From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com [209.85.208.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75CF280BFC for ; Thu, 18 Jul 2024 14:13:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721311988; cv=none; b=skf905v3cP5r4kVHUjiZJXMtnIKV5zZUGjHeNJkrlg1/2L5Zxl5/0vVQ+9UQkWDhf4nGYY6x8TZuCp+J0erNLb+JIXGUePB857z6MXLliwUgN/4T8Ul60UnuxoggGq44cW8dAl16Lhr/LtQnWtENH8RBZK86EcN+WpomIT4kbtU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721311988; c=relaxed/simple; bh=kda55T5p6sR1XrXr0l9y8AqtLlGfdhZx4P0bc+DHbso=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LKsSBDUTj9YuiIuP3MqXRG5crj4Dw0Wip/hzjDz1C3NmSSDyPdyGAKA51afzyuBOVvPX2mlQdXCAZ2Pzy7kXEnFbnc5iSnZ3ngK0nnJLh2vNBYFVVv0KsyoAs946XZMfHuTABnosPUSEToH2PsEa1PBrkfECJwCUooK0UKVCdcA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=openvpn.net; spf=pass smtp.mailfrom=openvpn.com; dkim=pass (2048-bit key) header.d=openvpn.net header.i=@openvpn.net header.b=XWX+M6ba; arc=none smtp.client-ip=209.85.208.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=openvpn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=openvpn.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=openvpn.net header.i=@openvpn.net header.b="XWX+M6ba" Received: by mail-lj1-f182.google.com with SMTP id 38308e7fff4ca-2ee920b0781so11142781fa.1 for ; Thu, 18 Jul 2024 07:13:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=openvpn.net; s=google; t=1721311984; x=1721916784; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=ac9q+rKHkywIBVov0WJ1nP1+L4Xb/lrh3Shrgq2vRC4=; b=XWX+M6baJbvivPQhIfhjyHF3KwLeupgTzVoeWLS9MSC8lY+6Z5vL03ifSsCmxPbU1i Gco3mKfyXmltA/2HyrAEWjnsuErg9y+kMRXgL/AgvT5EvFKniJKBtotamygfqoY6QvWF i1PsKl6SxiNTUKSceCjJIVoyQClVB+PPOTl8wpoRU5iUwJpsOXEjSWV1nOKjPQBSUZV5 SjZIM01dxA6/8qop789to81QL4g4ATqxZnfZddC/TtS2g2WCDRNnLJ78o7EuXyYUByEU hCB0a4S70XUiXyozRsRHecJtWgA1MIBediYMh6ySBJJ9p2hUBi701y84MfVQWJfmRLS9 TjoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721311984; x=1721916784; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ac9q+rKHkywIBVov0WJ1nP1+L4Xb/lrh3Shrgq2vRC4=; b=cnaACWVtnt/xG6a8LshJEos+062NWglO9gfGsUEX+N3oGPMYnz/6eiB5HW1irDA8OV MkRFMch0uRcrLUT5SjStk1NIPsnlzB0Tabizvoo+npzVx3irgIrBnzoegdyUQhGm3O56 EFjTQR8jemYnSCQAoVGOVogeZ0jZ5RU9EbLmcpJFyAIe+gY5pYVe1YGEBiVuOhOiiOG6 zohFtXrOLpD1svkYs1llOKW0dVnM2IUlFXxG0fB3k3oDD1sI8DAPsajuzuVEmFo0+Nad yM2HfuiC4HnQr+cT/ISnwBK2FUG6I/BL8Q9qa5rtcaas+af5WInWE32hwud4/MFEu0w7 /Zxg== X-Gm-Message-State: AOJu0YyfLuPMuRDOEwuYmJ6IzgwvKKSHxig1eAbhIByOTjjSP1rf5mXY lND3sGXaMp8mK6aI4nglyq4pYCKtBDwxPQhNMGhmy2qtUiaYnICcGAZ/wVeVQoY= X-Google-Smtp-Source: AGHT+IHpqr82NTgTIMtXhXgDkksVPLWU5Lyh7uwke82doFK4LtW/PJrayeBLmZUCFAFxeOjxgvIRdg== X-Received: by 2002:a05:6512:a8d:b0:52c:e192:5f5f with SMTP id 2adb3069b0e04-52ee53df0bfmr3763569e87.19.1721311984455; Thu, 18 Jul 2024 07:13:04 -0700 (PDT) Received: from ?IPV6:2001:67c:2fbc:1:14d5:6a6d:7aec:1e83? ([2001:67c:2fbc:1:14d5:6a6d:7aec:1e83]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a79bc820ebesm563844366b.197.2024.07.18.07.13.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 18 Jul 2024 07:13:04 -0700 (PDT) Message-ID: Date: Thu, 18 Jul 2024 16:15:04 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v3 10/24] ovpn: implement basic RX path (UDP) To: Sabrina Dubroca Cc: netdev@vger.kernel.org, Jakub Kicinski , Sergey Ryazanov , Paolo Abeni , Eric Dumazet , Andrew Lunn , Esben Haabendal References: <20240506011637.27272-1-antonio@openvpn.net> <20240506011637.27272-11-antonio@openvpn.net> <10c01ca1-c79a-41ab-b99b-deab81adb552@openvpn.net> <80351026-0d15-460a-8002-4b24b893fefa@openvpn.net> Content-Language: en-US From: Antonio Quartulli Autocrypt: addr=antonio@openvpn.net; keydata= xsFNBFN3k+ABEADEvXdJZVUfqxGOKByfkExNpKzFzAwHYjhOb3MTlzSLlVKLRIHxe/Etj13I X6tcViNYiIiJxmeHAH7FUj/yAISW56lynAEt7OdkGpZf3HGXRQz1Xi0PWuUINa4QW+ipaKmv voR4b1wZQ9cZ787KLmu10VF1duHW/IewDx9GUQIzChqQVI3lSHRCo90Z/NQ75ZL/rbR3UHB+ EWLIh8Lz1cdE47VaVyX6f0yr3Itx0ZuyIWPrctlHwV5bUdA4JnyY3QvJh4yJPYh9I69HZWsj qplU2WxEfM6+OlaM9iKOUhVxjpkFXheD57EGdVkuG0YhizVF4p9MKGB42D70pfS3EiYdTaKf WzbiFUunOHLJ4hyAi75d4ugxU02DsUjw/0t0kfHtj2V0x1169Hp/NTW1jkqgPWtIsjn+dkde dG9mXk5QrvbpihgpcmNbtloSdkRZ02lsxkUzpG8U64X8WK6LuRz7BZ7p5t/WzaR/hCdOiQCG RNup2UTNDrZpWxpwadXMnJsyJcVX4BAKaWGsm5IQyXXBUdguHVa7To/JIBlhjlKackKWoBnI Ojl8VQhVLcD551iJ61w4aQH6bHxdTjz65MT2OrW/mFZbtIwWSeif6axrYpVCyERIDEKrX5AV rOmGEaUGsCd16FueoaM2Hf96BH3SI3/q2w+g058RedLOZVZtyQARAQABzSdBbnRvbmlvIFF1 YXJ0dWxsaSA8YW50b25pb0BvcGVudnBuLm5ldD7Cwa0EEwEIAFcCGwMFCwkIBwMFFQoJCAsF FgIDAQACHgECF4AFCRWQ2TIWIQTKvaEoIBfCZyGYhcdI8My2j1nRTAUCYRUquBgYaGtwczov L2tleXMub3BlbnBncC5vcmcACgkQSPDMto9Z0UzmcxAAjzLeD47We0R4A/14oDKlZxXO0mKL fCzaWFsdhQCDhZkgxoHkYRektK2cEOh4Vd+CnfDcPs/iZ1i2+Zl+va79s4fcUhRReuwi7VCg 7nHiYSNC7qZo84Wzjz3RoGYyJ6MKLRn3zqAxUtFECoS074/JX1sLG0Z3hi19MBmJ/teM84GY IbSvRwZu+VkJgIvZonFZjbwF7XyoSIiEJWQC+AKvwtEBNoVOMuH0tZsgqcgMqGs6lLn66RK4 tMV1aNeX6R+dGSiu11i+9pm7sw8tAmsfu3kQpyk4SB3AJ0jtXrQRESFa1+iemJtt+RaSE5LK 5sGLAO+oN+DlE0mRNDQowS6q/GBhPCjjbTMcMfRoWPCpHZZfKpv5iefXnZ/xVj7ugYdV2T7z r6VL2BRPNvvkgbLZgIlkWyfxRnGh683h4vTqRqTb1wka5pmyBNAv7vCgqrwfvaV1m7J9O4B5 PuRjYRelmCygQBTXFeJAVJvuh2efFknMh41R01PP2ulXAQuVYEztq3t3Ycw6+HeqjbeqTF8C DboqYeIM18HgkOqRrn3VuwnKFNdzyBmgYh/zZx/dJ3yWQi/kfhR6TawAwz6GdbQGiu5fsx5t u14WBxmzNf9tXK7hnXcI24Z1z6e5jG6U2Swtmi8sGSh6fqV4dBKmhobEoS7Xl496JN2NKuaX jeWsF2rOwE0EZmhJFwEIAOAWiIj1EYkbikxXSSP3AazkI+Y/ICzdFDmiXXrYnf/mYEzORB0K vqNRQOdLyjbLKPQwSjYEt1uqwKaD1LRLbA7FpktAShDK4yIljkxhvDI8semfQ5WE/1Jj/I/Q U+4VXhkd6UvvpyQt/LiWvyAfvExPEvhiMnsg2zkQbBQ/M4Ns7ck0zQ4BTAVzW/GqoT2z03mg p1FhxkfzHMKPQ6ImEpuY5cZTQwrBUgWif6HzCtQJL7Ipa2fFnDaIHQeiJG0RXl/g9x3YlwWG sxOFrpWWsh6GI0Mo2W2nkinEIts48+wNDBCMcMlOaMYpyAI7fT5ziDuG2CBA060ZT7qqdl6b aXUAEQEAAcLBfAQYAQgAJhYhBMq9oSggF8JnIZiFx0jwzLaPWdFMBQJmaEkXAhsMBQkB4TOA AAoJEEjwzLaPWdFMbRUP/0t5FrjF8KY6uCU4Tx029NYKDN9zJr0CVwSGsNfC8WWonKs66QE1 pd6xBVoBzu5InFRWa2ed6d6vBw2BaJHC0aMg3iwwBbEgPn4Jx89QfczFMJvFm+MNc2DLDrqN zaQSqBzQ5SvUjxh8lQ+iqAhi0MPv4e2YbXD0ROyO+ITRgQVZBVXoPm4IJGYWgmVmxP34oUQh BM7ipfCVbcOFU5OPhd9/jn1BCHzir+/i0fY2Z/aexMYHwXUMha/itvsBHGcIEYKk7PL9FEfs wlbq+vWoCtUTUc0AjDgB76AcUVxxJtxxpyvES9aFxWD7Qc+dnGJnfxVJI0zbN2b37fX138Bf 27NuKpokv0sBnNEtsD7TY4gBz4QhvRNSBli0E5bGUbkM31rh4Iz21Qk0cCwR9D/vwQVsgPvG ioRqhvFWtLsEt/xKolOmUWA/jP0p8wnQ+3jY6a/DJ+o5LnVFzFqbK3fSojKbfr3bY33iZTSj DX9A4BcohRyqhnpNYyHL36gaOnNnOc+uXFCdoQkI531hXjzIsVs2OlfRufuDrWwAv+em2uOT BnRX9nFx9kPSO42TkFK55Dr5EDeBO3v33recscuB8VVN5xvh0GV57Qre+9sJrEq7Es9W609a +M0yRJWJEjFnMa/jsGZ+QyLD5QTL6SGuZ9gKI3W1SfFZOzV7hHsxPTZ6 Organization: OpenVPN Inc. In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 18/07/2024 15:40, Sabrina Dubroca wrote: > 2024-07-18, 15:27:42 +0200, Antonio Quartulli wrote: >> On 18/07/2024 15:11, Sabrina Dubroca wrote: >>>> basically the idea is: with our encapsulation we can guarantee that what >>>> entered the tunnel is also exiting the tunnel, without corruption. >>>> Therefore we claim that checksums are all correct. >>> >>> Can you be sure that they were correct when they went into the tunnel? >>> If not, I think you have to set CHECKSUM_NONE. >> >> I can't be sure, because on the sender side we don't validate checksums >> before encapsulation. >> >> If we assume that outgoing packets are always well formed and they can only >> be damaged while traveling on the link, then the current code should be ok. >> >> If we cannot make this assumption, then we need the receiver to verify all >> checksums before moving forward (which is what you are suggesting). >> >> Is it truly possible for the kernel to hand ovpn a packet with invalid >> checksums on the TX path? > > The networking stack shouldn't generate packets with broken checksums, > but it could happen. On a VPN server that's giving access to an > internal network, I think the packet could get corrupted on the > internal network and may be pushed without verification into the > tunnel. Right. In these cases the receiver would have a chance to detect and discard this packet. With the current ovpn code, instead, we are saying "everything is good, don't check" and the packet would be delivered to the upper layer. Ok, I think it makes sense to switch to CHECKSUM_NONE. (I wonder what the wireguard guys think about it :-)) > > It's also possible to inject them with packet sockets for > testing. Using scapy to send packets over your ovpn device should > allow you to do that. Thanks for the hint! > -- Antonio Quartulli OpenVPN Inc.