Declaration for COBOL calling C++

COBOL program C++ function
LINKAGE SECTION.
01 P1 PIC S9(9) USAGE IS BINARY.
01 P2 PIC S9(9) USAGE IS BINARY.
CALL 'CFUNC' USING BY VALUE P1
     RETURNING P2.
 
int CFUNC(int p1){
  int p2;
  p2=p1;
  return p2;
}