1 ;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
2 ;; Copyright (C) 1995,96,97,98 Free Software Foundation, Inc.
4 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
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.
28 (eval-when-compile (require 'cl
))
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" "Automoose-1" ; CancelMoose[tm]
51 "rbraver@ohww.norman.ok.us" ; Robert Braver
52 "clewis@ferret.ocunix.on.ca" ; Chris Lewis
53 "jem@xpat.com" ; Despammer from Korea
54 "snowhare@xmission.com" ; Benjamin "Snowhare" Franz
55 "red@redpoll.mrfs.oh.us (Richard E. Depew)" ; ARMM! ARMM!
57 "*List of NoCeM issuers to pay attention to.
59 This can also be a list of `(ISSUER CONDITIONS)' elements."
61 :type
'(repeat (choice string sexp
)))
63 (defcustom gnus-nocem-directory
64 (nnheader-concat gnus-article-save-directory
"NoCeM/")
65 "*Directory where NoCeM files will be stored."
69 (defcustom gnus-nocem-expiry-wait
15
70 "*Number of days to keep NoCeM headers in the cache."
74 (defcustom gnus-nocem-verifyer
'mc-verify
75 "*Function called to verify that the NoCeM message is valid.
76 One likely value is `mc-verify'. If the function in this variable
77 isn't bound, the message will be used unconditionally."
79 :type
'(radio (function-item mc-verify
)
80 (function :tag
"other")))
82 (defcustom gnus-nocem-liberal-fetch nil
83 "*If t try to fetch all messages which have @@NCM in the subject.
84 Otherwise don't fetch messages which have references or whose message-id
85 matches an previously scanned and verified nocem message."
89 ;;; Internal variables
91 (defvar gnus-nocem-active nil
)
92 (defvar gnus-nocem-alist nil
)
93 (defvar gnus-nocem-touched-alist nil
)
94 (defvar gnus-nocem-hashtb nil
)
95 (defvar gnus-nocem-seen-message-ids nil
)
99 (defun gnus-nocem-active-file ()
100 (concat (file-name-as-directory gnus-nocem-directory
) "active"))
102 (defun gnus-nocem-cache-file ()
103 (concat (file-name-as-directory gnus-nocem-directory
) "cache"))
106 ;; faster lookups for group names:
109 (defvar gnus-nocem-real-group-hashtb nil
110 "Real-name mappings of subscribed groups.")
112 (defun gnus-fill-real-hashtb ()
113 "Fill up a hash table with the real-name mappings from the user's active file."
114 (setq gnus-nocem-real-group-hashtb
(gnus-make-hashtable
115 (length gnus-newsrc-alist
)))
116 (mapcar (lambda (group)
117 (setq group
(gnus-group-real-name (car group
)))
118 (gnus-sethash group t gnus-nocem-real-group-hashtb
))
121 (defun gnus-nocem-scan-groups ()
122 "Scan all NoCeM groups for new NoCeM messages."
124 (let ((groups gnus-nocem-groups
)
125 (gnus-inhibit-demon t
)
126 group active gactive articles
)
127 (gnus-make-directory gnus-nocem-directory
)
128 ;; Load any previous NoCeM headers.
129 (gnus-nocem-load-cache)
130 ;; Get the group name mappings:
131 (gnus-fill-real-hashtb)
132 ;; Read the active file if it hasn't been read yet.
133 (and (file-exists-p (gnus-nocem-active-file))
134 (not gnus-nocem-active
)
136 (load (gnus-nocem-active-file) t t t
)))
137 ;; Go through all groups and see whether new articles have
139 (while (setq group
(pop groups
))
140 (if (not (setq gactive
(gnus-activate-group group
)))
141 () ; This group doesn't exist.
142 (setq active
(nth 1 (assoc group gnus-nocem-active
)))
143 (when (and (not (< (cdr gactive
) (car gactive
))) ; Empty group.
145 (< (cdr active
) (cdr gactive
))))
146 ;; Ok, there are new articles in this group, se we fetch the
149 (let ((dependencies (make-vector 10 nil
))
151 (nnheader-temp-write nil
154 (gnus-retrieve-headers
156 (gnus-uncompress-range
158 (if active
(1+ (cdr active
))
162 (gnus-get-newsgroup-headers-xover
163 articles nil dependencies
)
164 (gnus-get-newsgroup-headers dependencies
)))
165 (while (setq header
(pop headers
))
166 ;; We take a closer look on all articles that have
167 ;; "@@NCM" in the subject. Unless we already read
168 ;; this cross posted message. Nocem messages
169 ;; are not allowed to have references, so we can
170 ;; ignore scanning followups.
171 (and (string-match "@@NCM" (mail-header-subject header
))
172 (or gnus-nocem-liberal-fetch
173 (and (or (string= "" (mail-header-references
175 (null (mail-header-references header
)))
176 (not (member (mail-header-message-id header
)
177 gnus-nocem-seen-message-ids
))))
178 (gnus-nocem-check-article group header
)))))))
179 (setq gnus-nocem-active
180 (cons (list group gactive
)
181 (delq (assoc group gnus-nocem-active
)
182 gnus-nocem-active
)))))
183 ;; Save the results, if any.
184 (gnus-nocem-save-cache)
185 (gnus-nocem-save-active)))
187 (defun gnus-nocem-check-article (group header
)
188 "Check whether the current article is an NCM article and that we want it."
190 (gnus-message 7 "Checking article %d in %s for NoCeM..."
191 (mail-header-number header
) group
)
192 (let ((date (mail-header-date header
))
196 (nnmail-time-since (nnmail-date-to-time date
))
197 (nnmail-days-to-time gnus-nocem-expiry-wait
)))
198 (gnus-request-article-this-buffer (mail-header-number header
) group
)
199 (goto-char (point-min))
200 (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t
)
201 (delete-region (point-min) (match-beginning 0)))
202 (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t
)
203 (delete-region (match-end 0) (point-max)))
204 (goto-char (point-min))
205 ;; The article has to have proper NoCeM headers.
206 (when (and (setq b
(search-forward "\n@@BEGIN NCM HEADERS\n" nil t
))
207 (setq e
(search-forward "\n@@BEGIN NCM BODY\n" nil t
)))
208 ;; We get the name of the issuer.
209 (narrow-to-region b e
)
210 (setq issuer
(mail-fetch-field "issuer")
211 type
(mail-fetch-field "issuer"))
213 (if (not (gnus-nocem-message-wanted-p issuer type
))
214 (message "invalid NoCeM issuer: %s" issuer
)
215 (and (gnus-nocem-verify-issuer issuer
) ; She is who she says she is.
216 (gnus-nocem-enter-article) ; We gobble the message.
217 (push (mail-header-message-id header
) ; But don't come back for
218 gnus-nocem-seen-message-ids
))))))) ; second helpings.
220 (defun gnus-nocem-message-wanted-p (issuer type
)
221 (let ((issuers gnus-nocem-issuers
)
222 wanted conditions condition
)
224 ;; Do the quick check first.
225 ((member issuer issuers
)
227 ((setq conditions
(cdr (assoc issuer issuers
)))
228 ;; Check whether we want this type.
229 (while (setq condition
(pop conditions
))
232 (setq wanted
(string-match condition type
)))
233 ((and (consp condition
)
234 (eq (car condition
) 'not
)
235 (stringp (cadr condition
)))
236 (setq wanted
(not (string-match (cadr condition
) type
))))
238 (error "Invalid NoCeM condition: %S" condition
))))
241 (defun gnus-nocem-verify-issuer (person)
242 "Verify using PGP that the canceler is who she says she is."
243 (if (fboundp gnus-nocem-verifyer
)
245 (funcall gnus-nocem-verifyer
))
246 ;; If we don't have Mailcrypt, then we use the message anyway.
249 (defun gnus-nocem-enter-article ()
250 "Enter the current article into the NoCeM cache."
251 (goto-char (point-min))
252 (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t
))
253 (e (search-forward "\n@@END NCM BODY\n" nil t
))
254 (buf (current-buffer))
257 (narrow-to-region b
(1+ (match-beginning 0)))
258 (goto-char (point-min))
259 (while (search-forward "\t" nil t
)
262 (setq group
(let ((obarray gnus-active-hashtb
)) (read buf
)))))
265 ((not (symbolp group
))
266 ;; Ignore invalid entries.
268 ((not (boundp group
))
269 ;; Make sure all entries in the hashtb are bound.
272 (when (gnus-gethash (gnus-group-real-name (symbol-name group
))
273 gnus-nocem-real-group-hashtb
)
276 (while (= (following-char) ?
\t)
278 (setq id
(buffer-substring (point) (1- (search-forward "\t"))))
279 (unless (gnus-gethash id gnus-nocem-hashtb
)
280 ;; only store if not already present
281 (gnus-sethash id t gnus-nocem-hashtb
)
284 (while (= (following-char) ?
\t)
285 (forward-line 1))))))
287 (setq gnus-nocem-touched-alist t
)
288 (push (cons (let ((time (current-time))) (setcdr (cdr time
) nil
) time
)
293 (defun gnus-nocem-load-cache ()
294 "Load the NoCeM cache."
296 (unless gnus-nocem-alist
297 ;; The buffer doesn't exist, so we create it and load the NoCeM
299 (when (file-exists-p (gnus-nocem-cache-file))
300 (load (gnus-nocem-cache-file) t t t
)
301 (gnus-nocem-alist-to-hashtb))))
303 (defun gnus-nocem-save-cache ()
304 "Save the NoCeM cache."
305 (when (and gnus-nocem-alist
306 gnus-nocem-touched-alist
)
307 (nnheader-temp-write (gnus-nocem-cache-file)
308 (gnus-prin1 `(setq gnus-nocem-alist
',gnus-nocem-alist
)))
309 (setq gnus-nocem-touched-alist nil
)))
311 (defun gnus-nocem-save-active ()
312 "Save the NoCeM active file."
313 (nnheader-temp-write (gnus-nocem-active-file)
314 (gnus-prin1 `(setq gnus-nocem-active
',gnus-nocem-active
))))
316 (defun gnus-nocem-alist-to-hashtb ()
317 "Create a hashtable from the Message-IDs we have."
318 (let* ((alist gnus-nocem-alist
)
319 (pprev (cons nil alist
))
321 (expiry (nnmail-days-to-time gnus-nocem-expiry-wait
))
323 (setq gnus-nocem-hashtb
(gnus-make-hashtable (* (length alist
) 51)))
324 (while (setq entry
(car alist
))
325 (if (not (nnmail-time-less (nnmail-time-since (car entry
)) expiry
))
326 ;; This entry has expired, so we remove it.
327 (setcdr prev
(cdr alist
))
329 ;; This is ok, so we enter it into the hashtable.
330 (setq entry
(cdr entry
))
332 (gnus-sethash (car entry
) t gnus-nocem-hashtb
)
333 (setq entry
(cdr entry
))))
334 (setq alist
(cdr alist
)))))
336 (gnus-add-shutdown 'gnus-nocem-close
'gnus
)
338 (defun gnus-nocem-close ()
339 "Clear internal NoCeM variables."
340 (setq gnus-nocem-alist nil
341 gnus-nocem-hashtb nil
342 gnus-nocem-active nil
343 gnus-nocem-touched-alist nil
344 gnus-nocem-seen-message-ids nil
345 gnus-nocem-real-group-hashtb nil
))
347 (defun gnus-nocem-unwanted-article-p (id)
348 "Say whether article ID in the current group is wanted."
349 (and gnus-nocem-hashtb
350 (gnus-gethash id gnus-nocem-hashtb
)))
352 (provide 'gnus-nocem
)
354 ;;; gnus-nocem.el ends here