From owner-freebsd-net  Wed Apr 24  4:14:10 2002
Delivered-To: freebsd-net@freebsd.org
Received: from web12208.mail.yahoo.com (web12208.mail.yahoo.com [216.136.173.92])
	by hub.freebsd.org (Postfix) with SMTP id 97A7937B41A
	for <freebsd-net@freebsd.org>; Wed, 24 Apr 2002 04:14:01 -0700 (PDT)
Message-ID: <20020424111242.77223.qmail@web12208.mail.yahoo.com>
Received: from [203.124.128.243] by web12208.mail.yahoo.com via HTTP; Wed, 24 Apr 2002 04:12:42 PDT
Date: Wed, 24 Apr 2002 04:12:42 -0700 (PDT)
From: kshitij gunjikar <kshitijgunjikar@yahoo.com>
Subject: Record Routes 
To: freebsd-net@freebsd.org
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: owner-freebsd-net@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-net.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-net>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-net>
X-Loop: FreeBSD.org

Hi All,
  I have a question related to record routes in the
FreeBSD code. In the
ip_dooptions() fn in ip_input.c there is this code in
the Record Route
option.

/*
* If no space remains, ignore.
*/
off--; /* 0 origin */
if (off > optlen - (int)sizeof(struct in_addr))
break;
(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
    sizeof(ipaddr.sin_addr));
/*
* locate outgoing interface; if we're the destination,
* use the incoming interface (should be same).
*/
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
    (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
goto bad;
}

1.   Why is the ICMP_UNREACH_HOST generated?

2.  Because if a route is not found, then am I wrong
in saying
ICMP_UNREACH_NETWORK must be generated. Also, how does
ip_rtaddr() find out
that the IP address is not of the directly connected
networks?

Thanks in advance.

Regards
Kshitij



__________________________________________________
Do You Yahoo!?
Yahoo! Games - play chess, backgammon, pool and more
http://games.yahoo.com/

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message