On Tue, Jun 01, 2004 at 06:11:55PM -0400, Pierre A. Humblet wrote: > >Christopher Faylor wrote: >> >> On Mon, May 31, 2004 at 06:46:11PM -0400, Pierre A. Humblet wrote: >> >This patch prevents NtCreateFile from creating files with special >> >names such as NUL. >> >Because this needs to be checked very often, I tried to code it >> >efficiently with a binary search (it can perhaps be reused elsewhere). >> > >> >The new function is_special_name() overlaps with special_name(), >> >although there are small differences (it was designed from tests >> >on XP Home Ed). Perhaps these two can be merged one day. >> >> Haven't we already done a "GetFileAttributes" on the path by the time >> it reaches the NtCreateFile? If so, couldn't we just avoid trying to >> create a file which has "bad" attributes? > >Chris, > >Yes, we have done a "GetFileAttributes". I just checked the values. >For AUX, CON, COMx, LPTx, NUL and PRN, the attribute is 0x20, > FILE_ATTRIBUTE_ARCHIVE >For conin$, conout$ and clock$ it is FFFFFFFF >So we could filter on those values and only test for special names >if necessary. >Is that what you meant?
I was hoping there might be more state available than that. Oh well. Is the GetFileType call any better? I keep thinking that there is a layer of translation that we're missing here and we should be somehow using an enumeration that the OS provides rather than coming up with our own table. cgf
