idnits 2.17.1 draft-ietf-storm-iscsi-sam-02.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 : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) (A line matching the expected section header was found, but with an unexpected indentation: ' 9. IANA Considerations' ) -- The abstract seems to indicate that this document updates RFC3720, but the header doesn't have an 'Updates:' line to match this. -- The abstract seems to indicate that this document updates RFC5048, but the header doesn't have an 'Updates:' line to match this. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (March 2011) is 4789 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) == Unused Reference: 'SAM2' is defined on line 798, but no explicit reference was found in the text ** 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. 'RFCxxx' Summary: 4 errors (**), 0 flaws (~~), 2 warnings (==), 7 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Storage Maintenance (StorM) Working Group F. Knight 3 Internet Draft NetApp 4 Intended status: Standards Track M. Chadalapaka 5 Expires: October 2011 Hewlett-Packard Co. 6 Updates: 3720, 5048 March 2011 8 Internet Small Computer Systems Interface (iSCSI) SAM 9 draft-ietf-storm-iscsi-sam-02.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. RFC 3720 defines the iSCSI protocol. The current iSCSI 16 protocol (RFC 3720 and RFC 5048) is based on the SAM-2 version of 17 the SCSI family of protocols). This document defines additions 18 and changes to the iSCSI protocol to enabled additional features 19 that were added to the SCSI family of protocols through SAM-3, 20 SAM-4, and SAM-5. 22 This document updates RFC 3720 and RFC 5048 and the text in this 23 document supersedes the text in RFC 3720 and RFC 5048 when the 24 two differ. 26 Status of this Memo 28 This Internet-Draft is submitted to IETF in full conformance with 29 the provisions of BCP 78 and BCP 79. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF), its areas, and its working groups. Note that 33 other groups may also distribute working documents as Internet- 34 Drafts. 36 Internet-Drafts are draft documents valid for a maximum of six 37 months and may be updated, replaced, or obsoleted by other 38 documents at any time. It is inappropriate to use Internet- 39 Drafts as reference material or to cite them other than as "work 40 in progress." 42 The list of current Internet-Drafts can be accessed at 43 http://www.ietf.org/1id-abstracts.html. 45 The list of Internet-Draft Shadow Directories can be accessed at 46 http://www.ietf.org/shadow.html. 48 This Internet-Draft will expire October, 2011. 50 Copyright Notice 51 Internet-Draft iSCSI SAM March 11 53 Copyright (c) 2011 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with 61 respect to this document. Code Components extracted from this 62 document must include Simplified BSD License text as described in 63 Section 4.e of the Trust Legal Provisions and are provided without 64 warranty as described in the Simplified BSD License. 66 Table of Contents 68 1 Introduction........................................... 3 69 2 Definitions, Acronyms, and Document Summary............ 3 70 2.1 Definitions....................................... 3 71 2.2 Acronyms.......................................... 3 72 2.3 New Semantics..................................... 3 73 3 Terminology Mapping.................................... 4 74 4 Negotiation of New Feature Use......................... 7 75 5 SCSI Commands.......................................... 8 76 5.1 SCSI Command Additions............................ 8 77 5.1.1 Command Priority (byte 2)...................... 8 78 5.2 SCSI Response Additions........................... 9 79 5.2.1 Status Qualifier.............................. 10 80 5.2.2 Data Segment - Sense and Response Data Segment 10 81 6 Task Management Functions............................. 10 82 6.1 Existing Task Management Functions............... 10 83 6.2 Task Management Function Additions............... 10 84 6.2.1 LUN field..................................... 12 85 6.2.2 Referenced Task Tag........................... 12 86 6.2.3 RefCmdSN...................................... 12 87 6.3 Task Management Function Responses............... 13 88 6.3.1 Task Management Function Response Additions... 14 89 6.4 Task Management Requests Affecting Multiple Tasks 14 90 7 Login/Text Operational Text Keys...................... 15 91 7.1 New Operational Text Keys........................ 15 92 7.1.1 iSCSIProtocolLevel............................ 15 93 8 Security Considerations............................... 16 94 9 IANA Considerations................................... 16 95 10 References .......................................... 17 96 11 Acknowledgements .................................... 18 97 Internet-Draft iSCSI SAM March 11 99 1. Introduction 101 The original [RFC3720] was built based on the SAM-2 model for 102 SCSI. Several new features and capabilities have been added to 103 the SCSI Architecture Model in the intervening years (SAM5 is now 104 the current version of the SCSI Architecture Model). This 105 document is not a complete revision of [RFC3720]. Instead, this 106 document is intended as a companion document to [RFC3720] and 107 [RFC5048]. 109 The text in this document, however, updates and supersedes the 110 text in [RFC3720] and [RFC5048] whenever there is any conflict. 112 2. Definitions, Acronyms, and Document Summary 114 2.1 Definitions 116 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL 117 NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and 118 "OPTIONAL" in this document are to be interpreted as described in 119 [RFC2119]. 121 2.2 Acronyms 123 SAM4 SCSI Architecture Model - 4 124 SAM5 SCSI Architecture Model - 5 125 SAM SAM4 or SAM5 127 2.3 New Semantics 129 This document specifies new iSCSI semantics. This section 130 summarizes the contents of the document. 132 Section 3: The mapping of iSCSI objects to SAM5 objects 133 The iSCSI node may contain both initiator and 134 target capabilities. 136 Section 4: The protocol used to negotiate the use of the new 137 capabilities described in this document. 139 Section 5: New Command operations 140 The PRI field for SCSI command priority has been 141 added to the SCSI command PDU (see 5.1.1). 142 The Status Qualifier field has been added to the 143 SCSI response PDU (see 5.2.1). 144 Sense data may be returned (via autosense) for any 145 SCSI status, not just CHECK CONDITION (see 5.2.2). 147 Section 6: New Task Management Functions 148 Internet-Draft iSCSI SAM March 11 150 Four new task management functions (QUERY TASK, 151 QUERY TASK SET, I_T NEXUS RESET, and QUERY 152 ASYNCHRONOUS EVENT have been added (see 6.2). 153 A new "function succeeded" response has been added 154 (see 6.3.1). 156 Section 7: New Negotiation key 157 A new negotiation key has been added to enable the 158 use of the new features in section 5 and section 159 6. 161 3. Terminology Mapping 163 The iSCSI model (defined in [RFC3720]) uses different terminology 164 than the SCSI Architecture Model. In some cases, iSCSI uses 165 multiple terms to describe what in the SCSI Architecture Model is 166 described with a single term. The iSCSI terms and SAM terms are 167 not necessarily equivalent, but rather, the iSCSI terms represent 168 examples of the objects or classes described in SAM as follows: 170 Internet-Draft iSCSI SAM March 11 172 +-----------------------------+---------------------------+ 173 | RFCxxx Terminology | SAM Terminology | 174 +-----------------------------+---------------------------+ 175 | Network Entity | none | 176 +-----------------------------+---------------------------+ 177 | iSCSI Node | SCSI Device | 178 +-----------------------------+---------------------------+ 179 | iSCSI Name | SCSI Device Name | 180 +-----------------------------+---------------------------+ 181 | iSCSI Node Name | SCSI Device Name | 182 +-----------------------------+---------------------------+ 183 | iSCSI Initiator Node | SCSI Initiator Device | 184 +-----------------------------+---------------------------+ 185 | iSCSI Initiator Name | SCSI Device Name | 186 +-----------------------------+---------------------------+ 187 | iSCSI Initiator Port Name | SCSI Initiator Port Name | 188 | iSCSI Node Name + ',i,' + | | 189 | ISID | | 190 +-----------------------------+---------------------------+ 191 | iSCSI Target Node | SCSI Target Device | 192 +-----------------------------+---------------------------+ 193 | iSCSI Target Name | SCSI Device Name | 194 +-----------------------------+---------------------------+ 195 | iSCSI Target Port Name | SCSI Target Port Name | 196 | iSCSI Node Name + ',t,' + | | 197 | Target Portal Group Tag | | 198 +-----------------------------+---------------------------+ 199 | iSCSI Target Portal Group | SCSI Target Port | 200 +-----------------------------+---------------------------+ 201 | iSCSI Initiator Node + | SCSI Initiator Port | 202 | active ISID | | 203 +-----------------------------+---------------------------+ 204 | iSCSI Initiator Name + | I_T Nexus | 205 | ',i,' + ISID, iSCSI Target | | 206 | Name + ',t,' + Portal | | 207 | Group Tag | | 208 +-----------------------------+---------------------------+ 209 | Target Portal Group Tag | Relative Port ID | 210 +-----------------------------+---------------------------+ 212 ----------------------------------------------------------- 213 RFC EDITORS NOTE: The above reference (in row 1) to [RFCxxx] 214 should reference this RFC, and this note should be removed. 215 ----------------------------------------------------------- 216 Internet-Draft iSCSI SAM March 11 218 The following diagram shows an example of a combination target 219 device and initiator device. Such a configuration may exist in a 220 target device that implements a SCSI Copy Manager. This example 221 shows how a session that shares Network Portals within a Portal 222 Group may be established (see Target Portal Group 1). In 223 addition, this example shows the Initiator using a different 224 Portal Group than the Target Portal Group, but the Initiator 225 Portal group sharing Network Portal A with the Target Portal 226 Group. 228 ----------------------------IP Network--------------------- 229 | | | 230 +----|---------------|-------+ +----|------------+ 231 | +----------+ +----------+ | | +----------+ | 232 | | Network | | Network | | | | Network | | 233 | | Portal A | | Portal B | | | | Portal A | | 234 | +----------+ +----------+ | | +----------+ | 235 | | Target | | | | Initiator | 236 | | Portal | | | | Portal | 237 | | Group 1 | | | | Group 2 | 238 +----|---------------|-------+ +----|------------+ 239 | | | 240 +----------|---------------|--------------------|--------------------+ 241 | +--------|---------------|----+ +-------------|------------------+ | 242 | |+-------|---------------|---+| |+------------|-----------------+| | 243 | ||iSCSI Session (Target side)|| ||iSCSI Session (Initiator side)|| | 244 | || || || || | 245 | || (TSIH = 56) || || (SSID = 48) || | 246 | |+---------------------------+| |+------------------------------+| | 247 | | | | | | 248 | | iSCSI Target Node | | iSCSI Initiator Node | | 249 | +-----------------------------+ +--------------------------------+ | 250 | iSCSI Node | 251 | (within Network Entity, not shown) | 252 +--------------------------------------------------------------------+ 253 Internet-Draft iSCSI SAM March 11 255 4. Negotiation of New Feature Use 257 The iSCSIProtocolLevel operational text key (see 7.1.1) 258 containing a value of "2" or higher MUST be negotiated to enable 259 the use of features described in this RFC. 261 Note that an operational value of "2" or higher for this key on 262 an iSCSI session does not influence the SCSI level features in 263 any way on that I_T nexus. An operational value of "2" or higher 264 for this key permits the iSCSI-related features defined in this 265 document to be used on all connections on this iSCSI session. 266 SCSI level hand-shakes (e.g. commands, mode pages) eventually 267 determine the existence or lack of various SAM features available 268 for the I_T nexus between the two SCSI end points). To 269 summarize, negotiation of this key to "2" or higher is a 270 necessary but not a sufficient condition of SAM-4 compliant 271 feature usage at the SCSI protocol level. 273 For example, an iSCSI implementation may negotiate this new key 274 to "2" but respond to the new task management functions (see 6.2) 275 with a "Task management function not supported" (which indicates 276 a SCSI error that prevents the function from being performed). 277 In contrast, if the key is negotiated to "2", an iSCSI 278 implementation MUST NOT reject a task management function request 279 PDU that requests one of the new task management functions (such 280 a reject would report an iSCSI protocol error). 282 Internet-Draft iSCSI SAM March 11 284 5. SCSI Commands 286 5.1 SCSI Command Additions 288 The format of the SCSI Command PDU is: 290 Byte/ 0 | 1 | 2 | 3 | 291 / | | | | 292 |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| 293 +---------------+---------------+---------------+---------------+ 294 0|.|I| 0x01 |F|R|W|. .|ATTR | PRI | Reserved | 295 +---------------+---------------+---------------+---------------+ 296 4|TotalAHSLength | DataSegmentLength | 297 +---------------+---------------+---------------+---------------+ 298 8| Logical Unit Number (LUN) | 299 + + 300 12| | 301 +---------------+---------------+---------------+---------------+ 302 16| Initiator Task Tag | 303 +---------------+---------------+---------------+---------------+ 304 20| Expected Data Transfer Length | 305 +---------------+---------------+---------------+---------------+ 306 24| CmdSN | 307 +---------------+---------------+---------------+---------------+ 308 28| ExpStatSN | 309 +---------------+---------------+---------------+---------------+ 310 32/ SCSI Command Descriptor Block (CDB) / 311 +/ / 312 +---------------+---------------+---------------+---------------+ 313 48/ AHS (Optional) / 314 +---------------+---------------+---------------+---------------+ 315 x/ Header Digest (Optional) / 316 +---------------+---------------+---------------+---------------+ 317 y/ (DataSegment, Command Data) (Optional) / 318 +/ / 319 +---------------+---------------+---------------+---------------+ 320 z/ Data Digest (Optional) / 321 +---------------+---------------+---------------+---------------+ 323 5.1.1 Command Priority (byte 2) 325 The Command Priority (PRI) specifies the relative scheduling 326 importance of this task in relation to other SIMPLE tasks already 327 in the task set (see [SAM4]). 329 Section 10, iSCSI PDU Formats of [RFC3720], requires that senders 330 set this field to zero. A sender MUST NOT set this field to a 331 value other than zero unless the iSCSIProtocolLevel text key 332 Internet-Draft iSCSI SAM March 11 334 defined in section Error! Reference source not found. has been 335 negotiated on the session with a value of "2" or higher. 337 This field MUST be ignored by iSCSI targets unless the 338 iSCSIProtocolLevel text key with a value of "2" or higher as 339 defined in section Error! Reference source not found. was 340 negotiated on the session. 342 5.2 SCSI Response Additions 344 The format of the SCSI Response PDU is: 346 Byte/ 0 | 1 | 2 | 3 | 347 / | | | | 348 |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| 349 +---------------+---------------+---------------+---------------+ 350 0|.|.| 0x21 |1|. .|o|u|O|U|.| Response | Status | 351 +---------------+---------------+---------------+---------------+ 352 4|TotalAHSLength | DataSegmentLength | 353 +---------------+---------------+---------------+---------------+ 354 8| Status Qualifier | Reserved | 355 +---------------+---------------+---------------+---------------+ 356 12| Reserved | 357 +---------------+---------------+---------------+---------------+ 358 16| Initiator Task Tag | 359 +---------------+---------------+---------------+---------------+ 360 20| SNACK Tag or Reserved | 361 +---------------+---------------+---------------+---------------+ 362 24| StatSN | 363 +---------------+---------------+---------------+---------------+ 364 28| ExpCmdSN | 365 +---------------+---------------+---------------+---------------+ 366 32| MaxCmdSN | 367 +---------------+---------------+---------------+---------------+ 368 36| ExpDataSN or Reserved | 369 +---------------+---------------+---------------+---------------+ 370 40| Bidirectional Read Residual Count or Reserved | 371 +---------------+---------------+---------------+---------------+ 372 44| Residual Count or Reserved | 373 +---------------+---------------+---------------+---------------+ 374 48| Header-Digest (Optional) | 375 +---------------+---------------+---------------+---------------+ 376 / Data Segment (Optional) / 377 +/ / 378 +---------------+---------------+---------------+---------------+ 379 | Data-Digest (Optional) | 380 +---------------+---------------+---------------+---------------+ 381 Internet-Draft iSCSI SAM March 11 383 5.2.1 Status Qualifier 385 The Status Qualifier provides additional status information (see 386 [SAM4]). 388 As defined in Section 10, iSCSI PDU Formats of [RFC3720], 389 compliant senders already set this field to zero. Compliant 390 senders MUST NOT set this field to a value other than zero unless 391 the iSCSIProtocolLevel text key with a value of "2" or higher as 392 defined in section 7.1.1. was negotiated on the session. 394 This field MUST be ignored by receivers unless the 395 iSCSIProtocolLevel text key with a value of "2" or higher as 396 defined in section 7.1.1. was negotiated on the session. 398 5.2.2 Data Segment - Sense and Response Data Segment 400 Section 10.4.7 of [RFC3720] specifies that iSCSI targets MUST 401 support and enable autosense. If Status is CHECK CONDITION 402 (0x02), then the Data Segment MUST contain sense data for the 403 failed command. While [RFC3720] does not make any statements 404 about the state of the Data Segment when the Status is not CHECK 405 CONDITION (0x02)(i.e., the Data Segment is not prohibited from 406 containing sense data when the Status is not CHECK CONDITION), 407 negotiation of the iSCSIProtocolLevel text key with a value of 408 "2" or higher as defined in section Error! Reference source not 409 found. explicitly indicates that the Data Segment MAY contain 410 sense data at any time, no matter what value is set in the Status 411 field. 413 6. Task Management Functions 415 6.1 Existing Task Management Functions 417 Section 10.5 of [RFC3720] defines the semantics used to request 418 SCSI Task Management Functions be performed. The following task 419 management functions are defined: 421 1 - ABORT TASK 422 2 - ABORT TASK SET 423 3 - CLEAR ACA 424 4 - CLEAR TASK SET 425 5 - LOGICAL UNIT RESET 426 6 - TARGET WARM RESET 427 7 - TARGET COLD RESET 428 8 - TASK REASSIGN 429 Internet-Draft iSCSI SAM March 11 431 6.2 Task Management Function Additions 433 Additional task Management function codes are listed below. For 434 a more detailed description of SCSI task management, see [SAM5]. 436 9 - QUERY TASK - determines if the task identified by the 437 Referenced Task Tag field is present in the task set. 439 10 - QUERY TASK SET - determine if any task is present in the 440 task set. 442 11 - I_T NEXUS RESET - perform an I_T nexus loss function for 443 the I_T nexus of each logical unit accessible through the I_T 444 Nexus on which the task management function was received. 446 12 - QUERY ASYNCHRONOUS EVENT - determine if there is a unit 447 attention condition or a deferred error pending for the I_T_L 448 nexus on which the task management function was received. 450 These task management function requests MUST NOT be sent unless 451 the iSCSIProtocolLevel text key with a value of "2" or higher as 452 defined in section 7.1.1. was negotiated on the session. 454 Any compliant initiator that sends any of the new task management 455 functions defined in this section MUST also support all new task 456 management function responses (see 6.3.1). 458 For all of the task management functions detailed in this 459 section, the Task Management function response MUST be returned 460 as detailed in section 6.3 Task Management Function Response. 462 The iSCSI target MUST ensure that no responses for the tasks 463 covered by a task management function are sent to the iSCSI 464 initiator after the Task Management response except for a task 465 covered by a TASK REASSIGN, QUERY TASK, or QUERY TASK SET. 467 If a QUERY TASK is issued for a task created by an immediate 468 command then RefCmdSN MUST be that of the Task Management request 469 itself (i.e., CmdSN and RefCmdSN are equal); otherwise RefCmdSN 470 MUST be set to the CmdSN of the task to be queried (lower than 471 CmdSN). 473 At the target a QUERY TASK function MUST NOT be executed on a 474 Task Management request; such a request MUST result in Task 475 Management response of "Function rejected". 477 For the I_T NEXUS RESET function, the target device MUST respond 478 to the function as defined in [SAM4]. Each logical unit 479 accessible via the receiving I_T NEXUS MUST behave as dictated by 480 Internet-Draft iSCSI SAM March 11 482 the I_T nexus loss function in [SAM4] for the I_T nexus on which 483 the task management function was received. The target device 484 MUST drop all connections in the session over which this function 485 is recevied. Independent of the DefaultTime2Wait and 486 DefaultTime2Retain value applicable to the session over which 487 this function is received, the target device MUST consider each 488 participating connection in the session to have immediately timed 489 out, leading to FREE state. The resulting timeouts cause the 490 session timeout event defined in [RFC3720], which in turn 491 triggers the I_T nexus loss notification to the SCSI layer as 492 described in [RFC3720]. 494 6.2.1 LUN field 496 This field is required for functions that address a specific LU 497 (i.e., ABORT TASK, CLEAR TASK SET, ABORT TASK SET, CLEAR ACA, 498 LOGICAL UNIT RESET, QUERY TASK, QUERY TASK SET, and QUERY 499 ASYNCHRONOUS EVENT) and is reserved in all others. 501 6.2.2 Referenced Task Tag 503 The Initiator Task Tag of the task to be aborted for the ABORT 504 TASK function, reassigned for the TASK REASSIGN function, or 505 queried for the QUERY TASK function. For all other functions 506 this field MUST be set to the reserved value 0xffffffff. 508 6.2.3 RefCmdSN 510 If a QUERY TASK is issued for a task created by an immediate 511 command then RefCmdSN MUST be that of the Task Management request 512 itself (i.e., CmdSN and RefCmdSN are equal). 514 For a QUERY TASK of a task created by non-immediate command 515 RefCmdSN MUST be set to the CmdSN of the task identified by the 516 Referenced Task Tag field. Targets must use this field as 517 described in section 10.6.1 of [RFC3720] when the task identified 518 by the Referenced Task Tag field is not in the task set. 520 Internet-Draft iSCSI SAM March 11 522 6.3 Task Management Function Responses 524 Byte/ 0 | 1 | 2 | 3 | 525 / | | | | 526 |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| 527 +---------------+---------------+---------------+---------------+ 528 0|.|.| 0x22 |1| Reserved | Response | Reserved | 529 +---------------+---------------+---------------+---------------+ 530 4|TotalAHSLength | DataSegmentLength | 531 +-----------------------------------------------+---------------+ 532 8| Additional Response Information | Reserved | 533 +-----------------------------------------------+---------------+ 534 12| Reserved | 535 +---------------+---------------+---------------+---------------+ 536 16| Initiator Task Tag | 537 +---------------+---------------+---------------+---------------+ 538 20| Reserved | 539 +---------------+---------------+---------------+---------------+ 540 24| StatSN | 541 +---------------+---------------+---------------+---------------+ 542 28| ExpCmdSN | 543 +---------------+---------------+---------------+---------------+ 544 32| MaxCmdSN | 545 +---------------+---------------+---------------+---------------+ 546 36/ Reserved / 547 +/ / 548 +---------------+---------------+---------------+---------------+ 549 48| Header-Digest (Optional) | 550 +---------------+---------------+---------------+---------------+ 552 Section 10.6 of [RFC3720] defines the semantics used for 553 responses to SCSI Task Management Functions. The following 554 responses are defined in [RFC3720]: 556 0 - Function Complete. 557 1 - Task does not exist. 558 2 - LUN does not exist. 559 3 - Task still allegiant. 560 4 - Task allegiance reassignment not supported. 561 5 - Task management function not supported. 562 6 - Function authorization failed. 563 255 - Function rejected. 565 Responses to new task management functions (see 6.3.1) are listed 566 below. In addition, a new task Management response is listed 567 below. For a more detailed description of SCSI task management 568 responses, see [SAM5]. 570 Internet-Draft iSCSI SAM March 11 572 For the functions QUERY TASK, QUERY TASK SET, I_T NEXUS RESET, 573 and QUERY ASYNCHRONOUS EVENT, the target performs the requested 574 Task Management function and sends a Task Management response 575 back to the initiator. 577 6.3.1 Task Management Function Response Additions 579 The new response is listed below: 581 7 - Function succeeded. 583 In symbolic terms Response value 7 maps to the SCSI service 584 response of FUNCTION SUCCEEDED. 586 The task management function response of function succeeded MUST 587 be supported by an initiator that sends any of the new task 588 management functions (see 6.2). 590 For the QUERY TASK function, if the specified task is in the task 591 set, then the target returns a Response value of Function 592 succeeded and additional response information is returned as 593 specified in [SAM5]. If the specified task is not in the task 594 set, then the target returns a Response value of Function 595 complete. 597 For the QUERY TASK SET function, if there is any command present 598 in the task set from the specified I_T_L nexus, then the target 599 returns a Response value of Function succeeded. If there are no 600 commands present in the task set from the specified I_T_L nexus, 601 then the target returns a Response value of Function complete. 603 For the I_T NEXUS RESET function, after completion of the events 604 described in section 6.2 for this function, the target returns a 605 Response value of Function complete. However, because the target 606 drops all connections, the Service Response (defined by [SAM4]) 607 for this SCSI task management function may not be reliably 608 delivered to the issuing initiator port. 610 For the QUERY ASYNCHRONOUS EVENT, if there is a unit attention 611 condition or deferred error pending for the specified I_T_L 612 nexus, then the target returns a Response value of Function 613 succeeded and additional response information is returned as 614 specified in [SAM5]. If there is no unit attention or deferred 615 error pending for the specified I_T_L nexus then the target 616 returns a Response value of Function complete. 618 6.4 Task Management Requests Affecting Multiple Tasks 620 Section 4.1 of [RFC5048] defines the notion of "affected tasks" 621 in multi-task abort scenarios. This section adds to the list 622 Internet-Draft iSCSI SAM March 11 624 include in that section by defining the tasks affected by the I_T 625 NEXUS RESET function. 627 I_T NEXUS RESET: All outstanding tasks received on the I_T 628 nexus on which the function request was received for all 629 logical units accessible to the I_T nexus. 631 Section 4.1.2 of [RFC5048] and section 4.1.3 of [RFC5048] 632 identify semantics for task management functions that involve 633 multi-task abort operations. If an iSCSI implementation supports 634 the I_T NEXUS RESET function, it MUST also support the protocol 635 behavior as defined in those sections and follow the sequence of 636 actions as described in those sections when processing the I_T 637 NEXUS RESET function. 639 7. Login/Text Operational Text Keys 641 7.1 New Operational Text Keys 643 7.1.1 iSCSIProtocolLevel 645 Use: LO 646 Irrelevant when: SessionType = Discovery 647 Senders: Initiator and Target 648 Scope: SW 650 iSCSIProtocolLevel= 652 Default is 1. 653 Result function is Minimum. 655 This key is used to negotiate the use of iSCSI features that 656 require different levels of protocol support for proper 657 operation. This key is negotiated on the iSCSI session once the 658 session is in full feature phase. 660 Negotiation of the iSCSIProtocolLevel key to a value claimed by 661 an RFC indicates that both negotiating parties are compliant to 662 the RFC in question, and agree to support the corresponding 663 semantics on that iSCSI session. An operational value of iSCSI 664 ProtocolLevel = "x" on an iSCSI session requires that the iSCSI 665 protocol semantics on that iSCSI session be a logical superset of 666 the capabilities in all RFCs that have claimed values of an 667 iSCSIProtocolLevel less than "x". 669 An iSCSIProtocolLevel key negotiated to "2" or higher is required 670 to enable use of features defined in this RFC. 672 If the negotiation answer is ignored by the acceptor, or the 673 answer from the remote iSCSI end point is key=NotUnderstood, then 674 Internet-Draft iSCSI SAM March 11 676 the features defined in this RFC, and the features defined in any 677 RFC requiring a key value greater than "2" MUST NOT be used. 679 8. Security Considerations 681 At the time of writing this document does not introduce any new 682 security considerations other than those described in [RFC3720]. 683 Consequently, all the iSCSI-related security text in [RFC3723] is 684 also directly applicable to this document. 686 9. IANA Considerations 688 This document modifies or creates a number of iSCSI-related 689 registries. The following iSCSI-related registries are modified: 691 1. iSCSI Task Management Functions Codes 693 Name of the existing registry: "iSCSI TMF Codes" 695 Additional entries: 697 9, QUERY TASK, [RFCxxx] 699 10, QUERY TASK SET, [RFCxxx] 701 11, I_T NEXUS RESET, [RFCxxx] 703 12, QUERY ASYNCHRONOUS EVENT, [RFCxxx] 705 --------------------------------------------------------- 706 RFC EDITORS NOTE: The above reference to [RFCxxx] should 707 reference this RFC, and this note should be removed. 708 --------------------------------------------------------- 710 2. iSCSI Login/Text Keys 712 Name of the existing registry: "iSCSI Text Keys" 714 Additional entry: 716 iSCSIProtocolLevel = "2", [RFCxxx] 717 --------------------------------------------------------- 718 RFC EDITORS NOTE: The above references to [RFCxxx] should 719 reference this RFC, and this note should be removed. 720 --------------------------------------------------------- 722 This document creates the following iSCSI-related registries for 723 IANA to manage. 725 3. iSCSI Task Management Response Codes 726 Internet-Draft iSCSI SAM March 11 728 Name of new registry: "iSCSI TMF Response Codes" 730 Namespace details: Numerical values that can fit in 8 bits. 732 Information that must be provided to assign a new value: An 733 IESG-approved specification defining the semantics and 734 interoperability requirements of the proposed new value and 735 the fields to be recorded in the registry. 737 Assignment policy: 739 If the requested value is not already assigned, it may be 740 assigned to the requester. 742 8-254: Range reserved by iANA for assignment in this registry. 744 Fields to record in the registry: Assigned value, Operation 745 Name, and its associated RFC reference. 747 0x0, Function complete, [RFC3720] 749 0x1, Task does not exist, [RFC3720] 751 0x2, LUN does not exist, [RFC3720] 753 0x3, Task still allegiant, [RFC3720] 755 0x4, Task allegiance reassignment not supported, [RFC3720] 757 0x5, Task management function not supported, [RFC3720] 759 0x6, Function authorization failed, [RFC3720] 761 0x7, Function succeeded, [RFCxxx] 763 255, Function rejected, [RFC3720] 765 ------------------------------------------------------------ 766 RFC EDITORS NOTE: The above reference to [RFCxxx] should 767 reference this RFC, and this note should be removed. 768 ------------------------------------------------------------ 770 Allocation Policy: 772 Standards Action ([IANA]) 774 10. References 776 10.1 Normative References 777 Internet-Draft iSCSI SAM March 11 779 [RFC2119] Bradner, S. "Key Words for use in RFCs to Indicate 780 Requirement Levels", BCP 14, RFC 2119, March 1997. 782 [RFC3720] Satran, J., Meth, K., Sapuntzakis, C., Chadalapaka, 783 M., and E. Zeidner, "Internet Small Computer Systems 784 Interface (iSCSI)", RFC 3720, April 2004. 786 [RFC3723] Aboba, B., Tseng, J., Walker, J., Rangan, V., and 787 Travostino, F., "Securing Block Storage Protocols 788 over IP", RFC 3723, April 2004. 790 [RFC5048] Chadalapaka, M., "Internet Small Computer System 791 Interface (iSCSI) Corrections and Clarifications", 792 RFC 5048, October 2007. 794 [IANA] Narten, T. and H. Alvestrand, "Guidelines for Writing 795 an IANA Considerations Section in RFCs", BCP 26, RFC 796 5226,May 2008. 798 [SAM2] T10/1157D, SCSI Architecture Model - 2 (SAM-2). 800 [SAM4] ISO/IEC 14776-414, SCSI Architecture Model - 4 (SAM- 801 4). 803 [SAM5] T10/2104D rev r05, SCSI Architecture Model - 5 (SAM- 804 5), Committee Draft. 806 10.2 Additional Reference Sources 808 For more information on the SCSI Architecture Model, contact the 809 T10 group at http://www.t10.org. 811 11. Acknowledgements 813 The Storage Maintenance (STORM) Working Group in the Transport 814 Area of the IETF has been responsible for defining these 815 additions to the iSCSI protocol (apart from other relevant IP 816 Storage protocols). The editor acknowledges the contributions of 817 the entire working group. 819 The following individuals directly contributed to identifying 820 [RFCxxx] issues and/or suggesting resolutions to the issues 821 clarified in this document: David Black, Rob Elliott. This 822 document benefited from all of these contributions. 824 ------------------------------------------------------------ 825 RFC EDITORS NOTE: The above reference to [RFCxxx] should 826 reference this RFC, and this note should be removed. 827 ------------------------------------------------------------ 828 Internet-Draft iSCSI SAM March 11 830 Editor's Addresses 831 Frederick Knight 832 7301 Kit Creek Road 833 P.O. Box 13917 834 Research Triangle Park, NC 27709, USA 835 Phone: +1-919-476-5362 836 Email: knight@netapp.com 838 Mallikarjun Chadalapaka 839 Hewlett-Packard Company 840 8000 Foothills Blvd. 841 Roseville, CA 95747-5668, USA 842 Phone: +1-916-785-5621 843 EMail: cbm@rose.hp.com