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进一步阅读

tag-icon • tag-icon bash scripting dns dig
进一步阅读

我需要从域列表中检查邮件服务器的 IP 地址，看看它们是否与某个 IP 地址匹配。具体来说：

  1. 构建我要查询的域列表
  2. 挖掘每个域的 MX 记录
  3. 挖掘IP地址MX记录查询结果的A记录
  4. 如果任何 IP 与特定 IP 匹配，则返回“是”或“否”

我卡在第 3 步了。

这是到目前为止我的脚本的相关部分

#!/bin/bash
# Bulk DNS Lookup
#
# File name/path of domain list:
domain_list='domains.txt' # One FQDN per line in file.

# File name of output text
output='ns_output.txt'

# Clears previous output
> $output

# IP address of the nameserver used for lookups:
ns_ip='192.168.250.67'
#
# Seconds to wait between lookups:
loop_wait='1' # Is set to 1 second.

for domain in `cat $domain_list` # Start looping through domains
do
    echo $domain "Mail servers" >> $output
    MX=$(dig @$ns_ip MX $domain +short) #query MX records from domain list and store it as varial $MX
    echo $MX >> $output;
    echo " " >> $output
    echo " " >> $output
    sleep $loop_wait # Pause before the next lookup to avoid flooding NS
done;

问题是我不知道如何将输出转换为变量，以便我可以运行另一个 A 记录挖掘。

c****s.com Name Servers
c****s.com. 14400 IN NS ns1.a****l.com. yes

c****s.com Mail servers
10 mail.c*****s.com. 20 mail2.c****s.com.

有什么方法可以查询结果以返回 MX 查询返回的每个服务器的 IP 地址吗？

编辑：我尝试了每个人的答案，虽然它们都会起作用，但我发现吉尔斯最容易实现。这是我的最终代码：

    MX=$(dig @$ns_ip MX $domain +short) #query MX records from domain list and store it as variable $MX
    arr=( $MX ) #creates array variable for the MX record answers
    for ((i=1; i<${#arr[@]}; i+=2)); #since MX records have multiple answers, for loop goes through each answer
      do
        echo ${arr[i]} >> $output; #outputs each A record from above MX dig
        dig A +short "${arr[i]}" >> $output #queries A record for IP and writes answer
        MX_IP=$(dig A +short "${arr[i]}") #sets IP address from the dig to variable MX_IP
        if [[ "${arr[i]}" == *"a****d"* ]] #if the mail server host name contains a***d
          then
            echo "yes - spam filter" >> $output
          else
          if [[ $MX_IP == $CHECK_IP ]] #if not, check to see if the mail server's IP matches ours.
            then
              echo "yes - mail server"  >> $output
            else
              echo "no" >> $output
          fi
        fi

以下是示例输出（域名和 IP 因偏执而被审查）：

a***l.com Mail servers  lastmx.a****d.net. 
85.x.x.x 
209.x.x.x
95.x.x.x yes - spamfilter
....
mail.b***c.com.
72.x.x.x yes - mail server

backup.b***c.com.
50.x.x.x no

mail2.b***c.com.
50.x.x.x no

答案1

要走的路：

arr=( $MX )
for ((i=1; i<${#arr[@]}; i+=2)); do dig A +short "${arr[i]}"; done

 输出：

108.177.15.26
209.85.233.27
172.253.118.27
108.177.97.26
173.194.202.26

答案2

dig当然，BIND并不是唯一存在的工具。

使用 Daniel J. Bernstein 的 djbdns 工具集，这只是一句简单的话：

%猫域.txt
freebsd.org。
%
%xargs dnsmx < 域.txt | sed -E -e 's/[[:digit:]]+ //' | xargs dnsip
96.47.72.85
96.47.72.80
%

进一步阅读

  • 丹尼尔·J·伯恩斯坦 (1999)。dnsmx。DJBwares。
  • 丹尼尔·J·伯恩斯坦 (1999)。dnsip。DJBwares。

答案3

以下命令将仅返回主机名列表（它会删除权重和尾随句点）：

MX_HOSTS=$(dig MX google.com +short | sed 's/.* \(.*\)\.$/\1/')

然后你可以对其进行 for 循环：

for h in ${MX_HOSTS} ; do
  MX_IPS="${MX_IPS} $(dig $h +short)"
done

并测试：

[[ "${MX_IPS}" =~ "${CHECK_IP}" ]] && echo "yes" || echo "no"

答案4

对它进行了一些更改以解决 MX 记录 URL 而不是 IP，但我想我会分享以防其他人受益。

#!/usr/bin/env bash
# Bulk DNS Lookup

# File name/path of domain list:
domain_list='domains.txt' # One FQDN per line in file.

# File name of output text
output='ns_output.txt'

# Clears previous output
> $output

# IP address of the nameserver used for lookups:
ns_ip='192.168.85.54'
#
# Seconds to wait between lookups:
loop_wait='1' # Is set to 1 second.

for domain in `cat $domain_list` # Start looping through domains
  do
    MX=$(dig @$ns_ip MX $domain +short) #query MX records from domain list and store it as variable $MX
    #echo $MX >> $output;
    #echo $domain >> $output;
    arr=( $MX ) #creates array variable for the MX record answers
    echo ${arr[1]} >> $output; #outputs only one record from above MX dig
    
    : '
    for ((i=1; i<${#arr[@]}; i+=2)); #since MX records have multiple answers, for loop goes through each answer
      do
        #echo $domain >> $output;
        echo ${arr[i]} >> $output; #outputs each A record from above MX dig
        #dig A +short "${arr[i]}" >> $output #queries A record for IP and writes answer
      done
    '

  done;

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