lisp/url/url-http.el

   1 ;;; url-http.el --- HTTP retrieval routines
   2
   3 ;; Copyright (C) 1999, 2001, 2004, 2005, 2006  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 2, 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 (require 'url-gw)
  33 (require 'url-util)
  34 (require 'url-parse)
  35 (require 'url-cookie)
  36 (require 'mail-parse)
  37 (require 'url-auth)
  38 (require 'url)
  39 (autoload 'url-cache-create-filename "url-cache")
  40
  41 (defconst url-http-default-port 80 "Default HTTP port.")
  42 (defconst url-http-asynchronous-p t "HTTP retrievals are asynchronous.")
  43 (defalias 'url-http-expand-file-name 'url-default-expander)
  44
  45 (defvar url-http-real-basic-auth-storage nil)
  46 (defvar url-http-proxy-basic-auth-storage nil)
  47
  48 (defvar url-http-open-connections (make-hash-table :test 'equal
  49                                                    :size 17)
  50   "A hash table of all open network connections.")
  51
  52 (defvar url-http-version "1.1"
  53   "What version of HTTP we advertise, as a string.
  54 Valid values are 1.1 and 1.0.
  55 This is only useful when debugging the HTTP subsystem.
  56
  57 Setting this to 1.0 will tell servers not to send chunked encoding,
  58 and other HTTP/1.1 specific features.")
  59
  60 (defvar url-http-attempt-keepalives t
  61   "Whether to use a single TCP connection multiple times in HTTP.
  62 This is only useful when debugging the HTTP subsystem.  Setting to
  63 nil will explicitly close the connection to the server after every
  64 request.")
  65
  66 ;(eval-when-compile
  67 ;; These are all macros so that they are hidden from external sight
  68 ;; when the file is byte-compiled.
  69 ;;
  70 ;; This allows us to expose just the entry points we want.
  71
  72 ;; These routines will allow us to implement persistent HTTP
  73 ;; connections.
  74 (defsubst url-http-debug (&rest args)
  75   (if quit-flag
  76       (let ((proc (get-buffer-process (current-buffer))))
  77         ;; The user hit C-g, honor it!  Some things can get in an
  78         ;; incredibly tight loop (chunked encoding)
  79         (if proc
  80             (progn
  81               (set-process-sentinel proc nil)
  82               (set-process-filter proc nil)))
  83         (error "Transfer interrupted!")))
  84   (apply 'url-debug 'http args))
  85
  86 (defun url-http-mark-connection-as-busy (host port proc)
  87   (url-http-debug "Marking connection as busy: %s:%d %S" host port proc)
  88   (puthash (cons host port)
  89               (delq proc (gethash (cons host port) url-http-open-connections))
  90               url-http-open-connections)
  91   proc)
  92
  93 (defun url-http-mark-connection-as-free (host port proc)
  94   (url-http-debug "Marking connection as free: %s:%d %S" host port proc)
  95   (when (memq (process-status proc) '(open run connect))
  96     (set-process-buffer proc nil)
  97     (set-process-sentinel proc 'url-http-idle-sentinel)
  98     (puthash (cons host port)
  99              (cons proc (gethash (cons host port) url-http-open-connections))
 100              url-http-open-connections))
 101   nil)
 102
 103 (defun url-http-find-free-connection (host port)
 104   (let ((conns (gethash (cons host port) url-http-open-connections))
 105         (found nil))
 106     (while (and conns (not found))
 107       (if (not (memq (process-status (car conns)) '(run open connect)))
 108           (progn
 109             (url-http-debug "Cleaning up dead process: %s:%d %S"
 110                             host port (car conns))
 111             (url-http-idle-sentinel (car conns) nil))
 112         (setq found (car conns))
 113         (url-http-debug "Found existing connection: %s:%d %S" host port found))
 114       (pop conns))
 115     (if found
 116         (url-http-debug "Reusing existing connection: %s:%d" host port)
 117       (url-http-debug "Contacting host: %s:%d" host port))
 118     (url-lazy-message "Contacting host: %s:%d" host port)
 119     (url-http-mark-connection-as-busy
 120      host port
 121      (or found
 122          (let ((buf (generate-new-buffer " *url-http-temp*")))
 123            ;; `url-open-stream' needs a buffer in which to do things
 124            ;; like authentication.  But we use another buffer afterwards.
 125            (unwind-protect
 126                (let ((proc (url-open-stream host buf host port)))
 127                  ;; url-open-stream might return nil.
 128                  (when (processp proc)
 129                    ;; Drop the temp buffer link before killing the buffer.
 130                    (set-process-buffer proc nil))
 131                  proc)
 132              (kill-buffer buf)))))))
 133
 134 ;; Building an HTTP request
 135 (defun url-http-user-agent-string ()
 136   (if (or (eq url-privacy-level 'paranoid)
 137           (and (listp url-privacy-level)
 138                (memq 'agent url-privacy-level)))
 139       ""
 140     (format "User-Agent: %sURL/%s%s\r\n"
 141             (if url-package-name
 142                 (concat url-package-name "/" url-package-version " ")
 143               "")
 144             url-version
 145             (cond
 146              ((and url-os-type url-system-type)
 147               (concat " (" url-os-type "; " url-system-type ")"))
 148              ((or url-os-type url-system-type)
 149               (concat " (" (or url-system-type url-os-type) ")"))
 150              (t "")))))
 151
 152 (defun url-http-create-request (url &optional ref-url)
 153   "Create an HTTP request for URL, referred to by REF-URL."
 154   (declare (special proxy-object proxy-info
 155                     url-http-method url-http-data
 156                     url-http-extra-headers))
 157   (let* ((extra-headers)
 158          (request nil)
 159          (no-cache (cdr-safe (assoc "Pragma" url-http-extra-headers)))
 160          (proxy-obj (and (boundp 'proxy-object) proxy-object))
 161          (proxy-auth (if (or (cdr-safe (assoc "Proxy-Authorization"
 162                                               url-http-extra-headers))
 163                              (not proxy-obj))
 164                          nil
 165                        (let ((url-basic-auth-storage
 166                               'url-http-proxy-basic-auth-storage))
 167                          (url-get-authentication url nil 'any nil))))
 168          (real-fname (concat (url-filename (or proxy-obj url))
 169                              (url-recreate-url-attributes (or proxy-obj url))))
 170          (host (url-host (or proxy-obj url)))
 171          (auth (if (cdr-safe (assoc "Authorization" url-http-extra-headers))
 172                    nil
 173                  (url-get-authentication (or
 174                                           (and (boundp 'proxy-info)
 175                                                proxy-info)
 176                                           url) nil 'any nil))))
 177     (if (equal "" real-fname)
 178         (setq real-fname "/"))
 179     (setq no-cache (and no-cache (string-match "no-cache" no-cache)))
 180     (if auth
 181         (setq auth (concat "Authorization: " auth "\r\n")))
 182     (if proxy-auth
 183         (setq proxy-auth (concat "Proxy-Authorization: " proxy-auth "\r\n")))
 184
 185     ;; Protection against stupid values in the referer
 186     (if (and ref-url (stringp ref-url) (or (string= ref-url "file:nil")
 187                                            (string= ref-url "")))
 188         (setq ref-url nil))
 189
 190     ;; We do not want to expose the referer if the user is paranoid.
 191     (if (or (memq url-privacy-level '(low high paranoid))
 192             (and (listp url-privacy-level)
 193                  (memq 'lastloc url-privacy-level)))
 194         (setq ref-url nil))
 195
 196     ;; url-http-extra-headers contains an assoc-list of
 197     ;; header/value pairs that we need to put into the request.
 198     (setq extra-headers (mapconcat
 199                          (lambda (x)
 200                            (concat (car x) ": " (cdr x)))
 201                          url-http-extra-headers "\r\n"))
 202     (if (not (equal extra-headers ""))
 203         (setq extra-headers (concat extra-headers "\r\n")))
 204
 205     ;; This was done with a call to `format'.  Concatting parts has
 206     ;; the advantage of keeping the parts of each header together and
 207     ;; allows us to elide null lines directly, at the cost of making
 208     ;; the layout less clear.
 209     (setq request
 210           ;; We used to concat directly, but if one of the strings happens
 211           ;; to being multibyte (even if it only contains pure ASCII) then
 212           ;; every string gets converted with `string-MAKE-multibyte' which
 213           ;; turns the 127-255 codes into things like latin-1 accented chars
 214           ;; (it would work right if it used `string-TO-multibyte' instead).
 215           ;; So to avoid the problem we force every string to be unibyte.
 216           (mapconcat
 217            ;; FIXME: Instead of `string-AS-unibyte' we'd want
 218            ;; `string-to-unibyte', so as to properly signal an error if one
 219            ;; of the strings contains a multibyte char.
 220            'string-as-unibyte
 221            (delq nil
 222             (list
 223              ;; The request
 224              (or url-http-method "GET") " "
 225              (if proxy-obj (url-recreate-url proxy-obj) real-fname)
 226              " HTTP/" url-http-version "\r\n"
 227              ;; Version of MIME we speak
 228              "MIME-Version: 1.0\r\n"
 229              ;; (maybe) Try to keep the connection open
 230              "Connection: " (if (or proxy-obj
 231                                     (not url-http-attempt-keepalives))
 232                                 "close" "keep-alive") "\r\n"
 233                                 ;; HTTP extensions we support
 234              (if url-extensions-header
 235                  (format
 236                   "Extension: %s\r\n" url-extensions-header))
 237              ;; Who we want to talk to
 238              (if (/= (url-port (or proxy-obj url))
 239                      (url-scheme-get-property
 240                       (url-type (or proxy-obj url)) 'default-port))
 241                  (format
 242                   "Host: %s:%d\r\n" host (url-port (or proxy-obj url)))
 243                (format "Host: %s\r\n" host))
 244              ;; Who its from
 245              (if url-personal-mail-address
 246                  (concat
 247                   "From: " url-personal-mail-address "\r\n"))
 248              ;; Encodings we understand
 249              (if url-mime-encoding-string
 250                  (concat
 251                   "Accept-encoding: " url-mime-encoding-string "\r\n"))
 252              (if url-mime-charset-string
 253                  (concat
 254                   "Accept-charset: " url-mime-charset-string "\r\n"))
 255              ;; Languages we understand
 256              (if url-mime-language-string
 257                  (concat
 258                   "Accept-language: " url-mime-language-string "\r\n"))
 259              ;; Types we understand
 260              "Accept: " (or url-mime-accept-string "*/*") "\r\n"
 261              ;; User agent
 262              (url-http-user-agent-string)
 263              ;; Proxy Authorization
 264              proxy-auth
 265              ;; Authorization
 266              auth
 267              ;; Cookies
 268              (url-cookie-generate-header-lines host real-fname
 269                                                (equal "https" (url-type url)))
 270              ;; If-modified-since
 271              (if (and (not no-cache)
 272                       (member url-http-method '("GET" nil)))
 273                  (let ((tm (url-is-cached (or proxy-obj url))))
 274                    (if tm
 275                        (concat "If-modified-since: "
 276                                (url-get-normalized-date tm) "\r\n"))))
 277              ;; Whence we came
 278              (if ref-url (concat
 279                           "Referer: " ref-url "\r\n"))
 280              extra-headers
 281              ;; Length of data
 282              (if url-http-data
 283                  (concat
 284                   "Content-length: " (number-to-string
 285                                       (length url-http-data))
 286                   "\r\n"))
 287              ;; End request
 288              "\r\n"
 289              ;; Any data
 290              url-http-data))
 291            ""))
 292     (url-http-debug "Request is: \n%s" request)
 293     request))
 294
 295 ;; Parsing routines
 296 (defun url-http-clean-headers ()
 297   "Remove trailing \r from header lines.
 298 This allows us to use `mail-fetch-field', etc."
 299   (declare (special url-http-end-of-headers))
 300   (goto-char (point-min))
 301   (while (re-search-forward "\r$" url-http-end-of-headers t)
 302     (replace-match "")))
 303
 304 (defun url-http-handle-authentication (proxy)
 305   (declare (special status success url-http-method url-http-data
 306                     url-callback-function url-callback-arguments))
 307   (url-http-debug "Handling %s authentication" (if proxy "proxy" "normal"))
 308   (let ((auths (or (nreverse
 309                     (mail-fetch-field
 310                      (if proxy "proxy-authenticate" "www-authenticate")
 311                      nil nil t))
 312                   '("basic")))
 313         (type nil)
 314         (url (url-recreate-url url-current-object))
 315         (url-basic-auth-storage 'url-http-real-basic-auth-storage)
 316         auth
 317         (strength 0))
 318     ;; Cheating, but who cares? :)
 319     (if proxy
 320         (setq url-basic-auth-storage 'url-http-proxy-basic-auth-storage))
 321
 322     ;; find strongest supported auth
 323     (dolist (this-auth auths)
 324       (setq this-auth (url-eat-trailing-space
 325                        (url-strip-leading-spaces
 326                         this-auth)))
 327       (let* ((this-type
 328               (if (string-match "[ \t]" this-auth)
 329                   (downcase (substring this-auth 0 (match-beginning 0)))
 330                 (downcase this-auth)))
 331              (registered (url-auth-registered this-type))
 332              (this-strength (cddr registered)))
 333         (when (and registered (> this-strength strength))
 334           (setq auth this-auth
 335                 type this-type
 336                 strength this-strength))))
 337
 338     (if (not (url-auth-registered type))
 339         (progn
 340           (widen)
 341           (goto-char (point-max))
 342           (insert "<hr>Sorry, but I do not know how to handle " type
 343                   " authentication.  If you'd like to write it,"
 344                   " send it to " url-bug-address ".<hr>")
 345           (setq status t))
 346       (let* ((args (url-parse-args (subst-char-in-string ?, ?\; auth)))
 347              (auth (url-get-authentication url (cdr-safe (assoc "realm" args))
 348                                            type t args)))
 349         (if (not auth)
 350             (setq success t)
 351           (push (cons (if proxy "Proxy-Authorization" "Authorization") auth)
 352                 url-http-extra-headers)
 353           (let ((url-request-method url-http-method)
 354                 (url-request-data url-http-data)
 355                 (url-request-extra-headers url-http-extra-headers))
 356             (url-retrieve-internal url url-callback-function
 357                                    url-callback-arguments)))))))
 358
 359 (defun url-http-parse-response ()
 360   "Parse just the response code."
 361   (declare (special url-http-end-of-headers url-http-response-status
 362                     url-http-response-version))
 363   (if (not url-http-end-of-headers)
 364       (error "Trying to parse HTTP response code in odd buffer: %s" (buffer-name)))
 365   (url-http-debug "url-http-parse-response called in (%s)" (buffer-name))
 366   (goto-char (point-min))
 367   (skip-chars-forward " \t\n")          ; Skip any blank crap
 368   (skip-chars-forward "HTTP/")          ; Skip HTTP Version
 369   (setq url-http-response-version
 370         (buffer-substring (point)
 371                           (progn
 372                             (skip-chars-forward "[0-9].")
 373                             (point))))
 374   (setq url-http-response-status (read (current-buffer))))
 375
 376 (defun url-http-handle-cookies ()
 377   "Handle all set-cookie / set-cookie2 headers in an HTTP response.
 378 The buffer must already be narrowed to the headers, so `mail-fetch-field' will
 379 work correctly."
 380   (let ((cookies (mail-fetch-field "Set-Cookie" nil nil t))
 381         (cookies2 (mail-fetch-field "Set-Cookie2" nil nil t))
 382         (url-current-object url-http-target-url))
 383     (and cookies (url-http-debug "Found %d Set-Cookie headers" (length cookies)))
 384     (and cookies2 (url-http-debug "Found %d Set-Cookie2 headers" (length cookies2)))
 385     (while cookies
 386       (url-cookie-handle-set-cookie (pop cookies)))
 387 ;;;     (while cookies2
 388 ;;;       (url-cookie-handle-set-cookie2 (pop cookies)))
 389     )
 390   )
 391
 392 (defun url-http-parse-headers ()
 393  "Parse and handle HTTP specific headers.
 394 Return t if and only if the current buffer is still active and
 395 should be shown to the user."
 396   ;; The comments after each status code handled are taken from RFC
 397   ;; 2616 (HTTP/1.1)
 398   (declare (special url-http-end-of-headers url-http-response-status
 399                     url-http-response-version
 400                     url-http-method url-http-data url-http-process
 401                     url-callback-function url-callback-arguments))
 402
 403   (url-http-mark-connection-as-free (url-host url-current-object)
 404                                     (url-port url-current-object)
 405                                     url-http-process)
 406
 407   (if (or (not (boundp 'url-http-end-of-headers))
 408           (not url-http-end-of-headers))
 409       (error "Trying to parse headers in odd buffer: %s" (buffer-name)))
 410   (goto-char (point-min))
 411   (url-http-debug "url-http-parse-headers called in (%s)" (buffer-name))
 412   (url-http-parse-response)
 413   (mail-narrow-to-head)
 414   ;;(narrow-to-region (point-min) url-http-end-of-headers)
 415   (let ((connection (mail-fetch-field "Connection")))
 416     ;; In HTTP 1.0, keep the connection only if there is a
 417     ;; "Connection: keep-alive" header.
 418     ;; In HTTP 1.1 (and greater), keep the connection unless there is a
 419     ;; "Connection: close" header
 420     (cond
 421      ((string= url-http-response-version "1.0")
 422       (unless (and connection
 423                    (string= (downcase connection) "keep-alive"))
 424         (delete-process url-http-process)))
 425      (t
 426       (when (and connection
 427                  (string= (downcase connection) "close"))
 428         (delete-process url-http-process)))))
 429   (let ((class nil)
 430         (success nil))
 431     (setq class (/ url-http-response-status 100))
 432     (url-http-debug "Parsed HTTP headers: class=%d status=%d" class url-http-response-status)
 433     (url-http-handle-cookies)
 434
 435     (case class
 436       ;; Classes of response codes
 437       ;;
 438       ;; 5xx = Server Error
 439       ;; 4xx = Client Error
 440       ;; 3xx = Redirection
 441       ;; 2xx = Successful
 442       ;; 1xx = Informational
 443       (1                                ; Information messages
 444        ;; 100 = Continue with request
 445        ;; 101 = Switching protocols
 446        ;; 102 = Processing (Added by DAV)
 447        (url-mark-buffer-as-dead (current-buffer))
 448        (error "HTTP responses in class 1xx not supported (%d)" url-http-response-status))
 449       (2                                ; Success
 450        ;; 200 Ok
 451        ;; 201 Created
 452        ;; 202 Accepted
 453        ;; 203 Non-authoritative information
 454        ;; 204 No content
 455        ;; 205 Reset content
 456        ;; 206 Partial content
 457        ;; 207 Multi-status (Added by DAV)
 458        (case url-http-response-status
 459          ((204 205)
 460           ;; No new data, just stay at the same document
 461           (url-mark-buffer-as-dead (current-buffer))
 462           (setq success t))
 463          (otherwise
 464           ;; Generic success for all others.  Store in the cache, and
 465           ;; mark it as successful.
 466           (widen)
 467           (if (and url-automatic-caching (equal url-http-method "GET"))
 468               (url-store-in-cache (current-buffer)))
 469           (setq success t))))
 470       (3                                ; Redirection
 471        ;; 300 Multiple choices
 472        ;; 301 Moved permanently
 473        ;; 302 Found
 474        ;; 303 See other
 475        ;; 304 Not modified
 476        ;; 305 Use proxy
 477        ;; 307 Temporary redirect
 478        (let ((redirect-uri (or (mail-fetch-field "Location")
 479                                (mail-fetch-field "URI"))))
 480          (case url-http-response-status
 481            (300
 482             ;; Quoth the spec (section 10.3.1)
 483             ;; -------------------------------
 484             ;; The requested resource corresponds to any one of a set of
 485             ;; representations, each with its own specific location and
 486             ;; agent-driven negotiation information is being provided so
 487             ;; that the user can select a preferred representation and
 488             ;; redirect its request to that location.
 489             ;; [...]
 490             ;; If the server has a preferred choice of representation, it
 491             ;; SHOULD include the specific URI for that representation in
 492             ;; the Location field; user agents MAY use the Location field
 493             ;; value for automatic redirection.
 494             ;; -------------------------------
 495             ;; We do not support agent-driven negotiation, so we just
 496             ;; redirect to the preferred URI if one is provided.
 497             nil)
 498            ((301 302 307)
 499             ;; If the 301|302 status code is received in response to a
 500             ;; request other than GET or HEAD, the user agent MUST NOT
 501             ;; automatically redirect the request unless it can be
 502             ;; confirmed by the user, since this might change the
 503             ;; conditions under which the request was issued.
 504             (if (member url-http-method '("HEAD" "GET"))
 505                 ;; Automatic redirection is ok
 506                 nil
 507               ;; It is just too big of a pain in the ass to get this
 508               ;; prompt all the time.  We will just silently lose our
 509               ;; data and convert to a GET method.
 510               (url-http-debug "Converting `%s' request to `GET' because of REDIRECT(%d)"
 511                               url-http-method url-http-response-status)
 512               (setq url-http-method "GET"
 513                     url-http-data nil)))
 514            (303
 515             ;; The response to the request can be found under a different
 516             ;; URI and SHOULD be retrieved using a GET method on that
 517             ;; resource.
 518             (setq url-http-method "GET"
 519                   url-http-data nil))
 520            (304
 521             ;; The 304 response MUST NOT contain a message-body.
 522             (url-http-debug "Extracting document from cache... (%s)"
 523                             (url-cache-create-filename (url-view-url t)))
 524             (url-cache-extract (url-cache-create-filename (url-view-url t)))
 525             (setq redirect-uri nil
 526                   success t))
 527            (305
 528             ;; The requested resource MUST be accessed through the
 529             ;; proxy given by the Location field.  The Location field
 530             ;; gives the URI of the proxy.  The recipient is expected
 531             ;; to repeat this single request via the proxy.  305
 532             ;; responses MUST only be generated by origin servers.
 533             (error "Redirection thru a proxy server not supported: %s"
 534                    redirect-uri))
 535            (otherwise
 536             ;; Treat everything like '300'
 537             nil))
 538          (when redirect-uri
 539            ;; Clean off any whitespace and/or <...> cruft.
 540            (if (string-match "\\([^ \t]+\\)[ \t]" redirect-uri)
 541                (setq redirect-uri (match-string 1 redirect-uri)))
 542            (if (string-match "^<\\(.*\\)>$" redirect-uri)
 543                (setq redirect-uri (match-string 1 redirect-uri)))
 544
 545            ;; Some stupid sites (like sourceforge) send a
 546            ;; non-fully-qualified URL (ie: /), which royally confuses
 547            ;; the URL library.
 548            (if (not (string-match url-nonrelative-link redirect-uri))
 549                ;; Be careful to use the real target URL, otherwise we may
 550                ;; compute the redirection relative to the URL of the proxy.
 551                (setq redirect-uri
 552                      (url-expand-file-name redirect-uri url-http-target-url)))
 553            (let ((url-request-method url-http-method)
 554                  (url-request-data url-http-data)
 555                  (url-request-extra-headers url-http-extra-headers))
 556              ;; Remember that the request was redirected.
 557              (setf (car url-callback-arguments)
 558                    (nconc (list :redirect redirect-uri)
 559                           (car url-callback-arguments)))
 560               ;; Put in the current buffer a forwarding pointer to the new
 561               ;; destination buffer.
 562               ;; FIXME: This is a hack to fix url-retrieve-synchronously
 563               ;; without changing the API.  Instead url-retrieve should
 564               ;; either simply not return the "destination" buffer, or it
 565               ;; should take an optional `dest-buf' argument.
 566               (set (make-local-variable 'url-redirect-buffer)
 567                    (url-retrieve-internal
 568                     redirect-uri url-callback-function
 569                     url-callback-arguments))
 570               (url-mark-buffer-as-dead (current-buffer))))))
 571       (4                                ; Client error
 572        ;; 400 Bad Request
 573        ;; 401 Unauthorized
 574        ;; 402 Payment required
 575        ;; 403 Forbidden
 576        ;; 404 Not found
 577        ;; 405 Method not allowed
 578        ;; 406 Not acceptable
 579        ;; 407 Proxy authentication required
 580        ;; 408 Request time-out
 581        ;; 409 Conflict
 582        ;; 410 Gone
 583        ;; 411 Length required
 584        ;; 412 Precondition failed
 585        ;; 413 Request entity too large
 586        ;; 414 Request-URI too large
 587        ;; 415 Unsupported media type
 588        ;; 416 Requested range not satisfiable
 589        ;; 417 Expectation failed
 590        ;; 422 Unprocessable Entity (Added by DAV)
 591        ;; 423 Locked
 592        ;; 424 Failed Dependency
 593        (case url-http-response-status
 594          (401
 595           ;; The request requires user authentication.  The response
 596           ;; MUST include a WWW-Authenticate header field containing a
 597           ;; challenge applicable to the requested resource.  The
 598           ;; client MAY repeat the request with a suitable
 599           ;; Authorization header field.
 600           (url-http-handle-authentication nil))
 601          (402
 602           ;; This code is reserved for future use
 603           (url-mark-buffer-as-dead (current-buffer))
 604           (error "Somebody wants you to give them money"))
 605          (403
 606           ;; The server understood the request, but is refusing to
 607           ;; fulfill it.  Authorization will not help and the request
 608           ;; SHOULD NOT be repeated.
 609           (setq success t))
 610          (404
 611           ;; Not found
 612           (setq success t))
 613          (405
 614           ;; The method specified in the Request-Line is not allowed
 615           ;; for the resource identified by the Request-URI.  The
 616           ;; response MUST include an Allow header containing a list of
 617           ;; valid methods for the requested resource.
 618           (setq success t))
 619          (406
 620           ;; The resource identified by the request is only capable of
 621           ;; generating response entities which have content
 622           ;; characteristics nota cceptable according to the accept
 623           ;; headers sent in the request.
 624           (setq success t))
 625          (407
 626           ;; This code is similar to 401 (Unauthorized), but indicates
 627           ;; that the client must first authenticate itself with the
 628           ;; proxy.  The proxy MUST return a Proxy-Authenticate header
 629           ;; field containing a challenge applicable to the proxy for
 630           ;; the requested resource.
 631           (url-http-handle-authentication t))
 632          (408
 633           ;; The client did not produce a request within the time that
 634           ;; the server was prepared to wait.  The client MAY repeat
 635           ;; the request without modifications at any later time.
 636           (setq success t))
 637          (409
 638           ;; The request could not be completed due to a conflict with
 639           ;; the current state of the resource.  This code is only
 640           ;; allowed in situations where it is expected that the user
 641           ;; mioght be able to resolve the conflict and resubmit the
 642           ;; request.  The response body SHOULD include enough
 643           ;; information for the user to recognize the source of the
 644           ;; conflict.
 645           (setq success t))
 646          (410
 647           ;; The requested resource is no longer available at the
 648           ;; server and no forwarding address is known.
 649           (setq success t))
 650          (411
 651           ;; The server refuses to accept the request without a defined
 652           ;; Content-Length.  The client MAY repeat the request if it
 653           ;; adds a valid Content-Length header field containing the
 654           ;; length of the message-body in the request message.
 655           ;;
 656           ;; NOTE - this will never happen because
 657           ;; `url-http-create-request' automatically calculates the
 658           ;; content-length.
 659           (setq success t))
 660          (412
 661           ;; The precondition given in one or more of the
 662           ;; request-header fields evaluated to false when it was
 663           ;; tested on the server.
 664           (setq success t))
 665          ((413 414)
 666           ;; The server is refusing to process a request because the
 667           ;; request entity|URI is larger than the server is willing or
 668           ;; able to process.
 669           (setq success t))
 670          (415
 671           ;; The server is refusing to service the request because the
 672           ;; entity of the request is in a format not supported by the
 673           ;; requested resource for the requested method.
 674           (setq success t))
 675          (416
 676           ;; A server SHOULD return a response with this status code if
 677           ;; a request included a Range request-header field, and none
 678           ;; of the range-specifier values in this field overlap the
 679           ;; current extent of the selected resource, and the request
 680           ;; did not include an If-Range request-header field.
 681           (setq success t))
 682          (417
 683           ;; The expectation given in an Expect request-header field
 684           ;; could not be met by this server, or, if the server is a
 685           ;; proxy, the server has unambiguous evidence that the
 686           ;; request could not be met by the next-hop server.
 687           (setq success t))
 688          (otherwise
 689           ;; The request could not be understood by the server due to
 690           ;; malformed syntax.  The client SHOULD NOT repeat the
 691           ;; request without modifications.
 692           (setq success t)))
 693        ;; Tell the callback that an error occurred, and what the
 694        ;; status code was.
 695        (when success
 696          (setf (car url-callback-arguments)
 697                (nconc (list :error (list 'error 'http url-http-response-status))
 698                       (car url-callback-arguments)))))
 699       (5
 700        ;; 500 Internal server error
 701        ;; 501 Not implemented
 702        ;; 502 Bad gateway
 703        ;; 503 Service unavailable
 704        ;; 504 Gateway time-out
 705        ;; 505 HTTP version not supported
 706        ;; 507 Insufficient storage
 707        (setq success t)
 708        (case url-http-response-status
 709          (501
 710           ;; The server does not support the functionality required to
 711           ;; fulfill the request.
 712           nil)
 713          (502
 714           ;; The server, while acting as a gateway or proxy, received
 715           ;; an invalid response from the upstream server it accessed
 716           ;; in attempting to fulfill the request.
 717           nil)
 718          (503
 719           ;; The server is currently unable to handle the request due
 720           ;; to a temporary overloading or maintenance of the server.
 721           ;; The implication is that this is a temporary condition
 722           ;; which will be alleviated after some delay.  If known, the
 723           ;; length of the delay MAY be indicated in a Retry-After
 724           ;; header.  If no Retry-After is given, the client SHOULD
 725           ;; handle the response as it would for a 500 response.
 726           nil)
 727          (504
 728           ;; The server, while acting as a gateway or proxy, did not
 729           ;; receive a timely response from the upstream server
 730           ;; specified by the URI (e.g. HTTP, FTP, LDAP) or some other
 731           ;; auxiliary server (e.g. DNS) it needed to access in
 732           ;; attempting to complete the request.
 733           nil)
 734          (505
 735           ;; The server does not support, or refuses to support, the
 736           ;; HTTP protocol version that was used in the request
 737           ;; message.
 738           nil)
 739          (507                           ; DAV
 740           ;; The method could not be performed on the resource
 741           ;; because the server is unable to store the representation
 742           ;; needed to successfully complete the request.  This
 743           ;; condition is considered to be temporary.  If the request
 744           ;; which received this status code was the result of a user
 745           ;; action, the request MUST NOT be repeated until it is
 746           ;; requested by a separate user action.
 747           nil))
 748        ;; Tell the callback that an error occurred, and what the
 749        ;; status code was.
 750        (when success
 751          (setf (car url-callback-arguments)
 752                (nconc (list :error (list 'error 'http url-http-response-status))
 753                       (car url-callback-arguments)))))
 754       (otherwise
 755        (error "Unknown class of HTTP response code: %d (%d)"
 756               class url-http-response-status)))
 757     (if (not success)
 758         (url-mark-buffer-as-dead (current-buffer)))
 759     (url-http-debug "Finished parsing HTTP headers: %S" success)
 760     (widen)
 761     success))
 762
 763 ;; Miscellaneous
 764 (defun url-http-activate-callback ()
 765   "Activate callback specified when this buffer was created."
 766   (declare (special url-http-process
 767                     url-callback-function
 768                     url-callback-arguments))
 769   (url-http-mark-connection-as-free (url-host url-current-object)
 770                                     (url-port url-current-object)
 771                                     url-http-process)
 772   (url-http-debug "Activating callback in buffer (%s)" (buffer-name))
 773   (apply url-callback-function url-callback-arguments))
 774
 775 ;; )
 776
 777 ;; These unfortunately cannot be macros... please ignore them!
 778 (defun url-http-idle-sentinel (proc why)
 779   "Remove this (now defunct) process PROC from the list of open connections."
 780   (maphash (lambda (key val)
 781                 (if (memq proc val)
 782                     (puthash key (delq proc val) url-http-open-connections)))
 783               url-http-open-connections))
 784
 785 (defun url-http-end-of-document-sentinel (proc why)
 786   ;; Sentinel used for old HTTP/0.9 or connections we know are going
 787   ;; to die as the 'end of document' notifier.
 788   (url-http-debug "url-http-end-of-document-sentinel in buffer (%s)"
 789                   (process-buffer proc))
 790   (url-http-idle-sentinel proc why)
 791   (with-current-buffer (process-buffer proc)
 792     (goto-char (point-min))
 793     (if (not (looking-at "HTTP/"))
 794         ;; HTTP/0.9 just gets passed back no matter what
 795         (url-http-activate-callback)
 796       (if (url-http-parse-headers)
 797           (url-http-activate-callback)))))
 798
 799 (defun url-http-simple-after-change-function (st nd length)
 800   ;; Function used when we do NOT know how long the document is going to be
 801   ;; Just _very_ simple 'downloaded %d' type of info.
 802   (declare (special url-http-end-of-headers))
 803   (url-lazy-message "Reading %s..." (url-pretty-length nd)))
 804
 805 (defun url-http-content-length-after-change-function (st nd length)
 806   "Function used when we DO know how long the document is going to be.
 807 More sophisticated percentage downloaded, etc.
 808 Also does minimal parsing of HTTP headers and will actually cause
 809 the callback to be triggered."
 810   (declare (special url-current-object
 811                     url-http-end-of-headers
 812                     url-http-content-length
 813                     url-http-content-type
 814                     url-http-process))
 815   (if url-http-content-type
 816       (url-display-percentage
 817        "Reading [%s]... %s of %s (%d%%)"
 818        (url-percentage (- nd url-http-end-of-headers)
 819                        url-http-content-length)
 820        url-http-content-type
 821        (url-pretty-length (- nd url-http-end-of-headers))
 822        (url-pretty-length url-http-content-length)
 823        (url-percentage (- nd url-http-end-of-headers)
 824                        url-http-content-length))
 825     (url-display-percentage
 826      "Reading... %s of %s (%d%%)"
 827      (url-percentage (- nd url-http-end-of-headers)
 828                      url-http-content-length)
 829      (url-pretty-length (- nd url-http-end-of-headers))
 830      (url-pretty-length url-http-content-length)
 831      (url-percentage (- nd url-http-end-of-headers)
 832                      url-http-content-length)))
 833
 834   (if (> (- nd url-http-end-of-headers) url-http-content-length)
 835       (progn
 836         ;; Found the end of the document!  Wheee!
 837         (url-display-percentage nil nil)
 838         (url-lazy-message "Reading... done.")
 839         (if (url-http-parse-headers)
 840             (url-http-activate-callback)))))
 841
 842 (defun url-http-chunked-encoding-after-change-function (st nd length)
 843   "Function used when dealing with 'chunked' encoding.
 844 Cannot give a sophisticated percentage, but we need a different
 845 function to look for the special 0-length chunk that signifies
 846 the end of the document."
 847   (declare (special url-current-object
 848                     url-http-end-of-headers
 849                     url-http-content-type
 850                     url-http-chunked-length
 851                     url-http-chunked-counter
 852                     url-http-process url-http-chunked-start))
 853   (save-excursion
 854     (goto-char st)
 855     (let ((read-next-chunk t)
 856           (case-fold-search t)
 857           (regexp nil)
 858           (no-initial-crlf nil))
 859       ;; We need to loop thru looking for more chunks even within
 860       ;; one after-change-function call.
 861       (while read-next-chunk
 862         (setq no-initial-crlf (= 0 url-http-chunked-counter))
 863         (if url-http-content-type
 864             (url-display-percentage nil
 865              "Reading [%s]... chunk #%d"
 866              url-http-content-type url-http-chunked-counter)
 867           (url-display-percentage nil
 868            "Reading... chunk #%d"
 869            url-http-chunked-counter))
 870         (url-http-debug "Reading chunk %d (%d %d %d)"
 871                         url-http-chunked-counter st nd length)
 872         (setq regexp (if no-initial-crlf
 873                          "\\([0-9a-z]+\\).*\r?\n"
 874                        "\r?\n\\([0-9a-z]+\\).*\r?\n"))
 875
 876         (if url-http-chunked-start
 877             ;; We know how long the chunk is supposed to be, skip over
 878             ;; leading crap if possible.
 879             (if (> nd (+ url-http-chunked-start url-http-chunked-length))
 880                 (progn
 881                   (url-http-debug "Got to the end of chunk #%d!"
 882                                   url-http-chunked-counter)
 883                   (goto-char (+ url-http-chunked-start
 884                                 url-http-chunked-length)))
 885               (url-http-debug "Still need %d bytes to hit end of chunk"
 886                               (- (+ url-http-chunked-start
 887                                     url-http-chunked-length)
 888                                  nd))
 889               (setq read-next-chunk nil)))
 890         (if (not read-next-chunk)
 891             (url-http-debug "Still spinning for next chunk...")
 892           (if no-initial-crlf (skip-chars-forward "\r\n"))
 893           (if (not (looking-at regexp))
 894               (progn
 895            ;; Must not have received the entirety of the chunk header,
 896                 ;; need to spin some more.
 897                 (url-http-debug "Did not see start of chunk @ %d!" (point))
 898                 (setq read-next-chunk nil))
 899             (add-text-properties (match-beginning 0) (match-end 0)
 900                                  (list 'start-open t
 901                                        'end-open t
 902                                        'chunked-encoding t
 903                                        'face 'cursor
 904                                        'invisible t))
 905             (setq url-http-chunked-length (string-to-number (buffer-substring
 906                                                              (match-beginning 1)
 907                                                              (match-end 1))
 908                                                             16)
 909                   url-http-chunked-counter (1+ url-http-chunked-counter)
 910                   url-http-chunked-start (set-marker
 911                                           (or url-http-chunked-start
 912                                               (make-marker))
 913                                           (match-end 0)))
 914 ;           (if (not url-http-debug)
 915                 (delete-region (match-beginning 0) (match-end 0));)
 916             (url-http-debug "Saw start of chunk %d (length=%d, start=%d"
 917                             url-http-chunked-counter url-http-chunked-length
 918                             (marker-position url-http-chunked-start))
 919             (if (= 0 url-http-chunked-length)
 920                 (progn
 921                   ;; Found the end of the document!  Wheee!
 922                   (url-http-debug "Saw end of stream chunk!")
 923                   (setq read-next-chunk nil)
 924                   (url-display-percentage nil nil)
 925                   (goto-char (match-end 1))
 926                   (if (re-search-forward "^\r*$" nil t)
 927                       (url-http-debug "Saw end of trailers..."))
 928                   (if (url-http-parse-headers)
 929                       (url-http-activate-callback))))))))))
 930
 931 (defun url-http-wait-for-headers-change-function (st nd length)
 932   ;; This will wait for the headers to arrive and then splice in the
 933   ;; next appropriate after-change-function, etc.
 934   (declare (special url-current-object
 935                     url-http-end-of-headers
 936                     url-http-content-type
 937                     url-http-content-length
 938                     url-http-transfer-encoding
 939                     url-callback-function
 940                     url-callback-arguments
 941                     url-http-process
 942                     url-http-method
 943                     url-http-after-change-function
 944                     url-http-response-status))
 945   (url-http-debug "url-http-wait-for-headers-change-function (%s)"
 946                   (buffer-name))
 947   (when (not (bobp))
 948     (let ((end-of-headers nil)
 949           (old-http nil)
 950           (content-length nil))
 951       (goto-char (point-min))
 952       (if (and (looking-at ".*\n")      ; have one line at least
 953                (not (looking-at "^HTTP/[1-9]\\.[0-9]")))
 954           ;; Not HTTP/x.y data, must be 0.9
 955           ;; God, I wish this could die.
 956           (setq end-of-headers t
 957                 url-http-end-of-headers 0
 958                 old-http t)
 959         (when (re-search-forward "^\r*$" nil t)
 960           ;; Saw the end of the headers
 961           (url-http-debug "Saw end of headers... (%s)" (buffer-name))
 962           (setq url-http-end-of-headers (set-marker (make-marker)
 963                                                     (point))
 964                 end-of-headers t)
 965           (url-http-clean-headers)))
 966
 967       (if (not end-of-headers)
 968           ;; Haven't seen the end of the headers yet, need to wait
 969           ;; for more data to arrive.
 970           nil
 971         (if old-http
 972             (message "HTTP/0.9 How I hate thee!")
 973           (progn
 974             (url-http-parse-response)
 975             (mail-narrow-to-head)
 976             ;;(narrow-to-region (point-min) url-http-end-of-headers)
 977             (setq url-http-transfer-encoding (mail-fetch-field
 978                                               "transfer-encoding")
 979                   url-http-content-type (mail-fetch-field "content-type"))
 980             (if (mail-fetch-field "content-length")
 981                 (setq url-http-content-length
 982                       (string-to-number (mail-fetch-field "content-length"))))
 983             (widen)))
 984         (when url-http-transfer-encoding
 985           (setq url-http-transfer-encoding
 986                 (downcase url-http-transfer-encoding)))
 987
 988         (cond
 989          ((or (= url-http-response-status 204)
 990               (= url-http-response-status 205))
 991           (url-http-debug "%d response must have headers only (%s)."
 992                           url-http-response-status (buffer-name))
 993           (when (url-http-parse-headers)
 994             (url-http-activate-callback)))
 995          ((string= "HEAD" url-http-method)
 996           ;; A HEAD request is _ALWAYS_ terminated by the header
 997           ;; information, regardless of any entity headers,
 998           ;; according to section 4.4 of the HTTP/1.1 draft.
 999           (url-http-debug "HEAD request must have headers only (%s)."
1000                           (buffer-name))
1001           (when (url-http-parse-headers)
1002             (url-http-activate-callback)))
1003          ((string= "CONNECT" url-http-method)
1004           ;; A CONNECT request is finished, but we cannot stick this
1005           ;; back on the free connectin list
1006           (url-http-debug "CONNECT request must have headers only.")
1007           (when (url-http-parse-headers)
1008             (url-http-activate-callback)))
1009          ((equal url-http-response-status 304)
1010           ;; Only allowed to have a header section.  We have to handle
1011           ;; this here instead of in url-http-parse-headers because if
1012           ;; you have a cached copy of something without a known
1013           ;; content-length, and try to retrieve it from the cache, we'd
1014           ;; fall into the 'being dumb' section and wait for the
1015           ;; connection to terminate, which means we'd wait for 10
1016           ;; seconds for the keep-alives to time out on some servers.
1017           (when (url-http-parse-headers)
1018             (url-http-activate-callback)))
1019          (old-http
1020           ;; HTTP/0.9 always signaled end-of-connection by closing the
1021           ;; connection.
1022           (url-http-debug
1023            "Saw HTTP/0.9 response, connection closed means end of document.")
1024           (setq url-http-after-change-function
1025                 'url-http-simple-after-change-function))
1026          ((equal url-http-transfer-encoding "chunked")
1027           (url-http-debug "Saw chunked encoding.")
1028           (setq url-http-after-change-function
1029                 'url-http-chunked-encoding-after-change-function)
1030           (when (> nd url-http-end-of-headers)
1031             (url-http-debug
1032              "Calling initial chunked-encoding for extra data at end of headers")
1033             (url-http-chunked-encoding-after-change-function
1034              (marker-position url-http-end-of-headers) nd
1035              (- nd url-http-end-of-headers))))
1036          ((integerp url-http-content-length)
1037           (url-http-debug
1038            "Got a content-length, being smart about document end.")
1039           (setq url-http-after-change-function
1040                 'url-http-content-length-after-change-function)
1041           (cond
1042            ((= 0 url-http-content-length)
1043             ;; We got a NULL body!  Activate the callback
1044             ;; immediately!
1045             (url-http-debug
1046              "Got 0-length content-length, activating callback immediately.")
1047             (when (url-http-parse-headers)
1048               (url-http-activate-callback)))
1049            ((> nd url-http-end-of-headers)
1050             ;; Have some leftover data
1051             (url-http-debug "Calling initial content-length for extra data at end of headers")
1052             (url-http-content-length-after-change-function
1053              (marker-position url-http-end-of-headers)
1054              nd
1055              (- nd url-http-end-of-headers)))
1056            (t
1057             nil)))
1058          (t
1059           (url-http-debug "No content-length, being dumb.")
1060           (setq url-http-after-change-function
1061                 'url-http-simple-after-change-function)))))
1062     ;; We are still at the beginning of the buffer... must just be
1063     ;; waiting for a response.
1064     (url-http-debug "Spinning waiting for headers..."))
1065   (goto-char (point-max)))
1066
1067 ;;;###autoload
1068 (defun url-http (url callback cbargs)
1069   "Retrieve URL via HTTP asynchronously.
1070 URL must be a parsed URL.  See `url-generic-parse-url' for details.
1071 When retrieval is completed, the function CALLBACK is executed with
1072 CBARGS as the arguments."
1073   (check-type url vector "Need a pre-parsed URL.")
1074   (declare (special url-current-object
1075                     url-http-end-of-headers
1076                     url-http-content-type
1077                     url-http-content-length
1078                     url-http-transfer-encoding
1079                     url-http-after-change-function
1080                     url-callback-function
1081                     url-callback-arguments
1082                     url-http-method
1083                     url-http-extra-headers
1084                     url-http-data
1085                     url-http-chunked-length
1086                     url-http-chunked-start
1087                     url-http-chunked-counter
1088                     url-http-process
1089                     proxy-object))
1090   (let ((connection (url-http-find-free-connection (url-host url)
1091                                                    (url-port url)))
1092         (buffer (generate-new-buffer (format " *http %s:%d*"
1093                                              (url-host url)
1094                                              (url-port url)))))
1095     (if (not connection)
1096         ;; Failed to open the connection for some reason
1097         (progn
1098           (kill-buffer buffer)
1099           (setq buffer nil)
1100           (error "Could not create connection to %s:%d" (url-host url)
1101                  (url-port url)))
1102       (with-current-buffer buffer
1103         (mm-disable-multibyte)
1104         (setq url-current-object url
1105               mode-line-format "%b [%s]")
1106
1107         (dolist (var '(url-http-end-of-headers
1108                        url-http-content-type
1109                        url-http-content-length
1110                        url-http-transfer-encoding
1111                        url-http-after-change-function
1112                        url-http-response-version
1113                        url-http-response-status
1114                        url-http-chunked-length
1115                        url-http-chunked-counter
1116                        url-http-chunked-start
1117                        url-callback-function
1118                        url-callback-arguments
1119                        url-http-process
1120                        url-http-method
1121                        url-http-extra-headers
1122                        url-http-data
1123                        url-http-target-url))
1124           (set (make-local-variable var) nil))
1125         (make-local-variable 'proxy-object)
1126
1127         (setq url-http-method (or url-request-method "GET")
1128               url-http-extra-headers url-request-extra-headers
1129               url-http-data url-request-data
1130               url-http-process connection
1131               url-http-chunked-length nil
1132               url-http-chunked-start nil
1133               url-http-chunked-counter 0
1134               url-callback-function callback
1135               url-callback-arguments cbargs
1136               url-http-after-change-function 'url-http-wait-for-headers-change-function
1137               url-http-target-url (if (boundp 'proxy-object)
1138                                       proxy-object
1139                                     url-current-object))
1140
1141         (set-process-buffer connection buffer)
1142         (set-process-filter connection 'url-http-generic-filter)
1143         (let ((status (process-status connection)))
1144           (cond
1145            ((eq status 'connect)
1146             ;; Asynchronous connection
1147             (set-process-sentinel connection 'url-http-async-sentinel))
1148            ((eq status 'failed)
1149             ;; Asynchronous connection failed
1150             (error "Could not create connection to %s:%d" (url-host url)
1151                    (url-port url)))
1152            (t
1153             (set-process-sentinel connection 'url-http-end-of-document-sentinel)
1154             (process-send-string connection (url-http-create-request url)))))))
1155     buffer))
1156
1157 (defun url-http-async-sentinel (proc why)
1158   (declare (special url-callback-arguments))
1159   ;; We are performing an asynchronous connection, and a status change
1160   ;; has occurred.
1161   (with-current-buffer (process-buffer proc)
1162     (cond
1163      ((string= (substring why 0 4) "open")
1164       (set-process-sentinel proc 'url-http-end-of-document-sentinel)
1165       (process-send-string proc (url-http-create-request url-http-target-url)))
1166      (t
1167       (setf (car url-callback-arguments)
1168             (nconc (list :error (list 'error 'connection-failed why
1169                                       :host (url-host url-current-object)
1170                                       :service (url-port url-current-object)))
1171                    (car url-callback-arguments)))
1172       (url-http-activate-callback)))))
1173
1174 ;; Since Emacs 19/20 does not allow you to change the
1175 ;; `after-change-functions' hook in the midst of running them, we fake
1176 ;; an after change by hooking into the process filter and inserting
1177 ;; the data ourselves.  This is slightly less efficient, but there
1178 ;; were tons of weird ways the after-change code was biting us in the
1179 ;; shorts.
1180 (defun url-http-generic-filter (proc data)
1181   ;; Sometimes we get a zero-length data chunk after the process has
1182   ;; been changed to 'free', which means it has no buffer associated
1183   ;; with it.  Do nothing if there is no buffer, or 0 length data.
1184   (declare (special url-http-after-change-function))
1185   (and (process-buffer proc)
1186        (/= (length data) 0)
1187        (with-current-buffer (process-buffer proc)
1188          (url-http-debug "Calling after change function `%s' for `%S'" url-http-after-change-function proc)
1189          (funcall url-http-after-change-function
1190                   (point-max)
1191                   (progn
1192                     (goto-char (point-max))
1193                     (insert data)
1194                     (point-max))
1195                   (length data)))))
1196
1197 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1198 ;;; file-name-handler stuff from here on out
1199 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1200 (defalias 'url-http-symbol-value-in-buffer
1201   (if (fboundp 'symbol-value-in-buffer)
1202       'symbol-value-in-buffer
1203     (lambda (symbol buffer &optional unbound-value)
1204       "Return the value of SYMBOL in BUFFER, or UNBOUND-VALUE if it is unbound."
1205       (with-current-buffer buffer
1206         (if (not (boundp symbol))
1207             unbound-value
1208           (symbol-value symbol))))))
1209
1210 (defun url-http-head (url)
1211   (let ((url-request-method "HEAD")
1212         (url-request-data nil))
1213     (url-retrieve-synchronously url)))
1214
1215 ;;;###autoload
1216 (defun url-http-file-exists-p (url)
1217   (let ((status nil)
1218         (exists nil)
1219         (buffer (url-http-head url)))
1220     (if (not buffer)
1221         (setq exists nil)
1222       (setq status (url-http-symbol-value-in-buffer 'url-http-response-status
1223                                                     buffer 500)
1224             exists (and (integerp status)
1225                         (>= status 200) (< status 300)))
1226       (kill-buffer buffer))
1227     exists))
1228
1229 ;;;###autoload
1230 (defalias 'url-http-file-readable-p 'url-http-file-exists-p)
1231
1232 (defun url-http-head-file-attributes (url &optional id-format)
1233   (let ((buffer (url-http-head url)))
1234     (when buffer
1235       (prog1
1236           (list
1237            nil                          ;dir / link / normal file
1238            1                            ;number of links to file.
1239            0 0                          ;uid ; gid
1240            nil nil nil                  ;atime ; mtime ; ctime
1241            (url-http-symbol-value-in-buffer 'url-http-content-length
1242                                             buffer -1)
1243            (eval-when-compile (make-string 10 ?-))
1244            nil nil nil)          ;whether gid would change ; inode ; device.
1245         (kill-buffer buffer)))))
1246
1247 ;;;###autoload
1248 (defun url-http-file-attributes (url &optional id-format)
1249   (if (url-dav-supported-p url)
1250       (url-dav-file-attributes url id-format)
1251     (url-http-head-file-attributes url id-format)))
1252
1253 ;;;###autoload
1254 (defun url-http-options (url)
1255   "Return a property list describing options available for URL.
1256 This list is retrieved using the `OPTIONS' HTTP method.
1257
1258 Property list members:
1259
1260 methods
1261   A list of symbols specifying what HTTP methods the resource
1262   supports.
1263
1264 dav
1265   A list of numbers specifying what DAV protocol/schema versions are
1266   supported.
1267
1268 dasl
1269   A list of supported DASL search types supported (string form)
1270
1271 ranges
1272   A list of the units available for use in partial document fetches.
1273
1274 p3p
1275   The `Platform For Privacy Protection' description for the resource.
1276   Currently this is just the raw header contents.  This is likely to
1277   change once P3P is formally supported by the URL package or
1278   Emacs/W3."
1279   (let* ((url-request-method "OPTIONS")
1280          (url-request-data nil)
1281          (buffer (url-retrieve-synchronously url))
1282          (header nil)
1283          (options nil))
1284     (when (and buffer (= 2 (/ (url-http-symbol-value-in-buffer
1285                                'url-http-response-status buffer 0) 100)))
1286       ;; Only parse the options if we got a 2xx response code!
1287       (with-current-buffer buffer
1288         (save-restriction
1289           (save-match-data
1290             (mail-narrow-to-head)
1291
1292             ;; Figure out what methods are supported.
1293             (when (setq header (mail-fetch-field "allow"))
1294               (setq options (plist-put
1295                              options 'methods
1296                              (mapcar 'intern (split-string header "[ ,]+")))))
1297
1298             ;; Check for DAV
1299             (when (setq header (mail-fetch-field "dav"))
1300               (setq options (plist-put
1301                              options 'dav
1302                              (delq 0
1303                                    (mapcar 'string-to-number
1304                                            (split-string header "[, ]+"))))))
1305
1306             ;; Now for DASL
1307             (when (setq header (mail-fetch-field "dasl"))
1308               (setq options (plist-put
1309                              options 'dasl
1310                              (split-string header "[, ]+"))))
1311
1312             ;; P3P - should get more detailed here.  FIXME
1313             (when (setq header (mail-fetch-field "p3p"))
1314               (setq options (plist-put options 'p3p header)))
1315
1316             ;; Check for whether they accept byte-range requests.
1317             (when (setq header (mail-fetch-field "accept-ranges"))
1318               (setq options (plist-put
1319                              options 'ranges
1320                              (delq 'none
1321                                    (mapcar 'intern
1322                                            (split-string header "[, ]+"))))))
1323             ))))
1324     (if buffer (kill-buffer buffer))
1325     options))
1326
1327 ;; HTTPS.  This used to be in url-https.el, but that file collides
1328 ;; with url-http.el on systems with 8-character file names.
1329 (require 'tls)
1330
1331 ;;;###autoload
1332 (defconst url-https-default-port 443 "Default HTTPS port.")
1333 ;;;###autoload
1334 (defconst url-https-asynchronous-p t "HTTPS retrievals are asynchronous.")
1335 ;;;###autoload
1336 (defalias 'url-https-expand-file-name 'url-http-expand-file-name)
1337
1338 (defmacro url-https-create-secure-wrapper (method args)
1339   `(defun ,(intern (format (if method "url-https-%s" "url-https") method)) ,args
1340     ,(format "HTTPS wrapper around `%s' call." (or method "url-http"))
1341     (let ((url-gateway-method 'tls))
1342       (,(intern (format (if method "url-http-%s" "url-http") method))
1343        ,@(remove '&rest (remove '&optional args))))))
1344
1345 ;;;###autoload (autoload 'url-https "url-http")
1346 (url-https-create-secure-wrapper nil (url callback cbargs))
1347 ;;;###autoload (autoload 'url-https-file-exists-p "url-http")
1348 (url-https-create-secure-wrapper file-exists-p (url))
1349 ;;;###autoload (autoload 'url-https-file-readable-p "url-http")
1350 (url-https-create-secure-wrapper file-readable-p (url))
1351 ;;;###autoload (autoload 'url-https-file-attributes "url-http")
1352 (url-https-create-secure-wrapper file-attributes (url &optional id-format))
1353
1354 (provide 'url-http)
1355
1356 ;; arch-tag: ba7c59ae-c0f4-4a31-9617-d85f221732ee
1357 ;;; url-http.el ends here