memset (&mreq, 0, sizeof (mreq));
memcpy (&mreq.ipv6mr_multiaddr,
&addr->sin6_addr, sizeof (addr->sin6_addr));
mreq.ipv6mr_interface = 0; /* any */
memset (&mreq, 0, sizeof (mreq));
memcpy (&mreq.ipv6mr_multiaddr,
&addr->sin6_addr, sizeof (addr->sin6_addr));
mreq.ipv6mr_interface = 0; /* any */