On 9 Jan 2017, at 18:25, Marek Zarychta wrote:
On Sun, Jan 08, 2017 at 07:08:10PM +0100, Kristof Provost wrote:
On 8 Jan 2017, at 15:55, Marek Zarychta wrote:
The problem description doesn’t ring any bells with me, but I’m
also
not sure
I’ve fully understood it. Can you document a minimal reproduction
scenario,
with a pf.conf and perhaps network captures documenting the problem?
There’s certainly not been a conscious decision to break UDP
reply-to.
Let me apologize, the problem wasn't previously properly identified.
It
seems to be more problem of UDP protocol implementation than PF issue.
UDP sockets are opened and bound to address of the outgoing interface
(interface which has a route to the client). Because the socket is not
bound to the incoming interface, the PF reply-to rules couldn't be
evaluated. By the way, TCP sockets are bound to the interface where
the
traffic arrives and everything works fine.
This machine is i386 running 11.0-STABLE r311772
The problem remains unresolved. Are there any corresponding sysctls
correcting this behavior and enabling the opportunity to use PF
assisted
symmetric routing scenario again?
Thinking about this a bit more, I think the behaviour you see is
entirely
correct and expected. We’re talking about datagram sockets, and as
far as the
kernel is concerned there’s no relationship between the packet
you’ve just
received from address X and the packet you send to host X. There’s no
established connection. As a result it’s entirely free to choose its
source
address: you’re simply telling the kernel “Send this data to X”,
you’re not
adding “it’s from Y”.
If you want this to behave differently I think you’ll have to convince
your
application to open a socket per interface (binding it to that
interface), and
reply using the correct socket.
Regards,
Kristof
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-pf
To unsubscribe, send any mail to "[email protected]"
