#!/usr/bin/perl
#
# RFID access control program v1.0
#
# Copyright (c) 2016, Zach Metzinger
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# $Id: rfid_access.pl,v 1.1 2016/01/02 23:15:31 zmetzing Exp $
use warnings;
use strict;
use DB_File;
use Device::SerialPort qw( :PARAM :STAT 0.07 );
# Configuration parameters
my $db_fn = "nfc_auth_tags.db";
my $serial_port_device = "/dev/ttyO2";
my $relay_on_time = 10; # Seconds
# Note: See http://www.armhf.com/using-beaglebone-black-gpios/ for details on the following
my $sys_class_path = "/sys/class/gpio";
my $sys_class_export = "$sys_class_path/export";
my $sys_class_gpio = "$sys_class_path/gpio";
my $red_led_gpio = 32+12;
my $yel_led_gpio = 32+13;
my $grn_led_gpio = 32+15;
my $off_btn_gpio = 32+14; # Not currently used
my $on_relay_gpio = 48;
# Local vars
my %auth_tags;
my $tag_id;
my $nbytes;
my $nfc;
my $sysfh;
# Debugging hexdump subr
sub hexdump($)
{
my $offset = 0;
foreach my $chunk (unpack "(a16)*", $_[0])
{
my $hex = unpack "H*", $chunk; # hexadecimal magic
$chunk =~ tr/ -~/./c; # replace unprintables
$hex =~ s/(.{1,8})/$1 /gs; # insert spaces
printf "0x%08x (%05u) %-*s %s\n",
$offset, $offset, 36, $hex, $chunk;
$offset += 16;
}
}
# Banner
printf "DMS HAAS RFID access control program v1.0\n";
# Verify existance of database before starting
if (! -e $db_fn) {
die "Unable to find database nfc_auth_tags.db\n";
}
# Enable LEDs
if (! -e $sys_class_export) {
die "sysfs path $sys_class_export does not exist, are we on BBB?\n";
}
system("sudo chmod 222 $sys_class_export");
system("echo $red_led_gpio > $sys_class_export");
system("echo $yel_led_gpio > $sys_class_export");
system("echo $grn_led_gpio > $sys_class_export");
system("echo $on_relay_gpio > $sys_class_export");
system("sudo chmod -R go=rwX $sys_class_gpio$red_led_gpio/*");
system("sudo chmod -R go=rwX $sys_class_gpio$yel_led_gpio/*");
system("sudo chmod -R go=rwX $sys_class_gpio$grn_led_gpio/*");
system("sudo chmod -R go=rwX $sys_class_gpio$on_relay_gpio/*");
system("echo high > $sys_class_gpio$red_led_gpio/direction");
system("echo high > $sys_class_gpio$yel_led_gpio/direction");
system("echo high > $sys_class_gpio$grn_led_gpio/direction");
system("echo low > $sys_class_gpio$on_relay_gpio/direction");
# Initialize serial port
$nfc = new Device::SerialPort ($serial_port_device)
|| die "Can't open $serial_port_device: $!\n";
$nfc->user_msg(1);
$nfc->databits(8);
$nfc->baudrate(9600);
$nfc->parity("none");
$nfc->stopbits(1);
$nfc->handshake("none");
$nfc->read_char_time(0);
$nfc->read_const_time(250);
$nfc->write_settings || undef $nfc;
if (!defined($nfc)) {
die "Unable to open serial port: $!\n";
}
system("stty -F $serial_port_device raw");
printf "Ready to read tags\n";
while (1) {
# Light red LED, others off
system("echo 0 > $sys_class_gpio$red_led_gpio/value");
system("echo 1 > $sys_class_gpio$grn_led_gpio/value");
# Wait for serial port data to come in
($nbytes, $tag_id) = $nfc->read(255);
if ($nbytes == -1) {
die "EOF on serial port read\n";
}
# Only process if we got after the 1 second read timeout
if ($nbytes > 0) {
# FIXME: Dump for debug
#hexdump($tag_id);
if (($nbytes != 16) || (ord(substr($tag_id, 0, 1)) != 0x02)) {
printf "Got data on serial port, but does not fit tag format. Ignoring.\n";
} else {
# Extract tag id from framing
$tag_id = substr($tag_id, 1, 12);
# FIXME: Dump for debug
#hexdump($tag_id);
# Look up NFC tag ID in database
# Note: Only opening database long enough to look this up. That way, we don't have to
# manage a multi-access database right now. Could be solved with DB v2-v6 or mysql ..later
if (!defined(tie %auth_tags, "DB_File", $db_fn, O_RDONLY | O_EXCL, 0600, $DB_HASH)) {
printf "Cannot open database: $!\n";
} else {
if ($auth_tags{$tag_id}) {
printf "Tag $tag_id is authorized\n";
# If matched, close relay and light green LED
system("echo 1 > $sys_class_gpio$on_relay_gpio/value");
system("echo 1 > $sys_class_gpio$red_led_gpio/value");
system("echo 0 > $sys_class_gpio$grn_led_gpio/value");
sleep($relay_on_time);
} else {
printf "Tag $tag_id is NOT authorized\n";
}
untie %auth_tags;
}
# Release relay and light red RED
system("echo 0 > $sys_class_gpio$on_relay_gpio/value");
system("echo 0 > $sys_class_gpio$red_led_gpio/value");
system("echo 1 > $sys_class_gpio$grn_led_gpio/value");
}
}
}
