From: "Arnd Bergmann" <arnd@arndb.de>
To: "Fernando Fernandez Mancera" <fmancera@suse.de>,
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Subject: Re: [PATCH 01/13 RFC net-next] net: ipv4: introduce CONFIG_IPV4 to decouple the IPv4 stack
Date: Sun, 12 Jul 2026 13:01:52 +0200 [thread overview]
Message-ID: <12ffac6a-649a-4e4a-8d12-0b48171e1d95@app.fastmail.com> (raw)
In-Reply-To: <20260712013941.4570-2-fmancera@suse.de>
On Sun, Jul 12, 2026, at 03:38, Fernando Fernandez Mancera wrote:
> Historically, the IPv4 protocol has been linked to the core INET
> subsystem. Because shared infrastructure like the TCP/UDP engine,
> routing or INET hashtables live inside net/ipv4/, it has been impossible
> to compile a kernel with only IPv6 support.
>
> This patch introduces the CONFIG_IPV4 Kconfig symbol, which is set to
> 'def_bool y' for now. This does not allow to completely disable the
> IPv4 stack yet but it lays the necessary build-system work for that
> goal.
I expect this will cause additional (trivial) build regression in the
next step when randconfig builds run into obscure corner cases, either
with INET=y IPV4=n IPV6=y or with INET=y IPV4=n IPV6=n.
I can probably give your patch (with IPV4 visible or disabled) an
early go on the randconfig tree to find these more quickly.
If I run into regressions, should I just add more 'depends on IPV4',
or do you have other plans?
Should we have some logic to ensure that at least one of IPV4 or
IPV6 is enabled? I think this would work
config IPV4
bool "The IPv4 protocol" if IPV6
default INET
which only allows turning IPV4 off if IPV6 has enabled.
Arnd
next prev parent reply other threads:[~2026-07-12 11:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-12 1:38 [PATCH 00/13 RFC net-next] Allow compiling an IPv6-only kernel network stack Fernando Fernandez Mancera
2026-07-12 1:38 ` [PATCH 01/13 RFC net-next] net: ipv4: introduce CONFIG_IPV4 to decouple the IPv4 stack Fernando Fernandez Mancera
2026-07-12 11:01 ` Arnd Bergmann [this message]
2026-07-12 1:39 ` [PATCH 02/13 RFC net-next] net: core: add IPv4 fallback stubs and guards for CONFIG_IPV4=n Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 03/13 RFC net-next] net: inet: relocate ip_generic_getfrag and guard IPv4 socket logic Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 04/13 RFC net-next] net: tcp: move protocol agnostic TCP functions out of tcp_ipv4.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 05/13 RFC net-next] net: raw: split IPv4 specific logic into raw_ipv4.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 06/13 RFC net-next] net: udp: split IPv4 specific logic into udp_ipv4.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 07/13 RFC net-next] net: icmp: split IPv4 specific logic into icmp_ipv4.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 08/13 RFC net-next] net: ping: split IPv4 specific logic into ping_ipv4.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 09/13 RFC net-next] net: fib: split common nexthop logic to fib_core.c Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 10/13 RFC net-next] net: tunnel: guard IPv4 tunnel functions with CONFIG_IPV4 Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 11/13 RFC net-next] net: cipso: guard IPv4 packet manipulation functions Fernando Fernandez Mancera
2026-07-12 16:22 ` Paul Moore
2026-07-12 1:39 ` [PATCH 12/13 RFC net-next] netfilter: ipv4: guard ip_route_me_harder() with CONFIG_IPV4 Fernando Fernandez Mancera
2026-07-12 1:39 ` [PATCH 13/13 RFC net-next] net: ipv4: make CONFIG_IPV4 boolean Fernando Fernandez Mancera
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