// Winsock commodities :)
typedef unsigned int SOCKET;
const unsigned int INVALID_SOCKET = -1;
static SOCKET Connect(const std::string &interfaceIP, const std::string &bindIP, unsigned int port)
{
// Create UDP socket.
SOCKET sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (INVALID_SOCKET != sock_fd)
{
// "Share" socket address.
int sockOpt = 1;
setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, reinterpret_cast<char*>(&sockOpt), sizeof(int));
// Enlarge (or embiggen, if you will) recv. buffer.
sockOpt = 1024*512; // 0x80000;
setsockopt(sock_fd, SOL_SOCKET, SO_RCVBUF, reinterpret_cast<char *>(&sockOpt), sizeof(int));
// Bind to interface(s).
sockaddr_in address;
memset(&address, 0, sizeof(sockaddr_in));
address.sin_family = AF_INET;
address.sin_port = htons(port);
address.sin_addr.s_addr = inet_addr(interfaceIP.c_str()); /* INADDR_ANY */
int addrLen = sizeof(sockaddr_in);
if (0 == bind(sock_fd, reinterpret_cast<sockaddr *>(&address), addrLen))
{
// Join multicast.
ip_mreq multicast;
multicast.imr_multiaddr.s_addr = inet_addr(bindIP.c_str());
multicast.imr_interface = address.sin_addr;
if (0 == setsockopt(sock_fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, reinterpret_cast<char *>(&multicast), sizeof(ip_mreq)))
{
// Non-blocking socket, please.
// fcntl(sock_fd, F_SETFL, O_NONBLOCK);
std::cout << "Socket joined multicast: " << bindIP.c_str() << ":" << port << std::endl;
return sock_fd;
}
}
close(sock_fd);
}
std::cout << "Failed to join multicast: " << bindIP.c_str() << ":" << port << std::endl;
return INVALID_SOCKET;
}