draft-ietf-dots-data-channel-04.xml

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<?rfc tocdepth="3"?>
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<rfc category="std" docName="draft-ietf-dots-data-channel-03"
     ipr="trust200902">
  <front>
    <title abbrev="DOTS Data Channel">Distributed Denial-of-Service Open
    Threat Signaling (DOTS) Data Channel</title>

    <author fullname="Tirumaleswar Reddy" initials="T." surname="Reddy">
      <organization abbrev="McAfee">McAfee, Inc.</organization>

      <address>
        <postal>
          <street>Embassy Golf Link Business Park</street>

          <city>Bangalore</city>

          <region>Karnataka</region>

          <code>560071</code>

          <country>India</country>
        </postal>

        <email>kondtir@gmail.com</email>
      </address>
    </author>

    <author fullname="Mohamed Boucadair" initials="M." surname="Boucadair">
      <organization>Orange</organization>

      <address>
        <postal>
          <street></street>

          <city>Rennes</city>

          <region></region>

          <code>35000</code>

          <country>France</country>
        </postal>

        <email>mohamed.boucadair@orange.com</email>
      </address>
    </author>

    <author fullname="Kaname Nishizuka" initials="K." surname="Nishizuka">
      <organization>NTT Communications</organization>

      <address>
        <postal>
          <street>GranPark 16F 3-4-1 Shibaura, Minato-ku</street>

          <city>Tokyo</city>

          <region></region>

          <code>108-8118</code>

          <country>Japan</country>
        </postal>

        <email>kaname@nttv6.jp</email>
      </address>
    </author>

    <author fullname="Liang Xia" initials="L." surname="Xia">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street>101 Software Avenue, Yuhuatai District</street>

          <city>Nanjing, Jiangsu</city>

          <region></region>

          <code>210012</code>

          <country>China</country>
        </postal>

        <email>frank.xialiang@huawei.com</email>
      </address>
    </author>

    <author fullname="Prashanth Patil" initials="P." surname="Patil">
      <organization abbrev="Cisco">Cisco Systems, Inc.</organization>

      <address>
        <postal>
          <street></street>

          <street></street>

          <city></city>

          <country></country>
        </postal>

        <email>praspati@cisco.com</email>
      </address>
    </author>

    <author fullname="Andrew Mortensen" initials="A." surname="Mortensen">
      <organization>Arbor Networks, Inc.</organization>

      <address>
        <postal>
          <street>2727 S. State St</street>

          <city>Ann Arbor, MI</city>

          <region></region>

          <code>48104</code>

          <country>United States</country>
        </postal>

        <email>amortensen@arbor.net</email>
      </address>
    </author>

    <author fullname="Nik Teague" initials="N." surname="Teague">
      <organization>Verisign, Inc.</organization>

      <address>
        <postal>
          <street></street>

          <city></city>

          <region></region>

          <code></code>

          <country>United States</country>
        </postal>

        <email>nteague@verisign.com</email>
      </address>
    </author>

    <date />

    <workgroup>DOTS</workgroup>

    <abstract>
      <t>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.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="introduction" title="Introduction">
      <t>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.</t>

      <t>DDoS Open Threat Signaling (DOTS) defines two channels: signal and
      data channels <xref target="I-D.ietf-dots-architecture"></xref> (<xref
      target="channels"></xref>). 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 <xref
      target="I-D.ietf-dots-signal-channel"></xref>. The DOTS data channel is
      used for infrequent bulk data exchange between DOTS agents in the aim to
      significantly augment attack response coordination.<figure
          align="center" anchor="channels" title="DOTS Channels">
          <artwork><![CDATA[     +---------------+                                 +---------------+
     |               | <------- Signal Channel ------> |               |
     |  DOTS Client  |                                 |  DOTS Server  |
     |               | <=======  Data Channel  ======> |               |
     +---------------+                                 +---------------+]]></artwork>
        </figure></t>

      <t>Section 2 of <xref target="I-D.ietf-dots-architecture"></xref>
      identifies that the DOTS data channel is used to perform the tasks
      listed below:</t>

      <t><list style="symbols">
          <t>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: <list style="letters">
              <t>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.</t>

              <t>A network has partner sites from which only legitimate
              traffic arrives and the network wants to ensure that the traffic
              from 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.</t>
            </list></t>

          <t>Creating identifiers, such as names or aliases, for resources for
          which mitigation may be requested:<list style="letters">
              <t>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 <xref target="I-D.ietf-dots-requirements"></xref> and
              Section 2 in <xref
              target="I-D.ietf-dots-architecture"></xref>).</t>
            </list></t>
        </list></t>
    </section>

    <section anchor="notation" title="Notational Conventions and Terminology">
      <t>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 <xref
      target="RFC2119"></xref>.</t>

      <t>The reader should be familiar with the terms defined in <xref
      target="I-D.ietf-dots-architecture"></xref>.</t>

      <t>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.</t>
    </section>

    <section title="DOTS Data Channel">
      <t>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.</t>

      <t>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 <xref target="RFC8040"></xref>
      over TLS <xref target="RFC5246"></xref> over TCP is used for DOTS data
      channel (<xref target="fig_dots2"></xref>). RESTCONF uses HTTP methods
      to provide CRUD operations on a conceptual datastore containing
      YANG-defined data, which is compatible with a 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 <xref target="RFC8040"></xref> 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 <xref target="RFC8040"></xref>), for example,
      DOTS client can use RESTCONF to retrieve the company proprietary YANG
      model supported by the DOTS server.</t>

      <t>Note: This document uses RESTCONF, a protocol based on HTTP <xref
      target="RFC7230"></xref>, for configuring data defined in YANG version 1
      <xref target="RFC6020"></xref> or YANG version 1.1 <xref
      target="RFC7950"></xref>, using the datastore concepts defined in the
      Network Configuration Protocol (NETCONF) <xref target="RFC6241"></xref>.
      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.</t>

      <t><figure anchor="fig_dots2"
          title="Abstract Layering of DOTS data channel over RESTCONF over TLS">
          <artwork align="center"><![CDATA[          +--------------+
          |     DOTS     |
          +--------------+
          |   RESTCONF   |
          +--------------+
          |     TLS      |
          +--------------+
          |     TCP      |
          +--------------+
          |     IP       |
          +--------------+
]]></artwork>
        </figure></t>

      <t>JavaScript Object Notation (JSON) <xref target="RFC7159"> </xref>
      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 <xref
      target="RFC7951"></xref> for representing DOTS data channel
      configuration data defined using YANG (<xref target="YANG"></xref>) as
      JSON text.</t>

      <t>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 <xref
      target="RFC6520"></xref> verifies the DOTS server still has TLS state by
      returning a TLS message.</t>

      <section anchor="YANG" title="DOTS Data Channel YANG Model">
        <section title="Identifier Model Tree Structure">
          <t>This document defines a YANG <xref target="RFC6020"></xref>
          module 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.</t>

          <t>This document defines the YANG module
          "ietf-dots-data-channel-identifier", which has the following tree
          structure:</t>

          <t><figure>
              <artwork><![CDATA[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]]></artwork>
            </figure></t>
        </section>

        <section title="Identifier Model YANG Module">
          <t><figure>
              <artwork><![CDATA[<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";
      }
     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.";
                      }
                   }
                   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>
]]></artwork>
            </figure></t>
        </section>

        <section title="Filter Model YANG Module Tree Structure">
          <t>This document extends the "ietf-access-control-list" Access
          Control List (ACL) YANG module <xref
          target="I-D.ietf-netmod-acl-model"></xref> for the configuration of
          filtering rules. ACL is explained in Section 1 of <xref
          target="I-D.ietf-netmod-acl-model"></xref>.</t>

          <t>Examples of such configuration include:</t>

          <t><list style="symbols">
              <t>Black-list management, which enables a DOTS client to inform
              the DOTS server about sources from which traffic should be
              suppressed.</t>

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

              <t>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.</t>
            </list></t>

          <t>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 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.</t>

          <t>The "ietf-dots-access-control-list" module has the following
          structure:</t>

          <t><figure>
              <artwork><![CDATA[module: ietf-dots-access-control-list
  augment /ietf-acl:access-lists/ietf-acl:acl/ietf-acl:aces/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:aces/ietf-acl:ace:
    +--rw fragments?   empty]]></artwork>
            </figure></t>
        </section>

        <section title="Filter Model YANG Module">
          <t>This YANG module augments the "ietf-access-control-list" YANG
          module defined in <xref
          target="I-D.ietf-netmod-acl-model"></xref>.</t>

          <t><figure>
              <artwork><![CDATA[<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:aces/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:aces/ietf-acl:ace" {

      description "handle non-intial and initial fragments";

      leaf fragments {
          type empty;
          description "handle fragments.";
      }
    }
}
 <CODE ENDS>
]]></artwork>
            </figure></t>
        </section>
      </section>

      <section title="Identifiers">
        <section title="Create Identifiers">
          <t>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
          (<xref target="Figure1"></xref>).</t>

          <t><figure anchor="Figure1" title="POST to create identifiers">
              <artwork align="left"><![CDATA[ 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"
        ]
      }
    ]
  }
}

]]></artwork>
            </figure></t>

          <t>The header parameters are described below:</t>

          <t><list style="hanging">
              <t hangText="alias-name:">Name of the alias. This is a mandatory
              attribute.</t>

              <t hangText="target-ip:">IP addresses are separated by commas.
              This is an optional attribute.</t>

              <t hangText="target-prefix: ">Prefixes are separated by commas.
              This is an optional attribute.</t>

              <t hangText="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.</t>

              <t hangText="target-protocol: ">Values are taken from the IANA
              protocol registry <xref target="proto_numbers"></xref>. The
              value 0 has a special meaning for 'all protocols'. This is an
              optional attribute.</t>

              <t hangText="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.</t>

              <t hangText="uri: ">Uniform Resource Identifier (URI). This is
              an optional attribute.</t>
            </list></t>

          <t>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.</t>

          <t><xref target="Figure2"></xref> 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.</t>

          <t><figure anchor="Figure2" title="POST to create identifiers">
              <artwork align="left"><![CDATA[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
          }
        ]
      }
    ]
  }
}
]]></artwork>
            </figure></t>

          <t>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.</t>

          <t>The DOTS client can use the PUT request (Section 4.5 in <xref
          target="RFC8040"></xref>) to create or modify the aliases in the
          DOTS server.</t>
        </section>

        <section title="Delete Identifiers">
          <t>A DELETE request is used to delete identifiers maintained by a
          DOTS server (<xref target="Figure3"></xref>).</t>

          <figure anchor="Figure3" title="DELETE identifier">
            <artwork align="left"><![CDATA[  DELETE /restconf/data/ietf-dots-data-channel-identifier:identifier\
         /alias=Server1 HTTP/1.1
  Host: {host}:{port}
]]></artwork>
          </figure>

          <t>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 <xref target="RFC8040"></xref>. 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 <xref
          target="RFC8040"></xref>.</t>

          <t>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.</t>
        </section>

        <section title="Retrieving Installed Identifiers">
          <t>A GET request is used to retrieve the set of installed
          identifiers from a DOTS server (Section 3.3.1 in <xref
          target="RFC8040"></xref>). <xref target="Figure4"></xref> 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 <xref target="RFC8040"></xref>.</t>

          <figure anchor="Figure4"
                  title="GET to retrieve all the installed identifiers">
            <artwork align="left"><![CDATA[  GET /restconf/data/ietf-dots-data-channel-identifier:identifier?\
      content=config HTTP/1.1
  Host: {host}:{port}
  Accept: application/yang-data+json]]></artwork>
          </figure>

          <t><xref target="Figure6"></xref> shows response for all identifiers
          on the DOTS server.</t>

          <t><figure anchor="Figure6" title="Response body">
              <artwork align="left"><![CDATA[{
 "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-name": "Server2",
        "traffic-protocol": [
          6
        ], 
        "ip": [
          "2001:db8:6401::10",
          "2001:db8:6401::20"
        ],
        "port-range": [
          {
            "lower-port": 80
          }
        ]
      }
    ]
  }
}
]]></artwork>
            </figure></t>

          <t>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.</t>
        </section>
      </section>

      <section title="Filtering Rules">
        <t>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.</t>

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

        <section title="Install Filtering Rules">
          <t>A POST request is used to push filtering rules to a DOTS server.
          <xref target="Figure7"></xref> 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 <xref
          target="I-D.ietf-netmod-acl-model"></xref> and the ACL configuration
          XML for the filtering rule is specified in Section 4.3 of <xref
          target="I-D.ietf-netmod-acl-model"></xref>.</t>

          <t><figure anchor="Figure7" title="POST to install filterng rules">
              <artwork align="left"><![CDATA[  
  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-acl",
               "aces": {
                   "ace": [
                       {
                           "rule-name": "rule1",
                           "matches": {
                             "ipv4-acl": {
                               "source-ipv4-network": "192.0.2.0/24",
                               "destination-ipv4-network": "198.51.100.0/24"
                             }
                            },
                            "actions": { 
                                "deny": [null] 
                            }
                        }
                    ]
               }
          }   
      ]
   }
  }
]]></artwork>
            </figure></t>

          <t>The header parameters defined in <xref
          target="I-D.ietf-netmod-acl-model"></xref> are discussed below:</t>

          <t><list style="hanging">
              <t hangText="acl-name:">The name of access-list. This is a
              mandatory attribute.</t>

              <t hangText="acl-type:">Indicates the primary intended type of
              match criteria (e.g. IPv4, IPv6). This is a mandatory
              attribute.</t>

              <t hangText="protocol: ">Internet Protocol numbers. This is an
              optional attribute.</t>

              <t hangText="source-ipv4-network:">The source IPv4 prefix. This
              is an optional attribute.</t>

              <t hangText="destination-ipv4-network:">The destination IPv4
              prefix. This is an optional attribute.</t>

              <t hangText="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 <xref
              target="IEEE.754.1985"></xref>. If actions attribute is not
              specified in the request then the default action is "deny". This
              is an optional attribute.</t>
            </list></t>

          <t>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.</t>

          <t>The DOTS client can use the PUT request to create or modify the
          filtering rules in the DOTS server.</t>
        </section>

        <section title="Remove Filtering Rules">
          <t>A DELETE request is used to delete filtering rules from a DOTS
          server (<xref target="Figure9"></xref>).</t>

          <figure anchor="Figure9"
                  title="DELETE to remove the filtering rules">
            <artwork align="left"><![CDATA[  DELETE /restconf/data/ietf-access-control-list:access-lists/acl-name\
         =sample-ipv4-acl&acl-type=ipv4-acl HTTP/1.1
  Host: {host}:{port}
]]></artwork>
          </figure>

          <t>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.</t>
        </section>

        <section title="Retrieving Installed Filtering Rules  ">
          <t>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. <xref
          target="Figure10"></xref> shows how to retrieve all the filtering
          rules programmed by the DOTS client and the number of matches for
          the installed filtering rules.</t>

          <figure anchor="Figure10"
                  title="GET to retrieve the configuration data and state data for the filtering rules">
            <artwork align="left"><![CDATA[  GET /restconf/data/ietf-access-control-list:access-lists?content=all HTTP/1.1
  Host: {host}:{port}
  Accept: application/yang-data+json
]]></artwork>
          </figure>

          <t>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.</t>
        </section>
      </section>
    </section>

    <section title="IANA Considerations">
      <t>This specification registers new parameters for the DOTS data channel
      and establishes registries for mappings to JSON attributes.</t>

      <section title="DOTS Data Channel JSON Attribute Mappings Registry">
        <t>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.</t>
      </section>

      <section title="Registration Template">
        <t><list style="hanging">
            <t hangText="JSON Attribute:"><vspace /> JSON attribute name.</t>

            <t hangText="Description:"><vspace /> Brief description of the
            attribute.</t>

            <t hangText="Change Controller:"><vspace /> 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.</t>

            <t hangText="Specification Document(s):"><vspace /> 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.</t>
          </list></t>
      </section>

      <section title="Initial Registry Contents">
        <t><?rfc subcompact="yes"?><list style="symbols">
            <t>JSON Attribute: "alias-name"</t>

            <t>Description: Name of alias.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "traffic-protocol"</t>

            <t>Description: Internet protocol numbers.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "port-range"</t>

            <t>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).</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "lower-port"</t>

            <t>Description: Lower port number for port range.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "upper-port"</t>

            <t>Description: Upper port number for port range.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "ip"</t>

            <t>Description: IP address.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "prefix"</t>

            <t>Description: IP prefix</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "fqdn"</t>

            <t>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.</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list><list style="symbols">
            <t>JSON Attribute: "uri"</t>

            <t>Description: Uniform Resource Identifier (URI).</t>

            <t>Change Controller: IESG</t>

            <t>Specification Document(s): this document</t>
          </list></t>
      </section>
    </section>

    <section anchor="contr" title="Contributors">
      <t>The following individuals have contributed to this document:</t>

      <t>Dan Wing</t>

      <t>Email: dwing-ietf@fuggles.com</t>
    </section>

    <section anchor="security" title="Security Considerations">
      <t>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 <xref
      target="RFC7525"></xref> MUST be followed to avoid attacks on TLS.</t>

      <t>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 <xref
      target="RFC5925"></xref>. 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.</t>

      <t>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).</t>

      <t>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.</t>
    </section>

    <section anchor="ack" title="Acknowledgements">
      <t>Thanks to Christian Jacquenet, Roland Dobbins, Andrew Mortensen,
      Roman Danyliw, Ehud Doron, Russ White, Jon Shallow and Gilbert Clark for
      the discussion and comments.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include="reference.RFC.2119"?>

      <?rfc include="reference.RFC.7525"?>

      <?rfc include="reference.RFC.5925"
?>

      <?rfc include="reference.RFC.8040"?>

      <?rfc include="reference.I-D.ietf-dots-architecture"?>

      <?rfc include="reference.I-D.ietf-netmod-acl-model"?>

      <?rfc include="reference.RFC.5246"?>

      <?rfc include="reference.RFC.7951"?>

      <?rfc include="reference.RFC.7230"?>
    </references>

    <references title="Informative References">
      <?rfc include="reference.RFC.7159"?>

      <?rfc include="reference.RFC.6020"?>

      <?rfc include="reference.RFC.7950"?>

      <?rfc include="reference.RFC.6520"?>

      <?rfc include="reference.RFC.6241"?>

      <?rfc include="reference.I-D.ietf-dots-requirements"?>

      <?rfc include="reference.I-D.ietf-dots-signal-channel"?>

      <reference anchor="IEEE.754.1985">
        <front>
          <title>Standard for Binary Floating-Point Arithmetic</title>

          <author>
            <organization>Institute of Electrical and Electronics
            Engineers</organization>
          </author>

          <date month="August" year="1985" />
        </front>
      </reference>

      <reference anchor="proto_numbers"
                 target="http://www.iana.org/assignments/protocol-numbers">
        <front>
          <title>IANA, "Protocol Numbers"</title>

          <author>
            <organization></organization>
          </author>

          <date year="2011" />
        </front>
      </reference>
    </references>
  </back>
</rfc>