From: Flavio Leitner <redacted>
Date: Tue, 31 Jul 2007 15:29:40 -0300

On Tue, Jul 31, 2007 at 12:00:41AM -0300, Arnaldo Carvalho de Melo wrote:

quoted

On 7/30/07, David Miller [off-list ref] wrote:

quoted

Allowing non-datagram sockets to end up with a non-NULL inet->mc_list
in the first place is a bug.

Multicast subscriptions cannot even be used with TCP and DCCP, which
are the only two users of these connection oriented socket functions.

The first thing that TCP and DCCP do, in fact, for input packet
processing is drop the packet if it is not unicast.

Therefore the fix really is for the inet layer to reject multicast
subscription requests on sockets for which that absolutely does not
make sense.  There is no reason these functions in
inet_connection_sock.c should need to be mindful of multicast
state. :-)

Well, we can add a BUG_ON there then 8)

Flavio, take a look at  do_ip_setsockopt in net/ipv4/ip_sockglue.c, in
the IP_{ADD,DROP}_MEMBERSHIP labels.

Don't forget IPV6 (net/ipv6/ipv6_sockglue.c)

yes, right. What about the one below?

[NET]: Fix IP_ADD/DROP_MEMBERSHIP to handle only connectionless

Fix IP[V6]_ADD_MEMBERSHIP and IP[V6]_DROP_MEMBERSHIP to
return -EPROTO for connection oriented sockets.

Signed-off-by: Flavio Leitner <redacted>

This looks great, patch applied.

Thanks!