module ietf-i2nsf-ikeless {

    yang-version 1.1;

    namespace
      "urn:ietf:params:xml:ns:yang:ietf-i2nsf-ikeless";

    prefix nsfikels;

    import ietf-inet-types {
      prefix inet;
      reference
        "RFC 6991: Common YANG Data Types.";


    }
    import ietf-yang-types {
      prefix yang;
      reference
        "RFC 6991: Common YANG Data Types.";


    }
    import ietf-i2nsf-ikec {
      prefix nsfikec;
      reference
        "RFC 9061: A YANG Data Model for IPsec Flow Protection
        	  Based on Software-Defined Networking (SDN).";


    }
    import ietf-netconf-acm {
      prefix nacm;
      reference
        "RFC 8341: Network Configuration Access Control
        	  Model.";


    }

    organization "IETF I2NSF Working Group";

    contact
      "WG Web:  <https://datatracker.ietf.org/wg/i2nsf/>
     WG List: <mailto:i2nsf@ietf.org>

     Author: Rafael Marin-Lopez
              <mailto:rafa@um.es>

     Author: Gabriel Lopez-Millan
              <mailto:gabilm@um.es>

     Author: Fernando Pereniguez-Garcia
              <mailto:fernando.pereniguez@cud.upct.es>
    ";

    description
      "Data model for IKE-less case in the SDN-based IPsec flow
     protection service.

     The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL',
     'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED',
     'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this
     document are to be interpreted as described in BCP 14
     (RFC 2119) (RFC 8174) when, and only when, they appear
     in all capitals, as shown here.

     Copyright (c) 2021 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
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC 9061; see
     the RFC itself for full legal notices.";

    revision "2021-07-14" {
      description "Initial version.";
      reference
        "RFC 9061: A YANG Data Model for IPsec Flow Protection
        	  Based on Software-Defined Networking (SDN).";

    }


    feature ikeless-notification {
      description
        "This feature indicates that the server supports
       generating notifications in the ikeless module.

       To ensure broader applicability of this module,
       the notifications are marked as a feature.
       For the implementation of the IKE-less case,
       the NSF is expected to implement this
       feature.";
    }

    container ipsec-ikeless {
      description
        "Container for configuration of the IKE-less
       case. The container contains two additional
       containers: 'spd' and 'sad'.  The first allows the
       I2NSF Controller to configure IPsec policies in
       the Security Policy Database (SPD), and the second
       allows the I2NSF Controller to configure IPsec
       Security Associations (IPsec SAs) in the Security
       Association Database (SAD).";
      reference
        "RFC 4301: Security Architecture for the Internet Protocol.";

      container spd {
        description
          "Configuration of the Security Policy Database
         (SPD).";
        reference
          "RFC 4301: Security Architecture for the Internet Protocol,
          	  Section 4.4.1.2.";

        list spd-entry {
          key "name";
          ordered-by user;
          description
            "The SPD is represented as a list of SPD
           entries, where each SPD entry represents an
           IPsec policy.";
          leaf name {
            type string;
            description
              "SPD-entry-unique name to identify this
             entry.";
          }

          leaf direction {
            type nsfikec:ipsec-traffic-direction;
            mandatory true;
            description
              "Inbound traffic or outbound
             traffic.  In the IKE-less case, the
             I2NSF Controller needs to
             specify the policy direction to be
             applied in the NSF.  In the IKE case,
             this direction does not need to be
             specified, since IKE
             will determine the direction that the
             IPsec policy will require.";
          }

          leaf reqid {
            type uint64;
            default "0";
            description
              "This value allows linking this
             IPsec policy with IPsec SAs with the
             same reqid.  It is only required in
             the IKE-less model since, in the IKE
             case, this link is handled internally
             by IKE.";
          }

          container ipsec-policy-config {
            description
              "This container carries the
             configuration of an IPsec policy.";
            uses nsfikec:ipsec-policy-grouping;
          }  // container ipsec-policy-config
        }  // list spd-entry
      }  // container spd

      container sad {
        description
          "Configuration of the IPsec Security Association
         Database (SAD).";
        reference
          "RFC 4301: Security Architecture for the Internet Protocol,
          	  Section 4.4.2.1.";

        list sad-entry {
          key "name";
          ordered-by user;
          description
            "List of SAD entries that form the SAD.";
          leaf name {
            type string;
            description
              "SAD-entry-unique name to identify this
             entry.";
          }

          leaf reqid {
            type uint64;
            default "0";
            description
              "This value allows linking this
             IPsec SA with an IPsec policy with
             the same reqid.";
          }

          container ipsec-sa-config {
            description
              "This container allows configuring
             details of an IPsec SA.";
            leaf spi {
              type uint32 {
                range "0..max";
              }
              mandatory true;
              description
                "IPsec SA of Security Parameter Index (SPI).";
            }

            leaf ext-seq-num {
              type boolean;
              default "true";
              description
                "True if this IPsec SA is using extended
               sequence numbers.  If true, the 64-bit
               extended sequence number counter is used;
               if false, the normal 32-bit sequence
               number counter is used.";
            }

            leaf seq-overflow {
              type boolean;
              default "false";
              description
                "The flag indicating whether
               overflow of the sequence number
               counter should prevent transmission
               of additional packets on the IPsec
               SA (false) and, therefore, needs to
               be rekeyed or whether rollover is
               permitted (true).  If Authenticated
               Encryption with Associated Data
               (AEAD) is used (leaf
               esp-algorithms/encryption/algorithm-type),
               this flag MUST BE false. Setting this
               flag to true is strongly discouraged.";
            }

            leaf anti-replay-window-size {
              type uint32;
              default "64";
              description
                "To set the anti-replay window size.
               The default value is set to 64,
               following the recommendation in RFC 4303.";
              reference
                "RFC 4303: IP Encapsulating Security Payload (ESP),
                	  Section 3.4.3.";

            }

            container traffic-selector {
              description
                "The IPsec SA Traffic Selector.";
              uses nsfikec:selector-grouping;
            }  // container traffic-selector

            leaf protocol-parameters {
              type nsfikec:ipsec-protocol-params;
              default "esp";
              description
                "Security protocol of IPsec SA, only
               ESP so far.";
            }

            leaf mode {
              type nsfikec:ipsec-mode;
              default "transport";
              description
                "Tunnel or transport mode.";
            }

            container esp-sa {
              when
                "../protocol-parameters = 'esp'";
              description
                "In case the IPsec SA is an
               Encapsulation Security Payload
               (ESP), it is required to specify
               encryption and integrity
               algorithms and key materials.";
              container encryption {
                description
                  "Configuration of encryption or
                 AEAD algorithm for IPsec
                 Encapsulation Security Payload
                 (ESP).";
                leaf encryption-algorithm {
                  type nsfikec:encr-alg-t;
                  default "12";
                  description
                    "Configuration of ESP
                   encryption.  With AEAD
                   algorithms, the integrity-algorithm
                   leaf is not used.";
                }

                leaf key {
                  nacm:default-deny-all;
                  type yang:hex-string;
                  description
                    "ESP encryption key value.
                   If this leaf is not defined,
                   the key is not defined
                   (e.g., encryption is NULL).
                   The key length is
                   determined by the
                   length of the key set in
                   this leaf.  By default, it is
                   128 bits.";
                }

                leaf iv {
                  nacm:default-deny-all;
                  type yang:hex-string;
                  description
                    "ESP encryption IV value.  If
                   this leaf is not defined, the
                   IV is not defined (e.g.,
                   encryption is NULL).";
                }
              }  // container encryption

              container integrity {
                description
                  "Configuration of integrity for
                 IPsec Encapsulation Security
                 Payload (ESP).  This container
                 allows configuration of integrity
                 algorithms when no AEAD
                 algorithms are used and
                 integrity is required.";
                leaf integrity-algorithm {
                  type nsfikec:intr-alg-t;
                  default "12";
                  description
                    "Message Authentication Code
                   (MAC) algorithm to provide
                   integrity in ESP (default
                   AUTH_HMAC_SHA2_256_128).
                   With AEAD algorithms,
                   the integrity leaf is not
                   used.";
                }

                leaf key {
                  nacm:default-deny-all;
                  type yang:hex-string;
                  description
                    "ESP integrity key value.
                   If this leaf is not defined,
                   the key is not defined (e.g.,
                   AEAD algorithm is chosen and
                   integrity algorithm is not
                   required).  The key length is
                   determined by the length of
                   the key configured.";
                }
              }  // container integrity
            }  // container esp-sa

            container sa-lifetime-hard {
              description
                "IPsec SA hard lifetime.  The action
               associated is terminate and hold.";
              uses nsfikec:lifetime;
            }  // container sa-lifetime-hard

            container sa-lifetime-soft {
              description
                "IPsec SA soft lifetime.";
              uses nsfikec:lifetime;

              leaf action {
                type nsfikec:lifetime-action;
                description
                  "Action lifetime: terminate-clear,
                 terminate-hold, or replace.";
              }
            }  // container sa-lifetime-soft

            container tunnel {
              when "../mode = 'tunnel'";
              description
                "Endpoints of the IPsec tunnel.";
              uses nsfikec:tunnel-grouping;

              leaf-list dscp-values {
                type inet:dscp;
                description
                  "DSCP values allowed for ingress packets carried
                 over this IPsec SA.  If no values are specified, no
                 DSCP-specific filtering is applied.  When
                 ../bypass-dscp is false and a dscp-mapping is
                 defined, each value here would be the same as the
                 'inner' DSCP value for the DSCP mapping (list
                 dscp-mapping).";
                reference
                  "RFC 4301: Security Architecture for the Internet
                  	  Protocol, Section 4.4.2.1.";

              }
            }  // container tunnel

            container encapsulation-type {
              description
                "This container carries
               configuration information about
               the source and destination ports
               that will be used for ESP
               encapsulation of ESP packets and
               the type of encapsulation when NAT
               traversal is in place.";
              uses nsfikec:encap;
            }  // container encapsulation-type
          }  // container ipsec-sa-config

          container ipsec-sa-state {
            config false;
            description
              "Container describing IPsec SA state
             data.";
            container sa-lifetime-current {
              description
                "SAD lifetime current.";
              uses nsfikec:lifetime;
            }  // container sa-lifetime-current

            container replay-stats {
              description
                "State data about the anti-replay
               window.";
              container replay-window {
                description
                  "This container contains three
                 parameters that define the state
                 of the replay window: window size (w),
                 highest sequence number authenticated (t),
                 and lower bound of the window (b), according
                 to Appendix A2.1 in RFC 4303 (w = t - b + 1).";
                reference
                  "RFC 4303: IP Encapsulating Security Payload (ESP),
                  	  Appendix A.";

                leaf w {
                  type uint32;
                  description
                    "Size of the replay window.";
                }

                leaf t {
                  type uint64;
                  description
                    "Highest sequence number
                   authenticated so far,
                   upper bound of window.";
                }

                leaf b {
                  type uint64;
                  description
                    "Lower bound of window.";
                }
              }  // container replay-window

              leaf packet-dropped {
                type yang:counter64;
                description
                  "Packets dropped
                 because they are
                 replay packets.";
              }

              leaf failed {
                type yang:counter64;
                description
                  "Number of packets detected out
                 of the replay window.";
              }

              leaf seq-number-counter {
                type uint64;
                description
                  "A 64-bit counter when this
                 IPsec SA is using Extended
                 Sequence Number or 32-bit
                 counter when it is not.
                 Current value of sequence
                 number.";
              }
            }  // container replay-stats
          }  // container ipsec-sa-state
        }  // list sad-entry
      }  // container sad
    }  // container ipsec-ikeless

    notification sadb-acquire {
      if-feature ikeless-notification;
      description
        "The NSF detects and notifies that
       an IPsec SA is required for an
       outbound IP packet that has matched an SPD entry.
       The traffic-selector container in this
       notification contains information about
       the IP packet that triggered this
       notification.";
      leaf ipsec-policy-name {
        type string;
        mandatory true;
        description
          "It contains the SPD entry name (unique) of
         the IPsec policy that hits the IP-packet-required
         IPsec SA.  It is assumed the
         I2NSF Controller will have a copy of the
         information of this policy so it can
         extract all the information with this
         unique identifier.  The type of IPsec SA is
         defined in the policy so the security
         controller can also know the type of IPsec
         SA that MUST be generated.";
      }

      container traffic-selector {
        description
          "The IP packet that triggered the acquire
         and requires an IPsec SA.  Specifically, it
         will contain the IP source/mask and IP
         destination/mask, protocol (udp, tcp,
         etc.), and source and destination
         ports.";
        uses nsfikec:selector-grouping;
      }  // container traffic-selector
    }  // notification sadb-acquire

    notification sadb-expire {
      if-feature ikeless-notification;
      description
        "An IPsec SA expiration (soft or hard).";
      leaf ipsec-sa-name {
        type string;
        mandatory true;
        description
          "It contains the SAD entry name (unique) of
         the IPsec SA that is about to expire.  It is assumed
         the I2NSF Controller will have a copy of the
         IPsec SA information (except the cryptographic
         material and state data) indexed by this name
         (unique identifier) so it can know all the
         information (crypto algorithms, etc.) about
         the IPsec SA that has expired in order to
         perform a rekey (soft lifetime) or delete it
         (hard lifetime) with this unique identifier.";
      }

      leaf soft-lifetime-expire {
        type boolean;
        default "true";
        description
          "If this value is true, the lifetime expired is
         soft.  If it is false, the lifetime is hard.";
      }

      container lifetime-current {
        description
          "IPsec SA current lifetime.  If
         soft-lifetime-expired is true,
         this container is set with the
         lifetime information about current
         soft lifetime.
         It can help the NSF Controller
         to know which of the (soft) lifetime
         limits raised the event: time, bytes,
         packets, or idle.";
        uses nsfikec:lifetime;
      }  // container lifetime-current
    }  // notification sadb-expire

    notification sadb-seq-overflow {
      if-feature ikeless-notification;
      description
        "Sequence overflow notification.";
      leaf ipsec-sa-name {
        type string;
        mandatory true;
        description
          "It contains the SAD entry name (unique) of
         the IPsec SA that is about to have a sequence
         number overflow, and rollover is not permitted.
         When the NSF issues this event before reaching
         a sequence number, overflow is implementation
         specific and out of scope of this specification.
         It is assumed the I2NSF Controller will have a
         copy of the IPsec SA information (except the
         cryptographic material and state data) indexed
         by this name (unique identifier) so it can
         know all the information (crypto algorithms,
         etc.) about the IPsec SA in
         order to perform a rekey of the IPsec SA.";
      }
    }  // notification sadb-seq-overflow

    notification sadb-bad-spi {
      if-feature ikeless-notification;
      description
        "Notify when the NSF receives a packet with an
       incorrect SPI (i.e., not present in the SAD).";
      leaf spi {
        type uint32 {
          range "0..max";
        }
        mandatory true;
        description
          "SPI number contained in the erroneous IPsec
         packet.";
      }
    }  // notification sadb-bad-spi
  }  // module ietf-i2nsf-ikeless