DynaPoint Final

Hi everyone,

this is the final blog post about DynaPoint. Short recap: I created a daemon which regularily monitors the Internet connectivity and depending on that activates and deactivates the proper access points. That way the handling with APs would become easier as you already could tell the status by the AP’s SSID. I also created a LuCI component for it to make the configuration more easy.

In the past weeks I was able to add some new features, fix bugs and complete the LuCI component. Especially the latter was really interesting and gave me some knowledge about how LuCI works.

In the last post I mentioned that it’s better to verify Internet connectivity by using wget instead of just pinging an IP address.
Consequently I switched from Pingcheck to wget. I also added an option to use curl instead of wget. With curl you also get the option to choose the interface for the connection.
When you provide internet via VPN-interface you can explicitly check the connection of that interface now. The reason why I don’t use curl as default is because of curl’s rather large size. For some routers with only 4 MB of storage it might be too much.

I also added an “offline threshold”, which will delay the switch to offline mode. So for example when you set the interval to 60 seconds and offline_threshold to 5, the switch to offline mode will be made after 5 cycles of checking (=300 seconds).

So how does an example configuration look like?

To use dynapoint just add dynapoint_rule ‘internet’ and dynapoint_rule ‘!internet’ in the desired sections in /etc/config/wireless:

config wifi-iface
    option device ‘radio0’
    option network ‘lan2’
    option mode ‘ap’
    option encryption ‘none’
    option ssid ‘freifunk’
    option dynapoint_rule ‘internet’

config wifi-iface
    option device ‘radio0’
    option network ‘lan2’
    option mode ‘ap’
    option encryption ‘none’
    option ssid ‘freifunk-maintenance’
    option dynapoint_rule ‘!internet’

The configuration of dynapoint takes place in /etc/config/dynapoint:

config rule ‘internet’
    list hosts ‘http://www.example.com’
    list hosts ‘http://www.google.com’
    option interval ’60’
    option timeout ‘5’
    option offline_threshold ‘3’
    option add_hostname_to_ssid ‘0’
    option use_curl ‘1’
    option curl_interface ‘eth0’

All of that can also be configured via LuCI:

If you want to try out DynaPoint for yourself please visit https://github.com/thuehn/dynapoint for more information.

Future work

Currently there is only support for one AP per state. In the next weeks I want to add support for multiple APs per state.
Also I want to add support for more rules. At this time there is only support for one rule “internet”. I want to make this more generic and provide support for custom rules.

Acknowledgements

I want to thank my mentor Thomas Hühn for his excellent mentoring and great ideas during this project. 
Also of course thanks to Freifunk for letting me realize this project and thanks to Google for organizing GSoC.

DynaPoint update

Hi everyone,

here are some updates regarding DynaPoint. The idea was to create a daemon, which regularily checks the Internet connection and changes the used access point depending on the result. That way the handling with APs would become easier as you already could tell the status by the AP’s SSID.

A daemon with basic functionality is already working. After installation, there is one configuration step necessary.
You have to choose in /etc/config/wireless which AP should be used, if Internet connectivity is available and which one if the connectivity is lost. You can do that by adding “dynapoint 1” or “dynapoint 0” to the respecive wifi-iface section.

You can also configure dynapoint via LuCI, although it’s not yet complete.
I was struggeling a bit with it, because the documentation of LuCI is a bit minimalistic…
Here is a screenshot of how it currently looks like:

Next steps

To verify Internet connectivity, it is probably better to make a small http download than just ping an IP address.
Using “wget –spider” should be suitable for that.

Also, I will see if I can get rid of the required configuration step in /etc/config/wireless in the next weeks and provide fully automatic configuration.

If you want to test dynapoint for yourself, just go to https://github.com/thuehn/dynapoint.

DynaPoint – A dynamic access point validator and creator

Hi everybody,

 

I am Tobias, a Computer Science student at the TU-Berlin. I am glad to have the opportunity to participate at GSoC for Freifunk this year.

 

My project aims at making the handling with access points in OpenWrt/LEDE easier. The goal is defined as follows: Find an easily configurable solution (with reasonable defaults) for making the wireless access SSID in OpenWrt/LEDE dependent on a set of network conditions.

 

What does that mean? Consider the following example. You have a wireless access point with SSID “Freifunk”. Suddenly for whatever reason the AP looses Internet connectivity without anyone noticing it. When users now connect to this AP, expecting a working Internet connection, they get frustrated, because they can’t check their emails or surf the Internet.

 

With DynaPoint I want to develop a daemon, which regularly monitors the Internet connectivity. When it’s lost, the SSID will automatically be changed. In this example it could be changed to “Freifunk-offline”. When Internet connectivity is re-established, the SSID would automatically be changed back to “Freifunk”.

This way users as well as admins get informed about the state of an access point just by looking at the SSID.

 

To verify Internet connectivity the first obvious step would be to do a ping. For this purpose there already exists a package called pingcheck, which I am planning to use. Further steps could include DNS-Queries and HTTP-Downloads.

 

Speaking about easy configuration and reasonable defaults, I want to require as little configuration steps as possible, but also provide enough configuration options to be adjustable to different kind of setups. Ideally the configuration will also be possible via the LuCI web interface.

 

Until next time,

 

Tobias