Rework NETTIME:

- ditch NETTIME structure; create two structures RFC867 and RFC868
  instead
- make the UDP versions work
- comment fixes
- add copyright notice

scheme/lib/nettime.scm

@@ -3,61 +3,81 @@
 ;;; This file is part of the Scheme Untergrund Networking package.
 
 ;;; Copyright (c) 1998 by Eric Marsden
+;;; Copyright (c) 2003 by Mike Sperber <sperber@informatik.uni-tuebingen.de>
 ;;; For copyright information, see the file COPYING which comes with
 ;;; the distribution.
 
-;;; Overview ========================================================
-;;
-;; Most Unix hosts provide a Daytime service which sends the current
-;; date and time as a human-readable character string. The daytime
-;; service is typically served on port 13 as both TCP and UDP.
-;;
-;; The Time protocol provides a site-independent, machine readable
-;; date and time. A "time" consists of the number of seconds since
-;; midnight on 1st January 1900. The Time service is typically served
-;; on port 37 as TCP and UDP. The idea is that you can confirm your
-;; system's idea of the time by polling several independent sites on
-;; the network.
-
-
 ;;; Related work ======================================================
 ;;
 ;; * Time.pm is a Perl module by Graham Barr
 ;; * rfc868 describes the Time protocol
+;;   http://www.ietf.org/rfc/rfc868.txt
 ;; * rfc867 describes the Daytime protocol in all its glory
+;;   http://www.ietf.org/rfc/rfc867.txt
 ;; * for a genuinely useful protocol look at the Network Time Protocol
 ;; defined in rfc1305, which allows for the synchronization of clocks
 ;; on networked computers.
 
-
-
 ;; args host protocol, where host may be an IP number or a fqdn. we
 ;; subtract 70 years' worth of seconds at the end, since the time
 ;; protocol returns the number of seconds since 1900, whereas Unix
 ;; time is since 1970.
-(define (net-time host tcp/udp)
+
+(define (rfc868-time/tcp host)
   (let* ((hst-info (host-info host))
          (srvc-info (service-info "time" "tcp"))         
          (sock (socket-connect protocol-family/internet
-                               tcp/udp
+                               socket-type/stream
                                (host-info:name hst-info)
                                (service-info:port srvc-info)))
          (result (read-integer (socket:inport sock))))
     (close-socket sock)
     (- result 2208988800)))
 
+(define (rfc868-time/udp host . maybe-timeout)
+  (let* ((hst-info (host-info host))
+         (srvc-info (service-info "time" "udp"))
+	 (timeout (if (pair? maybe-timeout)
+		      (car maybe-timeout)
+		      #f))
+	 (socket (create-socket protocol-family/internet socket-type/datagram)))
+    (connect-socket socket
+		    (internet-address->socket-address
+		     (car (host-info:addresses hst-info))
+		     (service-info:port srvc-info)))
+    (send-message socket "")
+    (select-ports timeout (socket:inport socket))
+    (let ((result (read-integer (socket:inport socket))))
+      (close-socket socket)
+      (- result 2208988800))))
 
-(define (net-daytime host tcp/udp)
+(define (rfc867-daytime/tcp host)
   (let* ((hst-info (host-info host))
          (srvc-info (service-info "daytime" "tcp"))
          (sock (socket-connect protocol-family/internet
-                               tcp/udp
+                               socket-type/stream
                                (host-info:name hst-info)
                                (service-info:port srvc-info)))
          (result (read-string 20 (socket:inport sock))))
     (close-socket sock)
     result))
 
+(define (rfc867-daytime/udp host . maybe-timeout)
+  (let* ((hst-info (host-info host))
+         (srvc-info (service-info "daytime" "udp"))
+	 (timeout (if (pair? maybe-timeout)
+		      (car maybe-timeout)
+		      #f))
+	 (socket (create-socket protocol-family/internet socket-type/datagram)))
+    (connect-socket socket
+		    (internet-address->socket-address
+		     (car (host-info:addresses hst-info))
+		     (service-info:port srvc-info)))
+    (send-message socket "")
+    (select-ports timeout (socket:inport socket))
+    (let ((result (read-string 20 (socket:inport socket))))
+      (close-socket socket)
+      result)))
 
 ;; read 4 bytes from fd and build an integer from them
 (define (read-integer fd)
@@ -71,6 +91,3 @@
 ;; what about EOF??
 (define (read-byte fd)
   (char->ascii (read-char fd)))
-
-
-;; EOF

scheme/packages.scm

@@ -132,9 +132,11 @@
           pop3-quit
 	  pop3-error?))
 
-(define-interface nettime-interface
+(define-interface rfc868-interface
-  (export net-time
+  (export rfc868-time/tcp rfc868-time/udp))
-          net-daytime))
+
+(define-interface rfc867-interface
+  (export rfc867-daytime/tcp rfc867-daytime/udp))
 
 (define-interface dns-interface
   (export dns-clear-cache!		; clears the cache
@@ -449,7 +451,8 @@
 	crlf-io)
   (files (lib pop3)))
 
-(define-structure nettime nettime-interface
+(define-structures ((rfc867 rfc867-interface)
+		    (rfc868 rfc868-interface))
   (open scheme-with-scsh)
   (files (lib nettime)))