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(fd: 0, buf: &req, nbytes: sizeof(req));
39 if (n != sizeof(req)) {
40 fprintf(stream: debug_f, format: "invalid request %d\n", n);
41 return;
42 }
43
44 reply.status = req.is_set ?
45 handle_set_cmd(cmd: &req) :
46 handle_get_cmd(cmd: &req);
47
48 n = write(fd: 1, buf: &reply, n: sizeof(reply));
49 if (n != sizeof(reply)) {
50 fprintf(stream: debug_f, format: "reply failed %d\n", n);
51 return;
52 }
53 }
54}
55
56int main(void)
57{
58 debug_f = fopen(filename: "/dev/kmsg", modes: "w");
59 setvbuf(stream: debug_f, buf: 0, _IOLBF, n: 0);
60 fprintf(stream: debug_f, format: "<5>Started bpfilter\n");
61 loop();
62 fclose(stream: debug_f);
63 return 0;
64}
65

source code of linux/net/bpfilter/main.c