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authorPrzemyslaw Marczak <p.marczak@samsung.com>2014-04-02 10:20:04 +0200
committerTom Rini <trini@ti.com>2014-04-02 16:35:53 -0400
commit4e4815feae4d37032a7afce18a4c26074c51f159 (patch)
tree41f1273b4a7cf133d7dc33aeb0759959bf353286
parentd718ded056eefb6239bd2e0a57b7f6d99c6e9e4b (diff)
downloadtalos-obmc-uboot-4e4815feae4d37032a7afce18a4c26074c51f159.tar.gz
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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>
-rw-r--r--include/config_fallbacks.h14
-rw-r--r--include/uuid.h22
-rw-r--r--lib/Makefile3
-rw-r--r--lib/uuid.c66
4 files changed, 100 insertions, 5 deletions
diff --git a/include/config_fallbacks.h b/include/config_fallbacks.h
index d8339b26cc..c6b20fd297 100644
--- a/include/config_fallbacks.h
+++ b/include/config_fallbacks.h
@@ -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
diff --git a/include/uuid.h b/include/uuid.h
index e8feeed7a5..93027c1b28 100644
--- a/include/uuid.h
+++ b/include/uuid.h
@@ -7,15 +7,35 @@
#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
diff --git a/lib/Makefile b/lib/Makefile
index d7ff7caa35..27e4f78bfd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -60,8 +60,7 @@ obj-$(CONFIG_REGEX) += slre.o
obj-y += string.o
obj-y += time.o
obj-$(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
diff --git a/lib/uuid.c b/lib/uuid.c
index 8db865fc69..44d0c932ac 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -14,8 +14,22 @@
/*
* 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):
*
@@ -149,3 +163,51 @@ void uuid_bin_to_str(unsigned char *uuid_bin, char *uuid_str, int str_format)
}
}
}
+
+/*
+ * 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
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