields
 *          aflogmap            -   Path establishment insufficient mem log map
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Formative System Block successfully built
 *   RET_FAILURE		- Failed to allocate a System Block
 *
 *   SMP:	The PCCB is locked( EXTERNALLY ) allowing exclusive access to
 *		PCCB contents, postponing premature PB deletion, and as
 *		required by cippd_log_path() in case logging becomes necessary.
 *
 *   		The PB is locked( EXTERNALLY ) postponing potential deletion
 *		and allowing exclusive access to PB contents.
 */
u_long
cippd_build_sb( pccb, pb, cippdbp )
    PCCB		*pccb;
    PB			*pb;
    GVPPPDH		*cippdbp;
{
    register SB		*sb;
    register u_long	status = RET_SUCCESS;
    register CIPPD_START *bp = Cippd_start( Ppd_to_scs( cippdbp ));

    /* Insufficient memory for SB allocation aborts new path establishment.
     * Only the first such failure to establish a specific path is logged.
     * Logging of all subsequent failures is bypassed until after the CI PPD is
     * successful at allocating all required memory for establishment of the
     * specific path( see cippd_enab_path()).
     */
    if(( sb = pb->sb = scs_alloc_sb(( SIB * )bp ))) {
	pb->pinfo.protocol = bp->protocol;
	sb->sinfo.npaths = 0;
    } else {
	if( !Test_map( Aflogmap, Scaaddr_low( pb->pinfo.rport_addr ))) {
	    Set_map( Aflogmap, Scaaddr_low( pb->pinfo.rport_addr ))
	    ( void )cippd_log_path( pccb, pb, cippdbp, E_ALLOCFAIL );
	}
	status = RET_FAILURE;
    }
    return( status );
}

/*   Name:	cippd_comp_trys	- Compute Number of Transmission Attempts
 *
 *   Abstract:	This action routine computes the maximum number of attempts
 *		made by the finite state machine to transmit a CI PPD protocol
 *		packet.  The maximum number of attempts is computed as follows:
 *
 *		tries = ( port contact frequency ) / ( port polling frequency )
 *
 *		The current port polling interval is used as the port polling
 *		frequency.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cippd_itime		- CI PPD port timer interval
 *   cippdbp			- Address of CI PPD header in datagram
 *   pb				- Path Block pointer
 *   pccb			- Port Command and Control Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   pb				- Path Block pointer
 *	ppd.cippd		-  CI PPD specific PB fields
 *	    retry		-   Retry count
 *
 *   SMP:	The PCCB is locked( EXTERNALLY ) allowing exclusive access to
 *		PCCB contents.
 *
 *		The PB is locked( EXTERNALLY ) postponing potential deletion
 *		and allowing exclusive access to PB contents.
 */
void
cippd_comp_trys( pccb, pb, cippdbp )
    PCCB		*pccb;
    PB			*pb;
    GVPPPDH		*cippdbp;
{
    pb->Retry = ((( pccb->Contact >= cippd_itime ) ? pccb->Contact
						   : cippd_itime ) /
			pccb->Poll_interval );
}

/*   Name:	cippd_disb_path	- Disable CI PPD Path
 *
 *   Abstract:	This action routine directs the disablement of a CI PPD path.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cippdbp			- Address of CI PPD header in datagram/message
 *   pb				- Path Block pointer
 *   pccb			- Port Command and Control Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   pb				- Path Block pointer
 *	ppd.cippd		-  CI PPD specific PB fields
 *	    fsmpstatus		-   Finite State Machine path status flags
 *		path_closed	-    1
 *
 *   SMP:	The PCCB is locked( EXTERNALLY ) as required by PD functions
 *		which close virtual circuits.
 *
 *		The PB is locked( EXTERNALLY ) postponing potential deletion,
 *		allowing exclusive access to PB contents, and as required by
 *		PD functions which close virtual circuits.
 */
void
cippd_disb_path( pccb, pb, cippdbp )
    PCCB		*pccb;
    register PB		*pb;
    GVPPPDH		*cippdbp;
{
    /* Disable the path only if it has not already been disabled by the
     * appropriate port driver.
     */
    if( !pb->Fsmpstatus.path_closed ) {
	( void )( *pccb->Set_circuit )( pccb,
					pb,
					Scaaddr_low( pb->pinfo.rport_addr ),
					SET_VC_CLOSE );
	pb->Fsmpstatus.path_closed = 1;
    }
}

/*   Name:	cippd_enab_path	- Enable CI PPD Path
 *
 *   Abstract:	This action function directs the enablement of a CI PPD path.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cippdbp			- Address of CI PPD header in datagram
 *   pb				- Path Block pointer
 *	ppd.cippd		-  CI PPD specific PB fields
 *	    fsmpstatus		-   Finite State Machine path status flags
 *		path_closed	-    1
 *   pccb			- Port Command and Control Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   pb				- Path Block pointer
 *	ppd.cippd		-  CI PPD specific PB fields
 *	    fsmpstatus		-   Finite State Machine path status flags
 *		path_closed	-    Path already closed by port status bit
 *   pccb			- Port Command and Control Block pointer
 *      ppd.cippd               -  CI PPD specific PCCB fields
 *          aflogmap            -   Path establishment insufficient mem log map
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- CI PPD path is enabled
 *   RET_ALLOCFAIL		- Unable to allocate port specific buffer
 *
 *   SMP:	The PCCB is locked( EXTERNALLY ) allowing exclusive access to
 *		PCCB contents, postponing premature PB deletion, and as
 *		required both by PD functions which open virtual circuits and
 *		by cippd_log_path() in case logging becomes necessary.
 *
 *		The PB is locked( EXTERNALLY ) postponing potential deletion,
 *		allowing exclusive access to PB contents, and as required by
 *		PD functions which open virtual circuits.
 */
u_long
cippd_enab_path( pccb, pb, cippdbp )
    PCCB		*pccb;
    register PB		*pb;
    GVPPPDH		*cippdbp;
{
    register u_long	status;

    /* Insufficient memory for port specific buffer allocation is the only
     * reason for failure to enable a specific path.  This failure aborts new
     * path establishment and is logged.  Only the first such failure to
     * establish a specific path is logged.  Logging of all subsequent failures
     * is bypassed until after the CI PPD is successful at allocating all
     * required memory for establishment of the specific path( which occurs
     * with successful invocation of this very function ).
     */
    if( pb->Fsmpstatus.path_closed ) {
	status = ( *pccb->Set_circuit )( pccb,
					 pb,
				 	 Scaaddr_low( pb->pinfo.rport_addr ),
					 SET_VC_OPEN );
	if( status == RET_SUCCESS ) {
	    pb->Fsmpstatus.path_closed = 0;
	    Clear_map( Aflogmap, Scaaddr_low( pb->pinfo.rport_addr ))
	} else {
	    if( !Test_map( Aflogmap, Scaaddr_low( pb->pinfo.rport_addr ))) {
		Set_map( Aflogmap, Scaaddr_low( pb->pinfo.rport_addr ))
		( void )cippd_log_path( pccb, pb, NULL, E_ALLOCFAIL );
	    }
	}
    } else {
	( void )panic( PPDPANIC_POPEN );
    }
    return( status );
}

/*   Name:	cippd_enter_db	- Enter Path Block into Databases
 *
 *   Abstract:	This action function enters the PB representing the formative
 *		CI PPD path into the system-wide local port and configuration
 *		databases.  The formative SB is also entered into the
 *		system-wide configuration database provided the system is not
 *		currently known; otherwise, the formative SB is deallocated.
 *
 *		Existence of the new path is event logged and brought to the
 *		attention of SCS.
 *
 *		NOTE: No action function invoked following the invocation of
 *		      this one may ever return a failure status.  This is
 *		      because for all practical purposes the path is fully
 *		      established once this routine enters the PB into the
 *		      databases( see rule 4 at front of this module ).
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cippdbp			- Address of CI PPD header in datagram
 *   pb				- Path Block pointer
 *   pccb			- Port Command and Control Block pointer
 *   lk_scadb			- SCA database lock structure
 *   scs_config_db		- System-wide configuration database queue head
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   pb				- Path Block pointer
 *	flink			-  Database queuing pointers
 *	sb			-  SB pointer
 *   pccb			- Port Command and Control Block pointer
 *	lpinfo.ppd.cippd	-  CI PPD specific local port information
 *	    dbclogmap		-   Database conflict port logging bitmap
 *	    nform_paths		-   Current number of formative paths
 *	    npaths		-   Current number of paths
 *	ppd.cippd		-  CI PPD specific PCCB fields
 *	    elogopt.dbcoll	-   Database collision error information
 *	    elogopt.protocol	-   CI PPD protocol information
 *	    elogopt.rswtype	-   Remote system software type
 *	    form_pb		-   Formative PB queue
 *	    open_pb		-   PS_OPEN PB vector table
 *          tmologmap           -   Path establishment timeout log map
 *   sb				- System Block pointer
 *	flink			-  Database queuing pointers
 *	pbs			-  PB queue
 *	sinfo.npaths		-  Current number of paths
 *   scs_config_db		- System-wide configuration database queue
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Path Block entered into databases
 *   RET_FAILURE		- Conflict discovered within a database
 *
 *   SMP:	The SCA database is locked INTERNALLY whenever it was not
 *		locked EXTERNALLY prior to function invocation.  It is locked
 *		for traversing the system-wide configuration database and
 *		updating it with the formative PB and occasionally the
 *		formative SB.  It is also required by cippd_csyslev() in case
 *		common system level event logging becomes necessary.