lib: uuid: add functions to generate UUID version 4

This patch adds support to generate UUID (Universally Unique Identifier) in version 4 based on RFC4122, which is randomly. Source: https://www.ietf.org/rfc/rfc4122.txt Changes: - new configs: - CONFIG_LIB_UUID for compile lib/uuid.c - CONFIG_RANDOM_UUID for functions gen_rand_uuid() and gen_rand_uuid_str() - add configs dependency to include/config_fallbacks.h for lib uuid. lib/uuid.c: - add gen_rand_uuid() - this function writes 16 bytes len binary representation of UUID v4 to the memory at given address. - add gen_rand_uuid_str() - this function writes 37 bytes len hexadecimal ASCII string representation of UUID v4 to the memory at given address. Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com> Cc: Stephen Warren <swarren@nvidia.com> Cc: Lukasz Majewski <l.majewski@samsung.com> [trini: Add CONFIG_EFI_PARTITION to fallbacks] Signed-off-by: Tom Rini <trini@ti.com>

lib: uuid: add functions to generate UUID version 4
This patch adds support to generate UUID (Universally Unique Identifier) in version 4 based on RFC4122, which is randomly. Source: https://www.ietf.org/rfc/rfc4122.txt Changes: - new configs: - CONFIG_LIB_UUID for compile lib/uuid.c - CONFIG_RANDOM_UUID for functions gen_rand_uuid() and gen_rand_uuid_str() - add configs dependency to include/config_fallbacks.h for lib uuid. lib/uuid.c: - add gen_rand_uuid() - this function writes 16 bytes len binary representation of UUID v4 to the memory at given address. - add gen_rand_uuid_str() - this function writes 37 bytes len hexadecimal ASCII string representation of UUID v4 to the memory at given address. Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com> Cc: Stephen Warren <swarren@nvidia.com> Cc: Lukasz Majewski <l.majewski@samsung.com> [trini: Add CONFIG_EFI_PARTITION to fallbacks] Signed-off-by: Tom Rini <trini@ti.com>
Przemyslaw Marczak · Tom Rini
1 parent d718ded056
Showing 4 changed files with 100 additions and 5 deletions Side-by-side Diff
include/config_fallbacks.h
include/uuid.h
lib/Makefile
lib/uuid.c
@@ -55,6 +55,20 @@
 #define HAVE_BLOCK_DEVICE
 #endif
  
+#if (defined(CONFIG_PARTITION_UUIDS) || \
+	defined(CONFIG_EFI_PARTITION) || \
+	defined(CONFIG_RANDOM_UUID) || \
+	defined(CONFIG_BOOTP_PXE)) && \
+	!defined(CONFIG_LIB_UUID)
+#define CONFIG_LIB_UUID
+#endif
+
+#if defined(CONFIG_RANDOM_UUID) && \
+	!defined(CONFIG_LIB_RAND) && \
+	!defined(CONFIG_LIB_HW_RAND)
+#define CONFIG_LIB_RAND
+#endif
+
 #ifndef CONFIG_SYS_PROMPT
 #define CONFIG_SYS_PROMPT	"=> "
 #endif
@@ -7,16 +7,36 @@
 #ifndef __UUID_H__
 #define __UUID_H__
  
+/* This is structure is in big-endian */
+struct uuid {
+	unsigned int time_low;
+	unsigned short time_mid;
+	unsigned short time_hi_and_version;
+	unsigned char clock_seq_hi_and_reserved;
+	unsigned char clock_seq_low;
+	unsigned char node[6];
+} __packed;
+
 enum {
 	UUID_STR_FORMAT_STD,
 	UUID_STR_FORMAT_GUID
 };
  
 #define UUID_STR_LEN		36
-#define UUID_BIN_LEN		16
+#define UUID_BIN_LEN		sizeof(struct uuid)
  
+#define UUID_VERSION_MASK	0xf000
+#define UUID_VERSION_SHIFT	12
+#define UUID_VERSION		0x4
+
+#define UUID_VARIANT_MASK	0xc0
+#define UUID_VARIANT_SHIFT	7
+#define UUID_VARIANT		0x1
+
 int uuid_str_valid(const char *uuid);
 int uuid_str_to_bin(char *uuid_str, unsigned char *uuid_bin, int str_format);
 void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format);
+void gen_rand_uuid(unsigned char *uuid_bin);
+void gen_rand_uuid_str(char *uuid_str, int str_format);
 #endif
@@ -60,8 +60,7 @@
 obj-y += string.o
 obj-y += time.o
 obj-$(CONFIG_TRACE) += trace.o
-obj-$(CONFIG_BOOTP_PXE) += uuid.o
-obj-$(CONFIG_PARTITION_UUIDS) += uuid.o
+obj-$(CONFIG_LIB_UUID) += uuid.o
 obj-y += vsprintf.o
 obj-$(CONFIG_LIB_RAND) += rand.o
  
@@ -14,9 +14,23 @@
 /*
  * UUID - Universally Unique IDentifier - 128 bits unique number.
  *        There are 5 versions and one variant of UUID defined by RFC4122
- *        specification. Depends on version uuid number base on a time,
- *        host name, MAC address or random data.
+ *        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)
@@ -149,4 +163,52 @@
 		}
 	}
 }
+
+/*
+ * 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.
+*/
+#ifdef CONFIG_RANDOM_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);
+}
+#endif
...	...	@@ -55,6 +55,20 @@
55	55	#define HAVE_BLOCK_DEVICE
56	56	#endif
57	57
	58	+#if (defined(CONFIG_PARTITION_UUIDS) \|\| \
	59	+ defined(CONFIG_EFI_PARTITION) \|\| \
	60	+ defined(CONFIG_RANDOM_UUID) \|\| \
	61	+ defined(CONFIG_BOOTP_PXE)) && \
	62	+ !defined(CONFIG_LIB_UUID)
	63	+#define CONFIG_LIB_UUID
	64	+#endif
	65	+
	66	+#if defined(CONFIG_RANDOM_UUID) && \
	67	+ !defined(CONFIG_LIB_RAND) && \
	68	+ !defined(CONFIG_LIB_HW_RAND)
	69	+#define CONFIG_LIB_RAND
	70	+#endif
	71	+
58	72	#ifndef CONFIG_SYS_PROMPT
59	73	#define CONFIG_SYS_PROMPT "=> "
60	74	#endif
...	...	@@ -7,16 +7,36 @@
7	7	#ifndef __UUID_H__
8	8	#define __UUID_H__
9	9
	10	+/* This is structure is in big-endian */
	11	+struct uuid {
	12	+ unsigned int time_low;
	13	+ unsigned short time_mid;
	14	+ unsigned short time_hi_and_version;
	15	+ unsigned char clock_seq_hi_and_reserved;
	16	+ unsigned char clock_seq_low;
	17	+ unsigned char node[6];
	18	+} __packed;
	19	+
10	20	enum {
11	21	UUID_STR_FORMAT_STD,
12	22	UUID_STR_FORMAT_GUID
13	23	};
14	24
15	25	#define UUID_STR_LEN 36
16		-#define UUID_BIN_LEN 16
	26	+#define UUID_BIN_LEN sizeof(struct uuid)
17	27
	28	+#define UUID_VERSION_MASK 0xf000
	29	+#define UUID_VERSION_SHIFT 12
	30	+#define UUID_VERSION 0x4
	31	+
	32	+#define UUID_VARIANT_MASK 0xc0
	33	+#define UUID_VARIANT_SHIFT 7
	34	+#define UUID_VARIANT 0x1
	35	+
18	36	int uuid_str_valid(const char *uuid);
19	37	int uuid_str_to_bin(char uuid_str, unsigned char uuid_bin, int str_format);
20	38	void uuid_bin_to_str(unsigned char uuid_bin, char uuid_str, int str_format);
	39	+void gen_rand_uuid(unsigned char *uuid_bin);
	40	+void gen_rand_uuid_str(char *uuid_str, int str_format);
21	41	#endif
...	...	@@ -60,8 +60,7 @@
60	60	obj-y += string.o
61	61	obj-y += time.o
62	62	obj-$(CONFIG_TRACE) += trace.o
63		-obj-$(CONFIG_BOOTP_PXE) += uuid.o
64		-obj-$(CONFIG_PARTITION_UUIDS) += uuid.o
	63	+obj-$(CONFIG_LIB_UUID) += uuid.o
65	64	obj-y += vsprintf.o
66	65	obj-$(CONFIG_LIB_RAND) += rand.o
67	66
...	...	@@ -14,9 +14,23 @@
14	14	/*
15	15	* UUID - Universally Unique IDentifier - 128 bits unique number.
16	16	* There are 5 versions and one variant of UUID defined by RFC4122
17		- * specification. Depends on version uuid number base on a time,
18		- * host name, MAC address or random data.
	17	+ * specification. A UUID contains a set of fields. The set varies
	18	+ * depending on the version of the UUID, as shown below:
	19	+ * - time, MAC address(v1),
	20	+ * - user ID(v2),
	21	+ * - MD5 of name or URL(v3),
	22	+ * - random data(v4),
	23	+ * - SHA-1 of name or URL(v5),
19	24	*
	25	+ * Layout of UUID:
	26	+ * timestamp - 60-bit: time_low, time_mid, time_hi_and_version
	27	+ * version - 4 bit (bit 4 through 7 of the time_hi_and_version)
	28	+ * clock seq - 14 bit: clock_seq_hi_and_reserved, clock_seq_low
	29	+ * variant: - bit 6 and 7 of clock_seq_hi_and_reserved
	30	+ * node - 48 bit
	31	+ *
	32	+ * source: https://www.ietf.org/rfc/rfc4122.txt
	33	+ *
20	34	* UUID binary format (16 bytes):
21	35	*
22	36	* 4B-2B-2B-2B-6B (big endian - network byte order)
...	...	@@ -149,4 +163,52 @@
149	163	}
150	164	}
151	165	}
	166	+
	167	+/*
	168	+ * gen_rand_uuid() - this function generates a random binary UUID version 4.
	169	+ * In this version all fields beside 4 bits of version and
	170	+ * 2 bits of variant are randomly generated.
	171	+ *
	172	+ * @param uuid_bin - pointer to allocated array [16B]. Output is in big endian.
	173	+*/
	174	+#ifdef CONFIG_RANDOM_UUID
	175	+void gen_rand_uuid(unsigned char *uuid_bin)
	176	+{
	177	+ struct uuid uuid;
	178	+ unsigned int ptr = (unsigned int )&uuid;
	179	+ int i;
	180	+
	181	+ /* Set all fields randomly */
	182	+ for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++)
	183	+ *(ptr + i) = cpu_to_be32(rand());
	184	+
	185	+ clrsetbits_be16(&uuid.time_hi_and_version,
	186	+ UUID_VERSION_MASK,
	187	+ UUID_VERSION << UUID_VERSION_SHIFT);
	188	+
	189	+ clrsetbits_8(&uuid.clock_seq_hi_and_reserved,
	190	+ UUID_VARIANT_MASK,
	191	+ UUID_VARIANT << UUID_VARIANT_SHIFT);
	192	+
	193	+ memcpy(uuid_bin, &uuid, sizeof(struct uuid));
	194	+}
	195	+
	196	+/*
	197	+ * gen_rand_uuid_str() - this function generates UUID v4 (random) in two string
	198	+ * formats UUID or GUID.
	199	+ *
	200	+ * @param uuid_str - pointer to allocated array [37B].
	201	+ * @param - uuid output type: UUID - 0, GUID - 1
	202	+ */
	203	+void gen_rand_uuid_str(char *uuid_str, int str_format)
	204	+{
	205	+ unsigned char uuid_bin[UUID_BIN_LEN];
	206	+
	207	+ /* Generate UUID (big endian) */
	208	+ gen_rand_uuid(uuid_bin);
	209	+
	210	+ /* Convert UUID bin to UUID or GUID formated STRING */
	211	+ uuid_bin_to_str(uuid_bin, uuid_str, str_format);
	212	+}
	213	+#endif