diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 2431 |
1 files changed, 2431 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c new file mode 100644 index 000000000..249fa8d73 --- /dev/null +++ b/tools/lib/bpf/libbpf.c @@ -0,0 +1,2431 @@ +// SPDX-License-Identifier: LGPL-2.1 + +/* + * Common eBPF ELF object loading operations. + * + * 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 + * License as published by the Free Software Foundation; + * version 2.1 of the License (not later!) + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this program; if not, see <http://www.gnu.org/licenses> + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#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 <perf-sys.h> +#include <asm/unistd.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/bpf.h> +#include <linux/btf.h> +#include <linux/list.h> +#include <linux/limits.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/vfs.h> +#include <tools/libc_compat.h> +#include <libelf.h> +#include <gelf.h> + +#include "libbpf.h" +#include "bpf.h" +#include "btf.h" +#include "str_error.h" + +#ifndef EM_BPF +#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) +static int __base_pr(const char *format, ...) +{ + va_list args; + int err; + + va_start(args, format); + err = vfprintf(stderr, format, args); + va_end(args); + return err; +} + +static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr; +static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr; +static __printf(1, 2) libbpf_print_fn_t __pr_debug; + +#define __pr(func, fmt, ...) \ +do { \ + if ((func)) \ + (func)("libbpf: " fmt, ##__VA_ARGS__); \ +} while (0) + +#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__) +#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__) +#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__) + +void libbpf_set_print(libbpf_print_fn_t warn, + libbpf_print_fn_t info, + libbpf_print_fn_t debug) +{ + __pr_warning = warn; + __pr_info = info; + __pr_debug = debug; +} + +#define STRERR_BUFSIZE 128 + +#define CHECK_ERR(action, err, out) do { \ + err = action; \ + if (err) \ + goto out; \ +} while(0) + + +/* Copied from tools/perf/util/util.h */ +#ifndef zfree +# define zfree(ptr) ({ free(*ptr); *ptr = NULL; }) +#endif + +#ifndef zclose +# define zclose(fd) ({ \ + int ___err = 0; \ + if ((fd) >= 0) \ + ___err = close((fd)); \ + fd = -1; \ + ___err; }) +#endif + +#ifdef HAVE_LIBELF_MMAP_SUPPORT +# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP +#else +# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ +#endif + +/* + * bpf_prog should be a better name but it has been used in + * linux/filter.h. + */ +struct bpf_program { + /* Index in elf obj file, for relocation use. */ + int idx; + char *name; + int prog_ifindex; + char *section_name; + struct bpf_insn *insns; + size_t insns_cnt, main_prog_cnt; + enum bpf_prog_type type; + + struct reloc_desc { + enum { + RELO_LD64, + RELO_CALL, + } type; + int insn_idx; + union { + int map_idx; + int text_off; + }; + } *reloc_desc; + int nr_reloc; + + struct { + int nr; + int *fds; + } instances; + bpf_program_prep_t preprocessor; + + struct bpf_object *obj; + void *priv; + bpf_program_clear_priv_t clear_priv; + + enum bpf_attach_type expected_attach_type; +}; + +struct bpf_map { + int fd; + char *name; + size_t offset; + int map_ifindex; + struct bpf_map_def def; + __u32 btf_key_type_id; + __u32 btf_value_type_id; + void *priv; + bpf_map_clear_priv_t clear_priv; +}; + +static LIST_HEAD(bpf_objects_list); + +struct bpf_object { + char license[64]; + u32 kern_version; + + struct bpf_program *programs; + size_t nr_programs; + struct bpf_map *maps; + size_t nr_maps; + + bool loaded; + bool has_pseudo_calls; + + /* + * Information when doing elf related work. Only valid if fd + * is valid. + */ + struct { + int fd; + void *obj_buf; + size_t obj_buf_sz; + Elf *elf; + GElf_Ehdr ehdr; + Elf_Data *symbols; + size_t strtabidx; + struct { + GElf_Shdr shdr; + Elf_Data *data; + } *reloc; + int nr_reloc; + int maps_shndx; + int text_shndx; + } efile; + /* + * All loaded bpf_object is linked in a list, which is + * hidden to caller. bpf_objects__<func> handlers deal with + * all objects. + */ + struct list_head list; + + struct btf *btf; + + void *priv; + bpf_object_clear_priv_t clear_priv; + + char path[]; +}; +#define obj_elf_valid(o) ((o)->efile.elf) + +static void bpf_program__unload(struct bpf_program *prog) +{ + int i; + + if (!prog) + return; + + /* + * If the object is opened but the program was never loaded, + * it is possible that prog->instances.nr == -1. + */ + if (prog->instances.nr > 0) { + for (i = 0; i < prog->instances.nr; i++) + zclose(prog->instances.fds[i]); + } else if (prog->instances.nr != -1) { + pr_warning("Internal error: instances.nr is %d\n", + prog->instances.nr); + } + + prog->instances.nr = -1; + zfree(&prog->instances.fds); +} + +static void bpf_program__exit(struct bpf_program *prog) +{ + if (!prog) + return; + + if (prog->clear_priv) + prog->clear_priv(prog, prog->priv); + + prog->priv = NULL; + prog->clear_priv = NULL; + + bpf_program__unload(prog); + zfree(&prog->name); + zfree(&prog->section_name); + zfree(&prog->insns); + zfree(&prog->reloc_desc); + + prog->nr_reloc = 0; + prog->insns_cnt = 0; + prog->idx = -1; +} + +static int +bpf_program__init(void *data, size_t size, char *section_name, int idx, + struct bpf_program *prog) +{ + if (size < sizeof(struct bpf_insn)) { + pr_warning("corrupted section '%s'\n", section_name); + return -EINVAL; + } + + bzero(prog, sizeof(*prog)); + + prog->section_name = strdup(section_name); + if (!prog->section_name) { + pr_warning("failed to alloc name for prog under section(%d) %s\n", + idx, section_name); + goto errout; + } + + prog->insns = malloc(size); + if (!prog->insns) { + pr_warning("failed to alloc insns for prog under section %s\n", + section_name); + goto errout; + } + prog->insns_cnt = size / sizeof(struct bpf_insn); + memcpy(prog->insns, data, + prog->insns_cnt * sizeof(struct bpf_insn)); + prog->idx = idx; + prog->instances.fds = NULL; + prog->instances.nr = -1; + prog->type = BPF_PROG_TYPE_KPROBE; + + return 0; +errout: + bpf_program__exit(prog); + return -ENOMEM; +} + +static int +bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, + char *section_name, int idx) +{ + struct bpf_program prog, *progs; + int nr_progs, err; + + err = bpf_program__init(data, size, section_name, idx, &prog); + if (err) + return err; + + progs = obj->programs; + nr_progs = obj->nr_programs; + + progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0])); + if (!progs) { + /* + * In this case the original obj->programs + * is still valid, so don't need special treat for + * bpf_close_object(). + */ + pr_warning("failed to alloc a new program under section '%s'\n", + section_name); + bpf_program__exit(&prog); + return -ENOMEM; + } + + pr_debug("found program %s\n", prog.section_name); + obj->programs = progs; + obj->nr_programs = nr_progs + 1; + prog.obj = obj; + progs[nr_progs] = prog; + return 0; +} + +static int +bpf_object__init_prog_names(struct bpf_object *obj) +{ + Elf_Data *symbols = obj->efile.symbols; + struct bpf_program *prog; + size_t pi, si; + + for (pi = 0; pi < obj->nr_programs; pi++) { + const char *name = NULL; + + prog = &obj->programs[pi]; + + for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name; + si++) { + GElf_Sym sym; + + if (!gelf_getsym(symbols, si, &sym)) + continue; + if (sym.st_shndx != prog->idx) + continue; + if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL) + continue; + + name = elf_strptr(obj->efile.elf, + obj->efile.strtabidx, + sym.st_name); + if (!name) { + pr_warning("failed to get sym name string for prog %s\n", + prog->section_name); + return -LIBBPF_ERRNO__LIBELF; + } + } + + if (!name && prog->idx == obj->efile.text_shndx) + name = ".text"; + + if (!name) { + pr_warning("failed to find sym for prog %s\n", + prog->section_name); + return -EINVAL; + } + + prog->name = strdup(name); + if (!prog->name) { + pr_warning("failed to allocate memory for prog sym %s\n", + name); + return -ENOMEM; + } + } + + return 0; +} + +static struct bpf_object *bpf_object__new(const char *path, + void *obj_buf, + size_t obj_buf_sz) +{ + struct bpf_object *obj; + + obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1); + if (!obj) { + pr_warning("alloc memory failed for %s\n", path); + return ERR_PTR(-ENOMEM); + } + + strcpy(obj->path, path); + obj->efile.fd = -1; + + /* + * Caller of this function should also calls + * bpf_object__elf_finish() after data collection to return + * obj_buf to user. If not, we should duplicate the buffer to + * avoid user freeing them before elf finish. + */ + obj->efile.obj_buf = obj_buf; + obj->efile.obj_buf_sz = obj_buf_sz; + obj->efile.maps_shndx = -1; + + obj->loaded = false; + + INIT_LIST_HEAD(&obj->list); + list_add(&obj->list, &bpf_objects_list); + return obj; +} + +static void bpf_object__elf_finish(struct bpf_object *obj) +{ + if (!obj_elf_valid(obj)) + return; + + if (obj->efile.elf) { + elf_end(obj->efile.elf); + obj->efile.elf = NULL; + } + obj->efile.symbols = NULL; + + zfree(&obj->efile.reloc); + obj->efile.nr_reloc = 0; + zclose(obj->efile.fd); + obj->efile.obj_buf = NULL; + obj->efile.obj_buf_sz = 0; +} + +static int bpf_object__elf_init(struct bpf_object *obj) +{ + int err = 0; + GElf_Ehdr *ep; + + if (obj_elf_valid(obj)) { + pr_warning("elf init: internal error\n"); + return -LIBBPF_ERRNO__LIBELF; + } + + if (obj->efile.obj_buf_sz > 0) { + /* + * obj_buf should have been validated by + * bpf_object__open_buffer(). + */ + obj->efile.elf = elf_memory(obj->efile.obj_buf, + obj->efile.obj_buf_sz); + } else { + obj->efile.fd = open(obj->path, O_RDONLY); + if (obj->efile.fd < 0) { + char errmsg[STRERR_BUFSIZE]; + char *cp = str_error(errno, errmsg, sizeof(errmsg)); + + pr_warning("failed to open %s: %s\n", obj->path, cp); + return -errno; + } + + obj->efile.elf = elf_begin(obj->efile.fd, + LIBBPF_ELF_C_READ_MMAP, + NULL); + } + + if (!obj->efile.elf) { + pr_warning("failed to open %s as ELF file\n", + obj->path); + err = -LIBBPF_ERRNO__LIBELF; + goto errout; + } + + if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) { + pr_warning("failed to get EHDR from %s\n", + obj->path); + err = -LIBBPF_ERRNO__FORMAT; + goto errout; + } + ep = &obj->efile.ehdr; + + /* Old LLVM set e_machine to EM_NONE */ + if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) { + pr_warning("%s is not an eBPF object file\n", + obj->path); + err = -LIBBPF_ERRNO__FORMAT; + goto errout; + } + + return 0; +errout: + bpf_object__elf_finish(obj); + return err; +} + +static int +bpf_object__check_endianness(struct bpf_object *obj) +{ + static unsigned int const endian = 1; + + switch (obj->efile.ehdr.e_ident[EI_DATA]) { + case ELFDATA2LSB: + /* We are big endian, BPF obj is little endian. */ + if (*(unsigned char const *)&endian != 1) + goto mismatch; + break; + + case ELFDATA2MSB: + /* We are little endian, BPF obj is big endian. */ + if (*(unsigned char const *)&endian != 0) + goto mismatch; + break; + default: + return -LIBBPF_ERRNO__ENDIAN; + } + + return 0; + +mismatch: + pr_warning("Error: endianness mismatch.\n"); + return -LIBBPF_ERRNO__ENDIAN; +} + +static int +bpf_object__init_license(struct bpf_object *obj, + void *data, size_t size) +{ + memcpy(obj->license, data, + min(size, sizeof(obj->license) - 1)); + pr_debug("license of %s is %s\n", obj->path, obj->license); + return 0; +} + +static int +bpf_object__init_kversion(struct bpf_object *obj, + void *data, size_t size) +{ + u32 kver; + + if (size != sizeof(kver)) { + pr_warning("invalid kver section in %s\n", obj->path); + return -LIBBPF_ERRNO__FORMAT; + } + memcpy(&kver, data, sizeof(kver)); + obj->kern_version = kver; + pr_debug("kernel version of %s is %x\n", obj->path, + obj->kern_version); + return 0; +} + +static int compare_bpf_map(const void *_a, const void *_b) +{ + const struct bpf_map *a = _a; + const struct bpf_map *b = _b; + + return a->offset - b->offset; +} + +static int +bpf_object__init_maps(struct bpf_object *obj) +{ + int i, map_idx, map_def_sz, nr_maps = 0; + Elf_Scn *scn; + Elf_Data *data; + Elf_Data *symbols = obj->efile.symbols; + + if (obj->efile.maps_shndx < 0) + return -EINVAL; + if (!symbols) + return -EINVAL; + + scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d\n", + obj->efile.maps_shndx); + return -EINVAL; + } + + /* + * Count number of maps. Each map has a name. + * Array of maps is not supported: only the first element is + * considered. + * + * TODO: Detect array of map and report error. + */ + for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { + GElf_Sym sym; + + if (!gelf_getsym(symbols, i, &sym)) + continue; + if (sym.st_shndx != obj->efile.maps_shndx) + continue; + nr_maps++; + } + + /* Alloc obj->maps and fill nr_maps. */ + pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, + nr_maps, data->d_size); + + if (!nr_maps) + return 0; + + /* Assume equally sized map definitions */ + map_def_sz = data->d_size / nr_maps; + if (!data->d_size || (data->d_size % nr_maps) != 0) { + pr_warning("unable to determine map definition size " + "section %s, %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + return -EINVAL; + } + + obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); + if (!obj->maps) { + pr_warning("alloc maps for object failed\n"); + return -ENOMEM; + } + obj->nr_maps = nr_maps; + + /* + * fill all fd with -1 so won't close incorrect + * fd (fd=0 is stdin) when failure (zclose won't close + * negative fd)). + */ + for (i = 0; i < nr_maps; i++) + obj->maps[i].fd = -1; + + /* + * Fill obj->maps using data in "maps" section. + */ + for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { + GElf_Sym sym; + const char *map_name; + struct bpf_map_def *def; + + if (!gelf_getsym(symbols, i, &sym)) + continue; + if (sym.st_shndx != obj->efile.maps_shndx) + continue; + + map_name = elf_strptr(obj->efile.elf, + obj->efile.strtabidx, + sym.st_name); + obj->maps[map_idx].offset = sym.st_value; + if (sym.st_value + map_def_sz > data->d_size) { + pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", + obj->path, map_name); + return -EINVAL; + } + + obj->maps[map_idx].name = strdup(map_name); + if (!obj->maps[map_idx].name) { + pr_warning("failed to alloc map name\n"); + return -ENOMEM; + } + pr_debug("map %d is \"%s\"\n", map_idx, + obj->maps[map_idx].name); + def = (struct bpf_map_def *)(data->d_buf + sym.st_value); + /* + * If the definition of the map in the object file fits in + * bpf_map_def, copy it. Any extra fields in our version + * of bpf_map_def will default to zero as a result of the + * calloc above. + */ + if (map_def_sz <= sizeof(struct bpf_map_def)) { + memcpy(&obj->maps[map_idx].def, def, map_def_sz); + } else { + /* + * Here the map structure being read is bigger than what + * we expect, truncate if the excess bits are all zero. + * If they are not zero, reject this map as + * incompatible. + */ + char *b; + for (b = ((char *)def) + sizeof(struct bpf_map_def); + b < ((char *)def) + map_def_sz; b++) { + if (*b != 0) { + pr_warning("maps section in %s: \"%s\" " + "has unrecognized, non-zero " + "options\n", + obj->path, map_name); + return -EINVAL; + } + } + memcpy(&obj->maps[map_idx].def, def, + sizeof(struct bpf_map_def)); + } + map_idx++; + } + + qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); + return 0; +} + +static bool section_have_execinstr(struct bpf_object *obj, int idx) +{ + Elf_Scn *scn; + GElf_Shdr sh; + + scn = elf_getscn(obj->efile.elf, idx); + if (!scn) + return false; + + if (gelf_getshdr(scn, &sh) != &sh) + return false; + + if (sh.sh_flags & SHF_EXECINSTR) + return true; + + return false; +} + +static int bpf_object__elf_collect(struct bpf_object *obj) +{ + Elf *elf = obj->efile.elf; + GElf_Ehdr *ep = &obj->efile.ehdr; + Elf_Scn *scn = NULL; + int idx = 0, err = 0; + + /* Elf is corrupted/truncated, avoid calling elf_strptr. */ + if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { + pr_warning("failed to get e_shstrndx from %s\n", + obj->path); + return -LIBBPF_ERRNO__FORMAT; + } + + while ((scn = elf_nextscn(elf, scn)) != NULL) { + char *name; + GElf_Shdr sh; + Elf_Data *data; + + idx++; + if (gelf_getshdr(scn, &sh) != &sh) { + pr_warning("failed to get section(%d) header from %s\n", + idx, obj->path); + err = -LIBBPF_ERRNO__FORMAT; + goto out; + } + + name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); + if (!name) { + pr_warning("failed to get section(%d) name from %s\n", + idx, obj->path); + err = -LIBBPF_ERRNO__FORMAT; + goto out; + } + + data = elf_getdata(scn, 0); + if (!data) { + pr_warning("failed to get section(%d) data from %s(%s)\n", + idx, name, obj->path); + err = -LIBBPF_ERRNO__FORMAT; + goto out; + } + pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", + idx, name, (unsigned long)data->d_size, + (int)sh.sh_link, (unsigned long)sh.sh_flags, + (int)sh.sh_type); + + if (strcmp(name, "license") == 0) + err = bpf_object__init_license(obj, + data->d_buf, + data->d_size); + else if (strcmp(name, "version") == 0) + err = bpf_object__init_kversion(obj, + data->d_buf, + data->d_size); + else if (strcmp(name, "maps") == 0) + obj->efile.maps_shndx = idx; + else if (strcmp(name, BTF_ELF_SEC) == 0) { + obj->btf = btf__new(data->d_buf, data->d_size, + __pr_debug); + if (IS_ERR(obj->btf)) { + pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", + BTF_ELF_SEC, PTR_ERR(obj->btf)); + obj->btf = NULL; + } + } else if (sh.sh_type == SHT_SYMTAB) { + if (obj->efile.symbols) { + pr_warning("bpf: multiple SYMTAB in %s\n", + obj->path); + err = -LIBBPF_ERRNO__FORMAT; + } else { + obj->efile.symbols = data; + obj->efile.strtabidx = sh.sh_link; + } + } else if ((sh.sh_type == SHT_PROGBITS) && + (sh.sh_flags & SHF_EXECINSTR) && + (data->d_size > 0)) { + if (strcmp(name, ".text") == 0) + obj->efile.text_shndx = idx; + err = bpf_object__add_program(obj, data->d_buf, + data->d_size, name, idx); + if (err) { + char errmsg[STRERR_BUFSIZE]; + char *cp = str_error(-err, errmsg, sizeof(errmsg)); + + pr_warning("failed to alloc program %s (%s): %s", + name, obj->path, cp); + } + } else if (sh.sh_type == SHT_REL) { + void *reloc = obj->efile.reloc; + int nr_reloc = obj->efile.nr_reloc + 1; + int sec = sh.sh_info; /* points to other section */ + + /* Only do relo for section with exec instructions */ + if (!section_have_execinstr(obj, sec)) { + pr_debug("skip relo %s(%d) for section(%d)\n", + name, idx, sec); + continue; + } + + reloc = reallocarray(reloc, nr_reloc, + sizeof(*obj->efile.reloc)); + if (!reloc) { + pr_warning("realloc failed\n"); + err = -ENOMEM; + } else { + int n = nr_reloc - 1; + + obj->efile.reloc = reloc; + obj->efile.nr_reloc = nr_reloc; + + obj->efile.reloc[n].shdr = sh; + obj->efile.reloc[n].data = data; + } + } else { + pr_debug("skip section(%d) %s\n", idx, name); + } + if (err) + goto out; + } + + if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { + pr_warning("Corrupted ELF file: index of strtab invalid\n"); + return LIBBPF_ERRNO__FORMAT; + } + if (obj->efile.maps_shndx >= 0) { + err = bpf_object__init_maps(obj); + if (err) + goto out; + } + err = bpf_object__init_prog_names(obj); +out: + return err; +} + +static struct bpf_program * +bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) +{ + struct bpf_program *prog; + size_t i; + + for (i = 0; i < obj->nr_programs; i++) { + prog = &obj->programs[i]; + if (prog->idx == idx) + return prog; + } + return NULL; +} + +struct bpf_program * +bpf_object__find_program_by_title(struct bpf_object *obj, const char *title) +{ + struct bpf_program *pos; + + bpf_object__for_each_program(pos, obj) { + if (pos->section_name && !strcmp(pos->section_name, title)) + return pos; + } + return NULL; +} + +static int +bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, + Elf_Data *data, struct bpf_object *obj) +{ + Elf_Data *symbols = obj->efile.symbols; + int text_shndx = obj->efile.text_shndx; + int maps_shndx = obj->efile.maps_shndx; + struct bpf_map *maps = obj->maps; + size_t nr_maps = obj->nr_maps; + int i, nrels; + + pr_debug("collecting relocating info for: '%s'\n", + prog->section_name); + nrels = shdr->sh_size / shdr->sh_entsize; + + prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels); + if (!prog->reloc_desc) { + pr_warning("failed to alloc memory in relocation\n"); + return -ENOMEM; + } + prog->nr_reloc = nrels; + + for (i = 0; i < nrels; i++) { + GElf_Sym sym; + GElf_Rel rel; + unsigned int insn_idx; + struct bpf_insn *insns = prog->insns; + size_t map_idx; + + if (!gelf_getrel(data, i, &rel)) { + pr_warning("relocation: failed to get %d reloc\n", i); + return -LIBBPF_ERRNO__FORMAT; + } + + if (!gelf_getsym(symbols, + GELF_R_SYM(rel.r_info), + &sym)) { + pr_warning("relocation: symbol %"PRIx64" not found\n", + GELF_R_SYM(rel.r_info)); + return -LIBBPF_ERRNO__FORMAT; + } + pr_debug("relo for %lld value %lld name %d\n", + (long long) (rel.r_info >> 32), + (long long) sym.st_value, sym.st_name); + + if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) { + pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", + prog->section_name, sym.st_shndx); + return -LIBBPF_ERRNO__RELOC; + } + + insn_idx = rel.r_offset / sizeof(struct bpf_insn); + pr_debug("relocation: insn_idx=%u\n", insn_idx); + + if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) { + if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) { + pr_warning("incorrect bpf_call opcode\n"); + return -LIBBPF_ERRNO__RELOC; + } + prog->reloc_desc[i].type = RELO_CALL; + prog->reloc_desc[i].insn_idx = insn_idx; + prog->reloc_desc[i].text_off = sym.st_value; + obj->has_pseudo_calls = true; + continue; + } + + if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) { + pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n", + insn_idx, insns[insn_idx].code); + return -LIBBPF_ERRNO__RELOC; + } + + /* 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); + return -LIBBPF_ERRNO__RELOC; + } + + prog->reloc_desc[i].type = RELO_LD64; + prog->reloc_desc[i].insn_idx = insn_idx; + prog->reloc_desc[i].map_idx = map_idx; + } + return 0; +} + +static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) +{ + const struct btf_type *container_type; + const struct btf_member *key, *value; + struct bpf_map_def *def = &map->def; + const size_t max_name = 256; + char container_name[max_name]; + __s64 key_size, value_size; + __s32 container_id; + + if (snprintf(container_name, max_name, "____btf_map_%s", map->name) == + max_name) { + pr_warning("map:%s length of '____btf_map_%s' is too long\n", + map->name, map->name); + return -EINVAL; + } + + container_id = btf__find_by_name(btf, container_name); + if (container_id < 0) { + pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n", + map->name, container_name); + return container_id; + } + + container_type = btf__type_by_id(btf, container_id); + if (!container_type) { + pr_warning("map:%s cannot find BTF type for container_id:%u\n", + map->name, container_id); + return -EINVAL; + } + + if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT || + BTF_INFO_VLEN(container_type->info) < 2) { + pr_warning("map:%s container_name:%s is an invalid container struct\n", + map->name, container_name); + return -EINVAL; + } + + key = (struct btf_member *)(container_type + 1); + value = key + 1; + + key_size = btf__resolve_size(btf, key->type); + if (key_size < 0) { + pr_warning("map:%s invalid BTF key_type_size\n", + map->name); + return key_size; + } + + if (def->key_size != key_size) { + pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n", + map->name, (__u32)key_size, def->key_size); + return -EINVAL; + } + + value_size = btf__resolve_size(btf, value->type); + if (value_size < 0) { + pr_warning("map:%s invalid BTF value_type_size\n", map->name); + return value_size; + } + + if (def->value_size != value_size) { + pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n", + map->name, (__u32)value_size, def->value_size); + return -EINVAL; + } + + map->btf_key_type_id = key->type; + map->btf_value_type_id = value->type; + + return 0; +} + +int bpf_map__reuse_fd(struct bpf_map *map, int fd) +{ + struct bpf_map_info info = {}; + __u32 len = sizeof(info); + int new_fd, err; + char *new_name; + + err = bpf_obj_get_info_by_fd(fd, &info, &len); + if (err) + return err; + + new_name = strdup(info.name); + if (!new_name) + return -errno; + + new_fd = open("/", O_RDONLY | O_CLOEXEC); + if (new_fd < 0) { + err = -errno; + goto err_free_new_name; + } + + new_fd = dup3(fd, new_fd, O_CLOEXEC); + if (new_fd < 0) { + err = -errno; + goto err_close_new_fd; + } + + err = zclose(map->fd); + if (err) { + err = -errno; + goto err_close_new_fd; + } + free(map->name); + + map->fd = new_fd; + map->name = new_name; + map->def.type = info.type; + map->def.key_size = info.key_size; + map->def.value_size = info.value_size; + map->def.max_entries = info.max_entries; + map->def.map_flags = info.map_flags; + map->btf_key_type_id = info.btf_key_type_id; + map->btf_value_type_id = info.btf_value_type_id; + + return 0; + +err_close_new_fd: + close(new_fd); +err_free_new_name: + free(new_name); + return err; +} + +static int +bpf_object__create_maps(struct bpf_object *obj) +{ + struct bpf_create_map_attr create_attr = {}; + unsigned int i; + int err; + + for (i = 0; i < obj->nr_maps; i++) { + struct bpf_map *map = &obj->maps[i]; + struct bpf_map_def *def = &map->def; + char *cp, errmsg[STRERR_BUFSIZE]; + int *pfd = &map->fd; + + if (map->fd >= 0) { + pr_debug("skip map create (preset) %s: fd=%d\n", + map->name, map->fd); + continue; + } + + create_attr.name = map->name; + create_attr.map_ifindex = map->map_ifindex; + create_attr.map_type = def->type; + create_attr.map_flags = def->map_flags; + create_attr.key_size = def->key_size; + create_attr.value_size = def->value_size; + create_attr.max_entries = def->max_entries; + create_attr.btf_fd = 0; + create_attr.btf_key_type_id = 0; + create_attr.btf_value_type_id = 0; + + if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) { + create_attr.btf_fd = btf__fd(obj->btf); + create_attr.btf_key_type_id = map->btf_key_type_id; + create_attr.btf_value_type_id = map->btf_value_type_id; + } + + *pfd = bpf_create_map_xattr(&create_attr); + if (*pfd < 0 && create_attr.btf_key_type_id) { + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", + map->name, cp, errno); + create_attr.btf_fd = 0; + create_attr.btf_key_type_id = 0; + create_attr.btf_value_type_id = 0; + map->btf_key_type_id = 0; + map->btf_value_type_id = 0; + *pfd = bpf_create_map_xattr(&create_attr); + } + + if (*pfd < 0) { + size_t j; + + err = *pfd; + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("failed to create map (name: '%s'): %s\n", + map->name, cp); + for (j = 0; j < i; j++) + zclose(obj->maps[j].fd); + return err; + } + pr_debug("create map %s: fd=%d\n", map->name, *pfd); + } + + return 0; +} + +static int +bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, + struct reloc_desc *relo) +{ + struct bpf_insn *insn, *new_insn; + struct bpf_program *text; + size_t new_cnt; + + if (relo->type != RELO_CALL) + return -LIBBPF_ERRNO__RELOC; + + if (prog->idx == obj->efile.text_shndx) { + pr_warning("relo in .text insn %d into off %d\n", + relo->insn_idx, relo->text_off); + return -LIBBPF_ERRNO__RELOC; + } + + if (prog->main_prog_cnt == 0) { + text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx); + if (!text) { + pr_warning("no .text section found yet relo into text exist\n"); + return -LIBBPF_ERRNO__RELOC; + } + new_cnt = prog->insns_cnt + text->insns_cnt; + new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn)); + if (!new_insn) { + pr_warning("oom in prog realloc\n"); + return -ENOMEM; + } + memcpy(new_insn + prog->insns_cnt, text->insns, + text->insns_cnt * sizeof(*insn)); + prog->insns = new_insn; + prog->main_prog_cnt = prog->insns_cnt; + prog->insns_cnt = new_cnt; + pr_debug("added %zd insn from %s to prog %s\n", + text->insns_cnt, text->section_name, + prog->section_name); + } + insn = &prog->insns[relo->insn_idx]; + insn->imm += prog->main_prog_cnt - relo->insn_idx; + return 0; +} + +static int +bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) +{ + int i, err; + + if (!prog || !prog->reloc_desc) + return 0; + + for (i = 0; i < prog->nr_reloc; i++) { + if (prog->reloc_desc[i].type == RELO_LD64) { + struct bpf_insn *insns = prog->insns; + int insn_idx, map_idx; + + insn_idx = prog->reloc_desc[i].insn_idx; + map_idx = prog->reloc_desc[i].map_idx; + + if (insn_idx >= (int)prog->insns_cnt) { + pr_warning("relocation out of range: '%s'\n", + prog->section_name); + return -LIBBPF_ERRNO__RELOC; + } + insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD; + insns[insn_idx].imm = obj->maps[map_idx].fd; + } else { + err = bpf_program__reloc_text(prog, obj, + &prog->reloc_desc[i]); + if (err) + return err; + } + } + + zfree(&prog->reloc_desc); + prog->nr_reloc = 0; + return 0; +} + + +static int +bpf_object__relocate(struct bpf_object *obj) +{ + struct bpf_program *prog; + size_t i; + int err; + + for (i = 0; i < obj->nr_programs; i++) { + prog = &obj->programs[i]; + + err = bpf_program__relocate(prog, obj); + if (err) { + pr_warning("failed to relocate '%s'\n", + prog->section_name); + return err; + } + } + return 0; +} + +static int bpf_object__collect_reloc(struct bpf_object *obj) +{ + int i, err; + + if (!obj_elf_valid(obj)) { + pr_warning("Internal error: elf object is closed\n"); + return -LIBBPF_ERRNO__INTERNAL; + } + + for (i = 0; i < obj->efile.nr_reloc; i++) { + GElf_Shdr *shdr = &obj->efile.reloc[i].shdr; + Elf_Data *data = obj->efile.reloc[i].data; + int idx = shdr->sh_info; + struct bpf_program *prog; + + if (shdr->sh_type != SHT_REL) { + pr_warning("internal error at %d\n", __LINE__); + return -LIBBPF_ERRNO__INTERNAL; + } + + prog = bpf_object__find_prog_by_idx(obj, idx); + if (!prog) { + pr_warning("relocation failed: no section(%d)\n", idx); + return -LIBBPF_ERRNO__RELOC; + } + + err = bpf_program__collect_reloc(prog, + shdr, data, + obj); + if (err) + return err; + } + return 0; +} + +static int +load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, + const char *name, struct bpf_insn *insns, int insns_cnt, + char *license, u32 kern_version, int *pfd, int prog_ifindex) +{ + struct bpf_load_program_attr load_attr; + char *cp, errmsg[STRERR_BUFSIZE]; + char *log_buf; + int ret; + + memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); + load_attr.prog_type = type; + load_attr.expected_attach_type = expected_attach_type; + load_attr.name = name; + load_attr.insns = insns; + load_attr.insns_cnt = insns_cnt; + load_attr.license = license; + load_attr.kern_version = kern_version; + load_attr.prog_ifindex = prog_ifindex; + + if (!load_attr.insns || !load_attr.insns_cnt) + return -EINVAL; + + log_buf = malloc(BPF_LOG_BUF_SIZE); + if (!log_buf) + pr_warning("Alloc log buffer for bpf loader error, continue without log\n"); + + ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE); + + if (ret >= 0) { + *pfd = ret; + ret = 0; + goto out; + } + + ret = -LIBBPF_ERRNO__LOAD; + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("load bpf program failed: %s\n", cp); + + if (log_buf && log_buf[0] != '\0') { + ret = -LIBBPF_ERRNO__VERIFY; + pr_warning("-- BEGIN DUMP LOG ---\n"); + pr_warning("\n%s\n", log_buf); + pr_warning("-- END LOG --\n"); + } else if (load_attr.insns_cnt >= BPF_MAXINSNS) { + pr_warning("Program too large (%zu insns), at most %d insns\n", + load_attr.insns_cnt, BPF_MAXINSNS); + ret = -LIBBPF_ERRNO__PROG2BIG; + } else { + /* Wrong program type? */ + if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) { + int fd; + + load_attr.prog_type = BPF_PROG_TYPE_KPROBE; + load_attr.expected_attach_type = 0; + fd = bpf_load_program_xattr(&load_attr, NULL, 0); + if (fd >= 0) { + close(fd); + ret = -LIBBPF_ERRNO__PROGTYPE; + goto out; + } + } + + if (log_buf) + ret = -LIBBPF_ERRNO__KVER; + } + +out: + free(log_buf); + return ret; +} + +static int +bpf_program__load(struct bpf_program *prog, + char *license, u32 kern_version) +{ + int err = 0, fd, i; + + if (prog->instances.nr < 0 || !prog->instances.fds) { + if (prog->preprocessor) { + pr_warning("Internal error: can't load program '%s'\n", + prog->section_name); + return -LIBBPF_ERRNO__INTERNAL; + } + + prog->instances.fds = malloc(sizeof(int)); + if (!prog->instances.fds) { + pr_warning("Not enough memory for BPF fds\n"); + return -ENOMEM; + } + prog->instances.nr = 1; + prog->instances.fds[0] = -1; + } + + if (!prog->preprocessor) { + if (prog->instances.nr != 1) { + pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n", + prog->section_name, prog->instances.nr); + } + err = load_program(prog->type, prog->expected_attach_type, + prog->name, prog->insns, prog->insns_cnt, + license, kern_version, &fd, + prog->prog_ifindex); + if (!err) + prog->instances.fds[0] = fd; + goto out; + } + + for (i = 0; i < prog->instances.nr; i++) { + struct bpf_prog_prep_result result; + bpf_program_prep_t preprocessor = prog->preprocessor; + + bzero(&result, sizeof(result)); + err = preprocessor(prog, i, prog->insns, + prog->insns_cnt, &result); + if (err) { + pr_warning("Preprocessing the %dth instance of program '%s' failed\n", + i, prog->section_name); + goto out; + } + + if (!result.new_insn_ptr || !result.new_insn_cnt) { + pr_debug("Skip loading the %dth instance of program '%s'\n", + i, prog->section_name); + prog->instances.fds[i] = -1; + if (result.pfd) + *result.pfd = -1; + continue; + } + + err = load_program(prog->type, prog->expected_attach_type, + prog->name, result.new_insn_ptr, + result.new_insn_cnt, + license, kern_version, &fd, + prog->prog_ifindex); + + if (err) { + pr_warning("Loading the %dth instance of program '%s' failed\n", + i, prog->section_name); + goto out; + } + + if (result.pfd) + *result.pfd = fd; + prog->instances.fds[i] = fd; + } +out: + if (err) + pr_warning("failed to load program '%s'\n", + prog->section_name); + zfree(&prog->insns); + prog->insns_cnt = 0; + return err; +} + +static bool bpf_program__is_function_storage(struct bpf_program *prog, + struct bpf_object *obj) +{ + return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls; +} + +static int +bpf_object__load_progs(struct bpf_object *obj) +{ + size_t i; + int err; + + for (i = 0; i < obj->nr_programs; i++) { + if (bpf_program__is_function_storage(&obj->programs[i], obj)) + continue; + err = bpf_program__load(&obj->programs[i], + obj->license, + obj->kern_version); + if (err) + return err; + } + return 0; +} + +static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) +{ + switch (type) { + case BPF_PROG_TYPE_SOCKET_FILTER: + case BPF_PROG_TYPE_SCHED_CLS: + case BPF_PROG_TYPE_SCHED_ACT: + case BPF_PROG_TYPE_XDP: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_LWT_SEG6LOCAL: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + case BPF_PROG_TYPE_LIRC_MODE2: + case BPF_PROG_TYPE_SK_REUSEPORT: + return false; + case BPF_PROG_TYPE_UNSPEC: + case BPF_PROG_TYPE_KPROBE: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_RAW_TRACEPOINT: + default: + return true; + } +} + +static int bpf_object__validate(struct bpf_object *obj, bool needs_kver) +{ + if (needs_kver && obj->kern_version == 0) { + pr_warning("%s doesn't provide kernel version\n", + obj->path); + return -LIBBPF_ERRNO__KVERSION; + } + return 0; +} + +static struct bpf_object * +__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, + bool needs_kver) +{ + struct bpf_object *obj; + int err; + + if (elf_version(EV_CURRENT) == EV_NONE) { + pr_warning("failed to init libelf for %s\n", path); + return ERR_PTR(-LIBBPF_ERRNO__LIBELF); + } + + obj = bpf_object__new(path, obj_buf, obj_buf_sz); + if (IS_ERR(obj)) + return obj; + + CHECK_ERR(bpf_object__elf_init(obj), err, out); + CHECK_ERR(bpf_object__check_endianness(obj), err, out); + CHECK_ERR(bpf_object__elf_collect(obj), err, out); + CHECK_ERR(bpf_object__collect_reloc(obj), err, out); + CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out); + + bpf_object__elf_finish(obj); + return obj; +out: + bpf_object__close(obj); + return ERR_PTR(err); +} + +struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) +{ + /* param validation */ + if (!attr->file) + return NULL; + + pr_debug("loading %s\n", attr->file); + + return __bpf_object__open(attr->file, NULL, 0, + bpf_prog_type__needs_kver(attr->prog_type)); +} + +struct bpf_object *bpf_object__open(const char *path) +{ + struct bpf_object_open_attr attr = { + .file = path, + .prog_type = BPF_PROG_TYPE_UNSPEC, + }; + + return bpf_object__open_xattr(&attr); +} + +struct bpf_object *bpf_object__open_buffer(void *obj_buf, + size_t obj_buf_sz, + const char *name) +{ + char tmp_name[64]; + + /* param validation */ + if (!obj_buf || obj_buf_sz <= 0) + return NULL; + + if (!name) { + snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx", + (unsigned long)obj_buf, + (unsigned long)obj_buf_sz); + tmp_name[sizeof(tmp_name) - 1] = '\0'; + name = tmp_name; + } + pr_debug("loading object '%s' from buffer\n", + name); + + return __bpf_object__open(name, obj_buf, obj_buf_sz, true); +} + +int bpf_object__unload(struct bpf_object *obj) +{ + size_t i; + + if (!obj) + return -EINVAL; + + for (i = 0; i < obj->nr_maps; i++) + zclose(obj->maps[i].fd); + + for (i = 0; i < obj->nr_programs; i++) + bpf_program__unload(&obj->programs[i]); + + return 0; +} + +int bpf_object__load(struct bpf_object *obj) +{ + int err; + + if (!obj) + return -EINVAL; + + if (obj->loaded) { + pr_warning("object should not be loaded twice\n"); + return -EINVAL; + } + + obj->loaded = true; + + CHECK_ERR(bpf_object__create_maps(obj), err, out); + CHECK_ERR(bpf_object__relocate(obj), err, out); + CHECK_ERR(bpf_object__load_progs(obj), err, out); + + return 0; +out: + bpf_object__unload(obj); + pr_warning("failed to load object '%s'\n", obj->path); + return err; +} + +static int check_path(const char *path) +{ + char *cp, errmsg[STRERR_BUFSIZE]; + 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)) { + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("failed to statfs %s: %s\n", dir, cp); + 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) +{ + char *cp, errmsg[STRERR_BUFSIZE]; + 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)) { + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("failed to pin program: %s\n", cp); + return -errno; + } + pr_debug("pinned program '%s'\n", path); + + return 0; +} + +static int make_dir(const char *path) +{ + char *cp, errmsg[STRERR_BUFSIZE]; + int err = 0; + + if (mkdir(path, 0700) && errno != EEXIST) + err = -errno; + + if (err) { + cp = str_error(-err, errmsg, sizeof(errmsg)); + pr_warning("failed to mkdir %s: %s\n", path, cp); + } + 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) +{ + char *cp, errmsg[STRERR_BUFSIZE]; + 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)) { + cp = str_error(errno, errmsg, sizeof(errmsg)); + pr_warning("failed to pin map: %s\n", cp); + 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; + + if (!obj) + return; + + if (obj->clear_priv) + obj->clear_priv(obj, obj->priv); + + bpf_object__elf_finish(obj); + bpf_object__unload(obj); + btf__free(obj->btf); + + for (i = 0; i < obj->nr_maps; i++) { + zfree(&obj->maps[i].name); + if (obj->maps[i].clear_priv) + obj->maps[i].clear_priv(&obj->maps[i], + obj->maps[i].priv); + obj->maps[i].priv = NULL; + obj->maps[i].clear_priv = NULL; + } + zfree(&obj->maps); + obj->nr_maps = 0; + + if (obj->programs && obj->nr_programs) { + for (i = 0; i < obj->nr_programs; i++) + bpf_program__exit(&obj->programs[i]); + } + zfree(&obj->programs); + + list_del(&obj->list); + free(obj); +} + +struct bpf_object * +bpf_object__next(struct bpf_object *prev) +{ + struct bpf_object *next; + + if (!prev) + next = list_first_entry(&bpf_objects_list, + struct bpf_object, + list); + else + next = list_next_entry(prev, list); + + /* Empty list is noticed here so don't need checking on entry. */ + if (&next->list == &bpf_objects_list) + return NULL; + + return next; +} + +const char *bpf_object__name(struct bpf_object *obj) +{ + return obj ? obj->path : ERR_PTR(-EINVAL); +} + +unsigned int bpf_object__kversion(struct bpf_object *obj) +{ + return obj ? obj->kern_version : 0; +} + +int bpf_object__btf_fd(const struct bpf_object *obj) +{ + return obj->btf ? btf__fd(obj->btf) : -1; +} + +int bpf_object__set_priv(struct bpf_object *obj, void *priv, + bpf_object_clear_priv_t clear_priv) +{ + if (obj->priv && obj->clear_priv) + obj->clear_priv(obj, obj->priv); + + obj->priv = priv; + obj->clear_priv = clear_priv; + return 0; +} + +void *bpf_object__priv(struct bpf_object *obj) +{ + return obj ? obj->priv : ERR_PTR(-EINVAL); +} + +static struct bpf_program * +__bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) +{ + size_t idx; + + if (!obj->programs) + return NULL; + /* First handler */ + if (prev == NULL) + return &obj->programs[0]; + + if (prev->obj != obj) { + pr_warning("error: program handler doesn't match object\n"); + return NULL; + } + + idx = (prev - obj->programs) + 1; + if (idx >= obj->nr_programs) + return NULL; + return &obj->programs[idx]; +} + +struct bpf_program * +bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) +{ + struct bpf_program *prog = prev; + + do { + prog = __bpf_program__next(prog, obj); + } while (prog && bpf_program__is_function_storage(prog, obj)); + + return prog; +} + +int bpf_program__set_priv(struct bpf_program *prog, void *priv, + bpf_program_clear_priv_t clear_priv) +{ + if (prog->priv && prog->clear_priv) + prog->clear_priv(prog, prog->priv); + + prog->priv = priv; + prog->clear_priv = clear_priv; + return 0; +} + +void *bpf_program__priv(struct bpf_program *prog) +{ + return prog ? prog->priv : ERR_PTR(-EINVAL); +} + +void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) +{ + prog->prog_ifindex = ifindex; +} + +const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) +{ + const char *title; + + title = prog->section_name; + if (needs_copy) { + title = strdup(title); + if (!title) { + pr_warning("failed to strdup program title\n"); + return ERR_PTR(-ENOMEM); + } + } + + return title; +} + +int bpf_program__fd(struct bpf_program *prog) +{ + return bpf_program__nth_fd(prog, 0); +} + +int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, + bpf_program_prep_t prep) +{ + int *instances_fds; + + if (nr_instances <= 0 || !prep) + return -EINVAL; + + if (prog->instances.nr > 0 || prog->instances.fds) { + pr_warning("Can't set pre-processor after loading\n"); + return -EINVAL; + } + + instances_fds = malloc(sizeof(int) * nr_instances); + if (!instances_fds) { + pr_warning("alloc memory failed for fds\n"); + return -ENOMEM; + } + + /* fill all fd with -1 */ + memset(instances_fds, -1, sizeof(int) * nr_instances); + + prog->instances.nr = nr_instances; + prog->instances.fds = instances_fds; + prog->preprocessor = prep; + return 0; +} + +int bpf_program__nth_fd(struct bpf_program *prog, int n) +{ + int fd; + + if (!prog) + return -EINVAL; + + if (n >= prog->instances.nr || n < 0) { + pr_warning("Can't get the %dth fd from program %s: only %d instances\n", + n, prog->section_name, prog->instances.nr); + return -EINVAL; + } + + fd = prog->instances.fds[n]; + if (fd < 0) { + pr_warning("%dth instance of program '%s' is invalid\n", + n, prog->section_name); + return -ENOENT; + } + + return fd; +} + +void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) +{ + prog->type = type; +} + +static bool bpf_program__is_type(struct bpf_program *prog, + enum bpf_prog_type type) +{ + return prog ? (prog->type == type) : false; +} + +#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(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT); +BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP); +BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT); + +void bpf_program__set_expected_attach_type(struct bpf_program *prog, + enum bpf_attach_type type) +{ + prog->expected_attach_type = type; +} + +#define BPF_PROG_SEC_FULL(string, ptype, atype) \ + { string, sizeof(string) - 1, ptype, atype } + +#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_FULL(string, ptype, 0) + +#define BPF_S_PROG_SEC(string, ptype) \ + BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK, ptype) + +#define BPF_SA_PROG_SEC(string, ptype) \ + BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, ptype) + +static const struct { + const char *sec; + size_t len; + enum bpf_prog_type prog_type; + enum bpf_attach_type expected_attach_type; +} section_names[] = { + BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), + BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE), + BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE), + BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS), + BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT), + BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT), + BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT), + BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), + BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), + BPF_PROG_SEC("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB), + BPF_PROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK), + BPF_PROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE), + BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), + BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), + BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), + BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), + BPF_PROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS), + BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB), + BPF_PROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG), + BPF_PROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2), + BPF_SA_PROG_SEC("cgroup/bind4", BPF_CGROUP_INET4_BIND), + BPF_SA_PROG_SEC("cgroup/bind6", BPF_CGROUP_INET6_BIND), + BPF_SA_PROG_SEC("cgroup/connect4", BPF_CGROUP_INET4_CONNECT), + BPF_SA_PROG_SEC("cgroup/connect6", BPF_CGROUP_INET6_CONNECT), + BPF_SA_PROG_SEC("cgroup/sendmsg4", BPF_CGROUP_UDP4_SENDMSG), + BPF_SA_PROG_SEC("cgroup/sendmsg6", BPF_CGROUP_UDP6_SENDMSG), + BPF_S_PROG_SEC("cgroup/post_bind4", BPF_CGROUP_INET4_POST_BIND), + BPF_S_PROG_SEC("cgroup/post_bind6", BPF_CGROUP_INET6_POST_BIND), +}; + +#undef BPF_PROG_SEC +#undef BPF_PROG_SEC_FULL +#undef BPF_S_PROG_SEC +#undef BPF_SA_PROG_SEC + +int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, + enum bpf_attach_type *expected_attach_type) +{ + int i; + + if (!name) + return -EINVAL; + + for (i = 0; i < ARRAY_SIZE(section_names); i++) { + if (strncmp(name, section_names[i].sec, section_names[i].len)) + continue; + *prog_type = section_names[i].prog_type; + *expected_attach_type = section_names[i].expected_attach_type; + return 0; + } + return -EINVAL; +} + +static int +bpf_program__identify_section(struct bpf_program *prog, + enum bpf_prog_type *prog_type, + enum bpf_attach_type *expected_attach_type) +{ + return libbpf_prog_type_by_name(prog->section_name, prog_type, + expected_attach_type); +} + +int bpf_map__fd(struct bpf_map *map) +{ + return map ? map->fd : -EINVAL; +} + +const struct bpf_map_def *bpf_map__def(struct bpf_map *map) +{ + return map ? &map->def : ERR_PTR(-EINVAL); +} + +const char *bpf_map__name(struct bpf_map *map) +{ + return map ? map->name : NULL; +} + +__u32 bpf_map__btf_key_type_id(const struct bpf_map *map) +{ + return map ? map->btf_key_type_id : 0; +} + +__u32 bpf_map__btf_value_type_id(const struct bpf_map *map) +{ + return map ? map->btf_value_type_id : 0; +} + +int bpf_map__set_priv(struct bpf_map *map, void *priv, + bpf_map_clear_priv_t clear_priv) +{ + if (!map) + return -EINVAL; + + if (map->priv) { + if (map->clear_priv) + map->clear_priv(map, map->priv); + } + + map->priv = priv; + map->clear_priv = clear_priv; + return 0; +} + +void *bpf_map__priv(struct bpf_map *map) +{ + return map ? map->priv : ERR_PTR(-EINVAL); +} + +bool bpf_map__is_offload_neutral(struct bpf_map *map) +{ + return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; +} + +void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex) +{ + map->map_ifindex = ifindex; +} + +struct bpf_map * +bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) +{ + size_t idx; + struct bpf_map *s, *e; + + if (!obj || !obj->maps) + return NULL; + + s = obj->maps; + e = obj->maps + obj->nr_maps; + + if (prev == NULL) + return s; + + if ((prev < s) || (prev >= e)) { + pr_warning("error in %s: map handler doesn't belong to object\n", + __func__); + return NULL; + } + + idx = (prev - obj->maps) + 1; + if (idx >= obj->nr_maps) + return NULL; + return &obj->maps[idx]; +} + +struct bpf_map * +bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) +{ + struct bpf_map *pos; + + bpf_map__for_each(pos, obj) { + if (pos->name && !strcmp(pos->name, name)) + return pos; + } + return NULL; +} + +struct bpf_map * +bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) +{ + int i; + + for (i = 0; i < obj->nr_maps; i++) { + if (obj->maps[i].offset == offset) + return &obj->maps[i]; + } + return ERR_PTR(-ENOENT); +} + +long libbpf_get_error(const void *ptr) +{ + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + return 0; +} + +int bpf_prog_load(const char *file, enum bpf_prog_type type, + struct bpf_object **pobj, int *prog_fd) +{ + struct bpf_prog_load_attr attr; + + memset(&attr, 0, sizeof(struct bpf_prog_load_attr)); + attr.file = file; + attr.prog_type = type; + attr.expected_attach_type = 0; + + return bpf_prog_load_xattr(&attr, pobj, prog_fd); +} + +int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, + struct bpf_object **pobj, int *prog_fd) +{ + struct bpf_object_open_attr open_attr = {}; + struct bpf_program *prog, *first_prog = NULL; + enum bpf_attach_type expected_attach_type; + enum bpf_prog_type prog_type; + struct bpf_object *obj; + struct bpf_map *map; + int err; + + if (!attr) + return -EINVAL; + if (!attr->file) + return -EINVAL; + + open_attr.file = attr->file; + open_attr.prog_type = attr->prog_type; + + obj = bpf_object__open_xattr(&open_attr); + if (IS_ERR_OR_NULL(obj)) + return -ENOENT; + + bpf_object__for_each_program(prog, obj) { + /* + * If type is not specified, try to guess it based on + * section name. + */ + prog_type = attr->prog_type; + prog->prog_ifindex = attr->ifindex; + expected_attach_type = attr->expected_attach_type; + if (prog_type == BPF_PROG_TYPE_UNSPEC) { + err = bpf_program__identify_section(prog, &prog_type, + &expected_attach_type); + if (err < 0) { + pr_warning("failed to guess program type based on section name %s\n", + prog->section_name); + bpf_object__close(obj); + return -EINVAL; + } + } + + bpf_program__set_type(prog, prog_type); + bpf_program__set_expected_attach_type(prog, + expected_attach_type); + + if (!bpf_program__is_function_storage(prog, obj) && !first_prog) + first_prog = prog; + } + + bpf_map__for_each(map, obj) { + if (!bpf_map__is_offload_neutral(map)) + map->map_ifindex = attr->ifindex; + } + + if (!first_prog) { + pr_warning("object file doesn't contain bpf program\n"); + bpf_object__close(obj); + return -ENOENT; + } + + err = bpf_object__load(obj); + if (err) { + bpf_object__close(obj); + return -EINVAL; + } + + *pobj = obj; + *prog_fd = bpf_program__fd(first_prog); + return 0; +} + +enum bpf_perf_event_ret +bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv) +{ + volatile struct perf_event_mmap_page *header = mem; + __u64 data_tail = header->data_tail; + __u64 data_head = header->data_head; + int ret = LIBBPF_PERF_EVENT_ERROR; + void *base, *begin, *end; + + asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ + if (data_head == data_tail) + return LIBBPF_PERF_EVENT_CONT; + + base = ((char *)header) + page_size; + + begin = base + data_tail % size; + end = base + data_head % size; + + while (begin != end) { + struct perf_event_header *ehdr; + + ehdr = begin; + if (begin + ehdr->size > base + size) { + long len = base + size - begin; + + if (*buf_len < ehdr->size) { + free(*buf); + *buf = malloc(ehdr->size); + if (!*buf) { + ret = LIBBPF_PERF_EVENT_ERROR; + break; + } + *buf_len = ehdr->size; + } + + memcpy(*buf, begin, len); + memcpy(*buf + len, base, ehdr->size - len); + ehdr = (void *)*buf; + begin = base + ehdr->size - len; + } else if (begin + ehdr->size == base + size) { + begin = base; + } else { + begin += ehdr->size; + } + + ret = fn(ehdr, priv); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; + + data_tail += ehdr->size; + } + + __sync_synchronize(); /* smp_mb() */ + header->data_tail = data_tail; + + return ret; +} |