Storage Maintenance (StorM) Working Group Frederick Knight Internet Draft NetApp Intended status: Standards Track M. Chadalapaka Expires: February 2014 Microsoft August 2013 Internet Small Computer Systems Interface (iSCSI) SCSI Features Update draft-ietf-storm-iscsi-sam-09.txt Abstract Internet Small Computer Systems Interface (iSCSI) is a SCSI transport protocol that maps the SCSI family of protocols onto TCP/IP. The iSCSI protocol as specified in RFCxxx (and as previously specified by the combination of RFC 3720 and RFC 5048) is based on the SAM-2 (SCSI Architecture Model - 2) version of the SCSI family of protocols. This document defines enhancements to the iSCSI protocol to support certain additional features of the SCSI protocol that were defined in SAM-3, SAM-4, and SAM-5. This document is a companion document to RFCxxx. -------------------------------------------------------- RFC EDITORS NOTE: The above two references to RFCxxx should reference the RFC number assigned to the draft-ietf-storm- iscsi-cons-xx document, and this note should be removed. -------------------------------------------------------- Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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/1id-abstracts.html. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire February, 2014. Knight, et al. Expires February, 2014 [Page 1] Internet-Draft iSCSI SCSI Features Update August 13 Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction.................................................. 3 2. Definitions, Acronyms, and Document Summary................... 3 2.1 Definitions ........................................... 3 2.2 Acronyms .............................................. 3 2.3 New Semantics ......................................... 3 3. Terminology Mapping........................................... 4 4. New Feature Use............................................... 7 4.1 Negotiation of New Feature Use............................... 7 4.2 Impact on standard INQUIRY data.............................. 7 5. SCSI Commands................................................. 8 5.1 SCSI Command Additions ................................ 8 5.1.1 Command Priority (byte 2) ......................... 9 5.2 SCSI Response Additions .............................. 10 5.2.1 Status Qualifier ................................. 11 5.2.2 Data Segment - Sense and Response Data Segment ... 11 6. Task Management Functions.................................... 12 6.1 Task Management Function Request PDU ................. 12 6.2 Existing Task Management Functions ................... 12 6.3 Task Management Function Additions ................... 13 6.3.1 LUN field ........................................ 14 6.3.2 Referenced Task Tag .............................. 14 6.3.3 RefCmdSN ......................................... 15 6.4 Task Management Function Responses ................... 16 6.4.1 Task Management Function Response PDU ............ 16 6.4.2 Task Management Function Response Additions ...... 17 6.5 Task Management Requests Affecting Multiple Tasks .... 18 7. Login/Text Operational Text Keys............................. 18 7.1 New Operational Text Keys ............................ 18 7.1.1 iSCSIProtocolLevel ............................... 18 8. Security Considerations...................................... 19 9. IANA Considerations.......................................... 19 10. References.................................................. 22 11. Acknowledgements............................................ 23 Knight, et al. Expires February, 2014 Page 2 Internet-Draft iSCSI SCSI Features Update August 13 1. Introduction The original iSCSI protocol [RFC3720] was built based on the [SAM2] model for SCSI. Several new features and capabilities have been added to the SCSI Architecture Model in the intervening years (at the time of publication of this document, SAM-5 was the current version of the SCSI Architecture Model). This document is not a complete revision of [RFC3720]. Instead, this document is intended as a companion document to [draft-ietf-storm-iscsi- cons-xx]; this document may also be used as a companion document to the combination of [RFC3720] and [RFC5048], although both of those RFCs have been obsolete by [draft-ietf-storm-iscsi-cons- xx]. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [draft-ietf-storm- iscsi-cons-xx] should reference the RFC number assigned to that document, and this note should be removed. -------------------------------------------------------- 2. Definitions, Acronyms, and Document Summary 2.1 Definitions 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]. 2.2 Acronyms ISID Initiator Session Identifier LU Logical Unit PDU Protocol Data Unit SAM-5 SCSI Architecture Model - 5 (see [SAM5]) TMF Task Management Function 2.3 New Semantics This document specifies new iSCSI semantics. This section summarizes the contents of the document. Section 3: The mapping of iSCSI objects to SAM-5 objects The iSCSI node may contain both initiator and target capabilities. Section 4: The protocol used to negotiate the use of the new capabilities described in this document. Section 5: New Command operations Knight, et al. Expires February, 2014 Page 3 Internet-Draft iSCSI SCSI Features Update August 13 The PRI field for SCSI command priority has been added to the SCSI command PDU (see 5.1.1). The Status Qualifier field has been added to the SCSI response PDU (see 5.2.1). Sense data may be returned (via autosense) for any SCSI status, not just CHECK CONDITION (see 5.2.2). Section 6: New Task Management Functions Four new task management functions (QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, and QUERY ASYNCHRONOUS EVENT have been added (see 6.3). A new "function succeeded" response has been added (see 6.4.2). Section 7: New Negotiation key A new negotiation key has been added to enable the use of the new features in section 5 and section 6. 3. Terminology Mapping The iSCSI model (defined in [RFC-cons]) uses different terminology than the SCSI Architecture Model. In some cases, iSCSI uses multiple terms to describe what in the SCSI Architecture Model is described with a single term. The iSCSI terms and SAM-5 terms are not necessarily equivalent, but rather, the iSCSI terms represent examples of the objects or classes described in SAM-5 as follows: -------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 4 Internet-Draft iSCSI SCSI Features Update August 13 +-----------------------------+---------------------------+ | RFCxxx Terminology | SAM-5 Terminology | +-----------------------------+---------------------------+ | Network Entity | none | +-----------------------------+---------------------------+ | iSCSI Node | SCSI Device | +-----------------------------+---------------------------+ | iSCSI Name | SCSI Device Name | +-----------------------------+---------------------------+ | iSCSI Node Name | SCSI Device Name | +-----------------------------+---------------------------+ | iSCSI Initiator Node | SCSI Initiator Device | +-----------------------------+---------------------------+ | iSCSI Initiator Name | SCSI Device Name | +-----------------------------+---------------------------+ | iSCSI Initiator Port | SCSI Initiator Port | | Identifier; (i.e., iSCSI | Identifier | | Node Name + ,,,i, + ISID)*1 | | +-----------------------------+---------------------------+ | iSCSI Initiator Port Name; | SCSI Initiator Port Name | | (i.e., iSCSI Node Name + | | | ,,,i, + ISID)*1 | | +-----------------------------+---------------------------+ | iSCSI Target Node | SCSI Target Device | +-----------------------------+---------------------------+ | iSCSI Target Name | SCSI Device Name | +-----------------------------+---------------------------+ | iSCSI Target Port | SCSI Target Port | | Identifier; (i.e., iSCSI | Identifier | | Node Name + ,,,t, + | | | Target Portal Group Tag)*1 | | +-----------------------------+---------------------------+ | iSCSI Target Port Name; | SCSI Target Port Name | | (i.e., iSCSI Node Name + | | | ,,,t, + Target Portal | | | Group Tag)*1 | | +-----------------------------+---------------------------+ | iSCSI Target Portal Group | SCSI Target Port | +-----------------------------+---------------------------+ | iSCSI Initiator Name + | I_T Nexus Identifier | | ',i,' + ISID + iSCSI | | | Target Name + ',t,' + | | | Target Portal Group Tag | | +-----------------------------+---------------------------+ | Target Portal Group Tag | Relative Port ID | +-----------------------------+---------------------------+ *1 The text encoding of the ISID value and the Target Portal Group Tag value includes an initial ,,0X or ,,0x (see [RFC- cons]). Knight, et al. Expires February, 2014 Page 5 Internet-Draft iSCSI SCSI Features Update August 13 -------------------------------------------------------- RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] should reference this RFC, and this note should be removed. The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi-cons-xx], and this note should be removed. -------------------------------------------------------- The following diagram shows an example of a combination target device and initiator device. Such a configuration may exist in a target device that implements a SCSI Copy Manager. This example shows how a session that shares Network Portals within a Portal Group may be established (see Target Portal Group 1). In addition, this example shows the Initiator using a different Portal Group than the Target Portal Group, but the Initiator Portal group sharing Network Portal A with the Target Portal Group. ----------------------------IP Network--------------------- | | | +----|---------------|-------+ +----|------------+ | +----------+ +----------+ | | +----------+ | | | Network | | Network | | | | Network | | | | Portal A | | Portal B | | | | Portal A | | | +----------+ +----------+ | | +----------+ | | | Target | | | | Initiator | | | Portal | | | | Portal | | | Group 1 | | | | Group 2 | +----|---------------|-------+ +----|------------+ | | | +----------|---------------|--------------------|--------------------+ | +--------|---------------|----+ +-------------|------------------+ | | |+-------|---------------|---+| |+------------|-----------------+| | | ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| | | || || || || | | || (TSIH = 56) || || (SSID = 48) || | | |+---------------------------+| |+------------------------------+| | | | | | | | | | iSCSI Target Node | | iSCSI Initiator Node | | | +-----------------------------+ +--------------------------------+ | | iSCSI Node | | (within Network Entity, not shown) | +--------------------------------------------------------------------+ Knight, et al. Expires February, 2014 Page 6 Internet-Draft iSCSI SCSI Features Update August 13 4. New Feature Use 4.1 Negotiation of New Feature Use The iSCSIProtocolLevel operational text key (see 7.1.1) containing a value of "2" MUST be negotiated to enable the use of features described in this RFC. This is an iSCSI negotiation mechanism that enabled iSCSI support for corresponding SCSI capabilities (see [SAM5] and [SPC4]. For this reason, negotiation of this key to a value of "2" is necessary, but not sufficient for use of the SCSI capabilities enabled by the iSCSI features in this RFC. For example, an iSCSI implementation may negotiate this new key to "2" but respond to the new task management functions (see 6.3) with a "Task management function not supported" (which indicates a SCSI error that prevents the function from being performed). In contrast, if the key is negotiated to "2", an iSCSI implementation MUST NOT reject a task management function request PDU that requests one of the new task management functions (as such a reject would report an iSCSI protocol error). 4.2 Impact on standard INQUIRY data The negotiated value of the iSCSIProtocolLevel key is an increment from the base iSCSI version descriptor value (0960h)(see [SPC4]). If the SCSI device server returns an iSCSI version descriptor in the standard INQUIRY data, then the value returned in that iSCSI version descriptor MUST be set to the sum of the base value (0960h) plus the negotiated value of the iSCSIProtocolLevel key (for example, if the negotiated iSCSIProtocolLevel=2, then if an iSCSI version descriptor is returned in the standard INQUIRY data it is set to 0962h). -------------------------------------------------------- RFC EDITORS NOTE: The specification text in this section requires corresponding changes in a SCSI standard (SPC-4 or SPC-5) that is developed by INCITS Technical Committee T10. Confirmation that these T10 changes have been made is necessary before publishing this draft as an RFC; the contacts for obtaining this confirmation are the primary draft author (Frederick Knight) and storm WG chair (David Black). -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 7 Internet-Draft iSCSI SCSI Features Update August 13 5. SCSI Commands 5.1 SCSI Command Additions The format of the SCSI Command PDU is: Byte/ 0 | 1 | 2 | 3 | / | | | | |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| +---------------+---------------+---------------+---------------+ 0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved | +---------------+---------------+---------------+---------------+ 4|TotalAHSLength | DataSegmentLength | +---------------+---------------+---------------+---------------+ 8| Logical Unit Number (LUN) | + + 12| | +---------------+---------------+---------------+---------------+ 16| Initiator Task Tag | +---------------+---------------+---------------+---------------+ 20| Expected Data Transfer Length | +---------------+---------------+---------------+---------------+ 24| CmdSN | +---------------+---------------+---------------+---------------+ 28| ExpStatSN | +---------------+---------------+---------------+---------------+ 32/ SCSI Command Descriptor Block (CDB) / +/ / +---------------+---------------+---------------+---------------+ 48/ AHS (Optional) / +---------------+---------------+---------------+---------------+ x/ Header Digest (Optional) / +---------------+---------------+---------------+---------------+ y/ (DataSegment, Command Data) (Optional) / +/ / +---------------+---------------+---------------+---------------+ z/ Data Digest (Optional) / +---------------+---------------+---------------+---------------+ The SCSI Command PDU above is duplicated from [RFC-cons] for reference to show the PRI field. For any field other than the PRI field, the text in [RFC-cons] supersedes the text in section 5.1 of this document in the event the two documents conflict. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 8 Internet-Draft iSCSI SCSI Features Update August 13 5.1.1 Command Priority (byte 2) The Command Priority (PRI) is a four (4) bit field that specifies the relative scheduling importance of this command in relation to other commands already in the task set with SIMPLE task attributes(see [SAM5]). Section 11, iSCSI PDU Formats of [RFC-cons], requires that senders set this field to zero. A sender MUST NOT set this field to a value other than zero unless the iSCSIProtocolLevel text key defined in section 7.1.1 has been negotiated on the session with a value of "2". -------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- This field MUST be ignored by iSCSI targets unless the iSCSIProtocolLevel text key with a value of "2" as defined in section 7.1.1 was negotiated on the session. See [SAM5] for additional considerations on the use of the command priority field. Knight, et al. Expires February, 2014 Page 9 Internet-Draft iSCSI SCSI Features Update August 13 5.2 SCSI Response Additions The format of the SCSI Response PDU is: Byte/ 0 | 1 | 2 | 3 | / | | | | |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| +---------------+---------------+---------------+---------------+ 0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status | +---------------+---------------+---------------+---------------+ 4|TotalAHSLength | DataSegmentLength | +---------------+---------------+---------------+---------------+ 8| Status Qualifier | Reserved | +---------------+---------------+---------------+---------------+ 12| Reserved | +---------------+---------------+---------------+---------------+ 16| Initiator Task Tag | +---------------+---------------+---------------+---------------+ 20| SNACK Tag or Reserved | +---------------+---------------+---------------+---------------+ 24| StatSN | +---------------+---------------+---------------+---------------+ 28| ExpCmdSN | +---------------+---------------+---------------+---------------+ 32| MaxCmdSN | +---------------+---------------+---------------+---------------+ 36| ExpDataSN or Reserved | +---------------+---------------+---------------+---------------+ 40| Bidirectional Read Residual Count or Reserved | +---------------+---------------+---------------+---------------+ 44| Residual Count or Reserved | +---------------+---------------+---------------+---------------+ 48| Header-Digest (Optional) | +---------------+---------------+---------------+---------------+ / Data Segment (Optional) / +/ / +---------------+---------------+---------------+---------------+ | Data-Digest (Optional) | +---------------+---------------+---------------+---------------+ The SCSI Response PDU above is duplicated from [RFC-cons] for reference to show the Status Qualifier field. For any field other than the Status field, the Status Qualifier field, and the Data Segment - Sense and Response Data Segment field, the text in [RFC-cons] supersedes the text in section 5.2 of this document in the event the two documents conflict. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 10 Internet-Draft iSCSI SCSI Features Update August 13 5.2.1 Status Qualifier The Status Qualifier provides additional status information (see [SAM5]). As defined in Section 11, iSCSI PDU Formats of [RFC-cons], compliant senders already set this field to zero. Compliant senders MUST NOT set this field to a value other than zero unless the iSCSIProtocolLevel text key with a value of "2" as defined in section 7.1.1 was negotiated on the session. -------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- This field MUST be ignored by receivers unless the iSCSIProtocolLevel text key with a value of "2" as defined in section 7.1.1 was negotiated on the session. 5.2.2 Data Segment - Sense and Response Data Segment Section 11.4.7 of [RFC-cons] specifies that iSCSI targets MUST support and enable autosense. If Status is CHECK CONDITION (0x02), then the Data Segment MUST contain sense data for the failed command. While [RFC-cons] does not make any statements about the state of the Data Segment when the Status is not CHECK CONDITION (0x02)(i.e., the Data Segment is not prohibited from containing sense data when the Status is not CHECK CONDITION), negotiation of the iSCSIProtocolLevel text key with a value of "2" as defined in section 7.1.1 explicitly indicates that the Data Segment MAY contain sense data at any time, no matter what value is set in the Status field. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 11 Internet-Draft iSCSI SCSI Features Update August 13 6. Task Management Functions 6.1 Task Management Function Request PDU Byte/ 0 | 1 | 2 | 3 | / | | | | |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| +---------------+---------------+---------------+---------------+ 0|.|I| 0x02 |1| Function | Reserved | +---------------+---------------+---------------+---------------+ 4|TotalAHSLength | DataSegmentLength | +---------------+---------------+---------------+---------------+ 8| Logical Unit Number (LUN) | + + 12| | +---------------+---------------+---------------+---------------+ 16| Initiator Task Tag | +---------------+---------------+---------------+---------------+ 20| Referenced Task Tag or 0xffffffff | +---------------+---------------+---------------+---------------+ 24| CmdSN | +---------------+---------------+---------------+---------------+ 28| ExpStatSN | +---------------+---------------+---------------+---------------+ 32| RefCmdSN or Reserved | +---------------+---------------+---------------+---------------+ 36| ExpDataSN or Reserved | +---------------+---------------+---------------+---------------+ 40| Reserved / +/ / +---------------+---------------+---------------+---------------+ 48| Header-Digest (Optional) | +---------------+---------------+---------------+---------------+ The Task Management Function Request PDU above is duplicated from [RFC-cons] for reference only. [RFC-cons] supersedes the text in section 6.1 and 6.2 of this document in the event the two documents conflict. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- 6.2 Existing Task Management Functions Section 11.5 of [RFC-cons] defines the semantics used to request SCSI Task Management Functions be performed. The following task management functions are defined: Knight, et al. Expires February, 2014 Page 12 Internet-Draft iSCSI SCSI Features Update August 13 1 - ABORT TASK 2 - ABORT TASK SET 3 - CLEAR ACA 4 - CLEAR TASK SET 5 - LOGICAL UNIT RESET 6 - TARGET WARM RESET 7 - TARGET COLD RESET 8 - TASK REASSIGN -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- 6.3 Task Management Function Additions Additional task Management function codes are listed below. For a more detailed description of SCSI task management, see [SAM5]. 9 - QUERY TASK - determines if the command identified by the Referenced Task Tag field is present in the task set. 10 - QUERY TASK SET - determine if any command is present in the task set for the I_T_L Nexus on which the task management function was received. 11 - I_T NEXUS RESET - perform an I_T nexus loss function (see [SAM5]) for the I_T nexus on which the task management function was received. 12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit attention condition or a deferred error pending for the I_T_L nexus on which the task management function was received. These task management function requests MUST NOT be sent unless the iSCSIProtocolLevel text key with a value of "2" as defined in section 7.1.1 was negotiated on the session. Any compliant initiator that sends any of the new task management functions defined in this section MUST also support all new task management function responses (as specified in section 6.4.2). For all of the task management functions detailed in this section, the Task Management function response MUST be returned as detailed in section 6.4. The iSCSI target MUST ensure that no responses for the commands covered by a task management function are sent to the iSCSI initiator port after the Task Management response except for a commands covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK SET. Knight, et al. Expires February, 2014 Page 13 Internet-Draft iSCSI SCSI Features Update August 13 If a QUERY TASK is issued for a task created by an immediate command then RefCmdSN MUST be that of the Task Management request itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN MUST be set to the CmdSN of the task to be queried (lower than CmdSN). If the connection is still active (it is not undergoing an implicit or explicit logout), QUERY TASK MUST be issued on the same connection to which the task to be queried is allegiant at the time the Task Management request is issued. If the connection is implicitly or explicitly logged out (i.e., no other request will be issued on the failing connection and no other response will be received on the failing connection), then a QUERY TASK function request may be issued on another connection. This Task Management request will then establish a new allegiance for the command being queried. At the target a QUERY TASK function MUST NOT be executed on a Task Management request; such a request MUST result in Task Management response of "Function rejected". For the I_T NEXUS RESET function, the target device MUST respond to the function as defined in [SAM5]. Each logical unit accessible via the receiving I_T NEXUS MUST behave as dictated by the I_T nexus loss function in [SAM5] for the I_T nexus on which the task management function was received. The target device MUST drop all connections in the session over which this function is received. Independent of the DefaultTime2Wait and DefaultTime2Retain value applicable to the session over which this function is received, the target device MUST consider each participating connection in the session to have immediately timed out, leading to FREE state. The resulting timeouts cause the session timeout event defined in [RFC-cons], which in turn triggers the I_T nexus loss notification to the SCSI layer as described in [RFC-cons]. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- 6.3.1 LUN field This field is required for functions that address a specific LU (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY ASYNCHRONOUS EVENT) and is reserved in all others. 6.3.2 Referenced Task Tag Knight, et al. Expires February, 2014 Page 14 Internet-Draft iSCSI SCSI Features Update August 13 The Initiator Task Tag of the task to be aborted for the ABORT TASK function, reassigned for the TASK REASSIGN function, or queried for the QUERY TASK function. For all other functions this field MUST be set to the reserved value 0xffffffff. 6.3.3 RefCmdSN If a QUERY TASK is issued for a task created by an immediate command then RefCmdSN MUST be that of the Task Management request itself (i.e., CmdSN and RefCmdSN are equal). For a QUERY TASK of a task created by non-immediate command RefCmdSN MUST be set to the CmdSN of the task identified by the Referenced Task Tag field. Targets must use this field as described in section 11.6.1 of [RFC-cons] when the task identified by the Referenced Task Tag field is not in the task set. -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Knight, et al. Expires February, 2014 Page 15 Internet-Draft iSCSI SCSI Features Update August 13 6.4 Task Management Function Responses 6.4.1 Task Management Function Response PDU Byte/ 0 | 1 | 2 | 3 | / | | | | |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7| +---------------+---------------+---------------+---------------+ 0|.|.| 0x22 |1| Reserved | Response | Reserved | +---------------+---------------+---------------+---------------+ 4|TotalAHSLength | DataSegmentLength | +-----------------------------------------------+---------------+ 8| Additional Response Information | Reserved | +-----------------------------------------------+---------------+ 12| Reserved | +---------------+---------------+---------------+---------------+ 16| Initiator Task Tag | +---------------+---------------+---------------+---------------+ 20| Reserved | +---------------+---------------+---------------+---------------+ 24| StatSN | +---------------+---------------+---------------+---------------+ 28| ExpCmdSN | +---------------+---------------+---------------+---------------+ 32| MaxCmdSN | +---------------+---------------+---------------+---------------+ 36/ Reserved / +/ / +---------------+---------------+---------------+---------------+ 48| Header-Digest (Optional) | +---------------+---------------+---------------+---------------+ Section 11.6 of [RFC-cons] defines the semantics used for responses to SCSI Task Management Functions. The following responses are defined in [RFC-cons]: 0 - Function Complete. 1 - Task does not exist. 2 - LUN does not exist. 3 - Task still allegiant. 4 - Task allegiance reassignment not supported. 5 - Task management function not supported. 6 - Function authorization failed. 255 - Function rejected. The Task Management Function Response PDU above and the list of task management function responses above are duplicated from [RFC-cons] for reference only. [RFC-cons] supersedes the text in section 6.4.1 of this document in the event the two documents conflict. Knight, et al. Expires February, 2014 Page 16 Internet-Draft iSCSI SCSI Features Update August 13 -------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- Responses to new task management functions (see 6.4.2) are listed below. In addition, a new task Management response is listed below. For a more detailed description of SCSI task management responses, see [SAM5]. For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, and QUERY ASYNCHRONOUS EVENT, the target performs the requested Task Management function and sends a Task Management response back to the initiator. 6.4.2 Task Management Function Response Additions The new response is listed below: 7 - Function succeeded. In symbolic terms Response value 7 maps to the SCSI service response of FUNCTION SUCCEEDED in [SAM5]. The task management function response of "Function succeeded" MUST be supported by an initiator that sends any of the new task management functions (see 6.3). For the QUERY TASK function, if the specified task is in the task set, then the logical unit returns a Response value of Function succeeded and additional response information is returned as specified in [SAM5]. If the specified task is not in the task set, then the logical unit returns a Response value of Function complete. For the QUERY TASK SET function, if there is any command present in the task set from the specified I_T_L nexus, then the logical unit returns a Response value of Function succeeded. If there are no commands present in the task set from the specified I_T_L nexus, then the logical unit returns a Response value of Function complete. For the I_T NEXUS RESET function, after completion of the events described in section 6.3 for this function, the logical unit returns a Response value of Function complete. However, because the target drops all connections, the Service Response (defined by [SAM5]) for this SCSI task management function may not be reliably delivered to the issuing initiator port. For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention condition or deferred error pending for the specified I_T_L Knight, et al. Expires February, 2014 Page 17 Internet-Draft iSCSI SCSI Features Update August 13 nexus, then the logical unit returns a Response value of Function succeeded and additional response information is returned as specified in [SAM5]. If there is no unit attention or deferred error pending for the specified I_T_L nexus then the logical unit returns a Response value of Function complete. 6.5 Task Management Requests Affecting Multiple Tasks Section 4.1 of [RFC5048] defines the notion of "affected tasks" in multi-task abort scenarios. This section adds to the list include in that section by defining the tasks affected by the I_T NEXUS RESET function. I_T NEXUS RESET: All outstanding tasks received on the I_T nexus on which the function request was received for all logical units accessible to the I_T nexus. Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] identify semantics for task management functions that involve multi-task abort operations. If an iSCSI implementation supports the I_T NEXUS RESET function, it MUST also support the protocol behavior as defined in those sections and follow the sequence of actions as described in those sections when processing the I_T NEXUS RESET function. 7. Login/Text Operational Text Keys 7.1 New Operational Text Keys 7.1.1 iSCSIProtocolLevel Use: LO, IO Irrelevant when: SessionType = Discovery Senders: Initiator and Target Scope: SW iSCSIProtocolLevel= Default is 1. Result function is Minimum. This key is used to negotiate the use of iSCSI features that require different levels of protocol support (e.g., PDU formats, end node semantics) for proper operation. Negotiation of the iSCSIProtocolLevel key to a value corresponding to an RFC indicates that both negotiating parties are compliant to the RFC in question, and agree to support the corresponding PDU formats and semantics on that iSCSI session. Features using this key are expected to be cumulative. Knight, et al. Expires February, 2014 Page 18 Internet-Draft iSCSI SCSI Features Update August 13 An iSCSIProtocolLevel key negotiated to "0" indicates that the implementation does not claim a specific iSCSI protocol level. An iSCSIProtocolLevel key negotiated to "1" indicates that the implementation claims compliance with [RFC-cons]. -------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- An iSCSIProtocolLevel key negotiated to "2" is required to enable use of features defined in this RFC. If the negotiation answer is ignored by the acceptor, or the answer from the remote iSCSI end point is key=NotUnderstood, then the features defined in this RFC, and the features defined in any RFC requiring a key value greater than "2" MUST NOT be used. 8. Security Considerations Command priorities are relative values, not absolute values (see [SAM5] and affect collections of commands, not necessarily individual commands (see [SAM5]); if command priority is supported, it should be implemented in a fashion that avoids unwanted reduction or denial of service. All the iSCSI-related security text in [RFC3723] and the security text in [RFC-cons] is also directly applicable to this document. -------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFC-cons] should reference the RFC number assigned to [draft-ietf-storm-iscsi- cons-xx], and this note should be removed. -------------------------------------------------------- 9. IANA Considerations This document modifies or creates a number of iSCSI-related registries. The following iSCSI-related registries are modified: 1. iSCSI Task Management Functions Codes Name of the existing registry: "iSCSI Task Management Function Codes" Additional entries: 9, QUERY TASK, [RFCxxx] Knight, et al. Expires February, 2014 Page 19 Internet-Draft iSCSI SCSI Features Update August 13 10, QUERY TASK SET, [RFCxxx] 11, I_T NEXUS RESET, [RFCxxx] 12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 13-127, Unassigned, [RFCxxx] --------------------------------------------------------- RFC EDITORS NOTE: The above reference to [RFCxxx] should reference this RFC, and this note should be removed. The last entry (values 13-127 in the above list) should replace the existing entry for the "Unassigned" values. --------------------------------------------------------- 2. iSCSI Login/Text Keys Name of the existing registry: "iSCSI Login/Text Keys" Fields to record in the registry: Assigned value and its associated RFC reference: iSCSIProtocolLevel, [RFCxxx] --------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFCxxx] should reference this RFC, and this note should be removed. --------------------------------------------------------- This document creates the following iSCSI-related registries for IANA to manage. 3. iSCSI Protocol Level Name of new registry: "iSCSI Protocol Level" Namespace details: Numerical values from 0 to 31 Information that must be provided to assign a new value: An IESG-approved standards track specification defining the semantics and interoperability requirements of the proposed new value and the fields to be recorded in the registry. Assignment policy: The assignments of these values must be coordinated with the INCITS T10 committee; therefore review by an expert that maintains an association with that committee is required prior to IESG approval of the associated specification. After creation of the registry, values are to be assigned sequentially (for example, any value greater than 4 will not be assigned until after the value 4 has been assigned). Knight, et al. Expires February, 2014 Page 20 Internet-Draft iSCSI SCSI Features Update August 13 Special care must be taken in the assignment of new values in this registry. Compatibility and interoperability will be adversely impacted if proper care is not exercised. Features using this key are expected to be cumulative. For example, since this draft explicitly lists only value 2 for the features listed in this draft, it is expected that a new RFC assigning value 3 will also have the features listed in this RFC and therefore such an RFC is expected to either revise or replace this RFC. Assignments that do not follow this policy should be reviewed and approved by the INCITS T10 committee. 3-31: range available to IANA for assignment in this registry. Fields to record in the registry: Assigned value, description, and its associated RFC reference. 0, No version claimed, [RFCxxx] 1, RFC-cons, [RFCxxx] 2, RFCxxx, [RFCxxx] 3-31, Unassigned --------------------------------------------------------- RFC EDITORS NOTE: The above references to [RFCxxx] should reference this RFC, and this note should be removed. The above reference to RFC-cons should be replaced with the name of the [draft-ietf-storm-iscsi-cons-xx] document, and this note should be removed. All associated RFC references are to this document; even the reference for value 1. The description for value 1 however contains the RFC-cons name but should not have [] around the description (it is a description not a formal reference). The description for value 2 is the name of this RFC but should not contain the [] (again, a description not a formal reference). This note should be removed. --------------------------------------------------------- Allocation Policy: Expert review ([IANA]) and Standards Action ([IANA]) 4. iSCSI Task Management Function Response Codes Name of new registry: "iSCSI Task Management Function Response Codes" Namespace details: Numerical values that can fit in 8 bits. Knight, et al. Expires February, 2014 Page 21 Internet-Draft iSCSI SCSI Features Update August 13 Information that must be provided to assign a new value: An IESG-approved specification defining the semantics and interoperability requirements of the proposed new value and the fields to be recorded in the registry. Assignment policy: If the requested value is not already assigned, it may be assigned to the requester. 8-254: Range available to IANA for assignment in this registry. Fields to record in the registry: Assigned value, Operation Name, and its associated RFC reference. 0, Function complete, [RFC-cons] 1, Task does not exist, [RFC-cons] 2, LUN does not exist, [RFC-cons] 3, Task still allegiant, [RFC-cons] 4, Task allegiance reassignment not supported, [RFC-cons] 5, Task management function not supported, [RFC-cons] 6, Function authorization failed, [RFC-cons] 7, Function succeeded, [RFCxxx] 8-254, Unassigned 255, Function rejected, [RFC-cons] ------------------------------------------------------------ RFC EDITORS NOTE: The above reference to [RFCxxx] should reference this RFC, and this note should be removed. The above references to [RFC-cons] should reference the [draft-ietf-storm-iscsi-cons-xx] document, and this note should be removed. ------------------------------------------------------------ Allocation Policy: Standards Action ([IANA]) 10. References 10.1 Normative References Knight, et al. Expires February, 2014 Page 22 Internet-Draft iSCSI SCSI Features Update August 13 [RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and Travostino, F., "Securing Block Storage Protocols over IP", RFC 3723, April 2004. [RFC5048] Chadalapaka, M., "Internet Small Computer System Interface (iSCSI) Corrections and Clarifications", RFC 5048, October 2007. [draft-ietf-storm-iscsi-cons-xx] Chadalapaka, M., Satran, J., Kalman, M., "iSCSI Protocol (consolidated)", RFC xxx, Date 2013. ------------------------------------------------------------ RFC EDITORS NOTE: The above references to [draft-ietf-storm- iscsi-cons-xx] and RFC xxx should reference the RFC number assigned to that draft, and this note should be removed. ------------------------------------------------------------ [IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. [SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). [SAM5] T10/2104D rev r04, SCSI Architecture Model - 5 (SAM- 5), Committee Draft. [SPC4] T10/1731D rev r36, SCSI Primary Commands - 4 (SPC-4), Committee Draft. 10.2 Informative References [RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, M., and E. Zeidner, "Internet Small Computer Systems Interface (iSCSI)", RFC 3720, April 2004. 10.3 Additional Reference Sources For more information on the SCSI Architecture Model and SCSI Primary Commands - 4, contact the INCITS T10 Technical Committee for SCSI Storage Interfaces at http://www.t10.org. 11. Acknowledgements The Storage Maintenance (STORM) Working Group in the Transport Area of the IETF has been responsible for defining these additions to the iSCSI protocol (apart from other relevant IP Storage protocols). The editor acknowledges the contributions of the entire working group and other IETF reviewers. Knight, et al. Expires February, 2014 Page 23 Internet-Draft iSCSI SCSI Features Update August 13 The following individuals directly contributed to identifying [RFCxxx] issues and/or suggesting resolutions to the issues clarified in this document: David Black, Rob Elliott. This document benefited from all of these contributions. ------------------------------------------------------------ RFC EDITORS NOTE: The above reference to [RFCxxx] should reference this RFC, and this note should be removed. ------------------------------------------------------------ Author's Addresses: Frederick Knight 7301 Kit Creek Road P.O. Box 13917 Research Triangle Park, NC 27709, USA Phone: +1-919-476-5362 Email: knight@netapp.com Mallikarjun Chadalapaka Microsoft One Microsoft Way Redmond, WA 98052 USA Email: cbm@chadalapaka.com Knight, et al. Expires February, 2014 Page 24