Since v2021.5.0 home-assistant uses the ifaddr library in the zeroconf
component to enumerate network interfaces via netlink. Since discovery
is all over the place lets allow AF_NETLINK unconditionally.
It also relies on pyroute2 now, which additionally tries to access files
in /proc/net, so we relax ProtectProc a bit by default as well.
This leaves us with these options unsecured:
✗ PrivateNetwork= Service has access to the host's network 0.5
✗ RestrictAddressFamilies=~AF_(INET|INET6) Service may allocate Internet sockets 0.3
✗ DeviceAllow= Service has a device ACL with some special devices 0.1
✗ IPAddressDeny= Service does not define an IP address allow list 0.2
✗ PrivateDevices= Service potentially has access to hardware devices 0.2
✗ PrivateUsers= Service has access to other users 0.2
✗ SystemCallFilter=~@resources System call allow list defined for service, and @resources is included (e.g. ioprio_set is allowed) 0.2
✗ RestrictAddressFamilies=~AF_NETLINK Service may allocate netlink sockets 0.1
✗ RootDirectory=/RootImage= Service runs within the host's root directory 0.1
✗ SupplementaryGroups= Service runs with supplementary groups 0.1
✗ RestrictAddressFamilies=~AF_UNIX Service may allocate local sockets 0.1
✗ ProcSubset= Service has full access to non-process /proc files (/proc subset=) 0.1
→ Overall exposure level for home-assistant.service: 1.6 OK 🙂
Home-assistant through its `--runner` commandline flag supports sending
exit code 100 when the `homeassistant.restart` service is called.
With `RestartForceExitStatus` we can listen for that specific exit code
and restart the whole systemd unit, providing an actual clean restart
with fresh processes. Additional treat exit code 100 as a successful
termination.
This is what is still exposed, and it should still allow things to work
as usual.
✗ PrivateNetwork= Service has access to the host's … 0.5
✗ RestrictAddressFamilies=~AF_(INET… Service may allocate Internet soc… 0.3
✗ DeviceAllow= Service has a device ACL with som… 0.1
✗ IPAddressDeny= Service does not define an IP add… 0.2
✗ PrivateDevices= Service potentially has access to… 0.2
✗ PrivateUsers= Service has access to other users 0.2
✗ SystemCallFilter=~@resources System call allow list defined fo… 0.2
✗ RootDirectory=/RootImage= Service runs within the host's ro… 0.1
✗ SupplementaryGroups= Service runs with supplementary g… 0.1
✗ RestrictAddressFamilies=~AF_UNIX Service may allocate local sockets 0.1
→ Overall exposure level for home-assistant.service: 1.6 OK :-)
This can grow to as much as ~1.9 if you use one of the bluetooth or nmap
trackers or the emulated_hue component, all of which required elevated
permisssions.
We are running over 6000 tests by now and they take around 5 minutes
on faster machines and tests alot of components that endusers will not
actually be using. It is sufficient if we run them on package upgrades
and in the passthrough test.
hass will ignore the standard SIGTERM sent by systemd during stop/restart and we
then have to wait for the timeout after which systemd will forcefully kill the
process.
If instead if we send SIGINT, hass will shut down nicely.
There are many issues reported upstream about the inability to shut down/restart
and it is *supposed* to work with SIGTERM but doesn't.
HA doesn't mind the configuration being JSON instead of YAML but since YAML is
the official language, use that as it allows users to easily exchange config
data with other parties in the community.
Additionally, some settings based on NixOS configuation is set via defaultConfig
which is then merged with the user provided configration.
For now that just means http port and time zone but others can easily be added.
