There (3) issues in this document, each beginning 'ISSUE_n:'. Internet Printing Protocol Working Group Tom Hastings INTERNET DRAFT Xerox Expires 7 January 2001 Ira McDonald High North 7 July 2000 Internet Printing Protocol (IPP): Resource Objects and Get Resource Operations Copyright (C) The Internet Society (2000). All Rights Reserved. Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." To view the list of Internet-Draft Shadow Directories, see http://www.ietf.org/shadow.html. Abstract This document is a submission to the Internet Printing Protocol Working Group of the Internet Engineering Task Force (IETF). Comments should be submitted to the ipp@pwg.org mailing list. This IPP Get Resource document specifies an extension to IPP/1.0 [RFC-2565] [RFC-2566] and IPP/1.1 [IPP-MOD] [IPP-PRO]. This document extends the current closed IPP object model with a passive polymorphic object that is intended to satisfy most needs for new object types in the long-term evolution of IPP via an extensible object framework. This document defines: Resource object (passive polymorphic object); Resource get operations (e.g., Get-Resource-Attributes); Resource attributes (e.g., "resource-name"); new Printer attributes (e.g., "resource-type-supported"); Resource type of Driver (a morph of the Resource object); methods for supporting 'driver download' to IPP Client systems. Hastings, McDonald Expires 7 January 2001 [Page 1] Internet Draft IPP Get Resource Operations 7 July 2000 Table of Contents 1. Introduction ............................................... 4 2. IPP Model for Resources .................................... 5 2.1. Resource Object ........................................ 5 3. Terminology ................................................ 6 3.1. Conformance Terminology ................................ 6 3.2. Model Terminology ...................................... 6 4. Resource Operations ........................................ 7 4.1. Get-Resource-Attributes Operation ...................... 7 4.1.1. Get-Resource-Attributes Request .................... 8 4.1.2. Get-Resource-Attributes Response ................... 9 4.2. Get-Resource-Data Operation ............................ 10 4.2.1. Get-Resource-Data Request .......................... 10 4.2.2. Get-Resource-Data Response ......................... 10 4.3. Get-Resources Operation ................................ 11 4.3.1. Get-Resources Request .............................. 11 4.3.2. Get-Resources Response ............................. 12 4.4. Resource Operation Response Status Codes ............... 13 5. Resource Attributes ........................................ 14 5.1. Table of Required Resource Attributes .................. 14 5.2. Table of Optional Resource Attributes .................. 15 5.3. Resource Template Attributes ........................... 16 5.3.1. resource-info (text(127)) .......................... 16 5.3.2. resource-charset (charset) ......................... 16 5.3.3. resource-natural-language (naturalLanguage) ........ 16 5.3.4. resource-document-formats (1setOf mimeMediaType) ... 17 5.3.5. resource-os-types (1setOf type2 keyword) ........... 17 5.3.6. resource-data-present (boolean) .................... 17 5.3.7. resource-data-uri (1setOf uri) ..................... 18 5.3.8. resource-data-k-octets (integer(0:MAX)) ............ 18 5.3.9. resource-data-compression (type3 keyword) .......... 18 5.3.10. resource-create-date-time (dateTime) .............. 19 5.3.11. resource-duration (integer(0:MAX)) ................ 19 5.3.12. resource-persistence (boolean) .................... 19 5.4. Resource Description Attributes ........................ 20 5.4.1. resource-type (type2 keyword) ...................... 20 5.4.2. resource-name (name(127)) .......................... 20 5.4.3. resource-id (integer(1:MAX)) ....................... 20 5.4.4. resource-printer-uri (uri) ......................... 21 5.4.5. resource-create-user-name (name(MAX)) .............. 21 5.4.6. resource-create-time (integer(0:MAX)) .............. 21 5.4.7. resource-change-time (integer(0:MAX)) .............. 22 5.4.8. resource-refresh-time (integer(0:MAX)) ............. 22 5.4.9. resource-expiration-time (integer(0:MAX)) .......... 22 6. Driver Resource Type ....................................... 23 6.1. Table of Required Driver Resource Attributes ........... 23 6.2. Table of Optional Driver Resource Attributes ........... 23 6.3. Driver Resource Template Attributes .................... 24 6.3.1. driver-charset (1setOf charset) .................... 24 6.3.2. driver-natural-language (1setOf naturalLanguage) ... 24 Hastings, McDonald Expires 7 January 2001 [Page 2] Internet Draft IPP Get Resource Operations 7 July 2000 6.3.3. driver-file-type (type2 keyword) ................... 24 6.3.4. driver-file-name (name(MAX)) ....................... 25 7. Conformance Requirements ................................... 26 7.1. IPP Client Conformance Requirements .................... 26 7.2. IPP Printer Conformance Requirements ................... 26 7.2.1. Resource Operations ................................ 26 7.2.2. Resource Attributes ................................ 27 7.2.3. Driver Resource Attributes ......................... 27 8. IANA Considerations ........................................ 28 9. Internationalization Considerations ........................ 28 10. Security Considerations ................................... 28 11. Encodings of Additional Resource Tags ..................... 28 12. References ................................................ 28 13. Authors' Addresses ........................................ 29 14. Appendix A - Change History ............................... 30 14.1. 7 July 2000 - draft-ietf-ipp-get-resource-00.txt ...... 30 15. Full Copyright Statement .................................. 30 Hastings, McDonald Expires 7 January 2001 [Page 3] Internet Draft IPP Get Resource Operations 7 July 2000 1. Introduction See section 1 'Introduction' in [IPP-MOD] for a full description of the IPP document set and overview information about IPP. This document is a submission to the Internet Printing Protocol Working Group of the Internet Engineering Task Force (IETF). Comments should be submitted to the ipp@pwg.org mailing list. This IPP Get Resource document specifies an extension to IPP/1.0 [RFC-2565] [RFC-2566] and IPP/1.1 [IPP-MOD] [IPP-PRO]. This document extends the current closed IPP object model with a passive polymorphic object which is intended to satisfy most growth needs for new object types in the long-term evolution of IPP via an extensible object framework. This document defines: Resource object (passive polymorphic object); Resource get operations (e.g., Get-Resource-Attributes); Resource attributes (e.g., "resource-name"); new Printer attributes (e.g., "resource-type-supported"); Resource type of Driver (a morph of the Resource object); methods for supporting 'driver download' to IPP Client systems. This document does not specify other possible Resource operations (e.g., 'Create-Resource') or Resource types (e.g., 'font'). A future document may specify a complete set of system admin operations for Resource objects. This document is laid out as follows: - Section 2 adds the Resource object to the IPP object model. - Section 3 is the terminology used throughout the document. - Section 4 specifies the operations on Resource objects, including new status codes for Resource operations. - Section 5 specifies the attributes common to all Resource objects. - Section 6 specifies the Driver Resource type and its additional attributes - to allow client print support (e.g., driver) download (all or part of an IPP Client) from an IPP Printer. - Section 7 specifies the conformance requirements for this document. - Section 8, 9, and 10 specify IANA, internationalization, and security considerations. - Section 11 allocates new protocol encoding values for this document. Hastings, McDonald Expires 7 January 2001 [Page 4] Internet Draft IPP Get Resource Operations 7 July 2000 - Sections 12, 13, 14, and 15 list references, authors' addresses, change history, and full IETF copyright statement. 2. IPP Model for Resources See section 2 'IPP Objects' in [IPP-MOD] for a full description of the IPP object model and terminology. 2.1. Resource Object IPP Resource objects are used to model installed features or capabilities of IPP Printers (e.g., 'font'). All Resource object instances contain a common set of base Resource object attributes. Resource object instances MAY have an additional set of attributes, according to their "resource-type" and IPP Printer implementation. Resource objects instances MAY also have associated data, according to their "resource-type" and IPP Printer implementation. Resource data (if any) is available by reference in "resource-data-uri" or by value if "resource-data-present" is 'true' (i.e., a local copy of the Resource data is available on the IPP Printer). Section 4 describes each of the Resource operations in detail. Hastings, McDonald Expires 7 January 2001 [Page 5] Internet Draft IPP Get Resource Operations 7 July 2000 3. Terminology This specification document uses the terminology defined in this section. 3.1. Conformance Terminology The terms "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC-2119]. These terms are used to specify conformance requirements which apply if this specification is implemented (in addition to IPP/1.0 or higher). 3.2. Model Terminology See section 12.2 'Model Terminology' in [IPP-MOD]. Hastings, McDonald Expires 7 January 2001 [Page 6] Internet Draft IPP Get Resource Operations 7 July 2000 4. Resource Operations The common semantics of all IPP Resource operations are the ones defined for all IPP operations in [IPP-MOD], e.g., "operation-id", "status-code", "attributes-charset", etc. See section 3.1 'Common Semantics' in [IPP-MOD]. The following three Resource operations are REQUIRED for all IPP Printers to implement, if they implement Resource objects. 4.1. Get-Resource-Attributes Operation REQUIRED - for IPP Printers to implement. This operation allows an IPP Client to request the values of attributes of a Resource object instance and is similar to the Get-Job-Attributes operation (see section 3.2.5 in [IPP-MOD]). The only differences are that the operation is directed at a Resource object instance rather than a Job object instance, there is a "resource-type" operation attribute required when querying a Resource object, and the returned attribute group is a set of Resource object attributes rather than a set of Job object attributes. For Resources, the possible names of attribute groups are: - 'resource-template': the subset of the Resource Template attributes that the implementation supports for Resource objects. - 'resource-description': the subset of the Resource Description attributes that the implementation supports for Resource objects. - 'all': the special group 'all' that includes all attributes that the implementation supports for Resource objects. Since an IPP Client MAY request specific attributes or named groups, there is a potential that there is some overlap. For example, if an IPP Client requests 'resource-create-time' and 'resource-description', the IPP Client is actually requesting the "resource-create-time" attribute once by naming it explicitly, and once by inclusion in the 'resource-description' group. In such cases, the IPP Printer object NEED NOT return the attribute only once in the response even if it is requested multiple times. The IPP Client SHOULD NOT request the same attribute in multiple ways. It is NOT REQUIRED that a Resource object instance support all attributes belonging to a group (since some attributes are OPTIONAL). However it is REQUIRED that each Resource object instance support all Hastings, McDonald Expires 7 January 2001 [Page 7] Internet Draft IPP Get Resource Operations 7 July 2000 group names. 4.1.1. Get-Resource-Attributes Request The following groups of attributes are part of the Get-Resource-Attributes Request when the request is directed at a Resource object: Group 1: Operation Attributes Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.1 in [IPP-MOD]. Target: The "printer-uri" (uri) operation attribute which is the target for this operation as described in section 3.1.5 in [IPP-MOD]. ISSUE_1: The target of all IPP Resource operations is always simply "printer-uri" and separate required operation attributes are used to specify resource type and name or ID. This is like IPP Subscription objects but unlike the earlier IPP Job objects. Should we continue to follow the IPP Subscription object model? Resource Type: The "resource-type (type2 keyword)" attribute as described in section 5.2.1 in this document. Resource Name or ID: The "resource-name (name(127))" attribute as described in section 5.2.2 in this document OR the "resource-id (integer(1:MAX))" attribute as described in section 5.2.3 in this document. Requesting User Name: The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied by the IPP Client as described in section 8.3 in [IPP-MOD]. "requested-attributes" (1setOf keyword): The IPP Client OPTIONALLY supplies this attribute. The IPP Printer MUST support this attribute. It is a set of attribute names and/or attribute group names in whose values the requester is interested. If the IPP Client omits this attribute, the IPP Printer MUST respond as if this attribute had been supplied with a value of 'all'. Hastings, McDonald Expires 7 January 2001 [Page 8] Internet Draft IPP Get Resource Operations 7 July 2000 4.1.2. Get-Resource-Attributes Response The Printer object returns the following sets of attributes as part of the Get-Resource-Attributes Response: Group 1: Operation Attributes Status Message: In addition to the REQUIRED status code returned in every response, the response OPTIONALLY includes a "status-message" (text(255)) and/or a "detailed-status-message" (text(MAX)) operation attribute as described in sections 13 and 3.1.6 in [IPP-MOD]. Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as described in section 3.1.4.2 in [IPP-MOD]. The "attributes-natural-language" MAY be the natural language of the Resource object, rather than the one requested. Group 2: Unsupported Attributes See section 3.1.7 in [IPP-MOD] for details on returning Unsupported Attributes. The response NEED NOT contain the "requested-attributes" operation attribute with any supplied values (attribute keywords) that were requested by the IPP Client but are not supported by the IPP Printer. If the Printer object does include unsupported attributes referenced in "requested-attributes" and such attributes include group names, such as 'all', the unsupported attributes MUST NOT include attributes described in this document but not supported by the implementation. Group 3: Resource Object Attributes This is the set of requested attributes and their current values. The IPP Printer ignores (does not respond with) any requested attribute or value which is not supported or which is restricted by the security policy in force, including whether the requesting user is the user that created the Resource. However, the IPP Printer MUST respond with the 'unknown' value for any supported attribute (including all REQUIRED attributes) for which the IPP Printer does not know the value, unless it would violate the security policy. See the description of the "out-of-band" values in the beginning of Section 4.1 in [IPP-MOD]. Hastings, McDonald Expires 7 January 2001 [Page 9] Internet Draft IPP Get Resource Operations 7 July 2000 4.2. Get-Resource-Data Operation REQUIRED - for IPP Printers to implement. This operation allows an IPP Client to request the values of attributes of a Resource object instance AND the value of associated Resource data (i.e., this operation is like 'Print-Job'). This operation is a strict superset of the Get-Resource-Attributes operation above. The only difference is that the operation returns Resource data in addition to Resource attributes. This operation is only legal for certain values of "resource-type". Note: This operation is defined (rather than overloading the 'Get-Resource-Attributes' operation above) to simplify access control policies. Note that many possible future Resource types (e.g, 'font') have copyright and intellectual property considerations with respect to IPP Clients reading their associated data. 4.2.1. Get-Resource-Data Request See section 4.1.1 'Get-Resource-Attributes Request' in this document. The following groups of attributes are part of the Get-Resources request: Group 1: Operation Attributes See 'Group 1: Operation Attributes' in section 4.1.1 'Get-Resource-Attributes Request'. 4.2.2. Get-Resource-Data Response See section 4.1.2 'Get-Resource-Attributes Response' in this document. Group 1: Operation Attributes See 'Group 1: Operation Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. Group 2: Unsupported Attributes Hastings, McDonald Expires 7 January 2001 [Page 10] Internet Draft IPP Get Resource Operations 7 July 2000 See 'Group 2: Unsupported Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. Group 3: Resource Object Attributes See 'Group 3: Resource Object Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. Group 4: Resource Data Content See section 5.3.6 'resource-data-present' in this document. See section 3.2.1.1 'Print-Job Request' in [IPP-MOD]. The IPP Printer MUST return the Resource data content (if any) to the IPP Client, within the constraints of administratively configured access control policies and any applicable copyright or other intellectual property considerations. 4.3. Get-Resources Operation REQUIRED - for IPP Printers to implement. This operation allows an IPP Client to retrieve the list of Resource object instances (of a specified resource type) belonging to the target Printer object. The IPP Client may also supply a list of Resource attribute names and/or attribute group names. A group of Resource object attributes will be returned for each Resource object instance that is returned. This operation is similar to the Get-Resource-Attributes operation, except that this Get-Resources operation returns attributes from possibly more than one object. See section 3.2.6 'Get-Jobs Operation' in [IPP-MOD]. 4.3.1. Get-Resources Request The IPP Client submits the Get-Resources request to an IPP Printer object. The following groups of attributes are part of the Get-Resources request: Group 1: Operation Attributes Hastings, McDonald Expires 7 January 2001 [Page 11] Internet Draft IPP Get Resource Operations 7 July 2000 See 'Group 1: Operation Attributes' in section 4.1.1 'Get-Resource-Attributes Request'. Resource Name or ID: [omitted] "limit" (integer(1:MAX)): [added] The IPP Client OPTIONALLY supplies this attribute. The IPP Printer MUST MUST support this attribute. It is an integer value that determines the maximum number of resources that an IPP Client will receive from the IPP Printer. Groups 2 to N: Resource Filter Attributes [added] See 'Group 3: Resource Object Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. This is the set of filter attributes and their filter values. The IPP Printer ignores Resources which do not satisfy the specified filter. A multi-valued filter attribute matches if the corresponding Resource object instance attribute contains all of the one or more values of the multi-valued filter attribute. The filter criteria in each Resource Filter Attribute group MUST all be true for a match (logical AND within the set). But only ONE Resource Filter Group need be true for a match (logical OR across the sets). 4.3.2. Get-Resources Response The Printer object returns all of the Resource object instances, up to the number specified by the "limit" attribute, that match the criteria as defined by the filter attribute values supplied by the IPP Client in the request. It is possible that no Resource objects are returned since there may literally be none at the Printer, or there may be no Resource objects that match the criteria supplied by the IPP Client. If the IPP Client requests any Resource attributes at all, there is a set of Resource Object Attributes returned for each Resource object instance. It is not an error for the IPP Printer to return 0 Resources. If the response returns 0 Resources because there are no Resources matching the criteria, and the request would have returned 1 or more Resources with a status code of 'successful-ok' if there had been Resources matching the criteria, then the status code for 0 Resources MUST be Hastings, McDonald Expires 7 January 2001 [Page 12] Internet Draft IPP Get Resource Operations 7 July 2000 'successful-ok'. Group 1: Operation Attributes See 'Group 1: Operation Attributes' in section 4.3.1 'Get-Resources Request'. Group 2: Unsupported Attributes See 'Group 2: Unsupported Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. Groups 3 to N: Resource Object Attributes See 'Group 3: Resource Object Attributes' in section 4.1.2 'Get-Resource-Attributes Response'. Resource object instances are returned sorted by "resource-id". ISSUE_2: Resource object instances are always returned sorted by "resource-id" and not by "resource-name" (more user-friendly). Should we add an operation attribute to control the sort order? 4.4. Resource Operation Response Status Codes client-error-not-authenticated client-error-not-authorized client-error-resource-type-not-supported client-error-resource-data-not-supported client-error-resource-data-not-present Hastings, McDonald Expires 7 January 2001 [Page 13] Internet Draft IPP Get Resource Operations 7 July 2000 5. Resource Attributes 5.1. Table of Required Resource Attributes All IPP Printers that support Resource objects MUST implement the following REQUIRED attributes defined in this specification (on the Resource object or the Printer object): Resource Attribute Resource Attribute Type Operation or Resource Group Printer Attribute Printer Attribute Type ----------------------------------- -------------------------- resource-type (type2 keyword) resource-type [Operation group] resource-type-supported (1setOf type2 keyword) resource-name (name(127)) resource-name [Operation group] [none] resource-id (integer(1:MAX)) resource-id [Operation group] max-resources-supported (integer(0:MAX)) resource-printer-uri (uri) printer-uri [Operation group] printer-uri-supported (1setOf uri) resource-charset (charset) attributes-charset [Operation group] charset-configured (charset) charset-supported (1setOf charset) resource-natural-language (naturalLanguage) attributes-natural-language [Operation group] natural-language-configured (naturalLanguage) generated-natural-language-supported (1setOf naturalLanguage) resource-data-present (boolean) resource-data-present [Resource group] resource-data-present-supported (1setOf boolean) resource-data-uri (1setOf uri) resource-data-uri [Resource group] resource-data-schemes-supported (1setOf uri) resource-data-k-octets (integer(0:MAX)) Hastings, McDonald Expires 7 January 2001 [Page 14] Internet Draft IPP Get Resource Operations 7 July 2000 resource-data-k-octets [Resource group] resource-data-k-octets-supported (rangeOfInteger (0:MAX)) resource-data-compression (type3 keyword) resource-data-compression [Resource group] compression-supported (1setOf type3 keyword) resource-create-user-name (name(MAX)) requesting-user-name [Operation group] [none] resource-create-date-time (dateTime) resource-create-date-time [Resource group] [none] resource-create-time (integer(0:MAX)) [none] printer-current-time (integer(0:MAX)) resource-expiration-time (integer(0:MAX)) [none] [printer-current-time + duration] resource-duration (integer(0:MAX)) resource-duration [Resource group] resource-duration-default (integer(0:MAX)) resource-duration-supported (rangeOfInteger(0:MAX)) resource-persistence (boolean) resource-persistence [Resource group] resource-persistence-supported (boolean) 5.2. Table of Optional Resource Attributes All IPP Printers that support Resource objects MAY implement the following OPTIONAL attributes defined in this specification (on the Resource object or the Printer object): Resource Attribute Resource Attribute Type Operation or Resource Group Printer Attribute Printer Attribute Type ----------------------------------- -------------------------- resource-info (text(127)) resource-info [Resource group] [none] resource-document-formats (1setOf mimeMediaType) document-format-default (mimeMediaType) document-format-supported (1setOf mimeMediaType) resource-os-types (1setOf type2 keyword) Hastings, McDonald Expires 7 January 2001 [Page 15] Internet Draft IPP Get Resource Operations 7 July 2000 resource-os-types-default (1setOf type2 keyword) resource-os-types-supported (1setOf type2 keyword) resource-change-time (integer(0:MAX)) [none] [none] resource-refresh-time (integer(0:MAX)) [none] [none] 5.3. Resource Template Attributes 5.3.1. resource-info (text(127)) OPTIONAL - for IPP Printers to implement. This attribute specifies descriptive information about this Resource object. This may include manufacturer, version, copyright, etc. See section 4.4.6 'printer-info' and section 4.4.9 'printer-make-and-model' in [IPP-MOD]. 5.3.2. resource-charset (charset) REQUIRED - for IPP Printers to implement. This attribute specifies the charset of 'text' and 'name' attributes of the Resource and of textual data in the associated Resource data (if any). 5.3.3. resource-natural-language (naturalLanguage) REQUIRED - for IPP Printers to implement. This attribute specifies the natural language of 'text' and 'name' attributes of the Resource and of textual data in the associated Resource data (if any). Hastings, McDonald Expires 7 January 2001 [Page 16] Internet Draft IPP Get Resource Operations 7 July 2000 5.3.4. resource-document-formats (1setOf mimeMediaType) OPTIONAL - for IPP Printers to implement. This attribute specifies the list of document formats supported by the Resource. 5.3.5. resource-os-types (1setOf type2 keyword) OPTIONAL - for IPP Printers to implement. This attribute specifies the list of target operating system types of the Resource. See IANA registry of operating system names at [OS-TYPE]. 5.3.6. resource-data-present (boolean) REQUIRED - for IPP Printers to implement. The attribute indicates whether or not a local copy of the Resource data is present at the IPP Printer. When "resource-data-present" is 'true' on a Resource object instance, it indicates that the IPP Printer has stored a local copy of the Resource data or has fetched a local copy of the Resource data that was specified by reference in "resource-data-uri". When "resource-data-present" is 'false' on a Resource object instance and "resource-data-uri" is empty, it indicates that there is no Resource data. When "resource-data-present" is 'false' on a Resource object instance and "resource-data-uri" is non-empty, it indicates that the IPP Printer has NOT yet fetched a local copy of the Resource data that was specified by reference and the value of "resource-data-k-octets" is unverified. See section 5.3.7 "resource-data-uri" in this document. See section 5.3.8 "resource-data-k-octets" in this document. Hastings, McDonald Expires 7 January 2001 [Page 17] Internet Draft IPP Get Resource Operations 7 July 2000 5.3.7. resource-data-uri (1setOf uri) REQUIRED - for IPP Printers to implement. This attribute contains the URI of associated Resource data (if any) as a reference. Lazy Refresh: An IPP Printer NEED NOT immediately fetch a local copy of the Resource data specified by reference in "resource-data-uri", but MUST set "resource-data-present" to 'false' until a local copy is fetched. When an IPP Printer does fetch a local copy of the Resource data, it MUST set (REQUIRED) "resource-data-present" to 'true', set (REQUIRED) "resource-data-k-octets" to the actual size, and update the timestamp in the (OPTIONAL) "resource-refresh-time" attribute. ISSUE_3: This 'lazy refresh' behavior may have performance and 'stale data' consequences for IPP Clients. Because the manufacturer may also be slow to inform installed IPP Printers of a new version of a Resource (for update by means outside of this specification) the 'stale data' problem may also apply to IPP Printers. Should we add an operation attribute to prevent this 'lazy refresh' behavior? See section 5.3.6 "resource-data-present" in this document. See section 4.4.27 'reference-uri-schemes-supported' in [IPP-MOD]. See section 3.2.2 'Print-URI' in [IPP-MOD]. 5.3.8. resource-data-k-octets (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute contains the size of associated Resource data (if any). See 'Lazy Refresh' in section 5.3.7 'resource-data-uri' for IPP Printer behavior with respect to "resource-data-k-octets". See section 5.3.6 "resource-data-present" in this document. 5.3.9. resource-data-compression (type3 keyword) REQUIRED - for IPP Printers to implement. This attribute identifies the compression of the associated Resource Hastings, McDonald Expires 7 January 2001 [Page 18] Internet Draft IPP Get Resource Operations 7 July 2000 data (if any). See section 4.4.32 'compression-supported' in [IPP-MOD] for standard keyword values. 5.3.10. resource-create-date-time (dateTime) REQUIRED - for IPP Printers to implement. This attribute indicates the date and time at which the Resource object instance was created. Note: This time SHOULD reflect the actual 'build date' of the Resource data rather than simply the 'install date' on the IPP Printer, because this is more informative for the end user. See section 4.4.30 'printer-current-time' in [IPP-MOD]. See section 4.3.14.5 'date-time-at-creation' in [IPP-MOD]. 5.3.11. resource-duration (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute indicates length of the Resource object instance lease in seconds. See section 5.4.6 "resource-create-time" in this document. See section 5.4.9 "resource-expiration-time" in this document. 5.3.12. resource-persistence (boolean) REQUIRED - for IPP Printers to implement. This attribute indicates whether or not this Resource object instance is persistent (preserved by the IPP Printer across power cycles). A 'true' value specifies an infinite lease and supersedes "resource-duration" and "resource-expiration-time". A 'false' value specifies a finite lease and selects use of "resource-duration" and "resource-expiration-time". See section 5.3.11 "resource-duration" in this document. See section 5.4.9 "resource-expiration-time" in this document. Hastings, McDonald Expires 7 January 2001 [Page 19] Internet Draft IPP Get Resource Operations 7 July 2000 5.4. Resource Description Attributes 5.4.1. resource-type (type2 keyword) REQUIRED - for IPP Printers to implement. This attribute identifies the type of this Resource object instance which determines additional Resource attributes specific to the named type. The following standard keyword values are defined: 'driver': The Resource contains client print support files (e.g., a driver) for an IPP Client (see section 6 'Driver Resource Type' in this document) for this IPP Printer. 5.4.2. resource-name (name(127)) REQUIRED - for IPP Printers to implement. This attribute is the human-readable name of the Resource. This name is more user-friendly than the integer "resource-id" attribute. This name MUST be unique among Resources of the SAME "resource-type". IPP Printers MUST not allow Resource object instances of the SAME "resource-type" with duplicate "resource-name" values. Note: This attribute has been specified as REQUIRED (unlike "job-name") in the interests of ease-of-use. IPP Printers are expected to implement large numbers of Resource objects and the guaranteed presence of the user-friendly name will benefit ease-of-use. See section 4.3.5 'job-name' in [IPP-MOD]. 5.4.3. resource-id (integer(1:MAX)) REQUIRED - for IPP Printers to implement. This attribute contains the locally unique ID of the Resource. The IPP Printer, on creation of a new Resource (by means outside of this specification), generates an ID which identifies the new Resource on that Printer (but not globally). The zero '0' value is not included Hastings, McDonald Expires 7 January 2001 [Page 20] Internet Draft IPP Get Resource Operations 7 July 2000 to allow for compatibility with SNMP index values which also cannot be zero '0'. See section 4.3.2 'job-id' in [IPP-MOD]. 5.4.4. resource-printer-uri (uri) REQUIRED - for IPP Printers to implement. This attribute identifies the IPP Printer that hosts this Resource object instance. See section 4.3.3 'job-printer-uri' in [IPP-MOD]. 5.4.5. resource-create-user-name (name(MAX)) REQUIRED - for IPP Printers to implement. This attribute contains the name of the end user that created this Resource object instance. For factory-installed resources, "resource-create-user-name" MUST be set to the empty string to prevent namespace conflicts in end user networks. See section 4.3.6 'job-originating-user-name' in [IPP-MOD]. 5.4.6. resource-create-time (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute indicates the time at which the Resource object instance was created. Note: This time SHOULD reflect the actual 'build time' of the Resource data rather than simply the 'install time' on the IPP Printer, because this is more informative for the end user. See section 4.4.29 'printer-up-time' in [IPP-MOD]. See section 4.3.14.1 'time-at-creation' in [IPP-MOD]. Hastings, McDonald Expires 7 January 2001 [Page 21] Internet Draft IPP Get Resource Operations 7 July 2000 5.4.7. resource-change-time (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute indicates the time at which the Resource object instance was last changed. See section 5.4.6 "resource-create-time" in this document. See section 4.4.29 'printer-up-time' in [IPP-MOD]. 5.4.8. resource-refresh-time (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute indicates the time at which the Resource object instance was last refreshed (i.e., a local copy of the Resource data was made). See section 5.4.6 "resource-create-time" in this document. See section 4.4.29 'printer-up-time' in [IPP-MOD]. 5.4.9. resource-expiration-time (integer(0:MAX)) REQUIRED - for IPP Printers to implement. This attribute indicates the time at which the Resource object instance lease will expire. See section 5.4.6 "resource-create-time" in this document. See section 5.3.11 "resource-duration" in this document. See section 4.4.29 'printer-up-time' in [IPP-MOD]. See section 4.3.14.5 'date-time-at-creation' in [IPP-MOD]. Hastings, McDonald Expires 7 January 2001 [Page 22] Internet Draft IPP Get Resource Operations 7 July 2000 6. Driver Resource Type 6.1. Table of Required Driver Resource Attributes All IPP Printers that support Driver Resource objects MUST implement the following REQUIRED attributes defined in this specification (on the Driver Resource object or the Printer object): Driver Resource Attribute Driver Attribute Type Operation or Resource Group Printer Attribute Printer Attribute Type ------------------------------- -------------------------- driver-file-type (type2 keyword) driver-file-type [Resource group] driver-file-type-default (type2 keyword) driver-file-type-supported (1setOf type2 keyword) driver-file-name (name(MAX)) driver-file-name [Resource group] [none] 6.2. Table of Optional Driver Resource Attributes All IPP Printers that support Driver Resource objects MAY implement the following OPTIONAL attributes defined in this specification (on the Driver Resource object or the Printer object): Driver Resource Attribute Driver Attribute Type Operation or Resource Group Printer Attribute Printer Attribute Type ------------------------------- -------------------------- driver-charset (1setOf charset) driver-charset [Resource group] charset-configured (charset) charset-supported (1setOf charset) driver-natural-language (1setOf naturalLanguage) driver-natural-language [Resource group] natural-language-configured (naturalLanguage) generated-natural-language-configured (1setOf naturalLanguage) Hastings, McDonald Expires 7 January 2001 [Page 23] Internet Draft IPP Get Resource Operations 7 July 2000 6.3. Driver Resource Template Attributes 6.3.1. driver-charset (1setOf charset) OPTIONAL - for IPP Printers to implement. This attribute specifies the list of client charsets supported by the Driver Resource (when installed on the client system 6.3.2. driver-natural-language (1setOf naturalLanguage) OPTIONAL - for IPP Printers to implement. This attribute specifies the list of client natural languages supported by the Driver Resource (when installed on the client system 6.3.3. driver-file-type (type2 keyword) REQUIRED - for IPP Printers to implement. This attribute specifies the client file type of this Driver Resource (when installed on the client system). The following standard keyword values are defined: 'none': The Driver Resource contains client print support files i unspecified (opaque) format. 'exec': The Driver Resource contains client print support files i native executable format of the operating system(s) specified in "resource-os-types" attribute, for example '.exe' on Microsoft sy 'gpd': The Driver Resource contains client print support files in Microsoft GPD format. 'java': The Driver Resource contains client print support files i 'ppd': The Driver Resource contains client print support files in Adobe PPD format. 'printcap': The Driver Resource contains client print support fil the UNIX 'printcap' format. Hastings, McDonald Expires 7 January 2001 [Page 24] Internet Draft IPP Get Resource Operations 7 July 2000 'script': The Driver Resource contains client print support files native script format of the operating system(s) specified in the "resource-os-types" attribute, for example Bourne shell on UNIX s Note: This type may be ambiguous on some target operating system 'updf': The Driver Resource contains client print support files i (work-in-progress) PWG UPDF format. 6.3.4. driver-file-name (name(MAX)) REQUIRED - for IPP Printers to implement. This attribute specifies the client file name of this Driver Resource (when installed on the client system) or the empty string (if none configured). If this Driver Resource contains multiple client print support files, then "driver-file-name" SHOULD specify an 'install directory path'. Hastings, McDonald Expires 7 January 2001 [Page 25] Internet Draft IPP Get Resource Operations 7 July 2000 7. Conformance Requirements 7.1. IPP Client Conformance Requirements IPP Clients MUST supply the required operation attributes in Resource operations. 7.2. IPP Printer Conformance Requirements 7.2.1. Resource Operations All IPP Printers that support Resource objects MUST implement the following REQUIRED operations defined in this specification: Resource Operation ------------------ Get-Resources Get-Resource-Attributes Get-Resource-Data Hastings, McDonald Expires 7 January 2001 [Page 26] Internet Draft IPP Get Resource Operations 7 July 2000 7.2.2. Resource Attributes See section 5.1 'Table of Required Resource Attributes' and section 5.2 'Table of Optional Resource Attributes'. 7.2.3. Driver Resource Attributes See section 6.1 'Table of Required Driver Resource Attributes' and section 6.2 'Table of Optional Driver Resource Attributes'. Hastings, McDonald Expires 7 January 2001 [Page 27] Internet Draft IPP Get Resource Operations 7 July 2000 8. IANA Considerations See section 6 'IANA Considerations' in [IPP-MOD]. 9. Internationalization Considerations This IPP Resource Objects and Get Resource Operations specification continues support for the internationalization in [IPP-MOD] attributes containing text strings and names. See section 7 'Internationalization Considerations' in [IPP-MOD]. 10. Security Considerations This IPP Resource Objects and Get Resource Operations specification inherits the same security considerations for Resources as are specified for Jobs in [IPP-MOD]. See section 8 'Security Considerations' in [IPP-MOD]. 11. Encodings of Additional Resource Tags The section assigns values to new protocol tags as extensions to the encoding defined in [IPP-PRO]. The resource-attributes-tag delimits Resource Template Attributes Groups in requests and Resource Attributes Groups in responses. Tag Value (Hex) Tag Meaning --------------- ----------- 0x08 resource-attributes-tag 0x1E Get-Resource-Attributes operation 0x1F Get-Resource-Data operation 0x20 Get-Resources operation 12. References See section 9 'References' in [IPP-MOD]. [IPP-MOD] R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell. Hastings, McDonald Expires 7 January 2001 [Page 28] Internet Draft IPP Get Resource Operations 7 July 2000 IPP/1.1 Model and Semantics, , May 2000 (adopted by IESG as Proposed Standard in June 2000). [IPP-NOT] S. Isaacson, J. Martin, R. deBry, T. Hastings, M. Shepherd, R. Bergman. IPP Event Notification Specification, (work-in-progress), March 2000. [OS-TYPE] IANA Registry of Operating System Names at ftp://ftp.isi.edu/in-notes/iana/assignments/operating-system-names. 13. Authors' Addresses Tom Hastings Xerox Corporation 701 S Aviation Blvd, MS 834-03E El Segundo, CA 90245 Phone: +1 310-333-6413 Email: hastings@cp10.es.xerox.com Ira McDonald High North Inc 221 Ridge Ave Grand Marais, MI 49839 Phone: +1 906-494-2434 or +1 906-494-2697 Email: imcdonald@sharplabs.com Email: imcdonal@sdsp.mc.xerox.com Hastings, McDonald Expires 7 January 2001 [Page 29] Internet Draft IPP Get Resource Operations 7 July 2000 14. Appendix A - Change History [To be deleted before RFC publication] 14.1. 7 July 2000 - draft-ietf-ipp-get-resource-00.txt initial version 15. Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. 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