使用 arpalert 来做被动式arp防火墙 [2008-5-31 更新]

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使用 arpalert 来做被动式arp防火墙 [2008-5-31 更新]

#1

帖子 BigSnake.NET » 2008-03-19 22:18

我说的被动式是指在探测到欺骗时做出防护动作

在局域网环境中 arp 欺骗是个很头疼的问题, 尤其是网关不是自己控制的时候. 虽然自己可以绑定网关, 但是网关就没办法了. 结果导致网关的东西传不回来, 无法上网.

原理:
arpalert 监听网卡收到的 arp 包, 并根据规则(黑白名单等)调用一个防护脚本.

安装:
安装以下包:
libnet-arp-perl arpalert(建议用最新的 2.0.11 版, 2.0.10 前的版本处理名单时有问题)
另外将以下文本存为 /usr/local/sbin/arpdef.pl
加上可执行权限(755)
(已更新)

代码: 全选

#!/usr/bin/perl -w

use strict;
if ( $< ) {
        print "$0\n";
        system("sudo",($0,@ARGV));
        exit;
}

my $mac = $ARGV[0];
my $ip = $ARGV[1];

my ($gateip,$gatemac) = ("192.168.6.1","00:04:80:FA:3C:00");
exit 0 if (("\U$mac" eq "\U$gatemac") && ($ip eq $gateip));

#logging ..
my $date=`date +"%F %T"`;
chomp $date;
open (LOGFILE,">>/home/autumncat/log/arpdef.log");
if ( 4 <= $#ARGV ) {
        printf LOGFILE "%s    %s %15s %15s %6s %d (%s)\n",($date,@ARGV,"Null");
} else {
        printf LOGFILE "%s    manual executing.\n",$date;
}
close LOGFILE;

#correct gateway
# if (("\U$ip" eq $gateip)&&("\U$mac" ne $gatemac)) {
# send arp
        use Net::ARP;
        use Time::HiRes qw( usleep );
        my $ival = 40000;
        my $time = 60 * 1000000; #total time = 30sec
        for (my $i=0;$i<$time;$i+=$ival) {
                Net::ARP::send_packet(
                        'eth0',
                        "192.168.6.28", #my ip
                        $gateip,
                        "00:1A:4D:93:3D:44", # my mac
                        $gatemac,
                        'reply');
                usleep($ival);
        }
# }
设置
修改 /etc/arpalert/arpalert.conf
(调整了一下)

代码: 全选

#
# Copyright (c) 2005-2010 Thierry FOURNIER
# $Id: arpalert.conf.in 690 2008-03-31 18:36:43Z  $
# 
# Default config file
# 

# white list
maclist file = "/etc/arpalert/maclist.allow"

# black list
maclist alert file = "/etc/arpalert/maclist.deny"

# dump file
maclist leases file = "/var/lib/arpalert/arpalert.leases"

# list of authorized request
#auth request file = /etc/arpalert/authrq.conf

# log file
log file = "/var/log/arpalert.log"

# pid file
lock file = "/var/run/arpalert.pid"

# log level
use syslog = false

# log level
log level = 6

# user for privilege separation
user = arpalert

# rights for file creation
umask = 177

# only for debugging: this dump paquet received on standard output
dump packet = false

# run the program as daemon ?
daemon = false

# minimun time to wait between two leases dump
dump inter = 5

#Configure the network for catch only arp request.
#The detection type "new_mac" is desactived.
#This mode is used for CPU saving if Arpalert is running on a router
catch only arp = true

# comma separated interfaces to lesson
# if not precised, the soft select the first interface.
# by default select the first interface encontered
interface = eth0

# script launched on each detection
# parameters are:
#  - "mac adress of requestor"
#  - "ip of requestor"
#  - "supp. parm."
#  - "ethernet device listening on"
#  - "type of alert"
#  - optional : "ethernet vendor"
# type of alert:
# 0: ip change
# 1: mac address only detected but not in whithe list
# 2: mac address in black list
# 3: new mac address
# 4: unauthorized arp request
# 5: abusive number of arp request detected 
# 6: ethernet mac address different from arp mac address
# 7: global flood detection
# 8: new mac adress without ip
# 9: mac change
action on detect = "/usr/local/sbin/arpdef.pl"

# module launched on each detection
mod on detect = ""
# this chain is transfered to the init function of module loaded
mod config = ""

# script execution timeout (seconds)
execution timeout = 10

# maximun simultaneous lanched script
max alert = 8

# what data are dumped in leases file
dump black list = false
dump white list = false
dump new address = true

# after this time a mac adress is removed from memory (seconds) (default 1 month)
mac timeout = 259200

# after this limit the memory hash is cleaned (protect to arp flood)
max entry = 1000000

# this permit to send only one mismatch alert in this time (in seconds)
anti flood interval = 0  

# if the number of arp request in seconds exceed this value, all alerts are ignored for 
# "anti flood interval" time
anti flood global = 50

# vendor name
# add the mac vendor field in logs, alerts script and/or module execution
mac vendor file = "/etc/arpalert/oui.txt"
log mac vendor = true
alert mac vendor = true
mod mac vendor = true

# log if the adress is referenced in hash but is not in white list
log referenced address = false
alert on referenced address = false
mod on referenced address = false

# log if the mac adress is in black list
log deny address = true
alert on deny address = true
mod on deny address = true

# log if the adress isn't referenced
log new address = true
alert on new address = true
mod on new address = true

# log if the adress isn't referenced (for mac adress only)
log new mac address = true
alert on new mac address = true
mod on new mac address = true

# log if the ip adress id different from the last arp request with the same mac adress
log ip change = true
alert on ip change = true
mod on ip change = true

# log if the ip adress id different from the last arp request with the same mac adress
log mac change = true
alert on mac change = true
mod on mac change = true

# unauthorized arp request:
# log all the request not authorized in auth file
log unauth request = false
alert on unauth request = false
mod on unauth request = false
# dont analyse arp request for unknow hosts (not in white list)
ignore unknown sender = false
# ignore arp request with mac adresse of the lessoned interfaces for the authorizations checks
ignore me = true
# ignore windows self test
ignore self test = false
# suspend time method:
# 1: ignore all unauth alerts during "anti flood interval" time
# 2: ignore only tuple (mac address, ip address) during "anti flood interval" time
unauth ignore time method = 2

# log if the number of request per seconds are > "max request"
log request abus = true
alert on request abus = true
mod on request abus = true
# maximun request authorized by second
max request = 1000000

# log if the ethernet mac address are different than the arp amc address (only for requestor)
log mac error = true
alert on mac error = true
mod on mac error = true

# log if have too many arp request per seconds
log flood = false
alert on flood	= false
mod on flood = true
sudo visudo
加上一行

代码: 全选

arpalert ALL=NOPASSWD: /usr/local/sbin/arpdef.pl *
注意以上全部可执行文件都要只有root才能改, 以保安全
暂时好像比较有效, 应该还有得改进

PS:红色为更新处
上次由 BigSnake.NET 在 2008-05-31 12:50,总共编辑 2 次。
^_^ ~~~
要理解递归,首先要理解递归。

地球人都知道,理论上,理论跟实际是没有差别的,但实际上,理论跟实际的差别是相当大滴。
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#2

帖子 yaoms » 2008-03-19 22:24

先顶后看
Nothing 有事请发邮件到 yms541 AT gmail.com
alias 爱慕颇雷尔='mplayer'
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#3

帖子 zh8331609 » 2008-03-21 7:37

好好学习的就是
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#4

帖子 eexpress » 2008-03-21 8:50

private ip/mac不能从系统配置自动读取吗?
● 鸣学
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#5

帖子 tongttt » 2008-03-21 10:11

先学习下……
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#6

帖子 maikafei » 2008-03-21 14:53

这个要顶 :twisted:
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#7

帖子 bones7456 » 2008-03-21 15:09

顶球猫,学习了.
关注我的blog: ε==3
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#8

帖子 maikafei » 2008-03-21 16:29

怎么打开使用? :twisted:
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#9

帖子 maikafei » 2008-03-21 16:36

哇靠 ,到底怎么用? :roll:
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#10

帖子 maikafei » 2008-03-21 16:51

安装:
安装以下包:
libnet-arp-perl arpalert(我用的是自己编译的 2.0.9 版, 源里的版本应该没问题)
另外将以下文本存为 /usr/local/sbin/arpdef.pl
加上可执行权限(755)


加上可执行权限(755) ???? 这个怎么理解? 什么事755?
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#11

帖子 BigSnake.NET » 2008-03-21 16:51

还是有点未知的问题.. 先普通吧..
^_^ ~~~
要理解递归,首先要理解递归。

地球人都知道,理论上,理论跟实际是没有差别的,但实际上,理论跟实际的差别是相当大滴。
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#12

帖子 maikafei » 2008-03-21 16:53

晕,什么叫先普通啊? 楼主你说清楚些不行吗?
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#13

帖子 maikafei » 2008-03-21 16:56

后悔ing , 一不小心做了小白 :(
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#14

帖子 sixdegree » 2008-05-31 12:24

感谢楼主让我明白了ARP防火墙的原理。
在使用时,有时攻击比较强,导致同一时间有多个arpdef.pl进程运行。
我做了一点小修改,让它一次只能运行一个实例,不知效果如何。
下面是PATCH:

代码: 全选

*** arpdef.pl.ori	2008-05-31 12:11:20.000000000 +0800
--- arpdef.pl	2008-05-31 11:52:49.000000000 +0800
***************
*** 1,11 ****
--- 1,18 ----
  #!/usr/bin/perl -w
  
  use strict;
+ 
+ # Ensure only one copy of the perl script is running at a time
+ die if -e "/tmp/arpdef.lock";
+ 
  if ( $< ) {
          system("sudo",($0,@ARGV));
          exit;
  }
  
+ # Create lock file.
+ open LOCK,">/tmp/arpdef.lock";
+ 
  #logging ..
  open (LOGFILE,">>/tmp/arpdef.log");
  print LOGFILE (join " ",@ARGV);
***************
*** 33,35 ****
--- 40,44 ----
  # }
  print LOGFILE "\n";
  close LOGFILE;
+ close LOCK;
+ unlink "/tmp/arpdef.lock";
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#15

帖子 maikafei » 2008-06-02 1:39

加上可执行权限(755)


我用这个命令怎么不行?

sudo chmod +755 /usr/local/sbin/arpdef.pl


错误信息:

sunny@sunny-desktop:~$ sudo chmod +755 /usr/local/sbin/arpdef.pl
[sudo] password for sunny:
chmod: 无效的模式:“+755”
请尝试执行“chmod --help”来获取更多信息。
sunny@sunny-desktop:~$ sudo chmod +755 /usr/local/sbin/arpdef.pl
chmod: 无效的模式:“+755”
请尝试执行“chmod --help”来获取更多信息。
sunny@sunny-desktop:~$ sudo chmod + 755 /usr/local/sbin/arpdef.pl
chmod: 无法访问“755”: 没有该文件或目录
chmod: 无法访问“/usr/local/sbin/arpdef.pl”: 没有该文件或目录
sunny@sunny-desktop:~$ sudo chmod +755 /usr/local/sbin/arpdef.pl
chmod: 无效的模式:“+755”
请尝试执行“chmod --help”来获取更多信息。
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