Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* eBPF mini library */
2#include <stdlib.h>
3#include <stdio.h>
4#include <linux/unistd.h>
5#include <unistd.h>
6#include <string.h>
7#include <linux/netlink.h>
8#include <linux/bpf.h>
9#include <errno.h>
10#include <net/ethernet.h>
11#include <net/if.h>
12#include <linux/if_packet.h>
13#include <arpa/inet.h>
14#include "libbpf.h"
15
16static __u64 ptr_to_u64(void *ptr)
17{
18 return (__u64) (unsigned long) ptr;
19}
20
21int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
22 int max_entries, int map_flags)
23{
24 union bpf_attr attr = {
25 .map_type = map_type,
26 .key_size = key_size,
27 .value_size = value_size,
28 .max_entries = max_entries,
29 .map_flags = map_flags,
30 };
31
32 return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
33}
34
35int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
36{
37 union bpf_attr attr = {
38 .map_fd = fd,
39 .key = ptr_to_u64(key),
40 .value = ptr_to_u64(value),
41 .flags = flags,
42 };
43
44 return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
45}
46
47int bpf_lookup_elem(int fd, void *key, void *value)
48{
49 union bpf_attr attr = {
50 .map_fd = fd,
51 .key = ptr_to_u64(key),
52 .value = ptr_to_u64(value),
53 };
54
55 return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
56}
57
58int bpf_delete_elem(int fd, void *key)
59{
60 union bpf_attr attr = {
61 .map_fd = fd,
62 .key = ptr_to_u64(key),
63 };
64
65 return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
66}
67
68int bpf_get_next_key(int fd, void *key, void *next_key)
69{
70 union bpf_attr attr = {
71 .map_fd = fd,
72 .key = ptr_to_u64(key),
73 .next_key = ptr_to_u64(next_key),
74 };
75
76 return syscall(__NR_bpf, BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
77}
78
79#define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
80
81char bpf_log_buf[LOG_BUF_SIZE];
82
83int bpf_prog_load(enum bpf_prog_type prog_type,
84 const struct bpf_insn *insns, int prog_len,
85 const char *license, int kern_version)
86{
87 union bpf_attr attr = {
88 .prog_type = prog_type,
89 .insns = ptr_to_u64((void *) insns),
90 .insn_cnt = prog_len / sizeof(struct bpf_insn),
91 .license = ptr_to_u64((void *) license),
92 .log_buf = ptr_to_u64(bpf_log_buf),
93 .log_size = LOG_BUF_SIZE,
94 .log_level = 1,
95 };
96
97 /* assign one field outside of struct init to make sure any
98 * padding is zero initialized
99 */
100 attr.kern_version = kern_version;
101
102 bpf_log_buf[0] = 0;
103
104 return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
105}
106
107int bpf_obj_pin(int fd, const char *pathname)
108{
109 union bpf_attr attr = {
110 .pathname = ptr_to_u64((void *)pathname),
111 .bpf_fd = fd,
112 };
113
114 return syscall(__NR_bpf, BPF_OBJ_PIN, &attr, sizeof(attr));
115}
116
117int bpf_obj_get(const char *pathname)
118{
119 union bpf_attr attr = {
120 .pathname = ptr_to_u64((void *)pathname),
121 };
122
123 return syscall(__NR_bpf, BPF_OBJ_GET, &attr, sizeof(attr));
124}
125
126int open_raw_sock(const char *name)
127{
128 struct sockaddr_ll sll;
129 int sock;
130
131 sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
132 if (sock < 0) {
133 printf("cannot create raw socket\n");
134 return -1;
135 }
136
137 memset(&sll, 0, sizeof(sll));
138 sll.sll_family = AF_PACKET;
139 sll.sll_ifindex = if_nametoindex(name);
140 sll.sll_protocol = htons(ETH_P_ALL);
141 if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
142 printf("bind to %s: %s\n", name, strerror(errno));
143 close(sock);
144 return -1;
145 }
146
147 return sock;
148}
149
150int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
151 int group_fd, unsigned long flags)
152{
153 return syscall(__NR_perf_event_open, attr, pid, cpu,
154 group_fd, flags);
155}