TableLookupPrefix Inconsistencies Between VRF and Global RIBs

[crankynetman]

Hello!

When using the ListPathRequest RPC on a VRF, the TableLookupPrefix seems to be ignored and all prefixes are returned for the provided address family. Using this example in python, you can see the difference between the Global RIB and a VRF RIB when sending the same query and both tables have the same contents for example, given these two tables, global and the VRF named "ipt" respectively:

$ docker compose exec gobgp gobgp global rib -a ipv4
   Network              Next Hop             AS_PATH              Age        Attrs
*> 192.2.0.0/32         0.0.0.0                                   00:49:09   [{Origin: ?}]
*> 192.2.0.1/32         0.0.0.0                                   00:49:14   [{Origin: ?}]
$ docker compose exec gobgp gobgp vrf ipt rib -a ipv4
   Network              Next Hop             AS_PATH              Age        Attrs
*  192.2.0.0/32         0.0.0.0                                   01:14:48   [{Origin: ?}]
*  192.2.0.1/32         0.0.0.0                                   01:14:46   [{Origin: ?}]

Since these tables have essentially the same contents, if I issue a ListPathRequest RPC and filter the TableLookupPrefix to 192.2.0.0/32 I would expect to get back exactly one match per table. Given this example code, I get 2 responses (the entire table) when querying the VRF, but only the one (correct) response when querying the Global RIB:

Example Code:

import gobgp_pb2
import gobgp_pb2_grpc
import grpc
import ipaddress

ip = ipaddress.ip_interface("192.2.0.0/32")


_TIMEOUT_SECONDS = 1000
stub = gobgp_pb2_grpc.GobgpApiStub(grpc.insecure_channel("gobgp:50051"))

prefixes = [gobgp_pb2.TableLookupPrefix(prefix=str(ip))]
family_afi = gobgp_pb2.Family.AFI_IP

result = stub.ListPath(
    gobgp_pb2.ListPathRequest(
        table_type=gobgp_pb2.VRF,
        name="ipt",
        prefixes=prefixes,
        family=gobgp_pb2.Family(afi=family_afi, safi=gobgp_pb2.Family.SAFI_UNICAST),
    ),
    _TIMEOUT_SECONDS,
)

print(len(list(result)))

prefixes = [gobgp_pb2.TableLookupPrefix(prefix=str(ip))]
family_afi = gobgp_pb2.Family.AFI_IP

result2 = stub.ListPath(
    gobgp_pb2.ListPathRequest(
        table_type=gobgp_pb2.GLOBAL,
        prefixes=prefixes,
        family=gobgp_pb2.Family(afi=gobgp_pb2.Family.AFI_IP, safi=gobgp_pb2.Family.SAFI_UNICAST),
    ),
    _TIMEOUT_SECONDS,
)

print(len(list(result2)))

Response:

2
1

This is using GoBGP 3.33.0:

$ docker compose exec gobgp gobgp --version
gobgp version 3.33.0

Am I doing something wrong here? I've tried adding in RDs to the TableLookupPrefix as well, but to no avail. Any help is greatly appreciated, thank you very much in advance!

[crankynetman]

I've done a bit more testing on this, including trying out the newer API protobufs that @Tuetuopay has been working on to try and see if I've just been holding TableLookupPrefix wrong. Unfortunately, I still get the same issue.. I have an updated test script that I shoved into our repo that uses GoBGP:

https://github.com/esnet-security/SCRAM/blob/topic/chriscummings/test-gobgp-oneof-stuff/translator/test_file_thingy.py

Unfortunately, using the cleaner API defs didn't give any more credence to me holding TableLookupPrefix wrong, so I think that this is likely a bug (hopefully I'm wrong and I'm just not holding things right!)

[fujita]

I think that LookupPrefix isn't supported on a VRF.

[crankynetman]

That's a bit unfortunate. Is there a desire to add this functionality? It seems that perhaps we might want to log that it's not supported.

Is it supported via the CLI?