On 22/11/2015 17:48, Martin Pieuchot wrote:
On 22/11/15(Sun) 16:56, Momtchil Momtchev wrote:
On 22/11/2015 15:52, Martin Pieuchot wrote:
When you say "the bridge changed somewhat" are you saying that you see
a regression? Could you share your setup that, I guess work with 4.9,
and no longer work with 5.8.
I don't understand what you mean with "_BLOCKNONIPV6_ bridge". ifconfig(8)
clearly say:
blocknonip interface
Mark interface so that no non-IPv4, IPv6, ARP, or Reverse ARP
packets are accepted from it or forwarded to it from other
bridge member interfaces
I have a modified bridge that adds a new bridge option -
BLOCKNONIPV6 - to block IPv4 traffic but pass IPv6 traffic. There's no
regression, my only problem was that in 4.9 bridge_output() was never
used in my particular case. In 5.8 bridge_output() is used for some
strange forwarding of ARP packets - every ARP request on the internal
side coming from a bridge interface without an IP address (yes, only on
interfaces without an IP address) spawns an ARP request on the external
side. That request is coming from bridge_output(), not the usual bridge
code path in bridgeintr(). In a non-modified stock OpenBSD bridge this
would be the correct behaviour, so there is no bug here. It is just
somewhat weird that some ARP requests are forwarded through
bridge_output(), not through the usual code path.
My question is who uses bridge_output()? Except one obscure case
for sending back ICMP errors, normally all local traffic should
originate in the output() function of the underlying interface? Or am I
missing something?
If you think that my feature presents any interest, I can tidy it
up and submit it. It splits BLOCKNONIP into BLOCKNONIPV4 and
BLOCKNONIPV6. I need it because in my particular case IPv4 should be
NATed and IPv6 should be switched as you cannot split IPv6 into
arbitrary subnets below /64, so you have to keep it whole. It is the
only way to route and filter both IPv4 and IPv6 traffic with one
particular French broadband service provider but there could maybe be
other uses for it.
