From 1d98bf4fda5f76563a9718b59e3ac5a65fd36a51 Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Mon, 24 Mar 2014 14:39:08 +0200 Subject: [PATCH] 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 Signed-off-by: Marcel Holtmann --- net/bluetooth/smp.c | 48 +++++---------------------------------------- net/bluetooth/smp.h | 8 ++------ 2 files changed, 7 insertions(+), 49 deletions(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index b952041bf4a..10a8e622ab2 100644 --- 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 0d536b8b3f9..1277147a915 100644 --- 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 */ -- 2.46.0