#include <linux/unistd.h>#include <linux/bpf.h> #include <stdio.h>#include <stdlib.h>#include <stdint.h>#include <unistd.h>#include <string.h>#include <assert.h>#include <errno.h> #include <sys/types.h>#include <sys/socket.h> #include <bpf/bpf.h> #include "bpf_insn.h"#include "bpf_load.h"#include "sock_example.h" #define BPF_F_PIN	(1 << 0)#define BPF_F_GET	(1 << 1)#define BPF_F_PIN_GET	(BPF_F_PIN | BPF_F_GET) #define BPF_F_KEY	(1 << 2)#define BPF_F_VAL	(1 << 3)#define BPF_F_KEY_VAL	(BPF_F_KEY | BPF_F_VAL) #define BPF_M_UNSPEC	0#define BPF_M_MAP	1#define BPF_M_PROG	2 static void usage(void){	printf("Usage: fds_example [...]\n");	printf("       -F <file>   File to pin/get object\n");	printf("       -P          |- pin object\n");	printf("       -G          `- get object\n");	printf("       -m          eBPF map mode\n");	printf("       -k <key>    |- map key\n");	printf("       -v <value>  `- map value\n");	printf("       -p          eBPF prog mode\n");	printf("       -o <object> `- object file\n");	printf("       -h          Display this help.\n");} static int bpf_map_create(void){	return bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(uint32_t),			      sizeof(uint32_t), 1024, 0);} static int bpf_prog_create(const char *object){	static struct bpf_insn insns[] = {		BPF_MOV64_IMM(BPF_REG_0, 1),		BPF_EXIT_INSN(),	};	size_t insns_cnt = sizeof(insns) / sizeof(struct bpf_insn); 	if (object) {		assert(!load_bpf_file((char *)object));		return prog_fd[0];	} else {		return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,					insns, insns_cnt, "GPL", 0,					bpf_log_buf, BPF_LOG_BUF_SIZE);	}} static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,		      uint32_t value){	int fd, ret; 	if (flags & BPF_F_PIN) {		fd = bpf_map_create();		printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));		assert(fd > 0); 		ret = bpf_obj_pin(fd, file);		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));		assert(ret == 0);	} else {		fd = bpf_obj_get(file);		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));		assert(fd > 0);	} 	if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {		ret = bpf_map_update_elem(fd, &key, &value, 0);		printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,		       ret, strerror(errno));		assert(ret == 0);	} else if (flags & BPF_F_KEY) {		ret = bpf_map_lookup_elem(fd, &key, &value);		printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,		       ret, strerror(errno));		assert(ret == 0);	} 	return 0;} static int bpf_do_prog(const char *file, uint32_t flags, const char *object){	int fd, sock, ret; 	if (flags & BPF_F_PIN) {		fd = bpf_prog_create(object);		printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));		assert(fd > 0); 		ret = bpf_obj_pin(fd, file);		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));		assert(ret == 0);	} else {		fd = bpf_obj_get(file);		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));		assert(fd > 0);	} 	sock = open_raw_sock("lo");	assert(sock > 0); 	ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));	printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,	       ret, strerror(errno));	assert(ret == 0); 	return 0;} int main(int argc, char **argv){	const char *file = NULL, *object = NULL;	uint32_t key = 0, value = 0, flags = 0;	int opt, mode = BPF_M_UNSPEC; 	while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {		switch (opt) {		/* General args */		case 'F':			file = optarg;			break;		case 'P':			flags |= BPF_F_PIN;			break;		case 'G':			flags |= BPF_F_GET;			break;		/* Map-related args */		case 'm':			mode = BPF_M_MAP;			break;		case 'k':			key = strtoul(optarg, NULL, 0);			flags |= BPF_F_KEY;			break;		case 'v':			value = strtoul(optarg, NULL, 0);			flags |= BPF_F_VAL;			break;		/* Prog-related args */		case 'p':			mode = BPF_M_PROG;			break;		case 'o':			object = optarg;			break;		default:			goto out;		}	} 	if (!(flags & BPF_F_PIN_GET) || !file)		goto out; 	switch (mode) {	case BPF_M_MAP:		return bpf_do_map(file, flags, key, value);	case BPF_M_PROG:		return bpf_do_prog(file, flags, object);	}out:	usage();	return -1;}