DOTS                                                            T. Reddy
Internet-Draft                                                    McAfee
Intended status: Standards Track                            M. Boucadair
Expires: February 19, 2018                                        Orange
                                                            K. Nishizuka
                                                      NTT Communications
                                                                  L. Xia
                                                                  Huawei
                                                                P. Patil
                                                                   Cisco
                                                            A. Mortensen
                                                    Arbor Networks, Inc.
                                                               N. Teague
                                                          Verisign, Inc.
                                                         August 18, 2017


Distributed Denial-of-Service Open Threat Signaling (DOTS) Data Channel
                    draft-ietf-dots-data-channel-03

Abstract

   The document specifies a Distributed Denial-of-Service Open Threat
   Signaling (DOTS) data channel used for bulk exchange of data not
   easily or appropriately communicated through the DOTS signal channel
   under attack conditions.  This is a companion document to the DOTS
   signal channel specification.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on February 19, 2018.







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Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Notational Conventions and Terminology  . . . . . . . . . . .   4
   3.  DOTS Data Channel . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  DOTS Data Channel YANG Model  . . . . . . . . . . . . . .   6
       3.1.1.  Identifier Model structure  . . . . . . . . . . . . .   6
       3.1.2.  Identifier Model  . . . . . . . . . . . . . . . . . .   6
       3.1.3.  Filter Model structure  . . . . . . . . . . . . . . .   8
       3.1.4.  Filter Model  . . . . . . . . . . . . . . . . . . . .   9
     3.2.  Identifiers . . . . . . . . . . . . . . . . . . . . . . .  11
       3.2.1.  Create Identifiers  . . . . . . . . . . . . . . . . .  11
       3.2.2.  Delete Identifiers  . . . . . . . . . . . . . . . . .  13
       3.2.3.  Retrieving Installed Identifiers  . . . . . . . . . .  14
     3.3.  Filtering Rules . . . . . . . . . . . . . . . . . . . . .  16
       3.3.1.  Install Filtering Rules . . . . . . . . . . . . . . .  16
       3.3.2.  Remove Filtering Rules  . . . . . . . . . . . . . . .  18
       3.3.3.  Retrieving Installed Filtering Rules  . . . . . . . .  18
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  19
     4.1.  DOTS Data Channel JSON Attribute Mappings Registry  . . .  19
     4.2.  Registration Template . . . . . . . . . . . . . . . . . .  19
     4.3.  Initial Registry Contents . . . . . . . . . . . . . . . .  19
   5.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  21
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  21
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  21
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  22
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  22
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  23
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24







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1.  Introduction

   A distributed denial-of-service (DDoS) attack is an attempt to make
   machines or network resources unavailable to their intended users.
   In most cases, sufficient scale can be achieved by compromising
   enough end-hosts and using those infected hosts to perpetrate and
   amplify the attack.  The victim in this attack can be an application
   server, a client, a router, a firewall, or an entire network.

   DDoS Open Threat Signaling (DOTS) defines two channels: signal and
   data channels [I-D.ietf-dots-architecture] (Figure 1).  The DOTS
   signal channel used to convey that a network is under a DDOS attack
   to an upstream DOTS server so that appropriate mitigation actions are
   undertaken on the suspect traffic is further elaborated in
   [I-D.ietf-dots-signal-channel].  The DOTS data channel is used for
   infrequent bulk data exchange between DOTS agents in the aim to
   significantly augment attack response coordination.

     +---------------+                                 +---------------+
     |               | <------- Signal Channel ------> |               |
     |  DOTS Client  |                                 |  DOTS Server  |
     |               | <=======  Data Channel  ======> |               |
     +---------------+                                 +---------------+

                          Figure 1: DOTS Channels

   Section 2 of [I-D.ietf-dots-architecture] identifies that the DOTS
   data channel is used to perform the tasks listed below:

   o  Filter management, which enables a DOTS client to request the
      installation or removal of traffic filters, dropping or rate-
      limiting unwanted traffic and permitting white-listed traffic.
      Sample use cases for populating black- or white-list filtering
      rules are detailed hereafter:

      A.  If a network resource (DOTS client) detects a potential DDoS
          attack from a set of IP addresses, the DOTS client informs its
          servicing router (DOTS gateway) of all suspect IP addresses
          that need to be blocked or black-listed for further
          investigation.  The DOTS client could also specify a list of
          protocols and ports in the black-list rule.  That DOTS gateway
          in-turn propagates the black-listed IP addresses to the DOTS
          server which will undertake appropriate action so that traffic
          from these IP addresses to the target network (specified by
          the DOTS client) is blocked.

      B.  A network has partner sites from which only legitimate traffic
          arrives and the network wants to ensure that the traffic from



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          these sites is not penalized during DDOS attacks.  The DOTS
          client uses the DOTS data channel to convey the white-listed
          IP addresses or prefixes of the partner sites to its DOTS
          server.  The DOTS server uses this information to white-list
          flows from such IP addresses or prefixes reaching the network.

   o  Creating identifiers, such as names or aliases, for resources for
      which mitigation may be requested:

      A.  The DOTS client may submit to the DOTS server a collection of
          prefixes which it would like to refer to by alias when
          requesting mitigation.  The server can respond to this request
          with either with a success or failure response (see
          requirement OP-006 in [I-D.ietf-dots-requirements] and
          Section 2 in [I-D.ietf-dots-architecture]).

2.  Notational Conventions and Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   The reader should be familiar with the terms defined in
   [I-D.ietf-dots-architecture].

   For simplicity, all of the examples in this document use "/restconf"
   as the discovered RESTCONF API root path.  Many protocol header lines
   and message-body text within examples throughout the document are
   split into multiple lines for display purposes only.  When a line
   ends with backslash ('\') as the last character, the line is wrapped
   for display purposes.  It is to be considered to be joined to the
   next line by deleting the backslash, the following line break, and
   the leading whitespace of the next line.

3.  DOTS Data Channel

   The DOTS data channel is intended to be used for bulk data exchanges
   between DOTS agents.  Unlike the signal channel, which must operate
   nominally even when confronted with signal degradation due to packet
   loss, the data channel is not expected to be constructed to deal with
   DDoS attack conditions.

   As the primary function of the data channel is data exchange, a
   reliable transport is required in order for DOTS agents to detect
   data delivery success or failure.  RESTCONF [RFC8040] over TLS
   [RFC5246] over TCP is used for DOTS data channel (Figure 2).
   RESTCONF uses HTTP methods to provide CRUD operations on a conceptual
   datastore containing YANG-defined data, which is compatible with a



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   server which implements NETCONF datastores.  The HTTP POST, PUT,
   PATCH, and DELETE methods are used to edit data resources represented
   by DOTS data channel YANG data models.  These basic edit operations
   allow the DOTS data channel running configuration to be altered by a
   DOTS client.  DOTS data channel configuration data and state data can
   be retrieved with the GET method.  HTTP status codes are used to
   report success or failure for RESTCONF operations.  The DOTS client
   will perform the root resource discovery procedure discussed in
   Section 3.1 of [RFC8040] to determine the root of the RESTCONF API.
   After discovering the RESTCONF API root, the DOTS client MUST use
   this value as the initial part of the path in the request URI, in any
   subsequent request to the DOTS server.  The DOTS server can
   optionally support retrieval of the YANG modules it supports
   (Section 3.7 in [RFC8040]), for example, DOTS client can use RESTCONF
   to retrieve the company proprietary YANG model supported by the DOTS
   server.

   Note: This document uses RESTCONF, a protocol based on HTTP
   [RFC7230], for configuring data defined in YANG version 1 [RFC6020]
   or YANG version 1.1 [RFC7950], using the datastore concepts defined
   in the Network Configuration Protocol (NETCONF) [RFC6241].  RESTCONF
   combines the simplicity of the HTTP protocol with the predictability
   and automation potential of a schema-driven API.  RESTCONF offers a
   simple subset of NETCONF functionality and provides a simplified
   interface using REST-like API which addresses the needs of the DOTS
   data channel and hence an optimal choice.

                                  +--------------+
                                  |     DOTS     |
                                  +--------------+
                                  |   RESTCONF   |
                                  +--------------+
                                  |     TLS      |
                                  +--------------+
                                  |     TCP      |
                                  +--------------+
                                  |     IP       |
                                  +--------------+

    Figure 2: Abstract Layering of DOTS data channel over RESTCONF over
                                    TLS

   JavaScript Object Notation (JSON) [RFC7159] payload is used to
   propagate data channel specific payload messages that convey request
   parameters and response information such as errors.  This
   specification uses the encoding rules defined in [RFC7951] for
   representing DOTS data channel configuration data defined using YANG
   (Section 3.1) as JSON text.



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   A DOTS client registers itself to its DOTS server(s) in order to set
   up DOTS data channel related configuration data on the DOTS server
   and receive state data (i.e., non-configuration data) from the DOTS
   server.  A single DOTS data channel between DOTS agents can be used
   to exchange multiple requests and multiple responses.  To reduce DOTS
   client and DOTS server workload, DOTS client SHOULD re-use the TLS
   session.  While the communication to the DOTS server is quiescent,
   the DOTS client MAY probe the server to ensure it has maintained
   cryptographic state.  Such probes can also keep alive firewall or NAT
   bindings.  A TLS heartbeat [RFC6520] verifies the DOTS server still
   has TLS state by returning a TLS message.

3.1.  DOTS Data Channel YANG Model

3.1.1.  Identifier Model structure

   This document defines a YANG [RFC6020] data model for creating
   identifiers, such as names or aliases, for resources for which
   mitigation may be requested.  Such identifiers may then be used in
   subsequent DOTS signal channel exchanges to refer more efficiently to
   the resources under attack.

   This document defines the YANG module "ietf-dots-data-channel-
   identifier", which has the following structure:

   module: ietf-dots-data-channel-identifier
       +--rw identifier
          +--rw alias* [alias-name]
             +--rw alias-name           string
             +--rw target-ip*           inet:ip-address
             +--rw target-prefix*       inet:ip-prefix
             +--rw target-port-range* [lower-port upper-port]
             |  +--rw lower-port    inet:port-number
             |  +--rw upper-port    inet:port-number
             +--rw target-protocol*     uint8
             +--rw fqdn*                inet:domain-name
             +--rw uri*                 inet:uri

3.1.2.  Identifier Model

<CODE BEGINS> file "ietf-dots-data-channel-identifier@2017-08-03.yang"

module ietf-dots-data-channel-identifier {
      namespace "urn:ietf:params:xml:ns:yang:ietf-dots-data-channel-identifier";
      prefix "alias";
      import ietf-inet-types {
          prefix "inet";
      }



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     organization "McAfee, Inc.";
     contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>";

     description
       "This module contains YANG definition for
        configuring identifiers for resources using DOTS data channel";

     revision 2017-08-03 {
       reference
       "https://tools.ietf.org/html/draft-ietf-dots-data-channel";
     }

     container identifier {
          description "top level container for identifiers";
              list alias {
                   key alias-name;
                   description "list of identifiers";
                   leaf alias-name {
                      type string;
                      description "alias name";
                   }
                   leaf-list target-ip {
                      type inet:ip-address;
                      description "IPv4 or IPv6 address identifyting the target.";
                   }
                   leaf-list target-prefix {
                      type inet:ip-prefix;
                      description "IPv4 or IPv6 prefix identifyting the target.";
                   }
                   list target-port-range {
                      key "lower-port upper-port";
                      description
                           "Port range. When only lower-port is present,
                            it represents a single port.";
                      leaf lower-port {
                         type inet:port-number;
                         mandatory true;
                         description "Lower port number.";
                      }
                      leaf upper-port {
                         type inet:port-number;
                         must ". >= ../lower-port" {
                           error-message
                           "The upper-port must be greater than or
                            equal to lower-port";
                         }
                         description "Upper port number.";
                      }



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                   }
                   leaf-list target-protocol {
                      type uint8;
                      description "Identifies the target protocol number.";
                   }
                   leaf-list fqdn {
                     type inet:domain-name;
                     description "FQDN";
                   }
                   leaf-list uri {
                     type inet:uri;
                     description "URI";
                   }
              }
     }
  }
 <CODE ENDS>

3.1.3.  Filter Model structure

   This document extends the "ietf-access-control-list" Access Control
   List (ACL) YANG data model [I-D.ietf-netmod-acl-model] for the
   configuration of filtering rules.  ACL is explained in Section 1 of
   [I-D.ietf-netmod-acl-model].

   Examples of such configuration include:

   o  Black-list management, which enables a DOTS client to inform the
      DOTS server about sources from which traffic should be suppressed.

   o  White-list management, which enables a DOTS client to inform the
      DOTS server about sources from which traffic should always be
      accepted.

   o  Filter management, which enables a DOTS client to request the
      installation or removal of traffic filters, dropping or rate-
      limiting unwanted traffic and permitting white-listed traffic.

   This document defines the YANG module "ietf-dots-access-control-list"
   to extend the "ietf-access-control-list" module to handle fragmented
   packets and to support rate-limit action.  Filtering fragments adds
   an additional layer of protection against a denial-of-service (DoS)
   attack that uses only noninitial fragments.  When there is only Layer
   3 information in the ACL entry and the fragments keyword is present,
   for noninitial fragments matching the ACL entry, the deny or permit
   action associated with the ACL entry will be enforced and for initial
   or non-fragment matching the ACL entry, the the next ACL entry will
   be processed.  When there is both Layer 3 and Layer 4 information in



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   the ACL entry and the fragments keyword is present, the ACL action is
   conservative for both permit and deny actions.  The actions are
   conservative to not accidentally deny a fragmented portion of a flow
   because the fragments do not contain sufficient information to match
   all of the filter attributes.  In the deny action case, instead of
   denying a non-initial fragment, the next ACL entry is processed.  In
   the permit case, it is assumed that the Layer 4 information in the
   non-initial fragment, if available, matches the Layer 4 information
   in the ACL entry.

   The "ietf-dots-access-control-list" module has the following
   structure:

module: ietf-dots-access-control-list
  augment /ietf-acl:access-lists/ietf-acl:acl/ietf-acl:access-list-entries/ietf-acl:ace/ietf-acl:actions/ietf-acl:packet-handling:
    +--:(rate-limit)
       +--rw rate-limit?   decimal64
  augment /ietf-acl:access-lists/ietf-acl:acl/ietf-acl:access-list-entries/ietf-acl:ace:
    +--rw fragments?   empty

3.1.4.  Filter Model

   This YANG module augments the "ietf-access-control-list" YANG data
   model defined in [I-D.ietf-netmod-acl-model].



























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<CODE BEGINS> file "ietf-dots-access-control-list@2017-06-12.yang"

module ietf-dots-access-control-list {
      namespace "urn:ietf:params:xml:ns:yang:ietf-dots-access-control-list";
      prefix "dots-acl";
      import ietf-access-control-list {
       prefix "ietf-acl";
      }
      organization "McAfee, Inc.";
      contact "Konda, Tirumaleswar Reddy <TirumaleswarReddy_Konda@McAfee.com>";

      description
       "This module contains YANG definition for
        configuring filtering rules using DOTS data channel";

      revision 2017-06-12 {
       reference
       "https://tools.ietf.org/html/draft-ietf-dots-data-channel";
      }

    augment "/ietf-acl:access-lists/ietf-acl:acl/ietf-acl:access-list-entries/ietf-acl:ace/ietf-acl:actions/ietf-acl:packet-handling" {

      description "rate-limit action";

      case rate-limit {
        leaf rate-limit {
          type decimal64 {
           fraction-digits 2;
          }
          description "rate-limit action.";
        }
      }
    }

    augment "/ietf-acl:access-lists/ietf-acl:acl/ietf-acl:access-list-entries/ietf-acl:ace" {

      description "handle non-intial and initial fragments";

      leaf fragments {
          type empty;
          description "handle fragments.";
      }
    }
}
 <CODE ENDS>






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3.2.  Identifiers

3.2.1.  Create Identifiers

   A POST request is used to create identifiers, such as names or
   aliases, for resources for which a mitigation may be requested.  Such
   identifiers may then be used in subsequent DOTS signal channel
   exchanges to refer more efficiently to the resources under attack
   (Figure 3).

    POST /restconf/data/ietf-dots-data-channel-identifier HTTP/1.1
    Host: {host}:{port}
    Content-Format: "application/yang.api+json"
    {
     "ietf-dots-data-channel-identifier:identifier": {
       "alias": [
         {
           "alias-name": "string",
           "target-ip": [
             "string"
           ],
           "target-prefix": [
             "string"
           ],
           "target-port-range": [
             {
               "lower-port": integer,
               "upper-port": integer
             }
           ],
           "target-protocol": [
             integer
           ],
           "fqdn": [
             "string"
           ],
           "uri": [
             "string"
           ]
         }
       ]
     }
   }


                   Figure 3: POST to create identifiers

   The header parameters are described below:



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   alias-name:  Name of the alias.  This is a mandatory attribute.

   target-ip:  IP addresses are separated by commas.  This is an
      optional attribute.

   target-prefix:   Prefixes are separated by commas.  This is an
      optional attribute.

   target-port-range:   The port range, lower-port for lower port number
      and upper-port for upper port number.  For TCP, UDP, SCTP, or
      DCCP: the range of ports (e.g., 80 to 8080).  This is an optional
      attribute.

   target-protocol:   Values are taken from the IANA protocol registry
      [proto_numbers].  The value 0 has a special meaning for 'all
      protocols'.  This is an optional attribute.

   fqdn:   Fully Qualified Domain Name, is the full name of a system,
      rather than just its hostname.  For example, "venera" is a
      hostname, and "venera.isi.edu" is an FQDN.  This is an optional
      attribute.

   uri:   Uniform Resource Identifier (URI).  This is an optional
      attribute.

   In the POST request at least one of the attributes ip or prefix or
   fqdn or uri MUST be present.  DOTS agents can safely ignore Vendor-
   Specific parameters they don't understand.

   Figure 4 shows a POST request to create alias called "https1" for
   HTTP(S) servers with IP addresses 2001:db8:6401::1 and
   2001:db8:6401::2 listening on port 443.



















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   POST /restconf/data/ietf-dots-data-channel-identifier HTTP/1.1
   Host: www.example.com
   Content-Format: "application/yang.api+json"
   {
     "ietf-dots-data-channel-identifier:identifier": {
       "alias": [
         {
           "alias-name": "Server1",
           "target-protocol": [
             6
           ],
           "target-ip": [
             "2001:db8:6401::1",
             "2001:db8:6401::2"
           ],
           "target-port-range": [
             {
               "lower-port": 443
             }
           ]
         }
       ]
     }
   }

                   Figure 4: POST to create identifiers

   The DOTS server indicates the result of processing the POST request
   using HTTP response codes.  HTTP 2xx codes are success, HTTP 4xx
   codes are some sort of invalid requests and 5xx codes are returned if
   the DOTS server has erred or it is incapable of accepting the alias.
   Response code 201 (Created) will be returned in the response if the
   DOTS server has accepted the alias.  If the request is missing one or
   more mandatory attributes then 400 (Bad Request) will be returned in
   the response or if the request contains invalid or unknown parameters
   then 400 (Invalid query) will be returned in the response.  The HTTP
   response will include the JSON body received in the request.

   The DOTS client can use the PUT request (Section 4.5 in [RFC8040]) to
   create or modify the aliases in the DOTS server.

3.2.2.  Delete Identifiers

   A DELETE request is used to delete identifiers maintained by a DOTS
   server (Figure 5).






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     DELETE /restconf/data/ietf-dots-data-channel-identifier:identifier\
            /alias=Server1 HTTP/1.1
     Host: {host}:{port}

                        Figure 5: DELETE identifier

   In RESTCONF, URI-encoded path expressions are used.  A RESTCONF data
   resource identifier is encoded from left to right, starting with the
   top-level data node, according to the "api-path" rule defined in
   Section 3.5.3.1 of [RFC8040].  The data node in the above path
   expression is a YANG list node and MUST be encoded according to the
   rules defined in Section 3.5.1 of [RFC8040].

   If the DOTS server does not find the alias name conveyed in the
   DELETE request in its configuration data, then it responds with a 404
   (Not Found) error response code.  The DOTS server successfully
   acknowledges a DOTS client's request to remove the identifier using
   204 (No Content) in the response.

3.2.3.  Retrieving Installed Identifiers

   A GET request is used to retrieve the set of installed identifiers
   from a DOTS server (Section 3.3.1 in [RFC8040]).  Figure 6 shows how
   to retrieve all the identifiers that were instantiated by the DOTS
   client.  The content parameter and its permitted values are defined
   in Section 4.8.1 of [RFC8040].

     GET /restconf/data/ietf-dots-data-channel-identifier:identifier?\
         content=config HTTP/1.1
     Host: {host}:{port}
     Accept: application/yang-data+json

          Figure 6: GET to retrieve all the installed identifiers

   Figure 7 shows response for all identifiers on the DOTS server.
















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   {
    "ietf-dots-data-channel-identifier:identifier": [
     {
       "alias": [
         {
           "alias-name": "Server1",
           "traffic-protocol": [
             6
           ],
           "ip": [
             "2001:db8:6401::1",
             "2001:db8:6401::2"
           ],
           "port-range": [
             {
               "lower-port": 443
             }
           ]
         }
       ]
     },
     {
       "alias": [
         {
           "alias-name": "Server2",
           "traffic-protocol": [
             6
           ],
           "ip": [
             "2001:db8:6401::10",
             "2001:db8:6401::20"
           ],
           "port-range": [
             {
               "lower-port": 80
             }
           ]
         }
       ]
     }
    ]
   }

                          Figure 7: Response body

   If the DOTS server does not find the alias name conveyed in the GET
   request in its configuration data, then it responds with a 404 (Not
   Found) error response code.



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3.3.  Filtering Rules

   The DOTS server either receives the filtering rules directly from the
   DOTS client or via the DOTS gateway.  If the DOTS client signals the
   filtering rules via the DOTS gateway then the DOTS gateway validates
   if the DOTS client is authorized to signal the filtering rules and if
   the client is authorized propagates the rules to the DOTS server.
   Likewise, the DOTS server validates if the DOTS gateway is authorized
   to signal the filtering rules.  To create or purge filters, the DOTS
   client sends HTTP requests to the DOTS gateway.  The DOTS gateway
   validates the rules in the requests and proxies the requests
   containing the filtering rules to a DOTS server.  When the DOTS
   gateway receives the associated HTTP response from the DOTS server,
   it propagates the response back to the DOTS client.

   The following APIs define means for a DOTS client to configure
   filtering rules on a DOTS server.

3.3.1.  Install Filtering Rules

   A POST request is used to push filtering rules to a DOTS server.
   Figure 8 shows a POST request example to block traffic from
   192.0.2.0/24, destined to 198.51.100.0/24.  The ACL JSON
   configuration for the filtering rule is generated using the ACL YANG
   data model defined in [I-D.ietf-netmod-acl-model] and the ACL
   configuration XML for the filtering rule is specified in Section 4.3
   of [I-D.ietf-netmod-acl-model].
























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  POST /restconf/data/ietf-access-control-list HTTP/1.1
  Host: www.example.com
  Content-Format: "application/yang.api+json"
  {
   "ietf-access-control-list:access-lists": {
      "acl": [
          {
               "acl-name": "sample-ipv4-acl",
               "acl-type": "ipv4",
               "access-list-entries": {
                   "ace": [
                       {
                           "rule-name": "rule1",
                           "matches": {
                               "source-ipv4-network": "192.0.2.0/24",
                               "destination-ipv4-network": "198.51.100.0/24"
                            },
                            "actions": {
                                "deny": [null]
                            }
                        }
                    ]
               }
          }
      ]
   }
  }

                 Figure 8: POST to install filterng rules

   The header parameters defined in [I-D.ietf-netmod-acl-model] are
   discussed below:

   acl-name:  The name of access-list.  This is a mandatory attribute.

   acl-type:  Indicates the primary intended type of match criteria
      (e.g.  IPv4, IPv6).  This is a mandatory attribute.

   protocol:   Internet Protocol numbers.  This is an optional
      attribute.

   source-ipv4-network:  The source IPv4 prefix.  This is an optional
      attribute.

   destination-ipv4-network:  The destination IPv4 prefix.  This is an
      optional attribute.





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   actions:   "deny" or "permit" or "rate-limit".  "permit" action is
      used to white-list traffic. "deny" action is used to black-list
      traffic. "rate-limit" action is used to rate-limit traffic, the
      allowed traffic rate is represented in bytes per second indicated
      in IEEE floating point format [IEEE.754.1985].  If actions
      attribute is not specified in the request then the default action
      is "deny".  This is an optional attribute.

   The DOTS server indicates the result of processing the POST request
   using HTTP response codes.  HTTP 2xx codes are success, HTTP 4xx
   codes are some sort of invalid requests and 5xx codes are returned if
   the DOTS server has erred or it is incapable of configuring the
   filtering rules.  Response code 201 (Created) will be returned in the
   response if the DOTS server has accepted the filtering rules.  If the
   request is missing one or more mandatory attributes then 400 (Bad
   Request) will be returned in the response or if the request contains
   invalid or unknown parameters then 400 (Invalid query) will be
   returned in the response.

   The DOTS client can use the PUT request to create or modify the
   filtering rules in the DOTS server.

3.3.2.  Remove Filtering Rules

   A DELETE request is used to delete filtering rules from a DOTS server
   (Figure 9).

   DELETE /restconf/data/ietf-access-control-list:access-lists/acl-name\
          =sample-ipv4-acl&acl-type=ipv4 HTTP/1.1
   Host: {host}:{port}

              Figure 9: DELETE to remove the filtering rules

   If the DOTS server does not find the access list name and access list
   type conveyed in the DELETE request in its configuration data, then
   it responds with a 404 (Not Found) error response code.  The DOTS
   server successfully acknowledges a DOTS client's request to withdraw
   the filtering rules using 204 (No Content) response code, and removes
   the filtering rules as soon as possible.

3.3.3.  Retrieving Installed Filtering Rules

   The DOTS client periodically queries the DOTS server to check the
   counters for installed filtering rules.  A GET request is used to
   retrieve filtering rules from a DOTS server.  Figure 10 shows how to
   retrieve all the filtering rules programmed by the DOTS client and
   the number of matches for the installed filtering rules.




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  GET /restconf/data/ietf-access-control-list:access-lists?content=all HTTP/1.1
  Host: {host}:{port}
  Accept: application/yang-data+json

   Figure 10: GET to retrieve the configuration data and state data for
                            the filtering rules

   If the DOTS server does not find the access list name and access list
   type conveyed in the GET request in its configuration data, then it
   responds with a 404 (Not Found) error response code.

4.  IANA Considerations

   This specification registers new parameters for the DOTS data channel
   and establishes registries for mappings to JSON attributes.

4.1.  DOTS Data Channel JSON Attribute Mappings Registry

   A new registry will be requested from IANA, entitled "DOTS data
   channel JSON attribute Mappings Registry".  The registry is to be
   created as Expert Review Required.

4.2.  Registration Template

   JSON Attribute:
      JSON attribute name.

   Description:
      Brief description of the attribute.

   Change Controller:
      For Standards Track RFCs, list the "IESG".  For others, give the
      name of the responsible party.  Other details (e.g., postal
      address, email address, home page URI) may also be included.

   Specification Document(s):
      Reference to the document or documents that specify the parameter,
      preferably including URIs that can be used to retrieve copies of
      the documents.  An indication of the relevant sections may also be
      included but is not required.

4.3.  Initial Registry Contents

   o  JSON Attribute: "alias-name"
   o  Description: Name of alias.
   o  Change Controller: IESG
   o  Specification Document(s): this document




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   o  JSON Attribute: "traffic-protocol"
   o  Description: Internet protocol numbers.
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "port-range"
   o  Description: The port range, lower-port for lower port number and
      upper-port for upper port number.  For TCP, UDP, SCTP, or DCCP:
      the range of ports (e.g., 80 to 8080).
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "lower-port"
   o  Description: Lower port number for port range.
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "upper-port"
   o  Description: Upper port number for port range.
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "ip"
   o  Description: IP address.
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "prefix"
   o  Description: IP prefix
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "fqdn"
   o  Description: Fully Qualified Domain Name, is the full name of a
      system, rather than just its hostname.  For example, "venera" is a
      hostname, and "venera.isi.edu" is an FQDN.
   o  Change Controller: IESG
   o  Specification Document(s): this document

   o  JSON Attribute: "uri"
   o  Description: Uniform Resource Identifier (URI).
   o  Change Controller: IESG
   o  Specification Document(s): this document








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5.  Contributors

   The following individuals have contributed to this document:

   Dan Wing

   Email: dwing-ietf@fuggles.com

6.  Security Considerations

   Authenticated encryption MUST be used for data confidentiality and
   message integrity.  TLS based on client certificate MUST be used for
   mutual authentication.  The interaction between the DOTS agents
   requires Transport Layer Security (TLS) with a cipher suite offering
   confidentiality protection and the guidance given in [RFC7525] MUST
   be followed to avoid attacks on TLS.

   An attacker may be able to inject RST packets, bogus application
   segments, etc., regardless of whether TLS authentication is used.
   Because the application data is TLS protected, this will not result
   in the application receiving bogus 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 any bogus packets injected by an
   attacker will be rejected by the TCP-AO integrity check and therefore
   will never reach the TLS layer.

   Special care should be taken in order to ensure that the activation
   of the proposed mechanism won't have an impact on the stability of
   the network (including connectivity and services delivered over that
   network).

   Involved functional elements in the cooperation system must establish
   exchange instructions and notification over a secure and
   authenticated channel.  Adequate filters can be enforced to avoid
   that nodes outside a trusted domain can inject request such as
   deleting filtering rules.  Nevertheless, attacks can be initiated
   from within the trusted domain if an entity has been corrupted.
   Adequate means to monitor trusted nodes should also be enabled.

7.  Acknowledgements

   Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen,
   Roman Danyliw, Ehud Doron, Russ White, Jon Shallow and Gilbert Clark
   for the discussion and comments.







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8.  References

8.1.  Normative References

   [I-D.ietf-dots-architecture]
              Mortensen, A., Andreasen, F., Reddy, T.,
              christopher_gray3@cable.comcast.com, c., Compton, R., and
              N. Teague, "Distributed-Denial-of-Service Open Threat
              Signaling (DOTS) Architecture", draft-ietf-dots-
              architecture-04 (work in progress), July 2017.

   [I-D.ietf-netmod-acl-model]
              Bogdanovic, D., Jethanandani, M., Huang, L., Agarwal, S.,
              and D. Blair, "Network Access Control List (ACL) YANG Data
              Model", draft-ietf-netmod-acl-model-11 (work in progress),
              June 2017.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997, <https://www.rfc-
              editor.org/info/rfc2119>.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246,
              DOI 10.17487/RFC5246, August 2008, <https://www.rfc-
              editor.org/info/rfc5246>.

   [RFC5925]  Touch, J., Mankin, A., and R. Bonica, "The TCP
              Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
              June 2010, <https://www.rfc-editor.org/info/rfc5925>.

   [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
              Protocol (HTTP/1.1): Message Syntax and Routing",
              RFC 7230, DOI 10.17487/RFC7230, June 2014,
              <https://www.rfc-editor.org/info/rfc7230>.

   [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
              2015, <https://www.rfc-editor.org/info/rfc7525>.

   [RFC7951]  Lhotka, L., "JSON Encoding of Data Modeled with YANG",
              RFC 7951, DOI 10.17487/RFC7951, August 2016,
              <https://www.rfc-editor.org/info/rfc7951>.






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   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

8.2.  Informative References

   [I-D.ietf-dots-requirements]
              Mortensen, A., Moskowitz, R., and T. Reddy, "Distributed
              Denial of Service (DDoS) Open Threat Signaling
              Requirements", draft-ietf-dots-requirements-06 (work in
              progress), July 2017.

   [I-D.ietf-dots-signal-channel]
              Reddy, T., Boucadair, M., Patil, P., Mortensen, A., and N.
              Teague, "Distributed Denial-of-Service Open Threat
              Signaling (DOTS) Signal Channel", draft-ietf-dots-signal-
              channel-03 (work in progress), August 2017.

   [IEEE.754.1985]
              Institute of Electrical and Electronics Engineers,
              "Standard for Binary Floating-Point Arithmetic", August
              1985.

   [proto_numbers]
              "IANA, "Protocol Numbers"", 2011,
              <http://www.iana.org/assignments/protocol-numbers>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010, <https://www.rfc-
              editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6520]  Seggelmann, R., Tuexen, M., and M. Williams, "Transport
              Layer Security (TLS) and Datagram Transport Layer Security
              (DTLS) Heartbeat Extension", RFC 6520,
              DOI 10.17487/RFC6520, February 2012, <https://www.rfc-
              editor.org/info/rfc6520>.

   [RFC7159]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
              2014, <https://www.rfc-editor.org/info/rfc7159>.





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   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

Authors' Addresses

   Tirumaleswar Reddy
   McAfee, Inc.
   Embassy Golf Link Business Park
   Bangalore, Karnataka  560071
   India

   Email: kondtir@gmail.com


   Mohamed Boucadair
   Orange
   Rennes  35000
   France

   Email: mohamed.boucadair@orange.com


   Kaname Nishizuka
   NTT Communications
   GranPark 16F 3-4-1 Shibaura, Minato-ku
   Tokyo  108-8118
   Japan

   Email: kaname@nttv6.jp


   Liang Xia
   Huawei
   101 Software Avenue, Yuhuatai District
   Nanjing, Jiangsu  210012
   China

   Email: frank.xialiang@huawei.com


   Prashanth Patil
   Cisco Systems, Inc.

   Email: praspati@cisco.com






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   Andrew Mortensen
   Arbor Networks, Inc.
   2727 S. State St
   Ann Arbor, MI  48104
   United States

   Email: amortensen@arbor.net


   Nik Teague
   Verisign, Inc.
   United States

   Email: nteague@verisign.com





































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