#!/bin/sh
set --
dirs=$HOME
p=$HOME
while [ "$p" != "${p%/*}" ]
do
    p=${p%/*}
    dirs="$dirs $p/"
done

chown root:root $dirs
chmod go-w $dirs

cmd="/usr/sbin/sshd -D -e -f $HOME/.ssh/sshd_config -h $HOME/.ssh/id_ed25519"
/sbin/runuser -u u -- sh -c "set -x; $cmd"