You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
326 lines
9.8 KiB
326 lines
9.8 KiB
/*++ BUILD Version: 0001 // Increment this if a change has global effects
|
|
|
|
Copyright (c) 1991 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
dhcpmibm.c
|
|
|
|
Abstract:
|
|
|
|
Sample SNMP Extension Agent for Windows NT.
|
|
|
|
These files (dhcpdll.c, dhcpsmib.c, and dhcpmib.h) provide an example of
|
|
how to structure an Extension Agent DLL which works in conjunction with
|
|
the SNMP Extendible Agent for Windows NT.
|
|
|
|
Extensive comments have been included to describe its structure and
|
|
operation. See also "Microsoft Windows/NT SNMP Programmer's Reference".
|
|
|
|
Created:
|
|
|
|
28-Jun-1991
|
|
|
|
Revision History:
|
|
|
|
--*/
|
|
|
|
|
|
#ifdef UNICODE
|
|
#undef UNICODE
|
|
#endif
|
|
|
|
// General notes:
|
|
//
|
|
// Microsoft's Extendible Agent for Windows NT is implemented by dynamically
|
|
// linking to Extension Agent DLLs that implement portions of the MIB. These
|
|
// Extension Agents are configured in the Windows NT Registration Database.
|
|
// When the Extendible Agent Service is started, it queries the registry to
|
|
// determine which Extension Agent DLLs have been installed and need to be
|
|
// loaded and initialized. The Extendible Agent invokes various DLL entry
|
|
// points (examples follow in this file) to request MIB queries and obtain
|
|
// Extension Agent generated traps.
|
|
|
|
|
|
// Necessary includes.
|
|
|
|
#include <windows.h>
|
|
|
|
#include <snmp.h>
|
|
|
|
|
|
// Contains definitions for the table structure describing the MIB. This
|
|
// is used in conjunction with dhcpmib.c where the MIB requests are resolved.
|
|
|
|
#include "dhcpmib.h"
|
|
|
|
|
|
// Extension Agent DLLs need access to elapsed time agent has been active.
|
|
// This is implemented by initializing the Extension Agent with a time zero
|
|
// reference, and allowing the agent to compute elapsed time by subtracting
|
|
// the time zero reference from the current system time. This example
|
|
// Extension Agent implements this reference with dwTimeZero.
|
|
|
|
DWORD dwTimeZero = 0;
|
|
|
|
|
|
// Extension Agent DLLs that generate traps must create a Win32 Event object
|
|
// to communicate occurence of traps to the Extendible Agent. The event
|
|
// handle is given to the Extendible Agent when the Extension Agent is
|
|
// initialized, it should be NULL if traps will not be generated. This
|
|
// example Extension Agent simulates the occurance of traps with hSimulateTrap.
|
|
|
|
HANDLE hSimulateTrap = NULL;
|
|
|
|
|
|
// This is a standard Win32 DLL entry point. See the Win32 SDK for more
|
|
// information on its arguments and their meanings. This example DLL does
|
|
// not perform any special actions using this mechanism.
|
|
|
|
BOOL WINAPI DllMain(
|
|
HANDLE hDll,
|
|
DWORD dwReason,
|
|
LPVOID lpReserved)
|
|
{
|
|
switch(dwReason)
|
|
{
|
|
case DLL_PROCESS_ATTACH:
|
|
case DLL_PROCESS_DETACH:
|
|
case DLL_THREAD_ATTACH:
|
|
case DLL_THREAD_DETACH:
|
|
default:
|
|
break;
|
|
|
|
} // end switch()
|
|
|
|
return TRUE;
|
|
|
|
} // end DllEntryPoint()
|
|
|
|
|
|
// Extension Agent DLLs provide the following entry point to coordinate the
|
|
// initializations of the Extension Agent and the Extendible Agent. The
|
|
// Extendible Agent provides the Extension Agent with a time zero reference;
|
|
// and the Extension Agent provides the Extendible Agent with an Event handle
|
|
// for communicating occurence of traps, and an object identifier representing
|
|
// the root of the MIB subtree that the Extension Agent supports.
|
|
|
|
BOOL SnmpExtensionInit(
|
|
IN DWORD dwTimeZeroReference,
|
|
OUT HANDLE *hPollForTrapEvent,
|
|
OUT AsnObjectIdentifier *supportedView)
|
|
{
|
|
|
|
// Record the time reference provided by the Extendible Agent.
|
|
|
|
dwTimeZero = dwTimeZeroReference;
|
|
|
|
|
|
// Create an Event that will be used to communicate the occurence of traps
|
|
// to the Extendible Agent. The Extension Agent will assert this Event
|
|
// when a trap has occured. This is explained further later in this file.
|
|
|
|
if ((*hPollForTrapEvent = CreateEvent(NULL, FALSE, FALSE, NULL)) == NULL)
|
|
{
|
|
// Indicate error?, be sure that NULL is returned to Extendible Agent.
|
|
}
|
|
|
|
|
|
// Indicate the MIB view supported by this Extension Agent, an object
|
|
// identifier representing the sub root of the MIB that is supported.
|
|
|
|
*supportedView = MIB_OidPrefix; // NOTE! structure copy
|
|
|
|
|
|
// Record the trap Event. This example Extension Agent simulates traps by
|
|
// generating a trap after every given number of processed requests.
|
|
|
|
hSimulateTrap = *hPollForTrapEvent;
|
|
|
|
|
|
// Indicate that Extension Agent initialization was sucessfull.
|
|
|
|
return TRUE;
|
|
|
|
} // end SnmpExtensionInit()
|
|
|
|
|
|
// Extension Agent DLLs provide the following entry point to communcate traps
|
|
// to the Extendible Agent. The Extendible Agent will query this entry point
|
|
// when the trap Event (supplied at initialization time) is asserted, which
|
|
// indicates that zero or more traps may have occured. The Extendible Agent
|
|
// will repetedly call this entry point until FALSE is returned, indicating
|
|
// that all outstanding traps have been processed.
|
|
|
|
BOOL SnmpExtensionTrap(
|
|
OUT AsnObjectIdentifier *enterprise,
|
|
OUT AsnInteger *genericTrap,
|
|
OUT AsnInteger *specificTrap,
|
|
OUT AsnTimeticks *timeStamp,
|
|
OUT RFC1157VarBindList *variableBindings)
|
|
{
|
|
// The body of this routine is an extremely simple example/simulation of
|
|
// the trap functionality. A real implementation will be more complex.
|
|
|
|
|
|
// The following define data inserted into the trap below. The Lan Manager
|
|
// bytesAvailAlert from the Lan Manager Alerts-2 MIB is generated with an
|
|
// empty variable bindings list.
|
|
|
|
static UINT OidList[] = { 1, 3, 6, 1, 4, 1, 311, 2 };
|
|
static UINT OidListLen = 8;
|
|
|
|
|
|
// The following variable is used for the simulation, it allows a single
|
|
// trap to be generated and then causes FALSE to be returned indicating
|
|
// no more traps.
|
|
|
|
static whichTime = 0;
|
|
|
|
|
|
// The following if/else support the simulation.
|
|
|
|
if (whichTime == 0)
|
|
{
|
|
whichTime = 1; // Supports the simulation.
|
|
|
|
|
|
// Communicate the trap data to the Extendible Agent.
|
|
|
|
enterprise->idLength = OidListLen;
|
|
enterprise->ids = (UINT *)SnmpUtilMemAlloc(sizeof(UINT) * OidListLen);
|
|
|
|
if (NULL == enterprise->ids) {
|
|
whichTime = 0;
|
|
return FALSE;
|
|
}
|
|
memcpy(enterprise->ids, OidList, sizeof(UINT) * OidListLen);
|
|
|
|
*genericTrap = SNMP_GENERICTRAP_ENTERSPECIFIC;
|
|
|
|
*specificTrap = 1; // the bytesAvailAlert trap
|
|
|
|
*timeStamp = GetCurrentTime() - dwTimeZero;
|
|
|
|
variableBindings->list = NULL;
|
|
variableBindings->len = 0;
|
|
|
|
|
|
// Indicate that valid trap data exists in the parameters.
|
|
|
|
return TRUE;
|
|
}
|
|
else
|
|
{
|
|
whichTime = 0; // Supports the simulation.
|
|
|
|
|
|
// Indicate that no more traps are available and parameters do not
|
|
// refer to any valid data.
|
|
|
|
return FALSE;
|
|
}
|
|
|
|
} // end SnmpExtensionTrap()
|
|
|
|
|
|
// Extension Agent DLLs provide the following entry point to resolve queries
|
|
// for MIB variables in their supported MIB view (supplied at initialization
|
|
// time). The requestType is Get/GetNext/Set.
|
|
|
|
BOOL SnmpExtensionQuery(
|
|
IN BYTE requestType,
|
|
IN OUT RFC1157VarBindList *variableBindings,
|
|
OUT AsnInteger *errorStatus,
|
|
OUT AsnInteger *errorIndex)
|
|
{
|
|
static unsigned long requestCount = 0; // Supports the trap simulation.
|
|
UINT I;
|
|
|
|
|
|
try {
|
|
//
|
|
// Iterate through the variable bindings list to resolve individual
|
|
// variable bindings.
|
|
//
|
|
|
|
fDhcpMibVarsAccessed = FALSE;
|
|
for ( I=0;I < variableBindings->len;I++ )
|
|
{
|
|
*errorStatus = ResolveVarBind( &variableBindings->list[I],
|
|
requestType );
|
|
|
|
|
|
//
|
|
// Test and handle case where Get Next past end of MIB view supported
|
|
// by this Extension Agent occurs. Special processing is required to
|
|
// communicate this situation to the Extendible Agent so it can take
|
|
// appropriate action, possibly querying other Extension Agents.
|
|
//
|
|
|
|
if ( *errorStatus == SNMP_ERRORSTATUS_NOSUCHNAME &&
|
|
requestType == MIB_GETNEXT )
|
|
{
|
|
*errorStatus = SNMP_ERRORSTATUS_NOERROR;
|
|
|
|
|
|
// Modify variable binding of such variables so the OID points
|
|
// just outside the MIB view supported by this Extension Agent.
|
|
// The Extendible Agent tests for this, and takes appropriate
|
|
// action.
|
|
|
|
SnmpUtilOidFree( &variableBindings->list[I].name );
|
|
SnmpUtilOidCpy( &variableBindings->list[I].name, &MIB_OidPrefix );
|
|
variableBindings->list[I].name.ids[MIB_PREFIX_LEN-1] ++;
|
|
}
|
|
|
|
|
|
// If an error was indicated, communicate error status and error
|
|
// index to the Extendible Agent. The Extendible Agent will ensure
|
|
// that the origional variable bindings are returned in the response
|
|
// packet.
|
|
|
|
if ( *errorStatus != SNMP_ERRORSTATUS_NOERROR )
|
|
{
|
|
*errorIndex = I+1;
|
|
// goto Exit;
|
|
}
|
|
else
|
|
{
|
|
*errorIndex = 0;
|
|
}
|
|
}
|
|
|
|
} // end of try
|
|
except(EXCEPTION_EXECUTE_HANDLER) {
|
|
//
|
|
// for now do nothing
|
|
//
|
|
}
|
|
|
|
#if 0
|
|
// Supports the trap simulation.
|
|
|
|
if (++requestCount % 3 == 0 && hSimulateTrap != NULL)
|
|
SetEvent(hSimulateTrap);
|
|
|
|
|
|
// Indicate that Extension Agent processing was sucessfull.
|
|
|
|
|
|
#if 0
|
|
if (*errorStatus != SNMP_ERRORSTATUS_NOERROR)
|
|
{
|
|
return(FALSE);
|
|
}
|
|
|
|
return TRUE;
|
|
#endif
|
|
#endif
|
|
return SNMPAPI_NOERROR;
|
|
|
|
} // end SnmpExtensionQuery()
|
|
|
|
|
|
//-------------------------------- END --------------------------------------
|
|
|