1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
2 ;; Copyright (C) 1995,96,97 Free Software Foundation, Inc.
4 ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
34 (defgroup gnus-nocem nil
35 "NoCeM pseudo-cancellation treatment"
38 (defcustom gnus-nocem-groups
39 '("news.lists.filters" "news.admin.net-abuse.bulletins"
40 "alt.nocem.misc" "news.admin.net-abuse.announce")
41 "List of groups that will be searched for NoCeM messages."
43 :type '(repeat (string :tag "Group")))
45 (defcustom gnus-nocem-issuers
46 '("AutoMoose-1" "Automoose-1" ; CancelMoose[tm]
47 "rbraver@ohww.norman.ok.us" ; Robert Braver
48 "clewis@ferret.ocunix.on.ca" ; Chris Lewis
49 "jem@xpat.com" ; Despammer from Korea
50 "snowhare@xmission.com" ; Benjamin "Snowhare" Franz
51 "red@redpoll.mrfs.oh.us (Richard E. Depew)" ; ARMM! ARMM!
53 "List of NoCeM issuers to pay attention to."
55 :type '(repeat string))
57 (defcustom gnus-nocem-directory
58 (nnheader-concat gnus-article-save-directory "NoCeM/")
59 "*Directory where NoCeM files will be stored."
63 (defcustom gnus-nocem-expiry-wait 15
64 "*Number of days to keep NoCeM headers in the cache."
68 (defcustom gnus-nocem-verifyer 'mc-verify
69 "*Function called to verify that the NoCeM message is valid.
70 One likely value is `mc-verify'. If the function in this variable
71 isn't bound, the message will be used unconditionally."
73 :type '(radio (function-item mc-verify)
74 (function :tag "other")))
76 (defcustom gnus-nocem-liberal-fetch nil
77 "*If t try to fetch all messages which have @@NCM in the subject.
78 Otherwise don't fetch messages which have references or whose message-id
79 matches an previously scanned and verified nocem message."
83 ;;; Internal variables
85 (defvar gnus-nocem-active nil)
86 (defvar gnus-nocem-alist nil)
87 (defvar gnus-nocem-touched-alist nil)
88 (defvar gnus-nocem-hashtb nil)
89 (defvar gnus-nocem-seen-message-ids nil)
93 (defun gnus-nocem-active-file ()
94 (concat (file-name-as-directory gnus-nocem-directory) "active"))
96 (defun gnus-nocem-cache-file ()
97 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
100 ;; faster lookups for group names:
103 (defvar gnus-nocem-real-group-hashtb nil
104 "Real-name mappings of subscribed groups.")
106 (defun gnus-fill-real-hashtb ()
107 "Fill up a hash table with the real-name mappings from the user's
109 (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
110 (length gnus-newsrc-alist)))
111 (mapcar (lambda (group)
112 (setq group (gnus-group-real-name (car group)))
113 (gnus-sethash group t gnus-nocem-real-group-hashtb))
116 (defun gnus-nocem-scan-groups ()
117 "Scan all NoCeM groups for new NoCeM messages."
119 (let ((groups gnus-nocem-groups)
120 (gnus-inhibit-demon t)
121 group active gactive articles)
122 (gnus-make-directory gnus-nocem-directory)
123 ;; Load any previous NoCeM headers.
124 (gnus-nocem-load-cache)
125 ;; Get the group name mappings:
126 (gnus-fill-real-hashtb)
127 ;; Read the active file if it hasn't been read yet.
128 (and (file-exists-p (gnus-nocem-active-file))
129 (not gnus-nocem-active)
131 (load (gnus-nocem-active-file) t t t)))
132 ;; Go through all groups and see whether new articles have
134 (while (setq group (pop groups))
135 (if (not (setq gactive (gnus-activate-group group)))
136 () ; This group doesn't exist.
137 (setq active (nth 1 (assoc group gnus-nocem-active)))
138 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
140 (< (cdr active) (cdr gactive))))
141 ;; Ok, there are new articles in this group, se we fetch the
144 (let ((dependencies (make-vector 10 nil))
146 (nnheader-temp-write nil
149 (gnus-retrieve-headers
151 (gnus-uncompress-range
153 (if active (1+ (cdr active))
157 (gnus-get-newsgroup-headers-xover
158 articles nil dependencies)
159 (gnus-get-newsgroup-headers dependencies)))
160 (while (setq header (pop headers))
161 ;; We take a closer look on all articles that have
162 ;; "@@NCM" in the subject. Unless we already read
163 ;; this cross posted message. Nocem messages
164 ;; are not allowed to have references, so we can
165 ;; ignore scanning followups.
166 (and (string-match "@@NCM" (mail-header-subject header))
167 (or gnus-nocem-liberal-fetch
168 (and (or (string= "" (mail-header-references
170 (null (mail-header-references header)))
171 (not (member (mail-header-message-id header)
172 gnus-nocem-seen-message-ids))))
173 (gnus-nocem-check-article group header)))))))
174 (setq gnus-nocem-active
175 (cons (list group gactive)
176 (delq (assoc group gnus-nocem-active)
177 gnus-nocem-active)))))
178 ;; Save the results, if any.
179 (gnus-nocem-save-cache)
180 (gnus-nocem-save-active)))
182 (defun gnus-nocem-check-article (group header)
183 "Check whether the current article is an NCM article and that we want it."
185 (gnus-message 7 "Checking article %d in %s for NoCeM..."
186 (mail-header-number header) group)
187 (let ((date (mail-header-date header))
191 (nnmail-time-since (nnmail-date-to-time date))
192 (nnmail-days-to-time gnus-nocem-expiry-wait)))
193 (gnus-request-article-this-buffer (mail-header-number header) group)
194 (goto-char (point-min))
195 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
196 (delete-region (point-min) (match-beginning 0)))
197 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
198 (delete-region (match-end 0) (point-max)))
199 (goto-char (point-min))
200 ;; The article has to have proper NoCeM headers.
201 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
202 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
203 ;; We get the name of the issuer.
204 (narrow-to-region b e)
205 (setq issuer (mail-fetch-field "issuer"))
207 (or (member issuer gnus-nocem-issuers)
208 (message "invalid NoCeM issuer: %s" issuer))
209 (and (member issuer gnus-nocem-issuers) ; We like her....
210 (gnus-nocem-verify-issuer issuer) ; She is who she says she is...
211 (gnus-nocem-enter-article) ; We gobble the message..
212 (push (mail-header-message-id header) ; But don't come back for
213 gnus-nocem-seen-message-ids)))))) ; second helpings.
215 (defun gnus-nocem-verify-issuer (person)
216 "Verify using PGP that the canceler is who she says she is."
217 (if (fboundp gnus-nocem-verifyer)
219 (funcall gnus-nocem-verifyer))
220 ;; If we don't have Mailcrypt, then we use the message anyway.
223 (defun gnus-nocem-enter-article ()
224 "Enter the current article into the NoCeM cache."
225 (goto-char (point-min))
226 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
227 (e (search-forward "\n@@END NCM BODY\n" nil t))
228 (buf (current-buffer))
231 (narrow-to-region b (1+ (match-beginning 0)))
232 (goto-char (point-min))
233 (while (search-forward "\t" nil t)
236 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
239 ((not (symbolp group))
240 ;; Ignore invalid entries.
242 ((not (boundp group))
243 ;; Make sure all entries in the hashtb are bound.
246 (when (gnus-gethash (gnus-group-real-name (symbol-name group))
247 gnus-nocem-real-group-hashtb)
250 (while (= (following-char) ?\t)
252 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
253 (unless (gnus-gethash id gnus-nocem-hashtb)
254 ;; only store if not already present
255 (gnus-sethash id t gnus-nocem-hashtb)
258 (while (= (following-char) ?\t)
259 (forward-line 1))))))
261 (setq gnus-nocem-touched-alist t)
262 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
267 (defun gnus-nocem-load-cache ()
268 "Load the NoCeM cache."
270 (unless gnus-nocem-alist
271 ;; The buffer doesn't exist, so we create it and load the NoCeM
273 (when (file-exists-p (gnus-nocem-cache-file))
274 (load (gnus-nocem-cache-file) t t t)
275 (gnus-nocem-alist-to-hashtb))))
277 (defun gnus-nocem-save-cache ()
278 "Save the NoCeM cache."
279 (when (and gnus-nocem-alist
280 gnus-nocem-touched-alist)
281 (nnheader-temp-write (gnus-nocem-cache-file)
282 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
283 (setq gnus-nocem-touched-alist nil)))
285 (defun gnus-nocem-save-active ()
286 "Save the NoCeM active file."
287 (nnheader-temp-write (gnus-nocem-active-file)
288 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
290 (defun gnus-nocem-alist-to-hashtb ()
291 "Create a hashtable from the Message-IDs we have."
292 (let* ((alist gnus-nocem-alist)
293 (pprev (cons nil alist))
295 (expiry (nnmail-days-to-time gnus-nocem-expiry-wait))
297 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
298 (while (setq entry (car alist))
299 (if (not (nnmail-time-less (nnmail-time-since (car entry)) expiry))
300 ;; This entry has expired, so we remove it.
301 (setcdr prev (cdr alist))
303 ;; This is ok, so we enter it into the hashtable.
304 (setq entry (cdr entry))
306 (gnus-sethash (car entry) t gnus-nocem-hashtb)
307 (setq entry (cdr entry))))
308 (setq alist (cdr alist)))))
310 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
312 (defun gnus-nocem-close ()
313 "Clear internal NoCeM variables."
314 (setq gnus-nocem-alist nil
315 gnus-nocem-hashtb nil
316 gnus-nocem-active nil
317 gnus-nocem-touched-alist nil
318 gnus-nocem-seen-message-ids nil
319 gnus-nocem-real-group-hashtb nil))
321 (defun gnus-nocem-unwanted-article-p (id)
322 "Say whether article ID in the current group is wanted."
323 (gnus-gethash id gnus-nocem-hashtb))
325 (provide 'gnus-nocem)
327 ;;; gnus-nocem.el ends here