This is the first checked-in completely working version. It contains

nearly all concepts and simple implementations thereof needed to get a
simple HTTP/0.9 "compliant" server working (there are some hacks
needed that we don't yet provide, since the correct things will be
added shortly, like complete HTTP/1.1 request parsing.  The hacks
needed are provided as part of the basic HTTP/0.9 server demo in
src/test/basic-demo.cl).

Further work is needed to clean up some things, Entity and Resource
handling needs to be implemented right and less "naive" (the current
implementations are just simple place-holders to get things up and
running).  Connections need to have knowledge of client identity
(passed from the driver, this is implementation-specific stuff).
Logging needs to be implemented (probably as server mixins).
Condition handling needs to generate better responses for HTTP/0.9,
and the division between condition handling and normal handling needs
to be documented/rethought.  Content generation is totally missing
currently and needs to be implemented.  If this is all in place, an
HTTP/1.0 conforming server should be possible, and after porting the
drivers to ACL and LW, we can make a first release.

src/drivers/simple-cmu.cl

@@ -0,0 +1,65 @@
+;;;; CLASH --- The Common Lisp Adaptable Simple HTTP server
+;;;; This is copyrighted software.  See documentation for terms.
+;;;; 
+;;;; simple-cmu.cl --- Simple HTTP-Server driver for CMU CL
+;;;; 
+;;;; Checkout Tag: $Name$
+;;;; $Id$
+
+(in-package :CLASH)
+
+;;;; %File Description:
+;;;; 
+;;;; 
+;;;; 
+
+(defun ip-address-string (address)
+  (format nil "~D.~D.~D.~D"
+	  (ldb (byte 8 24) address)
+	  (ldb (byte 8 16) address)
+	  (ldb (byte 8 8)  address)
+	  (ldb (byte 8 0)  address)))
+
+(defun http-listener (port server)
+  (let ((fd (ext:create-inet-listener port)))
+    (unless fd (error "Cannot bind port ~D." port))
+    (unwind-protect
+	 (progn
+	   (setf (process-name *current-process*)
+		 (format nil
+			 "HTTP connection listener on port ~D with server ~A"
+			 port server))
+	   (format t "~&;;; Started lisp connection listener on ~
+                port ~d for server ~A~%" port server)
+	   (loop
+	       ;; Wait for new connection
+	       (process-wait-until-fd-usable fd :input)
+	       #+CLASH-DEBUG
+	       (format t "~&;;; At ~D Got Connection...~%"
+		       (get-internal-real-time))
+	       (multiple-value-bind (new-fd remote-host)
+		   (ext:accept-tcp-connection fd)
+		 #+CLASH-DEBUG
+		 (format t "~&;;; At ~D Have Connection...~%"
+			 (get-internal-real-time))
+		 (let* ((host-entry (ext:lookup-host-entry remote-host))
+			(stream (sys:make-fd-stream new-fd :input t :output t))
+			(connection (make-instance 'simple-connection
+						   :stream stream)))
+		   #+CLASH-DEBUG
+		   (format t "~&;;; At ~D Established Connection...~%"
+			   (get-internal-real-time))
+		   (make-process
+		    #'(lambda ()
+			(serve-connection server connection))
+		    :name (format nil "HTTP connection from ~A"
+				  (if host-entry
+				      (ext:host-entry-name host-entry)
+				      (ip-address-string remote-host))))))))
+      (when fd (unix:unix-close fd)))))
+
+(defun start-http-listener (port server)
+  (make-process #'(lambda () (http-listener port server))))
+
+(defun initialize-clash (&optional (idle-process mp::*initial-process*))
+  (setf mp::*idle-process* idle-process))