1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SCSI Primary Commands (SPC) parsing and emulation.
4  *
5  * (c) Copyright 2002-2013 Datera, Inc.
6  *
7  * Nicholas A. Bellinger <nab@kernel.org>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <asm/unaligned.h>
13 
14 #include <scsi/scsi_proto.h>
15 #include <scsi/scsi_common.h>
16 #include <scsi/scsi_tcq.h>
17 
18 #include <target/target_core_base.h>
19 #include <target/target_core_backend.h>
20 #include <target/target_core_fabric.h>
21 
22 #include "target_core_internal.h"
23 #include "target_core_alua.h"
24 #include "target_core_pr.h"
25 #include "target_core_ua.h"
26 #include "target_core_xcopy.h"
27 
28 static void spc_fill_alua_data(struct se_lun *lun, unsigned char *buf)
29 {
30 	struct t10_alua_tg_pt_gp *tg_pt_gp;
31 
32 	/*
33 	 * Set SCCS for MAINTENANCE_IN + REPORT_TARGET_PORT_GROUPS.
34 	 */
35 	buf[5]	= 0x80;
36 
37 	/*
38 	 * Set TPGS field for explicit and/or implicit ALUA access type
39 	 * and opteration.
40 	 *
41 	 * See spc4r17 section 6.4.2 Table 135
42 	 */
43 	rcu_read_lock();
44 	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
45 	if (tg_pt_gp)
46 		buf[5] |= tg_pt_gp->tg_pt_gp_alua_access_type;
47 	rcu_read_unlock();
48 }
49 
50 static u16
51 spc_find_scsi_transport_vd(int proto_id)
52 {
53 	switch (proto_id) {
54 	case SCSI_PROTOCOL_FCP:
55 		return SCSI_VERSION_DESCRIPTOR_FCP4;
56 	case SCSI_PROTOCOL_ISCSI:
57 		return SCSI_VERSION_DESCRIPTOR_ISCSI;
58 	case SCSI_PROTOCOL_SAS:
59 		return SCSI_VERSION_DESCRIPTOR_SAS3;
60 	case SCSI_PROTOCOL_SBP:
61 		return SCSI_VERSION_DESCRIPTOR_SBP3;
62 	case SCSI_PROTOCOL_SRP:
63 		return SCSI_VERSION_DESCRIPTOR_SRP;
64 	default:
65 		pr_warn("Cannot find VERSION DESCRIPTOR value for unknown SCSI"
66 			" transport PROTOCOL IDENTIFIER %#x\n", proto_id);
67 		return 0;
68 	}
69 }
70 
71 sense_reason_t
72 spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
73 {
74 	struct se_lun *lun = cmd->se_lun;
75 	struct se_portal_group *tpg = lun->lun_tpg;
76 	struct se_device *dev = cmd->se_dev;
77 	struct se_session *sess = cmd->se_sess;
78 
79 	/* Set RMB (removable media) for tape devices */
80 	if (dev->transport->get_device_type(dev) == TYPE_TAPE)
81 		buf[1] = 0x80;
82 
83 	buf[2] = 0x06; /* SPC-4 */
84 
85 	/*
86 	 * NORMACA and HISUP = 0, RESPONSE DATA FORMAT = 2
87 	 *
88 	 * SPC4 says:
89 	 *   A RESPONSE DATA FORMAT field set to 2h indicates that the
90 	 *   standard INQUIRY data is in the format defined in this
91 	 *   standard. Response data format values less than 2h are
92 	 *   obsolete. Response data format values greater than 2h are
93 	 *   reserved.
94 	 */
95 	buf[3] = 2;
96 
97 	/*
98 	 * Enable SCCS and TPGS fields for Emulated ALUA
99 	 */
100 	spc_fill_alua_data(lun, buf);
101 
102 	/*
103 	 * Set Third-Party Copy (3PC) bit to indicate support for EXTENDED_COPY
104 	 */
105 	if (dev->dev_attrib.emulate_3pc)
106 		buf[5] |= 0x8;
107 	/*
108 	 * Set Protection (PROTECT) bit when DIF has been enabled on the
109 	 * device, and the fabric supports VERIFY + PASS.  Also report
110 	 * PROTECT=1 if sess_prot_type has been configured to allow T10-PI
111 	 * to unprotected devices.
112 	 */
113 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
114 		if (dev->dev_attrib.pi_prot_type || cmd->se_sess->sess_prot_type)
115 			buf[5] |= 0x1;
116 	}
117 
118 	buf[7] = 0x2; /* CmdQue=1 */
119 
120 	/*
121 	 * ASCII data fields described as being left-aligned shall have any
122 	 * unused bytes at the end of the field (i.e., highest offset) and the
123 	 * unused bytes shall be filled with ASCII space characters (20h).
124 	 */
125 	memset(&buf[8], 0x20,
126 	       INQUIRY_VENDOR_LEN + INQUIRY_MODEL_LEN + INQUIRY_REVISION_LEN);
127 	memcpy(&buf[8], dev->t10_wwn.vendor,
128 	       strnlen(dev->t10_wwn.vendor, INQUIRY_VENDOR_LEN));
129 	memcpy(&buf[16], dev->t10_wwn.model,
130 	       strnlen(dev->t10_wwn.model, INQUIRY_MODEL_LEN));
131 	memcpy(&buf[32], dev->t10_wwn.revision,
132 	       strnlen(dev->t10_wwn.revision, INQUIRY_REVISION_LEN));
133 
134 	/*
135 	 * Set the VERSION DESCRIPTOR fields
136 	 */
137 	put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SAM5, &buf[58]);
138 	put_unaligned_be16(spc_find_scsi_transport_vd(tpg->proto_id), &buf[60]);
139 	put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SPC4, &buf[62]);
140 	if (cmd->se_dev->transport->get_device_type(dev) == TYPE_DISK)
141 		put_unaligned_be16(SCSI_VERSION_DESCRIPTOR_SBC3, &buf[64]);
142 
143 	buf[4] = 91; /* Set additional length to 91 */
144 
145 	return 0;
146 }
147 EXPORT_SYMBOL(spc_emulate_inquiry_std);
148 
149 /* unit serial number */
150 static sense_reason_t
151 spc_emulate_evpd_80(struct se_cmd *cmd, unsigned char *buf)
152 {
153 	struct se_device *dev = cmd->se_dev;
154 	u16 len;
155 
156 	if (dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL) {
157 		len = sprintf(&buf[4], "%s", dev->t10_wwn.unit_serial);
158 		len++; /* Extra Byte for NULL Terminator */
159 		buf[3] = len;
160 	}
161 	return 0;
162 }
163 
164 /*
165  * Generate NAA IEEE Registered Extended designator
166  */
167 void spc_gen_naa_6h_vendor_specific(struct se_device *dev,
168 				    unsigned char *buf)
169 {
170 	unsigned char *p = &dev->t10_wwn.unit_serial[0];
171 	u32 company_id = dev->t10_wwn.company_id;
172 	int cnt, off = 0;
173 	bool next = true;
174 
175 	/*
176 	 * Start NAA IEEE Registered Extended Identifier/Designator
177 	 */
178 	buf[off] = 0x6 << 4;
179 
180 	/* IEEE COMPANY_ID */
181 	buf[off++] |= (company_id >> 20) & 0xf;
182 	buf[off++] = (company_id >> 12) & 0xff;
183 	buf[off++] = (company_id >> 4) & 0xff;
184 	buf[off] = (company_id & 0xf) << 4;
185 
186 	/*
187 	 * Generate up to 36 bits of VENDOR SPECIFIC IDENTIFIER starting on
188 	 * byte 3 bit 3-0 for NAA IEEE Registered Extended DESIGNATOR field
189 	 * format, followed by 64 bits of VENDOR SPECIFIC IDENTIFIER EXTENSION
190 	 * to complete the payload.  These are based from VPD=0x80 PRODUCT SERIAL
191 	 * NUMBER set via vpd_unit_serial in target_core_configfs.c to ensure
192 	 * per device uniqeness.
193 	 */
194 	for (cnt = off + 13; *p && off < cnt; p++) {
195 		int val = hex_to_bin(*p);
196 
197 		if (val < 0)
198 			continue;
199 
200 		if (next) {
201 			next = false;
202 			buf[off++] |= val;
203 		} else {
204 			next = true;
205 			buf[off] = val << 4;
206 		}
207 	}
208 }
209 
210 /*
211  * Device identification VPD, for a complete list of
212  * DESIGNATOR TYPEs see spc4r17 Table 459.
213  */
214 sense_reason_t
215 spc_emulate_evpd_83(struct se_cmd *cmd, unsigned char *buf)
216 {
217 	struct se_device *dev = cmd->se_dev;
218 	struct se_lun *lun = cmd->se_lun;
219 	struct se_portal_group *tpg = NULL;
220 	struct t10_alua_lu_gp_member *lu_gp_mem;
221 	struct t10_alua_tg_pt_gp *tg_pt_gp;
222 	unsigned char *prod = &dev->t10_wwn.model[0];
223 	u32 prod_len;
224 	u32 unit_serial_len, off = 0;
225 	u16 len = 0, id_len;
226 
227 	off = 4;
228 
229 	/*
230 	 * NAA IEEE Registered Extended Assigned designator format, see
231 	 * spc4r17 section 7.7.3.6.5
232 	 *
233 	 * We depend upon a target_core_mod/ConfigFS provided
234 	 * /sys/kernel/config/target/core/$HBA/$DEV/wwn/vpd_unit_serial
235 	 * value in order to return the NAA id.
236 	 */
237 	if (!(dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL))
238 		goto check_t10_vend_desc;
239 
240 	/* CODE SET == Binary */
241 	buf[off++] = 0x1;
242 
243 	/* Set ASSOCIATION == addressed logical unit: 0)b */
244 	buf[off] = 0x00;
245 
246 	/* Identifier/Designator type == NAA identifier */
247 	buf[off++] |= 0x3;
248 	off++;
249 
250 	/* Identifier/Designator length */
251 	buf[off++] = 0x10;
252 
253 	/* NAA IEEE Registered Extended designator */
254 	spc_gen_naa_6h_vendor_specific(dev, &buf[off]);
255 
256 	len = 20;
257 	off = (len + 4);
258 
259 check_t10_vend_desc:
260 	/*
261 	 * T10 Vendor Identifier Page, see spc4r17 section 7.7.3.4
262 	 */
263 	id_len = 8; /* For Vendor field */
264 	prod_len = 4; /* For VPD Header */
265 	prod_len += 8; /* For Vendor field */
266 	prod_len += strlen(prod);
267 	prod_len++; /* For : */
268 
269 	if (dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL) {
270 		unit_serial_len = strlen(&dev->t10_wwn.unit_serial[0]);
271 		unit_serial_len++; /* For NULL Terminator */
272 
273 		id_len += sprintf(&buf[off+12], "%s:%s", prod,
274 				&dev->t10_wwn.unit_serial[0]);
275 	}
276 	buf[off] = 0x2; /* ASCII */
277 	buf[off+1] = 0x1; /* T10 Vendor ID */
278 	buf[off+2] = 0x0;
279 	/* left align Vendor ID and pad with spaces */
280 	memset(&buf[off+4], 0x20, INQUIRY_VENDOR_LEN);
281 	memcpy(&buf[off+4], dev->t10_wwn.vendor,
282 	       strnlen(dev->t10_wwn.vendor, INQUIRY_VENDOR_LEN));
283 	/* Extra Byte for NULL Terminator */
284 	id_len++;
285 	/* Identifier Length */
286 	buf[off+3] = id_len;
287 	/* Header size for Designation descriptor */
288 	len += (id_len + 4);
289 	off += (id_len + 4);
290 
291 	if (1) {
292 		struct t10_alua_lu_gp *lu_gp;
293 		u32 padding, scsi_name_len, scsi_target_len;
294 		u16 lu_gp_id = 0;
295 		u16 tg_pt_gp_id = 0;
296 		u16 tpgt;
297 
298 		tpg = lun->lun_tpg;
299 		/*
300 		 * Relative target port identifer, see spc4r17
301 		 * section 7.7.3.7
302 		 *
303 		 * Get the PROTOCOL IDENTIFIER as defined by spc4r17
304 		 * section 7.5.1 Table 362
305 		 */
306 		buf[off] = tpg->proto_id << 4;
307 		buf[off++] |= 0x1; /* CODE SET == Binary */
308 		buf[off] = 0x80; /* Set PIV=1 */
309 		/* Set ASSOCIATION == target port: 01b */
310 		buf[off] |= 0x10;
311 		/* DESIGNATOR TYPE == Relative target port identifer */
312 		buf[off++] |= 0x4;
313 		off++; /* Skip over Reserved */
314 		buf[off++] = 4; /* DESIGNATOR LENGTH */
315 		/* Skip over Obsolete field in RTPI payload
316 		 * in Table 472 */
317 		off += 2;
318 		put_unaligned_be16(lun->lun_rtpi, &buf[off]);
319 		off += 2;
320 		len += 8; /* Header size + Designation descriptor */
321 		/*
322 		 * Target port group identifier, see spc4r17
323 		 * section 7.7.3.8
324 		 *
325 		 * Get the PROTOCOL IDENTIFIER as defined by spc4r17
326 		 * section 7.5.1 Table 362
327 		 */
328 		rcu_read_lock();
329 		tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
330 		if (!tg_pt_gp) {
331 			rcu_read_unlock();
332 			goto check_lu_gp;
333 		}
334 		tg_pt_gp_id = tg_pt_gp->tg_pt_gp_id;
335 		rcu_read_unlock();
336 
337 		buf[off] = tpg->proto_id << 4;
338 		buf[off++] |= 0x1; /* CODE SET == Binary */
339 		buf[off] = 0x80; /* Set PIV=1 */
340 		/* Set ASSOCIATION == target port: 01b */
341 		buf[off] |= 0x10;
342 		/* DESIGNATOR TYPE == Target port group identifier */
343 		buf[off++] |= 0x5;
344 		off++; /* Skip over Reserved */
345 		buf[off++] = 4; /* DESIGNATOR LENGTH */
346 		off += 2; /* Skip over Reserved Field */
347 		put_unaligned_be16(tg_pt_gp_id, &buf[off]);
348 		off += 2;
349 		len += 8; /* Header size + Designation descriptor */
350 		/*
351 		 * Logical Unit Group identifier, see spc4r17
352 		 * section 7.7.3.8
353 		 */
354 check_lu_gp:
355 		lu_gp_mem = dev->dev_alua_lu_gp_mem;
356 		if (!lu_gp_mem)
357 			goto check_scsi_name;
358 
359 		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
360 		lu_gp = lu_gp_mem->lu_gp;
361 		if (!lu_gp) {
362 			spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
363 			goto check_scsi_name;
364 		}
365 		lu_gp_id = lu_gp->lu_gp_id;
366 		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
367 
368 		buf[off++] |= 0x1; /* CODE SET == Binary */
369 		/* DESIGNATOR TYPE == Logical Unit Group identifier */
370 		buf[off++] |= 0x6;
371 		off++; /* Skip over Reserved */
372 		buf[off++] = 4; /* DESIGNATOR LENGTH */
373 		off += 2; /* Skip over Reserved Field */
374 		put_unaligned_be16(lu_gp_id, &buf[off]);
375 		off += 2;
376 		len += 8; /* Header size + Designation descriptor */
377 		/*
378 		 * SCSI name string designator, see spc4r17
379 		 * section 7.7.3.11
380 		 *
381 		 * Get the PROTOCOL IDENTIFIER as defined by spc4r17
382 		 * section 7.5.1 Table 362
383 		 */
384 check_scsi_name:
385 		buf[off] = tpg->proto_id << 4;
386 		buf[off++] |= 0x3; /* CODE SET == UTF-8 */
387 		buf[off] = 0x80; /* Set PIV=1 */
388 		/* Set ASSOCIATION == target port: 01b */
389 		buf[off] |= 0x10;
390 		/* DESIGNATOR TYPE == SCSI name string */
391 		buf[off++] |= 0x8;
392 		off += 2; /* Skip over Reserved and length */
393 		/*
394 		 * SCSI name string identifer containing, $FABRIC_MOD
395 		 * dependent information.  For LIO-Target and iSCSI
396 		 * Target Port, this means "<iSCSI name>,t,0x<TPGT> in
397 		 * UTF-8 encoding.
398 		 */
399 		tpgt = tpg->se_tpg_tfo->tpg_get_tag(tpg);
400 		scsi_name_len = sprintf(&buf[off], "%s,t,0x%04x",
401 					tpg->se_tpg_tfo->tpg_get_wwn(tpg), tpgt);
402 		scsi_name_len += 1 /* Include  NULL terminator */;
403 		/*
404 		 * The null-terminated, null-padded (see 4.4.2) SCSI
405 		 * NAME STRING field contains a UTF-8 format string.
406 		 * The number of bytes in the SCSI NAME STRING field
407 		 * (i.e., the value in the DESIGNATOR LENGTH field)
408 		 * shall be no larger than 256 and shall be a multiple
409 		 * of four.
410 		 */
411 		padding = ((-scsi_name_len) & 3);
412 		if (padding)
413 			scsi_name_len += padding;
414 		if (scsi_name_len > 256)
415 			scsi_name_len = 256;
416 
417 		buf[off-1] = scsi_name_len;
418 		off += scsi_name_len;
419 		/* Header size + Designation descriptor */
420 		len += (scsi_name_len + 4);
421 
422 		/*
423 		 * Target device designator
424 		 */
425 		buf[off] = tpg->proto_id << 4;
426 		buf[off++] |= 0x3; /* CODE SET == UTF-8 */
427 		buf[off] = 0x80; /* Set PIV=1 */
428 		/* Set ASSOCIATION == target device: 10b */
429 		buf[off] |= 0x20;
430 		/* DESIGNATOR TYPE == SCSI name string */
431 		buf[off++] |= 0x8;
432 		off += 2; /* Skip over Reserved and length */
433 		/*
434 		 * SCSI name string identifer containing, $FABRIC_MOD
435 		 * dependent information.  For LIO-Target and iSCSI
436 		 * Target Port, this means "<iSCSI name>" in
437 		 * UTF-8 encoding.
438 		 */
439 		scsi_target_len = sprintf(&buf[off], "%s",
440 					  tpg->se_tpg_tfo->tpg_get_wwn(tpg));
441 		scsi_target_len += 1 /* Include  NULL terminator */;
442 		/*
443 		 * The null-terminated, null-padded (see 4.4.2) SCSI
444 		 * NAME STRING field contains a UTF-8 format string.
445 		 * The number of bytes in the SCSI NAME STRING field
446 		 * (i.e., the value in the DESIGNATOR LENGTH field)
447 		 * shall be no larger than 256 and shall be a multiple
448 		 * of four.
449 		 */
450 		padding = ((-scsi_target_len) & 3);
451 		if (padding)
452 			scsi_target_len += padding;
453 		if (scsi_target_len > 256)
454 			scsi_target_len = 256;
455 
456 		buf[off-1] = scsi_target_len;
457 		off += scsi_target_len;
458 
459 		/* Header size + Designation descriptor */
460 		len += (scsi_target_len + 4);
461 	}
462 	put_unaligned_be16(len, &buf[2]); /* Page Length for VPD 0x83 */
463 	return 0;
464 }
465 EXPORT_SYMBOL(spc_emulate_evpd_83);
466 
467 /* Extended INQUIRY Data VPD Page */
468 static sense_reason_t
469 spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
470 {
471 	struct se_device *dev = cmd->se_dev;
472 	struct se_session *sess = cmd->se_sess;
473 
474 	buf[3] = 0x3c;
475 	/*
476 	 * Set GRD_CHK + REF_CHK for TYPE1 protection, or GRD_CHK
477 	 * only for TYPE3 protection.
478 	 */
479 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
480 		if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT ||
481 		    cmd->se_sess->sess_prot_type == TARGET_DIF_TYPE1_PROT)
482 			buf[4] = 0x5;
483 		else if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE3_PROT ||
484 			 cmd->se_sess->sess_prot_type == TARGET_DIF_TYPE3_PROT)
485 			buf[4] = 0x4;
486 	}
487 
488 	/* logical unit supports type 1 and type 3 protection */
489 	if ((dev->transport->get_device_type(dev) == TYPE_DISK) &&
490 	    (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) &&
491 	    (dev->dev_attrib.pi_prot_type || cmd->se_sess->sess_prot_type)) {
492 		buf[4] |= (0x3 << 3);
493 	}
494 
495 	/* Set HEADSUP, ORDSUP, SIMPSUP */
496 	buf[5] = 0x07;
497 
498 	/* If WriteCache emulation is enabled, set V_SUP */
499 	if (target_check_wce(dev))
500 		buf[6] = 0x01;
501 	/* If an LBA map is present set R_SUP */
502 	spin_lock(&cmd->se_dev->t10_alua.lba_map_lock);
503 	if (!list_empty(&dev->t10_alua.lba_map_list))
504 		buf[8] = 0x10;
505 	spin_unlock(&cmd->se_dev->t10_alua.lba_map_lock);
506 	return 0;
507 }
508 
509 /* Block Limits VPD page */
510 static sense_reason_t
511 spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf)
512 {
513 	struct se_device *dev = cmd->se_dev;
514 	u32 mtl = 0;
515 	int have_tp = 0, opt, min;
516 
517 	/*
518 	 * Following spc3r22 section 6.5.3 Block Limits VPD page, when
519 	 * emulate_tpu=1 or emulate_tpws=1 we will be expect a
520 	 * different page length for Thin Provisioning.
521 	 */
522 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
523 		have_tp = 1;
524 
525 	buf[0] = dev->transport->get_device_type(dev);
526 	buf[3] = have_tp ? 0x3c : 0x10;
527 
528 	/* Set WSNZ to 1 */
529 	buf[4] = 0x01;
530 	/*
531 	 * Set MAXIMUM COMPARE AND WRITE LENGTH
532 	 */
533 	if (dev->dev_attrib.emulate_caw)
534 		buf[5] = 0x01;
535 
536 	/*
537 	 * Set OPTIMAL TRANSFER LENGTH GRANULARITY
538 	 */
539 	if (dev->transport->get_io_min && (min = dev->transport->get_io_min(dev)))
540 		put_unaligned_be16(min / dev->dev_attrib.block_size, &buf[6]);
541 	else
542 		put_unaligned_be16(1, &buf[6]);
543 
544 	/*
545 	 * Set MAXIMUM TRANSFER LENGTH
546 	 *
547 	 * XXX: Currently assumes single PAGE_SIZE per scatterlist for fabrics
548 	 * enforcing maximum HW scatter-gather-list entry limit
549 	 */
550 	if (cmd->se_tfo->max_data_sg_nents) {
551 		mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE) /
552 		       dev->dev_attrib.block_size;
553 	}
554 	put_unaligned_be32(min_not_zero(mtl, dev->dev_attrib.hw_max_sectors), &buf[8]);
555 
556 	/*
557 	 * Set OPTIMAL TRANSFER LENGTH
558 	 */
559 	if (dev->transport->get_io_opt && (opt = dev->transport->get_io_opt(dev)))
560 		put_unaligned_be32(opt / dev->dev_attrib.block_size, &buf[12]);
561 	else
562 		put_unaligned_be32(dev->dev_attrib.optimal_sectors, &buf[12]);
563 
564 	/*
565 	 * Exit now if we don't support TP.
566 	 */
567 	if (!have_tp)
568 		goto max_write_same;
569 
570 	/*
571 	 * Set MAXIMUM UNMAP LBA COUNT
572 	 */
573 	put_unaligned_be32(dev->dev_attrib.max_unmap_lba_count, &buf[20]);
574 
575 	/*
576 	 * Set MAXIMUM UNMAP BLOCK DESCRIPTOR COUNT
577 	 */
578 	put_unaligned_be32(dev->dev_attrib.max_unmap_block_desc_count,
579 			   &buf[24]);
580 
581 	/*
582 	 * Set OPTIMAL UNMAP GRANULARITY
583 	 */
584 	put_unaligned_be32(dev->dev_attrib.unmap_granularity, &buf[28]);
585 
586 	/*
587 	 * UNMAP GRANULARITY ALIGNMENT
588 	 */
589 	put_unaligned_be32(dev->dev_attrib.unmap_granularity_alignment,
590 			   &buf[32]);
591 	if (dev->dev_attrib.unmap_granularity_alignment != 0)
592 		buf[32] |= 0x80; /* Set the UGAVALID bit */
593 
594 	/*
595 	 * MAXIMUM WRITE SAME LENGTH
596 	 */
597 max_write_same:
598 	put_unaligned_be64(dev->dev_attrib.max_write_same_len, &buf[36]);
599 
600 	return 0;
601 }
602 
603 /* Block Device Characteristics VPD page */
604 static sense_reason_t
605 spc_emulate_evpd_b1(struct se_cmd *cmd, unsigned char *buf)
606 {
607 	struct se_device *dev = cmd->se_dev;
608 
609 	buf[0] = dev->transport->get_device_type(dev);
610 	buf[3] = 0x3c;
611 	buf[5] = dev->dev_attrib.is_nonrot ? 1 : 0;
612 
613 	return 0;
614 }
615 
616 /* Thin Provisioning VPD */
617 static sense_reason_t
618 spc_emulate_evpd_b2(struct se_cmd *cmd, unsigned char *buf)
619 {
620 	struct se_device *dev = cmd->se_dev;
621 
622 	/*
623 	 * From spc3r22 section 6.5.4 Thin Provisioning VPD page:
624 	 *
625 	 * The PAGE LENGTH field is defined in SPC-4. If the DP bit is set to
626 	 * zero, then the page length shall be set to 0004h.  If the DP bit
627 	 * is set to one, then the page length shall be set to the value
628 	 * defined in table 162.
629 	 */
630 	buf[0] = dev->transport->get_device_type(dev);
631 
632 	/*
633 	 * Set Hardcoded length mentioned above for DP=0
634 	 */
635 	put_unaligned_be16(0x0004, &buf[2]);
636 
637 	/*
638 	 * The THRESHOLD EXPONENT field indicates the threshold set size in
639 	 * LBAs as a power of 2 (i.e., the threshold set size is equal to
640 	 * 2(threshold exponent)).
641 	 *
642 	 * Note that this is currently set to 0x00 as mkp says it will be
643 	 * changing again.  We can enable this once it has settled in T10
644 	 * and is actually used by Linux/SCSI ML code.
645 	 */
646 	buf[4] = 0x00;
647 
648 	/*
649 	 * A TPU bit set to one indicates that the device server supports
650 	 * the UNMAP command (see 5.25). A TPU bit set to zero indicates
651 	 * that the device server does not support the UNMAP command.
652 	 */
653 	if (dev->dev_attrib.emulate_tpu != 0)
654 		buf[5] = 0x80;
655 
656 	/*
657 	 * A TPWS bit set to one indicates that the device server supports
658 	 * the use of the WRITE SAME (16) command (see 5.42) to unmap LBAs.
659 	 * A TPWS bit set to zero indicates that the device server does not
660 	 * support the use of the WRITE SAME (16) command to unmap LBAs.
661 	 */
662 	if (dev->dev_attrib.emulate_tpws != 0)
663 		buf[5] |= 0x40 | 0x20;
664 
665 	/*
666 	 * The unmap_zeroes_data set means that the underlying device supports
667 	 * REQ_OP_DISCARD and has the discard_zeroes_data bit set. This
668 	 * satisfies the SBC requirements for LBPRZ, meaning that a subsequent
669 	 * read will return zeroes after an UNMAP or WRITE SAME (16) to an LBA
670 	 * See sbc4r36 6.6.4.
671 	 */
672 	if (((dev->dev_attrib.emulate_tpu != 0) ||
673 	     (dev->dev_attrib.emulate_tpws != 0)) &&
674 	     (dev->dev_attrib.unmap_zeroes_data != 0))
675 		buf[5] |= 0x04;
676 
677 	return 0;
678 }
679 
680 /* Referrals VPD page */
681 static sense_reason_t
682 spc_emulate_evpd_b3(struct se_cmd *cmd, unsigned char *buf)
683 {
684 	struct se_device *dev = cmd->se_dev;
685 
686 	buf[0] = dev->transport->get_device_type(dev);
687 	buf[3] = 0x0c;
688 	put_unaligned_be32(dev->t10_alua.lba_map_segment_size, &buf[8]);
689 	put_unaligned_be32(dev->t10_alua.lba_map_segment_multiplier, &buf[12]);
690 
691 	return 0;
692 }
693 
694 static sense_reason_t
695 spc_emulate_evpd_00(struct se_cmd *cmd, unsigned char *buf);
696 
697 static struct {
698 	uint8_t		page;
699 	sense_reason_t	(*emulate)(struct se_cmd *, unsigned char *);
700 } evpd_handlers[] = {
701 	{ .page = 0x00, .emulate = spc_emulate_evpd_00 },
702 	{ .page = 0x80, .emulate = spc_emulate_evpd_80 },
703 	{ .page = 0x83, .emulate = spc_emulate_evpd_83 },
704 	{ .page = 0x86, .emulate = spc_emulate_evpd_86 },
705 	{ .page = 0xb0, .emulate = spc_emulate_evpd_b0 },
706 	{ .page = 0xb1, .emulate = spc_emulate_evpd_b1 },
707 	{ .page = 0xb2, .emulate = spc_emulate_evpd_b2 },
708 	{ .page = 0xb3, .emulate = spc_emulate_evpd_b3 },
709 };
710 
711 /* supported vital product data pages */
712 static sense_reason_t
713 spc_emulate_evpd_00(struct se_cmd *cmd, unsigned char *buf)
714 {
715 	int p;
716 
717 	/*
718 	 * Only report the INQUIRY EVPD=1 pages after a valid NAA
719 	 * Registered Extended LUN WWN has been set via ConfigFS
720 	 * during device creation/restart.
721 	 */
722 	if (cmd->se_dev->dev_flags & DF_EMULATED_VPD_UNIT_SERIAL) {
723 		buf[3] = ARRAY_SIZE(evpd_handlers);
724 		for (p = 0; p < ARRAY_SIZE(evpd_handlers); ++p)
725 			buf[p + 4] = evpd_handlers[p].page;
726 	}
727 
728 	return 0;
729 }
730 
731 static sense_reason_t
732 spc_emulate_inquiry(struct se_cmd *cmd)
733 {
734 	struct se_device *dev = cmd->se_dev;
735 	unsigned char *rbuf;
736 	unsigned char *cdb = cmd->t_task_cdb;
737 	unsigned char *buf;
738 	sense_reason_t ret;
739 	int p;
740 	int len = 0;
741 
742 	buf = kzalloc(SE_INQUIRY_BUF, GFP_KERNEL);
743 	if (!buf) {
744 		pr_err("Unable to allocate response buffer for INQUIRY\n");
745 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
746 	}
747 
748 	buf[0] = dev->transport->get_device_type(dev);
749 
750 	if (!(cdb[1] & 0x1)) {
751 		if (cdb[2]) {
752 			pr_err("INQUIRY with EVPD==0 but PAGE CODE=%02x\n",
753 			       cdb[2]);
754 			ret = TCM_INVALID_CDB_FIELD;
755 			goto out;
756 		}
757 
758 		ret = spc_emulate_inquiry_std(cmd, buf);
759 		len = buf[4] + 5;
760 		goto out;
761 	}
762 
763 	for (p = 0; p < ARRAY_SIZE(evpd_handlers); ++p) {
764 		if (cdb[2] == evpd_handlers[p].page) {
765 			buf[1] = cdb[2];
766 			ret = evpd_handlers[p].emulate(cmd, buf);
767 			len = get_unaligned_be16(&buf[2]) + 4;
768 			goto out;
769 		}
770 	}
771 
772 	pr_debug("Unknown VPD Code: 0x%02x\n", cdb[2]);
773 	ret = TCM_INVALID_CDB_FIELD;
774 
775 out:
776 	rbuf = transport_kmap_data_sg(cmd);
777 	if (rbuf) {
778 		memcpy(rbuf, buf, min_t(u32, SE_INQUIRY_BUF, cmd->data_length));
779 		transport_kunmap_data_sg(cmd);
780 	}
781 	kfree(buf);
782 
783 	if (!ret)
784 		target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, len);
785 	return ret;
786 }
787 
788 static int spc_modesense_rwrecovery(struct se_cmd *cmd, u8 pc, u8 *p)
789 {
790 	p[0] = 0x01;
791 	p[1] = 0x0a;
792 
793 	/* No changeable values for now */
794 	if (pc == 1)
795 		goto out;
796 
797 out:
798 	return 12;
799 }
800 
801 static int spc_modesense_control(struct se_cmd *cmd, u8 pc, u8 *p)
802 {
803 	struct se_device *dev = cmd->se_dev;
804 	struct se_session *sess = cmd->se_sess;
805 
806 	p[0] = 0x0a;
807 	p[1] = 0x0a;
808 
809 	/* No changeable values for now */
810 	if (pc == 1)
811 		goto out;
812 
813 	/* GLTSD: No implicit save of log parameters */
814 	p[2] = (1 << 1);
815 	if (target_sense_desc_format(dev))
816 		/* D_SENSE: Descriptor format sense data for 64bit sectors */
817 		p[2] |= (1 << 2);
818 
819 	/*
820 	 * From spc4r23, 7.4.7 Control mode page
821 	 *
822 	 * The QUEUE ALGORITHM MODIFIER field (see table 368) specifies
823 	 * restrictions on the algorithm used for reordering commands
824 	 * having the SIMPLE task attribute (see SAM-4).
825 	 *
826 	 *                    Table 368 -- QUEUE ALGORITHM MODIFIER field
827 	 *                         Code      Description
828 	 *                          0h       Restricted reordering
829 	 *                          1h       Unrestricted reordering allowed
830 	 *                          2h to 7h    Reserved
831 	 *                          8h to Fh    Vendor specific
832 	 *
833 	 * A value of zero in the QUEUE ALGORITHM MODIFIER field specifies that
834 	 * the device server shall order the processing sequence of commands
835 	 * having the SIMPLE task attribute such that data integrity is maintained
836 	 * for that I_T nexus (i.e., if the transmission of new SCSI transport protocol
837 	 * requests is halted at any time, the final value of all data observable
838 	 * on the medium shall be the same as if all the commands had been processed
839 	 * with the ORDERED task attribute).
840 	 *
841 	 * A value of one in the QUEUE ALGORITHM MODIFIER field specifies that the
842 	 * device server may reorder the processing sequence of commands having the
843 	 * SIMPLE task attribute in any manner. Any data integrity exposures related to
844 	 * command sequence order shall be explicitly handled by the application client
845 	 * through the selection of appropriate ommands and task attributes.
846 	 */
847 	p[3] = (dev->dev_attrib.emulate_rest_reord == 1) ? 0x00 : 0x10;
848 	/*
849 	 * From spc4r17, section 7.4.6 Control mode Page
850 	 *
851 	 * Unit Attention interlocks control (UN_INTLCK_CTRL) to code 00b
852 	 *
853 	 * 00b: The logical unit shall clear any unit attention condition
854 	 * reported in the same I_T_L_Q nexus transaction as a CHECK CONDITION
855 	 * status and shall not establish a unit attention condition when a com-
856 	 * mand is completed with BUSY, TASK SET FULL, or RESERVATION CONFLICT
857 	 * status.
858 	 *
859 	 * 10b: The logical unit shall not clear any unit attention condition
860 	 * reported in the same I_T_L_Q nexus transaction as a CHECK CONDITION
861 	 * status and shall not establish a unit attention condition when
862 	 * a command is completed with BUSY, TASK SET FULL, or RESERVATION
863 	 * CONFLICT status.
864 	 *
865 	 * 11b a The logical unit shall not clear any unit attention condition
866 	 * reported in the same I_T_L_Q nexus transaction as a CHECK CONDITION
867 	 * status and shall establish a unit attention condition for the
868 	 * initiator port associated with the I_T nexus on which the BUSY,
869 	 * TASK SET FULL, or RESERVATION CONFLICT status is being returned.
870 	 * Depending on the status, the additional sense code shall be set to
871 	 * PREVIOUS BUSY STATUS, PREVIOUS TASK SET FULL STATUS, or PREVIOUS
872 	 * RESERVATION CONFLICT STATUS. Until it is cleared by a REQUEST SENSE
873 	 * command, a unit attention condition shall be established only once
874 	 * for a BUSY, TASK SET FULL, or RESERVATION CONFLICT status regardless
875 	 * to the number of commands completed with one of those status codes.
876 	 */
877 	switch (dev->dev_attrib.emulate_ua_intlck_ctrl) {
878 	case TARGET_UA_INTLCK_CTRL_ESTABLISH_UA:
879 		p[4] = 0x30;
880 		break;
881 	case TARGET_UA_INTLCK_CTRL_NO_CLEAR:
882 		p[4] = 0x20;
883 		break;
884 	default:	/* TARGET_UA_INTLCK_CTRL_CLEAR */
885 		p[4] = 0x00;
886 		break;
887 	}
888 	/*
889 	 * From spc4r17, section 7.4.6 Control mode Page
890 	 *
891 	 * Task Aborted Status (TAS) bit set to zero.
892 	 *
893 	 * A task aborted status (TAS) bit set to zero specifies that aborted
894 	 * tasks shall be terminated by the device server without any response
895 	 * to the application client. A TAS bit set to one specifies that tasks
896 	 * aborted by the actions of an I_T nexus other than the I_T nexus on
897 	 * which the command was received shall be completed with TASK ABORTED
898 	 * status (see SAM-4).
899 	 */
900 	p[5] = (dev->dev_attrib.emulate_tas) ? 0x40 : 0x00;
901 	/*
902 	 * From spc4r30, section 7.5.7 Control mode page
903 	 *
904 	 * Application Tag Owner (ATO) bit set to one.
905 	 *
906 	 * If the ATO bit is set to one the device server shall not modify the
907 	 * LOGICAL BLOCK APPLICATION TAG field and, depending on the protection
908 	 * type, shall not modify the contents of the LOGICAL BLOCK REFERENCE
909 	 * TAG field.
910 	 */
911 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
912 		if (dev->dev_attrib.pi_prot_type || sess->sess_prot_type)
913 			p[5] |= 0x80;
914 	}
915 
916 	p[8] = 0xff;
917 	p[9] = 0xff;
918 	p[11] = 30;
919 
920 out:
921 	return 12;
922 }
923 
924 static int spc_modesense_caching(struct se_cmd *cmd, u8 pc, u8 *p)
925 {
926 	struct se_device *dev = cmd->se_dev;
927 
928 	p[0] = 0x08;
929 	p[1] = 0x12;
930 
931 	/* No changeable values for now */
932 	if (pc == 1)
933 		goto out;
934 
935 	if (target_check_wce(dev))
936 		p[2] = 0x04; /* Write Cache Enable */
937 	p[12] = 0x20; /* Disabled Read Ahead */
938 
939 out:
940 	return 20;
941 }
942 
943 static int spc_modesense_informational_exceptions(struct se_cmd *cmd, u8 pc, unsigned char *p)
944 {
945 	p[0] = 0x1c;
946 	p[1] = 0x0a;
947 
948 	/* No changeable values for now */
949 	if (pc == 1)
950 		goto out;
951 
952 out:
953 	return 12;
954 }
955 
956 static struct {
957 	uint8_t		page;
958 	uint8_t		subpage;
959 	int		(*emulate)(struct se_cmd *, u8, unsigned char *);
960 } modesense_handlers[] = {
961 	{ .page = 0x01, .subpage = 0x00, .emulate = spc_modesense_rwrecovery },
962 	{ .page = 0x08, .subpage = 0x00, .emulate = spc_modesense_caching },
963 	{ .page = 0x0a, .subpage = 0x00, .emulate = spc_modesense_control },
964 	{ .page = 0x1c, .subpage = 0x00, .emulate = spc_modesense_informational_exceptions },
965 };
966 
967 static void spc_modesense_write_protect(unsigned char *buf, int type)
968 {
969 	/*
970 	 * I believe that the WP bit (bit 7) in the mode header is the same for
971 	 * all device types..
972 	 */
973 	switch (type) {
974 	case TYPE_DISK:
975 	case TYPE_TAPE:
976 	default:
977 		buf[0] |= 0x80; /* WP bit */
978 		break;
979 	}
980 }
981 
982 static void spc_modesense_dpofua(unsigned char *buf, int type)
983 {
984 	switch (type) {
985 	case TYPE_DISK:
986 		buf[0] |= 0x10; /* DPOFUA bit */
987 		break;
988 	default:
989 		break;
990 	}
991 }
992 
993 static int spc_modesense_blockdesc(unsigned char *buf, u64 blocks, u32 block_size)
994 {
995 	*buf++ = 8;
996 	put_unaligned_be32(min(blocks, 0xffffffffull), buf);
997 	buf += 4;
998 	put_unaligned_be32(block_size, buf);
999 	return 9;
1000 }
1001 
1002 static int spc_modesense_long_blockdesc(unsigned char *buf, u64 blocks, u32 block_size)
1003 {
1004 	if (blocks <= 0xffffffff)
1005 		return spc_modesense_blockdesc(buf + 3, blocks, block_size) + 3;
1006 
1007 	*buf++ = 1;		/* LONGLBA */
1008 	buf += 2;
1009 	*buf++ = 16;
1010 	put_unaligned_be64(blocks, buf);
1011 	buf += 12;
1012 	put_unaligned_be32(block_size, buf);
1013 
1014 	return 17;
1015 }
1016 
1017 static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
1018 {
1019 	struct se_device *dev = cmd->se_dev;
1020 	char *cdb = cmd->t_task_cdb;
1021 	unsigned char buf[SE_MODE_PAGE_BUF], *rbuf;
1022 	int type = dev->transport->get_device_type(dev);
1023 	int ten = (cmd->t_task_cdb[0] == MODE_SENSE_10);
1024 	bool dbd = !!(cdb[1] & 0x08);
1025 	bool llba = ten ? !!(cdb[1] & 0x10) : false;
1026 	u8 pc = cdb[2] >> 6;
1027 	u8 page = cdb[2] & 0x3f;
1028 	u8 subpage = cdb[3];
1029 	int length = 0;
1030 	int ret;
1031 	int i;
1032 
1033 	memset(buf, 0, SE_MODE_PAGE_BUF);
1034 
1035 	/*
1036 	 * Skip over MODE DATA LENGTH + MEDIUM TYPE fields to byte 3 for
1037 	 * MODE_SENSE_10 and byte 2 for MODE_SENSE (6).
1038 	 */
1039 	length = ten ? 3 : 2;
1040 
1041 	/* DEVICE-SPECIFIC PARAMETER */
1042 	if (cmd->se_lun->lun_access_ro || target_lun_is_rdonly(cmd))
1043 		spc_modesense_write_protect(&buf[length], type);
1044 
1045 	/*
1046 	 * SBC only allows us to enable FUA and DPO together.  Fortunately
1047 	 * DPO is explicitly specified as a hint, so a noop is a perfectly
1048 	 * valid implementation.
1049 	 */
1050 	if (target_check_fua(dev))
1051 		spc_modesense_dpofua(&buf[length], type);
1052 
1053 	++length;
1054 
1055 	/* BLOCK DESCRIPTOR */
1056 
1057 	/*
1058 	 * For now we only include a block descriptor for disk (SBC)
1059 	 * devices; other command sets use a slightly different format.
1060 	 */
1061 	if (!dbd && type == TYPE_DISK) {
1062 		u64 blocks = dev->transport->get_blocks(dev);
1063 		u32 block_size = dev->dev_attrib.block_size;
1064 
1065 		if (ten) {
1066 			if (llba) {
1067 				length += spc_modesense_long_blockdesc(&buf[length],
1068 								       blocks, block_size);
1069 			} else {
1070 				length += 3;
1071 				length += spc_modesense_blockdesc(&buf[length],
1072 								  blocks, block_size);
1073 			}
1074 		} else {
1075 			length += spc_modesense_blockdesc(&buf[length], blocks,
1076 							  block_size);
1077 		}
1078 	} else {
1079 		if (ten)
1080 			length += 4;
1081 		else
1082 			length += 1;
1083 	}
1084 
1085 	if (page == 0x3f) {
1086 		if (subpage != 0x00 && subpage != 0xff) {
1087 			pr_warn("MODE_SENSE: Invalid subpage code: 0x%02x\n", subpage);
1088 			return TCM_INVALID_CDB_FIELD;
1089 		}
1090 
1091 		for (i = 0; i < ARRAY_SIZE(modesense_handlers); ++i) {
1092 			/*
1093 			 * Tricky way to say all subpage 00h for
1094 			 * subpage==0, all subpages for subpage==0xff
1095 			 * (and we just checked above that those are
1096 			 * the only two possibilities).
1097 			 */
1098 			if ((modesense_handlers[i].subpage & ~subpage) == 0) {
1099 				ret = modesense_handlers[i].emulate(cmd, pc, &buf[length]);
1100 				if (!ten && length + ret >= 255)
1101 					break;
1102 				length += ret;
1103 			}
1104 		}
1105 
1106 		goto set_length;
1107 	}
1108 
1109 	for (i = 0; i < ARRAY_SIZE(modesense_handlers); ++i)
1110 		if (modesense_handlers[i].page == page &&
1111 		    modesense_handlers[i].subpage == subpage) {
1112 			length += modesense_handlers[i].emulate(cmd, pc, &buf[length]);
1113 			goto set_length;
1114 		}
1115 
1116 	/*
1117 	 * We don't intend to implement:
1118 	 *  - obsolete page 03h "format parameters" (checked by Solaris)
1119 	 */
1120 	if (page != 0x03)
1121 		pr_err("MODE SENSE: unimplemented page/subpage: 0x%02x/0x%02x\n",
1122 		       page, subpage);
1123 
1124 	return TCM_UNKNOWN_MODE_PAGE;
1125 
1126 set_length:
1127 	if (ten)
1128 		put_unaligned_be16(length - 2, buf);
1129 	else
1130 		buf[0] = length - 1;
1131 
1132 	rbuf = transport_kmap_data_sg(cmd);
1133 	if (rbuf) {
1134 		memcpy(rbuf, buf, min_t(u32, SE_MODE_PAGE_BUF, cmd->data_length));
1135 		transport_kunmap_data_sg(cmd);
1136 	}
1137 
1138 	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, length);
1139 	return 0;
1140 }
1141 
1142 static sense_reason_t spc_emulate_modeselect(struct se_cmd *cmd)
1143 {
1144 	char *cdb = cmd->t_task_cdb;
1145 	bool ten = cdb[0] == MODE_SELECT_10;
1146 	int off = ten ? 8 : 4;
1147 	bool pf = !!(cdb[1] & 0x10);
1148 	u8 page, subpage;
1149 	unsigned char *buf;
1150 	unsigned char tbuf[SE_MODE_PAGE_BUF];
1151 	int length;
1152 	sense_reason_t ret = 0;
1153 	int i;
1154 
1155 	if (!cmd->data_length) {
1156 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1157 		return 0;
1158 	}
1159 
1160 	if (cmd->data_length < off + 2)
1161 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1162 
1163 	buf = transport_kmap_data_sg(cmd);
1164 	if (!buf)
1165 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1166 
1167 	if (!pf) {
1168 		ret = TCM_INVALID_CDB_FIELD;
1169 		goto out;
1170 	}
1171 
1172 	page = buf[off] & 0x3f;
1173 	subpage = buf[off] & 0x40 ? buf[off + 1] : 0;
1174 
1175 	for (i = 0; i < ARRAY_SIZE(modesense_handlers); ++i)
1176 		if (modesense_handlers[i].page == page &&
1177 		    modesense_handlers[i].subpage == subpage) {
1178 			memset(tbuf, 0, SE_MODE_PAGE_BUF);
1179 			length = modesense_handlers[i].emulate(cmd, 0, tbuf);
1180 			goto check_contents;
1181 		}
1182 
1183 	ret = TCM_UNKNOWN_MODE_PAGE;
1184 	goto out;
1185 
1186 check_contents:
1187 	if (cmd->data_length < off + length) {
1188 		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
1189 		goto out;
1190 	}
1191 
1192 	if (memcmp(buf + off, tbuf, length))
1193 		ret = TCM_INVALID_PARAMETER_LIST;
1194 
1195 out:
1196 	transport_kunmap_data_sg(cmd);
1197 
1198 	if (!ret)
1199 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1200 	return ret;
1201 }
1202 
1203 static sense_reason_t spc_emulate_request_sense(struct se_cmd *cmd)
1204 {
1205 	unsigned char *cdb = cmd->t_task_cdb;
1206 	unsigned char *rbuf;
1207 	u8 ua_asc = 0, ua_ascq = 0;
1208 	unsigned char buf[SE_SENSE_BUF];
1209 	bool desc_format = target_sense_desc_format(cmd->se_dev);
1210 
1211 	memset(buf, 0, SE_SENSE_BUF);
1212 
1213 	if (cdb[1] & 0x01) {
1214 		pr_err("REQUEST_SENSE description emulation not"
1215 			" supported\n");
1216 		return TCM_INVALID_CDB_FIELD;
1217 	}
1218 
1219 	rbuf = transport_kmap_data_sg(cmd);
1220 	if (!rbuf)
1221 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1222 
1223 	if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq))
1224 		scsi_build_sense_buffer(desc_format, buf, UNIT_ATTENTION,
1225 					ua_asc, ua_ascq);
1226 	else
1227 		scsi_build_sense_buffer(desc_format, buf, NO_SENSE, 0x0, 0x0);
1228 
1229 	memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
1230 	transport_kunmap_data_sg(cmd);
1231 
1232 	target_complete_cmd(cmd, SAM_STAT_GOOD);
1233 	return 0;
1234 }
1235 
1236 sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
1237 {
1238 	struct se_dev_entry *deve;
1239 	struct se_session *sess = cmd->se_sess;
1240 	struct se_node_acl *nacl;
1241 	struct scsi_lun slun;
1242 	unsigned char *buf;
1243 	u32 lun_count = 0, offset = 8;
1244 	__be32 len;
1245 
1246 	buf = transport_kmap_data_sg(cmd);
1247 	if (cmd->data_length && !buf)
1248 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1249 
1250 	/*
1251 	 * If no struct se_session pointer is present, this struct se_cmd is
1252 	 * coming via a target_core_mod PASSTHROUGH op, and not through
1253 	 * a $FABRIC_MOD.  In that case, report LUN=0 only.
1254 	 */
1255 	if (!sess)
1256 		goto done;
1257 
1258 	nacl = sess->se_node_acl;
1259 
1260 	rcu_read_lock();
1261 	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
1262 		/*
1263 		 * We determine the correct LUN LIST LENGTH even once we
1264 		 * have reached the initial allocation length.
1265 		 * See SPC2-R20 7.19.
1266 		 */
1267 		lun_count++;
1268 		if (offset >= cmd->data_length)
1269 			continue;
1270 
1271 		int_to_scsilun(deve->mapped_lun, &slun);
1272 		memcpy(buf + offset, &slun,
1273 		       min(8u, cmd->data_length - offset));
1274 		offset += 8;
1275 	}
1276 	rcu_read_unlock();
1277 
1278 	/*
1279 	 * See SPC3 r07, page 159.
1280 	 */
1281 done:
1282 	/*
1283 	 * If no LUNs are accessible, report virtual LUN 0.
1284 	 */
1285 	if (lun_count == 0) {
1286 		int_to_scsilun(0, &slun);
1287 		if (cmd->data_length > 8)
1288 			memcpy(buf + offset, &slun,
1289 			       min(8u, cmd->data_length - offset));
1290 		lun_count = 1;
1291 	}
1292 
1293 	if (buf) {
1294 		len = cpu_to_be32(lun_count * 8);
1295 		memcpy(buf, &len, min_t(int, sizeof len, cmd->data_length));
1296 		transport_kunmap_data_sg(cmd);
1297 	}
1298 
1299 	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8 + lun_count * 8);
1300 	return 0;
1301 }
1302 EXPORT_SYMBOL(spc_emulate_report_luns);
1303 
1304 static sense_reason_t
1305 spc_emulate_testunitready(struct se_cmd *cmd)
1306 {
1307 	target_complete_cmd(cmd, SAM_STAT_GOOD);
1308 	return 0;
1309 }
1310 
1311 sense_reason_t
1312 spc_parse_cdb(struct se_cmd *cmd, unsigned int *size)
1313 {
1314 	struct se_device *dev = cmd->se_dev;
1315 	unsigned char *cdb = cmd->t_task_cdb;
1316 
1317 	if (!dev->dev_attrib.emulate_pr &&
1318 	    ((cdb[0] == PERSISTENT_RESERVE_IN) ||
1319 	     (cdb[0] == PERSISTENT_RESERVE_OUT) ||
1320 	     (cdb[0] == RELEASE || cdb[0] == RELEASE_10) ||
1321 	     (cdb[0] == RESERVE || cdb[0] == RESERVE_10))) {
1322 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1323 	}
1324 
1325 	switch (cdb[0]) {
1326 	case MODE_SELECT:
1327 		*size = cdb[4];
1328 		cmd->execute_cmd = spc_emulate_modeselect;
1329 		break;
1330 	case MODE_SELECT_10:
1331 		*size = get_unaligned_be16(&cdb[7]);
1332 		cmd->execute_cmd = spc_emulate_modeselect;
1333 		break;
1334 	case MODE_SENSE:
1335 		*size = cdb[4];
1336 		cmd->execute_cmd = spc_emulate_modesense;
1337 		break;
1338 	case MODE_SENSE_10:
1339 		*size = get_unaligned_be16(&cdb[7]);
1340 		cmd->execute_cmd = spc_emulate_modesense;
1341 		break;
1342 	case LOG_SELECT:
1343 	case LOG_SENSE:
1344 		*size = get_unaligned_be16(&cdb[7]);
1345 		break;
1346 	case PERSISTENT_RESERVE_IN:
1347 		*size = get_unaligned_be16(&cdb[7]);
1348 		cmd->execute_cmd = target_scsi3_emulate_pr_in;
1349 		break;
1350 	case PERSISTENT_RESERVE_OUT:
1351 		*size = get_unaligned_be32(&cdb[5]);
1352 		cmd->execute_cmd = target_scsi3_emulate_pr_out;
1353 		break;
1354 	case RELEASE:
1355 	case RELEASE_10:
1356 		if (cdb[0] == RELEASE_10)
1357 			*size = get_unaligned_be16(&cdb[7]);
1358 		else
1359 			*size = cmd->data_length;
1360 
1361 		cmd->execute_cmd = target_scsi2_reservation_release;
1362 		break;
1363 	case RESERVE:
1364 	case RESERVE_10:
1365 		/*
1366 		 * The SPC-2 RESERVE does not contain a size in the SCSI CDB.
1367 		 * Assume the passthrough or $FABRIC_MOD will tell us about it.
1368 		 */
1369 		if (cdb[0] == RESERVE_10)
1370 			*size = get_unaligned_be16(&cdb[7]);
1371 		else
1372 			*size = cmd->data_length;
1373 
1374 		cmd->execute_cmd = target_scsi2_reservation_reserve;
1375 		break;
1376 	case REQUEST_SENSE:
1377 		*size = cdb[4];
1378 		cmd->execute_cmd = spc_emulate_request_sense;
1379 		break;
1380 	case INQUIRY:
1381 		*size = get_unaligned_be16(&cdb[3]);
1382 
1383 		/*
1384 		 * Do implicit HEAD_OF_QUEUE processing for INQUIRY.
1385 		 * See spc4r17 section 5.3
1386 		 */
1387 		cmd->sam_task_attr = TCM_HEAD_TAG;
1388 		cmd->execute_cmd = spc_emulate_inquiry;
1389 		break;
1390 	case SECURITY_PROTOCOL_IN:
1391 	case SECURITY_PROTOCOL_OUT:
1392 		*size = get_unaligned_be32(&cdb[6]);
1393 		break;
1394 	case EXTENDED_COPY:
1395 		*size = get_unaligned_be32(&cdb[10]);
1396 		cmd->execute_cmd = target_do_xcopy;
1397 		break;
1398 	case RECEIVE_COPY_RESULTS:
1399 		*size = get_unaligned_be32(&cdb[10]);
1400 		cmd->execute_cmd = target_do_receive_copy_results;
1401 		break;
1402 	case READ_ATTRIBUTE:
1403 	case WRITE_ATTRIBUTE:
1404 		*size = get_unaligned_be32(&cdb[10]);
1405 		break;
1406 	case RECEIVE_DIAGNOSTIC:
1407 	case SEND_DIAGNOSTIC:
1408 		*size = get_unaligned_be16(&cdb[3]);
1409 		break;
1410 	case WRITE_BUFFER:
1411 		*size = get_unaligned_be24(&cdb[6]);
1412 		break;
1413 	case REPORT_LUNS:
1414 		cmd->execute_cmd = spc_emulate_report_luns;
1415 		*size = get_unaligned_be32(&cdb[6]);
1416 		/*
1417 		 * Do implicit HEAD_OF_QUEUE processing for REPORT_LUNS
1418 		 * See spc4r17 section 5.3
1419 		 */
1420 		cmd->sam_task_attr = TCM_HEAD_TAG;
1421 		break;
1422 	case TEST_UNIT_READY:
1423 		cmd->execute_cmd = spc_emulate_testunitready;
1424 		*size = 0;
1425 		break;
1426 	case MAINTENANCE_IN:
1427 		if (dev->transport->get_device_type(dev) != TYPE_ROM) {
1428 			/*
1429 			 * MAINTENANCE_IN from SCC-2
1430 			 * Check for emulated MI_REPORT_TARGET_PGS
1431 			 */
1432 			if ((cdb[1] & 0x1f) == MI_REPORT_TARGET_PGS) {
1433 				cmd->execute_cmd =
1434 					target_emulate_report_target_port_groups;
1435 			}
1436 			*size = get_unaligned_be32(&cdb[6]);
1437 		} else {
1438 			/*
1439 			 * GPCMD_SEND_KEY from multi media commands
1440 			 */
1441 			*size = get_unaligned_be16(&cdb[8]);
1442 		}
1443 		break;
1444 	case MAINTENANCE_OUT:
1445 		if (dev->transport->get_device_type(dev) != TYPE_ROM) {
1446 			/*
1447 			 * MAINTENANCE_OUT from SCC-2
1448 			 * Check for emulated MO_SET_TARGET_PGS.
1449 			 */
1450 			if (cdb[1] == MO_SET_TARGET_PGS) {
1451 				cmd->execute_cmd =
1452 					target_emulate_set_target_port_groups;
1453 			}
1454 			*size = get_unaligned_be32(&cdb[6]);
1455 		} else {
1456 			/*
1457 			 * GPCMD_SEND_KEY from multi media commands
1458 			 */
1459 			*size = get_unaligned_be16(&cdb[8]);
1460 		}
1461 		break;
1462 	default:
1463 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1464 	}
1465 
1466 	return 0;
1467 }
1468 EXPORT_SYMBOL(spc_parse_cdb);
1469