From owner-freebsd-net@FreeBSD.ORG  Thu Feb 17 08:46:33 2005
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Date: Thu, 17 Feb 2005 11:46:29 +0300
From: Gleb Smirnoff <glebius@freebsd.org>
To: net@freebsd.org
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Subject: in_pcbconnect_setup() question
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X-List-Received-Date: Thu, 17 Feb 2005 08:46:33 -0000

  Dear networkers,

  I've noticed a small oddity in in_pcbconnect_setup(). According to SuS, in
case of connection-less socket layer, e.g. SOCK_DGRAM, the connect() syscall
should only choose local address and that's all. To server this purposes a
route lookup is done in in_pcbconnect_setup(). However, if route is pointing
to a loopback interface, it is not accepted.
(Not clear to me) comment is also present:

                /*
                 * If we found a route, use the address
                 * corresponding to the outgoing interface
                 * unless it is the loopback (in case a route
                 * to our address on another net goes to loopback).
                 */
                if (sro.ro_rt && !(sro.ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
                        ia = ifatoia(sro.ro_rt->rt_ifa);
                if (sro.ro_rt)
                        RTFREE(sro.ro_rt);

For example, this breaks connect() of a UDP socket to a blackhole-routed IP
address, which shouldn't return an error. I'd like to change this block to the
following:

                /*
                 * If we found a route, use the address
                 * corresponding to the outgoing interface.
		 */

                if (sro.ro_rt) {
                        ia = ifatoia(sro.ro_rt->rt_ifa);
                        RTFREE(sro.ro_rt);
		}

Is there any hidden obstacles? Can someone explain me this comment?

-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE