[Swan-dev] ikev1 retransmits: only save the received packet when responding

[D. Hugh Redelmeier]

Andrew:

I don't understand this title.

In IKEv1 both Initiator and Responder may need to retransmit.

Maybe you mean "Replying", not "responding"?  These are synonyms in 
english but a useful distinction can be made in IKE, I think.

If we are not replying, what would "remember_received_packet" actually do
(before your change)?  I would have guessed that it saved an empty chunk 
or the like.  But then this change would be unnecessary.

How have we lived without this so long?

commit 49cfd21870994d1afc038ecd0830c9ad0a14e6d1
Author: Andrew Cagney <cagney at gnu.org>
Date:   Tue May 29 09:24:49 2018 -0400

    ikev1 retransmits: only save the received packet when responding
    
    Should eliminate problems such as the responder, when receiving a
    response to its XAUTH request from the initiator (remember, an IKEv1
    exchange can flip initiator and responder part way through), would see
    the received packet matched .st_rpacket and assume it needed to
    re-transmit something.
    
    Really fix 8f440ae125a1d29eb4507bd94b123d22bbd3cb2a