C++ Pipe [How to get ipaddress or hostname of connected client.] - c++

Question

I wanna get client ip address or host name.
I'm using VS6.0 & VS2010 on Windows 7 Ultimate.
CreateNamedPipe(...) on Server is as follows :
SECURITY_ATTRIBUTES sa = {0};
hPipe = CreateNamedPipe(
_T("\\\\.\\pipe\\AnonymousPipe"), // pipe name
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
PIPE_UNLIMITED_INSTANCES,
0xD000,
0xD000,
NMPWAIT_USE_DEFAULT_WAIT,
&sa);
if (hPipe == INVALID_HANDLE_VALUE)
{
_tprintf(TEXT("CreateNamedPipe failed, GLE=%d.\n"), GetLastError());
return -1;
}
fConnected = ConnectNamedPipe(hPipe, NULL) ? TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
if (fConnected)
{
printf("Client connected, creating a processing thread.\n");
// Get Information Of Connected Client.
// Client Ip Address or Hostname.
}
How can I detect which client connected to server?
I can see the connection between server and client using netstat cmd line.
netstat -an|find "445"
TCP 0.0.0.0:445 0.0.0.0:0 LISTENING
TCP 0.0.0.0:445 192.168.125.115:4124 ESTABLISHED
TCP 0.0.0.0:445 192.168.125.192:4882 ESTABLISHED
String "192.168.125.115"&"192.168.125.192" is my target.
But I cannot find a way to detect connected client ip in programmatically in VS6.0.
Someone told me that use GetNamedPipeClientComputerName() to solve this problem. But
GetNamedPipeClientComputerName()
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Many client still using Windows XP.
I have searched a lot to solve the problem, but I could not find the code describing for this.
Thank you for all viewers.

Answer 1

how already answered in comments GetNamedPipeClientComputerName can be used for this. it available from Windows Vista. if want it on xp also it can be implemented in next way:
ULONG AltGetNamedPipeClientComputerName(HANDLE Pipe, PWSTR ClientComputerName, ULONG ClientComputerNameLength)
{
static const char AttributeName[] = "ClientComputerName";
if (HANDLE hEvent = CreateEvent(NULL, FALSE, FALSE, NULL))
{
IO_STATUS_BLOCK iosb;
NTSTATUS status = NtFsControlFile(Pipe,
hEvent,
NULL,
NULL,
&iosb,
FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE,
(void*)AttributeName,
sizeof(AttributeName),
ClientComputerName,
ClientComputerNameLength*sizeof(WCHAR));
if (status == STATUS_PENDING)
{
WaitForSingleObject(hEvent, INFINITE);
status = iosb.Status;
}
CloseHandle(hEvent);
return status == STATUS_NOT_FOUND ? ERROR_PIPE_LOCAL : RtlNtStatusToDosError(status);
}
return GetLastError();
}
this is general how really GetNamedPipeClientComputerName implemented internal. however if we use synchronous pipes (so created without FILE_FLAG_OVERLAPPED) we can simplify function - not need create event - NtFsControlFile never return STATUS_PENDING for synchronous handle.
ULONG AltGetNamedPipeClientComputerNameSync(HANDLE Pipe, PWSTR ClientComputerName, ULONG ClientComputerNameLength)
{
static const char AttributeName[] = "ClientComputerName";
IO_STATUS_BLOCK iosb;
NTSTATUS status = NtFsControlFile(Pipe,
hEvent,
NULL,
NULL,
&iosb,
FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE,
(void*)AttributeName,
sizeof(AttributeName),
ClientComputerName,
ClientComputerNameLength*sizeof(WCHAR));
return status == STATUS_NOT_FOUND ? ERROR_PIPE_LOCAL : RtlNtStatusToDosError(status);
}
from another side if we use asynchronous pipe - we can and not wait when FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE completed, but handle it asyncronous like other requests, which you handle async
one very important note - we can not use DeviceIoControl here, but only NtFsControlFile - this is because DeviceIoControl internally check dwIoControlCode and if it for FILE_DEVICE_FILE_SYSTEM call NtFsControlFile otherwise NtDeviceIoControlFile. the FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE defined in ntifs.h (from wdk) as
#define FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE CTL_CODE(FILE_DEVICE_NAMED_PIPE, 12, METHOD_BUFFERED, FILE_ANY_ACCESS)
for FILE_DEVICE_NAMED_PIPE DeviceIoControl call NtDeviceIoControlFile but we need NtFsControlFile exactly.
note that this worked only for server side pipe end (created by CreateNamedPipe) and in case client is remote. otherwise STATUS_NOT_FOUND will be returned from NtFsControlFile. the GetNamedPipeClientComputerName implementation special check for this code and convert it to ERROR_PIPE_LOCAL