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linux/tools/bpf/bpftool/map.c
Quentin Monnet 6b4384ff10 Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK" 
This reverts commit a777e18f1b.

In commit a777e18f1b ("bpftool: Use libbpf 1.0 API mode instead of
RLIMIT_MEMLOCK"), we removed the rlimit bump in bpftool, because the
kernel has switched to memcg-based memory accounting. Thanks to the
LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK, we attempted to keep compatibility
with other systems and ask libbpf to raise the limit for us if
necessary.

How do we know if memcg-based accounting is supported? There is a probe
in libbpf to check this. But this probe currently relies on the
availability of a given BPF helper, bpf_ktime_get_coarse_ns(), which
landed in the same kernel version as the memory accounting change. This
works in the generic case, but it may fail, for example, if the helper
function has been backported to an older kernel. This has been observed
for Google Cloud's Container-Optimized OS (COS), where the helper is
available but rlimit is still in use. The probe succeeds, the rlimit is
not raised, and probing features with bpftool, for example, fails.

A patch was submitted [0] to update this probe in libbpf, based on what
the cilium/ebpf Go library does [1]. It would lower the soft rlimit to
0, attempt to load a BPF object, and reset the rlimit. But it may induce
some hard-to-debug flakiness if another process starts, or the current
application is killed, while the rlimit is reduced, and the approach was
discarded.

As a workaround to ensure that the rlimit bump does not depend on the
availability of a given helper, we restore the unconditional rlimit bump
in bpftool for now.

  [0] https://lore.kernel.org/bpf/20220609143614.97837-1-quentin@isovalent.com/
  [1] https://github.com/cilium/ebpf/blob/v0.9.0/rlimit/rlimit.go#L39

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220610112648.29695-2-quentin@isovalent.com
2022-06-14 22:18:06 +02:00

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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2017-2018 Netronome Systems, Inc. */
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <net/if.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/hashmap.h>
#include "json_writer.h"
#include "main.h"
static struct hashmap *map_table;
static bool map_is_per_cpu(__u32 type)
{
return type == BPF_MAP_TYPE_PERCPU_HASH ||
type == BPF_MAP_TYPE_PERCPU_ARRAY ||
type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
}
static bool map_is_map_of_maps(__u32 type)
{
return type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
type == BPF_MAP_TYPE_HASH_OF_MAPS;
}
static bool map_is_map_of_progs(__u32 type)
{
return type == BPF_MAP_TYPE_PROG_ARRAY;
}
static int map_type_from_str(const char *type)
{
const char *map_type_str;
unsigned int i;
for (i = 0; ; i++) {
map_type_str = libbpf_bpf_map_type_str(i);
if (!map_type_str)
break;
/* Don't allow prefixing in case of possible future shadowing */
if (!strcmp(map_type_str, type))
return i;
}
return -1;
}
static void *alloc_value(struct bpf_map_info *info)
{
if (map_is_per_cpu(info->type))
return malloc(round_up(info->value_size, 8) *
get_possible_cpus());
else
return malloc(info->value_size);
}
static int do_dump_btf(const struct btf_dumper *d,
struct bpf_map_info *map_info, void *key,
void *value)
{
__u32 value_id;
int ret = 0;
/* start of key-value pair */
jsonw_start_object(d->jw);
if (map_info->btf_key_type_id) {
jsonw_name(d->jw, "key");
ret = btf_dumper_type(d, map_info->btf_key_type_id, key);
if (ret)
goto err_end_obj;
}
value_id = map_info->btf_vmlinux_value_type_id ?
: map_info->btf_value_type_id;
if (!map_is_per_cpu(map_info->type)) {
jsonw_name(d->jw, "value");
ret = btf_dumper_type(d, value_id, value);
} else {
unsigned int i, n, step;
jsonw_name(d->jw, "values");
jsonw_start_array(d->jw);
n = get_possible_cpus();
step = round_up(map_info->value_size, 8);
for (i = 0; i < n; i++) {
jsonw_start_object(d->jw);
jsonw_int_field(d->jw, "cpu", i);
jsonw_name(d->jw, "value");
ret = btf_dumper_type(d, value_id, value + i * step);
jsonw_end_object(d->jw);
if (ret)
break;
}
jsonw_end_array(d->jw);
}
err_end_obj:
/* end of key-value pair */
jsonw_end_object(d->jw);
return ret;
}
static json_writer_t *get_btf_writer(void)
{
json_writer_t *jw = jsonw_new(stdout);
if (!jw)
return NULL;
jsonw_pretty(jw, true);
return jw;
}
static void print_entry_json(struct bpf_map_info *info, unsigned char *key,
unsigned char *value, struct btf *btf)
{
jsonw_start_object(json_wtr);
if (!map_is_per_cpu(info->type)) {
jsonw_name(json_wtr, "key");
print_hex_data_json(key, info->key_size);
jsonw_name(json_wtr, "value");
print_hex_data_json(value, info->value_size);
if (btf) {
struct btf_dumper d = {
.btf = btf,
.jw = json_wtr,
.is_plain_text = false,
};
jsonw_name(json_wtr, "formatted");
do_dump_btf(&d, info, key, value);
}
} else {
unsigned int i, n, step;
n = get_possible_cpus();
step = round_up(info->value_size, 8);
jsonw_name(json_wtr, "key");
print_hex_data_json(key, info->key_size);
jsonw_name(json_wtr, "values");
jsonw_start_array(json_wtr);
for (i = 0; i < n; i++) {
jsonw_start_object(json_wtr);
jsonw_int_field(json_wtr, "cpu", i);
jsonw_name(json_wtr, "value");
print_hex_data_json(value + i * step,
info->value_size);
jsonw_end_object(json_wtr);
}
jsonw_end_array(json_wtr);
if (btf) {
struct btf_dumper d = {
.btf = btf,
.jw = json_wtr,
.is_plain_text = false,
};
jsonw_name(json_wtr, "formatted");
do_dump_btf(&d, info, key, value);
}
}
jsonw_end_object(json_wtr);
}
static void
print_entry_error_msg(struct bpf_map_info *info, unsigned char *key,
const char *error_msg)
{
int msg_size = strlen(error_msg);
bool single_line, break_names;
break_names = info->key_size > 16 || msg_size > 16;
single_line = info->key_size + msg_size <= 24 && !break_names;
printf("key:%c", break_names ? '\n' : ' ');
fprint_hex(stdout, key, info->key_size, " ");
printf(single_line ? " " : "\n");
printf("value:%c%s", break_names ? '\n' : ' ', error_msg);
printf("\n");
}
static void
print_entry_error(struct bpf_map_info *map_info, void *key, int lookup_errno)
{
/* For prog_array maps or arrays of maps, failure to lookup the value
* means there is no entry for that key. Do not print an error message
* in that case.
*/
if ((map_is_map_of_maps(map_info->type) ||
map_is_map_of_progs(map_info->type)) && lookup_errno == ENOENT)
return;
if (json_output) {
jsonw_start_object(json_wtr); /* entry */
jsonw_name(json_wtr, "key");
print_hex_data_json(key, map_info->key_size);
jsonw_name(json_wtr, "value");
jsonw_start_object(json_wtr); /* error */
jsonw_string_field(json_wtr, "error", strerror(lookup_errno));
jsonw_end_object(json_wtr); /* error */
jsonw_end_object(json_wtr); /* entry */
} else {
const char *msg = NULL;
if (lookup_errno == ENOENT)
msg = "<no entry>";
else if (lookup_errno == ENOSPC &&
map_info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY)
msg = "<cannot read>";
print_entry_error_msg(map_info, key,
msg ? : strerror(lookup_errno));
}
}
static void print_entry_plain(struct bpf_map_info *info, unsigned char *key,
unsigned char *value)
{
if (!map_is_per_cpu(info->type)) {
bool single_line, break_names;
break_names = info->key_size > 16 || info->value_size > 16;
single_line = info->key_size + info->value_size <= 24 &&
!break_names;
if (info->key_size) {
printf("key:%c", break_names ? '\n' : ' ');
fprint_hex(stdout, key, info->key_size, " ");
printf(single_line ? " " : "\n");
}
if (info->value_size) {
printf("value:%c", break_names ? '\n' : ' ');
fprint_hex(stdout, value, info->value_size, " ");
}
printf("\n");
} else {
unsigned int i, n, step;
n = get_possible_cpus();
step = round_up(info->value_size, 8);
if (info->key_size) {
printf("key:\n");
fprint_hex(stdout, key, info->key_size, " ");
printf("\n");
}
if (info->value_size) {
for (i = 0; i < n; i++) {
printf("value (CPU %02d):%c",
i, info->value_size > 16 ? '\n' : ' ');
fprint_hex(stdout, value + i * step,
info->value_size, " ");
printf("\n");
}
}
}
}
static char **parse_bytes(char **argv, const char *name, unsigned char *val,
unsigned int n)
{
unsigned int i = 0, base = 0;
char *endptr;
if (is_prefix(*argv, "hex")) {
base = 16;
argv++;
}
while (i < n && argv[i]) {
val[i] = strtoul(argv[i], &endptr, base);
if (*endptr) {
p_err("error parsing byte: %s", argv[i]);
return NULL;
}
i++;
}
if (i != n) {
p_err("%s expected %d bytes got %d", name, n, i);
return NULL;
}
return argv + i;
}
/* on per cpu maps we must copy the provided value on all value instances */
static void fill_per_cpu_value(struct bpf_map_info *info, void *value)
{
unsigned int i, n, step;
if (!map_is_per_cpu(info->type))
return;
n = get_possible_cpus();
step = round_up(info->value_size, 8);
for (i = 1; i < n; i++)
memcpy(value + i * step, value, info->value_size);
}
static int parse_elem(char **argv, struct bpf_map_info *info,
void *key, void *value, __u32 key_size, __u32 value_size,
__u32 *flags, __u32 **value_fd)
{
if (!*argv) {
if (!key && !value)
return 0;
p_err("did not find %s", key ? "key" : "value");
return -1;
}
if (is_prefix(*argv, "key")) {
if (!key) {
if (key_size)
p_err("duplicate key");
else
p_err("unnecessary key");
return -1;
}
argv = parse_bytes(argv + 1, "key", key, key_size);
if (!argv)
return -1;
return parse_elem(argv, info, NULL, value, key_size, value_size,
flags, value_fd);
} else if (is_prefix(*argv, "value")) {
int fd;
if (!value) {
if (value_size)
p_err("duplicate value");
else
p_err("unnecessary value");
return -1;
}
argv++;
if (map_is_map_of_maps(info->type)) {
int argc = 2;
if (value_size != 4) {
p_err("value smaller than 4B for map in map?");
return -1;
}
if (!argv[0] || !argv[1]) {
p_err("not enough value arguments for map in map");
return -1;
}
fd = map_parse_fd(&argc, &argv);
if (fd < 0)
return -1;
*value_fd = value;
**value_fd = fd;
} else if (map_is_map_of_progs(info->type)) {
int argc = 2;
if (value_size != 4) {
p_err("value smaller than 4B for map of progs?");
return -1;
}
if (!argv[0] || !argv[1]) {
p_err("not enough value arguments for map of progs");
return -1;
}
if (is_prefix(*argv, "id"))
p_info("Warning: updating program array via MAP_ID, make sure this map is kept open\n"
" by some process or pinned otherwise update will be lost");
fd = prog_parse_fd(&argc, &argv);
if (fd < 0)
return -1;
*value_fd = value;
**value_fd = fd;
} else {
argv = parse_bytes(argv, "value", value, value_size);
if (!argv)
return -1;
fill_per_cpu_value(info, value);
}
return parse_elem(argv, info, key, NULL, key_size, value_size,
flags, NULL);
} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
is_prefix(*argv, "exist")) {
if (!flags) {
p_err("flags specified multiple times: %s", *argv);
return -1;
}
if (is_prefix(*argv, "any"))
*flags = BPF_ANY;
else if (is_prefix(*argv, "noexist"))
*flags = BPF_NOEXIST;
else if (is_prefix(*argv, "exist"))
*flags = BPF_EXIST;
return parse_elem(argv + 1, info, key, value, key_size,
value_size, NULL, value_fd);
}
p_err("expected key or value, got: %s", *argv);
return -1;
}
static void show_map_header_json(struct bpf_map_info *info, json_writer_t *wtr)
{
const char *map_type_str;
jsonw_uint_field(wtr, "id", info->id);
map_type_str = libbpf_bpf_map_type_str(info->type);
if (map_type_str)
jsonw_string_field(wtr, "type", map_type_str);
else
jsonw_uint_field(wtr, "type", info->type);
if (*info->name)
jsonw_string_field(wtr, "name", info->name);
jsonw_name(wtr, "flags");
jsonw_printf(wtr, "%d", info->map_flags);
}
static int show_map_close_json(int fd, struct bpf_map_info *info)
{
char *memlock, *frozen_str;
int frozen = 0;
memlock = get_fdinfo(fd, "memlock");
frozen_str = get_fdinfo(fd, "frozen");
jsonw_start_object(json_wtr);
show_map_header_json(info, json_wtr);
print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
jsonw_uint_field(json_wtr, "bytes_key", info->key_size);
jsonw_uint_field(json_wtr, "bytes_value", info->value_size);
jsonw_uint_field(json_wtr, "max_entries", info->max_entries);
if (memlock)
jsonw_int_field(json_wtr, "bytes_memlock", atoll(memlock));
free(memlock);
if (info->type == BPF_MAP_TYPE_PROG_ARRAY) {
char *owner_prog_type = get_fdinfo(fd, "owner_prog_type");
char *owner_jited = get_fdinfo(fd, "owner_jited");
if (owner_prog_type) {
unsigned int prog_type = atoi(owner_prog_type);
const char *prog_type_str;
prog_type_str = libbpf_bpf_prog_type_str(prog_type);
if (prog_type_str)
jsonw_string_field(json_wtr, "owner_prog_type",
prog_type_str);
else
jsonw_uint_field(json_wtr, "owner_prog_type",
prog_type);
}
if (owner_jited)
jsonw_bool_field(json_wtr, "owner_jited",
!!atoi(owner_jited));
free(owner_prog_type);
free(owner_jited);
}
close(fd);
if (frozen_str) {
frozen = atoi(frozen_str);
free(frozen_str);
}
jsonw_int_field(json_wtr, "frozen", frozen);
if (info->btf_id)
jsonw_int_field(json_wtr, "btf_id", info->btf_id);
if (!hashmap__empty(map_table)) {
struct hashmap_entry *entry;
jsonw_name(json_wtr, "pinned");
jsonw_start_array(json_wtr);
hashmap__for_each_key_entry(map_table, entry,
u32_as_hash_field(info->id))
jsonw_string(json_wtr, entry->value);
jsonw_end_array(json_wtr);
}
emit_obj_refs_json(refs_table, info->id, json_wtr);
jsonw_end_object(json_wtr);
return 0;
}
static void show_map_header_plain(struct bpf_map_info *info)
{
const char *map_type_str;
printf("%u: ", info->id);
map_type_str = libbpf_bpf_map_type_str(info->type);
if (map_type_str)
printf("%s ", map_type_str);
else
printf("type %u ", info->type);
if (*info->name)
printf("name %s ", info->name);
printf("flags 0x%x", info->map_flags);
print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
printf("\n");
}
static int show_map_close_plain(int fd, struct bpf_map_info *info)
{
char *memlock, *frozen_str;
int frozen = 0;
memlock = get_fdinfo(fd, "memlock");
frozen_str = get_fdinfo(fd, "frozen");
show_map_header_plain(info);
printf("\tkey %uB value %uB max_entries %u",
info->key_size, info->value_size, info->max_entries);
if (memlock)
printf(" memlock %sB", memlock);
free(memlock);
if (info->type == BPF_MAP_TYPE_PROG_ARRAY) {
char *owner_prog_type = get_fdinfo(fd, "owner_prog_type");
char *owner_jited = get_fdinfo(fd, "owner_jited");
if (owner_prog_type || owner_jited)
printf("\n\t");
if (owner_prog_type) {
unsigned int prog_type = atoi(owner_prog_type);
const char *prog_type_str;
prog_type_str = libbpf_bpf_prog_type_str(prog_type);
if (prog_type_str)
printf("owner_prog_type %s ", prog_type_str);
else
printf("owner_prog_type %d ", prog_type);
}
if (owner_jited)
printf("owner%s jited",
atoi(owner_jited) ? "" : " not");
free(owner_prog_type);
free(owner_jited);
}
close(fd);
if (!hashmap__empty(map_table)) {
struct hashmap_entry *entry;
hashmap__for_each_key_entry(map_table, entry,
u32_as_hash_field(info->id))
printf("\n\tpinned %s", (char *)entry->value);
}
if (frozen_str) {
frozen = atoi(frozen_str);
free(frozen_str);
}
if (info->btf_id || frozen)
printf("\n\t");
if (info->btf_id)
printf("btf_id %d", info->btf_id);
if (frozen)
printf("%sfrozen", info->btf_id ? " " : "");
emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
printf("\n");
return 0;
}
static int do_show_subset(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
int *fds = NULL;
int nb_fds, i;
int err = -1;
fds = malloc(sizeof(int));
if (!fds) {
p_err("mem alloc failed");
return -1;
}
nb_fds = map_parse_fds(&argc, &argv, &fds);
if (nb_fds < 1)
goto exit_free;
if (json_output && nb_fds > 1)
jsonw_start_array(json_wtr); /* root array */
for (i = 0; i < nb_fds; i++) {
err = bpf_obj_get_info_by_fd(fds[i], &info, &len);
if (err) {
p_err("can't get map info: %s",
strerror(errno));
for (; i < nb_fds; i++)
close(fds[i]);
break;
}
if (json_output)
show_map_close_json(fds[i], &info);
else
show_map_close_plain(fds[i], &info);
close(fds[i]);
}
if (json_output && nb_fds > 1)
jsonw_end_array(json_wtr); /* root array */
exit_free:
free(fds);
return err;
}
static int do_show(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
__u32 id = 0;
int err;
int fd;
if (show_pinned) {
map_table = hashmap__new(hash_fn_for_key_as_id,
equal_fn_for_key_as_id, NULL);
if (IS_ERR(map_table)) {
p_err("failed to create hashmap for pinned paths");
return -1;
}
build_pinned_obj_table(map_table, BPF_OBJ_MAP);
}
build_obj_refs_table(&refs_table, BPF_OBJ_MAP);
if (argc == 2)
return do_show_subset(argc, argv);
if (argc)
return BAD_ARG();
if (json_output)
jsonw_start_array(json_wtr);
while (true) {
err = bpf_map_get_next_id(id, &id);
if (err) {
if (errno == ENOENT)
break;
p_err("can't get next map: %s%s", strerror(errno),
errno == EINVAL ? " -- kernel too old?" : "");
break;
}
fd = bpf_map_get_fd_by_id(id);
if (fd < 0) {
if (errno == ENOENT)
continue;
p_err("can't get map by id (%u): %s",
id, strerror(errno));
break;
}
err = bpf_obj_get_info_by_fd(fd, &info, &len);
if (err) {
p_err("can't get map info: %s", strerror(errno));
close(fd);
break;
}
if (json_output)
show_map_close_json(fd, &info);
else
show_map_close_plain(fd, &info);
}
if (json_output)
jsonw_end_array(json_wtr);
delete_obj_refs_table(refs_table);
if (show_pinned)
delete_pinned_obj_table(map_table);
return errno == ENOENT ? 0 : -1;
}
static int dump_map_elem(int fd, void *key, void *value,
struct bpf_map_info *map_info, struct btf *btf,
json_writer_t *btf_wtr)
{
if (bpf_map_lookup_elem(fd, key, value)) {
print_entry_error(map_info, key, errno);
return -1;
}
if (json_output) {
print_entry_json(map_info, key, value, btf);
} else if (btf) {
struct btf_dumper d = {
.btf = btf,
.jw = btf_wtr,
.is_plain_text = true,
};
do_dump_btf(&d, map_info, key, value);
} else {
print_entry_plain(map_info, key, value);
}
return 0;
}
static int maps_have_btf(int *fds, int nb_fds)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
int err, i;
for (i = 0; i < nb_fds; i++) {
err = bpf_obj_get_info_by_fd(fds[i], &info, &len);
if (err) {
p_err("can't get map info: %s", strerror(errno));
return -1;
}
if (!info.btf_id)
return 0;
}
return 1;
}
static struct btf *btf_vmlinux;
static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf)
{
int err = 0;
if (info->btf_vmlinux_value_type_id) {
if (!btf_vmlinux) {
btf_vmlinux = libbpf_find_kernel_btf();
err = libbpf_get_error(btf_vmlinux);
if (err) {
p_err("failed to get kernel btf");
return err;
}
}
*btf = btf_vmlinux;
} else if (info->btf_value_type_id) {
*btf = btf__load_from_kernel_by_id(info->btf_id);
err = libbpf_get_error(*btf);
if (err)
p_err("failed to get btf");
} else {
*btf = NULL;
}
return err;
}
static void free_map_kv_btf(struct btf *btf)
{
if (!libbpf_get_error(btf) && btf != btf_vmlinux)
btf__free(btf);
}
static void free_btf_vmlinux(void)
{
if (!libbpf_get_error(btf_vmlinux))
btf__free(btf_vmlinux);
}
static int
map_dump(int fd, struct bpf_map_info *info, json_writer_t *wtr,
bool show_header)
{
void *key, *value, *prev_key;
unsigned int num_elems = 0;
struct btf *btf = NULL;
int err;
key = malloc(info->key_size);
value = alloc_value(info);
if (!key || !value) {
p_err("mem alloc failed");
err = -1;
goto exit_free;
}
prev_key = NULL;
if (wtr) {
err = get_map_kv_btf(info, &btf);
if (err) {
goto exit_free;
}
if (show_header) {
jsonw_start_object(wtr); /* map object */
show_map_header_json(info, wtr);
jsonw_name(wtr, "elements");
}
jsonw_start_array(wtr); /* elements */
} else if (show_header) {
show_map_header_plain(info);
}
if (info->type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY &&
info->value_size != 8) {
const char *map_type_str;
map_type_str = libbpf_bpf_map_type_str(info->type);
p_info("Warning: cannot read values from %s map with value_size != 8",
map_type_str);
}
while (true) {
err = bpf_map_get_next_key(fd, prev_key, key);
if (err) {
if (errno == ENOENT)
err = 0;
break;
}
if (!dump_map_elem(fd, key, value, info, btf, wtr))
num_elems++;
prev_key = key;
}
if (wtr) {
jsonw_end_array(wtr); /* elements */
if (show_header)
jsonw_end_object(wtr); /* map object */
} else {
printf("Found %u element%s\n", num_elems,
num_elems != 1 ? "s" : "");
}
exit_free:
free(key);
free(value);
close(fd);
free_map_kv_btf(btf);
return err;
}
static int do_dump(int argc, char **argv)
{
json_writer_t *wtr = NULL, *btf_wtr = NULL;
struct bpf_map_info info = {};
int nb_fds, i = 0;
__u32 len = sizeof(info);
int *fds = NULL;
int err = -1;
if (argc != 2)
usage();
fds = malloc(sizeof(int));
if (!fds) {
p_err("mem alloc failed");
return -1;
}
nb_fds = map_parse_fds(&argc, &argv, &fds);
if (nb_fds < 1)
goto exit_free;
if (json_output) {
wtr = json_wtr;
} else {
int do_plain_btf;
do_plain_btf = maps_have_btf(fds, nb_fds);
if (do_plain_btf < 0)
goto exit_close;
if (do_plain_btf) {
btf_wtr = get_btf_writer();
wtr = btf_wtr;
if (!btf_wtr)
p_info("failed to create json writer for btf. falling back to plain output");
}
}
if (wtr && nb_fds > 1)
jsonw_start_array(wtr); /* root array */
for (i = 0; i < nb_fds; i++) {
if (bpf_obj_get_info_by_fd(fds[i], &info, &len)) {
p_err("can't get map info: %s", strerror(errno));
break;
}
err = map_dump(fds[i], &info, wtr, nb_fds > 1);
if (!wtr && i != nb_fds - 1)
printf("\n");
if (err)
break;
close(fds[i]);
}
if (wtr && nb_fds > 1)
jsonw_end_array(wtr); /* root array */
if (btf_wtr)
jsonw_destroy(&btf_wtr);
exit_close:
for (; i < nb_fds; i++)
close(fds[i]);
exit_free:
free(fds);
free_btf_vmlinux();
return err;
}
static int alloc_key_value(struct bpf_map_info *info, void **key, void **value)
{
*key = NULL;
*value = NULL;
if (info->key_size) {
*key = malloc(info->key_size);
if (!*key) {
p_err("key mem alloc failed");
return -1;
}
}
if (info->value_size) {
*value = alloc_value(info);
if (!*value) {
p_err("value mem alloc failed");
free(*key);
*key = NULL;
return -1;
}
}
return 0;
}
static int do_update(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
__u32 *value_fd = NULL;
__u32 flags = BPF_ANY;
void *key, *value;
int fd, err;
if (argc < 2)
usage();
fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
if (fd < 0)
return -1;
err = alloc_key_value(&info, &key, &value);
if (err)
goto exit_free;
err = parse_elem(argv, &info, key, value, info.key_size,
info.value_size, &flags, &value_fd);
if (err)
goto exit_free;
err = bpf_map_update_elem(fd, key, value, flags);
if (err) {
p_err("update failed: %s", strerror(errno));
goto exit_free;
}
exit_free:
if (value_fd)
close(*value_fd);
free(key);
free(value);
close(fd);
if (!err && json_output)
jsonw_null(json_wtr);
return err;
}
static void print_key_value(struct bpf_map_info *info, void *key,
void *value)
{
json_writer_t *btf_wtr;
struct btf *btf;
if (get_map_kv_btf(info, &btf))
return;
if (json_output) {
print_entry_json(info, key, value, btf);
} else if (btf) {
/* if here json_wtr wouldn't have been initialised,
* so let's create separate writer for btf
*/
btf_wtr = get_btf_writer();
if (!btf_wtr) {
p_info("failed to create json writer for btf. falling back to plain output");
btf__free(btf);
btf = NULL;
print_entry_plain(info, key, value);
} else {
struct btf_dumper d = {
.btf = btf,
.jw = btf_wtr,
.is_plain_text = true,
};
do_dump_btf(&d, info, key, value);
jsonw_destroy(&btf_wtr);
}
} else {
print_entry_plain(info, key, value);
}
btf__free(btf);
}
static int do_lookup(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
void *key, *value;
int err;
int fd;
if (argc < 2)
usage();
fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
if (fd < 0)
return -1;
err = alloc_key_value(&info, &key, &value);
if (err)
goto exit_free;
err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
if (err)
goto exit_free;
err = bpf_map_lookup_elem(fd, key, value);
if (err) {
if (errno == ENOENT) {
if (json_output) {
jsonw_null(json_wtr);
} else {
printf("key:\n");
fprint_hex(stdout, key, info.key_size, " ");
printf("\n\nNot found\n");
}
} else {
p_err("lookup failed: %s", strerror(errno));
}
goto exit_free;
}
/* here means bpf_map_lookup_elem() succeeded */
print_key_value(&info, key, value);
exit_free:
free(key);
free(value);
close(fd);
return err;
}
static int do_getnext(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
void *key, *nextkey;
int err;
int fd;
if (argc < 2)
usage();
fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
if (fd < 0)
return -1;
key = malloc(info.key_size);
nextkey = malloc(info.key_size);
if (!key || !nextkey) {
p_err("mem alloc failed");
err = -1;
goto exit_free;
}
if (argc) {
err = parse_elem(argv, &info, key, NULL, info.key_size, 0,
NULL, NULL);
if (err)
goto exit_free;
} else {
free(key);
key = NULL;
}
err = bpf_map_get_next_key(fd, key, nextkey);
if (err) {
p_err("can't get next key: %s", strerror(errno));
goto exit_free;
}
if (json_output) {
jsonw_start_object(json_wtr);
if (key) {
jsonw_name(json_wtr, "key");
print_hex_data_json(key, info.key_size);
} else {
jsonw_null_field(json_wtr, "key");
}
jsonw_name(json_wtr, "next_key");
print_hex_data_json(nextkey, info.key_size);
jsonw_end_object(json_wtr);
} else {
if (key) {
printf("key:\n");
fprint_hex(stdout, key, info.key_size, " ");
printf("\n");
} else {
printf("key: None\n");
}
printf("next key:\n");
fprint_hex(stdout, nextkey, info.key_size, " ");
printf("\n");
}
exit_free:
free(nextkey);
free(key);
close(fd);
return err;
}
static int do_delete(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
void *key;
int err;
int fd;
if (argc < 2)
usage();
fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
if (fd < 0)
return -1;
key = malloc(info.key_size);
if (!key) {
p_err("mem alloc failed");
err = -1;
goto exit_free;
}
err = parse_elem(argv, &info, key, NULL, info.key_size, 0, NULL, NULL);
if (err)
goto exit_free;
err = bpf_map_delete_elem(fd, key);
if (err)
p_err("delete failed: %s", strerror(errno));
exit_free:
free(key);
close(fd);
if (!err && json_output)
jsonw_null(json_wtr);
return err;
}
static int do_pin(int argc, char **argv)
{
int err;
err = do_pin_any(argc, argv, map_parse_fd);
if (!err && json_output)
jsonw_null(json_wtr);
return err;
}
static int do_create(int argc, char **argv)
{
LIBBPF_OPTS(bpf_map_create_opts, attr);
enum bpf_map_type map_type = BPF_MAP_TYPE_UNSPEC;
__u32 key_size = 0, value_size = 0, max_entries = 0;
const char *map_name = NULL;
const char *pinfile;
int err = -1, fd;
if (!REQ_ARGS(7))
return -1;
pinfile = GET_ARG();
while (argc) {
if (!REQ_ARGS(2))
return -1;
if (is_prefix(*argv, "type")) {
NEXT_ARG();
if (map_type) {
p_err("map type already specified");
goto exit;
}
map_type = map_type_from_str(*argv);
if ((int)map_type < 0) {
p_err("unrecognized map type: %s", *argv);
goto exit;
}
NEXT_ARG();
} else if (is_prefix(*argv, "name")) {
NEXT_ARG();
map_name = GET_ARG();
} else if (is_prefix(*argv, "key")) {
if (parse_u32_arg(&argc, &argv, &key_size,
"key size"))
goto exit;
} else if (is_prefix(*argv, "value")) {
if (parse_u32_arg(&argc, &argv, &value_size,
"value size"))
goto exit;
} else if (is_prefix(*argv, "entries")) {
if (parse_u32_arg(&argc, &argv, &max_entries,
"max entries"))
goto exit;
} else if (is_prefix(*argv, "flags")) {
if (parse_u32_arg(&argc, &argv, &attr.map_flags,
"flags"))
goto exit;
} else if (is_prefix(*argv, "dev")) {
NEXT_ARG();
if (attr.map_ifindex) {
p_err("offload device already specified");
goto exit;
}
attr.map_ifindex = if_nametoindex(*argv);
if (!attr.map_ifindex) {
p_err("unrecognized netdevice '%s': %s",
*argv, strerror(errno));
goto exit;
}
NEXT_ARG();
} else if (is_prefix(*argv, "inner_map")) {
struct bpf_map_info info = {};
__u32 len = sizeof(info);
int inner_map_fd;
NEXT_ARG();
if (!REQ_ARGS(2))
usage();
inner_map_fd = map_parse_fd_and_info(&argc, &argv,
&info, &len);
if (inner_map_fd < 0)
return -1;
attr.inner_map_fd = inner_map_fd;
} else {
p_err("unknown arg %s", *argv);
goto exit;
}
}
if (!map_name) {
p_err("map name not specified");
goto exit;
}
set_max_rlimit();
fd = bpf_map_create(map_type, map_name, key_size, value_size, max_entries, &attr);
if (fd < 0) {
p_err("map create failed: %s", strerror(errno));
goto exit;
}
err = do_pin_fd(fd, pinfile);
close(fd);
if (err)
goto exit;
if (json_output)
jsonw_null(json_wtr);
exit:
if (attr.inner_map_fd > 0)
close(attr.inner_map_fd);
return err;
}
static int do_pop_dequeue(int argc, char **argv)
{
struct bpf_map_info info = {};
__u32 len = sizeof(info);
void *key, *value;
int err;
int fd;
if (argc < 2)
usage();
fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
if (fd < 0)
return -1;
err = alloc_key_value(&info, &key, &value);
if (err)
goto exit_free;
err = bpf_map_lookup_and_delete_elem(fd, key, value);
if (err) {
if (errno == ENOENT) {
if (json_output)
jsonw_null(json_wtr);
else
printf("Error: empty map\n");
} else {
p_err("pop failed: %s", strerror(errno));
}
goto exit_free;
}
print_key_value(&info, key, value);
exit_free:
free(key);
free(value);
close(fd);
return err;
}
static int do_freeze(int argc, char **argv)
{
int err, fd;
if (!REQ_ARGS(2))
return -1;
fd = map_parse_fd(&argc, &argv);
if (fd < 0)
return -1;
if (argc) {
close(fd);
return BAD_ARG();
}
err = bpf_map_freeze(fd);
close(fd);
if (err) {
p_err("failed to freeze map: %s", strerror(errno));
return err;
}
if (json_output)
jsonw_null(json_wtr);
return 0;
}
static int do_help(int argc, char **argv)
{
if (json_output) {
jsonw_null(json_wtr);
return 0;
}
fprintf(stderr,
"Usage: %1$s %2$s { show | list } [MAP]\n"
" %1$s %2$s create FILE type TYPE key KEY_SIZE value VALUE_SIZE \\\n"
" entries MAX_ENTRIES name NAME [flags FLAGS] \\\n"
" [inner_map MAP] [dev NAME]\n"
" %1$s %2$s dump MAP\n"
" %1$s %2$s update MAP [key DATA] [value VALUE] [UPDATE_FLAGS]\n"
" %1$s %2$s lookup MAP [key DATA]\n"
" %1$s %2$s getnext MAP [key DATA]\n"
" %1$s %2$s delete MAP key DATA\n"
" %1$s %2$s pin MAP FILE\n"
" %1$s %2$s event_pipe MAP [cpu N index M]\n"
" %1$s %2$s peek MAP\n"
" %1$s %2$s push MAP value VALUE\n"
" %1$s %2$s pop MAP\n"
" %1$s %2$s enqueue MAP value VALUE\n"
" %1$s %2$s dequeue MAP\n"
" %1$s %2$s freeze MAP\n"
" %1$s %2$s help\n"
"\n"
" " HELP_SPEC_MAP "\n"
" DATA := { [hex] BYTES }\n"
" " HELP_SPEC_PROGRAM "\n"
" VALUE := { DATA | MAP | PROG }\n"
" UPDATE_FLAGS := { any | exist | noexist }\n"
" TYPE := { hash | array | prog_array | perf_event_array | percpu_hash |\n"
" percpu_array | stack_trace | cgroup_array | lru_hash |\n"
" lru_percpu_hash | lpm_trie | array_of_maps | hash_of_maps |\n"
" devmap | devmap_hash | sockmap | cpumap | xskmap | sockhash |\n"
" cgroup_storage | reuseport_sockarray | percpu_cgroup_storage |\n"
" queue | stack | sk_storage | struct_ops | ringbuf | inode_storage |\n"
" task_storage | bloom_filter }\n"
" " HELP_SPEC_OPTIONS " |\n"
" {-f|--bpffs} | {-n|--nomount} }\n"
"",
bin_name, argv[-2]);
return 0;
}
static const struct cmd cmds[] = {
{ "show", do_show },
{ "list", do_show },
{ "help", do_help },
{ "dump", do_dump },
{ "update", do_update },
{ "lookup", do_lookup },
{ "getnext", do_getnext },
{ "delete", do_delete },
{ "pin", do_pin },
{ "event_pipe", do_event_pipe },
{ "create", do_create },
{ "peek", do_lookup },
{ "push", do_update },
{ "enqueue", do_update },
{ "pop", do_pop_dequeue },
{ "dequeue", do_pop_dequeue },
{ "freeze", do_freeze },
{ 0 }
};
int do_map(int argc, char **argv)
{
return cmd_select(cmds, argc, argv, do_help);
}
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