From patchwork Wed May 12 10:34:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 436155 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E8BDC43460 for ; Wed, 12 May 2021 10:35:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BFFD611BF for ; Wed, 12 May 2021 10:35:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230295AbhELKgY (ORCPT ); Wed, 12 May 2021 06:36:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230109AbhELKgW (ORCPT ); Wed, 12 May 2021 06:36:22 -0400 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EE71C061574; Wed, 12 May 2021 03:35:14 -0700 (PDT) Received: by mail-pj1-x1042.google.com with SMTP id gc22-20020a17090b3116b02901558435aec1so3052065pjb.4; Wed, 12 May 2021 03:35:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KSPpb4n0QgZytgHJbxE+nZknmZTU2TdAbG7/Ft9zzS8=; b=fv5HzK/tCwtSxaqZWzGg4euVericjT0gZ0kf0ez0Aig4EmFZA4YHwfnvRlPH42/Hsd fAWIh+sTGrpmC3YTBdkdWZXj2L/9QREgIQzpxPSJ6SYp4JQCSlHCUfr32iT1feQv66Lw lgl0flZNunCXDN+iCDLX63BSm80YJxP1AynwzmLKN55UzxwdFn/CNeMhj6SE8xAkGp09 mbR6PTFIICOD5UWWm8ce2edU0BL3gqyJHyuWOkKSU3Usa3sCfBCOHY9/d7ZqV6cNDAc4 DWT7DBW6CFu2CbCKeFwaKYlslFaxkSctvlCSA9SNpVDkiwpovbv9YhEAZUrE8JMb8uDF oZlA== 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=KSPpb4n0QgZytgHJbxE+nZknmZTU2TdAbG7/Ft9zzS8=; b=sKQ69hR5N6Yzeww1e4oiaG4oLRj5R1cDmNhJWf/bXxVAplB6ucGOtLWkHxZJOfvQv3 MQmTEunX7NyQaqpjV54kMp2/06hBz6W6xeZRp8yMOIln/RvTOF5EY/NzK0BdaZg/HCeD FJnirbWjpjpQaiT+Xi63AH1SGjhf+80C7xGmiQa4VcgsBhBTC2rroA8eNAYWGe64zbw8 3cPeU4n4dXwyxQedu6wedt9hF1LGbWrs2F9usnpUTyHU51qkdJ8+nrEHwbQxOb8iX+GE c6MIkUjDlQ8jByiP+RLVrhx27cE54MZ6IHcTj3kHZbV0xoBuqLTra+2km1L5JUhhm8s7 DWTQ== X-Gm-Message-State: AOAM531JMQFpC346JjyJG0tLz+B/l5AHquVdITfIegdBbN2ASVYPoi5m 5d8o8NtQ9Y1Z1HzGW6ZCRRCFFEO3pmYOfQ== X-Google-Smtp-Source: ABdhPJwe9Gc9JqxamwrkxKQf2D8lb7nutrcEACyKEzywTyCxEL3S/V2BLJiHiP15iApR3dQlviOS+g== X-Received: by 2002:a17:902:8c97:b029:ee:f8c1:7bbe with SMTP id t23-20020a1709028c97b02900eef8c17bbemr34771224plo.8.1620815713334; Wed, 12 May 2021 03:35:13 -0700 (PDT) Received: from localhost ([2402:3a80:11c3:45ac:887c:70aa:e004:d014]) by smtp.gmail.com with ESMTPSA id q19sm15853415pgv.38.2021.05.12.03.35.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 May 2021 03:35:13 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Kumar Kartikeya Dwivedi , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Shaun Crampton , netdev@vger.kernel.org Subject: [PATCH bpf-next v7 0/3] Add TC-BPF API Date: Wed, 12 May 2021 16:04:48 +0530 Message-Id: <20210512103451.989420-1-memxor@gmail.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This is the seventh version of the TC-BPF series. It adds a simple API that uses netlink to attach the tc filter and its bpf classifier program. Currently, a user needs to shell out to the tc command line to be able to create filters and attach SCHED_CLS programs as classifiers. With the help of this API, it will be possible to use libbpf for doing all parts of bpf program setup and attach. Changelog contains details of patchset evolution. In an effort to keep discussion focused, this series doesn't have the high level TC-BPF API. It was clear that there is a need for a bpf_link API in the kernel, hence that will be submitted as a separate patchset based on this. The individual commit messages contain more details, and also a brief summary of the API. Changelog: ---------- v6 -> v7 v6: https://lore.kernel.org/bpf/20210504005023.1240974-1-memxor@gmail.com * Address all comments from Daniel * Rename BPF_NL_* to NL_* * Make bpf_tc_query only support targeted query * Adjust inconsistencies in the commit message * Drop RTM_GETTFILTER NLM_F_DUMP support * Other misc cleanups (also remove bpf_tc_query selftest for dump mode) v5 -> v6 v5: https://lore.kernel.org/bpf/20210428162553.719588-1-memxor@gmail.com * Address all comments from Andrii. * Reorganize selftest to make logical separation between each test's set up and clean up more clear to the reader. Also add a common way to test different combination of opts. * Cleanup the commit message a bit. * Fix instances of ret < 0 && ret == -ENOENT pattern everywhere. * Use C89 declaration syntax. * Drop PRIu32. * Move flags to bpf_tc_opts and bpf_tc_hook. * Other misc comments. v4 -> v5 v4: https://lore.kernel.org/bpf/20210423150600.498490-1-memxor@gmail.com * Added bpf_tc_hook to represent the attach location of a filter. * Removed the bpf_tc_ctx context object, refactored code to not assume shared open socket across operations on the same ctx. * Add a helper libbpf_nl_send_recv that wraps socket creation, sending and receiving the netlink message. * Extended netlink code to cut short message processing using BPF_NL_DONE. This is used in a few places to return early to the user and discard remaining data. * selftests rewrite and expansion, considering API is looking more solid now. * Documented the API assumptions and behaviour in the commit that adds it, along with a few basic usage examples. * Dropped documentation from libbpf.h. * Relax some restrictions on bpf_tc_query to make it more useful (e.g. to detect if any filters exist). * Incorporate other minor suggestions from previous review (Andrii and Daniel). v3 -> v4 v3: https://lore.kernel.org/bpf/20210420193740.124285-1-memxor@gmail.com * Added a concept of bpf_tc_ctx context structure representing the attach point. The qdisc setup and delete is tied to this object's lifetime if it succeeds in creating the clsact qdisc when the attach point is BPF_TC_INGRESS or BPF_TC_EGRESS. Qdisc is only deleted when there are no filters attached to it. * Refactored all API functions to take ctx. * Removed bpf_tc_info, bpf_tc_attach_id, instead reused bpf_tc_opts for filling in attributes in various API functions (including query). * Explicitly documented the expectation of each function regarding the opts fields set. Added some small notes for the defaults chosen by the API. * Rename bpf_tc_get_info to bpf_tc_query * Keep the netlink socket open in the context structure to save on open/close cycles for each operation. * Miscellaneous adjustments due to keeping the socket open. * Rewrote the tests, and also added tests for testing all preconditions of the TC-BPF API. * We now use bpf skeleton in examples and tests. v2 -> v3 v2: https://lore.kernel.org/bpf/20210419121811.117400-1-memxor@gmail.com * bpf_tc_cls_* -> bpf_tc_* rename * bpf_tc_attach_id now only consists of handle and priority, the two variables that user may or may not set. * bpf_tc_replace has been dropped, instead a replace bool is introduced in bpf_tc_opts for the same purpose. * bpf_tc_get_info now takes attach_id for filling in filter details during lookup instead of requiring user to do so. This also allows us to remove the fd parameter, as no matching is needed as long as we have all attributes necessary to identify a specific filter. * A little bit of code simplification taking into account the change above. * priority and protocol are now __u16 members in user facing API structs to reflect actual size. * Patch updating pkt_cls.h header has been removed, as it is unused now. * protocol and chain_index options have been dropped in bpf_tc_opts, protocol is always set to ETH_P_ALL, while chain_index is set as 0 by default in the kernel. This also means removal of chain_index from bpf_tc_attach_id, as it is unconditionally always 0. * bpf_tc_cls_change has been dropped * selftest now uses ASSERT_* macros v1-> v2 v1: https://lore.kernel.org/bpf/20210325120020.236504-1-memxor@gmail.com * netlink helpers have been renamed to object_action style. * attach_id now only contains attributes that are not explicitly set. Only the bare minimum info is kept in it. * protocol is now an optional and always set to ETH_P_ALL. * direct-action mode is always set. * skip_sw and skip_hw options have also been removed. * bpf_tc_cls_info struct now also returns the bpf program tag and id, as available in the netlink response. This came up as a requirement during discussion with people wanting to use this functionality. * support for attaching SCHED_ACT programs has been dropped, as it isn't useful without any support for binding loaded actions to a classifier. * the distinction between dev and block API has been dropped, there is now a single set of functions and user has to pass the special ifindex value to indicate operation on a shared filter block on their own. * The high level API returning a bpf_link is gone. This was already non- functional for pinning and typical ownership semantics. Instead, a separate patchset will be sent adding a bpf_link API for attaching SCHED_CLS progs to the kernel, and its corresponding libbpf API. * The clsact qdisc is now setup automatically in a best-effort fashion whenever user passes in the clsact ingress or egress parent id. This is done with exclusive mode, such that if an ingress or clsact qdisc is already set up, we skip the setup and move on with filter creation. * Other minor changes that came up during the course of discussion and rework. Kumar Kartikeya Dwivedi (3): libbpf: add netlink helpers libbpf: add low level TC-BPF API libbpf: add selftests for TC-BPF API tools/lib/bpf/libbpf.h | 43 ++ tools/lib/bpf/libbpf.map | 5 + tools/lib/bpf/netlink.c | 554 ++++++++++++++++-- tools/lib/bpf/nlattr.h | 48 ++ .../testing/selftests/bpf/prog_tests/tc_bpf.c | 395 +++++++++++++ .../testing/selftests/bpf/progs/test_tc_bpf.c | 12 + 6 files changed, 993 insertions(+), 64 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/tc_bpf.c create mode 100644 tools/testing/selftests/bpf/progs/test_tc_bpf.c