Compiling AppleTalk support for a Synology

[andyzickler]

I had Netatalk running via docker and it was working great until I upgraded to DSM 7.3.2. After that I would just get an error when trying to start the container atalkd: can't get interfaces, exiting. Some helpful troubleshooting from the community determined that the AppleTalk support had been removed from the kernel. Here's how I went about building the AppleTalk module for my Synology. I really didn't want to setup a build environment, but thankfully someone else already did in a Docker container.

Prereqs

1. A computer with Docker installed. You shouldn't try and compile this on your Synology
2. SSH and root access to the Synology

Building

1. Go to https://github.com/telnetdoogie/synology-kernelmodules and download a copy of the source
2. Edit Dockerfile and add RUN chmod +x apply_patches.sh entrypoint.sh below the COPY commands. (I have a PR to fix this, will remove once it's merged)
3. Edit entrypoint.sh. Replace the three make lines

make -j$(nproc) M=net/ipv4/netfilter modules
make -j$(nproc) M=net/ipv6/netfilter modules
make -j$(nproc) M=fs/overlayfs modules

with

make -j$(nproc) M=net/appletalk modules

Replace the copy lines

cp net/ipv4/netfilter/iptable_raw.ko $FINAL_FOLDER/iptable_raw.ko
cp net/ipv6/netfilter/ip6table_raw.ko $FINAL_FOLDER/ip6table_raw.ko
cp fs/overlayfs/overlay.ko $FINAL_FOLDER/overlay.ko

with

cp net/appletalk/appletalk.ko $FINAL_FOLDER/appletalk.ko

5. Figure out which CPU type you have. Go to https://kb.synology.com/en-global/DSM/tutorial/What_kind_of_CPU_does_my_NAS_have and look up your model number. Write down the Package Arch value
6. Build the docker container. docker build --platform linux/amd64 -t compile_modules . I'm running on an ARM Mac and so needed to add the platform tag. If you're on AMD or Intel you shouldn't need it
7. Run the container to compile docker run --privileged --rm -v ./compiled_modules:/compiled_modules:rw -e PLATFORM=YOUR_PACKAGE_ARCH compile_modules Remember to substitute your package arch from step 5
8. Copy appletalk.ko onto your Synology to /lib/modules. It will be in one of the subdirectories of compiled_modules
9. Run sudo insmod /lib/modules/appletalk.ko
10. Check that appletalk is enabled with lsmod | grep appletalk. You should set output like

appletalk              25810  0
psnap                   2004  1 appletalk

11. Netatalk should work again! You can clean up the Docker containers and images.

I'm not at all experienced with kernel building and I haven't yet needed to figure out how to ensure the module auto loads on startup. I figured I'd cross that bridge when i needed to. Any comments and corrections would be appreciated. Would also love to see someone else try this and report back.

[andyzickler]

If anyone is running Netatalk on their Synology can you post your model and DSM version? And if you already have appletalk support with lsmod | grep appletalk

[NJRoadfan]

Since you are compiling the kernel modules anyway, you may want to patch the AppleTalk kernel module to fix longstanding problems.

https://gist.github.com/VinDuv/4db433b6dce39d51a5b7847ee749b2a4

These have all been integrated into the latest kernel for quite a while, but Synology is a bit behind.