1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SCSI functions used by both the initiator and the target code.
4 */
5
6#include <linux/bug.h>
7#include <linux/kernel.h>
8#include <linux/string.h>
9#include <linux/errno.h>
10#include <linux/module.h>
11#include <uapi/linux/pr.h>
12#include <linux/unaligned.h>
13#include <scsi/scsi_common.h>
14
15MODULE_DESCRIPTION("SCSI functions used by both the initiator and the target code");
16MODULE_LICENSE("GPL v2");
17
18/* Command group 3 is reserved and should never be used. */
19const unsigned char scsi_command_size_tbl[8] = {
20 6, 10, 10, 12, 16, 12, 10, 10
21};
22EXPORT_SYMBOL(scsi_command_size_tbl);
23
24/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
25 * You may not alter any existing entry (although adding new ones is
26 * encouraged once assigned by ANSI/INCITS T10).
27 */
28static const char *const scsi_device_types[] = {
29 "Direct-Access ",
30 "Sequential-Access",
31 "Printer ",
32 "Processor ",
33 "WORM ",
34 "CD-ROM ",
35 "Scanner ",
36 "Optical Device ",
37 "Medium Changer ",
38 "Communications ",
39 "ASC IT8 ",
40 "ASC IT8 ",
41 "RAID ",
42 "Enclosure ",
43 "Direct-Access-RBC",
44 "Optical card ",
45 "Bridge controller",
46 "Object storage ",
47 "Automation/Drive ",
48 "Security Manager ",
49 "Direct-Access-ZBC",
50};
51
52/**
53 * scsi_device_type - Return 17-char string indicating device type.
54 * @type: type number to look up
55 */
56const char *scsi_device_type(unsigned type)
57{
58 if (type == 0x1e)
59 return "Well-known LUN ";
60 if (type == 0x1f)
61 return "No Device ";
62 if (type >= ARRAY_SIZE(scsi_device_types))
63 return "Unknown ";
64 return scsi_device_types[type];
65}
66EXPORT_SYMBOL(scsi_device_type);
67
68enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
69{
70 switch (type) {
71 case SCSI_PR_WRITE_EXCLUSIVE:
72 return PR_WRITE_EXCLUSIVE;
73 case SCSI_PR_EXCLUSIVE_ACCESS:
74 return PR_EXCLUSIVE_ACCESS;
75 case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
76 return PR_WRITE_EXCLUSIVE_REG_ONLY;
77 case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
78 return PR_EXCLUSIVE_ACCESS_REG_ONLY;
79 case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
80 return PR_WRITE_EXCLUSIVE_ALL_REGS;
81 case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
82 return PR_EXCLUSIVE_ACCESS_ALL_REGS;
83 }
84
85 return 0;
86}
87EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);
88
89enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
90{
91 switch (type) {
92 case PR_WRITE_EXCLUSIVE:
93 return SCSI_PR_WRITE_EXCLUSIVE;
94 case PR_EXCLUSIVE_ACCESS:
95 return SCSI_PR_EXCLUSIVE_ACCESS;
96 case PR_WRITE_EXCLUSIVE_REG_ONLY:
97 return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
98 case PR_EXCLUSIVE_ACCESS_REG_ONLY:
99 return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
100 case PR_WRITE_EXCLUSIVE_ALL_REGS:
101 return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
102 case PR_EXCLUSIVE_ACCESS_ALL_REGS:
103 return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
104 }
105
106 return 0;
107}
108EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);
109
110/**
111 * scsilun_to_int - convert a scsi_lun to an int
112 * @scsilun: struct scsi_lun to be converted.
113 *
114 * Description:
115 * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
116 * integer, and return the result. The caller must check for
117 * truncation before using this function.
118 *
119 * Notes:
120 * For a description of the LUN format, post SCSI-3 see the SCSI
121 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
122 *
123 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
124 * returns the integer: 0x0b03d204
125 *
126 * This encoding will return a standard integer LUN for LUNs smaller
127 * than 256, which typically use a single level LUN structure with
128 * addressing method 0.
129 */
130u64 scsilun_to_int(struct scsi_lun *scsilun)
131{
132 int i;
133 u64 lun;
134
135 lun = 0;
136 for (i = 0; i < sizeof(lun); i += 2)
137 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
138 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
139 return lun;
140}
141EXPORT_SYMBOL(scsilun_to_int);
142
143/**
144 * int_to_scsilun - reverts an int into a scsi_lun
145 * @lun: integer to be reverted
146 * @scsilun: struct scsi_lun to be set.
147 *
148 * Description:
149 * Reverts the functionality of the scsilun_to_int, which packed
150 * an 8-byte lun value into an int. This routine unpacks the int
151 * back into the lun value.
152 *
153 * Notes:
154 * Given an integer : 0x0b03d204, this function returns a
155 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
156 *
157 */
158void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
159{
160 int i;
161
162 memset(s: scsilun->scsi_lun, c: 0, n: sizeof(scsilun->scsi_lun));
163
164 for (i = 0; i < sizeof(lun); i += 2) {
165 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
166 scsilun->scsi_lun[i+1] = lun & 0xFF;
167 lun = lun >> 16;
168 }
169}
170EXPORT_SYMBOL(int_to_scsilun);
171
172/**
173 * scsi_normalize_sense - normalize main elements from either fixed or
174 * descriptor sense data format into a common format.
175 *
176 * @sense_buffer: byte array containing sense data returned by device
177 * @sb_len: number of valid bytes in sense_buffer
178 * @sshdr: pointer to instance of structure that common
179 * elements are written to.
180 *
181 * Notes:
182 * The "main elements" from sense data are: response_code, sense_key,
183 * asc, ascq and additional_length (only for descriptor format).
184 *
185 * Typically this function can be called after a device has
186 * responded to a SCSI command with the CHECK_CONDITION status.
187 *
188 * Return value:
189 * true if valid sense data information found, else false;
190 */
191bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
192 struct scsi_sense_hdr *sshdr)
193{
194 memset(s: sshdr, c: 0, n: sizeof(struct scsi_sense_hdr));
195
196 if (!sense_buffer || !sb_len)
197 return false;
198
199 sshdr->response_code = (sense_buffer[0] & 0x7f);
200
201 if (!scsi_sense_valid(sshdr))
202 return false;
203
204 if (sshdr->response_code >= 0x72) {
205 /*
206 * descriptor format
207 */
208 if (sb_len > 1)
209 sshdr->sense_key = (sense_buffer[1] & 0xf);
210 if (sb_len > 2)
211 sshdr->asc = sense_buffer[2];
212 if (sb_len > 3)
213 sshdr->ascq = sense_buffer[3];
214 if (sb_len > 7)
215 sshdr->additional_length = sense_buffer[7];
216 } else {
217 /*
218 * fixed format
219 */
220 if (sb_len > 2)
221 sshdr->sense_key = (sense_buffer[2] & 0xf);
222 if (sb_len > 7) {
223 sb_len = min(sb_len, sense_buffer[7] + 8);
224 if (sb_len > 12)
225 sshdr->asc = sense_buffer[12];
226 if (sb_len > 13)
227 sshdr->ascq = sense_buffer[13];
228 }
229 }
230
231 return true;
232}
233EXPORT_SYMBOL(scsi_normalize_sense);
234
235/**
236 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
237 * @sense_buffer: byte array of descriptor format sense data
238 * @sb_len: number of valid bytes in sense_buffer
239 * @desc_type: value of descriptor type to find
240 * (e.g. 0 -> information)
241 *
242 * Notes:
243 * only valid when sense data is in descriptor format
244 *
245 * Return value:
246 * pointer to start of (first) descriptor if found else NULL
247 */
248const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
249 int desc_type)
250{
251 int add_sen_len, add_len, desc_len, k;
252 const u8 * descp;
253
254 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
255 return NULL;
256 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
257 return NULL;
258 add_sen_len = (add_sen_len < (sb_len - 8)) ?
259 add_sen_len : (sb_len - 8);
260 descp = &sense_buffer[8];
261 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
262 descp += desc_len;
263 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
264 desc_len = add_len + 2;
265 if (descp[0] == desc_type)
266 return descp;
267 if (add_len < 0) // short descriptor ??
268 break;
269 }
270 return NULL;
271}
272EXPORT_SYMBOL(scsi_sense_desc_find);
273
274/**
275 * scsi_build_sense_buffer - build sense data in a buffer
276 * @desc: Sense format (non-zero == descriptor format,
277 * 0 == fixed format)
278 * @buf: Where to build sense data
279 * @key: Sense key
280 * @asc: Additional sense code
281 * @ascq: Additional sense code qualifier
282 *
283 **/
284void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
285{
286 if (desc) {
287 buf[0] = 0x72; /* descriptor, current */
288 buf[1] = key;
289 buf[2] = asc;
290 buf[3] = ascq;
291 buf[7] = 0;
292 } else {
293 buf[0] = 0x70; /* fixed, current */
294 buf[2] = key;
295 buf[7] = 0xa;
296 buf[12] = asc;
297 buf[13] = ascq;
298 }
299}
300EXPORT_SYMBOL(scsi_build_sense_buffer);
301
302/**
303 * scsi_set_sense_information - set the information field in a
304 * formatted sense data buffer
305 * @buf: Where to build sense data
306 * @buf_len: buffer length
307 * @info: 64-bit information value to be set
308 *
309 * Return value:
310 * 0 on success or -EINVAL for invalid sense buffer length
311 **/
312int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
313{
314 if ((buf[0] & 0x7f) == 0x72) {
315 u8 *ucp, len;
316
317 len = buf[7];
318 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
319 if (!ucp) {
320 buf[7] = len + 0xc;
321 ucp = buf + 8 + len;
322 }
323
324 if (buf_len < len + 0xc)
325 /* Not enough room for info */
326 return -EINVAL;
327
328 ucp[0] = 0;
329 ucp[1] = 0xa;
330 ucp[2] = 0x80; /* Valid bit */
331 ucp[3] = 0;
332 put_unaligned_be64(val: info, p: &ucp[4]);
333 } else if ((buf[0] & 0x7f) == 0x70) {
334 /*
335 * Only set the 'VALID' bit if we can represent the value
336 * correctly; otherwise just fill out the lower bytes and
337 * clear the 'VALID' flag.
338 */
339 if (info <= 0xffffffffUL)
340 buf[0] |= 0x80;
341 else
342 buf[0] &= 0x7f;
343 put_unaligned_be32(val: (u32)info, p: &buf[3]);
344 }
345
346 return 0;
347}
348EXPORT_SYMBOL(scsi_set_sense_information);
349
350/**
351 * scsi_set_sense_field_pointer - set the field pointer sense key
352 * specific information in a formatted sense data buffer
353 * @buf: Where to build sense data
354 * @buf_len: buffer length
355 * @fp: field pointer to be set
356 * @bp: bit pointer to be set
357 * @cd: command/data bit
358 *
359 * Return value:
360 * 0 on success or -EINVAL for invalid sense buffer length
361 */
362int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
363{
364 u8 *ucp, len;
365
366 if ((buf[0] & 0x7f) == 0x72) {
367 len = buf[7];
368 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
369 if (!ucp) {
370 buf[7] = len + 8;
371 ucp = buf + 8 + len;
372 }
373
374 if (buf_len < len + 8)
375 /* Not enough room for info */
376 return -EINVAL;
377
378 ucp[0] = 2;
379 ucp[1] = 6;
380 ucp[4] = 0x80; /* Valid bit */
381 if (cd)
382 ucp[4] |= 0x40;
383 if (bp < 0x8)
384 ucp[4] |= 0x8 | bp;
385 put_unaligned_be16(val: fp, p: &ucp[5]);
386 } else if ((buf[0] & 0x7f) == 0x70) {
387 len = buf[7];
388 if (len < 18)
389 buf[7] = 18;
390
391 buf[15] = 0x80;
392 if (cd)
393 buf[15] |= 0x40;
394 if (bp < 0x8)
395 buf[15] |= 0x8 | bp;
396 put_unaligned_be16(val: fp, p: &buf[16]);
397 }
398
399 return 0;
400}
401EXPORT_SYMBOL(scsi_set_sense_field_pointer);
402