/*++ BUILD Version: 0001 // Increment this if a change has global effects. Copyright (c) 1995 Microsoft Corporation Module Name : mib.c Abstract: This defines Auxiliary functions for defining an SNMP Extension Agent for collecting and querying Statistical information. Author: Murali R. Krishnan ( MuraliK ) 23-Feb-1995 Environment: User Mode -- Win32 Project: SNMP Extension DLL for HTTP Service DLL Functions Exported: UINT ResolveVarBinding(); UINT MibStatisticsWorker(); Revision History: --*/ # include "mib.h" static UINT MibLeafFunction( IN OUT RFC1157VarBind * pRfcVarBinding, IN UINT pduAction, IN struct _MIB_ENTRY * pMibeCurrent, IN struct _MIB_ENTRIES * pMibEntries, IN LPVOID pStatistics ); static UINT MibGetNextVar( IN OUT RFC1157VarBind * pRfcVarBinding, IN MIB_ENTRY * pMibeCurrent, IN MIB_ENTRIES * pMibEntries, IN LPVOID pStatistics ); static VOID PrintAsnObjectIdentifier( IN char * pszOidDescription, IN AsnObjectIdentifier * pAsno) { return; } // PrintAsnObjectIdentifier() UINT ResolveVarBinding( IN OUT RFC1157VarBind * pRfcVarBinding, IN BYTE pduAction, IN LPVOID pStatistics, IN LPMIB_ENTRIES pMibEntries ) /*++ Description: This function resolves a single variable binding. Modifies the variable on a GET or a GET-NEXT. Arguments: pRfcVarBinding pointer to RFC Variable Bindings pduAction Protocol Data Unit Action specified. pStatistics pointer to statisitcs data structure containing values of counter data. pMibEntries pointer to MIB_ENTRIES context information which contains prefix, array of MIB_ENTRIES and count of the entries. Returns: Standard PDU error codes. Note: --*/ { AsnObjectIdentifier AsnTempOid; LPMIB_ENTRY pMibScan; UINT pduResult = SNMP_ERRORSTATUS_NOERROR; LPMIB_ENTRY pMibUpperBound = pMibEntries->prgMibEntry + pMibEntries->cMibEntries; // // Search for the variable binding name in the mib. // for( pMibScan = pMibEntries->prgMibEntry; pMibScan < pMibUpperBound; pMibScan++) { int iCmpResult; // // Create a fully qualified OID for the current item in the MIB. // and use it for comparing against variable to be resolved. // SNMP_oidcpy( &AsnTempOid, pMibEntries->pOidPrefix); SNMP_oidappend( &AsnTempOid, &pMibScan->asnOid); iCmpResult = SNMP_oidcmp( &pRfcVarBinding->name, &AsnTempOid); SNMP_oidfree( &AsnTempOid); if ( iCmpResult == 0) { // // Found a match. Stop the search and process. // break; } else if ( iCmpResult < 0) { // // This could be the OID of a leaf ( withoug a trailing 0) or // it could contain an invalid OID ( between valid OIDs). // if ( pduAction == MIB_GETNEXT) { // // Advance the variable binding to next entry // SNMP_oidfree( &pRfcVarBinding->name); SNMP_oidcpy( &pRfcVarBinding->name, pMibEntries->pOidPrefix); SNMP_oidappend( &pRfcVarBinding->name, &pMibScan->asnOid); if ( ( pMibScan->bType != ASN_RFC1155_OPAQUE) && ( pMibScan->bType != ASN_SEQUENCE)) { pduAction = MIB_GET; } } else { pduResult = SNMP_ERRORSTATUS_NOSUCHNAME; } // // Stop and process the appropriate entry. // break; } // ( iCmpResult < 0) } // for if ( pMibScan >= pMibUpperBound) { pduResult = SNMP_ERRORSTATUS_NOSUCHNAME; } if ( pduResult == SNMP_ERRORSTATUS_NOERROR) { // // A match is found or further processing is required. // if ( pMibScan->pMibFunc == NULL) { // // This happens only if the match is for Group OID // pduResult = ( ( pduAction != MIB_GETNEXT) ? SNMP_ERRORSTATUS_NOSUCHNAME: MibGetNextVar( pRfcVarBinding, pMibScan, pMibEntries, pStatistics)); } else { pduResult = ( pMibScan->pMibFunc) ( pRfcVarBinding, pduAction, pMibScan, pMibEntries, pStatistics); } } return ( pduResult); } // ResolveVarBinding() UINT MibStatisticsWorker( IN OUT RFC1157VarBind * pRfcVarBinding, IN UINT pduAction, IN struct _MIB_ENTRY * pMibeCurrent, IN struct _MIB_ENTRIES * pMibEntries, IN LPVOID pStatistics ) /*++ This function resolves the variables assuming that there is statistical information ( sequence of counters) in the data passed in pStatistics. Arguments: pRfcVarBind pointer to RFC variable binding to be resolved. pduAction protocol data unit action to be taken. pMibeCurrent pointer to MIB_ENTRY which is o be used for resolution. pMibEntries pointer to MIB_ENTRIES structure to be used as context for resolving and performing the action. pStatistics pointer to sequence of counters used for data resolution. Returns: Standard PDU error codes. --*/ { UINT pduResult = SNMP_ERRORSTATUS_NOERROR; // default indicating action to be done at end of switch switch( pduAction) { case MIB_SET: case MIB_GETNEXT: // action is performed at the end of switch statement. break; case MIB_GETFIRST: case MIB_GET: // // If no statistics do no action. // If this is the header field ( non-leaf) do no action // Otherwise, perform action as if this is the leaf node. // if ( pStatistics == NULL || pMibeCurrent->lFieldOffset == -1) { pduResult = SNMP_ERRORSTATUS_GENERR; } // Action on this node is performed at the end of the switch statement. break; default: pduResult = SNMP_ERRORSTATUS_GENERR; break; } // switch() if ( pduResult == SNMP_ERRORSTATUS_NOERROR) { // // Use the generic leaf function to perform the action specified. // pduResult = MibLeafFunction( pRfcVarBinding, pduAction, pMibeCurrent, pMibEntries, pStatistics); } return ( pduResult); } // MibStatisticsWorker() static UINT MibLeafFunction( IN OUT RFC1157VarBind * pRfcVarBinding, IN UINT pduAction, IN struct _MIB_ENTRY * pMibeCurrent, IN struct _MIB_ENTRIES * pMibEntries, IN LPVOID pStatistics ) /*++ This function resolves the variables assuming that there is statistical information ( sequence of counters) in the data passed in pStatistics and that this is a leaf node of the MIB tree. This is a generic function for leaf nodes. Arguments: pRfcVarBind pointer to RFC variable binding to be resolved. pduAction protocol data unit action to be taken. pMibeCurrent pointer to MIB_ENTRY which is o be used for resolution. pMibEntries pointer to MIB_ENTRIES structure to be used as context for resolving and performing the action. pStatistics pointer to sequence of counters used for data resolution. Returns: Standard PDU error codes. --*/ { UINT pduResult = SNMP_ERRORSTATUS_NOSUCHNAME; // default is error value. switch( pduAction ) { case MIB_GETNEXT: // // Determine if we're within the range and not at the end. // If not within the range the above default pduResult == NOSUCHNAME // is the required error message. // if ( ( pMibeCurrent >= pMibEntries->prgMibEntry) && ( pMibeCurrent < ( pMibEntries->prgMibEntry + pMibEntries->cMibEntries))) { pduResult = MibGetNextVar( pRfcVarBinding, pMibeCurrent, pMibEntries, pStatistics); } break; case MIB_GETFIRST: case MIB_GET: // // Make sure that this variable's ACCESS is GET'able. // If the access prohibits from GETting it, report error as // NOSUCHNAME ( default value of pduResult in initialization above) // if(( pMibeCurrent->uiAccess == MIB_ACCESS_READ ) || ( pMibeCurrent->uiAccess == MIB_ACCESS_READWRITE ) ) { DWORD dwValue; // // Setup pRfcVarBinding's return value. // pRfcVarBinding->value.asnType = pMibeCurrent->bType; dwValue = *( (LPDWORD )((LPBYTE )pStatistics + pMibeCurrent->lFieldOffset)); pduResult = SNMP_ERRORSTATUS_NOERROR; // we found a value. switch( pMibeCurrent->bType) { case ASN_RFC1155_GAUGE: pRfcVarBinding->value.asnValue.gauge = (AsnGauge ) dwValue; break; case ASN_RFC1155_COUNTER: pRfcVarBinding->value.asnValue.counter = (AsnCounter ) dwValue; break; case ASN_INTEGER: pRfcVarBinding->value.asnValue.number = (AsnInteger ) dwValue; break; case ASN_RFC1155_IPADDRESS: case ASN_OCTETSTRING: // // Not supported for this MIB (yet). // Fall through to indicate generic error. // default: // // Sorry! Type in Mibe does not suit our purpose. // Indicate generic error. // pduResult = SNMP_ERRORSTATUS_GENERR; break; } // innner switch } // if ( valid read access) break; case MIB_SET: // // We don't support settable variables (yet). // Fall through for error. // default: pduResult = SNMP_ERRORSTATUS_GENERR; break; } // switch ( pduAction) return ( pduResult); } // MibLeafFunction() static UINT MibGetNextVar( IN OUT RFC1157VarBind * pRfcVarBinding, IN MIB_ENTRY * pMibeCurrent, IN MIB_ENTRIES * pMibEntries, IN LPVOID pStatistics) /*++ Description: This function sets the binding variable to iterate to the next variable. Arguments: pRfcVarBind pointer to RFC variable binding to be resolved. pMibeCurrent pointer to MIB_ENTRY which is o be used for resolution. pMibEntries pointer to MIB_ENTRIES structure to be used as context for resolving and performing the action. pStatistics pointer to sequence of counters used for data resolution. Returns: PDU Error Codes. --*/ { UINT pduResult = SNMP_ERRORSTATUS_NOSUCHNAME; LPMIB_ENTRY pMibUpperBound = pMibEntries->prgMibEntry + pMibEntries->cMibEntries; // // If within the range of MIB ENTRIES process. // if ( pMibeCurrent >= pMibEntries->prgMibEntry) { // // Scan through the remaining MIB Entries // LPMIB_ENTRY pMibeScan; for( pMibeScan = pMibeCurrent+1; pMibeScan < pMibUpperBound; pMibeScan++ ) { // // Setup variable bindings for the next MIB variable // SNMP_oidfree( &pRfcVarBinding->name); SNMP_oidcpy( &pRfcVarBinding->name, pMibEntries->pOidPrefix); SNMP_oidappend( &pRfcVarBinding->name, &pMibeScan->asnOid); // // If the function pointer is not NULL and the type of the MIB // variable is anything but OPAQUE, then call the function to // process the MIB variable. // if(( pMibeScan->pMibFunc != NULL ) && ( pMibeScan->bType != ASN_RFC1155_OPAQUE ) ) { pduResult = ( pMibeScan->pMibFunc)( pRfcVarBinding, MIB_GETFIRST, pMibeScan, pMibEntries, pStatistics); break; } // // On failure in the scan, pduResult will have default value // as initialized above in declaration. // } // for } return ( pduResult); } // MibGetNextVar()