From patchwork Fri Oct 21 01:15:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joanne Koong X-Patchwork-Id: 13014185 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFCCAC4332F for ; Fri, 21 Oct 2022 01:33:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229910AbiJUBdD (ORCPT ); Thu, 20 Oct 2022 21:33:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbiJUBdC (ORCPT ); Thu, 20 Oct 2022 21:33:02 -0400 Received: from 69-171-232-181.mail-mxout.facebook.com (69-171-232-181.mail-mxout.facebook.com [69.171.232.181]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 202E61FAE55 for ; Thu, 20 Oct 2022 18:33:00 -0700 (PDT) Received: by devbig010.atn6.facebook.com (Postfix, from userid 115148) id 5A91A12EA670E; Thu, 20 Oct 2022 18:15:24 -0700 (PDT) From: Joanne Koong To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, martin.lau@kernel.org, andrii@kernel.org, ast@kernel.org, netdev@vger.kernel.org, Kernel-team@fb.com, Joanne Koong Subject: [PATCH bpf-next v7 0/3] Add skb + xdp dynptrs Date: Thu, 20 Oct 2022 18:15:07 -0700 Message-Id: <20221021011510.1890852-1-joannelkoong@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patchset is the 2nd in the dynptr series. The 1st can be found here [0]. This patchset adds skb and xdp type dynptrs, which have two main benefits for packet parsing: * allowing operations on sizes that are not statically known at compile-time (eg variable-sized accesses). * more ergonomic and less brittle iteration through data (eg does not need manual if checking for being within bounds of data_end) When comparing the differences in runtime for packet parsing without dynptrs vs. with dynptrs for the more simple cases, there is no noticeable difference. For the more complex cases where lengths are non-statically known at compile time, there can be a significant speed-up when using dynptrs (eg a 2x speed up for cls redirection). Patch 3 contains more details as well as examples of how to use skb and xdp dynptrs. [0] https://lore.kernel.org/bpf/20220523210712.3641569-1-joannelkoong@gmail.com/ --- Changelog: v6 = https://lore.kernel.org/bpf/20220907183129.745846-1-joannelkoong@gmail.com/ v6 -> v7 * Change bpf_dynptr_data() to return read-only data slices if the skb prog is read-only (Martin) * Add test "skb_invalid_write" to test that writes to rd-only data slices are rejected v5 = https://lore.kernel.org/bpf/20220831183224.3754305-1-joannelkoong@gmail.com/ v5 -> v6 * Address kernel test robot errors by static inlining v4 = https://lore.kernel.org/bpf/20220822235649.2218031-1-joannelkoong@gmail.com/ v4 -> v5 * Address kernel test robot errors for configs w/out CONFIG_NET set * For data slices, return PTR_TO_MEM instead of PTR_TO_PACKET (Kumar) * Split selftests into subtests (Andrii) * Remove insn patching. Use rdonly and rdwr protos for dynptr skb construction (Andrii) * bpf_dynptr_data() returns NULL for rd-only dynptrs. There will be a separate bpf_dynptr_data_rdonly() added later (Andrii and Kumar) v3 = https://lore.kernel.org/bpf/20220822193442.657638-1-joannelkoong@gmail.com/ v3 -> v4 * Forgot to commit --amend the kernel test robot error fixups v2 = https://lore.kernel.org/bpf/20220811230501.2632393-1-joannelkoong@gmail.com/ v2 -> v3 * Fix kernel test robot build test errors v1 = https://lore.kernel.org/bpf/20220726184706.954822-1-joannelkoong@gmail.com/ v1 -> v2 * Return data slices to rd-only skb dynptrs (Martin) * bpf_dynptr_write allows writes to frags for skb dynptrs, but always invalidates associated data slices (Martin) * Use switch casing instead of ifs (Andrii) * Use 0xFD for experimental kind number in the selftest (Zvi) * Put selftest conversions w/ dynptrs into new files (Alexei) * Add new selftest "test_cls_redirect_dynptr.c" Joanne Koong (3): bpf: Add skb dynptrs bpf: Add xdp dynptrs selftests/bpf: tests for using dynptrs to parse skb and xdp buffers include/linux/bpf.h | 88 +- include/linux/filter.h | 38 + include/uapi/linux/bpf.h | 67 +- kernel/bpf/helpers.c | 91 +- kernel/bpf/verifier.c | 116 ++- net/core/filter.c | 119 ++- tools/include/uapi/linux/bpf.h | 67 +- .../selftests/bpf/prog_tests/cls_redirect.c | 25 + .../testing/selftests/bpf/prog_tests/dynptr.c | 74 +- .../selftests/bpf/prog_tests/l4lb_all.c | 2 + .../bpf/prog_tests/parse_tcp_hdr_opt.c | 93 ++ .../selftests/bpf/prog_tests/xdp_attach.c | 11 +- .../testing/selftests/bpf/progs/dynptr_fail.c | 111 ++ .../selftests/bpf/progs/dynptr_success.c | 23 + .../bpf/progs/test_cls_redirect_dynptr.c | 968 ++++++++++++++++++ .../bpf/progs/test_l4lb_noinline_dynptr.c | 469 +++++++++ .../bpf/progs/test_parse_tcp_hdr_opt.c | 119 +++ .../bpf/progs/test_parse_tcp_hdr_opt_dynptr.c | 110 ++ .../selftests/bpf/progs/test_xdp_dynptr.c | 235 +++++ .../selftests/bpf/test_tcp_hdr_options.h | 1 + 20 files changed, 2731 insertions(+), 96 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/parse_tcp_hdr_opt.c create mode 100644 tools/testing/selftests/bpf/progs/test_cls_redirect_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_l4lb_noinline_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt.c create mode 100644 tools/testing/selftests/bpf/progs/test_parse_tcp_hdr_opt_dynptr.c create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_dynptr.c