tags:

views:

74

answers:

1

trying to figure out what progress lock a file using the class below. can anyone explain whats going wrong here.

call:

private void button1_Click(object sender, EventArgs e)
{
    Console.WriteLine(Win32Processes.GetProcessesLockingFile("locked_file.dll").ToString());
}

output: System.Collections.Generic.List`1[System.Diagnostics.Process]

using this call:

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Text;
using System.Threading;

namespace FileLockInfo {

    public class Win32Processes {

        /// <summary>
        /// Return a list of processes that hold on the given file.
        /// </summary>
        public static List<Process> GetProcessesLockingFile (string filePath) {
            var procs = new List<Process>();

            foreach (var process in Process.GetProcesses()) {
                var files = GetFilesLockedBy(process);
                if (files.Contains(filePath)) procs.Add(process);
            }
            return procs;
        }

        /// <summary>
        /// Return a list of file locks held by the process.
        /// </summary>
        public static List<string> GetFilesLockedBy (Process process) {
            var outp = new List<string>();

            ThreadStart ts = delegate {
                try {
                    outp = UnsafeGetFilesLockedBy(process);
                } catch {
                }
            };


            try {
                var t = new Thread(ts);
                t.Start();
                if (!t.Join(250)) {
                    try {
                        t.Abort();
                    } catch { }
                }
            } catch {
            }

            return outp;
        }

        #region Inner Workings
        private static List<string> UnsafeGetFilesLockedBy (Process process) {
            try {
                var handles = GetHandles(process);
                var files = new List<string>();

                foreach (var handle in handles) {
                    var file = GetFilePath(handle, process);
                    if (file != null) files.Add(file);
                }

                return files;
            } catch {
                return new List<string>();
            }
        }

        const int CNST_SYSTEM_HANDLE_INFORMATION = 16;
        const uint STATUS_INFO_LENGTH_MISMATCH = 0xc0000004;
        private static string GetFilePath (Win32API.SYSTEM_HANDLE_INFORMATION sYSTEM_HANDLE_INFORMATION, Process process) {
            IntPtr m_ipProcessHwnd = Win32API.OpenProcess(Win32API.ProcessAccessFlags.All, false, process.Id);
            IntPtr ipHandle = IntPtr.Zero;
            var objBasic = new Win32API.OBJECT_BASIC_INFORMATION();
            IntPtr ipBasic = IntPtr.Zero;
            var objObjectType = new Win32API.OBJECT_TYPE_INFORMATION();
            IntPtr ipObjectType = IntPtr.Zero;
            var objObjectName = new Win32API.OBJECT_NAME_INFORMATION();
            IntPtr ipObjectName = IntPtr.Zero;
            string strObjectTypeName = "";
            string strObjectName = "";
            int nLength = 0;
            int nReturn = 0;
            IntPtr ipTemp = IntPtr.Zero;

            if (!Win32API.DuplicateHandle(m_ipProcessHwnd, sYSTEM_HANDLE_INFORMATION.Handle, Win32API.GetCurrentProcess(), out ipHandle, 0, false, Win32API.DUPLICATE_SAME_ACCESS))
                return null;

            ipBasic = Marshal.AllocHGlobal(Marshal.SizeOf(objBasic));
            Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectBasicInformation, ipBasic, Marshal.SizeOf(objBasic), ref nLength);
            objBasic = (Win32API.OBJECT_BASIC_INFORMATION)Marshal.PtrToStructure(ipBasic, objBasic.GetType());
            Marshal.FreeHGlobal(ipBasic);


            ipObjectType = Marshal.AllocHGlobal(objBasic.TypeInformationLength);
            nLength = objBasic.TypeInformationLength;
            while ((uint)(nReturn = Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectTypeInformation, ipObjectType, nLength, ref nLength)) == Win32API.STATUS_INFO_LENGTH_MISMATCH) {
                Marshal.FreeHGlobal(ipObjectType);
                ipObjectType = Marshal.AllocHGlobal(nLength);
            }

            objObjectType = (Win32API.OBJECT_TYPE_INFORMATION)Marshal.PtrToStructure(ipObjectType, objObjectType.GetType());
            if (Is64Bits()) {
                ipTemp = new IntPtr(Convert.ToInt64(objObjectType.Name.Buffer.ToString(), 10) >> 32);
            } else {
                ipTemp = objObjectType.Name.Buffer;
            }

            strObjectTypeName = Marshal.PtrToStringUni(ipTemp, objObjectType.Name.Length >> 1);
            Marshal.FreeHGlobal(ipObjectType);
            if (strObjectTypeName != "File")
                return null;

            nLength = objBasic.NameInformationLength;

            ipObjectName = Marshal.AllocHGlobal(nLength);
            while ((uint)(nReturn = Win32API.NtQueryObject(ipHandle, (int)Win32API.ObjectInformationClass.ObjectNameInformation, ipObjectName, nLength, ref nLength)) == Win32API.STATUS_INFO_LENGTH_MISMATCH) {
                Marshal.FreeHGlobal(ipObjectName);
                ipObjectName = Marshal.AllocHGlobal(nLength);
            }
            objObjectName = (Win32API.OBJECT_NAME_INFORMATION)Marshal.PtrToStructure(ipObjectName, objObjectName.GetType());

            if (Is64Bits()) {
                ipTemp = new IntPtr(Convert.ToInt64(objObjectName.Name.Buffer.ToString(), 10) >> 32);
            } else {
                ipTemp = objObjectName.Name.Buffer;
            }

            if (ipTemp != IntPtr.Zero) {

                byte[] baTemp = new byte[nLength];
                try {
                    Marshal.Copy(ipTemp, baTemp, 0, nLength);

                    strObjectName = Marshal.PtrToStringUni(Is64Bits() ? new IntPtr(ipTemp.ToInt64()) : new IntPtr(ipTemp.ToInt32()));
                } catch (AccessViolationException) {
                    return null;
                } finally {
                    Marshal.FreeHGlobal(ipObjectName);
                    Win32API.CloseHandle(ipHandle);
                }
            }

            string path = GetRegularFileNameFromDevice(strObjectName);
            try {
                return path;
            } catch {
                return null;
            }
        }

        private static string GetRegularFileNameFromDevice (string strRawName) {
            string strFileName = strRawName;
            foreach (string strDrivePath in Environment.GetLogicalDrives()) {
                StringBuilder sbTargetPath = new StringBuilder(Win32API.MAX_PATH);
                if (Win32API.QueryDosDevice(strDrivePath.Substring(0, 2), sbTargetPath, Win32API.MAX_PATH) == 0) {
                    return strRawName;
                }
                string strTargetPath = sbTargetPath.ToString();
                if (strFileName.StartsWith(strTargetPath)) {
                    strFileName = strFileName.Replace(strTargetPath, strDrivePath.Substring(0, 2));
                    break;
                }
            }
            return strFileName;
        }

        private static List<Win32API.SYSTEM_HANDLE_INFORMATION> GetHandles (Process process) {
            uint nStatus;
            int nHandleInfoSize = 0x10000;
            IntPtr ipHandlePointer = Marshal.AllocHGlobal(nHandleInfoSize);
            int nLength = 0;
            IntPtr ipHandle = IntPtr.Zero;

            while ((nStatus = Win32API.NtQuerySystemInformation(CNST_SYSTEM_HANDLE_INFORMATION, ipHandlePointer, nHandleInfoSize, ref nLength)) == STATUS_INFO_LENGTH_MISMATCH) {
                nHandleInfoSize = nLength;
                Marshal.FreeHGlobal(ipHandlePointer);
                ipHandlePointer = Marshal.AllocHGlobal(nLength);
            }

            byte[] baTemp = new byte[nLength];
            Marshal.Copy(ipHandlePointer, baTemp, 0, nLength);

            long lHandleCount = 0;
            if (Is64Bits()) {
                lHandleCount = Marshal.ReadInt64(ipHandlePointer);
                ipHandle = new IntPtr(ipHandlePointer.ToInt64() + 8);
            } else {
                lHandleCount = Marshal.ReadInt32(ipHandlePointer);
                ipHandle = new IntPtr(ipHandlePointer.ToInt32() + 4);
            }

            Win32API.SYSTEM_HANDLE_INFORMATION shHandle;
            List<Win32API.SYSTEM_HANDLE_INFORMATION> lstHandles = new List<Win32API.SYSTEM_HANDLE_INFORMATION>();

            for (long lIndex = 0; lIndex < lHandleCount; lIndex++) {
                shHandle = new Win32API.SYSTEM_HANDLE_INFORMATION();
                if (Is64Bits()) {
                    shHandle = (Win32API.SYSTEM_HANDLE_INFORMATION)Marshal.PtrToStructure(ipHandle, shHandle.GetType());
                    ipHandle = new IntPtr(ipHandle.ToInt64() + Marshal.SizeOf(shHandle) + 8);
                } else {
                    ipHandle = new IntPtr(ipHandle.ToInt64() + Marshal.SizeOf(shHandle));
                    shHandle = (Win32API.SYSTEM_HANDLE_INFORMATION)Marshal.PtrToStructure(ipHandle, shHandle.GetType());
                }
                if (shHandle.ProcessID != process.Id) continue;
                lstHandles.Add(shHandle);
            }
            return lstHandles;

        }

        private static bool Is64Bits () {
            return Marshal.SizeOf(typeof(IntPtr)) == 8 ? true : false;
        }

        internal class Win32API {
            [DllImport("ntdll.dll")]
            public static extern int NtQueryObject (IntPtr ObjectHandle, int
                ObjectInformationClass, IntPtr ObjectInformation, int ObjectInformationLength,
                ref int returnLength);

            [DllImport("kernel32.dll", SetLastError = true)]
            public static extern uint QueryDosDevice (string lpDeviceName, StringBuilder lpTargetPath, int ucchMax);

            [DllImport("ntdll.dll")]
            public static extern uint NtQuerySystemInformation (int
                SystemInformationClass, IntPtr SystemInformation, int SystemInformationLength,
                ref int returnLength);

            [DllImport("kernel32.dll")]
            public static extern IntPtr OpenProcess (ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, int dwProcessId);
            [DllImport("kernel32.dll")]
            public static extern int CloseHandle (IntPtr hObject);
            [DllImport("kernel32.dll", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool DuplicateHandle (IntPtr hSourceProcessHandle,
               ushort hSourceHandle, IntPtr hTargetProcessHandle, out IntPtr lpTargetHandle,
               uint dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwOptions);
            [DllImport("kernel32.dll")]
            public static extern IntPtr GetCurrentProcess ();

            public enum ObjectInformationClass : int {
                ObjectBasicInformation = 0,
                ObjectNameInformation = 1,
                ObjectTypeInformation = 2,
                ObjectAllTypesInformation = 3,
                ObjectHandleInformation = 4
            }

            [Flags]
            public enum ProcessAccessFlags : uint {
                All = 0x001F0FFF,
                Terminate = 0x00000001,
                CreateThread = 0x00000002,
                VMOperation = 0x00000008,
                VMRead = 0x00000010,
                VMWrite = 0x00000020,
                DupHandle = 0x00000040,
                SetInformation = 0x00000200,
                QueryInformation = 0x00000400,
                Synchronize = 0x00100000
            }

            [StructLayout(LayoutKind.Sequential)]
            public struct OBJECT_BASIC_INFORMATION { // Information Class 0
                public int Attributes;
                public int GrantedAccess;
                public int HandleCount;
                public int PointerCount;
                public int PagedPoolUsage;
                public int NonPagedPoolUsage;
                public int Reserved1;
                public int Reserved2;
                public int Reserved3;
                public int NameInformationLength;
                public int TypeInformationLength;
                public int SecurityDescriptorLength;
                public System.Runtime.InteropServices.ComTypes.FILETIME CreateTime;
            }

            [StructLayout(LayoutKind.Sequential)]
            public struct OBJECT_TYPE_INFORMATION { // Information Class 2
                public UNICODE_STRING Name;
                public int ObjectCount;
                public int HandleCount;
                public int Reserved1;
                public int Reserved2;
                public int Reserved3;
                public int Reserved4;
                public int PeakObjectCount;
                public int PeakHandleCount;
                public int Reserved5;
                public int Reserved6;
                public int Reserved7;
                public int Reserved8;
                public int InvalidAttributes;
                public GENERIC_MAPPING GenericMapping;
                public int ValidAccess;
                public byte Unknown;
                public byte MaintainHandleDatabase;
                public int PoolType;
                public int PagedPoolUsage;
                public int NonPagedPoolUsage;
            }

            [StructLayout(LayoutKind.Sequential)]
            public struct OBJECT_NAME_INFORMATION { // Information Class 1
                public UNICODE_STRING Name;
            }

            [StructLayout(LayoutKind.Sequential, Pack = 1)]
            public struct UNICODE_STRING {
                public ushort Length;
                public ushort MaximumLength;
                public IntPtr Buffer;
            }

            [StructLayout(LayoutKind.Sequential)]
            public struct GENERIC_MAPPING {
                public int GenericRead;
                public int GenericWrite;
                public int GenericExecute;
                public int GenericAll;
            }

            [StructLayout(LayoutKind.Sequential, Pack = 1)]
            public struct SYSTEM_HANDLE_INFORMATION { // Information Class 16
                public int ProcessID;
                public byte ObjectTypeNumber;
                public byte Flags; // 0x01 = PROTECT_FROM_CLOSE, 0x02 = INHERIT
                public ushort Handle;
                public int Object_Pointer;
                public UInt32 GrantedAccess;
            }

            public const int MAX_PATH = 260;
            public const uint STATUS_INFO_LENGTH_MISMATCH = 0xC0000004;
            public const int DUPLICATE_SAME_ACCESS = 0x2;
        }
        #endregion
    }
}
+2  A: 

You are calling .ToString on a list and that is why you are seeing the output : System.Collections.Generic.List`1[System.Diagnostics.Process].

You need to loop over the returned list from GetProcessesLockingFile and call the ProcessName property of the process object to get the name.

EDIT

ProcessName docs

EXAMPLE

List<Process> processes = Win32Processes.GetProcessesLockingFile("locked_file.dll");

foreach (Process proc in processes)
{
  Console.WriteLine("Process: " + proc.ProcessName);
}
Tony Abrams
can you please explain more about how to loop over GetProcessesLockingFile.
Power-Mosfet
An example was added.
Tony Abrams