structure Sec :> SEC = struct

open Init Util Sql

structure Req = Request(struct
			val table = "Sec"
			val adminGroup = "server"
			fun subject _ = "Security permissions change request"
			val template = "sec"
			val descr = "change"
			fun body (mail, req) =
			    (Mail.mwrite (mail, req);
			     Mail.mwrite (mail, "\n"))
			end)

fun findSubusers uname =
    let
	val uname_under = uname ^ "_"
	val inf = TextIO.openIn "/etc/passwd"

	fun loop subs =
	    case TextIO.inputLine inf of
		NONE => ListMergeSort.sort (fn (x, y) => String.compare (x, y) = GREATER) subs
	      | SOME line =>
		case String.fields (fn ch => ch = #":") line of
		    uname'::_ =>
		    if size uname' >= size uname_under
		       andalso String.substring (uname', 0, size uname_under) = uname_under then
			loop (uname' :: subs)
		    else
			loop subs
		  | _ => loop subs
    in
	loop []
	before TextIO.closeIn inf
    end

datatype socket_perms =
	 ANY
       | CLIENT_ONLY
       | SERVER_ONLY
       | NADA

fun inGroup (uname, grp) =
    let
	val uname_under = uname ^ "_"
	val inf = TextIO.openIn "/etc/group"

	fun loop () =
	    case TextIO.inputLine inf of
		NONE => false
	      | SOME line =>
		case String.fields (fn ch => ch = #":") line of
		    [gname, _, _, members]  =>
		    if gname = grp then
			mem (uname, String.fields (fn ch => ch = #",") members)
		    else
			loop ()
		  | _ => loop ()
    in
	loop ()
	before TextIO.closeIn inf
    end    

fun socketPerms uname =
    if inGroup (uname, "no-sockets") then
	NADA
    else if inGroup (uname, "no-cli-sockets") then
	if inGroup (uname, "no-serv-sockets") then
	    NADA
	else
	    SERVER_ONLY
    else if inGroup (uname, "no-serv-sockets") then
	CLIENT_ONLY
    else
	ANY

fun isTpe uname = inGroup (uname, "only-tpe")

end