From patchwork Mon Sep 21 14:36:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 11790149 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 638E059D for ; Mon, 21 Sep 2020 14:37:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20B5622B2D for ; Mon, 21 Sep 2020 14:37:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="BuWNVkVr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727570AbgIUOhB (ORCPT ); Mon, 21 Sep 2020 10:37:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727448AbgIUOhB (ORCPT ); Mon, 21 Sep 2020 10:37:01 -0400 Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECB53C061755 for ; Mon, 21 Sep 2020 07:37:00 -0700 (PDT) Received: by mail-wm1-x342.google.com with SMTP id q9so12382430wmj.2 for ; Mon, 21 Sep 2020 07:37:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=v8pcZTN+i/7Fb4vyTfG/UopYgDCcumlDoCD0Nm0/ODM=; b=BuWNVkVr+wdx6IkSh0we8UYHMffxew16ocu/iGlVvYfgUg4rEdJVZkztwR2qvUWYjb lDc1zsfBltXWC/+nWZ+9wHihwIGvCc/Q6Wq9NOKrL3vZHrzzjpPOPlyTHZjB6x+wFY6o f1CGSkr4HoW1CwUGvfjIjxF4VhJbuo01ipe7SbBU4fbK/1k2diIlFUUjVDNfxkTN1koc 5sXZk8Bkgawx9re+wKExncSEd750J/1+bCIneEXYBOm72sId9diP9GdgKobiWhtlxNVA NhNdNxERkEbKiF8DVGGnDBLJdA86/ST/PkCdSmwz6SloR33+7bOPaik7waYy7BJwdhSu io+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=v8pcZTN+i/7Fb4vyTfG/UopYgDCcumlDoCD0Nm0/ODM=; b=P4POM8jwLANRu2qABbHYZqKaozo5ndJJnUdBFvtfbd/Mp+ZBTYXTlG/yxXwSsMuEDx ZQRRPAVdOBTjXbqOroA3FzWoF8fxkhWmKCT4JNJNw0HbhmbPG+21Txzcr2SHTrIyu5+0 ryWi2ctsvEV04n6YC3Bs0l37zDYIGqNv+n2eUytEL9IlknQgBArEGX2i8R7fdsleM24T AVvs0Obk/bHXBZq1B4WNMlEMM/B4JeimnDLNF1qL683FnQx8wIA5hFIUKlWOiZZw98Rc FThSNClsIBNexepb9n/aJYvdSX4rIGd2O2Pf2VE+A0kiRzRCJmMrvT3X9Qw1B4lTFAVO /zDg== X-Gm-Message-State: AOAM532RTMG4rRu4OQQELF9Wi5T/SjkK8eJTq/mvHJVJ7fVE62HAoHIL +COmyzIxFXU3dR0KOFMvD6cNfw== X-Google-Smtp-Source: ABdhPJyUhXBQD62+KY+Pt4EzYAFVHYmRbhAVbXQ3qfCQzil0ho1EGOP5684hLHI3efWhFKAYI1JaUg== X-Received: by 2002:a1c:f20b:: with SMTP id s11mr203831wmc.144.1600699019590; Mon, 21 Sep 2020 07:36:59 -0700 (PDT) Received: from localhost.localdomain ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id c14sm20370753wrv.12.2020.09.21.07.36.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 21 Sep 2020 07:36:58 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , "David S. Miller" , Florian Westphal , Herbert Xu , Jakub Kicinski , Johannes Berg , Steffen Klassert , Stephen Suryaputra , netdev@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org Subject: [PATCH v3 0/7] xfrm: Add compat layer Date: Mon, 21 Sep 2020 15:36:50 +0100 Message-Id: <20200921143657.604020-1-dima@arista.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Changes since v2: - added struct xfrm_translator as API to register xfrm_compat.ko with xfrm_state.ko. This allows compilation of translator as a loadable module - fixed indention and collected reviewed-by (Johannes Berg) - moved boilerplate from commit messages into cover-letter (Steffen Klassert) - found on KASAN build and fixed non-initialised stack variable usage in the translator The resulting v2/v3 diff can be found here: https://gist.github.com/0x7f454c46/8f68311dfa1f240959fdbe7c77ed2259 Patches as a .git branch: https://github.com/0x7f454c46/linux/tree/xfrm-compat-v3 Changes since v1: - reworked patches set to use translator - separated the compat layer into xfrm_compat.c, compiled under XFRM_USER_COMPAT config - 32-bit messages now being sent in frag_list (like wext-core does) - instead of __packed add compat_u64 members in compat structures - selftest reworked to kselftest lib API - added netlink dump testing to the selftest XFRM is disabled for compatible users because of the UABI difference. The difference is in structures paddings and in the result the size of netlink messages differ. Possibility for compatible application to manage xfrm tunnels was disabled by: the commmit 19d7df69fdb2 ("xfrm: Refuse to insert 32 bit userspace socket policies on 64 bit systems") and the commit 74005991b78a ("xfrm: Do not parse 32bits compiled xfrm netlink msg on 64bits host"). This is my second attempt to resolve the xfrm/compat problem by adding the 64=>32 and 32=>64 bit translators those non-visibly to a user provide translation between compatible user and kernel. Previous attempt was to interrupt the message ABI according to a syscall by xfrm_user, which resulted in over-complicated code [1]. Florian Westphal provided the idea of translator and some draft patches in the discussion. In these patches, his idea is reused and some of his initial code is also present. There were a couple of attempts to solve xfrm compat problem: https://lkml.org/lkml/2017/1/20/733 https://patchwork.ozlabs.org/patch/44600/ http://netdev.vger.kernel.narkive.com/2Gesykj6/patch-net-next-xfrm-correctly-parse-netlink-msg-from-32bits-ip-command-on-64bits-host All the discussions end in the conclusion that xfrm should have a full compatible layer to correctly work with 32-bit applications on 64-bit kernels: https://lkml.org/lkml/2017/1/23/413 https://patchwork.ozlabs.org/patch/433279/ In some recent lkml discussion, Linus said that it's worth to fix this problem and not giving people an excuse to stay on 32-bit kernel: https://lkml.org/lkml/2018/2/13/752 There is also an selftest for ipsec tunnels. It doesn't depend on any library and compat version can be easy build with: make CFLAGS=-m32 net/ipsec [1]: https://lkml.kernel.org/r/20180726023144.31066-1-dima@arista.com Cc: "David S. Miller" Cc: Florian Westphal Cc: Herbert Xu Cc: Jakub Kicinski Cc: Johannes Berg Cc: Steffen Klassert Cc: Stephen Suryaputra Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: netdev@vger.kernel.org Dmitry Safonov (7): xfrm: Provide API to register translator module xfrm/compat: Add 64=>32-bit messages translator xfrm/compat: Attach xfrm dumps to 64=>32 bit translator netlink/compat: Append NLMSG_DONE/extack to frag_list xfrm/compat: Add 32=>64-bit messages translator xfrm/compat: Translate 32-bit user_policy from sockptr selftest/net/xfrm: Add test for ipsec tunnel MAINTAINERS | 1 + include/net/xfrm.h | 33 + net/netlink/af_netlink.c | 47 +- net/xfrm/Kconfig | 11 + net/xfrm/Makefile | 1 + net/xfrm/xfrm_compat.c | 625 +++++++ net/xfrm/xfrm_state.c | 77 +- net/xfrm/xfrm_user.c | 110 +- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 1 + tools/testing/selftests/net/ipsec.c | 2195 ++++++++++++++++++++++++ 11 files changed, 3066 insertions(+), 36 deletions(-) create mode 100644 net/xfrm/xfrm_compat.c create mode 100644 tools/testing/selftests/net/ipsec.c base-commit: ba4f184e126b751d1bffad5897f263108befc780