1 ;;; guile-websocket --- WebSocket client/server
2 ;;; Copyright © 2016 David Thompson <davet@gnu.org>
3 ;;; Copyright © 2017 Christopher Allan Webber <cwebber@dustycloud.org>
4 ;;; Copyright © 2019, 2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
5 ;;; Copyright © 2020 Rutger van Beusekom <rutger.van.beusekom@gmail.com>
7 ;;; This file is part of guile-websocket.
9 ;;; Guile-websocket is free software; you can redistribute it and/or modify
10 ;;; it under the terms of the GNU Lesser General Public License as
11 ;;; published by the Free Software Foundation; either version 3 of the
12 ;;; License, or (at your option) any later version.
14 ;;; Guile-websocket is distributed in the hope that it will be useful,
15 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 ;;; Lesser General Public License for more details.
19 ;;; You should have received a copy of the GNU Lesser General Public
20 ;;; License along with guile-websocket. If not, see
21 ;;; <http://www.gnu.org/licenses/>.
29 (define-module (8sync systems websocket client)
30 #:use-module (ice-9 match)
31 #:use-module (srfi srfi-26)
32 #:use-module (rnrs bytevectors)
33 #:use-module (rnrs io ports)
34 #:use-module (web request)
35 #:use-module (web response)
36 #:use-module (web uri)
37 #:use-module (oop goops)
39 #:use-module (8sync ports)
40 #:use-module (8sync contrib base64)
41 #:use-module (8sync systems websocket frame)
42 #:use-module (8sync systems websocket utils)
62 (define no-op (const #f))
64 (define-actor <websocket> (<actor>)
65 ((*init* websocket-init)
66 (close websocket-close)
68 (send websocket-send))
70 (state #:accessor .state #:init-value 'closed #:init-keyword #:state)
71 (socket #:accessor .socket #:init-value #f #:init-keyword #:socket)
72 (url #:getter .url #:init-value #f #:init-keyword #:url)
73 (uri #:accessor .uri #:init-value #f #:init-keyword #:uri)
74 (entropy-port #:accessor .entropy-port #:init-form (open-entropy-port))
75 (frames #:accessor .frames #:init-value '())
77 (on-close #:init-keyword #:on-close
80 (on-error #:init-keyword #:on-error
83 (on-message #:init-keyword #:on-message
84 #:accessor .on-message)
85 (on-open #:init-keyword #:on-open
89 (define-method (websocket-close (websocket <websocket>) message)
90 (when (websocket-open? websocket)
91 (false-if-exception (close-port (.socket websocket)))
92 (set! (.state websocket) 'closed)
93 (false-if-exception ((.on-close websocket) websocket))
94 (set! (.socket websocket) #f)))
96 (define-method (websocket-open (websocket <websocket>) message uri-or-string)
97 (if (websocket-closed? websocket)
98 (let ((uri (match uri-or-string
100 ((? string? str) (string->uri str)))))
101 (if (websocket-uri? uri)
104 (set! (.uri websocket) uri)
105 (let ((sock (make-client-socket uri)))
106 (set! (.socket websocket) sock)
107 (handshake websocket)
108 (websocket-loop websocket message)))
110 ((.on-error websocket) websocket (format #f "open failed: ~s: ~s" uri-or-string args))))
111 ((.on-error websocket) websocket (format #f "not a websocket uri: ~s" uri-or-string))))
112 ((.on-error websocket) websocket (format #f "cannot open websocket in state: ~s" (.state websocket)))))
114 (define (subbytevector bv start end)
115 (if (= (bytevector-length bv) end) bv
116 (let* ((length (- end start))
117 (sub (make-bytevector length)))
118 (bytevector-copy! bv start sub 0 length)
121 (define* (make-fragmented-frames data #:key (fragment-size (expt 2 15)))
122 (let ((length (if (string? data) (string-length data)
123 (bytevector-length data))))
124 (let loop ((offset 0))
125 (let* ((size (min fragment-size (- length offset)))
126 (end (+ offset size))
127 (final? (= end length))
128 (continuation? (not (zero? offset)))
129 (frame (if (string? data) (make-text-frame (substring data offset end) #:final? final? #:continuation? continuation?)
130 (make-binary-frame (subbytevector data offset end) #:final? final? #:continuation? continuation?))))
131 (if final? (list frame)
132 (cons frame (loop end)))))))
134 (define-method (websocket-send (websocket <websocket>) message data)
135 (catch #t ; expect: wrong-type-arg (open port), system-error
137 (let* ((frames (make-fragmented-frames data))
138 (frames? (pair? (.frames websocket))))
139 (set! (.frames websocket) (append (.frames websocket) frames))
142 (let ((frames (.frames websocket)))
144 (write-frame (car frames) (.socket websocket))
145 (set! (.frames websocket) (cdr (.frames websocket)))
148 (unless (and (memq key '(system-error wrong-type-arg))
150 (((or "put-u8" "put-bytevector") arg ...) #t)
152 (apply throw key args))
153 (let ((message (format #f "~a: ~s" key args)))
154 ((.on-error websocket) websocket (format #f "send failed: ~s ~a\n" websocket message))
155 (websocket-close websocket message)))))
157 (define-method (websocket-init (websocket <websocket>) message)
158 (and=> (.url websocket) (cut websocket-open websocket message <>)))
160 (define-method (websocket-socket-open? (websocket <websocket>))
161 "Return #t if .SOCKET of WEBSOCKET is open."
162 (not (port-closed? (.socket websocket))))
164 (define-method (websocket-loop (websocket <websocket>) message)
166 (define (handle-data-frame type data)
167 ((.on-message websocket)
170 ('text (utf8->string data))
173 (define (read-frame-maybe)
174 (and (not (eof-object? (lookahead-u8 (.socket websocket))))
175 (read-frame (.socket websocket))))
178 (websocket-close websocket message))
180 ((.on-open websocket) websocket)
182 (let loop ((fragments '())
184 (catch #t ;expect: wrong-type-arg (open port), system-error
186 (let* ((socket (.socket websocket))
187 (frame (and (websocket-open? websocket)
188 (read-frame-maybe))))
190 ;; EOF - port is closed.
191 ;; @@: Sometimes the eof object appears here as opposed to
192 ;; at lookahead, but I'm not sure why
193 ((or (not frame) (eof-object? frame))
195 ;; Per section 5.4, control frames may appear interspersed
196 ;; along with a fragmented message.
197 ((close-frame? frame)
198 ;; Per section 5.5.1, echo the close frame back to the
199 ;; socket before closing the socket. The socket may no
200 ;; longer be listening.
202 (write-frame (make-close-frame (frame-data frame)) socket))
205 ;; Per section 5.5.3, a pong frame must include the exact
206 ;; same data as the ping frame.
207 (write-frame (make-pong-frame (frame-data frame)) socket)
208 (loop fragments type))
209 ((pong-frame? frame) ; silently ignore pongs
210 (loop fragments type))
211 ((first-fragment-frame? frame) ; begin accumulating fragments
212 (loop (list frame) (frame-type frame)))
213 ((final-fragment-frame? frame) ; concatenate all fragments
214 (handle-data-frame type (frame-concatenate
215 (reverse (cons frame fragments))))
217 ((fragment-frame? frame) ; add a fragment
218 (loop (cons frame fragments) type))
219 ((data-frame? frame) ; unfragmented data frame
220 (handle-data-frame (frame-type frame) (frame-data frame))
224 (memq key '(system-error wrong-type-arg))
226 (((or "get-u8" "get-bytevector-n" "lookahead-u8") arg ...)
229 (apply throw key args))
230 (let ((message (format #f "~a: ~s" key args)))
231 ((.on-error websocket) websocket (format #f "read failed: ~s\n" websocket))
232 (if (websocket-socket-open? websocket) (loop '() #f)
233 (websocket-close websocket message)))))))
235 ;; See Section 3 - WebSocket URIs
236 (define (encrypted-websocket-scheme? uri)
237 "Return #t if the scheme for URI is 'wss', the secure WebSocket
239 (eq? (uri-scheme uri) 'wss))
241 (define (unencrypted-websocket-scheme? uri)
242 "Return #t if the scheme for URI is 'ws', the insecure WebSocket
244 (eq? (uri-scheme uri) 'ws))
246 (define (websocket-uri? uri)
247 "Return #t if URI is a valid WebSocket URI."
248 (and (or (encrypted-websocket-scheme? uri)
249 (unencrypted-websocket-scheme? uri))
250 (not (uri-fragment uri))))
252 (define (set-nonblocking! port)
253 (fcntl port F_SETFL (logior O_NONBLOCK (fcntl port F_GETFL)))
254 (setvbuf port 'block 1024))
256 (define (make-client-socket uri)
257 "Connect a socket to the remote resource described by URI."
258 (let* ((port (uri-port uri))
259 (info (car (getaddrinfo (uri-host uri)
261 (number->string port)
262 (symbol->string (uri-scheme uri)))
266 (sock (with-fluids ((%default-port-encoding #f))
267 (socket (addrinfo:fam info) SOCK_STREAM IPPROTO_IP))))
269 (set-nonblocking! sock)
270 ;; Disable buffering for websockets
273 ;; TODO: Configure I/O buffering?
274 (connect sock (addrinfo:addr info))
277 (define-method (write (o <websocket>) port)
278 (format port "#<websocket ~a ~a>"
282 (define-method (websocket-connecting? (websocket <websocket>))
283 "Return #t if WEBSOCKET is in the connecting state."
284 (eq? (.state websocket) 'connecting))
286 (define-method (websocket-open? (websocket <websocket>))
287 "Return #t if WEBSOCKET is in the open state."
288 (eq? (.state websocket) 'open))
290 (define-method (websocket-closing? (websocket <websocket>))
291 "Return #t if WEBSOCKET is in the closing state."
292 (eq? (.state websocket) 'closing))
294 (define-method (websocket-closed? (websocket <websocket>))
295 "Return #t if WEBSOCKET is in the closed state."
296 (eq? (.state websocket) 'closed))
298 (define-method (generate-client-key (websocket <websocket>))
299 "Return a random, base64 encoded nonce using the entropy source of
302 (get-bytevector-n (.entropy-port websocket) 16)))
304 ;; See Section 4.1 - Client Requirements
305 (define (make-handshake-request uri key)
306 "Create an HTTP request for initiating a WebSocket connection with
307 the remote resource described by URI, using a randomly generated nonce
309 (let ((headers `((host . (,(uri-host uri) . #f))
310 (upgrade . ("WebSocket"))
311 (connection . (upgrade))
312 (sec-websocket-key . ,key)
313 (sec-websocket-version . "13"))))
314 (build-request uri #:method 'GET #:headers headers)))
316 (define-method (handshake (websocket <websocket>))
317 "Perform the WebSocket handshake for the client WEBSOCKET."
318 (let ((key (generate-client-key websocket)))
319 (write-request (make-handshake-request (.uri websocket) key)
321 (let* ((response (read-response (.socket websocket)))
322 (headers (response-headers response))
323 (upgrade (assoc-ref headers 'upgrade))
324 (connection (assoc-ref headers 'connection))
325 (accept (assoc-ref headers 'sec-websocket-accept)))
326 ;; Validate the handshake.
327 (if (and (= (response-code response) 101)
328 (string-ci=? (car upgrade) "websocket")
329 (equal? connection '(upgrade))
330 (string=? (string-trim-both accept) (make-accept-key key)))
331 (set! (.state websocket) 'open)
333 (websocket-close websocket)
334 ((.on-error websocket) websocket
335 (format #f "websocket handshake failed: ~s"
336 (uri->string (.uri websocket)))))))))
338 (define (open-entropy-port)
339 "Return an open input port to a reliable source of entropy for the
341 (if (file-exists? "/dev/urandom")
342 (open-input-file "/dev/urandom")
343 ;; XXX: This works as a fall back but this isn't exactly a
344 ;; reliable source of entropy.
345 (make-soft-port (vector (const #f) (const #f) (const #f)
346 (lambda _ (let ((r (random 256))) (integer->char r)))
350 (define-method (websocket-close (websocket <websocket>))
351 "Close the WebSocket connection for the client WEBSOCKET."
352 (let ((socket (.socket websocket)))
353 (set! (.state websocket) 'closing)
354 (write-frame (make-close-frame (make-bytevector 0)) socket)
355 ;; Per section 5.5.1 , wait for the server to close the connection
356 ;; for a reasonable amount of time.
358 (match (select #() (vector socket) #() 1) ; 1 second timeout
359 ((#() #(socket) #()) ; there is output to read
360 (unless (port-eof? socket)
361 (read-frame socket) ; throw it away
364 (close-port (.entropy-port websocket))
365 (set! (.state websocket) 'closed)))