kern/75121: Wrong behaviour of IFF_LINK2 bit in 6in6 gifs?

[Hajimu UMEMOTO]

The following reply was made to PR kern/75121; it has been noted by GNATS.

From: Hajimu UMEMOTO <ume at freebsd.org>
To: FreeBSD-gnats-submit at freebsd.org
Cc: Antonio Tapiador del Dujo <atapiador at dit.upm.es>,
	Gleb Smirnoff <glebius at freebsd.org>
Subject: Re: kern/75121: Wrong behaviour of IFF_LINK2 bit in 6in6 gifs?
Date: Thu, 20 Jan 2005 19:57:12 +0900

 Hi,
 
  A> > The IFF_LINK2 means that incoming tunnel packets may come from interface
  A> > different to interface we use for sending out tunnel packets.
  A> 
  A> gif(4) man page talks about ingress filtering:
  A> "Ingress filtering can be turned off by IFF_LINK2 bit."
  A> that has to do with source addresses (RFC 2893, section 4.3)
  A> Then maybe this is a gif(4) man page bug. 
  
 glebius>  Yes, it is I think. Section 4.3 speaks about other kind of filtering.
 
 No, manpage of gif(4) is correct.  Ingress filtering is for preventing
 IP address spoofing of outer src address and dest address.
 
 Sincerely,
 
 --
 Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
 ume at mahoroba.org  ume@{,jp.}FreeBSD.org
 http://www.imasy.org/~ume/