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1// SPDX-License-Identifier: GPL-2.02/*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, 1021};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 is26 * 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 up55 */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 int112 * @scsilun: struct scsi_lun to be converted.113 *114 * Description:115 * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered116 * integer, and return the result. The caller must check for117 * truncation before using this function.118 *119 * Notes:120 * For a description of the LUN format, post SCSI-3 see the SCSI121 * 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 function124 * returns the integer: 0x0b03d204125 *126 * This encoding will return a standard integer LUN for LUNs smaller127 * than 256, which typically use a single level LUN structure with128 * 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_lun145 * @lun: integer to be reverted146 * @scsilun: struct scsi_lun to be set.147 *148 * Description:149 * Reverts the functionality of the scsilun_to_int, which packed150 * an 8-byte lun value into an int. This routine unpacks the int151 * back into the lun value.152 *153 * Notes:154 * Given an integer : 0x0b03d204, this function returns a155 * struct scsi_lun of: d2 04 0b 03 00 00 00 00156 *157 */158void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)159{160 int i;161 162 memset(scsilun->scsi_lun, 0, 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 or174 * descriptor sense data format into a common format.175 *176 * @sense_buffer: byte array containing sense data returned by device177 * @sb_len: number of valid bytes in sense_buffer178 * @sshdr: pointer to instance of structure that common179 * 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 has186 * 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(sshdr, 0, 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 format207 */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 format219 */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 data238 * @sb_len: number of valid bytes in sense_buffer239 * @desc_type: value of descriptor type to find240 * (e.g. 0 -> information)241 *242 * Notes:243 * only valid when sense data is in descriptor format244 *245 * Return value:246 * pointer to start of (first) descriptor if found else NULL247 */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 buffer276 * @desc: Sense format (non-zero == descriptor format,277 * 0 == fixed format)278 * @buf: Where to build sense data279 * @key: Sense key280 * @asc: Additional sense code281 * @ascq: Additional sense code qualifier282 *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 a304 * formatted sense data buffer305 * @buf: Where to build sense data306 * @buf_len: buffer length307 * @info: 64-bit information value to be set308 *309 * Return value:310 * 0 on success or -EINVAL for invalid sense buffer length311 **/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(info, &ucp[4]);333 } else if ((buf[0] & 0x7f) == 0x70) {334 /*335 * Only set the 'VALID' bit if we can represent the value336 * correctly; otherwise just fill out the lower bytes and337 * clear the 'VALID' flag.338 */339 if (info <= 0xffffffffUL)340 buf[0] |= 0x80;341 else342 buf[0] &= 0x7f;343 put_unaligned_be32((u32)info, &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 key352 * specific information in a formatted sense data buffer353 * @buf: Where to build sense data354 * @buf_len: buffer length355 * @fp: field pointer to be set356 * @bp: bit pointer to be set357 * @cd: command/data bit358 *359 * Return value:360 * 0 on success or -EINVAL for invalid sense buffer length361 */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(fp, &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(fp, &buf[16]);397 }398 399 return 0;400}401EXPORT_SYMBOL(scsi_set_sense_field_pointer);402