;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment ;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002 ;; Free Software Foundation, Inc. ;; Author: Lars Magne Ingebrigtsen ;; Keywords: news ;; This file is part of GNU Emacs. ;; GNU Emacs is free software; you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation; either version 2, or (at your option) ;; any later version. ;; GNU Emacs is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; You should have received a copy of the GNU General Public License ;; along with GNU Emacs; see the file COPYING. If not, write to the ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, ;; Boston, MA 02111-1307, USA. ;;; Commentary: ;;; Code: (eval-when-compile (require 'cl)) (require 'gnus) (require 'nnmail) (require 'gnus-art) (require 'gnus-sum) (require 'gnus-range) (defgroup gnus-nocem nil "NoCeM pseudo-cancellation treatment" :group 'gnus-score) (defcustom gnus-nocem-groups '("news.lists.filters" "news.admin.net-abuse.bulletins" "alt.nocem.misc" "news.admin.net-abuse.announce") "*List of groups that will be searched for NoCeM messages." :group 'gnus-nocem :type '(repeat (string :tag "Group"))) (defcustom gnus-nocem-issuers '("AutoMoose-1" ; CancelMoose[tm] "clewis@ferret.ocunix" ; Chris Lewis "cosmo.roadkill" "SpamHippo" "hweede@snafu.de") "*List of NoCeM issuers to pay attention to. This can also be a list of `(ISSUER CONDITION ...)' elements. See for an issuer registry." :group 'gnus-nocem :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html") :type '(repeat (choice string sexp))) (defcustom gnus-nocem-directory (nnheader-concat gnus-article-save-directory "NoCeM/") "*Directory where NoCeM files will be stored." :group 'gnus-nocem :type 'directory) (defcustom gnus-nocem-expiry-wait 15 "*Number of days to keep NoCeM headers in the cache." :group 'gnus-nocem :type 'integer) (defcustom gnus-nocem-verifyer 'mc-verify "*Function called to verify that the NoCeM message is valid. One likely value is `mc-verify'. If the function in this variable isn't bound, the message will be used unconditionally." :group 'gnus-nocem :type '(radio (function-item mc-verify) (function :tag "other"))) (defcustom gnus-nocem-liberal-fetch nil "*If t try to fetch all messages which have @@NCM in the subject. Otherwise don't fetch messages which have references or whose message-id matches a previously scanned and verified nocem message." :group 'gnus-nocem :type 'boolean) (defcustom gnus-nocem-check-article-limit 500 "*If non-nil, the maximum number of articles to check in any NoCeM group." :group 'gnus-nocem :version "21.1" :type '(choice (const :tag "unlimited" nil) (integer 1000))) (defcustom gnus-nocem-check-from t "Non-nil means check for valid issuers in message bodies. Otherwise don't bother fetching articles unless their author matches a valid issuer, which is much faster if you are selective about the issuers." :group 'gnus-nocem :version "21.1" :type 'boolean) ;;; Internal variables (defvar gnus-nocem-active nil) (defvar gnus-nocem-alist nil) (defvar gnus-nocem-touched-alist nil) (defvar gnus-nocem-hashtb nil) (defvar gnus-nocem-seen-message-ids nil) ;;; Functions (defun gnus-nocem-active-file () (concat (file-name-as-directory gnus-nocem-directory) "active")) (defun gnus-nocem-cache-file () (concat (file-name-as-directory gnus-nocem-directory) "cache")) ;; ;; faster lookups for group names: ;; (defvar gnus-nocem-real-group-hashtb nil "Real-name mappings of subscribed groups.") (defun gnus-fill-real-hashtb () "Fill up a hash table with the real-name mappings from the user's active file." (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable (length gnus-newsrc-alist))) (mapcar (lambda (group) (setq group (gnus-group-real-name (car group))) (gnus-sethash group t gnus-nocem-real-group-hashtb)) gnus-newsrc-alist)) (defun gnus-nocem-scan-groups () "Scan all NoCeM groups for new NoCeM messages." (interactive) (let ((groups gnus-nocem-groups) (gnus-inhibit-demon t) group active gactive articles check-headers) (gnus-make-directory gnus-nocem-directory) ;; Load any previous NoCeM headers. (gnus-nocem-load-cache) ;; Get the group name mappings: (gnus-fill-real-hashtb) ;; Read the active file if it hasn't been read yet. (and (file-exists-p (gnus-nocem-active-file)) (not gnus-nocem-active) (ignore-errors (load (gnus-nocem-active-file) t t t))) ;; Go through all groups and see whether new articles have ;; arrived. (while (setq group (pop groups)) (if (not (setq gactive (gnus-activate-group group))) () ; This group doesn't exist. (setq active (nth 1 (assoc group gnus-nocem-active))) (when (and (not (< (cdr gactive) (car gactive))) ; Empty group. (or (not active) (< (cdr active) (cdr gactive)))) ;; Ok, there are new articles in this group, se we fetch the ;; headers. (save-excursion (let ((dependencies (make-vector 10 nil)) headers header) (with-temp-buffer (setq headers (if (eq 'nov (gnus-retrieve-headers (setq articles (gnus-uncompress-range (cons (if active (1+ (cdr active)) (car gactive)) (cdr gactive)))) group)) (gnus-get-newsgroup-headers-xover articles nil dependencies) (gnus-get-newsgroup-headers dependencies))) (while (setq header (pop headers)) ;; We take a closer look on all articles that have ;; "@@NCM" in the subject. Unless we already read ;; this cross posted message. Nocem messages ;; are not allowed to have references, so we can ;; ignore scanning followups. (and (string-match "@@NCM" (mail-header-subject header)) (and gnus-nocem-check-from (let ((case-fold-search t)) (catch 'ok (mapcar (lambda (author) (if (consp author) (setq author (car author))) (if (string-match author (mail-header-from header)) (throw 'ok t))) gnus-nocem-issuers) nil))) (or gnus-nocem-liberal-fetch (and (or (string= "" (mail-header-references header)) (null (mail-header-references header))) (not (member (mail-header-message-id header) gnus-nocem-seen-message-ids)))) (push header check-headers))) (let* ((i 0) (check-headers (last check-headers gnus-nocem-check-article-limit)) (len (length check-headers))) (dolist (h check-headers) (gnus-message 7 "Checking article %d in %s for NoCeM (%d of %d)..." (mail-header-number h) group (incf i) len) (gnus-nocem-check-article group h))))))) (setq gnus-nocem-active (cons (list group gactive) (delq (assoc group gnus-nocem-active) gnus-nocem-active))))) ;; Save the results, if any. (gnus-nocem-save-cache) (gnus-nocem-save-active))) (defun gnus-nocem-check-article (group header) "Check whether the current article is an NCM article and that we want it." ;; Get the article. (let ((date (mail-header-date header)) (gnus-newsgroup-name group) issuer b e type) (when (or (not date) (time-less-p (time-since (date-to-time date)) (days-to-time gnus-nocem-expiry-wait))) (gnus-request-article-this-buffer (mail-header-number header) group) (goto-char (point-min)) (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t) (delete-region (point-min) (match-beginning 0))) (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t) (delete-region (match-end 0) (point-max))) (goto-char (point-min)) ;; The article has to have proper NoCeM headers. (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t)) (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t))) ;; We get the name of the issuer. (narrow-to-region b e) (setq issuer (mail-fetch-field "issuer") type (mail-fetch-field "issuer")) (widen) (if (not (gnus-nocem-message-wanted-p issuer type)) (message "invalid NoCeM issuer: %s" issuer) (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is. (gnus-nocem-enter-article) ; We gobble the message. (push (mail-header-message-id header) ; But don't come back for gnus-nocem-seen-message-ids))))))) ; second helpings. (defun gnus-nocem-message-wanted-p (issuer type) (let ((issuers gnus-nocem-issuers) wanted conditions condition) (cond ;; Do the quick check first. ((member issuer issuers) t) ((setq conditions (cdr (assoc issuer issuers))) ;; Check whether we want this type. (while (setq condition (pop conditions)) (cond ((stringp condition) (setq wanted (string-match condition type))) ((and (consp condition) (eq (car condition) 'not) (stringp (cadr condition))) (setq wanted (not (string-match (cadr condition) type)))) (t (error "Invalid NoCeM condition: %S" condition)))) wanted)))) (defun gnus-nocem-verify-issuer (person) "Verify using PGP that the canceler is who she says she is." (if (fboundp gnus-nocem-verifyer) (ignore-errors (funcall gnus-nocem-verifyer)) ;; If we don't have Mailcrypt, then we use the message anyway. t)) (defun gnus-nocem-enter-article () "Enter the current article into the NoCeM cache." (goto-char (point-min)) (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t)) (e (search-forward "\n@@END NCM BODY\n" nil t)) (buf (current-buffer)) ncm id group) (when (and b e) (narrow-to-region b (1+ (match-beginning 0))) (goto-char (point-min)) (while (search-forward "\t" nil t) (cond ((not (ignore-errors (setq group (let ((obarray gnus-active-hashtb)) (read buf))))) ;; An error. ) ((not (symbolp group)) ;; Ignore invalid entries. ) ((not (boundp group)) ;; Make sure all entries in the hashtb are bound. (set group nil)) (t (when (gnus-gethash (gnus-group-real-name (symbol-name group)) gnus-nocem-real-group-hashtb) ;; Valid group. (beginning-of-line) (while (eq (char-after) ?\t) (forward-line -1)) (setq id (buffer-substring (point) (1- (search-forward "\t")))) (unless (gnus-gethash id gnus-nocem-hashtb) ;; only store if not already present (gnus-sethash id t gnus-nocem-hashtb) (push id ncm)) (forward-line 1) (while (eq (char-after) ?\t) (forward-line 1)))))) (when ncm (setq gnus-nocem-touched-alist t) (push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time) ncm) gnus-nocem-alist)) t))) (defun gnus-nocem-load-cache () "Load the NoCeM cache." (interactive) (unless gnus-nocem-alist ;; The buffer doesn't exist, so we create it and load the NoCeM ;; cache. (when (file-exists-p (gnus-nocem-cache-file)) (load (gnus-nocem-cache-file) t t t) (gnus-nocem-alist-to-hashtb)))) (defun gnus-nocem-save-cache () "Save the NoCeM cache." (when (and gnus-nocem-alist gnus-nocem-touched-alist) (with-temp-file (gnus-nocem-cache-file) (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist))) (setq gnus-nocem-touched-alist nil))) (defun gnus-nocem-save-active () "Save the NoCeM active file." (with-temp-file (gnus-nocem-active-file) (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active)))) (defun gnus-nocem-alist-to-hashtb () "Create a hashtable from the Message-IDs we have." (let* ((alist gnus-nocem-alist) (pprev (cons nil alist)) (prev pprev) (expiry (days-to-time gnus-nocem-expiry-wait)) entry) (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51))) (while (setq entry (car alist)) (if (not (time-less-p (time-since (car entry)) expiry)) ;; This entry has expired, so we remove it. (setcdr prev (cdr alist)) (setq prev alist) ;; This is ok, so we enter it into the hashtable. (setq entry (cdr entry)) (while entry (gnus-sethash (car entry) t gnus-nocem-hashtb) (setq entry (cdr entry)))) (setq alist (cdr alist))))) (gnus-add-shutdown 'gnus-nocem-close 'gnus) (defun gnus-nocem-close () "Clear internal NoCeM variables." (setq gnus-nocem-alist nil gnus-nocem-hashtb nil gnus-nocem-active nil gnus-nocem-touched-alist nil gnus-nocem-seen-message-ids nil gnus-nocem-real-group-hashtb nil)) (defun gnus-nocem-unwanted-article-p (id) "Say whether article ID in the current group is wanted." (and gnus-nocem-hashtb (gnus-gethash id gnus-nocem-hashtb))) (provide 'gnus-nocem) ;;; gnus-nocem.el ends here