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