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diff --git a/doc/rfc/rfc6638.txt b/doc/rfc/rfc6638.txt new file mode 100644 index 0000000..39154d8 --- /dev/null +++ b/doc/rfc/rfc6638.txt @@ -0,0 +1,4371 @@ + + + + + + +Internet Engineering Task Force (IETF) C. Daboo +Request for Comments: 6638 Apple Inc. +Updates: 4791, 5546 B. Desruisseaux +Category: Standards Track Oracle +ISSN: 2070-1721 June 2012 + + + Scheduling Extensions to CalDAV + +Abstract + + This document defines extensions to the Calendaring Extensions to + WebDAV (CalDAV) "calendar-access" feature to specify a standard way + of performing scheduling operations with iCalendar-based calendar + components. This document defines the "calendar-auto-schedule" + feature of CalDAV. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6638. + +Copyright Notice + + Copyright (c) 2012 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. + + + + + + +Daboo & Desruisseaux Standards Track [Page 1] + +RFC 6638 CalDAV Scheduling June 2012 + + + This document may contain material from IETF Documents or IETF + Contributions published or made publicly available before November + 10, 2008. The person(s) controlling the copyright in some of this + material may not have granted the IETF Trust the right to allow + modifications of such material outside the IETF Standards Process. + Without obtaining an adequate license from the person(s) controlling + the copyright in such materials, this document may not be modified + outside the IETF Standards Process, and derivative works of it may + not be created outside the IETF Standards Process, except to format + it for publication as an RFC or to translate it into languages other + than English. + +Table of Contents + + 1. Introduction ....................................................5 + 1.1. Terminology ................................................6 + 1.2. Notational Conventions .....................................7 + 1.3. XML Namespaces and Processing ..............................7 + 2. Scheduling Support ..............................................8 + 2.1. Scheduling Outbox Collection ...............................9 + 2.1.1. CALDAV:schedule-outbox-URL Property ................10 + 2.2. Scheduling Inbox Collection ...............................10 + 2.2.1. CALDAV:schedule-inbox-URL Property .................11 + 2.3. Calendaring Reports Extensions ............................12 + 2.4. Additional Principal Properties ...........................12 + 2.4.1. CALDAV:calendar-user-address-set Property ..........12 + 2.4.2. CALDAV:calendar-user-type Property .................13 + 3. Scheduling Operations ..........................................14 + 3.1. Identifying Scheduling Object Resources ...................14 + 3.2. Handling Scheduling Object Resources ......................15 + 3.2.1. Organizer Scheduling Object Resources ..............15 + 3.2.1.1. Create ....................................16 + 3.2.1.2. Modify ....................................17 + 3.2.1.3. Remove ....................................18 + 3.2.2. Attendee Scheduling Object Resources ...............18 + 3.2.2.1. Allowed "Attendee" Changes ................18 + 3.2.2.2. Create ....................................19 + 3.2.2.3. Modify ....................................20 + 3.2.2.4. Remove ....................................21 + 3.2.3. HTTP Methods .......................................21 + 3.2.3.1. PUT .......................................22 + 3.2.3.2. DELETE ....................................22 + 3.2.3.3. COPY ......................................23 + 3.2.3.4. MOVE ......................................24 + + + + + + + +Daboo & Desruisseaux Standards Track [Page 2] + +RFC 6638 CalDAV Scheduling June 2012 + + + 3.2.4. Additional Method Preconditions ....................24 + 3.2.4.1. CALDAV:unique-scheduling-object-resource + Precondition ..............................24 + 3.2.4.2. CALDAV:same-organizer-in-all-components + Precondition ..............................25 + 3.2.4.3. CALDAV:allowed-organizer-scheduling- + object-change Precondition .............25 + 3.2.4.4. CALDAV:allowed-attendee-scheduling- + object-change Precondition .............26 + 3.2.5. DTSTAMP and SEQUENCE Properties ....................26 + 3.2.6. Restrict Recurrence Instances Sent to "Attendees" ..27 + 3.2.7. Forcing the Server to Send a Scheduling Message ....27 + 3.2.8. "Attendee" Participation Status ....................28 + 3.2.9. Schedule Status Values .............................29 + 3.2.10. Avoiding Conflicts when Updating Scheduling Object + Resources .........................................31 + 3.2.10.1. PUT .....................................33 + 3.2.10.2. DELETE, COPY, or MOVE ...................33 + 4. Processing Incoming Scheduling Messages ........................34 + 4.1. Processing "Organizer" Requests, Additions, and + Cancellations .............................................34 + 4.2. Processing "Attendee" Replies .............................35 + 4.3. Default Calendar Collection ...............................35 + 4.3.1. Additional Method Preconditions ....................36 + 4.3.1.1. CALDAV:default-calendar-needed + Precondition ..............................36 + 4.3.1.2. CALDAV:valid-schedule-default-calendar-URL + Precondition ..............................36 + 5. Request for Busy Time Information ..............................37 + 5.1. Status Codes ..............................................38 + 5.2. Additional Method Preconditions ...........................38 + 5.2.1. CALDAV:valid-scheduling-message Precondition .......38 + 5.2.2. CALDAV:valid-organizer Precondition ................39 + 6. Scheduling Privileges ..........................................39 + 6.1. Privileges on Scheduling Inbox Collections ................39 + 6.1.1. CALDAV:schedule-deliver Privilege ..................40 + 6.1.2. CALDAV:schedule-deliver-invite Privilege ...........40 + 6.1.3. CALDAV:schedule-deliver-reply Privilege ............40 + 6.1.4. CALDAV:schedule-query-freebusy Privilege ...........40 + 6.2. Privileges on Scheduling Outbox Collections ...............40 + 6.2.1. CALDAV:schedule-send Privilege .....................41 + 6.2.2. CALDAV:schedule-send-invite Privilege ..............41 + 6.2.3. CALDAV:schedule-send-reply Privilege ...............41 + 6.2.4. CALDAV:schedule-send-freebusy Privilege ............41 + 6.3. Aggregation of Scheduling Privileges ......................42 + + + + + + +Daboo & Desruisseaux Standards Track [Page 3] + +RFC 6638 CalDAV Scheduling June 2012 + + + 7. Additional iCalendar Property Parameters .......................42 + 7.1. Schedule Agent Parameter ..................................42 + 7.2. Schedule Force Send Parameter .............................44 + 7.3. Schedule Status Parameter .................................45 + 8. Additional Message Header Fields ...............................46 + 8.1. Schedule-Reply Request Header .............................46 + 8.2. Schedule-Tag Response Header ..............................46 + 8.3. If-Schedule-Tag-Match Request Header ......................47 + 9. Additional WebDAV Properties ...................................47 + 9.1. CALDAV:schedule-calendar-transp Property ..................47 + 9.2. CALDAV:schedule-default-calendar-URL Property .............48 + 9.3. CALDAV:schedule-tag Property ..............................49 + 10. XML Element Definitions .......................................50 + 10.1. CALDAV:schedule-response XML Element .....................50 + 10.2. CALDAV:response XML Element ..............................50 + 10.3. CALDAV:recipient XML Element .............................50 + 10.4. CALDAV:request-status XML Element ........................51 + 11. Security Considerations .......................................51 + 11.1. Preventing Denial-of-Service Attacks .....................51 + 11.2. Verifying Scheduling Operations ..........................52 + 11.3. Verifying Busy Time Information Requests .................52 + 11.4. Privacy Issues ...........................................53 + 11.5. Mitigation of iTIP Threats ...............................53 + 12. IANA Considerations ...........................................54 + 12.1. Message Header Field Registrations .......................54 + 12.1.1. Schedule-Reply ....................................54 + 12.1.2. Schedule-Tag ......................................54 + 12.1.3. If-Schedule-Tag-Match .............................54 + 12.2. iCalendar Property Parameter Registrations ...............55 + 12.3. iCalendar REQUEST-STATUS Value Registrations .............55 + 12.4. Additional iCalendar Elements Registries .................55 + 12.4.1. Schedule Agent Values Registry ....................56 + 12.4.2. Schedule Force Send Values Registry ...............56 + 13. Acknowledgements ..............................................56 + 14. References ....................................................57 + 14.1. Normative References .....................................57 + 14.2. Informative References ...................................58 + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 4] + +RFC 6638 CalDAV Scheduling June 2012 + + + Appendix A. Scheduling Privileges Summary .........................59 + A.1. Scheduling Inbox Privileges ................................59 + A.2. Scheduling Outbox Privileges ...............................60 + Appendix B. Example Scheduling Operations .........................60 + B.1. Example: "Organizer" Inviting Multiple "Attendees" .........61 + B.2. Example: "Attendee" Receiving an Invitation ................63 + B.3. Example: "Attendee" Replying to an Invitation ..............64 + B.4. Example: "Organizer" Receiving a Reply to an Invitation ....66 + B.5. Example: "Organizer" Requesting Busy Time Information ......69 + B.6. Example: User Attempting to Invite "Attendee" on + Behalf of "Organizer" ......................................71 + B.7. Example: "Attendee" Declining an Instance of a + Recurring Event ............................................72 + B.8. Example: "Attendee" Removing an Instance of a + Recurring Event ............................................75 + +1. Introduction + + This document specifies extensions to the CalDAV "calendar-access" + [RFC4791] feature to enable scheduling of iCalendar-based [RFC5545] + calendar components between calendar users. + + This extension leverages the scheduling methods defined in the + iCalendar Transport-independent Interoperability Protocol (iTIP) + [RFC5546] to permit calendar users to perform scheduling operations + such as schedule, reschedule, respond to scheduling request, or + cancel calendar components, as well as search for busy time + information. However, the following iTIP [RFC5546] features are not + covered: publishing, countering, delegating, refreshing, and + forwarding calendar components, as well as replacing the "Organizer" + of a calendar component. It is expected that future extensions will + be developed to address these. + + This specification defines a client/server scheduling protocol, where + the server is made responsible for sending scheduling messages and + processing incoming scheduling messages. The client operations of + creating, modifying, or deleting a calendar component in a calendar + are enough to trigger the server to deliver the necessary scheduling + messages to the appropriate calendar users. This approach is + sometimes referred to as "implicit scheduling". + + This specification only addresses how scheduling occurs with users on + a single system (i.e., scheduling between CalDAV servers, or some + other calendaring and scheduling system, is not defined). However, + this specification is compatible with servers being able to send or + receive scheduling messages with "external" users (e.g., using the + iCalendar Message-Based Interoperability Protocol (iMIP) [RFC6047]). + + + + +Daboo & Desruisseaux Standards Track [Page 5] + +RFC 6638 CalDAV Scheduling June 2012 + + + Section 3 defines the automated "Scheduling Operations" that allow a + client to store iCalendar data on a CalDAV server, with the server + taking specific actions in response. One of three scheduling + operations can take place -- "create", "modify", or "remove", based + on the HTTP method used for the request -- in addition to a + comparison between any existing and any new iCalendar data. + + Section 4 defines how the server processes scheduling messages sent + as the result of a scheduling operation. + + Section 5 defines how freebusy requests with an immediate response + are accomplished. + + Section 6 defines access control privileges for the scheduling + operations defined in this specification. + + For the majority of the following discussion, scheduling of events + will be discussed. However, scheduling of to-dos is also fully + supported by this specification. + + This specification has been under development for a number of years, + and most current implementations of CalDAV support it. With the + publication of this document, it is expected that all new CalDAV + implementations will support it by default. Interoperability tests + have been performed regularly. Significant issues with incompatible + CalDAV implementations are not anticipated. + +1.1. Terminology + + This specification reuses much of the same terminology as iCalendar + [RFC5545], iTIP [RFC5546], WebDAV [RFC4918], and CalDAV [RFC4791]. + Additional terms used by this specification are as follows: + + Scheduling object resource: A calendar object resource contained in + a calendar collection for which the server will take care of + sending scheduling messages on behalf of the owner of the calendar + collection. + + Organizer scheduling object resource: A scheduling object resource + owned by the "Organizer". + + Attendee scheduling object resource: A scheduling object resource + owned by an "Attendee". + + Scheduling operation: Add, change, or remove operations on a + scheduling object resource for which the server will deliver + scheduling messages to other calendar users. + + + + +Daboo & Desruisseaux Standards Track [Page 6] + +RFC 6638 CalDAV Scheduling June 2012 + + + Scheduling message: A calendar object that describes a scheduling + operation such as schedule, reschedule, reply, or cancel. + + Scheduling Outbox collection: A resource at which busy time + information requests are targeted. + + Scheduling Inbox collection: A collection in which incoming + scheduling messages are delivered. + +1.2. Notational Conventions + + 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 [RFC2119]. + + The Augmented BNF (ABNF) syntax used by this document to specify the + format definition of new iCalendar elements is defined in [RFC5234]. + + The ABNF syntax used by this document to specify the format + definition of new message header fields to be used with the HTTP/1.1 + protocol is described in Section 2.1 of [RFC2616]. Since this + Augmented BNF uses the basic production rules provided in Section 2.2 + of [RFC2616], these rules apply to this document as well. + + The term "protected" is used in the Conformance field of WebDAV + property definitions as defined in Section 15 of [RFC4918]. + + Calendaring and scheduling roles are referred to in quoted-strings of + text with the first character of each word in uppercase. For + example, "Organizer" refers to a role of a calendar user within the + scheduling protocol defined by [RFC5546]. + +1.3. XML Namespaces and Processing + + This document uses XML DTD fragments ([W3C.REC-xml-20081126], + Section 3.2) as a purely notational convention. WebDAV request and + response bodies cannot be validated by a DTD due to the specific + extensibility rules defined in Section 17 of [RFC4918] and due to the + fact that all XML elements defined by that specification use the XML + namespace name "DAV:". In particular, + + 1. element names use the "DAV:" namespace, + + 2. element ordering is irrelevant unless explicitly stated, + + + + + + + +Daboo & Desruisseaux Standards Track [Page 7] + +RFC 6638 CalDAV Scheduling June 2012 + + + 3. extension elements (elements not already defined as valid child + elements) can be added anywhere, except when explicitly stated + otherwise, and + + 4. extension attributes (attributes not already defined as valid for + this element) can be added anywhere, except when explicitly + stated otherwise. + + The XML elements specified in this document are defined in the + "urn:ietf:params:xml:ns:caldav" XML namespace registered by CalDAV + [RFC4791]. + + When XML element types in the namespaces "DAV:" and + "urn:ietf:params:xml:ns:caldav" are referenced in this document + outside of the context of an XML fragment, the strings "DAV:" and + "CALDAV:" will be prefixed to the element types, respectively. + + This document inherits, and sometimes extends, DTD productions from + Section 14 of [RFC4918]. + + Also note that some CalDAV XML element names are identical to WebDAV + XML element names, though their namespace differs. Care needs to be + taken not to confuse the two sets of names. + +2. Scheduling Support + + A server that supports the features described in this document is + REQUIRED to support the CalDAV "calendar-access" [RFC4791] feature. + Servers include "calendar-auto-schedule" as a field in the DAV + response header from an OPTIONS request on any resource that supports + any scheduling operations, properties, privileges, or methods. + + This specification introduces new collection resource types that are + used to manage scheduling object resources, and scheduling privileges + (as per Section 6), as well as provide scheduling functionality. It + is the server's responsibility to create these collection resources, + and clients have no way to create or delete them. + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 8] + +RFC 6638 CalDAV Scheduling June 2012 + + +2.1. Scheduling Outbox Collection + + A scheduling Outbox collection is used as the target for busy time + information requests, and to manage privileges that apply to outgoing + scheduling requests. + + A scheduling Outbox collection MUST report the DAV:collection and + CALDAV:schedule-outbox XML elements in the value of the DAV: + resourcetype property. The element type declaration for CALDAV: + schedule-outbox is + + <!ELEMENT schedule-outbox EMPTY> + + Example: + + <D:resourcetype xmlns:D="DAV:"> + <D:collection/> + <C:schedule-outbox xmlns:C="urn:ietf:params:xml:ns:caldav"/> + </D:resourcetype> + + A scheduling Outbox collection MUST NOT be a child (at any depth) of + a calendar collection resource. + + The following WebDAV properties specified in CalDAV "calendar-access" + [RFC4791] MAY also be defined on scheduling Outbox collections and + apply to scheduling messages submitted to the scheduling Outbox + collection with the POST method: + + o CALDAV:supported-calendar-component-set + + o CALDAV:supported-calendar-data + + o CALDAV:max-resource-size + + o CALDAV:min-date-time + + o CALDAV:max-date-time + + o CALDAV:max-attendees-per-instance + + The use of child resources in a scheduling Outbox collection is + reserved for future revisions or extensions of this specification. + + The following WebDAV property is defined on principal resources and + used to locate the corresponding Outbox collection for the associated + principal. + + + + + +Daboo & Desruisseaux Standards Track [Page 9] + +RFC 6638 CalDAV Scheduling June 2012 + + +2.1.1. CALDAV:schedule-outbox-URL Property + + Name: schedule-outbox-URL + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Identify the URL of the scheduling Outbox collection owned + by the associated principal resource. + + Protected: This property MAY be protected. + + PROPFIND behavior: This property SHOULD NOT be returned by a + PROPFIND DAV:allprop request (as defined in Section 14.2 of + [RFC4918]). + + COPY/MOVE behavior: This property value SHOULD be preserved in COPY + and MOVE operations. + + Description: This property is needed for a client to determine where + the scheduling Outbox collection of the current user is located so + that sending of scheduling messages can occur. If not present, + then the associated calendar user is not enabled for the sending + of scheduling messages on the server. + + Definition: + + <!ELEMENT schedule-outbox-URL (DAV:href)> + +2.2. Scheduling Inbox Collection + + A scheduling Inbox collection contains copies of incoming scheduling + messages. These can be requests sent by an "Organizer", or replies + sent by an "Attendee" in response to a request. The scheduling Inbox + collection is also used to manage scheduling privileges. + + A scheduling Inbox collection MUST report the DAV:collection and + CALDAV:schedule-inbox XML elements in the value of the DAV: + resourcetype property. The element type declaration for CALDAV: + schedule-inbox is + + <!ELEMENT schedule-inbox EMPTY> + + Example: + + <D:resourcetype xmlns:D="DAV:"> + <D:collection/> + <C:schedule-inbox xmlns:C="urn:ietf:params:xml:ns:caldav"/> + </D:resourcetype> + + + +Daboo & Desruisseaux Standards Track [Page 10] + +RFC 6638 CalDAV Scheduling June 2012 + + + Scheduling Inbox collections MUST only contain calendar object + resources that obey the restrictions specified in iTIP [RFC5546]. + Consequently, scheduling Inbox collections MUST NOT contain any types + of collection resources. Restrictions defined in Section 4.1 of + CalDAV "calendar-access" [RFC4791] on calendar object resources + contained in calendar collections (e.g., Unique Identifier ("UID") + uniqueness) do not apply to calendar object resources contained in a + scheduling Inbox collection. Thus, multiple calendar object + resources contained in a scheduling Inbox collection can have the + same "UID" property value (i.e., multiple scheduling messages for the + same calendar component). + + A scheduling Inbox collection MUST NOT be a child (at any depth) of a + calendar collection resource. + + The following WebDAV properties specified in CalDAV "calendar-access" + [RFC4791] MAY also be defined on scheduling Inbox collections and + apply to scheduling messages delivered to the collection: + + o CALDAV:supported-calendar-component-set + + o CALDAV:supported-calendar-data + + o CALDAV:max-resource-size + + o CALDAV:min-date-time + + o CALDAV:max-date-time + + o CALDAV:max-instances + + o CALDAV:max-attendees-per-instance + + o CALDAV:calendar-timezone + + The following WebDAV property is defined on principal resources and + used to locate the corresponding Inbox collection for the associated + principal. + +2.2.1. CALDAV:schedule-inbox-URL Property + + Name: schedule-inbox-URL + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Identify the URL of the scheduling Inbox collection owned + by the associated principal resource. + + + + +Daboo & Desruisseaux Standards Track [Page 11] + +RFC 6638 CalDAV Scheduling June 2012 + + + Protected: This property MAY be protected. + + PROPFIND behavior: This property SHOULD NOT be returned by a + PROPFIND DAV:allprop request (as defined in Section 14.2 of + [RFC4918]). + + COPY/MOVE behavior: This property value SHOULD be preserved in COPY + and MOVE operations. + + Description: This property allows a client to determine where the + scheduling Inbox collection of the current user is located so that + processing of scheduling messages can occur. If not present, then + the associated calendar user is not enabled for reception of + scheduling messages on the server. + + Definition: + + <!ELEMENT schedule-inbox-URL (DAV:href)> + +2.3. Calendaring Reports Extensions + + This specification extends the CALDAV:calendar-query and CALDAV: + calendar-multiget REPORTs to return results for calendar object + resources in scheduling Inbox collections. + + When a CALDAV:calendar-query REPORT includes a time-range query and + targets a scheduling Inbox collection, if any calendar object + resources contain "VEVENT" calendar components that do not include a + "DTSTART" iCalendar property (as allowed by iTIP [RFC5546]) then such + components MUST always match the time-range query test. + + Note that the CALDAV:free-busy-query REPORT is not supported on + scheduling Inbox collections. + +2.4. Additional Principal Properties + + This section defines new properties for WebDAV principal resources as + defined in [RFC3744]. These properties are likely to be protected, + but the server MAY allow them to be written by appropriate users. + +2.4.1. CALDAV:calendar-user-address-set Property + + Name: calendar-user-address-set + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Identify the calendar addresses of the associated principal + resource. + + + +Daboo & Desruisseaux Standards Track [Page 12] + +RFC 6638 CalDAV Scheduling June 2012 + + + Protected: This property MAY be protected. + + PROPFIND behavior: This property SHOULD NOT be returned by a + PROPFIND DAV:allprop request (as defined in Section 14.2 of + [RFC4918]). + + COPY/MOVE behavior: This property value SHOULD be preserved in COPY + and MOVE operations. + + Description: Support for this property is REQUIRED. This property + is needed to map calendar user addresses in iCalendar data to + principal resources and their associated scheduling Inbox and + Outbox collections. In the event that a user has no well-defined + identifier for his calendar user address, the URI of his principal + resource can be used. This property SHOULD be searchable using + the DAV:principal-property-search REPORT. The DAV:principal- + search-property-set REPORT SHOULD identify this property as such. + If not present, then the associated calendar user is not enabled + for scheduling on the server. + + Definition: + + <!ELEMENT calendar-user-address-set (DAV:href*)> + + Example: + + <C:calendar-user-address-set xmlns:D="DAV:" + xmlns:C="urn:ietf:params:xml:ns:caldav"> + <D:href>mailto:bernard@example.com</D:href> + <D:href>mailto:bernard.desruisseaux@example.com</D:href> + </C:calendar-user-address-set> + +2.4.2. CALDAV:calendar-user-type Property + + Name: calendar-user-type + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Identifies the calendar user type of the associated + principal resource. + + Value: Same values allowed for the iCalendar "CUTYPE" property + parameter defined in Section 3.2.3 of [RFC5545]. + + Protected: This property MAY be protected. + + + + + + +Daboo & Desruisseaux Standards Track [Page 13] + +RFC 6638 CalDAV Scheduling June 2012 + + + PROPFIND behavior: This property SHOULD NOT be returned by a + PROPFIND DAV:allprop request (as defined in Section 14.2 of + [RFC4918]). + + COPY/MOVE behavior: This property value SHOULD be preserved in COPY + and MOVE operations. + + Description: Clients can query principal resources in order to look + up "Attendees" available on the server. When doing this, it is + useful to know, or restrict the query to, certain types of + calendar users (e.g., only search for "people", or only search for + "rooms"). This property MAY be defined on principal resources to + indicate the type of calendar user associated with the principal + resource. Its value is the same as the iCalendar "CUTYPE" + property parameter that can be used on "ATTENDEE" properties. + This property SHOULD be searchable using the DAV:principal- + property-search REPORT. The DAV:principal-search-property-set + REPORT SHOULD identify this property as such. + + Definition: + + <!ELEMENT calendar-user-type (#PCDATA)> + + Example: + + <C:calendar-user-type + xmlns:C="urn:ietf:params:xml:ns:caldav">INDIVIDUAL< + /C:calendar-user-type> + +3. Scheduling Operations + + When a calendar object resource is created, modified, or removed from + a calendar collection, the server examines the calendar data and + checks to see whether the data represents a scheduling object + resource. If it does, the server will automatically attempt to + deliver a scheduling message to the appropriate calendar users. + Several types of scheduling operations can occur in this case, + equivalent to iTIP "REQUEST", "REPLY", "CANCEL", and "ADD" + operations. + +3.1. Identifying Scheduling Object Resources + + Calendar object resources on which the server performs scheduling + operations are referred to as scheduling object resources. There are + two types of scheduling object resources: organizer scheduling object + resources, and attendee scheduling object resources. + + + + + +Daboo & Desruisseaux Standards Track [Page 14] + +RFC 6638 CalDAV Scheduling June 2012 + + + A calendar object resource is considered to be a valid organizer + scheduling object resource if the "ORGANIZER" iCalendar property is + present and set in all the calendar components to a value that + matches one of the calendar user addresses of the owner of the + calendar collection. + + A calendar object resource is considered to be a valid attendee + scheduling object resource if the "ORGANIZER" iCalendar property is + present and set in all the calendar components to the same value and + doesn't match one of the calendar user addresses of the owner of the + calendar collection, and if at least one of the "ATTENDEE" iCalendar + property values matches one of the calendar user addresses of the + owner of the calendar collection. + + The creation of attendee scheduling object resources is typically + done by the server, with the resource being created in an appropriate + calendar collection (see Section 4.3). + +3.2. Handling Scheduling Object Resources + + The server's behavior when processing a scheduling object resource + depends on whether it is owned by the "Organizer" or an "Attendee" + specified in the calendar data. + +3.2.1. Organizer Scheduling Object Resources + + An "Organizer" can create, modify, or remove a scheduling object + resource, subject to access privileges, preconditions, and the + restrictions defined in Section 4.1 of [RFC4791]. These operations + are each described next, and how they are invoked via HTTP requests + is described in Section 3.2.3. + + The "Organizer" of a calendar component can also be an "Attendee" of + that calendar component. In such cases, the server MUST NOT send a + scheduling message to the "Attendee" that matches the "Organizer". + + The server SHOULD reject any attempt to set the "PARTSTAT" iCalendar + property parameter value of the "ATTENDEE" iCalendar property of + other users in the calendar object resource to a value other than + "NEEDS-ACTION" if the "SCHEDULE-AGENT" property parameter value is + not present or set to the value "SERVER". + + The server MAY reject attempts to create a scheduling object resource + that specifies a "UID" property value already specified in a + scheduling object resource contained in another calendar collection + of the "Organizer". + + + + + +Daboo & Desruisseaux Standards Track [Page 15] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.1.1. Create + + When an "Organizer" creates a scheduling object resource, the server + MUST inspect each "ATTENDEE" property to determine whether to send a + scheduling message. The table below indicates the appropriate iTIP + method used by the server, taking into account any "SCHEDULE-AGENT" + property parameter (see Section 7.1) specified on each "ATTENDEE" + property. + + +------------------+-------------+ + | SCHEDULE-AGENT | iTIP METHOD | + +------------------+-------------+ + | SERVER (default) | REQUEST | + | | | + | CLIENT | -- | + | | | + | NONE | -- | + +------------------+-------------+ + + "SCHEDULE-STATUS" iCalendar property parameters are added or changed + on "ATTENDEE" iCalendar properties in the scheduling object resource + being created as described in Section 7.3, with the value set as + described in Section 3.2.9. This will result in the created calendar + object resource differing from the calendar data sent in the HTTP + request. As a result, clients MAY reload the calendar data from the + server in order to update to the new server-generated state + information. + + The server MUST add a "SCHEDULE-STATUS" iCalendar property parameter + (see Section 7.3) to the "ATTENDEE" iCalendar property in the + scheduling object resource being created, and set its value as + described in Section 3.2.9. This will result in the created calendar + object resource differing from the calendar data sent in the HTTP + request. As a result, clients MAY reload the calendar data from the + server in order to update to the new server-generated state + information. Servers MUST NOT set the "SCHEDULE-STATUS" property + parameter on the "ATTENDEE" property of "Attendees" for which it did + not attempt to deliver a scheduling message. + + The server MUST return an error with the CALDAV:allowed-organizer- + scheduling-object-change precondition code (Section 3.2.4.3) when the + "Organizer" attempts to change the iCalendar data in a manner that is + forbidden. + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 16] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.1.2. Modify + + When an "Organizer" modifies a scheduling object resource, the server + MUST inspect each "ATTENDEE" property in both the original and + modified iCalendar data on a per-instance basis to determine whether + to send a scheduling message. The table below indicates the + appropriate iTIP method used by the server, taking into account any + "SCHEDULE-AGENT" property parameter (see Section 7.1) specified on + each "ATTENDEE" property. The values "SERVER", "CLIENT", and "NONE" + in the top and left titles of the table refer to the "SCHEDULE-AGENT" + parameter value of the "ATTENDEE" property, and the values "<Absent>" + and "<Removed>" are used to cover the cases where the "ATTENDEE" + property is not present (Original) or is being removed (Modified). + + +---------------+-----------------------------------------------+ + | | Modified | + | +-----------+-----------+-----------+-----------+ + | | <Removed> | SERVER | CLIENT | NONE | + | | | (default) | | | + +===+===========+===========+===========+===========+===========+ + | | <Absent> | -- | REQUEST / | -- | -- | + | O | | | ADD | | | + | r +-----------+-----------+-----------+-----------+-----------+ + | i | SERVER | CANCEL | REQUEST | CANCEL | CANCEL | + | g | (default) | | | | | + | i +-----------+-----------+-----------+-----------+-----------+ + | n | CLIENT | -- | REQUEST / | -- | -- | + | a | | | ADD | | | + | l +-----------+-----------+-----------+-----------+-----------+ + | | NONE | -- | REQUEST / | -- | -- | + | | | | ADD | | | + +---+-----------+-----------+-----------+-----------+-----------+ + + "SCHEDULE-STATUS" iCalendar property parameters are added or changed + on "ATTENDEE" iCalendar properties in the scheduling object resource + being modified as described in Section 7.3, with the value set as + described in Section 3.2.9. This will result in the created calendar + object resource differing from the calendar data sent in the HTTP + request. As a result, clients MAY reload the calendar data from the + server in order to update to the new server-generated state + information. + + The server MUST return an error with the CALDAV:allowed-organizer- + scheduling-object-change precondition code (Section 3.2.4.3) when the + "Organizer" attempts to change the iCalendar data in a manner that is + forbidden. + + + + + +Daboo & Desruisseaux Standards Track [Page 17] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.1.3. Remove + + When an "Organizer" removes a scheduling object resource, the server + MUST inspect each "ATTENDEE" property to determine whether to send a + scheduling message. The table below indicates the appropriate iTIP + method used by the server, taking into account any "SCHEDULE-AGENT" + property parameter (see Section 7.1) specified on each "ATTENDEE" + property. + + +------------------+-------------+ + | SCHEDULE-AGENT | iTIP METHOD | + +------------------+-------------+ + | SERVER (default) | CANCEL | + | | | + | CLIENT | -- | + | | | + | NONE | -- | + +------------------+-------------+ + +3.2.2. Attendee Scheduling Object Resources + + An "Attendee" can create, modify, or remove a scheduling object + resource. These operations are each described next, and how they are + invoked via HTTP requests is described in Section 3.2.3. + +3.2.2.1. Allowed "Attendee" Changes + + "Attendees" are allowed to make some changes to a scheduling object + resource, though key properties such as start time, end time, + location, and summary are typically under the control of the + "Organizer". + + Servers MUST allow "Attendees" to make the following iCalendar data + changes, subject to other restrictions, such as access privileges and + preconditions: + + 1. change their own "PARTSTAT" iCalendar property parameter value. + + 2. add, modify, or remove any "TRANSP" iCalendar properties. + + 3. add, modify, or remove any "PERCENT-COMPLETE" iCalendar + properties. + + 4. add, modify, or remove any "COMPLETED" iCalendar properties. + + 5. add, modify, or remove any "VALARM" iCalendar components. + + + + + +Daboo & Desruisseaux Standards Track [Page 18] + +RFC 6638 CalDAV Scheduling June 2012 + + + 6. add, modify, or remove the "CALSCALE" iCalendar property within + the top-level "VCALENDAR" component. + + 7. modify the "PRODID" iCalendar property within the top-level + "VCALENDAR" component. + + 8. add "EXDATE" iCalendar properties and possibly remove components + for overridden recurrence instances. + + 9. add, modify, or remove any "CREATED", "DTSTAMP", and + "LAST-MODIFIED" iCalendar properties. + + 10. add, modify, or remove "SCHEDULE-STATUS" iCalendar property + parameters on "ATTENDEE" properties that have a "SCHEDULE-AGENT" + parameter set to "CLIENT". + + 11. add new components to represent overridden recurrence instances, + provided the only changes to the recurrence instance follow the + rules above. + + The server MUST return an error with the CALDAV:allowed-attendee- + scheduling-object-change precondition code (Section 3.2.4.4) when the + "Attendee" attempts to change the iCalendar data in a manner + forbidden by the server. + +3.2.2.2. Create + + Typically, an "Attendee" does not create scheduling object resources, + as scheduling messages delivered to him on the server are + automatically processed by the server and placed on one of his + calendars (see Section 4). However, in some cases, a scheduling + message can get delivered directly to the client (e.g., via email + [RFC6047]), and the "Attendee" might wish to store that on the + server. In that case, the client creates a scheduling object + resource in a calendar belonging to the "Attendee". It can then set + the "SCHEDULE-AGENT" iCalendar property parameter on all "ORGANIZER" + iCalendar properties in the resource to determine how the server + treats the resource. The value of the "SCHEDULE-AGENT" iCalendar + property parameter on all "ORGANIZER" iCalendar properties MUST be + the same. + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 19] + +RFC 6638 CalDAV Scheduling June 2012 + + + +----------------+--------------------------------------------------+ + | SCHEDULE-AGENT | Action | + +----------------+--------------------------------------------------+ + | SERVER | The server will attempt to process changes to | + | (default) | the resource using the normal rules for attendee | + | | scheduling object resources. | + | | | + | CLIENT | The server does no special processing of the | + | | resource. The client is assumed to be handling | + | | "Attendee" replies, etc. | + | | | + | NONE | The server does no special processing of the | + | | resource. | + +----------------+--------------------------------------------------+ + + "SCHEDULE-STATUS" iCalendar property parameters are added or changed + on "ORGANIZER" iCalendar properties in the scheduling object resource + being created as described in Section 7.3, with the value set as + described in Section 3.2.9. + +3.2.2.3. Modify + + When a scheduling object resource is modified by an "Attendee", the + server's behavior depends on the value of the "SCHEDULE-AGENT" + iCalendar property parameter on the "ORGANIZER" iCalendar properties: + + +----------------+--------------------------------------------------+ + | SCHEDULE-AGENT | Action | + +----------------+--------------------------------------------------+ + | SERVER | The server will attempt to process the update | + | (default) | using the behavior listed below. | + | | | + | CLIENT | The server does no special processing of the | + | | resource. The client is assumed to be handling | + | | any "Attendee" replies, etc. | + | | | + | NONE | The server does no special processing of the | + | | resource. | + +----------------+--------------------------------------------------+ + + The server will inspect the changes by comparing the new scheduling + object resource with the existing scheduling object resource. + + If the "Attendee" changes one or more "PARTSTAT" iCalendar property + values on any component, or adds an overridden component with a + changed "PARTSTAT" property, then the server MUST deliver an iTIP + "REPLY" scheduling message to the "Organizer" to indicate the new + participation status of the "Attendee". + + + +Daboo & Desruisseaux Standards Track [Page 20] + +RFC 6638 CalDAV Scheduling June 2012 + + + If the "Attendee" adds an "EXDATE" property value to effectively + remove a recurrence instance, the server MUST deliver an iTIP "REPLY" + scheduling message to the "Organizer" to indicate that the "Attendee" + has declined the instance. + + "SCHEDULE-STATUS" iCalendar property parameters are added or changed + on "ORGANIZER" iCalendar properties in the scheduling object resource + being modified as described in Section 7.3, with the value set as + described in Section 3.2.9. This will result in the updated calendar + object resource differing from the calendar data sent in the HTTP + request. As a result, clients MAY reload the calendar data from the + server in order to update to the new server-generated state + information. + +3.2.2.4. Remove + + When a scheduling object resource is removed by an "Attendee", the + server's behavior depends on the value of the "SCHEDULE-AGENT" + iCalendar property parameter on the "ORGANIZER" iCalendar properties: + + +----------------+--------------------------------------------------+ + | SCHEDULE-AGENT | Action | + +----------------+--------------------------------------------------+ + | SERVER | The server will attempt to process the removal, | + | (default) | taking into account any "Schedule-Reply" request | + | | header as per Section 8.1. | + | | | + | CLIENT | The server does no special processing of the | + | | resource. The client is assumed to be handling | + | | any "Attendee" replies, etc. | + | | | + | NONE | The server does no special processing of the | + | | resource. | + +----------------+--------------------------------------------------+ + +3.2.3. HTTP Methods + + This section describes how the use of various HTTP [RFC2616] and + WebDAV [RFC4918] methods on a scheduling object resource will cause a + create, modify, or remove operation on that resource as described + above. The use of these methods is subject to the restrictions in + [RFC4791], in addition to what is described below. + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 21] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.3.1. PUT + + When the server receives a PUT method request, it MUST execute the + following operations, provided all appropriate preconditions are met: + + +------------------------+--------------------------+---------------+ + | Existing Destination | Resulting Destination | Server | + | Resource | Resource | Operation | + +------------------------+--------------------------+---------------+ + | None | Calendar object resource | None | + | | | | + | None | Scheduling object | Create | + | | resource | | + | | | | + | Calendar object | Calendar object resource | None | + | resource | | | + | | | | + | Calendar object | Scheduling object | Create | + | resource | resource | | + | Scheduling object | Calendar object resource | Remove | + | resource | | | + | | | | + | Scheduling object | Scheduling object | Modify | + | resource | resource | | + +------------------------+--------------------------+---------------+ + +3.2.3.2. DELETE + + When the server receives a DELETE method request targeted at a + scheduling object resource, it MUST execute the Remove operation. + + When the server receives a DELETE method request targeted at a + calendar collection, it MUST execute the Remove operation on all + scheduling object resources contained in the calendar collection. + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 22] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.3.3. COPY + + When the server receives a COPY method request, it MUST execute the + following operations based on the source and destination collections + in the request: + + +-----------------------+------------------------+------------------+ + | Source Collection | Destination Collection | Server Operation | + +-----------------------+------------------------+------------------+ + | Non-calendar | Non-calendar | None | + | collection | collection | | + | | | | + | Non-calendar | Calendar collection | (1) | + | collection | | | + | | | | + | Calendar collection | Non-calendar | None | + | | collection | | + | | | | + | Calendar collection | Calendar collection | (2) | + +-----------------------+------------------------+------------------+ + + Note (1): The rules in Section 3.2.3.1 are applied for the + destination of the COPY request. + + Note (2): The server MAY reject this as per Section 3.2.4.1; + otherwise, None. + + The behavior of a COPY method request on a calendar collection is + undefined. + + + + + + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 23] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.3.4. MOVE + + When the server receives a MOVE method request, it MUST execute the + following operations based on the source and destination collections + in the request: + + +-----------------------+------------------------+------------------+ + | Source Collection | Destination Collection | Server Operation | + +-----------------------+------------------------+------------------+ + | Non-calendar | Non-calendar | None | + | collection | collection | | + | | | | + | Non-calendar | Calendar collection | (1) | + | collection | | | + | | | | + | Calendar collection | Non-calendar | (2) | + | | collection | | + | | | | + | Calendar collection | Calendar collection | None | + +-----------------------+------------------------+------------------+ + + Note (1): The rules in Section 3.2.3.1 are applied for the + destination of the MOVE request. + + Note (2): The rules in Section 3.2.3.2 are applied for the source of + the MOVE request. + + The behavior of a MOVE method request on a calendar collection is + undefined. + +3.2.4. Additional Method Preconditions + + This specification defines method preconditions (see Section 16 of + WebDAV [RFC4918]), in addition to those in [RFC4791], to provide + machine-parseable information in error responses. + +3.2.4.1. CALDAV:unique-scheduling-object-resource Precondition + + Name: unique-scheduling-object-resource + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: PUT, COPY, and MOVE + + Use with: 403 Forbidden + + + + + + +Daboo & Desruisseaux Standards Track [Page 24] + +RFC 6638 CalDAV Scheduling June 2012 + + + Purpose: (precondition) -- Servers MAY reject requests to create a + scheduling object resource with an iCalendar "UID" property value + already in use by another scheduling object resource owned by the + same user in other calendar collections. Servers SHOULD report + the URL of the scheduling object resource that is already making + use of the same "UID" property value in the DAV:href element. + + Definition: + + <!ELEMENT unique-scheduling-object-resource (DAV:href?)> + + Example: + + <C:unique-scheduling-object-resource xmlns:D="DAV:" + xmlns:C="urn:ietf:params:xml:ns:caldav"> + <D:href>/home/bernard/calendars/personal/abc123.ics</D:href> + </C:unique-scheduling-object-resource> + +3.2.4.2. CALDAV:same-organizer-in-all-components Precondition + + Name: same-organizer-in-all-components + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: PUT, COPY, and MOVE + + Use with: 403 Forbidden + + Purpose: (precondition) -- All the calendar components in a + scheduling object resource MUST contain the same "ORGANIZER" + property value when present. + + Definition: + + <!ELEMENT same-organizer-in-all-components EMPTY> + +3.2.4.3. CALDAV:allowed-organizer-scheduling-object-change Precondition + + Name: allowed-organizer-scheduling-object-change + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: PUT, COPY, and MOVE + + Use with: 403 Forbidden + + + + + + +Daboo & Desruisseaux Standards Track [Page 25] + +RFC 6638 CalDAV Scheduling June 2012 + + + Purpose: (precondition) -- Servers MAY impose restrictions on + modifications allowed by an "Organizer". For instance, servers + MAY prevent the "Organizer" from setting the "PARTSTAT" property + parameter to a value other than "NEEDS-ACTION" if the + corresponding "ATTENDEE" property has the "SCHEDULE-AGENT" + property parameter set to "SERVER", or does not have the + "SCHEDULE-AGENT" property parameter. See Section 3.2.1. + + Definition: + + <!ELEMENT allowed-organizer-scheduling-object-change EMPTY> + +3.2.4.4. CALDAV:allowed-attendee-scheduling-object-change Precondition + + Name: allowed-attendee-scheduling-object-change + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: PUT, COPY, and MOVE + + Use with: 403 Forbidden + + Purpose: (precondition) -- Servers MAY impose restrictions on + modifications allowed by an "Attendee", subject to the allowed + changes specified in Section 3.2.2.1. + + Definition: + + <!ELEMENT allowed-attendee-scheduling-object-change EMPTY> + +3.2.5. DTSTAMP and SEQUENCE Properties + + The server MUST ensure that a "DTSTAMP" iCalendar property is present + and set the value to the UTC time that the scheduling message was + generated (as required by iCalendar). + + The server MUST ensure that for each type of scheduling operation, + the "SEQUENCE" iCalendar property value is updated as per iTIP + [RFC5546]. + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 26] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.6. Restrict Recurrence Instances Sent to "Attendees" + + Servers MUST ensure that "Attendees" only get information about + recurrence instances that explicitly include them as an "Attendee", + when delivering scheduling messages for recurring calendar + components. + + For example, if an "Attendee" is invited to only a single instance of + a recurring event, the organizer scheduling object resource will + contain an overridden instance in the form of a separate calendar + component. That separate calendar component will include the + "ATTENDEE" property referencing the "one-off" "Attendee". That + "Attendee" will not be listed in any other calendar components in the + scheduling object resource. Any scheduling messages delivered to the + "Attendee" will only contain information about this overridden + instance. + + As another example, an "Attendee" could be excluded from one instance + of a recurring event. In that case, the organizer scheduling object + resource will include an overridden instance with an "ATTENDEE" list + that does not include the "Attendee" being excluded. Any scheduling + messages delivered to the "Attendee" will not specify the overridden + instance but rather will include an "EXDATE" property in the "master" + component that defines the recurrence set. + +3.2.7. Forcing the Server to Send a Scheduling Message + + The iCalendar property parameter "SCHEDULE-FORCE-SEND", defined in + Section 7.2, can be used by a calendar user to force the server to + send a scheduling message to an "Attendee" or the "Organizer" in a + situation where the server would not normally send a scheduling + message. For instance, an "Organizer" could use this property + parameter to request an "Attendee" that previously declined an + invitation to reconsider his participation status without being + forced to modify the event. + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 27] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.8. "Attendee" Participation Status + + This section specifies additional requirements on the handling of the + "PARTSTAT" property parameter when the "SCHEDULE-AGENT" property + parameter on the corresponding "ATTENDEE" property is set to the + value "SERVER" or is not present. + + A reschedule occurs when any "DTSTART", "DTEND", "DURATION", "DUE", + "RRULE", "RDATE", or "EXDATE" property changes in a calendar + component such that existing recurrence instances are impacted by the + changes, as shown in the table below. Servers MUST reset the + "PARTSTAT" property parameter value of all "ATTENDEE" properties, + except the one that corresponds to the "Organizer", to "NEEDS-ACTION" + for each calendar component change that causes any instance to be + rescheduled. + + +-----------+-------------------------------------------------------+ + | Property | Server Action | + +-----------+-------------------------------------------------------+ + | DTSTART, | Any change to these properties results in "PARTSTAT" | + | DTEND, | being set to "NEEDS-ACTION". | + | DURATION, | | + | DUE | | + | | | + | RRULE | A change to or addition of this property that results | + | | in the addition of new recurring instances or a | + | | change in time for existing recurring instances | + | | results in "PARTSTAT" being reset to "NEEDS-ACTION" | + | | on each affected component. | + | | | + | RDATE | A change to or addition of this property that results | + | | in the addition of new recurring instances or a | + | | change in time for existing recurring instances | + | | results in "PARTSTAT" being reset to "NEEDS-ACTION" | + | | on each affected component. | + | | | + | EXDATE | A change to or removal of this property that results | + | | in the reinstatement of recurring instances results | + | | in "PARTSTAT" being set to "NEEDS-ACTION" on each | + | | affected component. | + +-----------+-------------------------------------------------------+ + + The server MAY allow the "Organizer's" client to change an + "Attendee's" "PARTSTAT" property parameter value to "NEEDS-ACTION" at + any other time (e.g., when the "LOCATION" property value changes, an + "Organizer" might wish to re-invite "Attendees" who might be impacted + by the change). + + + + +Daboo & Desruisseaux Standards Track [Page 28] + +RFC 6638 CalDAV Scheduling June 2012 + + +3.2.9. Schedule Status Values + + When scheduling with an "Attendee", there are two types of status + information that can be returned during the operation. The first + type of status information is a "delivery" status that indicates + whether the scheduling message from the "Organizer" to the "Attendee" + was delivered or not, or what the current status of delivery is. The + second type of status information is a "reply" status corresponding + to the "Attendee's" own "REQUEST-STATUS" information from the + scheduling message reply that is sent back to the "Organizer". + + Similarly, when an "Attendee" sends a reply back to the "Organizer", + there will be "delivery" status information for the scheduling + message sent to the "Organizer". However, there is no + "REQUEST-STATUS" sent back by the "Organizer", so there is no + equivalent of the "reply" status as per scheduling messages to + "Attendees". + + The "delivery" status information on an "ORGANIZER" or "ATTENDEE" + iCalendar property is conveyed in the "SCHEDULE-STATUS" property + parameter value (Section 7.3). The status code value for "delivery" + status can be one of the following: + + +----------+--------------------------------------------------------+ + | Delivery | Description | + | Status | | + | Code | | + +----------+--------------------------------------------------------+ + | 1.0 | The scheduling message is pending. That is, the | + | | server is still in the process of sending the message. | + | | The status code value can be expected to change once | + | | the server has completed its sending and delivery | + | | attempts. | + | | | + | 1.1 | The scheduling message has been successfully sent. | + | | However, the server does not have explicit information | + | | about whether the scheduling message was successfully | + | | delivered to the recipient. This state can occur with | + | | "store and forward" style scheduling protocols such as | + | | iMIP [RFC6047] (iTIP using email). | + | | | + | 1.2 | The scheduling message has been successfully | + | | delivered. | + | | | + + + + + + + +Daboo & Desruisseaux Standards Track [Page 29] + +RFC 6638 CalDAV Scheduling June 2012 + + + | 3.7 | The scheduling message was not delivered because the | + | | server did not recognize the calendar user address as | + | | a valid calendar user. Note that this code applies to | + | | both "Organizer" and "Attendee" calendar user | + | | addresses. | + | | | + | 3.8 | The scheduling message was not delivered due to | + | | insufficient privileges. Note that this code applies | + | | to privileges granted by both the "Organizer" and | + | | "Attendee" calendar users. | + | | | + | 5.1 | The scheduling message was not delivered because the | + | | server could not complete delivery of the message. | + | | This is likely due to a temporary failure, and the | + | | originator can try to send the message again at a | + | | later time. | + | | | + | 5.2 | The scheduling message was not delivered because the | + | | server was not able to find a way to deliver the | + | | message. This is likely a permanent failure, and the | + | | originator ought not try to send the message again, at | + | | least without verifying/correcting the calendar user | + | | address of the recipient. | + | | | + | 5.3 | The scheduling message was not delivered and was | + | | rejected because scheduling with that recipient is not | + | | allowed. This is likely a permanent failure, and the | + | | originator ought not try to send the message again. | + +----------+--------------------------------------------------------+ + + The status code for "reply" status can be any of the valid iTIP + [RFC5546] "REQUEST-STATUS" values. + + The 1.xx "REQUEST-STATUS" codes are new. This specification modifies + item (2) of Section 3.6 of [RFC5546] by adding the following + restriction: + + For a 1.xx code, all components MUST have exactly the same code. + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 30] + +RFC 6638 CalDAV Scheduling June 2012 + + + Definition of the new 1.xx codes is as follows: + +3.2.9.1. Status Code 1.0 + + Status Code: 1.0 + + Status Description: Pending. + + Status Exception Data: None. + + Description: Delivery of the iTIP message is pending. + +3.2.9.2. Status Code 1.1 + + Status Code: 1.1 + + Status Description: Sent. + + Status Exception Data: None. + + Description: The iTIP message has been sent, though no information + about successful delivery is known. + +3.2.9.3. Status Code 1.2 + + Status Code: 1.2 + + Status Description: Delivered. + + Status Exception Data: None. + + Description: The iTIP message has been sent and delivered. + +3.2.10. Avoiding Conflicts when Updating Scheduling Object Resources + + Scheduling object resources on the server might change frequently as + "Attendees" change their participation status, triggering updates to + the "Organizer", and refreshes of other "Attendees'" copies of the + scheduling object resource. This can lead to an "inconsequential" + change to a calendar user's data -- one that does not directly impact + the user's own participation status. When this occurs, clients have + to reload calendar data and reconcile with changes being made by + calendar users. To avoid the need for this, the server can instead + merge calendar data changes from a client with changes made as a + result of a scheduling operation carried out by some other calendar + user. + + + + + +Daboo & Desruisseaux Standards Track [Page 31] + +RFC 6638 CalDAV Scheduling June 2012 + + + This specification introduces a new WebDAV resource property CALDAV: + schedule-tag with a corresponding response header "Schedule-Tag", and + a new "If-Schedule-Tag-Match" request header to allow client changes + to be appropriately merged with server changes in the case where the + changes on the server were the result of an "inconsequential" + scheduling message update (one that simply updates the status + information of "Attendees" due to a reply from another "Attendee"). + + Servers MUST automatically resolve conflicts with "inconsequential" + changes done to scheduling object resources when the "If-Schedule- + Tag-Match" request header is specified. The If-Schedule-Tag-Match + request header applies only to the Request-URI, and not to the + destination of a COPY or MOVE. + + A response to any successful GET or PUT request targeting a + scheduling object resource MUST include a Schedule-Tag response + header with the value set to the same value as the CALDAV:schedule- + tag WebDAV property of the resource. + + A response to any successful COPY or MOVE request that specifies a + Destination request header targeting a scheduling object resource + MUST include a Schedule-Tag response header with the value set to the + same value as the CALDAV:schedule-tag WebDAV property of the + destination resource. + + Clients SHOULD use the If-Schedule-Tag-Match header on requests that + update scheduling object resources, instead of HTTP ETag-based + precondition tests (e.g., If-Match). Normal ETag-based precondition + tests are used in all other cases, e.g., for synchronization. + + The value of the CALDAV:schedule-tag property changes according to + these rules: + + o For an "Organizer's" copy of a scheduling object resource: + + 1. The server MUST NOT change the CALDAV:schedule-tag property + value when the scheduling object resource is updated as the + result of automatically processing a scheduling message reply + from an "Attendee". For instance, when an "Attendee" replies + to the "Organizer", the CALDAV:schedule-tag property is + unchanged after the "Organizer's" scheduling object resource + has been automatically updated by the server with the + "Attendee's" new participation status. + + 2. The server MUST change the CALDAV:schedule-tag property value + when the scheduling object resource is changed directly via an + HTTP request (e.g., PUT, COPY, or MOVE). + + + + +Daboo & Desruisseaux Standards Track [Page 32] + +RFC 6638 CalDAV Scheduling June 2012 + + + o For an "Attendee's" copy of a scheduling object resource: + + 1. The server MUST change the CALDAV:schedule-tag property value + when the scheduling object resource is changed as the result + of processing a scheduling message update from an "Organizer" + that contains changes other than just the participation status + of "Attendees". + + 2. The server MUST NOT change the CALDAV:schedule-tag property + value when the scheduling object resource is changed as the + result of processing a scheduling message update from an + "Organizer" that only specifies changes in the participation + status of "Attendees". For instance, when "Attendee" "A" + replies to "Organizer" "O", and "Attendee" "B" receives a + scheduling message update from "Organizer" "O" with the new + participation status of "Attendee" "A", the CALDAV:schedule- + tag property of "Attendee" "B"'s scheduling object resource + would remain the same. + + 3. The server MUST change the CALDAV:schedule-tag property value + when the scheduling object resource is changed directly via an + HTTP request (e.g., PUT, COPY, or MOVE). + +3.2.10.1. PUT + + Clients MAY use the If-Schedule-Tag-Match request header to do a PUT + request that ensures that "inconsequential" changes on the server do + not result in a precondition error. The value of the request header + is set to the last Schedule-Tag value received for the resource being + modified. If the value of the If-Schedule-Tag-Match header matches + the current value of the CALDAV:schedule-tag property, the server + MUST take any "ATTENDEE" property changes for all "Attendees" other + than the owner of the scheduling object resource and apply those to + the new resource being stored. Otherwise, the server MUST fail the + request with a 412 Precondition Failed status code. + +3.2.10.2. DELETE, COPY, or MOVE + + Clients MAY use the If-Schedule-Tag-Match request header to do a + DELETE, COPY, or MOVE request that ensures that "inconsequential" + changes on the server do not result in a precondition error. The + value of the request header is set to the last Schedule-Tag value + received for the resource being deleted. If the value of the + If-Schedule-Tag-Match header matches the current value of the CALDAV: + schedule-tag property, the server performs the normal DELETE, COPY, + or MOVE request processing for the resource. Otherwise, the server + MUST fail the request with a 412 Precondition Failed status code. + + + + +Daboo & Desruisseaux Standards Track [Page 33] + +RFC 6638 CalDAV Scheduling June 2012 + + +4. Processing Incoming Scheduling Messages + + Scheduling operations can cause the delivery of a scheduling message + into an "Organizer's" or "Attendee's" scheduling Inbox collection. + Servers MUST automatically process incoming scheduling messages using + the rules defined by [RFC5546], by creating or updating the + corresponding scheduling object resources on calendars owned by the + owner of the scheduling Inbox collection. In addition, the + scheduling message is stored in the scheduling Inbox collection as an + indicator to the client that a scheduling operation has taken place. + Scheduling messages are typically removed from the scheduling Inbox + collection by the client once the calendar user has acknowledged the + change. + + The server MUST take into account privileges on the scheduling Inbox + collection when processing incoming scheduling messages, to determine + whether delivery of the scheduling message is allowed. Privileges on + calendars containing any matching scheduling object resource are not + considered in this case (i.e., a schedule message from another user + can cause modifications to resources in calendar collections that the + other user would not normally have read or write access to). + Additionally, servers MUST take into account any scheduling Inbox + collection preconditions (see Section 2.2) when delivering the + scheduling message, and MUST take into account the similar + preconditions on any calendar collection that contains, or would + contain, the corresponding scheduling object resource. + +4.1. Processing "Organizer" Requests, Additions, and Cancellations + + For a scheduling message sent by an "Organizer", the server first + tries to locate a corresponding scheduling object resource belonging + to the "Attendee". If no matching scheduling object resource exists, + the server treats the scheduling message as a new message; otherwise, + it is treated as an update. + + In the case of a new message, the server processes the scheduling + message and creates a new scheduling object resource as per + Section 4.3. + + In the case of an update, the server processes the scheduling message + and updates the matching scheduling object resource belonging to the + "Attendee" to reflect the changes sent by the "Organizer". + + In each case, the scheduling message MUST only appear in the + "Attendee's" scheduling Inbox collection once all automatic + processing has been done. + + + + + +Daboo & Desruisseaux Standards Track [Page 34] + +RFC 6638 CalDAV Scheduling June 2012 + + +4.2. Processing "Attendee" Replies + + For a scheduling message reply sent by an "Attendee", the server + first locates the corresponding scheduling object resource belonging + to the "Organizer". If the corresponding scheduling object resource + cannot be found, the server SHOULD ignore the scheduling message. + + The server MUST then update the "PARTSTAT" iCalendar property + parameter value of each "ATTENDEE" iCalendar property in the + scheduling object resource to match the changes indicated in the + reply (taking into account the fact that an "Attendee" could have + created a new overridden iCalendar component to indicate different + participation status on one or more instances of a recurring event). + + The server MUST also update or add the "SCHEDULE-STATUS" property + parameter on each matching "ATTENDEE" iCalendar property and set its + value to that of the "REQUEST-STATUS" property in the reply, or to + "2.0" if "REQUEST-STATUS" is not present (also taking into account + recurrence instances). If there are multiple "REQUEST-STATUS" + properties in the reply, the "SCHEDULE-STATUS" property parameter + value is set to a comma-separated list of status codes, one from each + "REQUEST-STATUS" property. + + The server SHOULD send scheduling messages to all the other + "Attendees" indicating the change in participation status of the + "Attendee" replying, subject to the recurrence requirements of + Section 3.2.6. + + The scheduling message MUST only appear in the "Organizer's" + scheduling Inbox collection once all automatic processing has been + done. + +4.3. Default Calendar Collection + + The server processes scheduling messages received for an "Attendee" + by creating a new scheduling object resource in a calendar collection + belonging to the "Attendee", when one does not already exist. A + calendar user that is an "Attendee" in a scheduling operation MUST + have at least one valid calendar collection available. If there is + no valid calendar collection, then the server MUST reject the attempt + to deliver the scheduling message to the "Attendee". + + Servers MAY provide support for a default calendar collection -- that + is, the calendar collection in which new scheduling object resources + will be created. The CALDAV:schedule-default-calendar-URL WebDAV + property, which can be present on the scheduling Inbox collection of + a calendar user, specifies whether this calendar user has a default + calendar collection. See Section 9.2. + + + +Daboo & Desruisseaux Standards Track [Page 35] + +RFC 6638 CalDAV Scheduling June 2012 + + + Servers SHOULD create new scheduling object resources in the default + calendar collection, if the CALDAV:schedule-default-calendar-URL + WebDAV property is set. + + Servers MAY allow clients to change the default calendar collection + by changing the value of the CALDAV:schedule-default-calendar-URL + WebDAV property on the scheduling Inbox collection. However, the + server MUST ensure that any new value for that property refers to a + valid calendar collection belonging to the owner of the scheduling + Inbox collection. + + Servers MUST reject any attempt to delete the default calendar + collection. + +4.3.1. Additional Method Preconditions + + This specification defines additional method preconditions (see + Section 16 of WebDAV [RFC4918]) to provide machine-parseable + information in error responses. + +4.3.1.1. CALDAV:default-calendar-needed Precondition + + Name: default-calendar-needed + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: DELETE + + Use with: 403 Forbidden + + Purpose: (precondition) -- The client attempted to delete the + calendar collection currently referenced by the CALDAV:schedule- + default-calendar-URL property, or attempted to remove the CALDAV: + schedule-default-calendar-URL property on the scheduling Inbox + collection on a server that doesn't allow such operations. + + Definition: + + <!ELEMENT default-calendar-needed EMPTY> + +4.3.1.2. CALDAV:valid-schedule-default-calendar-URL Precondition + + Name: valid-schedule-default-calendar-URL + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: PROPPATCH + + + + +Daboo & Desruisseaux Standards Track [Page 36] + +RFC 6638 CalDAV Scheduling June 2012 + + + Use with: 403 Forbidden + + Purpose: (precondition) -- The client attempted to set the CALDAV: + schedule-default-calendar-URL property to a DAV:href element that + doesn't reference a valid calendar collection. Note: Servers that + do not allow clients to change the CALDAV:schedule-default- + calendar-URL property would simply return the DAV:cannot-modify- + protected-property precondition defined in Section 16 of WebDAV + [RFC4918]. + + Definition: + + <!ELEMENT valid-schedule-default-calendar-URL EMPTY> + +5. Request for Busy Time Information + + Busy time information of one or more calendar users can be determined + by submitting a POST request targeted at the scheduling Outbox + collection of the calendar user requesting the information (the + "Organizer"). To accomplish this, the request body MUST contain a + "VFREEBUSY" calendar component with the "METHOD" iCalendar property + set to the value "REQUEST" as specified in Section 3.3.2 of iTIP + [RFC5546]. The resource identified by the Request-URI MUST be a + resource collection of type CALDAV:schedule-outbox (Section 2.1). + The "ORGANIZER" property value in the "VFREEBUSY" component MUST + match one of the calendar user addresses of the owner of the Outbox + collection. + + A response to a busy time request that indicates status for one or + more calendar users MUST be an XML document with a CALDAV:schedule- + response XML element as its root element. This element MUST contain + one CALDAV:response element for each calendar user, with each such + element in turn containing elements that indicate which calendar user + they correspond to, the scheduling status for that calendar user, any + error codes, and an optional description. For a successful busy time + request, a CALDAV:calendar-data element is also present for each + calendar user, containing the actual busy time information (i.e., an + iCalendar "VFREEBUSY" component). See Section 10 for details on the + child elements. See Appendix B.5 for an example busy time request + and response. + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 37] + +RFC 6638 CalDAV Scheduling June 2012 + + +5.1. Status Codes + + The list below summarizes the most common status codes used for this + method. However, clients need to be prepared to handle other + 2/3/4/5xx series status codes as well. + + 200 (OK) - The command succeeded. + + 204 (No Content) - The command succeeded. + + 400 (Bad Request) - The client has provided an invalid scheduling + message. + + 403 (Forbidden) - The client cannot submit a scheduling message to + the specified Request-URI. + + 404 (Not Found) - The URL in the Request-URI was not present. + + 423 (Locked) - The specified resource is locked, and the client + either is not a lock owner or the lock type requires a lock token + to be submitted and the client did not submit it. + +5.2. Additional Method Preconditions + + The following are existing preconditions that are reused for the POST + method on an Outbox collection. + + o DAV:need-privileges [RFC3744] + + o CALDAV:supported-calendar-data [RFC4791] + + o CALDAV:valid-calendar-data [RFC4791] + + o CALDAV:max-resource-size [RFC4791] + + The following are new method preconditions for the POST method on an + Outbox collection. + +5.2.1. CALDAV:valid-scheduling-message Precondition + + Name: valid-scheduling-message + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: POST + + Use with: 400 Bad Request + + + + +Daboo & Desruisseaux Standards Track [Page 38] + +RFC 6638 CalDAV Scheduling June 2012 + + + Purpose: (precondition) -- The resource submitted in the POST + request MUST obey all the restrictions specified in Section 3.3.2 + of iTIP [RFC5546]. + + Definition: + + <!ELEMENT valid-scheduling-message EMPTY> + +5.2.2. CALDAV:valid-organizer Precondition + + Name: valid-organizer + + Namespace: urn:ietf:params:xml:ns:caldav + + Apply to: POST + + Use with: 403 Forbidden + + Purpose: (precondition) -- The "ORGANIZER" property value in the + POST request's scheduling message MUST match one of the calendar + user addresses of the owner of the scheduling Outbox collection + being targeted by the request. + + Definition: + + <!ELEMENT valid-organizer EMPTY> + +6. Scheduling Privileges + + New scheduling privileges are defined in this section. All the + scheduling privileges MUST be non-abstract and MUST appear in the + DAV:supported-privilege-set property of scheduling Outbox and Inbox + collections on which they are defined. + + The tables specified in Appendix A clarify which scheduling methods + (e.g., "REQUEST", "REPLY", etc.) are controlled by each scheduling + privilege defined in this section. + +6.1. Privileges on Scheduling Inbox Collections + + This section defines new WebDAV Access Control List (ACL) [RFC3744] + privileges that are defined for use on scheduling Inbox collections. + These privileges determine whether delivery of scheduling messages + from a calendar user is allowed by the calendar user who "owns" the + scheduling Inbox collection. This allows calendar users to choose + which other calendar users can schedule with them. + + + + + +Daboo & Desruisseaux Standards Track [Page 39] + +RFC 6638 CalDAV Scheduling June 2012 + + + Note that when a scheduling message is delivered to a calendar user, + in addition to a scheduling object resource being created in the + calendar user's scheduling Inbox collection, a new scheduling object + resource might be created or an existing one updated in a calendar + belonging to the calendar user. In that case, the ability to create + or update the scheduling object resource in the calendar is + controlled by the privileges assigned to the scheduling Inbox + collection. + + The privileges defined in this section are ignored if applied to a + resource other than a scheduling Inbox collection. + +6.1.1. CALDAV:schedule-deliver Privilege + + CALDAV:schedule-deliver is an aggregate privilege as per Section 6.3. + + <!ELEMENT schedule-deliver EMPTY> + +6.1.2. CALDAV:schedule-deliver-invite Privilege + + The CALDAV:schedule-deliver-invite privilege controls the processing + and delivery of scheduling messages coming from an "Organizer". + + <!ELEMENT schedule-deliver-invite EMPTY> + +6.1.3. CALDAV:schedule-deliver-reply Privilege + + The CALDAV:schedule-deliver-reply privilege controls the processing + and delivery of scheduling messages coming from an "Attendee". + + <!ELEMENT schedule-deliver-reply EMPTY> + +6.1.4. CALDAV:schedule-query-freebusy Privilege + + The CALDAV:schedule-query-freebusy privilege controls freebusy + requests targeted at the owner of the scheduling Inbox collection. + + <!ELEMENT schedule-query-freebusy EMPTY> + +6.2. Privileges on Scheduling Outbox Collections + + This section defines new WebDAV ACL [RFC3744] privileges that are + defined for use on scheduling Outbox collections. These privileges + determine which calendar users are allowed to send scheduling + messages on behalf of the calendar user who "owns" the scheduling + Outbox collection. This allows calendar users to choose other + calendar users who can act on their behalf (e.g., assistants working + on behalf of their boss). + + + +Daboo & Desruisseaux Standards Track [Page 40] + +RFC 6638 CalDAV Scheduling June 2012 + + + The privileges defined in this section are ignored if applied to a + resource other than a scheduling Outbox collection. + +6.2.1. CALDAV:schedule-send Privilege + + CALDAV:schedule-send is an aggregate privilege as per Section 6.3. + + <!ELEMENT schedule-send EMPTY> + +6.2.2. CALDAV:schedule-send-invite Privilege + + The CALDAV:schedule-send-invite privilege controls the sending of + scheduling messages by "Organizers". + + Users granted the DAV:bind privilege on a calendar collection, or the + DAV:write privilege on scheduling object resources, will also need + the CALDAV:schedule-send-invite privilege granted on the scheduling + Outbox collection of the owner of the calendar collection or + scheduling object resource in order to be allowed to create, modify, + or delete scheduling object resources in a way that will trigger the + CalDAV server to deliver scheduling messages to "Attendees". + + <!ELEMENT schedule-send-invite EMPTY> + +6.2.3. CALDAV:schedule-send-reply Privilege + + The CALDAV:schedule-send-reply privilege controls the sending of + scheduling messages by "Attendees". + + Users granted the DAV:bind privilege on a calendar collection, or the + DAV:write privilege on scheduling object resources, will also need + the CALDAV:schedule-send-reply privilege granted on the scheduling + Outbox collection of the owner of the calendar collection or + scheduling object resource in order to be allowed to create, modify, + or delete scheduling object resources in a way that will trigger the + CalDAV server to deliver scheduling message replies to the + "Organizer". + + <!ELEMENT schedule-send-reply EMPTY> + +6.2.4. CALDAV:schedule-send-freebusy Privilege + + The CALDAV:schedule-send-freebusy privilege controls the use of the + POST method to submit scheduling messages that specify the scheduling + method "REQUEST" with a "VFREEBUSY" calendar component. + + <!ELEMENT schedule-send-freebusy EMPTY> + + + + +Daboo & Desruisseaux Standards Track [Page 41] + +RFC 6638 CalDAV Scheduling June 2012 + + +6.3. Aggregation of Scheduling Privileges + + Server implementations MUST aggregate the scheduling privileges as + follows: + + DAV:all contains CALDAV:schedule-deliver and CALDAV:schedule-send; + + CALDAV:schedule-deliver contains CALDAV:schedule-deliver-invite, + CALDAV:schedule-deliver-reply, and CALDAV:schedule-query-freebusy; + + CALDAV:schedule-send contains CALDAV:schedule-send-invite, CALDAV: + schedule-send-reply, and CALDAV:schedule-send-freebusy. + + The following diagram illustrates how scheduling privileges are + aggregated according to the above requirements. + + [DAV:all] (aggregate) + | + +-- [CALDAV:schedule-deliver] (aggregate) + | | + | +-- [CALDAV:schedule-deliver-invite] + | +-- [CALDAV:schedule-deliver-reply] + | +-- [CALDAV:schedule-query-freebusy] + | + +-- [CALDAV:schedule-send] (aggregate) + | + +-- [CALDAV:schedule-send-invite] + +-- [CALDAV:schedule-send-reply] + +-- [CALDAV:schedule-send-freebusy] + +7. Additional iCalendar Property Parameters + + This specification defines additional iCalendar property parameters + to support the CalDAV scheduling extensions. + +7.1. Schedule Agent Parameter + + Parameter Name: SCHEDULE-AGENT + + Purpose: To specify the agent expected to deliver scheduling + messages to the corresponding "Organizer" or "Attendee". + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 42] + +RFC 6638 CalDAV Scheduling June 2012 + + + Format Definition: This property parameter is defined by the + following notation: + + scheduleagentparam = "SCHEDULE-AGENT" "=" + ("SERVER" ; The server handles scheduling + / "CLIENT" ; The client handles scheduling + / "NONE" ; No scheduling + / x-name ; Experimental type + / iana-token) ; Other IANA-registered type + ; + ; If the parameter is not present, its value defaults to SERVER. + ; "x-name" and "iana-token" are defined in Section 3.1 of + ; [RFC5545]. + + Description: This property parameter MAY be specified on "ORGANIZER" + or "ATTENDEE" iCalendar properties. In the absence of this + parameter, the value "SERVER" MUST be used for the default + behavior. The value determines whether or not a scheduling + operation on a server will cause a scheduling message to be sent + to the corresponding calendar user identified by the "ORGANIZER" + or "ATTENDEE" property value. When the value "SERVER" is + specified, or the parameter is absent, then it is the server's + responsibility to send a scheduling message as part of a + scheduling operation. When the value "CLIENT" is specified, that + indicates that the client is handling scheduling messages with the + calendar user itself. When "NONE" is specified, no scheduling + messages are being sent to the calendar user. + + Servers MUST NOT include this parameter in any scheduling messages + sent as the result of a scheduling operation. + + Clients MUST NOT include this parameter in any scheduling messages + that they themselves send. + + The parameter value MUST be the same on every "ORGANIZER" property + in a scheduling object resource. + + The parameter value MUST be the same on each "ATTENDEE" property + whose values match in a scheduling object resource. + + Servers and clients MUST treat x-name and iana-token values they + do not recognize the same way as they would the "NONE" value. + + Example: + + ORGANIZER;SCHEDULE-AGENT=SERVER:mailto:bernard@example.com + ATTENDEE;SCHEDULE-AGENT=NONE:mailto:cyrus@example.com + + + + +Daboo & Desruisseaux Standards Track [Page 43] + +RFC 6638 CalDAV Scheduling June 2012 + + +7.2. Schedule Force Send Parameter + + Parameter Name: SCHEDULE-FORCE-SEND + + Purpose: To force a scheduling message to be sent to the calendar + user specified by the property. + + Format Definition: This property parameter is defined by the + following notation: + + scheduleforcesendparam = "SCHEDULE-FORCE-SEND" "=" + ("REQUEST" ; Force a "REQUEST" + / "REPLY" ; Force a "REPLY" + / iana-token) + ; + ; "iana-token" is defined in Section 3.1 of [RFC5545]. Its value + ; MUST be an IANA-registered iCalendar "METHOD" property value. + + Description: This property parameter MAY be specified on "ATTENDEE" + and "ORGANIZER" properties on which the "SCHEDULE-AGENT" property + parameter is set to the value "SERVER" or is not specified. This + property parameter is used to force a server to send a scheduling + message to a specific calendar user in situations where the server + would not send a scheduling message otherwise (e.g., when no + change that warrants the delivery of a new scheduling message was + performed on the scheduling object resource). An "Organizer" MAY + specify this parameter on an "ATTENDEE" property with the value + "REQUEST" to force a "REQUEST" scheduling message to be sent to + this "Attendee". An "Attendee" MAY specify this parameter on the + "ORGANIZER" with the value "REPLY" to force a "REPLY" scheduling + message to be sent to the "Organizer". + + Servers MUST NOT preserve this property parameter in scheduling + object resources, nor include it in any scheduling messages sent + as the result of a scheduling operation. + + Clients MUST NOT include this parameter in any scheduling messages + that they themselves send. + + Servers MUST set the "SCHEDULE-STATUS" parameter of the "ATTENDEE" + or "ORGANIZER" to 2.3 (i.e., "Success; invalid property parameter + ignored"; see Section 3.6 of [RFC5546]) when the "SCHEDULE-FORCE- + SEND" parameter is set to an iana-token value they do not + recognize. + + + + + + + +Daboo & Desruisseaux Standards Track [Page 44] + +RFC 6638 CalDAV Scheduling June 2012 + + + Example: + + ORGANIZER;SCHEDULE-FORCE-SEND=REPLY:mailto:cyrus@example.com + ATTENDEE;SCHEDULE-FORCE-SEND=REQUEST:mailto:bernard@example.com + +7.3. Schedule Status Parameter + + Parameter Name: SCHEDULE-STATUS + + Purpose: To specify the status codes returned from processing of the + most recent scheduling message sent to the corresponding + "Attendee", or received from the corresponding "Organizer". + + Format Definition: This property parameter is defined by the + following notation: + + schedulestatusparam = "SCHEDULE-STATUS" "=" + ( statcode + / DQUOTE statcode *("," statcode) DQUOTE) + ; + ; "statcode" is defined in Section 3.8.8.3 of [RFC5545]. The + ; value is a single "statcode" or a comma-separated list of + ; "statcode" values. + + Description: This property parameter MAY be specified on the + "ATTENDEE" and "ORGANIZER" properties. + + Servers MUST only add or change this property parameter on any + "ATTENDEE" properties corresponding to calendar users who were + sent a scheduling message via a scheduling operation. Clients + SHOULD NOT change or remove this parameter if it was provided by + the server. In the case where the client is handling the + scheduling, the client MAY add, change, or remove this parameter + to indicate the last scheduling message status it received. + + Servers MUST add this parameter to any "ORGANIZER" properties + corresponding to calendar users who were sent a scheduling message + reply by an "Attendee" via a scheduling operation. Clients SHOULD + NOT change or remove this parameter if it was provided by the + server. In the case where the client is handling the scheduling, + the client MAY add, change, or remove this parameter to indicate + the last scheduling message status it received. + + Servers MUST NOT include this parameter in any scheduling messages + sent as the result of a scheduling operation. + + Clients MUST NOT include this parameter in any scheduling messages + that they themselves send. + + + +Daboo & Desruisseaux Standards Track [Page 45] + +RFC 6638 CalDAV Scheduling June 2012 + + + Values for this property parameter are described in Section 3.2.9. + + Example: + + ATTENDEE;SCHEDULE-STATUS="2.0":mailto:bernard@example.com + ATTENDEE;SCHEDULE-STATUS="2.0,2.4":mailto:cyrus@example.com + +8. Additional Message Header Fields + + This specification defines additional HTTP request and response + headers for use with CalDAV. + +8.1. Schedule-Reply Request Header + + Schedule-Reply = "Schedule-Reply" ":" ("T" | "F") + + Example: + + Schedule-Reply: F + + When an "Attendee" removes a scheduling object resource as per + Section 3.2.2.4, and the Schedule-Reply header is set to the value + "T" (true) or is not present, the server MUST send an appropriate + reply scheduling message with the "Attendee's" "PARTSTAT" iCalendar + property parameter value set to "DECLINED" as part of its normal + scheduling operation processing. + + When the Schedule-Reply header is set to the value "F" (false), the + server MUST NOT send a scheduling message as part of its normal + scheduling operation processing. + + The Schedule-Reply request header is used by a client to indicate to + a server whether or not a scheduling operation ought to occur when an + "Attendee" deletes a scheduling object resource. In particular, it + controls whether a reply scheduling message is sent to the + "Organizer" as a result of the removal. There are situations in + which unsolicited scheduling messages need to be silently removed (or + ignored) for security or privacy reasons. This request header allows + the scheduling object resource to be removed if such a need arises. + +8.2. Schedule-Tag Response Header + + The Schedule-Tag response header provides the current value of the + CALDAV:schedule-tag property value. The behavior of this response + header is described in Section 3.2.10. + + All scheduling object resources MUST support the Schedule-Tag header. + + + + +Daboo & Desruisseaux Standards Track [Page 46] + +RFC 6638 CalDAV Scheduling June 2012 + + + Schedule-Tag = "Schedule-Tag" ":" opaque-tag + ; "opaque-tag" is defined in Section 3.11 of [RFC2616]. + + Example: + + Schedule-Tag: "12ab34-cd56ef" + +8.3. If-Schedule-Tag-Match Request Header + + The If-Schedule-Tag-Match request header field is used with a method + to make it conditional. Clients can set this header to the value + returned in the Schedule-Tag response header, or the CALDAV:schedule- + tag property, of a scheduling object resource previously retrieved + from the server to avoid overwriting "consequential" changes to the + scheduling object resource. + + All scheduling object resources MUST support the If-Schedule-Tag- + Match header. + + If-Schedule-Tag-Match = "If-Schedule-Tag-Match" ":" opaque-tag + ; "opaque-tag" is defined in Section 3.11 of [RFC2616]. + + Example: + + If-Schedule-Tag-Match: "12ab34-cd56ef" + +9. Additional WebDAV Properties + + This specification defines the following new WebDAV properties for + use with CalDAV. + +9.1. CALDAV:schedule-calendar-transp Property + + Name: schedule-calendar-transp + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Determines whether the calendar object resources in a + calendar collection will affect the owner's busy time information. + + Protected: This property MAY be protected and SHOULD NOT be returned + by a PROPFIND DAV:allprop request (as defined in Section 14.2 of + [RFC4918]). + + COPY/MOVE behavior: This property value SHOULD be kept during a MOVE + operation, and SHOULD be copied and preserved in a COPY. + + + + + +Daboo & Desruisseaux Standards Track [Page 47] + +RFC 6638 CalDAV Scheduling June 2012 + + + Description: This property SHOULD be defined on all calendar + collections. If present, it contains one of two XML elements that + indicate whether the calendar object resources in the calendar + collection ought to contribute to the owner's busy time. When the + CALDAV:opaque element is used, all calendar object resources in + the corresponding calendar collection MUST contribute to busy + time, assuming that access privileges and other iCalendar + properties allow it to. When the CALDAV:transparent XML element + is used, the calendar object resources in the corresponding + calendar collection MUST NOT contribute to busy time. + + If this property is not present on a calendar collection, then the + default value CALDAV:opaque MUST be assumed. + + Definition: + + <!ELEMENT schedule-calendar-transp (opaque | transparent)> + + <!ELEMENT opaque EMPTY> + <!-- Affects busy time searches --> + + <!ELEMENT transparent EMPTY> + <!-- Invisible to busy time searches --> + + Example: + + <C:schedule-calendar-transp + xmlns:C="urn:ietf:params:xml:ns:caldav"> + <C:opaque/> + </C:schedule-calendar-transp> + +9.2. CALDAV:schedule-default-calendar-URL Property + + Name: schedule-default-calendar-URL + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Specifies a default calendar for an "Attendee" where new + scheduling object resources are created. + + Protected: This property MAY be protected in the case where a server + does not support changing the default calendar, or does not + support a default calendar. + + COPY/MOVE behavior: This property is only defined on a scheduling + Inbox collection that cannot be moved or copied. + + + + + +Daboo & Desruisseaux Standards Track [Page 48] + +RFC 6638 CalDAV Scheduling June 2012 + + + Description: This property MAY be defined on a scheduling Inbox + collection. If present, it contains zero or one DAV:href XML + elements. When a DAV:href element is present, its value indicates + a URL to a calendar collection that is used as the default + calendar. When no DAV:href element is present, it indicates that + there is no default calendar. In the absence of this property, + there is no default calendar. When there is no default calendar, + the server is free to choose the calendar in which a new + scheduling object resource is created. See Section 4.3. + + Definition: + + <!ELEMENT schedule-default-calendar-URL (DAV:href?)> + + Example: + + <C:schedule-default-calendar-URL xmlns:D="DAV:" + xmlns:C="urn:ietf:params:xml:ns:caldav"> + <D:href>/home/cyrus/calendars/work/</D:href> + </C:schedule-default-calendar-URL> + +9.3. CALDAV:schedule-tag Property + + Name: schedule-tag + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Indicates whether a scheduling object resource has had a + "consequential" change made to it. + + Value: opaque-tag (defined in Section 3.11 of [RFC2616]) + + Protected: This property MUST be protected, as only the server can + update the value. + + COPY/MOVE behavior: This property value is determined by the server + and MAY be different from the value on the source resource. + + Description: The CALDAV:schedule-tag property MUST be defined on all + scheduling object resources. This property is described in + Section 3.2.10. + + Definition: + + <!ELEMENT schedule-tag (#PCDATA)> + + + + + + +Daboo & Desruisseaux Standards Track [Page 49] + +RFC 6638 CalDAV Scheduling June 2012 + + + Example: + + <C:schedule-tag xmlns:C="urn:ietf:params:xml:ns:caldav" + >"12345-67890"</C:schedule-tag> + +10. XML Element Definitions + +10.1. CALDAV:schedule-response XML Element + + Name: schedule-response + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Contains the set of responses for a POST method request. + + Description: See Section 5. + + Definition: + + <!ELEMENT schedule-response (response*)> + +10.2. CALDAV:response XML Element + + Name: response + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: Contains a single response for a POST method request. + + Description: See Section 5. + + Definition: + + <!ELEMENT response (recipient, + request-status, + calendar-data?, + DAV:error?, + DAV:responsedescription?)> + + <!-- CALDAV:calendar-data is defined in Section 9.6 of + RFC 4791 and when used here uses the definition with + content (#PCDATA) only. --> + +10.3. CALDAV:recipient XML Element + + Name: recipient + + Namespace: urn:ietf:params:xml:ns:caldav + + + +Daboo & Desruisseaux Standards Track [Page 50] + +RFC 6638 CalDAV Scheduling June 2012 + + + Purpose: The calendar user address that the enclosing response for a + POST method request is for. + + Description: See Section 5. + + Definition: + + <!ELEMENT recipient (DAV:href)> + +10.4. CALDAV:request-status XML Element + + Name: request-status + + Namespace: urn:ietf:params:xml:ns:caldav + + Purpose: The iTIP "REQUEST-STATUS" property value for this response. + + Description: See Section 5. + + Definition: + + <!ELEMENT request-status (#PCDATA)> + +11. Security Considerations + + The process of scheduling involves the sending and receiving of + scheduling messages. As a result, the security problems related to + messaging in general are relevant here. In particular, the + authenticity of the scheduling messages needs to be verified. + Servers and clients MUST use an HTTP connection protected with + Transport Layer Security (TLS) as defined in [RFC2818] for all + scheduling operations. Clients MUST use the procedures detailed in + Section 6 of [RFC6125] to verify the authenticity of the server. + Servers MUST make use of HTTP authentication [RFC2617] to verify the + authenticity of the calendar user for whom the client is sending + requests. + +11.1. Preventing Denial-of-Service Attacks + + Servers MUST ensure that clients cannot consume excessive server + resources by carrying out "large" scheduling operations. In + particular, servers SHOULD enforce CALDAV:max-resource-size, CALDAV: + max-instances, and CALDAV:max-attendees-per-instance preconditions as + applicable for scheduling Inbox and Outbox collections. + + + + + + + +Daboo & Desruisseaux Standards Track [Page 51] + +RFC 6638 CalDAV Scheduling June 2012 + + +11.2. Verifying Scheduling Operations + + When handling a scheduling operation: + + 1. Servers MUST verify that the principal associated with the DAV: + owner of the calendar collection in which a scheduling object + resource is being manipulated contains a CALDAV:schedule-outbox- + URL property value. + + 2. Servers MUST verify that the currently authenticated user has the + CALDAV:schedule-send privilege, or a sub-privilege aggregated + under this privilege, on the scheduling Outbox collection of the + DAV:owner of the calendar collection in which a scheduling object + resource is being manipulated. + + 3. Servers MUST only deliver scheduling messages to recipients when + the CALDAV:schedule-deliver privilege, or a sub-privilege + aggregated under this privilege, is granted on the recipient's + scheduling Inbox collection for the principal associated with the + DAV:owner of the calendar collection in which a scheduling object + resource is being manipulated. + + 4. To prevent impersonation of calendar users, the server MUST + verify that the "ORGANIZER" property in an organizer scheduling + object resource matches one of the calendar user addresses of the + DAV:owner of the calendar collection in which the resource is + stored. + + 5. To prevent spoofing of an existing scheduling object resource, + servers MUST verify that the "UID" iCalendar property value in a + new scheduling object resource does not match that of an existing + scheduling object resource with a different "ORGANIZER" property + value. + +11.3. Verifying Busy Time Information Requests + + When handling a POST request on a scheduling Outbox collection: + + 1. Servers MUST verify that the principal associated with the + calendar user address specified in the "ORGANIZER" property of + the scheduling message data in the request contains a CALDAV: + schedule-outbox-URL property value that matches the scheduling + Outbox collection targeted by the request. + + 2. Servers MUST verify that the currently authenticated user has the + CALDAV:schedule-send privilege, or a sub-privilege aggregated + under this privilege, on the scheduling Outbox collection + targeted by the request. + + + +Daboo & Desruisseaux Standards Track [Page 52] + +RFC 6638 CalDAV Scheduling June 2012 + + + 3. Servers MUST only return valid freebusy information for + recipients when the CALDAV:schedule-deliver privilege, or a + sub-privilege aggregated under this privilege, is granted on the + recipient's scheduling Inbox collection for the principal + associated with the DAV:owner of the scheduling Outbox collection + targeted by the request. + +11.4. Privacy Issues + + This specification only defines how calendar users on the same server + are able to schedule with each other -- unauthenticated users have no + way to carry out scheduling operations. Access control privileges + (as per Section 6) can control which of those users can schedule with + others. Calendar users not wishing to expose their calendar + information to other users can do so by denying privileges to + specific users, or all users, for all scheduling operations, or + perhaps only freebusy. + + "Attendees" can also use the Schedule-Reply request header + (Section 8.1) with the value set to "F" to prevent notification to an + "Organizer" that a scheduling object resource was deleted. This + allows "Attendees" to remove unwanted scheduling messages without any + response to the "Organizer". + + Servers MUST NOT expose any private iCalendar data, or WebDAV + resource state information (URLs, WebDAV properties, etc.) for one + calendar user to another via scheduling messages or error responses + to scheduling operations. In particular, as per Section 8.1 of + [RFC4918], authorization errors MUST take preference over other + errors. + +11.5. Mitigation of iTIP Threats + + Section 6.1 of iTIP [RFC5546] defines a set of potential threats in a + scheduling system, and Section 6.2 of [RFC5546] defines + recommendations on how those can be addressed in protocols using + iTIP. This specification addresses the iTIP threats in the following + manner: + + Spoofing the "Organizer": Addressed by item 4 in Section 11.2. + + Spoofing the "Attendee": Addressed by Section 3.2.2.1 and item 2 in + Section 11.2. + + Unauthorized Replacement of the "Organizer": Addressed by item 5 in + Section 11.2. + + Eavesdropping and Data Integrity: Addressed by requiring TLS. + + + +Daboo & Desruisseaux Standards Track [Page 53] + +RFC 6638 CalDAV Scheduling June 2012 + + + Flooding a Calendar: Addressed by requirements in Section 11.1. + + Unauthorized REFRESH Requests: This specification does not support + the REFRESH method. + +12. IANA Considerations + +12.1. Message Header Field Registrations + + The message header fields below have been added to the Permanent + Message Header Field Registry (see [RFC3864]). + +12.1.1. Schedule-Reply + + Header field name: Schedule-Reply + + Applicable protocol: http + + Status: standard + + Author/Change controller: IETF + + Specification document(s): this specification (Section 8.1) + + Related information: none + +12.1.2. Schedule-Tag + + Header field name: Schedule-Tag + + Applicable protocol: http + + Status: standard + + Author/Change controller: IETF + + Specification document(s): this specification (Section 8.2) + + Related information: none + +12.1.3. If-Schedule-Tag-Match + + Header field name: If-Schedule-Tag-Match + + Applicable protocol: http + + Status: standard + + + + +Daboo & Desruisseaux Standards Track [Page 54] + +RFC 6638 CalDAV Scheduling June 2012 + + + Author/Change controller: IETF + + Specification document(s): this specification (Section 8.3) + + Related information: none + +12.2. iCalendar Property Parameter Registrations + + The following iCalendar property parameter names have been added to + the iCalendar Parameters Registry defined in Section 8.3.3 of + [RFC5545]. + + +---------------------+---------+-----------------------+ + | Parameter | Status | Reference | + +---------------------+---------+-----------------------+ + | SCHEDULE-AGENT | Current | RFC 6638, Section 7.1 | + | | | | + | SCHEDULE-STATUS | Current | RFC 6638, Section 7.3 | + | | | | + | SCHEDULE-FORCE-SEND | Current | RFC 6638, Section 7.2 | + +---------------------+---------+-----------------------+ + +12.3. iCalendar REQUEST-STATUS Value Registrations + + The following iCalendar "REQUEST-STATUS" values have been added to + the iCalendar REQUEST-STATUS Value Registry defined in Section 7.3 of + [RFC5546]. + + +-------------+---------+---------------------------+ + | Status Code | Status | Reference | + +-------------+---------+---------------------------+ + | 1.0 | Current | RFC 6638, Section 3.2.9.1 | + | | | | + | 1.1 | Current | RFC 6638, Section 3.2.9.2 | + | | | | + | 1.2 | Current | RFC 6638, Section 3.2.9.3 | + +-------------+---------+---------------------------+ + +12.4. Additional iCalendar Elements Registries + + Per this specification, two new IANA registries for iCalendar + elements have been added. Additional codes MAY be used, provided the + process described in Section 8.2.1 of [RFC5545] is used to register + them. + + + + + + + +Daboo & Desruisseaux Standards Track [Page 55] + +RFC 6638 CalDAV Scheduling June 2012 + + +12.4.1. Schedule Agent Values Registry + + The following table has been used to initialize the Schedule Agent + Values Registry. + + +----------------+---------+-----------------------+ + | Schedule Agent | Status | Reference | + +----------------+---------+-----------------------+ + | SERVER | Current | RFC 6638, Section 7.1 | + | | | | + | CLIENT | Current | RFC 6638, Section 7.1 | + | | | | + | NONE | Current | RFC 6638, Section 7.1 | + +----------------+---------+-----------------------+ + +12.4.2. Schedule Force Send Values Registry + + The following table has been used to initialize the Schedule Force + Send Values Registry. + + +---------------------+---------+-----------------------+ + | Schedule Force Send | Status | Reference | + +---------------------+---------+-----------------------+ + | REQUEST | Current | RFC 6638, Section 7.2 | + | | | | + | REPLY | Current | RFC 6638, Section 7.2 | + +---------------------+---------+-----------------------+ + +13. Acknowledgements + + The authors would like to thank the following individuals for + contributing their ideas and support for writing this specification: + Mike Douglass, Lisa Dusseault, Red Dutta, Jacob Farkas, Jeffrey + Harris, Helge Hess, Eliot Lear, Andrew McMillan, Alexey Melnikov, + Arnaud Quillaud, Julian F. Reschke, Wilfredo Sanchez Vega, and Simon + Vaillancourt. + + The authors would also like to thank the Calendaring and Scheduling + Consortium for advice with this specification, and for organizing + interoperability testing events to help refine it. + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 56] + +RFC 6638 CalDAV Scheduling June 2012 + + +14. References + +14.1. 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. + + [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., + Leach, P., Luotonen, A., and L. Stewart, "HTTP + Authentication: Basic and Digest Access Authentication", + RFC 2617, June 1999. + + [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. + + [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web + Distributed Authoring and Versioning (WebDAV) + Access Control Protocol", RFC 3744, May 2004. + + [RFC3864] Klyne, G., Nottingham, M., and J. Mogul, "Registration + Procedures for Message Header Fields", BCP 90, RFC 3864, + September 2004. + + [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, + "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, + March 2007. + + [RFC4918] Dusseault, L., Ed., "HTTP Extensions for Web Distributed + Authoring and Versioning (WebDAV)", RFC 4918, June 2007. + + [RFC5234] Crocker, D., Ed., and P. Overell, "Augmented BNF for + Syntax Specifications: ABNF", STD 68, RFC 5234, + January 2008. + + [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and + Scheduling Core Object Specification (iCalendar)", + RFC 5545, September 2009. + + [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent + Interoperability Protocol (iTIP)", RFC 5546, + December 2009. + + + + + + + +Daboo & Desruisseaux Standards Track [Page 57] + +RFC 6638 CalDAV Scheduling June 2012 + + + [RFC6125] Saint-Andre, P. and J. Hodges, "Representation and + Verification of Domain-Based Application Service Identity + within Internet Public Key Infrastructure Using X.509 + (PKIX) Certificates in the Context of Transport Layer + Security (TLS)", RFC 6125, March 2011. + + [W3C.REC-xml-20081126] + Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., + and F. Yergeau, "Extensible Markup Language (XML) 1.0 + (Fifth Edition)", World Wide Web Consortium + Recommendation REC-xml-20081126, November 2008, + <http://www.w3.org/TR/2008/REC-xml-20081126>. + +14.2. Informative References + + [RFC6047] Melnikov, A., Ed., "iCalendar Message-Based + Interoperability Protocol (iMIP)", RFC 6047, + December 2010. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 58] + +RFC 6638 CalDAV Scheduling June 2012 + + +Appendix A. Scheduling Privileges Summary + +A.1. Scheduling Inbox Privileges + + The following tables specify which scheduling privileges grant the + right to a calendar user to deliver a scheduling message to the + scheduling Inbox collection of another calendar user. The + appropriate behavior depends on the calendar component type as well + as the scheduling "METHOD" specified in the scheduling message. + + +--------------------------------+ + | METHOD for VEVENT and VTODO | + +-----------------------------+---------+-------+-----+--------+ + | Scheduling Inbox Privilege | REQUEST | REPLY | ADD | CANCEL | + +-----------------------------+---------+-------+-----+--------+ + | schedule-deliver | * | * | * | * | + | schedule-deliver-invite | * | | * | * | + | schedule-deliver-reply | | * | | | + | schedule-query-freebusy | | | | | + +-----------------------------+---------+-------+-----+--------+ + + + +----------------------+ + | METHOD for VFREEBUSY | + +-----------------------------+----------------------+ + | Scheduling Inbox Privilege | REQUEST | + +-----------------------------+----------------------+ + | schedule-deliver | * | + | schedule-deliver-invite | | + | schedule-deliver-reply | | + | schedule-query-freebusy | * | + +-----------------------------+----------------------+ + + + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 59] + +RFC 6638 CalDAV Scheduling June 2012 + + +A.2. Scheduling Outbox Privileges + + The following tables specify which scheduling privileges grant the + right to a calendar user to perform busy time information requests + and to submit scheduling messages to other calendar users as the + result of a scheduling operation. The appropriate behavior depends + on the calendar component type as well as the scheduling "METHOD" + specified in the scheduling message. + + +--------------------------------+ + | METHOD for VEVENT and VTODO | + +-----------------------------+---------+-------+-----+--------+ + | Scheduling Outbox Privilege | REQUEST | REPLY | ADD | CANCEL | + +-----------------------------+---------+-------+-----+--------+ + | schedule-send | * | * | * | * | + | schedule-send-invite | * | | * | * | + | schedule-send-reply | | * | | | + | schedule-send-freebusy | | | | | + +-----------------------------+---------+-------+-----+--------+ + + + +----------------------+ + | METHOD for VFREEBUSY | + +-----------------------------+----------------------+ + | Scheduling Outbox Privilege | REQUEST | + +-----------------------------+----------------------+ + | schedule-send | * | + | schedule-send-invite | | + | schedule-send-reply | | + | schedule-send-freebusy | * | + +-----------------------------+----------------------+ + +Appendix B. Example Scheduling Operations + + This section describes some example scheduling operations that give a + general idea of how scheduling is carried out between CalDAV clients + and servers from the perspective of meeting "Organizers" and + "Attendees". + + The server is assumed to be hosted in the "example.com" domain, and + users whose email addresses are at the "example.com" domain are + assumed to be hosted by the server. In addition, the email addresses + in the "example.net" domain are also valid email addresses for + calendar users hosted by the server. Calendar users with an email + address at the "example.org" domain are assumed to not be hosted by + the server. + + + + + +Daboo & Desruisseaux Standards Track [Page 60] + +RFC 6638 CalDAV Scheduling June 2012 + + + In the following examples, the requests and responses are incomplete + and are only for illustrative purposes. In particular, HTTP + authentication headers and behaviors are not shown, even though they + are required in normal operation. + +B.1. Example: "Organizer" Inviting Multiple "Attendees" + + In the following example, Cyrus invites Wilfredo, Bernard, and Mike + to a single instance event by simply creating a new scheduling object + resource in one of his calendar collections by using the PUT method. + + >> Request << + + PUT /home/cyrus/calendars/work/9263504FD3AD.ics HTTP/1.1 + Host: cal.example.com + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + If-None-Match: * + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185254Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:wilfredo@ + example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@ex + ample.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE:mailto:mike@example.org + END:VEVENT + END:VCALENDAR + + >> Response << + + HTTP/1.1 201 Created + Content-Length: 0 + + + +Daboo & Desruisseaux Standards Track [Page 61] + +RFC 6638 CalDAV Scheduling June 2012 + + + Date: Tue, 02 Jun 2009 18:52:54 GMT + Last-Modified: Tue, 02 Jun 2009 18:52:54 GMT + ETag: "d85561cfe74a4e785eb4639451b434fb" + Schedule-Tag: "488177c8-2ea7-4176-a6cb-fab8cfccdea2" + + Once the event creation has been completed, Cyrus's client will + retrieve the event back from the server to get the schedule status of + each "Attendee", as well as record the Schedule-Tag value for future + use. In this example, the server reports that a scheduling message + was delivered to Wilfredo, a scheduling message is still pending for + Bernard, and the server was unable to deliver a scheduling message to + Mike. + + >> Request << + + GET /home/cyrus/calendars/work/9263504FD3AD.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 18:52:58 GMT + Last-Modified: Tue, 02 Jun 2009 18:52:58 GMT + ETag: "eb897deabc8939589da116714bc99265" + Schedule-Tag: "488177c8-2ea7-4176-a6cb-fab8cfccdea2" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185300Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS= + 1.2:mailto:wilfredo@e + xample.com + + + + + +Daboo & Desruisseaux Standards Track [Page 62] + +RFC 6638 CalDAV Scheduling June 2012 + + + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS= + 1.0:mailto:bernard@example.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE;SCHEDULE-STATUS=3.7:mailto:mike@example.org + END:VEVENT + END:VCALENDAR + +B.2. Example: "Attendee" Receiving an Invitation + + In the following example, Wilfredo's client retrieves and deletes the + new scheduling message that appeared in his scheduling Inbox + collection after the server automatically processed it and created a + new scheduling object resource in his default calendar collection. + + >> Request << + + GET /home/wilfredo/calendars/inbox/27d93fc0a58c.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 18:59:58 GMT + Last-Modified: Tue, 02 Jun 2009 18:59:58 GMT + ETag: "da116714bc9926c89395895eb897deab" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + METHOD:REQUEST + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185254Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:wilfredo@ + example.com + + + + +Daboo & Desruisseaux Standards Track [Page 63] + +RFC 6638 CalDAV Scheduling June 2012 + + + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@ex + ample.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE:mailto:mike@example.org + END:VEVENT + END:VCALENDAR + + >> Request << + + DELETE /home/wilfredo/calendars/inbox/27d93fc0a58c.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 204 No Content + Date: Tue, 02 Jun 2009 20:40:36 GMT + +B.3. Example: "Attendee" Replying to an Invitation + + In the following example, Wilfredo accepts Cyrus's invitation and + sets an alarm reminder on the event. It uses the If-Schedule-Tag- + Match precondition behavior to ensure it does not overwrite any + significant changes from the "Organizer" that might have occurred + after it retrieved the initial resource data. + + >> Request << + + PUT /home/wilfredo/calendars/work/BB64861C2228.ics HTTP/1.1 + Host: cal.example.com + If-Schedule-Tag-Match: "e78f23ed-0188-4bab-938d-2aeb3324c7e8" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185254Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + + + +Daboo & Desruisseaux Standards Track [Page 64] + +RFC 6638 CalDAV Scheduling June 2012 + + + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =ACCEPTED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:wilfredo@exam + ple.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@ex + ample.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE:mailto:mike@example.org + BEGIN:VALARM + TRIGGER:-PT15M + ACTION:DISPLAY + DESCRIPTION:Reminder + END:VALARM + END:VEVENT + END:VCALENDAR + + >> Response << + + HTTP/1.1 200 OK + Content-Length: 0 + Date: Tue, 02 Jun 2009 18:57:54 GMT + Last-Modified: Tue, 02 Jun 2009 18:57:54 GMT + ETag: "eb4639451b434fbd85561cfe74a4e785" + Schedule-Tag: "8893ee45-eb9d-428f-b53c-c777daf19e41" + + Once the event modification has been completed, Wilfredo's client + will retrieve the event back from the server to get the schedule + status of the "Organizer". + + >> Request << + + GET /home/wilfredo/calendars/work/BB64861C2228.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 19:03:03 GMT + Last-Modified: Tue, 02 Jun 2009 19:02:21 GMT + ETag: "5eb897deabda116714bc9926c8939589" + Schedule-Tag: "8893ee45-eb9d-428f-b53c-c777daf19e41" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 65] + +RFC 6638 CalDAV Scheduling June 2012 + + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T190221Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo";SCHEDULE-STATUS=1.2:mailto:cyrus@ex + ample.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =ACCEPTED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:wilfredo@exam + ple.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@ex + ample.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE:mailto:mike@example.org + BEGIN:VALARM + TRIGGER:-PT15M + ACTION:DISPLAY + DESCRIPTION:Reminder + END:VALARM + END:VEVENT + END:VCALENDAR + +B.4. Example: "Organizer" Receiving a Reply to an Invitation + + On reception of Wilfredo's reply, Cyrus's server will automatically + update Cyrus's scheduling object resource, make Wilfredo's scheduling + message available in Cyrus's scheduling Inbox collection, and deliver + an updated scheduling message to Bernard to share Wilfredo's updated + participation status. In this example, Cyrus's client retrieves and + deletes this scheduling message in his scheduling Inbox collection. + + >> Request << + + GET /home/cyrus/calendars/inbox/c0a58c27d93f.ics HTTP/1.1 + Host: cal.example.com + + + + + + + +Daboo & Desruisseaux Standards Track [Page 66] + +RFC 6638 CalDAV Scheduling June 2012 + + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 19:05:02 GMT + Last-Modified: Tue, 02 Jun 2009 19:04:20 GMT + ETag: "9265eb897deabc8939589da116714bc9" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + METHOD:REPLY + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185754Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";PARTSTAT=ACCEPTED:mailto:w + ilfredo@example.com + REQUEST-STATUS:2.0;Success + END:VEVENT + END:VCALENDAR + + >> Request << + + DELETE /home/cyrus/calendars/inbox/c0a58c27d93f.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 204 No Content + Date: Tue, 02 Jun 2009 19:05:05 GMT + + Cyrus's client then retrieves the event back from the server with + Wilfredo's updated participation status. + + >> Request << + + GET /home/cyrus/calendars/work/9263504FD3AD.ics HTTP/1.1 + Host: cal.example.com + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 67] + +RFC 6638 CalDAV Scheduling June 2012 + + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 19:05:02 GMT + Last-Modified: Tue, 02 Jun 2009 19:04:20 GMT + ETag: "eb897deabc8939589da116714bc99265" + Schedule-Tag: "132cab27-1fe3-67ab-de13-abd348d1dee3" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T190420Z + DTSTART:20090602T160000Z + DTEND:20090602T170000Z + TRANSP:OPAQUE + SUMMARY:Lunch + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT + =ACCEPTED;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS=2.0: + mailto:wilfredo@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + NEEDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE;SCHEDULE-STATUS=1 + .0:mailto:bernard@example.net + ATTENDEE;CN="Mike Douglass";CUTYPE=INDIVIDUAL;PARTSTAT=NEEDS-A + CTION;RSVP=TRUE;SCHEDULE-STATUS=3.7:mailto:mike@example.org + END:VEVENT + END:VCALENDAR + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 68] + +RFC 6638 CalDAV Scheduling June 2012 + + +B.5. Example: "Organizer" Requesting Busy Time Information + + In this example, Cyrus requests the busy time information of + Wilfredo, Bernard, and Mike. + + >> Request << + + POST /home/cyrus/calendars/outbox/ HTTP/1.1 + Host: cal.example.com + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + METHOD:REQUEST + BEGIN:VFREEBUSY + UID:4FD3AD926350 + DTSTAMP:20090602T190420Z + DTSTART:20090602T000000Z + DTEND:20090604T000000Z + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega":mailto:wilfredo@example.com + ATTENDEE;CN="Bernard Desruisseaux":mailto:bernard@example.net + ATTENDEE;CN="Mike Douglass":mailto:mike@example.org + END:VFREEBUSY + END:VCALENDAR + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 20:07:34 GMT + Content-Type: application/xml; charset="utf-8" + Content-Length: xxxx + + <?xml version="1.0" encoding="utf-8" ?> + <C:schedule-response xmlns:D="DAV:" + xmlns:C="urn:ietf:params:xml:ns:caldav"> + <C:response> + <C:recipient> + <D:href>mailto:wilfredo@example.com</D:href> + </C:recipient> + <C:request-status>2.0;Success</C:request-status> + <C:calendar-data>BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + METHOD:REPLY + BEGIN:VFREEBUSY + + + +Daboo & Desruisseaux Standards Track [Page 69] + +RFC 6638 CalDAV Scheduling June 2012 + + + UID:4FD3AD926350 + DTSTAMP:20090602T200733Z + DTSTART:20090602T000000Z + DTEND:20090604T000000Z + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega":mailto:wilfredo@example.com + FREEBUSY;FBTYPE=BUSY:20090602T110000Z/20090602T120000Z + FREEBUSY;FBTYPE=BUSY:20090603T170000Z/20090603T180000Z + END:VFREEBUSY + END:VCALENDAR + </C:calendar-data> + </C:response> + <C:response> + <C:recipient> + <D:href>mailto:bernard@example.net</D:href> + </C:recipient> + <C:request-status>2.0;Success</C:request-status> + <C:calendar-data>BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Server//EN + METHOD:REPLY + BEGIN:VFREEBUSY + UID:4FD3AD926350 + DTSTAMP:20090602T200733Z + DTSTART:20090602T000000Z + DTEND:20090604T000000Z + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux":mailto:bernard@example.net + FREEBUSY;FBTYPE=BUSY:20090602T150000Z/20090602T160000Z + FREEBUSY;FBTYPE=BUSY:20090603T090000Z/20090603T100000Z + FREEBUSY;FBTYPE=BUSY:20090603T180000Z/20090603T190000Z + END:VFREEBUSY + END:VCALENDAR + </C:calendar-data> + </C:response> + <C:response> + <C:recipient> + <D:href>mailto:mike@example.org</D:href> + </C:recipient> + <C:request-status>3.7;Invalid calendar user</C:request-status> + </C:response> + </C:schedule-response> + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 70] + +RFC 6638 CalDAV Scheduling June 2012 + + +B.6. Example: User Attempting to Invite "Attendee" on Behalf of + "Organizer" + + In the following example, Cyrus attempts to create, on behalf of + Wilfredo, an event with Bernard specified as an "Attendee". The + request fails, since Wilfredo didn't grant Cyrus the right to invite + other calendar users on his behalf. + + >> Request << + + PUT /home/wilfredo/calendars/work/def456.ics HTTP/1.1 + Host: cal.example.com + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + If-None-Match: * + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VEVENT + UID:3504F926D3AD + SEQUENCE:0 + DTSTAMP:20090602T190221Z + DTSTART:20090602T230000Z + DTEND:20090603T000000Z + TRANSP:OPAQUE + SUMMARY:Dinner + ORGANIZER;CN="Wilfredo Sanchez Vega":mailto:wilfredo@example.com + ATTENDEE;CN="Wilfredo Sanchez Vega";CUTYPE=INDIVIDUAL;PARTSTAT=A + CCEPTED:mailto:wilfredo@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT=NE + EDS-ACTION;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@exampl + e.net + END:VEVENT + END:VCALENDAR + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 71] + +RFC 6638 CalDAV Scheduling June 2012 + + + >> Response << + + HTTP/1.1 403 Forbidden + Content-Type: application/xml; charset="utf-8" + Content-Length: xxxx + + <?xml version="1.0" encoding="utf-8" ?> + <D:error xmlns:D="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav"> + <D:need-privileges> + <D:resource> + <D:href>/home/wilfredo/calendars/outbox/</D:href> + <D:privilege><C:schedule-send-invite/></D:privilege> + </D:resource> + </D:need-privileges> + </D:error> + +B.7. Example: "Attendee" Declining an Instance of a Recurring Event + + In the following example, Bernard declines the second recurrence + instance of a daily recurring event he's been invited to by Cyrus. + + >> Request << + + PUT /home/bernard/calendars/work/4FD3AD926350.ics HTTP/1.1 + Host: cal.example.com + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + If-Schedule-Tag-Match: "7775FB30-7534-489E-A79A-0EA147B933EB" + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VTIMEZONE + TZID:America/Montreal + BEGIN:STANDARD + DTSTART:20071104T020000 + RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU + TZNAME:EST + TZOFFSETFROM:-0400 + TZOFFSETTO:-0500 + END:STANDARD + BEGIN:DAYLIGHT + DTSTART:20070311T020000 + RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU + TZNAME:EDT + TZOFFSETFROM:-0500 + TZOFFSETTO:-0400 + END:DAYLIGHT + + + +Daboo & Desruisseaux Standards Track [Page 72] + +RFC 6638 CalDAV Scheduling June 2012 + + + END:VTIMEZONE + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185254Z + DTSTART;TZID=America/Montreal:20090601T150000 + DTEND;TZID=America/Montreal:20090601T160000 + RRULE:FREQ=DAILY;INTERVAL=1;COUNT=5 + TRANSP:OPAQUE + SUMMARY:Review Internet-Draft + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + ACCEPTED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@exampl + e.net + END:VEVENT + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090603T183823Z + RECURRENCE-ID;TZID=America/Montreal:20090602T150000 + DTSTART;TZID=America/Montreal:20090602T150000 + DTEND;TZID=America/Montreal:20090602T160000 + TRANSP:TRANSPARENT + SUMMARY:Review Internet-Draft + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + DECLINED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@exampl + e.net + END:VEVENT + END:VCALENDAR + + >> Response << + + HTTP/1.1 200 OK + Content-Length: 0 + Date: Tue, 02 Jun 2009 18:52:54 GMT + Last-Modified: Tue, 02 Jun 2009 18:52:54 GMT + ETag: "d85561cfe74a4e785eb4639451b434fb" + Schedule-Tag: "488177c8-2ea7-4176-a6cb-fab8cfccdea2" + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 73] + +RFC 6638 CalDAV Scheduling June 2012 + + + Bernard's participation status update will cause his server to + deliver a scheduling message to Cyrus. Cyrus's client will find the + following reply message from Bernard in Cyrus's scheduling Inbox + collection: + + >> Request << + + GET /home/cyrus/calendars/inbox/9263504FD3AD.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 18:52:58 GMT + Last-Modified: Tue, 02 Jun 2009 18:52:58 GMT + ETag: "eb897deabc8939589da116714bc99265" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + METHOD:REPLY + BEGIN:VTIMEZONE + TZID:America/Montreal + BEGIN:STANDARD + DTSTART:20071104T020000 + RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU + TZNAME:EST + TZOFFSETFROM:-0400 + TZOFFSETTO:-0500 + END:STANDARD + BEGIN:DAYLIGHT + DTSTART:20070311T020000 + RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU + TZNAME:EDT + TZOFFSETFROM:-0500 + TZOFFSETTO:-0400 + END:DAYLIGHT + END:VTIMEZONE + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090603T183823Z + RECURRENCE-ID;TZID=America/Montreal:20090602T150000 + DTSTART;TZID=America/Montreal:20090602T150000 + DTEND;TZID=America/Montreal:20090602T160000 + SUMMARY:Review Internet-Draft + + + +Daboo & Desruisseaux Standards Track [Page 74] + +RFC 6638 CalDAV Scheduling June 2012 + + + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";PARTSTAT=DECLINED: + mailto:bernard@example.net + REQUEST-STATUS:2.0;Success + END:VEVENT + END:VCALENDAR + +B.8. Example: "Attendee" Removing an Instance of a Recurring Event + + In the following example, Bernard removes from his calendar the third + recurrence instance of a daily recurring event he's been invited to + by Cyrus. This is accomplished by the addition of an "EXDATE" + property to the scheduling object resource stored by Bernard. + + >> Request << + + PUT /home/bernard/calendars/work/4FD3AD926350.ics HTTP/1.1 + Host: cal.example.com + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + If-Schedule-Tag-Match: "488177c8-2ea7-4176-a6cb-fab8cfccdea2" + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + BEGIN:VTIMEZONE + TZID:America/Montreal + BEGIN:STANDARD + DTSTART:20071104T020000 + RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU + TZNAME:EST + TZOFFSETFROM:-0400 + TZOFFSETTO:-0500 + END:STANDARD + BEGIN:DAYLIGHT + DTSTART:20070311T020000 + RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU + TZNAME:EDT + TZOFFSETFROM:-0500 + TZOFFSETTO:-0400 + END:DAYLIGHT + END:VTIMEZONE + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090602T185254Z + DTSTART;TZID=America/Montreal:20090601T150000 + DTEND;TZID=America/Montreal:20090601T160000 + + + +Daboo & Desruisseaux Standards Track [Page 75] + +RFC 6638 CalDAV Scheduling June 2012 + + + RRULE:FREQ=DAILY;INTERVAL=1;COUNT=5 + EXDATE;TZID=America/Montreal:20090603T150000 + TRANSP:OPAQUE + SUMMARY:Review Internet-Draft + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + ACCEPTED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@exampl + e.net + END:VEVENT + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090603T183823Z + RECURRENCE-ID;TZID=America/Montreal:20090602T150000 + DTSTART;TZID=America/Montreal:20090602T150000 + DTEND;TZID=America/Montreal:20090602T160000 + TRANSP:TRANSPARENT + SUMMARY:Review Internet-Draft + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Cyrus Daboo";CUTYPE=INDIVIDUAL;PARTSTAT=ACCEPTED: + mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";CUTYPE=INDIVIDUAL;PARTSTAT= + DECLINED;ROLE=REQ-PARTICIPANT;RSVP=TRUE:mailto:bernard@exampl + e.net + END:VEVENT + END:VCALENDAR + + Bernard's deletion of a recurrence instance will cause his server to + deliver a scheduling message to Cyrus. Cyrus's client will find the + following reply message from Bernard in Cyrus's scheduling Inbox + collection: + + >> Request << + + GET /home/cyrus/calendars/inbox/6504923FD3AD.ics HTTP/1.1 + Host: cal.example.com + + >> Response << + + HTTP/1.1 200 OK + Date: Tue, 02 Jun 2009 18:52:58 GMT + Last-Modified: Tue, 02 Jun 2009 18:52:58 GMT + ETag: "eb897deabc8939589da116714bc99265" + Content-Type: text/calendar; charset="utf-8" + Content-Length: xxxx + + + + +Daboo & Desruisseaux Standards Track [Page 76] + +RFC 6638 CalDAV Scheduling June 2012 + + + BEGIN:VCALENDAR + VERSION:2.0 + PRODID:-//Example Corp.//CalDAV Client//EN + METHOD:REPLY + BEGIN:VTIMEZONE + TZID:America/Montreal + BEGIN:STANDARD + DTSTART:20071104T020000 + RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU + TZNAME:EST + TZOFFSETFROM:-0400 + TZOFFSETTO:-0500 + END:STANDARD + BEGIN:DAYLIGHT + DTSTART:20070311T020000 + RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU + TZNAME:EDT + TZOFFSETFROM:-0500 + TZOFFSETTO:-0400 + END:DAYLIGHT + END:VTIMEZONE + BEGIN:VEVENT + UID:9263504FD3AD + SEQUENCE:0 + DTSTAMP:20090603T183823Z + RECURRENCE-ID;TZID=America/Montreal:20090603T150000 + DTSTART;TZID=America/Montreal:20090603T150000 + DTEND;TZID=America/Montreal:20090603T160000 + SUMMARY:Review Internet-Draft + ORGANIZER;CN="Cyrus Daboo":mailto:cyrus@example.com + ATTENDEE;CN="Bernard Desruisseaux";PARTSTAT=DECLINED: + mailto:bernard@example.net + REQUEST-STATUS:2.0;Success + END:VEVENT + END:VCALENDAR + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 77] + +RFC 6638 CalDAV Scheduling June 2012 + + +Authors' Addresses + + Cyrus Daboo + Apple Inc. + 1 Infinite Loop + Cupertino, CA 95014 + USA + + EMail: cyrus@daboo.name + URI: http://www.apple.com/ + + + Bernard Desruisseaux + Oracle Corporation + 600 Blvd. de Maisonneuve West + Suite 1900 + Montreal, QC H3A 3J2 + CANADA + + EMail: bernard.desruisseaux@oracle.com + URI: http://www.oracle.com/ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Daboo & Desruisseaux Standards Track [Page 78] + |