[NETFRAME] Problems with packing an IP packet

[Matthew Topper]

I'm having some strange things happen with Net::Frame::Layer::IPv4 and pack.

What I'm doing is creating a dhcp request from scratch ( my $dhcp = "\x01"
etc etc ).  Then, I create a UDP message with Net::Frame::Layer::UDP,
including $dhcp as the payload.  Then, I create an IP packet with
Net::Frame::Layer::IPv4 with the results of $udp->pack as its payload.

If I do the following, the results look right:

my $data = $udp->pack;
my $whole = unpack 'H*', $data;
print "The whole UDP part: $whole\n";

What prints out looks like it's supposed to.  However, when I do the same
thing with the IP part, strange things happen.  I get this:

The whole thing: 4500015ca91d00008011907400000000ffffffff

Here's the diagnostics that I put into the program:

UDP Headers:
4e65743a3a4672616d653a3a4c617965723a3a5544503d41525241592830783832376438333029
UDP Payload:
01010600a99b02f50000800000000000000000000000000000000000000c6eb78dca00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000638253633501013709011c02030f060c2c2fff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
UDP Fields:  UDP: src:68  dst:67  length:328  checksum:0x87a4

UDP WHOLE:
00440043014887a401010600a99b02f50000800000000000000000000000000000000000000c6eb78dca00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000638253633501013709011c02030f060c2c2fff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
IP Headers:
4e65743a3a4672616d653a3a4c617965723a3a495076343d41525241592830783834373534353029
IP Payload:
00440043014887a401010600a99b02f50000800000000000000000000000000000000000000c6eb78dca00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000638253633501013709011c02030f060c2c2fff0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
IP Fields:  IPv4: version:4  hlen:5  tos:0x00  length:348  id:43293
IPv4: flags:0x00  offset:0  ttl:128  protocol:0x11  checksum:0x9074
IPv4: src:0.0.0.0  dst:255.255.255.255

The whole thing: 4500015ca91d00008011907400000000ffffffff


The lines that say headers are generated by doing this:
my $string = unpack "H*", $udp;
print "UDP Headers: $string\n";

Would parts of the source be useful in helping to diagnose this?  Am I going
about this in the wrong way? Thank you for any help.

Matthew Topper
SUNY Geneseo
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