2015-12-18  Christian Franke  <address@hidden>

	* non_posix.cc:  Add device_id() for Cygwin.

diff --git a/non_posix.cc b/non_posix.cc
index 480c71d..7d7217f 100644
--- a/non_posix.cc
+++ b/non_posix.cc
@@ -56,6 +56,57 @@ const char * device_id( const int fd )
   return id_str.c_str();
   }
 
+#elif defined(__CYGWIN__)
+
+#include <cstddef>
+#include <io.h>
+#include <windows.h>
+
+const char * device_id( const int fd )
+  {
+  HANDLE h = (HANDLE) _get_osfhandle( fd );
+  if( h == INVALID_HANDLE_VALUE )
+    return 0;
+
+  STORAGE_PROPERTY_QUERY query =
+    { StorageDeviceProperty, PropertyStandardQuery, { 0 } };
+  char buf[256] = "";
+  DWORD size = 0;
+
+  if( !DeviceIoControl( h, IOCTL_STORAGE_QUERY_PROPERTY, &query, sizeof(query),
+                        &buf, sizeof(buf)-1, &size, (LPOVERLAPPED)0 ) )
+    return 0;
+
+  const STORAGE_DEVICE_DESCRIPTOR * const pdesc =
+    reinterpret_cast< STORAGE_DEVICE_DESCRIPTOR * >( buf );
+  const unsigned first =
+    offsetof( STORAGE_DEVICE_DESCRIPTOR, RawDeviceProperties );
+
+  static std::string id_str;
+  if( first <= pdesc->VendorIdOffset && pdesc->VendorIdOffset < size )
+    id_str = &buf[pdesc->VendorIdOffset];
+  if( first <= pdesc->ProductIdOffset && pdesc->ProductIdOffset < size )
+    {
+    if(    pdesc->BusType != BusTypeAta
+        && pdesc->BusType != 0x0b ) // BusTypeSata
+      id_str += ' ';
+    id_str += &buf[pdesc->ProductIdOffset];
+    }
+  sanitize_string( id_str );
+  if( id_str.empty() )
+    return 0;
+
+  if( first <= pdesc->SerialNumberOffset && pdesc->SerialNumberOffset < size )
+    {
+    std::string id_serial( &buf[pdesc->SerialNumberOffset] );
+    sanitize_string( id_serial );
+    if ( !id_serial.empty() )
+      { id_str += "::"; id_str += id_serial; }
+    }
+
+  return id_str.c_str();
+  }
+
 #else				// use linux by default
 #include <linux/hdreg.h>