bpftool: introduce cgroup tree command
This commit introduces a new bpftool command: cgroup tree.
The idea is to iterate over the whole cgroup tree and print
all attached programs.
I was debugging a bpf/systemd issue, and found, that there is
no simple way to listen all bpf programs attached to cgroups.
I did master something in bash, but after some time got tired of it,
and decided, that adding a dedicated bpftool command could be
a better idea.
So, here it is:
$ sudo ./bpftool cgroup tree
CgroupPath
ID AttachType AttachFlags Name
/sys/fs/cgroup/system.slice/systemd-machined.service
18 ingress
17 egress
/sys/fs/cgroup/system.slice/systemd-logind.service
20 ingress
19 egress
/sys/fs/cgroup/system.slice/systemd-udevd.service
16 ingress
15 egress
/sys/fs/cgroup/system.slice/systemd-journald.service
14 ingress
13 egress
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Roman Gushchin
Daniel Borkmann
Родитель
ab8565af68
Коммит
2058b38371
|
|
@ -2,7 +2,12 @@
|
|||
// Copyright (C) 2017 Facebook
|
||||
// Author: Roman Gushchin <guro@fb.com>
|
||||
|
||||
#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>
|
||||
|
|
@ -53,7 +58,8 @@ static enum bpf_attach_type parse_attach_type(const char *str)
|
|||
}
|
||||
|
||||
static int show_bpf_prog(int id, const char *attach_type_str,
|
||||
const char *attach_flags_str)
|
||||
const char *attach_flags_str,
|
||||
int level)
|
||||
{
|
||||
struct bpf_prog_info info = {};
|
||||
__u32 info_len = sizeof(info);
|
||||
|
|
@ -78,7 +84,8 @@ static int show_bpf_prog(int id, const char *attach_type_str,
|
|||
jsonw_string_field(json_wtr, "name", info.name);
|
||||
jsonw_end_object(json_wtr);
|
||||
} else {
|
||||
printf("%-8u %-15s %-15s %-15s\n", info.id,
|
||||
printf("%s%-8u %-15s %-15s %-15s\n", level ? " " : "",
|
||||
info.id,
|
||||
attach_type_str,
|
||||
attach_flags_str,
|
||||
info.name);
|
||||
|
|
@ -88,7 +95,20 @@ static int show_bpf_prog(int id, const char *attach_type_str,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
|
||||
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, 0, NULL, NULL, &prog_cnt);
|
||||
if (ret)
|
||||
return -1;
|
||||
|
||||
return prog_cnt;
|
||||
}
|
||||
|
||||
static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
|
||||
int level)
|
||||
{
|
||||
__u32 prog_ids[1024] = {0};
|
||||
char *attach_flags_str;
|
||||
|
|
@ -123,7 +143,7 @@ static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
|
|||
|
||||
for (iter = 0; iter < prog_cnt; iter++)
|
||||
show_bpf_prog(prog_ids[iter], attach_type_strings[type],
|
||||
attach_flags_str);
|
||||
attach_flags_str, level);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -161,7 +181,7 @@ static int do_show(int argc, char **argv)
|
|||
* If we were able to get the show for at least one
|
||||
* attach type, let's return 0.
|
||||
*/
|
||||
if (show_attached_bpf_progs(cgroup_fd, type) == 0)
|
||||
if (show_attached_bpf_progs(cgroup_fd, type, 0) == 0)
|
||||
ret = 0;
|
||||
}
|
||||
|
||||
|
|
@ -173,6 +193,143 @@ 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;
|
||||
bool skip = true;
|
||||
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;
|
||||
}
|
||||
|
||||
for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
|
||||
int count = count_attached_bpf_progs(cgroup_fd, type);
|
||||
|
||||
if (count < 0 && errno != EINVAL) {
|
||||
p_err("can't query bpf programs attached to %s: %s",
|
||||
fpath, strerror(errno));
|
||||
close(cgroup_fd);
|
||||
return SHOW_TREE_FN_ERR;
|
||||
}
|
||||
if (count > 0) {
|
||||
skip = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (skip) {
|
||||
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);
|
||||
}
|
||||
|
||||
for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++)
|
||||
show_attached_bpf_progs(cgroup_fd, type, ftw->level);
|
||||
|
||||
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;
|
||||
int ret;
|
||||
|
||||
switch (argc) {
|
||||
case 0:
|
||||
cgroup_root = find_cgroup_root();
|
||||
if (!cgroup_root) {
|
||||
p_err("cgroup v2 isn't mounted");
|
||||
return -1;
|
||||
}
|
||||
break;
|
||||
case 1:
|
||||
cgroup_root = argv[0];
|
||||
break;
|
||||
default:
|
||||
p_err("too many parameters for cgroup tree");
|
||||
return -1;
|
||||
}
|
||||
|
||||
|
||||
if (json_output)
|
||||
jsonw_start_array(json_wtr);
|
||||
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);
|
||||
|
||||
if (argc == 0)
|
||||
free(cgroup_root);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int do_attach(int argc, char **argv)
|
||||
{
|
||||
enum bpf_attach_type attach_type;
|
||||
|
|
@ -289,6 +446,7 @@ static int do_help(int argc, char **argv)
|
|||
|
||||
fprintf(stderr,
|
||||
"Usage: %s %s { show | list } CGROUP\n"
|
||||
" %s %s tree [CGROUP_ROOT]\n"
|
||||
" %s %s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n"
|
||||
" %s %s detach CGROUP ATTACH_TYPE PROG\n"
|
||||
" %s %s help\n"
|
||||
|
|
@ -298,6 +456,7 @@ static int do_help(int argc, char **argv)
|
|||
" " HELP_SPEC_PROGRAM "\n"
|
||||
" " HELP_SPEC_OPTIONS "\n"
|
||||
"",
|
||||
bin_name, argv[-2],
|
||||
bin_name, argv[-2], bin_name, argv[-2],
|
||||
bin_name, argv[-2], bin_name, argv[-2]);
|
||||
|
||||
|
|
@ -307,6 +466,7 @@ static int do_help(int argc, char **argv)
|
|||
static const struct cmd cmds[] = {
|
||||
{ "show", do_show },
|
||||
{ "list", do_show },
|
||||
{ "tree", do_show_tree },
|
||||
{ "attach", do_attach },
|
||||
{ "detach", do_detach },
|
||||
{ "help", do_help },
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче