diff options
| -rw-r--r-- | include/libbb.h | 3 | ||||
| -rw-r--r-- | libbb/xfuncs.c | 63 | ||||
| -rw-r--r-- | util-linux/mkswap.c | 92 |
3 files changed, 79 insertions, 79 deletions
diff --git a/include/libbb.h b/include/libbb.h index be175d7..6e629d1 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -701,6 +701,9 @@ const char *make_human_readable_str(unsigned long long size, /* Put a string of hex bytes ("1b2e66fe"...), return advanced pointer */ char *bin2hex(char *buf, const char *cp, int count) FAST_FUNC; +/* Generate a UUID */ +void generate_uuid(uint8_t *buf) FAST_FUNC; + /* Last element is marked by mult == 0 */ struct suffix_mult { char suffix[4]; diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c index aa08129..e47b01d 100644 --- a/libbb/xfuncs.c +++ b/libbb/xfuncs.c @@ -209,3 +209,66 @@ int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp) { return tcsetattr(STDIN_FILENO, TCSANOW, tp); } + +void FAST_FUNC generate_uuid(uint8_t *buf) +{ + /* http://www.ietf.org/rfc/rfc4122.txt + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | time_low | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | time_mid | time_hi_and_version | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |clk_seq_and_variant | node (0-1) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | node (2-5) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * IOW, uuid has this layout: + * uint32_t time_low (big endian) + * uint16_t time_mid (big endian) + * uint16_t time_hi_and_version (big endian) + * version is a 4-bit field: + * 1 Time-based + * 2 DCE Security, with embedded POSIX UIDs + * 3 Name-based (MD5) + * 4 Randomly generated + * 5 Name-based (SHA-1) + * uint16_t clk_seq_and_variant (big endian) + * variant is a 3-bit field: + * 0xx Reserved, NCS backward compatibility + * 10x The variant specified in rfc4122 + * 110 Reserved, Microsoft backward compatibility + * 111 Reserved for future definition + * uint8_t node[6] + * + * For version 4, these bits are set/cleared: + * time_hi_and_version & 0x0fff | 0x4000 + * clk_seq_and_variant & 0x3fff | 0x8000 + */ + pid_t pid; + int i; + + i = open("/dev/urandom", O_RDONLY); + if (i >= 0) { + read(i, buf, 16); + close(i); + } + /* Paranoia. /dev/urandom may be missing. + * rand() is guaranteed to generate at least [0, 2^15) range, + * but lowest bits in some libc are not so "random". */ + srand(monotonic_us()); + pid = getpid(); + while (1) { + for (i = 0; i < 16; i++) + buf[i] ^= rand() >> 5; + if (pid == 0) + break; + srand(pid); + pid = 0; + } + + /* version = 4 */ + buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; + /* variant = 10x */ + buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; +} diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c index f718843..226831b 100644 --- a/util-linux/mkswap.c +++ b/util-linux/mkswap.c @@ -50,84 +50,6 @@ static void mkswap_selinux_setcontext(int fd, const char *path) # define mkswap_selinux_setcontext(fd, path) ((void)0) #endif -#if ENABLE_FEATURE_MKSWAP_UUID -static void mkswap_generate_uuid(uint8_t *buf) -{ - /* http://www.ietf.org/rfc/rfc4122.txt - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | time_low | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | time_mid | time_hi_and_version | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * |clk_seq_and_variant | node (0-1) | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * | node (2-5) | - * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - * IOW, uuid has this layout: - * uint32_t time_low (big endian) - * uint16_t time_mid (big endian) - * uint16_t time_hi_and_version (big endian) - * version is a 4-bit field: - * 1 Time-based - * 2 DCE Security, with embedded POSIX UIDs - * 3 Name-based (MD5) - * 4 Randomly generated - * 5 Name-based (SHA-1) - * uint16_t clk_seq_and_variant (big endian) - * variant is a 3-bit field: - * 0xx Reserved, NCS backward compatibility - * 10x The variant specified in rfc4122 - * 110 Reserved, Microsoft backward compatibility - * 111 Reserved for future definition - * uint8_t node[6] - * - * For version 4, these bits are set/cleared: - * time_hi_and_version & 0x0fff | 0x4000 - * clk_seq_and_variant & 0x3fff | 0x8000 - */ - pid_t pid; - int i; - char uuid_string[32]; - - i = open("/dev/urandom", O_RDONLY); - if (i >= 0) { - read(i, buf, 16); - close(i); - } - /* Paranoia. /dev/urandom may be missing. - * rand() is guaranteed to generate at least [0, 2^15) range, - * but lowest bits in some libc are not so "random". */ - srand(monotonic_us()); - pid = getpid(); - while (1) { - for (i = 0; i < 16; i++) - buf[i] ^= rand() >> 5; - if (pid == 0) - break; - srand(pid); - pid = 0; - } - - /* version = 4 */ - buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) | 0x40; - /* variant = 10x */ - buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80; - - bin2hex(uuid_string, (void*) buf, 16); - /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */ - printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n", - uuid_string, - uuid_string+8, - uuid_string+8+4, - uuid_string+8+4+4, - uuid_string+8+4+4+4 - ); -} -#else -# define mkswap_generate_uuid(buf) ((void)0) -#endif - #if 0 /* from Linux 2.6.23 */ /* * Magic header for a swap area. The first part of the union is @@ -190,7 +112,19 @@ int mkswap_main(int argc, char **argv) // Make a header. hdr is zero-filled so far... hdr[0] = 1; hdr[1] = (len / pagesize) - 1; - mkswap_generate_uuid((void*) &hdr[3]); +#if ENABLE_FEATURE_MKSWAP_UUID + char uuid_string[32]; + generate_uuid((void*) &hdr[3]); + bin2hex(uuid_string, (void*) &hdr[3], 16); + /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */ + printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n", + uuid_string, + uuid_string+8, + uuid_string+8+4, + uuid_string+8+4+4, + uuid_string+8+4+4+4 + ); +#endif // Write the header. Sync to disk because some kernel versions check // signature on disk (not in cache) during swapon. |