/*****************************************************************************
 *
 * $Workfile: SnmpMgr.cpp $
 *
 * Copyright (C) 1997 Hewlett-Packard Company.
 * Copyright (C) 1997 Microsoft Corporation.
 * All rights reserved.
 *
 * 11311 Chinden Blvd.
 * Boise, Idaho 83714
 *
 *****************************************************************************/

#include "precomp.h"

#include "stdoids.h"
#include "snmpmgr.h"


///////////////////////////////////////////////////////////////////////////////
//  CSnmpMgr::CSnmpMgr()

CSnmpMgr::CSnmpMgr() :
                    m_pAgent(NULL), m_pCommunity(NULL),m_pSession(NULL),
                    m_iLastError(NO_ERROR), m_iRetries(DEFAULT_RETRIES),
                    m_iTimeout(DEFAULT_TIMEOUT),
                    m_bRequestType(DEFAULT_SNMP_REQUEST)
{
}   // ::CSnmpMgr()


///////////////////////////////////////////////////////////////////////////////
//  CSnmpMgr::CSnmpMgr() -- establishes a session w/ a given agent
//          uses the default request type (get) & community name (public)

CSnmpMgr::CSnmpMgr( const char  in  *pHost,
                    const char  in  *pCommunity,
                    DWORD           dwDevIndex ) :
                        m_pAgent(NULL), m_pCommunity(NULL),m_pSession(NULL),
                        m_iLastError(NO_ERROR), m_iRetries(DEFAULT_RETRIES),
                        m_iTimeout(DEFAULT_TIMEOUT),
                        m_bRequestType(DEFAULT_SNMP_REQUEST)
{
    size_t cchAgent = strlen(pHost) + 1;
    m_pAgent = (LPSTR)SNMP_malloc(cchAgent * sizeof m_pAgent [0]);      // copy the agent
    if( m_pAgent != NULL )
    {
        StringCchCopyA (m_pAgent, cchAgent, pHost);
    }
    size_t cchCommunity = strlen(pCommunity) + 1;
    m_pCommunity = (LPSTR)SNMP_malloc(cchCommunity * sizeof m_pCommunity [0]);  // copy the community name
    if( m_pCommunity != NULL )
    {
        StringCchCopyA (m_pCommunity, cchCommunity, pCommunity);
    }

    m_bRequestType = DEFAULT_SNMP_REQUEST;      // set the default request type == GET request

    m_pSession = NULL;
    if ( !Open() )              // establish a session w/ the agent
    {
        m_iLastError = GetLastError();
    }

}   // ::CSnmpMgr()


                                                        ///////////////////////////////////////////////////////////////////////////////
//  CSnmpMgr::CSnmpMgr() -- establishes a session w/ a given agent
//          uses the default request type (get) & community name (public)

CSnmpMgr::CSnmpMgr( const char          in  *pHost,
                    const char          in  *pCommunity,
                    DWORD               in  dwDevIndex,
                    AsnObjectIdentifier in  *pMibObjId,
                    RFC1157VarBindList  out *pVarBindList) :
                        m_pAgent(NULL), m_pCommunity(NULL),m_pSession(NULL),
                        m_iLastError(NO_ERROR), m_iRetries(DEFAULT_RETRIES),
                        m_iTimeout(DEFAULT_TIMEOUT),
                        m_bRequestType(DEFAULT_SNMP_REQUEST)
{
    DWORD   dwRetCode = SNMPAPI_NOERROR;

    size_t cchAgent = strlen(pHost) + 1;
    m_pAgent = (LPSTR)SNMP_malloc(cchAgent * sizeof m_pAgent [0]);      // copy the agent
    if( m_pAgent != NULL )
    {
        StringCchCopyA (m_pAgent, cchAgent, pHost);
    }
    size_t cchCommunity = strlen(pCommunity) + 1;
    m_pCommunity = (LPSTR)SNMP_malloc(cchCommunity * sizeof m_pCommunity [0]);  // copy the community name
    if( m_pCommunity != NULL )
    {
        StringCchCopyA (m_pCommunity, cchCommunity, pCommunity);
    }

    m_bRequestType = DEFAULT_SNMP_REQUEST;      // set the default request type == GET request

    dwRetCode = BldVarBindList(pMibObjId, pVarBindList);
    if (dwRetCode == SNMPAPI_NOERROR)
    {
        m_pSession = NULL;
        if ( !Open() )              // establish a session w/ the agent
        {
            m_iLastError = GetLastError();
        }
    }

}   // ::CSnmpMgr()


///////////////////////////////////////////////////////////////////////////////
//  CSnmpMgr::~CSnmpMgr()

CSnmpMgr::~CSnmpMgr()
{
    if (m_pSession)     Close();    // close the session

    // delete the allocated memory from community & agent names
    if (m_pAgent)       SNMP_free(m_pAgent);
    if (m_pCommunity)   SNMP_free(m_pCommunity);

}   // ::~CSnmpMgr()


///////////////////////////////////////////////////////////////////////////////
//  Open() -- establishes a session
//      Error Codes:
//          SNMPAPI_NOERROR if successful
//          SNMPAPI_ERROR if fails

BOOL
CSnmpMgr::Open()
{
    m_iLastError = SNMPAPI_NOERROR;

    m_pSession = SnmpMgrOpen(m_pAgent, m_pCommunity, m_iTimeout, m_iRetries);
    if ( m_pSession == NULL )
    {
        m_iLastError = SNMPAPI_ERROR;
        m_pSession = NULL;
        return FALSE;
    }

    return TRUE;

}   // ::Open()


///////////////////////////////////////////////////////////////////////////////
//  Close() -- closes the previously established session

void
CSnmpMgr::Close()
{
    _ASSERTE( m_pSession != NULL);

    if ( !SnmpMgrClose(m_pSession) )
    {
        m_iLastError = GetLastError();
    }
    m_pSession = NULL;

}   // ::Close()


///////////////////////////////////////////////////////////////////////////////
//  Get() -- does an SNMP command (m_bRequestType) given a set of OIDs
//      Error Codes:
//              SNMP_ERRORSTATUS_NOERROR    if no error
//              SNMP_ERRORSTATUS_TOOBIG if the packet returned is big
//              SNMP_ERRORSTATUS_NOSUCHNAME if the OID isn't supported
//              SNMP_ERRORSTATUS_BADVALUE
//              SNMP_ERRORSTATUS_READONLY
//              SNMP_ERRORSTATUS_GENERR
//              SNMP_MGMTAPI_TIMEOUT        -- set by GetLastError()
//              SNMP_MGMTAPI_SELECT_FDERRORS    -- set by GetLastError()

int
CSnmpMgr::Get( RFC1157VarBindList   in  *pVariableBindings)
{
    int iRetCode = SNMP_ERRORSTATUS_NOERROR;

    AsnInteger  errorStatus;
    AsnInteger  errorIndex;

    if ( !SnmpMgrRequest( m_pSession, m_bRequestType, pVariableBindings, &errorStatus, &errorIndex) )
    {
        iRetCode = m_iLastError = GetLastError();
    }
    else
    {
        if (errorStatus > 0)
        {
            iRetCode = errorStatus;
        }
        else    // return the result of the variable bindings?
        {
            // variableBindings->list[x]->value contains the return value
        }
    }

    return iRetCode;

}   // ::Get()


///////////////////////////////////////////////////////////////////////////////
//  Walk -- given an object, it walks until the tree is done
//      Error Codes:
//              SNMP_ERRORSTATUS_TOOBIG if the packet returned is big
//              SNMP_ERRORSTATUS_NOSUCHNAME if the OID isn't supported
//              SNMP_ERRORSTATUS_BADVALUE
//              SNMP_ERRORSTATUS_READONLY
//              SNMP_ERRORSTATUS_GENERR
//              SNMP_MGMTAPI_TIMEOUT        -- set by GetLastError()
//              SNMP_MGMTAPI_SELECT_FDERRORS    -- set by GetLastError()

int
CSnmpMgr::Walk( RFC1157VarBindList  inout  *pVariableBindings)
{
    int iRetCode = SNMP_ERRORSTATUS_NOERROR;
    RFC1157VarBindList  variableBindings;
    UINT    numElements=0;
    LPVOID  pTemp;

    variableBindings.len = 0;
    variableBindings.list = NULL;

    variableBindings.len++;
    if ( (variableBindings.list = (RFC1157VarBind *)SNMP_realloc(variableBindings.list,
            sizeof(RFC1157VarBind) * variableBindings.len)) == NULL)
    {
        iRetCode = ERROR_NOT_ENOUGH_MEMORY;
        return iRetCode;
    }

    if ( !SnmpUtilVarBindCpy(&(variableBindings.list[variableBindings.len -1]), &(pVariableBindings->list[0])) )
    {
        iRetCode = ERROR_NOT_ENOUGH_MEMORY;
        return iRetCode;
    }

    AsnObjectIdentifier root;
    AsnObjectIdentifier tempOid;
    AsnInteger  errorStatus;
    AsnInteger  errorIndex;

    if (!SnmpUtilOidCpy(&root, &variableBindings.list[0].name))
    {
        iRetCode = ERROR_NOT_ENOUGH_MEMORY;
        goto CleanUp;
    }

    m_bRequestType = ASN_RFC1157_GETNEXTREQUEST;
    while(1)        // walk the MIB tree (or sub-tree)
    {
        if (!SnmpMgrRequest(m_pSession, m_bRequestType, &variableBindings,
                        &errorStatus, &errorIndex))
        {
            // The API is indicating an error.
            iRetCode = m_iLastError = GetLastError();
            break;
        }
        else
        {
            // The API succeeded, errors may be indicated from the remote agent.
            // Test for end of subtree or end of MIB.
            if (errorStatus == SNMP_ERRORSTATUS_NOSUCHNAME ||
                        SnmpUtilOidNCmp(&variableBindings.list[0].name, &root, root.idLength))
            {
                iRetCode = SNMP_ERRORSTATUS_NOSUCHNAME;
                break;
            }

            // Test for general error conditions or sucesss.
            if (errorStatus > 0)
            {
                iRetCode = errorStatus;
                break;
            }
            numElements++;
        } // end if()

        // append the variableBindings to the pVariableBindings
        _ASSERTE(pVariableBindings->len != 0);
        if ( ( pTemp = (RFC1157VarBind *)SNMP_realloc(pVariableBindings->list,
                sizeof(RFC1157VarBind) * (pVariableBindings->len + 1))) == NULL)
        {
            iRetCode = ERROR_NOT_ENOUGH_MEMORY;
            break;
        }
        else
        {
            pVariableBindings->list = (SnmpVarBind *)pTemp;
            pVariableBindings->len++;
        }

        if ( !SnmpUtilVarBindCpy(&(pVariableBindings->list[pVariableBindings->len -1]), &(variableBindings.list[0])) )
        {
            iRetCode = ERROR_NOT_ENOUGH_MEMORY;
            break;
        }

        // Prepare for the next iteration.  Make sure returned oid is
        // preserved and the returned value is freed
        if( SnmpUtilOidCpy(&tempOid, &variableBindings.list[0].name) )
        {
            SnmpUtilVarBindFree(&variableBindings.list[0]);

            if ( SnmpUtilOidCpy(&variableBindings.list[0].name, &tempOid))
            {
                variableBindings.list[0].value.asnType = ASN_NULL;

                SnmpUtilOidFree(&tempOid);
            }
            else
            {
                iRetCode = SNMP_ERRORSTATUS_GENERR;
                goto CleanUp;
            }
        }
        else
        {
            iRetCode = SNMP_ERRORSTATUS_GENERR;
            goto CleanUp;
        }


    } // end while()

CleanUp:
    // Free the variable bindings that have been allocated.
    SnmpUtilVarBindListFree(&variableBindings);
    SnmpUtilOidFree(&root);

    if (iRetCode == SNMP_ERRORSTATUS_NOSUCHNAME)
        if (numElements != 0)   // list is full; iRetCode indicates the end of the MIB
            iRetCode = SNMP_ERRORSTATUS_NOERROR;

    return (iRetCode);

}   // Walk()


///////////////////////////////////////////////////////////////////////////////
//  WalkNext -- given object(s), it walks until the table has no more object
//      entries. The end of the table is determined by the first item in the list.
//      Error Codes:
//              SNMP_ERRORSTATUS_TOOBIG if the packet returned is big
//              SNMP_ERRORSTATUS_NOSUCHNAME if the OID isn't supported
//              SNMP_ERRORSTATUS_BADVALUE
//              SNMP_ERRORSTATUS_READONLY
//              SNMP_ERRORSTATUS_GENERR
//              SNMP_MGMTAPI_TIMEOUT        -- set by GetLastError()
//              SNMP_MGMTAPI_SELECT_FDERRORS    -- set by GetLastError()

int
CSnmpMgr::WalkNext( RFC1157VarBindList  inout  *pVariableBindings)
{
    int iRetCode = SNMP_ERRORSTATUS_NOERROR;
    RFC1157VarBindList  variableBindings;
    UINT    numElements=0;
    UINT    len=0, i=0;
    LPVOID  pTemp;

    variableBindings.len = 0;
    variableBindings.list = NULL;

    variableBindings.len = pVariableBindings->len;
    if ( (variableBindings.list = (RFC1157VarBind *)SNMP_realloc(variableBindings.list,
            sizeof(RFC1157VarBind) * variableBindings.len)) == NULL)
    {
        iRetCode = ERROR_NOT_ENOUGH_MEMORY;
        return iRetCode;
    }

    for (i=0; i<variableBindings.len; i++)
    {
        if ( !SnmpUtilVarBindCpy(&(variableBindings.list[i]), &(pVariableBindings->list[i])) )
        {
            iRetCode = ERROR_NOT_ENOUGH_MEMORY;
            return iRetCode;
        }
    }

    AsnObjectIdentifier root;
    AsnObjectIdentifier tempOid;
    AsnInteger  errorStatus;
    AsnInteger  errorIndex;

    if (!SnmpUtilOidCpy(&root, &variableBindings.list[0].name))
    {
        iRetCode = ERROR_NOT_ENOUGH_MEMORY;
        goto CleanUp;
    }


    m_bRequestType = ASN_RFC1157_GETNEXTREQUEST;
    while(1)        // get the object(s) in the MIB table
    {
        if (!SnmpMgrRequest(m_pSession, m_bRequestType, &variableBindings,
                        &errorStatus, &errorIndex))
        {
            // The API is indicating an error.
            iRetCode = m_iLastError = GetLastError();
            break;
        }
        else
        {
            // The API succeeded, errors may be indicated from the remote agent.
            // Test for end of subtree or end of MIB.
            if (errorStatus == SNMP_ERRORSTATUS_NOSUCHNAME ||
                        SnmpUtilOidNCmp(&variableBindings.list[0].name, &root, root.idLength))
            {
                iRetCode = SNMP_ERRORSTATUS_NOSUCHNAME;
                break;
            }

            // Test for general error conditions or sucesss.
            if (errorStatus > 0)
            {
                iRetCode = errorStatus;
                break;
            }
            numElements++;
        } // end if()

        // append the variableBindings to the pVariableBindings
        _ASSERTE(pVariableBindings->len != 0);
        len = pVariableBindings->len;
        if ( (pTemp = (RFC1157VarBind *)SNMP_realloc(pVariableBindings->list,
                sizeof(RFC1157VarBind) * (pVariableBindings->len + variableBindings.len))) == NULL)
        {
            iRetCode = ERROR_NOT_ENOUGH_MEMORY;
            break;
        }
        else
        {
            pVariableBindings->list = (SnmpVarBind *)pTemp;
            pVariableBindings->len += variableBindings.len;
        }

        int j=0;
        for ( i=len; i < pVariableBindings->len; i++, j++)
        {
            if ( !SnmpUtilVarBindCpy(&(pVariableBindings->list[i]), &(variableBindings.list[j])) )
            {
                iRetCode = ERROR_NOT_ENOUGH_MEMORY;
                break;
            }
        }

        // Prepare for the next iteration.  Make sure returned oid is
        // preserved and the returned value is freed
        for (i=0; i<variableBindings.len; i++)
        {
            if ( SnmpUtilOidCpy(&tempOid, &variableBindings.list[i].name) )
            {
                SnmpUtilVarBindFree(&variableBindings.list[i]);
                if( SnmpUtilOidCpy(&variableBindings.list[i].name, &tempOid))
                {
                    variableBindings.list[i].value.asnType = ASN_NULL;
                    SnmpUtilOidFree(&tempOid);
                }
                else
                {
                    iRetCode = SNMP_ERRORSTATUS_GENERR;
                    goto CleanUp;
                }
            }
            else
            {
                iRetCode = SNMP_ERRORSTATUS_GENERR;
                goto CleanUp;
            }

        }

    } // end while()

CleanUp:
    // Free the variable bindings that have been allocated.
    SnmpUtilVarBindListFree(&variableBindings);
    SnmpUtilOidFree(&root);

    if (iRetCode == SNMP_ERRORSTATUS_NOSUCHNAME)
        if (numElements != 0)   // list is full; iRetCode indicates the end of the MIB
            iRetCode = SNMP_ERRORSTATUS_NOERROR;

    return (iRetCode);

}   // WalkNext()


///////////////////////////////////////////////////////////////////////////////
//  GetNext -- does an SNMP GetNext command on the set of OID(s)
//      Error Codes:
//              SNMP_ERRORSTATUS_TOOBIG if the packet returned is big
//              SNMP_ERRORSTATUS_NOSUCHNAME if the OID isn't supported
//              SNMP_ERRORSTATUS_BADVALUE
//              SNMP_ERRORSTATUS_READONLY
//              SNMP_ERRORSTATUS_GENERR
//              SNMP_MGMTAPI_TIMEOUT        -- set by GetLastError()
//              SNMP_MGMTAPI_SELECT_FDERRORS    -- set by GetLastError()

int
CSnmpMgr::GetNext(  RFC1157VarBindList  inout  *pVariableBindings)
{
    int iRetCode = SNMP_ERRORSTATUS_NOERROR;
    AsnInteger  errorStatus;
    AsnInteger  errorIndex;

    m_bRequestType = ASN_RFC1157_GETNEXTREQUEST;

    if ( !SnmpMgrRequest( m_pSession, m_bRequestType, pVariableBindings, &errorStatus, &errorIndex) )
    {
        iRetCode = m_iLastError = GetLastError();
    }
    else
    {
        if (errorStatus > 0)
        {
            iRetCode = errorStatus;
        }
        else    // return the result of the variable bindings?
        {
            // variableBindings->list[x]->value contains the return value
        }
    }

    return (iRetCode);

}   // GetNext()


///////////////////////////////////////////////////////////////////////////////
//  BldVarBindList -- given a category, it retuns the RFC1157VarBindList
//      Error Codes:
//          NO_ERROR if successful
//          ERROR_NOT_ENOUGH_MEMORY     if memory allocation failes
//          ERROR_INVALID_HANDLE        if can't build the variable bindings

DWORD
CSnmpMgr::BldVarBindList( AsnObjectIdentifier in     *pMibObjId,        // group identifier
                          RFC1157VarBindList  inout  *pVarBindList)
{
    DWORD   dwRetCode = SNMPAPI_NOERROR;
    LPVOID  pTemp;

    m_iLastError = SNMPAPI_NOERROR;
    while (pMibObjId->idLength != 0)
    {
        // setup the variable bindings
        CONST UINT uNewLen = pVarBindList->len + 1;
        if ( (pTemp = (RFC1157VarBind *)SNMP_realloc(pVarBindList->list,
                sizeof(RFC1157VarBind) * uNewLen)) == NULL)
        {
            m_iLastError = ERROR_NOT_ENOUGH_MEMORY;
            return ERROR_NOT_ENOUGH_MEMORY;
        }
        else
        {
            pVarBindList->list = (SnmpVarBind *)pTemp;
            pVarBindList-> len = uNewLen;
        }

        AsnObjectIdentifier reqObject;
        if ( !SnmpUtilOidCpy(&reqObject, pMibObjId) )
        {
            m_iLastError = ERROR_INVALID_HANDLE;
            return ERROR_INVALID_HANDLE;
        }

        pVarBindList->list[pVarBindList->len -1].name = reqObject;
        pVarBindList->list[pVarBindList->len -1].value.asnType = ASN_NULL;

        pMibObjId++;
    }

    return dwRetCode;

}   // BldVarBindList