-current kernel + -7 userland + carp + ipf = failure

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

I'm continuing trying to get carp(4) + default gateway working as 
described in:
http://mail-index.netbsd.org/tech-net/2017/03/14/msg006283.html

I was trying to test whether carp(4) worked any better in -current, so 
built a -current XEN3_DOMU kernel with carp added.

Firstly, I noticed that I had no network access at all. carp had 
successfully negotiated MASTER and BACKUP statuses on the hosts, but I 
could not ping anything:

xennet0: flags=8963<UP,BROADCAST,NOTRAILERS,RUNNING,PROMISC,SIMPLEX>
xennet0: flags=8963<MULTICAST> mtu 1500
	capabilities=2800<TCP4CSUM_Tx,UDP4CSUM_Tx>
	enabled=0
	ec_capabilities=1<VLAN_MTU>
	ec_enabled=0
	address: d6:41:19:58:cc:d5
	inet6 fe80::d441:19ff:fe58:ccd5%xennet0 prefixlen 64 scopeid 0x2
carp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	capabilities=2800<TCP4CSUM_Tx,UDP4CSUM_Tx>
	enabled=0
	carp: MASTER carpdev xennet0 vhid 1 advbase 1 advskew 0
	address: 00:00:5e:00:01:01
	inet 192.168.1.88 netmask 0xffffff00 broadcast 192.168.1.255

If I configure an IP address directly on xennet0 it works.

Secondly, I ran ipf -D and got the following:

panic: kernel diagnostic assertion "(flags & ~PFIL_ALL) == 0" failed: file 
"/usr/src/current/sys/net/pfil.c", line 363
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip 0xffffffff80206365 cs 0xe030 rflags 0x246 cr2 
0x71fad3ece8b0 ilevel 0 rsp 0xffffa0000cd33440
curlwp 0xffffa00000cd25a0 pid 644.1 lowest kstack 0xffffa0000cd302c0
Stopped in pid 644.1 (ipf) at   netbsd:breakpoint+0x5:  leave
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x140
nd6_hint() at netbsd:nd6_hint
pfil_remove_hook() at netbsd:pfil_remove_hook+0xc1
ipfdetach() at netbsd:ipfdetach+0xb1
ipf_ipf_ioctl() at netbsd:ipf_ipf_ioctl+0x6bb
ipfioctl() at netbsd:ipfioctl+0x8c
cdev_ioctl() at netbsd:cdev_ioctl+0x88
VOP_IOCTL() at netbsd:VOP_IOCTL+0x3b
vn_ioctl() at netbsd:vn_ioctl+0xa6
sys_ioctl() at netbsd:sys_ioctl+0x101
syscall() at netbsd:syscall+0x9c
--- syscall (number 54) ---
71fad3ece8ba:
ds          f008
es          3400
fs          3450
gs          8
rdi         0
rsi         a
rbp         ffffa0000cd33440
rbx         104
rdx         ffffffff806f5480    cpu_info_primary
rcx         0
rax         1
r8          ffffffff806f5480    cpu_info_primary
r9          8080808080808080
r10         ffffa0000cd333c0
r11         e033
r12         ffffffff806141a8    ostype+0xa68
r13         ffffa0000cd33488
r14         ffffa000008ef008
r15         10
rip         ffffffff80206365    breakpoint+0x5
cs          e030
rflags      246
rsp         ffffa0000cd33440
ss          e02b

NetBSD 7.99.71 (XEN3_DOMUCARP) #0: Thu May 11 17:09:15 BST 2017

--
Stephen