[B.A.T.M.A.N.] Current OpenWrt build

[B.A.T.M.A.N.] Current OpenWrt build

[Jay Brussels]

Antonio,

I am planning to start programming Ubiquiti and TP-Link Routers in two weeks for a very large BATMAN mesh deployment.

Although many patches I have seen on this list involves multicast traffic I have seen some others.  

Is the current OpenWrt release stable enough for deployment or are there some "must have" patches requiring a build from scratch for a successful deployment?


Jay Brussels
President
DSL Express
954-757-3254 
jay@dslx.net





-----Original Message-----
From: B.A.T.M.A.N [mailto:b.a.t.m.a.n-bounces@lists.open-mesh.org] On Behalf Of Krishnathiepan Rasanayagam
Sent: Wednesday, November 12, 2014 6:51 AM
To: The list for a Better Approach To Mobile Ad-hoc Networking
Subject: Re: [B.A.T.M.A.N.] Threads in batman-adv

yep. i should have :)
now only freading it out. sorry

thanks alot for replying :)

On Wed, Nov 12, 2014 at 2:47 PM, Antonio Quartulli <antonio@meshcoding.com> wrote:
>
>
> On 12/11/14 09:19, Krishnathiepan Rasanayagam wrote:
>> Hi All,
>>
>> Has anyone considered using threads in batman-adv?
>
> did you mean kthread? I don't think this would bring any real benefit.
> You should probably read/understand the rest of the networking stack 
> in the linux kernel to understand how incoming/outgoing packets are handled.
>
>> is is possible to use fork() send.c file?
>
> fork() is a function that is supposed to be used in *userspace* to 
> create a new *process*.
> This is neither available nor conceptually possible in kernel space.
>
> Maybe you should read a bit more about what you can do and what you 
> cannot do while developing a kernel module? :)
>
> --
> Antonio Quartulli
>



--
Best regards,
Krishna.

Re: [B.A.T.M.A.N.] Current OpenWrt build

[Bastian Bittorf]

* Jay Brussels <jay@dslx.net> [12.11.2014 14:50]:
> Is the current OpenWrt release stable enough for deployment or are there some "must have" patches requiring a build from scratch for a successful deployment?

Hi Mr. President,

Define 'stable'.
There are >2700 open issues in the bugtracker:
https://dev.openwrt.org/report/1

bye, bastian

Re: [B.A.T.M.A.N.] Current OpenWrt build

[Jay Brussels]

Hello Bastian,

I was referring to the BATMAN patches, not OpenWRT.  The bugtraker does have
162 BATMAN issues, most closed and none that are open that will affect my
application.

I have seen some patches on the listserver  that states certain mesh traffic
can cause a crash.  This is my primary concern.

Jay
 

-----Original Message-----
From: B.A.T.M.A.N [mailto:b.a.t.m.a.n-bounces@lists.open-mesh.org] On Behalf
Of Bastian Bittorf
Sent: Wednesday, November 12, 2014 8:54 AM
To: The list for a Better Approach To Mobile Ad-hoc Networking
Subject: Re: [B.A.T.M.A.N.] Current OpenWrt build

* Jay Brussels <jay@dslx.net> [12.11.2014 14:50]:
> Is the current OpenWrt release stable enough for deployment or are there
some "must have" patches requiring a build from scratch for a successful
deployment?

Hi Mr. President,

Define 'stable'.
There are >2700 open issues in the bugtracker:
https://dev.openwrt.org/report/1

bye, bastian

Re: [B.A.T.M.A.N.] Current OpenWrt build

[Sven Eckelmann]

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On Thursday 13 November 2014 10:30:14 Jay Brussels wrote:
> I have seen some patches on the listserver  that states certain mesh traffic
> can cause a crash.  This is my primary concern.

Which patches are you referring to? For example my patches for batctl [1] are
related to a recent patch for batctl tcpdump [2]. So it is neither strictly
batman-adv nor for anything in OpenWrt (the affected patch was not yet part of
any batctl release).

But there are things which might affect you depending on what you are doing.
For example, there is an RCU related fix [3] which is quite important when you
are using a Linux kernel < 3.9. But OpenWrt should not use such an old kernel
when compiling a recent OpenWrt version. But maybe you still do and we don't
know about it. So it is hard to guess what to say to your question.

It is also hard to guess whats your batman-adv configuration. For example I would
try to disable network-coding+dat and enable bridge loop avoidance - unless my
specific setup requires something else. I know that this is not the default
behavior but in my subjective experience the default causes more trouble. Just
for reference, this is the default when batman-adv was compiled with all
features:

 * bridge_loop_avoidance: disabled (I prefer "enabled" because it is better to
   be save than sorry after you've killed the network with an broadcast packet
   storm. But don't expect it to be a magical cure for every insane network
   setup you could imagine)
 * network_coding: enabled (I prefer disabled unless proven to be helpful in
   your specific network setup)
 * distributed_arp_table: enabled (I prefer disabled due to some problems I
   had with it)

This might be something which could be seen by some people as "not stable" and
others might disagree. Or they might completely disagree with my (not
science-based) opinion about the better default settings.

Also there is the problem that we don't know which feed you are using. For
example there is a patch [4] in the openwrt-routing feed which fixes the
problem that the batman-adv config file is cleared after and upgrade. This
commit (Hint!!!!) was never merged into the openwrt-feed-batman-adv.git. And
this feed also seems to point to an quite old batman-adv/batctl version by
default. This can be seen as "instability" depending on your personal view
and what you are using to get batman-adv in your firmware. It can affect you
but most likely doesn't affect you at all.

And to your question "Is the current OpenWrt release stable enough for
deployment". Lets first make it clear that I will now talk about software in
general and not batman-adv. Every software has some kind of problems. Many of
them are unknown and will hit you from behind when you expect it the least.
Therefore, making a general statement without knowing anything about your
"deployment" cannot be accurate nor valid. The buggiest software may run fine
in a specific environment and the most polished software may cause problems
when somebody just (accidentally) finds its Achilles heel. And this can even
happen when knowing your "deployment".

But lets just summarize:

 * can it be deployed?: yes, people already do it
 * is it stable enough for deployment?: cannot be answered (see below)
 * was it deployed and then worked stable?: yes
 * are there known problems not fixed in openwrt?: yes
 * are there known problems that affect you?: unknown
 * is it very likely that these known and fixed problems affect you when
   assuming everything done "the right way"?: not really
   (please correct me if there was some change which I missed in maint or ml)
 * is it possible that there are known and fixed problems which affect you
   assuming not everything is done "the right way"?: yes
 * will it work out of the box in every possible environment?: no
 * will it work in many setups?: yes
 * will it work in some other setups after changing the config?: yes
 * would these questions answered the same for many other sw projects?: YES

Kind regards,
	Sven

[1] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2014-November/012534.html
[2] http://git.open-mesh.org/batctl.git/commit/4c39fb823b86036df40187f8bd342fe5398c28ef
[3] http://git.open-mesh.org/batman-adv.git/commit/1e4a96a4cfdfdf57fecacf1c8fa493345a9fcc03
[4] https://github.com/openwrt-routing/packages/commit/bbcc138fc0bbef5094c3928d892076ae9a56a213

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Re: [B.A.T.M.A.N.] Current OpenWrt build

[Linus Lüssing]

On Sat, Nov 15, 2014 at 07:58:23PM +0100, Sven Eckelmann wrote:
>  * can it be deployed?: yes, people already do it

Is anyone using the latest batman-adv release with bridges?

Maybe I didn't make it clear enough that the outstanding multicast
issues and patches are severe (as in makes common setups
unusable).

Cheers, Linus

Re: [B.A.T.M.A.N.] Current OpenWrt build

[Sven Eckelmann]

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On Sunday 16 November 2014 07:28:26 Linus Lüssing wrote:
> On Sat, Nov 15, 2014 at 07:58:23PM +0100, Sven Eckelmann wrote:
> >  * can it be deployed?: yes, people already do it
> 
> Is anyone using the latest batman-adv release with bridges?
> 
> Maybe I didn't make it clear enough that the outstanding multicast
> issues and patches are severe (as in makes common setups
> unusable).

Hm, I am now not sure if we switched topics again. Maybe you can enlighten us.
Jay was not perfectly clear in his first mail what what he actually wanted to
know. His second mail was refining his question to something like "tell me if
I can deploy batman-adv from OpenWrt because I've read the term 'crash'
somewhere". I am sure that your critism of OpenWrt is valid and a good point
to make. But maybe we can make your answer a little bit more understandable
(at least for me):

You are saying something about "outstanding multicast issues and patches"
without defining what it means in this mails.

Are there known missing patches/issues for batman-adv which would break
"common setups"? If yes, why is multicast_mode enabled by default in
batman-adv?

Are there "only" missing patches/issues in the bridge code (the ones you've
linked to in the other mail [1]) of OpenWrt which breaks batman-adv with
multicast_mode? If yes, why is multicast_mode enabled by default in
batman-adv?

Are there "only" missing patches/issues in the bridge code (the ones you've
linked to in the other mail [1]) of OpenWrt which breaks batman-adv even
without multicast_mode?

Are these missing patches/issues only about bridges + multicast and not about
batman-adv?

Kind regards,
	Sven

[1] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2014-November/012554.html

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Re: [B.A.T.M.A.N.] Current OpenWrt build

[Sven Eckelmann]

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On Sunday 16 November 2014 09:50:43 Sven Eckelmann wrote:
> Hm, I am now not sure if we switched topics again. Maybe you can enlighten
> us. Jay was not perfectly clear in his first mail what what he actually
> wanted to know. His second mail was refining his question to something like
> "tell me if I can deploy batman-adv from OpenWrt because I've read the term
> 'crash' somewhere". I am sure that your critism of OpenWrt is valid and a
> good point to make. But maybe we can make your answer a little bit more
> understandable (at least for me):

Linus just explained me some of the problems in batman-adv. I don't know about
the bridge patches. These part can be explained by him.

> You are saying something about "outstanding multicast issues and patches"
> without defining what it means in this mails.

At least some patches [1] completely went under the radar and just got applied
to the repo in the maint [2, 3]. These are not part of any OpenWrt feed I know
of.

> Are there known missing patches/issues for batman-adv which would break
> "common setups"? If yes, why is multicast_mode enabled by default in
> batman-adv?

Yes, there are at least two known problems in batman-adv which are now fixed
in maint and can be cherry picked by you. Otherwise these problems
would enable multicast optimization when some nodes have bridges (which they
shouldn't). This is a bug a not missing feature. So it is still valid that
multicast_mode is enabled by default.

I would guess that you can either disable multicast_mode  or apply the
patches.

> Are there "only" missing patches/issues in the bridge code (the ones you've
> linked to in the other mail [1]) of OpenWrt which breaks batman-adv with
> multicast_mode? If yes, why is multicast_mode enabled by default in
> batman-adv?

I cannot really answer this and will leave it to Linus.

> Are there "only" missing patches/issues in the bridge code (the ones you've
> linked to in the other mail [1]) of OpenWrt which breaks batman-adv even
> without multicast_mode?

I cannot really answer this and will leave it to Linus.

> Are these missing patches/issues only about bridges + multicast and not
> about batman-adv?

There are at least some batman-adv unrelated problems in OpenWrt with
multicast and bridges [4].

Kind regards,
	Sven

[1] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2014-October/012486.html
[2] http://git.open-mesh.org/batman-adv.git/commit/33fdd2cb9fe20d90bc6bff369c9b57e849b317b6
[3] http://git.open-mesh.org/batman-adv.git/commit/9e9d48e829cd93ffbb5ced323caf046ebe963394
[4] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2014-November/012554.html

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Re: [B.A.T.M.A.N.] Current OpenWrt build

[Linus Lüssing]

On Sun, Nov 16, 2014 at 10:14:43AM +0100, Sven Eckelmann wrote:
> Yes, there are at least two known problems in batman-adv which are now fixed
> in maint and can be cherry picked by you. Otherwise these problems
> would enable multicast optimization when some nodes have bridges (which they
> shouldn't). This is a bug a not missing feature. So it is still valid that
> multicast_mode is enabled by default.
> 
> I would guess that you can either disable multicast_mode  or apply the
> patches.

Correct.

> 
> > Are there "only" missing patches/issues in the bridge code (the ones you've
> > linked to in the other mail [1]) of OpenWrt which breaks batman-adv with
> > multicast_mode? If yes, why is multicast_mode enabled by default in
> > batman-adv?
> 
> I cannot really answer this and will leave it to Linus.

Turning off multicast_mode is only intended for debugging
purposes at the moment. batman-adv should never break anything by
having multicast_mode enabled (which unfortunately, currently is
not the case for a release / OpenWRT but should be again after the two
multicast counter fixes which just hit the maint-branch trickled
through).

> 
> > Are there "only" missing patches/issues in the bridge code (the ones you've
> > linked to in the other mail [1]) of OpenWrt which breaks batman-adv even
> > without multicast_mode?
> 
> I cannot really answer this and will leave it to Linus.

Nope, the bridge patches in OpenWRT don't break the concept of the
multicast optimizations or multicast handling in general in
batman-adv. The issues of the state of the bridge code in BB are
unrelated to batman-adv and happen with any other enslaved network
device, too.

Re: [B.A.T.M.A.N.] Current OpenWrt build

[Linus Lüssing]

On Wed, Nov 12, 2014 at 07:47:10AM -0500, Jay Brussels wrote:
> Antonio,
> 
> I am planning to start programming Ubiquiti and TP-Link Routers in two weeks for a very large BATMAN mesh deployment.
> 
> Although many patches I have seen on this list involves multicast traffic I have seen some others.  
> 
> Is the current OpenWrt release stable enough for deployment or are there some "must have" patches requiring a build from scratch for a successful deployment?

Regarding Barrier-Breaker: The default settings in OpenWRT with
bridges are unfortunately broken (in that breakes multicast, which
means broken IPv6):

https://lists.openwrt.org/pipermail/openwrt-devel/2014-September/027859.html
https://lists.openwrt.org/pipermail/openwrt-devel/2014-September/027876.html

(the first one is my "favourite", a typical OpenWRT feature patch:
awesome idea, good intention, but being applied to the repo without any
peer-reviewing and broken; instead of going through upstream first...)


You'll probably want to disable the multicast-to-unicast feature
or even the bridge snooping as a whole for now.

Cheers, Linus