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 12 struct bpfilter_umh_ops bpfilter_ops; 13 EXPORT_SYMBOL_GPL(bpfilter_ops); 14 15 static 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(&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(bpfilter_ops.info.tgid)) 32 umd_cleanup_helper(&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); 40 out: 41 mutex_unlock(&bpfilter_ops.lock); 42 return err; 43 } 44 45 int 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, true); 49 } 50 51 int 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, USER_SOCKPTR(optval), len, 60 false); 61 } 62 63 static 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 } 71 device_initcall(bpfilter_sockopt_init); 72