idnits 2.17.1 draft-ietf-storm-iscsi-sam-04.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (August 2011) is 4638 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'RFCxxx' is mentioned on line 892, but not defined ** Obsolete normative reference: RFC 3720 (Obsoleted by RFC 7143) ** Obsolete normative reference: RFC 5048 (Obsoleted by RFC 7143) ** Obsolete normative reference: RFC 5226 (ref. 'IANA') (Obsoleted by RFC 8126) -- Possible downref: Non-RFC (?) normative reference: ref. 'SAM2' -- Possible downref: Non-RFC (?) normative reference: ref. 'SAM4' -- Possible downref: Non-RFC (?) normative reference: ref. 'SAM5' -- Possible downref: Non-RFC (?) normative reference: ref. 'SPC4' Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 5 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Storage Maintenance (StorM) Working Group Frederick Knight 2 Internet Draft NetApp 3 Intended status: Standards Track M. Chadalapaka 4 Expires: February 2012 Microsoft 5 August 2011 7 Internet Small Computer Systems Interface (iSCSI) SCSI Architecture 8 Features Update 9 draft-ietf-storm-iscsi-sam-04.txt 11 Abstract 13 Internet Small Computer Systems Interface (iSCSI) is a SCSI 14 transport protocol that maps the SCSI family of protocols onto 15 TCP/IP. The iSCSI protocol as specified in [draft-ietf-storm- 16 iscsi-cons-xx] (and as previously specified by the combination 17 of RFC 3720 and RFC 5048) is based on the SAM-2 (SCSI 18 Architecture Model - 2) version of the SCSI family of 19 protocols. This document defines enhancements to the iSCSI 20 protocol to support certain additional features of the SCSI 21 protocol that were defined in SAM-3, SAM-4, and SAM-5. 23 This document is a companion document to [draft-ietf-storm- 24 iscsi-cons-xx]. 26 -------------------------------------------------------- 27 RFC EDITORS NOTE: The above references to [draft-ietf-storm- 28 iscsi-cons-xx] should reference the RFC number assigned to 29 that document, and this note should be removed. 30 -------------------------------------------------------- 32 Status of this Memo 34 This Internet-Draft is submitted to IETF in full conformance with 35 the provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF), its areas, and its working groups. Note that 39 other groups may also distribute working documents as Internet- 40 Drafts. 42 Internet-Drafts are draft documents valid for a maximum of six 43 months and may be updated, replaced, or obsoleted by other 44 documents at any time. It is inappropriate to use Internet- 45 Drafts as reference material or to cite them other than as "work 46 in progress." 48 The list of current Internet-Drafts can be accessed at 49 http://www.ietf.org/1id-abstracts.html. 51 The list of Internet-Draft Shadow Directories can be accessed at 52 http://www.ietf.org/shadow.html. 54 This Internet-Draft will expire February, 2012. 56 Copyright Notice 58 Copyright (c) 2011 IETF Trust and the persons identified as the 59 document authors. All rights reserved. 61 This document is subject to BCP 78 and the IETF Trust's Legal 62 Provisions Relating to IETF Documents 63 (http://trustee.ietf.org/license-info) in effect on the date of 64 publication of this document. Please review these documents 65 carefully, as they describe your rights and restrictions with 66 respect to this document. Code Components extracted from this 67 document must include Simplified BSD License text as described in 68 Section 4.e of the Trust Legal Provisions and are provided 69 without warranty as described in the Simplified BSD License. 71 Table of Contents 73 1 Introduction.................................................. 3 74 2 Definitions, Acronyms, and Document Summary................... 3 75 2.1 Definitions ............................................ 3 76 2.2 Acronyms ............................................... 3 77 2.3 New Semantics .......................................... 3 78 3 Terminology Mapping........................................... 4 79 4 Negotiation of New Feature Use................................ 7 80 5 SCSI Commands................................................. 8 81 5.1 SCSI Command Additions ................................. 8 82 5.1.1 Command Priority (byte 2) .......................... 8 83 5.2 SCSI Response Additions ................................ 9 84 5.2.1 Status Qualifier .................................. 10 85 5.2.2 Data Segment - Sense and Response Data Segment .... 10 86 6 Task Management Functions.................................... 10 87 6.1 Existing Task Management Functions .................... 10 88 6.2 Task Management Function Additions .................... 10 89 6.2.1 LUN field ......................................... 12 90 6.2.2 Referenced Task Tag ............................... 12 91 6.2.3 RefCmdSN .......................................... 12 92 6.3 Task Management Function Responses .................... 13 93 6.3.1 Task Management Function Response Additions ....... 14 94 6.4 Task Management Requests Affecting Multiple Tasks ..... 14 95 7 Login/Text Operational Text Keys............................. 15 96 7.1 New Operational Text Keys ............................. 15 97 7.1.1 iSCSIProtocolLevel ................................ 15 98 8 Security Considerations...................................... 16 99 9 IANA Considerations.......................................... 16 100 10 References.................................................... 18 101 11 Acknowledgements.............................................. 19 102 1. Introduction 104 The original [RFC3720] was built based on the [SAM2] model for 105 SCSI. Several new features and capabilities have been added to 106 the SCSI Architecture Model in the intervening years (at the time 107 of publication of this document, SAM-5 was the current version of 108 the SCSI Architecture Model). This document is not a complete 109 revision of [RFC3720]. Instead, this document is intended as a 110 companion document to [draft-ietf-storm-iscsi-cons-xx]; this 111 document may also be used as a companion document to the 112 combination of [RFC3720] and [RFC5048], although both of those 113 RFCs have been obsolete by [draft-ietf-storm-iscsi-cons-xx]. 115 -------------------------------------------------------- 116 RFC EDITORS NOTE: The above references to [draft-ietf-storm- 117 iscsi-cons-xx] should reference the RFC number assigned to 118 that document, and this note should be removed. 119 -------------------------------------------------------- 121 2. Definitions, Acronyms, and Document Summary 123 2.1 Definitions 125 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 126 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 127 this document are to be interpreted as described in [RFC2119]. 129 2.2 Acronyms 131 ISID Initiator Session Identifier 132 LU Logical Unit 133 PDU Protocol Data Unit 134 SAM-4 SCSI Architecture Model - 4 (see [SAM4]) 135 SAM-5 SCSI Architecture Model - 5 (see [SAM5]) 136 TMF Task Management Function 138 2.3 New Semantics 140 This document specifies new iSCSI semantics. This section 141 summarizes the contents of the document. 143 Section 3: The mapping of iSCSI objects to SAM-5 objects 144 The iSCSI node may contain both initiator and 145 target capabilities. 147 Section 4: The protocol used to negotiate the use of the new 148 capabilities described in this document. 150 Section 5: New Command operations 151 The PRI field for SCSI command priority has been 152 added to the SCSI command PDU (see 5.1.1). 154 The Status Qualifier field has been added to the 155 SCSI response PDU (see 5.2.1). 156 Sense data may be returned (via autosense) for any 157 SCSI status, not just CHECK CONDITION (see 5.2.2). 159 Section 6: New Task Management Functions 160 Four new task management functions (QUERY TASK, 161 QUERY TASK SET, I_T NEXUS RESET, and QUERY 162 ASYNCHRONOUS EVENT have been added (see 6.2). 163 A new "function succeeded" response has been added 164 (see 6.3.1). 166 Section 7: New Negotiation key 167 A new negotiation key has been added to enable the 168 use of the new features in section 5 and section 6. 170 3. Terminology Mapping 172 The iSCSI model (defined in [RFC3720]) uses different terminology 173 than the SCSI Architecture Model. In some cases, iSCSI uses 174 multiple terms to describe what in the SCSI Architecture Model is 175 described with a single term. The iSCSI terms and SAM-5 terms 176 are not necessarily equivalent, but rather, the iSCSI terms 177 represent examples of the objects or classes described in SAM-5 178 as follows: 180 +-----------------------------+---------------------------+ 181 | RFCxxx Terminology | SAM-5 Terminology | 182 +-----------------------------+---------------------------+ 183 | Network Entity | none | 184 +-----------------------------+---------------------------+ 185 | iSCSI Node | SCSI Device | 186 +-----------------------------+---------------------------+ 187 | iSCSI Name | SCSI Device Name | 188 +-----------------------------+---------------------------+ 189 | iSCSI Node Name | SCSI Device Name | 190 +-----------------------------+---------------------------+ 191 | iSCSI Initiator Node | SCSI Initiator Device | 192 +-----------------------------+---------------------------+ 193 | iSCSI Initiator Name | SCSI Device Name | 194 +-----------------------------+---------------------------+ 195 | iSCSI Initiator Port Name | SCSI Initiator Port Name | 196 | iSCSI Node Name + ',i,' + | | 197 | ISID | | 198 +-----------------------------+---------------------------+ 199 | iSCSI Target Node | SCSI Target Device | 200 +-----------------------------+---------------------------+ 201 | iSCSI Target Name | SCSI Device Name | 202 +-----------------------------+---------------------------+ 203 | iSCSI Target Port Name | SCSI Target Port Name | 204 | iSCSI Node Name + ',t,' + | | 205 | Target Portal Group Tag | | 206 +-----------------------------+---------------------------+ 207 | iSCSI Target Portal Group | SCSI Target Port | 208 +-----------------------------+---------------------------+ 209 | iSCSI Initiator Node + | SCSI Initiator Port | 210 | active ISID | | 211 +-----------------------------+---------------------------+ 212 | iSCSI Initiator Name + | I_T Nexus | 213 | ',i,' + ISID, iSCSI Target | | 214 | Name + ',t,' + Portal | | 215 | Group Tag | | 216 +-----------------------------+---------------------------+ 217 | Target Portal Group Tag | Relative Port ID | 218 +-----------------------------+---------------------------+ 220 -------------------------------------------------------- 221 RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] 222 should reference this RFC, and this note should be removed. 223 -------------------------------------------------------- 225 The following diagram shows an example of a combination target 226 device and initiator device. Such a configuration may exist in a 227 target device that implements a SCSI Copy Manager. This example 228 shows how a session that shares Network Portals within a Portal 229 Group may be established (see Target Portal Group 1). In 230 addition, this example shows the Initiator using a different 231 Portal Group than the Target Portal Group, but the Initiator 232 Portal group sharing Network Portal A with the Target Portal 233 Group. 235 ----------------------------IP Network--------------------- 236 | | | 237 +----|---------------|-------+ +----|------------+ 238 | +----------+ +----------+ | | +----------+ | 239 | | Network | | Network | | | | Network | | 240 | | Portal A | | Portal B | | | | Portal A | | 241 | +----------+ +----------+ | | +----------+ | 242 | | Target | | | | Initiator | 243 | | Portal | | | | Portal | 244 | | Group 1 | | | | Group 2 | 245 +----|---------------|-------+ +----|------------+ 246 | | | 247 +----------|---------------|--------------------|--------------------+ 248 | +--------|---------------|----+ +-------------|------------------+ | 249 | |+-------|---------------|---+| |+------------|-----------------+| | 250 | ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| | 251 | || || || || | 252 | || (TSIH = 56) || || (SSID = 48) || | 253 | |+---------------------------+| |+------------------------------+| | 254 | | | | | | 255 | | iSCSI Target Node | | iSCSI Initiator Node | | 256 | +-----------------------------+ +--------------------------------+ | 257 | iSCSI Node | 258 | (within Network Entity, not shown) | 259 +--------------------------------------------------------------------+ 260 4. New Feature Use 262 4.1 Negotiation of New Feature Use 264 The iSCSIProtocolLevel operational text key (see 7.1.1) 265 containing a value of "2" or higher MUST be negotiated to enable 266 the use of features described in this RFC. 268 Note that an operational value of "2" or higher for this key on 269 an iSCSI session does not influence the SCSI level features in 270 any way on that I_T nexus. An operational value of "2" or higher 271 for this key permits the iSCSI-related features defined in this 272 document to be used on all connections on this iSCSI session. 273 SCSI level hand-shakes (e.g. commands, mode pages) eventually 274 determine the existence or lack of various SAM-5 features 275 available for the I_T nexus between the two SCSI end points). To 276 summarize, negotiation of this key to "2" or higher is a 277 necessary but not a sufficient condition of SAM-5 compliant 278 feature usage at the SCSI protocol level. 280 For example, an iSCSI implementation may negotiate this new key 281 to "2" but respond to the new task management functions (see 6.2) 282 with a "Task management function not supported" (which indicates 283 a SCSI error that prevents the function from being performed). 284 In contrast, if the key is negotiated to "2", an iSCSI 285 implementation MUST NOT reject a task management function request 286 PDU that requests one of the new task management functions (such 287 a reject would report an iSCSI protocol error). 289 4.2 Impact on standard INQUIRY data 291 The negotiated value of the iSCSIProtocolLevel key is an 292 increment from the base iSCSI version descriptor value 293 (0960h)(see [SPC4]). If the SCSI device server returns an iSCSI 294 version descriptor in the standard INQUIRY data, then the value 295 returned in that iSCSI version descriptor MUST be set to the sum 296 of the base value (0960h) plus the negotiated value of the 297 iSCSIProtocolLevel key (for example, if the negotiated 298 iSCSIProtocolLevel=2, then if an iSCSI version descriptor is 299 returned in the standard INQUIRY data it is set to 0962h). 301 5. SCSI Commands 303 5.1 SCSI Command Additions 305 The format of the SCSI Command PDU is: 307 Byte/ 0 | 1 | 2 | 3 | 308 / | | | | 309 |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| 310 +---------------+---------------+---------------+---------------+ 311 0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved | 312 +---------------+---------------+---------------+---------------+ 313 4|TotalAHSLength | DataSegmentLength | 314 +---------------+---------------+---------------+---------------+ 315 8| Logical Unit Number (LUN) | 316 + + 317 12| | 318 +---------------+---------------+---------------+---------------+ 319 16| Initiator Task Tag | 320 +---------------+---------------+---------------+---------------+ 321 20| Expected Data Transfer Length | 322 +---------------+---------------+---------------+---------------+ 323 24| CmdSN | 324 +---------------+---------------+---------------+---------------+ 325 28| ExpStatSN | 326 +---------------+---------------+---------------+---------------+ 327 32/ SCSI Command Descriptor Block (CDB) / 328 +/ / 329 +---------------+---------------+---------------+---------------+ 330 48/ AHS (Optional) / 331 +---------------+---------------+---------------+---------------+ 332 x/ Header Digest (Optional) / 333 +---------------+---------------+---------------+---------------+ 334 y/ (DataSegment, Command Data) (Optional) / 335 +/ / 336 +---------------+---------------+---------------+----------------+ 337 z/ Data Digest (Optional) / 338 +---------------+---------------+---------------+----------------+ 340 5.1.1 Command Priority (byte 2) 342 The Command Priority (PRI) specifies the relative scheduling 343 importance of this task in relation to other SIMPLE tasks already 344 in the task set (see [SAM4]). 346 Section 10, iSCSI PDU Formats of [RFC3720], requires that senders 347 set this field to zero. A sender MUST NOT set this field to a 348 value other than zero unless the iSCSIProtocolLevel text key 349 defined in section 7.1.1 has been negotiated on the session with 350 a value of "2" or higher. 352 This field MUST be ignored by iSCSI targets unless the 353 iSCSIProtocolLevel text key with a value of "2" or higher as 354 defined in section 7.1.1 was negotiated on the session. 356 5.2 SCSI Response Additions 358 The format of the SCSI Response PDU is: 360 Byte/ 0 | 1 | 2 | 3 | 361 / | | | | 362 |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| 363 +---------------+---------------+---------------+---------------+ 364 0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status | 365 +---------------+---------------+---------------+---------------+ 366 4|TotalAHSLength | DataSegmentLength | 367 +---------------+---------------+---------------+---------------+ 368 8| Status Qualifier | Reserved | 369 +---------------+---------------+---------------+---------------+ 370 12| Reserved | 371 +---------------+---------------+---------------+---------------+ 372 16| Initiator Task Tag | 373 +---------------+---------------+---------------+---------------+ 374 20| SNACK Tag or Reserved | 375 +---------------+---------------+---------------+---------------+ 376 24| StatSN | 377 +---------------+---------------+---------------+---------------+ 378 28| ExpCmdSN | 379 +---------------+---------------+---------------+---------------+ 380 32| MaxCmdSN | 381 +---------------+---------------+---------------+---------------+ 382 36| ExpDataSN or Reserved | 383 +---------------+---------------+---------------+---------------+ 384 40| Bidirectional Read Residual Count or Reserved | 385 +---------------+---------------+---------------+---------------+ 386 44| Residual Count or Reserved | 387 +---------------+---------------+---------------+---------------+ 388 48| Header-Digest (Optional) | 389 +---------------+---------------+---------------+---------------+ 390 / Data Segment (Optional) / 391 +/ / 392 +---------------+---------------+---------------+---------------+ 393 | Data-Digest (Optional) | 394 +---------------+---------------+---------------+---------------+ 396 5.2.1 Status Qualifier 398 The Status Qualifier provides additional status information (see 399 [SAM4]). 401 As defined in Section 10, iSCSI PDU Formats of [RFC3720], 402 compliant senders already set this field to zero. Compliant 403 senders MUST NOT set this field to a value other than zero unless 404 the iSCSIProtocolLevel text key with a value of "2" or higher as 405 defined in section 7.1.1 was negotiated on the session. 407 This field MUST be ignored by receivers unless the 408 iSCSIProtocolLevel text key with a value of "2" or higher as 409 defined in section 7.1.1 was negotiated on the session. 411 5.2.2 Data Segment - Sense and Response Data Segment 413 Section 10.4.7 of [RFC3720] specifies that iSCSI targets MUST 414 support and enable autosense. If Status is CHECK CONDITION 415 (0x02), then the Data Segment MUST contain sense data for the 416 failed command. While [RFC3720] does not make any statements 417 about the state of the Data Segment when the Status is not CHECK 418 CONDITION (0x02)(i.e., the Data Segment is not prohibited from 419 containing sense data when the Status is not CHECK CONDITION), 420 negotiation of the iSCSIProtocolLevel text key with a value of 421 "2" or higher as defined in section 7.1.1 explicitly indicates 422 that the Data Segment MAY contain sense data at any time, no 423 matter what value is set in the Status field. 425 6. Task Management Functions 427 6.1 Existing Task Management Functions 429 Section 10.5 of [RFC3720] defines the semantics used to request 430 SCSI Task Management Functions be performed. The following task 431 management functions are defined: 433 1 - ABORT TASK 434 2 - ABORT TASK SET 435 3 - CLEAR ACA 436 4 - CLEAR TASK SET 437 5 - LOGICAL UNIT RESET 438 6 - TARGET WARM RESET 439 7 - TARGET COLD RESET 440 8 - TASK REASSIGN 442 6.2 Task Management Function Additions 444 Additional task Management function codes are listed below. For 445 a more detailed description of SCSI task management, see [SAM5]. 447 9 - QUERY TASK - determines if the task identified by the 448 Referenced Task Tag field is present in the task set. 450 10 - QUERY TASK SET - determine if any task is present in the 451 task set for the I_T_L Nexus on which the task management 452 function was received. 454 11 - I_T NEXUS RESET - perform an I_T nexus loss function for 455 the I_T nexus of each logical unit accessible through the I_T 456 Nexus on which the task management function was received. 458 12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit 459 attention condition or a deferred error pending for the I_T_L 460 nexus on which the task management function was received. 462 These task management function requests MUST NOT be sent unless 463 the iSCSIProtocolLevel text key with a value of "2" or higher as 464 defined in section 7.1.1 was negotiated on the session. 466 Any compliant initiator that sends any of the new task management 467 functions defined in this section MUST also support all new task 468 management function responses (as specified in section 6.3.1). 470 For all of the task management functions detailed in this 471 section, the Task Management function response MUST be returned 472 as detailed in section 6.3 Task Management Function Response. 474 The iSCSI target MUST ensure that no responses for the tasks 475 covered by a task management function are sent to the iSCSI 476 initiator after the Task Management response except for a task 477 covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK SET. 479 If a QUERY TASK is issued for a task created by an immediate 480 command then RefCmdSN MUST be that of the Task Management request 481 itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN 482 MUST be set to the CmdSN of the task to be queried (lower than 483 CmdSN). 485 If the connection is still active (it is not undergoing an 486 implicit or explicit logout), QUERY TASK MUST be issued on the 487 same connection to which the task to be queried is allegiant at 488 the time the Task Management Request is issued. If the 489 connection is implicitly or explicitly logged out (i.e., no other 490 request will be issued on the failing connection and no other 491 response will be received on the failing connection), then a 492 QUERY TASK function request may be issued on another connection. 493 This Task Management request will then establish a new allegiance 494 for the command being queried. 496 At the target a QUERY TASK function MUST NOT be executed on a 497 Task Management request; such a request MUST result in Task 498 Management response of "Function rejected". 500 For the I_T NEXUS RESET function, the target device MUST respond 501 to the function as defined in [SAM4]. Each logical unit 502 accessible via the receiving I_T NEXUS MUST behave as dictated by 503 the I_T nexus loss function in [SAM4] for the I_T nexus on which 504 the task management function was received. The target device 505 MUST drop all connections in the session over which this function 506 is received. Independent of the DefaultTime2Wait and 507 DefaultTime2Retain value applicable to the session over which 508 this function is received, the target device MUST consider each 509 participating connection in the session to have immediately timed 510 out, leading to FREE state. The resulting timeouts cause the 511 session timeout event defined in [RFC3720], which in turn 512 triggers the I_T nexus loss notification to the SCSI layer as 513 described in [RFC3720]. 515 6.2.1 LUN field 517 This field is required for functions that address a specific LU 518 (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, 519 LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY 520 ASYNCHRONOUS EVENT) and is reserved in all others. 522 6.2.2 Referenced Task Tag 524 The Initiator Task Tag of the task to be aborted for the ABORT 525 TASK function, reassigned for the TASK REASSIGN function, or 526 queried for the QUERY TASK function. For all other functions 527 this field MUST be set to the reserved value 0xffffffff. 529 6.2.3 RefCmdSN 531 If a QUERY TASK is issued for a task created by an immediate 532 command then RefCmdSN MUST be that of the Task Management request 533 itself (i.e., CmdSN and RefCmdSN are equal). 535 For a QUERY TASK of a task created by non-immediate command 536 RefCmdSN MUST be set to the CmdSN of the task identified by the 537 Referenced Task Tag field. Targets must use this field as 538 described in section 10.6.1 of [RFC3720] when the task identified 539 by the Referenced Task Tag field is not in the task set. 541 6.3 Task Management Function Responses 543 Byte/ 0 | 1 | 2 | 3 | 544 / | | | | 545 |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| 546 +---------------+---------------+---------------+---------------+ 547 0|.|.| 0x22 |1| Reserved | Response | Reserved | 548 +---------------+---------------+---------------+---------------+ 549 4|TotalAHSLength | DataSegmentLength | 550 +-----------------------------------------------+---------------+ 551 8| Additional Response Information | Reserved | 552 +-----------------------------------------------+---------------+ 553 12| Reserved | 554 +---------------+---------------+---------------+---------------+ 555 16| Initiator Task Tag | 556 +---------------+---------------+---------------+---------------+ 557 20| Reserved | 558 +---------------+---------------+---------------+---------------+ 559 24| StatSN | 560 +---------------+---------------+---------------+---------------+ 561 28| ExpCmdSN | 562 +---------------+---------------+---------------+---------------+ 563 32| MaxCmdSN | 564 +---------------+---------------+---------------+---------------+ 565 36/ Reserved / 566 +/ / 567 +---------------+---------------+---------------+---------------+ 568 48| Header-Digest (Optional) | 569 +---------------+---------------+---------------+---------------+ 571 Section 10.6 of [RFC3720] defines the semantics used for 572 responses to SCSI Task Management Functions. The following 573 responses are defined in [RFC3720]: 575 0 - Function Complete. 576 1 - Task does not exist. 577 2 - LUN does not exist. 578 3 - Task still allegiant. 579 4 - Task allegiance reassignment not supported. 580 5 - Task management function not supported. 581 6 - Function authorization failed. 582 255 - Function rejected. 584 Responses to new task management functions (see 6.3.1) are listed 585 below. In addition, a new task Management response is listed 586 below. For a more detailed description of SCSI task management 587 responses, see [SAM5]. 589 For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, 590 and QUERY ASYNCHRONOUS EVENT, the target performs the requested 591 Task Management function and sends a Task Management response 592 back to the initiator. 594 6.3.1 Task Management Function Response Additions 596 The new response is listed below: 598 7 - Function succeeded. 600 In symbolic terms Response value 7 maps to the SCSI service 601 response of FUNCTION SUCCEEDED in [SAM4]. 603 The task management function response of "Function succeeded" 604 MUST be supported by an initiator that sends any of the new task 605 management functions (see 6.2). 607 For the QUERY TASK function, if the specified task is in the task 608 set, then the logical unit returns a Response value of Function 609 succeeded and additional response information is returned as 610 specified in [SAM5]. If the specified task is not in the task 611 set, then the logical unit returns a Response value of Function 612 complete. 614 For the QUERY TASK SET function, if there is any command present 615 in the task set from the specified I_T_L nexus, then the logical 616 unit returns a Response value of Function succeeded. If there 617 are no commands present in the task set from the specified I_T_L 618 nexus, then the logical unit returns a Response value of Function 619 complete. 621 For the I_T NEXUS RESET function, after completion of the events 622 described in section 6.2 for this function, the logical unit 623 returns a Response value of Function complete. However, because 624 the target drops all connections, the Service Response (defined 625 by [SAM4]) for this SCSI task management function may not be 626 reliably delivered to the issuing initiator port. 628 For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention 629 condition or deferred error pending for the specified I_T_L 630 nexus, then the logical unit returns a Response value of Function 631 succeeded and additional response information is returned as 632 specified in [SAM5]. If there is no unit attention or deferred 633 error pending for the specified I_T_L nexus then the logical unit 634 returns a Response value of Function complete. 636 6.4 Task Management Requests Affecting Multiple Tasks 638 Section 4.1 of [RFC5048] defines the notion of "affected tasks" 639 in multi-task abort scenarios. This section adds to the list 640 include in that section by defining the tasks affected by the I_T 641 NEXUS RESET function. 643 I_T NEXUS RESET: All outstanding tasks received on the I_T 644 nexus on which the function request was received for all 645 logical units accessible to the I_T nexus. 647 Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] 648 identify semantics for task management functions that involve 649 multi-task abort operations. If an iSCSI implementation supports 650 the I_T NEXUS RESET function, it MUST also support the protocol 651 behavior as defined in those sections and follow the sequence of 652 actions as described in those sections when processing the I_T 653 NEXUS RESET function. 655 7. Login/Text Operational Text Keys 657 7.1 New Operational Text Keys 659 7.1.1 iSCSIProtocolLevel 661 Use: LO, IO 662 Irrelevant when: SessionType = Discovery 663 Senders: Initiator and Target 664 Scope: SW 666 iSCSIProtocolLevel= 668 Default is 1. 669 Result function is Minimum. 671 This key is used to negotiate the use of iSCSI features that 672 require different levels of protocol support (e.g., PDU formats, 673 end node semantics) for proper operation. 675 Negotiation of the iSCSIProtocolLevel key to a value 676 corresponding to an RFC indicates that both negotiating parties 677 are compliant to the RFC in question, and agree to support the 678 corresponding PDU formats and semantics on that iSCSI session. 679 An operational value of iSCSI ProtocolLevel = "x" on an iSCSI 680 session requires that the iSCSI protocol semantics on that iSCSI 681 session be a logical superset of the capabilities in all RFCs 682 that have claimed values of an iSCSIProtocolLevel less than "x". 684 An iSCSIProtocolLevel key negotiated to "0" indicates that the 685 implementation does not claim a specific iSCSI protocol level. 687 An iSCSIProtocolLevel key negotiated to "2" or higher is required 688 to enable use of features defined in this RFC. 690 If the negotiation answer is ignored by the acceptor, or the 691 answer from the remote iSCSI end point is key=NotUnderstood, then 692 the features defined in this RFC, and the features defined in any 693 RFC requiring a key value greater than "2" MUST NOT be used. 695 8. Security Considerations 697 At the time of writing this document does not introduce any new 698 security considerations other than those described in [RFC3720]. 699 Consequently, all the iSCSI-related security text in [RFC3723] is 700 also directly applicable to this document. 702 9. IANA Considerations 704 This document modifies or creates a number of iSCSI-related 705 registries. The following iSCSI-related registries are modified: 707 1. iSCSI Task Management Functions Codes 709 Name of the existing registry: "iSCSI TMF Codes" 711 Additional entries: 713 9, QUERY TASK, [RFCxxx] 715 10, QUERY TASK SET, [RFCxxx] 717 11, I_T NEXUS RESET, [RFCxxx] 719 12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 721 --------------------------------------------------------- 722 RFC EDITORS NOTE: The above reference to [RFCxxx] should 723 reference this RFC, and this note should be removed. 724 --------------------------------------------------------- 726 2. iSCSI Login/Text Keys 728 Name of the existing registry: "iSCSI Text Keys" 730 Fields to record in the registry: Assigned value and its 731 associated RFC reference: 733 iSCSIProtocolLevel, [RFCxxx] 735 --------------------------------------------------------- 736 RFC EDITORS NOTE: The above references to [RFCxxx] should 737 reference this RFC, and this note should be removed. 738 --------------------------------------------------------- 740 This document creates the following iSCSI-related registries for 741 IANA to manage. 743 3. iSCSI Protocol Level 745 Name of new registry: "iSCSI Protocol Level" 747 Namespace details: Numerical values from 0 to 31 749 Information that must be provided to assign a new value: An 750 IESG-approved standards track specification defining the 751 semantics and interoperability requirements of the proposed 752 new value and the fields to be recorded in the registry. 754 Assignment policy: 756 The assignments of these values must be coordinated with the 757 ANSI/INCITS T10 committee; therefore review by an expert that 758 maintains an association with that committee is required prior 759 to IESG approval of the associated specification. After 760 creation of the registry, values are to be assigned 761 sequentially (for example, any value greater than 4 will not 762 be assigned until after the value 4 has been assigned). 764 1 and 3-31: range reserved by IANA for assignment in this 765 registry. 767 Fields to record in the registry: Assigned value, and its 768 associated RFC reference. 770 0, [RFCxxx] 772 2, [RFCxxx] 774 --------------------------------------------------------- 775 RFC EDITORS NOTE: The above references to [RFCxxx] should 776 reference this RFC, and this note should be removed. 777 --------------------------------------------------------- 779 Allocation Policy: 781 Expert review ([IANA]) and Standards Action ([IANA]) 783 4. iSCSI Task Management Response Codes 785 Name of new registry: "iSCSI TMF Response Codes" 787 Namespace details: Numerical values that can fit in 8 bits. 789 Information that must be provided to assign a new value: An 790 IESG-approved specification defining the semantics and 791 interoperability requirements of the proposed new value and 792 the fields to be recorded in the registry. 794 Assignment policy: 796 If the requested value is not already assigned, it may be 797 assigned to the requester. 799 8-254: Range reserved by iANA for assignment in this registry. 801 Fields to record in the registry: Assigned value, Operation 802 Name, and its associated RFC reference. 804 0x0, Function complete, [RFC3720] 806 0x1, Task does not exist, [RFC3720] 808 0x2, LUN does not exist, [RFC3720] 810 0x3, Task still allegiant, [RFC3720] 812 0x4, Task allegiance reassignment not supported, [RFC3720] 814 0x5, Task management function not supported, [RFC3720] 816 0x6, Function authorization failed, [RFC3720] 818 0x7, Function succeeded, [RFCxxx] 820 255, Function rejected, [RFC3720] 822 ------------------------------------------------------------ 823 RFC EDITORS NOTE: The above reference to [RFCxxx] should 824 reference this RFC, and this note should be removed. 825 ------------------------------------------------------------ 827 Allocation Policy: 829 Standards Action ([IANA]) 831 10. References 833 10.1 Normative References 835 [RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate 836 Requirement Levels", BCP 14, RFC 2119, March 1997. 838 [RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, 839 M., and E. Zeidner, "Internet Small Computer Systems 840 Interface (iSCSI)", RFC 3720, April 2004. 842 [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and 843 Travostino, F., "Securing Block Storage Protocols 844 over IP", RFC 3723, April 2004. 846 [RFC5048] Chadalapaka, M., "Internet Small Computer System 847 Interface (iSCSI) Corrections and Clarifications", 848 RFC 5048, October 2007. 850 [draft-ietf-storm-iscsi-cons-xx] Chadalapaka, M., Satran, J., 851 Kalman, M., "iSCSI Protocol (consolidated)", RFC xxx, 852 Date 2011. 854 ------------------------------------------------------------ 855 RFC EDITORS NOTE: The above references to [draft-ietf-storm- 856 iscsi-cons-xx] and [RFCxxx] should reference the RFC number 857 assigned to that draft, and this note should be removed. 858 ------------------------------------------------------------ 860 [IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing 861 an IANA Considerations Section in RFCs", BCP 26, RFC 862 5226, May 2008. 864 [SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). 866 [SAM4] ISO/IEC 14776-414, SCSI Architecture Model - 4 (SAM- 867 4). 869 [SAM5] T10/2104D rev r04, SCSI Architecture Model - 5 (SAM- 870 5), Committee Draft. 872 [SPC4] T10/1731D rev r23, SCSI Primary Commands - 4 (SPC-4), 873 Committee Draft. 875 10.2 Additional Reference Sources 877 For more information on the SCSI Architecture Model, contact the 878 T10 group at http://www.t10.org. 880 11. Acknowledgements 882 The Storage Maintenance (STORM) Working Group in the Transport 883 Area of the IETF has been responsible for defining these 884 additions to the iSCSI protocol (apart from other relevant IP 885 Storage protocols). The editor acknowledges the contributions of 886 the entire working group. 887 The following individuals directly contributed to identifying 888 [RFCxxx] issues and/or suggesting resolutions to the issues 889 clarified in this document: David Black, Rob Elliott. This 890 document benefited from all of these contributions. 891 ------------------------------------------------------------ 892 RFC EDITORS NOTE: The above reference to [RFCxxx] should 893 reference this RFC, and this note should be removed. 894 ------------------------------------------------------------ 896 Author's Addresses 898 Frederick Knight 899 7301 Kit Creek Road 900 P.O. Box 13917 901 Research Triangle Park, NC 27709, USA 902 Phone: +1-919-476-5362 903 Email: knight@netapp.com 905 Mallikarjun Chadalapaka 906 Microsoft 907 One Microsoft Way 908 Redmond, WA 98052 USA 909 Email: cbm@chadalapaka.com