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