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
13 FILE *debug_f;
14
handle_get_cmd(struct mbox_request * cmd)15 static 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
handle_set_cmd(struct mbox_request * cmd)26 static int handle_set_cmd(struct mbox_request *cmd)
27 {
28 return -ENOPROTOOPT;
29 }
30
loop(void)31 static 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
main(void)56 int 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 }
65