1/*
2 * common eBPF ELF operations.
3 *
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 */
8
9#include <stdlib.h>
10#include <memory.h>
11#include <unistd.h>
12#include <asm/unistd.h>
13#include <linux/bpf.h>
14#include "bpf.h"
15
16/*
17 * When building perf, unistd.h is override. Define __NR_bpf is
18 * required to be defined.
19 */
20#ifndef __NR_bpf
21# if defined(__i386__)
22#  define __NR_bpf 357
23# elif defined(__x86_64__)
24#  define __NR_bpf 321
25# elif defined(__aarch64__)
26#  define __NR_bpf 280
27# else
28#  error __NR_bpf not defined. libbpf does not support your arch.
29# endif
30#endif
31
32static __u64 ptr_to_u64(void *ptr)
33{
34	return (__u64) (unsigned long) ptr;
35}
36
37static int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
38		   unsigned int size)
39{
40	return syscall(__NR_bpf, cmd, attr, size);
41}
42
43int bpf_create_map(enum bpf_map_type map_type, int key_size,
44		   int value_size, int max_entries)
45{
46	union bpf_attr attr;
47
48	memset(&attr, '\0', sizeof(attr));
49
50	attr.map_type = map_type;
51	attr.key_size = key_size;
52	attr.value_size = value_size;
53	attr.max_entries = max_entries;
54
55	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
56}
57
58int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns,
59		     size_t insns_cnt, char *license,
60		     u32 kern_version, char *log_buf, size_t log_buf_sz)
61{
62	int fd;
63	union bpf_attr attr;
64
65	bzero(&attr, sizeof(attr));
66	attr.prog_type = type;
67	attr.insn_cnt = (__u32)insns_cnt;
68	attr.insns = ptr_to_u64(insns);
69	attr.license = ptr_to_u64(license);
70	attr.log_buf = ptr_to_u64(NULL);
71	attr.log_size = 0;
72	attr.log_level = 0;
73	attr.kern_version = kern_version;
74
75	fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
76	if (fd >= 0 || !log_buf || !log_buf_sz)
77		return fd;
78
79	/* Try again with log */
80	attr.log_buf = ptr_to_u64(log_buf);
81	attr.log_size = log_buf_sz;
82	attr.log_level = 1;
83	log_buf[0] = 0;
84	return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
85}
86