How To Retrieve 3270 LU Information For SNA Server Programmatically

ID: Q214629

The information in this article applies to:

Microsoft SNA Server, versions 3.0, 3.0SP1, 3.0SP2, 3.0SP3, 4.0, 4.0SP1

SUMMARY

SNA Server currently does not expose any APIs directly to gather 3270 status information. However, the APPC DISPLAY management verb does allow some information to be gathered on the status of the LUs. The following code is a continuation of Q214572 - "How To Retrieve Link Information For SNA Server Programmatically" that can be added to the program in that article to dump out to a console window the status of all 3270 LUs in a domain. This can possibly be modified to monitor for LU status changes in a monitoring application to report when some error conditions occur.

MORE INFORMATION

Using the code from Q214572 as a starting point, add the following three functions to the program.


/*****************************************************************************/ 
/* Get3270Info - calls the Display Management verb to get lu_0_3_info for a  */ 
/* particular server/node in the SNA Domain.                                 */ 
/*****************************************************************************/ 
void Get3270Info(dispvcb_t *dispvcb, dbufstruct *DataBuffer, char boxname[])
{
	dispvcb->display.opcode = AP_DISPLAY;
	dispvcb->display.init_sect_len = (unsigned long)&(((DISPLAY *)0)->sna_global_info_ptr);
	dispvcb->display.num_sections = 0x10;
	dispvcb->display.buffer_len = sizeof(DataBuffer->dbuf);
	dispvcb->display.buffer_ptr = DataBuffer->dbuf;
	strcpy( (char*)DataBuffer->dbuf, "CSEXTNID" );
	memcpy( DataBuffer->dbuf + 8, boxname,32 );
	dispvcb->display.lu_0_3_info = AP_YES;
	APPC( (long)dispvcb );
}

/*****************************************************************************/ 
/* Enumerate3270Data - This function goes through the LU_0_3_INFO_SECT and   */ 
/* prints out the information returned for each 3270 LU found.               */ 
/*****************************************************************************/ 
void Enumerate3270Data(dispvcb_t *dispvcb)
{
	LU_0_3_INFO_SECT *lu_0_3_info;
	LU_0_3_OVERLAY *lu_0_3_overlay;
	unsigned short i;

	char buffer1[20];

	lu_0_3_info = dispvcb->display.lu_0_3_info_ptr;

	lu_0_3_overlay = (LU_0_3_OVERLAY *)((char *)lu_0_3_info + lu_0_3_info->lu_0_3_init_sect_len);
	if (lu_0_3_info->num_lu_0_3s == 0)
	{
		printf("No 3270 type LUs found.\n");
	}
	else
	{
		for (i = 0; i < lu_0_3_info->num_lu_0_3s; i++)
		{
			SetupString( (char*)buffer1, (char*)lu_0_3_overlay->lu_long_name,8);
			printf("\tLU Name: %8.8s\n",buffer1);
			
			switch (lu_0_3_overlay->access_type)
			{
			case AP_3270_EMULATION:
					printf("\tAccess Type = 3270 Emulation\n");
					break;
			case AP_LUA:
					printf("\tAccess Type = LUA\n");
					break;
			default:
					printf("\tAccess Type = UNKNOWN\n");
					break;
			}

			switch (lu_0_3_overlay->lu_type)
			{
			case AP_LU0:
				printf("\tLU type = LU0\n");
				break;
			case AP_LU1:
				printf("\tLU type = LU1\n");
				break;
			case AP_LU2:
				printf("\tLU type = LU2\n");
				break;
			case AP_LU3:
				printf("\tLU type = LU3\n");
				break;
			default:
				printf("\tLU type = UNKNOWN\n");
				break;
			}
			
			switch (lu_0_3_overlay->sscp_lu_sess_state)
			{
			case AP_DEACTIVATED:
				printf("\tSSCP-LU Session State = Deactivated\n");
				break;
			case AP_ACTIVATED:
				printf("\tSSCP-LU Session State = Activated\n");
				break;
			case AP_ACTIVATING:
				printf("\tSSCP-LU Session State = Activating\n");
				break;
			case AP_DEACTIVATING:
				printf("\tSSCP-LU Session State = Deactivating\n");
				break;
			default:
				printf("\tSSCP-LU Session State = UNKNOWN\n");
				break;
			}

			switch (lu_0_3_overlay->lu_lu_sess_state)
			{
			case AP_NOT_BOUND:
				printf("\tLU-LU Session State = Not Bound\n");
				break;
			case AP_BOUND:
				printf("\tLU-LU Session State = Bound\n");
				break;
			case AP_BINDING:
				printf("\tLU-LU Session State = Binding\n");
				break;
			case AP_UNBINDING:
				printf("\tLU-LU Session State = Unbound\n");
				break;
			default:
				printf("\tLU-LU Session State = UNKNOWN\n");
				break;
			}

			lu_0_3_overlay = (LU_0_3_OVERLAY *)((char *)lu_0_3_overlay + lu_0_3_overlay->lu_0_3_entry_len);
			printf("\n"); //empty line
		}
	}
}

/*****************************************************************************/ 
/* Do3270LU - This function does most of the work. It loops through each     */ 
/* node, calling Get3270Info and Enumerate3270Data to display the status of  */ 
/* all available 3270 LUs in the domain.                                        */ 
/*****************************************************************************/ 
bool Do3270LU(namestruct *Names)
{
	dbufstruct DataBuffer;
	dispvcb_t dispvcb;
	char *dispvcbptr;
	int loop;

	dispvcbptr=(char *)&dispvcb;
	for (loop = 0; loop < Names->nodenumber; loop++)
	{
		CLEARDISPVCB;
		ZERODATABUFFER;
		Get3270Info(&dispvcb, &DataBuffer, Names->boxname[loop]); //lu_0_3_info
		if( dispvcb.display.primary_rc != AP_OK )
		{
			DisplayVerbFailed(dispvcb.display.primary_rc, dispvcb.display.secondary_rc);
			DSPAppcError(&dispvcb);
			return false;
		}
		else
		{
			printf("\nBoxName:Server: %.8s:%s\n",Names->nodename[loop],Names->shortname[loop]);
			Enumerate3270Data(&dispvcb);
		} //end else
	} //end for loop
	return true;
}

Next, change Main so that instead of calling DoLinkInfo(&gNames), you call GetNodes(&gNames). Recompile the application and run.

The output will be for EVERY 3270 LU on the domain, broken up by server or node. There is currently no way to pull this information for an individual link. However, the application can be modified to only query against one SNA Server or node. The following output is from an SNA Server with three nodes, with 3270 LUs configured on two of the nodes.



BoxName:Server: SNASERVR:COMPUTER.01
	LU Name:     PRT3
	Access Type = 3270 Emulation
	LU type = LU1
	SSCP-LU Session State = Deactivated
	LU-LU Session State = Not Bound

	LU Name:     PRT7
	Access Type = 3270 Emulation
	LU type = LU1
	SSCP-LU Session State = Activated
	LU-LU Session State = Not Bound


BoxName:Server: SNASRV02:COMPUTER.02
	LU Name:   DSP002
	Access Type = 3270 Emulation
	LU type = LU2
	SSCP-LU Session State = Activated
	LU-LU Session State = Not Bound

	LU Name:   DSP003
	Access Type = 3270 Emulation
	LU type = LU2
	SSCP-LU Session State = Activated
	LU-LU Session State = Bound

	LU Name:   DSP004
	Access Type = 3270 Emulation
	LU type = LU2
	SSCP-LU Session State = Deactivated
	LU-LU Session State = Not Bound


BoxName:Server: SNASRV03:COMPUTER.03
No 3270 type LUs found.
Completed

In the output above, for PRT3 is a printer LU that is not activated. PRT7 is an active print LU that is not currently in session. DSP002 is a 3270 emulator session where the user has started the session, but is at a SSCP screen. DSP003 is a session where the user is logged in. DSP004 is a 3270 LU that is not active.

For information on how to retrieve Link information, see Q214572. For information on how to use the NLS API to do EBCDIC - ASCII conversion see Q214649. For additional information, please see the SNA SDK documentation that is included with SNA Server.

Additional query words:


Keywords          : kbfile kbprg kbsample 
Version           : WINDOWS:3.0,3.0SP1,3.0SP2,3.0SP3,4.0,4.0SP1
Platform          : WINDOWS 
Issue type        : kbhowto kbinfo

Last Reviewed: January 21, 1999