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authorJohan Hedberg <johan.hedberg@intel.com>2015-06-11 13:52:29 +0300
committerMarcel Holtmann <marcel@holtmann.org>2015-06-12 12:38:45 +0300
commit821f37666815c9f3a7a4d195ce9184ad4d084942 (patch)
tree36596eee3edfdaf72e6ee5e0cee6bec31eb574c9 /net/bluetooth
parent035ad621b6e625e185fe7b6929788d1d83727079 (diff)
downloadlinux-821f37666815c9f3a7a4d195ce9184ad4d084942.tar.xz
Bluetooth: Read encryption key size for BR/EDR connections
Since Bluetooth 3.0 there's a HCI command available for reading the encryption key size of an BR/EDR connection. This information is essential e.g. for generating an LTK using SMP over BR/EDR, so store it as part of struct hci_conn. Signed-off-by: Johan Hedberg <johan.hedberg@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/hci_event.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 62934151431b..88c57b12a222 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2603,6 +2603,64 @@ unlock:
hci_dev_unlock(hdev);
}
+static void read_enc_key_size_complete(struct hci_dev *hdev, u8 status,
+ u16 opcode, struct sk_buff *skb)
+{
+ const struct hci_rp_read_enc_key_size *rp;
+ struct hci_conn *conn;
+ u16 handle;
+
+ BT_DBG("%s status 0x%02x", hdev->name, status);
+
+ if (!skb || skb->len < sizeof(*rp)) {
+ BT_ERR("%s invalid HCI Read Encryption Key Size response",
+ hdev->name);
+ return;
+ }
+
+ rp = (void *)skb->data;
+ handle = le16_to_cpu(rp->handle);
+
+ hci_dev_lock(hdev);
+
+ conn = hci_conn_hash_lookup_handle(hdev, handle);
+ if (!conn)
+ goto unlock;
+
+ /* If we fail to read the encryption key size, assume maximum
+ * (which is the same we do also when this HCI command isn't
+ * supported.
+ */
+ if (rp->status) {
+ BT_ERR("%s failed to read key size for handle %u", hdev->name,
+ handle);
+ conn->enc_key_size = HCI_LINK_KEY_SIZE;
+ } else {
+ conn->enc_key_size = rp->key_size;
+ }
+
+ if (conn->state == BT_CONFIG) {
+ conn->state = BT_CONNECTED;
+ hci_connect_cfm(conn, 0);
+ hci_conn_drop(conn);
+ } else {
+ u8 encrypt;
+
+ if (!test_bit(HCI_CONN_ENCRYPT, &conn->flags))
+ encrypt = 0x00;
+ else if (conn->type == ACL_LINK &&
+ test_bit(HCI_CONN_AES_CCM, &conn->flags))
+ encrypt = 0x02;
+ else
+ encrypt = 0x01;
+
+ hci_encrypt_cfm(conn, 0, encrypt);
+ }
+
+unlock:
+ hci_dev_unlock(hdev);
+}
+
static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
struct hci_ev_encrypt_change *ev = (void *) skb->data;
@@ -2662,6 +2720,35 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
goto unlock;
}
+ /* Try reading the encryption key size for encrypted ACL links */
+ if (!ev->status && ev->encrypt && conn->type == ACL_LINK) {
+ struct hci_cp_read_enc_key_size cp;
+ struct hci_request req;
+
+ /* Only send HCI_Read_Encryption_Key_Size if the
+ * controller really supports it. If it doesn't, assume
+ * the default size (16).
+ */
+ if (!(hdev->commands[20] & 0x10)) {
+ conn->enc_key_size = HCI_LINK_KEY_SIZE;
+ goto notify;
+ }
+
+ hci_req_init(&req, hdev);
+
+ cp.handle = cpu_to_le16(conn->handle);
+ hci_req_add(&req, HCI_OP_READ_ENC_KEY_SIZE, sizeof(cp), &cp);
+
+ if (hci_req_run_skb(&req, read_enc_key_size_complete)) {
+ BT_ERR("Sending HCI Read Encryption Key Size failed");
+ conn->enc_key_size = HCI_LINK_KEY_SIZE;
+ goto notify;
+ }
+
+ goto unlock;
+ }
+
+notify:
if (conn->state == BT_CONFIG) {
if (!ev->status)
conn->state = BT_CONNECTED;