Problems with Net::Packet (newbie)

admiralfreezbee has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

First of all: I'm a total newbie so sorry if I ask some basic question. I'm trying to write some kind of simplified DHCPv6 client/server application.

To do this I have my own subroutine that makes a DHCPv6 packet. That has to be wrapped in a UDP packet -> IP packet -> Ethernet packet (so I think, please correct me if I'm wrong).

This is my code:

$eth = Net::Packet::ETH->new(src=>$mac_end1,dst=>'ff:ff:ff:ff:ff:ff',t
+ype=>'34525');
$ip6 = Net::Packet::IPv6->new(dst => 'FF02::1:2');
$udp = Net::Packet::UDP->new(src=>546,dst=>547);
$data = make_sollicit();
$frame = Net::Packet::Frame->new(l2=>$eth,l3=>$ip6,l4=>$udp,l7=>$data)
+;
$frame->send();
[download]

The make sollicit is my own subroutine that generates the DHCPv6 packet. Now when I execute this, perl says: 'Can't call method getLength without a package or object reference at /usr/local/lib/perl/5.8.7/Net/Packet/UDP.pm line 114'

I'm guessing it's a simple mistake in the use of the Net::Packet modules. Can anyone help me? Or is there a better alternative to do this? I didn't find much more support for IPv6

Comment on Problems with Net::Packet (newbie) Select or Download Code

Replies are listed 'Best First'.
Re: Problems with Net::Packet (newbie) by fizbin (Chaplain) on Sep 13, 2005 at 16:47 UTC
Another poster has pointed out that the problem is that the argument in "l7" that you're passing to `Net::Packet::Frame->new` isn't a `Net::Packet` object. Therefore, let's fix that: `$eth = Net::Packet::ETH->new(src=>$mac_end1,dst=>'ff:ff:ff:ff:ff:ff',t +ype=>'34525'); $ip6 = Net::Packet::IPv6->new(dst => 'FF02::1:2'); $udp = Net::Packet::UDP->new(src=>546,dst=>547); $data = Net::Packet::Layer7->new(data => make_sollicit()); $frame = Net::Packet::Frame->new(l2=>$eth,l3=>$ip6,l4=>$udp,l7=>$data) +; $frame->send();` [download] Either that, or you could change `make_sollicit` so that it returns its data wrapped up in a `Net::Packet::Layer7` object. -- `@/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/; map{y/X_/\n /;print}map{pop@$_}@/for@/` [download]	[reply] [d/l] [select]
Re^2: Problems with Net::Packet (newbie) by Anonymous Monk on Sep 14, 2005 at 07:13 UTC
Thanks that did the trick! I still have weird problems but I'll try to solve them first without bothering you guys!	[reply]
Re: Problems with Net::Packet (newbie) by davidrw (Prior) on Sep 13, 2005 at 15:55 UTC
This is that line in the Net/Packet/UDP.pm source: `$totalLength += $frame->l7->getLength if $frame->l7;` [download] So it is expecting that `$frame->17` be an object that has a `getLength` method... in your case `$frame->17` is your `$data`, which is your `make_sollicit()`, so the question is, what exactly is `make_sollicit()`? Can you rewrite it so that it returns an object that supports getLength() ?	[reply] [d/l] [select]