Re: [Idr] I-D Action: draft-ietf-idr-shutdown-01.txt

I'm somewhat behind in my mail, but why was the data length of the notification message not sufficient?

The main motivation for asking is by having two distinct length fields, you now have two different overruns to deal with:
1. The data overruns the length field of the string. (Extra stuff, do what?)
2. The length of the string overruns the data. (Not enough stuff, completely malformed.)

-- Jeff

> On Nov 30, 2016, at 3:49 PM, Job Snijders <job@ntt.net> wrote:
> 
> Hi all,
> 
> The significant change between -00 and -01 is the addition of the
> "length" indicator as suggested by Bruno Decraene.
> 
> I manually created a PCAP file to show what the shutdown communication
> looks like on the wire. This file can be used to test wireshark, tcpdump
> and other packet analysers.
> 
> 	http://instituut.net/~job/shutdown.pcap <http://instituut.net/~job/shutdown.pcap>
> 
> This is the frame of interest:
> 
> Vurt:~ job$ tcpdump -XX -r shutdown.pcap -c 4,5 -v
> reading from file shutdown.pcap, link-type EN10MB (Ethernet)
> 20:19:25.904210 IP (tos 0xc0, ttl 64, id 53942, offset 0, flags [DF], proto TCP (6), length 198)
>    shutdown.meerval.net <http://shutdown.meerval.net/>.45016 > kiera.meerval.net.bgp: Flags [P.], cksum 0x9754 (correct), seq 791846767:791846913, ack 3734170538, win 2048, options [nop,nop,TS val 1416108449 ecr 4177813403], length 146: BGP
>    Notification Message (3), length: 146, Cease (6), subcode Administratively Shutdown (2)
>    0x0000:  5254 0097 e0df 5254 0021 7f49 0800 45c0  RT....RT.!.I..E.
>    0x0010:  00c6 d2b6 4000 4006 1c8b a5fe ff18 a5fe  ....@.@.........
>    0x0020:  ff1a afd8 00b3 2f32 9f6f de92 ebaa 8018  ....../2.o......
>    0x0030:  0800 9754 0000 0101 080a 5468 19a1 f904  ...T......Th....
>    0x0040:  5f9b ffff ffff ffff ffff ffff ffff ffff  _...............
>    0x0050:  ffff 0092 0306 027f 4e54 5420 7769 6c6c  ........NTT.will
>    0x0060:  2070 6572 666f 726d 206d 6169 6e74 656e  .perform.mainten
>    0x0070:  616e 6365 206f 6e20 7468 6973 2072 6f75  ance.on.this.rou
>    0x0080:  7465 722e 2054 6869 7320 6973 2074 7261  ter..This.is <http://this.is/>.tra
>    0x0090:  636b 6564 2069 6e20 5449 434b 4554 2d31  cked.in.TICKET-1
>    0x00a0:  2d32 3438 3234 3239 342e 2043 6f6e 7461  -24824294..Conta
>    0x00b0:  6374 206e 6f63 406e 7474 2e6e 6574 2066  ct.noc@ntt.net.f <mailto:ct.noc@ntt.net.f>
>    0x00c0:  6f72 206d 6f72 6520 696e 666f 726d 6174  or.more.informat
>    0x00d0:  696f 6e2e                                ion.
> 
> Kind regards,
> 
> Job
> 
> On Wed, Nov 30, 2016 at 08:55:01AM -0800, internet-drafts@ietf.org <mailto:internet-drafts@ietf.org> wrote:
>> 
>> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>> This draft is a work item of the Inter-Domain Routing of the IETF.
>> 
>>        Title           : BGP Administrative Shutdown with Additional Communication 
>>        Authors         : Job Snijders
>>                          Jakob Heitz
>>                          John Scudder
>> 	Filename        : draft-ietf-idr-shutdown-01.txt
>> 	Pages           : 6
>> 	Date            : 2016-11-30
>> 
>> Abstract:
>>   This document enhances the BGP Cease NOTIFICATION message
>>   "Administrative Shutdown" subcode for operators to transmit a short
>>   freeform message to describe why a BGP session was shutdown.
>> 
>> 
>> 
>> The IETF datatracker status page for this draft is:
>> https://datatracker.ietf.org/doc/draft-ietf-idr-shutdown/
>> 
>> There's also a htmlized version available at:
>> https://tools.ietf.org/html/draft-ietf-idr-shutdown-01
>> 
>> A diff from the previous version is available at:
>> https://www.ietf.org/rfcdiff?url2=draft-ietf-idr-shutdown-01
>> 
>> 
>> Please note that it may take a couple of minutes from the time of submission
>> until the htmlized version and diff are available at tools.ietf.org.
>> 
>> Internet-Drafts are also available by anonymous FTP at:
>> ftp://ftp.ietf.org/internet-drafts/
>> 
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> 
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