Network Working Group K. Murchison Internet-Draft CMU Intended status: Standards Track October 14, 2016 Expires: April 17, 2017 The Time Zone Data Distribution Service (TZDIST) Geolocate Extension draft-murchison-tzdist-geolocate-00 Abstract This document defines an extension to the Time Zone Data Distribution Service (RFC 7808) to allow a client to determine the correct time zone for a geographic point location using a 'geo' URI (RFC 5870). Open Issues o Does the 'geo' URI value have to be percent-encoded? o Should we advertise the supported coordinate reference systems (and if so, how?) or simply mandate crs=wgs84? o Should we discuss territorial and/or international waters? o What, if any, additional security and privacy concerns are introduced by this extension? 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 April 17, 2017. Murchison Expires April 17, 2017 [Page 1] Internet-Draft TZDIST Geolocate Extension October 2016 Copyright Notice Copyright (c) 2016 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 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. Conventions Used in This Document . . . . . . . . . . . . . . 3 3. "geolocate" Action . . . . . . . . . . . . . . . . . . . . . 3 3.1. Examples: geolocate action . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. Privacy Considerations . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6.1. Service Action Registration . . . . . . . . . . . . . . . 6 6.2. Registration of invalid-location Error URN . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction Clients using a Time Zone Data Distribution Service (TZDIST), particularly mobile clients, may not have prior knowledge of which time zone is appropriate for a particular geographic region. This specification defines a new TZDIST service action to allow a client to query a server with a geographic point location and have that server determine if the location lies within the boundaries of an existing time zone and return the corresponding time zone identifiers. This specification does not define the source of the time zone boundary data. It is assumed that a reliable and accurate source is available. Two such sources are [TZSHAPE] and [TZBB]. Murchison Expires April 17, 2017 [Page 2] Internet-Draft TZDIST Geolocate Extension October 2016 2. Conventions Used in This Document 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 [RFC2119]. 3. "geolocate" Action Name: gelocate Request-URI Template: {/service-prefix,data-prefix}/zones{?location} Description: This action allows a client to query the time zone data distribution service for the time zone identifier corresponding to the given geographic point location, specified as a 'geo' URI [RFC5870]. If the 'geo' URI specifies an uncertainty value (";u=" parameter), the server MUST return the time zone identifiers for all time zones whose boundary passes through the radius of uncertainty. In the absence of a client-supplied uncertainty value, the server MAY use an implicit uncertainty to coincide with any uncertainty in the time zone boundary data that it uses. If the 'geo' URI specifies a coordinate reference system (";crs=" parameter) that is unsupported by the server, the server SHOULD return a JSON "problem details" object [RFC7807] in the response body including a "type" member with an "invalid-location" error URN as defined below. Parameters: location= REQUIRED, and MUST occur only once. Response: The response has the same format as the "list" and "find" actions (see [RFC7808] Section 6.2), with one result object for each geolocated time zone. If for any reason the server can not determine a time zone in which the point is located (e.g. uninhabited location), it MUST return a "list" response containing zero time zone objects. Possible Error Codes urn:ietf:params:tzdist:error:invalid-location The "location" URI query parameter is missing, has an incorrect/unsupported value, or appears more than once. Murchison Expires April 17, 2017 [Page 3] Internet-Draft TZDIST Geolocate Extension October 2016 3.1. Examples: geolocate action The examples below presume that the timezone context path has been discovered (see [RFC7808] Section 4.2.1) to be "/tzdist". In this example the client asks for the time zone corresponding to Carnegie Mellon University. >> Request << GET /tzdist/zones?location=geo:40.44388,-79.94199 HTTP/1.1 Host: tz.example.com >> Response << HTTP/1.1 200 OK Date: Fri, 30 Sep 2016 12:28:03 GMT Content-Type: application/json; charset="utf-8" Content-Length: xxxx { "synctoken": "890939292-1466089793", "timezones": [ { "tzid": "America/New_York", "etag": "6602582-1466089793", "last-modified": "2016-06-16T15:09:53Z", "publisher": "IANA Time Zone Database", "version": "2016e", "aliases": [ "US/Eastern" ] } ] } Murchison Expires April 17, 2017 [Page 4] Internet-Draft TZDIST Geolocate Extension October 2016 In this example the client asks for the timezone corresponding to the Hoover Dam with an uncertainty of 25m. Note that the dam straddles the Nevada/Arizona state line and therefore a time zone boundary. >> Request << GET /tzdist/zones?location=geo:36.01596,-114.73748;u=25 HTTP/1.1 Host: tz.example.com >> Response << HTTP/1.1 200 OK Date: Fri, 30 Sep 2016 12:28:03 GMT Content-Type: application/json; charset="utf-8" Content-Length: xxxx { "synctoken": "890939292-1466089793", "timezones": [ { "tzid": "America/Los_Angeles", "etag": "52807330-1466089793", "last-modified": "2016-06-16T15:09:53Z", "publisher": "IANA Time Zone Database", "version": "2016e", "aliases": [ "US/Pacific" ] }, { "tzid": "America/Phoenix", "etag": "3297940-1466089793", "last-modified": "2016-06-16T15:09:53Z", "publisher": "IANA Time Zone Database", "version": "2016e", "aliases": [ "US/Arizona" ] } ] } 4. Security Considerations This specification does not introduce any additional security concerns beyond those described in [RFC7808] Murchison Expires April 17, 2017 [Page 5] Internet-Draft TZDIST Geolocate Extension October 2016 5. Privacy Considerations This specification does not introduce any additional privacy concerns beyond those described in [RFC7808]. 6. IANA Considerations 6.1. Service Action Registration This document defines the following new TZDIST Service Action to be added to the registry defined in Section 10.3.1 of [RFC7808]: +-------------+--------------------+ | Action Name | Reference | +-------------+--------------------+ | geolocate | RFCXXXX, Section 3 | +-------------+--------------------+ 6.2. Registration of invalid-location Error URN This section registers the "urn:ietf:params:tzdist:error:invalid- location" URN in the "TZDIST Identifiers" registry defined in Section 10.4 of [RFC7808]. URN: urn:ietf:params:tzdist:error:invalid-location Specification: RFCXXXX, Section 3 Repository: http://www.iana.org/assignments/tzdist-identifiers. Contact: IESG Index value: N/A. 7. Acknowledgments The author would like to thank the following individuals for contributing their ideas and support for writing this specification: Cyrus Daboo. 8. References 8.1. 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, . Murchison Expires April 17, 2017 [Page 6] Internet-Draft TZDIST Geolocate Extension October 2016 [RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource Identifier for Geographic Locations ('geo' URI)", RFC 5870, DOI 10.17487/RFC5870, June 2010, . [RFC7807] Nottingham, M. and E. Wilde, "Problem Details for HTTP APIs", RFC 7807, DOI 10.17487/RFC7807, March 2016, . [RFC7808] Douglass, M. and C. Daboo, "Time Zone Data Distribution Service", RFC 7808, DOI 10.17487/RFC7808, March 2016, . 8.2. Informative References [TZBB] Siroky, E., "Timezone Boundary Builder", . [TZSHAPE] Muller, E., "A set of shapefiles for the TZ timezones", . Author's Address Kenneth Murchison Carnegie Mellon University 5000 Forbes Avenue Pittsburgh, PA 15213 USA Email: murch@andrew.cmu.edu Murchison Expires April 17, 2017 [Page 7]