Bluetooth: Add support for using the crypto subsystem

This will allow using the crypto subsystem for encrypting data. As SMP
(Security Manager Protocol) is implemented almost entirely on the host
side and the crypto module already implements the needed methods
(AES-128), it makes sense to use it.

There's now a new module option to enable/disable SMP support.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

1 files changed, 18 insertions, 4 deletions

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 2240e96552f1..aa20bee97501 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -154,9 +154,13 @@ static void smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
 int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
 {
+        struct hci_conn *hcon = conn->hcon;
         __u8 authreq;
 
-        BT_DBG("conn %p hcon %p level 0x%2.2x", conn, conn->hcon, sec_level);
+        BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
+
+        if (IS_ERR(hcon->hdev->tfm))
+                return 1;
 
         switch (sec_level) {
         case BT_SECURITY_MEDIUM:
@@ -174,7 +178,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
                 return 1;
         }
 
-        if (conn->hcon->link_mode & HCI_LM_MASTER) {
+        if (hcon->link_mode & HCI_LM_MASTER) {
                 struct smp_cmd_pairing cp;
                 cp.io_capability = 0x00;
                 cp.oob_flag = 0x00;
@@ -198,6 +202,12 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
         __u8 reason;
         int err = 0;
 
+        if (IS_ERR(conn->hcon->hdev->tfm)) {
+                err = PTR_ERR(conn->hcon->hdev->tfm);
+                reason = SMP_PAIRING_NOTSUPP;
+                goto done;
+        }
+
         skb_pull(skb, sizeof(code));
 
         switch (code) {
@@ -233,11 +243,15 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
                 BT_DBG("Unknown command code 0x%2.2x", code);
 
                 reason = SMP_CMD_NOTSUPP;
-                smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
-                                                                &reason);
                 err = -EOPNOTSUPP;
+                goto done;
         }
 
+done:
+        if (reason)
+                smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
+                                                                &reason);
+
         kfree_skb(skb);
         return err;
 }