base: add tor service setup and config

the tor service provides hidden services for bitcoin and lightning.
in the latter case, both P2P and RPC/REST.

the commit also starts a new directory files. the idea is to mirror
config files layout in the target system.

apply.sh

@@ -9,6 +9,8 @@ rootdir="$SYSUPDATES_ROOTDIR"
 # base os
 cd "$rootdir"
 ./base/voidlinux.sh || exit 1
+cd "$rootdir"
+./base/tor.sh || exit_code=$?
 
 # nakamochi daemon and gui (ndg)
 cd "$rootdir"

base/tor.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+# the script installs tor and its config file from files/etc/tor/torrc.
+set -e
+xbps-install -y tor
+conffile=etc/tor/torrc
+test -f /$conffile && diff /$conffile files/$conffile
+if [ $? -ne 0 ]; then
+    cp /$conffile /$conffile.orig
+    cp files/$conffile /$conffile
+    ln -sfT /etc/sv/tor /var/service/tor
+    # don't touch the service if on manual control
+    test ! -f /etc/sv/tor/down && sv restart tor
+fi

files/etc/tor/torrc

@@ -0,0 +1,19 @@
+# tor daemon configuration based on
+# https://gitlab.torproject.org/tpo/core/tor/-/blob/main/src/config/torrc.sample.in
+#
+# NOTE: this file is auto-updated by nakamochi sysupdates
+# https://git.qcode.ch/nakamochi/sysupdates
+
+User tor
+Log notice syslog
+DataDirectory /ssd/tor
+
+# bitcoin P2P service over tor
+HiddenServiceDir /ssd/tor/bitcoind/
+HiddenServicePort 8333 127.0.0.1:8334
+
+# lnd lightning P2P, RPC and REST over tor
+HiddenServiceDir /ssd/tor/lnd/
+HiddenServicePort 9735 127.0.0.1:9735
+HiddenServicePort 10009 127.0.0.1:10009
+HiddenServicePort 10010 127.0.0.1:10010