I am looking for a way to accurately get the URL data from the tcp->{data} value using NetPacket. What I have right now seems to work but the data I am getting is sometimes incomplete. Any help on making this more accurate? What I need to do is quickly detect executable, pdf or other downloads so my other app can use the URL to retrieve the binary, analyze it and then if something is out of the ordinary perform further actions. 
...
my $object = Net::Pcap::open_live($dev, 1024, 1, 0, \$err);
...

sub token_data {
 my $data = shift;
 my @items = split (/\n|\r\n|\r/,$data);
 my $item;

 my $host = '';
 my $uri = '';
foreach $item (@items) {
        if ($item =~ /GET\s+(.*)\s+HTTP.*/) {
                $uri= $1;
        }
        if ($item =~ /Host:\s+(.*)/) {
                $host = $1;
        }
        if ($item =~ /User-Agent:\s+(.*)/) {
                $agent = $1;
                $agent =~ s/\(//g;
                $agent =~ s/\)//g;
        }
 }

 return "$host,$uri,$agent";
}


sub process_packet {
        my($user_data, $header, $pkt) = @_;
        my $ether_data = NetPacket::Ethernet::strip($pkt);
        my $ip = NetPacket::IP->decode($ether_data);
        my $tcp = NetPacket::TCP->decode(ip_strip(eth_strip($pkt)));

        if ($tcp->{data} =~ /GET|POST|get|post/) {
           if ($tcp->{data} =~ /.*Host:\s+(.*)/) {
              my $result = token_data ($tcp->{data});
              print "DEBG::$ip->{'src_ip'},$ip->{'dest_ip'},$tcp->{'de
+st_port'},$result\n";
              
           }
        }
}

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In reply to libpcap, netpacket and decoding http data by gk2010

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