url-http.el

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1	;;; url-http.el --- HTTP retrieval routines
2
3	;; Copyright (C) 1999, 2001, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
4
5	;; Author: Bill Perry <wmperry@gnu.org>
6	;; Keywords: comm, data, processes
7
8	;; This file is part of GNU Emacs.
9	;;
10	;; GNU Emacs is free software; you can redistribute it and/or modify
11	;; it under the terms of the GNU General Public License as published by
12	;; the Free Software Foundation; either version 3, or (at your option)
13	;; any later version.
14	;;
15	;; GNU Emacs is distributed in the hope that it will be useful,
16	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18	;; GNU General Public License for more details.
19	;;
20	;; You should have received a copy of the GNU General Public License
21	;; along with GNU Emacs; see the file COPYING. If not, write to the
22	;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
23	;; Boston, MA 02110-1301, USA.
24
25	;;; Commentary:
26
27	;;; Code:
28
29	(eval-when-compile (require 'cl))
30	(defvar url-http-extra-headers)
31	(defvar url-http-target-url)
32	(defvar url-http-proxy)
33	(defvar url-http-connection-opened)
34	(require 'url-gw)
35	(require 'url-util)
36	(require 'url-parse)
37	(require 'url-cookie)
38	(require 'mail-parse)
39	(require 'url-auth)
40	(require 'url)
41	(autoload 'url-cache-create-filename "url-cache")
42
43	(defconst url-http-default-port 80 "Default HTTP port.")
44	(defconst url-http-asynchronous-p t "HTTP retrievals are asynchronous.")
45	(defalias 'url-http-expand-file-name 'url-default-expander)
46
47	(defvar url-http-real-basic-auth-storage nil)
48	(defvar url-http-proxy-basic-auth-storage nil)
49
50	(defvar url-http-open-connections (make-hash-table :test 'equal
51	:size 17)
52	"A hash table of all open network connections.")
53
54	(defvar url-http-version "1.1"
55	"What version of HTTP we advertise, as a string.
56	Valid values are 1.1 and 1.0.
57	This is only useful when debugging the HTTP subsystem.
58
59	Setting this to 1.0 will tell servers not to send chunked encoding,
60	and other HTTP/1.1 specific features.")
61
62	(defvar url-http-attempt-keepalives t
63	"Whether to use a single TCP connection multiple times in HTTP.
64	This is only useful when debugging the HTTP subsystem. Setting to
65	nil will explicitly close the connection to the server after every
66	request.")
67
68	;(eval-when-compile
69	;; These are all macros so that they are hidden from external sight
70	;; when the file is byte-compiled.
71	;;
72	;; This allows us to expose just the entry points we want.
73
74	;; These routines will allow us to implement persistent HTTP
75	;; connections.
76	(defsubst url-http-debug (&rest args)
77	(if quit-flag
78	(let ((proc (get-buffer-process (current-buffer))))
79	;; The user hit C-g, honor it! Some things can get in an
80	;; incredibly tight loop (chunked encoding)
81	(if proc
82	(progn
83	(set-process-sentinel proc nil)
84	(set-process-filter proc nil)))
85	(error "Transfer interrupted!")))
86	(apply 'url-debug 'http args))
87
88	(defun url-http-mark-connection-as-busy (host port proc)
89	(url-http-debug "Marking connection as busy: %s:%d %S" host port proc)
90	(set-process-query-on-exit-flag proc t)
91	(puthash (cons host port)
92	(delq proc (gethash (cons host port) url-http-open-connections))
93	url-http-open-connections)
94	proc)
95
96	(defun url-http-mark-connection-as-free (host port proc)
97	(url-http-debug "Marking connection as free: %s:%d %S" host port proc)
98	(when (memq (process-status proc) '(open run connect))
99	(set-process-buffer proc nil)
100	(set-process-sentinel proc 'url-http-idle-sentinel)
101	(set-process-query-on-exit-flag proc nil)
102	(puthash (cons host port)
103	(cons proc (gethash (cons host port) url-http-open-connections))
104	url-http-open-connections))
105	nil)
106
107	(defun url-http-find-free-connection (host port)
108	(let ((conns (gethash (cons host port) url-http-open-connections))
109	(found nil))
110	(while (and conns (not found))
111	(if (not (memq (process-status (car conns)) '(run open connect)))
112	(progn
113	(url-http-debug "Cleaning up dead process: %s:%d %S"
114	host port (car conns))
115	(url-http-idle-sentinel (car conns) nil))
116	(setq found (car conns))
117	(url-http-debug "Found existing connection: %s:%d %S" host port found))
118	(pop conns))
119	(if found
120	(url-http-debug "Reusing existing connection: %s:%d" host port)
121	(url-http-debug "Contacting host: %s:%d" host port))
122	(url-lazy-message "Contacting host: %s:%d" host port)
123	(url-http-mark-connection-as-busy
124	host port
125	(or found
126	(let ((buf (generate-new-buffer *" url-http-temp"*)))
127	;; `url-open-stream' needs a buffer in which to do things
128	;; like authentication. But we use another buffer afterwards.
129	(unwind-protect
130	(let ((proc (url-open-stream host buf host port)))
131	;; url-open-stream might return nil.
132	(when (processp proc)
133	;; Drop the temp buffer link before killing the buffer.
134	(set-process-buffer proc nil))
135	proc)
136	(kill-buffer buf)))))))
137
138	;; Building an HTTP request
139	(defun url-http-user-agent-string ()
140	(if (or (eq url-privacy-level 'paranoid)
141	(and (listp url-privacy-level)
142	(memq 'agent url-privacy-level)))
143	""
144	(format "User-Agent: %sURL/%s%s\r\n"
145	(if url-package-name
146	(concat url-package-name "/" url-package-version " ")
147	"")
148	url-version
149	(cond
150	((and url-os-type url-system-type)
151	(concat " (" url-os-type "; " url-system-type ")"))
152	((or url-os-type url-system-type)
153	(concat " (" (or url-system-type url-os-type) ")"))
154	(t "")))))
155
156	(defun url-http-create-request (&optional ref-url)
157	"Create an HTTP request for `url-http-target-url', referred to by REF-URL."
158	(declare (special proxy-info
159	url-http-method url-http-data
160	url-http-extra-headers))
161	(let* ((extra-headers)
162	(request nil)
163	(no-cache (cdr-safe (assoc "Pragma" url-http-extra-headers)))
164	(using-proxy url-http-proxy)
165	(proxy-auth (if (or (cdr-safe (assoc "Proxy-Authorization"
166	url-http-extra-headers))
167	(not using-proxy))
168	nil
169	(let ((url-basic-auth-storage
170	'url-http-proxy-basic-auth-storage))
171	(url-get-authentication url-http-target-url nil 'any nil))))
172	(real-fname (concat (url-filename url-http-target-url)
173	(url-recreate-url-attributes url-http-target-url)))
174	(host (url-host url-http-target-url))
175	(auth (if (cdr-safe (assoc "Authorization" url-http-extra-headers))
176	nil
177	(url-get-authentication (or
178	(and (boundp 'proxy-info)
179	proxy-info)
180	url-http-target-url) nil 'any nil))))
181	(if (equal "" real-fname)
182	(setq real-fname "/"))
183	(setq no-cache (and no-cache (string-match "no-cache" no-cache)))
184	(if auth
185	(setq auth (concat "Authorization: " auth "\r\n")))
186	(if proxy-auth
187	(setq proxy-auth (concat "Proxy-Authorization: " proxy-auth "\r\n")))
188
189	;; Protection against stupid values in the referer
190	(if (and ref-url (stringp ref-url) (or (string= ref-url "file:nil")
191	(string= ref-url "")))
192	(setq ref-url nil))
193
194	;; We do not want to expose the referer if the user is paranoid.
195	(if (or (memq url-privacy-level '(low high paranoid))
196	(and (listp url-privacy-level)
197	(memq 'lastloc url-privacy-level)))
198	(setq ref-url nil))
199
200	;; url-http-extra-headers contains an assoc-list of
201	;; header/value pairs that we need to put into the request.
202	(setq extra-headers (mapconcat
203	(lambda (x)
204	(concat (car x) ": " (cdr x)))
205	url-http-extra-headers "\r\n"))
206	(if (not (equal extra-headers ""))
207	(setq extra-headers (concat extra-headers "\r\n")))
208
209	;; This was done with a call to `format'. Concatting parts has
210	;; the advantage of keeping the parts of each header together and
211	;; allows us to elide null lines directly, at the cost of making
212	;; the layout less clear.
213	(setq request
214	;; We used to concat directly, but if one of the strings happens
215	;; to being multibyte (even if it only contains pure ASCII) then
216	;; every string gets converted with `string-MAKE-multibyte' which
217	;; turns the 127-255 codes into things like latin-1 accented chars
218	;; (it would work right if it used `string-TO-multibyte' instead).
219	;; So to avoid the problem we force every string to be unibyte.
220	(mapconcat
221	;; FIXME: Instead of `string-AS-unibyte' we'd want
222	;; `string-to-unibyte', so as to properly signal an error if one
223	;; of the strings contains a multibyte char.
224	'string-as-unibyte
225	(delq nil
226	(list
227	;; The request
228	(or url-http-method "GET") " "
229	(if using-proxy (url-recreate-url url-http-target-url) real-fname)
230	" HTTP/" url-http-version "\r\n"
231	;; Version of MIME we speak
232	"MIME-Version: 1.0\r\n"
233	;; (maybe) Try to keep the connection open
234	"Connection: " (if (or using-proxy
235	(not url-http-attempt-keepalives))
236	"close" "keep-alive") "\r\n"
237	;; HTTP extensions we support
238	(if url-extensions-header
239	(format
240	"Extension: %s\r\n" url-extensions-header))
241	;; Who we want to talk to
242	(if (/= (url-port url-http-target-url)
243	(url-scheme-get-property
244	(url-type url-http-target-url) 'default-port))
245	(format
246	"Host: %s:%d\r\n" host (url-port url-http-target-url))
247	(format "Host: %s\r\n" host))
248	;; Who its from
249	(if url-personal-mail-address
250	(concat
251	"From: " url-personal-mail-address "\r\n"))
252	;; Encodings we understand
253	(if url-mime-encoding-string
254	(concat
255	"Accept-encoding: " url-mime-encoding-string "\r\n"))
256	(if url-mime-charset-string
257	(concat
258	"Accept-charset: " url-mime-charset-string "\r\n"))
259	;; Languages we understand
260	(if url-mime-language-string
261	(concat
262	"Accept-language: " url-mime-language-string "\r\n"))
263	;; Types we understand
264	"Accept: " (or url-mime-accept-string *"/") "\r\n"*
265	;; User agent
266	(url-http-user-agent-string)
267	;; Proxy Authorization
268	proxy-auth
269	;; Authorization
270	auth
271	;; Cookies
272	(url-cookie-generate-header-lines host real-fname
273	(equal "https" (url-type url-http-target-url)))
274	;; If-modified-since
275	(if (and (not no-cache)
276	(member url-http-method '("GET" nil)))
277	(let ((tm (url-is-cached url-http-target-url)))
278	(if tm
279	(concat "If-modified-since: "
280	(url-get-normalized-date tm) "\r\n"))))
281	;; Whence we came
282	(if ref-url (concat
283	"Referer: " ref-url "\r\n"))
284	extra-headers
285	;; Length of data
286	(if url-http-data
287	(concat
288	"Content-length: " (number-to-string
289	(length url-http-data))
290	"\r\n"))
291	;; End request
292	"\r\n"
293	;; Any data
294	url-http-data))
295	""))
296	(url-http-debug "Request is: \n%s" request)
297	request))
298
299	;; Parsing routines
300	(defun url-http-clean-headers ()
301	"Remove trailing \r from header lines.
302	This allows us to use `mail-fetch-field', etc."
303	(declare (special url-http-end-of-headers))
304	(goto-char (point-min))
305	(while (re-search-forward "\r$" url-http-end-of-headers t)
306	(replace-match "")))
307
308	(defun url-http-handle-authentication (proxy)
309	(declare (special status success url-http-method url-http-data
310	url-callback-function url-callback-arguments))
311	(url-http-debug "Handling %s authentication" (if proxy "proxy" "normal"))
312	(let ((auths (or (nreverse
313	(mail-fetch-field
314	(if proxy "proxy-authenticate" "www-authenticate")
315	nil nil t))
316	'("basic")))
317	(type nil)
318	(url (url-recreate-url url-current-object))
319	(url-basic-auth-storage 'url-http-real-basic-auth-storage)
320	auth
321	(strength 0))
322	;; Cheating, but who cares? :)
323	(if proxy
324	(setq url-basic-auth-storage 'url-http-proxy-basic-auth-storage))
325
326	;; find strongest supported auth
327	(dolist (this-auth auths)
328	(setq this-auth (url-eat-trailing-space
329	(url-strip-leading-spaces
330	this-auth)))
331	(let* ((this-type
332	(if (string-match "[ \t]" this-auth)
333	(downcase (substring this-auth 0 (match-beginning 0)))
334	(downcase this-auth)))
335	(registered (url-auth-registered this-type))
336	(this-strength (cddr registered)))
337	(when (and registered (> this-strength strength))
338	(setq auth this-auth
339	type this-type
340	strength this-strength))))
341
342	(if (not (url-auth-registered type))
343	(progn
344	(widen)
345	(goto-char (point-max))
346	(insert "<hr>Sorry, but I do not know how to handle " type
347	" authentication. If you'd like to write it,"
348	" send it to " url-bug-address ".<hr>")
349	(setq status t))
350	(let* ((args (url-parse-args (subst-char-in-string ?, ?\; auth)))
351	(auth (url-get-authentication url (cdr-safe (assoc "realm" args))
352	type t args)))
353	(if (not auth)
354	(setq success t)
355	(push (cons (if proxy "Proxy-Authorization" "Authorization") auth)
356	url-http-extra-headers)
357	(let ((url-request-method url-http-method)
358	(url-request-data url-http-data)
359	(url-request-extra-headers url-http-extra-headers))
360	(url-retrieve-internal url url-callback-function
361	url-callback-arguments)))))))
362
363	(defun url-http-parse-response ()
364	"Parse just the response code."
365	(declare (special url-http-end-of-headers url-http-response-status
366	url-http-response-version))
367	(if (not url-http-end-of-headers)
368	(error "Trying to parse HTTP response code in odd buffer: %s" (buffer-name)))
369	(url-http-debug "url-http-parse-response called in (%s)" (buffer-name))
370	(goto-char (point-min))
371	(skip-chars-forward " \t\n") ; Skip any blank crap
372	(skip-chars-forward "HTTP/") ; Skip HTTP Version
373	(setq url-http-response-version
374	(buffer-substring (point)
375	(progn
376	(skip-chars-forward "[0-9].")
377	(point))))
378	(setq url-http-response-status (read (current-buffer))))
379
380	(defun url-http-handle-cookies ()
381	"Handle all set-cookie / set-cookie2 headers in an HTTP response.
382	The buffer must already be narrowed to the headers, so `mail-fetch-field' will
383	work correctly."
384	(let ((cookies (nreverse (mail-fetch-field "Set-Cookie" nil nil t)))
385	(cookies2 (nreverse (mail-fetch-field "Set-Cookie2" nil nil t))))
386	(and cookies (url-http-debug "Found %d Set-Cookie headers" (length cookies)))
387	(and cookies2 (url-http-debug "Found %d Set-Cookie2 headers" (length cookies2)))
388	(while cookies
389	(url-cookie-handle-set-cookie (pop cookies)))
390	;;; (while cookies2
391	;;; (url-cookie-handle-set-cookie2 (pop cookies)))
392	)
393	)
394
395	(defun url-http-parse-headers ()
396	"Parse and handle HTTP specific headers.
397	Return t if and only if the current buffer is still active and
398	should be shown to the user."
399	;; The comments after each status code handled are taken from RFC
400	;; 2616 (HTTP/1.1)
401	(declare (special url-http-end-of-headers url-http-response-status
402	url-http-response-version
403	url-http-method url-http-data url-http-process
404	url-callback-function url-callback-arguments))
405
406	(url-http-mark-connection-as-free (url-host url-current-object)
407	(url-port url-current-object)
408	url-http-process)
409
410	(if (or (not (boundp 'url-http-end-of-headers))
411	(not url-http-end-of-headers))
412	(error "Trying to parse headers in odd buffer: %s" (buffer-name)))
413	(goto-char (point-min))
414	(url-http-debug "url-http-parse-headers called in (%s)" (buffer-name))
415	(url-http-parse-response)
416	(mail-narrow-to-head)
417	;;(narrow-to-region (point-min) url-http-end-of-headers)
418	(let ((connection (mail-fetch-field "Connection")))
419	;; In HTTP 1.0, keep the connection only if there is a
420	;; "Connection: keep-alive" header.
421	;; In HTTP 1.1 (and greater), keep the connection unless there is a
422	;; "Connection: close" header
423	(cond
424	((string= url-http-response-version "1.0")
425	(unless (and connection
426	(string= (downcase connection) "keep-alive"))
427	(delete-process url-http-process)))
428	(t
429	(when (and connection
430	(string= (downcase connection) "close"))
431	(delete-process url-http-process)))))
432	(let ((buffer (current-buffer))
433	(class nil)
434	(success nil))
435	(setq class (/ url-http-response-status 100))
436	(url-http-debug "Parsed HTTP headers: class=%d status=%d" class url-http-response-status)
437	(url-http-handle-cookies)
438
439	(case class
440	;; Classes of response codes
441	;;
442	;; 5xx = Server Error
443	;; 4xx = Client Error
444	;; 3xx = Redirection
445	;; 2xx = Successful
446	;; 1xx = Informational
447	(1 ; Information messages
448	;; 100 = Continue with request
449	;; 101 = Switching protocols
450	;; 102 = Processing (Added by DAV)
451	(url-mark-buffer-as-dead buffer)
452	(error "HTTP responses in class 1xx not supported (%d)" url-http-response-status))
453	(2 ; Success
454	;; 200 Ok
455	;; 201 Created
456	;; 202 Accepted
457	;; 203 Non-authoritative information
458	;; 204 No content
459	;; 205 Reset content
460	;; 206 Partial content
461	;; 207 Multi-status (Added by DAV)
462	(case url-http-response-status
463	((204 205)
464	;; No new data, just stay at the same document
465	(url-mark-buffer-as-dead buffer)
466	(setq success t))
467	(otherwise
468	;; Generic success for all others. Store in the cache, and
469	;; mark it as successful.
470	(widen)
471	(if (and url-automatic-caching (equal url-http-method "GET"))
472	(url-store-in-cache buffer))
473	(setq success t))))
474	(3 ; Redirection
475	;; 300 Multiple choices
476	;; 301 Moved permanently
477	;; 302 Found
478	;; 303 See other
479	;; 304 Not modified
480	;; 305 Use proxy
481	;; 307 Temporary redirect
482	(let ((redirect-uri (or (mail-fetch-field "Location")
483	(mail-fetch-field "URI"))))
484	(case url-http-response-status
485	(300
486	;; Quoth the spec (section 10.3.1)
487	;; -------------------------------
488	;; The requested resource corresponds to any one of a set of
489	;; representations, each with its own specific location and
490	;; agent-driven negotiation information is being provided so
491	;; that the user can select a preferred representation and
492	;; redirect its request to that location.
493	;; [...]
494	;; If the server has a preferred choice of representation, it
495	;; SHOULD include the specific URI for that representation in
496	;; the Location field; user agents MAY use the Location field
497	;; value for automatic redirection.
498	;; -------------------------------
499	;; We do not support agent-driven negotiation, so we just
500	;; redirect to the preferred URI if one is provided.
501	nil)
502	((301 302 307)
503	;; If the 301\|302 status code is received in response to a
504	;; request other than GET or HEAD, the user agent MUST NOT
505	;; automatically redirect the request unless it can be
506	;; confirmed by the user, since this might change the
507	;; conditions under which the request was issued.
508	(if (member url-http-method '("HEAD" "GET"))
509	;; Automatic redirection is ok
510	nil
511	;; It is just too big of a pain in the ass to get this
512	;; prompt all the time. We will just silently lose our
513	;; data and convert to a GET method.
514	(url-http-debug "Converting `%s' request to `GET' because of REDIRECT(%d)"
515	url-http-method url-http-response-status)
516	(setq url-http-method "GET"
517	url-http-data nil)))
518	(303
519	;; The response to the request can be found under a different
520	;; URI and SHOULD be retrieved using a GET method on that
521	;; resource.
522	(setq url-http-method "GET"
523	url-http-data nil))
524	(304
525	;; The 304 response MUST NOT contain a message-body.
526	(url-http-debug "Extracting document from cache... (%s)"
527	(url-cache-create-filename (url-view-url t)))
528	(url-cache-extract (url-cache-create-filename (url-view-url t)))
529	(setq redirect-uri nil
530	success t))
531	(305
532	;; The requested resource MUST be accessed through the
533	;; proxy given by the Location field. The Location field
534	;; gives the URI of the proxy. The recipient is expected
535	;; to repeat this single request via the proxy. 305
536	;; responses MUST only be generated by origin servers.
537	(error "Redirection thru a proxy server not supported: %s"
538	redirect-uri))
539	(otherwise
540	;; Treat everything like '300'
541	nil))
542	(when redirect-uri
543	;; Clean off any whitespace and/or <...> cruft.
544	(if (string-match "\$[^ \t]+\$[ \t]" redirect-uri)
545	(setq redirect-uri (match-string 1 redirect-uri)))
546	(if (string-match *"^<\$.\$>$"** redirect-uri)
547	(setq redirect-uri (match-string 1 redirect-uri)))
548
549	;; Some stupid sites (like sourceforge) send a
550	;; non-fully-qualified URL (ie: /), which royally confuses
551	;; the URL library.
552	(if (not (string-match url-nonrelative-link redirect-uri))
553	;; Be careful to use the real target URL, otherwise we may
554	;; compute the redirection relative to the URL of the proxy.
555	(setq redirect-uri
556	(url-expand-file-name redirect-uri url-http-target-url)))
557	(let ((url-request-method url-http-method)
558	(url-request-data url-http-data)
559	(url-request-extra-headers url-http-extra-headers))
560	;; Check existing number of redirects
561	(if (or (< url-max-redirections 0)
562	(and (> url-max-redirections 0)
563	(let ((events (car url-callback-arguments))
564	(old-redirects 0))
565	(while events
566	(if (eq (car events) :redirect)
567	(setq old-redirects (1+ old-redirects)))
568	(and (setq events (cdr events))
569	(setq events (cdr events))))
570	(< old-redirects url-max-redirections))))
571	;; url-max-redirections hasn't been reached, so go
572	;; ahead and redirect.
573	(progn
574	;; Remember that the request was redirected.
575	(setf (car url-callback-arguments)
576	(nconc (list :redirect redirect-uri)
577	(car url-callback-arguments)))
578	;; Put in the current buffer a forwarding pointer to the new
579	;; destination buffer.
580	;; FIXME: This is a hack to fix url-retrieve-synchronously
581	;; without changing the API. Instead url-retrieve should
582	;; either simply not return the "destination" buffer, or it
583	;; should take an optional `dest-buf' argument.
584	(set (make-local-variable 'url-redirect-buffer)
585	(url-retrieve-internal
586	redirect-uri url-callback-function
587	url-callback-arguments))
588	(url-mark-buffer-as-dead buffer))
589	;; We hit url-max-redirections, so issue an error and
590	;; stop redirecting.
591	(url-http-debug "Maximum redirections reached")
592	(setf (car url-callback-arguments)
593	(nconc (list :error (list 'error 'http-redirect-limit
594	redirect-uri))
595	(car url-callback-arguments)))
596	(setq success t))))))
597	(4 ; Client error
598	;; 400 Bad Request
599	;; 401 Unauthorized
600	;; 402 Payment required
601	;; 403 Forbidden
602	;; 404 Not found
603	;; 405 Method not allowed
604	;; 406 Not acceptable
605	;; 407 Proxy authentication required
606	;; 408 Request time-out
607	;; 409 Conflict
608	;; 410 Gone
609	;; 411 Length required
610	;; 412 Precondition failed
611	;; 413 Request entity too large
612	;; 414 Request-URI too large
613	;; 415 Unsupported media type
614	;; 416 Requested range not satisfiable
615	;; 417 Expectation failed
616	;; 422 Unprocessable Entity (Added by DAV)
617	;; 423 Locked
618	;; 424 Failed Dependency
619	(case url-http-response-status
620	(401
621	;; The request requires user authentication. The response
622	;; MUST include a WWW-Authenticate header field containing a
623	;; challenge applicable to the requested resource. The
624	;; client MAY repeat the request with a suitable
625	;; Authorization header field.
626	(url-http-handle-authentication nil))
627	(402
628	;; This code is reserved for future use
629	(url-mark-buffer-as-dead buffer)
630	(error "Somebody wants you to give them money"))
631	(403
632	;; The server understood the request, but is refusing to
633	;; fulfill it. Authorization will not help and the request
634	;; SHOULD NOT be repeated.
635	(setq success t))
636	(404
637	;; Not found
638	(setq success t))
639	(405
640	;; The method specified in the Request-Line is not allowed
641	;; for the resource identified by the Request-URI. The
642	;; response MUST include an Allow header containing a list of
643	;; valid methods for the requested resource.
644	(setq success t))
645	(406
646	;; The resource identified by the request is only capable of
647	;; generating response entities which have content
648	;; characteristics nota cceptable according to the accept
649	;; headers sent in the request.
650	(setq success t))
651	(407
652	;; This code is similar to 401 (Unauthorized), but indicates
653	;; that the client must first authenticate itself with the
654	;; proxy. The proxy MUST return a Proxy-Authenticate header
655	;; field containing a challenge applicable to the proxy for
656	;; the requested resource.
657	(url-http-handle-authentication t))
658	(408
659	;; The client did not produce a request within the time that
660	;; the server was prepared to wait. The client MAY repeat
661	;; the request without modifications at any later time.
662	(setq success t))
663	(409
664	;; The request could not be completed due to a conflict with
665	;; the current state of the resource. This code is only
666	;; allowed in situations where it is expected that the user
667	;; mioght be able to resolve the conflict and resubmit the
668	;; request. The response body SHOULD include enough
669	;; information for the user to recognize the source of the
670	;; conflict.
671	(setq success t))
672	(410
673	;; The requested resource is no longer available at the
674	;; server and no forwarding address is known.
675	(setq success t))
676	(411
677	;; The server refuses to accept the request without a defined
678	;; Content-Length. The client MAY repeat the request if it
679	;; adds a valid Content-Length header field containing the
680	;; length of the message-body in the request message.
681	;;
682	;; NOTE - this will never happen because
683	;; `url-http-create-request' automatically calculates the
684	;; content-length.
685	(setq success t))
686	(412
687	;; The precondition given in one or more of the
688	;; request-header fields evaluated to false when it was
689	;; tested on the server.
690	(setq success t))
691	((413 414)
692	;; The server is refusing to process a request because the
693	;; request entity\|URI is larger than the server is willing or
694	;; able to process.
695	(setq success t))
696	(415
697	;; The server is refusing to service the request because the
698	;; entity of the request is in a format not supported by the