Chinese DVR Alarm Server

dvr-alarm-server.pl

#!/usr/bin/perl

# Simple log/alarm server receiving and printing to console remote dvr/camera events. 
# Output is in CSV format.
# 
# Tested with:
#
# HandyKam DigiMiniCam HD camera HK101182
# http://www.handykam.com/Cameras-only/DigiMinicam-HD-camera/flypage.tpl.html
#
# Usage: perl dvr-alarm-server.pl | tee -a cam.csv

use IO::Socket;
use IO::Socket::INET;
use Sys::Syslog;
use Sys::Syslog qw(:DEFAULT setlogsock);
use Sys::Syslog qw(:standard :macros);
use Time::Local;
use JSON;
use Data::Dumper;

setlogsock("console");
openlog("dvr-alarm-server", "cons,pid", LOG_USER);

sub BuildPacket {
	my ($type, $params) = ($_[0], $_[1]);
	my @pkt_prefix_1;
	my @pkt_prefix_2;
	my @pkt_type;
	my $sid = 0;
	my $json = JSON->new;

	@pkt_prefix_1 = (0xff, 0x00, 0x00, 0x00);
	@pkt_prefix_2 =  (0x00, 0x00, 0x00, 0x00); 

	if ($type eq 'login') {
		@pkt_type = (0x00, 0x00, 0xe8, 0x03);
	} elsif ($type eq 'info') {
		@pkt_type = (0x00, 0x00, 0xfc, 0x03);
	}

	$sid = hex($params->{'SessionID'});

	my $pkt_prefix_data =  pack('c*', @pkt_prefix_1) . pack('i', $sid) . pack('c*', @pkt_prefix_2). pack('c*', @pkt_type);
	my $pkt_params_data =  $json->encode($params);
	my $pkt_data = $pkt_prefix_data . pack('i', length($pkt_params_data)) . $pkt_params_data;

	return $pkt_data;
}

sub GetReplyHead {
	my $sock = $_[0];
	my @reply_head_array;

	for (my $i = 0; $i < 5; $i++) {
		$sock->recv($data, 4);
		$reply_head[$i]  = unpack('i', $data);
		print OUT $data;
	}

	my $reply_head = {
		Prefix1 => $reply_head[0],
		Prefix2 => $reply_head[1],
		Prefix3 => $reply_head[2],
		Prefix4 => $reply_head[3],
		Content_Length => $reply_head[4]
	};

	return $reply_head;
}

my $sock = new IO::Socket::INET(
	LocalHost => '0.0.0.0',
	LocalPort => '15002',
	Proto => 'tcp',
	Listen => 1,
	Reuse => 1); 
	
die "Could not create socket: $!\n" unless $sock;

while (my ($client,$clientaddr) = $sock->accept()) {
	write_log("Connected from ".$client->peerhost());
	$pid = fork();

	die "Cannot fork: $!" unless defined($pid);

	if ($pid == 0) { 
		# Child process
		my $data = '';
		my $reply = GetReplyHead($client);
		
		# Client protocol detection
		$client->recv($data, $reply->{'Content_Length'});

		# Format CSV data
		# timestamp, address, channel, serialid, event, starttime, status, type
		my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(time());
		my $timestamp = sprintf("%4d-%02d-%02d %02d:%02d:%02d",$year+1900,$mday,$mon+1,$hour,$min,$sec); 
		my $json = decode_json($data);        
		print "$timestamp,$json->{Address},$json->{Channel},$json->{SerialID},$json->{Event},$json->{StartTime},$json->{Status},$json->{Type}\n";

		exit(0);   # Child process exits when it is done.
	}
}

close($sock);

sub write_log() {
	#my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtime(time());
	#my $timestamp = sprintf("%02d.%02d.%4d %02d:%02d:%02d",$mday,$mon+1,$year+1900,$hour,$min,$sec); 
	#print "$timestamp dvr-alarm-server[] " . $_[0] ."\n"; 
}