Guide@Debianizzati.Org

Old:UpHosts

Versione del 31 dic 2010 alle 09:36 di Paolo321 (discussione | contributi) (update script and text)

Introduzione

Premessa: esistono svariati sistemi di content filtering decisamente più raffinati e personalizzabili di questo.

Scopo di questo script è semplicemente bloccare l'accesso a hosts a vario titolo "malevoli" basandosi su liste disponibili online.

Tali host vengono inseriti in /etc/hosts come corrispondenti a 0.0.0.0 , bloccandone di fatto l'accesso.

  ATTENZIONE
questo script è stato creato per uso personale, in parte riadattando e modificando script altrui

(ringrazio tutti i rispettivi autori) e nonostante abbia cercato di testarlo al meglio, non posso offrire alcuna garanzia :-)


Paolo321 , 31 dicembre 2010


Funzionamento

Spero che lo script sia sufficientemente chiaro e si "spieghi da solo", comunque lo script esegue:

  • Controllo privilegi di root e presenza software richiesti
  • Controllo di quanto tempo è passato dall'ultima esecuzione (per evitare download troppo frequenti, vedi esempio sotto)
  • Backup dell'hosts file presistente (se non già effettuato)
  • Download delle liste
  • Adattamento del formato delle liste
    • Ogni lista richiede differenti azioni, questo purtroppo implica che le liste sono hard-coded e per aggiungerne o toglierne una è necessario modificare buona parte dello script
  • Lettura blacklist locale
  • Merge di tutte le liste, con ordinamento e eliminazione duplicati
  • Lettura whitelist locale e rimozione dalla blacklist degli host presenti
  • Creazione del nuovo file hosts
  • Importazione del file hosts di backup
    • Questo è necessario per garantire che host precedentemente presenti in /etc/hosts non vengano rimossi
    • A ogni esecuzione dello script il precedente file hosts è sovrascritto, e il file hosts di backup è reimportato
    • Eventuali modifiche permanenti al file hosts andranno quindi effettuate non in /etc/hosts ma nel file hosts di backup
  • Report numero hosts bloccati e uscita dello script


Note

  • Come default lo script cerca blacklist e whitelist locali nella sua directory, quindi si può ad esempio collocare il tutto in /opt/uphosts. Ovviamente si può cambiare i path nello script e usarne altri.
  • Uno script di questo tipo è comodo sia eseguito "unattended"; iIl wrapper zzz-uphosts-run esegue uphosts e reindirizza l'output nei log di sistema. Può ad esempio essere eseguito da /etc/network/if-up.d, oppure tramite cron (ma in questo secondo caso c'è da aggiungere un controllo sulla presenza di connessione internet). Lo script all'avvio controlla comunque quanto tempo è passato dall'ultima esecuzione (per evitare che ad esempio dieci connessioni-disconnessioni al giorno portino a dieci download delle liste)


Script

uphosts.sh

#!/bin/bash

# uphosts - Hosts File Updater

# README:
# Bad hosts are blocked putting them in the hosts file as 0.0.0.0
# To add other sources script must be manually modified
# Permanent entries must be added to the original file

# THIS SCRIPT HAS NO WARRANTY !

# Thanks to:
# http://ubuntuedintorni.wordpress.com/2009/06/29/di-script-dns-e-file-host/
# http://hostsfile.mine.nu/downloads/updatehosts.sh.txt

# 20101216 Paolo

#-----------------------------------------------------------------------

HOSTSPATH="/tmp/hosts-`date +%s`"		# Temp directory
HOSTSFILE="/etc/hosts"				# Hosts file
ORIGFILE="$HOSTSFILE.original"			# Backup file

CONFDIR="$(dirname $(readlink -f $0))"	# Parent directory of the script
BLACKLIST="$CONFDIR/uphosts-blacklist"	# Local Blacklist
WHITELIST="$CONFDIR/uphosts-whitelist"	# Whitelist

PROXYUSER="" #PROXYUSER="--proxy-user=user.name"
PROXYPASS="" #PROXYPASS="--proxy-password='password"

DAYS="2" # Update frequency

#-----------------------------------------------------------------------

# Checks for root privileges
if [ "$(whoami)" != 'root' ] ; then
	echo "You need to be root to execute uphosts. Exiting!"
	exit 1
fi

# Checks required packages
ABORT=0
builtin type -P wget     &>/dev/null || { echo -n "wget is missing."; ABORT=1; }
builtin type -P unzip    &>/dev/null || { echo -n "unzip is missing."; ABORT=1; }
builtin type -P fromdos  &>/dev/null || { echo -n "fromdos(tofrodos) is missing."; ABORT=1; }
builtin type -P grep     &>/dev/null || { echo -n "grep is missing."; ABORT=1; }

if [ $ABORT != 0 ] ; then
	echo " Exiting!"
	exit 2
fi

# Limits updates if uphosts is run often (i.e. at every if-up)
# If there is no original hosts file this is the first run on a fresh system, and update runs anyway
if [ -f "$ORIGFILE" ] && [ `find $HOSTSFILE -mtime -$DAYS` ] ; then
	echo "$HOSTSFILE is less than $DAYS days old. Exiting!"
	exit 3
fi

# If there is no original hosts file this is the first run on a fresh system
# (as above, but now original hosts file is saved)
if [ ! -f "$ORIGFILE" ] ; then
	echo "Backing up your previous hosts file ..."
	cp $HOSTSFILE $ORIGFILE
	#echo "OK"
fi

#-----------------------------------------------------------------------

mkdir $HOSTSPATH

# Every list has some specific tweaks :-)
# If there are any errors, the script exits. Merging lists partially could be unsafe

#### hphosts list
HFNAME1="hphosts"
HFSERVER1="http://support.it-mate.co.uk/downloads"
HFILE1="hphosts.zip"
HFILE1INT="HOSTS.txt" # Needed to specify which file from zip
# Downloading
echo -n "Retrieving $HFNAME1 from $HFSERVER1 ..."
wget -q -O $HOSTSPATH/$HFNAME1 $HFSERVER1/$HFILE1 $PROXYUSER $PROXYPASS || { echo " ERROR! Exiting!"; exit 11; }
unzip -p $HOSTSPATH/$HFNAME1 $HFILE1INT | fromdos | grep -v localhost | sed -e '/#.*/ d' -e '/^$/ d' -e 's/127.0.0.1/0.0.0.0/g' > $HOSTSPATH/hosts-$HFNAME1
echo " OK"

#### hphosts-partial list
HFNAME2="hphosts-partial"
HFSERVER2="http://www.hosts-file.net"
HFILE2="hphosts-partial.asp"
# Downloading
echo -n "Retrieving $HFNAME2 from $HFSERVER2 ..."
wget -q -O $HOSTSPATH/$HFNAME2 $HFSERVER2/$HFILE2 $PROXYUSER $PROXYPASS || { echo " ERROR! Exiting!"; exit 12; }
cat $HOSTSPATH/$HFNAME2 | fromdos | grep -v localhost | sed -e '/#.*/ d' -e '/^$/ d' -e 's/127.0.0.1/0.0.0.0/g' > $HOSTSPATH/hosts-$HFNAME2
echo " OK"

#### MVPs list
HFNAME3="mvps"
HFSERVER3="http://www.mvps.org/winhelp2002"
HFILE3="hosts.zip"
HFILE3INT="HOSTS" # Needed to specify which file from zip
# Downloading
echo -n "Retrieving $HFNAME3 from $HFSERVER3 ..."
wget -q -O $HOSTSPATH/$HFNAME3 $HFSERVER3/$HFILE3 $PROXYUSER $PROXYPASS || { echo " ERROR! Exiting!"; exit 13; }
unzip -p $HOSTSPATH/$HFNAME3 $HFILE3INT | fromdos | grep -v localhost | sed -e '/#.*/ d' -e '/^$/ d'  -e 's/127.0.0.1/0.0.0.0/g' > $HOSTSPATH/hosts-$HFNAME3
echo " OK"

#### hostsfile.mine.nu, 0.0.0.0 format
#HFNAME4="mine-nu-0"
#HFSERVER4="http://hostsfile.mine.nu.nyud.net"
#HFILE4="hosts0.zip"
## Downloading
#echo -n "Retrieving $HFNAME4 from $HFSERVER4 ..."
#wget -q -O $HOSTSPATH/$HFNAME4 $HFSERVER4/$HFILE4 $PROXYUSER $PROXYPASS || { echo " ERROR! Exiting!"; exit 14; }
#unzip -p $HOSTSPATH/$HFNAME4 | fromdos | grep -v localhost | sed -e '/#.*/ d' -e '/^$/ d' > $HOSTSPATH/hosts-$HFNAME4
#echo " OK"

#-----------------------------------------------------------------------

echo -n "Processing local blacklist $BLACKLIST ..."
if [ -f "$BLACKLIST" ] ; then
	cat $BLACKLIST | sed -e '/#.*/ d' -e '/^$/ d' -e 's/^/0.0.0.0 /g' > $HOSTSPATH/blacklist.ready
	echo " OK"
	echo -n "Merging lists ..."
	#cat $HOSTSPATH/hosts-$HFNAME1 $HOSTSPATH/hosts-$HFNAME2 $HOSTSPATH/hosts-$HFNAME3 $HOSTSPATH/hosts-$HFNAME4 $HOSTSPATH/blacklist.ready | sort | uniq > $HOSTSPATH/hosts.all
	cat $HOSTSPATH/hosts-$HFNAME1 $HOSTSPATH/hosts-$HFNAME2 $HOSTSPATH/hosts-$HFNAME3 $HOSTSPATH/blacklist.ready | sort | uniq > $HOSTSPATH/hosts.all
	echo " OK"
else
	echo " NOT FOUND"
	echo -n "Merging lists ..."
	#cat $HOSTSPATH/hosts-$HFNAME1 $HOSTSPATH/hosts-$HFNAME2 $HOSTSPATH/hosts-$HFNAME3 $HOSTSPATH/hosts-$HFNAME4 | sort | uniq > $HOSTSPATH/hosts.all
	cat $HOSTSPATH/hosts-$HFNAME1 $HOSTSPATH/hosts-$HFNAME2 $HOSTSPATH/hosts-$HFNAME3 | sort | uniq > $HOSTSPATH/hosts.all
	echo " OK"
fi

echo -n "Processing whitelist $WHITELIST ..."
if [ -f "$WHITELIST" ] ; then
	cat $WHITELIST | sed -e '/#.*/ d' -e '/^$/ d' > $HOSTSPATH/whitelist.ready
	grep -Fvf $HOSTSPATH/whitelist.ready $HOSTSPATH/hosts.all > $HOSTSPATH/hosts.all.2
	mv $HOSTSPATH/hosts.all.2 $HOSTSPATH/hosts.all
	echo " OK"
else
	echo " NOT FOUND"
fi

#-----------------------------------------------------------------------

echo -n "Writing hosts file $HOSTSFILE ..."
cat $ORIGFILE > $HOSTSFILE
echo " OK"

HOSTCOUNT=`cat $HOSTSPATH/hosts.all | wc -l`

echo "" >> $HOSTSFILE # to be sure the original file ends in a new-line
echo "" >> $HOSTSFILE

cat >> $HOSTSFILE << EOF
#==================================================================
#	
# `date`
# $HOSTCOUNT hosts blocked by uphosts
#
# Original file: $ORIGFILE
# Permanent changes can be done there, it is imported at every run
#
#==================================================================
EOF

echo "" >> $HOSTSFILE
cat $HOSTSPATH/hosts.all >> $HOSTSFILE

#rm -fv $HOSTSPATH/hosts*
echo "Update process complete - $HOSTCOUNT hosts blocked!"

zzz-uphosts-run

#!/bin/sh

# uphosts - Hosts File Updater
# zzz-uphosts-run

# wrapper for running uphosts logging output
# for example, from /etc/network/if-up.d

# In that case, this script is run by run-parts
# Check run-parts naming conventions: "must consist entirely of upper and lower case letters, digits, underscores, and hyphens"
# ie do not name this script foo.sh !!!

# 20101230 Paolo

UPHOSTSFILE="/opt/uphosts/uphosts.sh"
LOGGERPARAMS="-t uphosts"

$UPHOSTSFILE | logger $LOGGERPARAMS &

uphosts-blacklist

# uphosts - Hosts file updater
# Local Blacklist file

# Lines starting with hash are ignored
# Add hostnames below, one per line
# These entries are just merged adding 0.0.0.0
# Unlike whitelist, here foo.com means ONLY foo.com !

# eg.
# test12345.com
# test67890.com

uphosts-whitelist

# uphosts - Hosts file updater
# Whitelist file

# Lines starting with hash are ignored
# Add hostnames below, one per line
# These are grep patterns, so foo.com means EVERY matching line !

# eg.
# test12345.com
# test67890.com
Estratto da "https://guide.debianizzati.org/index.php?title=Old:UpHosts&oldid=22767"