planktoscope/scripts/raspbian_configuration/usr/bin/autohotspotN
2021-07-01 18:19:32 +02:00

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#!/bin/bash
#version 0.96-N/HS-I
#You may share this script on the condition a reference to RaspberryConnect.com
#must be included in copies or derivatives of this script.
#Network Wifi & Hotspot with Internet
#A script to switch between a wifi network and an Internet routed Hotspot
#A Raspberry Pi with a network port required for Internet in hotspot mode.
#Works at startup or with a seperate timer or manually without a reboot
#Other setup required find out more at
#http://www.raspberryconnect.com
wifidev="wlan0" #device name to use. Default is wlan0.
ethdev="eth0" #Ethernet port to use with IP tables
#use the command: iw dev ,to see wifi interface name
IFSdef=$IFS
cnt=0
#These four lines capture the wifi networks the RPi is setup to use
wpassid=$(awk '/ssid="/{ print $0 }' /etc/wpa_supplicant/wpa_supplicant.conf | awk -F'ssid=' '{ print $2 }' ORS=',' | sed 's/\"/''/g' | sed 's/,$//')
wpassid=$(echo "${wpassid//[$'\r\n']}")
IFS=","
ssids=($wpassid)
IFS=$IFSdef #reset back to defaults
#Note:If you only want to check for certain SSIDs
#Remove the # in in front of ssids=('mySSID1'.... below and put a # infront of all four lines above
# separated by a space, eg ('mySSID1' 'mySSID2')
#ssids=('mySSID1' 'mySSID2' 'mySSID3')
#Enter the Routers Mac Addresses for hidden SSIDs, seperated by spaces ie
#( '11:22:33:44:55:66' 'aa:bb:cc:dd:ee:ff' )
mac=()
ssidsmac=("${ssids[@]}" "${mac[@]}") #combines ssid and MAC for checking
createAdHocNetwork()
{
echo "Creating Hotspot"
ip link set dev "$wifidev" down
ip a add 192.168.4.1/24 brd + dev "$wifidev"
ip link set dev "$wifidev" up
dhcpcd -k "$wifidev" >/dev/null 2>&1
iptables -t nat -A POSTROUTING -o "$ethdev" -j MASQUERADE
iptables -A FORWARD -i "$ethdev" -o "$wifidev" -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i "$wifidev" -o "$ethdev" -j ACCEPT
systemctl start dnsmasq
systemctl start hostapd
echo 1 > /proc/sys/net/ipv4/ip_forward
}
KillHotspot()
{
echo "Shutting Down Hotspot"
ip link set dev "$wifidev" down
systemctl stop hostapd
systemctl stop dnsmasq
iptables -D FORWARD -i "$ethdev" -o "$wifidev" -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -D FORWARD -i "$wifidev" -o "$ethdev" -j ACCEPT
echo 0 > /proc/sys/net/ipv4/ip_forward
ip addr flush dev "$wifidev"
ip link set dev "$wifidev" up
dhcpcd -n "$wifidev" >/dev/null 2>&1
}
ChkWifiUp()
{
echo "Checking WiFi connection ok"
sleep 20 #give time for connection to be completed to router
if ! wpa_cli -i "$wifidev" status | grep 'ip_address' >/dev/null 2>&1
then #Failed to connect to wifi (check your wifi settings, password etc)
echo 'Wifi failed to connect, falling back to Hotspot.'
wpa_cli terminate "$wifidev" >/dev/null 2>&1
createAdHocNetwork
fi
}
chksys()
{
#After some system updates hostapd gets masked using Raspbian Buster, and above. This checks and fixes
#the issue and also checks dnsmasq is ok so the hotspot can be generated.
#Check Hostapd is unmasked and disabled
if systemctl -all list-unit-files hostapd.service | grep "hostapd.service masked" >/dev/null 2>&1 ;then
systemctl unmask hostapd.service >/dev/null 2>&1
fi
if systemctl -all list-unit-files hostapd.service | grep "hostapd.service enabled" >/dev/null 2>&1 ;then
systemctl disable hostapd.service >/dev/null 2>&1
systemctl stop hostapd >/dev/null 2>&1
fi
#Check dnsmasq is disabled
if systemctl -all list-unit-files dnsmasq.service | grep "dnsmasq.service masked" >/dev/null 2>&1 ;then
systemctl unmask dnsmasq >/dev/null 2>&1
fi
if systemctl -all list-unit-files dnsmasq.service | grep "dnsmasq.service enabled" >/dev/null 2>&1 ;then
systemctl disable dnsmasq >/dev/null 2>&1
systemctl stop dnsmasq >/dev/null 2>&1
fi
}
FindSSID()
{
#Check to see what SSID's and MAC addresses are in range
ssidChk=('NoSSid')
i=0; j=0
until [ $i -eq 1 ] #wait for wifi if busy, usb wifi is slower.
do
ssidreply=$((iw dev "$wifidev" scan ap-force | egrep "^BSS|SSID:") 2>&1) >/dev/null 2>&1
#echo "SSid's in range: " $ssidreply
printf '%s\n' "${ssidreply[@]}"
echo "Device Available Check try " $j
if (($j >= 10)); then #if busy 10 times goto hotspot
echo "Device busy or unavailable 10 times, going to Hotspot"
ssidreply=""
i=1
elif echo "$ssidreply" | grep "No such device (-19)" >/dev/null 2>&1; then
echo "No Device Reported, try " $j
NoDevice
elif echo "$ssidreply" | grep "Network is down (-100)" >/dev/null 2>&1 ; then
echo "Network Not available, trying again" $j
j=$((j + 1))
sleep 2
elif echo "$ssidreply" | grep "Read-only file system (-30)" >/dev/null 2>&1 ; then
echo "Temporary Read only file system, trying again"
j=$((j + 1))
sleep 2
elif echo "$ssidreply" | grep "Invalid exchange (-52)" >/dev/null 2>&1 ; then
echo "Temporary unavailable, trying again"
j=$((j + 1))
sleep 2
elif echo "$ssidreply" | grep -v "resource busy (-16)" >/dev/null 2>&1 ; then
echo "Device Available, checking SSid Results"
i=1
else #see if device not busy in 2 seconds
echo "Device unavailable checking again, try " $j
j=$((j + 1))
sleep 2
fi
done
for ssid in "${ssidsmac[@]}"
do
if (echo "$ssidreply" | grep "$ssid") >/dev/null 2>&1
then
#Valid SSid found, passing to script
echo "Valid SSID Detected, assesing Wifi status"
ssidChk=$ssid
return 0
else
#No Network found, NoSSid issued"
echo "No SSid found, assessing WiFi status"
ssidChk='NoSSid'
fi
done
}
NoDevice()
{
#if no wifi device,ie usb wifi removed, activate wifi so when it is
#reconnected wifi to a router will be available
echo "No wifi device connected"
wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
exit 1
}
chksys
FindSSID
#Create Hotspot or connect to valid wifi networks
if [ "$ssidChk" != "NoSSid" ]
then
echo 0 > /proc/sys/net/ipv4/ip_forward #deactivate ip forwarding
if systemctl status hostapd | grep "(running)" >/dev/null 2>&1
then #hotspot running and ssid in range
KillHotspot
echo "Hotspot Deactivated, Bringing Wifi Up"
wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
ChkWifiUp
elif { wpa_cli -i "$wifidev" status | grep 'ip_address'; } >/dev/null 2>&1
then #Already connected
echo "Wifi already connected to a network"
else #ssid exists and no hotspot running connect to wifi network
echo "Connecting to the WiFi Network"
wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
ChkWifiUp
fi
else #ssid or MAC address not in range
if systemctl status hostapd | grep "(running)" >/dev/null 2>&1
then
echo "Hostspot already active"
elif { wpa_cli status | grep "$wifidev"; } >/dev/null 2>&1
then
echo "Cleaning wifi files and Activating Hotspot"
wpa_cli terminate >/dev/null 2>&1
ip addr flush "$wifidev"
ip link set dev "$wifidev" down
rm -r /var/run/wpa_supplicant >/dev/null 2>&1
createAdHocNetwork
else #"No SSID, activating Hotspot"
createAdHocNetwork
fi
fi