;;; Commentary:
+;;; This module addresses a few aspects of spam control under Gnus. Page
+;;; breaks are used for grouping declarations and documentation relating to
+;;; each particular aspect.
+
+;;; The integration with Gnus is not yet complete. See various `FIXME'
+;;; comments, below, for supplementary explanations or discussions.
+
;;; Code:
+(require 'gnus-sum)
+
+;; FIXME! We should not require `dns' nor `message' until we actually
+;; need them. Best would be to declare needed functions as auto-loadable.
(require 'dns)
(require 'message)
-(defvar spam-blackhole-servers
- '("bl.spamcop.net" "relays.ordb.org" "dev.null.dk"
- "relays.visi.com" "rbl.maps.vix.com")
+(autoload 'bbdb-records "bbdb-com")
+
+;; Attempt to load BBDB macros
+(eval-when-compile
+ (condition-case nil
+ (require 'bbdb-com)
+ (file-error (defalias 'bbdb-search 'ignore))))
+
+;; autoload executable-find
+(eval-and-compile
+ ;; executable-find is not autoloaded in Emacs 20
+ (autoload 'executable-find "executable"))
+
+;; autoload ifile-spam-filter
+(eval-and-compile
+ (autoload 'ifile-spam-filter "ifile-gnus"))
+
+;;; Main parameters.
+
+(defvar spam-use-blacklist t
+ "True if the blacklist should be used.")
+
+(defvar spam-use-whitelist t
+ "True if the whitelist should be used.")
+
+(defvar spam-use-blackholes nil
+ ;; FIXME! Turned off for now. The DNS routines are said to be flaky.
+ "True if blackholes should be used.")
+
+(defvar spam-use-bogofilter t
+ "True if bogofilter should be used.")
+
+(defvar spam-use-bbdb t
+ "True if BBDB should be used.")
+
+(defvar spam-use-bbdb t
+ "True if ifile should be used.")
+
+(defvar spam-split-group "spam"
+ "Usual group name where spam should be split.")
+
+(defvar spam-junk-mailgroups
+ ;; FIXME! The mailgroup list evidently depends on other choices made by the
+ ;; user, so the built-in default below is not likely to be appropriate.
+ (cons spam-split-group '("mail.junk" "poste.pourriel"))
+ "Mailgroups which are dedicated by splitting to receive various junk.
+All unmarked article in such group receive the spam mark on group entry.")
+
+;; FIXME! For `spam-ham-marks' and `spam-spam-marks', I wonder if it would
+;; not be easier for the user to just accept a string of mark letters, instead
+;; of a list of Gnus variable names. In such case, the stunt of deferred
+;; evaluation would not be useful anymore. Lars?? :-)
+
+;; FIXME! It is rather questionable to see `K', `X' and `Y' as indicating
+;; positive ham. It much depends on how and why people use kill files, score
+;; files, and the kill command. Maybe it would be better, by default, to not
+;; process a message neither as ham nor spam, that is, just ignore it for
+;; learning purposes, when we are not sure of how the user sees it.
+;; But `r' and `R' should undoubtedly be seen as ham.
+
+;; FIXME! Some might consider overkill to define a list of spam marks. On
+;; the other hand, who knows, some users might for example like that
+;; explicitly `E'xpired articles be processed as positive spam.
+
+(defvar spam-ham-marks
+ (list gnus-del-mark gnus-read-mark gnus-killed-mark
+ gnus-kill-file-mark gnus-low-score-mark)
+ "Marks considered as being ham (positively not spam).
+Such articles will be transmitted to `bogofilter -n' on group exit.")
+
+(defvar spam-spam-marks
+ (list gnus-spam-mark)
+ "Marks considered as being spam (positively spam).
+Such articles will be transmitted to `bogofilter -s' on group exit.")
+
+;; FIXME! Ideally, the remainder of this page should be fully integrated
+;; within `gnus-sum.el'.
+
+;;; Key bindings for spam control.
+
+;; FIXME! The justification for `M-d' is that this is what Paul Graham
+;; suggests in his original article, and what Eric Raymond's patch for Mutt
+;; uses. But more importantly, that binding was still free in Summary mode!
+
+;; FIXME! Lars has not blessed the following key bindings yet. It looks
+;; convenient that the score analysis command uses a sequence ending with the
+;; letter `t', so it nicely parallels `B t' or `V t'. `M-d' is a kind of
+;; "alternate" `d', it is also the sequence suggested in Paul Graham article,
+;; and also in Eric Raymond's patch for Mutt. `S x' might be the more
+;; official key binding for `M-d'.
+
+(gnus-define-keys gnus-summary-mode-map
+ "St" spam-bogofilter-score
+ "Sx" gnus-summary-mark-as-spam
+ "\M-d" gnus-summary-mark-as-spam)
+
+;;; How to highlight a spam summary line.
+
+;; FIXME! Of course, `gnus-splash-face' has another purpose. Maybe a
+;; special face should be created, named and used instead, for spam lines.
+
+(push '((eq mark gnus-spam-mark) . gnus-splash-face)
+ gnus-summary-highlight)
+
+;;; Hooks dispatching. A bit raw for now.
+
+(defun spam-summary-prepare ()
+ (spam-mark-junk-as-spam-routine))
+
+(defun spam-summary-prepare-exit ()
+ (spam-bogofilter-register-routine))
+
+(add-hook 'gnus-summary-prepare-hook 'spam-summary-prepare)
+(add-hook 'gnus-summary-prepare-exit-hook 'spam-summary-prepare-exit)
+
+(defun spam-mark-junk-as-spam-routine ()
+ (when (member gnus-newsgroup-name spam-junk-mailgroups)
+ (let ((articles gnus-newsgroup-articles)
+ article)
+ (while articles
+ (setq article (pop articles))
+ (when (eq (gnus-summary-article-mark article) gnus-unread-mark)
+ (gnus-summary-mark-article article gnus-spam-mark))))))
+\f
+;;;; Spam determination.
+
+
+(defvar spam-list-of-checks
+ '((spam-use-blacklist . spam-check-blacklist)
+ (spam-use-whitelist . spam-check-whitelist)
+ (spam-use-bbdb . spam-check-bbdb)
+ (spam-use-ifile . spam-check-ifile)
+ (spam-use-blackholes . spam-check-blackholes)
+ (spam-use-bogofilter . spam-check-bogofilter))
+"The spam-list-of-checks list contains pairs associating a parameter
+variable with a spam checking function. If the parameter variable is
+true, then the checking function is called, and its value decides what
+happens. Each individual check may return `nil', `t', or a mailgroup
+name. The value `nil' means that the check does not yield a decision,
+and so, that further checks are needed. The value `t' means that the
+message is definitely not spam, and that further spam checks should be
+inhibited. Otherwise, a mailgroup name is returned where the mail
+should go, and further checks are also inhibited. The usual mailgroup
+name is the value of `spam-split-group', meaning that the message is
+definitely a spam.")
+
+(defun spam-split ()
+ "Split this message into the `spam' group if it is spam.
+This function can be used as an entry in `nnmail-split-fancy', for
+example like this: (: spam-split)
+
+See the Info node `(gnus)Fancy Mail Splitting' for more details."
+ (interactive)
+
+ (let ((list-of-checks spam-list-of-checks)
+ decision)
+ (while (and list-of-checks (not decision))
+ (let ((pair (pop list-of-checks)))
+ (when (eval (car pair))
+ (setq decision (apply (cdr pair))))))
+ (if (eq decision t)
+ nil
+ decision)))
+\f
+;;;; Blackholes.
+
+(defvar spam-blackhole-servers '("bl.spamcop.net"
+ "relays.ordb.org"
+ "dev.null.dk"
+ "relays.visi.com"
+ "rbl.maps.vix.com")
"List of blackhole servers.")
(defun spam-check-blackholes ()
- "Check the Recevieved headers for blackholed relays."
+ "Check the Receieved headers for blackholed relays."
(let ((headers (message-fetch-field "received"))
ips matches)
- (with-temp-buffer
- (insert headers)
- (goto-char (point-min))
- (while (re-search-forward
- "\\[\\([0-9]+.[0-9]+.[0-9]+.[0-9]+\\)\\]" nil t)
- (push (mapconcat 'identity
- (nreverse (split-string (match-string 1) "\\."))
- ".")
- ips)))
- (dolist (server spam-blackhole-servers)
- (dolist (ip ips)
- (when (query-dns (concat ip "." server))
- (push (list ip server (query-dns (concat ip "." server) 'TXT))
- matches))))
- matches))
+ (when headers
+ (with-temp-buffer
+ (insert headers)
+ (goto-char (point-min))
+ (while (re-search-forward
+ "\\[\\([0-9]+.[0-9]+.[0-9]+.[0-9]+\\)\\]" nil t)
+ (message "Blackhole search found host IP %s." (match-string 1))
+ (push (mapconcat 'identity
+ (nreverse (split-string (match-string 1) "\\."))
+ ".")
+ ips)))
+ (dolist (server spam-blackhole-servers)
+ (dolist (ip ips)
+ (when (query-dns (concat ip "." server))
+ (push (list ip server (query-dns (concat ip "." server) 'TXT))
+ matches)))))
+ (when matches
+ spam-split-group)))
+\f
+;;;; Blacklists and whitelists.
+
+(defvar spam-directory "~/News/spam/"
+ "When spam files are kept.")
+
+(defvar spam-whitelist (expand-file-name "whitelist" spam-directory)
+ "The location of the whitelist.
+The file format is one regular expression per line.
+The regular expression is matched against the address.")
+
+(defvar spam-blacklist (expand-file-name "blacklist" spam-directory)
+ "The location of the blacklist.
+The file format is one regular expression per line.
+The regular expression is matched against the address.")
+
+(defvar spam-whitelist-cache nil)
+(defvar spam-blacklist-cache nil)
+
+(defun spam-enter-whitelist (address)
+ "Enter ADDRESS into the whitelist."
+ (interactive "sAddress: ")
+ (spam-enter-list address spam-whitelist)
+ (setq spam-whitelist-cache nil))
+
+(defun spam-enter-blacklist (address)
+ "Enter ADDRESS into the blacklist."
+ (interactive "sAddress: ")
+ (spam-enter-list address spam-blacklist)
+ (setq spam-blacklist-cache nil))
+
+(defun spam-enter-list (address file)
+ "Enter ADDRESS into the given FILE, either the whitelist or the blacklist."
+ (unless (file-exists-p (file-name-directory file))
+ (make-directory (file-name-directory file) t))
+ (save-excursion
+ (set-buffer
+ (find-file-noselect file))
+ (goto-char (point-max))
+ (unless (bobp)
+ (insert "\n"))
+ (insert address "\n")
+ (save-buffer)))
+
+;;; returns nil if the sender is in the whitelist, spam-split-group otherwise
+(defun spam-check-whitelist ()
+ ;; FIXME! Should it detect when file timestamps change?
+ (unless spam-whitelist-cache
+ (setq spam-whitelist-cache (spam-parse-list spam-whitelist)))
+ (if (spam-from-listed-p spam-whitelist-cache) nil spam-split-group))
+
+;;; original idea from Alexander Kotelnikov <sacha@giotto.sj.ru>
+(condition-case nil
+ (progn
+ (require 'bbdb-com)
+ (defun spam-check-bbdb ()
+ "We want messages from people who are in the BBDB not to be split to spam"
+ (let ((who (message-fetch-field "from")))
+ (when who
+ (setq who (regexp-quote (cadr (gnus-extract-address-components who))))
+ (if (bbdb-search (bbdb-records) nil nil who) nil spam-split-group)))))
+ (file-error (setq spam-list-of-checks
+ (delete (assoc 'spam-use-bbdb spam-list-of-checks)
+ spam-list-of-checks))))
+
+;;; check the ifile backend; return nil if the mail was NOT classified as spam
+(condition-case nil
+ (progn
+ (require 'ifile-gnus)
+ ;;;
+ (defun spam-check-ifile ()
+ (let ((ifile-primary-spam-group spam-split-group))
+ (ifile-spam-filter nil))))
+ (file-error (setq spam-list-of-checks
+ (delete (assoc 'spam-use-ifile spam-list-of-checks)
+ spam-list-of-checks))))
+
+(defun spam-check-blacklist ()
+ ;; FIXME! Should it detect when file timestamps change?
+ (unless spam-blacklist-cache
+ (setq spam-blacklist-cache (spam-parse-list spam-blacklist)))
+ (and (spam-from-listed-p spam-blacklist-cache) spam-split-group))
+
+(eval-and-compile
+ (defalias 'spam-point-at-eol (if (fboundp 'point-at-eol)
+ 'point-at-eol
+ 'line-end-position)))
+
+(defun spam-parse-list (file)
+ (when (file-readable-p file)
+ (let (contents address)
+ (with-temp-buffer
+ (insert-file-contents file)
+ (while (not (eobp))
+ (setq address (buffer-substring (point) (spam-point-at-eol)))
+ (forward-line 1)
+ (unless (zerop (length address))
+ (setq address (regexp-quote address))
+ (while (string-match "\\\\\\*" address)
+ (setq address (replace-match ".*" t t address)))
+ (push address contents))))
+ (nreverse contents))))
+
+(defun spam-from-listed-p (cache)
+ (let ((from (message-fetch-field "from"))
+ found)
+ (while cache
+ (when (string-match (pop cache) from)
+ (setq found t
+ cache nil)))
+ found))
+
+\f
+;;;; Training via Bogofilter. Last updated 2002-09-02.
+
+;;; See Paul Graham article, at `http://www.paulgraham.com/spam.html'.
+
+;;; This page is for those wanting to control spam with the help of Eric
+;;; Raymond's speedy Bogofilter, see http://www.tuxedo.org/~esr/bogofilter.
+;;; This has been tested with a locally patched copy of version 0.4.
+
+;;; Make sure Bogofilter is installed. Bogofilter internally uses Judy fast
+;;; associative arrays, so you need to install Judy first, and Bogofilter
+;;; next. Fetch both distributions by visiting the following links and
+;;; downloading the latest version of each:
+;;;
+;;; http://sourceforge.net/projects/judy/
+;;; http://www.tuxedo.org/~esr/bogofilter/
+;;;
+;;; Unpack the Judy distribution and enter its main directory. Then do:
+;;;
+;;; ./configure
+;;; make
+;;; make install
+;;;
+;;; You will likely need to become super-user for the last step. Then, unpack
+;;; the Bogofilter distribution and enter its main directory:
+;;;
+;;; make
+;;; make install
+;;;
+;;; Here as well, you need to become super-user for the last step. Now,
+;;; initialises your word lists by doing, under your own identity:
+;;;
+;;; mkdir ~/.bogofilter
+;;; touch ~/.bogofilter/badlist
+;;; touch ~/.bogofilter/goodlist
+;;;
+;;; These two files are text files you may edit, but you normally don't!
+
+;;; The `M-d' command gets added to Gnus summary mode, marking current article
+;;; as spam, showing it with the `H' mark. Whenever you see a spam article,
+;;; make sure to mark its summary line with `M-d' before leaving the group.
+;;; Some groups, as per variable `spam-junk-mailgroups' below, receive articles
+;;; from Gnus splitting on clues added by spam recognisers, so for these
+;;; groups, we tack an `H' mark at group entry for all summary lines which
+;;; would otherwise have no other mark. Make sure to _remove_ `H' marks for
+;;; any article which is _not_ genuine spam, before leaving such groups: you
+;;; may use `M-u' to "unread" the article, or `d' for declaring it read the
+;;; non-spam way. When you leave a group, all `H' marked articles, saved or
+;;; unsaved, are sent to Bogofilter which will study them as spam samples.
+
+;;; Messages may also be deleted in various other ways, and unless
+;;; `spam-ham-marks-form' gets overridden below, marks `R' and `r' for default
+;;; read or explicit delete, marks `X' and 'K' for automatic or explicit
+;;; kills, as well as mark `Y' for low scores, are all considered to be
+;;; associated with articles which are not spam. This assumption might be
+;;; false, in particular if you use kill files or score files as means for
+;;; detecting genuine spam, you should then adjust `spam-ham-marks-form'. When
+;;; you leave a group, all _unsaved_ articles bearing any the above marks are
+;;; sent to Bogofilter which will study these as not-spam samples. If you
+;;; explicit kill a lot, you might sometimes end up with articles marked `K'
+;;; which you never saw, and which might accidentally contain spam. Best is
+;;; to make sure that real spam is marked with `H', and nothing else.
+
+;;; All other marks do not contribute to Bogofilter pre-conditioning. In
+;;; particular, ticked, dormant or souped articles are likely to contribute
+;;; later, when they will get deleted for real, so there is no need to use
+;;; them prematurely. Explicitly expired articles do not contribute, command
+;;; `E' is a way to get rid of an article without Bogofilter ever seeing it.
+
+;;; In a word, with a minimum of care for associating the `H' mark for spam
+;;; articles only, Bogofilter training all gets fairly automatic. You should
+;;; do this until you get a few hundreds of articles in each category, spam
+;;; or not. The shell command `head -1 ~/.bogofilter/*' shows both article
+;;; counts. The command `S S' in summary mode, either for debugging or for
+;;; curiosity, triggers Bogofilter into displaying in another buffer the
+;;; "spamicity" score of the current article (between 0.0 and 1.0), together
+;;; with the article words which most significantly contribute to the score.
+
+;;; The real way for using Bogofilter, however, is to have some use tool like
+;;; `procmail' for invoking it on message reception, then adding some
+;;; recognisable header in case of detected spam. Gnus splitting rules might
+;;; later trip on these added headers and react by sorting such articles into
+;;; specific junk folders as per `spam-junk-mailgroups'. Here is a possible
+;;; `.procmailrc' contents (still untested -- please tell me how it goes):
+;;;
+;;; :0HBf:
+;;; * ? bogofilter
+;;; | formail -bfI "X-Spam-Status: Yes"
+
+(defvar spam-output-buffer-name "*Bogofilter Output*"
+ "Name of buffer when displaying `bogofilter -v' output.")
+
+(defvar spam-spaminfo-header-regexp
+ ;; FIXME! In the following regexp, we should explain which tool produces
+ ;; which kind of header. I do not even remember them all by now. X-Junk
+ ;; (and previously X-NoSpam) are produced by the `NoSpam' tool, which has
+ ;; never been published, so it might not be reasonable leaving it in the
+ ;; list.
+ "^X-\\(jf\\|Junk\\|NoSpam\\|Spam\\|SB\\)[^:]*:"
+ "Regexp for spam markups in headers.
+Markup from spam recognisers, as well as `Xref', are to be removed from
+articles before they get registered by Bogofilter.")
+
+(defvar spam-bogofilter-path (executable-find "bogofilter")
+ "File path of the Bogofilter executable program.
+Force this variable to nil if you want to inhibit the functionality.")
+
+(defun spam-check-bogofilter ()
+ ;; Dynamic spam check. I do not know how to check the exit status,
+ ;; so instead, read `bogofilter -v' output.
+ (when (and spam-use-bogofilter spam-bogofilter-path)
+ (spam-bogofilter-articles nil "-v" (list (gnus-summary-article-number)))
+ (when (save-excursion
+ (set-buffer spam-output-buffer-name)
+ (goto-char (point-min))
+ (re-search-forward "Spamicity: \\(0\\.9\\|1\\.0\\)" nil t))
+ spam-split-group)))
+
+(defun spam-bogofilter-score ()
+ "Use `bogofilter -v' on the current article.
+This yields the 15 most discriminant words for this article and the
+spamicity coefficient of each, and the overall article spamicity."
+ (interactive)
+ (when (and spam-use-bogofilter spam-bogofilter-path)
+ (spam-bogofilter-articles nil "-v" (list (gnus-summary-article-number)))
+ (with-current-buffer spam-output-buffer-name
+ (unless (zerop (buffer-size))
+ (if (<= (count-lines (point-min) (point-max)) 1)
+ (progn
+ (goto-char (point-max))
+ (when (bolp)
+ (backward-char 1))
+ (message "%s" (buffer-substring (point-min) (point))))
+ (goto-char (point-min))
+ (display-buffer (current-buffer)))))))
+
+(defun spam-bogofilter-register-routine ()
+ (when (and spam-use-bogofilter spam-bogofilter-path)
+ (let ((articles gnus-newsgroup-articles)
+ article mark ham-articles spam-articles)
+ (while articles
+ (setq article (pop articles)
+ mark (gnus-summary-article-mark article))
+ (cond ((memq mark spam-spam-marks) (push article spam-articles))
+ ((memq article gnus-newsgroup-saved))
+ ((memq mark spam-ham-marks) (push article ham-articles))))
+ (when ham-articles
+ (spam-bogofilter-articles "ham" "-n" ham-articles))
+ (when spam-articles
+ (spam-bogofilter-articles "SPAM" "-s" spam-articles)))))
+
+(defvar spam-bogofilter-initial-timeout 40
+ "Timeout in seconds for the initial reply from the `bogofilter' program.")
+
+(defvar spam-bogofilter-subsequent-timeout 15
+ "Timeout in seconds for any subsequent reply from the `bogofilter' program.")
+
+(defun spam-bogofilter-articles (type option articles)
+ (let ((output-buffer (get-buffer-create spam-output-buffer-name))
+ (article-copy (get-buffer-create " *Bogofilter Article Copy*"))
+ (remove-regexp (concat spam-spaminfo-header-regexp "\\|Xref:"))
+ (counter 0)
+ prefix process article)
+ (when type
+ (setq prefix (format "Studying %d articles as %s..." (length articles)
+ type))
+ (message "%s" prefix))
+ (save-excursion (set-buffer output-buffer) (erase-buffer))
+ (setq process (start-process "bogofilter" output-buffer
+ spam-bogofilter-path "-F" option))
+ (process-kill-without-query process t)
+ (unwind-protect
+ (save-window-excursion
+ (while articles
+ (setq counter (1+ counter))
+ (when prefix
+ (message "%s %d" prefix counter))
+ (setq article (pop articles))
+ (gnus-summary-goto-subject article)
+ (gnus-summary-select-article)
+ (gnus-eval-in-buffer-window article-copy
+ (insert-buffer-substring gnus-original-article-buffer)
+ ;; Remove spam classification redundant headers: they may induce
+ ;; unwanted biases in later analysis.
+ (goto-char (point-min))
+ (while (not (or (eobp) (= (following-char) ?\n)))
+ (if (looking-at remove-regexp)
+ (delete-region (point)
+ (save-excursion (forward-line 1) (point)))
+ (forward-line 1)))
+ (goto-char (point-min))
+ ;; Bogofilter really wants From envelopes for counting articles.
+ ;; Fake one at the beginning, make sure there will be no other.
+ (if (looking-at "From ")
+ (forward-line 1)
+ (insert "From nobody " (current-time-string) "\n"))
+ (let (case-fold-search)
+ (while (re-search-forward "^From " nil t)
+ (beginning-of-line)
+ (insert ">")))
+ (process-send-region process (point-min) (point-max))
+ (erase-buffer))))
+ ;; Sending the EOF is unwind-protected. This is to prevent lost copies
+ ;; of `bogofilter', hung on reading their standard input, in case the
+ ;; whole registering process gets interrupted by the user.
+ (process-send-eof process))
+ (kill-buffer article-copy)
+ ;; Receive process output. It sadly seems that we still have to protect
+ ;; ourselves against hung `bogofilter' processes.
+ (let ((status (process-status process))
+ (timeout (* 1000 spam-bogofilter-initial-timeout))
+ (quanta 200)) ; also counted in milliseconds
+ (while (and (not (eq status 'exit)) (> timeout 0))
+ ;; `accept-process-output' timeout is counted in microseconds.
+ (setq timeout (if (accept-process-output process 0 (* 1000 quanta))
+ (* 1000 spam-bogofilter-subsequent-timeout)
+ (- timeout quanta))
+ status (process-status process)))
+ (if (eq status 'exit)
+ (when prefix
+ (message "%s done!" prefix))
+ ;; Sigh! The process did time out... Become brutal!
+ (interrupt-process process)
+ (message "%s %d INTERRUPTED! (Article %d, status %s)"
+ (or prefix "Bogofilter process...")
+ counter article status)
+ ;; Give some time for user to read. Sitting redisplays but gives up
+ ;; if input is pending. Sleeping does not give up, but it does not
+ ;; redisplay either. Mix both: let's redisplay and not give up.
+ (sit-for 1)
+ (sleep-for 3)))))
(provide 'spam)
-;;; spam.el ends here
+;;; spam.el ends here.
projects / gnus / blobdiff