On 21/12/15(Mon) 22:29, Vincent Gross wrote:
> On 12/21/15 11:36, Martin Pieuchot wrote:
> > Currently if you try to configure the same IPv6 address twice via the
> > SIOCAIFADDR_IN6 ioctl(2) the kernel will return EEXIST and the address
> > will be unset:
> >
> > # ifconfig vether0 inet6 2001::1
> > # ifconfig vether0 inet6 2001::1
> > ifconfig: SIOCAIFADDR: File exists
> >
> > Diff below fixes that by not inserting the local route if we're "just"
> > updating an existing address. sebastia@ confirmed it fixes his use
> > case, so I'm looking for oks.
> >
> > Index: netinet6/in6.c
> > ===================================================================
> > RCS file: /cvs/src/sys/netinet6/in6.c,v
> > retrieving revision 1.181
> > diff -u -p -r1.181 in6.c
> > --- netinet6/in6.c 3 Dec 2015 13:13:42 -0000 1.181
> > +++ netinet6/in6.c 18 Dec 2015 09:27:18 -0000
> [...]
> > @@ -454,12 +454,15 @@ in6_control(struct socket *so, u_long cm
> > return (EINVAL);
> > }
> >
> > + if (ia6 == NULL)
> > + newifaddr = 1;
> > +
> > /*
> > * Make the address tentative before joining multicast
> > * addresses, so that corresponding MLD responses would
> > * not have a tentative source address.
> > */
> > - if ((ia6 == NULL) && in6if_do_dad(ifp))
> > + if (newifaddr && in6if_do_dad(ifp))
> > ifra->ifra_flags |= IN6_IFF_TENTATIVE;
> >
> > /*
> [...]
> > @@ -489,6 +493,9 @@ in6_control(struct socket *so, u_long cm
> > /* Perform DAD, if needed. */
> > if (ia6->ia6_flags & IN6_IFF_TENTATIVE)
> > nd6_dad_start(&ia6->ia_ifa);
> > +
> > + if (!newifaddr)
> > + break;
> >
> > plen = in6_mask2len(&ia6->ia_prefixmask.sin6_addr, NULL);
> > if ((ifp->if_flags & IFF_LOOPBACK) || plen == 128) {
> >
>
> The "if (!newaddr)" should be moved above the "if (IN6_IFF_TENTATIVE)" ;
> this way the skipping of DAD when !newaddr is more explicit.
Thanks for the review, I just committed an updated version.
