From patchwork Fri Oct 20 05:32:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yan Zhai X-Patchwork-Id: 13430057 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 6198920E7 for ; Fri, 20 Oct 2023 05:32:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="HzbvMgu0" Received: from mail-qt1-x832.google.com (mail-qt1-x832.google.com [IPv6:2607:f8b0:4864:20::832]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2BFAD51 for ; Thu, 19 Oct 2023 22:32:50 -0700 (PDT) Received: by mail-qt1-x832.google.com with SMTP id d75a77b69052e-41cc0e9d92aso2610091cf.3 for ; Thu, 19 Oct 2023 22:32:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google09082023; t=1697779969; x=1698384769; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=KV869UUQKRDRmnZ80A1/n7z6+idYBNckQF54inYjS5g=; b=HzbvMgu0lCF6faIChfXVinjI8bdH8kCWR2utK3tXvu34fwxKuN+u7vQC/G26UceGv+ SzAlBbmmwoyVsMMJDSYTFzUfmx4HYcSpKW17SlKRor46zKxpjr6mwSaGGbxtPh0q8TgV yFKM4Ca7zSRagheV0IgDbFz4qAx4bITuix1XYKvWn7fxL9oGRbvNwfXRzE8OlLpwFzQo ypWPvQR5Vq97WzVambzsJJY1rCxxp6gIoMAoPfLEWaABiCZp25xVa0DQyTSr5qstDPcT 5/t822WT84u42eN7Th3pb3hEGHGm5n+IjmmX95weEKhR59aX+AtSUMlj/PwMdXA9gR5B QijA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697779969; x=1698384769; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=KV869UUQKRDRmnZ80A1/n7z6+idYBNckQF54inYjS5g=; b=nQW/gRRUgDyp+N/Epfcfs5X7EW8p9BFf1diAenk0L7okXftfq3ao13gAzCFeBQ9m45 bb7ixgfvVCbc7VhO3zusbmKyuKqu0+7sjlF3jAyzseaasBy8AmkZ/tS1Sp0SJFAaoWx9 9sxLPbOzrKoIgEXCD3CvB+UtBG4YyrYLgX+gCGFPanO6MFNa6sFQVgw4ro3J7J/aiiSd WSmc18ApQmbEOp3IhoSVT0pPIGbewBxllJm0ubxJEW/5Uw0rLARs/Q8jyje7/ku69uz6 3yv3FbDvvmwupfj1WlhZuYnlObaAnqj8zTFtQah3lX/c4xI85kL5ub3PUvor/JjeOHCI FeGg== X-Gm-Message-State: AOJu0YxcLhx+svMANy2u71kdrfgpg73VsmjlukcBWLJt80+VDwlqCr/A YYXpvKnhZMeL7B5X7IJLYr+YKBkXCzK12ZH1gK9vZw== X-Google-Smtp-Source: AGHT+IE/sGedLpUr4sLQdyiagGVmU5aZdQlN8A0vLvzrjxYrZUHQz/La835JeQyomnGiOmnneXe/Bg== X-Received: by 2002:a05:6214:d66:b0:66d:1e25:9774 with SMTP id 6-20020a0562140d6600b0066d1e259774mr916666qvs.61.1697779969555; Thu, 19 Oct 2023 22:32:49 -0700 (PDT) Received: from debian.debian ([140.141.197.139]) by smtp.gmail.com with ESMTPSA id g20-20020ad457b4000000b0065d0dcc28e3sm421513qvx.73.2023.10.19.22.32.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Oct 2023 22:32:49 -0700 (PDT) Date: Thu, 19 Oct 2023 22:32:47 -0700 From: Yan Zhai To: netdev@vger.kernel.org Cc: "David S. Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Aya Levin , Tariq Toukan , linux-kernel@vger.kernel.org, kernel-team@cloudflare.com, Florian Westphal , Willem de Bruijn , Alexander H Duyck Subject: [PATCH v3 net-next 1/3] ipv6: remove dst_allfrag test on ipv6 output Message-ID: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Patchwork-Delegate: kuba@kernel.org dst_allfrag was added before the first git commit: https://www.mail-archive.com/bk-commits-head@vger.kernel.org/msg03399.html The feature would send packets to the fragmentation path if a box receives a PMTU value with less than 1280 byte. However, since commit 9d289715eb5c ("ipv6: stop sending PTB packets for MTU < 1280"), such message would be simply discarded. The feature flag is neither supported in iproute2 utility. In theory one can still manipulate it with direct netlink message, but it is not ideal because it was based on obsoleted guidance of RFC-2460 (replaced by RFC-8200). The feature test would always return false at the moment, so remove it from the output path. Signed-off-by: Yan Zhai --- net/ipv6/ip6_output.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index a471c7e91761..ae87a3817d4a 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -189,7 +189,6 @@ static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu); if ((skb->len > mtu && !skb_is_gso(skb)) || - dst_allfrag(skb_dst(skb)) || (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) return ip6_fragment(net, sk, skb, ip6_finish_output2); else