module bbf-l2-dhcpv4-relay {

    yang-version 1.1;

    namespace
      "urn:bbf:yang:bbf-l2-dhcpv4-relay";

    prefix bbf-l2-d4r;

    import ietf-interfaces {
      prefix if;
    }
    import ietf-yang-types {
      prefix yang;
    }
    import bbf-if-type {
      prefix bbfift;
    }
    import bbf-l2-dhcpv4-relay-profile-common {
      prefix bbf-l2-d4r-pc;
    }

    organization
      "Broadband Forum <https://www.broadband-forum.org>
Common YANG Work Area";

    contact
      "Comments or questions about this Broadband Forum YANG module
should be directed to <mailto:help@broadband-forum.org>.

Editor:      Nick Hancock, Adtran

Editor:      Ludwig Pauwels, Nokia

PS Leader:   Joey Boyd, Adtran

WA Director: Joey Boyd, Adtran

WA Director: Sven Ooghe, Nokia";

    description
      "This module contains a collection of YANG definitions for
supporting the Broadband Forum requirements on subscriber
management via the DHCPv4 protocol as applicable to access
network equipment. As such, this module is specific to access
network equipment (e.g., BBF-specified Access Nodes and FTTdp
DPUs).

Copyright (c) 2017-2023, Broadband Forum

Redistribution and use in source and binary forms, with or
without modification, are permitted provided that the following
conditions are met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above
   copyright notice, this list of conditions and the following
   disclaimer in the documentation and/or other materials
   provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products
   derived from this software without specific prior written
   permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The above license is used as a license under copyright only.
Please reference the Forum IPR Policy for patent licensing terms
<https://www.broadband-forum.org/ipr-policy>.

Any moral rights which are necessary to exercise under the above
license grant are also deemed granted under this license.

This version of this YANG module is part of TR-383a7; see
the TR itself for full legal notices.";

    revision "2023-12-15" {
      description
        "Amendment 7.
* Approval Date:    2023-12-15.
* Publication Date: 2023-12-15.";
      reference
        "TR-383a7: Common YANG Modules
        	  <https://www.broadband-forum.org/technical/download/
        		   TR-383_Amendment-7.pdf>";

    }

    revision "2023-03-07" {
      description
        "Amendment 6.
* Approval Date:    2023-03-07.
* Publication Date: 2023-03-07.";
      reference
        "TR-383a6: Common YANG Modules
        	  <https://www.broadband-forum.org/technical/download/
        		   TR-383_Amendment-6.pdf>";

    }

    revision "2022-03-01" {
      description
        "Amendment 5.
* Approval Date:    2022-03-01.
* Publication Date: 2022-03-01.";
      reference
        "TR-383a5: Common YANG Modules
        	  <https://www.broadband-forum.org/technical/download/
        		   TR-383_Amendment-5.pdf>";

    }

    revision "2017-05-08" {
      description
        "Initial revision.
* Approval Date:    see revision date above.
* Publication Date: 2017-06-02.";
      reference
        "TR-383: Common YANG Modules
        	<https://www.broadband-forum.org/technical/download/
        		 TR-383.pdf>";

    }


    feature replace-option-82 {
      description
        "Indicates support for accepting DHCPv4 messages that contain
option 82 and forwarding the message after having replaced the
option 82 with a new one generated by the device itself.";
    }

    uses bbf-l2-d4r-pc:l2-dhcpv4-relay-profiles;

    augment /if:interfaces/if:interface {
      when
        "derived-from-or-self(if:type,
		     'bbfift:vlan-sub-interface')" {
        description
          "Applies only to VLAN sub-interfaces.";
      }
      description
        "Additions for L2 DHCPv4 Relay Agent on the VLAN
sub-interface.";
      container l2-dhcpv4-relay {
        presence
          "Enables the management of DHCPv4 message processing at this
VLAN sub-interface.";
        description
          "L2 DHCPv4 Relay Agent configuration parameters.

The presence of the container itself does not instantiate a
L2 DHCPv4 Relay Agent, this is dependent on the value of the
contained leaf 'enable'.

If the container is not present, no L2 DHCPv4 Relay Agent
functionality is performed on this interface. Any received
DHCPv4 messages are processed based on the layer 2 forwarding
configuration, e.g., VLAN sub-interface and/or layer 2
forwarding.";
        leaf enable {
          type boolean;
          default "false";
          description
            "Controls the L2 DHCPv4 Relay Agent processing of DHCPv4
messages received on this interface and messages to be sent
to this interface.

If 'true', enables the L2 DHCPv4 Relay Agent to process
DHCPv4 messages based on the additional Relay Agent
configuration.

If 'false', no L2 DHCPv4 Relay Agent functionality is
performed on this interface. Any received DHCPv4 messages
are processed based on the layer 2 forwarding
configuration, e.g., VLAN sub-interface and/or layer 2
forwarding.";
        }

        leaf trusted-port {
          type union {
            type boolean;
            type enumeration {
              enum "replace" {
                value 0;
                description
                  "For DHCPv4 messages containing option 82 information,
remove the existing option 82 information and replace
it based on the additional configuration for the L2
DHCPv4 Relay Agent.";
              }
            }
          }
          default "false";
          description
            "Affects the processing of DHCPv4 messages received on the
interface and contain option 82.

The value 'true' means messages containing option 82 are
accepted and forwarded with option 82 unchanged. When the
L2 DHCP Relay Agent receives in the downstream direction a
reply containing option 82, which is a copy of the value
that was passed in the upstream direction, then it does not
remove this and sends the message on the interface with
option 82 kept in.

The value 'false' means the DHCPv4 messages containing
option 82 shall be discarded.

The value 'replace' means that the DHCPv4 message received
on the interface will be modified before forwarding the
message. The option 82 that is present in downstream
messages, which is a copy of the one generated by the L2
DHCPv4 Relay Agent, shall be removed before sending the
message on the interface.

Does not affect the processing of DHCPv4 messages received
on the interface without option 82.";
        }

        leaf profile-ref {
          when "../enable = 'true'" {
            description
              "Applicable only when L2 DHCPv4 Relay Agent functionality
is enabled.";
          }
          type leafref {
            path "/bbf-l2-d4r:l2-dhcpv4-relay-profiles/bbf-l2-d4r:l2-dhcpv4-relay-profile/bbf-l2-d4r:name";
          }
          mandatory true;
          description
            "Reference to the DHCPv4 configuration profile.

Affects the processing of DHCPv4 messages received on the
interface and do not contain option 82. The existence of
the 'profile-ref' means that option 82 shall be added
before forwarding the message upstream. The content of
option 82 is determined by the referenced profile. When
option 82 is inserted in the upstream direction, then
option 82 shall be removed from the downstream replies
before sending the message on the interface.

Affects the processing of DHCPv4 messages received on the
interface with option 82 when 'trusted-port' is set to
'replace'. In that case the option 82 received on the
interface is removed and replaced by a newly generated one
according the referenced profile.

Does not affect the processing of DHCPv4 messages received
on the interface with option 82 when 'trusted-port' has a
value different from 'replace'.";
        }
      }  // container l2-dhcpv4-relay
    }

    augment /if:interfaces-state/if:interface/if:statistics {
      when
        "derived-from-or-self(../if:type,
		     'bbfift:vlan-sub-interface')" {
        description
          "Applies only to VLAN sub-interfaces.";
      }
      description
        "L2 DHCPv4 Relay Agent statistics.";
      container dhcpv4 {
        presence
          "L2 DHCPv4 Relay Agent functionality is enabled and L2 DHCPv4
Relay Agent statistics are available.";
        description
          "Container presents the message statistics related to the L2
DHCPv4 Relay Agent.";
        leaf in-bad-packets-from-client {
          type yang:counter32;
          units "messages";
          description
            "Bad DHCPv4 messages received on the interface. The messages
are received from a DHCPv4 Client connected to it (directly
or indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf in-bad-packets-from-server {
          type yang:counter32;
          units "messages";
          description
            "Bad DHCPv4 messages received on the interface. The messages
are received from a DHCPv4 Server connected to it (directly
or indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf in-packets-from-client {
          type yang:counter32;
          units "messages";
          description
            "Valid DHCPv4 messages received on the interface. The
messages are received from a DHCPv4 Client connected to it
(directly or indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf in-packets-from-server {
          type yang:counter32;
          units "messages";
          description
            "Valid DHCPv4 messages received on the interface. The
messages are received from a DHCPv4 Server connected to it
(directly or indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf out-packets-to-server {
          type yang:counter32;
          units "messages";
          description
            "Valid DHCPv4 messages sent to the interface. The messages
are sent to a DHCPv4 Server connected to it (directly or
indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf out-packets-to-client {
          type yang:counter32;
          units "messages";
          description
            "Valid DHCPv4 messages sent to the interface. The messages
are sent to a DHCPv4 Client connected to it (directly or
indirectly through a network).

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf option-82-inserted-packets-to-server {
          type yang:counter32;
          units "messages";
          description
            "DHCPv4 messages from a Client to a Server that pass this
interface and into which the L2 DHCPv4 Relay inserted
option 82.

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf option-82-removed-packets-to-client {
          type yang:counter32;
          units "messages";
          description
            "DHCPv4 messages from a Server to a Client that pass this
interface and from which the L2 DHCPv4 Relay removed option
82.

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }

        leaf option-82-not-inserted-to-server {
          type yang:counter32;
          units "messages";
          description
            "DHCPv4 messages from a Client to a Server that pass this
interface and for which the L2 DHCPv4 Relay did not insert
option 82 because after insertion the length would exceed
the maximum allowed packet size.

Discontinuities in the counter can occur at
re-initialization of the management system, and/or when the
L2 DHCPv4 Relay Agent functionality is disabled/enabled.";
        }
      }  // container dhcpv4
    }
  }  // module bbf-l2-dhcpv4-relay