using s perl script to parse an isc dhcp log, an merge it into a html table. so far so good, works as it should. in the script is an option to sort the results by ip adress. the result is not sorted by the last ip octet, so it will look like this:
192.168.250.149 192.168.250.2 192.168.250.228 and so on..
my skills in perl are very limited, so i need help to achieve this. this is the code part:
my @sorted = sort { ($data{$a}{'ip'}) cmp ($data{$b}{'ip'}) } %data;
thx in advance
Here is the complete script (Thx to Marcin Gosiewski)
use Socket;
use strict;
use warnings;
no warnings 'uninitialized';
# adjust this to match your files location: both log file and leases
# database. We use 2 last log files from logrotate, but you can add as many as you want
my @logfilenames = ( "/var/log/dhcpd.log");
# Alternately, on systems without explicit log (e.g. with systemd journals), use empty array of files:
### my @logfilenames = ( ); # if empty, use output from logprog below
my @logprog = qw ( sudo journalctl --no-pager -lu dhcpd );
# Delegate rights for logprog as root, e.g.
# echo 'www-data ALL=(root) NOPASSWD:/usr/bin/journalctl --no-pager -lu dhcpd' > /etc/sudoers.d/www-journalctl
my $leasedbname = "/var/lib/dhcp/dhcpd.leases";
my %data = ();
# optional, can be modified to produce local time
use Time::Local;
use POSIX 'strftime';
my $now = time();
# local variables, lease information stored here
my $ip="";
my $status="";
my $interface="";
my $sdate=""; # beginning of lease
my $stime="";
my $edate=""; # end of lease
my $etime="";
my $adate=""; # last update (ACK) sent to requesting server
my $atime="";
my $mac="";
my $hostname="";
my $dnsname=""; # reverse dns lookup for host
#######################################################################
# first gather data from logfile for all ACK actions
#######################################################################
# collect all lines from log files into memory...
my @lines = (); my @loglines=();
if (scalar @logfilenames > 0) {
foreach my $logfilename (@logfilenames)
{
open LOGFILE, '<', $logfilename;
chomp(@loglines = <LOGFILE>);
#printf "LINES1: " . scalar @loglines . " in " .$logfilename . "\n";
push(@lines, @loglines);
close(LOGFILE);
}
} else {
open LOGPROG, '-|', join (' ', @logprog) or die "Could not pipe from logprog";
chomp(@loglines = <LOGPROG>);
#printf "LINES1: " . scalar @loglines . " in " .$logfilename . "\n";
push(@lines, @loglines);
close(LOGPROG);
}
@loglines=();
#printf "TOTAL LINES: " . scalar @lines . "\n";
foreach my $line (@lines)
{
if ( $line !~ m/dhcpd[^:]*: DHCPACK/) { next;}
#printf "LINE: $line\n";
###############################
# Modify the following line to make regexp capture 6 groups from log line:
# 1 - date
# 2 - time
# 3 - ip
# 4 - mac
# 5 - hostname if available
# 6 - interface
#$line =~ m/(^.{10})T(.{8}).+,\ dhcpd: DHCPACK on (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}) to ((?:[0-9a-f]{2}[:-]){5}[0-9a-f]{2}.*) via (.+)/;
#$line =~ m/(^.{10})T(.{8}).+,\ dhcpd: DHCPACK on (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}) to ((?:[0-9a-f]{2}[:-]){5}[0-9a-f]{2}) (.*)via (.+)/;
$line =~ m/^(.{6}) (.{8})\ .+,?\ dhcpd[^:]*: DHCPACK on (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}) to ((?:[0-9a-f]{2}[:-]){5}[0-9a-f]{2}) (.*)via (.+)/;
# process the input
$adate="$1";
$atime="$2";
$ip="$3";
$mac="$4";
$hostname="$5";
$interface="$6";
#add some 'known' facts:
$status="ACK";
$sdate=""; #"FOREVER";
$stime="";
$edate="";
$etime="";
#create/update record for this mac_addr
#you can add extra check here if the IP address is not duplicated within
#ack history and choose only the newer one.
$data{"$mac"}->{'ip'} = "$ip";
$data{"$mac"}->{'status'} = "$status";
$data{"$mac"}->{'interface'} = "$interface";
$data{"$mac"}->{'adate'} = "$adate";
$data{"$mac"}->{'atime'} = "$atime";
$data{"$mac"}->{'sdate'} = "$sdate";
$data{"$mac"}->{'stime'} = "$stime";
$data{"$mac"}->{'edate'} = "$edate";
$data{"$mac"}->{'etime'} = "$etime";
$data{"$mac"}->{'mac'} = "$mac";
if (length($hostname) > 0) {
$hostname =~ s/^\ *\(*//;
$hostname =~ s/\)*\ *$//;
}
$data{"$mac"}->{'hostname'} = "$hostname";
}
#close(LOGFILE);
#######################################################################
# gather data from lease database for dynamic addresses
# update the records (for existing) or add new records
#######################################################################
my $isdata = 0;
my $type = "";
#this information is not present in leases database so we just set
#it to default values
$interface="dhcpd";
$status="ACTIVE";
$adate="-";
$atime="";
open LEASEDB, $leasedbname or die $!;
foreach my $line (<LEASEDB>)
{
chomp($line);
$isdata = 1 if $line =~ /^lease /;
$isdata = 0 if $line =~ /^}/;
if ($isdata)
{
if ($line =~ /^lease/)
{
$ip = (split(" ", $line))[1];
}
elsif ($line =~ /^ starts/)
{
($sdate, $stime) = (split(" ", $line))[2,3];
$sdate =~ s/\//-/g;
$stime =~ s/;//;
}
elsif ($line =~ /^ ends/)
{
($type, $edate, $etime) = (split(" ", $line))[1,2,3];
if($type eq "never;")
{
$edate="forever";
$etime=" ";
}
else
{
$edate =~ s/\//-/g;
$etime =~ s/;//;
}
}
elsif ($line =~ /^ hardware ethernet/)
{
$mac = (split(" ", $line))[2];
$mac =~ s/;//;
}
elsif ($line =~ /^ client-hostname/)
{
$hostname = (split(/\"/, $line))[1];
}
elsif($mac ne "")
{
#we have parsed the whole record, no more matching entries
#data is collected to variables. now push the record.
#now let's decide if we are updating the record or creating
#new record
# check against lease date, do not add expired leases
# convert lease end time to local time/date and compare with $now
my $y=0; my $m=0; my $d=0; my $H=0; my $M=0; my $S=0;
my $edatetime = $now;
($y, $m, $d) = split("-", $edate);
($H, $M, $S) = split(":", $etime);
$edatetime = timelocal($S,$M,$H,$d,$m-1,$y);
if($edatetime >= $now)
{
# now check if record exists
if(!defined($data{"$mac"}->{'mac'}))
{
#record does not exist, fill up default data
$data{"$mac"}->{'mac'} = "$mac";
$data{"$mac"}->{'interface'} = "$interface";
$data{"$mac"}->{'ip'} = "$ip";
$data{"$mac"}->{'hostname'} = "$hostname";
}
# record exists, let's check if we should update
$data{"$mac"}->{'status'} = "$status";
$data{"$mac"}->{'sdate'} = "$sdate";
$data{"$mac"}->{'stime'} = "$stime";
$data{"$mac"}->{'edate'} = "$edate";
$data{"$mac"}->{'etime'} = "$etime";
$data{"$mac"}->{'hostname'} = "$hostname";
#we do NOT update ACK time because we do not have it
#do NOT uncomment below
#$data{"$mac"}->{'adate'} = "$adate";
#$data{"$mac"}->{'atime'} = "$atime";
}
}
}
}
close(LEASEDB);
#######################################################################
# sort data
#######################################################################
#we sort by IP but you can sort by anything.
#my @sorted = sort { ($data{$a}{'ip'}) cmp ($data{$b}{'ip'}) } %data;
my @sorted = sort { ($data{$a}{'ip'}) cmp ($data{$b}{'ip'}) } %data;
#foreach my $key (@sorted) {
# printf $data{$key}{'ip'};
# };
#######################################################################
# Print out everything to the HTML table
#######################################################################
my $hostnamelong="";
printf "Content-type: text/html\n\n";
printf "<html><head><title>DHCP LOG</title></head>\n";
printf "<style> table, th, td { border: 1px solid lightgray; border-collapse: collapse; padding: 3px; } ";
printf "tr:nth-child(even) { background-color: #dddddd; } ";
printf "body { font-family: 'Courier New', monospace; }";
printf "</style>\n";
printf "<body>\n";
printf "<table border='1' cellpadding='6'>\n";
printf "<tr><th>IP</th><th>Status</th><th>Interface</th><th>Lease time</th><th>ACK time</th><th>Mac</th><th>Host</th></tr>\n";
foreach my $key (@sorted) {
if($data{$key}{'mac'} eq "") { next ; }
# BEGIN reverse dns lookup
# can optionally turn off reverse dns lookup (comment out below lines) which speeds up the process
# of table creation and is useless unless you have reverse dns populated for
# your fixed or dynamic leases uncomment single line below instead:
#
# version without reverse dns lookup:
#$hostnamelong = $data{$key}{'hostname'};
#
# version with reverse dns lookup:
# BEGIN
$dnsname = gethostbyaddr(inet_aton($data{$key}{'ip'}), AF_INET);
if($data{$key}{'hostname'} ne "")
{
$hostnamelong = $data{$key}{'hostname'} . " | " . $dnsname;
}
else
{
$hostnamelong = $dnsname;
}
$dnsname = "";
# END
printf "<tr>";
printf "<td>" . $data{$key}{'ip'} ."</td>";
printf "<td>" . $data{$key}{'status'} ."</td>";
printf "<td>" . $data{$key}{'interface'} ."</td>";
printf "<td>" . $data{$key}{'sdate'} . " " . $data{$key}{'stime'} ." - ";
printf $data{$key}{'edate'} . " " . $data{$key}{'etime'} ."</td>";
printf "<td>" . $data{$key}{'adate'} . " " . $data{$key}{'atime'} . "</td>";
printf "<td>" . $data{$key}{'mac'} ."</td>";
printf "<td>" . $hostnamelong ."</td>";
printf "</tr>\n";
}
printf "</table>\n";
printf "</body></html>\n";
You may use Socket's inet_aton
I think this is the way to get the keys of the hash sorted by the ip:
EDIT: Changed <=> in the sort to cmp as per HugoBoss's remarks below.
my @sorted = map{$_->[0]}
sort{ $a->[1] cmp $b->[1]}
map {[$_, inet_aton($data{$_}{ip})]} keys %data;