Bluetooth: Remove LTK re-encryption procedure

Due to several devices being unable to handle this procedure reliably
(resulting in forced disconnections before pairing completes) it's
better to remove it altogether.

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

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index b952041bf4ac7e74908fe3716a475d44a8a7389a..10a8e622ab2bc5016475d25119f233a4f1e1b03a 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -556,20 +556,6 @@ error:
        smp_failure(conn, reason);
 }
 
-static void smp_reencrypt(struct work_struct *work)
-{
-       struct smp_chan *smp = container_of(work, struct smp_chan,
-                                           reencrypt.work);
-       struct l2cap_conn *conn = smp->conn;
-       struct hci_conn *hcon = conn->hcon;
-       struct smp_ltk *ltk = smp->ltk;
-
-       BT_DBG("");
-
-       hci_le_start_enc(hcon, ltk->ediv, ltk->rand, ltk->val);
-       hcon->enc_key_size = ltk->enc_size;
-}
-
 static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
 {
        struct smp_chan *smp;
@@ -580,7 +566,6 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
 
        INIT_WORK(&smp->confirm, confirm_work);
        INIT_WORK(&smp->random, random_work);
-       INIT_DELAYED_WORK(&smp->reencrypt, smp_reencrypt);
 
        smp->conn = conn;
        conn->smp_chan = smp;
@@ -598,8 +583,6 @@ void smp_chan_destroy(struct l2cap_conn *conn)
 
        BUG_ON(!smp);
 
-       cancel_delayed_work_sync(&smp->reencrypt);
-
        complete = test_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
        mgmt_smp_complete(conn->hcon, complete);
 
@@ -1276,7 +1259,6 @@ int smp_distribute_keys(struct l2cap_conn *conn)
        struct smp_chan *smp = conn->smp_chan;
        struct hci_conn *hcon = conn->hcon;
        struct hci_dev *hdev = hcon->hdev;
-       bool ltk_encrypt;
        __u8 *keydist;
 
        BT_DBG("conn %p", conn);
@@ -1376,32 +1358,12 @@ int smp_distribute_keys(struct l2cap_conn *conn)
        if ((smp->remote_key_dist & 0x07))
                return 0;
 
-       /* Check if we should try to re-encrypt the link with the LTK.
-        * SMP_FLAG_LTK_ENCRYPT flag is used to track whether we've
-        * already tried this (in which case we shouldn't try again).
-        *
-        * The request will trigger an encryption key refresh event
-        * which will cause a call to auth_cfm and eventually lead to
-        * l2cap_core.c calling this smp_distribute_keys function again
-        * and thereby completing the process.
-        */
-       if (smp->ltk)
-               ltk_encrypt = !test_and_set_bit(SMP_FLAG_LTK_ENCRYPT,
-                                               &smp->smp_flags);
-       else
-               ltk_encrypt = false;
+       clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
+       cancel_delayed_work_sync(&conn->security_timer);
+       set_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
+       smp_notify_keys(conn);
 
-       /* Re-encrypt the link with LTK if possible */
-       if (ltk_encrypt && hcon->out) {
-               queue_delayed_work(hdev->req_workqueue, &smp->reencrypt,
-                                  SMP_REENCRYPT_TIMEOUT);
-       } else {
-               clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
-               cancel_delayed_work_sync(&conn->security_timer);
-               set_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
-               smp_notify_keys(conn);
-               smp_chan_destroy(conn);
-       }
+       smp_chan_destroy(conn);
 
        return 0;
 }

diff --git a/net/bluetooth/smp.h b/net/bluetooth/smp.h
index 0d536b8b3f9ad76eedb98a07af834c94a6180e66..1277147a915070e3a5256debdd98316fa1d916c5 100644 (file)
--- a/net/bluetooth/smp.h
+++ b/net/bluetooth/smp.h
@@ -118,11 +118,8 @@ struct smp_cmd_security_req {
 #define SMP_FLAG_TK_VALID      1
 #define SMP_FLAG_CFM_PENDING   2
 #define SMP_FLAG_MITM_AUTH     3
-#define SMP_FLAG_LTK_ENCRYPT   4
-#define SMP_FLAG_COMPLETE      5
-#define SMP_FLAG_INITIATOR     6
-
-#define SMP_REENCRYPT_TIMEOUT  msecs_to_jiffies(500)
+#define SMP_FLAG_COMPLETE      4
+#define SMP_FLAG_INITIATOR     5
 
 struct smp_chan {
        struct l2cap_conn *conn;
@@ -145,7 +142,6 @@ struct smp_chan {
        unsigned long   smp_flags;
        struct work_struct confirm;
        struct work_struct random;
-       struct delayed_work reencrypt;
 };
 
 /* SMP Commands */