/*
   * Copyright 2011 Calxeda, Inc.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include <common.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;
  }
  
  /*
   * uuid_str_to_bin() - convert string UUID or GUID to big endian binary data.
   *
   * @param uuid_str - pointer to UUID or GUID string [37B]
   * @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(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))
  		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     - UUID string format: 0 - UUID; 1 - GUID
   */
  void uuid_bin_to_str(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;
  	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_STD)
  		char_order = uuid_char_order;
  	else
  		char_order = guid_char_order;
  
  	for (i = 0; i < 16; i++) {
  		sprintf(uuid_str, "%02x", 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)
  {
  	struct uuid uuid;
  	unsigned int *ptr = (unsigned int *)&uuid;
  	int i;
  
  	/* Set all fields randomly */
  	for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
  		*(ptr + i) = cpu_to_be32(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, sizeof(struct uuid));
  }
  
  /*
   * 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);
  }
  
  #ifdef CONFIG_CMD_UUID
  int do_uuid(cmd_tbl_t *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
  ", uuid);
  	else
  		setenv(argv[1], uuid);
  
  	return CMD_RET_SUCCESS;
  }
  
  U_BOOT_CMD(uuid, CONFIG_SYS_MAXARGS, 1, do_uuid,
  	   "UUID - generate random Universally Unique Identifier",
  	   "[<varname>]
  "
  	   "Argument:
  "
  	   "varname: for set result in a environment variable
  "
  	   "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>]
  "
  	   "Argument:
  "
  	   "varname: for set result in a environment variable
  "
  	   "e.g. guid guid_env"
  );
  #endif /* CONFIG_CMD_UUID */
  #endif /* CONFIG_RANDOM_UUID || CONFIG_CMD_UUID */