143e89c2f1
If the kernel sends notification of an optimistic address then treat is a useable address (isGlobalPreferred()). Note that addresses flagged as IFA_F_OPTIMISTIC are simultaneously flagged as IFA_F_TENTATIVE (when the tentative state has cleared either DAD has succeeded or failed, and both flags are cleared regardless). Additionally: do not consider RFC 4193 ULA addresses sufficient for "global preffered". They are, by definition, of global scope but not sufficient for global reachability. Bug: 17769720 Change-Id: I759623b28fd52758f2d4d76d167f3cafd9319d6a