Development discussion of WireGuard
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From: Roman Mamedov <rm@romanrm.net>
To: Nico Schottelius <nico.schottelius@ungleich.ch>
Cc: tlhackque <tlhackque@yahoo.com>, wireguard@lists.zx2c4.com
Subject: Re: Source IP incorrect on multi homed systems
Date: Mon, 20 Feb 2023 01:42:52 +0500	[thread overview]
Message-ID: <20230220014252.21178988@nvm> (raw)
In-Reply-To: <87o7pp76a2.fsf@ungleich.ch>

On Sun, 19 Feb 2023 21:18:34 +0100
Nico Schottelius <nico.schottelius@ungleich.ch> wrote:

> If I am not mistaken that would mean in practice:
> 
>    if orignal_pkg.ip_dst == one_of_my_ips then
>       return_pkg.ip.src = orignal_pkg.ip_dst
>       return_pkg.ip.dst = orignal_pkg.ip_src
>    fi
> 
> For me that sounds like a sane approach (aside from
> my very simplified algorithm).

Except there is no request and response in WG, and as such no original or
return packet. Another peer contacts you, then some time later you contact the
other peer. Or the other way round.

WG-wise what will need to be done is to store in the each peer's information
structure the local IP that we are supposed to use for communication with that
peer; and updating it when receiving packets from the peer, using the
destination of those. So you would see a "Local IP" in each "peer" section
when doing a "wg show".

Also, until there is such IP initially stored, it will have to be some default
outgoing IP of the system towards that peer. BTW, how would this work in your
setup, what if not the peer contacts you first, but your machine needs to
contact the peer?

-- 
With respect,
Roman

  reply	other threads:[~2023-02-19 20:42 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
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 [this message]
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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