From: Florian Westphal <fw@strlen.de>
To: Phil Sutter <phil@nwl.cc>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>, netfilter-devel@vger.kernel.org
Subject: Re: [iptables PATCH 3/4] xshared: Prefer xtables_chain_protos lookup over getprotoent
Date: Thu, 10 Mar 2022 13:11:55 +0100 [thread overview]
Message-ID: <20220310121155.GF26501@breakpoint.cc> (raw)
In-Reply-To: <20220302151807.12185-4-phil@nwl.cc>
Phil Sutter <phil@nwl.cc> wrote:
> When dumping a large ruleset, common protocol matches such as for TCP
> port number significantly slow down rule printing due to repeated calls
> for getprotobynumber(). The latter does not involve any caching, so
> /etc/protocols is consulted over and over again.
> As a simple countermeasure, make functions converting between proto
> number and name prefer the built-in list of "well-known" protocols. This
> is not a perfect solution, repeated rules for protocol names libxtables
> does not cache (e.g. igmp or dccp) will still be slow. Implementing
> getprotoent() result caching could solve this.
Hmm, I think we could just extend xtables_chain_protos[].
Anyway, this looks safe to me, so
Acked-by: Florian Westphal <fw@strlen.de>
next prev parent reply other threads:[~2022-03-10 12:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 15:18 [iptables PATCH 0/4] Speed up iptables-nft-save Phil Sutter
2022-03-02 15:18 ` [iptables PATCH 1/4] nft: Simplify immediate parsing Phil Sutter
2022-03-10 12:09 ` Florian Westphal
2022-03-02 15:18 ` [iptables PATCH 2/4] nft: Speed up " Phil Sutter
2022-03-02 15:18 ` [iptables PATCH 3/4] xshared: Prefer xtables_chain_protos lookup over getprotoent Phil Sutter
2022-03-10 12:11 ` Florian Westphal [this message]
2022-03-10 12:20 ` Phil Sutter
[not found] ` <20220310122303.GC13772@breakpoint.cc>
2022-03-10 12:54 ` Phil Sutter
2022-03-02 15:18 ` [iptables PATCH 4/4] nft: Don't pass command state opaque to family ops callbacks Phil Sutter
2022-03-10 12:14 ` Florian Westphal
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