OPENWRT双频合一，2.4G自动切换5G

#!/bin/sh
# Modify by HSIAO-YANG CHEN
# crontab: * * * * *  /bin/sh /usr/kickass.sh
#

#强信号 -60
STRONG=-60
#弱信号 -78
WEAK=-78


# 指定日志文件和5G频段设备MAC保存地址
logfile="/tmp/kickass.log"
dev5gmacfile="/usr/devmac_5g.db" ;


#默认自动添加计划任务  
crontabsfile="/etc/crontabs/root"
if [ -z $( grep -i $0 "$crontabsfile" )  ] ; then
    echo "* * * * *  /bin/sh /usr/kickass.sh" >>$crontabsfile
    echo "Add task scheduler to crontabs"
fi
#只能运行一个kickass任务
if [  "$( ps | grep -c "kick" )" -gt 3 ] ; then
    echo "shell script already running "
else

    datetime=`date +%Y-%m-%d_%H:%M:%S`
    if [ ! -f "$logfile" ]; then
        echo "creating kickass logfile: $logfile"
        echo "$datetime: kickass log file created." > $logfile
    fi
    #踢除wlan-MAC列表
    kicklist=""; while true ; do

        datetime=`date +%Y-%m-%d_%H:%M:%S`
        #从文件中读取5G频段的MAC地址
        if [ -f "$dev5gmacfile" ] ; then
            dev5gmac=$(cat "$dev5gmacfile")
        fi

        # wlanlist for multiple wlans (e.g., 5GHz/2.4GHz)
        wlanlist="" ; wlanlist=$(ifconfig | grep -i wlan | grep -i -v sta | awk '{ print $1 }')
        #echo "$wlanlist"

        #获取多张网卡的SSID，为后面2.4G强信号判定是否踢除5G设备
        ssid2g5g="" ;    for wlan in $wlanlist ; do 
            ssid2g5g="$ssid2g5g $(iw $wlan info | grep ssid | awk '{ print $2 }')"
        done
        #echo "$ssid2g5g"
        #loop for each wlan
        wlan="" ; for wlan in $wlanlist ; do

            maclist="" ; maclist=$(iw $wlan station dump | awk '/Station/{print $2}')

            #5G频段的网卡AP
            if [ "$(iw $wlan info | grep center1 | awk '{ print $2 }')" -gt "14"  ];then
                #loop for each associated client (station)
                for mac in $maclist ; do
                    #新增5G频段的设备MAC
                    if [ -z "$(echo $dev5gmac | grep -i "$mac")"  ] ; then
                            echo "$mac" >> $dev5gmacfile
                        echo  "$datetime: Add new 5G wifi $mac success! " >> $logfile
                    fi
                    #获取信号强度
                    signal=$(iwinfo $wlan assoclist  | awk 'BEGIN{IGNORECASE=1}/'$mac'/{print $2}')
                    #踢除弱信号设备，终端尝试连接2.4G频段
                    if [ "$signal"  -le "$WEAK" ] ; then
                        #匹配2次踢除设备记录，启动踢除设备
                        if [ -n "$(echo $kicklist | grep -i "$wlan-$mac.*$wlan-$mac")" ] ; then
                            ubus call hostapd.$wlan del_client '{"addr":"'"$mac"'", "reason": 5, "deauth": True, "ban_time": 100}' 
                            echo  "$datetime: Kick $wlan MAC:$mac signal:$signal dBm switch 2.4G!" >> $logfile
                            #踢除设备记录删减
                            kicklist=$(echo $kicklist |sed "s/$wlan-$mac//g")
                        else
                            #踢除设备记录新增      
                            kicklist="$kicklist$wlan-$mac"
                        fi
                    else
                            #踢除设备记录删减
                            kicklist=$(echo $kicklist |sed "s/$wlan-$mac//g")
                    fi
                done
            else
                #2.4G频段的网卡AP
                for mac in $maclist ; do
                    signal=$(iwinfo $wlan assoclist  | awk 'BEGIN{IGNORECASE=1}/'$mac'/{print $2}')
                    #踢除弱信号设备
                    if [ "$signal"  -le "$WEAK" ] ; then
                        #匹配2次踢除设备记录，启动踢除设备
                        if [ -n "$(echo $kicklist | grep -i "$wlan-$mac.*$wlan-$mac")" ] ; then
                            ubus call hostapd.$wlan del_client '{"addr":"'"$mac"'", "reason": 5, "deauth": True, "ban_time": 3000}' 
                            echo  "$datetime: Kick $wlan MAC:$mac signal:$signal dBm tool weak!" >> $logfile
                            kicklist=$(echo $kicklist |sed "s/$wlan-$mac//g")
                        else      
                            kicklist="$kicklist$wlan-$mac"
                        fi
                    #踢除强信号，终端尝试连接5G频段(判断条件:信号比STRONG值大，终端MAC记录在5G频段里，有2个相同SSID的AP)
                     elif [ "$signal" -gt "$STRONG" -a -n "$(echo $dev5gmac | grep -i "$mac")" -a -n "$( echo "$ssid2g5g" | grep -i  "$(iw $wlan info | grep ssid | awk '{ print $2 }').*$(iw $wlan info | grep ssid | awk '{ print $2 }')" )"  ] ; then
                        if [ -n "$(echo $kicklist | grep -i "$wlan-$mac.*$wlan-$mac")" ] ; then
                            ubus call hostapd.$wlan del_client '{"addr":"'"$mac"'", "reason": 5, "deauth": True, "ban_time": 100}' 
                            echo  "$datetime: Kick $wlan MAC:$mac signal:$signal dBm switch 5G!" >> $logfile
                            kicklist=$(echo $kicklist |sed "s/$wlan-$mac//g")
                        else      
                            kicklist="$kicklist$wlan-$mac"
                        fi

                    else
                        kicklist=$(echo $kicklist |sed "s/$wlan-$mac//g")
                    fi
                done
            fi
        done
        #监测周期时间
        sleep 2s
    done
fi

解决设备连接上2.4G频段后，不能自动切换回5G频段。
解决思路：

1. 移动终端近距离连接上无线AP的5G频段，脚本将5G频段的设备MAC记录保存下来；
2. 当连接上2.4G频段的移动终端，靠近无线AP时，当2.4G的信号强度高于-60dBm，且设备MAC符合5G频段的设备MAC记录，自动踢除2.4G频段的连接，让移动终端自动切换回5G频段；
3. 当连接上5G频段的移动终端，远离无线AP时，当5G信号强度低于-75dBm，自动踢除5G频段的连接，让移动终端自动切换回信号强度较高的2.4G频段。

使用方法：

1. 将脚本保存在/usr/目录下，且赋予可执行权限；
2. 计划任务添加： * /bin/sh /usr/kickass.sh

脚本下载地址：kickass.zip