From 2b1b0d66704a8cafe83be7114ec4c15ab3a314ad Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 20 May 2016 17:01:04 -0700 Subject: [PATCH] lib/uuid.c: introduce a few more generic helpers There are new helpers in this patch: uuid_is_valid checks if a UUID is valid uuid_be_to_bin converts from string to binary (big endian) uuid_le_to_bin converts from string to binary (little endian) They will be used in future, i.e. in the following patches in the series. This also moves the indices arrays to lib/uuid.c to be shared accross modules. [andriy.shevchenko@linux.intel.com: fix typo] Signed-off-by: Andy Shevchenko Reviewed-by: Matt Fleming Cc: Dmitry Kasatkin Cc: Mimi Zohar Cc: Rasmus Villemoes Cc: Arnd Bergmann Cc: "Theodore Ts'o" Cc: Al Viro Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/uuid.h | 13 +++++++++ lib/uuid.c | 65 ++++++++++++++++++++++++++++++++++++++++++++ lib/vsprintf.c | 9 +++--- 3 files changed, 82 insertions(+), 5 deletions(-) diff --git a/include/linux/uuid.h b/include/linux/uuid.h index 91c2b6d9cbb7..e0b95e728a77 100644 --- a/include/linux/uuid.h +++ b/include/linux/uuid.h @@ -22,6 +22,11 @@ #include +/* + * The length of a UUID string ("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee") + * not including trailing NUL. + */ +#define UUID_STRING_LEN 36 static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2) { @@ -38,4 +43,12 @@ void generate_random_uuid(unsigned char uuid[16]); extern void uuid_le_gen(uuid_le *u); extern void uuid_be_gen(uuid_be *u); +bool __must_check uuid_is_valid(const char *uuid); + +extern const u8 uuid_le_index[16]; +extern const u8 uuid_be_index[16]; + +int uuid_le_to_bin(const char *uuid, uuid_le *u); +int uuid_be_to_bin(const char *uuid, uuid_be *u); + #endif diff --git a/lib/uuid.c b/lib/uuid.c index 6c81c0b0467e..82787f652fbc 100644 --- a/lib/uuid.c +++ b/lib/uuid.c @@ -19,10 +19,17 @@ */ #include +#include +#include #include #include #include +const u8 uuid_le_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; +EXPORT_SYMBOL(uuid_le_index); +const u8 uuid_be_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; +EXPORT_SYMBOL(uuid_be_index); + /*************************************************************** * Random UUID interface * @@ -65,3 +72,61 @@ void uuid_be_gen(uuid_be *bu) bu->b[6] = (bu->b[6] & 0x0F) | 0x40; } EXPORT_SYMBOL_GPL(uuid_be_gen); + +/** + * uuid_is_valid - checks if UUID string valid + * @uuid: UUID string to check + * + * Description: + * It checks if the UUID string is following the format: + * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx + * where x is a hex digit. + * + * Return: true if input is valid UUID string. + */ +bool uuid_is_valid(const char *uuid) +{ + unsigned int i; + + for (i = 0; i < UUID_STRING_LEN; i++) { + if (i == 8 || i == 13 || i == 18 || i == 23) { + if (uuid[i] != '-') + return false; + } else if (!isxdigit(uuid[i])) { + return false; + } + } + + return true; +} +EXPORT_SYMBOL(uuid_is_valid); + +static int __uuid_to_bin(const char *uuid, __u8 b[16], const u8 ei[16]) +{ + static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34}; + unsigned int i; + + if (!uuid_is_valid(uuid)) + return -EINVAL; + + for (i = 0; i < 16; i++) { + int hi = hex_to_bin(uuid[si[i]] + 0); + int lo = hex_to_bin(uuid[si[i]] + 1); + + b[ei[i]] = (hi << 4) | lo; + } + + return 0; +} + +int uuid_le_to_bin(const char *uuid, uuid_le *u) +{ + return __uuid_to_bin(uuid, u->b, uuid_le_index); +} +EXPORT_SYMBOL(uuid_le_to_bin); + +int uuid_be_to_bin(const char *uuid, uuid_be *u) +{ + return __uuid_to_bin(uuid, u->b, uuid_be_index); +} +EXPORT_SYMBOL(uuid_be_to_bin); diff --git a/lib/vsprintf.c b/lib/vsprintf.c index be0e7cf11e48..0967771d8f7f 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #ifdef CONFIG_BLOCK #include @@ -1304,19 +1305,17 @@ static noinline_for_stack char *uuid_string(char *buf, char *end, const u8 *addr, struct printf_spec spec, const char *fmt) { - char uuid[sizeof("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")]; + char uuid[UUID_STRING_LEN + 1]; char *p = uuid; int i; - static const u8 be[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; - static const u8 le[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; - const u8 *index = be; + const u8 *index = uuid_be_index; bool uc = false; switch (*(++fmt)) { case 'L': uc = true; /* fall-through */ case 'l': - index = le; + index = uuid_le_index; break; case 'B': uc = true;