From patchwork Fri Aug 28 19:36:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 261789 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=-12.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 3777BC433E2 for ; Fri, 28 Aug 2020 19:36:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 105542087D for ; Fri, 28 Aug 2020 19:36:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="KddCvohZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726851AbgH1Tgv (ORCPT ); Fri, 28 Aug 2020 15:36:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726594AbgH1TgV (ORCPT ); Fri, 28 Aug 2020 15:36:21 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1B17C06123A for ; Fri, 28 Aug 2020 12:36:15 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id c67so112478qkd.0 for ; Fri, 28 Aug 2020 12:36:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=zBAe1FVufzoZpYTUTqiD804lLPIX6uCCT1yy+dgE1R0=; b=KddCvohZ56o2AVqqwXHkreAu5TqUzxOPbr24pE24K7DzR01RvFXwmCOlfOs9aDDXJH 1Iep7lvJr0v8uXSQoyNz4oSw77YKZRtY+iK9bUJzo7CUKcy+/Nci2cg8i8I+t5s7w/Gq 55KSTmPErCfB4gC9lo9VIynDwlFgogKCKrGnW1d6yqLNdlsxqArVdMqNsJ3q83fD4IvG zJQyN6QwGw2HppVeLsAAj2Cdz5Oez7V64BdVi+ulD53Bz0oWBfbdx1NuohIFiWVUIZs3 fiQowoObbFpvQVGvSe+m24XyuoLr2ob1ufRmoQimUUS1v7TgfWyEqqbekIBiR6muthy/ Iolw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=zBAe1FVufzoZpYTUTqiD804lLPIX6uCCT1yy+dgE1R0=; b=l2E07p1TaLvXNTjLnKuC3AMZFl8qFi+QUWXoe5gfXrKpdixpIgYTaH3a4JCCVfwg26 wZyAMBgxXjvg5TLcbvIcQu/d7DeG36ioXSxO32G0ZRGalV6zqw7uVvufNMjR42L+jB1f Dxc93ynuJ5gKrl6j0XXMgdR2I19r+QEX8rIiwpfhL7jrX17jO5DBNnEkjCceKsegL0yF 1aP+UgV2QpTNbEoo+lPG7j/WeYq3FhPCB4E0GHuzTOjpGlkz+HhUqjNpzn+bhsOCs6aZ Ux57OmMCbvvrXm/tFece5aUa06c7QTHFvPjozYlYCgm9pEAri12ZSvgBJ9jdBNd3SrDw TIXg== X-Gm-Message-State: AOAM533jhNUUo/l3DZ1+mLFH+rfoIpE98AGaiwjjZg2Vj8Sr9mQ2Na55 WMIqvIGeLBnfR2Lj8HIl7Ash2Oa5CKOlRAzLPCa8F1zukL8Xr2tK56batiBsVPo8KWW0tdblKgQ 7ACY0CyXzV9CFIjNpLQr9WbUY3uLIGo/q6TLg2xY2mMlwIWiG1AMoFw== X-Google-Smtp-Source: ABdhPJyu6SsQjLtQW2oPoP8elya5iZ2x/CAWBmuOtKU9ApWz33BUmLgX2ZiWysjht3J5TmAOfnjQYo0= X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:1:7220:84ff:fe09:7732]) (user=sdf job=sendgmr) by 2002:ad4:458e:: with SMTP id x14mr86689qvu.111.1598643374913; Fri, 28 Aug 2020 12:36:14 -0700 (PDT) Date: Fri, 28 Aug 2020 12:36:00 -0700 In-Reply-To: <20200828193603.335512-1-sdf@google.com> Message-Id: <20200828193603.335512-6-sdf@google.com> Mime-Version: 1.0 References: <20200828193603.335512-1-sdf@google.com> X-Mailer: git-send-email 2.28.0.402.g5ffc5be6b7-goog Subject: [PATCH bpf-next v3 5/8] bpftool: support dumping metadata From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, YiFei Zhu , YiFei Zhu , Stanislav Fomichev Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: YiFei Zhu Added a flag "--metadata" to `bpftool prog list` to dump the metadata contents. For some formatting some BTF code is put directly in the metadata dumping. Sanity checks on the map and the kind of the btf_type to make sure we are actually dumping what we are expecting. A helper jsonw_reset is added to json writer so we can reuse the same json writer without having extraneous commas. Sample output: $ bpftool prog --metadata 6: cgroup_skb name prog tag bcf7977d3b93787c gpl [...] btf_id 4 metadata: metadata_a = "foo" metadata_b = 1 $ bpftool prog --metadata --json --pretty [{ "id": 6, [...] "btf_id": 4, "metadata": { "metadata_a": "foo", "metadata_b": 1 } } ] Cc: YiFei Zhu Signed-off-by: YiFei Zhu Signed-off-by: Stanislav Fomichev --- tools/bpf/bpftool/json_writer.c | 6 ++ tools/bpf/bpftool/json_writer.h | 3 + tools/bpf/bpftool/main.c | 10 +++ tools/bpf/bpftool/main.h | 1 + tools/bpf/bpftool/prog.c | 130 ++++++++++++++++++++++++++++++++ 5 files changed, 150 insertions(+) diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c index 86501cd3c763..7fea83bedf48 100644 --- a/tools/bpf/bpftool/json_writer.c +++ b/tools/bpf/bpftool/json_writer.c @@ -119,6 +119,12 @@ void jsonw_pretty(json_writer_t *self, bool on) self->pretty = on; } +void jsonw_reset(json_writer_t *self) +{ + assert(self->depth == 0); + self->sep = '\0'; +} + /* Basic blocks */ static void jsonw_begin(json_writer_t *self, int c) { diff --git a/tools/bpf/bpftool/json_writer.h b/tools/bpf/bpftool/json_writer.h index 35cf1f00f96c..8ace65cdb92f 100644 --- a/tools/bpf/bpftool/json_writer.h +++ b/tools/bpf/bpftool/json_writer.h @@ -27,6 +27,9 @@ void jsonw_destroy(json_writer_t **self_p); /* Cause output to have pretty whitespace */ void jsonw_pretty(json_writer_t *self, bool on); +/* Reset separator to create new JSON */ +void jsonw_reset(json_writer_t *self); + /* Add property name */ void jsonw_name(json_writer_t *self, const char *name); diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index 4a191fcbeb82..a681d568cfa7 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -28,6 +28,7 @@ bool show_pinned; bool block_mount; bool verifier_logs; bool relaxed_maps; +bool dump_metadata; struct pinned_obj_table prog_table; struct pinned_obj_table map_table; struct pinned_obj_table link_table; @@ -351,6 +352,10 @@ static int do_batch(int argc, char **argv) return err; } +enum bpftool_longonly_opts { + OPT_METADATA = 256, +}; + int main(int argc, char **argv) { static const struct option options[] = { @@ -362,6 +367,7 @@ int main(int argc, char **argv) { "mapcompat", no_argument, NULL, 'm' }, { "nomount", no_argument, NULL, 'n' }, { "debug", no_argument, NULL, 'd' }, + { "metadata", no_argument, NULL, OPT_METADATA }, { 0 } }; int opt, ret; @@ -371,6 +377,7 @@ int main(int argc, char **argv) json_output = false; show_pinned = false; block_mount = false; + dump_metadata = false; bin_name = argv[0]; hash_init(prog_table.table); @@ -412,6 +419,9 @@ int main(int argc, char **argv) libbpf_set_print(print_all_levels); verifier_logs = true; break; + case OPT_METADATA: + dump_metadata = true; + break; default: p_err("unrecognized option '%s'", argv[optind - 1]); if (json_output) diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index c46e52137b87..8750758e9150 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -90,6 +90,7 @@ extern bool show_pids; extern bool block_mount; extern bool verifier_logs; extern bool relaxed_maps; +extern bool dump_metadata; extern struct pinned_obj_table prog_table; extern struct pinned_obj_table map_table; extern struct pinned_obj_table link_table; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index d393eb8263a6..5d626c134e7d 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -151,6 +151,130 @@ static void show_prog_maps(int fd, __u32 num_maps) } } +static void show_prog_metadata(int fd, __u32 num_maps) +{ + const struct btf_type *t_datasec, *t_var; + struct bpf_map_info map_info = {}; + struct btf_var_secinfo *vsi; + struct btf *btf = NULL; + unsigned int i, vlen; + __u32 map_info_len; + void *value = NULL; + int key = 0; + int map_id; + int map_fd; + int err; + + if (!num_maps) + return; + + map_id = bpf_prog_find_metadata(fd); + if (map_id < 0) + return; + + map_fd = bpf_map_get_fd_by_id(map_id); + if (map_fd < 0) { + p_err("can't get map by id (%u): %s", map_id, strerror(errno)); + return; + } + + map_info_len = sizeof(map_info); + err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len); + if (err) { + p_err("can't get map info of id (%u): %s", map_id, + strerror(errno)); + goto out_close; + } + + value = malloc(map_info.value_size); + if (!value) { + p_err("mem alloc failed"); + goto out_close; + } + + if (bpf_map_lookup_elem(map_fd, &key, value)) { + p_err("metadata map lookup failed: %s", strerror(errno)); + goto out_free; + } + + err = btf__get_from_id(map_info.btf_id, &btf); + if (err || !btf) { + p_err("metadata BTF get failed: %s", strerror(-err)); + goto out_free; + } + + t_datasec = btf__type_by_id(btf, map_info.btf_value_type_id); + if (BTF_INFO_KIND(t_datasec->info) != BTF_KIND_DATASEC) { + p_err("bad metadata BTF"); + goto out_free; + } + + vlen = BTF_INFO_VLEN(t_datasec->info); + vsi = (struct btf_var_secinfo *)(t_datasec + 1); + + /* We don't proceed to check the kinds of the elements of the DATASEC. + * The verifier enforce then to be BTF_KIND_VAR. + */ + + if (json_output) { + struct btf_dumper d = { + .btf = btf, + .jw = json_wtr, + .is_plain_text = false, + }; + + jsonw_name(json_wtr, "metadata"); + + jsonw_start_object(json_wtr); + for (i = 0; i < vlen; i++) { + t_var = btf__type_by_id(btf, vsi[i].type); + + jsonw_name(json_wtr, btf__name_by_offset(btf, t_var->name_off)); + err = btf_dumper_type(&d, t_var->type, value + vsi[i].offset); + if (err) { + p_err("btf dump failed"); + break; + } + } + jsonw_end_object(json_wtr); + } else { + json_writer_t *btf_wtr = jsonw_new(stdout); + struct btf_dumper d = { + .btf = btf, + .jw = btf_wtr, + .is_plain_text = true, + }; + if (!btf_wtr) { + p_err("jsonw alloc failed"); + goto out_free; + } + + printf("\tmetadata:"); + + for (i = 0; i < vlen; i++) { + t_var = btf__type_by_id(btf, vsi[i].type); + + printf("\n\t\t%s = ", btf__name_by_offset(btf, t_var->name_off)); + + jsonw_reset(btf_wtr); + err = btf_dumper_type(&d, t_var->type, value + vsi[i].offset); + if (err) { + p_err("btf dump failed"); + break; + } + } + + jsonw_destroy(&btf_wtr); + } + +out_free: + btf__free(btf); + free(value); + +out_close: + close(map_fd); +} + static void print_prog_header_json(struct bpf_prog_info *info) { jsonw_uint_field(json_wtr, "id", info->id); @@ -228,6 +352,9 @@ static void print_prog_json(struct bpf_prog_info *info, int fd) emit_obj_refs_json(&refs_table, info->id, json_wtr); + if (dump_metadata) + show_prog_metadata(fd, info->nr_map_ids); + jsonw_end_object(json_wtr); } @@ -297,6 +424,9 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd) emit_obj_refs_plain(&refs_table, info->id, "\n\tpids "); printf("\n"); + + if (dump_metadata) + show_prog_metadata(fd, info->nr_map_ids); } static int show_prog(int fd)