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-rw-r--r--tools/bpf/bpftool/cgroup.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
new file mode 100644
index 000000000..b46a998d8
--- /dev/null
+++ b/tools/bpf/bpftool/cgroup.c
@@ -0,0 +1,655 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// 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>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+
+#include "main.h"
+
+#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_inet4_getpeername |\n" \
+ " cgroup_inet6_getpeername | cgroup_inet4_getsockname |\n" \
+ " cgroup_inet6_getsockname | cgroup_udp4_sendmsg |\n" \
+ " cgroup_udp6_sendmsg | cgroup_udp4_recvmsg |\n" \
+ " cgroup_udp6_recvmsg | cgroup_sysctl |\n" \
+ " cgroup_getsockopt | cgroup_setsockopt |\n" \
+ " 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_obj_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_obj_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)
+{
+ enum bpf_attach_type type;
+ bool no_prog = true;
+
+ for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
+ int count = count_attached_bpf_progs(cgroup_fd, type);
+
+ if (count < 0 && errno != EINVAL)
+ 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);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 09:44:15 +0000