我们网站上的资源如果没有设置防盗链，那么其他人可以通过资源链接盗用我们的资源，占用我们的带宽，影响我们网站对合法用户的服务质量。举个例子，假如我们网站上有一张图片，如下图所示：
复制图片地址，可以直接在浏览器中搜到我们的图片，也可以在其他地方通过该图片地址引用或下载该图片。
为了不让别人盗用我们的资源，我们可以在服务器上设置防盗链。
编辑虚拟主机配置文件
[root@cp1 vhosts]# vim test.conf
添加指定类型文件的防盗链
没错误重新加载配置文件
[root@cp1 vhosts]# /usr/local/nginx/sbin/nginx -t
nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful
[root@cp1 vhosts]# /usr/local/nginx/sbin/nginx -s reload
使用curl测试，看看百度能不能引用我们的图片
[root@cp1 vhosts]# curl -e "http://www.baidu.com" -I -x127.0.0.1:80 ‘http://www.test.com/data/attachment/forum/201702/24/020448ytywyltbbzatdgdo.jpg‘
HTTP/1.1 403 Forbidden
Server: nginx/1.6.2
Date: Thu, 23 Feb 2017 18:24:47 GMT
Content-Type: text/html
Content-Length: 168
Connection: keep-alive
正常情况下是可以访问的
[root@cp1 vhosts]# curl -I -x127.0.0.1:80 ‘http://www.test.com/data/attachment/forum/201702/24/020448ytywyltbbzatdgdo.jpg‘
HTTP/1.1 200 OK
Server: nginx/1.6.2
Date: Thu, 23 Feb 2017 18:22:34 GMT
Content-Type: image/jpeg
Content-Length: 188486
Last-Modified: Thu, 23 Feb 2017 18:04:49 GMT
Connection: keep-alive
ETag: "58af2441-2e046"
Expires: Fri, 10 Mar 2017 18:22:34 GMT
Cache-Control: max-age=1296000
Accept-Ranges: bytes
指定的白名单能访问我们的图片
[root@cp1 vhosts]# curl -e "http://www.test.com" -I -x127.0.0.1:80 ‘http://www.test.com/data/attachment/forum/201702/24/020448ytywyltbbzatdgdo.jpg‘
HTTP/1.1 200 OK
Server: nginx/1.6.2
Date: Thu, 23 Feb 2017 18:25:24 GMT
Content-Type: image/jpeg
Content-Length: 188486
Last-Modified: Thu, 23 Feb 2017 18:04:49 GMT
Connection: keep-alive
ETag: "58af2441-2e046"
Expires: Fri, 10 Mar 2017 18:25:24 GMT
Cache-Control: max-age=1296000
Accept-Ranges: bytes
[root@cp1 vhosts]# curl -e "http://www.aaa.com" -I -x127.0.0.1:80 ‘http://www.test.com/data/attachment/forum/201702/24/020448ytywyltbbzatdgdo.jpg‘
HTTP/1.1 200 OK
Server: nginx/1.6.2
Date: Thu, 23 Feb 2017 18:25:32 GMT
Content-Type: image/jpeg
Content-Length: 188486
Last-Modified: Thu, 23 Feb 2017 18:04:49 GMT
Connection: keep-alive
ETag: "58af2441-2e046"
Expires: Fri, 10 Mar 2017 18:25:32 GMT
Cache-Control: max-age=1296000
Accept-Ranges: bytes
其他不能访问我们的图片
[root@cp1 vhosts]# curl -e "http://www.google.com" -I -x127.0.0.1:80 ‘http://www.test.com/data/attachment/forum/201702/24/020448ytywyltbbzatdgdo.jpg‘
HTTP/1.1 403 Forbidden
Server: nginx/1.6.2
Date: Thu, 23 Feb 2017 18:24:24 GMT
Content-Type: text/html
Content-Length: 168
Connection: keep-alive
原文：http://rachy.blog.51cto.com/11428504/1901171