From patchwork Fri Jul 17 22:55:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Ambardar X-Patchwork-Id: 1331447 X-Patchwork-Delegate: bpf@iogearbox.net 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=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=gBWz+8dl; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B7mgh4yr6z9sRk for ; Sat, 18 Jul 2020 08:56:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727834AbgGQWz7 (ORCPT ); Fri, 17 Jul 2020 18:55:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbgGQWz7 (ORCPT ); Fri, 17 Jul 2020 18:55:59 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D185C0619D2; Fri, 17 Jul 2020 15:55:59 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id z3so6056335pfn.12; Fri, 17 Jul 2020 15:55:59 -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; bh=QdtE/wmAhW05sZUPuma2RrTvSoHqzbaenBHjoIn5xqU=; b=gBWz+8dl61r1GSerP4sA7je21spl+HEHE7M3zm1HMk/+NFkLzwk6pzChiClaDCfLok P7be1O9/DTpWVLPsuI4FaiP5mgw7JfMN2ePFfNY0yZBooW+iyGynDj85tJozO473VEPq R7Ujxwf1u1602SldEbunjmqn2/86XRGLtPOgdbrXU6j3nCgnJjKDjoDwaSBrI7BOsTWS LSrcDt6eqP0455mSGZBti36C6MpmnNIjVJ5bGkJv2o1Vk5bzjobjsYgjxOrdAv0ylzdS H0welAmswuTR2aixLrUyTTz6IZ6eQ+c9fDhr94rOfAWex2PKA8SOuTnd4Z0Rfjik0J5T buew== 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; bh=QdtE/wmAhW05sZUPuma2RrTvSoHqzbaenBHjoIn5xqU=; b=rCrAogkOnVXjp8msr4M19OGQyZSCg92ZcAw69ByMkmBQsO3R3Vft27J97cPQxDE5g4 CFc9ZYdeqDoI8/BN/JCFALPsBlnz+CNRtvh3b0xsTXpQTMZ0qAN8IgW4tlvhtkvJGQk3 ZNdyxSg+OM92ii99+uA0qBsj/qFBXusyOXzpoOugdb+cXJ7SxIyDR4Bpy/SjDXDBnvF6 5KocBciBkIUp6b2zwBghD4FpR//7Gp++TDWIqAwj0Hk8R/gY9exMBX7skMnKvqRUymiw mdGO37ZbhxP8NP/nnH9x44pK1jCEjDkJI2ft0sATRlLj/ict2jCIjrvppTI8Mnj2tSn+ OT3A== X-Gm-Message-State: AOAM531btmldcL+39mrEBzp3GFlLs8ZjcNXKU6f+rwNOGeOpO2cli7qP biGJrcdHAXSUcxteEV4FnkQ= X-Google-Smtp-Source: ABdhPJyi6yW86kzcaPaqYYpunKHuCOiiVfZSxn2lpbvXi/TPHVoYjGbq+kwm9hoiPBLdv2wk8wJdxw== X-Received: by 2002:a63:3151:: with SMTP id x78mr10768674pgx.210.1595026558778; Fri, 17 Jul 2020 15:55:58 -0700 (PDT) Received: from ubuntu.lan ([2001:470:e92d:10:3505:f2d8:29e6:fd26]) by smtp.gmail.com with ESMTPSA id 204sm8536759pfx.3.2020.07.17.15.55.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jul 2020 15:55:58 -0700 (PDT) From: Tony Ambardar X-Google-Original-From: Tony Ambardar To: Alexei Starovoitov , Daniel Borkmann Cc: Tony Ambardar , netdev@vger.kernel.org, bpf@vger.kernel.org, Quentin Monnet Subject: [PATCH bpf-next v3] bpftool: use only nftw for file tree parsing Date: Fri, 17 Jul 2020 15:55:43 -0700 Message-Id: <20200717225543.32126-1-Tony.Ambardar@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200716052926.10933-1-Tony.Ambardar () gmail ! com> References: <20200716052926.10933-1-Tony.Ambardar () gmail ! com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The bpftool sources include code to walk file trees, but use multiple frameworks to do so: nftw and fts. While nftw conforms to POSIX/SUSv3 and is widely available, fts is not conformant and less common, especially on non-glibc systems. The inconsistent framework usage hampers maintenance and portability of bpftool, in particular for embedded systems. Standardize code usage by rewriting one fts-based function to use nftw and clean up some related function warnings by extending use of "const char *" arguments. This change helps in building bpftool against musl for OpenWrt. Also fix an unsafe call to dirname() by duplicating the string to pass, since some implementations may directly alter it. The same approach is used in libbpf.c. Signed-off-by: Tony Ambardar --- V3: * clarify dirname() path copy in commit message * fix whitespace and rearrange comment for clarity * drop unnecessary initializers, rebalance Christmas tree * fixup error message and drop others not previously present * simplify malloc() + memset() -> calloc() and check for mem errors V2: * use _GNU_SOURCE to pull in getpagesize(), getline(), nftw() definitions * use "const char *" in open_obj_pinned() and open_obj_pinned_any() * make dirname() safely act on a string copy --- tools/bpf/bpftool/common.c | 132 +++++++++++++++++++++---------------- tools/bpf/bpftool/main.h | 4 +- 2 files changed, 78 insertions(+), 58 deletions(-) diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 29f4e7611ae8..2ecfafcd01df 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -1,10 +1,11 @@ // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) /* Copyright (C) 2017-2018 Netronome Systems, Inc. */ +#define _GNU_SOURCE #include #include #include -#include +#include #include #include #include @@ -160,24 +161,35 @@ int mount_tracefs(const char *target) return err; } -int open_obj_pinned(char *path, bool quiet) +int open_obj_pinned(const char *path, bool quiet) { - int fd; + char *pname; + int fd = -1; - fd = bpf_obj_get(path); + pname = strdup(path); + if (!pname) { + if (!quiet) + p_err("mem alloc failed"); + goto out_ret; + } + + fd = bpf_obj_get(pname); if (fd < 0) { if (!quiet) - p_err("bpf obj get (%s): %s", path, - errno == EACCES && !is_bpffs(dirname(path)) ? + p_err("bpf obj get (%s): %s", pname, + errno == EACCES && !is_bpffs(dirname(pname)) ? "directory not in bpf file system (bpffs)" : strerror(errno)); - return -1; + goto out_free; } +out_free: + free(pname); +out_ret: return fd; } -int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type) +int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type) { enum bpf_obj_type type; int fd; @@ -367,68 +379,76 @@ void print_hex_data_json(uint8_t *data, size_t len) jsonw_end_array(json_wtr); } +/* extra params for nftw cb*/ +static struct pinned_obj_table *build_fn_table; +static enum bpf_obj_type build_fn_type; + +static int do_build_table_cb(const char *fpath, const struct stat *sb, + int typeflag, struct FTW *ftwbuf) +{ + struct bpf_prog_info pinned_info; + __u32 len = sizeof(pinned_info); + struct pinned_obj *obj_node; + enum bpf_obj_type objtype; + int fd, err = 0; + + if (typeflag != FTW_F) + goto out_ret; + fd = open_obj_pinned(fpath, true); + if (fd < 0) + goto out_ret; + + objtype = get_fd_type(fd); + if (objtype != build_fn_type) + goto out_close; + + memset(&pinned_info, 0, sizeof(pinned_info)); + if (bpf_obj_get_info_by_fd(fd, &pinned_info, &len)) + goto out_close; + + obj_node = calloc(1, sizeof(*obj_node)); + if (!obj_node) { + err = -1; + goto out_close; + } + + obj_node->id = pinned_info.id; + obj_node->path = strdup(fpath); + if (!obj_node->path) { + err = -1; + free(obj_node); + goto out_close; + } + hash_add(build_fn_table->table, &obj_node->hash, obj_node->id); + +out_close: + close(fd); +out_ret: + return err; +} + int build_pinned_obj_table(struct pinned_obj_table *tab, enum bpf_obj_type type) { - struct bpf_prog_info pinned_info = {}; - struct pinned_obj *obj_node = NULL; - __u32 len = sizeof(pinned_info); struct mntent *mntent = NULL; - enum bpf_obj_type objtype; FILE *mntfile = NULL; - FTSENT *ftse = NULL; - FTS *fts = NULL; - int fd, err; + int flags = FTW_PHYS; + int nopenfd = 16; mntfile = setmntent("/proc/mounts", "r"); if (!mntfile) return -1; + build_fn_table = tab; + build_fn_type = type; + while ((mntent = getmntent(mntfile))) { - char *path[] = { mntent->mnt_dir, NULL }; + char *path = mntent->mnt_dir; if (strncmp(mntent->mnt_type, "bpf", 3) != 0) continue; - - fts = fts_open(path, 0, NULL); - if (!fts) - continue; - - while ((ftse = fts_read(fts))) { - if (!(ftse->fts_info & FTS_F)) - continue; - fd = open_obj_pinned(ftse->fts_path, true); - if (fd < 0) - continue; - - objtype = get_fd_type(fd); - if (objtype != type) { - close(fd); - continue; - } - memset(&pinned_info, 0, sizeof(pinned_info)); - err = bpf_obj_get_info_by_fd(fd, &pinned_info, &len); - if (err) { - close(fd); - continue; - } - - obj_node = malloc(sizeof(*obj_node)); - if (!obj_node) { - close(fd); - fts_close(fts); - fclose(mntfile); - return -1; - } - - memset(obj_node, 0, sizeof(*obj_node)); - obj_node->id = pinned_info.id; - obj_node->path = strdup(ftse->fts_path); - hash_add(tab->table, &obj_node->hash, obj_node->id); - - close(fd); - } - fts_close(fts); + if (nftw(path, do_build_table_cb, nopenfd, flags) == -1) + break; } fclose(mntfile); return 0; diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 78d34e860713..e3a79b5a9960 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -152,8 +152,8 @@ int cmd_select(const struct cmd *cmds, int argc, char **argv, int get_fd_type(int fd); const char *get_fd_type_name(enum bpf_obj_type type); char *get_fdinfo(int fd, const char *key); -int open_obj_pinned(char *path, bool quiet); -int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type); +int open_obj_pinned(const char *path, bool quiet); +int open_obj_pinned_any(const char *path, enum bpf_obj_type exp_type); int mount_bpffs_for_pin(const char *name); int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(int *, char ***)); int do_pin_fd(int fd, const char *name);