Bluetooth: Add run-time option to disable SMP bondable mode

This adds a function that will disable Bonding flag in
Authentication Requirements flag in SMP Pairing Request/Response.
This is needed for qualification purposes.

Signed-off-by: Mariusz Skamra <mariusz.skamra@codecoup.pl>

Author: MariuszSkamra

include/bluetooth/conn.h

@@ -386,6 +386,18 @@ struct bt_conn_cb {
  */
 void bt_conn_cb_register(struct bt_conn_cb *cb);
 
+/** Enable/disable bonding.
+ *
+ *  Set/clear the Bonding flag in the Authentication Requirements of
+ *  SMP Pairing Request/Response data.
+ *  The initial value of this flag depends on BT_BONDABLE Kconfig setting.
+ *  For the vast majority of applications calling this function shouldn't be
+ *  needed.
+ *
+ *  @param enable Value allowing/disallowing to be bondable.
+ */
+void bt_set_bondable(bool enable);
+
 /** @def BT_PASSKEY_INVALID
  *
  *  Special passkey value that can be used to disable a previously

subsys/bluetooth/host/smp.c

@@ -249,6 +249,7 @@ static struct bt_smp_br bt_smp_br_pool[CONFIG_BT_MAX_CONN];
 #endif /* CONFIG_BT_BREDR */
 
 static struct bt_smp bt_smp_pool[CONFIG_BT_MAX_CONN];
+static bool bondable = IS_ENABLED(CONFIG_BT_BONDABLE);
 static bool sc_supported;
 static bool sc_local_pkey_valid;
 static u8_t sc_public_key[64];
@@ -2267,6 +2268,11 @@ static int smp_init(struct bt_smp *smp)
 	return 0;
 }
 
+void bt_set_bondable(bool enable)
+{
+	bondable = enable;
+}
+
 static u8_t get_auth(u8_t auth)
 {
 	if (sc_supported) {
@@ -2281,6 +2287,12 @@ static u8_t get_auth(u8_t auth)
 		auth |= BT_SMP_AUTH_MITM;
 	}
 
+	if (bondable) {
+		auth |= BT_SMP_AUTH_BONDING;
+	} else {
+		auth &= ~BT_SMP_AUTH_BONDING;
+	}
+
 	return auth;
 }