I find this code and it sends UDP packet and all information in is ok, But in Ethernet header layer i find that the source mac-address is like: fe:ff:ff:ff:ff:ff So i ask how can i control the source mac address? How can i make sub-function to return the ethernet layer and i control of it like other layers?
#!/usr/bin/perl
######################################################################
+####
# Author: Lucas Thoresen
+ #
# Attribution: cleen -> http://www.perlmonks.org/index.pl?node_id=1757
+6 #
# Date: December 8, 2012
+ #
# Purpose: To demonstrate Perl UDP packet generation.
+ #
# Hopefully someone will find this useful. :]
+ #
######################################################################
+####
use strict;
use warnings;
use Socket;
# Source and destination IP/Hostname
my $ip_src = (gethostbyname($ARGV[0]))[4];
my $ip_dst = (gethostbyname($ARGV[1]))[4];
# Check to see if all parameters are present
if (!defined $ip_src or !defined $ip_dst) {
exit "Usage: $0 <source ip> <destination ip>\n";
}
# Setup the socket to be used 255 is IPPROTO_RAW)
socket(RAW, AF_INET, SOCK_RAW, 255) or die $!;
setsockopt(RAW, 0, 1, 1);
main();
# Main program
sub main {
my $packet;
# Add the layer 3 and 4 headers
$packet = ip_header();
$packet .= udp_header();
# Add in a data section
$packet .= payload();
# Fire!
send_packet($packet);
}
# Builds an IP header (Layer 3)
sub ip_header {
my $ip_ver = 4; # IP Version 4
+ (4 bits)
my $ip_header_len = 5; # IP Header Length
+ (4 bits)
my $ip_tos = 0; # Differentiated Servic
+es (8 bits)
my $ip_total_len = $ip_header_len + 20; # IP Header Length + Da
+ta (16 bits)
my $ip_frag_id = 0; # Identification Field
+ (16 bits)
my $ip_frag_flag = '000'; # IP Frag Flags (R DF M
+F) (3 bits)
my $ip_frag_offset = '0000000000000'; # IP Fragment Offset
+ (13 bits)
my $ip_ttl = 255; # IP TTL
+ (8 bits)
my $ip_proto = 17; # IP Protocol
+ (8 bits)
my $ip_checksum = 0; # IP Checksum
+ (16 bits)
my $ip_header = pack(
'H2 H2 n n B16 h2 c n a4 a4',
$ip_ver . $ip_header_len, $ip_tos, $ip_total_len,
$ip_frag_id, $ip_frag_flag . $ip_frag_offset,
$ip_ttl, $ip_proto, $ip_checksum,
$ip_src,
$ip_dst
);
return $ip_header;
}
# Builds a UDP header (Layer 4)
sub udp_header {
my $udp_src_port = 60; # UDP Sort Port
+ (16 bits)
my $udp_dst_port = 60; # UDP Dest Port
+ (16 btis)
my $udp_len = 8 + length(payload()); # UDP Length
+ (16 bits)
my $udp_checksum = 0; # UDP Checksum
+ (16 bits)
my $udp_header = pack(
'n n n n',
$udp_src_port, $udp_dst_port,
$udp_len, $udp_checksum
);
return $udp_header;
}
# Builds a data section
sub payload {
my $data = 'abcdefghijklmnopqrstuvwxyz hi';
# Pack the data in dynamically
my $payload = pack(
'a' . length($data), $data
);
return $payload;
}
# Send the packet
sub send_packet {
# @_ doesn't work, you need to use $_[0] as the param to the send
+sub!
send(RAW, $_[0], 0, pack('Sna4x8', AF_INET, 60, $ip_dst));
}
