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