This HOWTO describes how to generate a set of ipkg modules for 
providing support of freeDiameter in an OpenWRT system.

This HOWTO is written for OpenWRT 10.03 (BackFire) and no guarantee is provided
that it will work for you. Be prepared to eventually brick your routeur...

Table of contents:
0) Quick HOWTO: optimistic step-by-step instructions.
1) Prerequisites: get the OpenWRT development environment ready.
2) Supplied packages: use the existing packages when possible (gnutls, ...)
3) Other dependencies: provide for additional missing dependencies (sctp ...)
4) freediameter package: now create the freeDiameter package
5) Configuration: how to set the configuration on the router.

This HOWTO will NOT cover how to install OpenWRT on your access device, nor 
its basic configuration. Please refer to OpenWRT website for this type of HOWTOs.


==============================================
0) Quick HOWTO
==============================================
The following instructions should allow you to put freeDiameter on your OpenWRT-compatible router.
In case something goes wrong, you should follow the detailed instructions in the remaining of 
this file.

Be warned: playing with the software in your router may brick it, i.e. make it unusable forever. 
Do it at your own risk.

1) Get the OpenWRT environment:
$ git clone git://nbd.name/openwrt.git
$ cd openwrt

2) Get the feeds
$ cp feeds.conf.default feeds.conf
$ echo "src-hg freediameter http://www.freediameter.net/hg/fD-OWRT-packages" >> feeds.conf
$ scripts/feeds update
$ scripts/feeds install freeDiameter

3) Configure your image
$ make menuconfig
(set Target System and Target Profile as needed for your equipment)

- Network --->
   freeDiameter (M)

4) Build the image and packages, this takes a while
$ make world

5) Export the bin/* directory through a webserver. 
   We assume it is available at http://192.168.1.25/owrt
   
6) Flash the router with your new image -- THIS DESTROYS ALL CONFIG ON THE ROUTER!
$ ssh root@192.168.1.1
# cd /tmp
# wget http://192.168.1.25/owrt/openwrt-brcm47xx-squashfs.trx
    ;; change the file name with yours
# mtd -r write openwrt-brcm47xx-squashfs.trx linux
    ;; wait for reboot
$ telnet 192.168.1.1
# passwd
# sync

7) Update the opkg router's config to get your new packages
ssh root@192.168.1.1
# echo "src/gz chavroux http://192.168.1.25/owrt/packages" >> /etc/opkg.conf 
# opkg update

8) Install freeDiameter, you're done. Optionnaly, install also certtool on the router before, to 
   generate the TLS certificate.
# opkg install freeDiameter

==============================================
1) Prerequisites:
==============================================

We will first need a working OpenWRT toolchain environment. You can retrieve
pre-compiled binaries of such toolchains ("Image builder") on the OpenWRT website. Anyway,
in case the architecture you are interested in is not listed, you can build
the full toolchain from source. This is the path we are following in this HOWTO.

a) Retrieve the latest OpenWRT source, using subversion or git.
Since I have to go through a proxy, I use the later here, svn being quite annoying with proxies.
Note, the following commands must not be run as root.
$ git clone git://nbd.name/openwrt.git
 (Note: you might instead use "backfire.git" if you want to stick with an OpenWRT release.)
$ cd openwrt
$ cp feeds.conf.default feeds.conf

b) If you are using git, you have to edit the feeds.conf file to use git as well for packages.
Do the following modifications in this case:
$ vi feeds.conf
 Comment out this line:
src-svn packages https://svn.openwrt.org/openwrt/packages
 Add this line instead:
src-git packages git://nbd.name/packages.git

 You can leave uncommented the luci (for GNUTLS) and Xwrt (webif) repositories. Since these repositories
use svn over http, you can use subversion even if you are behind a proxy.

c) Then issue the following command to update the package list:
$ scripts/feeds update

d) Now, let's already create the toolchain and basic image.
$ make menuconfig

This will open a menu for you. You must select the target you are building for.
See http://wiki.openwrt.org/toh/start for the table of hardware and associated information.
In my case, I am using a Buffalo WZR-HP-G300NH router. I therefore select these options:
- Target System --->
   Atheros AR71xx/AR7240/AR913x
- Target Profile --->
   Buffalo WZR-HP-G300NH
   
For many routeurs, the recommended kernel is a 2.4x version. I have NOT tried with such kernel,
and the SCTP support is likely to be different in this generation of kernels. I strongly recommend
to go with a 2.6x kernel, whenever possible. 
   
e) Once configured, create the toolchain and default image (this takes a while):
$ make

After this command completes successfully, your build environment is ready.
The resulting image and packages are stored in the "bin/" subdirectory.
It is very convenient if you make this repository available in http to your routeur.

You should probably try at this early stage to flash your device with the image you have generated.
If the default basic image does not work, it is probably not worth adding new problems on top of it.

For troubleshooting, please consult OpenWRT documentation directly.
"make prereq" may help you building the initial image also.
See http://downloads.openwrt.org/docs/buildroot-documentation.html for additional information
concerning this step.

You should now be able to login on your routeur with telnet (first time) or ssh (after setting a password).

==============================================
2) Supplied packages:
==============================================

There are some dependencies of freeDiameter already available in the OpenWRT packages repository. 
You can check for the available packages with the script:
$ ./scripts/feeds search <package>

We will now describe how to install these dependencies. At the time this HOWTO is written, 
the OpenWRT repositories contain ipv6, gnutls, pthreads and hostapd. Follow these instruction to
build them.

Alternatively, you can find these packages pre-compiled in the OpenWRT packages repository.

a) GNU TLS packages
$ scripts/feeds install libgnutls

b) Select the following components in the menu:
$ make menuconfig
- Base system --->
   libpthread (M)
   
- Network --->
   hostapd (M)
   wpad-mini ( )

- Libraries --->
   SSL --->
     libgnutls (M)
   
- Kernel modules --->
   Network Support --->
     kmod-ipv6 (M)
     
Quit and save the new config, then:
$ make world

This will add a bunch of modules in your bin directory that will be required for freeDiameter.
Since we are removing the wpad-mini daemon from the base image, this image (trx or bin file) is also recompiled.

Note that if you are setting your device as WPA supplicant also (wireless client), you can select wpad instead of hostapd.
(in any case, the -mini version is not suitable since we will use the RADIUS authentication).


You should now reflash your routeur with the new firmware image. The simplest way to achieve if your routeur has enough
flash memory is to:
- copy the new trx image to your routeur's /tmp (using wget or scp)
- run this command (on the device) -- replace <newfile.trx> with your actual filename:
 root@OpenWrt:~# mtd -r write <newfile.trx> linux

WARNING: this will erase your existing configuration on the routeur. 
In case you need to save it, you may try the sysupgrade command instead.

This will reboot the device after writing the new image file.
Afterwards, if you have set up the http server on your development machine properly 
(let's assume it has IP address 192.168.1.25)
you can run the following command on your router:
 root@OpenWrt:~# echo "src/gz mydev http://192.168.1.25/packages" >> /etc/opkg.conf 
 root@OpenWrt:~# opkg update

Install the newly compiled packages with:
 root@OpenWrt:~# opkg install kmod-ipv6 hostapd libpthread

==============================================
3) Missing packages:
==============================================

UPDATE: Starting from revision r22917, sctp and kmod-sctp are included in the OpenWRT distribution, and have been removed
from freeDiameter package. One may consider using a freeDiameter package prior to 2010/09/05 in order to get the sctp 
package, or a more recent OpenWRT environment. 

PREVIOUS SITUATION: If you are using components prior to 2010/09/05, the following applies:
P: 
P: There are other dependencies for freeDiameter that are not provided by OpenWRT packages. 
P: For convenience, we include these meta-packages in the freeDiameter distribution -- but they
P: might not be up-to-date.
P: 
P: a) Adding the contributed directory to the feeds
P:   Add the following line in your feeds.conf file:
P: src-link freediameter /path/to/freediameter/contrib/OpenWRT/packages/
P: 
P: Then run: 
P: $ scripts/feeds update
P: 
P: This should allow you to install the missing dependencies as follow:
P: 
P: 
P: b) SCTP library (note: you might alternatively compile freeDiameter without SCTP support).
P: $ scripts/feeds install sctp
P: 
P: 
P: c) Select these components in the menu:
P: $ make menuconfig
P: - Libraries --->
P:    sctp (M)
P: 
P: Quit and save the new config, then:
P: $ make world
P: 
P: 
P: d) Install this on the router as well:
P:  root@OpenWrt:~# opkg update
P:  root@OpenWrt:~# opkg install sctp


==============================================
4) freediameter package:
==============================================

Now, your environment should be ready to compile the freeDiameter ipkg package.
$ scripts/feeds install freeDiameter

Note that in order to build this package, you need to have cmake & flex on your compilation machine.

$ make menuconfig
- Network --->
   freeDiameter (M)
   
Quit and save the new config, then:
$ make world

On your router, run:
# opkg update
# opkg install freeDiameter