#!/bin/sh

aliddns_ak=`uci get aliddns.base.app_key 2>/dev/null`
aliddns_sk=`uci get aliddns.base.app_secret 2>/dev/null`
aliddns_record_id=`uci get aliddns.base.record_id 2>/dev/null`
time=`uci get aliddns.base.time 2>/dev/null`
aliddns_enable=`uci get aliddns.base.enable`
aliddns_domain=`uci get aliddns.base.main_domain 2>/dev/null`
aliddns_name=`uci get aliddns.base.sub_domain 2>/dev/null`
interface=`uci get aliddns.base.interface 2>/dev/null`
DATE=$(date +'%Y-%m-%d %H:%M:%S')
timestamp=`date -u "+%Y-%m-%dT%H%%3A%M%%3A%SZ"`
ip=$(ifconfig $interface 2> /dev/null | grep 'inet addr' | awk '{print $2}' | cut -d: -f2  2>/dev/null)

check_aliddns() {
#ip=`wget -qO- http://whatismyip.akamai.com/ 2>/dev/null`
#current_ip=`nslookup $aliddns_name.$aliddns_domain | grep "Address 1"|tail -n1|cut -d' ' -f3  2>/dev/null`
current_ip=`echo $query_result | sed 's/.*,"Value":"\([0-9\.]*\)",.*/\1/'`
echo "$DATE 当前路由IP: ${ip}" >> /var/log/aliddns.log
echo "$DATE 远程解析IP: ${current_ip}" >> /var/log/aliddns.log
if [ "$ip" = "$current_ip" ]
then
   echo "$DATE IP未改变，无需更新" >> /var/log/aliddns.log
   exit 0
  else
   echo "$DATE 更新中..." >> /var/log/aliddns.log  
fi
}

urlencode() {
    # urlencode <string>

    local length="${#1}"
    i=0
    out=""
    for i in $(awk "BEGIN { for ( i=0; i<$length; i++ ) { print i; } }")
    do
        local c="${1:$i:1}"
        case $c in
            [a-zA-Z0-9._-]) out="$out$c" ;;
            *) out="$out`printf '%%%02X' "'$c"`" ;;
        esac
        i=$(($i + 1))
    done
    echo -n $out
}

send_request() {
    local args="AccessKeyId=$aliddns_ak&Action=$1&Format=json&$2&Version=2015-01-09"
    local hash=$(urlencode $(echo -n "GET&%2F&$(urlencode $args)" | openssl dgst -sha1 -hmac "$aliddns_sk&" -binary | openssl base64))
    wget -qO- "http://alidns.aliyuncs.com/?$args&Signature=$hash" 2> /dev/null
}

get_recordid() {
    grep -Eo '"RecordId":"[0-9]+"' | cut -d':' -f2 | tr -d '"'
}

query_recordid() {
    send_request "DescribeSubDomainRecords" "SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&SubDomain=$(urlencode "$aliddns_name").$aliddns_domain&Timestamp=$timestamp"
}

update_record() {
    send_request "UpdateDomainRecord" "RR=$(urlencode "$aliddns_name")&RecordId=$1&SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&Timestamp=$timestamp&Type=A&Value=$ip"
}

add_record() {
    send_request "AddDomainRecord&DomainName=$aliddns_domain" "RR=$(urlencode "$aliddns_name")&SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&Timestamp=$timestamp&Type=A&Value=$ip"
}

go_record() {
if [ "$aliddns_record_id" = "" ]
then
    aliddns_record_id=`echo $query_result | get_recordid`
fi
if [ "$aliddns_record_id" = "" ]
then
    aliddns_record_id=`add_record | get_recordid`
    echo "$DATE 添加 record $aliddns_record_id" >> /var/log/aliddns.log
else
    update_record $aliddns_record_id
    echo "$DATE 更新 record $aliddns_record_id" >> /var/log/aliddns.log
fi
# save to file
if [ "$aliddns_record_id" = "" ]; then
    # failed
    echo "$DATE : 更新出错,请检查设置！" >> /var/log/aliddns.log
    exit 0 
else
    uci set aliddns.base.record_id=$aliddns_record_id
    uci commit
    echo "$DATE : 更新成功！($ip)" >> /var/log/aliddns.log 
fi  
}
#将执行脚本写入crontab定时运行
add_aliddns_cru(){
wirtecron=$(cat /etc/crontabs/root | grep "$time * * * *" | grep aliddns)
if [ -z "$wirtecron" ];then
  sed -i '/aliddns/d' /etc/crontabs/root >/dev/null 2>&1
  echo "*/$time * * * * /usr/sbin/aliddns" >> /etc/crontabs/root 
fi
}

#清除过多记录
clean_log(){
logrow=$(grep -c "" /var/log/aliddns.log)
if [ $logrow -ge 15 ];then
  cat /dev/null > /var/log/aliddns.log
  echo "$DATE Log条数超限，清空处理！" >> /var/log/aliddns.log
fi
}

#停止服务
stop_aliddns(){
	#停掉cru里的任务
  sed -i '/aliddns/d' /etc/crontabs/root >/dev/null 2>&1
}

if [ "$aliddns_enable" != "1" ]; then
    stop_aliddns
    echo "$DATE : aliddns没有开启！" >> /var/log/aliddns.log
  else
    clean_log
    query_result=$(query_recordid)
    check_aliddns
    go_record
    add_aliddns_cru  
fi