355 lines
15 KiB
Common Lisp

(in-package :whatsxmpp)
(defvar *xmpp-debug-io* (make-broadcast-stream))
(defvar *xmpp-debug-out* (make-synonym-stream '*xmpp-debug-io*))
(defclass xmpp-component (event-emitter)
:initarg :socket
:accessor component-socket)
:initform (bt:make-recursive-lock "component socket lock")
:accessor component-socket-lock)
:initform (bt:make-recursive-lock "component data lock")
:accessor component-data-lock)
:initarg :sink
:accessor component-sink)
:initarg :name
:reader component-name)
:initform nil
:accessor component-stream-id)
:initarg :shared-secret
:reader component-shared-secret)
:initform (make-hash-table)
:accessor component-handlers)
:initform (make-hash-table :test 'equal)
:accessor component-promises)))
(defmacro with-component-data-lock ((comp) &body body)
`(bt:with-recursive-lock-held ((component-data-lock ,comp))
(defclass xmpp-source (cxml:broadcast-handler)
:initarg :component
:accessor source-component)
:initform 0
:accessor source-depth)))
(defun make-xmpp-source (comp)
(let ((ret (cxml:make-broadcast-handler)))
(change-class ret 'xmpp-source
:component comp)
(defmethod sax:start-document ((s xmpp-source))
(declare (ignore s))
(format *xmpp-debug-out* "~&XMPP --> [document started]~%"))
(defmethod sax:start-element ((s xmpp-source) namespace-uri local-name qname attributes)
(with-accessors ((depth source-depth) (comp source-component) (handlers cxml:broadcast-handler-handlers)) s
(incf depth)
(when (and (eql depth 1) (equal qname "stream:stream"))
(flet ((local-name-is-id (attr)
(equal (sax:attribute-local-name attr) "id")))
(let ((stream-id-attr (find-if #'local-name-is-id attributes)))
(when (not stream-id-attr)
(error "Server didn't send a stream ID"))
(format *xmpp-debug-out* "~&XMPP --> [stream started, ID ~A]~%" (sax:attribute-value stream-id-attr))
(with-component-data-lock (comp)
(setf (component-stream-id comp) (sax:attribute-value stream-id-attr))
(emit :stream-started comp))
(return-from sax:start-element))))
(when (eql depth 2)
(let ((dom-builder (cxml-dom:make-dom-builder)))
(format *xmpp-debug-out* "~&XMPP --> ")
(setf handlers (list (cxml:make-character-stream-sink *xmpp-debug-out*) dom-builder))
(sax:start-document dom-builder)))
(call-next-method s namespace-uri local-name qname attributes)))
(defmethod sax:end-element :before ((s xmpp-source) namespace-uri local-name qname)
(when (equal qname "stream:stream")
(error "Server closed the stream")))
(defmethod sax:end-element :after ((s xmpp-source) namespace-uri local-name qname)
(with-accessors ((depth source-depth) (comp source-component) (handlers cxml:broadcast-handler-handlers)) s
(decf depth)
(when (eql depth 1)
(let* ((debug-sink (first handlers))
(dom-builder (second handlers))
(stanza (sax:end-document dom-builder)))
(sax:end-document debug-sink)
(terpri *xmpp-debug-out*)
(setf handlers nil)
(emit :raw-stanza comp stanza)))))
(defclass xmpp-sink (cxml:broadcast-handler)
:initform t
:accessor sink-open)))
(defmethod sax:start-document ((s xmpp-sink))
(declare (ignore s))
(format *xmpp-debug-out* "~&XMPP <-- "))
(defmethod sax:end-element ((s xmpp-sink) namespace-uri local-name qname)
(if (and (sink-open s) (equal local-name "stream"))
;; The <stream:stream> element gets opened at the start of the connection
;; and closing it represents ending the connection. We therefore don't
;; want to close it...
;; Instead, send some empty characters to get the sinks to write the last ">"
;; bit of the opening tag.
(sax:characters s "")
(call-next-method s namespace-uri local-name qname))
(terpri *xmpp-debug-out*))
(defun close-xmpp-component (comp)
(bt:with-recursive-lock-held ((component-socket-lock comp))
(setf (sink-open (component-sink comp)) nil)
(write-sequence (babel:string-to-octets "</stream:stream>"
:encoding :utf-8)
(component-socket comp))
(force-output (component-socket comp))
(close (component-socket comp))))
(defun make-xmpp-sink (socket)
(let ((ret (cxml:make-broadcast-handler
(cxml:make-character-stream-sink *xmpp-debug-out*)
(cxml:make-octet-stream-sink socket))))
(change-class ret 'xmpp-sink)
(defmacro with-dom-xml-output (&body body)
`(cxml:with-xml-output (cxml-dom:make-dom-builder)
(defun component-listen-thread (comp)
"Listening thread for an XMPP component: constantly reads from the socket and emits new stanzas."
(format *debug-io* "Starting component listening thread~%")
;; ### Story time! ###
;; So I spent an hour debugging why this wasn't working.
;; And, long story short, if you just call CXML:PARSE with a stream
;; it gets converted into an 'xstream' inside CXML, which has a :SPEED
;; property. This :SPEED property controls how many bytes it tries to buffer
;; before actually doing the parsing and the goddamn default is 8192 (!!).
;; This obviously ain't gonna fly for our TCP socket, because the initial stream
;; start element is less than 8192 bytes. So we make our own stupid xstream
;; and specify the speed manually, and then it works.
;; Wouldn't it be nice if people documented this sort of thing?
;; ### Part II: The Fucking Stream Strikes Back ###
;; ...and, after another hour of debugging, I found out you have to specify the `name'
;; arg, otherwise it breaks -- but ONLY randomly and once you decide to deploy it
;; in production, of course.
(let ((source (make-xmpp-source comp))
(fucking-stream (cxml:make-xstream (component-socket comp)
:name (cxml::make-stream-name ; AAAARGH
:entity-name "main document"
:entity-kind :main
:uri nil)
:name "XMPP server stream"
:initial-speed 1)))
(cxml:parse fucking-stream source
:recode t)))
(defmacro with-component-xml-output ((comp) &body body)
(let ((ret-sym (gensym)))
`(with-accessors ((lock component-socket-lock) (socket component-socket) (sink component-sink))
(with-component-data-lock (,comp)
(bt:with-recursive-lock-held (lock)
(let ((,ret-sym nil))
(cxml:with-xml-output sink
(setf ,ret-sym ,@body))
(force-output socket)
(defun write-stream-header (comp)
(with-component-xml-output (comp)
(cxml:with-namespace ("stream" "http://etherx.jabber.org/streams")
(cxml:with-element "stream:stream"
(cxml:attribute "xmlns" +component-ns+)
(cxml:attribute "to" (component-name comp))))))
(defun component-stream-started (comp)
(with-component-xml-output (comp)
(cxml:with-element "handshake"
(cxml:attribute "xmlns" +component-ns+)
(cxml:text (string-downcase (sha1-hex (concatenate 'string (component-stream-id comp) (component-shared-secret comp))))))))
(defun register-component-iq-handler (comp handler-name func)
"Register FUNC to be called for the HANDLER-NAME IQ handler on COMP."
(with-component-data-lock (comp)
(setf (gethash handler-name (component-handlers comp)) func)))
(defun call-component-iq-handler (comp handler &rest args)
"Calls the IQ handler identified by the symbol HANDLER on COMP, with the provided ARGS."
(destructuring-bind (&key id to from &allow-other-keys) args
(with-component-data-lock (comp)
(let ((func (gethash handler (component-handlers comp))))
(unless func
(error 'stanza-error
:defined-condition "feature-not-implemented"
:text (format nil "No handler for ~A registered" handler)
:type "cancel"))
(let ((result (apply func comp args)))
(lambda (result-forms)
(eval `(with-component-xml-output (,comp)
(cxml:with-element "iq"
(cxml:attribute "type" "result")
(cxml:attribute "id" ,id)
(cxml:attribute "from" ,to)
(cxml:attribute "to" ,from)
(stanza-error (e)
(send-stanza-error comp
:stanza-type "iq"
:id id :to from :from to :e e))
(t (e)
(send-stanza-error comp
:stanza-type "iq"
:id id
:to from
:from to
:e (make-condition 'stanza-error
:defined-condition "internal-server-error"
:text (format nil "~A" e)
:type "cancel"))
(warn "IQ handler for ~A failed: ~A" handler e))))))
(defun handle-iq-get (comp id from stanza)
"Handles an IQ-get STANZA for component COMP."
(let* ((children (child-elements stanza))
(first-child (if (> (length children) 0)
(elt children 0)
(return-from handle-iq-get)))
(tag-name (dom:tag-name first-child))
(to (dom:get-attribute stanza "to"))
(xmlns (dom:get-attribute first-child "xmlns"))
((and (equal xmlns +disco-info-ns+) (equal tag-name "query"))
((and (equal xmlns +disco-items-ns+) (equal tag-name "query"))
((and (equal xmlns +vcard-temp-ns+) (equal tag-name "vCard"))
((and (equal xmlns +mam-ns+) (equal tag-name "query"))
((and (equal xmlns +ping-ns+) (equal tag-name "ping"))
(call-component-iq-handler comp handler-type
:to to
:id id
:from from
:stanza stanza)))
(defun handle-iq-response (comp stanza)
"Handles an IQ response STANZA for component COMP."
(with-component-data-lock (comp)
(let ((type (dom:get-attribute stanza "type"))
(id (dom:get-attribute stanza "id"))
(from (dom:get-attribute stanza "from")))
(if (or (equal type "get") (equal type "set"))
(handle-iq-get comp id from stanza)
((promise (gethash id (component-promises comp))))
(if promise
(format t "~&IQ ~A from ~A for ~A~%" type from id)
((equal type "result") (finish promise (child-elements stanza)))
((equal type "error") (signal-error promise (extract-stanza-error stanza)))
(t (warn "Invalid IQ stanza type: ~A" type)))
(setf promise nil))
(warn "Unsolicited IQ stanza from ~A of type ~A, ID ~A" from type id)))))))
(defun handle-presence (comp stanza)
"Handles a presence STANZA for component COMP."
(let* ((type (dom:get-attribute stanza "type"))
(from (dom:get-attribute stanza "from"))
(to (dom:get-attribute stanza "to"))
((equal type "subscribe") :presence-subscribe)
((equal type "probe") :presence-probe)
((equal type "unavailable") :presence-unavailable)
(t :presence))))
(emit event-name comp :from from :to to :type type :stanza stanza)))
(defun handle-message (comp stanza)
"Handles a message STANZA for component COMP."
(let* ((from (dom:get-attribute stanza "from"))
(to (dom:get-attribute stanza "to"))
(id (dom:get-attribute stanza "id"))
(children (child-elements stanza))
(body (get-node-named children "body"))
(marker (get-node-with-xmlns children +chat-markers-ns+))
(oob-element (get-node-with-xmlns children +oob-ns+))
(oob-url-element (when oob-element
(get-node-named (child-elements oob-element) "url")))
(chat-state (get-node-with-xmlns children +chat-states-ns+)))
(let* ((text (get-node-text body))
(oob-url (when oob-url-element
(get-node-text oob-url-element))))
(emit :text-message comp :from from :to to :body text :id id :stanza stanza
:oob-url oob-url)))
(let ((marker-type (dom:tag-name marker))
(msgid (dom:get-attribute marker "id")))
(emit :message-marker comp :from from :to to :type marker-type :marker-id msgid :id id :stanza stanza)))
(let ((state-type (dom:tag-name chat-state)))
(emit :chat-state comp :from from :to to :type state-type :id id :stanza stanza)))
(emit :message comp :from from :to to :id id :stanza stanza)))))
(defun component-stanza (comp stanza)
"Handles a STANZA received by component COMP."
(let* ((stanza (dom:document-element stanza))
(tag-name (dom:tag-name stanza)))
((equal tag-name "stream:error") (handle-stream-error comp stanza))
((equal tag-name "handshake") (handle-connection-complete comp))
((equal tag-name "iq") (handle-iq-response comp stanza))
((equal tag-name "presence") (handle-presence comp stanza))
((equal tag-name "message") (handle-message comp stanza))
(t (emit :stanza comp stanza)))))
(defun make-component (server port shared-secret name)
"Make a new XMPP component, connecting to SERVER on PORT with SHARED-SECRET."
(let* ((socket (socket-stream
(socket-connect server port
:element-type '(unsigned-byte 8))))
(component (make-instance 'xmpp-component
:socket socket
:sink (make-xmpp-sink socket)
:name name
:shared-secret shared-secret)))
(bt:make-thread (lambda ()
(component-listen-thread component))
:name "XMPP component listen thread")
(on :stream-started component (lambda ()
(component-stream-started component)))
(on :raw-stanza component (lambda (stanza)
(component-stanza component stanza)))
(write-stream-header component)