ejabberd-contrib/mod_spam_filter

mod_spam_filter - Filter spam messages based on JID/content

• Author: Holger Weiss holger@zedat.fu-berlin.de

Description

This module allows for filtering spam messages and subscription requests received from remote servers based on lists of known spammer JIDs and/or URLs mentioned in spam messages. Traffic classified as spam is rejected with an error (and an [info] message is logged) unless the sender is subscribed to the recipient's presence. An access rule can be specified to control which recipients are subject to spam filtering.

Configuration

To enable this module, configure it like this:

modules:
  mod_spam_filter:
    spam_jids_file: "/etc/ejabberd/spam-filter/jids.txt"
    spam_urls_file: "/etc/ejabberd/spam-filter/urls.txt"

The configurable mod_spam_filter options are:

• spam_dump_file (default: none)

  This option specifies the path to a file that messages classified as spam will be written to. The messages are dumped in raw XML format, and a <delay/> tag with the current timestamp is added. The @HOST@ keyword will be substituted with the name of the virtual host. Note that this module doesn't limit the file size, so if you use this option, make sure to monitor disk file usage and to rotate the file if necessary. After rotation, the command ejabberdctl reopen-log can be called to let the module reopen the spam dump file.

• spam_jids_file (default: none)

  This option specifies the path to a plain text file containing a list of known spammer JIDs, one JID per line. Messages and subscription requests sent from one of the listed JIDs will be classified as spam. Messages containing at least one of the listed JIDs will be classified as spam as well. Furthermore, the sender's JID will be cached, so that future traffic originating from that JID will also be classified as spam.

• spam_urls_file (default: none)

  This option specifies the path to a plain text file containing a list of URLs known to be mentioned in spam message bodies. Messages containing at least one of the listed URLs will be classified as spam. Furthermore, the sender's JID will be cached, so that future traffic originating from that JID will be classified as spam as well.

• access_spam (default: none)

  This option defines the access rule to control who will be subject to spam filtering. If the rule returns allow for a given recipient, spam messages aren't rejected for that recipient. By default, all recipients are subject to spam filtering.

• cache_size (default: 10000)

  This option specifies the maximum number of JIDs that will be cached due to sending spam URLs (see above). If that limit is exceeded, the least recently used entries are removed from the cache. Setting this option to 0 disables the caching feature. Note that separate caches are used for each virtual host, and that the caches aren't distributed across cluster nodes.

ejabberd Commands

This module provides ejabberdctl/API calls to reread the spam JID/URL files, to print the JID cache contents, and to remove entries from that cache. See:

$ ejabberdctl help reload-spam-filter-files
$ ejabberdctl help get-spam-filter-cache
$ ejabberdctl help expire-spam-filter-cache
$ ejabberdctl help drop-from-spam-filter-cache