Available configuration variables:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

CONFIG_AUTO_ROUTES	Device routes are added automagically by the kernel
CONFIG_SELF_CONSCIOUS	We're able to recognize whether route was installed by us
CONFIG_MULTIPLE_TABLES	The kernel supports multiple routing tables
CONFIG_ALL_TABLES_AT_ONCE	Kernel scanner wants to process all tables at once
CONFIG_MC_PROPER_SRC	Multicast packets have source address according to socket saddr field
CONFIG_RESTRICTED_PRIVILEGES	Implements restricted privileges using drop_uid()

CONFIG_UNIX_IFACE	Use Unix interface scanner
CONFIG_UNIX_SET		Use Unix route setting
CONFIG_UNIX_DONTROUTE   Use setsockopts DONTROUTE (undef for *BSD)
CONFIG_SKIP_MC_BIND	Don't call bind on multicast socket (def for *BSD)
CONFIG_LINUX_SCAN	Use Linux /proc/net/route scanner

CONFIG_ALL_MULTICAST	krt-iface: All devices support multicasting (i.e., ignore IFF_MULTICAST)
CONFIG_UNNUM_MULTICAST	krt-iface: We support multicasts on unnumbered PtP devices

CONFIG_LINUX_MC_MREQN	Linux: Use struct mreqn for multicasting
CONFIG_LINUX_MC_MREQ	Linux: Use struct mreq
CONFIG_LINUX_MC_MREQ_BIND	Linux: Use struct mreq and SO_BINDTODEVICE