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

[Jakub Kicinski]

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 :(

> 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