v4.19.13 snapshot.
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
new file mode 100644
index 0000000..ee7a976
--- /dev/null
+++ b/tools/bpf/bpftool/cgroup.c
@@ -0,0 +1,479 @@
+// SPDX-License-Identifier: GPL-2.0+
+// 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.h>
+
+#include "main.h"
+
+#define HELP_SPEC_ATTACH_FLAGS						\
+	"ATTACH_FLAGS := { multi | override }"
+
+#define HELP_SPEC_ATTACH_TYPES						       \
+	"       ATTACH_TYPE := { ingress | egress | sock_create |\n"	       \
+	"                        sock_ops | device | bind4 | bind6 |\n"	       \
+	"                        post_bind4 | post_bind6 | connect4 |\n"       \
+	"                        connect6 | sendmsg4 | sendmsg6 }"
+
+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",
+	[BPF_CGROUP_INET4_BIND] = "bind4",
+	[BPF_CGROUP_INET6_BIND] = "bind6",
+	[BPF_CGROUP_INET4_CONNECT] = "connect4",
+	[BPF_CGROUP_INET6_CONNECT] = "connect6",
+	[BPF_CGROUP_INET4_POST_BIND] = "post_bind4",
+	[BPF_CGROUP_INET6_POST_BIND] = "post_bind6",
+	[BPF_CGROUP_UDP4_SENDMSG] = "sendmsg4",
+	[BPF_CGROUP_UDP6_SENDMSG] = "sendmsg6",
+	[__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 show_bpf_prog(int id, const char *attach_type_str,
+			 const char *attach_flags_str,
+			 int level)
+{
+	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("%s%-8u %-15s %-15s %-15s\n", level ? "    " : "",
+		       info.id,
+		       attach_type_str,
+		       attach_flags_str,
+		       info.name);
+	}
+
+	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, 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;
+	__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++)
+		show_bpf_prog(prog_ids[iter], attach_type_strings[type],
+			      attach_flags_str, level);
+
+	return 0;
+}
+
+static int do_show(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 show");
+		goto exit;
+	} else if (argc > 1) {
+		p_err("too many parameters for cgroup show");
+		goto exit;
+	}
+
+	cgroup_fd = open(argv[0], O_RDONLY);
+	if (cgroup_fd < 0) {
+		p_err("can't open cgroup %s", 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 show for at least one
+		 * attach type, let's return 0.
+		 */
+		if (show_attached_bpf_progs(cgroup_fd, type, 0) == 0)
+			ret = 0;
+	}
+
+	if (json_output)
+		jsonw_end_array(json_wtr);
+
+	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;
+	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;
+	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[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;
+
+	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[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 { 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"
+		"\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], 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);
+}