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"))
99 (defun gnus-nocem-scan-groups ()
100 "Scan all NoCeM groups for new NoCeM messages."
102 (let ((groups gnus-nocem-groups)
103 group active gactive articles)
104 (gnus-make-directory gnus-nocem-directory)
105 ;; Load any previous NoCeM headers.
106 (gnus-nocem-load-cache)
107 ;; Read the active file if it hasn't been read yet.
108 (and (file-exists-p (gnus-nocem-active-file))
109 (not gnus-nocem-active)
111 (load (gnus-nocem-active-file) t t t)))
112 ;; Go through all groups and see whether new articles have
114 (while (setq group (pop groups))
115 (if (not (setq gactive (gnus-activate-group group)))
116 () ; This group doesn't exist.
117 (setq active (nth 1 (assoc group gnus-nocem-active)))
118 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
120 (< (cdr active) (cdr gactive))))
121 ;; Ok, there are new articles in this group, se we fetch the
124 (let ((dependencies (make-vector 10 nil))
126 (nnheader-temp-write nil
129 (gnus-retrieve-headers
131 (gnus-uncompress-range
133 (if active (1+ (cdr active))
137 (gnus-get-newsgroup-headers-xover
138 articles nil dependencies)
139 (gnus-get-newsgroup-headers dependencies)))
140 (while (setq header (pop headers))
141 ;; We take a closer look on all articles that have
142 ;; "@@NCM" in the subject. Unless we already read
143 ;; this cross posted message. Nocem messages
144 ;; are not allowed to have references, so we can
145 ;; ignore scanning followups.
146 (and (string-match "@@NCM" (mail-header-subject header))
147 (or gnus-nocem-liberal-fetch
148 (and (or (string= "" (mail-header-references
150 (null (mail-header-references header)))
151 (not (member (mail-header-message-id header)
152 gnus-nocem-seen-message-ids))))
153 (gnus-nocem-check-article group header)))))))
154 (setq gnus-nocem-active
155 (cons (list group gactive)
156 (delq (assoc group gnus-nocem-active)
157 gnus-nocem-active)))))
158 ;; Save the results, if any.
159 (gnus-nocem-save-cache)
160 (gnus-nocem-save-active)))
162 (defun gnus-nocem-check-article (group header)
163 "Check whether the current article is an NCM article and that we want it."
165 (gnus-message 7 "Checking article %d in %s for NoCeM..."
166 (mail-header-number header) group)
167 (let ((date (mail-header-date header))
171 (nnmail-time-since (nnmail-date-to-time date))
172 (nnmail-days-to-time gnus-nocem-expiry-wait)))
173 (gnus-request-article-this-buffer (mail-header-number header) group)
174 (goto-char (point-min))
175 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
176 (delete-region (point-min) (match-beginning 0)))
177 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
178 (delete-region (match-end 0) (point-max)))
179 (goto-char (point-min))
180 ;; The article has to have proper NoCeM headers.
181 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
182 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
183 ;; We get the name of the issuer.
184 (narrow-to-region b e)
185 (setq issuer (mail-fetch-field "issuer"))
187 (and (member issuer gnus-nocem-issuers) ; We like her....
188 (gnus-nocem-verify-issuer issuer) ; She is who she says she is...
189 (gnus-nocem-enter-article) ; We gobble the message..
190 (push (mail-header-message-id header) ; But don't come back for
191 gnus-nocem-seen-message-ids)))))) ; second helpings.
193 (defun gnus-nocem-verify-issuer (person)
194 "Verify using PGP that the canceler is who she says she is."
195 (if (fboundp gnus-nocem-verifyer)
196 (funcall gnus-nocem-verifyer)
197 ;; If we don't have Mailcrypt, then we use the message anyway.
200 (defun gnus-nocem-enter-article ()
201 "Enter the current article into the NoCeM cache."
202 (goto-char (point-min))
203 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
204 (e (search-forward "\n@@END NCM BODY\n" nil t))
205 (buf (current-buffer))
208 (narrow-to-region b (1+ (match-beginning 0)))
209 (goto-char (point-min))
210 (while (search-forward "\t" nil t)
213 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
216 ((not (symbolp group))
217 ;; Ignore invalid entries.
219 ((not (boundp group))
220 ;; Make sure all entries in the hashtb are bound.
223 (when (gnus-gethash (symbol-name group) gnus-newsrc-hashtb)
226 (while (= (following-char) ?\t)
228 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
229 (unless (gnus-gethash id gnus-nocem-hashtb)
230 ;; only store if not already present
231 (gnus-sethash id t gnus-nocem-hashtb)
234 (while (= (following-char) ?\t)
235 (forward-line 1))))))
237 (setq gnus-nocem-touched-alist t)
238 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
243 (defun gnus-nocem-load-cache ()
244 "Load the NoCeM cache."
246 (unless gnus-nocem-alist
247 ;; The buffer doesn't exist, so we create it and load the NoCeM
249 (when (file-exists-p (gnus-nocem-cache-file))
250 (load (gnus-nocem-cache-file) t t t)
251 (gnus-nocem-alist-to-hashtb))))
253 (defun gnus-nocem-save-cache ()
254 "Save the NoCeM cache."
255 (when (and gnus-nocem-alist
256 gnus-nocem-touched-alist)
257 (nnheader-temp-write (gnus-nocem-cache-file)
258 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
259 (setq gnus-nocem-touched-alist nil)))
261 (defun gnus-nocem-save-active ()
262 "Save the NoCeM active file."
263 (nnheader-temp-write (gnus-nocem-active-file)
264 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
266 (defun gnus-nocem-alist-to-hashtb ()
267 "Create a hashtable from the Message-IDs we have."
268 (let* ((alist gnus-nocem-alist)
269 (pprev (cons nil alist))
271 (expiry (nnmail-days-to-time gnus-nocem-expiry-wait))
273 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
274 (while (setq entry (car alist))
275 (if (not (nnmail-time-less (nnmail-time-since (car entry)) expiry))
276 ;; This entry has expired, so we remove it.
277 (setcdr prev (cdr alist))
279 ;; This is ok, so we enter it into the hashtable.
280 (setq entry (cdr entry))
282 (gnus-sethash (car entry) t gnus-nocem-hashtb)
283 (setq entry (cdr entry))))
284 (setq alist (cdr alist)))))
286 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
288 (defun gnus-nocem-close ()
289 "Clear internal NoCeM variables."
290 (setq gnus-nocem-alist nil
291 gnus-nocem-hashtb nil
292 gnus-nocem-active nil
293 gnus-nocem-touched-alist nil
294 gnus-nocem-seen-message-ids nil))
296 (defun gnus-nocem-unwanted-article-p (id)
297 "Say whether article ID in the current group is wanted."
298 (gnus-gethash id gnus-nocem-hashtb))
300 (provide 'gnus-nocem)
302 ;;; gnus-nocem.el ends here