mgmtapi.c

windows的snmp api源码

/*++

Routine Description:

    Cleanup session structure after processing response.

Arguments:

    pSMS - pointer to mgmtapi session structure.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = TRUE;
    SNMPAPI_STATUS status;

    // validate session ptr
    WSNMP_ASSERT(pSMS != NULL);

    // validate handle
    if (pSMS->hPdu != (HSNMP_PDU)NULL) {

        // free vbl
        FreeVbl(pSMS);

        // actually release pdu handle
        status = SnmpFreePdu(pSMS->hPdu);

        // validate return code
        if (WSNMP_FAILED(status)) {

            SNMPDBG((
                SNMP_LOG_ERROR,
                "MGMTAPI: SnmpFreePdu returned %d.\n",
                SnmpGetLastError(pSMS->hSnmpSession)
                ));

            // failure
            fOk = FALSE;
        }

        // re-initialize handle
        pSMS->hPdu = (HSNMP_PDU)NULL;
    }

    return fOk;
}


BOOL
CopyOid(
    AsnObjectIdentifier * pDstOID,
    smiLPOID              pSrcOID
    )

/*++

Routine Description:

    Copies object identifier from WinSNMP format to MGMTAPI format.

Arguments:

    pDstOID - points to MGMTAPI structure to receive OID.

    pSrcOID - points to WinSNMP structure to copy.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = FALSE;

    // validate pointers
    WSNMP_ASSERT(pDstOID != NULL);
    WSNMP_ASSERT(pSrcOID != NULL);
    WSNMP_ASSERT(pSrcOID->len != 0);
    WSNMP_ASSERT(pSrcOID->ptr != NULL);

    // store the number of subids
    pDstOID->idLength = pSrcOID->len;

    // allocate memory for subidentifiers
    pDstOID->ids = SnmpUtilMemAlloc(pDstOID->idLength * sizeof(DWORD));

    // validate pointer
    if (pDstOID->ids != NULL) {

        // transfer memory
        memcpy(pDstOID->ids,
               pSrcOID->ptr,
               pDstOID->idLength * sizeof(DWORD)
               );

        // success
        fOk = TRUE;
    }

    // now release memory for original oid
    SnmpFreeDescriptor(SNMP_SYNTAX_OID, (smiLPOPAQUE)pSrcOID);

    return fOk;
}


BOOL
CopyOctets(
    AsnOctetString * pDstOctets,
    smiLPOCTETS      pSrcOctets
    )

/*++

Routine Description:

    Copies octet string from WinSNMP format to MGMTAPI format.

Arguments:

    pDstOctets - points to MGMTAPI structure to receive octets.

    pSrcOctets - points to WinSNMP structure to copy.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = FALSE;
    SNMPAPI_STATUS status;

    // validate pointers
    WSNMP_ASSERT(pDstOctets != NULL);
    WSNMP_ASSERT(pSrcOctets != NULL);
    WSNMP_ASSERT(pSrcOctets->len != 0);
    WSNMP_ASSERT(pSrcOctets->ptr != NULL);

    // octet string allocated
    pDstOctets->dynamic = TRUE;

    // store the number of bytes
    pDstOctets->length = pSrcOctets->len;

    // allocate memory for octet string
    pDstOctets->stream = SnmpUtilMemAlloc(pDstOctets->length);

    // validate pointer
    if (pDstOctets->stream != NULL) {

        // transfer memory
        memcpy(pDstOctets->stream,
               pSrcOctets->ptr,
               pDstOctets->length
               );

        // success
        fOk = TRUE;
    }

    // now release memory for original string
    SnmpFreeDescriptor(SNMP_SYNTAX_OCTETS, (smiLPOPAQUE)pSrcOctets);

    return fOk;
}


CopyVb(
    PSNMP_MGR_SESSION pSMS,
    DWORD             iVarBind,
    SnmpVarBind *     pVarBind
    )

/*++

Routine Description:

    Copy variable binding from WinSNMP structure to MGMTAPI structure.

Arguments:

    pSMS - pointer to mgmtapi session structure.

    iVarBind - index of varbind structure to copy.

    pVarBind - pointer to varbind structure.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = FALSE;
    SNMPAPI_STATUS status;
    smiOID tmpOID;
    smiVALUE tmpValue;

    // validate session ptr
    WSNMP_ASSERT(pSMS != NULL);
    WSNMP_ASSERT(pVarBind != NULL);

    // attempt to retrieve varbind data from winsnmp structure
    status = SnmpGetVb(pSMS->hVbl, iVarBind, &tmpOID, &tmpValue);

    // validate return code
    if (WSNMP_SUCCEEDED(status)) {

        // transfer object identifier value
        fOk = CopyOid(&pVarBind->name, &tmpOID);

        // syntax values are equivalent
        pVarBind->value.asnType = (BYTE)(smiINT32)tmpValue.syntax;

        // determine syntax
        switch (tmpValue.syntax) {

        case SNMP_SYNTAX_INT32:

            // transfer signed int
            pVarBind->value.asnValue.number = tmpValue.value.sNumber;
            break;

        case SNMP_SYNTAX_UINT32:
        case SNMP_SYNTAX_CNTR32:
        case SNMP_SYNTAX_GAUGE32:
        case SNMP_SYNTAX_TIMETICKS:

            // transfer unsigned int
            pVarBind->value.asnValue.unsigned32 = tmpValue.value.uNumber;
            break;

        case SNMP_SYNTAX_CNTR64:

            // transfer 64-bit counter
            pVarBind->value.asnValue.counter64.LowPart =
                tmpValue.value.hNumber.lopart;
            pVarBind->value.asnValue.counter64.HighPart =
                tmpValue.value.hNumber.hipart;
            break;

        case SNMP_SYNTAX_OPAQUE:
        case SNMP_SYNTAX_IPADDR:
        case SNMP_SYNTAX_OCTETS:
        case SNMP_SYNTAX_BITS:

            // transfer octet string
            if (!CopyOctets(&pVarBind->value.asnValue.string,
                            &tmpValue.value.string)) {

                // re-initialize
                pVarBind->value.asnType = ASN_NULL;

                // failure
                fOk = FALSE;
            }

            break;

        case SNMP_SYNTAX_OID:

            // transfer object identifier
            if (!CopyOid(&pVarBind->value.asnValue.object,
                         &tmpValue.value.oid)) {

                // re-initialize
                pVarBind->value.asnType = ASN_NULL;

                // failure
                fOk = FALSE;
            }

            break;

        case SNMP_SYNTAX_NULL:
        case SNMP_SYNTAX_NOSUCHOBJECT:
        case SNMP_SYNTAX_NOSUCHINSTANCE:
        case SNMP_SYNTAX_ENDOFMIBVIEW:

            break; // do nothing...

        default:

            SNMPDBG((
                SNMP_LOG_ERROR,
                "MGMTAPI: SnmpGetVb returned invalid type.\n"
                ));

            // re-initialize
            pVarBind->value.asnType = ASN_NULL;

           // failure
            fOk = FALSE;

            break;
        }

    } else {

        SNMPDBG((
            SNMP_LOG_ERROR,
            "MGMTAPI: SnmpGetVb returned %d.\n",
            SnmpGetLastError(pSMS->hSnmpSession)
            ));
    }

    return fOk;
}


BOOL
CopyVbl(
    PSNMP_MGR_SESSION pSMS,
    SnmpVarBindList * pVarBindList
    )

/*++

Routine Description:

    Copy variable bindings from WinSNMP structure to MGMTAPI structure.

Arguments:

    pSMS - pointer to mgmtapi session structure.

    pVarBindList - pointer to varbind list structure.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = TRUE;

    // validate session ptr
    WSNMP_ASSERT(pSMS != NULL);
    WSNMP_ASSERT(pVarBindList != NULL);

    // initialize
    pVarBindList->len  = 0;
    pVarBindList->list = NULL;

    // validate varbind list handle
    if (pSMS->hVbl != (HSNMP_VBL)NULL) {

        // determine number of varbinds
        pVarBindList->len = SnmpCountVbl(pSMS->hVbl);

        // validate number of varbinds
        if (WSNMP_SUCCEEDED(pVarBindList->len)) {

            // allocate memory for varbinds
            pVarBindList->list = SnmpUtilMemAlloc(
                                    pVarBindList->len *
                                    sizeof(SnmpVarBind)
                                    );

            // validate pointer
            if (pVarBindList->list != NULL) {

                DWORD cVarBind = 1;
                SnmpVarBind * pVarBind;

                // save pointer to varbinds
                pVarBind = pVarBindList->list;

                // process varbinds in the list
                while (fOk && (cVarBind <= pVarBindList->len)) {

                    // copy varbind from winsnmp to mgmtapi
                    fOk = CopyVb(pSMS, cVarBind++, pVarBind++);
                }

            } else {

                SNMPDBG((
                    SNMP_LOG_ERROR,
                    "MGMTAPI: Could not allocate VBL.\n"
                    ));

                // re-initialize
                pVarBindList->len = 0;

                // failure
                fOk = FALSE;
            }

        } else if (pVarBindList->len != SNMPAPI_NOOP) {

            SNMPDBG((
                SNMP_LOG_ERROR,
                "MGMTAPI: SnmpCountVbl returned %s.\n",
                SnmpGetLastError(pSMS->hSnmpSession)
                ));

            // re-initialize
            pVarBindList->len = 0;

            // failure
            fOk = FALSE;
        }
    }

    if (!fOk) {

        // cleanup any varbinds allocated
        SnmpUtilVarBindListFree(pVarBindList);
    }

    return fOk;
}


BOOL
ParseVbl(
    PSNMP_MGR_SESSION pSMS,
    PTRAP_LIST_ENTRY  pTLE
    )

/*++

Routine Description:

    Parse varbind list for trap-related varbinds.

Arguments:

    pSMS - pointer to MGMTAPI session structure.

    pTLE - pointer to trap list entry.

Return Values:

    Returns true if successful.

--*/

{
    BOOL fOk = FALSE;
    SnmpVarBind * pVarBind;
    AsnObjectIdentifier * pOID;
    AsnNetworkAddress   * pAgentAddress = NULL;
    AsnObjectIdentifier * pEnterpriseOID = NULL;

    // object identifiers to convert snmpv2 trap format
    static UINT _sysUpTime[]             = { 1, 3, 6, 1, 2, 1, 1, 3       };
    static UINT _snmpTrapOID[]           = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 1 };
    static UINT _snmpAddress[]           = { 1, 3, 6, 1, 3, 1057, 1       };
    static UINT _snmpTrapEnterprise[]    = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 3 };
    static UINT _snmpTraps[]             = { 1, 3, 6, 1, 6, 3, 1, 1, 5    };

    static AsnObjectIdentifier sysUpTime          = DEFINE_OID(_sysUpTime);
    static AsnObjectIdentifier snmpTrapOID        = DEFINE_OID(_snmpTrapOID);
    static AsnObjectIdentifier snmpAddress        = DEFINE_OID(_snmpAddress);
    static AsnObjectIdentifier snmpTrapEnterprise = DEFINE_OID(_snmpTrapEnterprise);
    static AsnObjectIdentifier snmpTraps          = DEFINE_OID(_snmpTraps);

    // validate pointers
    WSNMP_ASSERT(pSMS != NULL);
    WSNMP_ASSERT(pTLE != NULL);

    // validate vbl have minimum entries
    if (pTLE->VarBindList.len >= MINVARBINDLEN) {

        // point to sysUpTime varbind structure
        pVarBind = &pTLE->VarBindList.list[SYSUPTIMEINDEX];

        // verify variable is sysUpTime
        if ((pVarBind->value.asnType == ASN_TIMETICKS) &&
            !SnmpUtilOidNCmp(&pVarBind->name,
                             &sysUpTime,
                             sysUpTime.idLength)) {

            // transfer sysUpTime value to trap entry
            pTLE->TimeStamp = pVarBind->value.asnValue.ticks;

        } else {

            SNMPDBG((
                SNMP_LOG_ERROR,
                "MGMTAPI: Could not find sysUpTime.\n"
                ));

            goto cleanup; // bail...
        }

        // see if any additional varbinds present
        if (pTLE->VarBindList.len > MINVARBINDLEN) {

            // point to snmpTrapEnterprise varbind structure (maybe)
            pVarBind = &pTLE->VarBindList.list[pTLE->VarBindList.len - 1];

            // verify variable is snmpTrapEnterprise
            if ((pVarBind->value.asnType == ASN_OBJECTIDENTIFIER) &&
                !SnmpUtilOidNCmp(&pVarBind->name,
                                 &snmpTrapEnterprise,
                                 snmpTrapEnterprise.idLength))  {

                // transfer enterprise oid to list entry
                pTLE->EnterpriseOID = pVarBind->value.asnValue.object;

                // store enterprise oid for later
                pEnterpriseOID = &pTLE->EnterpriseOID;

                // modify type to avoid deallocation
                pVarBind->value.asnType = ASN_NULL;

            } else {

                SNMPDBG((
                    SNMP_LOG_TRACE,
                    "MGMTAPI: Could not find snmpTrapEnterprise.\n"
                    ));
            }
        }

        // see if the agent address is present
        if (pTLE->VarBindList.len > MINVARBINDLEN+1) {