Re: kern/51301: 7.99.32 has broken IPv6 functionality of pkgsrc/net/openvpn

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Sat, Jul 2, 2016 at 4:00 PM, Paul Goyette <paul%whooppee.com@localhost> wrote:
> The following reply was made to PR kern/51301; it has been noted by GNATS.
>
> From: Paul Goyette <paul%whooppee.com@localhost>
> To: gnats-bugs%NetBSD.org@localhost
> Cc:
> Subject: Re: kern/51301: 7.99.32 has broken IPv6 functionality of pkgsrc/net/openvpn
> Date: Sat, 2 Jul 2016 14:55:28 +0800 (PHT)
>
>  Bisecting the time period between working and non-working kernels gets
>  us to the following commit.  A kernel built from sources just before
>  this commit works, while a kernel built from after the commits fails.

Thank your for the investigation. Could you provide outputs of
ifconfig tun0 and netstat -nr -f inet6 with kernels w/ and w/o the commit?

  ozaki-r

>
>  Module Name:    src
>  Committed By:   ozaki-r
>  Date:           Thu Jun 30 01:34:53 UTC 2016
>
>  Modified Files:
>           src/sys/net: if_spppsubr.c
>           src/sys/netinet: if_arp.c in.c
>           src/sys/netinet6: in6.c nd6.c
>
>  Log Message:
>  Make sure that ifaddr is published after its initialization finished
>
>  Basically we should insert an item to a collection (say a list) after
>  item's initialization has been completed to avoid accessing an item
>  that is initialized halfway. ifaddr (in{,6}_ifaddr) isn't processed
>  like so and needs to be fixed.
>
>  In order to do so, we need to tweak {arp,nd6}_rtrequest that depend
>  on that an ifaddr is inserted during its initialization; they explore
>  interface's address list to determine that rt_getkey(rt) of a given
>  rtentry is in the list to know whether the route's interface should
>  be a loopback, which doesn't work after the change. To make it work,
>  first check RTF_LOCAL flag that is set in rt_ifa_addlocal that calls
>  {arp,nd6}_rtrequest eventually. Note that we still need the original
>  code for the case to remove and re-add a local interface route.
>
>
>  To generate a diff of this commit:
>  cvs rdiff -u -r1.143 -r1.144 src/sys/net/if_spppsubr.c
>  cvs rdiff -u -r1.213 -r1.214 src/sys/netinet/if_arp.c
>  cvs rdiff -u -r1.168 -r1.169 src/sys/netinet/in.c
>  cvs rdiff -u -r1.201 -r1.202 src/sys/netinet6/in6.c
>  cvs rdiff -u -r1.197 -r1.198 src/sys/netinet6/nd6.c
>
>
>
>  +------------------+--------------------------+------------------------+
>  | Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
>  | (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
>  | Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
>  +------------------+--------------------------+------------------------+
>