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: - add new config: CONFIG_RANDOM_UUID: compile uuid.c and rand.c lib/uuid.c: - add gen_rand_uuid() - this function writes 16 bytes len binary representation 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.marc...@samsung.com> Cc: Jason Hobbs <jason.ho...@calxeda.com> Cc: Stephen Warren <swar...@nvidia.com> Cc: Lukasz Majewski <l.majew...@samsung.com> Cc: tr...@ti.com --- Changes v2: - put uuid generation changes in a separate commit - get_uuid_str() - change name to gen_rand_uuid_str() - add new function: gen_rand_uuid() - remove unnecessary '\0' at the end of uuid string - drop unnecessary error checking - functions now takes pointers to allocated memory instead of alloc it itself - add new config option: CONFIG_RANDOM_UUID Changes v3: - remove unused UUID_STR_BYTE_LEN - reword comments - remove null pointer checking from gen_rand_uuid() and gen_rand_uuid_str() - remove unneeded memset from gen_rand_uuid() - undo moving vsprintf.o object in lib/Makefile - add attribute "packed" to the uuid structure - gen_rand_uuid(): add endian functions for modify uuid data - gen_rand_uuid(): use memcpy() to store uuid data into given buffer for avoid unaligned access issues - change uuid version and variant masks to proper for use with clrsetbits_* - add #ifdef CONFIG_RANDOM_UUID to random uuid code for avoid warnings --- include/common.h | 5 +++- lib/Makefile | 3 +++ lib/uuid.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 84 insertions(+), 2 deletions(-) diff --git a/include/common.h b/include/common.h index 32377ad..20e9ae6 100644 --- a/include/common.h +++ b/include/common.h @@ -815,6 +815,8 @@ void udelay (unsigned long); void mdelay(unsigned long); /* lib/uuid.c */ +void gen_rand_uuid(unsigned char *uuid_bin); +void gen_rand_uuid_str(char *uuid_str); void uuid_bin_to_str(unsigned char *uuid, char *str); int uuid_str_to_bin(char *uuid, unsigned char *out); int uuid_str_valid(const char *uuid); @@ -831,7 +833,8 @@ char * strmhz(char *buf, unsigned long hz); /* lib/rand.c */ #if defined(CONFIG_RANDOM_MACADDR) || \ defined(CONFIG_BOOTP_RANDOM_DELAY) || \ - defined(CONFIG_CMD_LINK_LOCAL) + defined(CONFIG_CMD_LINK_LOCAL) || \ + defined(CONFIG_RANDOM_UUID) #define RAND_MAX -1U void srand(unsigned int seed); unsigned int rand(void); diff --git a/lib/Makefile b/lib/Makefile index 70962b2..fc7a24a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -62,7 +62,10 @@ obj-y += time.o obj-$(CONFIG_TRACE) += trace.o obj-$(CONFIG_BOOTP_PXE) += uuid.o obj-$(CONFIG_PARTITION_UUIDS) += uuid.o +obj-$(CONFIG_PARTITION_UUIDS) += rand.o obj-y += vsprintf.o +obj-$(CONFIG_RANDOM_UUID) += uuid.o +obj-$(CONFIG_RANDOM_UUID) += rand.o obj-$(CONFIG_RANDOM_MACADDR) += rand.o obj-$(CONFIG_BOOTP_RANDOM_DELAY) += rand.o obj-$(CONFIG_CMD_LINK_LOCAL) += rand.o diff --git a/lib/uuid.c b/lib/uuid.c index 925e501..0f22e14 100644 --- a/lib/uuid.c +++ b/lib/uuid.c @@ -7,8 +7,30 @@ #include <linux/ctype.h> #include <errno.h> #include <common.h> +#include <asm/io.h> +#include <part_efi.h> +#include <malloc.h> #define UUID_STR_LEN 36 +#define UUID_BIN_LEN 16 + +#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 + +/* 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; /* * This is what a UUID string looks like. @@ -21,7 +43,6 @@ * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx * le le le be be */ - int uuid_str_valid(const char *uuid) { int i, valid; @@ -95,3 +116,58 @@ void uuid_bin_to_str(unsigned char *uuid, char *str) } } } + +/* + * gen_rand_uuid() - this function generates a random binary UUID v4 and stores + * it into the memory pointed at by the supplied pointer, + * which must be 16 bytes in size + * + * Layout of UUID Version 4: + * 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 + * In this version all fields beside 4 bit version are randomly generated. + * source: https://www.ietf.org/rfc/rfc4122.txt + * + * @param uuid_bin pointer to 16 bytes len array +*/ +#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 a random string formatted + * UUID v4 and stores it into the memory pointed at by + * the supplied pointer, which must be 37 bytes in size + * + * @param uuid_str pointer to 37 bytes len array + */ +void gen_rand_uuid_str(char *uuid_str) +{ + unsigned char uuid_bin[UUID_BIN_LEN]; + + gen_rand_uuid(uuid_bin); + + uuid_bin_to_str(uuid_bin, uuid_str); +} +#endif -- 1.9.0 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot