From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35444C07E9C for ; Tue, 6 Jul 2021 13:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15FC161C93 for ; Tue, 6 Jul 2021 13:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232051AbhGFNa6 (ORCPT ); Tue, 6 Jul 2021 09:30:58 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:42844 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231453AbhGFNa5 (ORCPT ); Tue, 6 Jul 2021 09:30:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=iW5yXRiM6Z1EIUMT/gNK7q4J8fz+0rzrf1+DLiKdxpM=; b=SlEsc8WJ8dCWMCGBpOuP5kbHSX MQbmxA9+mGkDLJ46H816lJynbHV+Zzj0sHk+ZL+fgojNwBOs33QrmnXR09E3M2gv3lwoy4cG5u1Yp vk7jxpMGXCwQfEVQRrgoswm8CEWdScoVqO/cV1db6AID4SfQsnrVaTXBMP10FiZYQeOA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1m0l7L-00CO3c-V0; Tue, 06 Jul 2021 15:28:03 +0200 Date: Tue, 6 Jul 2021 15:28:03 +0200 From: Andrew Lunn To: Callum Sinclair Cc: dsahern@kernel.org, nikolay@nvidia.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linus.luessing@c0d3.blue Subject: Re: [PATCH] net: Allow any address multicast join for IP sockets Message-ID: References: <20210706011548.2201-1-callum.sinclair@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210706011548.2201-1-callum.sinclair@alliedtelesis.co.nz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 06, 2021 at 01:15:47PM +1200, Callum Sinclair wrote: > For an application to receive all multicast packets in a range such as > 224.0.0.1 - 239.255.255.255 each multicast IP address has to be joined > explicitly one at a time. > > Allow the any address to be passed to the IP_ADD_MEMBERSHIP and > IPV6_ADD_MEMBERSHIP socket option per interface. By joining the any > address the socket will receive all multicast packets that are received > on the interface. > > This allows any IP socket to be used for IGMP or MLD snooping. Do you really want all multicast frames, or just IGMP and MLD messages? What is the advantage of this solution over using pcap with a filter which matches on multicast? Andrew