Debian Bug report logs - #815793
IPv6 code ignores unsolicited router advertisements

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: IPv6 code ignores unsolicited router advertisements

Date: Wed, 24 Feb 2016 15:01:09 +0100

[Message part 1 (text/plain, inline)]

Package: systemd
Version: 229-1
Severity: important

Hi,

systemd 229 seems to ignore unsolicited router advertisements. This
breaks, for example, prefix changes. And it prevents the self-healing
characteristics of lost router solicitations.

tcpdump logs this:
14:41:40.062484 7e:79:61:31:55:28 > 33:33:00:00:00:01, ethertype IPv6 (0x86dd), length 294: fe80::1 > ff02::1: ICMP6, router advertisement, length 240

ip -6 r shows this:
[10/507]mh@banana:~$ ip -6 route
2a01:238:4071:3282::/64 dev eth0  proto kernel  metric 256  pref medium
fe80::/64 dev eth0  proto kernel  metric 256  pref medium
[11/508]mh@banana:~$ 

"see, no default route"

setting accept_ra to 1 for eth0 manually (something which is no longer
possible with systemd 229 via systemd configuration) brings the system
online when the next router advertisements comes in:

[3/503]mh@banana:~$ ip -6 r
2a01:238:4071:3282::/64 dev eth0  proto kernel  metric 256  pref medium
fe80::/64 dev eth0  proto kernel  metric 256  pref medium
default via fe80::1 dev eth0  proto ra  metric 1024  expires 1791sec hoplimit 64 pref high
[4/504]mh@banana:~$

Gee, systemd 229 breaks IPv6 in so many different ways, maybe Upstream
should have asked someone who knows how IPv6 works.

This is very very frustrating.

Greetings
Marc


-- Package-specific info:

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.4.2-zgws1 (SMP w/8 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd depends on:
ii  adduser         3.113+nmu3
ii  libacl1         2.2.52-3
ii  libapparmor1    2.10-3
ii  libaudit1       1:2.4.5-1
ii  libblkid1       2.27.1-3
ii  libc6           2.21-9
ii  libcap2         1:2.24-12
ii  libcap2-bin     1:2.24-12
ii  libcryptsetup4  2:1.7.0-2
ii  libgcrypt20     1.6.5-2
ii  libgpg-error0   1.21-2
ii  libkmod2        22-1
ii  liblzma5        5.1.1alpha+20120614-2.1
ii  libmount1       2.27.1-3
ii  libpam0g        1.1.8-3.2
ii  libseccomp2     2.2.3-3
ii  libselinux1     2.4-3
ii  libsystemd0     229-1
ii  mount           2.27.1-3
ii  util-linux      2.27.1-3

Versions of packages systemd recommends:
ii  dbus            1.10.6-1
ii  libpam-systemd  229-1

Versions of packages systemd suggests:
pn  systemd-container  <none>
pn  systemd-ui         <none>

Versions of packages systemd is related to:
ii  udev  229-1

-- Configuration Files:
/etc/systemd/resolved.conf changed [not included]

-- no debconf information

[systemd-delta.txt (text/x-diff, attachment)]

[systemd-analyze-dump.txt (text/plain, attachment)]

[dsh-enabled.txt (text/plain, attachment)]

[fstab (text/plain, attachment)]

Message #12 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: Marc Haber <mh+debian-packages@zugschlus.de>, 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Sun, 28 Feb 2016 22:20:22 +0100

Hello Marc,

Marc Haber [2016-02-24 15:01 +0100]:
> systemd 229 seems to ignore unsolicited router advertisements. This
> breaks, for example, prefix changes. And it prevents the self-healing
> characteristics of lost router solicitations.

Can you please report this and also #815884 upstream? I don't know
much about IPv6 routing I'm afraid, so I think you are in a better
position to explain/discuss this with Tom. Some regressions are
already covered by https://github.com/systemd/systemd/issues/2572
but not these  two.

In the meantime, I reverted the networkd handling of RA to go back to
the pre-229 behaviour.

Many thanks!

Martin
-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

Message #17 received at 815793-close@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: 815793-close@bugs.debian.org

Subject: Bug#815793: fixed in systemd 229-2

Date: Sun, 28 Feb 2016 23:53:07 +0000

Source: systemd
Source-Version: 229-2

We believe that the bug you reported is fixed in the latest version of
systemd, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 815793@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Martin Pitt <mpitt@debian.org> (supplier of updated systemd package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Format: 1.8
Date: Sun, 28 Feb 2016 22:16:12 +0100
Source: systemd
Binary: systemd systemd-sysv systemd-container systemd-journal-remote systemd-coredump libpam-systemd libnss-myhostname libnss-mymachines libnss-resolve libsystemd0 libsystemd-dev udev libudev1 libudev-dev udev-udeb libudev1-udeb systemd-dbg
Architecture: source amd64
Version: 229-2
Distribution: unstable
Urgency: medium
Maintainer: Debian systemd Maintainers <pkg-systemd-maintainers@lists.alioth.debian.org>
Changed-By: Martin Pitt <mpitt@debian.org>
Description:
 libnss-myhostname - nss module providing fallback resolution for the current hostname
 libnss-mymachines - nss module to resolve hostnames for local container instances
 libnss-resolve - nss module to resolve names via systemd-resolved
 libpam-systemd - system and service manager - PAM module
 libsystemd-dev - systemd utility library - development files
 libsystemd0 - systemd utility library
 libudev-dev - libudev development files
 libudev1   - libudev shared library
 libudev1-udeb - libudev shared library (udeb)
 systemd    - system and service manager
 systemd-container - systemd container/nspawn tools
 systemd-coredump - tools for storing and retrieving coredumps
 systemd-dbg - system and service manager (debug symbols)
 systemd-journal-remote - tools for sending and receiving remote journal logs
 systemd-sysv - system and service manager - SysV links
 udev       - /dev/ and hotplug management daemon
 udev-udeb  - /dev/ and hotplug management daemon (udeb)
Closes: 814566 814667 815020 815586 815793 815884 816132
Changes:
 systemd (229-2) unstable; urgency=medium
 .
   * time-util: map ALARM clockids to non-ALARM clockids in now(), to work on
     architectures which don't support CLOCK_BOOTTIME_ALARM. Fixes FTBFS on
     many architectures.
   * debian/systemd.postinst: Add missing newline to /etc/adjtime migration.
     (See #699554)
   * debian/systemd.postinst: Only try to enable tmp.mount if we actually
     copied it to /etc. Don't try to enable a generated unit. (LP: #1545707)
   * debian/tests/boot-and-services: Increase timeouts of test_bash_crash from
     5 to 10 seconds, and sync the journal after every iteration.
   * debian/extra/checkout-upstream: Try again after one minute if git checkout
     fails, to avoid failures from transient network errors.
   * debian/tests/systemd-fsckd: Use grub.d/50-cloudimg-settings.cfg as a
     template for generating our custom one instead of 90-autopkgtest.cfg. The
     latter does not exist on non-x86 architectures and is not relevant for
     this test.
   * debian/tests/boot-and-services: Skip journal test for test_bash_crash when
     running against upstream, as this currently fails most of the time. To be
     investigated.
   * debian/tests/networkd: Skip test_coldplug_dhcp_ip6 when running against
     upstream, as this is brittle there. To be investigated.
   * debian/tests/bootchart: Skip test if bootchart is not available or
     testing in upstream mode. bootchart got removed from master and will be
     moved to a separate repository.
   * debian/tests/boot-and-services: Show verbose journal output on failure in
     nspawn test, and sync journal before.
   * Move systemd-coredump socket and service into systemd-coredump binary
     package.
   * Revert changing the default core dump ulimit and core_pattern. This
     completely breaks core dumps without systemd-coredump. It's also
     contradicting core(8). (Closes: #815020)
   * Fix addresses for type "sit" tunnels. (Closes: #816132)
   * networkd: Go back to letting the kernel handle IPv6 router advertisements,
     as networkd's own currently has too many regressions. Thanks to Stefan
     Lippers-Hollmann for investigating this! (Closes: #814566,
     #814667, #815586, #815884, #815793)
Checksums-Sha1:
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 8f3f64e84bafa88d09952c5159f9b81a8e9f84dc 104192 libudev1_229-2_amd64.deb
 0ea74f0b64e0ece3104e2e7d47ec4d6961e03d6a 701838 systemd-container_229-2_amd64.deb
 856d3b5bbdd54786258a5bb1d7e9eb9737fd09f2 159860 systemd-coredump_229-2_amd64.deb
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 b66616a95d942dae475835f577eec0de120c86e6 61742 systemd-sysv_229-2_amd64.deb
 31f95d47c325286a304e58c72f4591b058eba2e7 3654292 systemd_229-2_amd64.deb
 eaeb339dbdc48e27a9fe4a0a23470a0b402e5602 266906 udev-udeb_229-2_amd64.udeb
 9bc0f1b3fb361f98eaac88a2df1ac06797c07b17 1039278 udev_229-2_amd64.deb
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 ef37d07be01e3cdd8611ab246526153886168b61005fe5eaa0286e6d529afd90 164916 libnss-resolve_229-2_amd64.deb
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Files:
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 da34adb504cc69ca1c00265fb85cdb91 120360 admin optional systemd_229-2.debian.tar.xz
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 084324f2bb552d1d8d6dbd51b30a85e3 165672 admin extra libnss-mymachines_229-2_amd64.deb
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Package-Type: udeb

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Message #22 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Mon, 29 Feb 2016 10:20:19 +0100

Hi Martin,

On Sun, Feb 28, 2016 at 10:20:22PM +0100, Martin Pitt wrote:
> Marc Haber [2016-02-24 15:01 +0100]:
> > systemd 229 seems to ignore unsolicited router advertisements. This
> > breaks, for example, prefix changes. And it prevents the self-healing
> > characteristics of lost router solicitations.
> 
> Can you please report this and also #815884 upstream? I don't know
> much about IPv6 routing I'm afraid, so I think you are in a better
> position to explain/discuss this with Tom. Some regressions are
> already covered by https://github.com/systemd/systemd/issues/2572
> but not these  two.

I think that it would not be productive if I tried communicating with
systemd upstream. We both consider each other toxic, and I'd rather
not mess with my sanity trying to be nice to a <censored>.

I lost my temper on systemd-devel in december and cannot write there
any more due to policy decision of the list owner. I doubt that a bug
report filed by me would get any helpful upstream attention.

So, I regret that in this case my answer is thanks, but no thanks.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #33 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: Marc Haber <mh+debian-packages@zugschlus.de>, 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 08:57:43 +0200

Control: reopen -1
Control: tag -1 moreinfo

Hello Marc,

while we reverted the change in 229, we don't want to carry the
reversion forever. Also, some problems were fixed already in 230, like
[1]. I forwarded this upstream to
https://github.com/systemd/systemd/issues/3663, and will now play
relay :-)

Marc Haber [2016-02-24 15:01 +0100]:
> systemd 229 seems to ignore unsolicited router advertisements. This
> breaks, for example, prefix changes. And it prevents the self-healing
> characteristics of lost router solicitations.
> 
> tcpdump logs this:
> 14:41:40.062484 7e:79:61:31:55:28 > 33:33:00:00:00:01, ethertype IPv6 (0x86dd), length 294: fe80::1 > ff02::1: ICMP6, router advertisement, length 240

Do you have some instructions how this can be reproduced? It sounds
like it should be possible to test this using a veth pair, possibly a
dnsmasq on one end, and some ip commands. Then I'd like to write a
test case for [2].

If this is hardware specific, can you please try this with 230 with
the patch reverted? I build packages for amd64 here:
https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
(there's also a Packages.gz so this can be used as an apt deb line)
There were a lot of changes to the RA handling in 230.

If it still happens, can you please run it in debugging mode with

  systemd-analyze set-log-level debug
  systemctl restart systemd-networkd

then reproduce the bug, and finally

  systemd-analyze set-log-level info
  journalctl -u systemd-networkd.service > /tmp/networkd.log

and append the log file here?

Thanks!

[1] https://github.com/systemd/systemd/issues/2572
[2] https://github.com/systemd/systemd/blob/master/test/networkd-test.py
-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

Message #44 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 09:03:04 +0200

Hi Martin,

On Wed, Jul 06, 2016 at 08:57:43AM +0200, Martin Pitt wrote:
> while we reverted the change in 229, we don't want to carry the
> reversion forever. Also, some problems were fixed already in 230, like
> [1]. I forwarded this upstream to
> https://github.com/systemd/systemd/issues/3663, and will now play
> relay :-)

Thanks for your consideration.

> Do you have some instructions how this can be reproduced? It sounds
> like it should be possible to test this using a veth pair, possibly a
> dnsmasq on one end, and some ip commands. Then I'd like to write a
> test case for [2].
> 
> If this is hardware specific, can you please try this with 230 with
> the patch reverted? I build packages for amd64 here:
> https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
> (there's also a Packages.gz so this can be used as an apt deb line)
> There were a lot of changes to the RA handling in 230.

I will try this, but since my current project is in a critical phase I
do not have too much time. I am confident that I can produce results
during july, but most probably not next weekend. I will keep you posted.

I recently bought new hardware for virtualization and will use
building the new system as test lab, so your request comes just at the
right time since I can now experiment without breaking productive
systems.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #49 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: Marc Haber <mh+debian-packages@zugschlus.de>, 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 09:29:35 +0200

Hey Marc,

Marc Haber [2016-07-06  9:03 +0200]:
> > Do you have some instructions how this can be reproduced? It sounds
> > like it should be possible to test this using a veth pair, possibly a
> > dnsmasq on one end, and some ip commands. Then I'd like to write a
> > test case for [2].
> > 
> > If this is hardware specific, can you please try this with 230 with
> > the patch reverted? I build packages for amd64 here:
> > https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
> > (there's also a Packages.gz so this can be used as an apt deb line)
> > There were a lot of changes to the RA handling in 230.
> 
> I will try this, but since my current project is in a critical phase I
> do not have too much time. I am confident that I can produce results
> during july, but most probably not next weekend. I will keep you posted.

Thanks. Testing the above packages will indeed take some time, but I
wondered if you could give me a hint whether this can be reproduced
with something like "set up a normal RA server/IPv6 networkd client"
(I know how to do that of course) and then change foo/run blah to
trigger this".

Thanks,

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

Message #54 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 09:42:33 +0200

On Wed, Jul 06, 2016 at 09:29:35AM +0200, Martin Pitt wrote:
> Marc Haber [2016-07-06  9:03 +0200]:
> > > Do you have some instructions how this can be reproduced? It sounds
> > > like it should be possible to test this using a veth pair, possibly a
> > > dnsmasq on one end, and some ip commands. Then I'd like to write a
> > > test case for [2].
> > > 
> > > If this is hardware specific, can you please try this with 230 with
> > > the patch reverted? I build packages for amd64 here:
> > > https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
> > > (there's also a Packages.gz so this can be used as an apt deb line)
> > > There were a lot of changes to the RA handling in 230.
> > 
> > I will try this, but since my current project is in a critical phase I
> > do not have too much time. I am confident that I can produce results
> > during july, but most probably not next weekend. I will keep you posted.
> 
> Thanks. Testing the above packages will indeed take some time, but I
> wondered if you could give me a hint whether this can be reproduced
> with something like "set up a normal RA server/IPv6 networkd client"
> (I know how to do that of course) and then change foo/run blah to
> trigger this".

I think this particular issue can be triggered by:

- set up a router running radvd
- start up a client with networkd and systemd IPv6 implementation
- manually remove any IPv6 address and IPv6 route from the client
- restart the radvd on the router

The client should pick up the prefix and route that the newly started
radvd announces. At least this would be my first test.

I _think_ that I stumbled upon this issue because the systemd IPv6
code sent out its _single_ router solicitation so early that the
network link was not yet up (thus, no IPv6 on the client), and then
proceeded to ignore the regular route updates sent out by the radvd
because it didn't ask for them.

Ignoring unsolicited announcements is state of the art for ARP and
DHCP to protect a system's caches against poisioning attacks, which is
probably the reason why this was implemented in systemd IPv6 code as
well. But, IPv6 works differently and it is necessary for network
functionality to listen and to act even on unsolicited router
announcements.

At least this is how I explained to myself why the code was written
this way. Too bad they didn't test it in reality but instead released
it.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #59 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: Marc Haber <mh+debian-packages@zugschlus.de>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 11:49:17 +0200

Hello Marc,

Marc Haber [2016-07-06  9:42 +0200]:
> I think this particular issue can be triggered by:
> 
> - set up a router running radvd
> - start up a client with networkd and systemd IPv6 implementation
> - manually remove any IPv6 address and IPv6 route from the client
> - restart the radvd on the router
> 
> The client should pick up the prefix and route that the newly started
> radvd announces. At least this would be my first test.

I did that now:

| ip link add name enc type veth peer name ens
| ip a add 2600::1/64 dev ens
| ip  link set ens up
|
| cat <<EOF > /tmp/ra.conf
| interface ens
| {
|    AdvSendAdvert on;
|    prefix 2600::1/64
|    {};
| };
| EOF
|
| radvd -C /tmp/ra.conf -n -m stderr -d2

Other terminal:

| mkdir -p /run/systemd/network
| cat <<EOF > /run/systemd/network/enc.network
| [Match]
| Name=enc
| 
| [Network]
| IPv6AcceptRouterAdvertisements=yes
| EOF
| 
| SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-networkd

I also ran "tcpdump -i ens" in parallel, as before. This does the
solicitation and picks up radvd's RA and I get some random 2600:*
address:

| Disc CLIENT: Received Router Advertisement: flags none preference medium lifetime 1800 sec
| NDisc CLIENT: Update prefix 2600:0000:0000:0000:0000:0000:0000:0001/64 lifetime 86400 expires in 1d
| ens: Updating address: 2600::7852:45ff:fed7:9ab4/64 (valid for 1d)

I now killed radvd, then "ip a del 2600:[..] dev enc", and restart
radvd. And once again networkd picks this up and adds an IPv6 address.

This looks the same for 229, 230/upstream and 230/sid (with the
reverted patch). Thus I cannot confirm that networkd ignores these
unsolicited router advertisements.

So re-trying with my test packages and getting a networkd debug log
would be appreciated. Thanks!

Martin
-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

Message #64 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 11:52:50 +0200

On Wed, Jul 06, 2016 at 11:49:17AM +0200, Martin Pitt wrote:
> This looks the same for 229, 230/upstream and 230/sid (with the
> reverted patch). Thus I cannot confirm that networkd ignores these
> unsolicited router advertisements.

Can you, just for reference, try with systemd 229-1, just to see
wheteher your setup triggers the bug in the same software version that
I reported it with?

> So re-trying with my test packages and getting a networkd debug log
> would be appreciated. Thanks!

Will try, but probably only later this or even next week.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #69 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Martin Pitt <mpitt@debian.org>

To: Marc Haber <mh+debian-packages@zugschlus.de>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 11:55:19 +0200

Hello Marc,

Marc Haber [2016-07-06 11:52 +0200]:
> On Wed, Jul 06, 2016 at 11:49:17AM +0200, Martin Pitt wrote:
> > This looks the same for 229, 230/upstream and 230/sid (with the
> > reverted patch). Thus I cannot confirm that networkd ignores these
> > unsolicited router advertisements.
> 
> Can you, just for reference, try with systemd 229-1

I did (that was the "229" above).

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

Message #76 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Wed, 6 Jul 2016 13:15:53 +0200

On Wed, Jul 06, 2016 at 11:55:19AM +0200, Martin Pitt wrote:
> Marc Haber [2016-07-06 11:52 +0200]:
> > On Wed, Jul 06, 2016 at 11:49:17AM +0200, Martin Pitt wrote:
> > > This looks the same for 229, 230/upstream and 230/sid (with the
> > > reverted patch). Thus I cannot confirm that networkd ignores these
> > > unsolicited router advertisements.
> > 
> > Can you, just for reference, try with systemd 229-1
> 
> I did (that was the "229" above).

Ah, I thought you meant 229 with the ipv6 code disabled. I will try to
reproduce things.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #83 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Fri, 15 Jul 2016 21:04:59 +0200

Hi Martin,

On Wed, Jul 06, 2016 at 08:57:43AM +0200, Martin Pitt wrote:
> while we reverted the change in 229, we don't want to carry the
> reversion forever. Also, some problems were fixed already in 230, like
> [1]. I forwarded this upstream to
> https://github.com/systemd/systemd/issues/3663, and will now play
> relay :-)
> 
> If this is hardware specific, can you please try this with 230 with
> the patch reverted? I build packages for amd64 here:
> https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
> (there's also a Packages.gz so this can be used as an apt deb line)
> There were a lot of changes to the RA handling in 230.

Unfortunately the system I have been seeing this on is a Banana Pi,
thus armhf, and I cannot run your test packages on this system. This
bug does not, however, show itself on a reference system running amd64
with 230-5pitti1.

I have found another showstopper IPv6 bug in 230-5pitti1 and have duly
reported it.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

Message #88 received at 815793@bugs.debian.org (full text, mbox, reply):

From: Marc Haber <mh+debian-packages@zugschlus.de>

To: Martin Pitt <mpitt@debian.org>

Cc: 815793@bugs.debian.org

Subject: Re: Bug#815793: IPv6 code ignores unsolicited router advertisements

Date: Sat, 16 Jul 2016 14:16:25 +0200

Hi Martin,

On Fri, Jul 15, 2016 at 09:04:59PM +0200, Marc Haber wrote:
> On Wed, Jul 06, 2016 at 08:57:43AM +0200, Martin Pitt wrote:
> > while we reverted the change in 229, we don't want to carry the
> > reversion forever. Also, some problems were fixed already in 230, like
> > [1]. I forwarded this upstream to
> > https://github.com/systemd/systemd/issues/3663, and will now play
> > relay :-)
> > 
> > If this is hardware specific, can you please try this with 230 with
> > the patch reverted? I build packages for amd64 here:
> > https://people.debian.org/~mpitt/tmp/systemd-userspace-ndisc/
> > (there's also a Packages.gz so this can be used as an apt deb line)
> > There were a lot of changes to the RA handling in 230.
> 
> Unfortunately the system I have been seeing this on is a Banana Pi,
> thus armhf, and I cannot run your test packages on this system. This
> bug does not, however, show itself on a reference system running amd64
> with 230-5pitti1.

I regret to inform you that we have a heisenbug here. When
reconfiguring and restarting radvd, systemd sometimes decides to act
on the new announcement, and sometimes doesn't.

For example, after receiving this announcement:

13:40:23.075889 IP6 (flowlabel 0x4717d, hlim 255, next-header ICMPv6 (58) payload length: 240) fe80::1 > ff02::1: [icmp6 sum ok] ICMP6,
        hop limit 64, Flags [none], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
          prefix info option (3), length 32 (4): 2a01:db8:0::3282::/64, Flags [onlink, auto], valid time 86400s, pref. time 14400s
          route info option (24), length 24 (3):  ::/0, pref=high, lifetime=1800s
          route info option (24), length 24 (3):  2000::/3, pref=high, lifetime=1800s
          route info option (24), length 24 (3):  2a01:db8:0::3280::/60, pref=high, lifetime=1800s
          route info option (24), length 24 (3):  2a01:db8:0::32b0::/60, pref=high, lifetime=1800s
          rdnss option (25), length 40 (5):  lifetime 600s, addr: 2a01:db8:0::3281::35:100 addr: 2a01:db8:0::328e::35:100
          dnssl option (31), length 48 (6):  lifetime 600s, domain(s): zugschlus.de. ka51.zugschlus.de.
          source link-address option (1), length 8 (1): 7e:79:61:31:55:28

systemd didn't configure an SLAAC IPv6 address on the interface. I
guess that this depends on whether and how many other IP addresses are
on the interface. It seems to work more reliably if the interface
doesn't already have an address from this prefix. If this is the case,
it is another proof of the gross misunderstanding of IPv6 that the
person writing this piece of the code has.

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Leimen, Germany    |  lose things."    Winona Ryder | Fon: *49 6224 1600402
Nordisch by Nature |  How to make an American Quilt | Fax: *49 6224 1600421

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