LXR linux/net/ipv4/bpfilter/sockopt.c

   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
  15void bpfilter_umh_cleanup(struct umd_info *info)
  16{
  17        fput(info->pipe_to_umh);
  18        fput(info->pipe_from_umh);
  19        put_pid(info->tgid);
  20        info->tgid = NULL;
  21}
  22EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup);
  23
  24static int bpfilter_mbox_request(struct sock *sk, int optname, sockptr_t optval,
  25                                 unsigned int optlen, bool is_set)
  26{
  27        int err;
  28        mutex_lock(&bpfilter_ops.lock);
  29        if (!bpfilter_ops.sockopt) {
  30                mutex_unlock(&bpfilter_ops.lock);
  31                request_module("bpfilter");
  32                mutex_lock(&bpfilter_ops.lock);
  33
  34                if (!bpfilter_ops.sockopt) {
  35                        err = -ENOPROTOOPT;
  36                        goto out;
  37                }
  38        }
  39        if (bpfilter_ops.info.tgid &&
  40            thread_group_exited(bpfilter_ops.info.tgid))
  41                bpfilter_umh_cleanup(&bpfilter_ops.info);
  42
  43        if (!bpfilter_ops.info.tgid) {
  44                err = bpfilter_ops.start();
  45                if (err)
  46                        goto out;
  47        }
  48        err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set);
  49out:
  50        mutex_unlock(&bpfilter_ops.lock);
  51        return err;
  52}
  53
  54int bpfilter_ip_set_sockopt(struct sock *sk, int optname, sockptr_t optval,
  55                            unsigned int optlen)
  56{
  57        return bpfilter_mbox_request(sk, optname, optval, optlen, true);
  58}
  59
  60int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
  61                            int __user *optlen)
  62{
  63        int len;
  64
  65        if (get_user(len, optlen))
  66                return -EFAULT;
  67
  68        return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(optval), len,
  69                                     false);
  70}
  71
  72static int __init bpfilter_sockopt_init(void)
  73{
  74        mutex_init(&bpfilter_ops.lock);
  75        bpfilter_ops.info.tgid = NULL;
  76        bpfilter_ops.info.driver_name = "bpfilter_umh";
  77
  78        return 0;
  79}
  80device_initcall(bpfilter_sockopt_init);
  81