Re: recent MFC code to 6-STABLE kills ipv6

Experiencing the problem over here, too.

# ifconfig gif0
gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
        tunnel inet 66.171.79.118 --> 64.86.88.116
        inet6 2001:5c0:8fff:fffe::553 --> 2001:5c0:8fff:fffe::552 prefixlen 128 
        inet6 fe80::20c:6eff:fe75:69aa%gif0 prefixlen 64 scopeid 0x5 

# ping6 2001:5c0:8fff:fffe::553
PING6(56=40+8+8 bytes) 2001:5c0:8fff:fffe::553 --> 2001:5c0:8fff:fffe::553
16 bytes from 2001:5c0:8fff:fffe::553, icmp_seq=0 hlim=64 time=1.658 ms
16 bytes from 2001:5c0:8fff:fffe::553, icmp_seq=1 hlim=64 time=0.720 ms
16 bytes from 2001:5c0:8fff:fffe::553, icmp_seq=2 hlim=64 time=0.681 ms
^C

Ping6 works fine:

However TCP traffic is broke, for example, when I try to telnet to the POP3
server here, I observe that pf is blocking the server's response packets with
this error:

# telnet 2001:5c0:8fff:fffe::553 110
Trying 2001:5c0:8fff:fffe::553...
^C

from pflog:
21:45:03.080452 rule 0/0(match): block in on gif0: 2001:5c0:8fff:fffe::553.110 > 2001:5c0:8fff:fffe::553.56716:  tcp 36 [bad hdr length 8 - too short, < 20]

This did not happen on earlier 6.0-current.

	-jr