The starting point for this page is https://wiki.openwrt.org/doc/uci/mptcp.
You can see how to test MPCTP with OpenWRT here:
http://mytechpg.blogspot.com/2016/01/multipath-tcp-how-to-test-mptcp-with.html
Here you can see how to build MPTCP for Raspberry PI with Yocto
MPTCP, Raspberrry PI and Yocto
How to build OpenWRT with MPTCP 0.90 support
I have created a patch for kernel 3.18.20 adding MPTCP 0.90 functionalities.
It is possible to download the patch from GitHub, with the command
git clone -b linux_3.18.20-mptcp_0.90 https://github.com/mytechpg/mptcp-kernel-patch.git
Then you can change the name to the mptcp_linux_kernel.patch file and copy inside the OpenWRT tree (in the target/linux directory).
To simplify this procedure, I have prepared a script to prepare OpenWRT 15.05 environment.
You can download with this command:
git clone -b patches_0.90 https://github.com/mytechpg/mptcp_openwrt.git
Then you can enter in the mptcp_openwrt directory and execute:
./prepare_openwrt.sh
The script will download OpenWRT and the kernel patch. Then it will apply the kernel patch and also other patches to iproute2 and add MPTCP util (the moment iproute2 patch is not aligned with MPTCP 0.90).
How to build OpenWRT with MPTCP support
First you have to configure your environment withmake menuconfig
Then, you can enable MPTCP in the kernel with:
make kernel_menuconfig
You can find MPTCP options under
Networking Support -> Networking options
My suggestion is to enable also other path-managers and schedulers, to select your optimal configuration via software.