From: Florian Westphal <fw@strlen.de>
To: Phil Sutter <phil@nwl.cc>
Cc: Florian Westphal <fw@strlen.de>,
Pablo Neira Ayuso <pablo@netfilter.org>,
netfilter-devel@vger.kernel.org
Subject: Re: [nft PATCH RFC] scanner: nat: Move to own scope
Date: Mon, 9 Aug 2021 17:18:33 +0200 [thread overview]
Message-ID: <20210809151833.GM607@breakpoint.cc> (raw)
In-Reply-To: <20210809140141.18976-1-phil@nwl.cc>
Phil Sutter <phil@nwl.cc> wrote:
> Unify nat, masquerade and redirect statements, they widely share their
> syntax.
> This seemingly valid change breaks the parser with this rule:
>
> | snat ip prefix to ip saddr map { 10.141.11.0/24 : 192.168.2.0/24 }
Yes.
> Problem is that 'prefix' is not in SC_IP and close_scope_ip called from
> parser_bison.y:5067 is not sufficient. I assumed explicit scope closing
> would eliminate this lookahead problem. Did I find a proof against the
> concept or is there a bug in my patch?
You have to keep 'prefix' in the global scope.
What should work as well is to permit 'prefix' from SCANSTATE_IP(6).
The problem is that the parser can't close the new 'IP' scope until
it has enough tokens available to match a complete bison rule.
So, it is in IP scope, sees 'prefix' (which will be STRING as the
PREFIX scan rule is off) and that ends up in a parser error due to lack
of a 'IP STRING' rule.
next prev parent reply other threads:[~2021-08-09 15:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-09 14:01 [nft PATCH RFC] scanner: nat: Move to own scope Phil Sutter
2021-08-09 15:18 ` Florian Westphal [this message]
2021-08-09 16:25 ` Phil Sutter
2021-08-09 18:45 ` Florian Westphal
2021-08-10 11:19 ` Phil Sutter
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=20210809151833.GM607@breakpoint.cc \
--to=fw@strlen.de \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=phil@nwl.cc \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).