Bluetooth: Make handle of hci_conn be unique

The handle of new hci_conn is always HCI_CONN_HANDLE_MAX + 1 if
the handle of the first hci_conn entry in hci_dev->conn_hash->list
is not HCI_CONN_HANDLE_MAX + 1. Use ida to manage the allocation of
hci_conn->handle to make it be unique.

Fixes: 9f78191cc9f1 ("Bluetooth: hci_conn: Always allocate unique handles")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

1 files changed, 32 insertions, 25 deletions

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 7727fe30e5c3..3735764b3169 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -153,6 +153,9 @@ static void hci_conn_cleanup(struct hci_conn *conn)
 
 	hci_conn_hash_del(hdev, conn);
 
+	if (HCI_CONN_HANDLE_UNSET(conn->handle))
+		ida_free(&hdev->unset_handle_ida, conn->handle);
+
 	if (conn->cleanup)
 		conn->cleanup(conn);
 
@@ -951,31 +954,18 @@ static void cis_cleanup(struct hci_conn *conn)
 	hci_le_remove_cig(hdev, conn->iso_qos.ucast.cig);
 }
 
-static u16 hci_conn_hash_alloc_unset(struct hci_dev *hdev)
+static int hci_conn_hash_alloc_unset(struct hci_dev *hdev)
 {
-	struct hci_conn_hash *h = &hdev->conn_hash;
-	struct hci_conn  *c;
-	u16 handle = HCI_CONN_HANDLE_MAX + 1;
-
-	rcu_read_lock();
-
-	list_for_each_entry_rcu(c, &h->list, list) {
-		/* Find the first unused handle */
-		if (handle == 0xffff || c->handle != handle)
-			break;
-		handle++;
-	}
-	rcu_read_unlock();
-
-	return handle;
+	return ida_alloc_range(&hdev->unset_handle_ida, HCI_CONN_HANDLE_MAX + 1,
+			       U16_MAX, GFP_ATOMIC);
 }
 
 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
-			      u8 role)
+			      u8 role, u16 handle)
 {
 	struct hci_conn *conn;
 
-	BT_DBG("%s dst %pMR", hdev->name, dst);
+	bt_dev_dbg(hdev, "dst %pMR handle 0x%4.4x", dst, handle);
 
 	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 	if (!conn)
@@ -983,7 +973,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
 
 	bacpy(&conn->dst, dst);
 	bacpy(&conn->src, &hdev->bdaddr);
-	conn->handle = hci_conn_hash_alloc_unset(hdev);
+	conn->handle = handle;
 	conn->hdev  = hdev;
 	conn->type  = type;
 	conn->role  = role;
@@ -1068,6 +1058,20 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
 	return conn;
 }
 
+struct hci_conn *hci_conn_add_unset(struct hci_dev *hdev, int type,
+				    bdaddr_t *dst, u8 role)
+{
+	int handle;
+
+	bt_dev_dbg(hdev, "dst %pMR", dst);
+
+	handle = hci_conn_hash_alloc_unset(hdev);
+	if (unlikely(handle < 0))
+		return NULL;
+
+	return hci_conn_add(hdev, type, dst, role, handle);
+}
+
 static void hci_conn_cleanup_child(struct hci_conn *conn, u8 reason)
 {
 	if (!reason)
@@ -1304,6 +1308,9 @@ u8 hci_conn_set_handle(struct hci_conn *conn, u16 handle)
 	if (conn->abort_reason)
 		return conn->abort_reason;
 
+	if (HCI_CONN_HANDLE_UNSET(conn->handle))
+		ida_free(&hdev->unset_handle_ida, conn->handle);
+
 	conn->handle = handle;
 
 	return 0;
@@ -1411,7 +1418,7 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 	if (conn) {
 		bacpy(&conn->dst, dst);
 	} else {
-		conn = hci_conn_add(hdev, LE_LINK, dst, role);
+		conn = hci_conn_add_unset(hdev, LE_LINK, dst, role);
 		if (!conn)
 			return ERR_PTR(-ENOMEM);
 		hci_conn_hold(conn);
@@ -1588,7 +1595,7 @@ static struct hci_conn *hci_add_bis(struct hci_dev *hdev, bdaddr_t *dst,
 		     memcmp(conn->le_per_adv_data, base, base_len)))
 		return ERR_PTR(-EADDRINUSE);
 
-	conn = hci_conn_add(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
+	conn = hci_conn_add_unset(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
 	if (!conn)
 		return ERR_PTR(-ENOMEM);
 
@@ -1632,7 +1639,7 @@ struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
 
 	BT_DBG("requesting refresh of dst_addr");
 
-	conn = hci_conn_add(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
+	conn = hci_conn_add_unset(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
 	if (!conn)
 		return ERR_PTR(-ENOMEM);
 
@@ -1680,7 +1687,7 @@ struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
 
 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
 	if (!acl) {
-		acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
+		acl = hci_conn_add_unset(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
 		if (!acl)
 			return ERR_PTR(-ENOMEM);
 	}
@@ -1740,7 +1747,7 @@ struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
 
 	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
 	if (!sco) {
-		sco = hci_conn_add(hdev, type, dst, HCI_ROLE_MASTER);
+		sco = hci_conn_add_unset(hdev, type, dst, HCI_ROLE_MASTER);
 		if (!sco) {
 			hci_conn_drop(acl);
 			return ERR_PTR(-ENOMEM);
@@ -1932,7 +1939,7 @@ struct hci_conn *hci_bind_cis(struct hci_dev *hdev, bdaddr_t *dst,
 	cis = hci_conn_hash_lookup_cis(hdev, dst, dst_type, qos->ucast.cig,
 				       qos->ucast.cis);
 	if (!cis) {
-		cis = hci_conn_add(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
+		cis = hci_conn_add_unset(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
 		if (!cis)
 			return ERR_PTR(-ENOMEM);
 		cis->cleanup = cis_cleanup;