Re: [B.A.T.M.A.N.] Batman-adv and Uevent (gateway/client modes)

[cmsv <cmsv@wirelesspt.net>]

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I took a look at your scripts and it seems we both have the same kind of
idea.

On 04/26/2013 04:40 PM, Gui Iribarren wrote:
> On 04/26/2013 09:30 PM, cmsv wrote:
>> I have reached a point where i need to start using the uevent
>> functionality to work around some network scenarios when the gateways
>> lose internet access but i am having a bit of a difficult time
>> understanding how to do it since making use of uevents which is
>> something new to me.
>>
>> The explanation here is not helping much either
>> http://www.open-mesh.org/projects/batman-adv/wiki/Uevent
>>
>> and i understand that i might need to go to the basics to understand it
>> and learn how to code.
>>
>> My need to use uevents to change a nodes behaviour is to change a node
>> from server to client and vice versa when it loses connectivity to the
>> WAN (not for example losing connectivity to the dsl router that is
>> actually the gateway but that has the node as a LAN client)
>>
>> I am assuming that uevents will allow me to work with this physical
>> setup correct?
>>
>> As far as i understand now and if i am not mistaken when a gateway loses
>> WAN connectivity the node that is making use of uevents will change  the
>> node from "server" to "client" on batman-adv .
> 
> That won't happen automatically, you need some userspace script to
> handle the event and change batman-adv gw mode
> 
correct.

> Please check
> 
> https://colectivo.altermundi.net/projects/altermesh-packages/repository/show/batman-adv-auto-gw-mode
> 
> 
> which in turn depends on
> 
> https://colectivo.altermundi.net/projects/altermesh-packages/repository/show/watchping

> 
> 
> you should read the source code of batman-adv-auto-gw-mode (just a few
> lines / files) and i'll comment a bit about it along this email,

The code is very much what i am looking for in terms of functionality


> you can grab the "binaries" (actually ipk-packaged bash scripts) and try
> them right away
> 
> http://chef.mesh.altermundi.net/downloads/r36139/ar71xx/packages/batman-adv-auto-gw-mode_2013-04-11-237-1_ar71xx.ipk
> 
> http://chef.mesh.altermundi.net/downloads/r36139/ar71xx/packages/watchping_2013-04-11-237-1_ar71xx.ipk
> 

I installed both and all files were installed in their proper
directories but for some reason it did not work :
# /etc/init.d/watchping start
uci: Entry not found

and :

# cat /etc/uci-defaults/watchping
#!/bin/sh

uci -q get system.@watchping[0] || {
        uci batch <<EOF
        add system watchping
        set system.@watchping[0].interface=wan
        set system.@watchping[0].timeout=2m
        set system.@watchping[0].pinghosts=8.8.8.8
        set system.@watchping[0].pinginterval=20s
        commit system
EOF
}


/etc/uci-defaults# ./watchping
cfg0a252a

inserted the code into /etc/config/system . that was the only way it got
there. Was it suppose to be auto-configured after the installation of
the package ?


> 
> 
> mind you, the default behaviour of sending the hostname in dhcp requests
> has changed in recent trunk builds, so this feature might not work
> reliable; but on the other hand, that might not make any difference in
> your scenario :) (you don't seem to care about hostnames)
> 
I am currently using:
DISTRIB_ID="OpenWrt"
DISTRIB_RELEASE="Attitude Adjustment"
DISTRIB_REVISION="r35153"
DISTRIB_CODENAME="attitude_adjustment"
DISTRIB_TARGET="ar71xx/generic"
DISTRIB_DESCRIPTION="OpenWrt Attitude Adjustment 12.09-rc1"

and will stay with AA for a while.

> 
> 
>> Now my question is if i can also make it to change the dhcp setup from
>> dhcp server to inactive and receive it´s dhcp service from another
>> gateway node
> 
>>
>> In theory  something like this would be executed on openwrt when a
>> gateway node detects no connectivity to the wan:
>>
>> uci set batman-adv.bat0.gw_mode=client ;
>> uci commit batman-adv ;
>> batman-adv reboot ;
>> uci set dhcp.lan.force=0 ;
>> uci set dhcp.lan.ignore=1 ;
>> uci commit dhcp ;
>> /etc/init.d/dnsmasq restart ;
>>
>> when it detects wan connectivity it will want to become a server and
>> will auto execute:
>>
>> uci set batman-adv.bat0.gw_mode=server ;
>> uci commit batman-adv ;
>> batman-adv reboot ;
>> uci set dhcp.lan.force=1 ;
>> uci set dhcp.lan.ignore=0 ;
>> uci commit dhcp ;
>> /etc/init.d/dnsmasq restart ;
>>
>> A small script can even be made in order so simplify things either
>> automatically or manually and lets call it:
>> gateway-mode
>> client-mode
> 
> this would equiv to
> 
> /etc/watchping/wan-ok.d/batman-gw
> /etc/watchping/wan-fail.d/batman-gw

I do see that inside these directories i have only a README file.
Are these directories to have my own scripts or other scripts that come
with your package ?


> 
>>
> 
>> Upon detecting no WAN connectivity the script will be activated.
>>
>> Am i on the right track so far (at least in theory) ?
>>
>> Now the second part is how to detect WAN connectivity which is different
>> from noticing that there is no connectivity to the actual gw router that
>> has the node on it's LAN.
>>
>> I thought about a ping test to a few address from which after 100% loss
>> reply from all; something or Uevent will activate the gateway/client
>> mode script but it creates another problem ahead.
>>
>> In a quick conversation with ordex on irc i understand that i have to
>> invoke the wiki docs uevent functions with the parameters i want at the
>> moment i decide.
>> This can be the gateway/client mode script
> 
> Yes, in my case /etc/hotplug.d/net/99-batman-gw


The only file i have there is /etc/hotplug.d/net/99-batman-adv  id you
rename me ?
your link to
batman-adv-auto-gw-mode/files/etc/hotplug.d/net/99-batman-gw is empty.
> 
>>
>> correct ?
>>
>> Since uevent is something new to me; can someone recommend some freshman
>> tutorial that may take me in the right direction. I have no clue where
>> or how to start looking to code it and also when coded; where will it be
>> added.
>>
>> I also would like to ask anyone that has uevent working how they are
>> using it for the same type of need and maybe even share some recipe.
>>
>>
>>
>>
>>
> 
> 

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