// SPDX-License-Identifier: GPL-2.0
/*
* SCSI functions used by both the initiator and the target code.
*/
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <asm/unaligned.h>
#include <scsi/scsi_common.h>
/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
* You may not alter any existing entry (although adding new ones is
* encouraged once assigned by ANSI/INCITS T10).
*/
static const char *const scsi_device_types[] = {
"Direct-Access ",
"Sequential-Access",
"Printer ",
"Processor ",
"WORM ",
"CD-ROM ",
"Scanner ",
"Optical Device ",
"Medium Changer ",
"Communications ",
"ASC IT8 ",
"ASC IT8 ",
"RAID ",
"Enclosure ",
"Direct-Access-RBC",
"Optical card ",
"Bridge controller",
"Object storage ",
"Automation/Drive ",
"Security Manager ",
"Direct-Access-ZBC",
};
/**
* scsi_device_type - Return 17-char string indicating device type.
* @type: type number to look up
*/
const char *scsi_device_type(unsigned type)
{
if (type == 0x1e)
return "Well-known LUN ";
if (type == 0x1f)
return "No Device ";
if (type >= ARRAY_SIZE(scsi_device_types))
return "Unknown ";
return scsi_device_types[type];
}
EXPORT_SYMBOL(scsi_device_type);
/**
* scsilun_to_int - convert a scsi_lun to an int
* @scsilun: struct scsi_lun to be converted.
*
* Description:
* Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
* integer, and return the result. The caller must check for
* truncation before using this function.
*
* Notes:
* For a description of the LUN format, post SCSI-3 see the SCSI
* Architecture Model, for SCSI-3 see the SCSI Controller Commands.
*
* Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
* returns the integer: 0x0b03d204
*
* This encoding will return a standard integer LUN for LUNs smaller
* than 256, which typically use a single level LUN structure with
* addressing method 0.
*/
u64 scsilun_to_int(struct scsi_lun *scsilun)
{
int i;
u64 lun;
lun = 0;
for (i = 0; i < sizeof(lun); i += 2)
lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
return lun;
}
EXPORT_SYMBOL(scsilun_to_int);
/**
* int_to_scsilun - reverts an int into a scsi_lun
* @lun: integer to be reverted
* @scsilun: struct scsi_lun to be set.
*
* Description:
* Reverts the functionality of the scsilun_to_int, which packed
* an 8-byte lun value into an int. This routine unpacks the int
* back into the lun value.
*
* Notes:
* Given an integer : 0x0b03d204, this function returns a
* struct scsi_lun of: d2 04 0b 03 00 00 00 00
*
*/
void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
{
int i;
memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
for (i = 0; i < sizeof(lun); i += 2) {
scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
scsilun->scsi_lun[i+1] = lun & 0xFF;
lun = lun >> 16;
}
}
EXPORT_SYMBOL(int_to_scsilun);
/**
* scsi_normalize_sense - normalize main elements from either fixed or
* descriptor sense data format into a common format.
*
* @sense_buffer: byte array containing sense data returned by device
* @sb_len: number of valid bytes in sense_buffer
* @sshdr: pointer to instance of structure that common
* elements are written to.
*
* Notes:
* The "main elements" from sense data are: response_code, sense_key,
* asc, ascq and additional_length (only for descriptor format).
*
* Typically this function can be called after a device has
* responded to a SCSI command with the CHECK_CONDITION status.
*
* Return value:
* true if valid sense data information found, else false;
*/
bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
struct scsi_sense_hdr *sshdr)
{
memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
if (!sense_buffer || !sb_len)
return false;
sshdr->response_code = (sense_buffer[0] & 0x7f);
if (!scsi_sense_valid(sshdr))
return false;
if (sshdr->response_code >= 0x72) {
/*
* descriptor format
*/
if (sb_len > 1)
sshdr->sense_key = (sense_buffer[1] & 0xf);
if (sb_len > 2)
sshdr->asc = sense_buffer[2];
if (sb_len > 3)
sshdr->ascq = sense_buffer[3];
if (sb_len > 7)
sshdr->additional_length = sense_buffer[7];
} else {
/*
* fixed format
*/
if (sb_len > 2)
sshdr->sense_key = (sense_buffer[2] & 0xf);
if (sb_len > 7) {
sb_len = (sb_len < (sense_buffer[7] + 8)) ?
sb_len : (sense_buffer[7] + 8);
if (sb_len > 12)
sshdr->asc = sense_buffer[12];
if (sb_len > 13)
sshdr->ascq = sense_buffer[13];
}
}
return true;
}
EXPORT_SYMBOL(scsi_normalize_sense);
/**
* scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
* @sense_buffer: byte array of descriptor format sense data
* @sb_len: number of valid bytes in sense_buffer
* @desc_type: value of descriptor type to find
* (e.g. 0 -> information)
*
* Notes:
* only valid when sense data is in descriptor format
*
* Return value:
* pointer to start of (first) descriptor if found else NULL
*/
const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
int desc_type)
{
int add_sen_len, add_len, desc_len, k;
const u8 * descp;
if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
return NULL;
if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
return NULL;
add_sen_len = (add_sen_len < (sb_len - 8)) ?
add_sen_len : (sb_len - 8);
descp = &sense_buffer[8];
for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
descp += desc_len;
add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
desc_len = add_len + 2;
if (descp[0] == desc_type)
return descp;
if (add_len < 0) // short descriptor ??
break;
}
return NULL;
}
EXPORT_SYMBOL(scsi_sense_desc_find);
/**
* scsi_build_sense_buffer - build sense data in a buffer
* @desc: Sense format (non-zero == descriptor format,
* 0 == fixed format)
* @buf: Where to build sense data
* @key: Sense key
* @asc: Additional sense code
* @ascq: Additional sense code qualifier
*
**/
void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
{
if (desc) {
buf[0] = 0x72; /* descriptor, current */
buf[1] = key;
buf[2] = asc;
buf[3] = ascq;
buf[7] = 0;
} else {
buf[0] = 0x70; /* fixed, current */
buf[2] = key;
buf[7] = 0xa;
buf[12] = asc;
buf[13] = ascq;
}
}
EXPORT_SYMBOL(scsi_build_sense_buffer);
/**
* scsi_set_sense_information - set the information field in a
* formatted sense data buffer
* @buf: Where to build sense data
* @buf_len: buffer length
* @info: 64-bit information value to be set
*
* Return value:
* 0 on success or -EINVAL for invalid sense buffer length
**/
int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
{
if ((buf[0] & 0x7f) == 0x72) {
u8 *ucp, len;
len = buf[7];
ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
if (!ucp) {
buf[7] = len + 0xc;
ucp = buf + 8 + len;
}
if (buf_len < len + 0xc)
/* Not enough room for info */
return -EINVAL;
ucp[0] = 0;
ucp[1] = 0xa;
ucp[2] = 0x80; /* Valid bit */
ucp[3] = 0;
put_unaligned_be64(info, &ucp[4]);
} else if ((buf[0] & 0x7f) == 0x70) {
/*
* Only set the 'VALID' bit if we can represent the value
* correctly; otherwise just fill out the lower bytes and
* clear the 'VALID' flag.
*/
if (info <= 0xffffffffUL)
buf[0] |= 0x80;
else
buf[0] &= 0x7f;
put_unaligned_be32((u32)info, &buf[3]);
}
return 0;
}
EXPORT_SYMBOL(scsi_set_sense_information);
/**
* scsi_set_sense_field_pointer - set the field pointer sense key
* specific information in a formatted sense data buffer
* @buf: Where to build sense data
* @buf_len: buffer length
* @fp: field pointer to be set
* @bp: bit pointer to be set
* @cd: command/data bit
*
* Return value:
* 0 on success or -EINVAL for invalid sense buffer length
*/
int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
{
u8 *ucp, len;
if ((buf[0] & 0x7f) == 0x72) {
len = buf[7];
ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
if (!ucp) {
buf[7] = len + 8;
ucp = buf + 8 + len;
}
if (buf_len < len + 8)
/* Not enough room for info */
return -EINVAL;
ucp[0] = 2;
ucp[1] = 6;
ucp[4] = 0x80; /* Valid bit */
if (cd)
ucp[4] |= 0x40;
if (bp < 0x8)
ucp[4] |= 0x8 | bp;
put_unaligned_be16(fp, &ucp[5]);
} else if ((buf[0] & 0x7f) == 0x70) {
len = buf[7];
if (len < 18)
buf[7] = 18;
buf[15] = 0x80;
if (cd)
buf[15] |= 0x40;
if (bp < 0x8)
buf[15] |= 0x8 | bp;
put_unaligned_be16(fp, &buf[16]);
}
return 0;
}
EXPORT_SYMBOL(scsi_set_sense_field_pointer);