summaryrefslogtreecommitdiffstats
path: root/samples/bpf/libbpf.c
blob: 65a8d48d2799e43a1cfbd57ba13e353b1fa3856a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/* eBPF mini library */
#include <stdlib.h>
#include <stdio.h>
#include <linux/unistd.h>
#include <unistd.h>
#include <string.h>
#include <linux/netlink.h>
#include <linux/bpf.h>
#include <errno.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <linux/if_packet.h>
#include <arpa/inet.h>
#include "libbpf.h"

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

int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
		   int max_entries)
{
	union bpf_attr attr = {
		.map_type = map_type,
		.key_size = key_size,
		.value_size = value_size,
		.max_entries = max_entries
	};

	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}

int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
{
	union bpf_attr attr = {
		.map_fd = fd,
		.key = ptr_to_u64(key),
		.value = ptr_to_u64(value),
		.flags = flags,
	};

	return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}

int bpf_lookup_elem(int fd, void *key, void *value)
{
	union bpf_attr attr = {
		.map_fd = fd,
		.key = ptr_to_u64(key),
		.value = ptr_to_u64(value),
	};

	return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}

int bpf_delete_elem(int fd, void *key)
{
	union bpf_attr attr = {
		.map_fd = fd,
		.key = ptr_to_u64(key),
	};

	return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
}

int bpf_get_next_key(int fd, void *key, void *next_key)
{
	union bpf_attr attr = {
		.map_fd = fd,
		.key = ptr_to_u64(key),
		.next_key = ptr_to_u64(next_key),
	};

	return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
}

#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))

char bpf_log_buf[LOG_BUF_SIZE];

int bpf_prog_load(enum bpf_prog_type prog_type,
		  const struct bpf_insn *insns, int prog_len,
		  const char *license, int kern_version)
{
	union bpf_attr attr = {
		.prog_type = prog_type,
		.insns = ptr_to_u64((void *) insns),
		.insn_cnt = prog_len / sizeof(struct bpf_insn),
		.license = ptr_to_u64((void *) license),
		.log_buf = ptr_to_u64(bpf_log_buf),
		.log_size = LOG_BUF_SIZE,
		.log_level = 1,
	};

	/* assign one field outside of struct init to make sure any
	 * padding is zero initialized
	 */
	attr.kern_version = kern_version;

	bpf_log_buf[0] = 0;

	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
}

int bpf_obj_pin(int fd, const char *pathname)
{
	union bpf_attr attr = {
		.pathname	= ptr_to_u64((void *)pathname),
		.bpf_fd		= fd,
	};

	return syscall(__NR_bpf, BPF_OBJ_PIN, &attr, sizeof(attr));
}

int bpf_obj_get(const char *pathname)
{
	union bpf_attr attr = {
		.pathname	= ptr_to_u64((void *)pathname),
	};

	return syscall(__NR_bpf, BPF_OBJ_GET, &attr, sizeof(attr));
}

int open_raw_sock(const char *name)
{
	struct sockaddr_ll sll;
	int sock;

	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
	if (sock < 0) {
		printf("cannot create raw socket\n");
		return -1;
	}

	memset(&sll, 0, sizeof(sll));
	sll.sll_family = AF_PACKET;
	sll.sll_ifindex = if_nametoindex(name);
	sll.sll_protocol = htons(ETH_P_ALL);
	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
		printf("bind to %s: %s\n", name, strerror(errno));
		close(sock);
		return -1;
	}

	return sock;
}

int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
		    int group_fd, unsigned long flags)
{
	return syscall(__NR_perf_event_open, attr, pid, cpu,
		       group_fd, flags);
}