Mobile IPv6 user space daemons for Android

This tutorial shows how to build the UMIP.org MIPv6 implementation for an Android phone. I recommend to read a previous post on the issue, where it is explained how to compile and configure the UMIP.org for an ordinary (Ubuntu) Linux environment.

Initially I have tried to use the prebuilt Android toolchain and after a lot of time spent trying to patch the code to fit the Bionic and other libraries requirements, I started looking for alternatives.

Thanks to Christian Graffe, who in his post on the Nautilus6 forum, give me the hints on how to go on. The solution to almost all my problems was using the CodeSourcery ARM GNU/Linux toolchain, which I’ve already used in my initial steps but I didn’t realize to use for compiling UMIP.

Requirements

Create a directory to held all the packages, libraries, etc.

$ mkdir mytestdir
$ cd mytestdir

The ~/mytestdir will be used from now on as the root path, but you can change it for the one you like. Just keep in mind to include -I and -L options for the different libraries.

Install CodeSourcery ARM GNU/Linux and include it in your path (better put it in your login script).

$ wget https://sourcery.mentor.com/sgpp/lite/arm/portal/package8741/public/arm-none-linux-gnueabi/arm-2011.03-41-arm-none-linux-gnueabi.bin
$ ./arm-2011.03-41-arm-none-linux-gnueabi.bin
...Follow the instructions...
$ export PATH=/Sourcery_G++_Lite/bin:$PATH

Note: CodeSourcery is now Mentor Graphics Sourcery Tools. To download lite toolchains follow the link and specifically for ARM this one [2]

Although it is not required as the UMIP.org source code includes its own crypto implementation you can compile it against OpenSSL library. This is up to you, so this step can be skipped.

Kernel configuration

On a previous post I have explained how to create a custom kernel and flash it. For running Mobile IPv6, it is required you enable at least the following options in your kernel configuration [3]:

General setup 
--> Prompt for development and/or incomplete code/drivers [CONFIG_EXPERIMENTAL]
--> System V IPC [CONFIG_SYSVIPC]

Networking support [CONFIG_NET]
--> Networking options
    --> Transformation user configuration interface [CONFIG_XFRM_USER]
    --> Transformation sub policy support [CONFIG_XFRM_SUB_POLICY]
    --> Transformation migrate database [CONFIG_XFRM_MIGRATE]
    --> PF_KEY sockets [CONFIG_NET_KEY]
    --> PF_KEY MIGRATE [CONFIG_NET_KEY_MIGRATE]
    --> TCP/IP networking [CONFIG_INET]
    --> The IPv6 protocol [CONFIG_IPV6]
        --> IPv6: AH transformation [CONFIG_INET6_AH]
        --> IPv6: ESP transformation [CONFIG_INET6_ESP]
        --> IPv6: IPComp transformation [CONFIG_INET6_IPCOMP]
        --> IPv6: Mobility [CONFIG_IPV6_MIP6]
        --> IPv6: IPsec transport mode [CONFIG_INET6_XFRM_MODE_TRANSPORT]
        --> IPv6: IPsec tunnel mode [CONFIG_INET6_XFRM_MODE_TUNNEL]
        --> IPv6: MIPv6 route optimization mode [CONFIG_INET6_XFRM_MODE_ROUTEOPTIMIZATION]
        --> IPv6: IPv6-in-IPv6 tunnel [CONFIG_IPV6_TUNNEL]
        --> IPv6: Multiple Routing Tables [CONFIG_IPV6_MULTIPLE_TABLES]
        --> IPv6: source address based routing [CONFIG_IPV6_SUBTREES]

File systems
--> Pseudo filesystems
    --> /proc file system support [CONFIG_PROC_FS]

OpenSSL library cross-compilation

Download OpenSSL source code. I have used v0.9.8r but I guess there shouldn’t be any problem with recent v1.

$ wget http://www.openssl.org/source/openssl-0.9.8r.tar.gz
$ tar xvfz openssl-0.9.8r.tar.gz
$ cd openssl-0.9.8r

Configure and compile for ARMv7 (it is the one for the Nexus S)

$ MACHINE=armv7 \
CROSSCOMPILE=arm-none-linux-gnueabi- \
CC=${CROSSCOMPILE}gcc \
AR=${CROSSCOMPILE}ar \
ARD=${CROSSCOMPILE}ar \
RANLIB=${CROSSCOMPILE}ranlib \
./config --prefix=$HOME/mytestdir/install

Change the install path if you want to.

Check the output of config just to be sure that everything has gone well and all the requirements are fulfilled. My system has the necessary libraries, but if yours doesn’t use apt-get install (if on Debian based Linux) to solve your problems.

$ make CFLAGS="-g -O2 -static" 
$ make install

Compile UMIP

Download UMIP.org from the git repository

$ git clone git://git.umip.org/umip.git umip
$ cd umip
$ autoreconf -ivf

---

Update:
As from a comment by Benjamin Green I have uploaded UMIP.org to GitHub, so now you can just get the code from there. If you want to modify anything just feel free.

$ git clone git://github.com/jlanza/umip.git

---

For the configuration step you have several options, depending on how and where you plan to use the binaries in the phone. In case you want them to be installed by default in your own ROM you can choose to put them under /system/local. If you want to manually install and run them you can put them in /data/local. The path of your choice should be included in as the prefix when running the configure script. Below you can find some examples.

$ ./configure --prefix=/system/local --host=arm-none-linux-gnueabi ARCH=arm CC="arm-none-linux-gnueabi-gcc" CROSS_COMPILE="arm-none-linux-gnueabi-" --sysconfdir=/system/usr/local/etc
$ ./configure --prefix=$HOME/mytestdir/install --host=arm-none-linux-gnueabi --build=x86_64-unknown-linux-gnu ARCH=arm CC="arm-none-linux-gnueabi-gcc" CROSS_COMPILE="arm-none-linux-gnueabi-" --enable-vt LDFLAGS="-L$HOME/mytestdir/install/lib" CPPFLAGS="-I$HOME/mytestdir/install/include"
$ ./configure --prefix=/data/local/umip --host=arm-none-linux-gnueabi --build=x86_64-unknown-linux-gnu ARCH=arm CC="arm-none-linux-gnueabi-gcc" CROSS_COMPILE="arm-none-linux-gnueabi-" --enable-vt LDFLAGS="-L$HOME/mytestdir/install/lib" CPPFLAGS="-I$HOME/mytestdir/install/include"

Note: The –enable-vt option enables a virtual terminal, which can be useful to retrieve the binding cache or binding update list information on the Home Agent or the Mobile Node. When compiling you get some warnings.

$ make CFLAGS="-g -O2 -static"

As a result of the compilation you will get the daemon mip6d (under src directory).

If you install ($ make install) the path would be the one you have set when running the configure script. Besides that the configure path will be the location to search for the different configuration files.

$ ls <install_dir>
./sbin
./sbin/mip6d
./share
./share/man
./share/man/man1
./share/man/man1/mip6d.1
./share/man/man7
./share/man/man7/mipv6.7
./share/man/man5
./share/man/man5/mip6d.conf.5

Running UMIP

The phone most of the times will act as the Mobile Node (MN). This is the reason why it is only included the configuration of the MN. More information on how to configure Home Agent (HA), etc. is available in [4]. Having said that, it is required you have a network with a HA and the different elements required.

In the umip/extra directory you can find several configuration examples for the different roles your node can play.

$ find . -iname "*.conf"
./extras/example-mn.conf
./extras/example-nemo-mn.conf
./extras/example-nemo-ha.conf
./extras/example-ha.conf
./extras/example-cn.conf

Our custom configuration for a MN, mip6d-mn.conf, is:

# MIPv6 Mobile Node
NodeConfig MN;

# Set DebugLevel to 0 if you do not want debug messages
DebugLevel 10;

# Enable the optimistic handovers
OptimisticHandoff enabled;

# Disable Route optimization with other MNs (it is not compatible 
# with IPsec Tunnel Payload)
DoRouteOptimizationMN enabled;
 
# Disable Route optimization with other CNs 
DoRouteOptimizationCN enabled;

UseCnBuAck enabled;

# List here the interfaces that you will use 
# on your mobile node. The available one with 
# the smallest preference number will be used.
Interface "wlan0" {
    MnIfPreference 1;
}

# Replace wlan0 with one of your interface used on
# your mobile node
MnHomeLink "wlan0" {
	# Set the HA address
	HomeAgentAddress 3ffe:2620:6:1::1;
	# Set the HA network mask
	HomeAddress 3ffe:2620:6:1::1234/64;

	# address opt.
	#MnRoPolicy 3ffe:2060:6:1::3    enabled;
	#MnRoPolicy                     disabled;
}

UseMnHaIPsec enabled;

IPsecPolicySet {
	HomeAgentAddress 3ffe:2620:6:1::1;
	HomeAddress 3ffe:2620:6:1::1234/64;

	IPsecPolicy HomeRegBinding UseESP;
	IPsecPolicy TunnelMh UseESP;
}

It has to be further checked how to include and manage multiple interfaces. In that case it should be included the following template configuration.

# List here the interfaces that you will use 
# on your mobile node. The available one with 
# the smallest preference number will be used.
Interface "wlan0" {
    MnIfPreference 1;
}

Interface "eth0" {
    MnIfPreference 2;
}

# Replace wlan0 with one of your interface used on
# your mobile node
MnHomeLink "wlan0" {
	# Set the HA address
	HomeAgentAddress 3ffe:2620:6:1::1;
	# Set the HA network mask
	HomeAddress 3ffe:2620:6:1::1234/64;

	# address opt.
	#MnRoPolicy 3ffe:2060:6:1::3    enabled;
	#MnRoPolicy                     disabled;
}

# Replace eth0 with one of your interface used on
# your mobile node
MnHomeLink "eth0" {
    HomeAgentAddress 2001:db8:ffff:0::1000;
    HomeAddress 2001:db8:ffff:0::1/64;
}

Note: Still to be tested.

Move the files to the phone and enter phone shell.

$ adb pull mip6d /data/local
$ adb pull mip6d-mn.conf /data/local
$ adb shell

Now you have the configuration for you MN, it is time to run it. On the phone, move to the directory where you have installed the mip6d daemon.

$ su
# cd /data/local
# ./mip6d -c ./mip6d-mn.conf

If you don’t set the -c option, the daemon will look at the default location you set at configuration and compilation time. Other options are available, just access the help.

$ ./mip6d -h
Usage: mip6d [options]
Options:
  -V, --version            Display version information and copyright
  -?, -h, --help           Display this help text
  -c                 Read configuration from 
      --vt-service   Set VT service (default=7777)

 These options override values read from config file:
  -d               Set debug level (0-10)
  -l                 Write debug log to  instead of stderr
  -C, --correspondent-node Node is CN
  -H, --home-agent         Node is HA
  -M, --mobile-node        Node is MN

For bug reporting, see URL:http://www.mobile-ipv6.org/bugs/.

If everything is setup correctly, the daemon should be running and your phone is behaving as a MN.

References

[1] Nautilus6 DSMIPv6 implementation Mailing List – Re: UMIP-DSMIPv6 current status
[2] Download Sourcery CodeBench Lite Edition for ARM
[3] How to install UMIP (kernel and userland)
[4] How to setup a Mobile IPv6 testbed (with IPsec static keying)