bird and on-interface p2p routes

[Eugene M. Zheganin]

Hello,

youm this question was asked like a gazillion times, but so far I faled 
to google the answer. So, I have a network softrouter on Linux which was 
clearly written by some ignorant folks; it operates the p2p tunX 
interface that doesn't have the remote IP set, only a local one. So bird 
does complain about "strange next-hop" when walking through the kernel 
routing table and seeing the local/self address as a gateway. Still, 
this is partially valid setup, because the hosts this softrouter injects 
into the kernel RT are reachable via p2p interface directly. I can 
declare these as a static routes reachable via tunX, but this setup 
lacks the automation (I will had to refresh thhe routes manually).

So, my though is like this: is it possible to convert these from 
"strange next-hop" routes to this

===Cut===

10.24.123.0/21        unicast [direct1 2023-12-07] * (200)
         dev tun0

===Cut===

via the export filter ? I tried the following approach but it seems like 
I'm missing something:

===Cut===

filter exportkernelv4 {
     if ifname = "tun0" then {
             print "attempting to change route attributes: ifname ", 
ifname, ", gw: ", gw, ", dest: ", dest;
             onlink = true;
             #unset(gw);
     }
     accept;
};

protocol kernel {
     learn;
     persist;
     scan time 20;
     ipv4 {
             import all;
             export filter exportkernelv4;
     };
}

===Cut===


What am I missing ? Seems like for some reason I just cannot merey 
unsert the gw attribute.


Thanks.

Eugene.