IFA_F_OPTIMISTIC is not supported?

IFA_F_OPTIMISTIC is not supported?

[soohoon.lee]

rtm_newaddr masks off OPTIMISTIC.

inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
...
        /* We ignore other flags so far. */
        ifa_flags &= IFA_F_NODAD | IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
                     IFA_F_NOPREFIXROUTE;

Is there any problem or not allowed?

I need to do something like adding a route for the address after adding the address but fails because the address is not useable yet.
I tried NODAD but there's still little delay until IFA_F_TENTATIVE is cleared.
	- rtm_newaddr sets IFA_F_TENTATIVE
	- set a timer for dad start with delay=0
	- some delay
	- dad starts but ends immediately because of NODAD flag, and clears TENTATIVE.

And it looks like OPTIMISTIC does what I need but kind of disabled like the code above.

Thanks,
Soohoon.

Re: IFA_F_OPTIMISTIC is not supported?

[Sabrina Dubroca]

2017-09-08, 10:29:03 -0400, soohoon.lee@f5.com wrote:
> rtm_newaddr masks off OPTIMISTIC.
> 
> inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
> ...
>         /* We ignore other flags so far. */
>         ifa_flags &= IFA_F_NODAD | IFA_F_HOMEADDRESS | IFA_F_MANAGETEMPADDR |
>                      IFA_F_NOPREFIXROUTE;
> 
> Is there any problem or not allowed?

I was planning to submit a patch to allow that soon (when net-next
reopens). While testing, I've found you need a few other small changes
once you allow userspace to set the optimistic flag on addresses.


Thanks,

-- 
Sabrina