add tinc-generate-mac tinc-generate-macc

.gitignore

@@ -1,4 +1,4 @@
 rsa_key.priv
 ecdsa_key.priv
-tinc-up
 tinc.conf
+tinc-macaddr

tinc-generate-mac

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+set -eu
+
+DIR=$(cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd)
+MACADDR_FILE="$DIR/tinc-macaddr"
+if [ -e "$MACADDR_FILE" ]; then
+  echo "Skip generating MAC: '$MACADDR_FILE' does already exists."
+  exit 1
+else
+  # Locally Administered Address Ranges:
+  #x2-xx-xx-xx-xx-xx
+  #x6-xx-xx-xx-xx-xx
+  #xA-xx-xx-xx-xx-xx
+  #xE-xx-xx-xx-xx-xx
+  # Replacing x with any hex value.
+  printf '02:1F:%02X:%02X:%02X:%02X\n' \
+    $[RANDOM%256] $[RANDOM%256] $[RANDOM%256] $[RANDOM%256] \
+    > "$MACADDR_FILE"
+fi
+cat $MACADDR_FILE