1// SPDX-License-Identifier: GPL-2.0
 2#define _GNU_SOURCE
 3#include <sys/uio.h>
 4#include <errno.h>
 5#include <stdio.h>
 6#include <sys/socket.h>
 7#include <fcntl.h>
 8#include <unistd.h>
 9#include "../../include/uapi/linux/bpf.h"
10#include <asm/unistd.h>
11#include "msgfmt.h"
12
13FILE *debug_f;
14
15static int handle_get_cmd(struct mbox_request *cmd)
16{
17	switch (cmd->cmd) {
18	case 0:
19		return 0;
20	default:
21		break;
22	}
23	return -ENOPROTOOPT;
24}
25
26static int handle_set_cmd(struct mbox_request *cmd)
27{
28	return -ENOPROTOOPT;
29}
30
31static void loop(void)
32{
33	while (1) {
34		struct mbox_request req;
35		struct mbox_reply reply;
36		int n;
37
38		n = read(0, &req, sizeof(req));
39		if (n != sizeof(req)) {
40			fprintf(debug_f, "invalid request %d\n", n);
41			return;
42		}
43
44		reply.status = req.is_set ?
45			handle_set_cmd(&req) :
46			handle_get_cmd(&req);
47
48		n = write(1, &reply, sizeof(reply));
49		if (n != sizeof(reply)) {
50			fprintf(debug_f, "reply failed %d\n", n);
51			return;
52		}
53	}
54}
55
56int main(void)
57{
58	debug_f = fopen("/dev/kmsg", "w");
59	setvbuf(debug_f, 0, _IOLBF, 0);
60	fprintf(debug_f, "<5>Started bpfilter\n");
61	loop();
62	fclose(debug_f);
63	return 0;
64}