From e3098be40bbde0fdd5fcfa6bf28491db421d333a Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Fri, 28 Feb 2014 18:10:03 +0200 Subject: [PATCH] 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 Signed-off-by: Marcel Holtmann --- net/bluetooth/smp.c | 22 +++++++++++++++++++--- net/bluetooth/smp.h | 3 +++ 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index e119d76f87a7..f886bcae1b7e 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -549,6 +549,20 @@ 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; @@ -559,6 +573,7 @@ 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; @@ -576,6 +591,8 @@ 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); @@ -1287,9 +1304,8 @@ int smp_distribute_keys(struct l2cap_conn *conn) /* 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 676395f93702..f55d83617218 100644 --- a/net/bluetooth/smp.h +++ b/net/bluetooth/smp.h @@ -121,6 +121,8 @@ struct smp_cmd_security_req { #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 @@ struct smp_chan { unsigned long smp_flags; struct work_struct confirm; struct work_struct random; + struct delayed_work reencrypt; }; /* SMP Commands */ -- 2.20.1