S. MaesE. Burger, Ed. Internet-Draft R. CromwellBEA Systems, Inc. Intended status: Standards Track R. Cromwell Expires: August 27, 2007 S. Maes Oracle Corporation February 23, 2007 WITHIN Search extension to the IMAP Protocol draft-ietf-lemonade-search-within-03draft-ietf-lemonade-search-within-04 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 3, 2006.August 27, 2007. Copyright Notice Copyright (C) The IETF Trust (2006).(2007). Abstract This document describes the WITHIN extension to IMAP SEARCH. IMAP SEARCH returns messages whose internal date is within or outside a specified interval. The mechanism described here, OLDER and YOUNGER, differs from BEFORE and SINCE in that the client specifies an interval, rather than a date. We expect WITHIN to be most useful for persistent searches from mobile devices. Conventions Used in this Document In examples, "C:" and "S:" indicate lines sent by the client and server respectively. 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 RFC 2119 . When describing the general syntax, we omit some definitions as RFC 3501  defines them. 1. Introduction This extension exposes two new search keys, OLDER and YOUNGER, each of which takes a non-zero integer argument corresponding to a time interval. The server calculates the time of interest by subtracting the time interval presented by the client, and either returning messages older or younger than the resultant time and date. 2. Protocol Operation An IMAP4 server that supports the capability described here MUST return "WITHIN" as one of the server supported capabilities in the CAPABILITY command. For both ofthe OLDER and YOUNGER search keys, the server calculates a target date and time by subtracting the interval onfrom the current date and time of the server. Servers MUST maintain at least a precisionThe server then compares the target time with the INTERNALDATE of an hourthe message, as specified in this calculation. The interval specificationIMAP . For OLDER, messages match if the INTERNALDATE is in seconds. The server honorsless recent than, or equal to, the interval requesttarget time. For YOUNGER, messages match if it hasthe precision to do so. IfINTERNALDATE is more recent than, or equal to, the server does not havetarget time. In some cases, the server may be unable, or unwilling, to use a precision of a single second. This is expected to honor the interval request,be the server MUST selectcase particularly for dynamically updated searches. In these cases, servers are permitted to reduce the closestprecision possible.used for date calulcations and comparisons, but SHOULD ensure that a precision of no less than an hour (3600 seconds) is used. This might mean re- running the search criteria only every hour for a dynamic search, for example. Clients MUST be aware that search results, whether viewed directly or through some other mechanism, MAY not be accurate as a result. For example, if the client requests messages that are younger than 4020 (67 minutes), but the server only performs searches with hourly accuracy (as mandated above), the server performs the search as if the client requested a 60-minute interval. The server then comparesNote the resultant date and time againstchoice of rounding up or down is at the INTERNALDATEdiscretion of the message set in question,server. However, rounding down to zero is NOT RECOMMENDED, as specifiedthis may result in IMAP ). For OLDER, messages match if the date and time is less recent then the INTERNALDATE. For YOUNGER,searches for messages match if the date and time is more recent then the INTERNALDATE. If the date and time matches the INTERNALDATE precisely, both OLDER andYOUNGER than a value being rounded to YOUNGER 0, which will match the message.always fail. 3. Formal Syntax The following syntax specification uses the Augmented Backus-Naur Form (ABNF) notation. Elements not defined here can be found in the formal syntax of ABNF , IMAP , and IMAP Extended ABNF  This document extends RFC 3501  with two new search keys: OLDER <interval> and YOUNGER <interval>. search-key /= ( "OLDER" | "YOUNGER" ) SP nz-number ; search-key defined in RFC 3501 4. Example C: a1 SEARCH UNSEEN YOUNGER 259200 S: a1 * SEARCH 4 8 15 16 23 42 Search for all unseen messages within the past 3 days (72 hours) according to the server's current time. 5. Security Considerations The WITHIN extension does not raise any security considerations which are not present in the base protocol. Considerations are the same as for IMAP . 6. IANA Considerations None. 7. Normative References  Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCP 14, March 1997.  Crispin, M., "Internet Message Access Protocol - Version 4rev1", RFC 3501, March 2003.  Melnikov, A. and C. Daboo, "Collected Extensions to IMAP4 ABNF", RFC 4466, April 2006. Appendix A. Acknowledgements The authors want to thank all who have contributed key insight and extensively reviewed and discussed the concepts of LPSEARCH and the authors of its early introduction in P-IMAP. We also want to give a special thanks to Alexey Melnikov,Arnt Gilbrandsen, Alexey Melnikov, Ken Murchison, Zoltan Ordogh, and most especially Dave Cridland for their review and suggestions, as well as thanks to Eric Burger for reformatting and editing the document to meet IETF publication standards.suggestions. Authors' Addresses Stephane H. MaesEric W. Burger (editor) BEA Systems, Inc. USA Phone: Fax: Email: firstname.lastname@example.org URI: Ray Cromwell Oracle Corporation 500 Oracle Parkway, M/S 4op634Parkway Redwood Shores, CA 94065 USA Email: email@example.com Ray Cromwellray.firstname.lastname@example.org Stephane H. Maes Oracle Corporation 500 Oracle ParkwayParkway, M/S 4op634 Redwood Shores, CA 94065 USA Email: email@example.com@oracle.com Full Copyright Statement Copyright (C) The IETF Trust (2006).(2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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