diff options
Diffstat (limited to 'psutil/arch/windows/proc_handles.c')
| -rw-r--r-- | psutil/arch/windows/proc_handles.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/psutil/arch/windows/proc_handles.c b/psutil/arch/windows/proc_handles.c new file mode 100644 index 00000000..30e7cd2d --- /dev/null +++ b/psutil/arch/windows/proc_handles.c @@ -0,0 +1,292 @@ +/* + * Copyright (c) 2009, Giampaolo Rodola'. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* + * This module retrieves handles opened by a process. + * We use NtQuerySystemInformation to enumerate them and NtQueryObject + * to obtain the corresponding file name. + * Since NtQueryObject hangs for certain handle types we call it in a + * separate thread which gets killed if it doesn't complete within 100ms. + * This is a limitation of the Windows API and ProcessHacker uses the + * same trick: https://github.com/giampaolo/psutil/pull/597 + * + * CREDITS: original implementation was written by Jeff Tang. + * It was then rewritten by Giampaolo Rodola many years later. + * Utility functions for getting the file handles and names were re-adapted + * from the excellent ProcessHacker. + */ + +#include <windows.h> +#include <Python.h> + +#include "../../_psutil_common.h" +#include "proc_utils.h" + + +#define THREAD_TIMEOUT 100 // ms +// Global object shared between the 2 threads. +PUNICODE_STRING globalFileName = NULL; + + +static int +psutil_enum_handles(PSYSTEM_HANDLE_INFORMATION_EX *handles) { + static ULONG initialBufferSize = 0x10000; + NTSTATUS status; + PVOID buffer; + ULONG bufferSize; + + bufferSize = initialBufferSize; + buffer = MALLOC_ZERO(bufferSize); + if (buffer == NULL) { + PyErr_NoMemory(); + return 1; + } + + while ((status = NtQuerySystemInformation( + SystemExtendedHandleInformation, + buffer, + bufferSize, + NULL + )) == STATUS_INFO_LENGTH_MISMATCH) + { + FREE(buffer); + bufferSize *= 2; + + // Fail if we're resizing the buffer to something very large. + if (bufferSize > 256 * 1024 * 1024) { + PyErr_SetString( + PyExc_RuntimeError, + "SystemExtendedHandleInformation buffer too big"); + return 1; + } + + buffer = MALLOC_ZERO(bufferSize); + if (buffer == NULL) { + PyErr_NoMemory(); + return 1; + } + } + + if (! NT_SUCCESS(status)) { + psutil_SetFromNTStatusErr(status, "NtQuerySystemInformation"); + FREE(buffer); + return 1; + } + + *handles = (PSYSTEM_HANDLE_INFORMATION_EX)buffer; + return 0; +} + + +static int +psutil_get_filename(LPVOID lpvParam) { + HANDLE hFile = *((HANDLE*)lpvParam); + NTSTATUS status; + ULONG bufferSize; + ULONG attempts = 8; + + bufferSize = 0x200; + globalFileName = MALLOC_ZERO(bufferSize); + if (globalFileName == NULL) { + PyErr_NoMemory(); + goto error; + } + + + // Note: also this is supposed to hang, hence why we do it in here. + if (GetFileType(hFile) != FILE_TYPE_DISK) { + SetLastError(0); + globalFileName->Length = 0; + return 0; + } + + // A loop is needed because the I/O subsystem likes to give us the + // wrong return lengths... + do { + status = NtQueryObject( + hFile, + ObjectNameInformation, + globalFileName, + bufferSize, + &bufferSize + ); + if (status == STATUS_BUFFER_OVERFLOW || + status == STATUS_INFO_LENGTH_MISMATCH || + status == STATUS_BUFFER_TOO_SMALL) + { + FREE(globalFileName); + globalFileName = MALLOC_ZERO(bufferSize); + if (globalFileName == NULL) { + PyErr_NoMemory(); + goto error; + } + } + else { + break; + } + } while (--attempts); + + if (! NT_SUCCESS(status)) { + psutil_SetFromNTStatusErr(status, "NtQuerySystemInformation"); + FREE(globalFileName); + globalFileName = NULL; + return 1; + } + + return 0; + +error: + if (globalFileName != NULL) { + FREE(globalFileName); + globalFileName = NULL; + } + return 1; +} + + +static DWORD +psutil_threaded_get_filename(HANDLE hFile) { + DWORD dwWait; + HANDLE hThread; + DWORD threadRetValue; + + hThread = CreateThread( + NULL, 0, (LPTHREAD_START_ROUTINE)psutil_get_filename, &hFile, 0, NULL); + if (hThread == NULL) { + PyErr_SetFromOSErrnoWithSyscall("CreateThread"); + return 1; + } + + // Wait for the worker thread to finish. + dwWait = WaitForSingleObject(hThread, THREAD_TIMEOUT); + + // If the thread hangs, kill it and cleanup. + if (dwWait == WAIT_TIMEOUT) { + psutil_debug( + "get handle name thread timed out after %i ms", THREAD_TIMEOUT); + if (TerminateThread(hThread, 0) == 0) { + PyErr_SetFromOSErrnoWithSyscall("TerminateThread"); + CloseHandle(hThread); + return 1; + } + CloseHandle(hThread); + return 0; + } + + if (dwWait == WAIT_FAILED) { + psutil_debug("WaitForSingleObject -> WAIT_FAILED"); + if (TerminateThread(hThread, 0) == 0) { + PyErr_SetFromOSErrnoWithSyscall( + "WaitForSingleObject -> WAIT_FAILED -> TerminateThread"); + CloseHandle(hThread); + return 1; + } + PyErr_SetFromOSErrnoWithSyscall("WaitForSingleObject"); + CloseHandle(hThread); + return 1; + } + + if (GetExitCodeThread(hThread, &threadRetValue) == 0) { + if (TerminateThread(hThread, 0) == 0) { + PyErr_SetFromOSErrnoWithSyscall( + "GetExitCodeThread (failed) -> TerminateThread"); + CloseHandle(hThread); + return 1; + } + + CloseHandle(hThread); + PyErr_SetFromOSErrnoWithSyscall("GetExitCodeThread"); + return 1; + } + CloseHandle(hThread); + return threadRetValue; +} + + +PyObject * +psutil_get_open_files(DWORD dwPid, HANDLE hProcess) { + PSYSTEM_HANDLE_INFORMATION_EX handlesList = NULL; + PSYSTEM_HANDLE_TABLE_ENTRY_INFO_EX hHandle = NULL; + HANDLE hFile = NULL; + ULONG i = 0; + BOOLEAN errorOccurred = FALSE; + PyObject* py_path = NULL; + PyObject* py_retlist = PyList_New(0);; + + if (!py_retlist) + return NULL; + + // Due to the use of global variables, ensure only 1 call + // to psutil_get_open_files() is running. + EnterCriticalSection(&PSUTIL_CRITICAL_SECTION); + + if (psutil_enum_handles(&handlesList) != 0) + goto error; + + for (i = 0; i < handlesList->NumberOfHandles; i++) { + hHandle = &handlesList->Handles[i]; + if ((ULONG_PTR)hHandle->UniqueProcessId != dwPid) + continue; + if (! DuplicateHandle( + hProcess, + hHandle->HandleValue, + GetCurrentProcess(), + &hFile, + 0, + TRUE, + DUPLICATE_SAME_ACCESS)) + { + // Will fail if not a regular file; just skip it. + continue; + } + + // This will set *globalFileName* global variable. + if (psutil_threaded_get_filename(hFile) != 0) + goto error; + + if ((globalFileName != NULL) && (globalFileName->Length > 0)) { + py_path = PyUnicode_FromWideChar(globalFileName->Buffer, + wcslen(globalFileName->Buffer)); + if (! py_path) + goto error; + if (PyList_Append(py_retlist, py_path)) + goto error; + Py_CLEAR(py_path); // also sets to NULL + } + + // Loop cleanup section. + if (globalFileName != NULL) { + FREE(globalFileName); + globalFileName = NULL; + } + CloseHandle(hFile); + hFile = NULL; + } + + goto exit; + +error: + Py_XDECREF(py_retlist); + errorOccurred = TRUE; + goto exit; + +exit: + if (hFile != NULL) + CloseHandle(hFile); + if (globalFileName != NULL) { + FREE(globalFileName); + globalFileName = NULL; + } + if (py_path != NULL) + Py_DECREF(py_path); + if (handlesList != NULL) + FREE(handlesList); + + LeaveCriticalSection(&PSUTIL_CRITICAL_SECTION); + if (errorOccurred == TRUE) + return NULL; + return py_retlist; +} |