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From:   Callum Sinclair <Callum.Sinclair@alliedtelesis.co.nz>
To:     Andrew Lunn <andrew@lunn.ch>
CC:     "dsahern@kernel.org" <dsahern@kernel.org>,
        "nikolay@nvidia.com" <nikolay@nvidia.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linus.luessing@c0d3.blue" <linus.luessing@c0d3.blue>
Subject: Re: [PATCH] net: Allow any address multicast join for IP sockets
Thread-Topic: [PATCH] net: Allow any address multicast join for IP sockets
Thread-Index: AQHXcgR3BnwxqirtmESI1bbFp3V9F6s1KEqAgAGaTzw=
Date:   Wed, 7 Jul 2021 02:00:29 +0000
Message-ID: <1625623229789.98509@alliedtelesis.co.nz>
References: <20210706011548.2201-1-callum.sinclair@alliedtelesis.co.nz>,<YORaY83GiD56/su0@lunn.ch>
In-Reply-To: <YORaY83GiD56/su0@lunn.ch>
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Hi Andrew=0A=
=0A=
Yes I want to receive all multicast frames.This is to configure=0A=
a userspace switch driver to prevent unknown multicast=0A=
routes being flooded unexpectedly to all switch ports.=0A=
=0A=
The advantage of using IP sockets over a pcap on raw sockets=0A=
is I can still use the Linux routing stack for sending and receiving=0A=
packets.=0A=
=0A=
Cheers=0A=
Callum=0A=
________________________________________=0A=
From: Andrew Lunn <andrew@lunn.ch>=0A=
Sent: Wednesday, July 7, 2021 1:28 AM=0A=
To: Callum Sinclair=0A=
Cc: dsahern@kernel.org; nikolay@nvidia.com; netdev@vger.kernel.org; linux-k=
ernel@vger.kernel.org; linus.luessing@c0d3.blue=0A=
Subject: Re: [PATCH] net: Allow any address multicast join for IP sockets=
=0A=
=0A=
On Tue, Jul 06, 2021 at 01:15:47PM +1200, Callum Sinclair wrote:=0A=
> For an application to receive all multicast packets in a range such as=0A=
> 224.0.0.1 - 239.255.255.255 each multicast IP address has to be joined=0A=
> explicitly one at a time.=0A=
>=0A=
> Allow the any address to be passed to the IP_ADD_MEMBERSHIP and=0A=
> IPV6_ADD_MEMBERSHIP socket option per interface. By joining the any=0A=
> address the socket will receive all multicast packets that are received=
=0A=
> on the interface.=0A=
>=0A=
> This allows any IP socket to be used for IGMP or MLD snooping.=0A=
=0A=
Do you really want all multicast frames, or just IGMP and MLD=0A=
messages?=0A=
=0A=
What is the advantage of this solution over using pcap with a filter=0A=
which matches on multicast?=0A=
=0A=
      Andrew=0A=