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kernel_samsung_a34x-permissive/tools/lib/bpf/libbpf.c
Fede2782 6db4831e98
Import A346BXXU4BWK2 kernel source 
Android 14
2024-04-28 15:51:13 +02:00

2432 lines
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// 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;
}
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