;;; Mudsync --- Live hackable MUD ;;; Copyright © 2016 Christopher Allan Webber ;;; ;;; This file is part of Mudsync. ;;; ;;; Mudsync is free software; you can redistribute it and/or modify it ;;; under the terms of the GNU General Public License as published by ;;; the Free Software Foundation; either version 3 of the License, or ;;; (at your option) any later version. ;;; ;;; Mudsync is distributed in the hope that it will be useful, but ;;; WITHOUT ANY WARRANTY; without even the implied warranty of ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ;;; General Public License for more details. ;;; ;;; You should have received a copy of the GNU General Public License ;;; along with Mudsync. If not, see . (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 nm-close-everything)) ;;; Networking ;;; ========== (define %default-server #f) (define %default-port 8889) (define-class () (server-socket #:getter nm-server-socket) ;; mapping of client -> client-id (clients #:getter 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 ) 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? (slot-set! nm 'server-socket 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) (<- nm (nm-send-input-to nm) 'client-closed #:client 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) (<- nm (nm-send-input-to nm) 'client-closed #:client 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))