#!/usr/bin/perl -w
# bmc@shmoo.com

use strict;
use warnings;
use Net::Pcap;

my $err;

die "$0 <delay> <input> <output>\n" if (scalar(@ARGV) != 3);
my ($delay, $input, $output) = @ARGV;

my $in = Net::Pcap::open_offline($input, \$err) || die "Cant open input file: $err";
my $out = Net::Pcap::dump_open($in, $output) || die Net::Pcap::geterr($in);
Net::Pcap::loop($in, -1, \&process, '');
Net::Pcap::close($in);
Net::Pcap::dump_close($out);

{
    my $time;
    my $count = 0;

    sub process {
        my ($data, $hdr, $pkt) = @_;
        if (!$time) {
            $time = $hdr->{'tv_sec'};
            $count = 0;
        }
        $hdr->{'tv_sec'} = $time + ($delay * $count);
        $count++;

        Net::Pcap::dump($out, $hdr, $pkt);
    }
}