Re: O_NOACCESS?

[Matt Thomas <matt%3am-software.com@localhost>]

On Feb 11, 2012, at 12:31 AM, Mouse wrote:

>>>> Why not use O_DIRECTORY (which is part of -current) and add that to
>>>> flags?
>>> Backporting that might be a better alternative.  What are its
>>> semantics?
>> It means the open will only succeed is the file is a directory.
> 
> Worth having, but not sufficient by itself, because it still requires
> something in the low two bits, and without something like O_NOACCESS
> there is nothing you can pass there that will let you open a directory
> you have neither read nor write access to (even if you have search
> access to it).

Right.  You add O_DIRECTORY to that check.

if ((flags & (FREAD|FWRITE)) == 0 && (flags & O_DIRECTORY) == 0)
        return EINVAL;
if ((flags & O_DIRECTORY) != 0 && (flags & (FREAD|FWRITE)) != 0)
        return EINVAL;