+(define-module (mudsync networking)
+ #:use-module (8sync systems actors)
+ #:use-module (8sync agenda)
+ #:use-module (ice-9 format)
+ #:use-module (ice-9 match)
+ #:use-module (oop goops)
+
+ #:export (;; Should we be exporting these?
+ %default-server
+ %default-port
+
+ <network-manager>
+ nm-close-everything))
+
+;;; Networking
+;;; ==========
+
+(define %default-server #f)
+(define %default-port 8889)
+
+(define-class <network-manager> (<actor>)
+ (server-socket #:accessor nm-server-socket)
+ ;; mapping of client -> client-id
+ (clients #:accessor nm-clients
+ #:init-thunk make-hash-table)
+ ;; send input to this actor
+ (send-input-to #:getter nm-send-input-to
+ #:init-keyword #:send-input-to)
+ (message-handler
+ #:init-value
+ (make-action-dispatch
+ ((start-listening actor message)
+ (nm-install-socket actor (message-ref message 'server %default-server)
+ (message-ref message 'port %default-port)))
+ ((send-to-client actor message client data)
+ (nm-send-to-client-id actor client data)))))
+
+(define-method (nm-close-everything (nm <network-manager>) remove-from-agenda)
+ "Shut it down!"
+ ;; close all clients
+ (hash-for-each
+ (lambda (_ client)
+ (close client)
+ (if remove-from-agenda
+ (8sync-port-remove client)))
+ (nm-clients nm))
+ ;; reset the clients list
+ (set! (nm-clients) (make-hash-table))
+ ;; close the server
+ (close (nm-server-socket nm))
+ (if remove-from-agenda
+ (8sync-port-remove (nm-server-socket nm))))
+
+;; Maximum number of backlogged connections when we listen
+(define %maximum-backlog-conns 128) ; same as SOMAXCONN on Linux 2.X,
+ ; says the intarwebs
+
+(define (nm-install-socket nm server port)
+ "Install socket on SERVER with PORT"
+ (let ((s (socket PF_INET ; ipv4
+ SOCK_STREAM ; two-way connection-based byte stream
+ 0))
+ (addr (if server
+ (inet-pton AF_INET server)
+ INADDR_LOOPBACK)))
+ ;; Totally mimed from the Guile manual. Not sure if we need this, but:
+ ;; http://www.unixguide.net/network/socketfaq/4.5.shtml
+ (setsockopt s SOL_SOCKET SO_REUSEADDR 1) ; reuse port even if port is busy
+ ;; Connecting to a non-specific address:
+ ;; (bind s AF_INET INADDR_ANY port)
+ ;; Should this be an option? Guess I don't know why we'd need it
+ ;; @@: If we wanted to support listening on a particular hostname,
+ ;; could see 8sync's irc.scm...
+ (bind s AF_INET addr port)
+ ;; Listen to connections
+ (listen s %maximum-backlog-conns)
+
+ ;; Throw a system-error rather than block on an (accept)
+ ;; that has nothing to do
+ (fcntl s F_SETFL
+ (logior O_NONBLOCK
+ (fcntl s F_GETFL)))
+
+ ;; @@: This is used in Guile's http server under the commit:
+ ;; * module/web/server/http.scm (http-open): Ignore SIGPIPE. Keeps the
+ ;; server from dying in some circumstances.
+ ;; (sigaction SIGPIPE SIG_IGN)
+ ;; Will this break other things that use pipes for us though?
+
+ (set! (nm-server-socket nm) s)
+
+ (format #t "Listening for clients in pid: ~s\n" (getpid))
+ (8sync-port s #:read (lambda (s) (nm-new-client nm s)))
+ ;; TODO: set up periodic close of idle connections?
+ ))
+
+(define (nm-new-client nm s)
+ "Handle new client coming in to socket S"
+ (let* ((client-connection (accept s))
+ (client-details (cdr client-connection))
+ (client (car client-connection)))
+ (format #t "New client: ~s\n" client-details)
+ (format #t "Client address: ~s\n"
+ (gethostbyaddr
+ (sockaddr:addr client-details)))
+
+ (let ((client-id (big-random-number)))
+ (hash-set! (nm-clients nm) client-id client)
+ ;; @@: Do we need an 8sync-port-wait here?
+ ;; Is such a thing even possible? :\
+ (8sync-port client #:read (nm-make-client-receive nm client-id))
+ (<- nm (nm-send-input-to nm) 'new-client #:client client-id))))
+
+(define (nm-make-client-receive nm client-id)
+ "Make a method to receive client data"
+ (let ((buffer '()))
+ (define (reset-buffer)
+ (set! buffer '()))
+ (define (should-read-char client)
+ (and (not (port-closed? client))
+ (char-ready? client)
+ (not (eof-object? (peek-char client)))))
+ (define (receive-handler client)
+ (while (should-read-char client)
+ (set! buffer (cons (read-char client) buffer))
+ (match buffer
+ (;; @@: Do we need the "char?"
+ (#\newline #\return (? char? line-chars) ...)
+ (let ((ready-line (list->string (reverse line-chars))))
+ ;; reset buffer
+ (set! buffer '())
+ ;; run it
+ (nm-handle-line nm client client-id ready-line)))
+ (_ #f)))
+ ;; Shut things down on closed port or EOF object
+ (cond
+ ((port-closed? client)
+ (nm-handle-port-closed nm client client-id))
+ ((and (char-ready? client)
+ (eof-object? (peek-char client)))
+ (nm-handle-port-eof nm client client-id))))
+ receive-handler))
+
+(define (nm-handle-port-closed nm client client-id)
+ "Handle a closed port"
+ (format #t "DEBUG: handled closed port ~x\n" client-id)
+ (8sync-port-remove client)
+ (hash-remove! (nm-clients nm) client-id))
+
+(define-method (nm-handle-port-eof nm client client-id)
+ "Handle seeing an EOF on port"
+ (format #t "DEBUG: handled eof-object on port ~x\n" client-id)
+ (close client)
+ (8sync-port-remove client)
+ (hash-remove! (nm-clients nm) client-id))
+
+(define-method (nm-handle-line nm client client-id line)
+ "Handle an incoming line of input from a client"
+ (<- nm (nm-send-input-to nm) 'client-input
+ #:data line
+ #:client client-id))
+
+(define-method (nm-send-to-client-id nm client-id data)
+ "Send DATA to TO-CLIENT id"
+ (define client-obj (hash-ref (nm-clients nm) client-id))
+ (if (not client-obj)
+ (throw 'no-such-client
+ "Asked to send data to client but that client doesn't exist"
+ #:client-id client-id
+ #:data data))
+ (display data client-obj))