; For further details about the directives used in this unit file, including
; the below, please refer to systemd's official documentation, available at
; https://www.freedesktop.org/software/systemd/man/systemd.exec.html.
;
;
;   - `ProtectSystem=strict` implies we mount the entire file system hierarchy
;     read-only for the processes invoked by the unit except for the API file
;     system subtrees /dev, /proc and /sys (which are protected by
;     PrivateDevices=, ProtectKernelTunables=, ProtectControlGroups=).
;
;   - `PrivateTmp=yes` secures access to temporary files of the process, and
;     makes sharing between processes via /tmp or /var/tmp impossible.
;
;   - `ProtectHome=yes` makes the directories /home, /root, and /run/user
;     inaccessible and empty for processes invoked by the unit.
;
;   - `ProtectControlGroups=yes` makes the Linux Control Groups hierarchies
;     (accessible through /sys/fs/cgroup) read-only to all processes invoked by
;     the unit. It also implies `MountAPIVFS=yes`.
;
;   - `RuntimeDirectory=unbound` creates a /run/unbound directory, owned by the
;     unit User and Group with read-write permissions (0755) as soon as the
;     unit starts. This allows unbound to store its pidfile. The directory and
;     its content are automatically removed by systemd when the unit stops.
;
;   - `NoNewPrivileges=yes` ensures that the service process and all its
;     children can never gain new privileges through execve().
;
;   - `RestrictSUIDSGID=yes` ensures that any attempts to set the set-user-ID
;     (SUID) or set-group-ID (SGID) bits on files or directories will be denied.
;
;   - `RestrictRealTime=yes` ensures that any attempts to enable realtime
;     scheduling in a process invoked by the unit will be denied.
;
;   - `RestrictNamespaces=yes` ensures that access to any kind of namespacing
;     is prohibited.
;
;   - `LockPersonality=yes` locks down the personality system call so that the
;     kernel execution domain may not be changed from the default.
;
;
[Unit]
Description=Validating, recursive, and caching DNS resolver
Documentation=man:unbound(8)
After=network-online.target
Before=nss-lookup.target
Wants=network-online.target nss-lookup.target

[Install]
WantedBy=multi-user.target

[Service]
ExecReload=+/bin/kill -HUP $MAINPID
ExecStart=@UNBOUND_SBIN_DIR@/unbound -d -p
NotifyAccess=main
Type=notify
CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_SETGID CAP_SETUID CAP_SYS_CHROOT CAP_SYS_RESOURCE CAP_NET_RAW
MemoryDenyWriteExecute=true
NoNewPrivileges=true
PrivateDevices=true
PrivateTmp=true
ProtectHome=true
ProtectClock=true
ProtectControlGroups=true
ProtectKernelLogs=true
ProtectKernelModules=true
# This breaks using socket options like 'so-rcvbuf'. Explicitly disable for visibility.
ProtectKernelTunables=false
ProtectProc=invisible
ProtectSystem=strict
RuntimeDirectory=unbound
ConfigurationDirectory=unbound
StateDirectory=unbound
RestrictAddressFamilies=AF_INET AF_INET6 AF_NETLINK AF_UNIX
RestrictRealtime=true
SystemCallArchitectures=native
SystemCallFilter=~@clock @cpu-emulation @debug @keyring @module mount @obsolete @resources
RestrictNamespaces=yes
LockPersonality=yes
RestrictSUIDSGID=yes
ReadWritePaths=@UNBOUND_RUN_DIR@ @UNBOUND_CHROOT_DIR@

# Below rules are needed when chroot is enabled (usually it's enabled by default).
# If chroot is disabled like chroot: "" then they may be safely removed.
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/dev:ro
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/run:ro
BindReadOnlyPaths=-/run/systemd/notify:@UNBOUND_CHROOT_DIR@/run/systemd/notify
BindReadOnlyPaths=-/dev/urandom:@UNBOUND_CHROOT_DIR@/dev/urandom
BindPaths=-/dev/log:@UNBOUND_CHROOT_DIR@/dev/log