datapath-windows: Add IPv6 conntrack ip fragment support on windows

Implementation on Windows:
IPv6 conntrack ip fragment feature use a link list to store ip
fragment. When ipv6 fragment module receives a fragment packet,
it will store length of the fragment, until to the received length
equal to the packet length before fragmented, it will reassemble
fragment packet to a complete packet and send the complete packet
to conntrack module. After conntrack processed the packet, fragment
module will divide the complete packet into small fragment and send
it to destination. Currently, ipv6 was implemented in a indenpent
module, for the reason it can reduce the risk of introduce bug to
ipv4 fragmenb module.

Testing Topology:
On the Windows VM runs on the ESXi host, two hyper-v ports attached
to the ovs bridge; one hyper-v port worked as client and the
other port worked as server.

Testing Case:
1.UdpV6
  a) UdpV6 fragment with multiple ipv6 extension fields.
  b) UdpV6 fragment in normal scenario.
  c) UdpV6 fragment in nat scenario.

2.IcmpV6
  a) IcmpV6 fragment in normal scenario.
  b) IcmpV6 fragment in nat scenario.

Signed-off-by: ldejing <ldejing@vmware.com>
Signed-off-by: Alin-Gabriel Serdean <aserdean@ovn.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 843abc7ac..d5ec09813 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,8 @@ Post-v3.0.0
    - ovs-appctl:
      * "ovs-appctl ofproto/trace" command can now display port names with the
        "--names" option.
+   - Windows:
+     * Conntrack IPv6 fragment support.
 
 
 v3.0.0 - 15 Aug 2022