u-boot/lib/uuid.c
Rasmus Villemoes c0364ce1c6 doc/README.gpt: define partition type GUID for U-Boot environment
When setting aside a GPT partition for holding the U-Boot environment,
having a partition type GUID [1] indicating "Linux filesystem" (as
most tools default to) is somewhat misleading - and there's no other
well-known type GUID that is better suited. So to have a canonical
value to put into the type field, define

    3de21764-95bd-54bd-a5c3-4abe786f38a8

to mean a partition holding a U-Boot environment.

This is a v5 namespace-name GUID [2], generated [3] from a namespace
of "25cbcde0-8642-47c6-a298-1a3a57cd256b" and name "U-Boot
environment".

Should future type GUIDs be defined in the context of U-Boot, it's
sensible to use that same namespace GUID.

[1] https://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs
[2] https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions_3_and_5_(namespace_name-based)
[3] https://www.uuidtools.com/v5

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
2021-01-16 14:49:09 -05:00

330 lines
8.4 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2011 Calxeda, Inc.
*/
#include <common.h>
#include <command.h>
#include <env.h>
#include <rand.h>
#include <time.h>
#include <uuid.h>
#include <linux/ctype.h>
#include <errno.h>
#include <common.h>
#include <asm/io.h>
#include <part_efi.h>
#include <malloc.h>
/*
* UUID - Universally Unique IDentifier - 128 bits unique number.
* There are 5 versions and one variant of UUID defined by RFC4122
* specification. A UUID contains a set of fields. The set varies
* depending on the version of the UUID, as shown below:
* - time, MAC address(v1),
* - user ID(v2),
* - MD5 of name or URL(v3),
* - random data(v4),
* - SHA-1 of name or URL(v5),
*
* Layout of UUID:
* timestamp - 60-bit: time_low, time_mid, time_hi_and_version
* version - 4 bit (bit 4 through 7 of the time_hi_and_version)
* clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
* variant: - bit 6 and 7 of clock_seq_hi_and_reserved
* node - 48 bit
*
* source: https://www.ietf.org/rfc/rfc4122.txt
*
* UUID binary format (16 bytes):
*
* 4B-2B-2B-2B-6B (big endian - network byte order)
*
* UUID string is 36 length of characters (36 bytes):
*
* 0 9 14 19 24
* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
* be be be be be
*
* where x is a hexadecimal character. Fields are separated by '-'s.
* When converting to a binary UUID, le means the field should be converted
* to little endian and be means it should be converted to big endian.
*
* UUID is also used as GUID (Globally Unique Identifier) with the same binary
* format but it differs in string format like below.
*
* GUID:
* 0 9 14 19 24
* xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
* le le le be be
*
* GUID is used e.g. in GPT (GUID Partition Table) as a partiions unique id.
*/
int uuid_str_valid(const char *uuid)
{
int i, valid;
if (uuid == NULL)
return 0;
for (i = 0, valid = 1; uuid[i] && valid; i++) {
switch (i) {
case 8: case 13: case 18: case 23:
valid = (uuid[i] == '-');
break;
default:
valid = isxdigit(uuid[i]);
break;
}
}
if (i != UUID_STR_LEN || !valid)
return 0;
return 1;
}
#ifdef CONFIG_PARTITION_TYPE_GUID
static const struct {
const char *string;
efi_guid_t guid;
} list_guid[] = {
{"system", PARTITION_SYSTEM_GUID},
{"mbr", LEGACY_MBR_PARTITION_GUID},
{"msft", PARTITION_MSFT_RESERVED_GUID},
{"data", PARTITION_BASIC_DATA_GUID},
{"linux", PARTITION_LINUX_FILE_SYSTEM_DATA_GUID},
{"raid", PARTITION_LINUX_RAID_GUID},
{"swap", PARTITION_LINUX_SWAP_GUID},
{"lvm", PARTITION_LINUX_LVM_GUID},
{"u-boot-env", PARTITION_U_BOOT_ENVIRONMENT},
};
/*
* uuid_guid_get_bin() - this function get GUID bin for string
*
* @param guid_str - pointer to partition type string
* @param guid_bin - pointer to allocated array for big endian output [16B]
*/
int uuid_guid_get_bin(const char *guid_str, unsigned char *guid_bin)
{
int i;
for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
if (!strcmp(list_guid[i].string, guid_str)) {
memcpy(guid_bin, &list_guid[i].guid, 16);
return 0;
}
}
return -ENODEV;
}
/*
* uuid_guid_get_str() - this function get string for GUID.
*
* @param guid_bin - pointer to string with partition type guid [16B]
*
* Returns NULL if the type GUID is not known.
*/
const char *uuid_guid_get_str(const unsigned char *guid_bin)
{
int i;
for (i = 0; i < ARRAY_SIZE(list_guid); i++) {
if (!memcmp(list_guid[i].guid.b, guid_bin, 16)) {
return list_guid[i].string;
}
}
return NULL;
}
#endif
/*
* uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
*
* @param uuid_str - pointer to UUID or GUID string [37B] or GUID shorcut
* @param uuid_bin - pointer to allocated array for big endian output [16B]
* @str_format - UUID string format: 0 - UUID; 1 - GUID
*/
int uuid_str_to_bin(const char *uuid_str, unsigned char *uuid_bin,
int str_format)
{
uint16_t tmp16;
uint32_t tmp32;
uint64_t tmp64;
if (!uuid_str_valid(uuid_str)) {
#ifdef CONFIG_PARTITION_TYPE_GUID
if (!uuid_guid_get_bin(uuid_str, uuid_bin))
return 0;
#endif
return -EINVAL;
}
if (str_format == UUID_STR_FORMAT_STD) {
tmp32 = cpu_to_be32(simple_strtoul(uuid_str, NULL, 16));
memcpy(uuid_bin, &tmp32, 4);
tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 9, NULL, 16));
memcpy(uuid_bin + 4, &tmp16, 2);
tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 14, NULL, 16));
memcpy(uuid_bin + 6, &tmp16, 2);
} else {
tmp32 = cpu_to_le32(simple_strtoul(uuid_str, NULL, 16));
memcpy(uuid_bin, &tmp32, 4);
tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 9, NULL, 16));
memcpy(uuid_bin + 4, &tmp16, 2);
tmp16 = cpu_to_le16(simple_strtoul(uuid_str + 14, NULL, 16));
memcpy(uuid_bin + 6, &tmp16, 2);
}
tmp16 = cpu_to_be16(simple_strtoul(uuid_str + 19, NULL, 16));
memcpy(uuid_bin + 8, &tmp16, 2);
tmp64 = cpu_to_be64(simple_strtoull(uuid_str + 24, NULL, 16));
memcpy(uuid_bin + 10, (char *)&tmp64 + 2, 6);
return 0;
}
/*
* uuid_bin_to_str() - convert big endian binary data to string UUID or GUID.
*
* @param uuid_bin: pointer to binary data of UUID (big endian) [16B]
* @param uuid_str: pointer to allocated array for output string [37B]
* @str_format: bit 0: 0 - UUID; 1 - GUID
* bit 1: 0 - lower case; 2 - upper case
*/
void uuid_bin_to_str(const unsigned char *uuid_bin, char *uuid_str,
int str_format)
{
const u8 uuid_char_order[UUID_BIN_LEN] = {0, 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, 11, 12, 13, 14, 15};
const u8 guid_char_order[UUID_BIN_LEN] = {3, 2, 1, 0, 5, 4, 7, 6, 8,
9, 10, 11, 12, 13, 14, 15};
const u8 *char_order;
const char *format;
int i;
/*
* UUID and GUID bin data - always in big endian:
* 4B-2B-2B-2B-6B
* be be be be be
*/
if (str_format & UUID_STR_FORMAT_GUID)
char_order = guid_char_order;
else
char_order = uuid_char_order;
if (str_format & UUID_STR_UPPER_CASE)
format = "%02X";
else
format = "%02x";
for (i = 0; i < 16; i++) {
sprintf(uuid_str, format, uuid_bin[char_order[i]]);
uuid_str += 2;
switch (i) {
case 3:
case 5:
case 7:
case 9:
*uuid_str++ = '-';
break;
}
}
}
/*
* gen_rand_uuid() - this function generates a random binary UUID version 4.
* In this version all fields beside 4 bits of version and
* 2 bits of variant are randomly generated.
*
* @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
*/
#if defined(CONFIG_RANDOM_UUID) || defined(CONFIG_CMD_UUID)
void gen_rand_uuid(unsigned char *uuid_bin)
{
u32 ptr[4];
struct uuid *uuid = (struct uuid *)ptr;
int i;
srand(get_ticks() + rand());
/* Set all fields randomly */
for (i = 0; i < 4; i++)
ptr[i] = rand();
clrsetbits_be16(&uuid->time_hi_and_version,
UUID_VERSION_MASK,
UUID_VERSION << UUID_VERSION_SHIFT);
clrsetbits_8(&uuid->clock_seq_hi_and_reserved,
UUID_VARIANT_MASK,
UUID_VARIANT << UUID_VARIANT_SHIFT);
memcpy(uuid_bin, uuid, 16);
}
/*
* gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
* formats UUID or GUID.
*
* @param uuid_str - pointer to allocated array [37B].
* @param - uuid output type: UUID - 0, GUID - 1
*/
void gen_rand_uuid_str(char *uuid_str, int str_format)
{
unsigned char uuid_bin[UUID_BIN_LEN];
/* Generate UUID (big endian) */
gen_rand_uuid(uuid_bin);
/* Convert UUID bin to UUID or GUID formated STRING */
uuid_bin_to_str(uuid_bin, uuid_str, str_format);
}
#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_CMD_UUID)
int do_uuid(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
char uuid[UUID_STR_LEN + 1];
int str_format;
if (!strcmp(argv[0], "uuid"))
str_format = UUID_STR_FORMAT_STD;
else
str_format = UUID_STR_FORMAT_GUID;
if (argc > 2)
return CMD_RET_USAGE;
gen_rand_uuid_str(uuid, str_format);
if (argc == 1)
printf("%s\n", uuid);
else
env_set(argv[1], uuid);
return CMD_RET_SUCCESS;
}
U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
"UUID - generate random Universally Unique Identifier",
"[<varname>]\n"
"Argument:\n"
"varname: for set result in a environment variable\n"
"e.g. uuid uuid_env"
);
U_BOOT_CMD(guid, CONFIG_SYS_MAXARGS, 1, do_uuid,
"GUID - generate Globally Unique Identifier based on random UUID",
"[<varname>]\n"
"Argument:\n"
"varname: for set result in a environment variable\n"
"e.g. guid guid_env"
);
#endif /* CONFIG_CMD_UUID */
#endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */