diff options
Diffstat (limited to 'tools/bpf/bpftool/common.c')
-rw-r--r-- | tools/bpf/bpftool/common.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c new file mode 100644 index 000000000000..2bd3b280e6dd --- /dev/null +++ b/tools/bpf/bpftool/common.c @@ -0,0 +1,405 @@ +/* + * 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 <fts.h> +#include <libgen.h> +#include <mntent.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/mount.h> +#include <sys/types.h> +#include <sys/vfs.h> + +#include <bpf.h> + +#include "main.h" + +void p_err(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + if (json_output) { + jsonw_start_object(json_wtr); + jsonw_name(json_wtr, "error"); + jsonw_vprintf_enquote(json_wtr, fmt, ap); + jsonw_end_object(json_wtr); + } else { + fprintf(stderr, "Error: "); + vfprintf(stderr, fmt, ap); + fprintf(stderr, "\n"); + } + va_end(ap); +} + +void p_info(const char *fmt, ...) +{ + va_list ap; + + if (json_output) + return; + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + fprintf(stderr, "\n"); + va_end(ap); +} + +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; +} + +static int mnt_bpffs(const char *target, char *buff, size_t bufflen) +{ + bool bind_done = false; + + while (mount("", target, "none", MS_PRIVATE | MS_REC, NULL)) { + if (errno != EINVAL || bind_done) { + snprintf(buff, bufflen, + "mount --make-private %s failed: %s", + target, strerror(errno)); + return -1; + } + + if (mount(target, target, "none", MS_BIND, NULL)) { + snprintf(buff, bufflen, + "mount --bind %s %s failed: %s", + target, target, strerror(errno)); + return -1; + } + + bind_done = true; + } + + if (mount("bpf", target, "bpf", 0, "mode=0700")) { + snprintf(buff, bufflen, "mount -t bpf bpf %s failed: %s", + target, strerror(errno)); + return -1; + } + + return 0; +} + +int open_obj_pinned(char *path) +{ + int fd; + + fd = bpf_obj_get(path); + if (fd < 0) { + p_err("bpf obj get (%s): %s", path, + errno == EACCES && !is_bpffs(dirname(path)) ? + "directory not in bpf file system (bpffs)" : + strerror(errno)); + return -1; + } + + return fd; +} + +int open_obj_pinned_any(char *path, enum bpf_obj_type exp_type) +{ + enum bpf_obj_type type; + int fd; + + fd = open_obj_pinned(path); + if (fd < 0) + return -1; + + type = get_fd_type(fd); + if (type < 0) { + close(fd); + return type; + } + if (type != exp_type) { + p_err("incorrect object type: %s", 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)) +{ + char err_str[ERR_MAX_LEN]; + unsigned int id; + char *endptr; + char *file; + char *dir; + int err; + int fd; + + if (!is_prefix(*argv, "id")) { + p_err("expected 'id' got %s", *argv); + return -1; + } + NEXT_ARG(); + + id = strtoul(*argv, &endptr, 0); + if (*endptr) { + p_err("can't parse %s as ID", *argv); + return -1; + } + NEXT_ARG(); + + if (argc != 1) + usage(); + + fd = get_fd_by_id(id); + if (fd < 0) { + p_err("can't get prog by id (%u): %s", id, strerror(errno)); + return -1; + } + + err = bpf_obj_pin(fd, *argv); + if (!err) + goto out_close; + + file = malloc(strlen(*argv) + 1); + strcpy(file, *argv); + dir = dirname(file); + + if (errno != EPERM || is_bpffs(dir)) { + p_err("can't pin the object (%s): %s", *argv, strerror(errno)); + goto out_free; + } + + /* Attempt to mount bpffs, then retry pinning. */ + err = mnt_bpffs(dir, err_str, ERR_MAX_LEN); + if (!err) { + err = bpf_obj_pin(fd, *argv); + if (err) + p_err("can't pin the object (%s): %s", *argv, + strerror(errno)); + } else { + err_str[ERR_MAX_LEN - 1] = '\0'; + p_err("can't mount BPF file system to pin the object (%s): %s", + *argv, err_str); + } + +out_free: + free(file); +out_close: + close(fd); + return err; +} + +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) { + p_err("can't read link type: %s", strerror(errno)); + return -1; + } + if (n == sizeof(path)) { + p_err("can't read link type: path too long!"); + 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) { + p_err("can't open fdinfo: %s", 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]) { + p_err("malformed fdinfo!?"); + free(line); + return NULL; + } + value++; + + len = strlen(value); + memmove(line, value, len); + line[len - 1] = '\0'; + + return line; + } + + p_err("key '%s' not found in fdinfo", key); + free(line); + fclose(fdi); + return NULL; +} + +void print_hex_data_json(uint8_t *data, size_t len) +{ + unsigned int i; + + jsonw_start_array(json_wtr); + for (i = 0; i < len; i++) + jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]); + jsonw_end_array(json_wtr); +} + +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; + + mntfile = setmntent("/proc/mounts", "r"); + if (!mntfile) + return -1; + + while ((mntent = getmntent(mntfile))) { + char *path[] = { mntent->mnt_dir, NULL }; + + 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); + 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); + } + fclose(mntfile); + return 0; +} + +void delete_pinned_obj_table(struct pinned_obj_table *tab) +{ + struct pinned_obj *obj; + struct hlist_node *tmp; + unsigned int bkt; + + hash_for_each_safe(tab->table, bkt, tmp, obj, hash) { + hash_del(&obj->hash); + free(obj->path); + free(obj); + } +} |