diff options
Diffstat (limited to 'util-linux')
| -rw-r--r-- | util-linux/mkswap.c | 92 |
1 files changed, 13 insertions, 79 deletions
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. |