Re: Death by extension header (was:RE: New Version Notification for draft-li-6man-hbh-fwd-hdr-00.txt)
Toerless Eckert <tte@cs.fau.de> Tue, 14 July 2020 07:36 UTC
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Date: Tue, 14 Jul 2020 09:36:12 +0200
From: Toerless Eckert <tte@cs.fau.de>
To: Gyan Mishra <hayabusagsm@gmail.com>
Cc: "Pengshuping (Peng Shuping)" <pengshuping@huawei.com>, "6man@ietf.org" <6man@ietf.org>, Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>, Tom Herbert <tom@herbertland.com>
Subject: Re: Death by extension header (was:RE: New Version Notification for draft-li-6man-hbh-fwd-hdr-00.txt)
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Hi Gyan, On Tue, Jul 14, 2020 at 02:37:12AM -0400, Gyan Mishra wrote: > >From a historical perspective the slow path and fast path has some vendor > connotations into it ???cxxxx???. I think its used pretty consistently throughout the industry. If you have an example of a router that has something other vendors would call slowpath but calls it differently, i would be interested to know such alternative terms. > I think any document within the IETF should stay clear of anything that is > a vendor terminology. Definitely agreed if something is really specific to a subset of vendors instead of the most widely used term. I think its the most widely used term. > The concept of ???punt??? meanIng send to control plane also has vendor > connotation and should not be used. I think the same applies here as what i said above for slow/fast path. Btw: these are just comments about my best understanding about terminology. Not an endorsement to base any upcoming work on those terms. I already sent emails as to the opposite. > I personally like control plane and data plane processing of extension > headers. Do you have a good definition for control-plane and data-plane processing ? E.g.: inband-signaling, is that decidedly control-plane for data-plane to you ? Cheers Toerless > Gyan > > On Mon, Jul 13, 2020 at 11:35 PM Pengshuping (Peng Shuping) < > pengshuping@huawei.com> wrote: > > > > > > > > -----Original Message----- > > > From: ipv6 [mailto:ipv6-bounces@ietf.org] On Behalf Of Tom Herbert > > > Sent: Tuesday, July 14, 2020 3:31 AM > > > To: Toerless Eckert <tte@cs.fau.de> > > > Cc: Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>; 6man@ietf.org > > > Subject: Re: Death by extension header (was:RE: New Version Notification > > > for draft-li-6man-hbh-fwd-hdr-00.txt) > > > > > > On Mon, Jul 13, 2020 at 12:18 PM Toerless Eckert <tte@cs.fau.de> wrote: > > > > > > > > And now find me any single IETF RFC that even uses the term slow-path > > > > and fast-path to formalize requirements against them. We are just not > > > > explicit enough about this. Hence my example of redooing router-alert > > > > as the most simple example. Not that i think this would be most > > > > important, but just to make the community consider that we need to be > > > > more diligent about protocol specs in this respect. > > > > > > > > > > Toerless, > > > > > > I wouldn't expect any IETF to use the term "slow path" and "fast path". > > RFCs > > > tend to describe protocol behavior and generally themselves don't care > > > whether they are processed in a slow path or fast path as long as the > > > external behavior is conformant. If you want to make these terms > > explicit it > > > seems like we would need to quantify in exact terms what a slow path is > > and > > > exactly what a fast path is-- that is, they need normative definitions > > if we are > > > to set normative requirements around them. > > > > But do we still need to differentiate "control plane" and "forwarding > > plane"? The processing capability in bps and pps of the two planes are > > different, so the corresponding terms are used as "slow path" and "fast > > path", respectively. > > > > There are some HBH options such as RA* that carry the information that > > need to be consumed by the "control plane", so they will be sent to the > > "control plane" anyway. While other HBH options carry the information that > > will not be consumed by the "control plane" but still sent to the "control > > plane" / "slow path", which cause problems. > > > > * > > https://www.iana.org/assignments/ipv6-routeralert-values/ipv6-routeralert-values.xhtml#ipv6-routeralert-values-1 > > > > Shuping > > > > > > > > Tom > > > > > > > Some maximum amount of fast-path extensions is already in specs as an > > > > example, but it too is not comprehensive enough to feel more confident > > > > about safe extensibility. > > > > > > > > And we need to break free of the rfc8200 constraints whenever we > > > > deploy the network protocol in controlled networks. rfc8200 is such a > > > > career limiter when comparing IPv6 with MPLS for this type of > > > > use-cases. Not to speak of the unnecessary long addresses. > > > > > > > > Oh well... > > > > > > > > Cheers > > > > Toerless > > > > > > > > On Fri, Jul 10, 2020 at 06:43:59PM +0000, Ron Bonica wrote: > > > > > Tom, > > > > > > > > > > Given that you parse the extension header chain on the fast path, HBH > > > and destination options can be categorized as follows: > > > > > > > > > > 1) unrecognized (ACT 00, 01, 10, and 11) > > > > > 2) recognized and processed on the fast path > > > > > 3) recognized and processed on the slow path > > > > > > > > > > Types 1 and 2 cannot be used in a DoS attack, because they are never > > > sent to the slow path. Type 3 is the dangerous one. > > > > > > > > > > I think that an implementation is safe if it only recognizes options > > that it > > > can process on the fast path. It may also be safe if it severely rate > > limits > > > packets as it sends them to the slow path. > > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Juniper Business Use Only > > > > > > > > > > -----Original Message----- > > > > > From: Tom Herbert <tom@herbertland.com> > > > > > Sent: Friday, July 10, 2020 2:29 PM > > > > > To: Ron Bonica <rbonica@juniper.net> > > > > > Cc: Pengshuping (Peng Shuping) <pengshuping@huawei.com>; > > > > > 6man@ietf.org > > > > > Subject: Re: Death by extension header (was:RE: New Version > > > > > Notification for draft-li-6man-hbh-fwd-hdr-00.txt) > > > > > > > > > > [External Email. Be cautious of content] > > > > > > > > > > > > > > > On Fri, Jul 10, 2020 at 11:18 AM Ron Bonica <rbonica@juniper.net> > > > wrote: > > > > > > > > > > > > Tom, > > > > > > > > > > > > I am forking a new thread since this is not directly related to > > Shuping's > > > draft. > > > > > > > > > > > > Any variable length extension header can be used in a DoS attack. > > So, if > > > a node encounters a packet that satisfies any of the following criteria, > > it > > > should discard the packet and send an ICMP message as described in > > > > > https://urldefense.com/v3/__https://tools.ietf.org/html/draft-herbert-6ma > > > n-icmp-limits-03__;!!NEt6yMaO-gk!XnKPvkz9vBtVNlSCx0SqcojVpo2uBgeSDJ > > > zZEJa2fLd1NTKb53H0w3Ue2Xxv7iGB$ . > > > > > > > > > > > > - The extension header chain is longer than the node can process > > > > > > - An individual extension header is longer than the node can > > > > > > process > > > > > > - The total number of options contained by all instances of the > > HBH and > > > Destination Options header exceeds the number or options that the node > > > can process. > > > > > > > > > > > > > > > > Ron, > > > > > > > > > > Right, those are the ICMP errors for the allowance to drop or ignore > > > extension headers in section 5.3 of RFC8504, there's also default limits > > > suggested in that doc. Do you think this is sufficient in routers to get > > past the > > > DOS concern? > > > > > > > > > > Tom > > > > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > > > > > > > Juniper Business Use Only > > > > > > > > > > > > -----Original Message----- > > > > > > From: Tom Herbert <tom@herbertland.com> > > > > > > Sent: Friday, July 10, 2020 1:13 PM > > > > > > To: Ron Bonica <rbonica@juniper.net> > > > > > > Cc: Pengshuping (Peng Shuping) <pengshuping@huawei.com>; > > > > > > 6man@ietf.org > > > > > > Subject: Re: New Version Notification for > > > > > > draft-li-6man-hbh-fwd-hdr-00.txt > > > > > > > > > > > > [External Email. Be cautious of content] > > > > > > > > > > > > > > > > > > On Fri, Jul 10, 2020 at 7:59 AM Ron Bonica > > > <rbonica=40juniper.net@dmarc.ietf.org> wrote: > > > > > > > > > > > > > > Peng, > > > > > > > > > > > > > > While your solution may require refinement, I think that you have > > > latched on to a problem that needs to be solved. HBH Options, as they > > were > > > originally conceived in RFC 1883, are very useful. > > > > > > > > > > > > > > When IPv6 was first implemented on high-speed routers (circa > > 2000), > > > HBH options were not yet well-understood and ASICs were not so capable as > > > they are today. So, early IPv6 implementation dispatched all packet that > > > contain HBH options to their slow path. In these implementations, a large > > > flow of IPv6 packets could congest the slow path, causing other critical > > > functions that are executed on the slow path to fail. These critical > > functions > > > include routing and network management. > > > > > > > > > > > > > > To mitigate this DoS vulnerability, many operators deployed > > Access > > > Control Lists (ACLs) that discard all packets containing HBH Options. > > This > > > introduced a circular problem: > > > > > > > > > > > > > > - An implementation problem caused HBH to become a DoS vector > > > > > > > - Because HBH was a DoS vector, network operators deployed ACLs > > > > > > > that discard packets containing HBH > > > > > > > - Because network operators deployed ACLs that discard packets > > > > > > > containing HBH, network designers stopped defining new HBH > > > > > > > Options > > > > > > > - Because network designers stopped defining new HBH Options, > > > > > > > the community was not motivated to fix the implementation > > > > > > > problem that cause HBH to become a DoS vector > > > > > > > > > > > > > > If we can fix the implementation problem that caused HBH to > > > become a DoS vector, we can break this cycle and start using HBH Options. > > > > > > > > > > > > > Ron, > > > > > > > > > > > > I think there were "protocol problems" in the original design of > > HBH. > > > > > > The requirement that _all_ routers in the path process Hop-by-Hop > > > options was in retrospect too austere, and the possibility that an > > attacker > > > could stuff a packet with hundreds of bogus options, only limited by MTU, > > > was, again in retrospect, a pretty obvious DOS vector. > > > > > > I believe these problems have been addressed in RFC8200 and > > > RFC8504. > > > > > > We certainly welcome the feedback from router vendors whether these > > > mitigations are sufficient to make HBH options deployable. > > > > > > > > > > > > Tom > > > > > > > > > > > > > Let's continue to work on a solution. > > > > > > > > > > > > > > > > > Ron > > > > > > > > > > > > > > > > > > > > > > > > > > > > Juniper Business Use Only > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: ipv6 <ipv6-bounces@ietf.org> On Behalf Of Pengshuping > > > > > > > (Peng > > > > > > > Shuping) > > > > > > > Sent: Thursday, July 2, 2020 12:07 PM > > > > > > > To: 6man@ietf.org > > > > > > > Subject: FW: New Version Notification for > > > > > > > draft-li-6man-hbh-fwd-hdr-00.txt > > > > > > > > > > > > > > [External Email. Be cautious of content] > > > > > > > > > > > > > > > > > > > > > Hi Folks, > > > > > > > > > > > > > > We have just uploaded a new draft aiming to analyze and tackle > > the > > > issues faced by the Hop-by-Hop Options Header, which has been sparsely > > > used without any form of large scale deployment. > > > > > > > > > > > > > > However, as IPv6 is being rapidly and widely deployed worldwide, > > > more and more new services that requires hop-by-hop forwarding process > > > behavior are emerging, and also the already defined over ten HBH Options > > > are going to be used widely in practice. > > > > > > > > > > > > > > We look forward to hearing your feedback and comments, and try to > > > release the benefits that could be provided by HBH Options header > > > altogether. > > > > > > > > > > > > > > Best regards, > > > > > > > Shuping > > > > > > > > > > > > > > -----Original Message----- > > > > > > > From: internet-drafts@ietf.org [mailto:internet-drafts@ietf.org] > > > > > > > Sent: Thursday, July 2, 2020 11:31 PM > > > > > > > To: Lizhenbin <lizhenbin@huawei.com>; Pengshuping (Peng Shuping) > > > > > > > <pengshuping@huawei.com> > > > > > > > Subject: New Version Notification for > > > > > > > draft-li-6man-hbh-fwd-hdr-00.txt > > > > > > > > > > > > > > > > > > > > > A new version of I-D, draft-li-6man-hbh-fwd-hdr-00.txt has been > > > successfully submitted by Shuping Peng and posted to the IETF repository. > > > > > > > > > > > > > > Name: draft-li-6man-hbh-fwd-hdr > > > > > > > Revision: 00 > > > > > > > Title: Hop-by-Hop Forwarding Options Header > > > > > > > Document date: 2020-07-03 > > > > > > > Group: Individual Submission > > > > > > > Pages: 10 > > > > > > > URL: > > > > > https://urldefense.com/v3/__https://www.ietf.org/internet-drafts/draft-li-6 > > > man-hbh-fwd-hdr-00.txt__;!!NEt6yMaO-gk!QoInpMGHwaC7LsKAVISa9A00d > > > bzuCmO7S4CG2fZYHGYeOXYwVmtNTFnzgB-bqLrg$ > > > > > > > Status: > > > > > https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-li-6man- > > > hbh-fwd-hdr/__;!!NEt6yMaO-gk!QoInpMGHwaC7LsKAVISa9A00dbzuCmO7S > > > 4CG2fZYHGYeOXYwVmtNTFnzgM5iPE22$ > > > > > > > Htmlized: > > > > > https://urldefense.com/v3/__https://tools.ietf.org/html/draft-li-6man-hbh-f > > > wd-hdr-00__;!!NEt6yMaO-gk!QoInpMGHwaC7LsKAVISa9A00dbzuCmO7S4C > > > G2fZYHGYeOXYwVmtNTFnzgPvsH43l$ > > > > > > > Htmlized: > > > > > https://urldefense.com/v3/__https://datatracker.ietf.org/doc/html/draft-li- > > > 6man-hbh-fwd-hdr__;!!NEt6yMaO-gk!QoInpMGHwaC7LsKAVISa9A00dbzuC > > > mO7S4CG2fZYHGYeOXYwVmtNTFnzgBQxbwZb$ > > > > > > > > > > > > > > > > > > > > > Abstract: > > > > > > > RFC8200 specifies the HBH header that is assumed to be > > > processed by > > > > > > > each hop in the delivery path of the packet. However, RFC8200 > > > also > > > > > > > expects that nodes processing the HBH header have been > > > explicitly > > > > > > > configured to do so. Therefore, it cannot be assumed that a > > > HBH > > > > > > > header present in the packet is processed. It all depends on > > the > > > > > > > configuration of each node across the path. Moreover, in most > > > of > > > > > > > networks today, the processing of the HBH header is done in > > the > > > > > > > control plane (slow processing path) which incurs several > > > limitations > > > > > > > among which resources consumption and security risk. > > > > > > > > > > > > > > For these reasons, over time, the Hop-by-Hop Options header > > > has been > > > > > > > sparsely used without any form of large scale deployment. > > Also, > > > most > > > > > > > of already defined HBH options are forwarding options which > > > contain > > > > > > > forwarding plane information that needs not to be sent to the > > > control > > > > > > > plane. > > > > > > > > > > > > > > This document proposes a new Hop-by-Hop Forwarding Options > > > Header in > > > > > > > order to carry Hop-by-Hop options that are solely intended to > > > and > > > > > > > processed by the forwarding plane. This new HBH header is > > > confined > > > > > > > in and dedicated to the forwarding plane while the current HBH > > > header > > > > > > > can still be used for control plane options. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 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. > > > > > > > > > > > > > > The IETF Secretariat > > > > > > > > > > > > > > > > > > > > > ---------------------------------------------------------------- > > > > > > > ---- IETF IPv6 working group mailing list ipv6@ietf.org > > > > > > > Administrative > > > > > > > Requests: > > > > > > > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinf > > > > > > > o/ip > > > > > > > v6 > > > > > > > > > > __;!!NEt6yMaO-gk!QoInpMGHwaC7LsKAVISa9A00dbzuCmO7S4CG2fZYHGYe > > > OXY > > > > > > > wVmt > > > > > > > NT > > > > > > > FnzgEBbFhyl$ > > > > > > > ---------------------------------------------------------------- > > > > > > > ---- > > > > > > > > > > > > > > ---------------------------------------------------------------- > > > > > > > ---- IETF IPv6 working group mailing list ipv6@ietf.org > > > > > > > Administrative > > > > > > > Requests: > > > > > > > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinf > > > > > > > o/ip > > > > > > > v6 > > > > > > > > > > __;!!NEt6yMaO-gk!Qu9y9Ou2SvlYIZjMQa3hBXcu08HG3W4BBIcFoOHCfp41H > > > tk > > > > > > > dIYu > > > > > > > Ds > > > > > > > XM8uyxPWt9N$ > > > > > > > ---------------------------------------------------------------- > > > > > > > ---- > > > > > -------------------------------------------------------------------- > > > > > IETF IPv6 working group mailing list ipv6@ietf.org Administrative > > > > > Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > > > > -------------------------------------------------------------------- > > > > > > > > -- > > > > --- > > > > tte@cs.fau.de > > > > > > -------------------------------------------------------------------- > > > IETF IPv6 working group mailing list > > > ipv6@ietf.org > > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > > -------------------------------------------------------------------- > > > > -------------------------------------------------------------------- > > IETF IPv6 working group mailing list > > ipv6@ietf.org > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > > -------------------------------------------------------------------- > > > -- > > <http://www.verizon.com/> > > *Gyan Mishra* > > *Network Solutions A**rchitect * > > > > *M 301 502-134713101 Columbia Pike *Silver Spring, MD -- --- tte@cs.fau.de
- Death by extension header (was:RE: New Version No… Ron Bonica
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- RE: Death by extension header (was:RE: New Versio… Ron Bonica
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header (was:RE: New Versio… Warren Kumari
- RE: Death by extension header (was:RE: New Versio… Ron Bonica
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Fernando Gont
- Re: Death by extension header (was:RE: New Versio… Fernando Gont
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header (was:RE: New Versio… Fernando Gont
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header Fernando Gont
- Re: Death by extension header (was:RE: New Versio… Fernando Gont
- Re: Death by extension header Tom Herbert
- RE: Death by extension header (was:RE: New Versio… Ron Bonica
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- RE: Death by extension header (was:RE: New Versio… Pengshuping (Peng Shuping)
- Re: Death by extension header (was:RE: New Versio… Gyan Mishra
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- RE: Death by extension header (was:RE: New Versio… Jakob Heitz (jheitz)
- Re: Death by extension header (was:RE: New Versio… Tom Herbert
- Re: Death by extension header Joel M. Halpern
- Re: Death by extension header (was:RE: New Versio… Robert Raszuk
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Gyan Mishra
- Re: Death by extension header (was:RE: New Versio… Jeff Tantsura
- Re: Death by extension header Brian E Carpenter
- Re: Death by extension header (was:RE: New Versio… Gyan Mishra
- Re: Death by extension header Toerless Eckert
- Re: Death by extension header (was:RE: New Versio… Philip Homburg
- Re: Death by extension header Nick Hilliard
- Re: Death by extension header (was:RE: New Versio… Robert Raszuk
- Re: Death by extension header Toerless Eckert
- Re: Death by extension header Toerless Eckert