[Swan-dev] nat: ikeport commit broke DDNS tests

[Paul Wouters]

the ikev2-ddns* test cases broke on this commit:

paul at thinkpad:~/libreswan ((cc04507...)|BISECTING)$ git bisect bad
cc045076885ee1f7eab1ac8fbb9c88187961bc01 is the first bad commit
commit cc045076885ee1f7eab1ac8fbb9c88187961bc01
Author: Andrew Cagney <cagney at gnu.org>
Date:   Wed Jun 24 22:19:01 2020 -0400

     nat: when only one {left,right}ikeport, default other end to 4500 and not 500

     For {left,right}ikeport to work wth NAT it must enable espinudp,
     and that means all incomming messages on that port must include
     the ESP=0 prefix, and that means anything but port 500 (because
     an exchange with port 500 never has ESP=0 prefix added).

  programs/pluto/connections.c   | 33 +++++++++++++----------
  programs/pluto/iface.c         | 22 +++++++++-------
  programs/pluto/iface.h         | 59 ++++++++++++++++++++++++++++++------------
  programs/pluto/iface_tcp.c     |  6 ++---
  programs/pluto/iface_udp.c     |  9 ++++---
  programs/pluto/ikev1_send.c    | 22 +++++++++++-----
  programs/pluto/ikev2_message.c | 15 +++++++++--
  programs/pluto/initiate.c      | 19 ++++++++++----
  programs/pluto/send.c          |  8 +++++-
  9 files changed, 133 insertions(+), 60 deletions(-)


When the now-oriented connection tries to send a packet, it prob is
missing a port or something and the OS returns errno 22, and the
packet never appears on the wire.

Paul