windows-server-2003/com/ole32/dcomss/olescm/excladdr.cxx

//+-------------------------------------------------------------------
//
//  File:       excladdr.cxx
//
//  Contents:   Implements classes for managing the current address 
//              exclusion list
//
//  Classes:    CAddrExclusionMgr 
//
//  History:    07-Oct-00   jsimmons      Created
//--------------------------------------------------------------------

#include "act.hxx"


// The single instance of this object
CAddrExclusionMgr gAddrExclusionMgr;

CAddrExclusionMgr::CAddrExclusionMgr() :
                _dwNumStrings(0),
                _ppszStrings(NULL),
                _bInitRegistry(FALSE)
{
}

// 
// GetExclusionList
//
// Returns the current exclusion list.
//
HRESULT CAddrExclusionMgr::GetExclusionList(
                DWORD* pdwNumStrings,
                LPWSTR** pppszStrings)
{
    gpClientLock->LockExclusive();

    // Handle easy case
    if (_dwNumStrings == 0)
    {
        *pdwNumStrings = 0;
        *pppszStrings = NULL;
        gpClientLock->UnlockExclusive();
        return S_OK;
    }

    DWORD i;
    DWORD dwCopiedStrings;
    LPWSTR* ppszCopiedStrings;      

    ppszCopiedStrings = (LPWSTR*)MIDL_user_allocate(sizeof(WCHAR*) * _dwNumStrings);
    if (!ppszCopiedStrings)
    {
        gpClientLock->UnlockExclusive();
        return E_OUTOFMEMORY;
    }

    dwCopiedStrings = 0;
    for (i = 0; i < _dwNumStrings; i++)
    {
        if (_ppszStrings[i])
        {
            ppszCopiedStrings[i] = (LPWSTR)MIDL_user_allocate(
            sizeof(WCHAR) * (lstrlen(_ppszStrings[i]) + 1));
            if (!ppszCopiedStrings[i])
            {
                // failure in the middle.  cleanup previous allocations and return
                for (i = 0; i < _dwNumStrings; i++)
                {
                    if (ppszCopiedStrings[i])
                        MIDL_user_free(ppszCopiedStrings[i]);
                }
                MIDL_user_free(ppszCopiedStrings);
                gpClientLock->UnlockExclusive();
                return E_OUTOFMEMORY;
            }

            lstrcpy(ppszCopiedStrings[i], _ppszStrings[i]);
            dwCopiedStrings++;
        }
    }

    *pdwNumStrings = dwCopiedStrings;
    *pppszStrings = ppszCopiedStrings;

    gpClientLock->UnlockExclusive();

    return S_OK;
}

// 
// SetExclusionList
//
// Sets the current exclusion list, and pushes the
// new bindings to all current running processes 
// registered with COM.
//
HRESULT CAddrExclusionMgr::SetExclusionList(
                DWORD dwNumStrings,
                LPWSTR* ppszStrings)
{
    HRESULT hr = S_OK;
    RPC_STATUS status;
    DWORD i, j;
    LPWSTR* ppszStringsNew = NULL;

    gpClientLock->LockExclusive();

    if (dwNumStrings > 0)
    {
        ppszStringsNew = (LPWSTR*)PrivMemAlloc(sizeof(WCHAR*) * dwNumStrings);
        if (!ppszStringsNew)
        {
            gpClientLock->UnlockExclusive();
            return E_OUTOFMEMORY;
        }

        for (i = 0; i < dwNumStrings; i++)
        {
            // Skip any null entries.  Assert in debug builds since
            // this is likely a sign of a broken app
            ASSERT(ppszStrings[i]);
            if (!ppszStrings[i])
                continue;

            ppszStringsNew[i] = (LPWSTR)PrivMemAlloc(
            sizeof(WCHAR) * (lstrlen(ppszStrings[i]) + 1));
            if (!ppszStringsNew[i])
            {
                // free up any earlier allocations that succeeded
                for (j = 0; j < i; j++)
                    PrivMemFree(ppszStringsNew[j]);

                PrivMemFree(ppszStringsNew);

                gpClientLock->UnlockExclusive();

                // and return error
                return E_OUTOFMEMORY;
            }

            lstrcpy(ppszStringsNew[i], ppszStrings[i]);
        }
    }

    // Get rid of the old list
    FreeCurrentBuffers();

    // Save off the new one
    _dwNumStrings = dwNumStrings;
    _ppszStrings = ppszStringsNew;

    // Recompute the bindings
    status = ComputeNewResolverBindings();
    if (status != RPC_S_OK)
    {
        hr = E_OUTOFMEMORY;
    }

    gpClientLock->UnlockExclusive();

    if (status == RPC_S_OK)
    {
        // Update currently running processes   
        PushCurrentBindings();
    }

    return hr;
}

// 
// EnableDisableDynamicTracking
//
// Turns on\off the dynamic address binding feature, and updates
// the registry key accordingly.
//
HRESULT CAddrExclusionMgr::EnableDisableDynamicTracking(BOOL fEnable)
{
    HRESULT hr = S_OK;
    LONG error;
    HKEY hOle;
    WCHAR* szY = L"Y";
    WCHAR* szN = L"N";

    gpClientLock->LockExclusive();

    // Open the registry key and change the value
    error = RegOpenKeyEx(HKEY_LOCAL_MACHINE, 
                         L"SOFTWARE\\Microsoft\\OLE", 
                         NULL, 
                         KEY_WRITE,
                         &hOle);
    if (error == ERROR_SUCCESS)
    {   
        error = RegSetValueEx(hOle,
                              L"EnableSystemDynamicIPTracking",
                              0,
                              REG_SZ,
                              (BYTE*)(fEnable ? szY : szN),
                              4); // 4 = one wchar + null
        if (error == ERROR_SUCCESS)
        {
            // Reset the global.  Will be seen immediately
            gbDynamicIPChangesEnabled = fEnable ? TRUE : FALSE;
        }
        else
        {
            hr = HRESULT_FROM_WIN32(GetLastError());
        }

        CloseHandle(hOle);
    }
    else
    {
        hr = HRESULT_FROM_WIN32(GetLastError());
    }

    gpClientLock->UnlockExclusive();

    return hr;
}


//
//  IsExcludedAddress
//
//  Checks to see if the specified address is in our
//  current exclusion list.
//
BOOL CAddrExclusionMgr::IsExcludedAddress(LPWSTR pszAddress)
{
    DWORD i;

    ASSERT(gpClientLock->HeldExclusive());
    ASSERT(_ppszStrings);

    for (i = 0; i < _dwNumStrings; i++)
    {       
        if (_ppszStrings[i])
        {
            if (lstrcmpi(_ppszStrings[i], pszAddress) == 0)
            {
                // found it in the list
                return TRUE;
            }
        }
    }
    return FALSE;
}

// 
// BuildExclusionDSA
//
// Constructs a new dsa and puts it in *ppdsaOut; the new 
// dsa is the same as pdsaSrc, minus any addresses that are
// currently in the exclusion list.
//
HRESULT CAddrExclusionMgr::BuildExclusionDSA(                                                                                   
                                DUALSTRINGARRAY* pdsaSrc,
                                DUALSTRINGARRAY** ppdsaOut
                                )
{
    ASSERT(pdsaSrc && ppdsaOut);
    ASSERT(dsaValid(pdsaSrc));

    ASSERT(gpClientLock->HeldExclusive());

    SCMVDATEHEAP();

    DWORD i;
    BOOL bDone;
    USHORT* pStart;
    USHORT* pCurrent;
    USHORT* pCurrentNew;
    DWORD dwBindingsToExclude = 0;
    USHORT usNewDSALen = 0;
    DUALSTRINGARRAY* pdsaNew;
    BOOL* afIsExcludedAddress;

    *ppdsaOut = NULL;

    // If our list is empty, nothing to do
    if (_dwNumStrings == 0)
        return dsaAllocateAndCopy(ppdsaOut, pdsaSrc);

    // Allocate an array of bools on the stack.  This 
    // will be used to remember if an address is excluded
    // or not on the first pass, so we don't have to be
    // figure that out again on the second pass.
    //
    // Note that I will almost always allocate too much stack
    // memory -- better that than not enough.   To be exact
    // I'd have to make an extra pass thru the dsa to see how 
    // many string bindings there are - which sorta defeats
    // the purpose.
    afIsExcludedAddress = (BOOL*)_alloca(sizeof(BOOL) * pdsaSrc->wSecurityOffset);

    // First make one pass thru the incoming dsa to 
    // see how many addresses we should retain, and
    // calculate how much space they will need.
    bDone = FALSE;
    pStart = pCurrent = &(pdsaSrc->aStringArray[0]);
    i = 0;
    do
    {
        // Find end of the current string binding.  Be careful
        // to handle cases where there are no string bindings.
        while (*pCurrent != 0)
            pCurrent++;

        if ((i > 0) && (pCurrent == pStart) ||
            ((i == 0) && (*(pCurrent+1) == 0)))
        {
            // either found a zero after the previous
            // binding, or we found two zeroes in a row
            // at the beginning of pdsaSrc->aStringArray.
            bDone = TRUE;
        }
        else
        {               
            i++;  // count total # of strings found

            STRINGBINDING* psb = (STRINGBINDING*)pStart;

            // We only exclude addresses if they are using tcp
            if (psb->wTowerId == ID_TCP &&
                IsExcludedAddress(&(psb->aNetworkAddr)))
            {
                dwBindingsToExclude++;
                afIsExcludedAddress[i] = TRUE;
            }
            else
            {
                // Add string len plus 2 (space for towerid + null terminator)
                usNewDSALen = usNewDSALen + (USHORT) (lstrlen(&(psb->aNetworkAddr)) + 2);
                afIsExcludedAddress[i] = FALSE;
            }
            // advance to next string binding
            pCurrent++; 
            pStart = pCurrent;
        }
    } while (!bDone);

    // If there are no addresses that need excluding, just copy
    // and return the incoming bindings.
    if (dwBindingsToExclude == 0)
        return dsaAllocateAndCopy(ppdsaOut, pdsaSrc);

    // If we didn't find any string bindings to use at all, then we 
    // need to manually add a word for the initial NULL.
    if (usNewDSALen == 0)
        usNewDSALen = 1;

    // Add space for wNumEntries + wSecurityOffset
    usNewDSALen += (sizeof(USHORT) * 2);

    // Add size of all security bindings
    usNewDSALen += ((pdsaSrc->wNumEntries - pdsaSrc->wSecurityOffset));

    // Add one for the string bindings terminating NULL.
    usNewDSALen++;

    // Allocate the memory
    pdsaNew = (DUALSTRINGARRAY*)MIDL_user_allocate(usNewDSALen * sizeof(USHORT));
    if (!pdsaNew)
        return E_OUTOFMEMORY;

    ZeroMemory(pdsaNew, usNewDSALen * sizeof(USHORT));

    // Set length
    pdsaNew->wNumEntries = usNewDSALen - 2; // don't count wNumEntries\wSecOffset

    // Initialize ptr into the new dsa
    pCurrentNew = &(pdsaNew->aStringArray[0]);

    // If we are excluding all of the string bindings in pdsaSrc, then 
    // there's no need to make a second pass
    if (dwBindingsToExclude == i)
    {
        // No string bindings left at all.  Not a very useful 
        // situation.  Need to add the initial NULL:
        *pCurrentNew = NULL;
        pCurrentNew++;
    }
    else
    {
        // Make a second pass, copying the non-excluded addresses
        // over to the new dsa as we go.
        bDone = FALSE;
        pStart = pCurrent = &(pdsaSrc->aStringArray[0]);
        i = 0;          
        do              
        {
            // Find end of the current string binding
            while (*pCurrent != 0)
                pCurrent++;

            if ((i > 0) && (pCurrent == pStart) ||
                ((i == 0) && (*(pCurrent+1) == 0)))
            {
                // either found a zero after the previous
                // binding, or we found two zeroes in a row
                // at the beginning of pdsaSrc->aStringArray.
                bDone = TRUE;
            }
            else
            {
                i++;  // count total # of strings found

                if (!afIsExcludedAddress[i]) // remembered from first pass above
                {
                    STRINGBINDING* psb = (STRINGBINDING*)pStart;
                    STRINGBINDING* psbNew = (STRINGBINDING*)pCurrentNew;

                    // Copy tower id
                    psbNew->wTowerId = psb->wTowerId;
                    // Copy address
                    lstrcpy(&(psbNew->aNetworkAddr), &(psb->aNetworkAddr));
                    // Move cursor for new dsa (2=towerid + null terminator)
                    pCurrentNew += (2 + lstrlen(&(psbNew->aNetworkAddr)));
                }
                pCurrent++;
                pStart = pCurrent;
            }
        } while (!bDone);
    }

    // Add final null terminator for string bindings
    *pCurrentNew = NULL;   // points to after last string binding, NULL it out
    pCurrentNew++;         // now points to first security binding

    // Set security offset
    pdsaNew->wSecurityOffset = (unsigned short)(pCurrentNew - &(pdsaNew->aStringArray[0]));

    // Copy security bindings en masse
    memcpy(pCurrentNew, 
    &(pdsaSrc->aStringArray[pdsaSrc->wSecurityOffset]),
    (pdsaSrc->wNumEntries - pdsaSrc->wSecurityOffset) * sizeof(USHORT));

    ASSERT(dsaValid(pdsaNew));

    // Success
    *ppdsaOut = pdsaNew;

    SCMVDATEHEAP();

    return S_OK;
}

//
//  InitializeFromRegistry
//  
//  Reads initial address list from registry.  Can only
//  be called once, after that subsequent calls will be
//  ignored.
//
void CAddrExclusionMgr::InitializeFromRegistry()
{
    ASSERT(gpClientLock->HeldExclusive());  

    if (_bInitRegistry)
        return;

    _bInitRegistry = TRUE; // this is it, success or fail

    // UNDONE -- if we wanted to, we could support persisting
    // the exclusion list in the registry, and read it out
    // here shortly after boot.

    return;
}

// Private function, no lock needed
void CAddrExclusionMgr::FreeCurrentBuffers()
{
    ASSERT((_dwNumStrings == 0 && _ppszStrings == 0) ||
           (_dwNumStrings != 0 && _ppszStrings != 0));

    DWORD i;

    for (i = 0; i < _dwNumStrings; i++)
    {
        PrivMemFree(_ppszStrings[i]);
    }

    if (_ppszStrings)
        PrivMemFree(_ppszStrings);

    _dwNumStrings = 0;
    _ppszStrings = NULL;

    return;
}