I realized now that I forgot to send a reply here. I will write the tests sometime around this week and then send them on a new differential.
Thanks for the commit, @kp :)

Update the date on the manpages

I enclosed the code with a #ifdef HAVE_NET_IF_PFLOG_H to allow for building with WITHOUT_PF=1

Added support for IPv6 Link-local addresses
Use interface FIB when looking up IPv6 source address

In D40102#913177, @melifaro wrote:

Thanks for submitting it! That's quite a nice addition. Any thoughts on supporting IPv6 link-locals? (Maybe they work out-of-the box, but often it's not the case).

I rebased and addressed the last comments.

Ping @kp
I think we are good for a style(9) check

Removed pfsync_kstatus usage from ifpfsync.c.

Rebase
Reduce duplication between SIOCSETPFSYNC and SIOCSETPFSYNCNV.

Remove another allocation failure check
Prevent leak of ifr.ifr_cap_nv.buffer

I think I addressed all comments. I will submit the updated patch in a moment.

Add new ioctls that use nvlists

I am currently working on the implementation using nvlists.

Rebase
Replace bzero() with memset() in new code