树莓派无线中继的实现

安装openssl:

sudo apt-get install openssl
sudo apt-get install libssl-dev build-essential zlibc zlib-bin libidn11-dev libidn11

下载wpa_supplicant

wget http://hostap.epitest.fi/releases/wpa_supplicant-2.0.tar.gz
tar -xzvf  wpa_supplicant-2.0.tar.gz
cd wpa_supplicant-2.0
cd wpa_supplicant
vi .config

粘贴以下内容保存

#.config
 #
 # Uncomment following two lines and fix the paths if you have installed openssl
 # in non-default location
 #CFLAGS += -I/usr/local/openssl/include
 #LIBS += -L/usr/local/openssl/lib
 # Driver interface for Host AP driver
 #CONFIG_DRIVER_HOSTAP=y
 # Driver interface for Agere driver
 #CONFIG_DRIVER_HERMES=y
 # Change include directories to match with the local setup
 #CFLAGS += -I../../hcf -I../../include -I../../include/hcf
 #CFLAGS += -I../../include/wireless
 # Driver interface for Prism54 driver
 # (Note: Prism54 is not yet supported, i.e., this will not work as-is and is
 # for developers only)
 #CONFIG_DRIVER_PRISM54=y
 # Driver interface for ndiswrapper
 #CONFIG_DRIVER_NDISWRAPPER=y
 # Driver interface for Atmel driver
 #CONFIG_DRIVER_ATMEL=y
 # Driver interface for Broadcom driver
 #CONFIG_DRIVER_BROADCOM=y
 # Example path for wlioctl.h; change to match your configuration
 #CFLAGS += -I/opt/WRT54GS/release/src/include
 # Driver interface for Intel ipw2100/2200 driver
 #CONFIG_DRIVER_IPW=y
 CONFIG_DRIVER_MADWIFI=y
 # Change include directories to match with the local setup
 CFLAGS += -I../madwif
 CONFIG_DRIVER_WEXT=y
 # Driver interface for FreeBSD net80211 layer (e.g., Atheros driver)
 #CONFIG_DRIVER_BSD=y
 #CFLAGS += -I/usr/local/include
 #LIBS += -L/usr/local/lib
 # Driver interface for Windows NDIS
 #CONFIG_DRIVER_NDIS=y
 #CFLAGS += -I/usr/include/w32api/ddk
 #LIBS += -L/usr/local/lib
 # For native build using mingw
 #CONFIG_NATIVE_WINDOWS=y
 # Additional directories for cross-compilation on Linux host for mingw target
 #CFLAGS += -I/opt/mingw/mingw32/include/ddk
 #LIBS += -L/opt/mingw/mingw32/lib
 #CC=mingw32-gcc
 # Driver interface for development testing
 #CONFIG_DRIVER_TEST=y
 # Driver interface for wired Ethernet drivers
 #CONFIG_DRIVER_WIRED=y
 CONFIG_IEEE8021X_EAPOL=y
 # EAP-MD5 (automatically included if EAP-TTLS is enabled)
 CONFIG_EAP_MD5=y
 # EAP-MSCHAPv2 (automatically included if EAP-PEAP is enabled)
 CONFIG_EAP_MSCHAPV2=y
 # EAP-TLS
 CONFIG_EAP_TLS=y
 # EAL-PEAP
 CONFIG_EAP_PEAP=y
 # EAP-TTLS
 CONFIG_EAP_TTLS=y
 # EAP-GTC
 CONFIG_EAP_GTC=y 
 # EAP-OTP
 CONFIG_EAP_OTP=y
 # LEAP
 CONFIG_EAP_LEAP=y
 # PKCS#12 (PFX) support (used to read private key and certificate file from
 # a file that usually has extension .p12 or .pfx)
 CONFIG_PKCS12=y
 # Include control interface for external programs, e.g, wpa_cli
 CONFIG_CTRL_IFACE=y

编译与安装：

make
make install

配置并连接路由器：

#! /bin/sh -
insmod /etc/Wireless/RT2870STA/mt7601Usta.ko
wlan_no="ra0"

echo Please choose WiFi connect mode
echo "(1,no_pass),(2,wpa_psk),(3,wpa2_psk)"
read conn_mod

if [ "$conn_mod" = "1" ]
then
        #1.1 get essid
        echo Welcom to no_pass mode!
        iwlist $wlan_no scan | grep ESSID
        echo Please choose a essid:
        read inputssid
        if [ `iwlist $wlan_no scan | grep $inputssid`x != "x" ]
                then
                echo "input ok!"
                #1.2 connect!
                iwconfig $wlan_no essid $inputssid
                dhclient $wlan_no
        fi
        echo done
fi

if [ "$conn_mod" = "2" ]
then
        #2.1 copy wlan wpa psk config file to /etc/wpa_supplicant/
        cp wpa_supplicant.wpa /etc/wpa_supplicant/wpa_supplicant.conf
        #2.2 get essid and password phrase
        echo Welcom to wpa_psk mode!
        iwlist $wlan_no scan | grep ESSID
        echo Please choose a essid:
        read inputssid
        if [ `iwlist $wlan_no scan | grep $inputssid`x != "x" ]
                then
                echo "input ok!"
                echo "please input your password:c"
                read inputpass
                ph_pass=`wpa_passphrase $inputssid $inputpass | grep psk= | sed -n 2p | awk -F '=' '{print $2}'`
                echo $ph_pass
                #2.3 modify /etc/wpa_supplicant/wpa_supplicant.conf
                sed -i "s/my_network/$inputssid/g" /etc/wpa_supplicant/wpa_supplicant.conf
                sed -i "s/"secret_password"/$ph_pass/g" /etc/wpa_supplicant/wpa_supplicant.conf
                #2.4 connect!
                wpa_supplicant -B -i $wlan_no -D wext -c /etc/wpa_supplicant/wpa_supplicant.conf
                dhclient $wlan_no
        fi
        echo done

fi

if [ "$conn_mod" = "3" ]
then
        #3.1 copy wlan wpa2 psk config file to /etc/wpa_supplicant/
        cp wpa_supplicant.wpa2 /etc/wpa_supplicant/wpa_supplicant.conf
        #3.2 get essid and password phrase
        echo Welcom to wpa2_psk mode!
        iwlist $wlan_no scan | grep ESSID
        echo Please choose a essid:
        read inputssid
        if [ `iwlist $wlan_no scan | grep $inputssid`x != "x" ]
                then
                echo "input ok!"
                echo "please input your password:c"
                read inputpass
                ph_pass=`wpa_passphrase $inputssid $inputpass | grep psk= | sed -n 2p | awk -F '=' '{print $2}'`
                echo $ph_pass
                #3.3 modify /etc/wpa_supplicant/wpa_supplicant.conf
                sed -i "s/my_network/$inputssid/g" /etc/wpa_supplicant/wpa_supplicant.conf
                sed -i "s/"secret_password"/$ph_pass/g" /etc/wpa_supplicant/wpa_supplicant.conf
                #3.4 connect!
                wpa_supplicant -B -i $wlan_no -D wext -c /etc/wpa_supplicant/wpa_supplicant.conf
                dhclient $wlan_no
        fi
        echo done

fi

配置文件1(wpa_supplicant.wpa).

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
eapol_version=1
# ap_scan=2 was the one for me you may try 0 or 1 indstead of 2
ap_scan=2
fast_reauth=1

network={
        ssid="my_network"
        proto=WPA
        key_mgmt=WPA-PSK
        pairwise=TKIP
        group=TKIP
        psk="secret_password"
}

配置文件2（wpa_supplicant.wpa2）

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
ap_scan=1

network={
        ssid="my_network"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP
        psk="secret_password"
}

ap脚本：

#! /bin/sh -
# use ra0 as a gateway
# use wlan0(rtl8192cu) as an AP

wlan_gw_no="ra0"
wlan_no="wlan0"
ifconfig $wlan_no 172.16.0.1/16

sudo iptables -F
iptables -t filter -F
iptables -t nat -F
iptables -t mangle -F

gw=`ifconfig | awk 'BEGIN{FS="
";RS=""} NR==3 {print $2}' | awk '{print $2}' | awk -F ':' '{print $2}'`
#sudo iptables -t nat -A POSTROUTING -o $wlan_gw_no -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -o $wlan_gw_no -s 172.16.1.0/24 -j SNAT --to-source $gw
iptables -nL -vv -t nat

killall dnsmasq
killall hostapd

ifconfig $wlan_no 172.16.0.1/16
hostapd -B /etc/hostapd/hostapd.conf
/etc/init.d/dnsmasq restart

echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
echo 1 > /proc/sys/net/ipv4/ip_forward

sleep 5
echo dhcp:
ps -e | grep dns
echo hosapd:
ps -e | grep ap

结束