'ip mroute x.y.z.0/len a.b.c.d' does work for multicast RPF

[arundesigan]

I using the stable/8.1 branch and running into the following issue, basically none of the routes that were added using the ' ip mroute ...' command does not resolve the multicast RPF. For ex.,

frr-vtysh# sh ip rpf
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, F - PBR,
f - OpenFabric,
> - selected route, * - FIB route, q - queued, r - rejected, b - backup
t - trapped, o - offload failure

C> 10.65.13.0/24 is directly connected, eth0, 01:40:55
C> 11.1.1.0/24 is directly connected, eth6, 01:40:55
C> 12.1.1.0/24 is directly connected, eth5, 01:40:55
S> 14.1.1.0/24 [1/0] via 100.64.0.92, mcast0, weight 1, 01:39:51
S> 15.1.1.0/25 [1/0] via 192.168.1.2, eth1, weight 1, 01:37:48
S> 16.1.1.0/24 [1/0] via 100.64.0.92, mcast0, weight 1, 01:35:11
C> 100.64.0.0/16 is directly connected, mcast0, 01:40:55
C> 192.168.1.0/24 is directly connected, eth1, 01:40:55
C> 192.168.2.0/24 is directly connected, eth2, 01:40:55
C> 192.168.3.0/24 is directly connected, eth3, 01:40:55
C> 192.168.4.0/24 is directly connected, eth4, 01:40:55
frr-vtysh# sh ip rpf 14.1.1.0
% No match for RPF lookup
frr-vtysh# sh ip rpf 15.1.1.1
% No match for RPF lookup
frr-vtysh# sh ip rpf 192.168.1.1
Routing entry for 192.168.1.0/24 using Unicast RIB
Known via "connected", distance 0, metric 0, best
Last update 01:41:21 ago

• directly connected, eth1

I tracked this down to this piece of code that is skipped in rib_install_kernel() if the safi is NOT SAFI_UNICAST, hence rib_match() skips this entry even though the prefix match happens. Rightly, the route is not added to the kernel, but then without dest->selected_fib, rib_match fails.
...
    /* Update fib selection */
    dest->selected_fib = re;
...

Do you guys know if this is intentional, if so how do I make the 'ip mroute' work for multicast RPF. Thanks and highly appreciate a response.

[donaldsharp]

This is currently broken for multicast RPF lookup. I believe it is on someone's radar to get fixed

[arundesigan]

Thanks for the response. Is there an issue open for this already? I did find a way to resolve it (perhaps not fully) and can share the changes that I have.

[arundesigan]

Hi

Is this fixed in 8.2.2 release?