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 Update files: - include/common.h - lib/Makefile - lib/uuid.c lib/uuid.c: - add gen_rand_uuid() - this function writes 16 bytes len binary representation UUID v4 to address given by user. - add gen_rand_uuid_str() - this function writes 37 bytes len hexadecimal ASCII string representation of 16 bytes binary UUID to address given by user. Signed-off-by: Przemyslaw Marczak <p.marc...@samsung.com> cc: Stephen Warren <swar...@nvidia.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 --- include/common.h | 5 +++- lib/Makefile | 4 ++- lib/uuid.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 88 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..64a430f 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -59,10 +59,12 @@ obj-y += linux_string.o obj-$(CONFIG_REGEX) += slre.o obj-y += string.o obj-y += time.o +obj-y += vsprintf.o obj-$(CONFIG_TRACE) += trace.o obj-$(CONFIG_BOOTP_PXE) += uuid.o obj-$(CONFIG_PARTITION_UUIDS) += uuid.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 803bdcd..c0218ba 100644 --- a/lib/uuid.c +++ b/lib/uuid.c @@ -7,6 +7,29 @@ #include <linux/ctype.h> #include <errno.h> #include <common.h> +#include <part_efi.h> +#include <malloc.h> + +#define UUID_STR_LEN 36 +#define UUID_STR_BYTE_LEN 37 +#define UUID_BIN_BYTE_LEN 16 + +#define UUID_VERSION_CLEAR_BITS 0x0fff +#define UUID_VERSION_SHIFT 12 +#define UUID_VERSION 0x4 + +#define UUID_VARIANT_CLEAR_BITS 0x3f +#define UUID_VARIANT_SHIFT 7 +#define UUID_VARIANT 0x1 + +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]; +}; /* * This is what a UUID string looks like. @@ -94,3 +117,61 @@ void uuid_bin_to_str(unsigned char *uuid, char *str) } } } + +/* + * gen_rand_uuid() - this function generates 16 bytes len UUID V4 (randomly) + * and stores it at a given pointer. + * + * 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 +*/ +void gen_rand_uuid(unsigned char *uuid_bin) +{ + struct uuid *uuid = (struct uuid *)uuid_bin; + unsigned int *ptr = (unsigned int *)uuid_bin; + int i; + + if (!uuid_bin) + return; + + memset(uuid_bin, 0x0, sizeof(struct uuid)); + + /* Set all fields randomly */ + for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++) + *(ptr + i) = rand(); + + /* Set V4 format */ + uuid->time_hi_and_version &= UUID_VERSION_CLEAR_BITS; + uuid->time_hi_and_version |= UUID_VERSION << UUID_VERSION_SHIFT; + + uuid->clock_seq_hi_and_reserved &= UUID_VARIANT_CLEAR_BITS; + uuid->clock_seq_hi_and_reserved |= UUID_VARIANT << UUID_VARIANT_SHIFT; +} + +/* + * gen_rand_uuid_str() - this function generates UUID v4 (randomly) + * into 36 character hexadecimal ASCII string representation of a 128-bit + * (16 octets) UUID (Universally Unique Identifier) version 4 based on RFC4122 + * and stores it at a given pointer. + * + * @param uuid_str pointer to 37 bytes len array + */ +void gen_rand_uuid_str(char *uuid_str) +{ + unsigned char uuid_bin[UUID_BIN_BYTE_LEN]; + + if (!uuid_str) + return; + + gen_rand_uuid(uuid_bin); + + uuid_bin_to_str(uuid_bin, uuid_str); +} -- 1.7.9.5 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
