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Showing posts with label Parental Control. Show all posts
Showing posts with label Parental Control. Show all posts

Tuesday, June 04, 2019

Web Interface for Parental Control

This continues the Parental Control post from last month.

First of all, in order to protect the web page, we need an authentication method. A simple user/password will do for the moment (it's not perfect, you can bypass it by accessing directly the /cgi-bin/script.sh, but for the purpose of this exercise is OK-ish) .

Make sure that in the lighttpd.conf, mod_auth and mod_access are loaded,
server.modules += ( "mod_access" )
server.modules += ( "mod_auth" )

and the host section is protected

HTTP["url"] =~ "^/" {
auth.backend = "plain"
auth.backend.plain.userfile = "/jffs/lighttpd/.lighttpdpassword"
auth.require = ( "/" => (
"method" => "basic",
"realm" => "Password protected Parental Control",
"require" => "valid-user"
))}
(where /jffs/lighttpd/.lighttpdpassword contains the plaintext credentials, let's say parent:password)


The following index.html must be placed into the lighthttpd www root (/jffs/www/):

<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
   <title>Parental Control</title>
     <form action="../cgi-bin/ai.sh" method="POST">
     <button name="name" value="value" style="background-color:lime;height:150px;width:400px"> Allow internet </button>
     </form><p><br>
     <form action="../cgi-bin/ag.sh" method="POST">
     <button name="name" value="value" style="background-color:yellowgreen;height:150px;width:400px">  Allow games  </button>
     </form><p><br>
     <form action="../cgi-bin/ay.sh" method="POST">
     <button name="name" value="value" style="background-color:khaki;height:150px;width:400px">  Allow only YouTube  </button>
     </form><p><br>
     <form action="../cgi-bin/ni.sh" method="POST">
     <button name="name" value="value" style="background-color:red;height:150px;width:400px"> No internet </button>
     </form><p><br>
     <form action="../cgi-bin/ng.sh" method="POST">
     <button name="name" value="value" style="background-color:lightcoral;height:150px;width:400px">  No games  </button>
     </form><p><br>
     <form action="../cgi-bin/lst.sh" method="POST">
     <button name="name" value="value" style="background-color:cyan;height:150px;width:400px">  Show actual  </button>
     </form>
 </head>
</html>

The following scripts will be placed into the ./cgi-bin folder:

ag.sh
#!/bin/sh
OUTPUT=$('/jffs/allow_game ; sleep 1; iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

ai.sh
#!/bin/sh
OUTPUT=$('/jffs/del_fw ;sleep 1; iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

ay.sh
#!/bin/sh
OUTPUT=$('/jffs/allow_yt ; sleep 1; iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

lst.sh
#!/bin/sh
OUTPUT=$('iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi;' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

ng.sh
#!/bin/sh
OUTPUT=$('/jffs/disable_game && iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

ni.sh
#!/bin/sh
OUTPUT=$('/jffs/add_fw && iptables -L FORWARD | grep DROP | grep -v "DROP       0    --  anywhere             anywhere" | if grep -q "DROP       0    --  192.168.1.128/28    anywhere"; then echo NO Internet; else echo Allow Internet; fi; if grep -qm1 "#" /tmp/yt-block.conf; then echo Allow YT; else echo NO YT; fi; if grep -qm1 "#" /tmp/games-block.conf; then echo Allow Games; else echo NO Games; fi' | awk 'BEGIN{print "<table>"} {print "<tr>";for(i=1;i<=NF;i++)print "<td>" $i"</td>";print "</tr>"} END{print "</table>"}')
echo "Content-type: text/html"
echo ""
echo "<html><head><title>Parental Control</title></head><body>"
echo "Rules are: $OUTPUT <br><p>"
echo "<form><input type='button' style='background-color:cyan;height:200px;width:400px' value='Back' onclick='history.back()'></form>"
echo "</body></html>"

Now a very simple web page will allow you to control the kids internet from any browser:

Friday, May 03, 2019

Parental control

Because you can't let the kids on YouTube 24/7 and some games are really addictive :)

The router must run OpenWRT or DD-WRT.

The kids devices must be assigned IP's from a certain range, let's say 192.168.1.128/28 by adding some lines similar to the following one into Additional Dnsmasq Options:
dhcp-host=set:red,AA:BB:CC:00:DD:22,kids-tv,192.168.1.130,43200m


A series of scripts must be put in /jffs/ and called by a cron job:

cat add_fw
#!/bin/sh
iptables -I FORWARD 1 -s 192.168.1.128/28 -j DROP
iptables -I FORWARD 2 -s 192.168.1.128/28 -m conntrack -j DROP --ctstate RELATED,ESTABLISHED

cat del_fw
#!/bin/sh
iptables -D FORWARD -s 192.168.1.128/28 -j DROP
iptables -D FORWARD -s 192.168.1.128/28 -m conntrack -j DROP --ctstate RELATED,ESTABLISHED

cat disable_game
#!/bin/sh
# DNS Rules
sed -e 's/^#//' -i /tmp/games-block.conf
sed -e 's/^#//' -i /tmp/yt-block.conf
restart_dns
# Force kids DNS to local
iptables -t nat -A PREROUTING -i br0 -s 192.168.1.128/28 -p udp --dport 53 -j DNAT --to 192.168.1.1
iptables -t nat -A PREROUTING -i br0 -s 192.168.1.128/28 -p tcp --dport 53 -j DNAT --to 192.168.1.1
# Block all ports over :500
iptables -I FORWARD 5 -p tcp --source 192.168.1.128/28 --dport 500:65535 -j DROP

cat allow_game
#!/bin/sh
# Remove DNS rules
sed 's/^\([^#]\)/#\1/g' -i /tmp/games-block.conf
sed 's/^\([^#]\)/#\1/g' -i /tmp/yt-block.conf
restart_dns
# Remove Force kids DNS to local
iptables -t nat -D PREROUTING -i br0 -s 192.168.1.128/28 -p udp --dport 53 -j DNAT --to 192.168.1.1
iptables -t nat -D PREROUTING -i br0 -s 192.168.1.128/28 -p tcp --dport 53 -j DNAT --to 192.168.1.1
# Unblock all ports over :500
iptables -D FORWARD -p tcp --source 192.168.1.128/28 --dport 500:65535 -j DROP


I do have an extra script that allow access to YouTube, without allowing games, this one is called only from a html page that I'll explain in a later post:

cat allow_yt
#!/bin/sh
sed 's/^\([^#]\)/#\1/g' -i /tmp/yt-block.conf
restart_dns


Those scripts are called by cron jobs that makes sure we don't have internet during the sleep hours and games & YouTube are permitted only during the weekend:
00 21 * * 0-4 root /jffs/add_fw
30 22 * * 5,6 root /jffs/add_fw
00 08 * * * root /jffs/del_fw
30 17 * * 5 root /jffs/allow_game
30 17 * * 0 root /jffs/disable_game


In order to block the DNS requests, the following Additional Dnsmasq Options needs to be added:
conf-file=/tmp/yt-block.conf
conf-file=/tmp/games-block.conf


The files /tmp/yt-block.conf and /tmp/games-block.conf are created by the startup script:
stopservice dnsmasq
echo "#address=/.roblox.com/192.168.1.1
#address=/.rbxcdn.com/192.168.1.1
#address=/.epicgames.com/192.168.1.1
#address=/.fortnitegame.com/192.168.1.1
#address=/.easyanticheat.com/192.168.1.1
#address=/.pixelgunserver.com/192.168.1.1
#address=/.applovin.com/192.168.1.1
#address=/.clashroyaleapp.com/192.168.1.1
#address=/.applifier.com/192.168.1.1
#address=/.chartboost.com/192.168.1.1
#address=/.fyber.com/192.168.1.1
#address=/.twitch.tv/192.168.1.1
#address=/.ttvnw.net/192.168.1.1
#address=/.leagueoflegends.com/192.168.1.1
#address=/.pvp.net/192.168.1.1
#address=/.riotgames.com/192.168.1.1
#address=/.garenanow.com/192.168.1.1
#address=/.ea.com/192.168.1.1
#address=/.respawn.com/192.168.1.1
#address=/.origin.com/192.168.1.1" > /tmp/games-block.conf
echo "#address=/.youtube.com/192.168.1.1
#address=/youtube.googleapis.com/192.168.1.1
#address=/youtubei.googleapis.com/192.168.1.1
#address=/.ytimg.com/192.168.1.1
#address=/ytimg.l.google.com/192.168.1.1
#address=/youtube.l.google.com/192.168.1.1
#address=/.googlevideo.com/192.168.1.1
#address=/.youtube-nocookie.com/192.168.1.1
#address=/.youtu.be/192.168.1.1" > /tmp/yt-block.conf
startservice dnsmasq


An "easy" way to run those scripts besides the scheduled cron jobs, is from the DD-WRT Administration -> Commands page: