Bluetooth: Delay LTK encryption to let remote receive all keys
Some devices may refuse to re-encrypt with the LTK if they haven't
received all our keys yet. This patch adds a 250ms delay before
attempting re-encryption with the LTK.
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 e119d76..f886bca 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -549,6 +549,20 @@
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;
@@ -559,6 +573,7 @@
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;
@@ -576,6 +591,8 @@
BUG_ON(!smp);
+ cancel_delayed_work_sync(&smp->reencrypt);
+
complete = test_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
mgmt_smp_complete(conn->hcon, complete);
@@ -1287,9 +1304,8 @@
/* Re-encrypt the link with LTK if possible */
if (ltk_encrypt && hcon->out) {
- struct smp_ltk *ltk = smp->ltk;
- hci_le_start_enc(hcon, ltk->ediv, ltk->rand, ltk->val);
- hcon->enc_key_size = ltk->enc_size;
+ 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);
diff --git a/net/bluetooth/smp.h b/net/bluetooth/smp.h
index 676395f..f55d836 100644
--- a/net/bluetooth/smp.h
+++ b/net/bluetooth/smp.h
@@ -121,6 +121,8 @@
#define SMP_FLAG_LTK_ENCRYPT 4
#define SMP_FLAG_COMPLETE 5
+#define SMP_REENCRYPT_TIMEOUT msecs_to_jiffies(250)
+
struct smp_chan {
struct l2cap_conn *conn;
u8 preq[7]; /* SMP Pairing Request */
@@ -140,6 +142,7 @@
unsigned long smp_flags;
struct work_struct confirm;
struct work_struct random;
+ struct delayed_work reencrypt;
};
/* SMP Commands */