tech-net: Re: unconnected inpcb and redirects

Subject: Re: unconnected inpcb and redirects
To: None <tech-net@netbsd.org, kml@netbsd.org>
From: None <itojun@iijlab.net>
List: tech-net
Date: 12/05/2000 14:52:16

>	it looks that in_pcbnotify() needs to flush inpcb.inp_route more
>	frequently for unconnected sockets, on ICMP redirect case.
>	scneario is like this:
>	- from unconnected inpcb, packet is sent to final destination A,
>	 using gateway B. inpcb caches the routing entry into inpcb.inp_route.
>	- B was not the best gateway, so B sends an ICMP redirect.
>	- because we have used an unconnected inpcb, the inpcb will not be
>	 notified of ICMP redirect (see in_pcbnotify), and will keep an
>	 obsolete cache entry in inpcb.inp_route.
>	- ICMP redirects will be issued every time we send a packet from
>	 the unconnected inpcb, to A.
>	is my understanding correct?
	jinmei@kame found another issue - inpcb.inp_route will become bogus
	on inbound ICMP too big (or more fragment) packet.
itojun