From: David Kerr <david@kerr.net>
To: wireguard@lists.zx2c4.com
Subject: Re: Source IP incorrect on multi homed systems
Date: Sun, 19 Feb 2023 11:32:23 -0500 [thread overview]
Message-ID: <CAJJxGdGSYR_mofRVpZDQsifjZJXXSNNsPqUV-RfWDMO0N2P2dQ@mail.gmail.com> (raw)
In-Reply-To: <7d7bc930-65d9-f13e-cedc-e0451407be85@chil.at>
Without getting into the debate of whether wireguard is acting
correctly or not, I think there is a possible workaround.
1. In the iptables mangle table PREROUTING, match the incoming
interface and destination address and --set-xmark a firewall MARK
unique to this interface/destination
2. Create a new ip route table that sets the default route to go out
on the interface with the source address you want (same as destination
address in iptables)
3. Create a new ip rule that sends all packets with firewall mark set
in iptables to the routing table you just created
Repeat above for each interface/address you need to mangle, with a
unique firewall mark and routing table for each.
It may be necessary to use CONNMARK in PREROUTING and OUTPUT to
--restore_mark. I can't remember if this is needed or not, its been a
while since I configured iptables with this.
This should ensure that any packet that comes into an
interface/address is replied to from the same interface/address.
David
On Sun, Feb 19, 2023 at 9:44 AM Christoph Loesch <wireguard-mail@chil.at> wrote:
>
> Hi,
>
> I don't think no one wants to fix it, there are several users having this issue. I rather guess no one could find a suitable solution to fix it.
>
> @Nico: did you try to delete the affected route and add it again with the correct source IP ?
>
> as I mentioned it in https://lists.zx2c4.com/pipermail/wireguard/2021-November/007324.html
>
> ip route del <NET>
> ip route add <NET> dev <ALIAS_DEV> src <SRC_IP>
>
> This way I was able to (at least temporary) fix this issue on multi homed systems.
>
> Kind regards,
> Christoph
>
> Am 19.02.2023 um 13:13 schrieb Nico Schottelius:
> > Hey Sebastian,
> >
> > Sebastian Hyrwall <sh@keff.org> writes:
> >
> >> It is kinda. It's been mentioned multiple times over the years but no one seems to want to fix it. Atleast you should be able to specify bind/src ip in the
> >> config. I gave up WG because of it. Wasn't accepted by my projects security policy since src ip could not be configured.
> >>
> >> There is an unofficial patch however,
> >>
> >> https://github.com/torvalds/linux/commit/5fa98082093344c86345f9f63305cae9d5f9f281
> > the binding is somewhat related to this issue and I was looking for that
> > feature some time ago, too. While it is correlated and I would really
> > appreciate binding support, I am not sure whether the linked patch does
> > actually fix the problem I am seeing in multi homed devices.
> >
> > As long as wireguard does not reply with the same IP address it was
> > contacted with, packets will get dropped on stateful firewalls, because
> > the returning packet does not match the state session database.
> >
> > Best regards,
> >
> > Nico
> >
> > --
> > Sustainable and modern Infrastructures by ungleich.ch
next prev parent reply other threads:[~2023-02-19 16:32 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-18 20:14 Nico Schottelius
[not found] ` <CAHx9msc1cNV80YU7HRmQ9gsjSEiVZ=pb31aYqfP62hy8DeuGZA@mail.gmail.com>
2023-02-18 22:34 ` Nico Schottelius
2023-02-19 0:45 ` Mike O'Connor
2023-02-19 8:01 ` Nico Schottelius
2023-02-19 9:19 ` Mikma
2023-02-19 12:04 ` Nico Schottelius
2023-02-19 12:10 ` Nico Schottelius
2023-02-19 18:59 ` Peter Linder
[not found] ` <2ed829aaed9fec59ac2a9b32c4ce0a9005b8d8b850be81c81a226791855fe4eb@mu.id>
2023-02-19 12:13 ` Nico Schottelius
2023-02-19 14:39 ` Christoph Loesch
2023-02-19 16:32 ` David Kerr [this message]
2023-02-19 16:54 ` Sebastian Hyrvall
2023-02-19 18:04 ` Janne Johansson
2023-02-19 18:08 ` Sebastian Hyrvall
2023-02-19 20:11 ` Nico Schottelius
2023-02-19 17:05 ` tlhackque
2023-02-19 18:37 ` David Kerr
2023-02-19 18:52 ` tlhackque
2023-02-19 18:42 ` tlhackque
2023-02-19 20:18 ` Nico Schottelius
2023-02-19 20:42 ` Roman Mamedov
2023-02-19 21:19 ` Nico Schottelius
2023-02-19 22:06 ` tlhackque
2023-02-19 22:42 ` Src addr code review (Was: Source IP incorrect on multi homed systems) Daniel Gröber
2023-02-20 0:28 ` 曹煜
2023-02-20 10:40 ` Nico Schottelius
2023-02-20 11:21 ` 曹煜
2023-02-20 9:47 ` Nico Schottelius
2023-02-20 20:43 ` dxld
2023-02-19 21:39 ` Source IP incorrect on multi homed systems tlhackque
[not found] ` <CADGd2DoE6TCtCxxWL7JWyNW5+yy_Pe+9MNzHznbudMWLTXQreA@mail.gmail.com>
2023-02-19 18:30 ` Fwd: " John Lauro
2023-02-19 22:28 ` tlhackque
2023-02-20 0:58 ` Luiz Angelo Daros de Luca
2023-02-19 20:02 ` Nico Schottelius
2023-02-20 11:09 Janne Johansson
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