I am learning network programming.
My current I idea is to create an application to benchmark multicast
performance.
I am having trouble enabling a socket to receive multicast traffic.
Below is a sample of my code. I have used hard coded socket option
constants as I have found no definitive header file.
When the MC group join executes, setsockopt() returns an unknown
error.
Can someone show me the proper sequence to enable a socket to
receive multicast traffic.
use strict;
use Socket;
my $IPPROTO_IP = getprotobyname ('ip');
# IPPROTO Level Options
my $IP_ADD_MEMBERSHIP = 5; # set only
my $IP_DROP_MEMBERSHIP = 6; # set only
my $IP_MULTICAST_IF = 2; # get/set
my $IP_MULTICAST_LOOP = 4; # get/set
my $IP_MULTICAST_TTL = 3; # get/set
my $IP_OPTIONS = 1;
my $SOL_SOCKET = 0xffff;
# SOCKET Level Options
my $SO_DEBUG = 1;
my $SO_ACCEPTCONN = 2;
my $SO_REUSEADDR = 4;
my $SO_KEEPALIVE = 8;
my $SO_DONTROUTE = 16;
my $SO_BROADCAST = 32;
my $SO_USELOOPBACK = 64;
my $SO_LINGER = 128;
my $SO_OOBINLINE = 256;
my $SO_SNDBUF = 0x1001;
my $SO_RCVBUF = 0x1002;
my $SO_SNDLOWAT = 0x1003;
my $SO_RCVLOWAT = 0x1004;
my $SO_SNDTIMEO = 0x1005;
my $SO_RCVTIMEO = 0x1006;
my $SO_ERROR = 0x1007;
my $SO_TYPE = 0x1008;
my $rxaddr = inet_aton ('192.168.1.101');
my $mcrxaddr = inet_aton ('239.255.255.123');
my $transport = getprotobyname ('udp');
my $rxport = 4001;
my $ucreceiver = sockaddr_in ($rxport, $rxaddr);
my $mcreceiver = sockaddr_in ($rxport, $mcrxaddr);
socket (UDP_SOCK, PF_INET, SOCK_DGRAM, $transport) or die "udp_s2:
socket creation failed: $!n";
setsockopt (UDP_SOCK, $IPPROTO_IP, $SO_REUSEADDR, pack ("l", 0)) or
die ("Reuse");
setsockopt (UDP_SOCK, $SOL_SOCKET, $SO_RCVBUF, pack ("L", 233000))
or die ("RCVBUFF");
setsockopt (UDP_SOCK, $IPPROTO_IP, $IP_MULTICAST_LOOP, pack ("l",
0)) or die ("Loop");
bind (UDP_SOCK, $ucreceiver) or die "upd_s2: bind to address failed:
$!n";
setsockopt (UDP_SOCK, $IPPROTO_IP, $IP_ADD_MEMBERSHIP, $rxaddr) or
die "ADD MC GROUP: $!n";
close (UDP_SOCK);
.
