From: Florian Westphal <fw@strlen.de>
To: Phil Sutter <phil@nwl.cc>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>, Eric Garver <e@erig.me>,
netfilter-devel@vger.kernel.org
Subject: Re: [nft PATCH v2] src: Convert ip {s,d}addr to IPv4-mapped as needed
Date: Wed, 10 Dec 2025 16:14:49 +0100 [thread overview]
Message-ID: <aTmOaUEmL0P_h0sy@strlen.de> (raw)
In-Reply-To: <20251210150333.14654-1-phil@nwl.cc>
Phil Sutter <phil@nwl.cc> wrote:
> Note that adding IPv4 addresses to sets of type ip6addr_type is still
> rejected although easily enabled by passing AI_V4MAPPED flag to
> getaddrinfo(): Since this also resolves DNS names, users may
> unexpectedly add a host's IPv4 address in mapped notation if the name
> doesn't resolve to an IPv6 address for whatever reason. If we really
> want to open this can of worms, it deserves a separate patch anyway.
I think we should force AI_NUMERICHOST when AI_V4MAPPED gets added, i.e.
never autofill in a v4mapped address for ip6addr_type when all we had
was a name.
> +# ip saddr ::ffff:1.2.3.4
> +ip test-ip4 input
> + [ payload load 4b @ network header + 12 => reg 1 ]
> + [ cmp eq reg 1 0x04030201 ]
Makes sense, no expansion.
> +# ip saddr @ip6addrset
> +ip test-ip4 input
> + [ immediate reg 1 0x00000000 0x00000000 0xffff0000 ]
> + [ payload load 4b @ network header + 12 => reg 11 ]
> + [ lookup reg 1 set ip6addrset ]
Looks good to me, thanks for working on this.
next prev parent reply other threads:[~2025-12-10 15:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-10 15:03 [nft PATCH v2] src: Convert ip {s,d}addr to IPv4-mapped as needed Phil Sutter
2025-12-10 15:14 ` Florian Westphal [this message]
2025-12-10 15:28 ` Phil Sutter
2025-12-10 16:03 ` Florian Westphal
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