path: root/tools/lib/bpf/bpf.c

// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)

/*
 * common eBPF ELF operations.
 *
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License (not later!)
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not,  see <http://www.gnu.org/licenses>
 */

#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <errno.h>
#include <linux/bpf.h>
#include <limits.h>
#include "bpf.h"
#include "libbpf.h"
#include "libbpf_internal.h"

/*
 * When building perf, unistd.h is overridden. __NR_bpf is
 * required to be defined explicitly.
 */
#ifndef __NR_bpf
# if defined(__i386__)
#  define __NR_bpf 357
# elif defined(__x86_64__)
#  define __NR_bpf 321
# elif defined(__aarch64__)
#  define __NR_bpf 280
# elif defined(__sparc__)
#  define __NR_bpf 349
# elif defined(__s390__)
#  define __NR_bpf 351
# elif defined(__arc__)
#  define __NR_bpf 280
# elif defined(__mips__) && defined(_ABIO32)
#  define __NR_bpf 4355
# elif defined(__mips__) && defined(_ABIN32)
#  define __NR_bpf 6319
# elif defined(__mips__) && defined(_ABI64)
#  define __NR_bpf 5315
# else
#  error __NR_bpf not defined. libbpf does not support your arch.
# endif
#endif

static inline __u64 ptr_to_u64(const void *ptr)
{
	return (__u64) (unsigned long) ptr;
}

static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
			  unsigned int size)
{
	return syscall(__NR_bpf, cmd, attr, size);
}

static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr,
			     unsigned int size)
{
	int fd;

	fd = sys_bpf(cmd, attr, size);
	return ensure_good_fd(fd);
}

#define PROG_LOAD_ATTEMPTS 5

static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts)
{
	int fd;

	do {
		fd = sys_bpf_fd(BPF_PROG_LOAD, attr, size);
	} while (fd < 0 && errno == EAGAIN && --attempts > 0);

	return fd;
}

int bpf_map_create(enum bpf_map_type map_type,
		   const char *map_name,
		   __u32 key_size,
		   __u32 value_size,
		   __u32 max_entries,
		   const struct bpf_map_create_opts *opts)
{
	const size_t attr_sz = offsetofend(union bpf_attr, map_extra);
	union bpf_attr attr;
	int fd;

	memset(&attr, 0, attr_sz);

	if (!OPTS_VALID(opts, bpf_map_create_opts))
		return libbpf_err(-EINVAL);

	attr.map_type = map_type;
	if (map_name)
		strncat(attr.map_name, map_name, sizeof(attr.map_name) - 1);
	attr.key_size = key_size;
	attr.value_size = value_size;
	attr.max_entries = max_entries;

	attr.btf_fd = OPTS_GET(opts, btf_fd, 0);
	attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0);
	attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0);
	attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0);

	attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0);
	attr.map_flags = OPTS_GET(opts, map_flags, 0);
	attr.map_extra = OPTS_GET(opts, map_extra, 0);
	attr.numa_node = OPTS_GET(opts, numa_node, 0);
	attr.map_ifindex = OPTS_GET(opts, map_ifindex, 0);

	fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, attr_sz);
	return libbpf_err_errno(fd);
}

int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
{
	LIBBPF_OPTS(bpf_map_create_opts, p);

	p.map_flags = create_attr->map_flags;
	p.numa_node = create_attr->numa_node;
	p.btf_fd = create_attr->btf_fd;
	p.btf_key