[openib-general] [PATCH] multicast: add support for MGID 0

[Hal Rosenstock]

Hi Sean,

On Wed, 2006-07-26 at 20:10, Sean Hefty wrote:
> Add support to join a multicast group with MGID = 0, with the actual
> MGID of the group returned by the SA.  The multicast module must be able
> to handle multiple requests for MGID = 0, with each request causing a
> new multicast group to be created.
> 
> Also enhance the API for ib_get_mcmember_rec() to support a requested
> MGID of 0.  In this case, a default MCMemberRecord is returned to the
> user and may be used when creating a new multicast group.  Currently,
> the default values are hard-coded by the multicast module, but that can
> be extended in the future or overridden by the user before creating
> the group.
> 
> Signed-off-by: Sean Hefty <sean.hefty at intel.com>
> ---

[snip...]

> Index: core/multicast.c
> ===================================================================
> --- core/multicast.c	(revision 8695)
> +++ core/multicast.c	(working copy)

[snip...]

> +	if (mgid && memcmp(mgid, &mgid0, sizeof mgid0)) {
> +		spin_lock_irqsave(&port->lock, flags);
> +		group = mcast_find(port, mgid);
> +		if (group)
> +			*rec = group->rec;
> +		else
> +			ret = -EADDRNOTAVAIL;
> +		spin_unlock_irqrestore(&port->lock, flags);
> +	} else {
> +		memset(rec, 0, sizeof *rec);
> +		ib_get_cached_gid(device, port_num, 0, &rec->port_gid);
> +		rec->pkey = 0xFFFF;
> +		get_random_bytes(&rec->qkey, sizeof rec->qkey);
> +		rec->join_state = 1;
> +	}

These are the hard coded values for pkey, qkey, and join state mentioned
above. Should there be module parameters to override them ?

Also, where do the other parameters (components) that are necessary to
create a group come from ?

Another option would be to obtain all of them from the appropriate
(partition based) IPoIB broadcast group.

-- Hal