#### Anti-spam ruleset ###########################################
# This script provides some foundational anti-spam
# rules. It does not do any form of content filtering,
# but this can be implemented by other scripts and
# modules as desired.
#
# The following chains are available as extension
# points:
#
# ::user/spam_check_message_content
#   Apply additional checks to messages that may be spam
#
# ::user/spam_check_subscription_request
#   Apply additional checks to subscription requests
#
# ::user/spam_handle_unknown_custom
#   Override default handling of stanzas that weren't explicitly
#   passed or rejected by the anti-spam checks
#
# ::user/spam_reject_custom
#   Override default handling of stanzas that have
#   been recognised as spam (default is to bounce
#   a policy-violation error)
##################################################################

#### General rules for all incoming stanzas ######################
::deliver

LOG=Considering $(stanza:top_tag())

# Pass stanzas that a user sends to their own account
TO SELF?
PASS.

# Pass stanzas that are addressed to a valid full JID
TO FULL JID?
PASS.

# Pass stanzas from contacts
SUBSCRIBED?
PASS.

# Run extra rules that apply to messages only
KIND: message
JUMP CHAIN=user/spam_check_message

# Run extra rules that apply to presence stanzas only
KIND: presence
JUMP CHAIN=user/spam_check_presence

JUMP CHAIN=user/spam_handle_unknown

# Default is to allow, override this with
# the 'user/spam_handle_unknown' chain
PASS.

#### Rules for messages ##########################################
::user/spam_check_message

# Non-chat message types often generate pop-ups in clients,
# so we won't accept them from strangers
NOT TYPE: chat
JUMP CHAIN=user/spam_reject

# This chain can be used by other scripts
# and modules that analyze message content
JUMP CHAIN=user/spam_check_message_content

##################################################################

#### Rules for presence stanzas ##################################
::user/spam_check_presence

# These may be received if rosters get out of sync and are harmless
# because they will not be routed to the client unless necessary
TYPE: unsubscribe|unsubscribed
PASS.

# We don't want to receive presence from random strangers,
# but still allow subscription requests
NOT TYPE: subscribe
DROP.

# This chain can be used by other scripts
# and modules to filter subscription requests
JUMP CHAIN=user/spam_check_subscription_request

##################################################################

#### Stanzas reaching this chain will be rejected ################
::user/spam_reject

# This chain can be used by other scripts
# and modules to override the default behaviour
# when rejecting spam stanzas
JUMP CHAIN=user/spam_reject_custom

LOG=Rejecting suspected spam: $(stanza:top_tag())
BOUNCE=policy-violation

##################################################################

#### Stanzas that may be spam, but we're not sure either way######
::user/spam_handle_unknown

# This chain can be used by other scripts
# and modules to apply additional checks, or to
# override the default behaviour
JUMP CHAIN=user/spam_handle_unknown_custom

#LOG=[debug] Spam check allowing: $(stanza:top_tag())

##################################################################