complexhistoryinspect.aml

(* doPrivileged : (unit -> a) -> a *)
(* passed a function f that is run on unit--used in the stack inspection mechanism *)
fun doPrivileged f = f ()

val currPerms:Ref List (String,List Arg) = ref (newAllPermission ("","")::Nil)

fun updatePerms(st) =
  (*  let val _ = print "inside updatePerms" in *)
    currPerms := (case st of 
			 ({{doPrivileged}} (_,_)::{any}(_,fi)::tail) =>
			 getPermissions ((getFileName fi), 
					 policyfile) 
		       | {any} (_,fi)::tail =>
			 intersectPermissions (!currPerms, 
					       getPermissions ((getFileName fi), 
							       policyfile))
		       | _ => !currPerms)
(*end*)

val isUpdate = (fn (st) =>
    case st of 
	{{updatePerms}} (_,_)::tail => True
      | {any} (_,_)::tail => isUpdate tail
      | Nil => False)

advice before (any) (arg,st,fi) =
	      if isUpdate st
	      then arg
	      else ((updatePerms st);arg)

fun checkStack (st, 
		p : (String,List Arg)) : Bool =
    impliesPermissions (!currPerms, p)