// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (C) 2017 Facebook
// Author: Roman Gushchin <[email protected]>
#define _XOPEN_SOURCE 500
#include <errno.h>
#include <fcntl.h>
#include <ftw.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/btf.h>
#include "main.h"
static const int cgroup_attach_types[] = {
BPF_CGROUP_INET_INGRESS,
BPF_CGROUP_INET_EGRESS,
BPF_CGROUP_INET_SOCK_CREATE,
BPF_CGROUP_INET_SOCK_RELEASE,
BPF_CGROUP_INET4_BIND,
BPF_CGROUP_INET6_BIND,
BPF_CGROUP_INET4_POST_BIND,
BPF_CGROUP_INET6_POST_BIND,
BPF_CGROUP_INET4_CONNECT,
BPF_CGROUP_INET6_CONNECT,
BPF_CGROUP_UNIX_CONNECT,
BPF_CGROUP_INET4_GETPEERNAME,
BPF_CGROUP_INET6_GETPEERNAME,
BPF_CGROUP_UNIX_GETPEERNAME,
BPF_CGROUP_INET4_GETSOCKNAME,
BPF_CGROUP_INET6_GETSOCKNAME,
BPF_CGROUP_UNIX_GETSOCKNAME,
BPF_CGROUP_UDP4_SENDMSG,
BPF_CGROUP_UDP6_SENDMSG,
BPF_CGROUP_UNIX_SENDMSG,
BPF_CGROUP_UDP4_RECVMSG,
BPF_CGROUP_UDP6_RECVMSG,
BPF_CGROUP_UNIX_RECVMSG,
BPF_CGROUP_SOCK_OPS,
BPF_CGROUP_DEVICE,
BPF_CGROUP_SYSCTL,
BPF_CGROUP_GETSOCKOPT,
BPF_CGROUP_SETSOCKOPT,
BPF_LSM_CGROUP
};
#define HELP_SPEC_ATTACH_FLAGS \
"ATTACH_FLAGS := { multi | override }"
#define HELP_SPEC_ATTACH_TYPES \
" ATTACH_TYPE := { cgroup_inet_ingress | cgroup_inet_egress |\n" \
" cgroup_inet_sock_create | cgroup_sock_ops |\n" \
" cgroup_device | cgroup_inet4_bind |\n" \
" cgroup_inet6_bind | cgroup_inet4_post_bind |\n" \
" cgroup_inet6_post_bind | cgroup_inet4_connect |\n" \
" cgroup_inet6_connect | cgroup_unix_connect |\n" \
" cgroup_inet4_getpeername | cgroup_inet6_getpeername |\n" \
" cgroup_unix_getpeername | cgroup_inet4_getsockname |\n" \
" cgroup_inet6_getsockname | cgroup_unix_getsockname |\n" \
" cgroup_udp4_sendmsg | cgroup_udp6_sendmsg |\n" \
" cgroup_unix_sendmsg | cgroup_udp4_recvmsg |\n" \
" cgroup_udp6_recvmsg | cgroup_unix_recvmsg |\n" \
" cgroup_sysctl | cgroup_getsockopt |\n" \
" cgroup_setsockopt | cgroup_inet_sock_release }"
static unsigned int query_flags;
static struct btf *btf_vmlinux;
static __u32 btf_vmlinux_id;
static enum bpf_attach_type parse_attach_type(const char *str)
{
const char *attach_type_str;
enum bpf_attach_type type;
for (type = 0; ; type++) {
attach_type_str = libbpf_bpf_attach_type_str(type);
if (!attach_type_str)
break;
if (!strcmp(str, attach_type_str))
return type;
}
/* Also check traditionally used attach type strings. For these we keep
* allowing prefixed usage.
*/
for (type = 0; ; type++) {
attach_type_str = bpf_attach_type_input_str(type);
if (!attach_type_str)
break;
if (is_prefix(str, attach_type_str))
return type;
}
return __MAX_BPF_ATTACH_TYPE;
}
static void guess_vmlinux_btf_id(__u32 attach_btf_obj_id)
{
struct bpf_btf_info btf_info = {};
__u32 btf_len = sizeof(btf_info);
char name[16] = {};
int err;
int fd;
btf_info.name = ptr_to_u64(name);
btf_info.name_len = sizeof(name);
fd = bpf_btf_get_fd_by_id(attach_btf_obj_id);
if (fd < 0)
return;
err = bpf_btf_get_info_by_fd(fd, &btf_info, &btf_len);
if (err)
goto out;
if (btf_info.kernel_btf && strncmp(name, "vmlinux", sizeof(name)) == 0)
btf_vmlinux_id = btf_info.id;
out:
close(fd);
}
static int show_bpf_prog(int id, enum bpf_attach_type attach_type,
const char *attach_flags_str,
int level)
{
char prog_name[MAX_PROG_FULL_NAME];
const char *attach_btf_name = NULL;
struct bpf_prog_info info = {};
const char *attach_type_str;
__u32 info_len = sizeof(info);
int prog_fd;
prog_fd = bpf_prog_get_fd_by_id(id);
if (prog_fd < 0)
return -1;
if (bpf_prog_get_info_by_fd(prog_fd, &info, &info_len)) {
close(prog_fd);
return -1;
}
attach_type_str = libbpf_bpf_attach_type_str(attach_type);
if (btf_vmlinux) {
if (!btf_vmlinux_id)
guess_vmlinux_btf_id(info.attach_btf_obj_id);
if (btf_vmlinux_id == info.attach_btf_obj_id &&
info.attach_btf_id < btf__type_cnt(btf_vmlinux)) {
const struct btf_type *t =
btf__type_by_id(btf_vmlinux, info.attach_btf_id);
attach_btf_name =
btf__name_by_offset(btf_vmlinux, t->name_off);
}
}
get_prog_full_name(&info, prog_fd, prog_name, sizeof(prog_name));
if (json_output) {
jsonw_start_object(json_wtr);
jsonw_uint_field(json_wtr, "id", info.id);
if (attach_type_str)
jsonw_string_field(json_wtr, "attach_type", attach_type_str);
else
jsonw_uint_field(json_wtr, "attach_type", attach_type);
if (!(query_flags & BPF_F_QUERY_EFFECTIVE))
jsonw_string_field(json_wtr, "attach_flags", attach_flags_str);
jsonw_string_field(json_wtr, "name", prog_name);
if (attach_btf_name)
jsonw_string_field(json_wtr, "attach_btf_name", attach_btf_name);
jsonw_uint_field(json_wtr, "attach_btf_obj_id", info.attach_btf_obj_id);
jsonw_uint_field(json_wtr, "attach_btf_id", info.attach_btf_id);
jsonw_end_object(json_wtr);
} else {
printf("%s%-8u ", level ? " " : "", info.id);
if (attach_type_str)
printf("%-15s", attach_type_str);
else
printf("type %-10u", attach_type);
if (query_flags & BPF_F_QUERY_EFFECTIVE)
printf(" %-15s", prog_name);
else
printf(" %-15s %-15s", attach_flags_str, prog_name);
if (attach_btf_name)
printf(" %-15s", attach_btf_name);
else if (info.attach_btf_id)
printf(" attach_btf_obj_id=%d attach_btf_id=%d",
info.attach_btf_obj_id, info.attach_btf_id);
printf("\n");
}
close(prog_fd);
return 0;
}
static int count_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
{
__u32 prog_cnt = 0;
int ret;
ret = bpf_prog_query(cgroup_fd, type, query_flags, NULL,
NULL, &prog_cnt);
if (ret)
return -1;
return prog_cnt;
}
static int cgroup_has_attached_progs(int cgroup_fd)
{
unsigned int i = 0;
bool no_prog = true;
for (i = 0; i < ARRAY_SIZE(cgroup_attach_types); i++) {
int count = count_attached_bpf_progs(cgroup_fd, cgroup_attach_types[i]);
if (count < 0)
return -1;
if (count > 0) {
no_prog = false;
break;
}
}
return no_prog ? 0 : 1;
}
static int show_effective_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
int level)
{
LIBBPF_OPTS(bpf_prog_query_opts, p);
__u32 prog_ids[1024] = {0};
__u32 iter;
int ret;
p.query_flags = query_flags;
p.prog_cnt = ARRAY_SIZE(prog_ids);
p.prog_ids = prog_ids;
ret = bpf_prog_query_opts(cgroup_fd, type, &p);
if (ret)
return ret;
if (p.prog_cnt == 0)
return 0;
for (iter = 0; iter < p.prog_cnt; iter++)
show_bpf_prog(prog_ids[iter], type, NULL, level);
return 0;
}
static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
int level)
{
LIBBPF_OPTS(bpf_prog_query_opts, p);
__u32 prog_attach_flags[1024] = {0};
const char *attach_flags_str;
__u32 prog_ids[1024] = {0};
char buf[32];
__u32 iter;
int ret;
p.query_flags = query_flags;
p.prog_cnt = ARRAY_SIZE(prog_ids);
p.prog_ids = prog_ids;
p.prog_attach_flags = prog_attach_flags;
ret = bpf_prog_query_opts(cgroup_fd, type, &p);
if (ret)
return ret;
if (p.prog_cnt == 0)
return 0;
for (iter = 0; iter < p.prog_cnt; iter++) {
__u32 attach_flags;
attach_flags = prog_attach_flags[iter] ?: p.attach_flags;
switch (attach_flags) {
case BPF_F_ALLOW_MULTI:
attach_flags_str = "multi";
break;
case BPF_F_ALLOW_OVERRIDE:
attach_flags_str = "override";
break;
case 0:
attach_flags_str = "";
break;
default:
snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags);
attach_flags_str = buf;
}
show_bpf_prog(prog_ids[iter], type,
attach_flags_str, level);
}
return 0;
}
static int show_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
int level)
{
return query_flags & BPF_F_QUERY_EFFECTIVE ?
show_effective_bpf_progs(cgroup_fd, type, level) :
show_attached_bpf_progs(cgroup_fd, type, level);
}
static int do_show(int argc, char **argv)
{
enum bpf_attach_type type;
int has_attached_progs;
const char *path;
int cgroup_fd;
int ret = -1;
query_flags = 0;
if (!REQ_ARGS(1))
return -1;
path = GET_ARG();
while (argc) {
if (is_prefix(*argv, "effective")) {
if (query_flags & BPF_F_QUERY_EFFECTIVE) {
p_err("duplicated argument: %s", *argv);
return -1;
}
query_flags |= BPF_F_QUERY_EFFECTIVE;
NEXT_ARG();
} else {
p_err("expected no more arguments, 'effective', got: '%s'?",
*argv);
return -1;
}
}
cgroup_fd = open(path, O_RDONLY);
if (cgroup_fd < 0) {
p_err("can't open cgroup %s", path);
goto exit;
}
has_attached_progs = cgroup_has_attached_progs(cgroup_fd);
if (has_attached_progs < 0) {
p_err("can't query bpf programs attached to %s: %s",
path, strerror(errno));
goto exit_cgroup;
} else if (!has_attached_progs) {
ret = 0;
goto exit_cgroup;
}
if (json_output)
jsonw_start_array(json_wtr);
else if (query_flags & BPF_F_QUERY_EFFECTIVE)
printf("%-8s %-15s %-15s\n", "ID", "AttachType", "Name");
else
printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType",
"AttachFlags", "Name");
btf_vmlinux = libbpf_find_kernel_btf();
for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
/*
* Not all attach types may be supported, so it's expected,
* that some requests will fail.
* If we were able to get the show for at least one
* attach type, let's return 0.
*/
if (show_bpf_progs(cgroup_fd, type, 0) == 0)
ret = 0;
}
if (json_output)
jsonw_end_array(json_wtr);
exit_cgroup:
close(cgroup_fd);
exit:
return ret;
}
/*
* To distinguish nftw() errors and do_show_tree_fn() errors
* and avoid duplicating error messages, let's return -2
* from do_show_tree_fn() in case of error.
*/
#define NFTW_ERR -1
#define SHOW_TREE_FN_ERR -2
static int do_show_tree_fn(const char *fpath, const struct stat *sb,
int typeflag, struct FTW *ftw)
{
enum bpf_attach_type type;
int has_attached_progs;
int cgroup_fd;
if (typeflag != FTW_D)
return 0;
cgroup_fd = open(fpath, O_RDONLY);
if (cgroup_fd < 0) {
p_err("can't open cgroup %s: %s", fpath, strerror(errno));
return SHOW_TREE_FN_ERR;
}
has_attached_progs = cgroup_has_attached_progs(cgroup_fd);
if (has_attached_progs < 0) {
p_err("can't query bpf programs attached to %s: %s",
fpath, strerror(errno));
close(cgroup_fd);
return SHOW_TREE_FN_ERR;
} else if (!has_attached_progs) {
close(cgroup_fd);
return 0;
}
if (json_output) {
jsonw_start_object(json_wtr);
jsonw_string_field(json_wtr, "cgroup", fpath);
jsonw_name(json_wtr, "programs");
jsonw_start_array(json_wtr);
} else {
printf("%s\n", fpath);
}
btf_vmlinux = libbpf_find_kernel_btf();
for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++)
show_bpf_progs(cgroup_fd, type, ftw->level);
if (errno == EINVAL)
/* Last attach type does not support query.
* Do not report an error for this, especially because batch
* mode would stop processing commands.
*/
errno = 0;
if (json_output) {
jsonw_end_array(json_wtr);
jsonw_end_object(json_wtr);
}
close(cgroup_fd);
return 0;
}
static char *find_cgroup_root(void)
{
struct mntent *mnt;
FILE *f;
f = fopen("/proc/mounts", "r");
if (f == NULL)
return NULL;
while ((mnt = getmntent(f))) {
if (strcmp(mnt->mnt_type, "cgroup2") == 0) {
fclose(f);
return strdup(mnt->mnt_dir);
}
}
fclose(f);
return NULL;
}
static int do_show_tree(int argc, char **argv)
{
char *cgroup_root, *cgroup_alloced = NULL;
int ret;
query_flags = 0;
if (!argc) {
cgroup_alloced = find_cgroup_root();
if (!cgroup_alloced) {
p_err("cgroup v2 isn't mounted");
return -1;
}
cgroup_root = cgroup_alloced;
} else {
cgroup_root = GET_ARG();
while (argc) {
if (is_prefix(*argv, "effective")) {
if (query_flags & BPF_F_QUERY_EFFECTIVE) {
p_err("duplicated argument: %s", *argv);
return -1;
}
query_flags |= BPF_F_QUERY_EFFECTIVE;
NEXT_ARG();
} else {
p_err("expected no more arguments, 'effective', got: '%s'?",
*argv);
return -1;
}
}
}
if (json_output)
jsonw_start_array(json_wtr);
else if (query_flags & BPF_F_QUERY_EFFECTIVE)
printf("%s\n"
"%-8s %-15s %-15s\n",
"CgroupPath",
"ID", "AttachType", "Name");
else
printf("%s\n"
"%-8s %-15s %-15s %-15s\n",
"CgroupPath",
"ID", "AttachType", "AttachFlags", "Name");
switch (nftw(cgroup_root, do_show_tree_fn, 1024, FTW_MOUNT)) {
case NFTW_ERR:
p_err("can't iterate over %s: %s", cgroup_root,
strerror(errno));
ret = -1;
break;
case SHOW_TREE_FN_ERR:
ret = -1;
break;
default:
ret = 0;
}
if (json_output)
jsonw_end_array(json_wtr);
free(cgroup_alloced);
return ret;
}
static int do_attach(int argc, char **argv)
{
enum bpf_attach_type attach_type;
int cgroup_fd, prog_fd;
int attach_flags = 0;
int ret = -1;
int i;
if (argc < 4) {
p_err("too few parameters for cgroup attach");
goto exit;
}
cgroup_fd = open(argv[0], O_RDONLY);
if (cgroup_fd < 0) {
p_err("can't open cgroup %s", argv[0]);
goto exit;
}
attach_type = parse_attach_type(argv[1]);
if (attach_type == __MAX_BPF_ATTACH_TYPE) {
p_err("invalid attach type");
goto exit_cgroup;
}
argc -= 2;
argv = &argv[2];
prog_fd = prog_parse_fd(&argc, &argv);
if (prog_fd < 0)
goto exit_cgroup;
for (i = 0; i < argc; i++) {
if (is_prefix(argv[i], "multi")) {
attach_flags |= BPF_F_ALLOW_MULTI;
} else if (is_prefix(argv[i], "override")) {
attach_flags |= BPF_F_ALLOW_OVERRIDE;
} else {
p_err("unknown option: %s", argv[i]);
goto exit_cgroup;
}
}
if (bpf_prog_attach(prog_fd, cgroup_fd, attach_type, attach_flags)) {
p_err("failed to attach program");
goto exit_prog;
}
if (json_output)
jsonw_null(json_wtr);
ret = 0;
exit_prog:
close(prog_fd);
exit_cgroup:
close(cgroup_fd);
exit:
return ret;
}
static int do_detach(int argc, char **argv)
{
enum bpf_attach_type attach_type;
int prog_fd, cgroup_fd;
int ret = -1;
if (argc < 4) {
p_err("too few parameters for cgroup detach");
goto exit;
}
cgroup_fd = open(argv[0], O_RDONLY);
if (cgroup_fd < 0) {
p_err("can't open cgroup %s", argv[0]);
goto exit;
}
attach_type = parse_attach_type(argv[1]);
if (attach_type == __MAX_BPF_ATTACH_TYPE) {
p_err("invalid attach type");
goto exit_cgroup;
}
argc -= 2;
argv = &argv[2];
prog_fd = prog_parse_fd(&argc, &argv);
if (prog_fd < 0)
goto exit_cgroup;
if (bpf_prog_detach2(prog_fd, cgroup_fd, attach_type)) {
p_err("failed to detach program");
goto exit_prog;
}
if (json_output)
jsonw_null(json_wtr);
ret = 0;
exit_prog:
close(prog_fd);
exit_cgroup:
close(cgroup_fd);
exit:
return ret;
}
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 } CGROUP [**effective**]\n"
" %1$s %2$s tree [CGROUP_ROOT] [**effective**]\n"
" %1$s %2$s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n"
" %1$s %2$s detach CGROUP ATTACH_TYPE PROG\n"
" %1$s %2$s help\n"
"\n"
HELP_SPEC_ATTACH_TYPES "\n"
" " HELP_SPEC_ATTACH_FLAGS "\n"
" " HELP_SPEC_PROGRAM "\n"
" " HELP_SPEC_OPTIONS " |\n"
" {-f|--bpffs} }\n"
"",
bin_name, argv[-2]);
return 0;
}
static const struct cmd cmds[] = {
{ "show", do_show },
{ "list", do_show },
{ "tree", do_show_tree },
{ "attach", do_attach },
{ "detach", do_detach },
{ "help", do_help },
{ 0 }
};
int do_cgroup(int argc, char **argv)
{
return cmd_select(cmds, argc, argv, do_help);
}
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