bpftool: introduce cgroup tree command (2058b383) · Commits · 戴 / test

tools/bpf/bpftool/cgroup.c

+165 −5

Original line number	Diff line number	Diff line
		@@ -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 },

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