From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Jeremy Sowden <jeremy@azazel.net>
Cc: Netfilter Devel <netfilter-devel@vger.kernel.org>
Subject: Re: [PATCH nft v3] evaluate: fix expr_set_context call for shift binops.
Date: Wed, 8 Jan 2020 23:35:51 +0100 [thread overview]
Message-ID: <20200108223551.g33ci5nwkvez6moo@salvia> (raw)
In-Reply-To: <20200106223510.496948-1-jeremy@azazel.net>
On Mon, Jan 06, 2020 at 10:35:10PM +0000, Jeremy Sowden wrote:
> expr_evaluate_binop calls expr_set_context for shift expressions to set
> the context data-type to `integer`. This clobbers the byte-order of the
> context, resulting in unexpected conversions to NBO. For example:
>
> $ sudo nft flush ruleset
> $ sudo nft add table t
> $ sudo nft add chain t c '{ type filter hook output priority mangle; }'
> $ sudo nft add rule t c oif lo tcp dport ssh ct mark set '0x10 | 0xe'
> $ sudo nft add rule t c oif lo tcp dport ssh ct mark set '0xf << 1'
> $ sudo nft list table t
> table ip t {
> chain c {
> type filter hook output priority mangle; policy accept;
> oif "lo" tcp dport 22 ct mark set 0x0000001e
> oif "lo" tcp dport 22 ct mark set 0x1e000000
> }
> }
>
> Replace it with a call to __expr_set_context and set the byteorder to
> that of the left operand since this is the value being shifted.
Looks good, applied, thanks Jeremy.
prev parent reply other threads:[~2020-01-08 22:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-20 19:02 [PATCH nftables] evaluate: remove expr_set_context call Jeremy Sowden
2019-12-24 23:12 ` Jeremy Sowden
2019-12-24 23:16 ` Jeremy Sowden
2019-12-24 23:14 ` [PATCH nft v2] evaluate: fix expr_set_context call for shift binops Jeremy Sowden
2020-01-06 9:28 ` Pablo Neira Ayuso
2020-01-06 9:31 ` Jeremy Sowden
2020-01-06 22:35 ` [PATCH nft v3] " Jeremy Sowden
2020-01-08 22:35 ` Pablo Neira Ayuso [this message]
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