一、squid acl访问控制
mv squid.conf squid.conf.backup
egrep -v "^#|^$" squid.conf.backup > squid.conf
[[email protected] etc]# wc -l squid.conf
44 squid.conf
1）对url进行关键字过滤
在squid.conf文件中添加如下两行：
acl qq url_regex -i ^http://.*qq.*$
http_access deny qq
在浏览器中进行访问www.baidu.com，测试结果如下（注意一定要使用代理访问）：
然后使用命令让squid重读配置文件：
[[email protected] ~]# squid -k reconfig
[[email protected] ~]# lsof -i :3128
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
squid 22446 squid 15w IPv4 43702 0t0 TCP *:squid (LISTEN)
squid 22446 squid 17u IPv4 43646 0t0 TCP 192.168.49.135:squid->192.168.49.1:11361 (ESTABLISHED)
再次在浏览器中打开www.baidu.com，查看结果如下：
已经出现"Access Denied"错误，说明配置生效。
2）对url路径中的关键字进行过滤
将上面添加的两行注释掉，再添加如下两行：
acl qq_path urlpath_regex -i \.*qq*
http_access deny qq_path
然后让squid重读配置文件：
squid -k reconfig
最后在浏览器中进行访问测试：
打开http://im.qq.com/正常。
打开http://im.qq.com/pcqq/出现“Access Denied”错误，说明基于urlpath的acl规则生效，注意：urlpath是对http://*.*.*.*/ 后面的路径起作用的，因此http://im.qq.com/打开正常。
3）生产案例
限制使用BT和下载mp3:
acl BT urlpath_regix -i \.torrent$.
acl BT urlpath_regix -i \.torrent$ \.mp3$
http_access deny BT
限制访问某些网站：
acl sex url_regex -i ^http://.*sex.*$
http_access deny sex
二、配置web界面查看squid相关配置
1、首先安装apache
yum -y install httpd
2、配置并启动apache
[[email protected] etc]# cp /etc/httpd/conf/httpd.conf /etc/httpd/conf/httpd.conf.bak
[[email protected] etc]# vi /etc/httpd/conf/httpd.conf
[[email protected] etc]# diff /etc/httpd/conf/httpd.conf.bak /etc/httpd/conf/httpd.conf
136c136
< Listen 80
---
> Listen 8001 #修改监听端口为8001，这里也可以不改，但是一般不适用80端口
1009a1010,1015
> ScriptAlias "/squid" "/usr/local/squid/libexec/cachemgr.cgi" #创建一个别名，使用cachemgr.cgi
> <Location "/squid"> #添加一个apache访问路径
> Order deny,allow
> Deny from all
> Allow from all
> </Location>
[[email protected] etc]# /etc/init.d/httpd start
Starting httpd: httpd: apr_sockaddr_info_get() failed for squid.contoso.com
httpd: Could not reliably determine the server‘s fully qualified domain name, using 127.0.0.1 for ServerName
[ OK ]
[[email protected] etc]#
3、修改squid.conf默认配置
因为在squid的默认配置文件中有http_access deny !Safe_ports一行，所以需要把上面配置的8001端口添加到Safe_ports中，不然会出现访问拒绝错误。
acl Safe_ports port 8001
3、在浏览器中查看
输入访问url，http://192.168.49.135:8001/squid/，用户名密码默认为空。
打开之后，可以看到很多squid相关的信息。
比如可以看squid缓存的对象，虽然命令行也可以进行查看，但是这里提供了一个方便的web界面。
三、使用squid做透明代理
| 主机名 | 角色 | IP地址 |
| squid.contoso.com | squid代理服务器 |
eth0:192.168.49.135 eth1:172.16.49.135 |
| ldapserver.contoso.com | squid客户端 | eth1:172.16.49.139 |
1)编辑squid配置文件
主要是修改如下两点：
a.设置http_port为透明代理模式
b.添加相关参数如下：
cache_mem 90 MB #注意90后面有一个空格，不然会有警告：WARNING: No units on ‘cache_mem 90MB‘, assuming 90.00 bytes
cache_swap_low 90
cache_swap_high 95
maximum_object_size 8192 KB
minimum_object_size 0 KB
maximum_object_size_in_memory 4096 KB
memory_replacement_policy lru
emulate_httpd_log on
[[email protected] etc]# cp squid.conf squid.conf.bak$(date +%F)
[[email protected] etc]# vi squid.conf
[[email protected] etc]# diff squid.conf.bak2016-10-16 squid.conf
36c36
< http_port 3128
---
> http_port 3128 transparent #设置透明代理模式
51a52,61
>
> cache_mem 90 MB
> cache_swap_low 90
> cache_swap_high 95
>
> maximum_object_size 8192 KB
> minimum_object_size 0 KB
> maximum_object_size_in_memory 4096 KB
> memory_replacement_policy lru
> emulate_httpd_log on
2）修改防火墙设置
添加防火墙规则：
[[email protected] etc]# iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-ports 3128
[[email protected] etc]# iptables -t nat -A POSTROUTING -o eth0 -s 172.16.49.0/24 -j MASQUERADE
3）开启ipv4转发功能
[[email protected] etc]# sed -i ‘/net.ipv4.ip_forward/s/0/1/‘ /etc/sysctl.conf
[[email protected] etc]# grep ip_forward /etc/sysctl.conf
net.ipv4.ip_forward = 1
[[email protected] etc]# sysctl -p
4）测试squid客户端网络
[[email protected] ~]# ifconfig eth1
eth1 Link encap:Ethernet HWaddr 00:0C:29:A5:4C:68
inet addr:172.16.49.139 Bcast:172.16.49.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fea5:4c68/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:349 errors:0 dropped:0 overruns:0 frame:0
TX packets:223 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:30075 (29.3 KiB) TX bytes:24303 (23.7 KiB)
[[email protected] ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.16.49.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
169.254.0.0 0.0.0.0 255.255.0.0 U 1003 0 0 eth1
[[email protected] ~]# ping 202.96.128.86
connect: Network is unreachable
[[email protected] ~]# ping www.baidu.com
ping: unknown host www.baidu.com
5）重读squid配置
squid -k reconfig
6）将squid服务器的内网IP地址设置为squid客户端的默认网关
[[email protected] ~]# route add default gw 172.16.49.135
[[email protected] ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.16.49.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
169.254.0.0 0.0.0.0 255.255.0.0 U 1003 0 0 eth1
0.0.0.0 172.16.49.135 0.0.0.0 UG 0 0 0 eth1
7）测试squid透明代理
在squid服务器上：
[[email protected] network-scripts]# squid -k rotate #日志轮询
[[email protected] network-scripts]# tail -f /usr/local/squid/var/logs/access.log #观察访问日志
在squid客户端上：
[[email protected] ~]# ping www.baidu.com
PING www.a.shifen.com (14.215.177.38) 56(84) bytes of data.
64 bytes from 14.215.177.38: icmp_seq=1 ttl=127 time=8.00 ms
64 bytes from 14.215.177.38: icmp_seq=2 ttl=127 time=8.13 ms
64 bytes from 14.215.177.38: icmp_seq=3 ttl=127 time=7.89 ms
64 bytes from 14.215.177.38: icmp_seq=4 ttl=127 time=35.1 ms
^C
--- www.a.shifen.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3229ms
rtt min/avg/max/mdev = 7.890/14.790/35.124/11.740 ms
squid客户端已经可以通过squid服务器上网了。