Re: [PATCH v2 1/2] man/man2/landlock_add_rule.2: Clarify ephemeral port range

["Günther Noack" <gnoack3000@gmail.com>]

On Tue, Nov 03, 2026 at 12:39:31AM +0100, Matthieu Buffet wrote:
> Clarify that ephemeral port range can differ from system to system, and
> that an application can choose exactly which ephemeral port will be
> chosen next (as long as it is within the kernel-wide
> ip_local_port_range).
> 
> Signed-off-by: Matthieu Buffet <matthieu@buffet.re>
> ---
>  man/man2/landlock_add_rule.2 | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/man/man2/landlock_add_rule.2 b/man/man2/landlock_add_rule.2
> index 94bc63068935..253498bfa2cf 100644
> --- a/man/man2/landlock_add_rule.2
> +++ b/man/man2/landlock_add_rule.2
> @@ -109,9 +109,13 @@ is the network port in host endianness.
>  It should be noted that port 0 passed to
>  .BR bind (2)
>  will bind to an available port from the ephemeral port range.
> -This can be configured in the
> +The range is configured globally in the
>  .I /proc/sys/net/ipv4/ip_local_port_range
> -sysctl (also used for IPv6).
> +sysctl (also used for IPv6),
> +and can be further restricted per socket using
> +.BR setsockopt (2)
> +with
> +.BR IP_LOCAL_PORT_RANGE (2const).
>  .IP
>  A Landlock rule with port 0
>  and the
> 
> base-commit: c189a6b2e4dd2e74f3b360b24e489e27f4e45bad
> -- 
> 2.47.3
> 

Reviewed-by: Günther Noack <gnoack3000@gmail.com>

I think Mickaël's Reviewed-by from [1] should also count since you
addressed the grammar nit from [2].

The high level remark from [2] still stands, please don't forget to
ideally update the kernel documentation in line with these changes, so
that it uses the same wording on both sides.

Thanks,
–Günther

[1] https://lore.kernel.org/all/20260929.hooQuaaf9An5@digikod.net/
[2] https://lore.kernel.org/all/20260926.6c13f561a21f@gnoack.org/