Question

如何获取父进程的ID

Answer 1

NTDLL.DLL中有一个函数叫NtQueryInformationProcess，用它可以将指定类型的进程信息拷贝到某个缓冲。其原型如下：

NTSYSAPI
NTSTATUS
NTAPI
NtQueryInformationProcess (
IN HANDLE ProcessHandle, // 进程句柄
IN PROCESSINFOCLASS InformationClass, // 信息类型
OUT PVOID ProcessInformation, // 缓冲指针
IN ULONG ProcessInformationLength, // 以字节为单位的缓冲大小
OUT PULONG ReturnLength OPTIONAL // 写入缓冲的字节数
);
第一个参数是希望操作的进程句柄，这个句柄必须以PROCESS_QUERY_INFORMATION模式存取。为了取得一个句柄，我们必须用OpenProcess函数：
HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION,FALSE,dwProcessID);
第二个参数是请求信息的类型，这个参数可以有许多个值，本文例子中将用ProcessBasicInformation （值为0）。
因此，如果第二个参数是ProcessBasicInformation的话，则第三个参数必须为一个指针指向结构PROCESS_BASIC_INFORMATION：
typedef struct
{
DWORD ExitStatus; // 接收进程终止状态
DWORD PebBaseAddress; // 接收进程环境块地址
DWORD AffinityMask; // 接收进程关联掩码
DWORD BasePriority; // 接收进程的优先级类
ULONG UniqueProcessId; // 接收进程ID
ULONG InheritedFromUniqueProcessId; //接收父进程ID
} PROCESS_BASIC_INFORMATION;

这个结构的最后一个参数是InheritedFromUniqueProcessId，它就是我们所要的东西。

DWORD dwParentPID;
LONG status;
PROCESS_BASIC_INFORMATION pbi;

status = NtQueryInformationProcess( hProcess,
ProcessBasicInformation,
(PVOID)&pbi,
sizeof(PROCESS_BASIC_INFORMATION),
NULL );

if (!status)
dwParentPID = pbi.InheritedFromUniqueProcessId;

[cpp] view plaincopy
// parent.cpp (Windows NT/2000)
//
// This example will show the method how you can retrieve the parent
// process ID on Windows NT/2000 using the NT Native API
//
//
// (c)1999 Ashot Oganesyan K, SmartLine, Inc
// mailto:ashot@aha.ru, http://www.protect-me.com, http://www.codepile.com

#include <windows.h>
#include <stdio.h>

#define ProcessBasicInformation 0

typedef struct
{
DWORD ExitStatus;
DWORD PebBaseAddress;
DWORD AffinityMask;
DWORD BasePriority;
ULONG UniqueProcessId;
ULONG InheritedFromUniqueProcessId;
} PROCESS_BASIC_INFORMATION;

// ntdll!NtQueryInformationProcess (NT specific!)
//
// The function copies the process information of the
// specified type into a buffer
//
// NTSYSAPI
// NTSTATUS
// NTAPI
// NtQueryInformationProcess(
// IN HANDLE ProcessHandle, // handle to process
// IN PROCESSINFOCLASS InformationClass, // information type
// OUT PVOID ProcessInformation, // pointer to buffer
// IN ULONG ProcessInformationLength, // buffer size in bytes
// OUT PULONG ReturnLength OPTIONAL // pointer to a 32-bit
// // variable that receives
// // the number of bytes
// // written to the buffer
// );
typedef LONG (WINAPI *PROCNTQSIP)(HANDLE,UINT,PVOID,ULONG,PULONG);

PROCNTQSIP NtQueryInformationProcess;

DWORD GetParentProcessID(DWORD dwId);

void main(int argc, char* argv[])
{
if (argc<2)
{
printf("Usage:\n\nparent.exe ProcId\n");
return;
}

NtQueryInformationProcess = (PROCNTQSIP)GetProcAddress(
GetModuleHandle("ntdll"),
"NtQueryInformationProcess"
);

if (!NtQueryInformationProcess)
return;

DWORD dwId;
sscanf(argv[1],"%lu",&dwId);

printf("Parent PID for %lu is %lu\n",dwId,GetParentProcessID(dwId));

}

DWORD GetParentProcessID(DWORD dwId)
{
LONG status;
DWORD dwParentPID = (DWORD)-1;
HANDLE hProcess;
PROCESS_BASIC_INFORMATION pbi;

// Get process handle
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION,FALSE,dwId);
if (!hProcess)
return (DWORD)-1;

// Retrieve information
status = NtQueryInformationProcess( hProcess,
ProcessBasicInformation,
(PVOID)&pbi,
sizeof(PROCESS_BASIC_INFORMATION),
NULL
);

// Copy parent Id on success
if (!status)
dwParentPID = pbi.InheritedFromUniqueProcessId;

CloseHandle (hProcess);

return dwParentPID;
}