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Match specific netbios flag?

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Subject: Match specific netbios flag?
From: "k bah" <kbah@linuxmail.org>
Date: Thu, 17 May 2007 07:00:58 +0800
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 Hi,

 I'm using kernel 2.6.17, iptables 1.3.5.
 
 Is there a way to match specific netbios ns flags? I did not find any on the 
iptables man page.

 I'm trying to log it like this:

 -A INPUT -s 10.1.1.15 -i eth1 -p udp -m string --string "elease" --algo bm 
--to 65535 -j LOG --log-prefix "received release from 015"

 where 10.1.1.1 is the machine with iptables, the internal net router. 
10.1.1.15 is Windows XP.

 I would like to match it with a flag, not a string, to be more secure (netbios 
ns flag 0x3010)

 the packet captured with wireshark is:
-------------
...
11164 11877.336283 10.1.1.15              10.1.1.255            NBNS     
Release NB HT015<20>
...
NetBIOS Name Service
    Transaction ID: 0x808f
    Flags: 0x3010 (Release)
        0... .... .... .... = Response: Message is a query
        .011 0... .... .... = Opcode: Release (6)
        .... ..0. .... .... = Truncated: Message is not truncated
        .... ...0 .... .... = Recursion desired: Don't do query recursively
        .... .... ...1 .... = Broadcast: Broadcast packet
    Questions: 1
    Answer RRs: 0
    Authority RRs: 0
    Additional RRs: 1
    Queries
        HT015<20>: type NB, class IN
            Name: HT015<20> (Server service)
            Type: NB
            Class: IN
    Additional records
        HT015<20>: type NB, class IN
            Name: HT015<20> (Server service)
            Type: NB
            Class: IN
            Time to live: 0 time
            Data length: 6
            Flags: 0x0 (B-node, unique)
                0... .... .... .... = Unique name
                .00. .... .... .... = B-node
            Addr: 10.1.1.15
-------------

 I want to know when that host went offline by turning the computer off, or 
because of some physical failure, as a broken cable, or disconnected cable on 
the switch.

 thanks,

 kbah

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