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_insn.h"
18#include "bpf_load.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
61 if (object) {
62 assert(!load_bpf_file((char *)object));
63 return prog_fd[0];
64 } else {
65 return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,
66 insns, insns_cnt, "GPL", 0,
67 bpf_log_buf, BPF_LOG_BUF_SIZE);
68 }
69}
70
71static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,
72 uint32_t value)
73{
74 int fd, ret;
75
76 if (flags & BPF_F_PIN) {
77 fd = bpf_map_create();
78 printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));
79 assert(fd > 0);
80
81 ret = bpf_obj_pin(fd, file);
82 printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
83 assert(ret == 0);
84 } else {
85 fd = bpf_obj_get(file);
86 printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
87 assert(fd > 0);
88 }
89
90 if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {
91 ret = bpf_map_update_elem(fd, &key, &value, 0);
92 printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,
93 ret, strerror(errno));
94 assert(ret == 0);
95 } else if (flags & BPF_F_KEY) {
96 ret = bpf_map_lookup_elem(fd, &key, &value);
97 printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,
98 ret, strerror(errno));
99 assert(ret == 0);
100 }
101
102 return 0;
103}
104
105static int bpf_do_prog(const char *file, uint32_t flags, const char *object)
106{
107 int fd, sock, ret;
108
109 if (flags & BPF_F_PIN) {
110 fd = bpf_prog_create(object);
111 printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));
112 assert(fd > 0);
113
114 ret = bpf_obj_pin(fd, file);
115 printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
116 assert(ret == 0);
117 } else {
118 fd = bpf_obj_get(file);
119 printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
120 assert(fd > 0);
121 }
122
123 sock = open_raw_sock("lo");
124 assert(sock > 0);
125
126 ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));
127 printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,
128 ret, strerror(errno));
129 assert(ret == 0);
130
131 return 0;
132}
133
134int main(int argc, char **argv)
135{
136 const char *file = NULL, *object = NULL;
137 uint32_t key = 0, value = 0, flags = 0;
138 int opt, mode = BPF_M_UNSPEC;
139
140 while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {
141 switch (opt) {
142
143 case 'F':
144 file = optarg;
145 break;
146 case 'P':
147 flags |= BPF_F_PIN;
148 break;
149 case 'G':
150 flags |= BPF_F_GET;
151 break;
152
153 case 'm':
154 mode = BPF_M_MAP;
155 break;
156 case 'k':
157 key = strtoul(optarg, NULL, 0);
158 flags |= BPF_F_KEY;
159 break;
160 case 'v':
161 value = strtoul(optarg, NULL, 0);
162 flags |= BPF_F_VAL;
163 break;
164
165 case 'p':
166 mode = BPF_M_PROG;
167 break;
168 case 'o':
169 object = optarg;
170 break;
171 default:
172 goto out;
173 }
174 }
175
176 if (!(flags & BPF_F_PIN_GET) || !file)
177 goto out;
178
179 switch (mode) {
180 case BPF_M_MAP:
181 return bpf_do_map(file, flags, key, value);
182 case BPF_M_PROG:
183 return bpf_do_prog(file, flags, object);
184 }
185out:
186 usage();
187 return -1;
188}
189
