#!/usr/bin/env bash

# Ceci est un script bash ayant pour but de créer un partage de connection
#
#

ssid=🦄
passphrase=chocolat

ip=10.5.6.11
range=24
network=10.5.6.0/24
dhcp_range=$(echo 10.5.6.{12\,,254}),12h


function guess_wifi {
    for i in `ls /sys/class/net/`; do
        if [ -d "/sys/class/net/$i/wireless" ] ; then
            _interface="$i"
        fi
    done
    echo "${_interface}"
}
function guess_internet {
    echo $(ip route show | grep 'default' |  \
                    sed 's/.*dev/dev/' | sed 's/scope//' | \
                    sed 's/src \([[:digit:]]\{1,3\}\.\)\{3\}[[:digit:]]\{1,3\}//g' | \
                    sed 's/link//' |
                    tr -s ' ' |
                    cut -d' ' -f 2)
}


#net.ipv4.ip_forward=1
#sudo snnnnet.ipv4.ip_forward=1
#sudo systnnet.ipv4.ip_forward=1
#sudo sysctl -w net.ipv4.ip_forward=1

echo 'Voici la configuration des interfaces :'
sudo ip a
echo
echo
echo 'Veuillez vérifier la table de routage :'
sudo ip r
echo


echo 'Activation de IP fowarding'
sudo sysctl -w net.ipv4.ip_forward=1

if [ -z "${1}" ] ; then
    echo "Détection automatique de l'interface Wifi"
    interface=$(guess_wifi)
else
    interface="${1}"
fi

echo "Interface Wifi : ${interface}"


if [ -z "${2}" ] ; then
    echo "Détection automatique de l'interface connectée à internet"
    interface_internet="$(guess_internet)"
else
    interface="${2}"
fi

echo "Interface internet : ${interface_internet}"


# sudo iw dev wlp3s0 interface add wlan1 type station
sudo pkill dnsmasq


echo "Configuration de l'IP 10.5.6.11"
sudo ip a r "${ip}/${range}" dev "$interface"

echo "Configuration de DNSQMASQ"

cat <<< $(
echo "
listen-address=${ip}
interface=${interface}
dhcp-range=${dhcp_range}"
) > /tmp/dnsmasq_hotspot.conf



echo 'Lancement de DNSMASQ (DHCP sur le réseau 10.5.6.0/24)'
if sudo dnsmasq --conf-file=/tmp/dnsmasq_hotspot.conf ; then
    echo 'Ok dnsmasq prêt'
else
    echo 'Erreur : Impossible de démarrer dnsmasq'
    echo 'Abandon'
    exit 1
fi

echo "Activation de l'interface ${interface}"
sudo ip link set "${interface}" up

echo 'Ajout du réseau dans la table de routage'
sudo ip r add 10.5.6.0/24 via 10.5.6.11 dev "${interface}"


echo "Routage des connections internet"
sudo sysctl net.ipv4.ip_forward=1
sudo iptables -t nat -A POSTROUTING -o "${interface_internet}" -j MASQUERADE
sudo iptables -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i "${interface}" -o "${interface_internet}" -j ACCEPT



echo "Configuration de hostapd"

cat <<< $(
echo "
interface=${interface}
ssid=${ssid}

wpa=1
wpa_passphrase=${passphrase}

channel=1
hw_mode=g

logger_syslog=-1
logger_syslog_level=2
logger_stdout=-1
logger_stdout_level=2

ctrl_interface=/var/run/hostapd
ctrl_interface_group=0

beacon_int=100
dtim_period=2
max_num_sta=255
rts_threshold=2347
fragm_threshold=2346
macaddr_acl=0
auth_algs=3
ignore_broadcast_ssid=0

wmm_enabled=1
wmm_ac_bk_cwmin=4
wmm_ac_bk_cwmax=10
wmm_ac_bk_aifs=7
wmm_ac_bk_txop_limit=0
wmm_ac_bk_acm=0
wmm_ac_be_aifs=3
wmm_ac_be_cwmin=4
wmm_ac_be_cwmax=10
wmm_ac_be_txop_limit=0
wmm_ac_be_acm=0
wmm_ac_vi_aifs=2
wmm_ac_vi_cwmin=3
wmm_ac_vi_cwmax=4
wmm_ac_vi_txop_limit=94
wmm_ac_vi_acm=0
wmm_ac_vo_aifs=2
wmm_ac_vo_cwmin=2
wmm_ac_vo_cwmax=3
wmm_ac_vo_txop_limit=47
wmm_ac_vo_acm=0

vht_oper_chwidth=3
eap_message=hello
eapol_key_index_workaround=0
eap_server=0"
) > /tmp/hostapd.conf



echo "Lancement du hostpot Wifi"
if sudo hostapd /tmp/hostapd.conf ; then
    echo 'Yeah, i wish you enjoyed it'
else
    echo 'Error: there is a problem with hostapd'
fi

echo 'Clean des iptables'
sudo iptables --flush
sudo iptables -t nat --flush

echo 'Clean config'

rm /tmp/dnsmasq_hotspot.conf /tmp/hostapd.conf

echo 'Bye 💋'
echo 'Have a nice day <3'