1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
2 ;; Copyright (C) 1995,96 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 '("alt.nocem.misc" "news.admin.net-abuse.announce")
40 "List of groups that will be searched for NoCeM messages."
42 :type '(repeat (string :tag "Group")))
44 (defcustom gnus-nocem-issuers
45 '("AutoMoose-1" "Automoose-1" ; CancelMoose[tm]
46 "rbraver@ohww.norman.ok.us" ; Robert Braver
47 "clewis@ferret.ocunix.on.ca;" ; Chris Lewis
48 "jem@xpat.com;" ; Despammer from Korea
49 "snowhare@xmission.com" ; Benjamin "Snowhare" Franz
50 "red@redpoll.mrfs.oh.us (Richard E. Depew)"
52 "List of NoCeM issuers to pay attention to."
54 :type '(repeat string))
56 (defcustom gnus-nocem-directory
57 (nnheader-concat gnus-article-save-directory "NoCeM/")
58 "*Directory where NoCeM files will be stored."
62 (defcustom gnus-nocem-expiry-wait 15
63 "*Number of days to keep NoCeM headers in the cache."
67 (defcustom gnus-nocem-verifyer 'mc-verify
68 "*Function called to verify that the NoCeM message is valid.
69 One likely value is `mc-verify'. If the function in this variable
70 isn't bound, the message will be used unconditionally."
72 :type '(radio (function-item mc-verify)
73 (function :tag "other")))
75 (defcustom gnus-nocem-liberal-fetch nil
76 "*If t try to fetch all messages which have @@NCM in the subject.
77 Otherwise don't fetch messages which have references or whose messsage-id
78 matches an previously scanned and verified nocem message."
82 ;;; Internal variables
84 (defvar gnus-nocem-active nil)
85 (defvar gnus-nocem-alist nil)
86 (defvar gnus-nocem-touched-alist nil)
87 (defvar gnus-nocem-hashtb nil)
88 (defvar gnus-nocem-seen-message-ids nil)
92 (defun gnus-nocem-active-file ()
93 (concat (file-name-as-directory gnus-nocem-directory) "active"))
95 (defun gnus-nocem-cache-file ()
96 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
98 (defun gnus-nocem-scan-groups ()
99 "Scan all NoCeM groups for new NoCeM messages."
101 (let ((groups gnus-nocem-groups)
102 group active gactive articles)
103 (gnus-make-directory gnus-nocem-directory)
104 ;; Load any previous NoCeM headers.
105 (gnus-nocem-load-cache)
106 ;; Read the active file if it hasn't been read yet.
107 (and (file-exists-p (gnus-nocem-active-file))
108 (not gnus-nocem-active)
110 (load (gnus-nocem-active-file) t t t)))
111 ;; Go through all groups and see whether new articles have
113 (while (setq group (pop groups))
114 (if (not (setq gactive (gnus-activate-group group)))
115 () ; This group doesn't exist.
116 (setq active (nth 1 (assoc group gnus-nocem-active)))
117 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
119 (< (cdr active) (cdr gactive))))
120 ;; Ok, there are new articles in this group, se we fetch the
123 (let ((dependencies (make-vector 10 nil))
125 (nnheader-temp-write nil
128 (gnus-retrieve-headers
130 (gnus-uncompress-range
132 (if active (1+ (cdr active))
136 (gnus-get-newsgroup-headers-xover
137 articles nil dependencies)
138 (gnus-get-newsgroup-headers dependencies)))
139 (while (setq header (pop headers))
140 ;; We take a closer look on all articles that have
141 ;; "@@NCM" in the subject. Unless we already read
142 ;; this cross posted message. Nocem messages
143 ;; are not allowed to have references, so we can
144 ;; ignore scanning followups.
145 (and (string-match "@@NCM" (mail-header-subject header))
146 (or gnus-nocem-liberal-fetch
147 (and (string= "" (mail-header-references header))
148 (not (member (mail-header-message-id header)
149 gnus-nocem-seen-message-ids))))
150 (gnus-nocem-check-article group header)))))))
151 (setq gnus-nocem-active
152 (cons (list group gactive)
153 (delq (assoc group gnus-nocem-active)
154 gnus-nocem-active)))))
155 ;; Save the results, if any.
156 (gnus-nocem-save-cache)
157 (gnus-nocem-save-active)))
159 (defun gnus-nocem-check-article (group header)
160 "Check whether the current article is an NCM article and that we want it."
162 (gnus-message 7 "Checking article %d in %s for NoCeM..."
163 (mail-header-number header) group)
164 (let ((date (mail-header-date header))
168 (nnmail-time-since (nnmail-date-to-time date))
169 (nnmail-days-to-time gnus-nocem-expiry-wait)))
170 (gnus-request-article-this-buffer (mail-header-number header) group)
171 (goto-char (point-min))
172 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
173 (delete-region (point-min) (match-beginning 0)))
174 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
175 (delete-region (match-end 0) (point-max)))
176 (goto-char (point-min))
177 ;; The article has to have proper NoCeM headers.
178 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
179 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
180 ;; We get the name of the issuer.
181 (narrow-to-region b e)
182 (setq issuer (mail-fetch-field "issuer"))
184 (and (member issuer gnus-nocem-issuers) ; We like her....
185 (gnus-nocem-verify-issuer issuer) ; She is who she says she is...
186 (gnus-nocem-enter-article) ; We gobble the message..
187 (push (mail-header-message-id header) ; But don't come back for
188 gnus-nocem-seen-message-ids)))))) ; second helpings.
191 (defun gnus-nocem-verify-issuer (person)
192 "Verify using PGP that the canceler is who she says she is."
193 (if (fboundp gnus-nocem-verifyer)
194 (funcall gnus-nocem-verifyer)
195 ;; If we don't have Mailcrypt, then we use the message anyway.
198 (defun gnus-nocem-enter-article ()
199 "Enter the current article into the NoCeM cache."
200 (goto-char (point-min))
201 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
202 (e (search-forward "\n@@END NCM BODY\n" nil t))
203 (buf (current-buffer))
206 (narrow-to-region b (1+ (match-beginning 0)))
207 (goto-char (point-min))
208 (while (search-forward "\t" nil t)
210 (setq group (let ((obarray gnus-active-hashtb)) (read buf))))
211 (if (not (boundp group))
212 ;; Make sure all entries in the hashtb are bound.
214 (when (gnus-gethash (symbol-name group) gnus-newsrc-hashtb)
217 (while (= (following-char) ?\t)
219 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
220 (unless (gnus-gethash id gnus-nocem-hashtb)
221 ;; only store if not already present
222 (gnus-sethash id t gnus-nocem-hashtb)
225 (while (= (following-char) ?\t)
226 (forward-line 1))))))
228 (setq gnus-nocem-touched-alist t)
229 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
234 (defun gnus-nocem-load-cache ()
235 "Load the NoCeM cache."
236 (unless gnus-nocem-alist
237 ;; The buffer doesn't exist, so we create it and load the NoCeM
239 (when (file-exists-p (gnus-nocem-cache-file))
240 (load (gnus-nocem-cache-file) t t t)
241 (gnus-nocem-alist-to-hashtb))))
243 (defun gnus-nocem-save-cache ()
244 "Save the NoCeM cache."
245 (when (and gnus-nocem-alist
246 gnus-nocem-touched-alist)
247 (nnheader-temp-write (gnus-nocem-cache-file)
248 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
249 (setq gnus-nocem-touched-alist nil)))
251 (defun gnus-nocem-save-active ()
252 "Save the NoCeM active file."
253 (nnheader-temp-write (gnus-nocem-active-file)
254 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
256 (defun gnus-nocem-alist-to-hashtb ()
257 "Create a hashtable from the Message-IDs we have."
258 (let* ((alist gnus-nocem-alist)
259 (pprev (cons nil alist))
261 (expiry (nnmail-days-to-time gnus-nocem-expiry-wait))
263 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
264 (while (setq entry (car alist))
265 (if (not (nnmail-time-less (nnmail-time-since (car entry)) expiry))
266 ;; This entry has expired, so we remove it.
267 (setcdr prev (cdr alist))
269 ;; This is ok, so we enter it into the hashtable.
270 (setq entry (cdr entry))
272 (gnus-sethash (car entry) t gnus-nocem-hashtb)
273 (setq entry (cdr entry))))
274 (setq alist (cdr alist)))))
276 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
278 (defun gnus-nocem-close ()
279 "Clear internal NoCeM variables."
280 (setq gnus-nocem-alist nil
281 gnus-nocem-hashtb nil
282 gnus-nocem-active nil
283 gnus-nocem-touched-alist nil
284 gnus-nocem-seen-message-ids nil))
286 (defun gnus-nocem-unwanted-article-p (id)
287 "Say whether article ID in the current group is wanted."
288 (gnus-gethash id gnus-nocem-hashtb))
290 (provide 'gnus-nocem)
292 ;;; gnus-nocem.el ends here