1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2004
4 ;; Free Software Foundation, Inc.
7 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs; see the file COPYING. If not, write to the
24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;; Boston, MA 02111-1307, USA.
31 (eval-when-compile (require 'cl))
39 (defgroup gnus-nocem nil
40 "NoCeM pseudo-cancellation treatment"
43 (defcustom gnus-nocem-groups
44 '("news.lists.filters" "news.admin.net-abuse.bulletins"
45 "alt.nocem.misc" "news.admin.net-abuse.announce")
46 "*List of groups that will be searched for NoCeM messages."
48 :type '(repeat (string :tag "Group")))
50 (defcustom gnus-nocem-issuers
51 '("AutoMoose-1" ; CancelMoose[tm]
52 "clewis@ferret.ocunix" ; Chris Lewis
56 "*List of NoCeM issuers to pay attention to.
58 This can also be a list of `(ISSUER CONDITION ...)' elements.
60 See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
63 :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
64 :type '(repeat (choice string sexp)))
66 (defcustom gnus-nocem-directory
67 (nnheader-concat gnus-article-save-directory "NoCeM/")
68 "*Directory where NoCeM files will be stored."
72 (defcustom gnus-nocem-expiry-wait 15
73 "*Number of days to keep NoCeM headers in the cache."
77 (defcustom gnus-nocem-verifyer 'mc-verify
78 "*Function called to verify that the NoCeM message is valid.
79 One likely value is `mc-verify'. If the function in this variable
80 isn't bound, the message will be used unconditionally."
82 :type '(radio (function-item mc-verify)
83 (function :tag "other")))
85 (defcustom gnus-nocem-liberal-fetch nil
86 "*If t try to fetch all messages which have @@NCM in the subject.
87 Otherwise don't fetch messages which have references or whose message-id
88 matches a previously scanned and verified nocem message."
92 (defcustom gnus-nocem-check-article-limit 500
93 "*If non-nil, the maximum number of articles to check in any NoCeM group."
96 :type '(choice (const :tag "unlimited" nil)
99 (defcustom gnus-nocem-check-from t
100 "Non-nil means check for valid issuers in message bodies.
101 Otherwise don't bother fetching articles unless their author matches a
102 valid issuer, which is much faster if you are selective about the issuers."
107 ;;; Internal variables
109 (defvar gnus-nocem-active nil)
110 (defvar gnus-nocem-alist nil)
111 (defvar gnus-nocem-touched-alist nil)
112 (defvar gnus-nocem-hashtb nil)
113 (defvar gnus-nocem-seen-message-ids nil)
117 (defun gnus-nocem-active-file ()
118 (concat (file-name-as-directory gnus-nocem-directory) "active"))
120 (defun gnus-nocem-cache-file ()
121 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
124 ;; faster lookups for group names:
127 (defvar gnus-nocem-real-group-hashtb nil
128 "Real-name mappings of subscribed groups.")
130 (defun gnus-fill-real-hashtb ()
131 "Fill up a hash table with the real-name mappings from the user's active file."
132 (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
133 (length gnus-newsrc-alist)))
134 (mapcar (lambda (group)
135 (setq group (gnus-group-real-name (car group)))
136 (gnus-sethash group t gnus-nocem-real-group-hashtb))
139 (defun gnus-nocem-scan-groups ()
140 "Scan all NoCeM groups for new NoCeM messages."
142 (let ((groups gnus-nocem-groups)
143 (gnus-inhibit-demon t)
144 group active gactive articles check-headers)
145 (gnus-make-directory gnus-nocem-directory)
146 ;; Load any previous NoCeM headers.
147 (gnus-nocem-load-cache)
148 ;; Get the group name mappings:
149 (gnus-fill-real-hashtb)
150 ;; Read the active file if it hasn't been read yet.
151 (and (file-exists-p (gnus-nocem-active-file))
152 (not gnus-nocem-active)
154 (load (gnus-nocem-active-file) t t t)))
155 ;; Go through all groups and see whether new articles have
157 (while (setq group (pop groups))
158 (if (not (setq gactive (gnus-activate-group group)))
159 () ; This group doesn't exist.
160 (setq active (nth 1 (assoc group gnus-nocem-active)))
161 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
163 (< (cdr active) (cdr gactive))))
164 ;; Ok, there are new articles in this group, se we fetch the
167 (let ((dependencies (make-vector 10 nil))
172 (gnus-retrieve-headers
174 (gnus-uncompress-range
176 (if active (1+ (cdr active))
180 (gnus-get-newsgroup-headers-xover
181 articles nil dependencies)
182 (gnus-get-newsgroup-headers dependencies)))
183 (while (setq header (pop headers))
184 ;; We take a closer look on all articles that have
185 ;; "@@NCM" in the subject. Unless we already read
186 ;; this cross posted message. Nocem messages
187 ;; are not allowed to have references, so we can
188 ;; ignore scanning followups.
189 (and (string-match "@@NCM" (mail-header-subject header))
190 (and gnus-nocem-check-from
191 (let ((case-fold-search t))
196 (setq author (car author)))
198 author (mail-header-from header))
202 (or gnus-nocem-liberal-fetch
203 (and (or (string= "" (mail-header-references
205 (null (mail-header-references header)))
206 (not (member (mail-header-message-id header)
207 gnus-nocem-seen-message-ids))))
208 (push header check-headers)))
211 (last check-headers gnus-nocem-check-article-limit))
212 (len (length check-headers)))
213 (dolist (h check-headers)
215 7 "Checking article %d in %s for NoCeM (%d of %d)..."
216 (mail-header-number h) group (incf i) len)
217 (gnus-nocem-check-article group h)))))))
218 (setq gnus-nocem-active
219 (cons (list group gactive)
220 (delq (assoc group gnus-nocem-active)
221 gnus-nocem-active)))))
222 ;; Save the results, if any.
223 (gnus-nocem-save-cache)
224 (gnus-nocem-save-active)))
226 (defun gnus-nocem-check-article (group header)
227 "Check whether the current article is an NCM article and that we want it."
229 (let ((date (mail-header-date header))
230 (gnus-newsgroup-name group)
234 (time-since (date-to-time date))
235 (days-to-time gnus-nocem-expiry-wait)))
236 (gnus-request-article-this-buffer (mail-header-number header) group)
237 (goto-char (point-min))
238 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
239 (delete-region (point-min) (match-beginning 0)))
240 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
241 (delete-region (match-end 0) (point-max)))
242 (goto-char (point-min))
243 ;; The article has to have proper NoCeM headers.
244 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
245 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
246 ;; We get the name of the issuer.
247 (narrow-to-region b e)
248 (setq issuer (mail-fetch-field "issuer")
249 type (mail-fetch-field "issuer"))
251 (if (not (gnus-nocem-message-wanted-p issuer type))
252 (message "invalid NoCeM issuer: %s" issuer)
253 (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
254 (gnus-nocem-enter-article) ; We gobble the message.
255 (push (mail-header-message-id header) ; But don't come back for
256 gnus-nocem-seen-message-ids))))))) ; second helpings.
258 (defun gnus-nocem-message-wanted-p (issuer type)
259 (let ((issuers gnus-nocem-issuers)
260 wanted conditions condition)
262 ;; Do the quick check first.
263 ((member issuer issuers)
265 ((setq conditions (cdr (assoc issuer issuers)))
266 ;; Check whether we want this type.
267 (while (setq condition (pop conditions))
270 (setq wanted (string-match condition type)))
271 ((and (consp condition)
272 (eq (car condition) 'not)
273 (stringp (cadr condition)))
274 (setq wanted (not (string-match (cadr condition) type))))
276 (error "Invalid NoCeM condition: %S" condition))))
279 (defun gnus-nocem-verify-issuer (person)
280 "Verify using PGP that the canceler is who she says she is."
281 (if (fboundp gnus-nocem-verifyer)
283 (funcall gnus-nocem-verifyer))
284 ;; If we don't have Mailcrypt, then we use the message anyway.
287 (defun gnus-nocem-enter-article ()
288 "Enter the current article into the NoCeM cache."
289 (goto-char (point-min))
290 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
291 (e (search-forward "\n@@END NCM BODY\n" nil t))
292 (buf (current-buffer))
295 (narrow-to-region b (1+ (match-beginning 0)))
296 (goto-char (point-min))
297 (while (search-forward "\t" nil t)
300 (setq group (let ((obarray gnus-nocem-real-group-hashtb))
304 ((not (symbolp group))
305 ;; Ignore invalid entries.
307 ((not (boundp group))
308 ;; Make sure all entries in the hashtb are bound.
311 (when (gnus-gethash (gnus-group-real-name (symbol-name group))
312 gnus-nocem-real-group-hashtb)
315 (while (eq (char-after) ?\t)
317 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
318 (unless (gnus-gethash id gnus-nocem-hashtb)
319 ;; only store if not already present
320 (gnus-sethash id t gnus-nocem-hashtb)
323 (while (eq (char-after) ?\t)
324 (forward-line 1))))))
326 (setq gnus-nocem-touched-alist t)
327 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
332 (defun gnus-nocem-load-cache ()
333 "Load the NoCeM cache."
335 (unless gnus-nocem-alist
336 ;; The buffer doesn't exist, so we create it and load the NoCeM
338 (when (file-exists-p (gnus-nocem-cache-file))
339 (load (gnus-nocem-cache-file) t t t)
340 (gnus-nocem-alist-to-hashtb))))
342 (defun gnus-nocem-save-cache ()
343 "Save the NoCeM cache."
344 (when (and gnus-nocem-alist
345 gnus-nocem-touched-alist)
346 (with-temp-file (gnus-nocem-cache-file)
347 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
348 (setq gnus-nocem-touched-alist nil)))
350 (defun gnus-nocem-save-active ()
351 "Save the NoCeM active file."
352 (with-temp-file (gnus-nocem-active-file)
353 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
355 (defun gnus-nocem-alist-to-hashtb ()
356 "Create a hashtable from the Message-IDs we have."
357 (let* ((alist gnus-nocem-alist)
358 (pprev (cons nil alist))
360 (expiry (days-to-time gnus-nocem-expiry-wait))
362 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
363 (while (setq entry (car alist))
364 (if (not (time-less-p (time-since (car entry)) expiry))
365 ;; This entry has expired, so we remove it.
366 (setcdr prev (cdr alist))
368 ;; This is ok, so we enter it into the hashtable.
369 (setq entry (cdr entry))
371 (gnus-sethash (car entry) t gnus-nocem-hashtb)
372 (setq entry (cdr entry))))
373 (setq alist (cdr alist)))))
375 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
377 (defun gnus-nocem-close ()
378 "Clear internal NoCeM variables."
379 (setq gnus-nocem-alist nil
380 gnus-nocem-hashtb nil
381 gnus-nocem-active nil
382 gnus-nocem-touched-alist nil
383 gnus-nocem-seen-message-ids nil
384 gnus-nocem-real-group-hashtb nil))
386 (defun gnus-nocem-unwanted-article-p (id)
387 "Say whether article ID in the current group is wanted."
388 (and gnus-nocem-hashtb
389 (gnus-gethash id gnus-nocem-hashtb)))
391 (provide 'gnus-nocem)
393 ;;; gnus-nocem.el ends here