Update bdbood.txt plus add a script to keep it fresh

libbitdht/src/bitdht/bdboot_generate.sh

@@ -0,0 +1,55 @@
+#!/bin/bash
+
+<<LICENSE
+
+Copyright (C) 2020  Gioacchino Mazzurco <gio@eigenlab.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+LICENSE
+
+<<README
+Generate a clean DHT bootstrap node list.
+Feeds on previously known nodes from standard input and a few well known
+mainline DHT bootstrap nodes. Prints only nodes that appears to be active to a
+quick nmap check. Make sure your internet connection is working well before
+using this.
+
+Example usage:
+--------------------------------
+cat bdboot.txt | bdboot_generate.sh | tee /tmp/bdboot_generated.txt
+cat /tmp/bdboot_generated.txt | sort -u > bdboot.txt
+--------------------------------
+README
+
+function check_dht_host()
+{
+	mHost="$1"
+	mPort="$2"
+	
+	sudo nmap -oG - -sU -p $mPort $mHost | grep open | \
+		awk '{print $2" "$5}' | awk -F/ '{print $1}'
+}
+
+cat | while read line; do
+	hostIP="$(echo $line | awk '{print $1}')"
+	hostPort="$(echo $line | awk '{print $2}')"
+	check_dht_host $hostIP $hostPort
+done
+
+check_dht_host router.utorrent.com 6881
+check_dht_host router.bittorrent.com 6881
+check_dht_host dht.libtorrent.org 25401
+check_dht_host dht.transmissionbt.com 6881
+