From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-52003.amazon.com (smtp-fw-52003.amazon.com [52.119.213.152]) (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 CD45123C8CF for ; Tue, 8 Apr 2025 17:33:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.119.213.152 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744133585; cv=none; b=nhw/WdiR1Vt5DiaFYJnY0C4Lu/S0zou5hFnevmhiMyFv9Hz29AIP5rYbnFawGJYk7X4s94l/9A7N3cw9NleQO7/7jaeUCPmpYt2Ykezy88Vx144fDcrtnenEFl+y3Ly9V3qWHbS7wqsG+S2K5cEMywvIsfdb1BI4IBzvxpWIARc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744133585; c=relaxed/simple; bh=QUF6pxteZBFB9QVoVGyr00hJUIzPlGKpDScG483P/ec=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=exwA9Laz91Sd8nRI8LTh9DUmi8EAwYiuKH64PswMrKrvQb+rBYGwpdj6jObQTjmGU/sTrK2KbAIPMeT1g4uP2gIRgKA/3nWB6wUnGQpMmR/pMiXoLat9PddgZixJQBIb4SgmtmJvrT8SLpoOLI7Znn7N7o8rLQovFFD6LOfhdas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.jp; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=gogQkN54; arc=none smtp.client-ip=52.119.213.152 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="gogQkN54" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1744133584; x=1775669584; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7/jsW/uTOWM537jqlVPjiwP18j9rDKapLR48hsvKGG8=; b=gogQkN540ZAFHeINrsccqg4lfhbGiwLqGB6fBFRpqsOGiJXmhZZ2QwQQ S9iLK/Jtit/JUN8pLc0GKfqeLLKsV5OiypVzTznwI72ctLA3YUxJ5CQlb 6XLlmkQ00x2E4AMccKD0aauaqfmszUgPJq81wTgiazIiflaX4ix91snD2 g=; X-IronPort-AV: E=Sophos;i="6.15,198,1739836800"; d="scan'208";a="81902356" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.43.8.6]) by smtp-border-fw-52003.iad7.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Apr 2025 17:33:00 +0000 Received: from EX19MTAUWC001.ant.amazon.com [10.0.38.20:36807] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.49.222:2525] with esmtp (Farcaster) id f1726e36-8c61-4fca-b42e-59e5e02a6709; Tue, 8 Apr 2025 17:32:59 +0000 (UTC) X-Farcaster-Flow-ID: f1726e36-8c61-4fca-b42e-59e5e02a6709 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWC001.ant.amazon.com (10.250.64.174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Tue, 8 Apr 2025 17:32:59 +0000 Received: from 6c7e67bfbae3.amazon.com (10.106.100.5) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Tue, 8 Apr 2025 17:32:55 +0000 From: Kuniyuki Iwashima To: CC: , , , , , , , , , , , , , , Subject: Re: [PATCH v1 net-next 2/4] net: Retire DCCP. Date: Tue, 8 Apr 2025 10:31:20 -0700 Message-ID: <20250408173246.38170-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D037UWC003.ant.amazon.com (10.13.139.231) To EX19D004ANA001.ant.amazon.com (10.37.240.138) From: Pablo Neira Ayuso Date: Tue, 8 Apr 2025 18:37:36 +0200 > Hi Kuniyuki, > > On Mon, Apr 07, 2025 at 04:17:49PM -0700, Kuniyuki Iwashima wrote: > > DCCP was orphaned in 2021 by commit 054c4610bd05 ("MAINTAINERS: dccp: > > move Gerrit Renker to CREDITS"), which noted that the last maintainer > > had been inactive for five years. > > > > In recent years, it has become a playground for syzbot, and most changes > > to DCCP have been odd bug fixes triggered by syzbot. Apart from that, > > the only changes have been driven by treewide or networking API updates > > or adjustments related to TCP. > > > > Thus, in 2023, we announced we would remove DCCP in 2025 via commit > > b144fcaf46d4 ("dccp: Print deprecation notice."). > > > > Since then, only one individual has contacted the netdev mailing list. [0] > > > > There is ongoing research for Multipath DCCP. The repository is hosted > > on GitHub [1], and development is not taking place through the upstream > > community. While the repository is published under the GPLv2 license, > > the scheduling part remains proprietary, with a LICENSE file [2] stating: > > > > "This is not Open Source software." > > > > The researcher mentioned a plan to address the licensing issue, upstream > > the patches, and step up as a maintainer, but there has been no further > > communication since then. > > > > Maintaining DCCP for a decade without any real users has become a burden. > > > > Therefore, it's time to remove it. > > > > Removing DCCP will also provide significant benefits to TCP. It allows > > us to freely reorganize the layout of struct inet_connection_sock, which > > is currently shared with DCCP, and optimize it to reduce the number of > > cachelines accessed in the TCP fast path. > > Netfilter parses skbuffs, in that sense, it is a middlebox. Main > concern on my side is that it could break rulesets, even for people > that don't really see dccp traffic ever, ruleset could stop loading. > > I would keep the netfilter bits aside by now, based on your netfilter > updates, we can internally discuss how to phase out dccp support to > get aligned with netdev maintainers, as it seems there is a wish to > reduce debt in this front. Fair enough. I'll drop the netfilter stuff in v2. > > Having said, this Netfilter does not rely on any of this socket > structures, I think it should not be an impediment for your tree > spring cleanup (IIRC we have no hard dependencies on CONFIG_DCCP). Yes, actually I split changes for net/dccp, netfilter, and LSM initially, and then, even without net/dccp, netfilter compiled successfully if include/linux/dccp.h (dccp_hdr etc) was not removed. Thanks! --- pw-bot: cr