IPv6 multicast in 2.4.25 broken?

[Ignacy Gawedzki <ig@lri.fr>]

Hi,

It seems that simple multicast support in IPv6 has ceased working
starting at kernel version 2.4.25-pre4.  More specifically, receiving
multicast packets (those with destination address ff05::1 or ff02::1) is
broken (read: sending is okay).  The same binary run on kernels 2.4.24
and earlier works with no problem.

I tried as many combinations of USAGI patches and kernel versions as I
could, but cannot figure the exact source of the problem.  I did not
inspect the diffs with enough attention, though.

Another funny thing is that the changelog for version 2.4.25-pre4
doesn't mention any change to IPv6 code.

Did anyone have similar experience and or suggestions?

I have not subscribed to the linux-kernel list, because of its high
traffic, so please CC me the replies.

Thanks,

Ignacy

PS: The detailed way in which I prepare the socket is the following:

  Open a UDP socket in IPv6 protocol family.

  Bind it to network interface using SO_BINDTODEVICE.

  Set the multicast network interface using IPV6_MULTICAST_IF.
  
  Bind it to the network interface's address (which is set manually to
  fec0::1).
  
  Set the multicast hops with IPV6_MULTICAST_HOPS to 1.
  
  Set the multicast membership to ff02::1 (or ff05::1) using
  IPV6_ADD_MEMBERSHIP.
  
  Unset the multicast loop using IPV6_MULTICAST_LOOP.

Note: the same socket is used to send and receive multicast packets.

-- 
To err is human, to moo bovine.