Re: [asio-users] Boost.Asio Multicast on a host with multiple interfaces - filtering/knowing on incoming interface

[Ramon C. <ram...@ct...>]

Re,

Answering my own question, this seems to work and is slightly more portable
than IP_PKTINFO. I am not sure that SO_BINDTODEVICE is available in all
targeted systems in order to suggest the option to be included in a new
release :)

Apologies for the inconvenience this may have caused. 

Let me thank Christoff for the excellent library that Boost.Asio is. 

Ramon.



aio::ip::address if_address        = aio::ip::address::from_string
(if_address_str);
aio::ip::address multicast_address = aio::ip::address::from_string
("224.0.0.1");

// bind address
aio::ip::address listen_address    = multicast_address;
aio::ip::udp::endpoint listen_endpoint(listen_address, port_);

// open the socket
socket_.open (listen_endpoint.protocol());

// SO_BINDTODEVICE				
if ((::setsockopt (socket_.native(), SOL_SOCKET, SO_BINDTODEVICE, 
    ifp_->name().c_str(), ifp_->name().size() + 1) == -1))
{
	throw std::runtime_error("setsockopt() SO_BINDTODEVICE");

} 

// bind
socket_.set_option (aio::ip::udp::socket::reuse_address(true));

socket_.bind (listen_endpoint);						

// disable loopback
socket_.set_option(aio::ip::multicast::enable_loopback(false));

// set oif - the socket will use this interface as outgoing interface
socket_.set_option(aio::ip::multicast::outbound_interface(if_address.to_v4()
));

// set mcast group - join group - 				
socket_.set_option(aio::ip::multicast::join_group(multicast_address.to_v4(),
if_address.to_v4()));