pbdrv/bluetooth: Add cancel & disconnect.

This commit adds support for rfcomm socket disconnection and
cancellation. It also unifies some of the error checking in the
rfcomm listen and connect functions in btstack.

Author: jaguilar

lib/pbio/drv/bluetooth/bluetooth.c

@@ -548,6 +548,7 @@ void pbdrv_bluetooth_cancel_operation_request(void) {
     #if PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
     // Revisit: Cancel all.
     pbdrv_bluetooth_classic_task_context.cancel = true;
+    pbdrv_bluetooth_rfcomm_cancel_connection();
     #endif // PBDRV_CONFIG_BLUETOOTH_NUM_CLASSIC_CONNECTIONS
 }
 
@@ -684,6 +685,8 @@ pbio_error_t pbdrv_bluetooth_close_user_tasks(pbio_os_state_t *state, pbio_os_ti
     // Requests peripheral operations to cancel, if they support it.
     pbdrv_bluetooth_cancel_operation_request();
 
+    pbdrv_bluetooth_rfcomm_disconnect_all();
+
     for (peri_index = 0; peri_index < PBDRV_CONFIG_BLUETOOTH_NUM_PERIPHERALS; peri_index++) {
         peri = pbdrv_bluetooth_peripheral_get_by_index(peri_index);
 

lib/pbio/drv/bluetooth/bluetooth.h

@@ -97,6 +97,17 @@ typedef struct {
 
 pbio_error_t pbdrv_bluetooth_inquiry_scan_func(pbio_os_state_t *state, void *context);
 
+// The following functions are defined in each Bluetooth implementation that
+// supports RFCOMM sockets.
+
+// Cancels all pending connection attempts. Called e.g. when the user interrupts
+// execution to drop into the debug REPL.
+void pbdrv_bluetooth_rfcomm_cancel_connection();
+
+// Disconnects all active RFCOMM connections and cleans up all sockets. Called
+// during user program termination.
+void pbdrv_bluetooth_rfcomm_disconnect_all();
+
 #endif // PBDRV_CONFIG_BLUETOOTH
 
 #endif // _INTERNAL_PBDRV_BLUETOOTH_H_