Bluetooth: Add blacklist support for incoming connections

In some circumstances it could be desirable to reject incoming
connections on the baseband level. This patch adds this feature through
two new ioctl's: HCIBLOCKADDR and HCIUNBLOCKADDR. Both take a simple
Bluetooth address as a parameter. BDADDR_ANY can be used with
HCIUNBLOCKADDR to remove all devices from the blacklist.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

3 files changed, 94 insertions, 1 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2f768de87011..aeb2982310a0 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -562,6 +562,7 @@ static int hci_dev_do_close(struct hci_dev *hdev)
 	hci_dev_lock_bh(hdev);
 	inquiry_cache_flush(hdev);
 	hci_conn_hash_flush(hdev);
+	hci_blacklist_clear(hdev);
 	hci_dev_unlock_bh(hdev);
 
 	hci_notify(hdev, HCI_DEV_DOWN);
@@ -923,6 +924,8 @@ int hci_register_dev(struct hci_dev *hdev)
 
 	hci_conn_hash_init(hdev);
 
+	INIT_LIST_HEAD(&hdev->blacklist.list);
+
 	memset(&hdev->stat, 0, sizeof(struct hci_dev_stats));
 
 	atomic_set(&hdev->promisc, 0);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 786b5de0bac4..43feeef3c498 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -952,7 +952,7 @@ static inline void hci_conn_request_evt(struct hci_dev *hdev, struct sk_buff *sk
 
 	mask |= hci_proto_connect_ind(hdev, &ev->bdaddr, ev->link_type);
 
-	if (mask & HCI_LM_ACCEPT) {
+	if ((mask & HCI_LM_ACCEPT) && !hci_blacklist_lookup(hdev, &ev->bdaddr)) {
 		/* Connection accepted */
 		struct inquiry_entry *ie;
 		struct hci_conn *conn;
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 38f08f6b86f6..4f170a595934 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -165,6 +165,86 @@ static int hci_sock_release(struct socket *sock)
 	return 0;
 }
 
+struct bdaddr_list *hci_blacklist_lookup(struct hci_dev *hdev, bdaddr_t *bdaddr)
+{
+	struct list_head *p;
+	struct bdaddr_list *blacklist = &hdev->blacklist;
+
+	list_for_each(p, &blacklist->list) {
+		struct bdaddr_list *b;
+
+		b = list_entry(p, struct bdaddr_list, list);
+
+		if (bacmp(bdaddr, &b->bdaddr) == 0)
+			return b;
+	}
+
+	return NULL;
+}
+
+static int hci_blacklist_add(struct hci_dev *hdev, void __user *arg)
+{
+	bdaddr_t bdaddr;
+	struct bdaddr_list *entry;
+
+	if (copy_from_user(&bdaddr, arg, sizeof(bdaddr)))
+		return -EFAULT;
+
+	if (bacmp(&bdaddr, BDADDR_ANY) == 0)
+		return -EBADF;
+
+	if (hci_blacklist_lookup(hdev, &bdaddr))
+		return -EEXIST;
+
+	entry = kzalloc(sizeof(struct bdaddr_list), GFP_KERNEL);
+	if (!entry)
+		return -ENOMEM;
+
+	bacpy(&entry->bdaddr, &bdaddr);
+
+	list_add(&entry->list, &hdev->blacklist.list);
+
+	return 0;
+}
+
+int hci_blacklist_clear(struct hci_dev *hdev)
+{
+	struct list_head *p, *n;
+	struct bdaddr_list *blacklist = &hdev->blacklist;
+
+	list_for_each_safe(p, n, &blacklist->list) {
+		struct bdaddr_list *b;
+
+		b = list_entry(p, struct bdaddr_list, list);
+
+		list_del(p);
+		kfree(b);
+	}
+
+	return 0;
+}
+
+static int hci_blacklist_del(struct hci_dev *hdev, void __user *arg)
+{
+	bdaddr_t bdaddr;
+	struct bdaddr_list *entry;
+
+	if (copy_from_user(&bdaddr, arg, sizeof(bdaddr)))
+		return -EFAULT;
+
+	if (bacmp(&bdaddr, BDADDR_ANY) == 0)
+		return hci_blacklist_clear(hdev);
+
+	entry = hci_blacklist_lookup(hdev, &bdaddr);
+	if (!entry)
+		return -ENOENT;
+
+	list_del(&entry->list);
+	kfree(entry);
+
+	return 0;
+}
+
 /* Ioctls that require bound socket */
 static inline int hci_sock_bound_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
 {
@@ -194,6 +274,16 @@ static inline int hci_sock_bound_ioctl(struct sock *sk, unsigned int cmd, unsign
 	case HCIGETAUTHINFO:
 		return hci_get_auth_info(hdev, (void __user *) arg);
 
+	case HCIBLOCKADDR:
+		if (!capable(CAP_NET_ADMIN))
+			return -EACCES;
+		return hci_blacklist_add(hdev, (void __user *) arg);
+
+	case HCIUNBLOCKADDR:
+		if (!capable(CAP_NET_ADMIN))
+			return -EACCES;
+		return hci_blacklist_del(hdev, (void __user *) arg);
+
 	default:
 		if (hdev->ioctl)
 			return hdev->ioctl(hdev, cmd, arg);