1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
3 ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
4 ;; 2005 Free Software Foundation, Inc.
6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is free software; you can redistribute it and/or modify
12 ;; it under the terms of the GNU General Public License as published by
13 ;; the Free Software Foundation; either version 2, or (at your option)
16 ;; GNU Emacs is distributed in the hope that it will be useful,
17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 ;; GNU General Public License for more details.
21 ;; You should have received a copy of the GNU General Public License
22 ;; along with GNU Emacs; see the file COPYING. If not, write to the
23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 ;; Boston, MA 02110-1301, USA.
30 (eval-when-compile (require 'cl))
38 (defgroup gnus-nocem nil
39 "NoCeM pseudo-cancellation treatment."
42 (defcustom gnus-nocem-groups
43 '("news.lists.filters" "news.admin.net-abuse.bulletins"
44 "alt.nocem.misc" "news.admin.net-abuse.announce")
45 "*List of groups that will be searched for NoCeM messages."
47 :type '(repeat (string :tag "Group")))
49 (defcustom gnus-nocem-issuers
50 '("AutoMoose-1" ; CancelMoose[tm]
51 "clewis@ferret.ocunix" ; Chris Lewis
55 "*List of NoCeM issuers to pay attention to.
57 This can also be a list of `(ISSUER CONDITION ...)' elements.
59 See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
62 :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
63 :type '(repeat (choice string sexp)))
65 (defcustom gnus-nocem-directory
66 (nnheader-concat gnus-article-save-directory "NoCeM/")
67 "*Directory where NoCeM files will be stored."
71 (defcustom gnus-nocem-expiry-wait 15
72 "*Number of days to keep NoCeM headers in the cache."
76 (defcustom gnus-nocem-verifyer (lambda ()
77 (pgg-verify-region (point-min) (point-max)))
78 "*Function called to verify that the NoCeM message is valid.
79 One likely value is the function using `pgg-verify-region'.
80 If the function in this variable isn't bound, the message will be used
83 :type '(radio (function (lambda ()
84 (pgg-verify-region (point-min) (point-max))))
85 (function-item mc-verify)
86 (function :tag "other")))
88 (defcustom gnus-nocem-liberal-fetch nil
89 "*If t try to fetch all messages which have @@NCM in the subject.
90 Otherwise don't fetch messages which have references or whose message-id
91 matches a previously scanned and verified nocem message."
95 (defcustom gnus-nocem-check-article-limit 500
96 "*If non-nil, the maximum number of articles to check in any NoCeM group."
99 :type '(choice (const :tag "unlimited" nil)
102 (defcustom gnus-nocem-check-from t
103 "Non-nil means check for valid issuers in message bodies.
104 Otherwise don't bother fetching articles unless their author matches a
105 valid issuer, which is much faster if you are selective about the issuers."
110 ;;; Internal variables
112 (defvar gnus-nocem-active nil)
113 (defvar gnus-nocem-alist nil)
114 (defvar gnus-nocem-touched-alist nil)
115 (defvar gnus-nocem-hashtb nil)
116 (defvar gnus-nocem-seen-message-ids nil)
120 (defun gnus-nocem-active-file ()
121 (concat (file-name-as-directory gnus-nocem-directory) "active"))
123 (defun gnus-nocem-cache-file ()
124 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
127 ;; faster lookups for group names:
130 (defvar gnus-nocem-real-group-hashtb nil
131 "Real-name mappings of subscribed groups.")
133 (defun gnus-fill-real-hashtb ()
134 "Fill up a hash table with the real-name mappings from the user's active file."
135 (if (hash-table-p gnus-nocem-real-group-hashtb)
136 (clrhash gnus-nocem-real-group-hashtb)
137 (setq gnus-nocem-real-group-hashtb (make-hash-table :test 'equal)))
138 (mapcar (lambda (group)
139 (setq group (gnus-group-real-name (car group)))
140 (puthash group t gnus-nocem-real-group-hashtb))
143 (defun gnus-nocem-scan-groups ()
144 "Scan all NoCeM groups for new NoCeM messages."
146 (let ((groups gnus-nocem-groups)
147 (gnus-inhibit-demon t)
148 group active gactive articles check-headers)
149 (gnus-make-directory gnus-nocem-directory)
150 ;; Load any previous NoCeM headers.
151 (gnus-nocem-load-cache)
152 ;; Get the group name mappings:
153 (gnus-fill-real-hashtb)
154 ;; Read the active file if it hasn't been read yet.
155 (and (file-exists-p (gnus-nocem-active-file))
156 (not gnus-nocem-active)
158 (load (gnus-nocem-active-file) t t t)))
159 ;; Go through all groups and see whether new articles have
161 (while (setq group (pop groups))
162 (if (not (setq gactive (gnus-activate-group group)))
163 () ; This group doesn't exist.
164 (setq active (nth 1 (assoc group gnus-nocem-active)))
165 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
167 (< (cdr active) (cdr gactive))))
168 ;; Ok, there are new articles in this group, se we fetch the
171 (let ((dependencies (make-vector 10 nil))
176 (gnus-retrieve-headers
178 (gnus-uncompress-range
180 (if active (1+ (cdr active))
184 (gnus-get-newsgroup-headers-xover
185 articles nil dependencies)
186 (gnus-get-newsgroup-headers dependencies)))
187 (while (setq header (pop headers))
188 ;; We take a closer look on all articles that have
189 ;; "@@NCM" in the subject. Unless we already read
190 ;; this cross posted message. Nocem messages
191 ;; are not allowed to have references, so we can
192 ;; ignore scanning followups.
193 (and (string-match "@@NCM" (mail-header-subject header))
194 (and gnus-nocem-check-from
195 (let ((case-fold-search t))
200 (setq author (car author)))
202 author (mail-header-from header))
206 (or gnus-nocem-liberal-fetch
207 (and (or (string= "" (mail-header-references
209 (null (mail-header-references header)))
210 (not (member (mail-header-message-id header)
211 gnus-nocem-seen-message-ids))))
212 (push header check-headers)))
215 (last check-headers gnus-nocem-check-article-limit))
216 (len (length check-headers)))
217 (dolist (h check-headers)
219 7 "Checking article %d in %s for NoCeM (%d of %d)..."
220 (mail-header-number h) group (incf i) len)
221 (gnus-nocem-check-article group h)))))))
222 (setq gnus-nocem-active
223 (cons (list group gactive)
224 (delq (assoc group gnus-nocem-active)
225 gnus-nocem-active)))))
226 ;; Save the results, if any.
227 (gnus-nocem-save-cache)
228 (gnus-nocem-save-active)))
230 (defun gnus-nocem-check-article (group header)
231 "Check whether the current article is an NCM article and that we want it."
233 (let ((date (mail-header-date header))
234 (gnus-newsgroup-name group)
238 (time-since (date-to-time date))
239 (days-to-time gnus-nocem-expiry-wait)))
240 (gnus-request-article-this-buffer (mail-header-number header) group)
241 (goto-char (point-min))
242 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
243 (delete-region (point-min) (match-beginning 0)))
244 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
245 (delete-region (match-end 0) (point-max)))
246 (goto-char (point-min))
247 ;; The article has to have proper NoCeM headers.
248 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
249 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
250 ;; We get the name of the issuer.
251 (narrow-to-region b e)
252 (setq issuer (mail-fetch-field "issuer")
253 type (mail-fetch-field "type"))
255 (if (not (gnus-nocem-message-wanted-p issuer type))
256 (message "invalid NoCeM issuer: %s" issuer)
257 (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
258 (gnus-nocem-enter-article) ; We gobble the message.
259 (push (mail-header-message-id header) ; But don't come back for
260 gnus-nocem-seen-message-ids))))))) ; second helpings.
262 (defun gnus-nocem-message-wanted-p (issuer type)
263 (let ((issuers gnus-nocem-issuers)
264 wanted conditions condition)
266 ;; Do the quick check first.
267 ((member issuer issuers)
269 ((setq conditions (cdr (assoc issuer issuers)))
270 ;; Check whether we want this type.
271 (while (setq condition (pop conditions))
274 (when (string-match condition type)
276 ((and (consp condition)
277 (eq (car condition) 'not)
278 (stringp (cadr condition)))
279 (when (string-match (cadr condition) type)
282 (error "Invalid NoCeM condition: %S" condition))))
285 (defun gnus-nocem-verify-issuer (person)
286 "Verify using PGP that the canceler is who she says she is."
287 (if (functionp gnus-nocem-verifyer)
289 (funcall gnus-nocem-verifyer))
290 ;; If we don't have Mailcrypt, then we use the message anyway.
293 (defun gnus-nocem-enter-article ()
294 "Enter the current article into the NoCeM cache."
295 (goto-char (point-min))
296 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
297 (e (search-forward "\n@@END NCM BODY\n" nil t))
298 (buf (current-buffer))
301 (narrow-to-region b (1+ (match-beginning 0)))
302 (goto-char (point-min))
303 (while (search-forward "\t" nil t)
306 (setq group (gnus-group-real-name (symbol-name (read buf))))
307 (gethash group gnus-nocem-real-group-hashtb)))
313 (while (eq (char-after) ?\t)
315 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
316 (unless (if (hash-table-p gnus-nocem-hashtb)
317 (gethash id gnus-nocem-hashtb)
318 (setq gnus-nocem-hashtb (make-hash-table :test 'equal))
320 ;; only store if not already present
321 (puthash id t gnus-nocem-hashtb)
324 (while (eq (char-after) ?\t)
327 (setq gnus-nocem-touched-alist t)
328 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
333 (defun gnus-nocem-load-cache ()
334 "Load the NoCeM cache."
336 (unless gnus-nocem-alist
337 ;; The buffer doesn't exist, so we create it and load the NoCeM
339 (when (file-exists-p (gnus-nocem-cache-file))
340 (load (gnus-nocem-cache-file) t t t)
341 (gnus-nocem-alist-to-hashtb))))
343 (defun gnus-nocem-save-cache ()
344 "Save the NoCeM cache."
345 (when (and gnus-nocem-alist
346 gnus-nocem-touched-alist)
347 (with-temp-file (gnus-nocem-cache-file)
348 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
349 (setq gnus-nocem-touched-alist nil)))
351 (defun gnus-nocem-save-active ()
352 "Save the NoCeM active file."
353 (with-temp-file (gnus-nocem-active-file)
354 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
356 (defun gnus-nocem-alist-to-hashtb ()
357 "Create a hashtable from the Message-IDs we have."
358 (let* ((alist gnus-nocem-alist)
359 (pprev (cons nil alist))
361 (expiry (days-to-time gnus-nocem-expiry-wait))
363 (if (hash-table-p gnus-nocem-hashtb)
364 (clrhash gnus-nocem-hashtb)
365 (setq gnus-nocem-hashtb (make-hash-table :test 'equal)))
366 (while (setq entry (car alist))
367 (if (not (time-less-p (time-since (car entry)) expiry))
368 ;; This entry has expired, so we remove it.
369 (setcdr prev (cdr alist))
371 ;; This is ok, so we enter it into the hashtable.
372 (setq entry (cdr entry))
374 (puthash (car entry) t gnus-nocem-hashtb)
375 (setq entry (cdr entry))))
376 (setq alist (cdr alist)))))
378 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
380 (defun gnus-nocem-close ()
381 "Clear internal NoCeM variables."
382 (setq gnus-nocem-alist nil
383 gnus-nocem-hashtb nil
384 gnus-nocem-active nil
385 gnus-nocem-touched-alist nil
386 gnus-nocem-seen-message-ids nil
387 gnus-nocem-real-group-hashtb nil))
389 (defun gnus-nocem-unwanted-article-p (id)
390 "Say whether article ID in the current group is wanted."
391 (and gnus-nocem-hashtb
392 (gethash id gnus-nocem-hashtb)))
394 (provide 'gnus-nocem)
396 ;;; gnus-nocem.el ends here