最近用 postfix + dovecot 搭建了一个邮件服务器， 被人当做垃圾邮件转发器，经过配置postfix 的黑白名单， postfix 提示成功的 REJECT 了垃圾邮件， 不过还是有无数的IP地址， 连接过来要进行发送邮件， 虽然垃圾邮件被拒绝了，但是未知连接太多，造成 maillog 日志越变越大， 拖慢 postfix 的运行速度， 总得想个办法解决。要是能把这些无用的IP地址直接用防火墙拒绝就好了。 思路有了，我们就着手处理吧。
这些垃圾IP地址全部是
tail -f /var/log/maillog 查看日志如下所示：
这日志还是很有规律的， 是不是 ？
Aug 20 12:11:40 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <ykrt@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<ykrt@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:41 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <yanghabi@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<yanghabi@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:41 www postfix/smtpd[18026]: NOQUEUE: reject: RCPT from 36-224-135-60.dynamic-ip.hinet.net[36.224.135.60]: 554 5.7.1 <dygui@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vqjpdghrcnaf@163.com> to=<dygui@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:42 www postfix/smtpd[18023]: NOQUEUE: reject: RCPT from 114-45-29-112.dynamic.hinet.net[114.45.29.112]: 554 5.1.8 <ekiczlqpkuezc@yahoo.com.jp>: Sender address rejected: Domain not found; from=<ekiczlqpkuezc@yahoo.com.jp> to=<fet77111@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:43 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <zen19762001@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<zen19762001@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:43 www postfix/smtpd[18026]: NOQUEUE: reject: RCPT from 36-224-135-60.dynamic-ip.hinet.net[36.224.135.60]: 554 5.7.1 <to1477889900@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vqjpdghrcnaf@163.com> to=<to1477889900@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:44 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <x19781024@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<x19781024@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:44 www postfix/smtpd[18023]: NOQUEUE: reject: RCPT from 114-45-29-112.dynamic.hinet.net[114.45.29.112]: 554 5.1.8 <ekiczlqpkuezc@yahoo.com.jp>: Sender address rejected: Domain not found; from=<ekiczlqpkuezc@yahoo.com.jp> to=<jay791028@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:45 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <juliessy@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<juliessy@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:45 www postfix/smtpd[18026]: too many errors after RCPT from 36-224-135-60.dynamic-ip.hinet.net[36.224.135.60] Aug 20 12:11:45 www postfix/smtpd[18026]: disconnect from 36-224-135-60.dynamic-ip.hinet.net[36.224.135.60] Aug 20 12:11:46 www postfix/smtpd[18023]: too many errors after RCPT from 114-45-29-112.dynamic.hinet.net[114.45.29.112] Aug 20 12:11:46 www postfix/smtpd[18023]: disconnect from 114-45-29-112.dynamic.hinet.net[114.45.29.112] Aug 20 12:11:47 www postfix/smtpd[18033]: NOQUEUE: reject: RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61]: 554 5.7.1 <xsip@yahoo.com.tw>: Recipient address rejected: Access denied; from=<vpjcmwqinpnpg@anet.net.tw> to=<xsip@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:11:49 www postfix/smtpd[18033]: too many errors after RCPT from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61] Aug 20 12:11:49 www postfix/smtpd[18033]: disconnect from 36-224-133-61.dynamic-ip.hinet.net[36.224.133.61] Aug 20 12:14:10 www postfix/smtpd[18097]: connect from 36-224-136-82.dynamic-ip.hinet.net[36.224.136.82] Aug 20 12:14:11 www postfix/smtpd[18097]: NOQUEUE: reject: RCPT from 36-224-136-82.dynamic-ip.hinet.net[36.224.136.82]: 554 5.7.1 <rzxijhkiefau@yahoo.com.tw>: Sender address rejected: Access denied; from=<rzxijhkiefau@yahoo.com.tw> to=<ina12350@yahoo.com.tw> proto=SMTP helo=<115.28.81.191> Aug 20 12:14:11 www postfix/smtpd[18097]: NOQUEUE: reject: RCPT from 36-224-136-82.dynamic-ip.hinet.net[36.224.136.82]: 554 5.7.1 <rzxijhkiefau@yahoo.com.tw>: Sender address rejected: Access denied; from=<rzxijhkiefau@yahoo.com.tw> to=<ilovemyself414@yahoo.com.tw> proto=SMTP helo=<115.28.81.191>
too many errors after RCPT from 后面的IP地址获取， 动态加入到防火墙进行拒绝就行。
思路有了， 我就写个小程序来分析日志吧，我写的是C的， 不过用perl 或者 shell 脚本可能更简单。
反正用自己最熟悉的语言就行。
dyn.c 源代码文件的内容如下 ：
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define BUF_LEN 4096
#define DATA_LEN 4096*10
int main (int argc, char** argv)
{
//too many errors after RCPT from 36-224-128-99.dynamic-ip.hinet.net[36.224.128.99]
//too many errors after RCPT from 118-169-22-28.dynamic.hinet.net[118.169.22.28]
char buf[BUF_LEN] = {0};
const char* sep = "too many errors after RCPT from";
while (1)
{
memset (buf, 0, sizeof(buf));
char* tp = fgets (buf, sizeof(buf)-1, stdin);
if (tp != NULL)
{
char* p = strstr(buf, sep);
if (p != NULL)
{
char* p1 = p + strlen(sep);
while (*p1 != ‘\0‘ && *p1 != ‘.‘)
{
p1++;
}
*p1 = ‘\0‘;
*(p-1) = ‘\0‘;
int x1, x2, x3, x4;
int ret = sscanf(p, "too many errors after RCPT from %d-%d-%d-%d", &x1, &x2, &x3, &x4);
//printf ("Get IP = %d.%d.%d.%d\n", x1,x2,x3,x4);
if (ret == 4)
{
char ebuf[512] = {0};
snprintf(ebuf, sizeof(ebuf)-1, "iptables -I INPUT -s %d.%d.%d.%d -j DROP", x1,x2,x3,x4);
system (ebuf);
printf ("%s\n", ebuf);
}
}
}
}
return 0;
}
我的dyn可执行文件在 /root 目录， 所以用 命令：
nohup tail -f /var/log/maillog | /root/dyn &
让它自己跑吧。
过一段时间后， 我们再看maillog日志， 已经基本没有 不认识的IP地址再连接过来打算发邮件了。
动态分析maillog日志，把恶意链接直接用防火墙禁止,布布扣,bubuko.com
原文：http://blog.csdn.net/langeldep/article/details/38704291