diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 264 |
1 files changed, 236 insertions, 28 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 84e6b35da4bd..ac6eb863b2a4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4,6 +4,7 @@ * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> * Copyright (C) 2015 Huawei Inc. + * Copyright (C) 2017 Nicira, Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -22,15 +23,21 @@ #include <stdlib.h> #include <stdio.h> #include <stdarg.h> +#include <libgen.h> #include <inttypes.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <errno.h> #include <asm/unistd.h> +#include <linux/err.h> #include <linux/kernel.h> #include <linux/bpf.h> #include <linux/list.h> +#include <linux/limits.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/vfs.h> #include <libelf.h> #include <gelf.h> @@ -41,6 +48,10 @@ #define EM_BPF 247 #endif +#ifndef BPF_FS_MAGIC +#define BPF_FS_MAGIC 0xcafe4a11 +#endif + #define __printf(a, b) __attribute__((format(printf, a, b))) __printf(1, 2) @@ -779,7 +790,7 @@ static int bpf_program__collect_reloc(struct bpf_program *prog, size_t nr_maps, GElf_Shdr *shdr, Elf_Data *data, Elf_Data *symbols, - int maps_shndx) + int maps_shndx, struct bpf_map *maps) { int i, nrels; @@ -829,7 +840,15 @@ bpf_program__collect_reloc(struct bpf_program *prog, return -LIBBPF_ERRNO__RELOC; } - map_idx = sym.st_value / sizeof(struct bpf_map_def); + /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */ + for (map_idx = 0; map_idx < nr_maps; map_idx++) { + if (maps[map_idx].offset == sym.st_value) { + pr_debug("relocation: find map %zd (%s) for insn %u\n", + map_idx, maps[map_idx].name, insn_idx); + break; + } + } + if (map_idx >= nr_maps) { pr_warning("bpf relocation: map_idx %d large than %d\n", (int)map_idx, (int)nr_maps - 1); @@ -953,7 +972,8 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) err = bpf_program__collect_reloc(prog, nr_maps, shdr, data, obj->efile.symbols, - obj->efile.maps_shndx); + obj->efile.maps_shndx, + obj->maps); if (err) return err; } @@ -1227,6 +1247,191 @@ out: return err; } +static int check_path(const char *path) +{ + struct statfs st_fs; + char *dname, *dir; + int err = 0; + + if (path == NULL) + return -EINVAL; + + dname = strdup(path); + if (dname == NULL) + return -ENOMEM; + + dir = dirname(dname); + if (statfs(dir, &st_fs)) { + pr_warning("failed to statfs %s: %s\n", dir, strerror(errno)); + err = -errno; + } + free(dname); + + if (!err && st_fs.f_type != BPF_FS_MAGIC) { + pr_warning("specified path %s is not on BPF FS\n", path); + err = -EINVAL; + } + + return err; +} + +int bpf_program__pin_instance(struct bpf_program *prog, const char *path, + int instance) +{ + int err; + + err = check_path(path); + if (err) + return err; + + if (prog == NULL) { + pr_warning("invalid program pointer\n"); + return -EINVAL; + } + + if (instance < 0 || instance >= prog->instances.nr) { + pr_warning("invalid prog instance %d of prog %s (max %d)\n", + instance, prog->section_name, prog->instances.nr); + return -EINVAL; + } + + if (bpf_obj_pin(prog->instances.fds[instance], path)) { + pr_warning("failed to pin program: %s\n", strerror(errno)); + return -errno; + } + pr_debug("pinned program '%s'\n", path); + + return 0; +} + +static int make_dir(const char *path) +{ + int err = 0; + + if (mkdir(path, 0700) && errno != EEXIST) + err = -errno; + + if (err) + pr_warning("failed to mkdir %s: %s\n", path, strerror(-err)); + return err; +} + +int bpf_program__pin(struct bpf_program *prog, const char *path) +{ + int i, err; + + err = check_path(path); + if (err) + return err; + + if (prog == NULL) { + pr_warning("invalid program pointer\n"); + return -EINVAL; + } + + if (prog->instances.nr <= 0) { + pr_warning("no instances of prog %s to pin\n", + prog->section_name); + return -EINVAL; + } + + err = make_dir(path); + if (err) + return err; + + for (i = 0; i < prog->instances.nr; i++) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%d", path, i); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_program__pin_instance(prog, buf, i); + if (err) + return err; + } + + return 0; +} + +int bpf_map__pin(struct bpf_map *map, const char *path) +{ + int err; + + err = check_path(path); + if (err) + return err; + + if (map == NULL) { + pr_warning("invalid map pointer\n"); + return -EINVAL; + } + + if (bpf_obj_pin(map->fd, path)) { + pr_warning("failed to pin map: %s\n", strerror(errno)); + return -errno; + } + + pr_debug("pinned map '%s'\n", path); + return 0; +} + +int bpf_object__pin(struct bpf_object *obj, const char *path) +{ + struct bpf_program *prog; + struct bpf_map *map; + int err; + + if (!obj) + return -ENOENT; + + if (!obj->loaded) { + pr_warning("object not yet loaded; load it first\n"); + return -ENOENT; + } + + err = make_dir(path); + if (err) + return err; + + bpf_map__for_each(map, obj) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%s", path, + bpf_map__name(map)); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_map__pin(map, buf); + if (err) + return err; + } + + bpf_object__for_each_program(prog, obj) { + char buf[PATH_MAX]; + int len; + + len = snprintf(buf, PATH_MAX, "%s/%s", path, + prog->section_name); + if (len < 0) + return -EINVAL; + else if (len >= PATH_MAX) + return -ENAMETOOLONG; + + err = bpf_program__pin(prog, buf); + if (err) + return err; + } + + return 0; +} + void bpf_object__close(struct bpf_object *obj) { size_t i; @@ -1419,37 +1624,33 @@ static void bpf_program__set_type(struct bpf_program *prog, prog->type = type; } -int bpf_program__set_tracepoint(struct bpf_program *prog) -{ - if (!prog) - return -EINVAL; - bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT); - return 0; -} - -int bpf_program__set_kprobe(struct bpf_program *prog) -{ - if (!prog) - return -EINVAL; - bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE); - return 0; -} - static bool bpf_program__is_type(struct bpf_program *prog, enum bpf_prog_type type) { return prog ? (prog->type == type) : false; } -bool bpf_program__is_tracepoint(struct bpf_program *prog) -{ - return bpf_program__is_type(prog, BPF_PROG_TYPE_TRACEPOINT); -} - -bool bpf_program__is_kprobe(struct bpf_program *prog) -{ - return bpf_program__is_type(prog, BPF_PROG_TYPE_KPROBE); -} +#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ +int bpf_program__set_##NAME(struct bpf_program *prog) \ +{ \ + if (!prog) \ + return -EINVAL; \ + bpf_program__set_type(prog, TYPE); \ + return 0; \ +} \ + \ +bool bpf_program__is_##NAME(struct bpf_program *prog) \ +{ \ + return bpf_program__is_type(prog, TYPE); \ +} \ + +BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); +BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); +BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS); +BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT); +BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT); +BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP); +BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT); int bpf_map__fd(struct bpf_map *map) { @@ -1537,3 +1738,10 @@ bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) } return ERR_PTR(-ENOENT); } + +long libbpf_get_error(const void *ptr) +{ + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + return 0; +} |