Re: [PATCH v2] conf: Support CIDR notation for -a/--address option

[Stefano Brivio <sbrivio@redhat.com>]

On Wed, 17 Dec 2025 16:31:42 -0500
Jon Maloy <jmaloy@redhat.com> wrote:

> Extend the -a/--address option to accept addresses in CIDR notation
> (e.g., 192.168.1.1/24 or 2001:db8::1/64) as an alternative to using
> separate -a and -n options.
> 
> Add conf_addr_prefix() helper function that:
> - Parses address strings with optional /prefix suffix

That's not the prefix, that's the prefix length.

> - Validates prefix length based on address family (0-32 for IPv4,
>   0-128 for IPv6)
> - Returns address family and fills address/prefix output parameters
> 
> For IPv4, the prefix is stored in ip4.prefix_len when provided.
> Multiple CIDR addresses use last-wins semantics for the prefix,
> consistent with how addresses are handled currently. However,
> mixing -n and CIDR notation results in an error to catch likely
> user mistakes.
> 
> Also fix a bug in conf_ip4_prefix() that was incorrectly using the
> global 'optarg' instead of its 'arg' parameter.
> 
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> 
> ---
> v2: Fixed incorrect error printout, as noted by Laurent Vivier.
>     We now keep the old semantics, i.e., allowing multiple -a
>     options for each protocol. This semantics looks wrong,
>     but will anyway be fixed in my upcoming series.
> 
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> ---
>  conf.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 84 insertions(+), 15 deletions(-)

man page update is missing altogether.

Not a full review, but it will be easier to review once the new
behaviour is documented.

-- 
Stefano