From patchwork Sat May 16 04:06:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Daniel T. Lee" X-Patchwork-Id: 219109 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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 BF71AC433E1 for ; Sat, 16 May 2020 04:06:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95FB120728 for ; Sat, 16 May 2020 04:06:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="A+ygEkPl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726735AbgEPEG0 (ORCPT ); Sat, 16 May 2020 00:06:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726602AbgEPEGY (ORCPT ); Sat, 16 May 2020 00:06:24 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A964C061A0C; Fri, 15 May 2020 21:06:24 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id m7so1746527plt.5; Fri, 15 May 2020 21:06:24 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=69tjF3a4OFKCsc0Suj1Ize0A/9vk7YvpZYxYpPATVNs=; b=A+ygEkPloDrKoJCbM8DKJgnCFvm9fajsnVBtAWe6Rz8rR2EhInvupAHU5JqD1e2u6k 26gp8ZTeH8CuyDDbouJhGdJOcGGnkBAMSQtjzMd1bSIs52HktBhrEaA9nRejTh6I6N5J pmmGW/zK9L6P7qth8JMuAIP2SmqBhZrfXDrmyJnPQF6q2unYybJrFKJSvzbAwff5h+0A vEd9aAXky4CHRMXxYMqC6tt/Kn20GckLjLmr4ToX5B5zHHsUo0sUEAPdy7hEZC2r6Ldq W3zIvdogKJsF3EAeBC7erFJegn8oYTaRm/KBMi3/DvM2XmPFZGlh6+aLgG+YfQOgQxNE ZPNQ== 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=69tjF3a4OFKCsc0Suj1Ize0A/9vk7YvpZYxYpPATVNs=; b=jaw/E8kYGd5VjUp1C4RwAw/b24zu882ovJRnJ6IAY8bEzbXu9bVmLIRIsI/KMO+BxZ qMm9LX0yK8vbS3p7Vd7FTLwewWBMJVp+zKraiKrFXpkA14+/H/WOrZj+C4fmvQt0XIER ab5RVOpQhauTca7n0lrAT4ZHcCWQ8ECmEL0nwOHUQonsCxoa1Xg3Lg2Su01iApk5AfnG cm+xJCpSYQOJJ+/KdGt7Bg44+f163BwOaK3jUcSzl1Nz1Jb8DXZ353SbIjlOQiVSza7e CQys5uFcghmfqi8uu4Gdj3bft50PHIvFEAGjmq7l3qTB2Z81uN/zzuOFpwV3D3vd5Gyq oDEg== X-Gm-Message-State: AOAM5331vr8STKSF9zXxcqgnOqRl9JBEl/Uvq4nQ1+yPPJEHMkLP3Gpo oyHomlCzeGYs9joeKmhFNA== X-Google-Smtp-Source: ABdhPJxKqIaVXSk0PawNtkWfsQ7uHPGxZwQJeJ83CRxcqvqLtIt/lWeg8vP6x1SBFukAK0lhPc+nQw== X-Received: by 2002:a17:90a:7f83:: with SMTP id m3mr7301561pjl.147.1589601983761; Fri, 15 May 2020 21:06:23 -0700 (PDT) Received: from localhost.localdomain ([219.255.158.173]) by smtp.gmail.com with ESMTPSA id b11sm98663pjz.54.2020.05.15.21.06.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2020 21:06:23 -0700 (PDT) From: "Daniel T. Lee" To: Daniel Borkmann , Alexei Starovoitov Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko , John Fastabend , Yonghong Song Subject: [PATCH bpf-next v2 3/5] samples: bpf: refactor tail call user progs with libbpf Date: Sat, 16 May 2020 13:06:06 +0900 Message-Id: <20200516040608.1377876-4-danieltimlee@gmail.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200516040608.1377876-1-danieltimlee@gmail.com> References: <20200516040608.1377876-1-danieltimlee@gmail.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org BPF tail call uses the BPF_MAP_TYPE_PROG_ARRAY type map for calling into other BPF programs and this PROG_ARRAY should be filled prior to use. Currently, samples with the PROG_ARRAY type MAP fill this program array with bpf_load. For bpf_load to fill this map, kernel BPF program must specify the section with specific format of / (e.g. SEC("socket/0")) But by using libbpf instead of bpf_load, user program can specify which programs should be added to PROG_ARRAY. The advantage of this approach is that you can selectively add only the programs you want, rather than adding all of them to PROG_ARRAY, and it's much more intuitive than the traditional approach. This commit refactors user programs with the PROG_ARRAY type MAP with libbpf instead of using bpf_load. Signed-off-by: Daniel T. Lee --- Changes in V2: - refactor pointer error check with libbpf_get_error - on bpf object open failure, return instead jump to cleanup samples/bpf/Makefile | 4 +-- samples/bpf/sockex3_user.c | 64 ++++++++++++++++++++++++------------ samples/bpf/tracex5_user.c | 66 +++++++++++++++++++++++++++++++++----- 3 files changed, 103 insertions(+), 31 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 4c91e5914329..8403e4762306 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -63,12 +63,12 @@ TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o fds_example-objs := fds_example.o sockex1-objs := sockex1_user.o sockex2-objs := sockex2_user.o -sockex3-objs := bpf_load.o sockex3_user.o +sockex3-objs := sockex3_user.o tracex1-objs := tracex1_user.o $(TRACE_HELPERS) tracex2-objs := tracex2_user.o tracex3-objs := tracex3_user.o tracex4-objs := tracex4_user.o -tracex5-objs := bpf_load.o tracex5_user.o $(TRACE_HELPERS) +tracex5-objs := tracex5_user.o $(TRACE_HELPERS) tracex6-objs := tracex6_user.o tracex7-objs := tracex7_user.o test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c index bbb1cd0666a9..4dbee7427d47 100644 --- a/samples/bpf/sockex3_user.c +++ b/samples/bpf/sockex3_user.c @@ -1,18 +1,13 @@ // SPDX-License-Identifier: GPL-2.0 #include #include -#include #include -#include "bpf_load.h" +#include #include "sock_example.h" #include #include #include -#define PARSE_IP 3 -#define PARSE_IP_PROG_FD (prog_fd[0]) -#define PROG_ARRAY_FD (map_fd[0]) - struct flow_key_record { __be32 src; __be32 dst; @@ -30,31 +25,55 @@ struct pair { int main(int argc, char **argv) { + int i, sock, key, fd, main_prog_fd, jmp_table_fd, hash_map_fd; struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_program *prog; + struct bpf_object *obj; char filename[256]; + const char *title; FILE *f; - int i, sock, err, id, key = PARSE_IP; - struct bpf_prog_info info = {}; - uint32_t info_len = sizeof(info); snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); setrlimit(RLIMIT_MEMLOCK, &r); - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + jmp_table_fd = bpf_object__find_map_fd_by_name(obj, "jmp_table"); + hash_map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map"); + if (jmp_table_fd < 0 || hash_map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; } - /* Test fd array lookup which returns the id of the bpf_prog */ - err = bpf_obj_get_info_by_fd(PARSE_IP_PROG_FD, &info, &info_len); - assert(!err); - err = bpf_map_lookup_elem(PROG_ARRAY_FD, &key, &id); - assert(!err); - assert(id == info.id); + bpf_object__for_each_program(prog, obj) { + fd = bpf_program__fd(prog); + + title = bpf_program__title(prog, false); + if (sscanf(title, "socket/%d", &key) != 1) { + fprintf(stderr, "ERROR: finding prog failed\n"); + goto cleanup; + } + + if (key == 0) + main_prog_fd = fd; + else + bpf_map_update_elem(jmp_table_fd, &key, &fd, BPF_ANY); + } sock = open_raw_sock("lo"); - assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd[4], + /* attach BPF program to socket */ + assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &main_prog_fd, sizeof(__u32)) == 0); if (argc > 1) @@ -69,8 +88,8 @@ int main(int argc, char **argv) sleep(1); printf("IP src.port -> dst.port bytes packets\n"); - while (bpf_map_get_next_key(map_fd[2], &key, &next_key) == 0) { - bpf_map_lookup_elem(map_fd[2], &next_key, &value); + while (bpf_map_get_next_key(hash_map_fd, &key, &next_key) == 0) { + bpf_map_lookup_elem(hash_map_fd, &next_key, &value); printf("%s.%05d -> %s.%05d %12lld %12lld\n", inet_ntoa((struct in_addr){htonl(next_key.src)}), next_key.port16[0], @@ -80,5 +99,8 @@ int main(int argc, char **argv) key = next_key; } } + +cleanup: + bpf_object__close(obj); return 0; } diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c index c2317b39e0d2..98dad57a96c4 100644 --- a/samples/bpf/tracex5_user.c +++ b/samples/bpf/tracex5_user.c @@ -1,15 +1,21 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include +#include #include #include #include #include #include -#include "bpf_load.h" +#include #include #include "trace_helpers.h" +#ifdef __mips__ +#define MAX_ENTRIES 6000 /* MIPS n64 syscalls start at 5000 */ +#else +#define MAX_ENTRIES 1024 +#endif + /* install fake seccomp program to enable seccomp code path inside the kernel, * so that our kprobe attached to seccomp_phase1() can be triggered */ @@ -28,16 +34,57 @@ static void install_accept_all_seccomp(void) int main(int ac, char **argv) { - FILE *f; - char filename[256]; struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; + int key, fd, progs_fd; + char filename[256]; + const char *title; + FILE *f; - snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); setrlimit(RLIMIT_MEMLOCK, &r); - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); - return 1; + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + printf("finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; + } + + progs_fd = bpf_object__find_map_fd_by_name(obj, "progs"); + if (progs_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + bpf_object__for_each_program(prog, obj) { + title = bpf_program__title(prog, false); + /* register only syscalls to PROG_ARRAY */ + if (sscanf(title, "kprobe/%d", &key) != 1) + continue; + + fd = bpf_program__fd(prog); + bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY); } install_accept_all_seccomp(); @@ -47,5 +94,8 @@ int main(int ac, char **argv) read_trace_pipe(); +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); return 0; }