iptables 学习总结--匹配条件(四)

╰+攻爆jí腚メ 2022-05-23 04:55 269阅读 0赞

1.指定多个源地址(多个IP之间用`,`隔开)

iptables -t filter -A INPUT -s 192.168.1.111,192.168.1.110 -j ACCEPT

查看结果

[root@localhost ~]# iptables -t filter -vnxL INPUT
    Chain INPUT (policy ACCEPT 57 packets, 3972 bytes)
        pkts      bytes target     prot opt in     out     source               destination
        6004   504336 ACCEPT     all  -- * * 192.168.1.39 0.0.0.0/0
           0        0 ACCEPT     all  -- * * 192.168.1.39 0.0.0.0/0
           0        0 ACCEPT     all  -- * * 192.168.1.111 0.0.0.0/0
           0        0 ACCEPT     all  -- * * 192.168.1.110 0.0.0.0/0

--------------------

指定某个网段

iptables -t filter -F INPUT 
    iptables -t filter -I INPUT -s 10.39.0.0/16 -j DROP

查看结果

[root@localhost ~]# iptables -t filter -vnxL INPUT
    Chain INPUT (policy ACCEPT 37 packets, 2820 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 DROP       all  --  *      *       10.39.0.0/16         0.0.0.0/0

--------------------

非(!)

iptables -t filter -F
    iptables -t filter -A INPUT ! -s 10.39.0.123 -j DROP

![11111][]

--------------------

匹配目标地址

丢掉从192.168.1.39 发往192.168.1.61的报文

iptables -t filter -F 
    iptables -t filter -A INPUT -s 192.168.1.39 -d 192.168.1.61 -j DROP

[root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 108 packets, 7632 bytes)
     pkts bytes target     prot opt in     out     source               destination
       67  5628 DROP       all  --  *      *       192.168.1.39         192.168.1.61

不指定源地址

[root@localhost ~]# iptables -t filter -R INPUT 1 -d 192.168.1.61 -j DROP

![11][]

--------------------

匹配协议类型`-p tcp(dup,icmp)`

root@localhost ~]# iptables -t filter -I INPUT -s 192.168.1.39 -d 192.168.1.61 -p udp -j DROP
    [root@localhost ~]# iptables -t filter -nxvL INPUT --line
    Chain INPUT (policy ACCEPT 20 packets, 1560 bytes)
    num      pkts      bytes target     prot opt in     out     source               destination
    1           0        0 DROP       udp  --  *      *       192.168.1.39         192.168.1.61

--------------------

匹配网卡`-i(-o) interface`

iptables -t filter -A INPUT -i enp0s8 -s 192.168.1.34 -j ACCEPT

[root@localhost ~]# iptables -t filter -A INPUT -i enp0s8 -s 192.168.1.34 -j ACCEPT
    [root@localhost ~]# iptables -t filter -nxvL INPUT --line
    Chain INPUT (policy ACCEPT 13 packets, 972 bytes)
    num      pkts      bytes target     prot opt in     out     source               destination
    1           0        0 ACCEPT     all  --  enp0s8 *       192.168.1.34         0.0.0.0/0

--------------------

扩展匹配条件

匹配端口`--dport port(--sport port)` \-m 表示模块

[root@localhost ~]# iptables -t filter -A INPUT -s 192.168.1.39 -p tcp -m tcp --dport 22 -d 192.168.1.61 -j REJECT
    [root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 87 packets, 6492 bytes)
     pkts bytes target     prot opt in     out     source               destination
        0     0 REJECT     tcp  --  *      *       192.168.1.39         192.168.1.61         tcp dpt:22 reject-with icmp-port-unreachable

结果

[root@fabric-cli ~]# ssh 192.168.1.61
    ssh: connect to host 192.168.1.61 port 22: Connection refused

root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 7 packets, 488 bytes)
     pkts bytes target     prot opt in     out     source               destination
        1    60 REJECT     tcp  -- * * 192.168.1.39 192.168.1.61 tcp dpt:22 reject-with icmp-port-unreachable
        0     0 ACCEPT     tcp  -- * * 192.168.1.39 192.168.1.61 tcp spt:22

匹配连续的某个范围的端口

iptables -t filter -A INPUT -s 192.168.1.61 -d 192.168.1.39 -p tcp --dport 22:25 -j ACCEPT
    
    [root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 89 packets, 7158 bytes)
     pkts bytes target     prot opt in     out     source               destination
        2   120 REJECT     tcp  --  *      *       192.168.1.39         192.168.1.61         tcp dpt:22 reject-with icmp-port-unreachable
        0     0 ACCEPT     tcp  --  *      *       192.168.1.39         192.168.1.61         tcp spt:22
        0     0 ACCEPT     tcp  --  *      *       192.168.1.61         192.168.1.39         tcp dpts:22:25

匹配离散的多个端口`(-m multiport --dports)`

iptables -t filter -A INPUT -s 192.168.1.111 -p tcp -m multiport --dports 49,36,80 -j ACCEPT

[root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 9 packets, 636 bytes)
     pkts bytes target     prot opt in     out     source               destination
        2   120 REJECT     tcp  -- * * 192.168.1.39 192.168.1.61 tcp dpt:22 reject-with icmp-port-unreachable
        0     0 ACCEPT     tcp  -- * * 192.168.1.39 192.168.1.61 tcp spt:22
        0     0 ACCEPT     tcp  -- * * 192.168.1.61 192.168.1.39 tcp dpts:22:25
        0     0 ACCEPT     tcp  -- * * 192.168.1.111 0.0.0.0/0 multiport dports 49,36,80

--------------------

iprange扩展模块`(--src-range,--dst--range)`

[root@localhost ~]# iptables -t filter -F INPUT
    
    
    iptables -t filter -I INPUT -m iprange --src-range 192.168.1.1-192.168.1.34 -j ACCEPT
    
    [root@localhost ~]# iptables -t filter -nvL INPUT
    Chain INPUT (policy ACCEPT 1 packets, 76 bytes)
     pkts bytes target     prot opt in     out     source               destination
       15  1080 ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0            source IP range 192.168.1.1-192.168.1.34

--------------------

string 模块`(-m string --algo bm(kmp) --string "CICD")`  
含有`HEllO WORLD`的报文就会拒绝

iptables -t filter -I INPUT -m string --algo bm  --string "HEllO WORLD" -j REJECT
    
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0            STRING match  "HEllO WORLD" ALGO name bm TO 65535 reject-with icmp-port-unreachable
          56     4411 ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0            source IP range 192.168.1.1-192.168.1.34

--------------------

time 模块`(-m time --timestart 09:00:00 --timestop 18:00:00)`

[root@localhost ~]# iptables -t filter -I OUTPUT -p tcp --dport 80 -m time --timestart 09:00:00 --timestop 18:00:00 -j REJECT
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0            STRING match  "HEllO WORLD" ALGO name bm TO 65535 reject-with icmp-port-unreachable
         285    20569 ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0            source IP range 192.168.1.1-192.168.1.34
    [root@localhost ~]# iptables -t filter -nvxL OUTPUT
    Chain OUTPUT (policy ACCEPT 19 packets, 2600 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:80 TIME from 09:00:00 to 18:00:00 UTC reject-with icmp-port-unreachable

[root@localhost ~]# iptables -t filter -I OUTPUT -p tcp --dport 80 -m time --weekdays 6,7 -j REJECT

[root@localhost ~]# iptables -t filter -I OUTPUT -p tcp --dport 80 -m time --monthdays 6,7 -j REJECT

[root@localhost ~]# iptables -t filter -I OUTPUT -p tcp --dport 80 -m time --datestart 2018-12-24 --datestop 2018-12-28 -j REJECT

--------------------

connlimit模块`--connlimit-above`

[root@localhost ~]# iptables -t filter -I INPUT -p tcp --dport 80 -m connlimit --connlimit-above 2 -j REJECT
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 19 packets, 1376 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:80 #conn src/32 > 2 reject-with icmp-port-unreachable

root@localhost ~]# iptables -t filter -I INPUT -p tcp --dport 80 -m connlimit ! --connlimit-above 2 -j REJECT
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 7 packets, 488 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:80 #conn src/32 <= 2 reject-with icmp-port-unreachable
           0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:80 #conn src/32 > 2 reject-with icmp-port-unreachable

[root@localhost ~]# iptables -t filter -I INPUT -p tcp --dport 80 -m connlimit ! --connlimit-above 2  --connlimit-mask 27 -j REJECT

[root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 14 packets, 1357 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     tcp  -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 #conn src/27 <= 2 reject-with icmp-port-unreachable
           0        0 REJECT     tcp  -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 #conn src/32 <= 2 reject-with icmp-port-unreachable
           0        0 REJECT     tcp  -- * * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 #conn src/32 > 2 reject-with icmp-port-unreachable

--------------------

limit扩展模块(–limit-brust)  
限制每秒流入的包的数量

[root@localhost ~]# iptables -t filter -I INPUT -p icmp -m limit --limit 10/minute -j ACCEPT
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 9 packets, 636 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0            limit: avg 10/min burst 5

--------------------

tcp 扩展模块 –tcp-flags

tcp头的结构  
![tcp][]

匹配tcp第一次握手的报文

[root@localhost ~]# iptables -t filter -I INPUT -p tcp -m tcp --dport 22 --tcp-flags SYN,ACK,FIN,RST,URG,PSH SYN -j REJECT
    
    [root@localhost ~]# iptables -t filter -nvxL INPUT
    Chain INPUT (policy ACCEPT 10 packets, 712 bytes)
        pkts      bytes target     prot opt in     out     source               destination
           0        0 REJECT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0            tcp dpt:22 flags:0x3F/0x02 reject-with icmp-port-unreachable
           0        0 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0            limit: avg 10/min burst 5

–tcp-flags SYN,ACK,FIN,RST,URG,PSH SYN 这个的意思是要匹配SYN,ACK,FIN,RST,URG,PSH这五个标志为，且SYN为1的报文

匹配tcp第二次握手的报文

[root@localhost ~]# iptables -t filter -I INPUT -p tcp -m tcp --dport 22 --tcp-flags SYN,ACK,FIN,RST,URG,PSH SYN,ACK -j REJECT

上述可以简写成  
用`ALL`来表示`SYN,ACK,FIN,RST,URG,PSH`

[root@localhost ~]# iptables -t filter -I INPUT -p tcp -m tcp --dport 22 --tcp-flags ALL SYN-j REJECT
    [root@localhost ~]# iptables -t filter -I INPUT -p tcp -m tcp --dport 22 --tcp-flags ALL SYN,ACK -j REJECT

匹配tcp新建请求链接的报文

iptables -t filter -I INPUT -p tcp -m tcp --dport 22 --syn -j REJECT

参考  
[匹配条件][Link 1]  
[iprange][]

[11111]: /images/20220523/b6997b04a0204197a8102a852008d410.png
[11]: /images/20220523/994b875810ba43459afb4760a5b54750.png
[tcp]: /images/20220523/2932217249174a578167685f678dee38.png
[Link 1]: http://www.zsythink.net/archives/1544
[iprange]: http://www.zsythink.net/archives/1564