1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002
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))
32 (eval-when-compile (require 'gnus-clfns))
40 (defgroup gnus-nocem nil
41 "NoCeM pseudo-cancellation treatment"
44 (defcustom gnus-nocem-groups
45 '("news.lists.filters" "news.admin.net-abuse.bulletins"
46 "alt.nocem.misc" "news.admin.net-abuse.announce")
47 "*List of groups that will be searched for NoCeM messages."
49 :type '(repeat (string :tag "Group")))
51 (defcustom gnus-nocem-issuers
52 '("AutoMoose-1" ; CancelMoose[tm]
53 "clewis@ferret.ocunix" ; Chris Lewis
57 "*List of NoCeM issuers to pay attention to.
59 This can also be a list of `(ISSUER CONDITION ...)' elements.
61 See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
64 :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
65 :type '(repeat (choice string sexp)))
67 (defcustom gnus-nocem-directory
68 (nnheader-concat gnus-article-save-directory "NoCeM/")
69 "*Directory where NoCeM files will be stored."
73 (defcustom gnus-nocem-expiry-wait 15
74 "*Number of days to keep NoCeM headers in the cache."
78 (defcustom gnus-nocem-verifyer 'mc-verify
79 "*Function called to verify that the NoCeM message is valid.
80 One likely value is `mc-verify'. If the function in this variable
81 isn't bound, the message will be used unconditionally."
83 :type '(radio (function-item mc-verify)
84 (function :tag "other")))
86 (defcustom gnus-nocem-liberal-fetch nil
87 "*If t try to fetch all messages which have @@NCM in the subject.
88 Otherwise don't fetch messages which have references or whose message-id
89 matches a previously scanned and verified nocem message."
93 (defcustom gnus-nocem-check-article-limit 500
94 "*If non-nil, the maximum number of articles to check in any NoCeM group."
97 :type '(choice (const :tag "unlimited" nil)
100 (defcustom gnus-nocem-check-from t
101 "Non-nil means check for valid issuers in message bodies.
102 Otherwise don't bother fetching articles unless their author matches a
103 valid issuer, which is much faster if you are selective about the issuers."
108 ;;; Internal variables
110 (defvar gnus-nocem-active nil)
111 (defvar gnus-nocem-alist nil)
112 (defvar gnus-nocem-touched-alist nil)
113 (defvar gnus-nocem-hashtb nil)
114 (defvar gnus-nocem-seen-message-ids nil)
118 (defun gnus-nocem-active-file ()
119 (concat (file-name-as-directory gnus-nocem-directory) "active"))
121 (defun gnus-nocem-cache-file ()
122 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
125 ;; faster lookups for group names:
128 (defvar gnus-nocem-real-group-hashtb nil
129 "Real-name mappings of subscribed groups.")
131 (defun gnus-fill-real-hashtb ()
132 "Fill up a hash table with the real-name mappings from the user's active file."
133 (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
134 (length gnus-newsrc-alist)))
135 (mapcar (lambda (group)
136 (setq group (gnus-group-real-name (car group)))
137 (gnus-sethash group t gnus-nocem-real-group-hashtb))
140 (defun gnus-nocem-scan-groups ()
141 "Scan all NoCeM groups for new NoCeM messages."
143 (let ((groups gnus-nocem-groups)
144 (gnus-inhibit-demon t)
145 group active gactive articles check-headers)
146 (gnus-make-directory gnus-nocem-directory)
147 ;; Load any previous NoCeM headers.
148 (gnus-nocem-load-cache)
149 ;; Get the group name mappings:
150 (gnus-fill-real-hashtb)
151 ;; Read the active file if it hasn't been read yet.
152 (and (file-exists-p (gnus-nocem-active-file))
153 (not gnus-nocem-active)
155 (load (gnus-nocem-active-file) t t t)))
156 ;; Go through all groups and see whether new articles have
158 (while (setq group (pop groups))
159 (if (not (setq gactive (gnus-activate-group group)))
160 () ; This group doesn't exist.
161 (setq active (nth 1 (assoc group gnus-nocem-active)))
162 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
164 (< (cdr active) (cdr gactive))))
165 ;; Ok, there are new articles in this group, se we fetch the
168 (let ((dependencies (make-vector 10 nil))
173 (gnus-retrieve-headers
175 (gnus-uncompress-range
177 (if active (1+ (cdr active))
181 (gnus-get-newsgroup-headers-xover
182 articles nil dependencies)
183 (gnus-get-newsgroup-headers dependencies)))
184 (while (setq header (pop headers))
185 ;; We take a closer look on all articles that have
186 ;; "@@NCM" in the subject. Unless we already read
187 ;; this cross posted message. Nocem messages
188 ;; are not allowed to have references, so we can
189 ;; ignore scanning followups.
190 (and (string-match "@@NCM" (mail-header-subject header))
191 (and gnus-nocem-check-from
192 (let ((case-fold-search t))
197 (setq author (car author)))
199 author (mail-header-from header))
203 (or gnus-nocem-liberal-fetch
204 (and (or (string= "" (mail-header-references
206 (null (mail-header-references header)))
207 (not (member (mail-header-message-id header)
208 gnus-nocem-seen-message-ids))))
209 (push header check-headers)))
212 (last check-headers gnus-nocem-check-article-limit))
213 (len (length check-headers)))
214 (dolist (h check-headers)
216 7 "Checking article %d in %s for NoCeM (%d of %d)..."
217 (mail-header-number h) group (incf i) len)
218 (gnus-nocem-check-article group h)))))))
219 (setq gnus-nocem-active
220 (cons (list group gactive)
221 (delq (assoc group gnus-nocem-active)
222 gnus-nocem-active)))))
223 ;; Save the results, if any.
224 (gnus-nocem-save-cache)
225 (gnus-nocem-save-active)))
227 (defun gnus-nocem-check-article (group header)
228 "Check whether the current article is an NCM article and that we want it."
230 (let ((date (mail-header-date header))
231 (gnus-newsgroup-name group)
235 (time-since (date-to-time date))
236 (days-to-time gnus-nocem-expiry-wait)))
237 (gnus-request-article-this-buffer (mail-header-number header) group)
238 (goto-char (point-min))
239 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
240 (delete-region (point-min) (match-beginning 0)))
241 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
242 (delete-region (match-end 0) (point-max)))
243 (goto-char (point-min))
244 ;; The article has to have proper NoCeM headers.
245 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
246 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
247 ;; We get the name of the issuer.
248 (narrow-to-region b e)
249 (setq issuer (mail-fetch-field "issuer")
250 type (mail-fetch-field "issuer"))
252 (if (not (gnus-nocem-message-wanted-p issuer type))
253 (message "invalid NoCeM issuer: %s" issuer)
254 (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
255 (gnus-nocem-enter-article) ; We gobble the message.
256 (push (mail-header-message-id header) ; But don't come back for
257 gnus-nocem-seen-message-ids))))))) ; second helpings.
259 (defun gnus-nocem-message-wanted-p (issuer type)
260 (let ((issuers gnus-nocem-issuers)
261 wanted conditions condition)
263 ;; Do the quick check first.
264 ((member issuer issuers)
266 ((setq conditions (cdr (assoc issuer issuers)))
267 ;; Check whether we want this type.
268 (while (setq condition (pop conditions))
271 (setq wanted (string-match condition type)))
272 ((and (consp condition)
273 (eq (car condition) 'not)
274 (stringp (cadr condition)))
275 (setq wanted (not (string-match (cadr condition) type))))
277 (error "Invalid NoCeM condition: %S" condition))))
280 (defun gnus-nocem-verify-issuer (person)
281 "Verify using PGP that the canceler is who she says she is."
282 (if (fboundp gnus-nocem-verifyer)
284 (funcall gnus-nocem-verifyer))
285 ;; If we don't have Mailcrypt, then we use the message anyway.
288 (defun gnus-nocem-enter-article ()
289 "Enter the current article into the NoCeM cache."
290 (goto-char (point-min))
291 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
292 (e (search-forward "\n@@END NCM BODY\n" nil t))
293 (buf (current-buffer))
296 (narrow-to-region b (1+ (match-beginning 0)))
297 (goto-char (point-min))
298 (while (search-forward "\t" nil t)
301 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
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