diff --git a/published/201407/Encrypting Your Cat Photos.md b/published/201407/Encrypting Your Cat Photos.md old mode 100755 new mode 100644 diff --git a/published/201505/20150326 How to set up server monitoring system with Monit.md b/published/201505/20150326 How to set up server monitoring system with Monit.md old mode 100755 new mode 100644 diff --git a/sources/tech/20151215 How to block network traffic by country on Linux.md b/sources/tech/20151215 How to block network traffic by country on Linux.md deleted file mode 100644 index 14bdbad711..0000000000 --- a/sources/tech/20151215 How to block network traffic by country on Linux.md +++ /dev/null @@ -1,112 +0,0 @@ -FSSlc translating - -How to block network traffic by country on Linux -================================================================================ -As a system admin who maintains production Linux servers, there are circumstances where you need to **selectively block or allow network traffic based on geographic locations**. For example, you are experiencing denial-of-service attacks mostly originating from IP addresses registered with a particular country. You want to block SSH logins from unknown foreign countries for security reasons. Your company has a distribution right to online videos, which requires it to legally stream to particular countries only. You need to prevent any local host from uploading documents to any non-US remote cloud storage due to geo-restriction company policies. - -All these scenarios require an ability to set up a firewall which does **country-based traffic filtering**. There are a couple of ways to do that. For one, you can use TCP wrappers to set up conditional blocking for individual applications (e.g., SSH, NFS, httpd). The downside is that the application you want to protect must be built with TCP wrappers support. Besides, TCP wrappers are not universally available across different platforms (e.g., Arch Linux [dropped][2] its support). An alternative approach is to set up [ipset][3] with country-based GeoIP information and apply it to iptables rules. The latter approach is more promising as the iptables-based filtering is application-agnostic and easy to set up. - -In this tutorial, I am going to present **another iptables-based GeoIP filtering which is implemented with xtables-addons**. For those unfamiliar with it, xtables-addons is a suite of extensions for netfilter/iptables. Included in xtables-addons is a module called xt_geoip which extends the netfilter/iptables to filter, NAT or mangle packets based on source/destination countries. For you to use xt_geoip, you don't need to recompile the kernel or iptables, but only need to build xtables-addons as modules, using the current kernel build environment (/lib/modules/`uname -r`/build). Reboot is not required either. As soon as you build and install xtables-addons, xt_geoip is immediately usable with iptables. - -As for the comparison between xt_geoip and ipset, the [official source][3] mentions that xt_geoip is superior to ipset in terms of memory foot print. But in terms of matching speed, hash-based ipset might have an edge. - -In the rest of the tutorial, I am going to show **how to use iptables/xt_geoip to block network traffic based on its source/destination countries**. - -### Install Xtables-addons on Linux ### - -Here is how you can compile and install xtables-addons on various Linux platforms. - -To build xtables-addons, you need to install a couple of dependent packages first. - -#### Install Dependencies on Debian, Ubuntu or Linux Mint #### - - $ sudo apt-get install iptables-dev xtables-addons-common libtext-csv-xs-perl pkg-config - -#### Install Dependencies on CentOS, RHEL or Fedora #### - -CentOS/RHEL 6 requires EPEL repository being set up first (for perl-Text-CSV_XS). - - $ sudo yum install gcc-c++ make automake kernel-devel-`uname -r` wget unzip iptables-devel perl-Text-CSV_XS - -#### Compile and Install Xtables-addons #### - -Download the latest `xtables-addons` source code from the [official site][4], and build/install it as follows. - - $ wget http://downloads.sourceforge.net/project/xtables-addons/Xtables-addons/xtables-addons-2.10.tar.xz - $ tar xf xtables-addons-2.10.tar.xz - $ cd xtables-addons-2.10 - $ ./configure - $ make - $ sudo make install - -Note that for Red Hat based systems (CentOS, RHEL, Fedora) which have SELinux enabled by default, it is necessary to adjust SELinux policy as follows. Otherwise, SELinux will prevent iptables from loading xt_geoip module. - - $ sudo chcon -vR --user=system_u /lib/modules/$(uname -r)/extra/*.ko - $ sudo chcon -vR --type=lib_t /lib64/xtables/*.so - -### Install GeoIP Database for Xtables-addons ### - -The next step is to install GeoIP database which will be used by xt_geoip for IP-to-country mapping. Conveniently, the xtables-addons source package comes with two helper scripts for downloading GeoIP database from MaxMind and converting it into a binary form recognized by xt_geoip. These scripts are found in geoip folder inside the source package. Follow the instructions below to build and install GeoIP database on your system. - - $ cd geoip - $ ./xt_geoip_dl - $ ./xt_geoip_build GeoIPCountryWhois.csv - $ sudo mkdir -p /usr/share/xt_geoip - $ sudo cp -r {BE,LE} /usr/share/xt_geoip - -According to [MaxMind][5], their GeoIP database is 99.8% accurate on a country-level, and the database is updated every month. To keep the locally installed GeoIP database up-to-date, you want to set up a monthly [cron job][6] to refresh the local GeoIP database as often. - -### Block Network Traffic Originating from or Destined to a Country ### - -Once xt_geoip module and GeoIP database are installed, you can immediately use the geoip match options in iptables command. - - $ sudo iptables -m geoip --src-cc country[,country...] --dst-cc country[,country...] - -Countries you want to block are specified using [two-letter ISO3166 code][7] (e.g., US (United States), CN (China), IN (India), FR (France)). - -For example, if you want to block incoming traffic from Yemen (YE) and Zambia (ZM), the following iptables command will do. - - $ sudo iptables -I INPUT -m geoip --src-cc YE,ZM -j DROP - -If you want to block outgoing traffic destined to China (CN), run the following command. - - $ sudo iptables -A OUTPUT -m geoip --dst-cc CN -j DROP - -The matching condition can also be "negated" by prepending "!" to "--src-cc" or "--dst-cc". For example: - -If you want to block all incoming non-US traffic on your server, run this: - - $ sudo iptables -I INPUT -m geoip ! --src-cc US -j DROP - -![](https://c2.staticflickr.com/6/5654/23665427845_050241b03f_c.jpg) - -#### For Firewall-cmd Users #### - -Some distros such as CentOS/RHEL 7 or Fedora have replaced iptables with firewalld as the default firewall service. On such systems, you can use firewall-cmd to block traffic using xt_geoip similarly. The above three examples can be rewritten with firewall-cmd as follows. - - $ sudo firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -m geoip --src-cc YE,ZM -j DROP - $ sudo firewall-cmd --direct --add-rule ipv4 filter OUTPUT 0 -m geoip --dst-cc CN -j DROP - $ sudo firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -m geoip ! --src-cc US -j DROP - -### Conclusion ### - -In this tutorial, I presented iptables/xt_geoip which is an easy way to filter network packets based on their source/destination countries. This can be a useful arsenal to deploy in your firewall system if needed. As a final word of caution, I should mention that GeoIP-based traffic filtering is not a foolproof way to ban certain countries on your server. GeoIP database is by nature inaccurate/incomplete, and source/destination geography can easily be spoofed using VPN, Tor or any compromised relay hosts. Geography-based filtering can even block legitimate traffic that should not be banned. Understand this limitation before you decide to deploy it in your production environment. - --------------------------------------------------------------------------------- - -via: http://xmodulo.com/block-network-traffic-by-country-linux.html - -作者：[Dan Nanni][a] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]:http://xmodulo.com/author/nanni -[1]:https://www.archlinux.org/news/dropping-tcp_wrappers-support/ -[2]:http://xmodulo.com/block-unwanted-ip-addresses-linux.html -[3]:http://xtables-addons.sourceforge.net/geoip.php -[4]:http://xtables-addons.sourceforge.net/ -[5]:https://support.maxmind.com/geoip-faq/geoip2-and-geoip-legacy-databases/how-accurate-are-your-geoip2-and-geoip-legacy-databases/ -[6]:http://ask.xmodulo.com/add-cron-job-linux.html -[7]:https://en.wikipedia.org/wiki/ISO_3166-1 diff --git a/translated/tech/20151215 How to block network traffic by country on Linux.md b/translated/tech/20151215 How to block network traffic by country on Linux.md new file mode 100644 index 0000000000..5d04b20a2b --- /dev/null +++ b/translated/tech/20151215 How to block network traffic by country on Linux.md @@ -0,0 +1,110 @@ +如何在 Linux 中根据国家位置来阻断网络流量 +================================================================================ +作为一名维护 Linux 生产服务器的系统管理员，你可能会遇到这样一些情形：你需要 **根据地理位置，选择性地阻断或允许网络流量通过。** 例如你正经历一次由注册在某个特定国家的 IP 发起的 DoS 攻击；或者基于安全考虑，你想阻止来自未知国家的 SSH 登陆请求；又或者你的公司对某些在线视频有分销权，它要求只能合法地在特定的国家内发行；抑或是由于公司的政策，你需要阻止任意一个本地主机将文件上传至任意一个非美国的远程云端存储。 + +所有的上述情形都需要设置防火墙，使之具有 **过滤基于国家位置的流量** 的功能。有几个方法可以做到这一点，其中之一是你可以使用 TCP wrappers 来为个人应用（例如 SSH，NFS， httpd）设置有条件的阻塞。但其缺点是你想要保护的那个应用必须以支持 TCP wrappers 的方式构建。另外，TCP wrappers 并不总是能够在各个平台中获取到（例如，Arch Linux [放弃了][2]对它的支持）。另一种方式是结合基于国家的 GeoIP 信息，设置 [ipset][3]，并将它应用到 iptables 的规则中。后一种方式看起来更有希望一些，因为基于 iptables 的过滤器是与应用无关的，且容易设置。 + +在本教程中，我将展示 **另一个基于 iptables 的 GeoIP 过滤器，它由 xtables-addons 来实现**。对于那些不熟悉它的人来说， xtables-addons 是针对 netfilter/iptables 的一系列扩展。一个包含在 xtables-addons 中的名为 xt_geoip 的模块扩展了 netfilter/iptables 的功能，使得它可以根据流量来自或流向的国家来进行过滤，IP 掩蔽(NAT) 或丢包。若你想使用 xt_geoip，你不必重新编译内核或 iptables，你只需要使用当前的内核构建环境(/lib/modules/`uname -r`/build) 以模块的形式构建 xtables-addons。同时也不需要进行重启。只要你构建并安装了 xtables-addons ， xt_geoip 便能够配合 iptables 使用。 + +至于 xt_geoip 和 ipset 之间的比较，[xtables-addons 的官方网站][3] 上是这么说的： 相比于 ipset，xt_geoip 在内存占用上更胜一筹，但对于匹配速度，基于哈希的 ipset 可能更有优势。 + +在教程的余下部分，我将展示 ** 如何使用 iptables/xt_geoip 来根据流量的来源地或流入的国家阻断网络流量 **。 + +### 在 Linux 中安装 xtables-addons ### + +下面介绍如何在各种 Linux 平台中编译和安装 xtables-addons。 + +为了编译 xtables-addons，首先你需要安装一些依赖软件包。 + +#### 在 Debian，Ubuntu 或 Linux Mint 中安装依赖 #### + + $ sudo apt-get install iptables-dev xtables-addons-common libtext-csv-xs-perl pkg-config + +#### 在 CentOS，RHEL 或 Fedora 中安装依赖 #### + +CentOS/RHEL 6 需要事先设置好 EPEL 仓库(为 perl-Text-CSV_XS 所需要)。 + + $ sudo yum install gcc-c++ make automake kernel-devel-`uname -r` wget unzip iptables-devel perl-Text-CSV_XS + +#### 编译并安装 xtables-addons #### + +从 `xtables-addons` 的[官方网站][4] 下载源码包，然后按照下面的指令编译安装它。 + + $ wget http://downloads.sourceforge.net/project/xtables-addons/Xtables-addons/xtables-addons-2.10.tar.xz + $ tar xf xtables-addons-2.10.tar.xz + $ cd xtables-addons-2.10 + $ ./configure + $ make + $ sudo make install + +需要注意的是，对于基于红帽的系统(CentOS, RHEL, Fedora)，它们默认开启了 SELinux，所以有必要像下面这样调整 SELinux 的策略。否则，SELinux 将阻止 iptables 加载 xt_geoip 模块。 + + $ sudo chcon -vR --user=system_u /lib/modules/$(uname -r)/extra/*.ko + $ sudo chcon -vR --type=lib_t /lib64/xtables/*.so + +### 为 xtables-addons 安装 GeoIP 数据库 ### + +下一步是安装 GeoIP 数据库，它将被 xt_geoip 用来查询 IP 地址与国家地区之间的对应关系。方便的是，`xtables-addons` 的源码包中带有两个帮助脚本，它们被用来从 MaxMind 下载 GeoIP 数据库并将它转化为 xt_geoip 可识别的二进制形式文件；而它们可以在源码包中的 geoip 目录下找到。请遵循下面的指导来在你的系统中构建和安装 GeoIP 数据库。 + + $ cd geoip + $ ./xt_geoip_dl + $ ./xt_geoip_build GeoIPCountryWhois.csv + $ sudo mkdir -p /usr/share/xt_geoip + $ sudo cp -r {BE,LE} /usr/share/xt_geoip + +根据 [MaxMind][5] 的说明,他们的 GeoIP 数据库能够以 99.8% 的准确率识别出 ip 所对应的国家，并且每月这个数据库将进行更新。为了使得本地安装的 GeoIP 数据是最新的，或许你需要设置一个按月执行的 [cron job][6] 来时常更新你本地的 GeoIP 数据库。 + +### 阻断来自或流向某个国家的网络流量 ### + +一旦 xt_geoip 模块和 GeoIP 数据库安装好后，你就可以在 iptabels 命令中使用 geoip 的匹配选项。 + + $ sudo iptables -m geoip --src-cc country[,country...] --dst-cc country[,country...] + +你想要阻断流量的那些国家是使用[2个字母的 ISO3166 代码][7] 来特别指定的(例如 US（美国）、CN（中国）、IN（印度）、FR（法国）)。 + +例如，假如你想阻断来自也门(YE) 和 赞比亚(ZM) 的流量，下面的 iptabels 命令便可以达到此目的。 + + $ sudo iptables -I INPUT -m geoip --src-cc YE,ZM -j DROP + +假如你想阻断流向中国(CN) 的流量，可以运行下面的命令： + + $ sudo iptables -A OUTPUT -m geoip --dst-cc CN -j DROP + +匹配条件也可以通过在 "--src-cc" 或 "--dst-cc" 选项前加 "!" 来达到相反的目的： + +假如你想在你的服务器上阻断来自所有非美国的流量，可以运行： + + $ sudo iptables -I INPUT -m geoip ! --src-cc US -j DROP + +![](https://c2.staticflickr.com/6/5654/23665427845_050241b03f_c.jpg) + +#### 对于使用 Firewall-cmd 的用户 #### + +某些发行版本例如 CentOS/RHEL7 或 Fedora 已经用 firewalld 替代了 iptables 来作为默认的防火墙服务。在这些系统中，你可以类似使用 xt_geoip 那样，使用 firewall-cmd 来阻断流量。利用 firewall-cmd 命令，上面的三个例子可被重新写为： + + $ sudo firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -m geoip --src-cc YE,ZM -j DROP + $ sudo firewall-cmd --direct --add-rule ipv4 filter OUTPUT 0 -m geoip --dst-cc CN -j DROP + $ sudo firewall-cmd --direct --add-rule ipv4 filter INPUT 0 -m geoip ! --src-cc US -j DROP + +### 总结 ### + +在本教程中，我展示了使用 iptables/xt_geoip 来根据流量的来源地或流入的国家轻松地阻断网络流量。假如你有这方面的需求，把它部署到你的防火墙系统中可以使之成为一个实用的办法。作为最后的警告，我应该提醒你的是：在你的服务器上通过基于 GeoIP 的流量过滤来禁止特定国家的流量并不总是万无一失的。GeoIP 数据库本身就不是很准确或齐全，且流量的来源或目的地可以轻易地通过使用 VPN、Tor 或其他任意易受攻击的中继主机来达到欺骗的目的。基于地理位置的过滤器甚至可能会阻止本不该阻止的合法网络流量。在你决定把它部署到你的生产环境之前请仔细考虑这个限制。 + +-------------------------------------------------------------------------------- + +via: http://xmodulo.com/block-network-traffic-by-country-linux.html + +作者：[Dan Nanni][a] +译者：[FSSlc](https://github.com/FSSlc) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:http://xmodulo.com/author/nanni +[1]:https://www.archlinux.org/news/dropping-tcp_wrappers-support/ +[2]:http://xmodulo.com/block-unwanted-ip-addresses-linux.html +[3]:http://xtables-addons.sourceforge.net/geoip.php +[4]:http://xtables-addons.sourceforge.net/ +[5]:https://support.maxmind.com/geoip-faq/geoip2-and-geoip-legacy-databases/how-accurate-are-your-geoip2-and-geoip-legacy-databases/ +[6]:http://ask.xmodulo.com/add-cron-job-linux.html +[7]:https://en.wikipedia.org/wiki/ISO_3166-1