CONFIG_MC_PROPER_SRC Multicast packets have source address according to socket saddr field
CONFIG_SKIP_MC_BIND Don't call bind on multicast socket (def for *BSD)
+CONFIG_NO_IFACE_BIND Bind to iface is not available, use workarounds (def for *BSD)
CONFIG_UNIX_DONTROUTE Use setsockopts DONTROUTE (undef for *BSD)
+CONFIG_USE_HDRINCL Use IP_HDRINCL instead of control messages for source address on raw IP sockets.
CONFIG_RESTRICTED_PRIVILEGES Implements restricted privileges using drop_uid()