Bugfix/validate-user-provided-file-object-paths (#1197)

* Fixed BACnet file object path name unintended path traversals by optionally restricting path name content with BACNET_FILE_PATH_RESTRICTED define.

* Added POSIX file path name checking for AtomicReadFile and AtomicWriteFile example applications. Prohibits use of relative and absolute file paths when BACNET_FILE_PATH_RESTRICTED is non-zero.

src/bacnet/basic/object/bacfile.c

@@ -29,9 +29,6 @@
 #include "bacnet/basic/sys/keylist.h"
 #include "bacnet/basic/tsm/tsm.h"
 
-#ifndef FILE_RECORD_SIZE
-#define FILE_RECORD_SIZE MAX_OCTET_STRING_BYTES
-#endif
 struct object_data {
     char *Object_Name;
     char *Pathname;