1// SPDX-License-Identifier: GPL-2.0
2#include <linux/init.h>
3#include <linux/module.h>
4#include <linux/uaccess.h>
5#include <linux/bpfilter.h>
6#include <uapi/linux/bpf.h>
7#include <linux/wait.h>
8#include <linux/kmod.h>
9#include <linux/fs.h>
10#include <linux/file.h>
11
12struct bpfilter_umh_ops bpfilter_ops;
13EXPORT_SYMBOL_GPL(bpfilter_ops);
14
15static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval,
16 unsigned int optlen, bool is_set)
17{
18 int err;
19 mutex_lock(&bpfilter_ops.lock);
20 if (!bpfilter_ops.sockopt) {
21 mutex_unlock(lock: &bpfilter_ops.lock);
22 request_module("bpfilter");
23 mutex_lock(&bpfilter_ops.lock);
24
25 if (!bpfilter_ops.sockopt) {
26 err = -ENOPROTOOPT;
27 goto out;
28 }
29 }
30 if (bpfilter_ops.info.tgid &&
31 thread_group_exited(pid: bpfilter_ops.info.tgid))
32 umd_cleanup_helper(info: &bpfilter_ops.info);
33
34 if (!bpfilter_ops.info.tgid) {
35 err = bpfilter_ops.start();
36 if (err)
37 goto out;
38 }
39 err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set);
40out:
41 mutex_unlock(lock: &bpfilter_ops.lock);
42 return err;
43}
44
45int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval,
46 unsigned int optlen)
47{
48 return bpfilter_mbox_request(sk, optname, optval, optlen, is_set: true);
49}
50
51int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
52 int __user *optlen)
53{
54 int len;
55
56 if (get_user(len, optlen))
57 return -EFAULT;
58
59 return bpfilter_mbox_request(sk, optname, optval: USER_SOCKPTR(p: optval), optlen: len,
60 is_set: false);
61}
62
63static int __init bpfilter_sockopt_init(void)
64{
65 mutex_init(&bpfilter_ops.lock);
66 bpfilter_ops.info.tgid = NULL;
67 bpfilter_ops.info.driver_name = "bpfilter_umh";
68
69 return 0;
70}
71device_initcall(bpfilter_sockopt_init);
72

source code of linux/net/ipv4/bpfilter/sockopt.c