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