Manage Wifi connections on Raspberry PI

Question

I am working on using a Raspberry Pi in an embedded project that will utilize wifi to communicate with external devices. The device should be able to act either as a standalone wifi hotspot that devices can connect to or in the case of the presence of an existing wifi network it should connect to that network so that the user does not have to give up his internet connection in order to connect to the device. I plan on making the device start up in hotspot mode, the user can then use the web interface to enter the details of a network that he wants the device to connect to, whenever the specified parameters fails to establish a connection then it defaults back to hotspot mode.

Now the technical stuff I am struggling with is that I want to implement the control software in C# running with Mono on Arch Linux on the Rapsberry Pi. I am struggling the find the Apis or libraries needed to manage the Linux wifi connection. On Windows it seems as if managedwifi.codeplex.com can be used but it does not seem to be compatible with Linux.

My last resort would obviously be to execute shell commands and then parse their outputs, but considering how crude and possibly unreliable that would be this is obviously my last resort.

Any ideas regarding what I should do?

PS. Another thing I might consider before using shell scripts, if it makes a difference is to use Raspbian or some other distro instead.

Answer 1

1. Actually calling shell commands from a managed code is not a very bad idea. They are reliable, very well tested and mostly lightweight and sometimes just a wrapper around kernel or other modules function. This is also seems to be the same method Node.js modules use when they want to access something lowlevel or related to networking. For example see this source code: node-wireless/node_modules/wireless/index.js

2. If you don't like it this way there is always "Interop". The same way that you can DllImport() libraries in Windows, you can do in Linux. See here: http://www.mono-project.com/Interop_with_Native_Libraries

IMHO the second solution doesn't worth the effort. Calling shell commands is elegant and neat enough.

Answer 2

my pi is starting into wlan0 as AP with hostapd, when a AP also a lighttpd is starting and give a web interface do change the settings. the web interface verify and write the input in a sqlite3. a second script is doing the canges according to my changes. (like add, edit or remove wifis in wpa_supplicant, reset wlan0 to be a part of an existing wlan like set to dhcp, tell wpa_supplicants...)

except the lighttpd and sqlite3 all components are already on the Raspery. you dont need any mono or c-libraries

for writing the scripts i use python but also perl is working (even php for the frontend)