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From: Darren Reed <darrenr@cyber.com.au>
Message-Id: <199705240258.MAA11722@plum.cyber.com.au>
Subject: Re: cvs commit: src/sys/netinet ip_icmp.c
To: julian@FreeBSD.ORG (Julian Elischer)
Date: Sat, 24 May 1997 12:58:08 +1000 (EST)
Cc: cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG, cvs-sys@FreeBSD.ORG
In-Reply-To: <199705232217.PAA25661@freefall.freebsd.org> from "Julian Elischer" at May 23, 97 03:17:34 pm
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In some mail I received from Julian Elischer, sie wrote
> 
> julian      1997/05/23 15:17:34 PDT
> 
>   Modified files:        (Branch: WHISTLE_NET_BRANCH_1)
>     sys/netinet          ip_icmp.c 
>   Log:
>   Submitted by:	archie@whistle.com
>   don't look for a matching receive interface if the packet was not received.
>   This can happen if an icmp UNREACH or similar is being generated
>   by firewall code. (Prior to firewall code this was not possible).

This series of changes intrigues me.  When I came upon this problem, I at
first thought it a problem and then realised that for locally generated
packets, this situation is usually handled by functions returning an error
code (i.e. EHOSTUNREACH or similar) rather than there being an ICMP packet
to respond to.

IMHO, ipfw shouldn't send an ICMP response to a locally generated packet.

Darren