< draft-ietf-dots-signal-channel-14.txt   draft-ietf-dots-signal-channel-15.txt >
DOTS T. Reddy DOTS T. Reddy, Ed.
Internet-Draft McAfee Internet-Draft McAfee
Intended status: Standards Track M. Boucadair Intended status: Standards Track M. Boucadair, Ed.
Expires: June 21, 2018 Orange Expires: July 14, 2018 Orange
P. Patil P. Patil
Cisco Cisco
A. Mortensen A. Mortensen
Arbor Networks, Inc. Arbor Networks, Inc.
N. Teague N. Teague
Verisign, Inc. Verisign, Inc.
December 18, 2017 January 10, 2018
Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal
Channel Channel
draft-ietf-dots-signal-channel-14 draft-ietf-dots-signal-channel-15
Abstract Abstract
This document specifies the DOTS signal channel, a protocol for This document specifies the DOTS signal channel, a protocol for
signaling the need for protection against Distributed Denial-of- signaling the need for protection against Distributed Denial-of-
Service (DDoS) attacks to a server capable of enabling network Service (DDoS) attacks to a server capable of enabling network
traffic mitigation on behalf of the requesting client. traffic mitigation on behalf of the requesting client.
A companion document defines the DOTS data channel, a separate A companion document defines the DOTS data channel, a separate
reliable communication layer for DOTS management and configuration reliable communication layer for DOTS management and configuration
skipping to change at page 2, line 20 skipping to change at page 2, line 20
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 21, 2018. This Internet-Draft will expire on July 14, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
skipping to change at page 2, line 48 skipping to change at page 2, line 48
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions and Terminology . . . . . . . . . . . 5 2. Notational Conventions and Terminology . . . . . . . . . . . 5
3. Design Overview . . . . . . . . . . . . . . . . . . . . . . . 6 3. Design Overview . . . . . . . . . . . . . . . . . . . . . . . 6
4. DOTS Signal Channel: Messages & Behaviors . . . . . . . . . . 8 4. DOTS Signal Channel: Messages & Behaviors . . . . . . . . . . 8
4.1. DOTS Server(s) Discovery . . . . . . . . . . . . . . . . 8 4.1. DOTS Server(s) Discovery . . . . . . . . . . . . . . . . 8
4.2. CoAP URIs . . . . . . . . . . . . . . . . . . . . . . . . 8 4.2. CoAP URIs . . . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . 9 4.3. Happy Eyeballs for DOTS Signal Channel . . . . . . . . . 9
4.4. DOTS Mitigation Methods . . . . . . . . . . . . . . . . . 10 4.4. DOTS Mitigation Methods . . . . . . . . . . . . . . . . . 10
4.4.1. Request Mitigation . . . . . . . . . . . . . . . . . 11 4.4.1. Request Mitigation . . . . . . . . . . . . . . . . . 11
4.4.2. Retrieve Information Related to a Mitigation . . . . 20 4.4.2. Retrieve Information Related to a Mitigation . . . . 22
4.4.3. Efficacy Update from DOTS Clients . . . . . . . . . . 28 4.4.3. Efficacy Update from DOTS Clients . . . . . . . . . . 31
4.4.4. Withdraw a Mitigation . . . . . . . . . . . . . . . . 30 4.4.4. Withdraw a Mitigation . . . . . . . . . . . . . . . . 33
4.5. DOTS Signal Channel Session Configuration . . . . . . . . 32 4.5. DOTS Signal Channel Session Configuration . . . . . . . . 34
4.5.1. Discover Configuration Parameters . . . . . . . . . . 33 4.5.1. Discover Configuration Parameters . . . . . . . . . . 36
4.5.2. Convey DOTS Signal Channel Session Configuration . . 37 4.5.2. Convey DOTS Signal Channel Session Configuration . . 39
4.5.3. Delete DOTS Signal Channel Session Configuration . . 43 4.5.3. Delete DOTS Signal Channel Session Configuration . . 45
4.6. Redirected Signaling . . . . . . . . . . . . . . . . . . 44 4.6. Redirected Signaling . . . . . . . . . . . . . . . . . . 46
4.7. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 45 4.7. Heartbeat Mechanism . . . . . . . . . . . . . . . . . . . 47
5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . . . 47 5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . . . 49
5.1. Tree Structure . . . . . . . . . . . . . . . . . . . . . 47 5.1. Tree Structure . . . . . . . . . . . . . . . . . . . . . 49
5.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 49 5.2. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 51
6. Mapping Parameters to CBOR . . . . . . . . . . . . . . . . . 62 6. Mapping Parameters to CBOR . . . . . . . . . . . . . . . . . 66
7. (D)TLS Protocol Profile and Performance Considerations . . . 63 7. (D)TLS Protocol Profile and Performance Considerations . . . 67
7.1. (D)TLS Protocol Profile . . . . . . . . . . . . . . . . . 63 7.1. (D)TLS Protocol Profile . . . . . . . . . . . . . . . . . 67
7.2. (D)TLS 1.3 Considerations . . . . . . . . . . . . . . . . 64 7.2. (D)TLS 1.3 Considerations . . . . . . . . . . . . . . . . 69
7.3. MTU and Fragmentation . . . . . . . . . . . . . . . . . . 65 7.3. MTU and Fragmentation . . . . . . . . . . . . . . . . . . 70
8. Mutual Authentication of DOTS Agents & Authorization of DOTS 8. Mutual Authentication of DOTS Agents & Authorization of DOTS
Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Clients . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 68 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 72
9.1. DOTS Signal Channel UDP and TCP Port Number . . . . . . . 68 9.1. DOTS Signal Channel UDP and TCP Port Number . . . . . . . 72
9.2. Well-Known 'dots' URI . . . . . . . . . . . . . . . . . . 68 9.2. Well-Known 'dots' URI . . . . . . . . . . . . . . . . . . 72
9.3. CoAP Response Code . . . . . . . . . . . . . . . . . . . 68 9.3. CoAP Response Code . . . . . . . . . . . . . . . . . . . 73
9.4. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 69 9.4. DOTS Signal Channel CBOR Mappings Registry . . . . . . . 73
9.4.1. Registration Template . . . . . . . . . . . . . . . . 69 9.4.1. Registration Template . . . . . . . . . . . . . . . . 73
9.4.2. Initial Registry Contents . . . . . . . . . . . . . . 69 9.4.2. Initial Registry Contents . . . . . . . . . . . . . . 74
9.5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . 75 9.5. DOTS Signal Channel YANG Module . . . . . . . . . . . . . 80
10. Implementation Status . . . . . . . . . . . . . . . . . . . . 75 10. Implementation Status . . . . . . . . . . . . . . . . . . . . 80
10.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 76 10.1. nttdots . . . . . . . . . . . . . . . . . . . . . . . . 81
11. Security Considerations . . . . . . . . . . . . . . . . . . . 76 11. Security Considerations . . . . . . . . . . . . . . . . . . . 81
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 77 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 82
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 77 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 82
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 78 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 82
14.1. Normative References . . . . . . . . . . . . . . . . . . 78 14.1. Normative References . . . . . . . . . . . . . . . . . . 82
14.2. Informative References . . . . . . . . . . . . . . . . . 80 14.2. Informative References . . . . . . . . . . . . . . . . . 85
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 84 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 89
1. Introduction 1. Introduction
A distributed denial-of-service (DDoS) attack is an attempt to make A distributed denial-of-service (DDoS) attack is an attempt to make
machines or network resources unavailable to their intended users. machines or network resources unavailable to their intended users.
In most cases, sufficient scale can be achieved by compromising In most cases, sufficient scale can be achieved by compromising
enough end-hosts and using those infected hosts to perpetrate and enough end-hosts and using those infected hosts to perpetrate and
amplify the attack. The victim in this attack can be an application amplify the attack. The victim in this attack can be an application
server, a host, a router, a firewall, or an entire network. server, a host, a router, a firewall, or an entire network.
skipping to change at page 6, line 36 skipping to change at page 6, line 36
+---------------------+ +---------------------+
| CoAP | | CoAP |
+----------+----------+ +----------+----------+
| TLS | DTLS | | TLS | DTLS |
+----------+----------+ +----------+----------+
| TCP | UDP | | TCP | UDP |
+----------+----------+ +----------+----------+
| IP | | IP |
+---------------------+ +---------------------+
Figure 3: Abstract Layering of DOTS signal channel over CoAP over Figure 3: Abstract Layering of DOTS Signal Channel over CoAP over
(D)TLS (D)TLS
By default, a DOTS signal channel MUST run over port number TBD as By default, a DOTS signal channel MUST run over port number TBD as
defined in Section 9.1, for both UDP and TCP, unless the DOTS server defined in Section 9.1, for both UDP and TCP, unless the DOTS server
has a mutual agreement with its DOTS clients to use a different port has a mutual agreement with its DOTS clients to use a different port
number. DOTS clients may alternatively support means to dynamically number. DOTS clients may alternatively support means to dynamically
discover the ports used by their DOTS servers. In order to use a discover the ports used by their DOTS servers. In order to use a
distinct port number (as opposed to TBD), DOTS clients and servers distinct port number (as opposed to TBD), DOTS clients and servers
should support a configurable parameter to supply the port number to should support a configurable parameter to supply the port number to
use. The rationale for not using the default port number 5684 use. The rationale for not using the default port number 5684
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such as errors. In order to allow the use of the same data models, such as errors. In order to allow the use of the same data models,
[RFC7951] specifies the JSON encoding of YANG-modeled data. A [RFC7951] specifies the JSON encoding of YANG-modeled data. A
similar effort for CBOR is defined in [I-D.ietf-core-yang-cbor]. All similar effort for CBOR is defined in [I-D.ietf-core-yang-cbor]. All
parameters in the payload of the DOTS signal channel are mapped to parameters in the payload of the DOTS signal channel are mapped to
CBOR types as specified in Section 6. CBOR types as specified in Section 6.
From that standpoint, this document specifies a YANG data model for From that standpoint, this document specifies a YANG data model for
representing mitigation scopes and DOTS signal channel session representing mitigation scopes and DOTS signal channel session
configuration data (Section 5). Representing these data as CBOR data configuration data (Section 5). Representing these data as CBOR data
is assumed to follow the rules in [I-D.ietf-core-yang-cbor] or those is assumed to follow the rules in [I-D.ietf-core-yang-cbor] or those
in [RFC7951] combined with JSON/CBOR conversion rules in [RFC7049]. . in [RFC7951] combined with JSON/CBOR conversion rules in [RFC7049].
In order to prevent fragmentation, DOTS agents must follow the In order to prevent fragmentation, DOTS agents must follow the
recommendations documented in Section 4.6 of [RFC7252]. Refer to recommendations documented in Section 4.6 of [RFC7252]. Refer to
Section 7.3 for more details. Section 7.3 for more details.
DOTS agents MUST support GET, PUT, and DELETE CoAP methods. The DOTS agents MUST support GET, PUT, and DELETE CoAP methods. The
payload included in CoAP responses with 2.xx and 3.xx Response Codes payload included in CoAP responses with 2.xx and 3.xx Response Codes
MUST be of content type "application/cbor" (Section 5.5.1 of MUST be of content type "application/cbor" (Section 5.5.1 of
[RFC7252]). CoAP responses with 4.xx and 5.xx error Response Codes [RFC7252]). CoAP responses with 4.xx and 5.xx error Response Codes
MUST include a diagnostic payload (Section 5.5.2 of [RFC7252]). The MUST include a diagnostic payload (Section 5.5.2 of [RFC7252]). The
skipping to change at page 9, line 15 skipping to change at page 9, line 15
desired DOTS operation. desired DOTS operation.
+-----------------------+----------------+-------------+ +-----------------------+----------------+-------------+
| Operation | Operation path | Details | | Operation | Operation path | Details |
+-----------------------+----------------+-------------+ +-----------------------+----------------+-------------+
| Mitigation | /v1/mitigate | Section 4.4 | | Mitigation | /v1/mitigate | Section 4.4 |
+-----------------------+----------------+-------------+ +-----------------------+----------------+-------------+
| Session configuration | /v1/config | Section 4.5 | | Session configuration | /v1/config | Section 4.5 |
+-----------------------+----------------+-------------+ +-----------------------+----------------+-------------+
Table 1: Operations and their corresponding URIs Table 1: Operations and their Corresponding URIs
4.3. Happy Eyeballs for DOTS Signal Channel 4.3. Happy Eyeballs for DOTS Signal Channel
[I-D.ietf-dots-requirements] mentions that DOTS agents will have to [I-D.ietf-dots-requirements] mentions that DOTS agents will have to
support both connectionless and connection-oriented protocols. As support both connectionless and connection-oriented protocols. As
such, the DOTS signal channel is designed to operate with DTLS over such, the DOTS signal channel is designed to operate with DTLS over
UDP and TLS over TCP. Further, a DOTS client may acquire a list of UDP and TLS over TCP. Further, a DOTS client may acquire a list of
IPv4 and IPv6 addresses (Section 4.1), each of which can be used to IPv4 and IPv6 addresses (Section 4.1), each of which can be used to
contact the DOTS server using UDP and TCP. The following specifies contact the DOTS server using UDP and TCP. The following specifies
the procedure to follow to select the address family and the the procedure to follow to select the address family and the
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server can enable mitigation on behalf of the DOTS client by server can enable mitigation on behalf of the DOTS client by
communicating the DOTS client's request to the mitigator and relaying communicating the DOTS client's request to the mitigator and relaying
selected mitigator feedback to the requesting DOTS client. selected mitigator feedback to the requesting DOTS client.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Uri-Path: "cuid=xyz"
Content-Type: "application/cbor" Content-Type: "application/cbor"
{ {
"mitigation-scope": { "mitigation-scope": {
"client-identifier": [
"string"
],
"scope": [ "scope": [
{ {
"mitigation-id": integer, "mitigation-id": integer,
"target-prefix": [ "target-prefix": [
"string" "string"
], ],
"target-port-range": [ "target-port-range": [
{ {
"lower-port": integer, "lower-port": integer,
"upper-port": integer "upper-port": integer
skipping to change at page 12, line 47 skipping to change at page 12, line 45
], ],
"alias-name": [ "alias-name": [
"string" "string"
], ],
"lifetime": integer "lifetime": integer
} }
] ]
} }
} }
Figure 5: PUT to convey DOTS mitigation requests Figure 5: PUT to Convey DOTS Mitigation Requests
The parameters are described below: The parameters are described below:
client-identifier: The client identifier MAY be conveyed by a cuid: Stands for Client Unique Identifier. A unique identifier that
server-side DOTS gateway to propagate the DOTS client identity is meant to prevent collisions among DOTS clients from the same
from the gateway's client-side to the gateway's server-side, and domain. It MUST be generated by DOTS clients. A variety of
from the gateway's server-side to the DOTS server. 'client- methods can be used to generate such identifier, e.g.,
identifier' MAY be used by the final DOTS server for policy cryptographic means [RFC4086], mimic the algorithm in [RFC4941],
enforcement purposes. prepend a timestamp to a randomly generated identifier, etc.
Implementations MAY use the form "identifier@host", for example
The 'client-identifier' value MUST be assigned by the server-side "7dec-11d0-a765-00a0c91e6bf6@foo.bar.example".
DOTS gateway in a manner that ensures that there is zero
probability that the same value will be assigned to a different
DOTS client. The server-side DOTS gateway MUST conceal
potentially sensitive DOTS client identity information.
If aggregating DOTS mitigation requests received from multiple The CUID is intended to be stable when communicating with a given
DOTS clients is enabled, the server-side DOTS gateway has to DOTS server, i.e., the CUID used by a DOTS client SHOULD NOT
include a list of 'client-identifier' values; each value is change over time. Distinct CUIDs MAY be used per DOTS server.
pointing to a unique DOTS client that is in the aggregated list.
It is out of scope of this document to specify how aggregation is
implemented by a DOTS gateway.
The client-identifier attribute MUST NOT be generated and included DOTS servers MUST treat CUIDs as opaque values and MUST only
by DOTS clients. compare CUIDs for equality. That is, DOTS servers must not
interpret CUIDs. DOTS servers MUST return 4.09 (Conflict) error
code to a DOTS peer to notify that the CUID is already in-use by
another DOTS client of the same domain. Upon receipt of that
error code, a new CUID MUST be generated by the DOTS peer.
DOTS servers MUST ignore client-identifier attributes that are Client-domain DOTS gateways MAY rewrite the CUIDs used by internal
directly supplied by source DOTS clients. This implies that first DOTS clients. Triggers for such rewriting are out of scope.
server-side DOTS gateways MUST strip client-identifier attributes
supplied by DOTS clients. DOTS servers MAY support a
configuration parameter to identify DOTS gateways that are trusted
to supply client-identifier attributes.
This is an optional attribute. This is a mandatory attribute.
mitigation-id: Identifier for the mitigation request represented mitigation-id: Identifier for the mitigation request represented
with an integer. This identifier MUST be unique for each with an integer. This identifier MUST be unique for each
mitigation request bound to the DOTS client, i.e., the mitigation request bound to the DOTS client, i.e., the
'mitigation-id' parameter value in the mitigation request needs to 'mitigation-id' parameter value in the mitigation request needs to
be unique relative to the 'mitigation-id' parameter values of be unique relative to the 'mitigation-id' parameter values of
active mitigation requests conveyed from the DOTS client to the active mitigation requests conveyed from the DOTS client to the
DOTS server. This identifier MUST be generated by the DOTS DOTS server. This identifier MUST be generated by the DOTS
client. This document does not make any assumption about how this client. This document does not make any assumption about how this
identifier is generated. identifier is generated.
skipping to change at page 15, line 8 skipping to change at page 14, line 47
lifetime: Lifetime of the mitigation request in seconds. The lifetime: Lifetime of the mitigation request in seconds. The
RECOMMENDED lifetime of a mitigation request is 3600 seconds (60 RECOMMENDED lifetime of a mitigation request is 3600 seconds (60
minutes) -- this value was chosen to be long enough so that minutes) -- this value was chosen to be long enough so that
refreshing is not typically a burden on the DOTS client, while refreshing is not typically a burden on the DOTS client, while
expiring the request where the client has unexpectedly quit in a expiring the request where the client has unexpectedly quit in a
timely manner. DOTS clients MUST include this parameter in their timely manner. DOTS clients MUST include this parameter in their
mitigation requests. Upon the expiry of this lifetime, and if the mitigation requests. Upon the expiry of this lifetime, and if the
request is not refreshed, the mitigation request is removed. The request is not refreshed, the mitigation request is removed. The
request can be refreshed by sending the same request again. request can be refreshed by sending the same request again.
A lifetime of 0 in a mitigation request is an invalid value. A lifetime of '0' in a mitigation request is an invalid value.
A lifetime of negative one (-1) indicates indefinite lifetime for A lifetime of negative one (-1) indicates indefinite lifetime for
the mitigation request. The DOTS server MAY refuse indefinite the mitigation request. The DOTS server MAY refuse indefinite
lifetime, for policy reasons; the granted lifetime value is lifetime, for policy reasons; the granted lifetime value is
returned in the response. DOTS clients MUST be prepared to not be returned in the response. DOTS clients MUST be prepared to not be
granted mitigations with indefinite lifetimes. granted mitigations with indefinite lifetimes.
The DOTS server MUST always indicate the actual lifetime in the The DOTS server MUST always indicate the actual lifetime in the
response and the remaining lifetime in status messages sent to the response and the remaining lifetime in status messages sent to the
DOTS client. DOTS client.
This is a mandatory attribute. This is a mandatory attribute.
In deployments where server-domain DOTS gateways are enabled,
identity information about the origin source client domain has to be
supplied to the DOTS server. That information is meant to assist the
DOTS server to enforce some policies. Figure 6 shows an example of a
request relayed by a server-domain DOTS gateway.
Header: PUT (Code=0.03)
Uri-Host: "host"
Uri-Path: ".well-known"
Uri-Path: "dots"
Uri-Path: "version"
Uri-Path: "mitigate"
Uri-Path: "cuid=xyz"
Content-Type: "application/cbor"
{
"mitigation-scope": {
"client-domain-hash": "string",
"scope": [
{
"mitigation-id": integer,
"target-prefix": [
"string"
],
"target-port-range": [
{
"lower-port": integer,
"upper-port": integer
}
],
"target-protocol": [
integer
],
"target-fqdn": [
"string"
],
"target-uri": [
"string"
],
"alias-name": [
"string"
],
"lifetime": integer
}
]
}
}
Figure 6: PUT to Convey DOTS Mitigation Request as relayed by a
Server-Domain DOTS Gateway
The DOTS gateway may add the following parameter:
client-domain-hash: The client identifier MAY be conveyed by a
server-domain DOTS gateway to propagate the source domain identity
from the gateway's client-side to the gateway's server-side, and
from the gateway's server-side to the DOTS server. 'client-domain-
hash' MAY be used by the final DOTS server for policy enforcement
purposes (e.g., enforce a quota on filtering rules).
The 'client-domain-hash' value MUST be assigned by the server-
domain DOTS gateway in a manner that ensures that there is zero
probability that the same value will be assigned to a different
client domain.
If the DOTS client is using the certificate provisioned by the
Enrollment over Secure Transport (EST) server [RFC7030] in the
DOTS gateway-domain to authenticate itself to the DOTS gateway,
the 'client-domain-hash' value may be the output of a
cryptographic hash algorithm whose input is the DER-encoded ASN.1
representation of the Subject Public Key Info (SPKI) of an X.509
certificate. In this version of the specification, the
cryptographic hash algorithm used is SHA-256 [RFC6234]. The
output of the cryptographic hash algorithm is truncated to 16
bytes; truncation is done by stripping off the final 16 bytes.
The truncated output is base64url encoded.
The 'client-domain-hash' attribute MUST NOT be generated and
included by DOTS clients.
DOTS servers MUST ignore 'client-domain-hash' attributes that are
directly supplied by source DOTS clients or client-domain DOTS
gateways. This implies that first server-domain DOTS gateways
MUST strip 'client-domain-hash' attributes supplied by DOTS
clients. DOTS servers MAY support a configuration parameter to
identify DOTS gateways that are trusted to supply 'client-domain-
hash' attributes.
Only singe-valued 'client-domain-hash' are defined in this
document.
This is an optional attribute.
Because of the complexity to handle partial failure cases, this Because of the complexity to handle partial failure cases, this
specification does not allow for including multiple mitigation specification does not allow for including multiple mitigation
requests in the same PUT request. Concretely, a DOTS client MUST NOT requests in the same PUT request. Concretely, a DOTS client MUST NOT
include multiple 'scope' parameters in the same PUT request. include multiple 'scope' parameters in the same PUT request.
The CBOR key values for the parameters are defined in Section 6. The CBOR key values for the parameters are defined in Section 6.
Section 9 defines how the CBOR key values can be allocated to Section 9 defines how the CBOR key values can be allocated to
standard bodies and vendors. standard bodies and vendors.
FQDN and URI mitigation scopes may be thought of as a form of scope FQDN and URI mitigation scopes may be thought of as a form of scope
alias, in which the addresses to which the domain name or URI resolve alias, in which the addresses to which the domain name or URI resolve
represent the full scope of the mitigation. represent the full scope of the mitigation.
In the PUT request at least one of the attributes 'target-prefix' or In the PUT request at least one of the attributes 'target-prefix' or
'target-fqdn' or 'target-uri 'or 'alias-name' MUST be present. 'target-fqdn' or 'target-uri 'or 'alias-name' MUST be present.
Attributes with emty values MUST NOT be present in a request. Attributes with empty values MUST NOT be present in a request.
The relative order of two mitigation requests from a DOTS client is The relative order of two mitigation requests from a DOTS client is
determined by comparing their respective 'mitigation-id' values. If determined by comparing their respective 'mitigation-id' values. If
two mitigation requests have overlapping mitigation scopes, the two mitigation requests have overlapping mitigation scopes, the
mitigation request with the highest numeric 'mitigation-id' value mitigation request with the highest numeric 'mitigation-id' value
will override the other mitigation request. Two mitigation-ids from will override the other mitigation request. Two mitigation-ids from
a DOTS client are overlapping if there is a common IP address, IP a DOTS client are overlapping if there is a common IP address, IP
prefix, FQDN, URI, or alias-name. To avoid maintaining a long list prefix, FQDN, URI, or alias-name. To avoid maintaining a long list
of overlapping mitigation requests from a DOTS client and avoid of overlapping mitigation requests from a DOTS client and avoid
error-prone provisioning of mitigation requests from a DOTS client, error-prone provisioning of mitigation requests from a DOTS client,
the overlapped lower numeric 'mitigation-id' MUST be automatically the overlapped lower numeric 'mitigation-id' MUST be automatically
deleted and no longer available at the DOTS server. deleted and no longer available at the DOTS server.
The Uri-Path option carries a major and minor version nomenclature to The Uri-Path option carries a major and minor version nomenclature to
manage versioning and DOTS signal channel in this specification uses manage versioning and DOTS signal channel in this specification uses
v1 major version. v1 major version.
Figure 6 shows a PUT request example to signal that ports 80, 8080, Figure 7 shows a PUT request example to signal that ports 80, 8080,
and 443 used by 2001:db8:6401::1 and 2001:db8:6401::2 servers are and 443 used by 2001:db8:6401::1 and 2001:db8:6401::2 servers are
under attack (illustrated in JSON diagnostic notation). under attack (illustrated in JSON diagnostic notation). The presence
of 'client-domain-hash' indicates that a server-domain DOTS gateway
has modified the initial PUT request sent by the DOTS client.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "www.example.com" Uri-Host: "www.example.com"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "v1" Uri-Path: "v1"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Uri-Path: "cuid=xyz"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"mitigation-scope": { "mitigation-scope": {
"client-identifier": [ "client-domain-hash": "dz6pHjaADkaFTbjr0JGBpw",
"dz6pHjaADkaFTbjr0JGBpw"
],
"scope": [ "scope": [
{ {
"mitigation-id": 12332, "mitigation-id": 12332,
"target-prefix": [ "target-prefix": [
"2001:db8:6401::1/128", "2001:db8:6401::1/128",
"2001:db8:6401::2/128" "2001:db8:6401::2/128"
], ],
"target-port-range": [ "target-port-range": [
{ {
"lower-port": 80 "lower-port": 80
skipping to change at page 16, line 51 skipping to change at page 19, line 42
} }
], ],
"target-protocol": [ "target-protocol": [
6 6
] ]
} }
] ]
} }
} }
Figure 6: PUT for DOTS signal Figure 7: PUT for DOTS Mitigation Request
The corresponding CBOR encoding format is shown in Figure 7. The corresponding CBOR encoding format is shown in Figure 8.
A1 # map(1) A1 # map(1)
01 # unsigned(1) 01 # unsigned(1)
A2 # map(2) A2 # map(2)
18 20 # unsigned(32) 18 24 # unsigned(36)
81 # array(1)
76 # text(22) 76 # text(22)
647A3670486A6141446B614654626A72304A47427077 # "dz6pHjaADkaFTbjr0JGBpw" 647A3670486A6141446B614654626A72304A47427077 # "dz6pHjaADkaFTbjr0JGBpw"
02 # unsigned(2) 02 # unsigned(2)
81 # array(1) 81 # array(1)
A4 # map(4) A4 # map(4)
03 # unsigned(3) 03 # unsigned(3)
19 302C # unsigned(12332) 19 302C # unsigned(12332)
04 # unsigned(4) 18 23 # unsigned(35)
82 # array(2) 82 # array(2)
74 # text(20) 74 # text(20)
323030313A6462383A363430313A3A312F313238 # "2001:db8:6401::1/128" 323030313A6462383A363430313A3A312F313238 # "2001:db8:6401::1/128"
74 # text(20) 74 # text(20)
323030313A6462383A363430313A3A322F313238 # "2001:db8:6401::2/128" 323030313A6462383A363430313A3A322F313238 # "2001:db8:6401::2/128"
05 # unsigned(5) 05 # unsigned(5)
83 # array(3) 83 # array(3)
A1 # map(1) A1 # map(1)
06 # unsigned(6) 06 # unsigned(6)
18 50 # unsigned(80) 18 50 # unsigned(80)
A1 # map(1) A1 # map(1)
06 # unsigned(6) 06 # unsigned(6)
19 01BB # unsigned(443) 19 01BB # unsigned(443)
A1 # map(1) A1 # map(1)
06 # unsigned(6) 06 # unsigned(6)
19 1F90 # unsigned(8080) 19 1F90 # unsigned(8080)
08 # unsigned(8) 08 # unsigned(8)
81 # array(1) 81 # array(1)
06 # unsigned(6) 06 # unsigned(6)
Figure 7: PUT for DOTS signal (CBOR) Figure 8: PUT for DOTS Mitigation Request (CBOR)
If the DOTS client is using the certificate provisioned by the
Enrollment over Secure Transport (EST) server [RFC7030] in the DOTS
gateway-domain to authenticate itself to the DOTS gateway, then the
'client-identifier' value can be the output of a cryptographic hash
algorithm whose input is the DER-encoded ASN.1 representation of the
Subject Public Key Info (SPKI) of an X.509 certificate.
In this version of the specification, the cryptographic hash
algorithm used is SHA-256 [RFC6234]. The output of the cryptographic
hash algorithm is truncated to 16 bytes; truncation is done by
stripping off the final 16 bytes. The truncated output is base64url
encoded.
In both DOTS signal and data channel sessions, the DOTS client MUST In both DOTS signal and data channel sessions, the DOTS client MUST
authenticate itself to the DOTS server (Section 8). The DOTS server authenticate itself to the DOTS server (Section 8). The DOTS server
may use the algorithm presented in Section 7 of [RFC7589] to derive may use the algorithm presented in Section 7 of [RFC7589] to derive
the DOTS client identity or username from the client certificate. the DOTS client identity or username from the client certificate.
The DOTS client identity allows the DOTS server to accept mitigation The DOTS client identity allows the DOTS server to accept mitigation
requests with scopes that the DOTS client is authorized to manage. requests with scopes that the DOTS client is authorized to manage.
The DOTS server couples the DOTS signal and data channel sessions The DOTS server couples the DOTS signal and data channel sessions
using the DOTS client identity and the 'client-identifier' parameter using the DOTS client identity or the 'client-domain-hash' parameter
value, so the DOTS server can validate whether the aliases conveyed value, so the DOTS server can validate whether the aliases conveyed
in the mitigation request were indeed created by the same DOTS client in the mitigation request were indeed created by the same DOTS client
using the DOTS data channel session. If the aliases were not created using the DOTS data channel session. If the aliases were not created
by the DOTS client, the DOTS server returns 4.00 (Bad Request) in the by the DOTS client, the DOTS server MUST return 4.00 (Bad Request) in
response. the response.
The DOTS server couples the DOTS signal channel sessions using the The DOTS server couples the DOTS signal channel sessions using the
DOTS client identity and the 'client-identifier' parameter value, and DOTS client identity or the 'client-domain-hash' parameter value, and
the DOTS server uses 'mitigation-id' parameter value to detect the DOTS server uses 'mitigation-id' and 'cuid' parameter values to
duplicate mitigation requests. If the mitigation request contains detect duplicate mitigation requests. If the mitigation request
the alias-name and other parameters identifying the target resources contains the alias-name and other parameters identifying the target
(such as, 'target-prefix', 'target-port-range', 'target-fqdn', or resources (such as, 'target-prefix', 'target-port-range', 'target-
'target-uri'), then the DOTS server appends the parameter values in fqdn', or 'target-uri'), the DOTS server appends the parameter values
'alias-name' with the corresponding parameter values in 'target- in 'alias-name' with the corresponding parameter values in 'target-
prefix', 'target-port-range', 'target-fqdn', or 'target-uri'. prefix', 'target-port-range', 'target-fqdn', or 'target-uri'.
The DOTS server indicates the result of processing the PUT request The DOTS server indicates the result of processing the PUT request
using CoAP response codes. CoAP 2.xx codes are success. CoAP 4.xx using CoAP response codes. CoAP 2.xx codes are success. CoAP 4.xx
codes are some sort of invalid requests (client errors). COAP 5.xx codes are some sort of invalid requests (client errors). COAP 5.xx
codes are returned if the DOTS server has erred or is currently codes are returned if the DOTS server has erred or is currently
unavailable to provide mitigation in response to the mitigation unavailable to provide mitigation in response to the mitigation
request from the DOTS client. request from the DOTS client.
Figure 8 shows an example of a PUT request that is successfully Figure 9 shows an example of a PUT request that is successfully
processed (i.e., CoAP 2.xx response codes). processed by a DOTS server (i.e., CoAP 2.xx response codes).
{ {
"mitigation-scope": { "mitigation-scope": {
"client-identifier": [ "client-domain-hash": "dz6pHjaADkaFTbjr0JGBpw",
"string"
],
"scope": [ "scope": [
{ {
"mitigation-id": 12332, "mitigation-id": 12332,
"lifetime": 3600 "lifetime": 3600
} }
] ]
} }
} }
Figure 8: 2.xx response body Figure 9: 2.xx Response Body
If the request is missing one or more mandatory attributes, or If the request is missing one or more mandatory attributes, or
includes multiple 'scope' parameters, or contains invalid or unknown includes multiple 'scope' parameters, or contains invalid or unknown
parameters, the DOTS server MUST reply with 4.00 (Bad Request). DOTS parameters, the DOTS server MUST reply with 4.00 (Bad Request). DOTS
agents can safely ignore Vendor-Specific parameters they don't agents can safely ignore Vendor-Specific parameters they don't
understand. understand.
A DOTS server that receives a mitigation request with a lifetime set A DOTS server that receives a mitigation request with a lifetime set
to '0' MUST reply with a 4.00 (Bad Request). to '0' MUST reply with a 4.00 (Bad Request).
If the DOTS server does not find the 'mitigation-id' parameter value If the DOTS server does not find the 'mitigation-id' parameter value
conveyed in the PUT request in its configuration data, it MAY accept conveyed in the PUT request in its configuration data, it MAY accept
the mitigation request by sending back a 2.01 (Created) response to the mitigation request by sending back a 2.01 (Created) response to
the DOTS client; the DOTS server will consequently try to mitigate the DOTS client; the DOTS server will consequently try to mitigate
the attack. the attack.
If the DOTS server finds the 'mitigation-id' parameter value conveyed If the DOTS server finds the 'mitigation-id' parameter value conveyed
in the PUT request in its configuration data, it MAY update the in the PUT request in its configuration data bound to that DOTS
mitigation request, and a 2.04 (Changed) response is returned to client, it MAY update the mitigation request, and a 2.04 (Changed)
indicate a successful update of the mitigation request. response is returned to indicate a successful update of the
mitigation request.
If the request is conflicting with an existing mitigation request If the request is conflicting with an existing mitigation request
from a different DOTS client, and the DOTS server decides to maintain from a different DOTS client, and the DOTS server decides to maintain
the conflicting mitigation request, the DOTS server returns 4.09 the conflicting mitigation request, the DOTS server returns 4.09
(Conflict) [RFC8132] to the requesting DOTS client. The response (Conflict) [RFC8132] to the requesting DOTS client. The response
includes enough information for a DOTS client to recognize the source includes enough information for a DOTS client to recognize the source
of the conflict (refer to 'conflict-information' specified in of the conflict (refer to 'conflict-information' specified in
Section 4.4.2). Section 4.4.2).
For a mitigation request to continue beyond the initial negotiated For a mitigation request to continue beyond the initial negotiated
lifetime, the DOTS client has to refresh the current mitigation lifetime, the DOTS client has to refresh the current mitigation
request by sending a new PUT request. This PUT request MUST use the request by sending a new PUT request. This PUT request MUST use the
same 'mitigation-id' value, and MUST repeat all the other parameters same 'mitigation-id' value, and MUST repeat all the other parameters
as sent in the original mitigation request apart from a possible as sent in the original mitigation request apart from a possible
change to the lifetime parameter value. change to the lifetime parameter value.
The DOTS gateway, which inserted a 'client-identifier' attribute in a The DOTS gateway, which inserted a 'client-domain-hash' attribute in
request, MUST strip the 'client-identifier' parameter in the a request, MUST strip the 'client-domain-hash' parameter in the
corresponding response before forwarding the response to the DOTS corresponding response before forwarding the response to the DOTS
client. client. If we consider the example depicted in Figure 9, the message
that will be relayed by the DOTS gateway is shown in Figure 10.
{
"mitigation-scope": {
"scope": [
{
"mitigation-id": 12332,
"lifetime": 3600
}
]
}
}
Figure 10: 2.xx Response Body Relayed by a DOTS Gateway
4.4.2. Retrieve Information Related to a Mitigation 4.4.2. Retrieve Information Related to a Mitigation
A GET request is used by a DOTS client to retrieve information A GET request is used by a DOTS client to retrieve information
(including status) of DOTS mitigations from a DOTS server. (including status) of DOTS mitigations from a DOTS server.
The same considerations for manipulating 'client-identifier' The same considerations for manipulating 'client-domain-hash'
parameter by a DOTS gateway specified in Section 4.4.1 MUST be parameter by server-domain DOTS gateways specified in Section 4.4.1
followed for GET requests. MUST be followed for GET requests.
If the DOTS server does not find the 'mitigation-id' parameter value If the DOTS server does not find the 'mitigation-id' parameter value
conveyed in the GET request in its configuration data for the conveyed in the GET request in its configuration data for the
requesting DOTS client or the one identified by 'client-identifier', requesting DOTS client or the one identified by 'client-domain-hash',
it MUST respond with a 4.04 (Not Found) error response code. it MUST respond with a 4.04 (Not Found) error response code.
Likewise, the same error MUST be returned as a response to a request Likewise, the same error MUST be returned as a response to a request
to retrieve all mitigation records of a given DOTS client if the DOTS to retrieve all mitigation records of a given DOTS client if the DOTS
server does not find any mitigation record for that DOTS client or server does not find any mitigation record for that DOTS client or
the one identified by 'client-identifier'. the one identified by 'client-domain-hash'.
The 'c' (content) parameter and its permitted values defined in The 'c' (content) parameter and its permitted values defined in
[I-D.ietf-core-comi] can be used to retrieve non-configuration data [I-D.ietf-core-comi] can be used to retrieve non-configuration data
(attack mitigation status) or configuration data or both. The DOTS (attack mitigation status) or configuration data or both. The DOTS
server may support this optional filtering capability. It can safely server may support this optional filtering capability. It can safely
ignore it if not supported. ignore it if not supported.
The following examples illustrate how a DOTS client retrieves active The following examples illustrate how a DOTS client retrieves active
mitigation requests from a DOTS server. In particular: mitigation requests from a DOTS server. In particular:
o Figure 9 shows the example of a GET request to retrieve all DOTS o Figure 11 shows the example of a GET request to retrieve all DOTS
mitigation requests signaled by a DOTS client. mitigation requests signaled by a DOTS client.
o Figure 10 shows the example of a GET request to retrieve a o Figure 12 shows the example of a GET request to retrieve a
specific DOTS mitigation request signaled by a DOTS client. The specific DOTS mitigation request signaled by a DOTS client. The
configuration data to be reported in the response is formatted in configuration data to be reported in the response is formatted in
the same order it was processed by the DOTS server. the same order it was processed by the DOTS server.
These two examples assume the default of "c=a"; that is, the DOTS These two examples assume the default of "c=a"; that is, the DOTS
client asks for all data to be reported by the DOTS server. client asks for all data to be reported by the DOTS server.
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Uri-Query: "cuid=xyz"
Observe : 0 Observe : 0
{
"mitigation-scope": {
"client-identifier": [
"dz6pHjaADkaFTbjr0JGBpw"
]
}
}
Figure 9: GET to retrieve all DOTS mitigation requests Figure 11: GET to Retrieve all DOTS Mitigation Requests
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Uri-Query: "cuid=xyz"
Uri-Query: "mitigation-id=12332"
Observe : 0 Observe : 0
Content-Format: "application/cbor"
{
"mitigation-scope": {
"client-identifier": [
"dz6pHjaADkaFTbjr0JGBpw"
],
"scope": [
{
"mitigation-id": 12332
}
]
}
}
Figure 10: GET to retrieve a specific DOTS mitigation request Figure 12: GET to Retrieve a Specific DOTS Mitigation Request
Figure 11 shows a response example of all active mitigation requests Figure 13 shows a response example of all active mitigation requests
associated with the DOTS client on the DOTS server and the mitigation associated with the DOTS client on the DOTS server and the mitigation
status of each mitigation request. status of each mitigation request.
{ {
"mitigation-scope": { "mitigation-scope": {
"scope": [ "scope": [
{ {
"mitigation-id": 12332, "mitigation-id": 12332,
"mitigation-start": 1507818434.00, "mitigation-start": 1507818434.00,
"target-protocol": [ "target-prefix": [
17 "2001:db8:6401::1/128",
], "2001:db8:6401::2/128"
"lifetime": 1800, ],
"status": 2, "target-protocol": [
"bytes-dropped": 134334555, 17
"bps-dropped": 43344, ],
"pkts-dropped": 333334444, "lifetime": 1800,
"pps-dropped": 432432 "status": 2,
}, "bytes-dropped": 134334555,
{ "bps-dropped": 43344,
"mitigation-id": 12333, "pkts-dropped": 333334444,
"mitigation-start": 1507818393.00, "pps-dropped": 432432
"target-protocol": [ },
6 {
], "mitigation-id": 12333,
"lifetime": 1800, "mitigation-start": 1507818393.00,
"status": 3, "target-prefix": [
"bytes-dropped": 0, "2001:db8:6401::1/128",
"bps-dropped": 0, "2001:db8:6401::2/128"
"pkts-dropped": 0, ],
"pps-dropped": 0 "target-protocol": [
} 6
] ],
"lifetime": 1800,
"status": 3,
"bytes-dropped": 0,
"bps-dropped": 0,
"pkts-dropped": 0,
"pps-dropped": 0
}
]
} }
} }
Figure 11: Response body Figure 13: Response Body to a Get Request
The mitigation status parameters are described below: The mitigation status parameters are described below:
mitigation-start: Mitigation start time is expressed in seconds mitigation-start: Mitigation start time is expressed in seconds
relative to 1970-01-01T00:00Z in UTC time (Section 2.4.1 of relative to 1970-01-01T00:00Z in UTC time (Section 2.4.1 of
[RFC7049]). The encoding is modified so that the leading tag 1 [RFC7049]). The encoding is modified so that the leading tag 1
(epoch-based date/time) MUST be omitted. (epoch-based date/time) MUST be omitted.
This is a mandatory attribute. This is a mandatory attribute.
lifetime: The remaining lifetime of the mitigation request, in lifetime: The remaining lifetime of the mitigation request, in
seconds. seconds.
This is a mandatory attribute. This is a mandatory attribute.
skipping to change at page 23, line 40 skipping to change at page 26, line 50
conflict-cause: Indicates the cause of the conflict. The conflict-cause: Indicates the cause of the conflict. The
following values are defined: following values are defined:
1: Overlapping targets. 'conflict-scope' provides more details 1: Overlapping targets. 'conflict-scope' provides more details
about the conflicting target clauses. about the conflicting target clauses.
2: Conflicts with an existing white list. This code is 2: Conflicts with an existing white list. This code is
returned when the DDoS mitigation detects source addresses/ returned when the DDoS mitigation detects source addresses/
prefixes in the white-listed ACLs are attacking the target. prefixes in the white-listed ACLs are attacking the target.
3: CUID Collision. This code is returned when a DOTS client
uses a CUID that is already used by another DOTS client of
the same domain.
conflict-scope Indicates the conflict scope. It may include a conflict-scope Indicates the conflict scope. It may include a
list of IP addresses, a list of prefixes, a list of port list of IP addresses, a list of prefixes, a list of port
numbers, a list of target protocols, a list of FQDNs, a list of numbers, a list of target protocols, a list of FQDNs, a list of
URIs, a list of alias-names, or references to conflicting ACLs. URIs, a list of alias-names, or references to conflicting ACLs.
retry-timer Indicates, in seconds, the time after which the DOTS retry-timer Indicates, in seconds, the time after which the DOTS
client may re-issue the same request. The DOTS server returns client may re-issue the same request. The DOTS server returns
'retry-timer' only to DOTS client(s) for which a mitigation 'retry-timer' only to DOTS client(s) for which a mitigation
request is deactivated. Any retransmission of the same request is deactivated. Any retransmission of the same
mitigation request before the expiry of this timer is likely to mitigation request before the expiry of this timer is likely to
skipping to change at page 25, line 14 skipping to change at page 28, line 14
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Parameter | Description | | Parameter | Description |
| value | | | value | |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 1 | Attack mitigation is in progress (e.g., changing the | | 1 | Attack mitigation is in progress (e.g., changing the |
| | network path to re-route the inbound traffic to DOTS | | | network path to re-route the inbound traffic to DOTS |
| | mitigator). | | | mitigator). |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 2 | Attack is successfully mitigated (e.g., traffic is | | 2 | Attack is successfully mitigated (e.g., traffic is |
| | redirected to a DDOS mitigator and attack traffic is | | | redirected to a DDoS mitigator and attack traffic is |
| | dropped). | | | dropped). |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 3 | Attack has stopped and the DOTS client can withdraw | | 3 | Attack has stopped and the DOTS client can withdraw |
| | the mitigation request. | | | the mitigation request. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 4 | Attack has exceeded the mitigation provider | | 4 | Attack has exceeded the mitigation provider |
| | capability. | | | capability. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 5 | DOTS client has withdrawn the mitigation request and | | 5 | DOTS client has withdrawn the mitigation request and |
| | the mitigation is active but terminating. | | | the mitigation is active but terminating. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 6 | Attack mitigation is now terminated. | | 6 | Attack mitigation is now terminated. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 7 | Attack mitigation is withdrawn. | | 7 | Attack mitigation is withdrawn. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 8 | Attack mitigation is rejected. | | 8 | Attack mitigation is rejected. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
Table 2: Values of 'status' parameter Table 2: Values of 'status' Parameter
The observe option defined in [RFC7641] extends the CoAP core The observe option defined in [RFC7641] extends the CoAP core
protocol with a mechanism for a CoAP client to "observe" a resource protocol with a mechanism for a CoAP client to "observe" a resource
on a CoAP server: The client retrieves a representation of the on a CoAP server: The client retrieves a representation of the
resource and requests this representation be updated by the server as resource and requests this representation be updated by the server as
long as the client is interested in the resource. A DOTS client long as the client is interested in the resource. A DOTS client
conveys the observe option set to '0' in the GET request to receive conveys the observe option set to '0' in the GET request to receive
unsolicited notifications of attack mitigation status from the DOTS unsolicited notifications of attack mitigation status from the DOTS
server. server.
Unidirectional notifications within the bidirectional signal channel Unidirectional notifications within the bidirectional signal channel
allows unsolicited message delivery, enabling asynchronous allows unsolicited message delivery, enabling asynchronous
notifications between the agents. Due to the higher likelihood of notifications between the agents. Due to the higher likelihood of
packet loss during a DDoS attack, the DOTS server periodically sends packet loss during a DDoS attack, the DOTS server periodically sends
attack mitigation status to the DOTS client and also notifies the attack mitigation status to the DOTS client and also notifies the
DOTS client whenever the status of the attack mitigation changes. If DOTS client whenever the status of the attack mitigation changes. If
the DOTS server cannot maintain a RTT estimate, it SHOULD NOT send the DOTS server cannot maintain a RTT estimate, it SHOULD NOT send
more than one unsolicited notification every 3 seconds, and SHOULD more than one unsolicited notification every 3 seconds, and SHOULD
use an even less aggressive rate whenever possible (case 2 in use an even less aggressive rate whenever possible (case 2 in
Section 3.1.3 of [RFC8085]). Section 3.1.3 of [RFC8085]). The DOTS server MUST use the same CUID
as the one used by the DOTS client to observe a mitigation request.
When conflicting requests are detected, the DOTS server enforces the When conflicting requests are detected, the DOTS server enforces the
corresponding policy (e.g., accept all requests, reject all requests, corresponding policy (e.g., accept all requests, reject all requests,
accept only one request but reject all the others, ...). It is accept only one request but reject all the others, ...). It is
assumed that this policy is supplied by the DOTS server administrator assumed that this policy is supplied by the DOTS server administrator
or it is a default behavior of the DOTS server implementation. Then, or it is a default behavior of the DOTS server implementation. Then,
the DOTS server sends notification message(s) to the DOTS client(s) the DOTS server sends notification message(s) to the DOTS client(s)
at the origin of the conflict. A conflict notification message at the origin of the conflict. A conflict notification message
includes information about the conflict cause, scope, and the status includes information about the conflict cause, scope, and the status
of the mitigation request(s). For example, of the mitigation request(s). For example,
skipping to change at page 26, line 48 skipping to change at page 29, line 48
A DOTS client that is no longer interested in receiving notifications A DOTS client that is no longer interested in receiving notifications
from the DOTS server can simply "forget" the observation. When the from the DOTS server can simply "forget" the observation. When the
DOTS server sends the next notification, the DOTS client will not DOTS server sends the next notification, the DOTS client will not
recognize the token in the message and thus will return a Reset recognize the token in the message and thus will return a Reset
message. This causes the DOTS server to remove the associated entry. message. This causes the DOTS server to remove the associated entry.
Alternatively, the DOTS client can explicitly deregister itself by Alternatively, the DOTS client can explicitly deregister itself by
issuing a GET request that has the Token field set to the token of issuing a GET request that has the Token field set to the token of
the observation to be cancelled and includes an Observe Option with the observation to be cancelled and includes an Observe Option with
the value set to '1' (deregister). the value set to '1' (deregister).
Figure 12 shows an example of a DOTS client requesting a DOTS server Figure 14 shows an example of a DOTS client requesting a DOTS server
to send notifications related to a given mitigation request. to send notifications related to a given mitigation request.
DOTS Client DOTS Server +-----------+ +-----------+
| | |DOTS client| |DOTS server|
| GET /<mitigation-id number> | +-----------+ +-----------+
| Token: 0x4a | Registration | |
| Observe: 0 | | GET /<mitigation-id number> |
+------------------------------>| | Token: 0x4a | Registration
| | | Observe: 0 |
| 2.05 Content | +------------------------------>|
| Token: 0x4a | Notification of | |
| Observe: 12 | the current state | 2.05 Content |
| status: "mitigation | | Token: 0x4a | Notification of
| in progress" | | Observe: 12 | the current state
|<------------------------------+ | status: "mitigation |
| 2.05 Content | | in progress" |
| Token: 0x4a | Notification upon |<------------------------------+
| Observe: 44 | a state change | 2.05 Content |
| status: "mitigation | | Token: 0x4a | Notification upon
| complete" | | Observe: 44 | a state change
|<------------------------------+ | status: "mitigation |
| 2.05 Content | | complete" |
| Token: 0x4a | Notification upon |<------------------------------+
| Observe: 60 | a state change | 2.05 Content |
| status: "attack stopped" | | Token: 0x4a | Notification upon
|<------------------------------+ | Observe: 60 | a state change
| | | status: "attack stopped" |
|<------------------------------+
| |
Figure 12: Notifications of attack mitigation status Figure 14: Notifications of Attack Mitigation Status
4.4.2.1. Mitigation Status 4.4.2.1. Mitigation Status
The DOTS client can send the GET request at frequent intervals The DOTS client can send the GET request at frequent intervals
without the Observe option to retrieve the configuration data of the without the Observe option to retrieve the configuration data of the
mitigation request and non-configuration data (i.e., the attack mitigation request and non-configuration data (i.e., the attack
status). The frequency of polling the DOTS server to get the status). The frequency of polling the DOTS server to get the
mitigation status should follow the transmission guidelines given in mitigation status should follow the transmission guidelines given in
Section 3.1.3 of [RFC8085]. If the DOTS server has been able to Section 3.1.3 of [RFC8085]. If the DOTS server has been able to
mitigate the attack and the attack has stopped, the DOTS server mitigate the attack and the attack has stopped, the DOTS server
indicates as such in the status, and the DOTS client recalls the indicates as such in the status, and the DOTS client recalls the
mitigation request by issuing a DELETE request for the mitigation-id. mitigation request by issuing a DELETE request for the 'mitigation-
id'.
A DOTS client SHOULD react to the status of the attack as per the A DOTS client SHOULD react to the status of the attack as per the
information sent by the DOTS server rather than acknowledging by information sent by the DOTS server rather than acknowledging by
itself, using its own means, that the attack has been mitigated. itself, using its own means, that the attack has been mitigated.
This ensures that the DOTS client does not recall a mitigation This ensures that the DOTS client does not recall a mitigation
request prematurely because it is possible that the DOTS client does request prematurely because it is possible that the DOTS client does
not sense the DDOS attack on its resources but the DOTS server could not sense the DDoS attack on its resources but the DOTS server could
be actively mitigating the attack and the attack is not completely be actively mitigating the attack and the attack is not completely
averted. averted.
4.4.3. Efficacy Update from DOTS Clients 4.4.3. Efficacy Update from DOTS Clients
While DDoS mitigation is active, due to the likelihood of packet While DDoS mitigation is active, due to the likelihood of packet
loss, a DOTS client MAY periodically transmit DOTS mitigation loss, a DOTS client MAY periodically transmit DOTS mitigation
efficacy updates to the relevant DOTS server. A PUT request is used efficacy updates to the relevant DOTS server. A PUT request is used
to convey the mitigation efficacy update to the DOTS server. to convey the mitigation efficacy update to the DOTS server.
skipping to change at page 28, line 32 skipping to change at page 31, line 35
may send a PUT request to convey an efficacy update to the DOTS may send a PUT request to convey an efficacy update to the DOTS
server followed by a DELETE request to withdraw the mitigation server followed by a DELETE request to withdraw the mitigation
request, but the DELETE request arrives at the DOTS server before the request, but the DELETE request arrives at the DOTS server before the
PUT request. To handle out-of-order delivery of requests, if an If- PUT request. To handle out-of-order delivery of requests, if an If-
Match option is present in the PUT request and the 'mitigation-id' in Match option is present in the PUT request and the 'mitigation-id' in
the request matches a mitigation request from that DOTS client, then the request matches a mitigation request from that DOTS client, then
the request is processed. If no match is found, the PUT request is the request is processed. If no match is found, the PUT request is
silently ignored. silently ignored.
An example of an efficacy update message, which includes an If-Match An example of an efficacy update message, which includes an If-Match
option with an empty value, is depicted in Figure 13. option with an empty value, is depicted in Figure 15.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Uri-Path: "cuid=xyz"
Content-Format: "application/cbor" Content-Format: "application/cbor"
If-Match: If-Match:
{ {
"mitigation-scope": { "mitigation-scope": {
"client-identifier": [
"string"
],
"scope": [ "scope": [
{ {
"mitigation-id": integer, "mitigation-id": integer,
"target-prefix": [ "target-prefix": [
"string" "string"
], ],
"target-port-range": [ "target-port-range": [
{ {
"lower-port": integer, "lower-port": integer,
"upper-port": integer "upper-port": integer
skipping to change at page 29, line 49 skipping to change at page 32, line 47
"alias-name": [ "alias-name": [
"string" "string"
], ],
"lifetime": integer, "lifetime": integer,
"attack-status": integer "attack-status": integer
} }
] ]
} }
} }
Figure 13: Efficacy Update Figure 15: Efficacy Update
The 'attack-status' parameter is a mandatory attribute when The 'attack-status' parameter is a mandatory attribute when
performing an efficacy update. The various possible values contained performing an efficacy update. The various possible values contained
in the 'attack-status' parameter are described in Table 3. in the 'attack-status' parameter are described in Table 3.
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| Parameter | Description | | Parameter | Description |
| value | | | value | |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 1 | The DOTS client determines that it is still under | | 1 | The DOTS client determines that it is still under |
| | attack. | | | attack. |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
| 2 | The DOTS client determines that the attack is | | 2 | The DOTS client determines that the attack is |
| | successfully mitigated (e.g., attack traffic is not | | | successfully mitigated (e.g., attack traffic is not |
| | seen). | | | seen). |
+-----------+-------------------------------------------------------+ +-----------+-------------------------------------------------------+
Table 3: Values of 'attack-status' parameter Table 3: Values of 'attack-status' Parameter
The DOTS server indicates the result of processing a PUT request The DOTS server indicates the result of processing a PUT request
using CoAP response codes. The response code 2.04 (Changed) is using CoAP response codes. The response code 2.04 (Changed) is
returned if the DOTS server has accepted the mitigation efficacy returned if the DOTS server has accepted the mitigation efficacy
update. The error response code 5.03 (Service Unavailable) is update. The error response code 5.03 (Service Unavailable) is
returned if the DOTS server has erred or is incapable of performing returned if the DOTS server has erred or is incapable of performing
the mitigation. the mitigation.
4.4.4. Withdraw a Mitigation 4.4.4. Withdraw a Mitigation
A DELETE request is used to withdraw a DOTS mitigation request from a A DELETE request is used to withdraw a DOTS mitigation request from a
DOTS server (Figure 14). DOTS server (Figure 16).
The same considerations for manipulating 'client-identifier' The same considerations for manipulating 'client-domain-hash'
parameter by a DOTS gateway, as specified in Section 4.4.1, MUST be parameter by DOTS gateways, as specified in Section 4.4.1, MUST be
followed for DELETE requests. followed for DELETE requests.
Header: DELETE (Code=0.04) Header: DELETE (Code=0.04)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "mitigate" Uri-Path: "mitigate"
Content-Format: "application/cbor" Uri-Query: "cuid=xyz"
{ Uri-Query: "mitigation-id=123"
"mitigation-scope": {
"client-identifier": [
"string"
],
"scope": [
{
"mitigation-id": integer
}
]
}
}
Figure 14: Withdraw DOTS signal Figure 16: Withdraw a DOTS Mitigation
If the request does not include a 'mitigation-id' parameter, the DOTS If the request does not include a 'mitigation-id' parameter, the DOTS
server MUST reply with a 4.00 (Bad Request). server MUST reply with a 4.00 (Bad Request).
Once the request is validated, the DOTS server immediately Once the request is validated, the DOTS server immediately
acknowledges a DOTS client's request to withdraw the DOTS signal acknowledges a DOTS client's request to withdraw the DOTS signal
using 2.02 (Deleted) response code with no response payload. A 2.02 using 2.02 (Deleted) response code with no response payload. A 2.02
(Deleted) Response Code is returned even if the 'mitigation-id' (Deleted) Response Code is returned even if the 'mitigation-id'
parameter value conveyed in the DELETE request does not exist in its parameter value conveyed in the DELETE request does not exist in its
configuration data before the request. configuration data before the request.
skipping to change at page 32, line 35 skipping to change at page 35, line 5
b. Missing heartbeats allowed (missing-hb-allowed): This variable b. Missing heartbeats allowed (missing-hb-allowed): This variable
indicates the maximum number of consecutive heartbeat messages indicates the maximum number of consecutive heartbeat messages
for which a DOTS agent did not receive a response before for which a DOTS agent did not receive a response before
concluding that the session is disconnected or defunct. concluding that the session is disconnected or defunct.
c. Acceptable signal loss ratio: Maximum retransmissions, c. Acceptable signal loss ratio: Maximum retransmissions,
retransmission timeout value, and other message transmission retransmission timeout value, and other message transmission
parameters for the DOTS signal channel. parameters for the DOTS signal channel.
The same or distinct configuration sets may be used during attack The same or distinct configuration sets may be used during times when
('attack-time-config') and peace times ('peace-time-config'). This a mitigation is active ('mitigating-config') and when no mitigation
is particularly useful for DOTS servers that might want to reduce is active ('idle-config'). This is particularly useful for DOTS
heartbeat frequency or cease heartbeat exchanges when an active DOTS servers that might want to reduce heartbeat frequency or cease
client has not requested mitigation. If distinct configuration are heartbeat exchanges when an active DOTS client has not requested
used, DOTS agents MUST follow the appropriate configuration set as a mitigation. If distinct configurations are used, DOTS agents MUST
function of the mitigation activity (e.g., if no mitigation request follow the appropriate configuration set as a function of the
is active, 'peace-time-config'-related values must be followed). mitigation activity (e.g., if no mitigation request is active, 'idle-
Additionally, DOTS agents MUST automatically switch to the other config'-related values must be followed). Additionally, DOTS agents
configuration upon a change in the mitigation activity (e.g., if an MUST automatically switch to the other configuration upon a change in
attack mitigation is launched after a peacetime, the DOTS agent the mitigation activity (e.g., if an attack mitigation is launched
switches from 'peace-time-config' to 'attack-time-config'-related after a peacetime, the DOTS agent switches from 'idle-config' to
values). 'mitigating-config'-related values).
Requests and responses are deemed reliable by marking them as Requests and responses are deemed reliable by marking them as
Confirmable (CON) messages. DOTS signal channel session Confirmable (CON) messages. DOTS signal channel session
configuration requests and responses are marked as Confirmable configuration requests and responses are marked as Confirmable
messages. As explained in Section 2.1 of [RFC7252], a Confirmable messages. As explained in Section 2.1 of [RFC7252], a Confirmable
message is retransmitted using a default timeout and exponential message is retransmitted using a default timeout and exponential
back-off between retransmissions, until the DOTS server sends an back-off between retransmissions, until the DOTS server sends an
Acknowledgement message (ACK) with the same Message ID conveyed from Acknowledgement message (ACK) with the same Message ID conveyed from
the DOTS client. the DOTS client.
skipping to change at page 33, line 36 skipping to change at page 36, line 9
that would help it correlate this response, thereby unexpecting that would help it correlate this response, thereby unexpecting
the retransmission message. The DOTS client will send a Reset the retransmission message. The DOTS client will send a Reset
message so it does not receive any more retransmissions. This message so it does not receive any more retransmissions. This
behavior is normal and not an indication of an error (see behavior is normal and not an indication of an error (see
Section 5.3.2 of [RFC7252] for more details). Section 5.3.2 of [RFC7252] for more details).
4.5.1. Discover Configuration Parameters 4.5.1. Discover Configuration Parameters
A GET request is used to obtain acceptable (e.g., minimum and maximum A GET request is used to obtain acceptable (e.g., minimum and maximum
values) and current configuration parameters on the DOTS server for values) and current configuration parameters on the DOTS server for
DOTS signal channel session configuration. DOTS signal channel session configuration. This procedure occurs
between a DOTS client and its immediate peer DOTS server. As such,
this GET request MUST NOT be relayed by an on-path DOTS gateway.
Figure 15 shows how to obtain acceptable configuration parameters for Figure 17 shows how to obtain acceptable configuration parameters for
the DOTS server. the DOTS server.
Header: GET (Code=0.01) Header: GET (Code=0.01)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "config" Uri-Path: "config"
Figure 15: GET to retrieve configuration Figure 17: GET to Retrieve Configuration
The DOTS server in the 2.05 (Content) response conveys the current, The DOTS server in the 2.05 (Content) response conveys the current,
minimum, and maximum attribute values acceptable by the DOTS server minimum, and maximum attribute values acceptable by the DOTS server
(Figure 16). (Figure 18).
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"attack-time-config": { "signal-config": {
"mitigating-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
skipping to change at page 34, line 33 skipping to change at page 37, line 5
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"ack-timeout": { "ack-timeout": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": number, "current-value-decimal": number,
"min-value": number, "min-value-decimal": number,
"max-value": number "max-value-decimal": number
} }
}, },
"peace-time-config": { "idle-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
skipping to change at page 35, line 4 skipping to change at page 37, line 25
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"max-retransmit": { "max-retransmit": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"ack-timeout": { "ack-timeout": {
"current-value": integer, "current-value": integer,
"min-value": integer, "min-value": integer,
"max-value": integer "max-value": integer
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": number, "current-value-decimal": number,
"min-value": number, "min-value-decimal": number,
"max-value": number "max-value-decimal": number
} }
}, },
"trigger-mitigation": { "trigger-mitigation": {
"current-value": boolean "current-value": boolean
}, }
"config-interval": {
"current-value": integer,
"min-value": integer,
"max-value": integer
}
} }
}
Figure 16: GET response body Figure 18: GET Configuration Response Body
Figure 17 shows an example of acceptable and current configuration Figure 19 shows an example of acceptable and current configuration
parameters on a DOTS server for DOTS signal channel session parameters on a DOTS server for DOTS signal channel session
configuration. The same acceptable configuration is used during configuration. The same acceptable configuration is used during
attack and peace times. attack and peace times.
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"attack-time-config": { "signal-config": {
"mitigating-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": 30, "current-value": 30,
"min-value": 15, "min-value": 15,
"max-value": 240 "max-value": 240
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": 5, "current-value": 5,
"min-value": 3, "min-value": 3,
"max-value": 9 "max-value": 9
}, },
skipping to change at page 36, line 9 skipping to change at page 38, line 27
"current-value": 3, "current-value": 3,
"min-value": 2, "min-value": 2,
"max-value": 15 "max-value": 15
}, },
"ack-timeout": { "ack-timeout": {
"current-value": 2, "current-value": 2,
"min-value": 1, "min-value": 1,
"max-value": 30 "max-value": 30
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": 1.5, "current-value-decimal": 1.5,
"min-value": 1.1, "min-value-decimal": 1.1,
"max-value": 4.0 "max-value-decimal": 4.0
} }
}, },
"peace-time-config": { "idle-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": 30, "current-value": 30,
"min-value": 15, "min-value": 15,
"max-value": 240 "max-value": 240
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": 5, "current-value": 5,
"min-value": 3, "min-value": 3,
"max-value": 9 "max-value": 9
}, },
skipping to change at page 36, line 34 skipping to change at page 39, line 4
}, },
"max-retransmit": { "max-retransmit": {
"current-value": 3, "current-value": 3,
"min-value": 2, "min-value": 2,
"max-value": 15 "max-value": 15
}, },
"ack-timeout": { "ack-timeout": {
"current-value": 2, "current-value": 2,
"min-value": 1, "min-value": 1,
"max-value": 30 "max-value": 30
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": 1.5, "current-value-decimal": 1.5,
"min-value": 1.1, "min-value-decimal": 1.1,
"max-value": 4.0 "max-value-decimal": 4.0
} }
}, },
"trigger-mitigation": { "trigger-mitigation": {
"current-value": true "current-value": true
}, }
"config-interval": {
"current-value": 1439,
"min-value": 0,
"max-value": 65535
}
} }
}
Figure 17: Configuration response body Figure 19: Example of a Configuration Response Body
4.5.2. Convey DOTS Signal Channel Session Configuration 4.5.2. Convey DOTS Signal Channel Session Configuration
A PUT request is used to convey the configuration parameters for the A PUT request is used to convey the configuration parameters for the
signal channel (e.g., heartbeat interval, maximum retransmissions). signal channel (e.g., heartbeat interval, maximum retransmissions).
Message transmission parameters for CoAP are defined in Section 4.8 Message transmission parameters for CoAP are defined in Section 4.8
of [RFC7252]. The RECOMMENDED values of transmission parameter of [RFC7252]. The RECOMMENDED values of transmission parameter
values are ack-timeout (2 seconds), max-retransmit (3), ack-random- values are ack-timeout (2 seconds), max-retransmit (3), ack-random-
factor (1.5). In addition to those parameters, the RECOMMENDED factor (1.5). In addition to those parameters, the RECOMMENDED
specific DOTS transmission parameter values are 'heartbeat-interval' specific DOTS transmission parameter values are 'heartbeat-interval'
skipping to change at page 37, line 35 skipping to change at page 39, line 50
standpoint, this specification recommends a minimum heartbeat- standpoint, this specification recommends a minimum heartbeat-
interval of 15 seconds and a maximum heartbeat-interval of 240 interval of 15 seconds and a maximum heartbeat-interval of 240
seconds. The recommended value of 30 seconds is selected to seconds. The recommended value of 30 seconds is selected to
anticipate the expiry of NAT state. anticipate the expiry of NAT state.
A heartbeat-interval of 30 seconds may be seen as too chatty in A heartbeat-interval of 30 seconds may be seen as too chatty in
some deployments. For such deployments, DOTS agents may negotiate some deployments. For such deployments, DOTS agents may negotiate
longer heartbeat-interval values to prevent any network overload longer heartbeat-interval values to prevent any network overload
with too frequent keepalives. with too frequent keepalives.
Different heartbeat intervals can be defined for 'mitigation-
config' and 'idle-config' to reduce being too chatty during idle
times. If there is an on-path translator between the DOTS client
(standalone or part of a DOTS gateway) and the DOTS server, the
'mitigation-config' heartbeat-interval has to be smaller than the
translator session timeout. It is recommended that the 'idle-
config' heartbeat-interval is also smaller than the translator
session timeout to prevent translator transversal issues, or set
to '0'. Means to discover the lifetime assigned by a translator
are out of scope.
When a confirmable "CoAP Ping" is sent, and if there is no response, When a confirmable "CoAP Ping" is sent, and if there is no response,
the "CoAP Ping" is retransmitted max-retransmit number of times by the "CoAP Ping" is retransmitted max-retransmit number of times by
the CoAP layer using an initial timeout set to a random duration the CoAP layer using an initial timeout set to a random duration
between ack-timeout and (ack-timeout*ack-random-factor) and between ack-timeout and (ack-timeout*ack-random-factor) and
exponential back-off between retransmissions. By choosing the exponential back-off between retransmissions. By choosing the
recommended transmission parameters, the "CoAP Ping" will timeout recommended transmission parameters, the "CoAP Ping" will timeout
after 45 seconds. If the DOTS agent does not receive any response after 45 seconds. If the DOTS agent does not receive any response
from the peer DOTS agent for 'missing-hb-allowed' number of from the peer DOTS agent for 'missing-hb-allowed' number of
consecutive "CoAP Ping" confirmable messages, it concludes that the consecutive "CoAP Ping" confirmable messages, it concludes that the
DOTS signal channel session is disconnected. A DOTS client MUST NOT DOTS signal channel session is disconnected. A DOTS client MUST NOT
skipping to change at page 38, line 14 skipping to change at page 40, line 40
The signal channel session configuration is applicable to a single The signal channel session configuration is applicable to a single
DOTS signal channel session between the DOTS agents. DOTS signal channel session between the DOTS agents.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "config" Uri-Path: "config"
Uri-Path: "session-id=123"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": integer, "mitigating-config": {
"attack-time-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": integer "current-value": integer
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": integer "current-value": integer
}, },
"max-retransmit": { "max-retransmit": {
"current-value": integer "current-value": integer
}, },
"ack-timeout": { "ack-timeout": {
"current-value": integer "current-value": integer
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": number "current-value-decimal": number
} }
}, },
"peace-time-config": { "idle-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": integer "current-value": integer
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": integer "current-value": integer
}, },
"max-retransmit": { "max-retransmit": {
"current-value": integer "current-value": integer
}, },
"ack-timeout": { "ack-timeout": {
"current-value": integer "current-value": integer
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": number "current-value-decimal": number
} }
}, },
"trigger-mitigation": boolean, "trigger-mitigation": boolean,
"config-interval": integer "config-interval": integer
} }
} }
Figure 18: PUT to convey the DOTS signal channel session Figure 20: PUT to Convey the DOTS Signal Channel Session
configuration data. Configuration Data
The parameters in Figure 18 are described below: The parameters in Figure 20 are described below:
session-id: Identifier for the DOTS signal channel session session-id: Identifier for the DOTS signal channel session
configuration data represented as an integer. This identifier configuration data represented as an integer. This identifier
MUST be generated by the DOTS client. This document does not make MUST be generated by the DOTS client. This document does not make
any assumption about how this identifier is generated. any assumption about how this identifier is generated.
This is a mandatory attribute. This is a mandatory attribute.
attack-time-config: Set of configuration parameters to use when an mitigation-config: Set of configuration parameters to use when a
attack is active. The following parameters may be included: mitigation is active. The following parameters may be included:
heartbeat-interval: Time interval in seconds between two heartbeat-interval: Time interval in seconds between two
consecutive heartbeat messages. consecutive heartbeat messages.
'0' is used to disable the heartbeat mechanism. '0' is used to disable the heartbeat mechanism.
This is an optional attribute. This is an optional attribute.
missing-hb-allowed: Maximum number of consecutive heartbeat missing-hb-allowed: Maximum number of consecutive heartbeat
messages for which the DOTS agent did not receive a response messages for which the DOTS agent did not receive a response
skipping to change at page 40, line 5 skipping to change at page 42, line 32
ACK_TIMEOUT parameter in CoAP). ACK_TIMEOUT parameter in CoAP).
This is an optional attribute. This is an optional attribute.
ack-random-factor: Random factor used to influence the timing of ack-random-factor: Random factor used to influence the timing of
retransmissions (referred to as ACK_RANDOM_FACTOR parameter in retransmissions (referred to as ACK_RANDOM_FACTOR parameter in
CoAP). CoAP).
This is an optional attribute. This is an optional attribute.
peace-time-config: Set of configuration parameters to use during idle-config: Set of configuration parameters to use when no
peacetime. This attribute has the same structure as 'attack-time- mitigation is active. This attribute has the same structure as
config'. 'mitigating-config'.
trigger-mitigation: If the parameter value is set to 'false', then trigger-mitigation: If the parameter value is set to 'false', then
DDoS mitigation is triggered only when the DOTS signal channel DDoS mitigation is triggered only when the DOTS signal channel
session is lost. Automated mitigation on loss of signal is session is lost. Automated mitigation on loss of signal is
discussed in Section 3.3.3 of [I-D.ietf-dots-architecture]. discussed in Section 3.3.3 of [I-D.ietf-dots-architecture].
If the DOTS client ceases to respond to heartbeat messages, the If the DOTS client ceases to respond to heartbeat messages, the
DOTS server can detect that the DOTS session is lost. DOTS server can detect that the DOTS session is lost.
The default value of the parameter is 'true'. The default value of the parameter is 'true'.
This is an optional attribute. This is an optional attribute.
config-interval: This parameter is returned to indicate the time config-interval: This parameter is returned to indicate the time
interval expressed in minutes, which a DOTS agent must wait for interval expressed in seconds, which a DOTS agent must wait for
before re-contacting its peer in order to retrieve the signal before re-contacting its peer in order to retrieve the signal
channel configuration data. channel configuration data.
'0' is used to disable this refresh mechanism. '0' is used to disable this refresh mechanism.
If a non-null value of 'config-interval' is received by a DOTS If a non-zero value of 'config-interval' is received by a DOTS
agent, it has to issue a PUT request to refresh the configuration client, it has to issue a PUT request to refresh the configuration
parameters for the signal channel before the expiry of 'config- parameters for the signal channel before the expiry of 'config-
interval'. When a DDoS attack is active, refresh requests MUST interval'. When a DDoS attack is active, refresh requests MUST
NOT be sent by DOTS clients and the DOTS server MUST NOT terminate NOT be sent by DOTS clients and the DOTS server MUST NOT terminate
the (D)TLS session after the expiry of 'config-interval'. the (D)TLS session after the expiry of 'config-interval'.
This mechanism allows to update the configuration data if a change This mechanism allows to update the configuration data if a change
occurs at the DOTS server side. For example, the new occurs at the DOTS server side. For example, the new
configuration may instruct a DOTS client to cease heartbeats or configuration may instruct a DOTS client to cease heartbeats or
reduce heartbeat frequency. reduce heartbeat frequency.
skipping to change at page 41, line 12 skipping to change at page 43, line 38
This is an optional attribute. This is an optional attribute.
At least one of the attributes 'heartbeat-interval', 'missing-hb- At least one of the attributes 'heartbeat-interval', 'missing-hb-
allowed', 'max-retransmit', 'ack-timeout', 'ack-random-factor', and allowed', 'max-retransmit', 'ack-timeout', 'ack-random-factor', and
'trigger-mitigation' MUST be present in the PUT request. The PUT 'trigger-mitigation' MUST be present in the PUT request. The PUT
request with a higher numeric 'session-id' value overrides the DOTS request with a higher numeric 'session-id' value overrides the DOTS
signal channel session configuration data installed by a PUT request signal channel session configuration data installed by a PUT request
with a lower numeric 'session-id' value. with a lower numeric 'session-id' value.
Figure 19 shows a PUT request example to convey the configuration Figure 21 shows a PUT request example to convey the configuration
parameters for the DOTS signal channel. In this example, heartbeat parameters for the DOTS signal channel. In this example, heartbeat
mechanism is disabled during peacetime, while the heartbeat interval mechanism is disabled when no mitigation is active, while the
is set to '91' when an attack is active. heartbeat interval is set to '91' when a mitigation is active.
Header: PUT (Code=0.03) Header: PUT (Code=0.03)
Uri-Host: "www.example.com" Uri-Host: "www.example.com"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "v1" Uri-Path: "v1"
Uri-Path: "config" Uri-Path: "config"
Uri-Path: "session-id=123"
Content-Format: "application/cbor" Content-Format: "application/cbor"
{ {
"signal-config": { "signal-config": {
"session-id": 1234534333242, "mitigating-config": {
"attack-time-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": 91 "current-value": 91
}, },
"missing-hb-allowed": { "missing-hb-allowed": {
"current-value": 3 "current-value": 3
}, },
"max-retransmit": { "max-retransmit": {
"current-value": 7 "current-value": 7
}, },
"ack-timeout": { "ack-timeout": {
"current-value": 5 "current-value": 5
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": 1.5 "current-value-decimal": 1.5
} }
}, },
"peace-time-config": { "idle-config": {
"heartbeat-interval": { "heartbeat-interval": {
"current-value": 0 "current-value": 0
}, },
"max-retransmit": { "max-retransmit": {
"current-value": 7 "current-value": 7
}, },
"ack-timeout": { "ack-timeout": {
"current-value": 5 "current-value": 5
}, },
"ack-random-factor": { "ack-random-factor": {
"current-value": 1.5 "current-value-decimal": 1.5
} }
}, },
"trigger-mitigation": false "trigger-mitigation": false
} }
} }
Figure 19: PUT to convey the configuration parameters Figure 21: PUT to Convey the Configuration Parameters
The DOTS server indicates the result of processing the PUT request The DOTS server indicates the result of processing the PUT request
using CoAP response codes: using CoAP response codes:
o If the DOTS server finds the 'session-id' parameter value conveyed o If the DOTS server finds the 'session-id' parameter value conveyed
in the PUT request in its configuration data and if the DOTS in the PUT request in its configuration data and if the DOTS
server has accepted the updated configuration parameters, then server has accepted the updated configuration parameters, then
2.04 (Changed) code is returned in the response. 2.04 (Changed) code is returned in the response.
o If the DOTS server does not find the 'session-id' parameter value o If the DOTS server does not find the 'session-id' parameter value
skipping to change at page 43, line 36 skipping to change at page 45, line 36
DOTS server. Upon receipt of the 4.22 error response code, the DOTS server. Upon receipt of the 4.22 error response code, the
DOTS client should request the maximum and minimum attribute DOTS client should request the maximum and minimum attribute
values acceptable to the DOTS server (Section 4.5.1). values acceptable to the DOTS server (Section 4.5.1).
The DOTS client may re-try and send the PUT request with updated The DOTS client may re-try and send the PUT request with updated
attribute values acceptable to the DOTS server. attribute values acceptable to the DOTS server.
4.5.3. Delete DOTS Signal Channel Session Configuration 4.5.3. Delete DOTS Signal Channel Session Configuration
A DELETE request is used to delete the installed DOTS signal channel A DELETE request is used to delete the installed DOTS signal channel
session configuration data (Figure 20). session configuration data (Figure 22).
Header: DELETE (Code=0.04) Header: DELETE (Code=0.04)
Uri-Host: "host" Uri-Host: "host"
Uri-Path: ".well-known" Uri-Path: ".well-known"
Uri-Path: "dots" Uri-Path: "dots"
Uri-Path: "version" Uri-Path: "version"
Uri-Path: "config" Uri-Path: "config"
Content-Format: "application/cbor" Uri-Query: "session-id=123"
Figure 20: DELETE configuration Figure 22: DELETE Configuration
The DOTS server resets the DOTS signal channel session configuration The DOTS server resets the DOTS signal channel session configuration
back to the default values and acknowledges a DOTS client's request back to the default values and acknowledges a DOTS client's request
to remove the DOTS signal channel session configuration using 2.02 to remove the DOTS signal channel session configuration using 2.02
(Deleted) response code. (Deleted) response code.
4.6. Redirected Signaling 4.6. Redirected Signaling
Redirected DOTS signaling is discussed in detail in Section 3.2.2 of Redirected DOTS signaling is discussed in detail in Section 3.2.2 of
[I-D.ietf-dots-architecture]. [I-D.ietf-dots-architecture].
If a DOTS server wants to redirect a DOTS client to an alternative If a DOTS server wants to redirect a DOTS client to an alternative
DOTS server for a signal session, then the response code 3.00 DOTS server for a signal session, then the response code 3.00
(alternate server) will be returned in the response to the client. (alternate server) will be returned in the response to the DOTS
client.
The DOTS server can return the error response code 3.00 in response The DOTS server can return the error response code 3.00 in response
to a PUT request from the DOTS client or convey the error response to a PUT request from the DOTS client or convey the error response
code 3.00 in a unidirectional notification response from the DOTS code 3.00 in a unidirectional notification response from the DOTS
server. server.
The DOTS server in the error response conveys the alternate DOTS The DOTS server in the error response conveys the alternate DOTS
server's FQDN, and the alternate DOTS server's IP address(es) and server's FQDN, and the alternate DOTS server's IP address(es) and
time to live values in the CBOR body (Figure 21). time to live values in the CBOR body (Figure 23).
{ {
"alt-server": "string", "alt-server": "string",
"alt-server-record": [ "alt-server-record": [
{ {
"addr": "string", "addr": "string",
"ttl" : integer "ttl" : integer
} }
] ]
} }
Figure 21: Error response body Figure 23: Redirected Server Error Response Body
The parameters are described below: The parameters are described below:
alt-server: FQDN of an alternate DOTS server. alt-server: FQDN of an alternate DOTS server.
addr: IP address of an alternate DOTS server. addr: IP address of an alternate DOTS server.
ttl: Time to live (TTL) represented as an integer number of seconds. ttl: Time to live (TTL) represented as an integer number of seconds.
Figure 22 shows a 3.00 response example to convey the DOTS alternate Figure 24 shows a 3.00 response example to convey the DOTS alternate
server 'alt-server.example', its IP addresses 2001:db8:6401::1 and server 'alt-server.example', its IP addresses 2001:db8:6401::1 and
2001:db8:6401::2, and TTL values 3600 and 1800. 2001:db8:6401::2, and TTL values 3600 and 1800.
{ {
"alt-server": "alt-server.example", "alt-server": "alt-server.example",
"alt-server-record": [ "alt-server-record": [
{ {
"ttl" : 3600, "ttl" : 3600,
"addr": "2001:db8:6401::1" "addr": "2001:db8:6401::1"
}, },
{ {
"ttl" : 1800, "ttl" : 1800,
"addr": "2001:db8:6401::2" "addr": "2001:db8:6401::2"
} }
] ]
} }
Figure 22: Example of error response body Figure 24: Example of Redirected Server Error Response Body
When the DOTS client receives 3.00 response, it considers the current When the DOTS client receives 3.00 response, it considers the current
request as failed, but SHOULD try re-sending the request to the request as failed, but SHOULD try re-sending the request to the
alternate DOTS server. During a DDOS attack, the DNS server may be alternate DOTS server. During a DDoS attack, the DNS server may be
the target of another DDoS attack, alternate DOTS server's IP the target of another DDoS attack, alternate DOTS server's IP
addresses conveyed in the 3.00 response help the DOTS client skip DNS addresses conveyed in the 3.00 response help the DOTS client skip DNS
lookup of the alternate DOTS server. The DOTS client can then try to lookup of the alternate DOTS server. The DOTS client can then try to
establish a UDP or a TCP session with the alternate DOTS server. The establish a UDP or a TCP session with the alternate DOTS server. The
DOTS client SHOULD implement a DNS64 function to handle the scenario DOTS client SHOULD implement a DNS64 function to handle the scenario
where an IPv6-only DOTS client communicates with an IPv4-only where an IPv6-only DOTS client communicates with an IPv4-only
alternate DOTS server. alternate DOTS server.
4.7. Heartbeat Mechanism 4.7. Heartbeat Mechanism
skipping to change at page 45, line 48 skipping to change at page 47, line 48
its peer DOTS agent, and may consider a session terminated in the its peer DOTS agent, and may consider a session terminated in the
prolonged absence of a peer agent heartbeat. prolonged absence of a peer agent heartbeat.
While the communication between the DOTS agents is quiescent, the While the communication between the DOTS agents is quiescent, the
DOTS client will probe the DOTS server to ensure it has maintained DOTS client will probe the DOTS server to ensure it has maintained
cryptographic state and vice versa. Such probes can also keep cryptographic state and vice versa. Such probes can also keep
firewalls and/or stateful translators bindings alive. This probing firewalls and/or stateful translators bindings alive. This probing
reduces the frequency of establishing a new handshake when a DOTS reduces the frequency of establishing a new handshake when a DOTS
signal needs to be conveyed to the DOTS server. signal needs to be conveyed to the DOTS server.
In order to avoid complications due to the presence of some stateful DOTS servers MAY trigger their heartbeat requests immediately after
translators and firewalls (e.g., discard an incoming packet because receiving heartbeat probes from peer DOTS clients. As a reminder, it
no matching state is found), DOTS servers MAY trigger their heartbeat is the responsibility of DOTS clients to ensure that on-path
requests immediately after receiving heartbeat probes from peer DOTS translators/firewalls are maintaining a binding so that the same
clients. external IP address and/or port number is retained for the DOTS
session.
In case of a massive DDoS attack that saturates the incoming link(s) In case of a massive DDoS attack that saturates the incoming link(s)
to the DOTS client, all traffic from the DOTS server to the DOTS to the DOTS client, all traffic from the DOTS server to the DOTS
client will likely be dropped, although the DOTS server receives client will likely be dropped, although the DOTS server receives
heartbeat requests in addition to DOTS messages sent by the DOTS heartbeat requests in addition to DOTS messages sent by the DOTS
client. In this scenario, the DOTS agents MUST behave differently to client. In this scenario, the DOTS agents MUST behave differently to
handle message transmission and DOTS session liveliness during link handle message transmission and DOTS session liveliness during link
saturation: saturation:
o The DOTS client MUST NOT consider the DOTS session terminated even o The DOTS client MUST NOT consider the DOTS session terminated even
skipping to change at page 47, line 20 skipping to change at page 49, line 20
5.1. Tree Structure 5.1. Tree Structure
This document defines the YANG module "ietf-dots-signal" This document defines the YANG module "ietf-dots-signal"
(Section 5.2), which has the following tree structure. A DOTS signal (Section 5.2), which has the following tree structure. A DOTS signal
message can either be a mitigation or a configuration message. message can either be a mitigation or a configuration message.
module: ietf-dots-signal module: ietf-dots-signal
+--rw dots-signal +--rw dots-signal
+--rw (message-type)? +--rw (message-type)?
+--:(mitigation-scope) +--:(mitigation-scope)
| +--rw client-identifier* binary | +--rw client-domain-hash? string
| +--rw scope* [mitigation-id] | +--rw scope* [cuid mitigation-id]
| +--rw cuid string
| +--rw mitigation-id int32 | +--rw mitigation-id int32
| +--rw target-prefix* inet:ip-prefix | +--rw target-prefix* inet:ip-prefix
| +--rw target-port-range* [lower-port upper-port] | +--rw target-port-range* [lower-port upper-port]
| | +--rw lower-port inet:port-number | | +--rw lower-port inet:port-number
| | +--rw upper-port inet:port-number | | +--rw upper-port inet:port-number
| +--rw target-protocol* uint8 | +--rw target-protocol* uint8
| +--rw target-fqdn* inet:domain-name | +--rw target-fqdn* inet:domain-name
| +--rw target-uri* inet:uri | +--rw target-uri* inet:uri
| +--rw alias-name* string | +--rw alias-name* string
| +--rw lifetime? int32 | +--rw lifetime? int32
skipping to change at page 48, line 5 skipping to change at page 50, line 6
| | +--ro target-fqdn* inet:domain-name | | +--ro target-fqdn* inet:domain-name
| | +--ro target-uri* inet:uri | | +--ro target-uri* inet:uri
| | +--ro alias-name* string | | +--ro alias-name* string
| | +--ro acl-list* [acl-name acl-type] | | +--ro acl-list* [acl-name acl-type]
| | +--ro acl-name -> /ietf-acl:access-lists/acl/acl-name | | +--ro acl-name -> /ietf-acl:access-lists/acl/acl-name
| | +--ro acl-type -> /ietf-acl:access-lists/acl/acl-type | | +--ro acl-type -> /ietf-acl:access-lists/acl/acl-type
| +--ro pkts-dropped? yang:zero-based-counter64 | +--ro pkts-dropped? yang:zero-based-counter64
| +--ro bps-dropped? yang:zero-based-counter64 | +--ro bps-dropped? yang:zero-based-counter64
| +--ro bytes-dropped? yang:zero-based-counter64 | +--ro bytes-dropped? yang:zero-based-counter64
| +--ro pps-dropped? yang:zero-based-counter64 | +--ro pps-dropped? yang:zero-based-counter64
+--:(configuration) | +--rw attack-status? enumeration
+--rw session-id int32 +--:(signal-config)
+--rw attack-time-config | +--rw session-id int32
| +--rw heartbeat-interval | +--rw mitigating-config
| | +--rw max-value? int16 | | +--rw heartbeat-interval
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw missing-hb-allowed | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw missing-hb-allowed
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw max-retransmit | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw max-retransmit
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw ack-timeout | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw ack-timeout
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw ack-random-factor | | | +--rw current-value? int16
| +--rw max-value? decimal64 | | +--rw ack-random-factor
| +--rw min-value? decimal64 | | +--rw max-value-decimal? decimal64
| +--rw current-value? decimal64 | | +--rw min-value-decimal? decimal64
+--rw peace-time-config | | +--rw current-value-decimal? decimal64
| +--rw heartbeat-interval | +--rw idle-config
| | +--rw max-value? int16 | | +--rw heartbeat-interval
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw missing-hb-allowed | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw missing-hb-allowed
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw max-retransmit | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw max-retransmit
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw ack-timeout | | | +--rw current-value? int16
| | +--rw max-value? int16 | | +--rw ack-timeout
| | +--rw min-value? int16 | | | +--rw max-value? int16
| | +--rw current-value? int16 | | | +--rw min-value? int16
| +--rw ack-random-factor | | | +--rw current-value? int16
| +--rw max-value? decimal64 | | +--rw ack-random-factor
| +--rw min-value? decimal64 | | +--rw max-value-decimal? decimal64
| +--rw current-value? decimal64 | | +--rw min-value-decimal? decimal64
+--rw trigger-mitigation? boolean | | +--rw current-value-decimal? decimal64
+--rw config-interval? int32 | +--rw trigger-mitigation? boolean
| +--rw config-interval? int32
+--:(redirected-signal)
+--rw alt-server string
+--rw alt-server-record* [addr]
+--rw addr inet:ip-address
+--rw ttl? int32
5.2. YANG Module 5.2. YANG Module
<CODE BEGINS> file "ietf-dots-signal@2017-12-19.yang" <CODE BEGINS> file "ietf-dots-signal@2018-01-09.yang"
module ietf-dots-signal { module ietf-dots-signal {
yang-version 1.1; yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal"; namespace "urn:ietf:params:xml:ns:yang:ietf-dots-signal";
prefix "signal"; prefix "signal";
import ietf-inet-types {prefix "inet";} import ietf-inet-types {prefix "inet";}
import ietf-yang-types {prefix yang;} import ietf-yang-types {prefix yang;}
import ietf-access-control-list {prefix "ietf-acl";} import ietf-access-control-list {prefix "ietf-acl";}
organization "IETF DDoS Open Threat Signaling (DOTS) Working Group"; organization "IETF DDoS Open Threat Signaling (DOTS) Working Group";
contact contact
"Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com> "WG Web: <https://datatracker.ietf.org/wg/dots/>
Mohamed Boucadair <mohamed.boucadair@orange.com> WG List: <mailto:dots@ietf.org>
Prashanth Patil <praspati@cisco.com>
Andrew Mortensen <amortensen@arbor.net>
Nik Teague <nteague@verisign.com>";
description Editor: Konda, Tirumaleswar Reddy
"This module contains YANG definition for the signaling <mailto:TirumaleswarReddy_Konda@McAfee.com>
messages exchanged between a DOTS client and a DOTS server.
Copyright (c) 2017 IETF Trust and the persons identified as Editor: Mohamed Boucadair
authors of the code. All rights reserved. <mailto:mohamed.boucadair@orange.com>
Redistribution and use in source and binary forms, with or Author: Prashanth Patil
without modification, is permitted pursuant to, and subject <mailto:praspati@cisco.com>
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see Author: Andrew Mortensen
the RFC itself for full legal notices."; <mailto:amortensen@arbor.net>
revision 2017-12-19 { Author: Nik Teague
description <mailto:nteague@verisign.com>";
"Initial revision.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
grouping target { description
description "This module contains YANG definition for the signaling
"Specifies the scope of the mitigation request."; messages exchanged between a DOTS client and a DOTS server.
leaf-list target-prefix { Copyright (c) 2017 IETF Trust and the persons identified as
type inet:ip-prefix; authors of the code. All rights reserved.
description
"IPv4 or IPv6 prefix identifying the target.";
}
list target-port-range { Redistribution and use in source and binary forms, with or
key "lower-port upper-port"; without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
description This version of this YANG module is part of RFC XXXX; see
"Port range. When only lower-port is the RFC itself for full legal notices.";
present, it represents a single port.";
leaf lower-port { revision 2018-01-09 {
type inet:port-number; description
mandatory true; "Initial revision.";
description "Lower port number."; reference
} "RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf upper-port { grouping target {
type inet:port-number; description
must ". >= ../lower-port" { "Specifies the targets of the mitigation request.";
error-message
"The upper port number must be greater than
or equal to lower port number.";
}
description "Upper port number.";
}
}
leaf-list target-protocol { leaf-list target-prefix {
type uint8; type inet:ip-prefix;
description description
"Identifies the target protocol number. "IPv4 or IPv6 prefix identifying the target.";
}
The value '0' means 'all protocols'. list target-port-range {
key "lower-port upper-port";
Values are taken from the IANA protocol registry: description
https://www.iana.org/assignments/protocol-numbers/ "Port range. When only lower-port is
protocol-numbers.xhtml present, it represents a single port.";
For example, 6 for TCP or 17 for UDP."; leaf lower-port {
} type inet:port-number;
mandatory true;
description "Lower port number.";
}
leaf-list target-fqdn { leaf upper-port {
type inet:domain-name; type inet:port-number;
description "FQDN identifying the target."; must ". >= ../lower-port" {
} error-message
"The upper port number must be greater than
or equal to lower port number.";
}
description "Upper port number.";
}
}
leaf-list target-uri { leaf-list target-protocol {
type inet:uri; type uint8;
description "URI identifying the target."; description
} "Identifies the target protocol number.
leaf-list alias-name { The value '0' means 'all protocols'.
type string;
description "alias name";
}
}
grouping mitigation-scope { Values are taken from the IANA protocol registry:
description https://www.iana.org/assignments/protocol-numbers/
"Specifies the scope of the mitigation request."; protocol-numbers.xhtml
leaf-list client-identifier { For example, 6 for TCP or 17 for UDP.";
type binary; }
description
"The client identifier may be conveyed by
the DOTS gateway to propagate the DOTS client
identification information from the gateway's
client-side to the gateway's server-side,
and from the gateway's server-side to the DOTS
server.
It may be used by the final DOTS server leaf-list target-fqdn {
for policy enforcement purposes."; type inet:domain-name;
} description "FQDN identifying the target.";
}
list scope { leaf-list target-uri {
key mitigation-id; type inet:uri;
description description "URI identifying the target.";
"The scope of the request."; }
leaf mitigation-id { leaf-list alias-name {
type int32; type string;
description description "alias name";
"Mitigation request identifier. }
}
This identifier must be unique for each mitigation grouping mitigation-scope {
request bound to the DOTS client."; description
} "Specifies the scope of the mitigation request.";
uses target; leaf client-domain-hash {
leaf lifetime { type string;
type int32; description
units "seconds"; "The client domain hash may be conveyed by
default 3600; the server-domain DOTS gateway to propagate the
description client domain identification information from the
"Indicates the lifetime of the mitigation request."; gateway's client-side to the gateway's server-side,
reference and from the gateway's server-side to the DOTS
"RFC XXXX: Distributed Denial-of-Service Open Threat server.
Signaling (DOTS) Signal Channel";
}
leaf mitigation-start { It may be used by the final DOTS server
type int64; for policy enforcement purposes.";
units "seconds"; }
description
"Mitigation start time is represented in seconds
relative to 1970-01-01T00:00Z in UTC time.";
}
leaf status { list scope {
type enumeration { key "cuid mitigation-id";
enum "attack-mitigation-in-progress" { description
value 1; "The scope of the request.";
description
"Attack mitigation is in progress (e.g., changing
the network path to re-route the inbound traffic
to DOTS mitigator).";
}
enum "attack-successfully-mitigated" { leaf cuid {
value 2; type string;
description description
"Attack is successfully mitigated (e.g., traffic "A unique identifier that is randomly
is redirected to a DDOS mitigator and attack generated by a DOTS client to prevent
traffic is dropped or blackholed)."; request collisions.";
} }
enum "attack-stopped" { leaf mitigation-id {
value 3; type int32;
description description
"Attack has stopped and the DOTS client can "Mitigation request identifier.
withdraw the mitigation request.";
}
enum "attack-exceeded-capability" { This identifier must be unique for each mitigation
value 4; request bound to the DOTS client.";
description }
"Attack has exceeded the mitigation provider
capability.";
}
enum "dots-client-withdrawn-mitigation" { uses target;
value 5;
description
"DOTS client has withdrawn the mitigation
request and the mitigation is active but
terminating.";
}
enum "attack-mitigation-terminated" { leaf lifetime {
value 6; type int32;
description units "seconds";
"Attack mitigation is now terminated."; default 3600;
} description
"Indicates the lifetime of the mitigation request.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
enum "attack-mitigation-withdrawn" { leaf mitigation-start {
value 7; type int64;
description units "seconds";
"Attack mitigation is withdrawn."; description
} "Mitigation start time is represented in seconds
relative to 1970-01-01T00:00Z in UTC time.";
}
enum "attack-mitigation-rejected" { leaf status {
value 8; type enumeration {
description enum "attack-mitigation-in-progress" {
"Attack mitigation is rejected."; value 1;
} description
} "Attack mitigation is in progress (e.g., changing
config false; the network path to re-route the inbound traffic
description to DOTS mitigator).";
"Indicates the status of a mitigation request. }
It must be included in responses only.";
}
container conflict-information { enum "attack-successfully-mitigated" {
config false; value 2;
description description
"Indicates that a conflict is detected. "Attack is successfully mitigated (e.g., traffic
Must only be used for responses."; is redirected to a DDoS mitigator and attack
traffic is dropped or blackholed).";
}
leaf conflict-status { enum "attack-stopped" {
value 3;
description
"Attack has stopped and the DOTS client can
withdraw the mitigation request.";
}
enum "attack-exceeded-capability" {
value 4;
description
"Attack has exceeded the mitigation provider
capability.";
}
enum "dots-client-withdrawn-mitigation" {
value 5;
description
"DOTS client has withdrawn the mitigation
request and the mitigation is active but
terminating.";
}
enum "attack-mitigation-terminated" {
value 6;
description
"Attack mitigation is now terminated.";
}
enum "attack-mitigation-withdrawn" {
value 7;
description
"Attack mitigation is withdrawn.";
}
enum "attack-mitigation-rejected" {
value 8;
description
"Attack mitigation is rejected.";
}
}
config false;
description
"Indicates the status of a mitigation request.
It must be included in responses only.";
}
container conflict-information {
config false;
description
"Indicates that a conflict is detected.
Must only be used for responses.";
leaf conflict-status {
type enumeration {
enum "request-inactive-other-active" {
value 1;
description
"DOTS Server has detected conflicting mitigation
requests from different DOTS clients.
This mitigation request is currently inactive
until the conflicts are resolved. Another
mitigation request is active.";
}
enum "request-active" {
value 2;
description
"DOTS Server has detected conflicting mitigation
requests from different DOTS clients.
This mitigation request is currently active.";
}
enum "all-requests-inactive" {
value 3;
description
"DOTS Server has detected conflicting mitigation
requests from different DOTS clients. All
conflicting mitigation requests are inactive.";
}
}
description
"Indicates the conflict status.
It must be included in responses only.";
}
leaf conflict-cause {
type enumeration { type enumeration {
enum "request-inactive-other-active" { enum "overlapping-targets" {
value 1; value 1;
description description
"DOTS Server has detected conflicting mitigation "Overlapping targets. conflict-scope provides
requests from different DOTS clients. more details about the exact conflict.";
This mitigation request is currently inactive
until the conflicts are resolved. Another
mitigation request is active.";
} }
enum "request-active" { enum "conflict-with-whitelist" {
value 2; value 2;
description description
"DOTS Server has detected conflicting mitigation "Conflicts with an existing white list.
requests from different DOTS clients.
This mitigation request is currently active.";
}
enum "all-requests-inactive" { This code is returned when the DDoS mitigation
detects that some of the source addresses/prefixes
listed in the white list ACLs are actually
attacking the target.";
}
enum "cuid-collision" {
value 3; value 3;
description description
"DOTS Server has detected conflicting mitigation "Conflicts with the CUID used by another
requests from different DOTS clients. All DOTS client of the same domain.";
conflicting mitigation requests are inactive.";
} }
} }
description description
"Indicates the conflict status. "Indicates the cause of the conflict.
It must be included in responses only."; It must be included in responses only.";
} }
leaf conflict-cause { leaf retry-timer {
type enumeration { type int32;
enum "overlapping-targets" { units "seconds";
value 1; description
description "The DOTS client must not re-send the
"Overlapping targets. conflict-scope provides same request before the expiry of this timer.
more details about the exact conflict."; It must be included in responses, only.";
} }
enum "conflict-with-whitelist" { container conflict-scope {
value 2; description
description "Provides more information about the conflict scope.";
"Conflicts with an existing white list.
This code is returned when the DDoS mitigation uses target {
detects that some of the source addresses/prefixes when "../conflict-cause = 'overlapping-targets'";
listed in the white list ACLs are actually }
attacking the target.";
list acl-list {
when "../../conflict-cause = 'conflict-with-whitelist'";
key "acl-name acl-type";
description
"List of conflicting ACLs";
leaf acl-name {
type leafref {
path "/ietf-acl:access-lists/ietf-acl:acl" +
"/ietf-acl:acl-name";
} }
} description
description "Reference to the conflicting ACL name bound to
"Indicates the cause of the conflict. a DOTS client.";
}
It must be included in responses only."; leaf acl-type {
} type leafref {
path "/ietf-acl:access-lists/ietf-acl:acl" +
"/ietf-acl:acl-type";
}
description
"Reference to the conflicting ACL type bound to
a DOTS client.";
}
}
}
}
leaf retry-timer { leaf pkts-dropped {
type int32; type yang:zero-based-counter64;
units "seconds"; config false;
description description
"The DOTS client must not re-send the "Number of dropped packets";
same request before the expiry of this timer. }
It must be included in responses, only.";
}
container conflict-scope { leaf bps-dropped {
description type yang:zero-based-counter64;
"Provides more information about the conflict scope."; config false;
description
"The average number of dropped bytes per second for
the mitigation request since the attack
mitigation is triggered.";
}
uses target { leaf bytes-dropped {
when "../conflict-cause = 'overlapping-targets'"; type yang:zero-based-counter64;
} units 'bytes';
config false;
description
"Counter for dropped packets; in bytes.";
}
list acl-list { leaf pps-dropped {
when "../../conflict-cause = 'conflict-with-whitelist'"; type yang:zero-based-counter64;
key "acl-name acl-type"; config false;
description description
"List of conflicting ACLs"; "The average number of dropped packets per second
for the mitigation request since the attack
mitigation is triggered.";
}
leaf acl-name { leaf attack-status {
type leafref { type enumeration {
path "/ietf-acl:access-lists/ietf-acl:acl" + enum "under-attack" {
"/ietf-acl:acl-name"; value 1;
} description
description "The DOTS client determines that it is still under
"Reference to the conflicting ACL name bound to attack.";
a DOTS client."; }
}
leaf acl-type { enum "attack-successfully-mitigated" {
type leafref { value 2;
path "/ietf-acl:access-lists/ietf-acl:acl" + description
"/ietf-acl:acl-type"; "The DOTS client determines that the attack is
} successfully mitigated.";
description }
"Reference to the conflicting ACL type bound to }
a DOTS client."; description
} "Indicates the status of an attack as seen by the
} DOTS client.";
} }
} }
leaf pkts-dropped { }
type yang:zero-based-counter64;
config false;
description
"Number of dropped packets";
}
leaf bps-dropped { grouping config-parameters {
type yang:zero-based-counter64; description
config false; "Subset of DOTS signal channel session configuration.";
description
"The average number of dropped bytes per second for
the mitigation request since the attack
mitigation is triggered.";
}
leaf bytes-dropped { container heartbeat-interval {
type yang:zero-based-counter64; description
units 'bytes'; "DOTS agents regularly send heartbeats to each other
config false; after mutual authentication is successfully
description completed in order to keep the DOTS signal channel
"Counter for dropped packets; in bytes."; open.";
}
leaf pps-dropped { leaf max-value {
type yang:zero-based-counter64; type int16;
config false; units "seconds";
description description
"The average number of dropped packets per second "Maximum acceptable value.";
for the mitigation request since the attack reference
mitigation is triggered."; "RFC XXXX: Distributed Denial-of-Service Open Threat
} Signaling (DOTS) Signal Channel";
} }
}
grouping config-parameters { leaf min-value {
description type int16;
"Subset of DOTS signal channel session configuration."; units "seconds";
description
"Minimum acceptable value.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf current-value {
type int16;
units "seconds";
default 30;
description
"Current value.
container heartbeat-interval { '0' means that heartbeat mechanism is deactivated.";
description reference
"DOTS agents regularly send heartbeats to each other "RFC XXXX: Distributed Denial-of-Service Open Threat
after mutual authentication is successfully Signaling (DOTS) Signal Channel";
completed in order to keep the DOTS signal channel }
open."; }
leaf max-value { container missing-hb-allowed {
type int16; description
units "seconds"; "Maximum number of missing heartbeats allowed.";
description
"Maximum acceptable value.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf min-value { leaf max-value {
type int16; type int16;
units "seconds"; description
description "Maximum acceptable value.";
"Minimum acceptable value.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf current-value {
type int16;
units "seconds";
default 30;
description
"Current value.
'0' means that heartbeat mechanism is deactivated."; reference
reference "RFC XXXX: Distributed Denial-of-Service Open Threat
"RFC XXXX: Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel";
Signaling (DOTS) Signal Channel"; }
}
}
container missing-hb-allowed { leaf min-value {
description type int16;
"Maximum number of missing heartbeats allowed."; description
"Minimum acceptable value.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf current-value {
type int16;
default 5;
description
"Current value.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
}
leaf max-value { container max-retransmit {
type int16; description
description "Maximum number of retransmissions of a Confirmable
"Maximum acceptable value."; message.";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf min-value { leaf max-value {
type int16; type int16;
description description
"Minimum acceptable value."; "Maximum acceptable value.";
reference
"Section 4.8 of RFC 7552.";
}
reference leaf min-value {
"RFC XXXX: Distributed Denial-of-Service Open Threat type int16;
Signaling (DOTS) Signal Channel"; description
} "Minimum acceptable value.";
leaf current-value { reference
type int16; "Section 4.8 of RFC 7552.";
default 5; }
description leaf current-value {
"Current value."; type int16;
reference default 3;
"RFC XXXX: Distributed Denial-of-Service Open Threat description
Signaling (DOTS) Signal Channel"; "Current value.";
} reference
} "RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
}
container max-retransmit { container ack-timeout {
description description
"Maximum number of retransmissions of a Confirmable "Initial retransmission timeout value.";
message.";
leaf max-value { leaf max-value {
type int16; type int16;
description units "seconds";
"Maximum acceptable value."; description
reference "Maximum value.";
"Section 4.8 of RFC 7552."; reference
} "Section 4.8 of RFC 7552.";
}
leaf min-value { leaf min-value {
type int16; type int16;
description units "seconds";
"Minimum acceptable value."; description
reference "Minimum value.";
"Section 4.8 of RFC 7552."; reference
} "Section 4.8 of RFC 7552.";
leaf current-value { }
type int16; leaf current-value {
default 3; type int16;
description units "seconds";
"Current value."; default 2;
reference description
"RFC XXXX: Distributed Denial-of-Service Open Threat "Current value.";
Signaling (DOTS) Signal Channel"; reference
} "Section 4.8 of RFC 7552.";
} }
}
container ack-timeout { container ack-random-factor {
description description
"Initial retransmission timeout value."; "Random factor used to influence the timing of
retransmissions.";
leaf max-value { leaf max-value-decimal {
type int16; type decimal64 {
units "seconds"; fraction-digits 2;
description }
"Maximum value."; description
reference "Maximum acceptable value.";
"Section 4.8 of RFC 7552."; reference
} "Section 4.8 of RFC 7552.";
}
leaf min-value { leaf min-value-decimal {
type int16; type decimal64 {
units "seconds"; fraction-digits 2;
description }
"Minimum value."; description
reference "Minimum acceptable value.";
"Section 4.8 of RFC 7552."; reference
} "Section 4.8 of RFC 7552.";
leaf current-value { }
type int16; leaf current-value-decimal {
units "seconds"; type decimal64 {
default 2; fraction-digits 2;
description }
"Current value."; default 1.5;
reference description
"Section 4.8 of RFC 7552."; "Current value.";
} reference
} "Section 4.8 of RFC 7552.";
}
}
}
container ack-random-factor { grouping signal-config {
description description
"Random factor used to influence the timing of "DOTS signal channel session configuration.";
retransmissions.";
leaf max-value { leaf session-id {
type decimal64 { type int32;
fraction-digits 2; mandatory true;
} description
description "An identifier for the DOTS signal channel
"Maximum acceptable value."; session configuration data.";
reference }
"Section 4.8 of RFC 7552.";
}
leaf min-value { container mitigating-config {
type decimal64 { description
fraction-digits 2; "Configuration parameters to use when a mitigation is active.";
uses config-parameters;
}
} container idle-config {
description description
"Minimum acceptable value."; "Configuration parameters to use when no mitigation is
reference active.";
"Section 4.8 of RFC 7552."; uses config-parameters;
} }
leaf current-value {
type decimal64 {
fraction-digits 2;
}
default 1.5;
description
"Current value.";
reference
"Section 4.8 of RFC 7552.";
}
}
}
grouping signal-config { leaf trigger-mitigation {
description type boolean;
"DOTS signal channel session configuration."; default true;
description
"If false, then mitigation is triggered
only when the DOTS server channel session is lost";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf session-id { leaf config-interval {
type int32; type int32;
mandatory true; units "seconds";
description description
"An identifier for the DOTS signal channel "This parameter is returned by a DOTS server to
session configuration data."; a requesting DOTS client to indicate the time interval
} after which the DOTS client must contact the DOTS
server in order to retrieve the signal channel
configuration data.
container attack-time-config { This mechanism allows the update of the configuration
description data if a change occurs.
"Configuration paramaters to use when an attack is active.";
uses config-parameters;
}
container peace-time-config { For example, the new configuration may instruct
description a DOTS client to cease heartbeats or reduce
"Configuration paramaters to use in peacetime."; heartbeat frequency.
uses config-parameters;
}
leaf trigger-mitigation { '0' is used to disable this refresh mechanism.";
type boolean; }
default true; }
description
"If false, then mitigation is triggered
only when the DOTS server channel session is lost";
reference
"RFC XXXX: Distributed Denial-of-Service Open Threat
Signaling (DOTS) Signal Channel";
}
leaf config-interval { grouping redirected-signal {
type int32; description
units "minutes"; "Grouping for the redirected signaling.";
description
"This parameter is returned by a DOTS server to
a requesting DOTS client to indicate the time interval
after which the DOTS client must contact the DOTS
server in order to retrieve the signal channel
configuration data.
This mechanism allows the update of the configuration leaf alt-server {
data if a change occurs. type string;
mandatory true;
description
"Alias of an alternate server.";
}
list alt-server-record {
key "addr";
description
"List of records for the alternate server.";
For example, the new configuration may instruct leaf addr {
a DOTS client to cease heartbeats or reduce type inet:ip-address;
heartbeat frequency. description
"IPv4 or IPv6 address identifying the server.";
}
'0' is used to disable this refresh mechanism."; leaf ttl {
} type int32;
} description
"TTL associated with this record.";
}
}
}
container dots-signal { container dots-signal {
description description
"Main container for DOTS signal message. "Main container for DOTS signal message.
A DOTS signal message can be a mitigation message or A DOTS signal message can be a mitigation message or
a configuration message."; a configuration message.";
choice message-type { choice message-type {
description description
"Either a mitigation or a configuration message."; "Can be a mitigation, a configuration, or a redirect
message.";
case mitigation-scope { case mitigation-scope {
description description
"Mitigation scope of a mitigation message."; "Mitigation scope of a mitigation message.";
uses mitigation-scope; uses mitigation-scope;
} }
case configuration { case signal-config {
description description
"Configuration message."; "Configuration message.";
uses signal-config; uses signal-config;
} }
} case redirected-signal {
} description
} "Redirected signaling.";
<CODE ENDS> uses redirected-signal;
}
}
}
}
<CODE ENDS>
6. Mapping Parameters to CBOR 6. Mapping Parameters to CBOR
All parameters in the payload of the DOTS signal channel MUST be All parameters in the payload of the DOTS signal channel MUST be
mapped to CBOR types as shown in Table 4 and are assigned an integer mapped to CBOR types as shown in Table 4 and are assigned an integer
key to save space. The recipient of the payload MAY reject the key to save space. The recipient of the payload MAY reject the
information if it is not suitably mapped. information if it is not suitably mapped.
/----------------------+----------------+--------------------------\ +-----------------------+----------+--------------------+
| Parameter name | CBOR key | CBOR major type of value | | Parameter Name | CBOR Key | CBOR Major Type |
+----------------------+----------------+--------------------------+ +-----------------------+----------+--------------------+
| mitigation-scope | 1 | 5 (map) | | mitigation-scope | 1 | 5 (map) |
| scope | 2 | 5 (map) | | scope | 2 | 5 (map) |
| mitigation-id | 3 | 0 (unsigned) | | mitigation-id | 3 | 0 (unsigned) |
| acl-list | 4 | 4 | | acl-list | 4 | 4 |
| target-port-range | 5 | 4 | | target-port-range | 5 | 4 |
| lower-port | 6 | 0 | | lower-port | 6 | 0 |
| upper-port | 7 | 0 | | upper-port | 7 | 0 |
| target-protocol | 8 | 4 | | target-protocol | 8 | 4 |
| target-fqdn | 9 | 4 | | target-fqdn | 9 | 4 |
| target-uri | 10 | 4 | | target-uri | 10 | 4 |
| alias-name | 11 | 4 | | alias-name | 11 | 4 |
| lifetime | 12 | 0 | | lifetime | 12 | 0 |
| attack-status | 13 | 0 | | attack-status | 13 | 0 |
| signal-config | 14 | 5 | | signal-config | 14 | 5 (map) |
| heartbeat-interval | 15 | 5 (map) | | heartbeat-interval | 15 | 5 (map) |
| max-retransmit | 16 | 5 (map) | | max-retransmit | 16 | 5 (map) |
| ack-timeout | 17 | 5 (map) | | ack-timeout | 17 | 5 (map) |
| ack-random-factor | 18 | 5 (map) | | ack-random-factor | 18 | 5 (map) |
| min-value | 19 | 0 | | min-value | 19 | 0 |
| max-value | 20 | 0 | | max-value | 20 | 0 |
| status | 21 | 0 | | status | 21 | 0 |
| conflict-information | 22 | 5 (map) | | conflict-information | 22 | 5 (map) |
| conflict-status | 23 | 0 | | conflict-status | 23 | 0 |
| conflict-cause | 24 | 0 | | conflict-cause | 24 | 0 |
| retry-timer | 25 | 0 | | retry-timer | 25 | 0 |
| bytes-dropped | 26 | 0 | | bytes-dropped | 26 | 0 |
| bps-dropped | 27 | 0 | | bps-dropped | 27 | 0 |
| pkts-dropped | 28 | 0 | | pkts-dropped | 28 | 0 |
| pps-dropped | 29 | 0 | | pps-dropped | 29 | 0 |
| session-id | 30 | 0 | | session-id | 30 | 0 |
| trigger-mitigation | 31 | 7 (simple types) | | trigger-mitigation | 31 | 7 (simple types) |
| missing-hb-allowed | 32 | 5 (map) | | missing-hb-allowed | 32 | 5 (map) |
| current-value | 33 | 0 | | current-value | 33 | 0 |
| mitigation-start | 34 | 7 (floating-point) | | mitigation-start | 34 | 7 (floating-point) |
| target-prefix | 35 | 4 (array) | | target-prefix | 35 | 4 (array) |
| client-identifier | 36 | 2 (byte string) | | client-domain-hash | 36 | 3 |
| alt-server | 37 | 2 | | alt-server | 37 | 3 |
| alt-server-record | 38 | 4 | | alt-server-record | 38 | 4 |
| addr | 39 | 2 | | addr | 39 | 3 |
| ttl | 40 | 0 | | ttl | 40 | 0 |
| conflict-scope | 41 | 5 (map) | | conflict-scope | 41 | 5 (map) |
| acl-name | 42 | 3 | | acl-name | 42 | 3 |
| acl-type | 43 | 3 | | acl-type | 43 | 3 |
| config-interval | 44 | 0 | | config-interval | 44 | 0 |
| attack-time-config | 45 | 5 (map) | | mitigating-config | 45 | 5 (map) |
| peace-time-config | 46 | 5 (map) | | idle-config | 46 | 5 (map) |
\----------------------+----------------+--------------------------/ | cuid | 47 | 3 |
Table 4: CBOR mappings used in DOTS signal channel message | min-value-decimal | 48 | 7 |
| max-value-decimal | 49 | 7 |
| current-value-decimal | 50 | 7 |
+-----------------------+----------+--------------------+
Table 4: CBOR Mappings Used in DOTS Signal Channel Messages
7. (D)TLS Protocol Profile and Performance Considerations 7. (D)TLS Protocol Profile and Performance Considerations
7.1. (D)TLS Protocol Profile 7.1. (D)TLS Protocol Profile
This section defines the (D)TLS protocol profile of DOTS signal This section defines the (D)TLS protocol profile of DOTS signal
channel over (D)TLS and DOTS data channel over TLS. channel over (D)TLS and DOTS data channel over TLS.
There are known attacks on (D)TLS, such as man-in-the-middle and There are known attacks on (D)TLS, such as man-in-the-middle and
protocol downgrade attacks. These are general attacks on (D)TLS and, protocol downgrade attacks. These are general attacks on (D)TLS and,
skipping to change at page 63, line 48 skipping to change at page 68, line 4
server, and connects to its configured DOTS server, the server may server, and connects to its configured DOTS server, the server may
present it with a PKIX certificate. In order to ensure proper present it with a PKIX certificate. In order to ensure proper
authentication, a DOTS client MUST verify the entire certification authentication, a DOTS client MUST verify the entire certification
path per [RFC5280]. The DOTS client additionally uses [RFC6125] path per [RFC5280]. The DOTS client additionally uses [RFC6125]
validation techniques to compare the domain name with the certificate validation techniques to compare the domain name with the certificate
provided. provided.
A key challenge to deploying DOTS is the provisioning of DOTS A key challenge to deploying DOTS is the provisioning of DOTS
clients, including the distribution of keying material to DOTS clients, including the distribution of keying material to DOTS
clients to enable the required mutual authentication of DOTS agents. clients to enable the required mutual authentication of DOTS agents.
EST defines a method of certificate enrollment by which domains EST defines a method of certificate enrollment by which domains
operating DOTS servers may provide DOTS clients with all the operating DOTS servers may provide DOTS clients with all the
necessary cryptographic keying material, including a private key and necessary cryptographic keying material, including a private key and
a certificate to authenticate themselves. One deployment option is a certificate to authenticate themselves. One deployment option is
DOTS clients behave as EST clients for certificate enrollment from an DOTS clients behave as EST clients for certificate enrollment from an
EST server provisioned by the mitigation provider. This document EST server provisioned by the mitigation provider. This document
does not specify which EST mechanism the DOTS client uses to achieve does not specify which EST mechanism the DOTS client uses to achieve
initial enrollment. initial enrollment.
The Server Name Indication (SNI) extension [RFC6066] defines a
mechanism for a client to tell a (D)TLS server the name of the server
it wants to contact. This is a useful extension for hosting
environments where multiple virtual servers are reachable over a
single IP address. The DOTS client may or may not know if it is
interacting with a DOTS server in the hosting environment, so the
DOTS client SHOULD include the DOTS server FQDN in the SNI extension.
Implementations compliant with this profile MUST implement all of the Implementations compliant with this profile MUST implement all of the
following items: following items:
o DTLS record replay detection (Section 3.3 of [RFC6347]) to protect o DTLS record replay detection (Section 3.3 of [RFC6347]) to protect
against replay attacks. against replay attacks.
o (D)TLS session resumption without server-side state [RFC5077] to o (D)TLS session resumption without server-side state [RFC5077] to
resume session and convey the DOTS signal. resume session and convey the DOTS signal.
o Raw public keys [RFC7250] or PSK handshake [RFC4279] which reduces o Raw public keys [RFC7250] or PSK handshake [RFC4279] which reduces
skipping to change at page 65, line 22 skipping to change at page 69, line 38
to convey the DOTS mitigation request message and, if there is no to convey the DOTS mitigation request message and, if there is no
response from the server after multiple retries, the DOTS client response from the server after multiple retries, the DOTS client
can resume the (D)TLS session in 0-RTT mode using PSK. can resume the (D)TLS session in 0-RTT mode using PSK.
Section 8 of [I-D.ietf-tls-tls13] discusses some mechanisms to Section 8 of [I-D.ietf-tls-tls13] discusses some mechanisms to
implement to limit the impact of replay attacks on 0-RTT data. If implement to limit the impact of replay attacks on 0-RTT data. If
TLS1.3 is used, DOTS servers must implement one of these TLS1.3 is used, DOTS servers must implement one of these
mechanisms. mechanisms.
A simplified TLS 1.3 handshake with 0-RTT DOTS mitigation request A simplified TLS 1.3 handshake with 0-RTT DOTS mitigation request
message exchange is shown in Figure 23. message exchange is shown in Figure 25.
DOTS Client DOTS Server DOTS Client DOTS Server
ClientHello ClientHello
(Finished) (Finished)
(0-RTT DOTS signal message) (0-RTT DOTS signal message)
(end_of_early_data) --------> (end_of_early_data) -------->
ServerHello ServerHello
{EncryptedExtensions} {EncryptedExtensions}
{ServerConfiguration} {ServerConfiguration}
{Certificate} {Certificate}
{CertificateVerify} {CertificateVerify}
{Finished} {Finished}
<-------- [DOTS signal message] <-------- [DOTS signal message]
{Finished} --------> {Finished} -------->
[DOTS signal message] <-------> [DOTS signal message] [DOTS signal message] <-------> [DOTS signal message]
Figure 23: TLS 1.3 handshake with 0-RTT Figure 25: TLS 1.3 handshake with 0-RTT
7.3. MTU and Fragmentation 7.3. MTU and Fragmentation
To avoid DOTS signal message fragmentation and the subsequent To avoid DOTS signal message fragmentation and the subsequent
decreased probability of message delivery, DOTS agents MUST ensure decreased probability of message delivery, DOTS agents MUST ensure
that the DTLS record MUST fit within a single datagram. If the path that the DTLS record MUST fit within a single datagram. If the path
MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD MTU is not known to the DOTS server, an IP MTU of 1280 bytes SHOULD
be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP be assumed. The length of the URL MUST NOT exceed 256 bytes. If UDP
is used to convey the DOTS signal messages then the DOTS client must is used to convey the DOTS signal messages then the DOTS client must
consider the amount of record expansion expected by the DTLS consider the amount of record expansion expected by the DTLS
skipping to change at page 67, line 5 skipping to change at page 71, line 17
(D)TLS based upon client certificate can be used for mutual (D)TLS based upon client certificate can be used for mutual
authentication between DOTS agents. If a DOTS gateway is involved, authentication between DOTS agents. If a DOTS gateway is involved,
DOTS clients and DOTS gateways MUST perform mutual authentication; DOTS clients and DOTS gateways MUST perform mutual authentication;
only authorized DOTS clients are allowed to send DOTS signals to a only authorized DOTS clients are allowed to send DOTS signals to a
DOTS gateway. The DOTS gateway and the DOTS server MUST perform DOTS gateway. The DOTS gateway and the DOTS server MUST perform
mutual authentication; a DOTS server only allows DOTS signal channel mutual authentication; a DOTS server only allows DOTS signal channel
messages from an authorized DOTS gateway, thereby creating a two-link messages from an authorized DOTS gateway, thereby creating a two-link
chain of transitive authentication between the DOTS client and the chain of transitive authentication between the DOTS client and the
DOTS server. DOTS server.
The DOTS server SHOULD support certificate-based client
authentication. The DOTS client SHOULD respond to the DOTS server's
TLS certificate request message with the PKIX certificate held by the
DOTS client. DOTS client certificate validation MUST be performed as
per [RFC5280] and the DOTS client certificate MUST conform to the
[RFC5280] certificate profile. If a DOTS client does not support TLS
client certificate authentication, it MUST support pre-shared key
based or raw public key based client authentication.
+-----------------------------------------------+ +-----------------------------------------------+
| example.com domain +---------+ | | example.com domain +---------+ |
| | AAA | | | | AAA | |
| +---------------+ | Server | | | +---------------+ | Server | |
| | Application | +------+--+ | | | Application | +------+--+ |
| | server +<-----------------+ ^ | | | server +<-----------------+ ^ |
| | (DOTS client) | | | | | | (DOTS client) | | | |
| +---------------+ | | | | +---------------+ | | |
| V V | example.net domain | V V | example.net domain
| +-----+----+--+ | +---------------+ | +-----+----+--+ | +---------------+
| +--------------+ | | | | | | +--------------+ | | | | |
| | Guest +<-----x----->+ DOTS +<------>+ DOTS | | | Guest +<-----x----->+ DOTS +<------>+ DOTS |
| | (DOTS client)| | Gateway | | | Server | | | (DOTS client)| | gateway | | | server |
| +--------------+ | | | | | | +--------------+ | | | | |
| +----+--------+ | +---------------+ | +----+--------+ | +---------------+
| ^ | | ^ |
| | | | | |
| +----------------+ | | | +----------------+ | |
| | DDOS detector | | | | | DDoS detector | | |
| | (DOTS client) +<---------------+ | | | (DOTS client) +<---------------+ |
| +----------------+ | | +----------------+ |
+-----------------------------------------------+ +-----------------------------------------------+
Figure 24: Example of Authentication and Authorization of DOTS Agents Figure 26: Example of Authentication and Authorization of DOTS Agents
In the example depicted in Figure 24, the DOTS gateway and DOTS In the example depicted in Figure 26, the DOTS gateway and DOTS
clients within the 'example.com' domain mutually authenticate with clients within the 'example.com' domain mutually authenticate with
each other. After the DOTS gateway validates the identity of a DOTS each other. After the DOTS gateway validates the identity of a DOTS
client, it communicates with the AAA server in the 'example.com' client, it communicates with the AAA server in the 'example.com'
domain to determine if the DOTS client is authorized to request DDoS domain to determine if the DOTS client is authorized to request DDoS
mitigation. If the DOTS client is not authorized, a 4.01 mitigation. If the DOTS client is not authorized, a 4.01
(Unauthorized) is returned in the response to the DOTS client. In (Unauthorized) is returned in the response to the DOTS client. In
this example, the DOTS gateway only allows the application server and this example, the DOTS gateway only allows the application server and
DDoS attack detector to request DDOS mitigation, but does not permit DDoS attack detector to request DDoS mitigation, but does not permit
the user of type 'guest' to request DDoS mitigation. the user of type 'guest' to request DDoS mitigation.
Also, DOTS gateways and servers located in different domains MUST Also, DOTS gateways and servers located in different domains MUST
perform mutual authentication (e.g., using certificates). A DOTS perform mutual authentication (e.g., using certificates). A DOTS
server will only allow a DOTS gateway with a certificate for a server will only allow a DOTS gateway with a certificate for a
particular domain to request mitigation for that domain. In particular domain to request mitigation for that domain. In
reference to Figure 24, the DOTS server only allows the DOTS gateway reference to Figure 26, the DOTS server only allows the DOTS gateway
to request mitigation for 'example.com' domain and not for other to request mitigation for 'example.com' domain and not for other
domains. domains.
9. IANA Considerations 9. IANA Considerations
This specification registers a service port (Section 9.1), an URI This specification registers a service port (Section 9.1), an URI
suffix in the Well-Known URIs registry (Section 9.2), a CoAP response suffix in the Well-Known URIs registry (Section 9.2), a CoAP response
code (Section 9.3), a YANG module (Section 9.5). It also creates a code (Section 9.3), a YANG module (Section 9.5). It also creates a
registry for mappings to CBOR (Section 9.4). registry for mappings to CBOR (Section 9.4).
skipping to change at page 68, line 46 skipping to change at page 73, line 14
9.3. CoAP Response Code 9.3. CoAP Response Code
IANA is requested to add the following entry to the "CoAP Response IANA is requested to add the following entry to the "CoAP Response
Codes" sub-registry available at https://www.iana.org/assignments/ Codes" sub-registry available at https://www.iana.org/assignments/
core-parameters/core-parameters.xhtml#response-codes: core-parameters/core-parameters.xhtml#response-codes:
+------+------------------+-----------+ +------+------------------+-----------+
| Code | Description | Reference | | Code | Description | Reference |
+------+------------------+-----------+ +------+------------------+-----------+
| 3.00 | Alternate server | [RFCXXXX] | | 3.00 | Alternate Server | [RFCXXXX] |
+------+------------------+-----------+ +------+------------------+-----------+
Table 4: CoAP Response Code Table 5: CoAP Response Code
9.4. DOTS Signal Channel CBOR Mappings Registry 9.4. DOTS Signal Channel CBOR Mappings Registry
The document requests IANA to create a new registry, entitled "DOTS The document requests IANA to create a new registry, entitled "DOTS
Signal Channel CBOR Mappings Registry". The structure of this Signal Channel CBOR Mappings Registry". The structure of this
registry is provided in Section 9.4.1. registry is provided in Section 9.4.1.
The registry is initially populated with the values in Section 9.4.2. The registry is initially populated with the values in Section 9.4.2.
Values from that registry MUST be assigned via Expert Review Values from that registry MUST be assigned via Expert Review
skipping to change at page 74, line 4 skipping to change at page 78, line 17
o CBOR Key Value: 33 o CBOR Key Value: 33
o CBOR Major Type: 0 o CBOR Major Type: 0
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: mitigation-start o Parameter Name: mitigation-start
o CBOR Key Value: 34 o CBOR Key Value: 34
o CBOR Major Type: 7 o CBOR Major Type: 7
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: target-prefix o Parameter Name: target-prefix
o CBOR Key Value: 35 o CBOR Key Value: 35
o CBOR Major Type: 4 o CBOR Major Type: 4
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: client-identifier o Parameter Name: client-domain-hash
o CBOR Key Value: 36 o CBOR Key Value: 36
o CBOR Major Type: 2 o CBOR Major Type: 3
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: alt-server o Parameter Name: alt-server
o CBOR Key Value: 37 o CBOR Key Value: 37
o CBOR Major Type: 2 o CBOR Major Type: 3
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: alt-server-record o Parameter Name: alt-server-record
o CBOR Key Value: 38 o CBOR Key Value: 38
o CBOR Major Type: 4 o CBOR Major Type: 4
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: addr o Parameter Name: addr
o CBOR Key Value: 39 o CBOR Key Value: 39
o CBOR Major Type: 2 o CBOR Major Type: 3
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: ttl o Parameter Name: ttl
o CBOR Key Value: 40 o CBOR Key Value: 40
o CBOR Major Type: 0 o CBOR Major Type: 0
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: conflict-scope o Parameter Name: conflict-scope
skipping to change at page 75, line 16 skipping to change at page 79, line 30
o CBOR Major Type: 3 o CBOR Major Type: 3
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: config-interval o Parameter Name: config-interval
o CBOR Key Value: 44 o CBOR Key Value: 44
o CBOR Major Type: 0 o CBOR Major Type: 0
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: attack-time-config o Parameter Name: mitigating-config
o CBOR Key Value: 45 o CBOR Key Value: 45
o CBOR Major Type: 5 o CBOR Major Type: 5
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: peace-time-config o Parameter Name: idle-config
o CBOR Key Value: 46 o CBOR Key Value: 46
o CBOR Major Type: 5 o CBOR Major Type: 5
o Change Controller: IESG o Change Controller: IESG
o Specification Document(s): this document o Specification Document(s): this document
o Parameter Name: cuid
o CBOR Key Value: 47
o CBOR Major Type: 3
o Change Controller: IESG
o Specification Document(s): this document
o Parameter Name: min-value-decimal
o CBOR Key Value: 48
o CBOR Major Type: 7
o Change Controller: IESG
o Specification Document(s): this document
o Parameter Name: max-value-decimal
o CBOR Key Value: 49
o CBOR Major Type: 7
o Change Controller: IESG
o Specification Document(s): this document
o Parameter Name: current-value-decimal
o CBOR Key Value: 50
o CBOR Major Type: 7
o Change Controller: IESG
o Specification Document(s): this document
9.5. DOTS Signal Channel YANG Module 9.5. DOTS Signal Channel YANG Module
This document requests IANA to register the following URI in the This document requests IANA to register the following URI in the
"IETF XML Registry" [RFC3688]: "IETF XML Registry" [RFC3688]:
URI: urn:ietf:params:xml:ns:yang:ietf-dots-signal URI: urn:ietf:params:xml:ns:yang:ietf-dots-signal
Registrant Contact: The IESG. Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace. XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG module in This document requests IANA to register the following YANG module in
skipping to change at page 76, line 38 skipping to change at page 81, line 28
implement a full DOTS protocol specification in accordance with implement a full DOTS protocol specification in accordance with
the nurturing DOTS protocol. the nurturing DOTS protocol.
Implementation: https://github.com/nttdots/go-dots Implementation: https://github.com/nttdots/go-dots
Level of maturity: It is an early implementation of the DOTS Level of maturity: It is an early implementation of the DOTS
protocol. Messaging between DOTS clients and DOTS servers has protocol. Messaging between DOTS clients and DOTS servers has
been tested. Level of maturity will increase in accordance with been tested. Level of maturity will increase in accordance with
the nurturing DOTS protocol. the nurturing DOTS protocol.
Coverage: Capability of DOTS client: sending DOTS messages to the Coverage: Capability of DOTS client: sending DOTS messages to the
DOTS server in CoAP over DTLS as dots-signal. Capability of DOTS DOTS server in CoAP over DTLS as dots-signal. Capability of DOTS
server: receiving dots-signal, validating received dots-signal, server: receiving dots-signal, validating received dots-signal,
starting mitigation by handing over the dots-signal to DDOS starting mitigation by handing over the dots-signal to DDoS
mitigator. mitigator.
Licensing: It will be open-sourced with BSD 3-clause license. Licensing: It will be open-sourced with BSD 3-clause license.
Implementation experience: It is implemented in Go-lang. Core Implementation experience: It is implemented in Go-lang. Core
specification of signaling is mature to be implemented, however, specification of signaling is mature to be implemented, however,
finding good libraries(like DTLS, CoAP) is rather difficult. finding good libraries(like DTLS, CoAP) is rather difficult.
Contact: Kaname Nishizuka <kaname@nttv6.jp> Contact: Kaname Nishizuka <kaname@nttv6.jp>
11. Security Considerations 11. Security Considerations
Authenticated encryption MUST be used for data confidentiality and Authenticated encryption MUST be used for data confidentiality and
skipping to change at page 77, line 24 skipping to change at page 82, line 13
TLS authentication is used. Because the application data is TLS TLS authentication is used. Because the application data is TLS
protected, this will not result in the application receiving bogus protected, this will not result in the application receiving bogus
data, but it will constitute a DoS on the connection. This attack data, but it will constitute a DoS on the connection. This attack
can be countered by using TCP-AO [RFC5925]. If TCP-AO is used, then can be countered by using TCP-AO [RFC5925]. If TCP-AO is used, then
any bogus packets injected by an attacker will be rejected by the any bogus packets injected by an attacker will be rejected by the
TCP-AO integrity check and therefore will never reach the TLS layer. TCP-AO integrity check and therefore will never reach the TLS layer.
In order to prevent leaking internal information outside a client- In order to prevent leaking internal information outside a client-
domain, DOTS gateways located in the client-domain SHOULD NOT reveal domain, DOTS gateways located in the client-domain SHOULD NOT reveal
the identification information that pertains to internal DOTS clients the identification information that pertains to internal DOTS clients
(client-identifier) unless explicitly configured to do so. (e.g., source IP address, client's hostname) unless explicitly
configured to do so.
Special care should be taken in order to ensure that the activation Special care should be taken in order to ensure that the activation
of the proposed mechanism will not impact the stability of the of the proposed mechanism will not impact the stability of the
network (including connectivity and services delivered over that network (including connectivity and services delivered over that
network). network).
12. Contributors 12. Contributors
The following individuals have contributed to this document: The following individuals have contributed to this document:
skipping to change at page 78, line 13 skipping to change at page 83, line 9
enhanced this specification. enhanced this specification.
14. References 14. References
14.1. Normative References 14.1. Normative References
[I-D.ietf-core-coap-tcp-tls] [I-D.ietf-core-coap-tcp-tls]
Bormann, C., Lemay, S., Tschofenig, H., Hartke, K., Bormann, C., Lemay, S., Tschofenig, H., Hartke, K.,
Silverajan, B., and B. Raymor, "CoAP (Constrained Silverajan, B., and B. Raymor, "CoAP (Constrained
Application Protocol) over TCP, TLS, and WebSockets", Application Protocol) over TCP, TLS, and WebSockets",
draft-ietf-core-coap-tcp-tls-10 (work in progress), draft-ietf-core-coap-tcp-tls-11 (work in progress),
October 2017. December 2017.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004, DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>. <https://www.rfc-editor.org/info/rfc3688>.
skipping to change at page 79, line 5 skipping to change at page 83, line 46
[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known [RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
Uniform Resource Identifiers (URIs)", RFC 5785, Uniform Resource Identifiers (URIs)", RFC 5785,
DOI 10.17487/RFC5785, April 2010, DOI 10.17487/RFC5785, April 2010,
<https://www.rfc-editor.org/info/rfc5785>. <https://www.rfc-editor.org/info/rfc5785>.
[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, DOI 10.17487/RFC5925, Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
June 2010, <https://www.rfc-editor.org/info/rfc5925>. June 2010, <https://www.rfc-editor.org/info/rfc5925>.
[RFC6066] Eastlake 3rd, D., "Transport Layer Security (TLS)
Extensions: Extension Definitions", RFC 6066,
DOI 10.17487/RFC6066, January 2011,
<https://www.rfc-editor.org/info/rfc6066>.
[RFC6125] Saint-Andre, P. and J. Hodges, "Representation and [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and
Verification of Domain-Based Application Service Identity Verification of Domain-Based Application Service Identity
within Internet Public Key Infrastructure Using X.509 within Internet Public Key Infrastructure Using X.509
(PKIX) Certificates in the Context of Transport Layer (PKIX) Certificates in the Context of Transport Layer
Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March Security (TLS)", RFC 6125, DOI 10.17487/RFC6125, March
2011, <https://www.rfc-editor.org/info/rfc6125>. 2011, <https://www.rfc-editor.org/info/rfc6125>.
[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms [RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
(SHA and SHA-based HMAC and HKDF)", RFC 6234, (SHA and SHA-based HMAC and HKDF)", RFC 6234,
DOI 10.17487/RFC6234, May 2011, DOI 10.17487/RFC6234, May 2011,
skipping to change at page 80, line 34 skipping to change at page 85, line 34
Mortensen, A., Andreasen, F., Reddy, T., Mortensen, A., Andreasen, F., Reddy, T.,
christopher_gray3@cable.comcast.com, c., Compton, R., and christopher_gray3@cable.comcast.com, c., Compton, R., and
N. Teague, "Distributed-Denial-of-Service Open Threat N. Teague, "Distributed-Denial-of-Service Open Threat
Signaling (DOTS) Architecture", draft-ietf-dots- Signaling (DOTS) Architecture", draft-ietf-dots-
architecture-05 (work in progress), October 2017. architecture-05 (work in progress), October 2017.
[I-D.ietf-dots-data-channel] [I-D.ietf-dots-data-channel]
Reddy, T., Boucadair, M., Nishizuka, K., Xia, L., Patil, Reddy, T., Boucadair, M., Nishizuka, K., Xia, L., Patil,
P., Mortensen, A., and N. Teague, "Distributed Denial-of- P., Mortensen, A., and N. Teague, "Distributed Denial-of-
Service Open Threat Signaling (DOTS) Data Channel", draft- Service Open Threat Signaling (DOTS) Data Channel", draft-
ietf-dots-data-channel-10 (work in progress), December ietf-dots-data-channel-11 (work in progress), December
2017. 2017.
[I-D.ietf-dots-requirements] [I-D.ietf-dots-requirements]
Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed
Denial of Service (DDoS) Open Threat Signaling Denial of Service (DDoS) Open Threat Signaling
Requirements", draft-ietf-dots-requirements-08 (work in Requirements", draft-ietf-dots-requirements-10 (work in
progress), December 2017. progress), January 2018.
[I-D.ietf-dots-use-cases] [I-D.ietf-dots-use-cases]
Dobbins, R., Migault, D., Fouant, S., Moskowitz, R., Dobbins, R., Migault, D., Fouant, S., Moskowitz, R.,
Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS Teague, N., Xia, L., and K. Nishizuka, "Use cases for DDoS
Open Threat Signaling", draft-ietf-dots-use-cases-09 (work Open Threat Signaling", draft-ietf-dots-use-cases-09 (work
in progress), November 2017. in progress), November 2017.
[I-D.ietf-netmod-yang-tree-diagrams] [I-D.ietf-netmod-yang-tree-diagrams]
Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft- Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
ietf-netmod-yang-tree-diagrams-02 (work in progress), ietf-netmod-yang-tree-diagrams-04 (work in progress),
October 2017. December 2017.
[I-D.ietf-tls-dtls13] [I-D.ietf-tls-dtls13]
Rescorla, E., Tschofenig, H., and N. Modadugu, "The Rescorla, E., Tschofenig, H., and N. Modadugu, "The
Datagram Transport Layer Security (DTLS) Protocol Version Datagram Transport Layer Security (DTLS) Protocol Version
1.3", draft-ietf-tls-dtls13-22 (work in progress), 1.3", draft-ietf-tls-dtls13-22 (work in progress),
November 2017. November 2017.
[I-D.ietf-tls-tls13] [I-D.ietf-tls-tls13]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", draft-ietf-tls-tls13-22 (work in progress), Version 1.3", draft-ietf-tls-tls13-22 (work in progress),
skipping to change at page 81, line 34 skipping to change at page 86, line 34
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network [RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022, Address Translator (Traditional NAT)", RFC 3022,
DOI 10.17487/RFC3022, January 2001, DOI 10.17487/RFC3022, January 2001,
<https://www.rfc-editor.org/info/rfc3022>. <https://www.rfc-editor.org/info/rfc3022>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005, RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>. <https://www.rfc-editor.org/info/rfc3986>.
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005,
<https://www.rfc-editor.org/info/rfc4086>.
[RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram [RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram
Congestion Control Protocol (DCCP)", RFC 4340, Congestion Control Protocol (DCCP)", RFC 4340,
DOI 10.17487/RFC4340, March 2006, DOI 10.17487/RFC4340, March 2006,
<https://www.rfc-editor.org/info/rfc4340>. <https://www.rfc-editor.org/info/rfc4340>.
[RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing [RFC4632] Fuller, V. and T. Li, "Classless Inter-domain Routing
(CIDR): The Internet Address Assignment and Aggregation (CIDR): The Internet Address Assignment and Aggregation
Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August Plan", BCP 122, RFC 4632, DOI 10.17487/RFC4632, August
2006, <https://www.rfc-editor.org/info/rfc4632>. 2006, <https://www.rfc-editor.org/info/rfc4632>.
[RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet [RFC4732] Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
Denial-of-Service Considerations", RFC 4732, Denial-of-Service Considerations", RFC 4732,
DOI 10.17487/RFC4732, December 2006, DOI 10.17487/RFC4732, December 2006,
<https://www.rfc-editor.org/info/rfc4732>. <https://www.rfc-editor.org/info/rfc4732>.
[RFC4787] Audet, F., Ed. and C. Jennings, "Network Address [RFC4787] Audet, F., Ed. and C. Jennings, "Network Address
Translation (NAT) Behavioral Requirements for Unicast Translation (NAT) Behavioral Requirements for Unicast
UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January UDP", BCP 127, RFC 4787, DOI 10.17487/RFC4787, January
2007, <https://www.rfc-editor.org/info/rfc4787>. 2007, <https://www.rfc-editor.org/info/rfc4787>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<https://www.rfc-editor.org/info/rfc4941>.
[RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol",
RFC 4960, DOI 10.17487/RFC4960, September 2007, RFC 4960, DOI 10.17487/RFC4960, September 2007,
<https://www.rfc-editor.org/info/rfc4960>. <https://www.rfc-editor.org/info/rfc4960>.
[RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common [RFC4987] Eddy, W., "TCP SYN Flooding Attacks and Common
Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007, Mitigations", RFC 4987, DOI 10.17487/RFC4987, August 2007,
<https://www.rfc-editor.org/info/rfc4987>. <https://www.rfc-editor.org/info/rfc4987>.
[RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig, [RFC5077] Salowey, J., Zhou, H., Eronen, P., and H. Tschofenig,
"Transport Layer Security (TLS) Session Resumption without "Transport Layer Security (TLS) Session Resumption without
skipping to change at page 84, line 7 skipping to change at page 89, line 15
[RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG", [RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG",
RFC 7951, DOI 10.17487/RFC7951, August 2016, RFC 7951, DOI 10.17487/RFC7951, August 2016,
<https://www.rfc-editor.org/info/rfc7951>. <https://www.rfc-editor.org/info/rfc7951>.
[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage [RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage
Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,
March 2017, <https://www.rfc-editor.org/info/rfc8085>. March 2017, <https://www.rfc-editor.org/info/rfc8085>.
Authors' Addresses Authors' Addresses
Tirumaleswar Reddy Tirumaleswar Reddy (editor)
McAfee, Inc. McAfee, Inc.
Embassy Golf Link Business Park Embassy Golf Link Business Park
Bangalore, Karnataka 560071 Bangalore, Karnataka 560071
India India
Email: kondtir@gmail.com Email: kondtir@gmail.com
Mohamed Boucadair Mohamed Boucadair (editor)
Orange Orange
Rennes 35000 Rennes 35000
France France
Email: mohamed.boucadair@orange.com Email: mohamed.boucadair@orange.com
Prashanth Patil Prashanth Patil
Cisco Systems, Inc. Cisco Systems, Inc.
Email: praspati@cisco.com Email: praspati@cisco.com
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