#!/bin/sh

# 20040508 _M Modified for snfrv2r3 release.

# 20040102 _M Modified for snfrv2r2 release.
# Also improved file collision avoidance using DATE functions.

# 20021204 _M Modified for sniffer2 release. No other changes.

# sniffer - 20021106 _M ##############################################
#
# This script is a template for using SortMonster's Message Sniffer
# on Postfix systems. It is derived from the FILTER_README distributed
# with Postfix.
#
# This script accepts the message, writes it to a file, scans it with
# the sniffer utility, and then delivers the message if there is no
# pattern match. If a pattern match is found then there are a number
# of options included in this script.
#
# The default action is to write a header to the message indicating
# the symbol for the pattern match.
#
# In practice, the system administrator should adjust this script to
# interpret the response from sniffer and take some appropriate action.
# In that respect, this script is only a good starting point.
#
#
######################################################################

# Localize the inspection directory, sniffer installation, and
# sendmail command. It is VITAL that the sniffer utility is named with
# a .exe extension so that it can rewrite it's file name to produce it's
# log file and to read it's rule file. Both of those must be in the same
# directory along with the binary.

INSPECT_DIR=DATADIR/PACKAGE_NAME
SNIFFER_EXE=PREFIX/sbin/SNFClient
SENDMAIL="/usr/sbin/sendmail -G -i"
MSGFILE=$INSPECT_DIR/`date +%Y%m%d%H%M%S`_$$_$RANDOM.msg

# Define Exit codes from <sysexits.h>

EX_OK=0
EX_TEMPFAIL=75
EX_UNAVAILABLE=69


# Clean up when when aborting.

trap "rm -f $MSGFILE*" 1 2 3 15


# Move to our filter directory where we perform our inspections.

cd $INSPECT_DIR || { echo $INSPECT_DIR does not exist; exit $EX_TEMPFAIL; }


# Copy the message to a temp file for processing.

cat > $MSGFILE || { echo Cannot save mail to file; exit $EX_TEMPFAIL; }


# Now that we have the message as a file we can process it with
# Message Sniffer. The sniffer utility will return a nonzero value if
# it finds a pattern match.

$SNIFFER_EXE $MSGFILE || {

  # If we're here, we know sniffer found a match. So, what do we do?

  ##################################################################
  #                                                                #
  # *ONE* OF THE FOLLOWING BLOCKS MUST BE UNCOMMENTED. THE DEFAULT #
  # IS THE MESSAGE HEADER BLOCK.                                   #
  #                                                                #
  ##################################################################

  #### Uncomment this section to reject (bounce) the message.
  #
  #  echo Message content rejected, symbol = $?;
  #  rm -f $MSGFILE*;
  #  exit $EX_UNAVAILABLE;

  #### Uncomment this section to eat the message.
  #
  #  echo Message content destroyed, symbol = $?;
  #  rm -f $MSGFILE*
  #  exit $EX_OK;

  #### Uncomment this section to hold the message for review.
  #
  # echo Message Content Held For Review, symbol = $?;
  # exit $EX_OK;

  #### Uncomment this section to add a header to the message.

  echo X-SortMonster-Msg-Sniffer-Match: Symbol-$? > $MSGFILE.x;
  cat $MSGFILE.x $MSGFILE > $MSGFILE.y;
  $SENDMAIL "$@" < $MSGFILE.y;
  rm -f $MSGFILE*;
  exit $EX_OK;

  # NOTE: The value returned by the sniffer program is an integer
  # representing the rule/group that was matched. That value may be
  # any integer from 1 through 64. The value is derived from the
  # matching rule's symbol (mod 64)+1. The actual symbol will be
  # accurately recorded in the log file. This is a correction from
  # the demo version which uses an older code base.

 }


# At this point we want to deliver the message as-is. We reinject
# the message with our sendmail command and then clean up our temp
# file(s).

$SENDMAIL "$@" < $MSGFILE
rm -f $MSGFILE*
exit $?