tailscale

Running Tailscale on the DevTerm-R01

These are my notes for running Tailscale for the DevTerm-R01.

Note this is pre Linux 6.2, which will have proper Allwinner D1 support rendering many of these instructions obsolete.

Tailscale will not install due to missing the tun.ko module which is not included in the default R-01 kernel. Trying to start tailscaled will give the following error in /var/log/syslog

Jan 26 02:25:17 localhost systemd[1]: Started Tailscale node agent.
Jan 26 02:25:17 localhost tailscaled[1074605]: wgengine.NewUserspaceEngine(tun "tailscale0") ...
Jan 26 02:25:17 localhost tailscaled[1074605]: Linux kernel version: 5.4.61
Jan 26 02:25:17 localhost tailscaled[1074605]: is CONFIG_TUN enabled in your kernel? `modprobe tun` failed with: modprobe: FATAL: Module tun not found in directory /lib/modules/5.4.61
Jan 26 02:25:19 localhost tailscaled[1074605]: tun module not loaded nor found on disk
Jan 26 02:25:19 localhost tailscaled[1074605]: wgengine.NewUserspaceEngine(tun "tailscale0") error: tstun.New("tailscale0"): CreateTUN("tailscale0") failed; /dev/net/tun does not exist
Jan 26 02:25:19 localhost tailscaled[1074605]: flushing log.
Jan 26 02:25:19 localhost tailscaled[1074605]: logger closing down

Building Kernel

It is faster to cross-compile kernel on x86 in a Ubuntu 22.04 VM, if done on the R-01 it could take a very long time.

Also see: https://github.com/clockworkpi/DevTerm/wiki/Create-DevTerm-R01-OS-image-from-scratch#how-to-compile-kernel

Install Required Packages

sudo apt install gcc-11-riscv64-linux-gnu binutils-riscv64-linux-gnu qemu-user-static build-essential git wget curl vim libncurses-dev flex automake autoconf bison libssl-dev

Building the kernel

1. Clone git source from ccu

git clone https://github.com/cuu/last_linux-5.4.git

2. Setup Crossbuild toolchain in /opt https://github.com/cuu/toolchain-thead-glibc

tar -xvzf riscv64-glibc-gcc-thead_20200702.tar.gz

3. Edit ~/.baschr to include path

export PATH=/home/micheal/riscv64-glibc-gcc-thead_20200702/bin/:$PATH

4. Copy config.gz for running kernel config from devterm

scp [email protected]:/proc/config.gz
mv config.gz git/last_linux-5.4/
gunzip config.gz
mv config .config

4. Make menuconfig to select CONFIG_TUN driver

make CROSS_COMPILE=riscv64-unknown-linux-gnu- ARCH=riscv menuconfig

5. This will load in .config copied from the devterm and populate everything

6. Select TUN/TAP device support

see: https://tailscale.com/

Linux Kernel Configuration
└─> Device Drivers
└─> Network device support
└─> Universal TUN/TAP device driver support

7. Compile kernel

Edit ./m.sh to include LOCALVERSION= after each make in order to avoid adding a + to the kernel version, which can cause version magic errors.

mkdir -p test/boot
./m.sh

Adding Tunnel Drivers to R-01

Kernel modules are in /home/micheal/git/last_linux-5.4/test/rootfs/lib/modules/5.4.61

Create tarball with these to copy to the DevTerm

cd /home/micheal/git/last_linux-5.4/test/rootfs/lib/modules
tar -cvzf 5.4.61.modules.tar.gz 5.4.61/

On DevTerm, backup original modules

cd /lib/modules
sudo mv 5.4.61 5.4.61.orig

Untar new modules and rename directory

cd /lib/modules
sudo tar -xvzf ~/5.4.61.modules.tar.gz

Load module

modprobe tun

This will show the module loaded properly in dmesg

tun: Universal TUN/TAP device driver, 1.6

Start tailscaled

sudo service tailscaled start

Configure tailscale

sudo tailscale up