[PATCH 01/13 net-next] net: ipv4: introduce CONFIG_IPV4 to decouple the IPv4 stack

[Fernando Fernandez Mancera]

On 9/10/26 4:48 PM, 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.
> 
> In addition, multiple subsystems Kconfig symbols across networking
> features like tunnels, drivers and filesystems have been adjusted to
> depend on IPv4. Keep on mind that follow-up work is required to convert
> the Kconfig symbol to bool and remove the dependency on IPv4 where it
> makes sense.
> 
> Signed-off-by: Fernando Fernandez Mancera <fmancera at suse.de>
FWIW, I just checked and the following symbols that are currently marked 
as "depends on IPV4" can already be compiled without IPV4:

IPV6_MIP6, IPV6_ILA and IPV6_MROUTE

They will be adjusted on the next revision of the series. A re-check for 
all the symbols will be performed.

Thanks,
Fernando.