1#include <linux/unistd.h>
2#include <linux/bpf.h>
3
4#include <stdio.h>
5#include <stdlib.h>
6#include <stdint.h>
7#include <unistd.h>
8#include <string.h>
9#include <assert.h>
10#include <errno.h>
11
12#include <sys/types.h>
13#include <sys/socket.h>
14
15#include <bpf/bpf.h>
16
17#include <bpf/libbpf.h>
18#include "bpf_insn.h"
19#include "sock_example.h"
20
21#define BPF_F_PIN (1 << 0)
22#define BPF_F_GET (1 << 1)
23#define BPF_F_PIN_GET (BPF_F_PIN | BPF_F_GET)
24
25#define BPF_F_KEY (1 << 2)
26#define BPF_F_VAL (1 << 3)
27#define BPF_F_KEY_VAL (BPF_F_KEY | BPF_F_VAL)
28
29#define BPF_M_UNSPEC 0
30#define BPF_M_MAP 1
31#define BPF_M_PROG 2
32
33char bpf_log_buf[BPF_LOG_BUF_SIZE];
34
35static void usage(void)
36{
37 printf("Usage: fds_example [...]\n");
38 printf(" -F <file> File to pin/get object\n");
39 printf(" -P |- pin object\n");
40 printf(" -G `- get object\n");
41 printf(" -m eBPF map mode\n");
42 printf(" -k <key> |- map key\n");
43 printf(" -v <value> `- map value\n");
44 printf(" -p eBPF prog mode\n");
45 printf(" -o <object> `- object file\n");
46 printf(" -h Display this help.\n");
47}
48
49static int bpf_map_create(void)
50{
51 return bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(uint32_t),
52 sizeof(uint32_t), 1024, 0);
53}
54
55static int bpf_prog_create(const char *object)
56{
57 static struct bpf_insn insns[] = {
58 BPF_MOV64_IMM(BPF_REG_0, 1),
59 BPF_EXIT_INSN(),
60 };
61 size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn);
62 struct bpf_object *obj;
63 int prog_fd;
64
65 if (object) {
66 assert(!bpf_prog_load(object, BPF_PROG_TYPE_UNSPEC,
67 &obj, &prog_fd));
68 return prog_fd;
69 } else {
70 return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
71 insns, insns_cnt, "GPL", 0,
72 bpf_log_buf, BPF_LOG_BUF_SIZE);
73 }
74}
75
76static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,
77 uint32_t value)
78{
79 int fd, ret;
80
81 if (flags & BPF_F_PIN) {
82 fd = bpf_map_create();
83 printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));
84 assert(fd > 0);
85
86 ret = bpf_obj_pin(fd, file);
87 printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
88 assert(ret == 0);
89 } else {
90 fd = bpf_obj_get(file);
91 printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
92 assert(fd > 0);
93 }
94
95 if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {
96 ret = bpf_map_update_elem(fd, &key, &value, 0);
97 printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,
98 ret, strerror(errno));
99 assert(ret == 0);
100 } else if (flags & BPF_F_KEY) {
101 ret = bpf_map_lookup_elem(fd, &key, &value);
102 printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,
103 ret, strerror(errno));
104 assert(ret == 0);
105 }
106
107 return 0;
108}
109
110static int bpf_do_prog(const char *file, uint32_t flags, const char *object)
111{
112 int fd, sock, ret;
113
114 if (flags & BPF_F_PIN) {
115 fd = bpf_prog_create(object);
116 printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));
117 assert(fd > 0);
118
119 ret = bpf_obj_pin(fd, file);
120 printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
121 assert(ret == 0);
122 } else {
123 fd = bpf_obj_get(file);
124 printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
125 assert(fd > 0);
126 }
127
128 sock = open_raw_sock("lo");
129 assert(sock > 0);
130
131 ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));
132 printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,
133 ret, strerror(errno));
134 assert(ret == 0);
135
136 return 0;
137}
138
139int main(int argc, char **argv)
140{
141 const char *file = NULL, *object = NULL;
142 uint32_t key = 0, value = 0, flags = 0;
143 int opt, mode = BPF_M_UNSPEC;
144
145 while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {
146 switch (opt) {
147
148 case 'F':
149 file = optarg;
150 break;
151 case 'P':
152 flags |= BPF_F_PIN;
153 break;
154 case 'G':
155 flags |= BPF_F_GET;
156 break;
157
158 case 'm':
159 mode = BPF_M_MAP;
160 break;
161 case 'k':
162 key = strtoul(optarg, NULL, 0);
163 flags |= BPF_F_KEY;
164 break;
165 case 'v':
166 value = strtoul(optarg, NULL, 0);
167 flags |= BPF_F_VAL;
168 break;
169
170 case 'p':
171 mode = BPF_M_PROG;
172 break;
173 case 'o':
174 object = optarg;
175 break;
176 default:
177 goto out;
178 }
179 }
180
181 if (!(flags & BPF_F_PIN_GET) || !file)
182 goto out;
183
184 switch (mode) {
185 case BPF_M_MAP:
186 return bpf_do_map(file, flags, key, value);
187 case BPF_M_PROG:
188 return bpf_do_prog(file, flags, object);
189 }
190out:
191 usage();
192 return -1;
193}
194
