364 lines
11 KiB
C
364 lines
11 KiB
C
/*
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* gendll.c v0.11 March 14, 1996
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*
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****************************************************************************
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* *
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* (C) Copyright 1995, 1996 DIGITAL EQUIPMENT CORPORATION *
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* *
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* This software is an unpublished work protected under the *
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* the copyright laws of the United States of America, all *
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* rights reserved. *
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* *
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* In the event this software is licensed for use by the United *
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* States Government, all use, duplication or disclosure by the *
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* United States Government is subject to restrictions as set *
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* forth in either subparagraph (c)(1)(ii) of the Rights in *
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* Technical Data And Computer Software Clause at DFARS *
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* 252.227-7013, or the Commercial Computer Software Restricted *
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* Rights Clause at FAR 52.221-19, whichever is applicable. *
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* *
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****************************************************************************
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*
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* Facility:
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*
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* SNMP Extension Agent
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*
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* Abstract:
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*
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* This module contains the code for plugging into the Windows NT Extendible
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* Agent. It contains the dll's main routine and the three exported SNMP
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* routines.
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*
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* Functions:
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*
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* DllMain()
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* SnmpExtensionInit()
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* SnmpExtensionTrap()
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* SnmpExtensionQuery()
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*
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* Author:
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* Miriam Amos Nihart, Kathy Faust
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*
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* Date:
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* 2/17/95
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*
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* Revision History:
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* 6/26/95 KKF, register using Subroot_oid
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* 7/31/95 ags readded above code + uncommented calls to SNMP_oidfree
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* 3/14/96 kkf, modified SNMPExtensionTrap
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*/
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// General notes:
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//
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// Microsoft's Extendible Agent for Windows NT is implemented by dynamically
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// linking to Extension Agent DLLs that implement portions of the MIB. These
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// Extension Agents are configured in the Windows NT Registration Database.
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// When the Extendible Agent Service is started, it queries the registry to
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// determine which Extension Agent DLLs have been installed and need to be
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// loaded and initialized. The Extendible Agent invokes various DLL entry
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// points (examples follow in this file) to request MIB queries and obtain
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// Extension Agent generated traps.
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// Necessary includes.
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#include <windows.h>
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#include <malloc.h>
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#include <stdio.h>
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#include <snmp.h>
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//
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// The file mib.h is a user supplied header file (could be from a code
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// generator). This file should contain the definition, macros, forward
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// declarations, etc. The file mib_xtrn.h contains the external
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// declarations for the variable tables and classes composing this MIB.
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//
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#include "mib.h"
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#include "mib_xtrn.h"
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// Extension Agent DLLs need access to the elapsed time that the agent has
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// been active. This is implemented by initializing the Extension Agent
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// with a time zero reference, and allowing the agent to compute elapsed
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// time by subtracting the time zero reference from the current system time.
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// This example Extension Agent implements this reference with dwTimeZero.
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DWORD dwTimeZero = 0 ;
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extern DWORD dwTimeZero ;
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//
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// Trap Queue
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//
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q_hdr_t trap_q = { NULL, NULL } ;
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extern q_hdr_t trap_q ; // make it global
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HANDLE hTrapQMutex ;
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extern HANDLE hTrapQMutex ;
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HANDLE hEnabledTraps ;
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extern HANDLE hEnabledTraps ;
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/*
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* DllMain
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*
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* This is a standard Win32 DLL entry point. See the Win32 SDK for more
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* information on its arguments and their meanings. This example DLL does
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* not perform any special actions using this mechanism.
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*
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* Arguments:
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*
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* Results:
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*
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* Side Effects:
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*
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*/
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BOOL WINAPI
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DllMain( HANDLE hDll ,
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DWORD dwReason ,
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LPVOID lpReserved )
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{
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switch( dwReason )
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{
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case DLL_PROCESS_ATTACH :
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case DLL_PROCESS_DETACH :
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case DLL_THREAD_ATTACH :
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case DLL_THREAD_DETACH :
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default :
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break ;
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}
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return TRUE ;
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} /* end of DllMain() (the DllEntryPoint) */
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/*
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* SnmpExtensionInit
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*
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* Extension Agent DLLs provide the following entry point to coordinate the
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* initializations of the Extension Agent and the Extendible Agent. The
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* Extendible Agent provides the Extension Agent with a time zero reference;
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* and the Extension Agent provides the Extendible Agent with an Event
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* handle for communicating occurence of traps, and an object identifier
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* representing the root of the MIB subtree that the Extension Agent
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* supports.
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*
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* Traps support is determined by the user in the UserMibInit() routine.
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* If a valid handle from CreateEvent() is returned in the argument
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* hPollForTrapEvent, then traps have been implemented and the SNMP
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* Extendible Agent will poll this Extension Agent to retrieve the traps
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* upon notification through the SetEvent() routine. Polling is done
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* through the SnmpExtensionTrap() routine. If NULL is returned in the
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* argument hPollForTrapEvent, there are no traps.
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*
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* Arguments:
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*
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* Results:
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*
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*/
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BOOL WINAPI
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SnmpExtensionInit( IN DWORD dwTimeZeroReference ,
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OUT HANDLE *hPollForTrapEvent ,
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OUT AsnObjectIdentifier *supportedView )
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{
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// Record the time reference provided by the Extendible Agent.
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dwTimeZero = dwTimeZeroReference ;
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// Indicate the MIB view supported by this Extension Agent, an object
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// identifier representing the sub root of the MIB that is supported.
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*supportedView = Subroot_oid ; // NOTE! structure copy
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// *supportedView = *(class_info[ 0 ].oid) ; // NOTE! structure copy
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// Call the User's initialization routine
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if ( !UserMibInit( hPollForTrapEvent ) )
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return FALSE ;
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// Indicate that Extension Agent initialization was successful.
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return TRUE ;
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} /* end of SnmpExtensionInit() */
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/*
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* SnmpExtensionTrap
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*
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* Extension Agent DLLs provide the following entry point to communicate
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* traps to the Extendible Agent. The Extendible Agent will query this
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* entry point when the trap Event (supplied at initialization time) is
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* asserted, which indicates that zero or more traps may have occured.
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* The Extendible Agent will repetedly call this entry point until FALSE
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* is returned, indicating that all outstanding traps have been processed.
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*
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* Arguments:
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*
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* Results:
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*
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|=========================================================================
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| There are no Traps associated with the HostMIB. Consequently this
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| routine is taken over and used to refresh the cached information
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| associated with SNMP attribute "hrProcessorLoad" (in "HRPROCES.C") thru
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| a call to function "hrProcessLoad_Refresh()" (also in "HRPROCES.C").
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| This function is being entered because a timer has expired that was
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| initialized by code in "TrapInit()" (in "GENNT.C"). The timer automatically
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| resets itself.
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| All the standard generated code is subsumed by a simple call to
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| "hrProcessLoad_Refresh()".
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*/
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BOOL WINAPI
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SnmpExtensionTrap( OUT AsnObjectIdentifier *enterprise ,
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OUT AsnInteger *genericTrap ,
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OUT AsnInteger *specificTrap ,
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OUT AsnTimeticks *timeStamp ,
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OUT RFC1157VarBindList *variableBindings )
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{
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#if 0
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tcb_t *entry ;
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// Traps are process by processing the traps on the trap queue.
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// The Extendible Agent will call this routine upon the receipt of
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// the event on the handle passed back in the SnmpExtensionInit routine.
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// The Extendible Agent calls this return back as long as this routine
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// returns true.
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// acquire mutex for trap_q
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WaitForSingleObject( hTrapQMutex, INFINITE ) ;
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// Dequeue a trap entry
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QUEUE_REMOVE( trap_q, entry ) ;
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// release the mutex for trap_q
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ReleaseMutex( hTrapQMutex ) ;
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if (entry == NULL)
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return FALSE ;
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*enterprise = entry->enterprise ; // note structure copy
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*genericTrap = entry->genericTrap ;
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*specificTrap = entry->specificTrap ;
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*timeStamp = entry->timeStamp ;
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*variableBindings = entry->varBindList ; // note structure copy
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free(entry) ;
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return TRUE ;
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#endif
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/*
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|========================
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| Special HostMIB code:
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*/
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/* Re-fetch CPU statistics from kernel */
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hrProcessLoad_Refresh();
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/* Don't call again until the timer goes off again */
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return FALSE;
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} /* end of SnmpExtensionTrap() */
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/*
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* SnmpExtensionQuery
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*
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* Extension Agent DLLs provide the following entry point to resolve queries
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* for MIB variables in their supported MIB view (supplied at initialization
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* time). The requestType is Get/GetNext/Set.
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*
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* Arguments:
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*
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* Results:
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*
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*/
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BOOL WINAPI
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SnmpExtensionQuery( IN BYTE requestType ,
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IN OUT RFC1157VarBindList *variableBindings ,
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OUT AsnInteger *errorStatus ,
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OUT AsnInteger *errorIndex )
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{
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UINT index ;
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UINT *tmp ;
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UINT status ;
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// Iterate through the variable bindings list to resolve individual
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// variable bindings.
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for ( index = 0 ; index < variableBindings->len ; index++ )
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{
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*errorStatus = ResolveVarBind( &variableBindings->list[ index ] ,
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requestType ) ;
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// Test and handle case where Get Next past end of MIB view supported
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// by this Extension Agent occurs. Special processing is required to
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// communicate this situation to the Extendible Agent so it can take
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// appropriate action, possibly querying other Extension Agents.
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if ( *errorStatus == SNMP_ERRORSTATUS_NOSUCHNAME &&
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requestType == MIB_ACTION_GETNEXT )
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{
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*errorStatus = SNMP_ERRORSTATUS_NOERROR ;
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// Modify variable binding of such variables so the OID points
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// just outside the MIB view supported by this Extension Agent.
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// The Extendible Agent tests for this, and takes appropriate
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// action.
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SNMP_oidfree( &variableBindings->list[ index ].name ) ;
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status = SNMP_oidcpy( &variableBindings->list[ index ].name, &Subroot_oid ) ;
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if ( !status )
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{
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*errorStatus = SNMP_ERRORSTATUS_GENERR;
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}
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else
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{
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tmp = variableBindings->list[ index ].name.ids ;
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(tmp[ SUBROOT_LENGTH - 1 ])++ ;
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}
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}
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// If an error was indicated, communicate error status and error
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// index to the Extendible Agent. The Extendible Agent will ensure
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// that the origional variable bindings are returned in the response
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// packet.
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if ( *errorStatus != SNMP_ERRORSTATUS_NOERROR )
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{
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*errorIndex = index + 1 ;
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goto Exit ;
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}
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}
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Exit:
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// Indicate that Extension Agent processing was sucessfull.
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return SNMPAPI_NOERROR ;
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} /* end of SnmpExtensionQuery() */
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/* end of gendll.c */
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