diff options
author | Jakub Kicinski <jakub.kicinski@netronome.com> | 2017-10-05 06:10:04 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2017-10-05 07:45:06 +0300 |
commit | 71bb428fe2c19512ac671d5ee16ef3e73e1b49a8 (patch) | |
tree | 69a3005a095804dcdb3600b177d019fd2fba2c24 /tools/bpf/bpftool/common.c | |
parent | a92bb546cff0b31d96d5919ebfeda9c678756b42 (diff) | |
download | linux-71bb428fe2c19512ac671d5ee16ef3e73e1b49a8.tar.xz |
tools: bpf: add bpftool
Add a simple tool for querying and updating BPF objects on the system.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools/bpf/bpftool/common.c')
-rw-r--r-- | tools/bpf/bpftool/common.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c new file mode 100644 index 000000000000..df8396a0c400 --- /dev/null +++ b/tools/bpf/bpftool/common.c @@ -0,0 +1,216 @@ +/* + * Copyright (C) 2017 Netronome Systems, Inc. + * + * This software is dual licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree or the BSD 2-Clause License provided below. You have the + * option to license this software under the complete terms of either license. + * + * The BSD 2-Clause License: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/* Author: Jakub Kicinski <kubakici@wp.pl> */ + +#include <errno.h> +#include <libgen.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <linux/limits.h> +#include <linux/magic.h> +#include <sys/types.h> +#include <sys/vfs.h> + +#include <bpf.h> + +#include "main.h" + +static bool is_bpffs(char *path) +{ + struct statfs st_fs; + + if (statfs(path, &st_fs) < 0) + return false; + + return (unsigned long)st_fs.f_type == BPF_FS_MAGIC; +} + +int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type) +{ + enum bpf_obj_type type; + int fd; + + fd = bpf_obj_get(path); + if (fd < 0) { + err("bpf obj get (%s): %s\n", path, + errno == EACCES && !is_bpffs(dirname(path)) ? + "directory not in bpf file system (bpffs)" : + strerror(errno)); + return -1; + } + + type = get_fd_type(fd); + if (type < 0) { + close(fd); + return type; + } + if (type != exp_type) { + err("incorrect object type: %s\n", get_fd_type_name(type)); + close(fd); + return -1; + } + + return fd; +} + +int do_pin_any(int argc, char **argv, int (*get_fd_by_id)(__u32)) +{ + unsigned int id; + char *endptr; + int err; + int fd; + + if (!is_prefix(*argv, "id")) { + err("expected 'id' got %s\n", *argv); + return -1; + } + NEXT_ARG(); + + id = strtoul(*argv, &endptr, 0); + if (*endptr) { + err("can't parse %s as ID\n", *argv); + return -1; + } + NEXT_ARG(); + + if (argc != 1) + usage(); + + fd = get_fd_by_id(id); + if (fd < 0) { + err("can't get prog by id (%u): %s\n", id, strerror(errno)); + return -1; + } + + err = bpf_obj_pin(fd, *argv); + close(fd); + if (err) { + err("can't pin the object (%s): %s\n", *argv, + errno == EACCES && !is_bpffs(dirname(*argv)) ? + "directory not in bpf file system (bpffs)" : + strerror(errno)); + return -1; + } + + return 0; +} + +const char *get_fd_type_name(enum bpf_obj_type type) +{ + static const char * const names[] = { + [BPF_OBJ_UNKNOWN] = "unknown", + [BPF_OBJ_PROG] = "prog", + [BPF_OBJ_MAP] = "map", + }; + + if (type < 0 || type >= ARRAY_SIZE(names) || !names[type]) + return names[BPF_OBJ_UNKNOWN]; + + return names[type]; +} + +int get_fd_type(int fd) +{ + char path[PATH_MAX]; + char buf[512]; + ssize_t n; + + snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd); + + n = readlink(path, buf, sizeof(buf)); + if (n < 0) { + err("can't read link type: %s\n", strerror(errno)); + return -1; + } + if (n == sizeof(path)) { + err("can't read link type: path too long!\n"); + return -1; + } + + if (strstr(buf, "bpf-map")) + return BPF_OBJ_MAP; + else if (strstr(buf, "bpf-prog")) + return BPF_OBJ_PROG; + + return BPF_OBJ_UNKNOWN; +} + +char *get_fdinfo(int fd, const char *key) +{ + char path[PATH_MAX]; + char *line = NULL; + size_t line_n = 0; + ssize_t n; + FILE *fdi; + + snprintf(path, sizeof(path), "/proc/%d/fdinfo/%d", getpid(), fd); + + fdi = fopen(path, "r"); + if (!fdi) { + err("can't open fdinfo: %s\n", strerror(errno)); + return NULL; + } + + while ((n = getline(&line, &line_n, fdi))) { + char *value; + int len; + + if (!strstr(line, key)) + continue; + + fclose(fdi); + + value = strchr(line, '\t'); + if (!value || !value[1]) { + err("malformed fdinfo!?\n"); + free(line); + return NULL; + } + value++; + + len = strlen(value); + memmove(line, value, len); + line[len - 1] = '\0'; + + return line; + } + + err("key '%s' not found in fdinfo\n", key); + free(line); + fclose(fdi); + return NULL; +} |