altq on a gif tunnel

[Anthony Mallet <tho%useless-ficus.net@localhost>]

Hi,

I was trying to setup a basic altqd configuration on a machine running
-current + npf + gif(4) tunnel on a re(4) interface.

Even with the most basic altq.conf file, altqstat shows no traffic
stats:
# cat altq.conf
interface gif0 bandwidth 1M priq
class priq gif0 default NULL priority 9 default
# altqstat -i gif0
gif0:
[default] handle:0xa pri:9
  measured: 0bps qlen: 0 period:0
     packets:0 (0 bytes) drops:0

While with the same basic setup on the underlying re(4) interface:
# cat altq.conf
interface re1 bandwidth 1M priq
class priq re1 default NULL priority 9 default
# altqstat -i re1
re1:
[default] handle:0xa pri:9
  measured: 860.92kbps qlen: 1 period:19341
     packets:192941 (275003856 bytes) drops:404

I was wondering if this is a known limitation, or if there is
something simple enough that I could do to fix this (given that I have
no particular knowledge about the NetBSD network internals).
Should I file a PR?

Thanks!