LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Ahmed S. Darwish" <darwish.07@gmail.com>
To: Adrian Bunk <bunk@kernel.org>
Cc: Kyle Moffett <mrmacman_g4@mac.com>,
	Casey Schaufler <casey@schaufler-ca.com>,
	akpm@osdl.org, torvalds@osdl.org,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Smackv10: Smack rules grammar + their stateful parser
Date: Tue, 6 Nov 2007 16:05:13 +0200	[thread overview]
Message-ID: <20071106140504.GA6310@ubuntu> (raw)
In-Reply-To: <20071106133446.GI26163@stusta.de>

On Tue, Nov 06, 2007 at 02:34:46PM +0100, Adrian Bunk wrote:
> On Tue, Nov 06, 2007 at 07:49:26AM -0500, Kyle Moffett wrote:
> > On Nov 06, 2007, at 07:23:36, Ahmed S. Darwish wrote:
> >> On 11/6/07, Adrian Bunk <bunk@kernel.org> wrote:
> >>> On Tue, Nov 06, 2007 at 01:34:05PM +0200, Ahmed S. Darwish wrote:
> >>>> As far as I understand the problem now, isspace() accepts the 0xa0 
> >>>> character which might collide with some of UTF-8 encoded characters 
> >>>> cause the high bit is set.
> >>
> >> I admit I'm not experienced in such encoding stuff, but shouldn't the 
> >> ASCII and the ASCII-compatible UTF-8 encodings be enough for the labels?
> >>
> >>> It would not work if someone would e.g. give you UTF-16 encoded strings, 
> >>> but I don't see this happening in practice.
> >>
> >> Won't this complicate the code too much ?
> >
> > Well the VFS (for example) certainly doesn't support any encodings other 
> > than various extended-ASCII forms (which includes UTF-8).  Something like 
> > UTF-16 has extra null characters in-between every normal character, and as 
> > such would fail completely if passed to the VFS.
> 
> Good point.
> 
> > Personally I think that isspace() accepting character 0xA0 is a bug, as 
> > there are several variants of extended ASCII only one of which has that 
> > character as a space.  Others have it as ?? (accented A), etc.
> 
> But even then Smack would still have a similar problem with isgraph().
> 

Great, To summarize the discussion. Will there be a problem in 
accepting ASCII and the UTF-8 ASCII _subset_ _only_ and  return 
-EINVAL for all other cases/ecnodings ?.

i.e. The fragment I sent in a previous message:

/* Filter UTF-8 non-ascii compatible bytes (> 0x7F) */
if (!isascii(c)) return -EINVAL; 
/* Filter unwanted ascii chars */
if (!isspace(c) && !isgraph(c)) return -EINVAL; 

> > In addition 
> > the "canonical" internal text format of the kernel is UTF-8 as that 
> > encoding can represent any character in any other encoding and it is 
> > backwards-compatible with traditional ASCII.
> > 
> > Cheers,
> > Kyle Moffett-
> 
> cu
> Adrian
> 

--
Ahmed S. Darwish
Homepage: http://darwish.07.googlepages.com
Blog: http://darwish-07.blogspot.com

  reply	other threads:[~2007-11-06 14:05 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-02 20:50 [PATCH] Version 10 (2.6.24-rc1) Smack: Simplified Mandatory Access Control Kernel Casey Schaufler
2007-11-03 16:43 ` [PATCH] Smackv10: Smack rules grammar + their stateful parser Ahmed S. Darwish
2007-11-03 18:30   ` Kyle Moffett
2007-11-03 22:12     ` Ahmed S. Darwish
2007-11-04 12:28   ` Pavel Machek
2007-11-04 13:23     ` Ahmed S. Darwish
2007-11-04 16:37       ` Casey Schaufler
2007-11-05  9:41     ` Ahmed S. Darwish
2007-11-05 16:21       ` Linus Torvalds
2007-11-05 21:56         ` Tetsuo Handa
2007-11-06 10:00           ` Adrian Bunk
2007-11-06 12:27             ` Tetsuo Handa
2007-11-06 13:58               ` Adrian Bunk
2007-11-06 14:32                 ` Tetsuo Handa
2007-11-06 14:59                   ` Adrian Bunk
2007-11-06 15:27                     ` Tetsuo Handa
2007-11-06 22:42                       ` Adrian Bunk
2007-11-05 23:38         ` Ahmed S. Darwish
2007-11-06  8:06         ` Adrian Bunk
2007-11-06 15:39           ` Linus Torvalds
2007-11-06 23:00             ` Adrian Bunk
2007-11-06 23:08               ` Linus Torvalds
2007-11-07  0:07                 ` Adrian Bunk
2007-11-07  0:27                   ` Linus Torvalds
2007-11-07  0:43                     ` Adrian Bunk
2007-11-07  1:03                       ` Tetsuo Handa
2007-11-07  1:06                       ` Linus Torvalds
2007-11-07  1:59                         ` Adrian Bunk
2007-11-07  4:09                           ` Linus Torvalds
2007-11-07 15:08                           ` Alan Cox
2007-11-04 20:06   ` Ahmed S. Darwish
2007-11-05  0:56   ` [PATCH] Smackv10: Smack rules grammar + their stateful parser(2) Ahmed S. Darwish
2007-11-10 17:05     ` Jakob Oestergaard
2007-11-10 19:45       ` Ahmed S. Darwish
2007-11-11 12:44     ` Pavel Machek
2007-11-11 18:37       ` Ahmed S. Darwish
2007-11-06  6:33   ` [PATCH] Smackv10: Smack rules grammar + their stateful parser Adrian Bunk
2007-11-06  8:26     ` Kyle Moffett
2007-11-06  8:56       ` Adrian Bunk
2007-11-06 11:02         ` Alan Cox
2007-11-06 11:34         ` Ahmed S. Darwish
2007-11-06 11:47           ` Adrian Bunk
2007-11-06 12:23             ` Ahmed S. Darwish
2007-11-06 12:49               ` Kyle Moffett
2007-11-06 13:34                 ` Adrian Bunk
2007-11-06 14:05                   ` Ahmed S. Darwish [this message]
2007-11-06 14:10                     ` Adrian Bunk
2007-11-06 14:30                       ` Ahmed S. Darwish
2007-11-06 15:53                 ` Linus Torvalds
2007-11-07 10:56                   ` [PATCH] Fix isspace() and other ctype.h functions to ignore chars 128-255 Kyle Moffett

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20071106140504.GA6310@ubuntu \
    --to=darwish.07@gmail.com \
    --cc=akpm@osdl.org \
    --cc=bunk@kernel.org \
    --cc=casey@schaufler-ca.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mrmacman_g4@mac.com \
    --cc=torvalds@osdl.org \
    --subject='Re: [PATCH] Smackv10: Smack rules grammar + their stateful parser' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox