5 files changed, 59 insertions, 14 deletions
diff --git a/retiolum/bin/apply-custom-hosts-patches b/retiolum/bin/apply-custom-hosts-patches
deleted file mode 100755
index 2b2fda80..00000000
--- a/retiolum/bin/apply-custom-hosts-patches
+++ /dev/null
@@ -1,8 +0,0 @@
-#! /bin/sh
-set -euf
-
-patch=/etc/tinc/retiolum/hosts.patch
-
-if test -e $patch; then
-  patch -N -d /etc/tinc/retiolum/hosts -r - < $patch
-fi
diff --git a/retiolum/bin/list-known-public-addresses b/retiolum/bin/list-known-public-addresses
new file mode 100755
index 00000000..21b1c389
--- /dev/null
+++ b/retiolum/bin/list-known-public-addresses
@@ -0,0 +1,38 @@
+#! /bin/sh
+#
+# printf '%s %s\n' hostname IP-address for each known public retiolum address
+#
+set -eu
+
+_list_hostname_address() {
+  cd /etc/tinc/retiolum/hosts
+  grep --with-filename '^Address' * |
+  sed -n '
+    s/: */ /
+    s/ *= */ /
+    s/ Address \([a-zA-Z0-9.:_]*\) \?.*/ \1/p'
+}
+_lookup_address() {
+  sed '
+    /:/!{/ [0-9.]*$/!{s/ / `dig +short /;s/$/` \&/}}
+    s/^/echo /
+    $s/$/\nwait/
+  ' | sh
+}
+_filter_public() {
+  sed '
+    # drop private IPv4 addresses
+    / 10\./d
+    / 172\.\(1[6-9]\|2[0-9]\|3[01]\)\./d
+    / 192\.168\./d
+    # TODO drop private IPv6 addresses
+  '
+}
+_filter_online() {
+  awk '
+    {print"nc -zw 2 "$2" 655 2>/dev/null && echo "$1" "$2" &"}
+    END {print"wait"}
+  ' | sh
+}
+
+_list_hostname_address | _lookup_address | _filter_public
diff --git a/retiolum/bin/patch-retiolum-hosts b/retiolum/bin/patch-retiolum-hosts
new file mode 100755
index 00000000..69d7b92c
--- /dev/null
+++ b/retiolum/bin/patch-retiolum-hosts
@@ -0,0 +1,13 @@
+#! /bin/sh
+#
+# Apply custom retiolum hosts patches, if any.
+#
+# usage: patch-retiolum-hosts [--reverse]
+#
+set -euf
+
+patch=/etc/tinc/retiolum/hosts.patch
+
+if test -e $patch; then
+  patch -N -d /etc/tinc/retiolum/hosts -r - "$@" < $patch
+fi
diff --git a/retiolum/bin/update-retiolum-hosts b/retiolum/bin/update-retiolum-hosts
index 2a379459..214ac205 100755
--- a/retiolum/bin/update-retiolum-hosts
+++ b/retiolum/bin/update-retiolum-hosts
@@ -1,5 +1,5 @@
 #! /bin/sh
-set -eu
+set -euf
 
 if test "${nosudo-false}" != true -a `id -u` != 0; then
   echo "we're going sudo..." >&2
@@ -11,6 +11,4 @@ fi
 cd $(dirname $(readlink -f $0))/..
 
 mkdir -p /etc/tinc/retiolum/hosts
-cp -v -r hosts/* /etc/tinc/retiolum/hosts
-pkill -HUP tincd
-pkill -ALRM tincd
+rsync -va --delete hosts/ /etc/tinc/retiolum/hosts/
diff --git a/retiolum/bin/update_tinc_hosts b/retiolum/bin/update_tinc_hosts
index 7be30c2a..ce1be497 100755
--- a/retiolum/bin/update_tinc_hosts
+++ b/retiolum/bin/update_tinc_hosts
@@ -7,8 +7,12 @@ if test "${nosudo-false}" != true -a `id -u` != 0; then
   exit 23 # go to hell
 fi
 
-DIRNAME=`dirname $0`
-export PATH="`readlink -f $DIRNAME`:$PATH"
+list_hosts="$(
+  basename="`readlink -f "$0"`"
+  bindir="`dirname "$basename"`"
+  echo "$bindir/hosts"
+)"
+hosts() { "$list_hosts"; }
 
 hosts="${hosts-/etc/hosts}"