Bluetooth: Add a flag to indicate that SMP is going on

Add HCI_CONN_LE_SMP_PEND flag to indicate that SMP is pending
for that connection. This allows to have information that an SMP
procedure is going on for that connection.

We use the HCI_CONN_ENCRYPT_PEND to indicate that encryption
(HCI_LE_Start_Encryption) is pending for that connection.

While a SMP procedure is going on we hold an reference to the
connection, to avoid disconnections.

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

2 files changed, 37 insertions, 11 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index b3bdb482bbe6..8136752d824b 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -986,8 +986,10 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
         if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
                 del_timer_sync(&conn->info_timer);
 
-        if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
+        if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend)) {
                 del_timer(&conn->security_timer);
+                hci_conn_put(hcon);
+        }
 
         hcon->l2cap_data = NULL;
         kfree(conn);
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 20c82c7000ac..f0c67f62a08e 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -248,6 +248,9 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
         BT_DBG("conn %p", conn);
 
+        if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend))
+                hci_conn_hold(conn->hcon);
+
         conn->preq[0] = SMP_CMD_PAIRING_REQ;
         memcpy(&conn->preq[1], req, sizeof(*req));
         skb_pull(skb, sizeof(*req));
@@ -397,6 +400,9 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
                 memset(stk + conn->smp_key_size, 0,
                                 SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
 
+                if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
+                        return SMP_UNSPECIFIED;
+
                 hci_le_start_enc(hcon, ediv, rand, stk);
                 hcon->enc_key_size = conn->smp_key_size;
         } else {
@@ -430,9 +436,11 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
         BT_DBG("conn %p", conn);
 
-        if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
+        if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend))
                 return 0;
 
+        hci_conn_hold(hcon);
+
         skb_pull(skb, sizeof(*rp));
 
         memset(&cp, 0, sizeof(cp));
@@ -443,8 +451,6 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
         smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
 
-        set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
-
         return 0;
 }
 
@@ -461,19 +467,13 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
         if (IS_ERR(hcon->hdev->tfm))
                 return 1;
 
-        if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
-                return 0;
-
         if (sec_level == BT_SECURITY_LOW)
                 return 1;
 
         if (hcon->sec_level >= sec_level)
                 return 1;
 
-        authreq = seclevel_to_authreq(sec_level);
-
         if (hcon->link_mode & HCI_LM_MASTER) {
-                struct smp_cmd_pairing cp;
                 struct link_key *key;
 
                 key = hci_find_link_key_type(hcon->hdev, conn->dst,
@@ -481,12 +481,28 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
                 if (key) {
                         struct key_master_id *master = (void *) key->data;
 
+                        if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND,
+                                                        &hcon->pend))
+                                goto done;
+
                         hci_le_start_enc(hcon, master->ediv, master->rand,
                                                                 key->val);
                         hcon->enc_key_size = key->pin_len;
 
                         goto done;
                 }
+        }
+
+        if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend))
+                return 0;
+
+        /* While SMP is going on */
+        hci_conn_hold(hcon);
+
+        authreq = seclevel_to_authreq(sec_level);
+
+        if (hcon->link_mode & HCI_LM_MASTER) {
+                struct smp_cmd_pairing cp;
 
                 build_pairing_cmd(conn, &cp, NULL, authreq);
                 conn->preq[0] = SMP_CMD_PAIRING_REQ;
@@ -501,7 +517,6 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
 
 done:
         hcon->pending_sec_level = sec_level;
-        set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
 
         return 0;
 }
@@ -619,6 +634,9 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
         if (IS_ERR(conn->hcon->hdev->tfm))
                 return PTR_ERR(conn->hcon->hdev->tfm);
 
+        if (!test_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend))
+                return 0;
+
         rsp = (void *) &conn->prsp[1];
 
         /* The responder sends its keys first */
@@ -689,5 +707,11 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
                 *keydist &= ~SMP_DIST_SIGN;
         }
 
+        if (conn->hcon->out || force) {
+                clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend);
+                del_timer(&conn->security_timer);
+                hci_conn_put(conn->hcon);
+        }
+
         return 0;
 }