On Tue, Jun 17, 2025 at 9:12 PM Simon Horman [off-list ref] wrote:

In his review of v1 [*] Jacob said:

  "Hm. In many cases any non-zero value might be interpreted as "enabled" I
   suppose that is simply "undefined behavior"?

Looking over the parsing and use of ip_forward_use_pmtu (I did not check
the other parameters whose documentation this patch updates) I would take
Jacob's remark a few steps further.

It seems to me that values of 0-255 are accepted and while 0 means
disabled, all the other values mean enabled. That is because that
what the code does. And being part of the UAPI it can't be changed.

So I don't think it is correct to describe only values 0/1 having defined
behaviour. Because the code defines behaviour for all the values in the
range 0-255.

[*] https://lore.kernel.org/netdev/8b53b5be-82eb-458c-8269-d296bffcef33@intel.com/ (local)

...

well , Thanks for the clarification , i will only keep patch 1/2 in
the next post