bpftool: implement cgroup bpf operations
This patch adds basic cgroup bpf operations to bpftool:
cgroup list, attach and detach commands.
Usage is described in the corresponding man pages,
and examples are provided.
Syntax:
$ bpftool cgroup list CGROUP
$ bpftool cgroup attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]
$ bpftool cgroup detach CGROUP ATTACH_TYPE PROG
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
new file mode 100644
index 0000000..34ca303
--- /dev/null
+++ b/tools/bpf/bpftool/cgroup.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (C) 2017 Facebook
+// Author: Roman Gushchin <guro@fb.com>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <bpf.h>
+
+#include "main.h"
+
+#define HELP_SPEC_ATTACH_FLAGS \
+ "ATTACH_FLAGS := { multi | override }"
+
+#define HELP_SPEC_ATTACH_TYPES \
+ "ATTACH_TYPE := { ingress | egress | sock_create | sock_ops | device }"
+
+static const char * const attach_type_strings[] = {
+ [BPF_CGROUP_INET_INGRESS] = "ingress",
+ [BPF_CGROUP_INET_EGRESS] = "egress",
+ [BPF_CGROUP_INET_SOCK_CREATE] = "sock_create",
+ [BPF_CGROUP_SOCK_OPS] = "sock_ops",
+ [BPF_CGROUP_DEVICE] = "device",
+ [__MAX_BPF_ATTACH_TYPE] = NULL,
+};
+
+static enum bpf_attach_type parse_attach_type(const char *str)
+{
+ enum bpf_attach_type type;
+
+ for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
+ if (attach_type_strings[type] &&
+ is_prefix(str, attach_type_strings[type]))
+ return type;
+ }
+
+ return __MAX_BPF_ATTACH_TYPE;
+}
+
+static int list_bpf_prog(int id, const char *attach_type_str,
+ const char *attach_flags_str)
+{
+ struct bpf_prog_info info = {};
+ __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;
+ }
+
+ if (json_output) {
+ jsonw_start_object(json_wtr);
+ jsonw_uint_field(json_wtr, "id", info.id);
+ jsonw_string_field(json_wtr, "attach_type",
+ attach_type_str);
+ jsonw_string_field(json_wtr, "attach_flags",
+ attach_flags_str);
+ jsonw_string_field(json_wtr, "name", info.name);
+ jsonw_end_object(json_wtr);
+ } else {
+ printf("%-8u %-15s %-15s %-15s\n", info.id,
+ attach_type_str,
+ attach_flags_str,
+ info.name);
+ }
+
+ close(prog_fd);
+ return 0;
+}
+
+static int list_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
+{
+ __u32 prog_ids[1024] = {0};
+ char *attach_flags_str;
+ __u32 prog_cnt, iter;
+ __u32 attach_flags;
+ char buf[32];
+ int ret;
+
+ prog_cnt = ARRAY_SIZE(prog_ids);
+ ret = bpf_prog_query(cgroup_fd, type, 0, &attach_flags, prog_ids,
+ &prog_cnt);
+ if (ret)
+ return ret;
+
+ if (prog_cnt == 0)
+ return 0;
+
+ 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;
+ }
+
+ for (iter = 0; iter < prog_cnt; iter++)
+ list_bpf_prog(prog_ids[iter], attach_type_strings[type],
+ attach_flags_str);
+
+ return 0;
+}
+
+static int do_list(int argc, char **argv)
+{
+ enum bpf_attach_type type;
+ int cgroup_fd;
+ int ret = -1;
+
+ if (argc < 1) {
+ p_err("too few parameters for cgroup list\n");
+ goto exit;
+ } else if (argc > 1) {
+ p_err("too many parameters for cgroup list\n");
+ goto exit;
+ }
+
+ cgroup_fd = open(argv[0], O_RDONLY);
+ if (cgroup_fd < 0) {
+ p_err("can't open cgroup %s\n", argv[1]);
+ goto exit;
+ }
+
+ if (json_output)
+ jsonw_start_array(json_wtr);
+ else
+ printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType",
+ "AttachFlags", "Name");
+
+ 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 list for at least one
+ * attach type, let's return 0.
+ */
+ if (list_attached_bpf_progs(cgroup_fd, type) == 0)
+ ret = 0;
+ }
+
+ if (json_output)
+ jsonw_end_array(json_wtr);
+
+ close(cgroup_fd);
+exit:
+ 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\n");
+ goto exit;
+ }
+
+ cgroup_fd = open(argv[0], O_RDONLY);
+ if (cgroup_fd < 0) {
+ p_err("can't open cgroup %s\n", argv[1]);
+ goto exit;
+ }
+
+ attach_type = parse_attach_type(argv[1]);
+ if (attach_type == __MAX_BPF_ATTACH_TYPE) {
+ p_err("invalid attach type\n");
+ 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\n", 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\n");
+ goto exit;
+ }
+
+ cgroup_fd = open(argv[0], O_RDONLY);
+ if (cgroup_fd < 0) {
+ p_err("can't open cgroup %s\n", argv[1]);
+ 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: %s %s list CGROUP\n"
+ " %s %s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n"
+ " %s %s detach CGROUP ATTACH_TYPE PROG\n"
+ " %s %s help\n"
+ "\n"
+ " " HELP_SPEC_ATTACH_TYPES "\n"
+ " " HELP_SPEC_ATTACH_FLAGS "\n"
+ " " HELP_SPEC_PROGRAM "\n"
+ " " HELP_SPEC_OPTIONS "\n"
+ "",
+ bin_name, argv[-2], bin_name, argv[-2],
+ bin_name, argv[-2], bin_name, argv[-2]);
+
+ return 0;
+}
+
+static const struct cmd cmds[] = {
+ { "list", do_list },
+ { "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);
+}