MiniDumpWriteDump() into a named pipe then ReadFile() - c++

Question

What I would like to do is use MiniDumpWriteDump() write to a named pipe and then read/write it myself. I am able to perform the dump successfully if I write the contents to a file directly. However, while writing to the named pipe has been successful the subsequent read/write operation does not go so well. I can read all the data out of the pipe but then when it's written the DMP file appears to be corrupted.
Here is the ReadFile() logic:
while (ReadFile(hInboundPipe, &vecBuffer[dwOffset], vecBuffer.size() - dwOffset, &dwRead, NULL)) {
dwOffset += dwRead;
while (dwOffset >= vecBuffer.size()) {
vecBuffer.resize(vecBuffer.size() + iBuffer * sizeof(char));
}
}
Here is the WriteFile() logic:
HANDLE hDumpFile = CreateFileW(L"C:\\test.dmp", GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
WriteFile(hDumpFile , &vecBuffer[0], dwOffset, &dwOutBytes, NULL);
CloseHandle(hDumpFile);
I'm not certain if it's applicable to the root cause but here is the named pipe setup:
HANDLE hInboundPipe = CreateNamedPipe(
szPipeName,
PIPE_ACCESS_DUPLEX,
PIPE_WAIT | PIPE_TYPE_BYTE,
PIPE_UNLIMITED_INSTANCES,
0,
0,
(DWORD)-1,
&SecAttrib);
There are not any errors being reported back from GetLastError(). Am I missing something obvious?
EDIT: Adding how the MiniDumpWriteDump() is being done in response to a comment.
HANDLE hDump = CreateFile(szPipeName, GENERIC_ALL, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
MiniDumpWriteDump(hProcess, pid, hDump, mdValue, NULL, NULL, NULL);
CloseHandle(hDump);
UPDATE:
I was under the impression that reading by chunks was somehow dropping data. To test this I increased the buffer of the named pipe to accommodate the entire dump without any resizing. I also increased the vecBuffer size to match. Now when performing the ReadFile() operation I receive the entire dump but it is still off. I'm still playing with various named pipe settings trying to figure out what needs to be done to get MiniDumpWriteDump() to provide valid output to a named pipe.

Answer 1

It appears this cannot be done. See the comments for more information. Writing directly to a named pipe from MiniDumpWriteDump() cannot be done because the handle that is passed in must have the ability to seek. Named pipes do not have that functionality, therefore you must use a legitimate file handle.