Add method for checking is the device listed as connected in OS

Signed-off-by: Szczepan Zalega <szczepan@nitrokey.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/device.cc b/device.cc
index 532ba2e..42c6883 100644
--- a/device.cc
+++ b/device.cc
@@ -106,6 +106,24 @@ int Device::recv(void *packet) {
   return status;
 }
 
+bool Device::is_connected() {
+  Log::instance()(__PRETTY_FUNCTION__, Loglevel::DEBUG_L2);
+  std::lock_guard<std::mutex> lock(mex_dev_com);
+  if (mp_devhandle==nullptr){
+    return false;
+  }
+  auto pInfo = hid_enumerate(m_vid, m_pid);
+  if (pInfo != nullptr){
+    hid_free_enumeration(pInfo);
+    return true;
+  }
+  return false;
+
+//  alternative:
+//  unsigned char buf[1];
+//  return hid_read_timeout(mp_devhandle, buf, sizeof(buf), 20) != -1;
+}
+
 Stick10::Stick10():
   Device(0x20a0, 0x4108, DeviceModel::PRO, 100ms, 20, 100ms)
   {}
diff --git a/include/device.h b/include/device.h
index 4001d45..5965f99 100644
--- a/include/device.h
+++ b/include/device.h
@@ -52,6 +52,8 @@ public:
    */
   virtual int recv(void *packet);
 
+  bool is_connected();
+
   int get_retry_receiving_count() const { return m_retry_receiving_count; };
   int get_retry_sending_count() const { return m_retry_sending_count; };
   std::chrono::milliseconds get_retry_timeout() const { return m_retry_timeout; };