[ripd] bugs #261, #262: Fix RIPv1 info-leak and unauthenticated route updates

[ripd] bugs #261, #262: Fix RIPv1 info-leak and unauthenticated route updates

2006-05-04 Paul Jakma <paul.jakma@sun.com>

	* (general) Fixes for bugs #261 and 262. Thanks to
	  Konstantin V. Gavrilenko <kos@arhont.com> for the problem
	  reports, testing of a series of proposed patches and comment
	  on the proposed changes in behaviour.
	* rip_interface.c: (ip_rip_authentication_mode_cmd) Parse all
	  of the command before making any changes to configured state.
	* ripd.c: (rip_read) RIP version control should be absolute and
          always apply, fixes bug #261 by allowing RIPv1 to be disabled.
	  Fix bug #262: If authentication is enabled, then
	  unauthenticated packets should not be accepted. We do however
	  make an exception for RIPv1 REQUEST packets, to which we will
	  reply as RIPv1 can now be disabled fully, to allow ripd to
	  still provide routing /information/ to simple devices.