Yang Data Model for Service Function Chaining
draft-penno-sfc-yang-00

Netmod                                                          R. Penno
Internet-Draft                                                  P. Quinn
Intended status: Standards Track                           Cisco Systems
Expires: June 23, 2014                                 December 20, 2013

             Yang Data Model for Service Function Chaining
                        draft-penno-sfc-yang-00

Abstract

   This document defines a YANG data model that can be used to configure
   and manage Service Function Chains.

Requirements Language

   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 RFC 2119 [RFC2119].

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 June 23, 2014.

Copyright Notice

   Copyright (c) 2013 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

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   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Definitions and Acronyms  . . . . . . . . . . . . . . . . . .   2
   3.  VXLAN-GPE . . . . . . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Module  Structure . . . . . . . . . . . . . . . . . . . .   3
     3.2.  VXLAN -GPE Configuration Model  . . . . . . . . . . . . .   3
   4.  Service Function Chain  . . . . . . . . . . . . . . . . . . .   6
     4.1.  Module Structure  . . . . . . . . . . . . . . . . . . . .   6
     4.2.  Service Function Chain Configuration Model  . . . . . . .   6
   5.  Service Node  . . . . . . . . . . . . . . . . . . . . . . . .   9
     5.1.  Module Structure  . . . . . . . . . . . . . . . . . . . .   9
     5.2.  Service Node Configuration Model  . . . . . . . . . . . .  10
   6.  Service Function Path . . . . . . . . . . . . . . . . . . . .  13
     6.1.  Module Structure  . . . . . . . . . . . . . . . . . . . .  13
     6.2.  Service Function Path Configuration Model . . . . . . . .  13
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  16
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  17
     10.2.  Informative References . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

1.  Introduction

   YANG [RFC6020] is a data definition language that was introduced to
   define the contents of a conceptual data store that allows networked
   devices to be managed using NETCONF [RFC6241].  YANG is proving
   relevant beyond its initial confines, as bindings to other interfaces
   (e.g. ReST) and encodings other than XML (e.g. JSON) are being
   defined.  Furthermore, YANG data models can be used as the basis of
   implementation for other interfaces, such as CLI and programmatic
   APIs.

   This document defines a YANG data model that can be used to configure
   and manage Service Function Chains

2.  Definitions and Acronyms

   The reader should be familiar with the terms contained in
   [I-D.quinn-sfc-arch], [I-D.quinn-sfc-problem-statement]
   ,[I-D.quinn-nsh] and [I-D.quinn-vxlan-gpe]

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3.  VXLAN-GPE

   This model describes the VXLAN-GPE encapsulation when used as a
   overlay mechanism to create service function paths.  VXLAN is one of
   many transport protocols that can be used to setup service chaining
   overlays.

3.1.  Module Structure

   module: vxlan-gpe
      +--rw vxlan-gpe-header
         +--rw gpe-header-flag-value?   vxlan-gpw-header-flag-type
         +--rw reserved?                uint8
         +--rw protocol-type?           uint16
         +--rw vni*                     uint8
         +--rw reserved2?               uint8

3.2.  VXLAN -GPE Configuration Model

<CODE BEGINS> file "vxlan-gpe@2013-12-04.yang"

module vxlan-gpe {

  namespace "urn:cisco:params:xml:ns:yang:vxlan-gpe";

  prefix vxlan-gpe;

  import ietf-inet-types { prefix inet; }
  import ietf-yang-types { prefix yang; }

  organization "Cisco Systems, Inc.";
  contact "Reinaldo Penno <repenno@cisco.com>";

  description
    "This module contains a collection of YANG definitions for
     managing service function chains.

     Copyright (c) 2013 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     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

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     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX; see
     the RFC itself for full legal notices.";

     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.

  revision 2013-11-26 {
    description
    "Initial revision.";
  }

//    0                   1                   2                   3
//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |       Source Port = xxxx      |       Dest Port = 4789        |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |           UDP Length          |        UDP Checksum           |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |R|R|R|R|I|P|R|R|   Reserved    |   Protocol Type               |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//   |                VXLAN Network Identifier (VNI) |   Reserved    |
//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

  typedef vxlan-gpw-header-flag-type {
    type bits {
      bit r1 {
        position 0;
        description "reserved";
      }
      bit r2 {
        position 1;
        description "reserved";
      }
      bit r3 {
        position 2;
        description "reserved";
      }
      bit r4 {
        position 3;
        description "reserved";
      }
      bit i {

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        position 5;
        description "Some description";
      }
      bit p {
        position 6;
        description "Some description";
      }
      bit r7 {
        position 7;
        description "reserved";
      }
      bit r8 {
        position 8;
        description "reserved";
      }
    }
    description "vxlan-gpe Header Flags";
    reference "http://tools.ietf.org/html/draft-quinn-vxlan-gpe-01";
  }

  container vxlan-gpe-header {
    description "Network Service Base header";

    leaf gpe-header-flag-value {
        type vxlan-gpw-header-flag-type;
    }

    leaf reserved {
      default 0;
      type uint8;
    }

    leaf protocol-type {
      type uint16;
      // Reinaldo: Another option is to import Opendaylight L2 Types so have ethertype
    }

    leaf-list vni {
      type uint8;
      min-elements 3;
      max-elements 3;
    }

    leaf reserved2 {
      default 0;
      type uint8 {
        range "0 .. 255";
      }

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      description "Reserved field";
    }
  }
}

</CODE ENDS>

4.  Service Function Chain

   This model describes a service function chain which is basically an
   ordered list of services.  But a service function chain does not
   specify exactly which service (firewal1 vs. firewall2) will be used
   to actually process packets.

4.1.  Module Structure

   module: service-function-chain
      +--rw service-function
      |  +--rw name               string
      |  +--rw type?              service-function-type
      |  +--rw ip-host-address?   inet:ip-address
      |  +--rw context-headers*   uint32
      +--rw service-function-chain
         +--rw service-function*   string

4.2.  Service Function Chain Configuration Model

<CODE BEGINS> file "service-function-chain@2013-12-04.yang"

module service-function-chain {

  namespace "urn:cisco:params:xml:ns:yang:sfc-sf";

  prefix sfc-sf;

  import ietf-inet-types { prefix inet; }
  import ietf-yang-types { prefix yang; }

  organization "Cisco Systems, Inc.";
  contact "Reinaldo Penno <repenno@cisco.com>";

  description
    "This module contains a collection of YANG definitions for
     managing service function chains.

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     Copyright (c) 2013 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     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).

     This version of this YANG module is part of RFC XXXX; see
     the RFC itself for full legal notices.";

     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.

  revision 2013-11-26 {
    description
    "Initial revision.";
  }

  // Service Function

  // Service Function Type definitions

  identity service-function-type-indentity {
    description
      "Base identity from which specific service function types are
      derived.";
  }

  identity firewall {
    base "service-function-type-indentity";
    description "Firewall";
  }

  identity dpi {
    base "service-function-type-indentity";
    description "Deep Packet Inspection";
  }

  identity napt44 {
    base "service-function-type-indentity";
    description "Network Address and Port Translation 44";

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  }

  typedef service-function-type {
    type identityref {
      base "service-function-type-indentity";
    }
  }

  container service-function {
    description
      "A network or application based packet
      treatment, application, compute or storage resource, used
      singularly or in concert with other service functions within a
      service chain to enable a service offered by an operator.

      A non-exhaustive list of Service Functions includes: firewalls,
      WAN and application acceleration, Deep Packet Inspection (DPI),
      server load balancers, NAT44 [RFC3022], NAT64 [RFC6146], HOST_ID
      injection, HTTP Header Enrichment functions, TCP optimizer, etc.";
    leaf name {
      type string;
      description
             "The name of the service function.";
      mandatory true;
    }
    leaf type {
      type service-function-type;
    }
    leaf ip-host-address {
      type inet:ip-address;
    }
    uses network-service-context-header;
  }

  // Service Function Chain

  container service-function-chain {
    description
      "A service chain defines the required functions and
      associated order (service-function1 --> service-function 2) that
      must be applied to packets and/or frames.  A service chain does
      not specify the network location or specific instance of service
      functions (e.g. firewall1 vs. firewall2).";
    leaf-list service-function {
      type string;
      ordered-by user;
      description

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        "A list of service functions that compose the service chain";
    }
  }

/*
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Network Platform Context                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Network Shared Context                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Service Platform Context                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Service Shared Context                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

*/

  grouping network-service-context-header {
    description "Network Service context header";
    leaf-list context-headers {
      type uint32;
      min-elements 4;
      max-elements 4;
    }
  }
}

</CODE ENDS>

5.  Service Node

   A Service Node is a virtual or physical element that houses one or
   more service functions.  A Service node might contain an entire
   service function chain or be part of a larger service function chain.

5.1.  Module Structure

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   module: service-node
      +--rw service-node
         +--rw name                string
         +--rw type?               service-node-type
         +--rw transport?          transport-type
         +--rw service-function*   string
         +--rw ip-host-address?    inet:ip-address

5.2.  Service Node Configuration Model

 <CODE BEGINS> file "service-node@2013-12-04.yang"

 module service-node {

   namespace "urn:cisco:params:xml:ns:yang:sfc-sn";

   prefix sfc-sn;

   import ietf-inet-types { prefix inet; }
   import ietf-yang-types { prefix yang; }

   organization "Cisco Systems, Inc.";
   contact "Reinaldo Penno <repenno@cisco.com>";

   description
     "This module contains a collection of YANG definitions for
      managing service function chains.

      Copyright (c) 2013 IETF Trust and the persons identified as
      authors of the code.  All rights reserved.

      Redistribution and use in source and binary forms, with or
      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).

      This version of this YANG module is part of RFC XXXX; see
      the RFC itself for full legal notices.";

      // RFC Ed.: replace XXXX with actual RFC number and remove this
      // note.

      // RFC Ed.: update the date below with the date of RFC publication

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      // and remove this note.

   revision 2013-11-26 {
     description
     "Initial revision.";
   }

   // Transport type definitions

   identity transport-type-identity {
     description
       "Base identity from which specific service function types are
       derived.";
   }

   identity vxlan-gpe {
     base "transport-type-identity";
     description "programmable vxlan transport type";
   }

   typedef transport-type {
     type identityref {
       base "transport-type-identity";
     }
   }

   // Service Nodes

   // Service Node Type definitions

   identity service-node-type-identity {
     description
           "Base identity from which specific service function types are
           derived.";
   }

   identity egress {
     base "service-node-type-identity";
     description "Last node in the chain";
   }

   identity ingress {
     base "service-node-type-identity";
     description "First node in the chain";
   }

   identity middle {
     base "service-node-type-identity";

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     description "Service nodes in the middle of the chain";
   }

   identity legacy {
     base "service-node-type-identity";
     description "Service Nodes that need a proxy function";
   }

   typedef service-node-type {
     type identityref {
       base "service-node-type-identity";
     }
   }

   container service-node {
     description
       "Physical or virtual element that hosts one or
       more service functions and has one or more network locators
       associated with it for reachability and service delivery.";
     leaf name {
       type string;
       description
              "The name of the service node.";
       mandatory true;
     }
     leaf type {
       type service-node-type;
     }
     leaf transport {
       type transport-type;
     }
     leaf-list service-function {
       type string;
       description
         "A list of service functions resident in this service node";
     }
     leaf ip-host-address {
       type inet:ip-address;
     }
   }
 }

 </CODE ENDS>

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6.  Service Function Path

   A Service Function Path is an instantiation of a service function
   chain.  It specifies the actual service functions (e.g. firewall1)
   and the transport encapsulation used in the overlay.

6.1.  Module Structure

   module: service-function-path
      +--rw service-function-path
         +--rw service-function*            string
         +--rw transport?                   sfc-sn:transport-type
         +--rw service-header-flag-value?   service-header-flag-type
         +--rw protocol-type?               uint8
         +--rw service-index?               uint8
         +--rw service-path*                uint8
         +--rw reserved?                    uint8

6.2.  Service Function Path Configuration Model

<CODE BEGINS> file "service-function-path@2013-12-04.yang"

module service-function-path {

  namespace "urn:cisco:params:xml:ns:yang:sfc-path";

  prefix sfc-path;

  import ietf-inet-types { prefix inet; }
  import ietf-yang-types { prefix yang; }
  import service-node {prefix sfc-sn; }

  organization "Cisco Systems, Inc.";
  contact "Reinaldo Penno <repenno@cisco.com>";

  description
    "This module contains a collection of YANG definitions for
     managing service function chains.

     Copyright (c) 2013 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     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

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     (http://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC XXXX; see
     the RFC itself for full legal notices.";

     // RFC Ed.: replace XXXX with actual RFC number and remove this
     // note.

     // RFC Ed.: update the date below with the date of RFC publication
     // and remove this note.

  revision 2013-12-04 {
    description
    "Initial revision.";
  }

  // Service Function Path

  container service-function-path {
    description
      "A service chain defines the required functions and
      associated order (service-function1 --> service-function 2) that
      must be applied to packets and/or frames.  A service chain does
      not specify the network location or specific instance of service
      functions (e.g. firewall1 vs. firewall2).";
    leaf-list service-function {
      type string;
      ordered-by user;
      description
        "A list of service functions that compose the service chain";
    }
    leaf transport {
      type sfc-sn:transport-type;
    }
    uses network-service-base-header;
  }

/*
   Base Service Header:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |O|C|R|R|R|R|R|R| Protocol Type                 |Service Index  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                 Service path                  | Reserved      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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   Flags: 8
   Protocol Type (PT): 16
   Service Index: 8
   Service path: 24
   Reserved: 8
*/

  typedef service-header-flag-type {
    type bits {
      bit oam {
        position 0;
        description
          "Indicates that this packet is an operations and management
          (OAM) packet";
      }
      bit context-use {
        position 1;
        description
          "If a context header is not in use, the value of that context
          header MUST be zero";
      }
      bit r1 {
        position 2;
        description "Some description";
      }
      bit r2 {
        position 3;
        description "Some description";
      }
      bit r3 {
        position 4;
        description "Some description";
      }
      bit r4 {
        position 5;
        description "Some description";
      }
      bit r5 {
        position 6;
        description "Some description";
      }
      bit r6 {
        position 7;
        description "Some description";
      }
    }
    description "Service-Header Flags";
    reference "http://tools.ietf.org/html/draft-quinn-nsh-00";

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  }

  grouping network-service-base-header {
    description "Network Service Base header";

    leaf service-header-flag-value {
        type service-header-flag-type;
    }

    leaf protocol-type {
        type uint8;
        // Reinaldo: Another option is to import Opendaylight L2 Types so have ethertype
    }

    leaf service-index {
      type uint8 {
        range "0 .. 255";
      }
      description "TTL functionality and location within the service
            path";
    }
    leaf-list service-path {
      type uint8;
      min-elements 3;
      max-elements 3;
    }

    leaf reserved {
      default 0;
      type uint8 {
        range "0 .. 255";
      }
      description "Reserved field";
    }
  }
}

<CODE ENDS>

7.  IANA Considerations

   TBD

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8.  Security Considerations

9.  Acknowledgements

   thanks to Jan Medved for reviews and suggestions.

10.  References

10.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

10.2.  Informative References

   [I-D.quinn-nsh]
              Quinn, P., Fernando, R., Guichard, J., Surendra, S.,
              Agarwal, P., Manur, R., Chauhan, A., Smith, M., Yadav, N.,
              McConnell, B., and C. Wright, "Network Service Header",
              draft-quinn-nsh-01 (work in progress), July 2013.

   [I-D.quinn-sfc-arch]
              Quinn, P., Guichard, J., Surendra, S., Pignataro, C.,
              Agarwal, P., Manur, R., Leymann, N., Smith, M., Yadav, N.,
              Gray, K., Nadeau, T., and K. Kevin, "Service Function
              Chaining (SFC) Architecture", draft-quinn-sfc-arch-02
              (work in progress), October 2013.

   [I-D.quinn-sfc-problem-statement]
              Quinn, P., Guichard, J., Surendra, S., Agarwal, P., Manur,
              R., Chauhan, A., Leymann, N., Boucadair, M., Jacquenet,
              C., Smith, M., Yadav, N., Elzur, U., Nadeau, T., Gray, K.,
              McConnell, B., and K. Kevin, "Service Function Chaining
              Problem Statement", draft-quinn-sfc-problem-statement-01
              (work in progress), October 2013.

   [I-D.quinn-vxlan-gpe]
              Quinn, P., Agarwal, P., Fernando, R., Lewis, D., Kreeger,
              L., Smith, M., and N. Yadav, "Generic Protocol Extension
              for VXLAN", draft-quinn-vxlan-gpe-01 (work in progress),
              October 2013.

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Authors' Addresses

   Reinaldo Penno
   Cisco Systems
   170 West Tasman Dr
   San Jose  CA
   USA

   Email: repenno@cisco.com

   Paul Quinn
   Cisco Systems
   170 West Tasman Dr
   San Jose  CA
   USA

   Email: paulq@cisco.com

Penno & Quinn             Expires June 23, 2014                [Page 18]