Re: [ros-dev] [ros-diffs] [pschweitzer] 53823: [KERNEL32] Simplify overcomplicated function CreateHardlinkW(), and SEHify it.

[Alex Ionescu]

Why are you putting SEH everywhere??? Just to avoid goto? This is infinitely
retarded. Exceptions should not be used as a mechanism for flow control.

Best regards,
Alex Ionescu


On Sat, Sep 24, 2011 at 3:51 AM, <pschweitzer(a)svn.reactos.org> wrote:

>   Author: pschweitzer
>  Date: Sat Sep 24 07:51:21 2011
>  New Revision: 53823
>
>  URL: http://svn.reactos.org/svn/reactos?rev=53823&view=rev
>  Log:
>  [KERNEL32]
>  Simplify overcomplicated function CreateHardlinkW(), and SEHify it.
>
>  Modified:
>     trunk/reactos/dll/win32/kernel32/client/file/hardlink.c
>
>  Modified: trunk/reactos/dll/win32/kernel32/client/file/hardlink.c
>  URL:
>
> http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/kernel32/client/…
>
>  ==============================================================================
>  --- trunk/reactos/dll/win32/kernel32/client/file/hardlink.c [iso-8859-1]
>  (original)
>  +++ trunk/reactos/dll/win32/kernel32/client/file/hardlink.c [iso-8859-1]
>  Sat Sep 24 07:51:21 2011
>  @@ -2,11 +2,10 @@
>   *
>   * COPYRIGHT:       See COPYING in the top level directory
>   * PROJECT:         ReactOS system libraries
>  - * FILE:            lib/kernel32/file/hardlink.c
>  + * FILE:            dll/win32/kernel32/client/file/hardlink.c
>   * PURPOSE:         Hardlink functions
>   * PROGRAMMER:      Thomas Weidenmueller (w3seek(a)users.sourceforge.net)
>  - * UPDATE HISTORY:
>  - *                  Created 13/03/2004
>  + *                  Pierre Schweitzer (pierre.schweitzer(a)reactos.org)
>   */
>
>   /* INCLUDES
>  *****************************************************************/
>  @@ -27,169 +26,110 @@
>                  LPCWSTR lpExistingFileName,
>                  LPSECURITY_ATTRIBUTES lpSecurityAttributes)
>   {
>  -  UNICODE_STRING LinkTarget, LinkName;
>  -  LPVOID lpSecurityDescriptor;
>  -  PFILE_LINK_INFORMATION LinkInformation;
>  -  IO_STATUS_BLOCK IoStatus;
>  -  NTSTATUS Status;
>  -  BOOL Ret = FALSE;
>  +    NTSTATUS Status;
>  +    BOOL Ret = FALSE;
>  +    ULONG NeededSize;
>  +    IO_STATUS_BLOCK IoStatusBlock;
>  +    OBJECT_ATTRIBUTES ObjectAttributes;
>  +    HANDLE hTarget = INVALID_HANDLE_VALUE;
>  +    PFILE_LINK_INFORMATION LinkInformation = NULL;
>  +    UNICODE_STRING LinkTarget = {0, 0, NULL}, LinkName = {0, 0, NULL};
>
>  -  if(!lpFileName || !lpExistingFileName)
>  -  {
>  -    SetLastError(ERROR_INVALID_PARAMETER);
>  -    return FALSE;
>  -  }
>  +    TRACE("CreateHardLinkW: %S, %S, %p\n", lpFileName, lpExistingFileName,
>  lpSecurityAttributes);
>
>  -  lpSecurityDescriptor = (lpSecurityAttributes ?
>  lpSecurityAttributes->lpSecurityDescriptor : NULL);
>  +    /* Validate parameters */
>  +    if(!lpFileName || !lpExistingFileName)
>  +    {
>  +        SetLastError(ERROR_INVALID_PARAMETER);
>  +        return FALSE;
>  +    }
>
>  -  if(RtlDetermineDosPathNameType_U((LPWSTR)lpFileName) == 1 ||
>  -     RtlDetermineDosPathNameType_U((LPWSTR)lpExistingFileName) == 1)
>  -  {
>  -    WARN("CreateHardLinkW() cannot handle UNC Paths!\n");
>  -    SetLastError(ERROR_INVALID_NAME);
>  -    return FALSE;
>  -  }
>  +    _SEH2_TRY
>  +    {
>  +        /* Get target UNC path */
>  +        if (!RtlDosPathNameToNtPathName_U(lpExistingFileName, &LinkTarget,
>  NULL, NULL))
>  +        {
>  +            SetLastError(ERROR_PATH_NOT_FOUND);
>  +            _SEH2_LEAVE;
>  +        }
>
>  -  if(RtlDosPathNameToNtPathName_U(lpExistingFileName, &LinkTarget, NULL,
>  NULL))
>  -  {
>  -    ULONG NeededSize = RtlGetFullPathName_U((LPWSTR)lpExistingFileName, 0,
>  NULL, NULL);
>  -    if(NeededSize > 0)
>  +        /* Open target */
>  +        InitializeObjectAttributes(&ObjectAttributes,
>  +                                   &LinkTarget,
>  +                                   OBJ_CASE_INSENSITIVE,
>  +                                   NULL,
>  +                                   (lpSecurityAttributes ?
>  lpSecurityAttributes->lpSecurityDescriptor : NULL));
>  +
>  +        Status = NtOpenFile(&hTarget,
>  +                            SYNCHRONIZE | FILE_WRITE_ATTRIBUTES,
>  +                            &ObjectAttributes,
>  +                            &IoStatusBlock,
>  +                            FILE_SHARE_READ | FILE_SHARE_WRITE |
>  FILE_SHARE_DELETE,
>  +                            FILE_SYNCHRONOUS_IO_NONALERT |
>  FILE_OPEN_REPARSE_POINT);
>  +        if (!NT_SUCCESS(Status))
>  +        {
>  +            BaseSetLastNTError(Status);
>  +            _SEH2_LEAVE;
>  +        }
>  +
>  +        /* Get UNC path name for link */
>  +        if (!RtlDosPathNameToNtPathName_U(lpFileName, &LinkName, NULL,
>  NULL))
>  +        {
>  +            SetLastError(ERROR_PATH_NOT_FOUND);
>  +            _SEH2_LEAVE;
>  +        }
>  +
>  +        /* Prepare data for link */
>  +        NeededSize = sizeof(FILE_LINK_INFORMATION) + LinkName.Length;
>  +        LinkInformation = RtlAllocateHeap(RtlGetProcessHeap(), 0,
>  NeededSize);
>  +        if (!LinkInformation)
>  +        {
>  +            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
>  +            _SEH2_LEAVE;
>  +        }
>  +
>  +        RtlMoveMemory(LinkInformation->FileName, LinkName.Buffer,
>  LinkName.Length);
>  +        LinkInformation->ReplaceIfExists = FALSE;
>  +        LinkInformation->RootDirectory = 0;
>  +        LinkInformation->FileNameLength = LinkName.Length;
>  +
>  +        /* Create hard link */
>  +        Status = NtSetInformationFile(hTarget,
>  +                                      &IoStatusBlock,
>  +                                      LinkInformation,
>  +                                      NeededSize,
>  +                                      FileLinkInformation);
>  +        if (NT_SUCCESS(Status))
>  +        {
>  +            Ret = TRUE;
>  +        }
>  +    }
>  +    _SEH2_FINALLY
>      {
>  -      LPWSTR lpNtLinkTarget = RtlAllocateHeap(RtlGetProcessHeap(),
>  HEAP_ZERO_MEMORY, NeededSize * sizeof(WCHAR));
>  -      if(lpNtLinkTarget != NULL)
>  -      {
>  -        LPWSTR lpFilePart;
>  +        if (LinkTarget.Buffer)
>  +        {
>  +            RtlFreeHeap(RtlGetProcessHeap(), 0, LinkTarget.Buffer);
>  +        }
>
>  -        if(RtlGetFullPathName_U((LPWSTR)lpExistingFileName, NeededSize,
>  lpNtLinkTarget, &lpFilePart) &&
>  -           (*lpNtLinkTarget) != L'\0')
>  +        if (hTarget != INVALID_HANDLE_VALUE)
>          {
>  -          UNICODE_STRING CheckDrive, LinkDrive;
>  -          WCHAR wCheckDrive[10];
>  +            NtClose(hTarget);
>  +        }
>
>  -          swprintf(wCheckDrive, L"\\??\\%c:", (WCHAR)(*lpNtLinkTarget));
>  -          RtlInitUnicodeString(&CheckDrive, wCheckDrive);
>  +        if (LinkName.Buffer)
>  +        {
>  +            RtlFreeHeap(RtlGetProcessHeap(), 0, LinkName.Buffer);
>  +        }
>
>  -          RtlZeroMemory(&LinkDrive, sizeof(UNICODE_STRING));
>  +        if (LinkInformation)
>  +        {
>  +            RtlFreeHeap(RtlGetProcessHeap(), 0, LinkInformation);
>  +        }
>  +    }
>  +    _SEH2_END;
>
>  -          LinkDrive.Buffer = RtlAllocateHeap(RtlGetProcessHeap(),
>  HEAP_ZERO_MEMORY, (MAX_PATH + 1) * sizeof(WCHAR));
>  -          if(LinkDrive.Buffer != NULL)
>  -          {
>  -            HANDLE hFile, hTarget;
>  -            OBJECT_ATTRIBUTES ObjectAttributes;
>  -
>  -            InitializeObjectAttributes(&ObjectAttributes,
>  -                                       &CheckDrive,
>  -                                       OBJ_CASE_INSENSITIVE,
>  -                                       NULL,
>  -                                       NULL);
>  -
>  -            Status = NtOpenSymbolicLinkObject(&hFile, 1,
>  &ObjectAttributes);
>  -            if(NT_SUCCESS(Status))
>  -            {
>  -              UNICODE_STRING LanManager;
>  -
>  -              RtlInitUnicodeString(&LanManager,
>  L"\\Device\\LanmanRedirector\\");
>  -
>  -              NtQuerySymbolicLinkObject(hFile, &LinkDrive, NULL);
>  -
>  -              if(!RtlPrefixUnicodeString(&LanManager, &LinkDrive, TRUE))
>  -              {
>  -                InitializeObjectAttributes(&ObjectAttributes,
>  -                                           &LinkTarget,
>  -                                           OBJ_CASE_INSENSITIVE,
>  -                                           NULL,
>  -                                           lpSecurityDescriptor);
>  -                Status = NtOpenFile(&hTarget,
>  -                                    SYNCHRONIZE | DELETE,
>  -                                    &ObjectAttributes,
>  -                                    &IoStatus,
>  -                                    FILE_SHARE_READ | FILE_SHARE_WRITE |
>  FILE_SHARE_DELETE,
>  -                                    FILE_SYNCHRONOUS_IO_NONALERT |
>  FILE_OPEN_FOR_BACKUP_INTENT | FILE_OPEN_REPARSE_POINT);
>  -                if(NT_SUCCESS(Status))
>  -                {
>  -                  if(RtlDosPathNameToNtPathName_U(lpFileName, &LinkName,
>  NULL, NULL))
>  -                  {
>  -                    NeededSize = sizeof(FILE_LINK_INFORMATION) +
>  LinkName.Length + sizeof(WCHAR);
>  -                    LinkInformation = RtlAllocateHeap(RtlGetProcessHeap(),
>  HEAP_ZERO_MEMORY, NeededSize);
>  -                    if(LinkInformation != NULL)
>  -                    {
>  -                      LinkInformation->ReplaceIfExists = FALSE;
>  -                      LinkInformation->RootDirectory = 0;
>  -                      LinkInformation->FileNameLength = LinkName.Length;
>  -                      RtlCopyMemory(LinkInformation->FileName,
>  LinkName.Buffer, LinkName.Length);
>  -
>  -                      Status = NtSetInformationFile(hTarget, &IoStatus,
>  LinkInformation, NeededSize, FileLinkInformation);
>  -                      if(NT_SUCCESS(Status))
>  -                      {
>  -                        Ret = TRUE;
>  -                      }
>  -                      else
>  -                      {
>  -                        BaseSetLastNTError(Status);
>  -                      }
>  -
>  -                      RtlFreeHeap(RtlGetProcessHeap(), 0,
>  LinkInformation);
>  -                    }
>  -                    else
>  -                    {
>  -                      SetLastError(ERROR_NOT_ENOUGH_MEMORY);
>  -                    }
>  -                  }
>  -                  else
>  -                  {
>  -                    SetLastError(ERROR_PATH_NOT_FOUND);
>  -                  }
>  -                  NtClose(hTarget);
>  -                }
>  -                else
>  -                {
>  -                  WARN("Unable to open link destination
> \"%wZ\"!\n",
>  &LinkTarget);
>  -                  BaseSetLastNTError(Status);
>  -                }
>  -              }
>  -              else
>  -              {
>  -                WARN("Path \"%wZ\" must not be a mapped drive!\n",
>  &LinkDrive);
>  -                SetLastError(ERROR_INVALID_NAME);
>  -              }
>  -
>  -              NtClose(hFile);
>  -            }
>  -            else
>  -            {
>  -              BaseSetLastNTError(Status);
>  -            }
>  -          }
>  -          else
>  -          {
>  -            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
>  -          }
>  -        }
>  -        else
>  -        {
>  -          SetLastError(ERROR_INVALID_NAME);
>  -        }
>  -        RtlFreeHeap(RtlGetProcessHeap(), 0, lpNtLinkTarget);
>  -      }
>  -      else
>  -      {
>  -        SetLastError(ERROR_NOT_ENOUGH_MEMORY);
>  -      }
>  -    }
>  -    else
>  -    {
>  -      SetLastError(ERROR_INVALID_NAME);
>  -    }
>  -    RtlFreeHeap(RtlGetProcessHeap(), 0, LinkTarget.Buffer);
>  -  }
>  -  else
>  -  {
>  -    SetLastError(ERROR_PATH_NOT_FOUND);
>  -  }
>  -
>  -  return Ret;
>  +    return Ret;
>   }
>  -
>
>   /*
>   * @implemented
>  @@ -199,26 +139,32 @@
>                  LPCSTR lpExistingFileName,
>                  LPSECURITY_ATTRIBUTES lpSecurityAttributes)
>   {
>  -  PWCHAR FileNameW, ExistingFileNameW;
>  -  BOOL Ret;
>  +    BOOL Ret;
>  +    PUNICODE_STRING lpFileNameW;
>  +    UNICODE_STRING ExistingFileNameW;
>
>  -  if(!lpFileName || !lpExistingFileName)
>  -  {
>  -    SetLastError(ERROR_INVALID_PARAMETER);
>  -    return FALSE;
>  -  }
>  +    lpFileNameW = Basep8BitStringToStaticUnicodeString(lpFileName);
>  +    if (!lpFileNameW)
>  +    {
>  +        return FALSE;
>  +    }
>
>  -  if (!(FileNameW = FilenameA2W(lpFileName, FALSE)))
>  -    return FALSE;
>  +    if (!lpExistingFileName)
>  +    {
>  +        SetLastError(ERROR_INVALID_PARAMETER);
>  +        return FALSE;
>  +    }
>
>  -  if (!(ExistingFileNameW = FilenameA2W(lpExistingFileName, TRUE)))
>  -    return FALSE;
>  +    if (!Basep8BitStringToDynamicUnicodeString(&ExistingFileNameW,
>  lpExistingFileName))
>  +    {
>  +        return FALSE;
>  +    }
>
>  -  Ret = CreateHardLinkW(FileNameW , ExistingFileNameW ,
>  lpSecurityAttributes);
>  +    Ret = CreateHardLinkW(lpFileNameW->Buffer, ExistingFileNameW.Buffer,
>  lpSecurityAttributes);
>
>  -  RtlFreeHeap(RtlGetProcessHeap(), 0, ExistingFileNameW);
>  +    RtlFreeHeap(RtlGetProcessHeap(), 0, ExistingFileNameW.Buffer);
>
>  -  return Ret;
>  +    return Ret;
>   }
>
>   /* EOF */
>
>
>