isisd, ospf6d, ripngd: Do not allow v6 LL's to be redist connected in

The rib process of handling routes has been unified a bit more
and as a result v6 LL routes are now showing up as a result
of a `redistribute connected`.  Doing anything with these
routes is a policy decision that should be enforced by the
individual routing daemons not by zebra.  As such add a bit
of code to isisd, ripngd and opsf6d to handle them.  The bgp daemon
already handles this situation.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

isisd/isis_zebra.c

@@ -362,6 +362,10 @@ static int isis_zebra_read(int command, struct zclient *zclient,
 	if (zapi_route_decode(zclient->ibuf, &api) < 0)
 		return -1;
 
+	if (api.prefix.family == AF_INET6
+	    && IN6_IS_ADDR_LINKLOCAL(&api.prefix.u.prefix6))
+		return 0;
+
 	/*
 	 * Avoid advertising a false default reachability. (A default
 	 * route installed by IS-IS gets redistributed from zebra back

ospf6d/ospf6_zebra.c

@@ -226,6 +226,9 @@ static int ospf6_zebra_read_route(int command, struct zclient *zclient,
 	if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 		return 0;
 
+	if (IN6_IS_ADDR_LINKLOCAL(&api.prefix.u.prefix6))
+		return 0;
+
 	ifindex = api.nexthops[0].ifindex;
 	nexthop = &api.nexthops[0].gate.ipv6;
 

ripngd/ripng_zebra.c

@@ -126,6 +126,9 @@ static int ripng_zebra_read_route(int command, struct zclient *zclient,
 	if (CHECK_FLAG(api.message, ZAPI_MESSAGE_SRCPFX))
 		return 0;
 
+	if (IN6_IS_ADDR_LINKLOCAL(&api.prefix.u.prefix6))
+		return 0;
+
 	nexthop = api.nexthops[0].gate.ipv6;
 	ifindex = api.nexthops[0].ifindex;