Re: [PATCH RESEND net-next v3 2/2] tcp: add LINUX_MIB_PAWS_TW_REJECTED counter

["Jiayuan Chen" <jiayuan.chen@linux.dev>]

April 8, 2025 at 23:19, "Jakub Kicinski" <kuba@kernel.org> wrote:

> 
> On Tue, 08 Apr 2025 14:57:29 +0000 Jiayuan Chen wrote:
> > 
> > > When TCP is in TIME_WAIT state, PAWS verification uses
> >  > LINUX_PAWSESTABREJECTED, which is ambiguous and cannot be distinguished
> >  > from other PAWS verification processes.
> >  > Moreover, when PAWS occurs in TIME_WAIT, we typically need to pay special
> >  > attention to upstream network devices, so we added a new counter, like the
> >  > existing PAWS_OLD_ACK one.
> >  > 
> > 
> > 
> >  I really dislike the repetition of "upstream network devices".
> >  Is it mentioned in some RFC ? 
> >  
> >  I used this term to refer to devices that are located in the path of the
> >  TCP connection
> > 
> 
> Could we use some form of: "devices that are located in the path of the
> TCP connection" ? Maybe just "devices in the networking path" ?
> I hope that will be sufficiently clear in all contexts.
> 
> Upstream devices sounds a little like devices which have drivers in
> 
> upstream Linux kernel :(


That makes sense :).

Thanks.

> > 
> > such as firewalls, NATs, or routers, which can perform
> >  SNAT or DNAT and these network devices use addresses from their own limited
> >  address pools to masquerade the source address during forwarding, this
> >  can cause PAWS verification to fail more easily.
> > 
> >  You are right that this term is not mentioned in RFC but it's commonly used
> >  in IT infrastructure contexts. Sorry to have caused misunderstandings.
> 
> -- 
> 
> pw-bot: cr
>