1 files changed, 80 insertions, 0 deletions
diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c
new file mode 100644
index 000000000..1b34cb9a7
--- /dev/null
+++ b/net/ipv4/bpfilter/sockopt.c
@@ -0,0 +1,80 @@
+// 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 *optval,
+			    int __user *optlen)
+{
+	int len;
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	return bpfilter_mbox_request(sk, optname, USER_SOCKPTR(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);