sr with filter not working on loopback on OpenBSD

[sthen]

Brief description

Using sr with filter= parameters when sending to addresses reached via lo0 results in replies not being picked up.

Scapy version

2.6.1

Python version

3.12.8

Operating system

OpenBSD amd64 -current

Additional environment information

No response

How to reproduce

>>> p = sr1(IP(dst="127.0.0.1")/ICMP()/"XXXXXXXXXXX", filter="ip", timeout=3)
Begin emission

Finished sending 1 packets

Received 0 packets, got 0 answers, remaining 1 packets

Trying the same with another local IP address results in the same issue. The same without filter succeeds. The same with a filter but a remote IP address succeeds.

Actual result

No response

Expected result

No response

Related resources

No response

[guedou]

Thanks for your detailed message. Unfortunately, the loopback interface is a strange beast, that does not exactly work like a regular one. Is filter working ion a regular interface?