Get the name of the connected wifi connection every 4 seconds - c++

I use the following function to get the name of the connected WiFi connection. The function is called repeatedly every 4 seconds to monitor connection changes. But after a while, the function no longer works as before, and fails returning false.
bool GetConnectedConnectionsName(wstring connection_names[50], int& number)
{
HANDLE h_client = NULL;
DWORD dwMaxClient = 2;
DWORD dwCurVersion = 0;
DWORD result = 0;
DWORD dwRetVal = 0;
int iRet = 0;
WCHAR GuidString[39] = { 0 };
unsigned int i, j, k;
PWLAN_INTERFACE_INFO_LIST p_if_list = NULL;
PWLAN_INTERFACE_INFO p_if_info = NULL;
PWLAN_AVAILABLE_NETWORK_LIST p_bss_list = NULL;
PWLAN_AVAILABLE_NETWORK p_bss_entry = NULL;
int iRSSI = 0;
result = WlanOpenHandle(dwMaxClient, NULL, &dwCurVersion, &h_client);
if (result != ERROR_SUCCESS)
{
if (p_bss_list != NULL)
WlanFreeMemory(p_bss_list);
if (p_if_list != NULL)
WlanFreeMemory(p_if_list);
return false;
}
result = WlanEnumInterfaces(h_client, NULL, &p_if_list);
if (result != ERROR_SUCCESS)
{
if (p_bss_list != NULL)
WlanFreeMemory(p_bss_list);
if (p_if_list != NULL)
WlanFreeMemory(p_if_list);
return false;
}
for (i = 0; i < (int)p_if_list->dwNumberOfItems; i++)
{
p_if_info = (WLAN_INTERFACE_INFO*)&p_if_list->InterfaceInfo[i];
result = WlanGetAvailableNetworkList(h_client,
&p_if_info->InterfaceGuid,
0,
NULL,
&p_bss_list);
if (result != ERROR_SUCCESS)
{
if (p_bss_list != NULL)
WlanFreeMemory(p_bss_list);
if (p_if_list != NULL)
WlanFreeMemory(p_if_list);
return false;
}
else
{
number = 0;
for (j = 0; j < p_bss_list->dwNumberOfItems; j++)
{
p_bss_entry = (WLAN_AVAILABLE_NETWORK*)&p_bss_list->Network[j];
if (p_bss_entry->dwFlags && (p_bss_entry->dwFlags & WLAN_AVAILABLE_NETWORK_CONNECTED))
{
connection_names[number] = wstring(p_bss_entry->strProfileName);
number++;
}
}
}
}
if (p_bss_list != NULL)
WlanFreeMemory(p_bss_list);
if (p_if_list != NULL)
WlanFreeMemory(p_if_list);
return true;
}
What's wrong, and how can I solve the problem?

Related

get the default string using EvtFormatMessage

I am trying to get the base string in the DLL using EvtFormatMessage but no matter what I do its not working. The windows help page made it sound like you can use the values and valuecount parameters to change the default behavior but when I change them nothing is printed.
Another attempt I made was to go through the publishers metadata and match it with the correct eventId and version but the EvtOpenEventMetadatEnum has no items for it to iterate through for all events publishers. It works for time change events but not for other events.
This is the code I have to return the message string. hMetadata is the publisher metadata and hEvent is the event metadata
LPWSTR GetMessageString(EVT_HANDLE hMetadata, EVT_HANDLE hEvent, EVT_FORMAT_MESSAGE_FLAGS FormatId, DWORD MsgID)
{
LPWSTR pBuffer = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status = ERROR_SUCCESS;
if (!fpEvtFormatMessage(hMetadata, hEvent, MsgID, 0, NULL, FormatId, dwBufferSize, pBuffer, &dwBufferUsed))
{
status = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status)
{
// An event can contain one or more keywords. The function returns keywords
// as a list of keyword strings. To process the list, you need to know the
// size of the buffer, so you know when you have read the last string, or you
// can terminate the list of strings with a second null terminator character
// as this example does.
if ((EvtFormatMessageKeyword == FormatId))
pBuffer[dwBufferSize - 1] = L'\0';
else
dwBufferSize = dwBufferUsed;
pBuffer = (LPWSTR)malloc(dwBufferSize * sizeof(WCHAR));
if (pBuffer)
{
fpEvtFormatMessage(hMetadata, hEvent, MsgID, 0, NULL, FormatId, dwBufferSize, pBuffer, &dwBufferUsed);
// Add the second null terminator character.
if ((EvtFormatMessageKeyword == FormatId))
pBuffer[dwBufferUsed - 1] = L'\0';
}
else
{
TRACE5(_T("malloc failed\n"));
}
}
else if (ERROR_EVT_MESSAGE_NOT_FOUND == status || ERROR_EVT_MESSAGE_ID_NOT_FOUND == status)
;
else
{
TRACE5(_T("EvtFormatMessage failed with %u\n"), status);
}
}
This is the code that is supposed to match the event I have with the template event in the dll
hEvents = fpEvtOpenEventMetadataEnum(g_hMetadata, 0);
if (NULL == hEvents)
{
TRACE5(_T("EvtOpenEventMetadataEnum failed with %lu\n"), GetLastError());
goto cleanup;
}
// Enumerate the events and print each event's metadata.
while (run)
{
hEvent = fpEvtNextEventMetadata(hEvents, 0);
if (NULL == hEvent)
{
if (ERROR_NO_MORE_ITEMS != (status = GetLastError()))
{
TRACE5(_T("EvtNextEventMetadata failed with %lu\n"), status);
}
break;
}
msgId = getEventID(g_hMetadata, hEvent, &tempVersion);
if (dwMsgID == msgId && tempVersion == version) {
PEVT_VARIANT pProperty = NULL; // Contains a metadata value
PEVT_VARIANT pTemp = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status2 = ERROR_SUCCESS;
if (!fpEvtGetEventMetadataProperty(hEvent, EventMetadataEventMessageID, 0, dwBufferSize, pProperty, &dwBufferUsed))
{
status2 = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status2)
{
dwBufferSize = dwBufferUsed;
pTemp = (PEVT_VARIANT)realloc(pProperty, dwBufferSize);
if (pTemp)
{
pProperty = pTemp;
pTemp = NULL;
fpEvtGetEventMetadataProperty(hEvent, EventMetadataEventMessageID, 0, dwBufferSize, pProperty, &dwBufferUsed);
}
else
{
TRACE5(_T("realloc failed\n"));
status2 = ERROR_OUTOFMEMORY;
goto cleanup;
}
}
if (ERROR_SUCCESS != (status2 = GetLastError()))
{
TRACE5(_T("EvtGetEventMetadataProperty failed with %d\n"), GetLastError());
goto cleanup;
}
}
if (-1 == pProperty->UInt32Val)
{
*pStrNonExpLibMsg = "Message string: \n";
}
else
{
*pStrNonExpLibMsg = GetMessageString(g_hMetadata, NULL, EvtFormatMessageId, pProperty->UInt32Val);
if (pMessage)
{
free(pMessage);
}
}
run = false;
break;
}
fpEvtClose(hEvent);
hEvent = NULL;
}
cleanup:
if (hEvents)
fpEvtClose(hEvents);
if (hEvent)
fpEvtClose(hEvent);
return status;
}
DWORD getEventID(EVT_HANDLE g_hMetadata, EVT_HANDLE hEvent, DWORD *evtVersion)
{
PEVT_VARIANT pProperty = NULL; // Contains a metadata value
PEVT_VARIANT pTemp = NULL;
DWORD dwBufferSize = 0;
DWORD dwBufferUsed = 0;
DWORD status = ERROR_SUCCESS;
DWORD retValue = NULL;
// Get the specified metadata property. If the pProperty buffer is not big enough, reallocate the buffer.
for (int i = 0; i < 2; i++)
{
if (!fpEvtGetEventMetadataProperty(hEvent, (EVT_EVENT_METADATA_PROPERTY_ID)i, 0, dwBufferSize, pProperty, &dwBufferUsed))
{
status = GetLastError();
if (ERROR_INSUFFICIENT_BUFFER == status)
{
dwBufferSize = dwBufferUsed;
pTemp = (PEVT_VARIANT)realloc(pProperty, dwBufferSize);
if (pTemp)
{
pProperty = pTemp;
pTemp = NULL;
fpEvtGetEventMetadataProperty(hEvent, (EVT_EVENT_METADATA_PROPERTY_ID)i, 0, dwBufferSize, pProperty, &dwBufferUsed);
}
else
{
TRACE5(_T("realloc failed\n"));
status = ERROR_OUTOFMEMORY;
goto cleanup;
}
}
if (ERROR_SUCCESS != (status = GetLastError()))
{
TRACE5(_T("EvtGetEventMetadataProperty failed with %d\n"), GetLastError());
goto cleanup;
}
}
if (i == 0)
{
retValue = pProperty->UInt32Val;
}
else
{
*evtVersion = pProperty->UInt32Val;
}
RtlZeroMemory(pProperty, dwBufferUsed);
}

Printing from a process spawned from a service on Windows 2008 server

The short version:
I have written a small program to print a report. This program is exec'ed from our proprietary server, that is running as a windows service. It works in our development environment, but not on our customer's network.
When I attempt to access the printing system in the failing case, I get a "No default printer" error. We had the customer create a new login account that has a default printer defined, and restarted the server using that login account. Same error.
Note that this error is generated when trying to find a specified printer, not when we try to print to it.
Is there any way to convince a server-spawned process that printers do, in fact, exist?
The long version:
In our "current" production environment, we have the following:
1. a proprietary server that runs as a service under windows.
2. a desktop client
--> accesses data via that service
--> uses fastreport4 to generate reports
--> developed using C++Builder6 (and VCL)
3. a PocketPC-based application that runs on scanning devices
--> uses Apache to communicate with the service
--> also uses Apache to poke a cgi-bin application that will bring up
the desktop app in stealth mode, run a report, and print it.
I have been tasked with re-implementing the Pocket-PC functionality on an Android-based scanning device, and removing the Apache layer from the architecture. In the Android app, I've written a communication layer to access the server (service) directly (the same way the desktop does). The server has the ability to exec applications, so I've written a small one to just gather data, and call fastreport to format and print it.
Works great. No problem. ... in our development environment. It works in our office network with the server running on a Windows 7 system. It works when run from the command line on our customer's Windows 2008 server. It does not work when run from the service on the customer's server.
So here's the code. In my current revision, I have try/catch and debug print statements around (nearly) every line of code. I removed them for readability.
bool __fastcall TFormReportRunner::mySetPrinter(const char* name)
{
char pDevice[MAX_PATH];
char pDriver[MAX_PATH];
char APort[100];
UINT ADeviceMode;
bool printerFound = false;
bool errorFound = false;
String PrinterPort = String(name).UpperCase();
TPrinter* Prntr;
// I added this bit to see if it helps. Seems to make no difference
bool rc = SetDefaultPrinter("");
Prntr = Printer();
if (Prntr == NULL)
{
LogErrorMsg("Printer() returned null.");
return false;
}
int i = Prntr->Printers->Count - 1;
for (; i >= 0; i--)
{
// In the failing case, this next statement is the one that causes an exception.
Prntr->PrinterIndex = i;
Prntr->GetPrinter(pDevice, pDriver, APort, ADeviceMode);
DWORD SizeNeeded = 0;
HANDLE PrinterHandle;
if (OpenPrinter(pDevice, &PrinterHandle, NULL) == 0)
{
LogErrorMsg("Could not open printer");
return false;
}
GetPrinter(PrinterHandle, 2, NULL, 0, &SizeNeeded);
if (SizeNeeded == 0)
{
ClosePrinter(PrinterHandle);
LogErrorMsg("Could not retrieve printer info size");
return false;
}
PRINTER_INFO_2 PrinterInfo2;
char* buffer = new char[SizeNeeded];
if (GetPrinter(PrinterHandle, 2, buffer, SizeNeeded, &SizeNeeded) == 0)
{
ClosePrinter(PrinterHandle);
delete [] buffer;
LogErrorMsg("Could not retrieve printer info");
return false;
}
String PortName = ((PRINTER_INFO_2*)buffer)->pPortName;
delete [] buffer;
ClosePrinter(PrinterHandle);
if (PrinterPort == PortName)
{
frxReport1->PrintOptions->Printer = pDevice;
break;
}
}
Prntr->PrinterIndex = i;
return true;
}
One of the customer's IT guys says that in order to have the Apache version work they have to run Apache as administrator with a defined default printer AND have that admin account logged in for printing to work. He suspects that if we run our service in the same configuration it will start to work. I have not been able to replicate that on our network. My admin account always works, whether anyone is currently logged into the system, or not. But this is Windows 7/Professional, and not a server version.
This has got to be possible... Apache's doing it. If it can find a printer and print to it, I should be able to, right?
Any hints or help will be greatly appreciated. Anything. Really. :)
Thanks,
-Karen
Edit: Adding server-side code.
A couple of notes, first. One, this was written 20-ish years ago (by someone else). Two, it is NOT a VCL app (and was compiled with the Microsoft compiler). Three, we will not change it. Recompiling with current compilers is WAY too risky for something that is otherwise working.
int myServer::RunProcess2(ClientCall *call, vector<string> &args, vector<string> &env, const char* input, unsigned int insize,
string *output, string *error)
{
CancelProcess2(); // only one process allowed per connection
string cmdline;
for (unsigned int i = 0; i < args.size(); i++)
{
if (i != 0)
cmdline += ' ';
cmdline += args[i];
}
env.push_back(EnvPATH);
int size = 1;
for (unsigned int i = 0; i < env.size(); i++)
{
size += env[i].size() + 1;
}
char *environment = (char*)malloc(size);
if (environment == NULL)
{
call->error = "Could not allocate memory for process environment variables";
return 0;
}
char *ptr = environment;
for (unsigned int i = 0; i < env.size(); i++)
{
size = env[i].size() + 1;
memcpy(ptr, env[i].c_str(), size);
ptr += size;
}
ptr[0] = '\0';
HANDLE hInputReadPipe = NULL, hInputWritePipe = NULL;
HANDLE hReadPipe, hWritePipe;
HANDLE hErrorReadPipe, hErrorWritePipe;
SECURITY_ATTRIBUTES sa;
sa.nLength = sizeof(sa);
sa.lpSecurityDescriptor = NULL;
sa.bInheritHandle = true;
// create output pipe
if (CreatePipe(&hReadPipe, &hWritePipe, &sa, 4096) == 0)
{
free(environment);
call->error = "Error creation Pipe";
return 0;
}
// create error pipe
if (CreatePipe(&hErrorReadPipe, &hErrorWritePipe, &sa, 4096) == 0)
{
CloseHandle(hReadPipe);
CloseHandle(hWritePipe);
free(environment);
call->error = "Error creating Pipe";
return 0;
}
if (insize > 0)
{
// create input pipe
if (CreatePipe(&hInputReadPipe, &hInputWritePipe, &sa, 4096) == 0)
{
CloseHandle(hReadPipe);
CloseHandle(hWritePipe);
CloseHandle(hErrorReadPipe);
CloseHandle(hErrorWritePipe);
free(environment);
call->error = "Error creating Pipe";
return 0;
}
}
STARTUPINFO si;
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
si.wShowWindow = SW_HIDE;
si.hStdOutput = hWritePipe;
si.hStdError = hErrorWritePipe;
si.hStdInput = hInputReadPipe;
PROCESS_INFORMATION pi;
if (CreateProcess(NULL, (char*)cmdline.c_str(), NULL, NULL, true, 0, environment, NULL, &si, &pi) == 0)
{
CloseHandle(hErrorReadPipe);
CloseHandle(hErrorWritePipe);
CloseHandle(hReadPipe);
CloseHandle(hWritePipe);
if (hInputReadPipe != NULL)
{
CloseHandle(hInputReadPipe);
CloseHandle(hInputWritePipe);
}
free(environment);
call->error = string("Error executing command: ") + cmdline + "\n" + GetErrorText();
return 0;
}
report_handle = pi.hProcess;
CloseHandle(hErrorWritePipe);
CloseHandle(hWritePipe);
if (hErrorReadPipe != NULL)
CloseHandle(hInputReadPipe);
char buffer[4097];
DWORD BytesAvail;
DWORD BytesRead = 0;
DWORD BytesWritten = 0;
DWORD BytesToRead = sizeof(buffer) - 1;
DWORD BytesToWrite = insize;
bool finished_readpipe = false, finished_errorpipe = false;
bool finished_inputpipe = (insize == 0);
int wait_time = 1;
bool error_occurred = false;
while (finished_readpipe == false || finished_errorpipe == false || finished_inputpipe == false)
{
if (finished_inputpipe == false)
{
if (BytesToWrite <= 0)
{
CloseHandle(hInputWritePipe);
hInputWritePipe = NULL;
finished_inputpipe = true;
continue;
}
BytesAvail = 1000;
/*if (PeekNamedPipe(hInputWritePipe, NULL, NULL, NULL, &BytesAvail, NULL) == 0)
{
DWORD temp = GetLastError();
// pipe has been closed
finished_inputpipe = true;
continue;
}*/
if (BytesAvail > 0)
{
if (BytesAvail > BytesToWrite)
BytesAvail = BytesToWrite;
if (WriteFile(hInputWritePipe, input, BytesAvail, &BytesWritten, NULL) == 0)
{
if (GetLastError() == ERROR_NO_DATA)
{
int a = 2; // Pipe was closed (normal exit path).
}
finished_inputpipe = true;
continue;
}
input += BytesWritten;
BytesToWrite -= BytesWritten;
if (BytesToWrite == 0)
{
finished_inputpipe = true;
}
continue;
}
}
if (finished_readpipe == false)
{
while (true)
{
if (PeekNamedPipe(hReadPipe, NULL, NULL, NULL, &BytesAvail, NULL) == 0)
{
// pipe has been closed
finished_readpipe = true;
break;
}
if (BytesAvail <= 0)
break;
if (BytesAvail > sizeof(buffer) - 1)
BytesAvail = sizeof(buffer) - 1;
if (ReadFile(hReadPipe, buffer, BytesAvail, &BytesRead, NULL) == 0)
{
finished_readpipe = true;
break;
}
if (BytesRead == 0)
{
finished_readpipe = true;
break;
}
buffer[BytesRead] = '\0';
*output += buffer;
if (output->length() >= MAX_PROCESS_OUTPUT)
{
finished_inputpipe = true;
finished_readpipe = true;
finished_errorpipe = true;
error_occurred = true;
call->error = "Output limit reached";
}
}
if (finished_readpipe == true)
continue;
}
if (finished_errorpipe == false)
{
while (true)
{
if (PeekNamedPipe(hErrorReadPipe, NULL, NULL, NULL, &BytesAvail, NULL) == 0)
{
// pipe has been closed
finished_errorpipe = true;
break;
}
if (BytesAvail <= 0)
break;
if (BytesAvail > sizeof(buffer) - 1)
BytesAvail = sizeof(buffer) - 1;
if (ReadFile(hErrorReadPipe, buffer, BytesAvail, &BytesRead, NULL) == 0)
{
finished_errorpipe = true;
break;
}
if (BytesRead == 0)
{
finished_errorpipe = true;
break;
}
buffer[BytesRead] = '\0';
*error += buffer;
if (error->length() >= MAX_PROCESS_OUTPUT)
{
finished_inputpipe = true;
finished_readpipe = true;
finished_errorpipe = true;
error_occurred = true;
call->error = "Error output limit reached";
}
}
if (finished_errorpipe == true)
continue;
}
// don't tie up the server
if (wait_time < 100)
wait_time++;
Sleep(wait_time);
}
if (error_occurred == false)
WaitForSingleObject(pi.hProcess, INFINITE);
process_mutex.lock();
report_handle = NULL;
process_mutex.unlock();
DWORD exit_code = 0;
GetExitCodeProcess(pi.hProcess, &exit_code);
CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);
CloseHandle(hReadPipe);
CloseHandle(hErrorReadPipe);
if (hInputWritePipe != NULL)
CloseHandle(hInputWritePipe);
free(environment);
return exit_code;
}

C++ WINAPI Shared memory dynamic arrays

I'm trying to share an array of structs containing 2 dynamic arrays using shared memory to use the structs in another process. So far I can share an array of structs but these do not contain dynamic arrays yet. Any help on completing this problem would be great.
Expected:
typedef struct {
int id;
int type;
int count;
int[] values;
int[] settings;
} Entry;
Current code:
typedef struct {
int id;
int type;
int count;
} Entry;
BOOL DumpEntries(TCHAR* memName) {
int size = entries.size() * sizeof(Entry) + sizeof(DWORD);
::hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, size, memName);
if (::hMapObject == NULL) {
return FALSE;
}
::vMapData = MapViewOfFile(::hMapObject, FILE_MAP_ALL_ACCESS, 0, 0, size);
if (::vMapData == NULL) {
CloseHandle(::hMapObject);
return FALSE;
}
(*(DWORD*)::vMapData) = entries.size();
Entry* eArray = (Entry*)(((DWORD*)::vMapData) + 1);
for(int i = entries.size() - 1; i >= 0; i--) eArray[i] = entries.at(i);
UnmapViewOfFile(::vMapData);
return TRUE;
}
BOOL ReadEntries(TCHAR* memName, Entry** entries, DWORD &number_of_entries) {
HANDLE hMapFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, memName);
if (hMapFile == NULL) {
return FALSE;
}
DWORD *num_entries = (DWORD*)MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, 0);
if (num_entries == NULL) {
CloseHandle(hMapFile);
return FALSE;
}
number_of_entries = *num_entries;
if(number_of_entries == 0)
{
// special case: when no entries was found in buffer
*entries = NULL;
return true;
}
Entry* tmpEntries = (Entry*)(num_entries + 1);
*entries = new Entry[*num_entries];
for (UINT i = 0; i < *num_entries; i++) {
(*entries)[i] = tmpEntries[i];
}
UnmapViewOfFile(num_entries);
CloseHandle(hMapFile);
return TRUE;
}
You can't pass pointers across process boundaries, so you can't store pointers inside the struct items that you put in the shared memory. What you can do is allocate the shared memory block itself to be large enough to hold all of the array data, and then use offsets to access the various arrays as needed, eg:
typedef struct
{
int id;
int type;
int count;
int *values;
int *settings;
} Entry;
#pragma pack(push, 1)
typedef struct
{
int id;
int type;
int count;
DWORD values_offset;
DWORD values_count; // if different than 'int count'
DWORD settings_offset;
DWORD settings_count; // if different than 'int count'
} SharedMemEntry;
#pragma pack(pop)
BOOL DumpEntries(TCHAR* memName)
{
DWORD NumValues = 0;
DWORD NumSettings = 0;
// or whatever your container actually is...
for(std::vector<Entry>::reverse_iterator iter = entries.rbegin();
iter != entries.rend(); ++iter)
{
Entry &e = *iter;
// or whatever you have to do to calculate how many
// integers are in the values[] and settings[] arrays...
//
NumValues += e.count;
NumSettings += e.count;
}
DWORD memsize = sizeof(DWORD) +
(entries.size() * sizeof(SharedMemEntry)) +
(sizeof(int) * NumValues) +
(sizeof(int) * NumSettings);
if (hMapObject != NULL)
CloseHandle(hMapObject);
hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, memsize, memName);
if (hMapObject == NULL) {
return FALSE;
}
BYTE *vMapData = (BYTE*) MapViewOfFile(hMapObject, FILE_MAP_WRITE, 0, 0, memsize);
if (vMapData == NULL) {
CloseHandle(hMapObject);
hMapObject = NULL;
return FALSE;
}
DWORD *pEntryCount = (DWORD*) vMapData;
*pEntryCount = entries.size();
SharedMemEntry* pEntries = (SharedMemEntry*) (pEntryCount + 1);
int *pValues = (int*) (pEntries + entries.size());
int *pSettings = (int*) (pValues + NumValues);
// or whatever your container actually is...
for(std::vector<Entry>::reverse_iterator iter = entries.rbegin();
iter != entries.rend(); ++iter)
{
Entry &e = *iter;
SharedMemEntry &eEntry = *pEntries++;
eEntry.id = e.id;
eEntry.type = e.type;
eEntry.count = e.count;
eEntry.values_offset = ((BYTE*)pValues - vMapData);
eEntry.values_count = e.count; // or whatever you need...
for(DWORD k = 0; k < eEntry.values_count; ++k) {
*pValues++ = e.values[k];
}
eEntry.settings_offset = ((BYTE*)pSettings - vMapData);
eEntry.settings_count = e.count; // or whatever you need...
for(DWORD k = 0; k < eEntry.settings_count; ++k) {
*pSettings++ = e.settings[k];
}
}
UnmapViewOfFile(vMapData);
return TRUE;
}
BOOL ReadEntries(TCHAR* memName, Entry** entries, DWORD &num_entries)
{
HANDLE hMapFile = OpenFileMapping(FILE_MAP_READ, FALSE, memName);
if (hMapFile == NULL) {
return FALSE;
}
BYTE *vMapData = (BYTE*) MapViewOfFile(hMapFile, FILE_MAP_READ, 0, 0, 0);
if (vMapData == NULL) {
CloseHandle(hMapFile);
return FALSE;
}
DWORD *pEntryCount = (DWORD*) vMapData;
num_entries = *pEntryCount;
if (num_entries == 0)
{
// special case: when no entries was found in buffer
*entries = NULL;
}
else
{
SharedMemEntry *pEntries = (SharedMemEntry*) (pEntryCount + 1);
*entries = new Entry[num_entries];
for (DWORD i = 0; i < num_entries; ++i)
{
Entry &e = (*entries)[i];
SharedMemEntry &eEntry = pEntries[i];
e.id = eEntry.id;
e.type = eEntry.type;
e.count = eEntry.count;
e.values = new int[eEntry.values_count];
e.settings = new int[eEntry.settings_count];
int *pValues = (int*) (vMapData + eEntry.values_offset);
for(DWORD j = 0; j < eEntry.values_count; ++j) {
e.values[j] = pValues[j];
}
int *pSettings = (int*) (vMapData + eEntry.settings_offset);
for(DWORD j = 0; j < eEntry.settings_count; ++j) {
e.settings[j] = pSettings[j];
}
}
}
UnmapViewOfFile(vMapData);
CloseHandle(hMapFile);
return TRUE;
}
Alternatively, you should consider automating the memory management and loops instead of doing everything manually:
typedef struct
{
int id;
int type;
int count;
std::vector<int> values;
std::vector<int> settings;
} Entry;
#pragma pack(push, 1)
typedef struct
{
int id;
int type;
int count;
DWORD values_offset;
DWORD values_count; // if different than 'int count'
DWORD settings_offset;
DWORD settings_count; // if different than 'int count'
} SharedMemEntry;
#pragma pack(pop)
BOOL DumpEntries(TCHAR* memName)
{
DWORD NumValues = 0;
DWORD NumSettings = 0;
// or whatever your container actually is...
for(std::vector<Entry>::reverse_iterator iter = entries.rbegin();
iter != entries.rend(); ++iter)
{
Entry &e = *iter;
NumValues += e.values.size();
NumSettings += e.settings.size();
}
DWORD memsize = sizeof(DWORD) +
(entries.size() * sizeof(SharedMemEntry)) +
(sizeof(int) * NumValues) +
(sizeof(int) * NumSettings);
if (hMapObject != NULL)
CloseHandle(hMapObject);
hMapObject = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, memsize, memName);
if (!hMapObject) {
return FALSE;
}
std::unique_ptr<void, decltype(&UnmapViewOfFile)> uMapData( MapViewOfFile(hMapObject, FILE_MAP_WRITE, 0, 0, memsize), &UnmapViewOfFile );
BYTE *vMapData = (BYTE*) uMapData.get();
if (!vMapData) {
CloseHandle(hMapObject);
hMapObject = NULL;
return FALSE;
}
DWORD *pEntryCount = (DWORD*) vMapData;
*pEntryCount = entries.size();
SharedMemEntry* pEntries = (SharedMemEntry*) (pEntryCount + 1);
int *pValues = (int*) (pEntries + entries.size());
int *pSettings = (int*) (pValues + NumValues);
// or whatever your container actually is...
for(std::vector<Entry>::reverse_iterator iter = entries.rbegin();
iter != entries.rend(); ++iter)
{
Entry &e = *iter;
SharedMemEntry &eEntry = *pEntries++;
eEntry.id = e.id;
eEntry.type = e.type;
eEntry.count = e.count;
eEntry.values_offset = ((BYTE*)pValues - vMapData);
eEntry.values_count = e.values.size();
pValues = std::copy(e.values.begin(), e.values.end(), pValues);
eEntry.settings_offset = ((BYTE*)pSettings - vMapData);
eEntry.settings_count = e.settings.size();
pSettings = std::copy(e.settings.begin(), e.settings.end(), pSettings);
}
return TRUE;
}
// or whatever container type you want...
BOOL ReadEntries(TCHAR* memName, std::vector<Entry> &entries)
{
entries.clear();
std::unique_ptr<std::remove_pointer<HANDLE>::type, decltype(&CloseHandle)> uMapFile( OpenFileMapping(FILE_MAP_READ, FALSE, memName), &CloseHandle );
HANDLE hMapFile = uMapFile.get();
if (!hMapFile) {
return FALSE;
}
std::unique_ptr<void, decltype(&UnmapViewOfFile)> uMapData( MapViewOfFile(hMapFile, FILE_MAP_READ, 0, 0, 0), &UnmapViewOfFile );
BYTE *vMapData = (BYTE*) uMapData.get();
if (!vMapData) {
return FALSE;
}
DWORD *pEntryCount = (DWORD*) vMapData;
DWORD num_entries = *pEntryCount;
if (num_entries != 0)
{
entries.resize(num_entries);
SharedMemEntry *pEntries = (SharedMemEntry*) (pEntryCount + 1);
for (DWORD i = 0; i < num_entries; ++i)
{
Entry &e = entries[i];
SharedMemEntry &eEntry = pEntries[i];
e.id = eEntry.id;
e.type = eEntry.type;
e.count = eEntry.count;
e.values.reserve(eEntry.values_count);
e.settings.reserve(eEntry.settings_count);
int *pValues = (int*) (vMapData + eEntry.values_offset);
std::copy(pValues, pValues + eEntry.values_count, std::back_inserter(e.values));
int *pSettings = (int*) (vMapData + eEntry.settings_offset);
std::copy(pSettings, pSettings + eEntry.settings_count, std::back_inserter(e.settings));
}
}
return TRUE;
}
Either way, make sure you provide some kind of synchronization between DumpEntries() and ReadEntries(), such as with shared events from CreateEvent(), so that ReadEntries() does not try to read from the memory while DumpEntries() is still writing to it, and vice versa.

Thread not completing properly, preventing application close

I'm writing a win32 form application and drawing it with Direct2D. I have a few cross threaded functions to do animations on it and I'm doing web requests with WinHTTP. The issue is, when I use any WinHttp functions (even just opening an HINTERNET session), it will cause the thread not to terminate properly. After I run the 'login' process once, the program cannot exit calmly. I've posted the relevant code below:
//the login process
void __cdecl processloginasync(void* arg)
{
//getting text from textboxes, etc.
if(usernamestr.find(L'#') != wstring::npos && usernamestr.find(L".") != wstring::npos) {
swapdrawmode(1);
_beginthread(loadwheel,NULL,arg);
void* result = NULL;
unsigned sz = 0;
int rescode = web_request(L"appurl.mywebsite.com/func.php",ss.str().c_str(),result,sz);
//other code to handle the reply...
swapdrawmode(0);
}
else {
error_str = L"Invalid email address.";
err = TRUE;
}
if(err == TRUE) {
textopacity = 0;
animatemode = 0;
_beginthread(animatetext,NULL,arg);
}
//I realize I haven't called 'free' on result, I'll fix that.
}
//the web_request function
int web_request (const wchar_t* server, const wchar_t* object, void*& dest, unsigned& size)
{
vector<void*> retval;
vector<unsigned> szs;
HINTERNET hSess = NULL, hConn = NULL, hReq = NULL;
int res = 0;
DWORD dwDownloaded = 0;
DWORD dwSize = 0;
DWORD retcode = NULL;
short err = FALSE;
const wchar_t* accepted_types[] = {
L"image/*",
L"text/*",
NULL
};
hSess = WinHttpOpen(L"smartCARS2 Web/1.1",WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
if(hSess)
hConn = WinHttpConnect(hSess,server,INTERNET_DEFAULT_HTTP_PORT, NULL);
else {
err = TRUE;
retcode = HTTP_OPEN_FAILED;
}
if(hConn)
hReq = WinHttpOpenRequest(hConn, NULL, object, NULL, WINHTTP_NO_REFERER,accepted_types,NULL);
else {
err = TRUE;
retcode = HTTP_CONN_FAILED;
}
if(hReq)
res = WinHttpSendRequest(hReq, WINHTTP_NO_ADDITIONAL_HEADERS, NULL, WINHTTP_NO_REQUEST_DATA, NULL, NULL, NULL);
else {
err = TRUE;
retcode = HTTP_OPENREQ_FAILED;
}
if(res)
res = WinHttpReceiveResponse(hReq, NULL);
else {
err = TRUE;
retcode = HTTP_SEND_REQ_FAILED;
}
DWORD tsize = 0;
if(res) {
do {
dwSize = 0;
if(!WinHttpQueryDataAvailable(hReq, &dwSize)) {
retcode = HTTP_COULD_NOT_QUERY_SIZE;
err = TRUE;
break;
}
if(!dwSize)
break;
tsize += dwSize;
void* rets = malloc(dwSize + 1);
if(!rets) {
break;
}
if(!WinHttpReadData(hReq, (void*)rets, dwSize, &dwDownloaded)) {
retcode = HTTP_COULD_NOT_READ_DATA;
err = TRUE;
break;
}
if(!dwDownloaded) {
retcode = HTTP_COULD_NOT_DOWNLOAD;
err = TRUE;
break;
}
szs.push_back(dwSize);
retval.push_back(rets);
} while(dwSize > 0);
}
size = tsize;
unsigned int sz = retval.size();
dest = malloc(tsize);
tsize = 0;
for(unsigned i = 0; i < sz; i++) {
memcpy((BYTE*)dest + tsize,retval[i],szs[i]);
free(retval[i]);
tsize += szs[i];
}
if(hSess)
WinHttpCloseHandle(hSess);
if(hConn)
WinHttpCloseHandle(hConn);
if(hReq)
WinHttpCloseHandle(hReq);
if(err == TRUE)
return retcode;
return 0;
}
As far as I know, as soon as the main thread terminates, the others are not waited for. So the problem is probably in your main thread. You just need to attach a debugger if not already being debugged (Debug | Attach to process in VS) to a zombie process and press "Break all", then use "Threads" and "Call stack" windows to figure what's happening.

Change Mac address by adapter description

I'm using the excellent tool provided by Nate True # http://devices.natetrue.com/macshift/
It changes the Mac address by the adapter name. This is the source code:
const int versionMajor = 1;
const int versionMinor = 1;
#include <windows.h>
#include <objbase.h>
#include <netcon.h>
#include <stdio.h>
#include "validmacs.h"
void SetMAC(char * AdapterName, char * NewMAC) {
HKEY hListKey = NULL;
HKEY hKey = NULL;
RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}",
0, KEY_READ, &hListKey);
if (!hListKey) {
printf("Failed to open adapter list key\n");
return;
}
FILETIME writtenTime;
char keyNameBuf[512], keyNameBuf2[512];
DWORD keyNameBufSiz = 512;
DWORD crap;
int i = 0;
bool found = false;
while (RegEnumKeyEx(hListKey, i++, keyNameBuf, &keyNameBufSiz, 0, NULL, NULL, &writtenTime)
== ERROR_SUCCESS) {
_snprintf(keyNameBuf2, 512, "%s\\Connection", keyNameBuf);
hKey = NULL;
RegOpenKeyEx(hListKey, keyNameBuf2, 0, KEY_READ, &hKey);
if (hKey) {
keyNameBufSiz = 512;
if (RegQueryValueEx(hKey, "Name", 0, &crap, (LPBYTE)keyNameBuf2, &keyNameBufSiz)
== ERROR_SUCCESS && strcmp(keyNameBuf2, AdapterName) == 0) {
printf("Adapter ID is %s\n", keyNameBuf);
found = true;
break;
}
RegCloseKey(hKey);
}
keyNameBufSiz = 512;
}
RegCloseKey(hListKey);
if (!found) {
printf("Could not find adapter name '%s'.\nPlease make sure this is the name you gave it in Network Connections.\n", AdapterName);
return;
}
RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002bE10318}",
0, KEY_READ, &hListKey);
if (!hListKey) {
printf("Failed to open adapter list key in Phase 2\n");
return;
}
i = 0;
char buf[512];
while (RegEnumKeyEx(hListKey, i++, keyNameBuf2, &keyNameBufSiz, 0, NULL, NULL, &writtenTime)
== ERROR_SUCCESS) {
hKey = NULL;
RegOpenKeyEx(hListKey, keyNameBuf2, 0, KEY_READ | KEY_SET_VALUE, &hKey);
if (hKey) {
keyNameBufSiz = 512;
if ((RegQueryValueEx(hKey, "NetCfgInstanceId", 0, &crap, (LPBYTE)buf, &keyNameBufSiz)
== ERROR_SUCCESS) && (strcmp(buf, keyNameBuf) == 0)) {
RegSetValueEx(hKey, "NetworkAddress", 0, REG_SZ, (LPBYTE)NewMAC, strlen(NewMAC) + 1);
//printf("Updating adapter index %s (%s=%s)\n", keyNameBuf2, buf, keyNameBuf);
//break;
}
RegCloseKey(hKey);
}
keyNameBufSiz = 512;
}
RegCloseKey(hListKey);
}
void ResetAdapter(char * AdapterName) {
struct _GUID guid = {0xBA126AD1,0x2166,0x11D1,0};
memcpy(guid.Data4, "\xB1\xD0\x00\x80\x5F\xC1\x27\x0E", 8);
unsigned short * buf = new unsigned short[strlen(AdapterName)+1];
void (__stdcall *NcFreeNetConProperties) (NETCON_PROPERTIES *);
HMODULE NetShell_Dll = LoadLibrary("Netshell.dll");
if (!NetShell_Dll) {
printf("Couldn't load Netshell.dll\n");
return;
}
NcFreeNetConProperties = (void (__stdcall *)(struct tagNETCON_PROPERTIES *))GetProcAddress(NetShell_Dll, "NcFreeNetconProperties");
if (!NcFreeNetConProperties) {
printf("Couldn't load required DLL function\n");
return;
}
for (unsigned int i = 0; i <= strlen(AdapterName); i++) {
buf[i] = AdapterName[i];
}
CoInitialize(0);
INetConnectionManager * pNCM = NULL;
HRESULT hr = ::CoCreateInstance(guid,
NULL,
CLSCTX_ALL,
__uuidof(INetConnectionManager),
(void**)&pNCM);
if (!pNCM)
printf("Failed to instantiate required object\n");
else {
IEnumNetConnection * pENC;
pNCM->EnumConnections(NCME_DEFAULT, &pENC);
if (!pENC) {
printf("Could not enumerate Network Connections\n");
}
else {
INetConnection * pNC;
ULONG fetched;
NETCON_PROPERTIES * pNCP;
do {
pENC->Next(1, &pNC, &fetched);
if (fetched && pNC) {
pNC->GetProperties(&pNCP);
if (pNCP) {
if (wcscmp(pNCP->pszwName, buf) == 0) {
pNC->Disconnect();
pNC->Connect();
}
NcFreeNetConProperties(pNCP);
}
}
} while (fetched);
pENC->Release();
}
pNCM->Release();
}
FreeLibrary(NetShell_Dll);
CoUninitialize ();
}
bool IsValidMAC(char * str) {
if (strlen(str) != 12) return false;
for (int i = 0; i < 12; i++) {
if ((str[i] < '0' || str[i] > '9')
&& (str[i] < 'a' || str[i] > 'f')
&& (str[i] < 'A' || str[i] > 'F')) {
return false;
}
}
return true;
}
void ShowHelp() {
printf("Usage: macshift [options] [mac-address]\n\n");
printf("Options:\n");
printf("\t-i [adapter-name] The adapter name from Network Connections.\n");
printf("\t-r Uses a random MAC address. This is the default.\n");
printf("\t-d Restores the original MAC address.\n");
printf("\t--help Shows this screen.\n\n");
printf("Macshift uses special undocumented functions in the Windows COM Interface that\n");
printf(" allow you to change an adapter's MAC address without needing to restart.\n");
printf("When you change a MAC address, all your connections are closed automatically\n");
printf(" and your adapter is reset.\n");
}
//Generates a random MAC that is actually plausible
void RandomizeMAC(char * newmac) {
_snprintf(newmac, 6, "%06X", rand() % numMacs);
for (int i = 3; i < 6; i++) {
_snprintf(&newmac[i*2], 2, "%02X", rand() & 0xFF);
}
newmac[12] = 0;
}
int main(int argc, char * * argv) {
printf("Macshift v%i.%i, MAC Changing Utility by Nathan True, macshift#natetrue.com\n\n", versionMajor, versionMinor);
//Parse commandline arguments
char * adapter = "Wireless";
char newmac[13];
int i;
if (argc == 1) {
ShowHelp();
return 0;
}
//Start out with a random MAC
srand(GetTickCount());
RandomizeMAC(newmac);
for (i = 1; i < argc; i++) {
if (argv[i][0] == '-') {
switch (argv[i][1]) {
case '-': //Extended argument
if (strcmp(argv[i]+2, "help") == 0) {
ShowHelp();
return 0;
}
break;
case 'r': //Random setting, this is the default
break;
case 'i': //Adapter name follows
if (argc > i + 1) adapter = argv[++i];
break;
case 'd': //Reset the MAC address
newmac[0] = 0;
}
}
else {
if (IsValidMAC(argv[i])) strncpy(newmac, argv[i], 13);
else printf("MAC String %s is not valid. MAC addresses must m/^[0-9a-fA-F]{12}$/.\n", argv[i]);
}
}
printf("Setting MAC on adapter '%s' to %s...\n", adapter, newmac[0] ? newmac : "original MAC");
SetMAC(adapter, newmac);
printf("Resetting adapter...\n");
fflush(stdout);
ResetAdapter(adapter);
printf("Done\n");
return 0;
}
I would like to change the Mac address by the description of an adapter, in addition to the name. So I need to modify this code so that if a matching name is not found, it falls back to changing the mac based on the description.
This is an example adapter:
name: Local Area Connection
description: Marvell Yukon 88E8055 PCI-E Gigabit Ethernet Controller
Unfortunately, being a Java developer I have limited experience with C++, so any help would be greatly appreciated.
Here's a C sample of GetAdaptersInfo, it prints out each adapters name and description (you can easily adapt it for your code by calling SetMAC on a match):
VOID EnumerateNetworkAdapters(VOID)
{
ULONG len = 0;
if (ERROR_BUFFER_OVERFLOW == GetAdaptersInfo(NULL, &len))
{
IP_ADAPTER_INFO *ipai;
ipai = malloc(len);
if (NO_ERROR == GetAdaptersInfo(ipai, &len))
{
IP_ADAPTER_INFO *p = ipai;
do
{
printf("name=%s description=%s\n", p->AdapterName, p->Description);
}
while (p = p->Next);
}
free(ipai);
}
}
Link against "Iphlpapi.lib".
Use GetAdaptersAddresses to get the adapter name(PIP_ADAPTER_ADDRESSES::FriendlyName) by comparing the description(PIP_ADAPTER_ADDRESSES::Description) before the call to SetMAC(). Example can be found in above MSDN link.