From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3129F3A7F6B; Wed, 1 Jul 2026 20:54:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782939262; cv=none; b=T2SUpCW2CHPOeU0mDnB0u22qxuYga/vpPmFvrouUlBaMYTeOeZ6DKf9qWgRxL5NAbXOp4CVsIasOYv9UdXXCuE2eqcYjHdG2qaGGjUDhDoMzS7ckmesWik/R5i+4PgNHRoo/LoqiK+aFAvFD4r8XZRxuQvFfoCWXDYozChngBRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782939262; c=relaxed/simple; bh=pflyARrIC1PkECp+vY/Xn1BVY0ujTQ/JDr52eHmBJF4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NgS0bahADaddHMUFsUq/HKV/sv6Kc7Y8mRvAvUibKVmm22/ehlAPLD37F6SnsYh9dlINnqhvkN56pU6zyKKc0aUJyjDmWu2YrMk3DqJ1E2oKAZhSqJzxVUFJcHSNgQFFAy0HQHQbYtm4+CKTaScHa0eTC2q4AC6jYdeQnjZEi6E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=bP5Y1uth; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="bP5Y1uth" Message-ID: <75aafe76-fa22-4985-b277-fb51debf8852@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1782939256; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sTSQsuTdzdnUYTD7BTPntQLkPU6l8HPheSNnHeBOHHQ=; b=bP5Y1uth5XwlVbKmRMA1yvUclZCCZcHoAQdvdFQRqGGeW3y0luZx3MAiC8IP9y14Z/U4gQ bpnlxzMOMOJjiyVRS/Tlp3I0aOLPSj8XDkLexvIfGXcrXvugY/SLz00wwQyddbRkT60fF7 msh/WM6xC58NsXos//1rGdxe5gS/big= Date: Wed, 1 Jul 2026 21:54:13 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net-next 1/3] net: ipv4: report multicast group user count To: Yuyang Huang Cc: "David S. Miller" , Andrew Lunn , David Ahern , Donald Hunter , Eric Dumazet , Ido Schimmel , Jakub Kicinski , Paolo Abeni , Shuah Khan , Simon Horman , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org References: <20260630110207.37841-1-sigefriedhyy@gmail.com> <20260630110207.37841-2-sigefriedhyy@gmail.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: <20260630110207.37841-2-sigefriedhyy@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 30/06/2026 12:02, Yuyang Huang wrote: > RTM_GETMULTICAST has been part of the rtnetlink ABI for a long time > and already reports IPv4 multicast group membership through > IFA_MULTICAST and IFA_CACHEINFO. It does not report how many consumers > hold each membership, so userspace still has to parse /proc/net/igmp to > get the Users column. > > Add IFA_MC_USERS as a u32 attribute carrying ip_mc_list::users in > RTM_GETMULTICAST replies and entry-lifecycle notifications. > > This gives iproute2 enough information to migrate the IPv4 part of > "ip maddr show" from procfs parsing to rtnetlink. > > Signed-off-by: Yuyang Huang > --- > Documentation/netlink/specs/rt-addr.yaml | 4 ++++ > include/uapi/linux/if_addr.h | 1 + > net/ipv4/igmp.c | 2 ++ > 3 files changed, 7 insertions(+) > Reviewed-by: Vadim Fedorenko