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// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/bpfilter.h>
#include <uapi/linux/bpf.h>
#include <linux/wait.h>
#include <linux/kmod.h>
#include <linux/fs.h>
#include <linux/file.h>
struct bpfilter_umh_ops bpfilter_ops;
EXPORT_SYMBOL_GPL(bpfilter_ops);
void bpfilter_umh_cleanup(struct umd_info *info)
{
fput(info->pipe_to_umh);
fput(info->pipe_from_umh);
put_pid(info->tgid);
info->tgid = NULL;
}
EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup);
static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval,
unsigned int optlen, bool is_set)
{
int err;
mutex_lock(&bpfilter_ops.lock);
if (!bpfilter_ops.sockopt) {
mutex_unlock(&bpfilter_ops.lock);
request_module("bpfilter");
mutex_lock(&bpfilter_ops.lock);
if (!bpfilter_ops.sockopt) {
err = -ENOPROTOOPT;
goto out;
}
}
if (bpfilter_ops.info.tgid &&
thread_group_exited(bpfilter_ops.info.tgid))
bpfilter_umh_cleanup(&bpfilter_ops.info);
if (!bpfilter_ops.info.tgid) {
err = bpfilter_ops.start();
if (err)
goto out;
}
err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set);
out:
mutex_unlock(&bpfilter_ops.lock);
return err;
}
int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval,
unsigned int optlen)
{
return bpfilter_mbox_request(sk, optname, optval, optlen, true);
}
int bpfilter_ip_get_sockopt(struct sock *sk, int optname,
char __user *user_optval, int __user *optlen)
{
sockptr_t optval;
int err, len;
if (get_user(len, optlen))
return -EFAULT;
err = init_user_sockptr(&optval, user_optval);
if (err)
return err;
return bpfilter_mbox_request(sk, optname, optval, len, false);
}
static int __init bpfilter_sockopt_init(void)
{
mutex_init(&bpfilter_ops.lock);
bpfilter_ops.info.tgid = NULL;
bpfilter_ops.info.driver_name = "bpfilter_umh";
return 0;
}
device_initcall(bpfilter_sockopt_init);
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