* Netfilter redirect does not work with wireguard
@ 2019-11-07 16:38 Nico Schottelius
2019-11-07 21:50 ` Ivan Labáth
0 siblings, 1 reply; 3+ messages in thread
From: Nico Schottelius @ 2019-11-07 16:38 UTC (permalink / raw)
To: WireGuard mailing list
Hello,
I am experimenting with nft / netfilter redirects to support wireguard
packets on *any* udp port. I tried using the following configuration for
nftables:
[17:34:14] vpn-2a0ae5c1:~# cat /etc/nftables.conf
#!/usr/sbin/nft -f
flush ruleset
table ip nat {
chain prerouting {
type nat hook prerouting priority 0;
# SSH works
tcp dport != 22 redirect to 22
# wireguard doesn't
udp dport != 51820 redirect to 51820
}
chain postrouting {
type nat hook postrouting priority 0;
}
}
However as you can see in the comments, this does not work with
wireguard, however it does work with SSH.
I can see that wireguard is kernel space, and ssh user space, but does
that cause the netfilter part to be skipped or am I doing some silly
mistake here?
Best regards,
Nico
--
Modern, affordable, Swiss Virtual Machines. Visit www.datacenterlight.ch
_______________________________________________
WireGuard mailing list
WireGuard@lists.zx2c4.com
https://lists.zx2c4.com/mailman/listinfo/wireguard
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Netfilter redirect does not work with wireguard 2019-11-07 16:38 Netfilter redirect does not work with wireguard Nico Schottelius @ 2019-11-07 21:50 ` Ivan Labáth 2019-11-08 15:29 ` Nico Schottelius 0 siblings, 1 reply; 3+ messages in thread From: Ivan Labáth @ 2019-11-07 21:50 UTC (permalink / raw) To: Nico Schottelius; +Cc: WireGuard mailing list Hello, have you checked the source port of replies, or whether there are any replies? # tcpdump -nn Tcpdump should show pre-NAT addresses on incoming packets and AFAIK post-NAT on outgoing packets, i.e. what goes on the wire. You might need to apply SNAT on outgoing packets, which might happen automatically with TCP connection tracking, but I wouldn't really expect it on connection-less UDP. Regards, Ivan On Thu, Nov 07, 2019 at 05:38:42PM +0100, Nico Schottelius wrote: > > Hello, > > I am experimenting with nft / netfilter redirects to support wireguard > packets on *any* udp port. I tried using the following configuration for > nftables: > > [17:34:14] vpn-2a0ae5c1:~# cat /etc/nftables.conf > #!/usr/sbin/nft -f > > flush ruleset > > table ip nat { > chain prerouting { > type nat hook prerouting priority 0; > > # SSH works > tcp dport != 22 redirect to 22 > > # wireguard doesn't > udp dport != 51820 redirect to 51820 > } > > chain postrouting { > type nat hook postrouting priority 0; > } > } > > However as you can see in the comments, this does not work with > wireguard, however it does work with SSH. > > I can see that wireguard is kernel space, and ssh user space, but does > that cause the netfilter part to be skipped or am I doing some silly > mistake here? > > Best regards, > > Nico > > > -- > Modern, affordable, Swiss Virtual Machines. Visit www.datacenterlight.ch > _______________________________________________ > WireGuard mailing list > WireGuard@lists.zx2c4.com > https://lists.zx2c4.com/mailman/listinfo/wireguard _______________________________________________ WireGuard mailing list WireGuard@lists.zx2c4.com https://lists.zx2c4.com/mailman/listinfo/wireguard ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Netfilter redirect does not work with wireguard 2019-11-07 21:50 ` Ivan Labáth @ 2019-11-08 15:29 ` Nico Schottelius 0 siblings, 0 replies; 3+ messages in thread From: Nico Schottelius @ 2019-11-08 15:29 UTC (permalink / raw) To: Ivan Labáth; +Cc: WireGuard mailing list Hello, there are actually no replies at all, which is why I *assumed* that the packets do not actually arrive at the wireguard code. How does wireguard integrate into the kernel / netfilter flow? Or in other words, how is the expected behaviour of something like what I am trying to do? Best, Nico p.s.: I was also thinking about needing SNAT, but I don't see any replies generated at the moment. Ivan Labáth <labawi-wg@matrix-dream.net> writes: > Hello, > > have you checked the source port of replies, or whether > there are any replies? > > # tcpdump -nn > > Tcpdump should show pre-NAT addresses on incoming packets > and AFAIK post-NAT on outgoing packets, i.e. what goes on > the wire. > > You might need to apply SNAT on outgoing packets, which > might happen automatically with TCP connection tracking, > but I wouldn't really expect it on connection-less UDP. > > Regards, > Ivan > > On Thu, Nov 07, 2019 at 05:38:42PM +0100, Nico Schottelius wrote: >> >> Hello, >> >> I am experimenting with nft / netfilter redirects to support wireguard >> packets on *any* udp port. I tried using the following configuration for >> nftables: >> >> [17:34:14] vpn-2a0ae5c1:~# cat /etc/nftables.conf >> #!/usr/sbin/nft -f >> >> flush ruleset >> >> table ip nat { >> chain prerouting { >> type nat hook prerouting priority 0; >> >> # SSH works >> tcp dport != 22 redirect to 22 >> >> # wireguard doesn't >> udp dport != 51820 redirect to 51820 >> } >> >> chain postrouting { >> type nat hook postrouting priority 0; >> } >> } >> >> However as you can see in the comments, this does not work with >> wireguard, however it does work with SSH. >> >> I can see that wireguard is kernel space, and ssh user space, but does >> that cause the netfilter part to be skipped or am I doing some silly >> mistake here? >> >> Best regards, >> >> Nico >> >> >> -- >> Modern, affordable, Swiss Virtual Machines. Visit www.datacenterlight.ch >> _______________________________________________ >> WireGuard mailing list >> WireGuard@lists.zx2c4.com >> https://lists.zx2c4.com/mailman/listinfo/wireguard -- Modern, affordable, Swiss Virtual Machines. Visit www.datacenterlight.ch _______________________________________________ WireGuard mailing list WireGuard@lists.zx2c4.com https://lists.zx2c4.com/mailman/listinfo/wireguard ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-11-08 15:28 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-11-07 16:38 Netfilter redirect does not work with wireguard Nico Schottelius 2019-11-07 21:50 ` Ivan Labáth 2019-11-08 15:29 ` Nico Schottelius
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.