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Date: Wed, 12 Nov 2003 22:30:12 -0500
From: Damian Gerow <dgerow@afflictions.org>
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Subject: Re: tcp hostcache and ip fastforward for review
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I've been thinking about this all day...

Thus spake Jesper Skriver <jesper@freebsd.org> [23:53:26 11/12/03:
: > +	/*
: > +	 * Only unicast IP, not from loopback, no L2 or IP broadcast,
: > +	 * no multicast, no INADDR_ANY
: > +	 */
: > +	if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) ||
: > +	    (ntohl(ip->ip_src.s_addr) == (u_long)INADDR_BROADCAST) ||
: 
: #jesper
: You will never see packets with a multicast source address.

Do you mean:

Any packets with a multicast source address will be dropped by the kernel
before this point, or that no host will ever send a packet with a
multicast source address?

In the former, that's fine.  In the latter, how does one guarantee that
there isn't a malicious host out there sending spoofed multicast-source
packets?

  - Damian