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Separate 'get a handle' code from 'open/allocate an ADAPTER' code
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@bonsaiviking
bonsaiviking committed Apr 8, 2022
1 parent 97ddf24 commit e9eccab
Showing 1 changed file with 104 additions and 79 deletions.
183 changes: 104 additions & 79 deletions packetWin7/Dll/Packet32.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1041,6 +1041,7 @@ static PCHAR WChar2SChar(LPCWCH string)
without performing a copy. This function tries to increase the size of that buffer.
NOTE: this function is used for NPF adapters, only.
Npcap NOTE: This may no longer be necessary. Testing required.
*/

BOOLEAN PacketSetMaxLookaheadsize (LPADAPTER AdapterObject)
Expand Down Expand Up @@ -1413,39 +1414,93 @@ BOOL PacketStartService()
return Result;
}

/*!
\brief Opens an adapter using the NPF device driver.
\param AdapterName A string containing the name of the device to open.
\return If the function succeeds, the return value is the pointer to a properly initialized ADAPTER object,
otherwise the return value is NULL.
\note internal function used by PacketOpenAdapter() and AddAdapter()
*/
_Use_decl_annotations_
LPADAPTER PacketOpenAdapterNPF(PCCH AdapterNameA)
static HANDLE PacketGetAdapterHandle(PCCH AdapterNameA)
{
DWORD error;
LPADAPTER lpAdapter;

CHAR SymbolicLinkA[MAX_PATH];
CHAR SymbolicLinkA[MAX_PATH] = {0};
HRESULT hrStatus = S_OK;
DWORD err = ERROR_SUCCESS;
HANDLE hFile = INVALID_HANDLE_VALUE;

// Create the NPF device name from the original device name
TRACE_ENTER();

TRACE_PRINT1("Trying to open adapter %hs", AdapterNameA);

#define DEVICE_PREFIX "\\Device\\"

if (strlen(AdapterNameA) <= strlen(DEVICE_PREFIX))
{
TRACE_PRINT("Device name too short.");
TRACE_EXIT();
SetLastError(ERROR_INVALID_NAME);
return INVALID_HANDLE_VALUE;
}
hrStatus = StringCchPrintfA(SymbolicLinkA, MAX_PATH, "\\\\.\\Global\\%s", AdapterNameA + strlen(DEVICE_PREFIX));
if (FAILED(hrStatus))
{
TRACE_PRINT1("Failed to format symbolic link: %08x", hrStatus);
TRACE_EXIT();
// STRSAFE_E_INSUFFICIENT_BUFFER
SetLastError(ERROR_BUFFER_OVERFLOW);
return INVALID_HANDLE_VALUE;
}

// Start the driver service and/or Helper if needed
// Though don't bother if we already have a valid pipe to NpcapHelper
if (g_hNpcapHelperPipe == INVALID_HANDLE_VALUE)
PacketStartService();

// Try NpcapHelper to request handle if we are in Non-Admin mode.
if (NpcapIsAdminOnlyMode())
{
PacketStartService();
if (NpcapIsAdminOnlyMode())
if (g_hNpcapHelperPipe == INVALID_HANDLE_VALUE)
{
// NpcapHelper Initialization, used for accessing the driver with Administrator privilege.
NpcapStartHelper();
if (g_hNpcapHelperPipe == INVALID_HANDLE_VALUE)
{
err = GetLastError();
TRACE_PRINT("Could not contact NpcapHelper");
TRACE_EXIT();
SetLastError(err);
return INVALID_HANDLE_VALUE;
}
}
hFile = NpcapRequestHandle(SymbolicLinkA, &err);
TRACE_PRINT1("Driver handle from NpcapHelper = %08x", hFile);
if (hFile == INVALID_HANDLE_VALUE)
{
TRACE_PRINT1("ErrorCode = %d", err);
SetLastError(err);
return INVALID_HANDLE_VALUE;
}
}
else
{
// Try if it is possible to open the adapter immediately
hFile = CreateFileA(SymbolicLinkA, GENERIC_WRITE | GENERIC_READ,
0, NULL, OPEN_EXISTING, 0, 0);
err = GetLastError();
TRACE_PRINT2("SymbolicLinkA = %hs, hFile = %08x", SymbolicLinkA, hFile);
}
TRACE_EXIT();
SetLastError(err);
return hFile;
}

/*!
\brief Opens an adapter using the NPF device driver.
\param AdapterName A string containing the name of the device to open.
\return If the function succeeds, the return value is the pointer to a properly initialized ADAPTER object,
otherwise the return value is NULL.
\note internal function used by PacketOpenAdapter() and AddAdapter()
*/
_Use_decl_annotations_
LPADAPTER PacketOpenAdapterNPF(PCCH AdapterNameA)
{
DWORD error;
LPADAPTER lpAdapter;

TRACE_ENTER();

lpAdapter=(LPADAPTER)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(ADAPTER));
if (lpAdapter==NULL)
Expand All @@ -1459,84 +1514,49 @@ LPADAPTER PacketOpenAdapterNPF(PCCH AdapterNameA)

lpAdapter->NumWrites=1;

#define DEVICE_PREFIX "\\Device\\"
lpAdapter->hFile = PacketGetAdapterHandle(AdapterNameA);

if (strlen(AdapterNameA) > strlen(DEVICE_PREFIX))
{
StringCchPrintfA(SymbolicLinkA, MAX_PATH, "\\\\.\\Global\\%s", AdapterNameA + strlen(DEVICE_PREFIX));
}
else
{
ZeroMemory(SymbolicLinkA, sizeof(SymbolicLinkA));
}

/* }*/

//
// NOTE GV 20061114 This is a sort of breaking change. In the past we were putting what
// we could fit inside this variable. Now we simply put NOTHING. It's just useless
//
ZeroMemory(lpAdapter->SymbolicLink, sizeof(lpAdapter->SymbolicLink));

// Try NpcapHelper to request handle if we are in Non-Admin mode.
if (g_hNpcapHelperPipe != INVALID_HANDLE_VALUE)
{
//try if it is possible to open the adapter immediately
DWORD dwErrorReceived;
lpAdapter->hFile = NpcapRequestHandle(SymbolicLinkA, &dwErrorReceived);
TRACE_PRINT1("Driver handle from NpcapHelper = %08x", lpAdapter->hFile);
do {
error=GetLastError();
if (lpAdapter->hFile == INVALID_HANDLE_VALUE)
{
TRACE_PRINT1("ErrorCode = %d", dwErrorReceived);
SetLastError(dwErrorReceived);
TRACE_PRINT("PacketOpenAdapterNPF: Failed to get adapter handle");
break;
}
}
else
{
// Try if it is possible to open the adapter immediately
lpAdapter->hFile = CreateFileA(SymbolicLinkA, GENERIC_WRITE | GENERIC_READ,
0, NULL, OPEN_EXISTING, 0, 0);
TRACE_PRINT2("SymbolicLinkA = %hs, lpAdapter->hFile = %08x", SymbolicLinkA, lpAdapter->hFile);
}

if (lpAdapter->hFile != INVALID_HANDLE_VALUE)
{

if(PacketSetReadEvt(lpAdapter)==FALSE){
if(!PacketSetReadEvt(lpAdapter)) {
error=GetLastError();
TRACE_PRINT("PacketOpenAdapterNPF: Unable to open the read event");
if (lpAdapter->hFile != NULL)
CloseHandle(lpAdapter->hFile);
HeapFree(GetProcessHeap(), 0, lpAdapter);
//set the error to the one on which we failed

TRACE_PRINT1("PacketOpenAdapterNPF: PacketSetReadEvt failed, LastError=%8.8x",error);
TRACE_EXIT();


SetLastError(error);
return NULL;
}

PacketSetMaxLookaheadsize(lpAdapter);
break;
}

if (!PacketSetMaxLookaheadsize(lpAdapter)) {
error=GetLastError();
TRACE_PRINT("PacketOpenAdapterNPF: Unable to set lookahead");
break;
}
//
// Indicate that this is a device managed by NPF.sys
//
lpAdapter->Flags = INFO_FLAG_NDIS_ADAPTER;


StringCchCopyA(lpAdapter->Name, ADAPTER_NAME_LENGTH, AdapterNameA);
if (FAILED(StringCchCopyA(lpAdapter->Name, ADAPTER_NAME_LENGTH, AdapterNameA)))
{
error = ERROR_BUFFER_OVERFLOW;
TRACE_PRINT("PacketOpenAdapterNPF: Unable to copy adapter name");
break;
}

TRACE_PRINT("Successfully opened adapter");
TRACE_EXIT();
return lpAdapter;
}
} while (FALSE);

TRACE_PRINT1("PacketOpenAdapterNPF: LastError= %8.8x",error);
PacketCloseAdapter(lpAdapter);

error=GetLastError();
HeapFree(GetProcessHeap(), 0, lpAdapter);
//set the error to the one on which we failed
TRACE_PRINT1("PacketOpenAdapterNPF: CreateFile failed, LastError= %8.8x",error);
TRACE_EXIT();
SetLastError(error);
return NULL;
Expand Down Expand Up @@ -1929,9 +1949,14 @@ VOID PacketCloseAdapter(LPADAPTER lpAdapter)
}
else
{
SetEvent(lpAdapter->ReadEvent);
CloseHandle(lpAdapter->ReadEvent);
CloseHandle(lpAdapter->hFile);
if (lpAdapter->ReadEvent != NULL) {
SetEvent(lpAdapter->ReadEvent);
CloseHandle(lpAdapter->ReadEvent);
lpAdapter->ReadEvent = NULL;
}
if (lpAdapter->hFile != INVALID_HANDLE_VALUE && lpAdapter->hFile != NULL) {
CloseHandle(lpAdapter->hFile);
}
HeapFree(GetProcessHeap(), 0, lpAdapter);
}

Expand Down

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