JMAP                                                     R. Cordier, Ed.
Internet-Draft                                            M. Bailly, Ed.
Intended status: Standards Track                                Linagora
Expires: September 5, 2020                                 March 4, 2020


                            JMAP for Quotas
                       draft-ietf-jmap-quotas-01

Abstract

   This document specifies a data model for handling quotas on accounts
   with a server using JMAP.

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 https://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 September 5, 2020.

Copyright Notice

   Copyright (c) 2020 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
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.






Cordier & Bailly        Expires September 5, 2020               [Page 1]


Internet-Draft                 JMAP Quotas                    March 2020


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Notational conventions  . . . . . . . . . . . . . . . . .   2
     1.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
       1.2.1.  Quota . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Addition to the capabilities object . . . . . . . . . . .   3
       1.3.1.  urn::ietf::params::jmap::quota  . . . . . . . . . . .   3
     1.4.  Push  . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Quota definition  . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  The Scope Data Type . . . . . . . . . . . . . . . . . . .   4
     2.2.  The ResourceType Data Type  . . . . . . . . . . . . . . .   4
     2.3.  The Quota Object  . . . . . . . . . . . . . . . . . . . .   4
     2.4.  Example . . . . . . . . . . . . . . . . . . . . . . . . .   5
     2.5.  Quota/get . . . . . . . . . . . . . . . . . . . . . . . .   6
       2.5.1.  Example . . . . . . . . . . . . . . . . . . . . . . .   6
     2.6.  Quota/changes . . . . . . . . . . . . . . . . . . . . . .   7
       2.6.1.  Example . . . . . . . . . . . . . . . . . . . . . . .   7
     2.7.  Quota/query . . . . . . . . . . . . . . . . . . . . . . .   8
     2.8.  Quota/queryChanges  . . . . . . . . . . . . . . . . . . .   9
   3.  Security considerations . . . . . . . . . . . . . . . . . . .   9
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
     4.1.  JMAP Capability Registration for "quota"  . . . . . . . .   9
   5.  Normative References  . . . . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   JMAP ([RFC8620] - JSON Meta Application Protocol) is a generic
   protocol for synchronising data, such as mails, calendars or
   contacts, between a client and a server.  It is optimised for mobile
   and web environments, and aims to provide a consistent interface to
   different data types.

   This specification defines a data model for handling mail quotas over
   JMAP, allowing you to read and explain quota information.

   This specification does not address quota administration, which
   should be handled by other means.

1.1.  Notational conventions

   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 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.




Cordier & Bailly        Expires September 5, 2020               [Page 2]


Internet-Draft                 JMAP Quotas                    March 2020


   Type signatures, examples and property descriptions in this document
   follow the conventions established in section 1.1 of [RFC8620].  Data
   types defined in the core specification are also used in this
   document.

   Servers MUST support all properties specified for the new data types
   defined in this document.

1.2.  Terminology

1.2.1.  Quota

   A quota is a numeric upper limit that the server is enforcing.
   Quotas are applied to accounts.

1.3.  Addition to the capabilities object

   The capabilities object is returned as part of the JMAP Session
   object; see [RFC8620], section 2.

   This document defines one additional capability URI.

1.3.1.  urn::ietf::params::jmap::quota

   This represents support for the Quota data type and associated API
   methods.  The value of this property in the JMAP session capabilities
   property is an empty object.

   The value of this property in an account's accountCapabilities
   property is an object that MUST contain the following information on
   server capabilities and permissions for that account:

   o  *quotaIds:* "Id[]" (default: "[]") A list of quota ids bound to
      that account, or "[]" if that account has no quota restrictions.

1.4.  Push

   Servers MUST support the JMAP push mechanisms, as specified in
   [RFC8620] Section 7, to receive notifications when the state changes
   for the Quota type defined in this specification.

2.  Quota definition

   The quota is an object that displays the limit set to an account
   usage as well as the current usage in regard to that limit.






Cordier & Bailly        Expires September 5, 2020               [Page 3]


Internet-Draft                 JMAP Quotas                    March 2020


2.1.  The Scope Data Type

   The *Scope* is a "String" from an enumeration defined list of values,
   handled by the server.

   It explains the entities this value applies to.  Some custom
   specifications might provide some additional values.  If the client
   does not specify custom scope specifications in the "using" parameter
   of the request, the server should respond the JSON value "null",
   instead of answering a scope value that the client does not support.
   Standard values are:

   o  "account": Applies for this account

   o  "domain": All users of this domain share this part of the quota

   o  "global": All users of this mail server share this part of the
      quota

2.2.  The ResourceType Data Type

   The *ResourceType* is a "String" from an enumeration defined list of
   values, handled by the server.

   A resource type is like an unit of measure for the quota usage.  Some
   custom specifications might provide some additional values.  If the
   client does not specify custom resource type specifications in the
   "using" parameter of the request, the server should respond the JSON
   value "null", instead of answering a resource type value that the
   client does not support.  Standard values are:

   o  "count": The quota is measured in number of data type objects.
      For example, a quota can have a limit of 50 "Mail" objects.

   o  "size": The quota is measured in size.  The default unit is in
      "bytes", but a server can decide of the unit it wants to use (like
      in "octets").  For example, a quota can have a limit of 25000
      "bytes"

2.3.  The Quota Object

   The quota object MUST contain the following fields:

   o  *id*: "Id" The unique identifier for this object.  It should
      respect the JMAP ID datatype defined in section 1.2 of [RFC8620]

   o  *resourceType*: "ResourceType" The resource type of the quota.




Cordier & Bailly        Expires September 5, 2020               [Page 4]


Internet-Draft                 JMAP Quotas                    March 2020


   o  *used*: "UnsignedInt" The current usage of the mailbox.
      Computation of this value is handled by the server.

   o  *limit*: "UnsignedInt" The hard limit set by this quota object.
      No more outgoing and ingoing messages should be allowed if we
      reach this limit.  It should higher than the "warnLimit" and the
      "softLimit".

   o  *scope*: "Scope" The "Scope" of this quota.

   o  *name*: "String" The name of the quota object.  Useful for
      managing quotas and use queries for searching.

   o  *datatypes*: "String[]" A list of all the data types values that
      are applying to this quota.  This allows to assign quotas to
      separated or shared data types.  This MAY include data types the
      client does not recognise.  Clients MUST ignore any unknown data
      type in the list.

   The quota object MAY contain the following field:

   o  *warnLimit*: "UnsignedInt|null" The warn limit set by this quota
      object.  It can be used to send a warning to an user that he is
      going to reach the hard limit soon, but no action is taken.  If
      set, it should be lower than the "softLimit" and the "limit".

   o  *softLimit*: "UnsignedInt|null" The soft limit set by this quota
      object.  It can be used to block outgoing messages, but still
      allowing incoming messages.  If set, it should be higher than the
      "warnLimit" but lower than the "limit".

   o  *description*: "String|null" Arbitrary free, human readable,
      description of this quota.  Might be used to explain where the
      limit comes from and explain the entities this quota applies to.

2.4.  Example















Cordier & Bailly        Expires September 5, 2020               [Page 5]


Internet-Draft                 JMAP Quotas                    March 2020


             {
               "id": "2a06df0d-9865-4e74-a92f-74dcc814270e",
               "resourceType": "count",
               "used": 1056,
               "warnLimit": 1600,
               "softLimit": 1800,
               "limit": 2000,
               "scope": "account",
               "name": "bob@example.com",
               "description": "Personal account usage",
               "datatypes" : [ "Mail", "Calendar", "Contact" ]
             }

2.5.  Quota/get

   Standard "/get" method as described in [RFC8620] section 5.1.  The
   ids argument may be "null" to fetch all at once.

2.5.1.  Example

   Request fetching all quotas related to an account :

                        [[ "Quota/get", {
                          "accountId": "u33084183",
                          "ids": null
                        }, "0" ]]

   With response :























Cordier & Bailly        Expires September 5, 2020               [Page 6]


Internet-Draft                 JMAP Quotas                    March 2020


            [[ "Quota/get", {
              "accountId": "u33084183",
              "state": "78540",
              "list": [{
                "id": "2a06df0d-9865-4e74-a92f-74dcc814270e",
                "resourceType": "count",
                "used": 1056,
                "warnLimit": 1600,
                "softLimit": 1800,
                "limit": 2000,
                "scope": "account",
                "name": "bob@example.com",
                "description": "Personal account usage",
                "datatypes" : [ "Mail", "Calendar", "Contact" ]
              }, {
                "id": "3b06df0e-3761-4s74-a92f-74dcc963501x",
                "resourceType": "size",
                ...
              }, ...],
              "notFound": []
            }, "0" ]]

2.6.  Quota/changes

   Standard "/changes" method as described in [RFC8620] section 5.2 but
   with one extra argument to the response:

   o  *updatedProperties*: "String[]|null" If only the "used" Quota
      properties has changed since the old state, this will be the list
      of properties that may have changed.  If the server is unable to
      tell if only "used" has changed, it MUST just be null.

   Since "used" frequently changes but other properties are generally
   only changed rarely, the server can help the client optimise data
   transfer by keeping track of changes to Quota usage separate from
   other state changes.  The updatedProperties array may be used
   directly via a back-reference in a subsequent Quota/get call in the
   same request, so only these properties are returned if nothing else
   has changed.

   Servers MAY decide to add other properties to the list that they
   judge changing frequently.

2.6.1.  Example

   Request:





Cordier & Bailly        Expires September 5, 2020               [Page 7]


Internet-Draft                 JMAP Quotas                    March 2020


                     [[ "Quota/changes", {
                       "accountId": "u33084183",
                       "sinceState": "10824",
                       "maxChanges": 20
                     }, "0" ],
                     [ "Quota/get", {
                       "accountId": "u33084183",
                       "#ids": {
                         "resultOf": "0",
                         "name": "Quota/changes",
                         "path": "/updated"
                       },
                       "#properties": {
                         "resultOf": "0",
                         "name": "Quota/changes",
                         "path": "/updatedProperties"
                       }
                     }, "1" ]]

   Response:

          [[ "Quota/changes", {
            "accountId": "u33084183",
            "oldState": "10824",
            "newState": "10826",
            "hasMoreChanges": false,
            "created": [],
            "updated": ["2a06df0d-9865-4e74-a92f-74dcc814270e"],
            "destroyed": []
          }, "0" ],
          [ "Quota/get", {
            "accountId": "u33084183",
            "state": "10826",
            "list": [{
              "id": "2a06df0d-9865-4e74-a92f-74dcc814270e",
              "used": 1246
            }],
            "notFound": []
          }, "1" ]]

2.7.  Quota/query

   This is a standard "/query" method as described in [RFC8620],
   Section 5.5.

   A *FilterCondition* object has the following properties, any of which
   may be omitted:




Cordier & Bailly        Expires September 5, 2020               [Page 8]


Internet-Draft                 JMAP Quotas                    March 2020


   o  *name*: "String" The Quota _name_ property contains the given
      string.

   o  *scopes*: "Scope[]" The Quota _scope_ property must be in this
      list to match the condition.

   o  *resourceTypes*: "ResourceType[]" The Quota _resourceType_
      property must be in this list to match the condition.

   o  *datatypes*: "String[]" The Quota _datatypes_ property must
      contain the elements in this list to match the condition.

   A Quota object matches the FilterCondition if and only if all of the
   given conditions match.  If zero properties are specified, it is
   automatically true for all objects.

   The following Quota properties MUST be supported for sorting:

   o  *name*

   o  *used*

2.8.  Quota/queryChanges

   This is a standard "/queryChanges" method as described in [RFC8620],
   Section 5.6.

3.  Security considerations

   All security considerations of JMAP ([RFC8620]) apply to this
   specification.

4.  IANA Considerations

4.1.  JMAP Capability Registration for "quota"

   IANA will register the "quota" JMAP Capability as follows:

   Capability Name: "urn:ietf:params:jmap:quota"

   Specification document: this document

   Intended use: common

   Change Controller: IETF

   Security and privacy considerations: this document, section 4.




Cordier & Bailly        Expires September 5, 2020               [Page 9]


Internet-Draft                 JMAP Quotas                    March 2020


5.  Normative References

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

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8620]  Jenkins, N. and C. Newman, "The JSON Meta Application
              Protocol (JMAP)", RFC 8620, DOI 10.17487/RFC8620, July
              2019, <https://www.rfc-editor.org/info/rfc8620>.

Authors' Addresses

   Rene Cordier (editor)
   Linagora
   100 Terrasse Boieldieu - Tour Franklin
   Paris - La Defense CEDEX  92042
   France

   Email: rcordier@linagora.com
   URI:   https://www.linagora.com


   Michael Bailly (editor)
   Linagora
   100 Terrasse Boieldieu - Tour Franklin
   Paris - La Defense CEDEX  92042
   France

   Email: mbailly@linagora.com
   URI:   https://www.linagora.com
















Cordier & Bailly        Expires September 5, 2020              [Page 10]