Bluetooth: Remove SMP data specific crypto context

Now that each HCI device has its own AES crypto context we don't need
the one stored in the SMP data any more. This patch removes the variable
from struct smp_chan and updates the SMP code to use the per-hdev crypto
context.

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

net/bluetooth/smp.c

@@ -413,20 +413,16 @@ static void confirm_work(struct work_struct *work)
 {
 	struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
 	struct l2cap_conn *conn = smp->conn;
-	struct crypto_blkcipher *tfm;
+	struct hci_dev *hdev = conn->hcon->hdev;
+	struct crypto_blkcipher *tfm = hdev->tfm_aes;
 	struct smp_cmd_pairing_confirm cp;
 	int ret;
 	u8 res[16], reason;
 
 	BT_DBG("conn %p", conn);
 
-	tfm = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(tfm)) {
-		reason = SMP_UNSPECIFIED;
-		goto error;
-	}
-
-	smp->tfm = tfm;
+	/* Prevent mutual access to hdev->tfm_aes */
+	hci_dev_lock(hdev);
 
 	if (conn->hcon->out)
 		ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
@@ -436,6 +432,9 @@ static void confirm_work(struct work_struct *work)
 		ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
 			     conn->hcon->dst_type, &conn->hcon->dst,
 			     conn->hcon->src_type, &conn->hcon->src, res);
+
+	hci_dev_unlock(hdev);
+
 	if (ret) {
 		reason = SMP_UNSPECIFIED;
 		goto error;
@@ -457,7 +456,8 @@ static void random_work(struct work_struct *work)
 	struct smp_chan *smp = container_of(work, struct smp_chan, random);
 	struct l2cap_conn *conn = smp->conn;
 	struct hci_conn *hcon = conn->hcon;
-	struct crypto_blkcipher *tfm = smp->tfm;
+	struct hci_dev *hdev = hcon->hdev;
+	struct crypto_blkcipher *tfm = hdev->tfm_aes;
 	u8 reason, confirm[16], res[16], key[16];
 	int ret;
 
@@ -468,6 +468,9 @@ static void random_work(struct work_struct *work)
 
 	BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
 
+	/* Prevent mutual access to hdev->tfm_aes */
+	hci_dev_lock(hdev);
+
 	if (hcon->out)
 		ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
 			     hcon->src_type, &hcon->src,
@@ -476,6 +479,9 @@ static void random_work(struct work_struct *work)
 		ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
 			     hcon->dst_type, &hcon->dst,
 			     hcon->src_type, &hcon->src, res);
+
+	hci_dev_unlock(hdev);
+
 	if (ret) {
 		reason = SMP_UNSPECIFIED;
 		goto error;
@@ -562,9 +568,6 @@ void smp_chan_destroy(struct l2cap_conn *conn)
 
 	BUG_ON(!smp);
 
-	if (smp->tfm)
-		crypto_free_blkcipher(smp->tfm);
-
 	kfree(smp);
 	conn->smp_chan = NULL;
 	conn->hcon->smp_conn = NULL;

net/bluetooth/smp.h

@@ -133,7 +133,6 @@ struct smp_chan {
 	u8		id_addr_type;
 	u8		irk[16];
 	unsigned long	smp_flags;
-	struct crypto_blkcipher	*tfm;
 	struct work_struct confirm;
 	struct work_struct random;
 };