Suggestion regarding a new option for IPFW2

[Louis A. Mamakos]

TCP resets MUST already come with the source address rewritten 
otherwise it won't match up with the connection attempt on the
original host.  If you look in ip_fw2.c:

        /*
         * Assume we are sending a RST (or a keepalive in the reverse
         * direction), swap src and destination addresses and ports.
         */
        ip->ip_src.s_addr = htonl(id->dst_ip);
        ip->ip_dst.s_addr = htonl(id->src_ip);
        tcp->th_sport = htons(id->dst_port);
        tcp->th_dport = htons(id->src_port);

appears in the send_pkt() function which appears to be called to
send the reset segments.

louie