Howto Start TFTP server on macOS

When working with devices that requires TFTP server like flash router via TFTP, ... we could either deploy a using docker or using build-in TFTP daemon in macOS.

Deploy TFTP Server with docker

This method could apply to either Linux/macOS/Windows using docker or podman with bind mount to a folder tftpboot inside the current folder.

docker run -d -p 0.0.0.0:69:69/udp -v ./tftpboot:/var/tftpboot -i -t docker.io/pghalliday/tftp

docker-compose file:

version: '2'
services:
  tftpd:
    image: docker.io/pghalliday/tftp
    container_name: tftpd
    volumes:
      - ./tftpboot:/var/tftpboot
    tty: true
    ports:
      - "69:69/udp"

macOS TFTP Daemon

macOS has built in TFTP daemon - which is useful for developer to transfer firmware during development.

Daemon location: /System/Library/LaunchDaemons/tftp.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Disabled</key>
	<true/>
	<key>Label</key>
	<string>com.apple.tftpd</string>
	<key>ProgramArguments</key>
	<array>
		<string>/usr/libexec/tftpd</string>
		<string>-i</string>
		<string>/private/tftpboot</string>
	</array>
	<key>inetdCompatibility</key>
	<dict>
		<key>Wait</key>
		<true/>
	</dict>
	<key>InitGroups</key>
	<true/>
	<key>Sockets</key>
	<dict>
		<key>Listeners</key>
		<dict>
			<key>SockServiceName</key>
			<string>tftp</string>
			<key>SockType</key>
			<string>dgram</string>
		</dict>
	</dict>
</dict>
</plist>

Modify TFTP service parameters

From above TFTP daemon settings, by default, TFTP folder location is /private/tftpboot. As files under /System is protected by SIP, so we could leave with this default location and add needed files into this default path: /private/tftpboot

However, remember to chmod whole folder and added files with correct permission, else TFTP client can't get that file.

# chmod whole folder to 777
sudo chmod -R 777 /private/tftpboot

# add a file (let's say fw.bin and also chmod 777)
cp fw.bin /private/tftpboot
chmod 777 /private/tftpboot/fw.bin

Start and Stop daemon

Start daemon:

sudo launchctl load -F /System/Library/LaunchDaemons/tftp.plist

Stop daemon:

sudo launchctl unload /System/Library/LaunchDaemons/tftp.plist

Test with tftp client

We could test how TFTP daemon is running with build-in tftp client.

## Fetch file fw.bin
tftp -e 127.0.0.1
tftp> get fw.bin
Received 4979 bytes in 0.0 seconds

## In case file is not available
get fw.bin
Error code 256: File not found

Good luck!