Don't check that the ipv6 source address of a neighbor advertisment is
from a neighbor's address. Sthen@ dug out RFC 4861 4.4 that says that
the source address is "An address assigned to the interface from which
the advertisement is sent." -- which can be from a network that the
receiver does not know about. Indeed my provider sends such a neighbor
advertisment for my default gateway, which breaks my uplink.
Claudio@ added this check for symetry with NetBSD code when he added
the same check to nd6_ns_input(), where it is needed to fix
CVE-2008-2476. See also OpenBSD 4.2 errata 15.
ok claudio@, kn@
UnifiedSplitRaw