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.
33 (defgroup gnus-nocem nil
34 "NoCeM pseudo-cancellation treatment"
37 (defcustom gnus-nocem-groups
38 '("alt.nocem.misc" "news.admin.net-abuse.announce")
39 "List of groups that will be searched for NoCeM messages."
41 :type '(repeat (string :tag "Group")))
43 (defcustom gnus-nocem-issuers
44 '("AutoMoose-1" "Automoose-1" ; CancelMoose[tm]
45 "rbraver@ohww.norman.ok.us" ; Robert Braver
46 "clewis@ferret.ocunix.on.ca;" ; Chris Lewis
47 "jem@xpat.com;" ; Despammer from Korea
48 "snowhare@xmission.com" ; Benjamin "Snowhare" Franz
49 "red@redpoll.mrfs.oh.us (Richard E. Depew)"
51 "List of NoCeM issuers to pay attention to."
53 :type '(repeat string))
55 (defcustom gnus-nocem-directory
56 (nnheader-concat gnus-article-save-directory "NoCeM/")
57 "*Directory where NoCeM files will be stored."
61 (defcustom gnus-nocem-expiry-wait 15
62 "*Number of days to keep NoCeM headers in the cache."
66 (defcustom gnus-nocem-verifyer 'mc-verify
67 "*Function called to verify that the NoCeM message is valid.
68 One likely value is `mc-verify'. If the function in this variable
69 isn't bound, the message will be used unconditionally."
71 :type '(radio (function-item mc-verify)
72 (function :tag "other")))
74 ;;; Internal variables
76 (defvar gnus-nocem-active nil)
77 (defvar gnus-nocem-alist nil)
78 (defvar gnus-nocem-touched-alist nil)
79 (defvar gnus-nocem-hashtb nil)
83 (defun gnus-nocem-active-file ()
84 (concat (file-name-as-directory gnus-nocem-directory) "active"))
86 (defun gnus-nocem-cache-file ()
87 (concat (file-name-as-directory gnus-nocem-directory) "cache"))
89 (defun gnus-nocem-scan-groups ()
90 "Scan all NoCeM groups for new NoCeM messages."
92 (let ((groups gnus-nocem-groups)
93 group active gactive articles)
94 (gnus-make-directory gnus-nocem-directory)
95 ;; Load any previous NoCeM headers.
96 (gnus-nocem-load-cache)
97 ;; Read the active file if it hasn't been read yet.
98 (and (file-exists-p (gnus-nocem-active-file))
99 (not gnus-nocem-active)
101 (load (gnus-nocem-active-file) t t t)
103 ;; Go through all groups and see whether new articles have
105 (while (setq group (pop groups))
106 (if (not (setq gactive (gnus-activate-group group)))
107 () ; This group doesn't exist.
108 (setq active (nth 1 (assoc group gnus-nocem-active)))
109 (when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
111 (< (cdr active) (cdr gactive))))
112 ;; Ok, there are new articles in this group, se we fetch the
115 (let ((dependencies (make-vector 10 nil))
117 (nnheader-temp-write nil
120 (gnus-retrieve-headers
122 (gnus-uncompress-range
124 (if active (1+ (cdr active))
128 (gnus-get-newsgroup-headers-xover
129 articles nil dependencies)
130 (gnus-get-newsgroup-headers dependencies)))
132 ;; We take a closer look on all articles that have
133 ;; "@@NCM" in the subject.
134 (when (string-match "@@NCM"
135 (mail-header-subject (car headers)))
136 (gnus-nocem-check-article group (car headers)))
137 (setq headers (cdr headers)))))))
138 (setq gnus-nocem-active
139 (cons (list group gactive)
140 (delq (assoc group gnus-nocem-active)
141 gnus-nocem-active)))))
142 ;; Save the results, if any.
143 (gnus-nocem-save-cache)
144 (gnus-nocem-save-active)))
146 (defun gnus-nocem-check-article (group header)
147 "Check whether the current article is an NCM article and that we want it."
149 (gnus-message 7 "Checking article %d in %s for NoCeM..."
150 (mail-header-number header) group)
151 (let ((date (mail-header-date header))
155 (nnmail-time-since (nnmail-date-to-time date))
156 (nnmail-days-to-time gnus-nocem-expiry-wait)))
157 (gnus-request-article-this-buffer (mail-header-number header) group)
158 (goto-char (point-min))
159 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
160 (delete-region (point-min) (match-beginning 0)))
161 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
162 (delete-region (match-end 0) (point-max)))
163 (goto-char (point-min))
164 ;; The article has to have proper NoCeM headers.
165 (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
166 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
167 ;; We get the name of the issuer.
168 (narrow-to-region b e)
169 (setq issuer (mail-fetch-field "issuer"))
171 (and (member issuer gnus-nocem-issuers) ; We like her...
172 (gnus-nocem-verify-issuer issuer) ; She is who she says she is..
173 (gnus-nocem-enter-article)))))) ; We gobble the message.
175 (defun gnus-nocem-verify-issuer (person)
176 "Verify using PGP that the canceler is who she says she is."
177 (if (fboundp gnus-nocem-verifyer)
178 (funcall gnus-nocem-verifyer)
179 ;; If we don't have Mailcrypt, then we use the message anyway.
182 (defun gnus-nocem-enter-article ()
183 "Enter the current article into the NoCeM cache."
184 (goto-char (point-min))
185 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
186 (e (search-forward "\n@@END NCM BODY\n" nil t))
187 (buf (current-buffer))
190 (narrow-to-region b (1+ (match-beginning 0)))
191 (goto-char (point-min))
192 (while (search-forward "\t" nil t)
194 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))
196 (if (not (boundp group))
197 ;; Make sure all entries in the hashtb are bound.
199 (when (gnus-gethash (symbol-name group) gnus-newsrc-hashtb)
202 (while (= (following-char) ?\t)
204 (setq id (buffer-substring (point) (1- (search-forward "\t"))))
206 (gnus-sethash id t gnus-nocem-hashtb)
208 (while (= (following-char) ?\t)
211 (setq gnus-nocem-touched-alist t)
212 (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
214 gnus-nocem-alist)))))
216 (defun gnus-nocem-load-cache ()
217 "Load the NoCeM cache."
218 (unless gnus-nocem-alist
219 ;; The buffer doesn't exist, so we create it and load the NoCeM
221 (when (file-exists-p (gnus-nocem-cache-file))
222 (load (gnus-nocem-cache-file) t t t)
223 (gnus-nocem-alist-to-hashtb))))
225 (defun gnus-nocem-save-cache ()
226 "Save the NoCeM cache."
227 (when (and gnus-nocem-alist
228 gnus-nocem-touched-alist)
229 (nnheader-temp-write (gnus-nocem-cache-file)
230 (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
231 (setq gnus-nocem-touched-alist nil)))
233 (defun gnus-nocem-save-active ()
234 "Save the NoCeM active file."
235 (nnheader-temp-write (gnus-nocem-active-file)
236 (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
238 (defun gnus-nocem-alist-to-hashtb ()
239 "Create a hashtable from the Message-IDs we have."
240 (let* ((alist gnus-nocem-alist)
241 (pprev (cons nil alist))
243 (expiry (nnmail-days-to-time gnus-nocem-expiry-wait))
245 (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
246 (while (setq entry (car alist))
247 (if (not (nnmail-time-less (nnmail-time-since (car entry)) expiry))
248 ;; This entry has expired, so we remove it.
249 (setcdr prev (cdr alist))
251 ;; This is ok, so we enter it into the hashtable.
252 (setq entry (cdr entry))
254 (gnus-sethash (car entry) t gnus-nocem-hashtb)
255 (setq entry (cdr entry))))
256 (setq alist (cdr alist)))))
258 (gnus-add-shutdown 'gnus-nocem-close 'gnus)
260 (defun gnus-nocem-close ()
261 "Clear internal NoCeM variables."
262 (setq gnus-nocem-alist nil
263 gnus-nocem-hashtb nil
264 gnus-nocem-active nil
265 gnus-nocem-touched-alist nil))
267 (defun gnus-nocem-unwanted-article-p (id)
268 "Say whether article ID in the current group is wanted."
269 (gnus-gethash id gnus-nocem-hashtb))
271 (provide 'gnus-nocem)
273 ;;; gnus-nocem.el ends here