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From: Phil Sutter <phil@nwl.cc>
To: Fernando Fernandez Mancera <ffmancera@riseup.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nft v2 1/6] osf: add version fingerprint support
Date: Wed, 13 Mar 2019 16:34:55 +0100	[thread overview]
Message-ID: <20190313153455.GN4851@orbyte.nwl.cc> (raw)
In-Reply-To: <2b070950-1441-ae1b-fe52-72dc7bc4455e@riseup.net>

On Wed, Mar 13, 2019 at 04:22:27PM +0100, Fernando Fernandez Mancera wrote:
> On 3/13/19 4:06 PM, Phil Sutter wrote:
> > Hi Fernando,
> > 
> > On Wed, Mar 13, 2019 at 03:15:51PM +0100, Fernando Fernandez Mancera wrote:
> >> On 3/13/19 12:27 PM, Phil Sutter wrote:
> >>> On Wed, Mar 13, 2019 at 11:14:04AM +0100, Fernando Fernandez Mancera wrote:
> >>>> Hi Phil,
> >>>>
> >>>> On 3/13/19 10:44 AM, Phil Sutter wrote:
> >>>>> Hi Fernando,
> >>>>>
> >>>>> On Mon, Mar 11, 2019 at 04:14:12PM +0100, Fernando Fernandez Mancera wrote:
> >>>>>> Add support for version fingerprint in "osf" expression. Example:
> >>>>>>
> >>>>>> table ip foo {
> >>>>>> 	chain bar {
> >>>>>> 		type filter hook input priority filter; policy accept;
> >>>>>> 		osf ttl skip name "Linux"
> >>>>>> 		osf ttl skip name version "Linux:4.20"
> >>>>>> 	}
> >>>>>> }
> >>>>>
> >>>>> The syntax seems overly complicated to me, although I'm not really
> >>>>> familiar with OSF so may lack background knowledge. Any reason why you
> >>>>> didn't go with 'osf ttl skip name "Linux" version "4.20"' instead?
> >>>>>
> >>>>
> >>>> You are right, 'osf ttl skip name "Linux" version "4.20"' was my first
> >>>> thought but in compilation time the parser applies shift-reduce to the
> >>>> expression.. I decided 'osf ttl skip name version "Linux:4.20"' to avoid
> >>>> a complex workaround in the parser.
> >>>
> >>> Shift/reduce warnings often require voodoo to fix, but it's not
> >>> impossible. :)
> >>>
> >>> Regarding my suggestion, I see that this string is actually the
> >>> right-hand-side of a relational expression. To implement what I had in
> >>> mind you would have to turn osf expression into a statement.
> >>>
> >>>> The fingerprints database syntax is "genre:version:subtype:details" so
> >>>> the nft 'osf' expression syntax is like the original one.
> >>>
> >>> Can we deduce required flags from the given string on RHS? I.e. by
> >>> looking at the amount of semi-colons and the number of characters
> >>> between them? I'm assuming the syntax works like "genre::subtype" and
> >>> "genre:::details" to omit certain parts, is that correct?
> >>>
> >>
> >> Yes that is correct. We can do that if you think it is more suitable. Do
> >> we all agree then?
> > 
> > I think reducing redundancy is always a good thing. Only having to
> > specify the string and extracting the required info from it would make
> > it easier for users I guess.
> > 
> > That whole string is sent to the kernel, right? So it wouldn't make
> > sense to split the fields it is made up from into separate properties in
> > JSON, correct?
> > 
> > Thanks, Phil
> > 
> 
> Yes, that makes sense. In this case, we don't need flags support anymore
> so it reduces the patch series. Should we continue with the
> implementation of the flags support or just forget about it until needed
> again?

What other flags do you have in mind?

Cheers, Phil

  reply	other threads:[~2019-03-13 15:35 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-11 15:14 [PATCH nft v2 1/6] osf: add version fingerprint support Fernando Fernandez Mancera
2019-03-11 15:14 ` [PATCH nft v2 2/6] json: osf: add version json support Fernando Fernandez Mancera
2019-03-11 15:14 ` [PATCH nft v2 3/6] tests: py: add osf tests with versions Fernando Fernandez Mancera
2019-03-11 15:14 ` [PATCH nft v2 4/6] doc: add osf version option to man page Fernando Fernandez Mancera
2019-03-11 15:14 ` [PATCH nft v2 5/6] files: osf: update pf.os with newer OS fingerprints Fernando Fernandez Mancera
2019-03-11 15:14 ` [PATCH nft v2 6/6] files: pf.os: merge the signatures spllited by version Fernando Fernandez Mancera
2019-03-13  9:44 ` [PATCH nft v2 1/6] osf: add version fingerprint support Phil Sutter
2019-03-13 10:14   ` Fernando Fernandez Mancera
2019-03-13 11:27     ` Phil Sutter
2019-03-13 14:15       ` Fernando Fernandez Mancera
2019-03-13 15:06         ` Phil Sutter
2019-03-13 15:22           ` Fernando Fernandez Mancera
2019-03-13 15:34             ` Phil Sutter [this message]
2019-03-13 16:46               ` Fernando Fernandez Mancera
2019-03-14 11:14                 ` Fernando Fernandez Mancera
2019-03-14 13:58                   ` Pablo Neira Ayuso
2019-03-14 17:34                     ` Phil Sutter
2019-03-14 18:24                       ` Fernando Fernandez Mancera
2019-03-15 10:03                         ` Phil Sutter
2019-03-15 17:13                           ` Pablo Neira Ayuso
2019-03-15 20:21                             ` Fernando Fernandez Mancera
2019-03-16  9:05                               ` Pablo Neira Ayuso
2019-03-17 17:10                                 ` Fernando Fernandez Mancera
2019-03-18 17:42                             ` Phil Sutter
2019-03-19 11:06                               ` Pablo Neira Ayuso
2019-03-20 13:46                                 ` Phil Sutter
2019-03-21  8:32                                   ` Pablo Neira Ayuso
2019-03-21 11:15                                     ` Phil Sutter
2019-03-21 11:18                                       ` Pablo Neira Ayuso
2019-03-21 14:06                                         ` Phil Sutter
2019-03-21 16:57                                           ` Pablo Neira Ayuso
2019-03-21 18:14                                             ` Phil Sutter
2019-03-14 20:07                       ` Pablo Neira Ayuso
2019-03-14 20:13                         ` [PATCH nft v2 1/6] osf: add version fingerprint supportg Pablo Neira Ayuso

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