From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 912AE43866; Mon, 8 Jan 2024 17:42:40 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 617D340693; Mon, 8 Jan 2024 17:42:40 +0100 (CET) Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by mails.dpdk.org (Postfix) with ESMTP id 581774064E for ; Mon, 8 Jan 2024 17:42:39 +0100 (CET) Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-1d4414ec9c7so5992995ad.0 for ; Mon, 08 Jan 2024 08:42:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1704732158; x=1705336958; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=B3ivaljlPq5jawlUBnyNFmL552eCGjvfgkPIg/gheI8=; b=u809MAdfmgulOFLhIzq/HIgDgcJDNMbn4IJql3Ett8yFuc+kjfJICFvDtOVExv5sMQ hCPnrqJiKVerKZFGpbDCGW4d2XB9uJ4+wZJX5W4PZq7MK81rpHAuPgP1s0tDHg0PvMeQ D7FHLmIYOIovWtp0rCsjG7kmO/HH7OyF+DejzVQhc41Lkjn7po/6gESkPGZFtXPL62QV C4TDR4+2MYvbR6XRQTemsoeMaXjMsxL377E8/rPwwSlQ2WSd/HRFyfIvOWuvhPkWAf1E rSLRipQk0jSbx5qKZDiGP5kVRjk6Os94cqPRgtrj/7NcQApcE6bIErlj44S/ppGhU9lP GKMQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704732158; x=1705336958; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=B3ivaljlPq5jawlUBnyNFmL552eCGjvfgkPIg/gheI8=; b=W/0WogePZBRK2YLbX3+v4fvwpw2jUPOGSBQKc6G/PNRQ8/W28NtDMxst/wLxYJhsJc camgUIVTU96kaqLvk1Di5PgnuoaiZ8d/zd3JB2j6W44pQKcrd4lezt/3HZqJRhcNR5jb tSeiLNoVGrDyIQSx1+GgO3nhvC7MyVpHSBGNCMUp5LZ+gqSsonQSmUWBRai9j1oERdEK 5ODX6ekbGP6sQ6a4LPfnAfN/Gmw1hqA51IogveIrsvUJ9NtOYlwCw9K5zYbG4V+HTEFv 4LLFYCOaaDZ/tJwJOJcktPAgCRMJ+jBNUt7Mf7hcL94yM2KAV+CBZYuXLHEK3wgY3wqk g1zg== X-Gm-Message-State: AOJu0YxvZzFQvcf0PCQQRw+5gErfJ5DMPEIudujCVMj4WcbBQ0viBlmv kct+9xVsP7+G+EOKgztSlGFKOV3OIxYjN+0UPa7UuyrFlPw= X-Google-Smtp-Source: AGHT+IHwh93E0TkXG8Fy9HwXcIyZVRsTnhgAINxFC+YELn538b4ExiMuaW6B0etL6qkv5vtU7yBjmQ== X-Received: by 2002:a17:903:280c:b0:1d4:47d4:82c6 with SMTP id kp12-20020a170903280c00b001d447d482c6mr1252943plb.99.1704732158516; Mon, 08 Jan 2024 08:42:38 -0800 (PST) Received: from hermes.local (204-195-123-141.wavecable.com. [204.195.123.141]) by smtp.gmail.com with ESMTPSA id v20-20020a1709028d9400b001d05456394csm121900plo.28.2024.01.08.08.42.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Jan 2024 08:42:38 -0800 (PST) Date: Mon, 8 Jan 2024 08:42:32 -0800 From: Stephen Hemminger To: =?UTF-8?B?6ZKf?= Cc: dev@dpdk.org Subject: Re: why DPDK reassembles IP fragment packets with AF_PACKET Message-ID: <20240108084232.09500487@hermes.local> In-Reply-To: <731d30bf.7034.18ce8c16f15.Coremail.gdsgsx2002@163.com> References: <731d30bf.7034.18ce8c16f15.Coremail.gdsgsx2002@163.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Mon, 8 Jan 2024 19:07:20 +0800 (CST) =E9=92=9F wrote: > Hi All, >=20 >=20 > Recently I debug ovs-dpdk with AF_PACKET mode. When IP fragment packets = are received via DPDK, the IP fragment packets are reassembled by DPDK. Aft= er reassembly, the packet length is over 1518. They are discarded by OVS be= cause of oversize packets. >=20 >=20 > I don't understandy why PACKET_FLAG_DEFRAG is set for AF_PACKET mode. >=20 >=20 Not sure, but it looks like the af_packet wants to hash packets for fanout. Hashin of fragments won't work correctly, and packet will arrive on differe= nt queues if fragmented.