site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com User-agent: Thunderbird 2.0.0.21 (Macintosh/20090302) On Apr 23, 2009, at 3:14 PM, Kevin Brock wrote: Kevin _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... Michael Smith wrote: If I do the same thing, but modify the TCP destination port so that it is headed for a different application, it fails. Your description here is a bit brief, but I did want to ask the obvious; are you redirecting *all* of the TCP session to the new port, i.e. including the handshake? Yes. The big problem is that even the SYN doesn't get there. I've debugged up to tcp_input(), but it doesn't make it as far as the call to tcp_output() which would generate the SYN ACK response. As far as it's made it I can see that a) all of the IP header information was verified, and b) all of the TCP header information was verified. If not, you might be having issues with the sequence numbers... Since it starts from the SYN and I'm not changing packet sizes the sequence numbers won't be changing. This email sent to site_archiver@lists.apple.com