From patchwork Mon Nov 16 06:53:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 1400665 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=HOjFzCqm; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CZKZ22qG3z9sTR for ; Mon, 16 Nov 2020 17:54:34 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727418AbgKPGxr (ORCPT ); Mon, 16 Nov 2020 01:53:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56782 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726768AbgKPGxq (ORCPT ); Mon, 16 Nov 2020 01:53:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605509625; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vkLPf2AEOhVOZlO9cgrNsBmby/+0L7S8jCp57tH6JJY=; b=HOjFzCqmojOgsA8g9zBANkShbds6H2C6wnlTwKYMqY6kiFR9KCEerPk+bjhWsBh5FcZunq RtyiZUgsdJVvqvRTMDdmPjeRNsDNum8Y4IRCubA3JdQTTmnjiMQdeEXK700Wou99MLyH38 9YqgPLW4z81cZF80roNY2cOkkspD3U8= Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-534-aXg7LwJMOpyJ1TwaK2UC9A-1; Mon, 16 Nov 2020 01:53:43 -0500 X-MC-Unique: aXg7LwJMOpyJ1TwaK2UC9A-1 Received: by mail-pg1-f199.google.com with SMTP id i67so10962641pgc.3 for ; Sun, 15 Nov 2020 22:53:42 -0800 (PST) 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=vkLPf2AEOhVOZlO9cgrNsBmby/+0L7S8jCp57tH6JJY=; b=GLui8GH8gMn6VKieQy5mExADNFgNyp+vMN8KqZdFH2xrbd1aqiSj75xEDdfQiUGH4b CZSvzfipwkRCC4kRbgk1J0VHBIQtf5gIDvl2/06e+XpW8T1q5NVgTsmjeMYvlHfOmpgp 16dL1NXkphgosF7zaBFZSCNxdFlx5ccnQaTo3m8jNGFoP8k/tNyNCiZ0BwYXof8gZeB5 cEbuBo9JzJpTSaispHB8VX6IG68Y6jkvb0gb6wLYzJdOZ3TA4CmBjONfWMGcxYle12RU KOXASBitusR599kfVCYe4ps1NJSNDgQYYS6zT7b69WYIPvy+gIOGtrPS9MLTXPnqz+8m rqnQ== X-Gm-Message-State: AOAM533Q89Fm9c7p+Iuz++RK1vuKZE5yaaXvPrT+NTEhmcGkmtG0VBWg QA9uUKEhT9hoA85CSzsaDW7FWAFV5jLz1ZxEYOxvVIqmapheDO2+fYA6ecaJ5xMHiKu1d8TyknD Xxaev0WIOil7yMVg= X-Received: by 2002:a17:90a:154a:: with SMTP id y10mr13682064pja.6.1605509621706; Sun, 15 Nov 2020 22:53:41 -0800 (PST) X-Google-Smtp-Source: ABdhPJwaXTHSWhZ7qw2lhA9wIHbz+w4JrEy9LaIN4wkBl9Q086mgYWKhCyALJV27chhcvgY1b2ALDg== X-Received: by 2002:a17:90a:154a:: with SMTP id y10mr13682051pja.6.1605509621493; Sun, 15 Nov 2020 22:53:41 -0800 (PST) Received: from localhost.localdomain.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 16sm18645837pjf.36.2020.11.15.22.53.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 22:53:40 -0800 (PST) From: Hangbin Liu To: Stephen Hemminger , David Ahern Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc , =?utf-8?q?Toke_H=C3=B8il?= =?utf-8?q?and-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv5 iproute2-next 1/5] configure: add check_libbpf() for later libbpf support Date: Mon, 16 Nov 2020 14:53:01 +0800 Message-Id: <20201116065305.1010651-2-haliu@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201116065305.1010651-1-haliu@redhat.com> References: <20201109070802.3638167-1-haliu@redhat.com> <20201116065305.1010651-1-haliu@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds a check to see if we have libbpf support. By default the system libbpf will be used, but static linking against a custom libbpf version can be achieved by passing libbpf DESTDIR to variable LIBBPF_DIR for configure. Add another variable LIBBPF_FORCE to control whether to build iproute2 with libbpf. If set to on, then force to build with libbpf and exit if not available. If set to off, then force to not build with libbpf. Signed-off-by: Hangbin Liu --- v5: 1) Fix LIBBPF_DIR typo and description, use libbpf DESTDIR as LIBBPF_DIR dest. v4: 1) Remove duplicate LIBBPF_CFLAGS 2) Remove un-needed -L since using static libbpf.a 3) Fix == not supported in dash 4) Extend LIBBPF_FORCE to support on/off, when set to on, stop building when there is no libbpf support. If set to off, discard libbpf check. 5) Print libbpf version after checking v3: Check function bpf_program__section_name() separately and only use it on higher libbpf version. v2: No update --- configure | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) diff --git a/configure b/configure index 307912aa..290b4c86 100755 --- a/configure +++ b/configure @@ -2,6 +2,11 @@ # SPDX-License-Identifier: GPL-2.0 # This is not an autoconf generated configure # +# Influential LIBBPF environment variables: +# LIBBPF_FORCE={on,off} on: require link against libbpf; +# off: disable libbpf probing +# LIBBPF_DIR Path to libbpf DESTDIR to use + INCLUDE=${1:-"$PWD/include"} # Output file which is input to Makefile @@ -240,6 +245,106 @@ check_elf() fi } +have_libbpf_basic() +{ + cat >$TMPDIR/libbpf_test.c < +int main(int argc, char **argv) { + bpf_program__set_autoload(NULL, false); + bpf_map__ifindex(NULL); + bpf_map__set_pin_path(NULL, NULL); + bpf_object__open_file(NULL, NULL); + return 0; +} +EOF + + $CC -o $TMPDIR/libbpf_test $TMPDIR/libbpf_test.c $LIBBPF_CFLAGS $LIBBPF_LDLIBS >/dev/null 2>&1 + local ret=$? + + rm -f $TMPDIR/libbpf_test.c $TMPDIR/libbpf_test + return $ret +} + +have_libbpf_sec_name() +{ + cat >$TMPDIR/libbpf_sec_test.c < +int main(int argc, char **argv) { + void *ptr; + bpf_program__section_name(NULL); + return 0; +} +EOF + + $CC -o $TMPDIR/libbpf_sec_test $TMPDIR/libbpf_sec_test.c $LIBBPF_CFLAGS $LIBBPF_LDLIBS >/dev/null 2>&1 + local ret=$? + + rm -f $TMPDIR/libbpf_sec_test.c $TMPDIR/libbpf_sec_test + return $ret +} + +check_force_libbpf_on() +{ + # if set LIBBPF_FORCE=on but no libbpf support, just exist the config + # process to make sure we don't build without libbpf. + if [ "$LIBBPF_FORCE" = on ]; then + echo " LIBBPF_FORCE=on set, but couldn't find a usable libbpf" + exit 1 + fi +} + +check_libbpf() +{ + # if set LIBBPF_FORCE=off, disable libbpf entirely + if [ "$LIBBPF_FORCE" = off ]; then + echo "no" + return + fi + + if ! ${PKG_CONFIG} libbpf --exists && [ -z "$LIBBPF_DIR" ] ; then + echo "no" + check_force_libbpf_on + return + fi + + if [ $(uname -m) = x86_64 ]; then + local LIBBPF_LIBDIR="${LIBBPF_DIR}/usr/lib64" + else + local LIBBPF_LIBDIR="${LIBBPF_DIR}/usr/lib" + fi + + if [ -n "$LIBBPF_DIR" ]; then + LIBBPF_CFLAGS="-I${LIBBPF_DIR}/usr/include" + LIBBPF_LDLIBS="${LIBBPF_LIBDIR}/libbpf.a -lz -lelf" + LIBBPF_VERSION=$(PKG_CONFIG_LIBDIR=${LIBBPF_LIBDIR}/pkgconfig ${PKG_CONFIG} libbpf --modversion) + else + LIBBPF_CFLAGS=$(${PKG_CONFIG} libbpf --cflags) + LIBBPF_LDLIBS=$(${PKG_CONFIG} libbpf --libs) + LIBBPF_VERSION=$(${PKG_CONFIG} libbpf --modversion) + fi + + if ! have_libbpf_basic; then + echo "no" + echo " libbpf version $LIBBPF_VERSION is too low, please update it to at least 0.1.0" + check_force_libbpf_on + return + else + echo "HAVE_LIBBPF:=y" >>$CONFIG + echo 'CFLAGS += -DHAVE_LIBBPF ' $LIBBPF_CFLAGS >> $CONFIG + echo 'LDLIBS += ' $LIBBPF_LDLIBS >>$CONFIG + fi + + # bpf_program__title() is deprecated since libbpf 0.2.0, use + # bpf_program__section_name() instead if we support + if have_libbpf_sec_name; then + echo "HAVE_LIBBPF_SECTION_NAME:=y" >>$CONFIG + echo 'CFLAGS += -DHAVE_LIBBPF_SECTION_NAME ' >> $CONFIG + fi + + echo "yes" + echo " libbpf version $LIBBPF_VERSION" +} + check_selinux() # SELinux is a compile time option in the ss utility { @@ -385,6 +490,9 @@ check_setns echo -n "SELinux support: " check_selinux +echo -n "libbpf support: " +check_libbpf + echo -n "ELF support: " check_elf From patchwork Mon Nov 16 06:53:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 1400666 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; 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Sun, 15 Nov 2020 22:53:46 -0800 (PST) X-Google-Smtp-Source: ABdhPJwmaGVu+t7ZbOBx0vFozNp9igw9I29CUKRaFxIWA6fWbP03UpRsV+/2lpujDWWmbV1OOTnHzA== X-Received: by 2002:a63:1d12:: with SMTP id d18mr12230112pgd.314.1605509626163; Sun, 15 Nov 2020 22:53:46 -0800 (PST) Received: from localhost.localdomain.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 16sm18645837pjf.36.2020.11.15.22.53.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 22:53:45 -0800 (PST) From: Hangbin Liu To: Stephen Hemminger , David Ahern Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc , =?utf-8?q?Toke_H=C3=B8il?= =?utf-8?q?and-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv5 iproute2-next 2/5] lib: rename bpf.c to bpf_legacy.c Date: Mon, 16 Nov 2020 14:53:02 +0800 Message-Id: <20201116065305.1010651-3-haliu@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201116065305.1010651-1-haliu@redhat.com> References: <20201109070802.3638167-1-haliu@redhat.com> <20201116065305.1010651-1-haliu@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This is a preparation for later main libbpf support in iproute2. bpf.c is moved to bpf_legacy.c first. A new file bpf_glue.c is added which could call both legacy libbpf code. There are two wrapper functions added for ipvrf. Function bpf_prog_load() is removed as it's conflict with libbpf function name. Signed-off-by: Hangbin Liu --- v5: Fix bpf_prog_load_dev typo. v4: Add new file bpf_glue.c v2-v3: no update --- include/bpf_util.h | 10 +++++++--- ip/ipvrf.c | 6 +++--- lib/Makefile | 2 +- lib/bpf_glue.c | 35 +++++++++++++++++++++++++++++++++++ lib/{bpf.c => bpf_legacy.c} | 15 +++------------ 5 files changed, 49 insertions(+), 19 deletions(-) create mode 100644 lib/bpf_glue.c rename lib/{bpf.c => bpf_legacy.c} (99%) diff --git a/include/bpf_util.h b/include/bpf_util.h index 63db07ca..82217cc6 100644 --- a/include/bpf_util.h +++ b/include/bpf_util.h @@ -274,12 +274,16 @@ int bpf_trace_pipe(void); void bpf_print_ops(struct rtattr *bpf_ops, __u16 len); -int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t size_insns, const char *license, char *log, - size_t size_log); +int bpf_prog_load_dev(enum bpf_prog_type type, const struct bpf_insn *insns, + size_t size_insns, const char *license, __u32 ifindex, + char *log, size_t size_log); +int bpf_program_load(enum bpf_prog_type type, const struct bpf_insn *insns, + size_t size_insns, const char *license, char *log, + size_t size_log); int bpf_prog_attach_fd(int prog_fd, int target_fd, enum bpf_attach_type type); int bpf_prog_detach_fd(int target_fd, enum bpf_attach_type type); +int bpf_program_attach(int prog_fd, int target_fd, enum bpf_attach_type type); int bpf_dump_prog_info(FILE *f, uint32_t id); diff --git a/ip/ipvrf.c b/ip/ipvrf.c index 28dd8e25..42779e5c 100644 --- a/ip/ipvrf.c +++ b/ip/ipvrf.c @@ -256,8 +256,8 @@ static int prog_load(int idx) BPF_EXIT_INSN(), }; - return bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, prog, sizeof(prog), - "GPL", bpf_log_buf, sizeof(bpf_log_buf)); + return bpf_program_load(BPF_PROG_TYPE_CGROUP_SOCK, prog, sizeof(prog), + "GPL", bpf_log_buf, sizeof(bpf_log_buf)); } static int vrf_configure_cgroup(const char *path, int ifindex) @@ -288,7 +288,7 @@ static int vrf_configure_cgroup(const char *path, int ifindex) goto out; } - if (bpf_prog_attach_fd(prog_fd, cg_fd, BPF_CGROUP_INET_SOCK_CREATE)) { + if (bpf_program_attach(prog_fd, cg_fd, BPF_CGROUP_INET_SOCK_CREATE)) { fprintf(stderr, "Failed to attach prog to cgroup: '%s'\n", strerror(errno)); goto out; diff --git a/lib/Makefile b/lib/Makefile index 13f4ee15..7c8a197c 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -5,7 +5,7 @@ CFLAGS += -fPIC UTILOBJ = utils.o rt_names.o ll_map.o ll_types.o ll_proto.o ll_addr.o \ inet_proto.o namespace.o json_writer.o json_print.o \ - names.o color.o bpf.o exec.o fs.o cg_map.o + names.o color.o bpf_legacy.o bpf_glue.o exec.o fs.o cg_map.o NLOBJ=libgenl.o libnetlink.o mnl_utils.o diff --git a/lib/bpf_glue.c b/lib/bpf_glue.c new file mode 100644 index 00000000..fd4fcc94 --- /dev/null +++ b/lib/bpf_glue.c @@ -0,0 +1,35 @@ +/* + * bpf_glue.c BPF code to call both legacy and libbpf code + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Hangbin Liu + * + */ +#include "bpf_util.h" +#ifdef HAVE_LIBBPF +#include +#endif + +int bpf_program_load(enum bpf_prog_type type, const struct bpf_insn *insns, + size_t size_insns, const char *license, char *log, + size_t size_log) +{ +#ifdef HAVE_LIBBPF + return bpf_load_program(type, insns, size_insns, license, 0, log, size_log); +#else + return bpf_prog_load_dev(type, insns, size_insns, license, 0, log, size_log); +#endif +} + +int bpf_program_attach(int prog_fd, int target_fd, enum bpf_attach_type type) +{ +#ifdef HAVE_LIBBPF + return bpf_prog_attach(prog_fd, target_fd, type, 0); +#else + return bpf_prog_attach_fd(prog_fd, target_fd, type); +#endif +} diff --git a/lib/bpf.c b/lib/bpf_legacy.c similarity index 99% rename from lib/bpf.c rename to lib/bpf_legacy.c index c7d45077..4246fb76 100644 --- a/lib/bpf.c +++ b/lib/bpf_legacy.c @@ -1087,10 +1087,9 @@ int bpf_prog_detach_fd(int target_fd, enum bpf_attach_type type) return bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); } -static int bpf_prog_load_dev(enum bpf_prog_type type, - const struct bpf_insn *insns, size_t size_insns, - const char *license, __u32 ifindex, - char *log, size_t size_log) +int bpf_prog_load_dev(enum bpf_prog_type type, const struct bpf_insn *insns, + size_t size_insns, const char *license, __u32 ifindex, + char *log, size_t size_log) { union bpf_attr attr = {}; @@ -1109,14 +1108,6 @@ static int bpf_prog_load_dev(enum bpf_prog_type type, return bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); } -int bpf_prog_load(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t size_insns, const char *license, char *log, - size_t size_log) -{ - return bpf_prog_load_dev(type, insns, size_insns, license, 0, - log, size_log); -} - #ifdef HAVE_ELF struct bpf_elf_prog { enum bpf_prog_type type; From patchwork Mon Nov 16 06:53:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 1400667 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; 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Sun, 15 Nov 2020 22:53:51 -0800 (PST) X-Google-Smtp-Source: ABdhPJwDqq5TVuAven52BENNtCmxY/kvpkaZZxd+8lcziF0FukT2P0/rDLHTopAPVXL6cVTJwR8phw== X-Received: by 2002:a17:90a:aa8f:: with SMTP id l15mr2318678pjq.135.1605509630853; Sun, 15 Nov 2020 22:53:50 -0800 (PST) Received: from localhost.localdomain.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 16sm18645837pjf.36.2020.11.15.22.53.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 22:53:50 -0800 (PST) From: Hangbin Liu To: Stephen Hemminger , David Ahern Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc , =?utf-8?q?Toke_H=C3=B8il?= =?utf-8?q?and-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv5 iproute2-next 3/5] lib: add libbpf support Date: Mon, 16 Nov 2020 14:53:03 +0800 Message-Id: <20201116065305.1010651-4-haliu@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201116065305.1010651-1-haliu@redhat.com> References: <20201109070802.3638167-1-haliu@redhat.com> <20201116065305.1010651-1-haliu@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch converts iproute2 to use libbpf for loading and attaching BPF programs when it is available, which is started by Toke's implementation[1]. With libbpf iproute2 could correctly process BTF information and support the new-style BTF-defined maps, while keeping compatibility with the old internal map definition syntax. The old iproute2 bpf code is kept and will be used if no suitable libbpf is available. When using libbpf, wrapper code in bpf_legacy.c ensures that iproute2 will still understand the old map definition format, including populating map-in-map and tail call maps before load. In bpf_libbpf.c, we init iproute2 ctx and elf info first to check the legacy bytes. When handling the legacy maps, for map-in-maps, we create them manually and re-use the fd as they are associated with id/inner_id. For pin maps, we only set the pin path and let libbp load to handle it. For tail calls, we find it first and update the element after prog load. Other maps/progs will be loaded by libbpf directly. [1] https://lore.kernel.org/bpf/20190820114706.18546-1-toke@redhat.com/ Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Hangbin Liu --- v4: Move ipvrf code to patch 02 Move HAVE_LIBBPF inside HAVE_ELF definition as libbpf depends on elf. v3: Add a new function get_bpf_program__section_name() to choose whether use bpf_program__title() or not. v2: Remove self defined IS_ERR_OR_NULL and use libbpf_get_error() instead. Add ipvrf with libbpf support. --- include/bpf_util.h | 11 ++ lib/Makefile | 4 + lib/bpf_legacy.c | 178 +++++++++++++++++++++++ lib/bpf_libbpf.c | 353 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 546 insertions(+) create mode 100644 lib/bpf_libbpf.c diff --git a/include/bpf_util.h b/include/bpf_util.h index 82217cc6..d4f66de9 100644 --- a/include/bpf_util.h +++ b/include/bpf_util.h @@ -304,4 +304,15 @@ static inline int bpf_recv_map_fds(const char *path, int *fds, return -1; } #endif /* HAVE_ELF */ + +#ifdef HAVE_LIBBPF +int iproute2_bpf_elf_ctx_init(struct bpf_cfg_in *cfg); +int iproute2_bpf_fetch_ancillary(void); +int iproute2_get_root_path(char *root_path, size_t len); +bool iproute2_is_pin_map(const char *libbpf_map_name, char *pathname); +bool iproute2_is_map_in_map(const char *libbpf_map_name, struct bpf_elf_map *imap, + struct bpf_elf_map *omap, char *omap_name); +int iproute2_find_map_name_by_id(unsigned int map_id, char *name); +int iproute2_load_libbpf(struct bpf_cfg_in *cfg); +#endif /* HAVE_LIBBPF */ #endif /* __BPF_UTIL__ */ diff --git a/lib/Makefile b/lib/Makefile index 7c8a197c..fb6c31ec 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -7,6 +7,10 @@ UTILOBJ = utils.o rt_names.o ll_map.o ll_types.o ll_proto.o ll_addr.o \ inet_proto.o namespace.o json_writer.o json_print.o \ names.o color.o bpf_legacy.o bpf_glue.o exec.o fs.o cg_map.o +ifeq ($(HAVE_LIBBPF),y) +UTILOBJ += bpf_libbpf.o +endif + NLOBJ=libgenl.o libnetlink.o mnl_utils.o all: libnetlink.a libutil.a diff --git a/lib/bpf_legacy.c b/lib/bpf_legacy.c index 4246fb76..bc869c3f 100644 --- a/lib/bpf_legacy.c +++ b/lib/bpf_legacy.c @@ -940,6 +940,9 @@ static int bpf_do_parse(struct bpf_cfg_in *cfg, const bool *opt_tbl) static int bpf_do_load(struct bpf_cfg_in *cfg) { if (cfg->mode == EBPF_OBJECT) { +#ifdef HAVE_LIBBPF + return iproute2_load_libbpf(cfg); +#endif cfg->prog_fd = bpf_obj_open(cfg->object, cfg->type, cfg->section, cfg->ifindex, cfg->verbose); @@ -3155,4 +3158,179 @@ int bpf_recv_map_fds(const char *path, int *fds, struct bpf_map_aux *aux, close(fd); return ret; } + +#ifdef HAVE_LIBBPF +/* The following functions are wrapper functions for libbpf code to be + * compatible with the legacy format. So all the functions have prefix + * with iproute2_ + */ +int iproute2_bpf_elf_ctx_init(struct bpf_cfg_in *cfg) +{ + struct bpf_elf_ctx *ctx = &__ctx; + + return bpf_elf_ctx_init(ctx, cfg->object, cfg->type, cfg->ifindex, cfg->verbose); +} + +int iproute2_bpf_fetch_ancillary(void) +{ + struct bpf_elf_ctx *ctx = &__ctx; + struct bpf_elf_sec_data data; + int i, ret = 0; + + for (i = 1; i < ctx->elf_hdr.e_shnum; i++) { + ret = bpf_fill_section_data(ctx, i, &data); + if (ret < 0) + continue; + + if (data.sec_hdr.sh_type == SHT_PROGBITS && + !strcmp(data.sec_name, ELF_SECTION_MAPS)) + ret = bpf_fetch_maps_begin(ctx, i, &data); + else if (data.sec_hdr.sh_type == SHT_SYMTAB && + !strcmp(data.sec_name, ".symtab")) + ret = bpf_fetch_symtab(ctx, i, &data); + else if (data.sec_hdr.sh_type == SHT_STRTAB && + !strcmp(data.sec_name, ".strtab")) + ret = bpf_fetch_strtab(ctx, i, &data); + if (ret < 0) { + fprintf(stderr, "Error parsing section %d! Perhaps check with readelf -a?\n", + i); + return ret; + } + } + + if (bpf_has_map_data(ctx)) { + ret = bpf_fetch_maps_end(ctx); + if (ret < 0) { + fprintf(stderr, "Error fixing up map structure, incompatible struct bpf_elf_map used?\n"); + return ret; + } + } + + return ret; +} + +int iproute2_get_root_path(char *root_path, size_t len) +{ + struct bpf_elf_ctx *ctx = &__ctx; + int ret = 0; + + snprintf(root_path, len, "%s/%s", + bpf_get_work_dir(ctx->type), BPF_DIR_GLOBALS); + + ret = mkdir(root_path, S_IRWXU); + if (ret && errno != EEXIST) { + fprintf(stderr, "mkdir %s failed: %s\n", root_path, strerror(errno)); + return ret; + } + + return 0; +} + +bool iproute2_is_pin_map(const char *libbpf_map_name, char *pathname) +{ + struct bpf_elf_ctx *ctx = &__ctx; + const char *map_name, *tmp; + unsigned int pinning; + int i, ret = 0; + + for (i = 0; i < ctx->map_num; i++) { + if (ctx->maps[i].pinning == PIN_OBJECT_NS && + ctx->noafalg) { + fprintf(stderr, "Missing kernel AF_ALG support for PIN_OBJECT_NS!\n"); + return false; + } + + map_name = bpf_map_fetch_name(ctx, i); + if (!map_name) { + return false; + } + + if (strcmp(libbpf_map_name, map_name)) + continue; + + pinning = ctx->maps[i].pinning; + + if (bpf_no_pinning(ctx, pinning) || !bpf_get_work_dir(ctx->type)) + return false; + + if (pinning == PIN_OBJECT_NS) + ret = bpf_make_obj_path(ctx); + else if ((tmp = bpf_custom_pinning(ctx, pinning))) + ret = bpf_make_custom_path(ctx, tmp); + if (ret < 0) + return false; + + bpf_make_pathname(pathname, PATH_MAX, map_name, ctx, pinning); + + return true; + } + + return false; +} + +bool iproute2_is_map_in_map(const char *libbpf_map_name, struct bpf_elf_map *imap, + struct bpf_elf_map *omap, char *omap_name) +{ + struct bpf_elf_ctx *ctx = &__ctx; + const char *inner_map_name, *outer_map_name; + int i, j; + + for (i = 0; i < ctx->map_num; i++) { + inner_map_name = bpf_map_fetch_name(ctx, i); + if (!inner_map_name) { + return false; + } + + if (strcmp(libbpf_map_name, inner_map_name)) + continue; + + if (!ctx->maps[i].id || + ctx->maps[i].inner_id || + ctx->maps[i].inner_idx == -1) + continue; + + *imap = ctx->maps[i]; + + for (j = 0; j < ctx->map_num; j++) { + if (!bpf_is_map_in_map_type(&ctx->maps[j])) + continue; + if (ctx->maps[j].inner_id != ctx->maps[i].id) + continue; + + *omap = ctx->maps[j]; + outer_map_name = bpf_map_fetch_name(ctx, j); + memcpy(omap_name, outer_map_name, strlen(outer_map_name) + 1); + + return true; + } + } + + return false; +} + +int iproute2_find_map_name_by_id(unsigned int map_id, char *name) +{ + struct bpf_elf_ctx *ctx = &__ctx; + const char *map_name; + int i, idx = -1; + + for (i = 0; i < ctx->map_num; i++) { + if (ctx->maps[i].id == map_id && + ctx->maps[i].type == BPF_MAP_TYPE_PROG_ARRAY) { + idx = i; + break; + } + } + + if (idx < 0) + return -1; + + map_name = bpf_map_fetch_name(ctx, idx); + if (!map_name) + return -1; + + memcpy(name, map_name, strlen(map_name) + 1); + return 0; +} +#endif /* HAVE_LIBBPF */ #endif /* HAVE_ELF */ diff --git a/lib/bpf_libbpf.c b/lib/bpf_libbpf.c new file mode 100644 index 00000000..26694b43 --- /dev/null +++ b/lib/bpf_libbpf.c @@ -0,0 +1,353 @@ +/* + * bpf_libbpf.c BPF code relay on libbpf + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Authors: Hangbin Liu + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include + +#include "bpf_util.h" + +static int verbose_print(enum libbpf_print_level level, const char *format, va_list args) +{ + return vfprintf(stderr, format, args); +} + +static int silent_print(enum libbpf_print_level level, const char *format, va_list args) +{ + if (level > LIBBPF_WARN) + return 0; + + /* Skip warning from bpf_object__init_user_maps() for legacy maps */ + if (strstr(format, "has unrecognized, non-zero options")) + return 0; + + return vfprintf(stderr, format, args); +} + +static const char *get_bpf_program__section_name(const struct bpf_program *prog) +{ +#ifdef HAVE_LIBBPF_SECTION_NAME + return bpf_program__section_name(prog); +#else + return bpf_program__title(prog, false); +#endif +} + +static int create_map(const char *name, struct bpf_elf_map *map, + __u32 ifindex, int inner_fd) +{ + struct bpf_create_map_attr map_attr = {}; + + map_attr.name = name; + map_attr.map_type = map->type; + map_attr.map_flags = map->flags; + map_attr.key_size = map->size_key; + map_attr.value_size = map->size_value; + map_attr.max_entries = map->max_elem; + map_attr.map_ifindex = ifindex; + map_attr.inner_map_fd = inner_fd; + + return bpf_create_map_xattr(&map_attr); +} + +static int create_map_in_map(struct bpf_object *obj, struct bpf_map *map, + struct bpf_elf_map *elf_map, int inner_fd, + bool *reuse_pin_map) +{ + char pathname[PATH_MAX]; + const char *map_name; + bool pin_map = false; + int map_fd, ret = 0; + + map_name = bpf_map__name(map); + + if (iproute2_is_pin_map(map_name, pathname)) { + pin_map = true; + + /* Check if there already has a pinned map */ + map_fd = bpf_obj_get(pathname); + if (map_fd > 0) { + if (reuse_pin_map) + *reuse_pin_map = true; + close(map_fd); + return bpf_map__set_pin_path(map, pathname); + } + } + + map_fd = create_map(map_name, elf_map, bpf_map__ifindex(map), inner_fd); + if (map_fd < 0) { + fprintf(stderr, "create map %s failed\n", map_name); + return map_fd; + } + + ret = bpf_map__reuse_fd(map, map_fd); + if (ret < 0) { + fprintf(stderr, "map %s reuse fd failed\n", map_name); + goto err_out; + } + + if (pin_map) { + ret = bpf_map__set_pin_path(map, pathname); + if (ret < 0) + goto err_out; + } + + return 0; +err_out: + close(map_fd); + return ret; +} + +static int +handle_legacy_map_in_map(struct bpf_object *obj, struct bpf_map *inner_map, + const char *inner_map_name) +{ + int inner_fd, outer_fd, inner_idx, ret = 0; + struct bpf_elf_map imap, omap; + struct bpf_map *outer_map; + /* What's the size limit of map name? */ + char outer_map_name[128]; + bool reuse_pin_map = false; + + /* Deal with map-in-map */ + if (iproute2_is_map_in_map(inner_map_name, &imap, &omap, outer_map_name)) { + ret = create_map_in_map(obj, inner_map, &imap, -1, NULL); + if (ret < 0) + return ret; + + inner_fd = bpf_map__fd(inner_map); + outer_map = bpf_object__find_map_by_name(obj, outer_map_name); + ret = create_map_in_map(obj, outer_map, &omap, inner_fd, &reuse_pin_map); + if (ret < 0) + return ret; + + if (!reuse_pin_map) { + inner_idx = imap.inner_idx; + outer_fd = bpf_map__fd(outer_map); + ret = bpf_map_update_elem(outer_fd, &inner_idx, &inner_fd, 0); + if (ret < 0) + fprintf(stderr, "Cannot update inner_idx into outer_map\n"); + } + } + + return ret; +} + +static int find_legacy_tail_calls(struct bpf_program *prog, struct bpf_object *obj) +{ + unsigned int map_id, key_id; + const char *sec_name; + struct bpf_map *map; + char map_name[128]; + int ret; + + /* Handle iproute2 tail call */ + sec_name = get_bpf_program__section_name(prog); + ret = sscanf(sec_name, "%i/%i", &map_id, &key_id); + if (ret != 2) + return -1; + + ret = iproute2_find_map_name_by_id(map_id, map_name); + if (ret < 0) { + fprintf(stderr, "unable to find map id %u for tail call\n", map_id); + return ret; + } + + map = bpf_object__find_map_by_name(obj, map_name); + if (!map) + return -1; + + /* Save the map here for later updating */ + bpf_program__set_priv(prog, map, NULL); + + return 0; +} + +static int update_legacy_tail_call_maps(struct bpf_object *obj) +{ + int prog_fd, map_fd, ret = 0; + unsigned int map_id, key_id; + struct bpf_program *prog; + const char *sec_name; + struct bpf_map *map; + + bpf_object__for_each_program(prog, obj) { + map = bpf_program__priv(prog); + if (!map) + continue; + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) + continue; + + sec_name = get_bpf_program__section_name(prog); + ret = sscanf(sec_name, "%i/%i", &map_id, &key_id); + if (ret != 2) + continue; + + map_fd = bpf_map__fd(map); + ret = bpf_map_update_elem(map_fd, &key_id, &prog_fd, 0); + if (ret < 0) { + fprintf(stderr, "Cannot update map key for tail call!\n"); + return ret; + } + } + + return 0; +} + +static int handle_legacy_maps(struct bpf_object *obj) +{ + char pathname[PATH_MAX]; + struct bpf_map *map; + const char *map_name; + int map_fd, ret = 0; + + bpf_object__for_each_map(map, obj) { + map_name = bpf_map__name(map); + + ret = handle_legacy_map_in_map(obj, map, map_name); + if (ret) + return ret; + + /* If it is a iproute2 legacy pin maps, just set pin path + * and let bpf_object__load() to deal with the map creation. + * We need to ignore map-in-maps which have pinned maps manually + */ + map_fd = bpf_map__fd(map); + if (map_fd < 0 && iproute2_is_pin_map(map_name, pathname)) { + ret = bpf_map__set_pin_path(map, pathname); + if (ret) { + fprintf(stderr, "map '%s': couldn't set pin path.\n", map_name); + break; + } + } + + } + + return ret; +} + +static int load_bpf_object(struct bpf_cfg_in *cfg) +{ + struct bpf_program *p, *prog = NULL; + struct bpf_object *obj; + char root_path[PATH_MAX]; + struct bpf_map *map; + int prog_fd, ret = 0; + + ret = iproute2_get_root_path(root_path, PATH_MAX); + if (ret) + return ret; + + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, open_opts, + .relaxed_maps = true, + .pin_root_path = root_path, + ); + + obj = bpf_object__open_file(cfg->object, &open_opts); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return -ENOENT; + } + + bpf_object__for_each_program(p, obj) { + /* Only load the programs that will either be subsequently + * attached or inserted into a tail call map */ + if (find_legacy_tail_calls(p, obj) < 0 && cfg->section && + strcmp(get_bpf_program__section_name(p), cfg->section)) { + ret = bpf_program__set_autoload(p, false); + if (ret) + return -EINVAL; + continue; + } + + bpf_program__set_type(p, cfg->type); + bpf_program__set_ifindex(p, cfg->ifindex); + if (!prog) + prog = p; + } + + bpf_object__for_each_map(map, obj) { + if (!bpf_map__is_offload_neutral(map)) + bpf_map__set_ifindex(map, cfg->ifindex); + } + + if (!prog) { + fprintf(stderr, "object file doesn't contain sec %s\n", cfg->section); + return -ENOENT; + } + + /* Handle iproute2 legacy pin maps and map-in-maps */ + ret = handle_legacy_maps(obj); + if (ret) + goto unload_obj; + + ret = bpf_object__load(obj); + if (ret) + goto unload_obj; + + ret = update_legacy_tail_call_maps(obj); + if (ret) + goto unload_obj; + + prog_fd = fcntl(bpf_program__fd(prog), F_DUPFD_CLOEXEC, 1); + if (prog_fd < 0) + ret = -errno; + else + cfg->prog_fd = prog_fd; + +unload_obj: + /* Close obj as we don't need it */ + bpf_object__close(obj); + return ret; +} + +/* Load ebpf and return prog fd */ +int iproute2_load_libbpf(struct bpf_cfg_in *cfg) +{ + int ret = 0; + + if (cfg->verbose) + libbpf_set_print(verbose_print); + else + libbpf_set_print(silent_print); + + ret = iproute2_bpf_elf_ctx_init(cfg); + if (ret < 0) { + fprintf(stderr, "Cannot initialize ELF context!\n"); + return ret; + } + + ret = iproute2_bpf_fetch_ancillary(); + if (ret < 0) { + fprintf(stderr, "Error fetching ELF ancillary data!\n"); + return ret; + } + + ret = load_bpf_object(cfg); + if (ret) + return ret; + + return cfg->prog_fd; +} From patchwork Mon Nov 16 06:53:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hangbin Liu X-Patchwork-Id: 1400668 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; 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Sun, 15 Nov 2020 22:53:55 -0800 (PST) From: Hangbin Liu To: Stephen Hemminger , David Ahern Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc , =?utf-8?q?Toke_H=C3=B8il?= =?utf-8?q?and-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv5 iproute2-next 4/5] examples/bpf: move struct bpf_elf_map defined maps to legacy folder Date: Mon, 16 Nov 2020 14:53:04 +0800 Message-Id: <20201116065305.1010651-5-haliu@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201116065305.1010651-1-haliu@redhat.com> References: <20201109070802.3638167-1-haliu@redhat.com> <20201116065305.1010651-1-haliu@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Hangbin Liu --- examples/bpf/README | 14 +++++++++----- examples/bpf/{ => legacy}/bpf_cyclic.c | 2 +- examples/bpf/{ => legacy}/bpf_graft.c | 2 +- examples/bpf/{ => legacy}/bpf_map_in_map.c | 2 +- examples/bpf/{ => legacy}/bpf_shared.c | 2 +- examples/bpf/{ => legacy}/bpf_tailcall.c | 2 +- 6 files changed, 14 insertions(+), 10 deletions(-) rename examples/bpf/{ => legacy}/bpf_cyclic.c (95%) rename examples/bpf/{ => legacy}/bpf_graft.c (97%) rename examples/bpf/{ => legacy}/bpf_map_in_map.c (96%) rename examples/bpf/{ => legacy}/bpf_shared.c (97%) rename examples/bpf/{ => legacy}/bpf_tailcall.c (98%) diff --git a/examples/bpf/README b/examples/bpf/README index 1bbdda3f..732bcc83 100644 --- a/examples/bpf/README +++ b/examples/bpf/README @@ -1,8 +1,12 @@ eBPF toy code examples (running in kernel) to familiarize yourself with syntax and features: - - bpf_shared.c -> Ingress/egress map sharing example - - bpf_tailcall.c -> Using tail call chains - - bpf_cyclic.c -> Simple cycle as tail calls - - bpf_graft.c -> Demo on altering runtime behaviour - - bpf_map_in_map.c -> Using map in map example + - legacy/bpf_shared.c -> Ingress/egress map sharing example + - legacy/bpf_tailcall.c -> Using tail call chains + - legacy/bpf_cyclic.c -> Simple cycle as tail calls + - legacy/bpf_graft.c -> Demo on altering runtime behaviour + - legacy/bpf_map_in_map.c -> Using map in map example + +Note: Users should use new BTF way to defined the maps, the examples +in legacy folder which is using struct bpf_elf_map defined maps is not +recommanded. diff --git a/examples/bpf/bpf_cyclic.c b/examples/bpf/legacy/bpf_cyclic.c similarity index 95% rename from examples/bpf/bpf_cyclic.c rename to examples/bpf/legacy/bpf_cyclic.c index 11d1c061..33590730 100644 --- a/examples/bpf/bpf_cyclic.c +++ b/examples/bpf/legacy/bpf_cyclic.c @@ -1,4 +1,4 @@ -#include "../../include/bpf_api.h" +#include "../../../include/bpf_api.h" /* Cyclic dependency example to test the kernel's runtime upper * bound on loops. Also demonstrates on how to use direct-actions, diff --git a/examples/bpf/bpf_graft.c b/examples/bpf/legacy/bpf_graft.c similarity index 97% rename from examples/bpf/bpf_graft.c rename to examples/bpf/legacy/bpf_graft.c index 07113d4a..f4c920cc 100644 --- a/examples/bpf/bpf_graft.c +++ b/examples/bpf/legacy/bpf_graft.c @@ -1,4 +1,4 @@ -#include "../../include/bpf_api.h" +#include "../../../include/bpf_api.h" /* This example demonstrates how classifier run-time behaviour * can be altered with tail calls. We start out with an empty diff --git a/examples/bpf/bpf_map_in_map.c b/examples/bpf/legacy/bpf_map_in_map.c similarity index 96% rename from examples/bpf/bpf_map_in_map.c rename to examples/bpf/legacy/bpf_map_in_map.c index ff0e623a..575f8812 100644 --- a/examples/bpf/bpf_map_in_map.c +++ b/examples/bpf/legacy/bpf_map_in_map.c @@ -1,4 +1,4 @@ -#include "../../include/bpf_api.h" +#include "../../../include/bpf_api.h" #define MAP_INNER_ID 42 diff --git a/examples/bpf/bpf_shared.c b/examples/bpf/legacy/bpf_shared.c similarity index 97% rename from examples/bpf/bpf_shared.c rename to examples/bpf/legacy/bpf_shared.c index 21fe6f1e..05b2b9ef 100644 --- a/examples/bpf/bpf_shared.c +++ b/examples/bpf/legacy/bpf_shared.c @@ -1,4 +1,4 @@ -#include "../../include/bpf_api.h" +#include "../../../include/bpf_api.h" /* Minimal, stand-alone toy map pinning example: * diff --git a/examples/bpf/bpf_tailcall.c b/examples/bpf/legacy/bpf_tailcall.c similarity index 98% rename from examples/bpf/bpf_tailcall.c rename to examples/bpf/legacy/bpf_tailcall.c index 161eb606..8ebc554c 100644 --- a/examples/bpf/bpf_tailcall.c +++ b/examples/bpf/legacy/bpf_tailcall.c @@ -1,5 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#include "../../include/bpf_api.h" +#include "../../../include/bpf_api.h" #define ENTRY_INIT 3 #define ENTRY_0 0 From patchwork Mon Nov 16 06:53:05 2020 Content-Type: text/plain; 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Sun, 15 Nov 2020 22:54:00 -0800 (PST) Received: from localhost.localdomain.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 16sm18645837pjf.36.2020.11.15.22.53.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 15 Nov 2020 22:53:59 -0800 (PST) From: Hangbin Liu To: Stephen Hemminger , David Ahern Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , David Miller , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, Jiri Benc , =?utf-8?q?Toke_H=C3=B8il?= =?utf-8?q?and-J=C3=B8rgensen?= , Hangbin Liu Subject: [PATCHv5 iproute2-next 5/5] examples/bpf: add bpf examples with BTF defined maps Date: Mon, 16 Nov 2020 14:53:05 +0800 Message-Id: <20201116065305.1010651-6-haliu@redhat.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201116065305.1010651-1-haliu@redhat.com> References: <20201109070802.3638167-1-haliu@redhat.com> <20201116065305.1010651-1-haliu@redhat.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Users should try use the new BTF defined maps instead of struct bpf_elf_map defined maps. The tail call examples are not added yet as libbpf doesn't currently support declaratively populating tail call maps. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Hangbin Liu --- examples/bpf/README | 6 ++++ examples/bpf/bpf_graft.c | 66 +++++++++++++++++++++++++++++++++++ examples/bpf/bpf_map_in_map.c | 55 +++++++++++++++++++++++++++++ examples/bpf/bpf_shared.c | 53 ++++++++++++++++++++++++++++ include/bpf_api.h | 13 +++++++ 5 files changed, 193 insertions(+) create mode 100644 examples/bpf/bpf_graft.c create mode 100644 examples/bpf/bpf_map_in_map.c create mode 100644 examples/bpf/bpf_shared.c diff --git a/examples/bpf/README b/examples/bpf/README index 732bcc83..b7261191 100644 --- a/examples/bpf/README +++ b/examples/bpf/README @@ -1,6 +1,12 @@ eBPF toy code examples (running in kernel) to familiarize yourself with syntax and features: +- BTF defined map examples + - bpf_graft.c -> Demo on altering runtime behaviour + - bpf_shared.c -> Ingress/egress map sharing example + - bpf_map_in_map.c -> Using map in map example + +- legacy struct bpf_elf_map defined map examples - legacy/bpf_shared.c -> Ingress/egress map sharing example - legacy/bpf_tailcall.c -> Using tail call chains - legacy/bpf_cyclic.c -> Simple cycle as tail calls diff --git a/examples/bpf/bpf_graft.c b/examples/bpf/bpf_graft.c new file mode 100644 index 00000000..8066dcce --- /dev/null +++ b/examples/bpf/bpf_graft.c @@ -0,0 +1,66 @@ +#include "../../include/bpf_api.h" + +/* This example demonstrates how classifier run-time behaviour + * can be altered with tail calls. We start out with an empty + * jmp_tc array, then add section aaa to the array slot 0, and + * later on atomically replace it with section bbb. Note that + * as shown in other examples, the tc loader can prepopulate + * tail called sections, here we start out with an empty one + * on purpose to show it can also be done this way. + * + * tc filter add dev foo parent ffff: bpf obj graft.o + * tc exec bpf dbg + * [...] + * Socket Thread-20229 [001] ..s. 138993.003923: : fallthrough + * -0 [001] ..s. 138993.202265: : fallthrough + * Socket Thread-20229 [001] ..s. 138994.004149: : fallthrough + * [...] + * + * tc exec bpf graft m:globals/jmp_tc key 0 obj graft.o sec aaa + * tc exec bpf dbg + * [...] + * Socket Thread-19818 [002] ..s. 139012.053587: : aaa + * -0 [002] ..s. 139012.172359: : aaa + * Socket Thread-19818 [001] ..s. 139012.173556: : aaa + * [...] + * + * tc exec bpf graft m:globals/jmp_tc key 0 obj graft.o sec bbb + * tc exec bpf dbg + * [...] + * Socket Thread-19818 [002] ..s. 139022.102967: : bbb + * -0 [002] ..s. 139022.155640: : bbb + * Socket Thread-19818 [001] ..s. 139022.156730: : bbb + * [...] + */ + +struct { + __uint(type, BPF_MAP_TYPE_PROG_ARRAY); + __uint(key_size, sizeof(uint32_t)); + __uint(value_size, sizeof(uint32_t)); + __uint(max_entries, 1); + __uint(pinning, LIBBPF_PIN_BY_NAME); +} jmp_tc __section(".maps"); + +__section("aaa") +int cls_aaa(struct __sk_buff *skb) +{ + printt("aaa\n"); + return TC_H_MAKE(1, 42); +} + +__section("bbb") +int cls_bbb(struct __sk_buff *skb) +{ + printt("bbb\n"); + return TC_H_MAKE(1, 43); +} + +__section_cls_entry +int cls_entry(struct __sk_buff *skb) +{ + tail_call(skb, &jmp_tc, 0); + printt("fallthrough\n"); + return BPF_H_DEFAULT; +} + +BPF_LICENSE("GPL"); diff --git a/examples/bpf/bpf_map_in_map.c b/examples/bpf/bpf_map_in_map.c new file mode 100644 index 00000000..39c86268 --- /dev/null +++ b/examples/bpf/bpf_map_in_map.c @@ -0,0 +1,55 @@ +#include "../../include/bpf_api.h" + +struct inner_map { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(key_size, sizeof(uint32_t)); + __uint(value_size, sizeof(uint32_t)); + __uint(max_entries, 1); +} map_inner __section(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS); + __uint(key_size, sizeof(uint32_t)); + __uint(value_size, sizeof(uint32_t)); + __uint(max_entries, 1); + __uint(pinning, LIBBPF_PIN_BY_NAME); + __array(values, struct inner_map); +} map_outer __section(".maps") = { + .values = { + [0] = &map_inner, + }, +}; + +__section("egress") +int emain(struct __sk_buff *skb) +{ + struct bpf_elf_map *map_inner; + int key = 0, *val; + + map_inner = map_lookup_elem(&map_outer, &key); + if (map_inner) { + val = map_lookup_elem(map_inner, &key); + if (val) + lock_xadd(val, 1); + } + + return BPF_H_DEFAULT; +} + +__section("ingress") +int imain(struct __sk_buff *skb) +{ + struct bpf_elf_map *map_inner; + int key = 0, *val; + + map_inner = map_lookup_elem(&map_outer, &key); + if (map_inner) { + val = map_lookup_elem(map_inner, &key); + if (val) + printt("map val: %d\n", *val); + } + + return BPF_H_DEFAULT; +} + +BPF_LICENSE("GPL"); diff --git a/examples/bpf/bpf_shared.c b/examples/bpf/bpf_shared.c new file mode 100644 index 00000000..99a332f4 --- /dev/null +++ b/examples/bpf/bpf_shared.c @@ -0,0 +1,53 @@ +#include "../../include/bpf_api.h" + +/* Minimal, stand-alone toy map pinning example: + * + * clang -target bpf -O2 [...] -o bpf_shared.o -c bpf_shared.c + * tc filter add dev foo parent 1: bpf obj bpf_shared.o sec egress + * tc filter add dev foo parent ffff: bpf obj bpf_shared.o sec ingress + * + * Both classifier will share the very same map instance in this example, + * so map content can be accessed from ingress *and* egress side! + * + * This example has a pinning of PIN_OBJECT_NS, so it's private and + * thus shared among various program sections within the object. + * + * A setting of PIN_GLOBAL_NS would place it into a global namespace, + * so that it can be shared among different object files. A setting + * of PIN_NONE (= 0) means no sharing, so each tc invocation a new map + * instance is being created. + */ + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(key_size, sizeof(uint32_t)); + __uint(value_size, sizeof(uint32_t)); + __uint(max_entries, 1); + __uint(pinning, LIBBPF_PIN_BY_NAME); /* or LIBBPF_PIN_NONE */ +} map_sh __section(".maps"); + +__section("egress") +int emain(struct __sk_buff *skb) +{ + int key = 0, *val; + + val = map_lookup_elem(&map_sh, &key); + if (val) + lock_xadd(val, 1); + + return BPF_H_DEFAULT; +} + +__section("ingress") +int imain(struct __sk_buff *skb) +{ + int key = 0, *val; + + val = map_lookup_elem(&map_sh, &key); + if (val) + printt("map val: %d\n", *val); + + return BPF_H_DEFAULT; +} + +BPF_LICENSE("GPL"); diff --git a/include/bpf_api.h b/include/bpf_api.h index 89d3488d..82c47089 100644 --- a/include/bpf_api.h +++ b/include/bpf_api.h @@ -19,6 +19,19 @@ #include "bpf_elf.h" +/** libbpf pin type. */ +enum libbpf_pin_type { + LIBBPF_PIN_NONE, + /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */ + LIBBPF_PIN_BY_NAME, +}; + +/** Type helper macros. */ + +#define __uint(name, val) int (*name)[val] +#define __type(name, val) typeof(val) *name +#define __array(name, val) typeof(val) *name[] + /** Misc macros. */ #ifndef __stringify