// 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>
#include <dm/uclass.h>
#include <rng.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(hextoul(uuid_str, NULL));
                memcpy(uuid_bin, &tmp32, 4);

                tmp16 = cpu_to_be16(hextoul(uuid_str + 9, NULL));
                memcpy(uuid_bin + 4, &tmp16, 2);

                tmp16 = cpu_to_be16(hextoul(uuid_str + 14, NULL));
                memcpy(uuid_bin + 6, &tmp16, 2);
        } else {
                tmp32 = cpu_to_le32(hextoul(uuid_str, NULL));
                memcpy(uuid_bin, &tmp32, 4);

                tmp16 = cpu_to_le16(hextoul(uuid_str + 9, NULL));
                memcpy(uuid_bin + 4, &tmp16, 2);

                tmp16 = cpu_to_le16(hextoul(uuid_str + 14, NULL));
                memcpy(uuid_bin + 6, &tmp16, 2);
        }

        tmp16 = cpu_to_be16(hextoul(uuid_str + 19, NULL));
        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, ret;
        struct udevice *devp;
        u32 randv = 0;

        if (IS_ENABLED(CONFIG_DM_RNG)) {
                ret = uclass_get_device(UCLASS_RNG, 0, &devp);
                if (!ret) {
                        ret = dm_rng_read(devp, &randv, sizeof(randv));
                        if (ret < 0)
                                randv = 0;
                }
        }
        if (randv)
                srand(randv);
        else
                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 */