1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
8 ;; This file is part of GNU Emacs.
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)
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.
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., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
29 (eval-when-compile (require 'cl))
37 (defgroup gnus-nocem nil
38 "NoCeM pseudo-cancellation treatment"
41 (defcustom gnus-nocem-groups
42 '("news.lists.filters" "news.admin.net-abuse.bulletins"
43 "alt.nocem.misc" "news.admin.net-abuse.announce")
44 "*List of groups that will be searched for NoCeM messages."
46 :type '(repeat (string :tag "Group")))
48 (defcustom gnus-nocem-issuers
49 '("AutoMoose-1" ; CancelMoose[tm]
50 "clewis@ferret.ocunix" ; Chris Lewis
54 "*List of NoCeM issuers to pay attention to.
56 This can also be a list of `(ISSUER CONDITION ...)' elements.
58 See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
61 :type '(repeat (choice string sexp)))
63 (defcustom gnus-nocem-directory
64 (nnheader-concat gnus-article-save-directory "NoCeM/")
65 "*Directory where NoCeM files will be stored."
69 (defcustom gnus-nocem-expiry-wait 15
70 "*Number of days to keep NoCeM headers in the cache."
74 (defcustom gnus-nocem-verifyer 'mc-verify
75 "*Function called to verify that the NoCeM message is valid.
76 One likely value is `mc-verify'. If the function in this variable
77 isn't bound, the message will be used unconditionally."
79 :type '(radio (function-item mc-verify)
80 (function :tag "other")))
82 (defcustom gnus-nocem-liberal-fetch nil
83 "*If t try to fetch all messages which have @@NCM in the subject.
84 Otherwise don't fetch messages which have references or whose message-id
85 matches an previously scanned and verified nocem message."
89 (defcustom gnus-nocem-check-article-limit nil
90 "*If non-nil, the maximum number of articles to check in any NoCeM group."
92 :type '(choice (const :tag "unlimited" nil)
95 (defcustom gnus-nocem-check-from t
96 "Non-nil means check for valid issuers in message bodies.
97 Otherwise don't bother fetching articles unless their author matches a
98 valid issuer, which is much faster if you are selective about the issuers."
102 ;;; Internal variables
104 (defvar gnus-nocem-active nil)
105 (defvar gnus-nocem-alist nil)
106 (defvar gnus-nocem-touched-alist nil)
107 (defvar gnus-nocem-hashtb nil)
108 (defvar gnus-nocem-seen-message-ids nil)
112 (defun gnus-nocem-active-file ()
113 (concat (file-name-as-directory gnus-nocem-directory) "active"))
115 (defun gnus-nocem-cache-file ()
116 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
119 ;; faster lookups for group names:
122 (defvar gnus-nocem-real-group-hashtb nil
123 "Real-name mappings of subscribed groups.")
125 (defun gnus-fill-real-hashtb ()
126 "Fill up a hash table with the real-name mappings from the user's active file."
127 (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
128 (length gnus-newsrc-alist)))
129 (mapcar (lambda (group)
130 (setq group (gnus-group-real-name (car group)))
131 (gnus-sethash group t gnus-nocem-real-group-hashtb))
134 (defun gnus-nocem-scan-groups ()
135 "Scan all NoCeM groups for new NoCeM messages."
137 (let ((groups gnus-nocem-groups)
138 (gnus-inhibit-demon t)
139 group active gactive articles check-headers)
140 (gnus-make-directory gnus-nocem-directory)
141 ;; Load any previous NoCeM headers.
142 (gnus-nocem-load-cache)
143 ;; Get the group name mappings:
144 (gnus-fill-real-hashtb)
145 ;; Read the active file if it hasn't been read yet.
146 (and (file-exists-p (gnus-nocem-active-file))
147 (not gnus-nocem-active)
149 (load (gnus-nocem-active-file) t t t)))
150 ;; Go through all groups and see whether new articles have
152 (while (setq group (pop groups))
153 (if (not (setq gactive (gnus-activate-group group)))
154 () ; This group doesn't exist.
155 (setq active (nth 1 (assoc group gnus-nocem-active)))
156 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
158 (< (cdr active) (cdr gactive))))
159 ;; Ok, there are new articles in this group, se we fetch the
162 (let ((dependencies (make-vector 10 nil))
167 (gnus-retrieve-headers
169 (gnus-uncompress-range
171 (if active (1+ (cdr active))
175 (gnus-get-newsgroup-headers-xover
176 articles nil dependencies)
177 (gnus-get-newsgroup-headers dependencies)))
178 (while (setq header (pop headers))
179 ;; We take a closer look on all articles that have
180 ;; "@@NCM" in the subject. Unless we already read
181 ;; this cross posted message. Nocem messages
182 ;; are not allowed to have references, so we can
183 ;; ignore scanning followups.
184 (and (string-match "@@NCM" (mail-header-subject header))
185 (and gnus-nocem-check-from
186 (let ((case-fold-search t))
191 (setq author (car author)))
193 author (mail-header-from header))
197 (or gnus-nocem-liberal-fetch
198 (and (or (string= "" (mail-header-references
200 (null (mail-header-references header)))
201 (not (member (mail-header-message-id header)
202 gnus-nocem-seen-message-ids))))
203 (push header check-headers)))
206 (last check-headers gnus-nocem-check-article-limit))
207 (len (length check-headers)))
208 (dolist (h check-headers)
210 7 "Checking article %d in %s for NoCeM (%d of %d)..."
211 (mail-header-number h) group (incf i) len)
212 (gnus-nocem-check-article group h)))))))
213 (setq gnus-nocem-active
214 (cons (list group gactive)
215 (delq (assoc group gnus-nocem-active)
216 gnus-nocem-active)))))
217 ;; Save the results, if any.
218 (gnus-nocem-save-cache)
219 (gnus-nocem-save-active)))
221 (defun gnus-nocem-check-article (group header)
222 "Check whether the current article is an NCM article and that we want it."
224 (let ((date (mail-header-date header))
225 (gnus-newsgroup-name group)
229 (time-since (date-to-time date))
230 (days-to-time gnus-nocem-expiry-wait)))
231 (gnus-request-article-this-buffer (mail-header-number header) group)
232 (goto-char (point-min))
233 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
234 (delete-region (point-min) (match-beginning 0)))
235 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
236 (delete-region (match-end 0) (point-max)))
237 (goto-char (point-min))
238 ;; The article has to have proper NoCeM headers.
239 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
240 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
241 ;; We get the name of the issuer.
242 (narrow-to-region b e)
243 (setq issuer (mail-fetch-field "issuer")
244 type (mail-fetch-field "issuer"))
246 (if (not (gnus-nocem-message-wanted-p issuer type))
247 (message "invalid NoCeM issuer: %s" issuer)
248 (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
249 (gnus-nocem-enter-article) ; We gobble the message.
250 (push (mail-header-message-id header) ; But don't come back for
251 gnus-nocem-seen-message-ids))))))) ; second helpings.
253 (defun gnus-nocem-message-wanted-p (issuer type)
254 (let ((issuers gnus-nocem-issuers)
255 wanted conditions condition)
257 ;; Do the quick check first.
258 ((member issuer issuers)
260 ((setq conditions (cdr (assoc issuer issuers)))
261 ;; Check whether we want this type.
262 (while (setq condition (pop conditions))
265 (setq wanted (string-match condition type)))
266 ((and (consp condition)
267 (eq (car condition) 'not)
268 (stringp (cadr condition)))
269 (setq wanted (not (string-match (cadr condition) type))))
271 (error "Invalid NoCeM condition: %S" condition))))
274 (defun gnus-nocem-verify-issuer (person)
275 "Verify using PGP that the canceler is who she says she is."
276 (if (fboundp gnus-nocem-verifyer)
278 (funcall gnus-nocem-verifyer))
279 ;; If we don't have Mailcrypt, then we use the message anyway.
282 (defun gnus-nocem-enter-article ()
283 "Enter the current article into the NoCeM cache."
284 (goto-char (point-min))
285 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
286 (e (search-forward "\n@@END NCM BODY\n" nil t))
287 (buf (current-buffer))
290 (narrow-to-region b (1+ (match-beginning 0)))
291 (goto-char (point-min))
292 (while (search-forward "\t" nil t)
295 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
298 ((not (symbolp group))
299 ;; Ignore invalid entries.
301 ((not (boundp group))
302 ;; Make sure all entries in the hashtb are bound.
305 (when (gnus-gethash (gnus-group-real-name (symbol-name group))
306 gnus-nocem-real-group-hashtb)
309 (while (eq (char-after) ?\t)
311 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
312 (unless (gnus-gethash id gnus-nocem-hashtb)
313 ;; only store if not already present
314 (gnus-sethash id t gnus-nocem-hashtb)
317 (while (eq (char-after) ?\t)
318 (forward-line 1))))))
320 (setq gnus-nocem-touched-alist t)
321 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
326 (defun gnus-nocem-load-cache ()
327 "Load the NoCeM cache."
329 (unless gnus-nocem-alist
330 ;; The buffer doesn't exist, so we create it and load the NoCeM
332 (when (file-exists-p (gnus-nocem-cache-file))
333 (load (gnus-nocem-cache-file) t t t)
334 (gnus-nocem-alist-to-hashtb))))
336 (defun gnus-nocem-save-cache ()
337 "Save the NoCeM cache."
338 (when (and gnus-nocem-alist
339 gnus-nocem-touched-alist)
340 (with-temp-file (gnus-nocem-cache-file)
341 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
342 (setq gnus-nocem-touched-alist nil)))
344 (defun gnus-nocem-save-active ()
345 "Save the NoCeM active file."
346 (with-temp-file (gnus-nocem-active-file)
347 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
349 (defun gnus-nocem-alist-to-hashtb ()
350 "Create a hashtable from the Message-IDs we have."
351 (let* ((alist gnus-nocem-alist)
352 (pprev (cons nil alist))
354 (expiry (days-to-time gnus-nocem-expiry-wait))
356 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
357 (while (setq entry (car alist))
358 (if (not (time-less-p (time-since (car entry)) expiry))
359 ;; This entry has expired, so we remove it.
360 (setcdr prev (cdr alist))
362 ;; This is ok, so we enter it into the hashtable.
363 (setq entry (cdr entry))
365 (gnus-sethash (car entry) t gnus-nocem-hashtb)
366 (setq entry (cdr entry))))
367 (setq alist (cdr alist)))))
369 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
371 (defun gnus-nocem-close ()
372 "Clear internal NoCeM variables."
373 (setq gnus-nocem-alist nil
374 gnus-nocem-hashtb nil
375 gnus-nocem-active nil
376 gnus-nocem-touched-alist nil
377 gnus-nocem-seen-message-ids nil
378 gnus-nocem-real-group-hashtb nil))
380 (defun gnus-nocem-unwanted-article-p (id)
381 "Say whether article ID in the current group is wanted."
382 (and gnus-nocem-hashtb
383 (gnus-gethash id gnus-nocem-hashtb)))
385 (provide 'gnus-nocem)
387 ;;; gnus-nocem.el ends here