linux屏蔽海外流量(仅允许国内访问)

方法一：使用大神的开源脚本，屏蔽指定国家地区的IP访问

wget https://raw.githubusercontent.com/iiiiiii1/Block-IPs-from-countries/master/block-ips.sh
sh block-ips.sh

方法二：使用IPIP的数据库进行流量屏蔽（推荐，目前已支持centos6和7还有ubuntu系统)

#!/bin/bash
#判断是否具有root权限
root_need() {
    if [[ $EUID -ne 0 ]]; then
        echo "Error:This script must be run as root!" 1>&2
        exit 1
    fi
}

#检查系统分支及版本(主要是：分支->>版本>>决定命令格式)
check_release() {
    if uname -a | grep el7  ; then
        release="centos7"
    elif uname -a | grep el6 ; then
        release="centos6"
        yum install ipset -y
    elif cat /etc/issue |grep -i ubuntu ; then
        release="ubuntu"
        apt install ipset -y
    fi
}

#安装必要的软件(wget),并下载中国IP网段文件(最后将局域网地址也放进去)
get_china_ip() {
    #安装必要的软件(wget)
    rpm --help >/dev/null 2>&1 && rpm -qa |grep wget >/dev/null 2>&1 ||yum install -y wget ipset >/dev/null 2>&1 
    dpkg --help >/dev/null 2>&1 && dpkg -l |grep wget >/dev/null 2>&1 ||apt-get install wget ipset -y >/dev/null 2>&1

    #该文件由IPIP维护更新，大约一月一次更新(也可以用我放在国内的存储的版本，2023-3-10日版)
    #[ -f china_ip_list.txt ] && mv china_ip_list.txt china_ip_list.txt.old
    #wget https://github.com/17mon/china_ip_list/blob/master/china_ip_list.txt
    #cat china_ip_list.txt | grep 'js-file-line">' | awk -F '>' '{print $2}' |awk -F'<' '{print $1}' >> china_ip.txt
    #rm -rf china_ip_list.txt
    wget https://qiniu.wsfnk.com/china_ip.txt

    #放行局域网地址
    echo "192.168.0.0/18" >> china_ip.txt
    echo "10.0.0.0/8" >> china_ip.txt
    echo "172.16.0.0/12" >> china_ip.txt
}

#只允许国内IP访问
ipset_only_china() {
    echo "ipset create whitelist-china hash:net hashsize 10000 maxelem 1000000" > /etc/ip-black.sh
    for i in $( cat china_ip.txt )
    do
            echo "ipset add whitelist-china $i" >> /etc/ip-black.sh
    done
    echo "iptables -I INPUT -m set --match-set whitelist-china src -j ACCEPT" >> /etc/ip-black.sh
    #拒绝非国内和内网地址发起的tcp连接请求（tcp syn 包）（注意，只是屏蔽了入向的tcp syn包，该主机主动访问国外资源不用影响）
    echo "iptables  -A INPUT -p tcp --syn -m connlimit --connlimit-above 0 -j DROP" >> /etc/ip-black.sh
    #拒绝非国内和内网发起的ping探测（不影响本机ping外部主机）
    echo "iptables  -A INPUT -p icmp -m icmp --icmp-type 8 -j DROP" >> /etc/ip-black.sh
    #echo "iptables -A INPUT -j DROP" >> /etc/ip-black.sh
    rm -rf china_ip.txt
}

run_setup() {
    chmod +x /etc/rc.local
    sh /etc/ip-black.sh
    rm -rf /etc/ip-black.sh
    #下面这句主要是兼容centos6不能使用"-f"参数
    ipset save whitelist-china -f /etc/ipset.conf || ipset save whitelist-china > /etc/ipset.conf
    [ $release = centos7 ] && echo "ipset restore -f /etc/ipset.conf" >> /etc/rc.local
    [ $release = centos6 ] && echo "ipset restore < /etc/ipset.conf" >> /etc/rc.local
    echo "iptables -I INPUT -m set --match-set whitelist-china src -j ACCEPT" >> /etc/rc.local
    echo "iptables  -A INPUT -p tcp --syn -m connlimit --connlimit-above 0 -j DROP" >> /etc/rc.local
    echo "iptables  -A INPUT -p icmp -m icmp --icmp-type 8 -j DROP" >> /etc/rc.local
    #echo "iptables -A INPUT -j DROP" >> /etc/rc.local
}

main() {
    check_release
    get_china_ip
    ipset_only_china

case "$release" in
centos6)
    run_setup
    ;;
centos7)
    chmod +x /etc/rc.d/rc.local
    run_setup
    ;;
ubuntu)
    sed -i '/exit 0/d' /etc/rc.local
    run_setup
    echo "exit 0" >> /etc/rc.local
    ;;
esac
}
main