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/*
* libuuid - library for generating UUIDs
*
* Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
* Copyright (C) 2002 Tim Jansen
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU
* Library General Public License.
* %End-Header%
*
* 2002-12-15, tim@tjansen.de:
* merged all *.c files,
* replaced all function that are not needed to generate a time uuid,
* added createUUID()
*/
#include "uuid.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#ifndef _SVID_SOURCE
#define _SVID_SOURCE
#endif
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_SRANDOM
#define srand(x) srandom(x)
#define rand() random()
#endif
typedef unsigned char uuid_t[16];
typedef unsigned char __u8;
typedef unsigned short __u16;
typedef unsigned int __u32;
struct uuid {
__u32 time_low;
__u16 time_mid;
__u16 time_hi_and_version;
__u16 clock_seq;
__u8 node[6];
};
void uuid_unpack(const uuid_t in, struct uuid *uu)
{
const __u8 *ptr = in;
__u32 tmp;
tmp = *ptr++;
tmp = (tmp << 8) | *ptr++;
tmp = (tmp << 8) | *ptr++;
tmp = (tmp << 8) | *ptr++;
uu->time_low = tmp;
tmp = *ptr++;
tmp = (tmp << 8) | *ptr++;
uu->time_mid = tmp;
tmp = *ptr++;
tmp = (tmp << 8) | *ptr++;
uu->time_hi_and_version = tmp;
tmp = *ptr++;
tmp = (tmp << 8) | *ptr++;
uu->clock_seq = tmp;
memcpy(uu->node, ptr, 6);
}
static int get_random_fd(void)
{
struct timeval tv;
static int fd = -2;
int i;
if (fd == -2) {
gettimeofday(&tv, 0);
fd = open("/dev/urandom", O_RDONLY);
if (fd == -1)
fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec);
}
/* Crank the random number generator a few times */
gettimeofday(&tv, 0);
for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--)
rand();
return fd;
}
/*
* Generate a series of random bytes. Use /dev/urandom if possible,
* and if not, use srandom/random.
*/
static void get_random_bytes(void *buf, int nbytes)
{
int i, fd = get_random_fd();
int lose_counter = 0;
char *cp = (char *) buf;
if (fd >= 0) {
while (nbytes > 0) {
i = read(fd, cp, nbytes);
if (i <= 0) {
if (lose_counter++ > 16)
break;
continue;
}
nbytes -= i;
cp += i;
lose_counter = 0;
}
}
/* XXX put something better here if no /dev/random! */
for (i = 0; i < nbytes; i++)
*cp++ = rand() & 0xFF;
return;
}
/* Assume that the gettimeofday() has microsecond granularity */
#define MAX_ADJUSTMENT 10
static int get_clock(__u32 *clock_high, __u32 *clock_low, __u16 *ret_clock_seq)
{
static int adjustment = 0;
static struct timeval last = {0, 0};
static __u16 clock_seq;
struct timeval tv;
unsigned long long clock_reg;
try_again:
gettimeofday(&tv, 0);
if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
get_random_bytes(&clock_seq, sizeof(clock_seq));
clock_seq &= 0x1FFF;
last = tv;
last.tv_sec--;
}
if ((tv.tv_sec < last.tv_sec) ||
((tv.tv_sec == last.tv_sec) &&
(tv.tv_usec < last.tv_usec))) {
clock_seq = (clock_seq+1) & 0x1FFF;
adjustment = 0;
last = tv;
} else if ((tv.tv_sec == last.tv_sec) &&
(tv.tv_usec == last.tv_usec)) {
if (adjustment >= MAX_ADJUSTMENT)
goto try_again;
adjustment++;
} else {
adjustment = 0;
last = tv;
}
clock_reg = tv.tv_usec*10 + adjustment;
clock_reg += ((unsigned long long) tv.tv_sec)*10000000;
clock_reg += (((unsigned long long) 0x01B21DD2) << 32) + 0x13814000;
*clock_high = clock_reg >> 32;
*clock_low = clock_reg;
*ret_clock_seq = clock_seq;
return 0;
}
static void uuid_pack(const struct uuid *uu, uuid_t ptr)
{
__u32 tmp;
unsigned char *out = ptr;
tmp = uu->time_low;
out[3] = (unsigned char) tmp;
tmp >>= 8;
out[2] = (unsigned char) tmp;
tmp >>= 8;
out[1] = (unsigned char) tmp;
tmp >>= 8;
out[0] = (unsigned char) tmp;
tmp = uu->time_mid;
out[5] = (unsigned char) tmp;
tmp >>= 8;
out[4] = (unsigned char) tmp;
tmp = uu->time_hi_and_version;
out[7] = (unsigned char) tmp;
tmp >>= 8;
out[6] = (unsigned char) tmp;
tmp = uu->clock_seq;
out[9] = (unsigned char) tmp;
tmp >>= 8;
out[8] = (unsigned char) tmp;
memcpy(out+10, uu->node, 6);
}
static void uuid_generate_time(uuid_t out)
{
static unsigned char node_id[6];
struct uuid uu;
__u32 clock_mid;
get_random_bytes(node_id, 6);
get_clock(&clock_mid, &uu.time_low, &uu.clock_seq);
uu.clock_seq |= 0x8000;
uu.time_mid = (__u16) clock_mid;
uu.time_hi_and_version = (clock_mid >> 16) | 0x1000;
memcpy(uu.node, node_id, 6);
uuid_pack(&uu, out);
}
static void uuid_unparse(const uuid_t uu, char *out)
{
struct uuid uuid;
uuid_unpack(uu, &uuid);
sprintf(out,
"%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
uuid.time_low, uuid.time_mid, uuid.time_hi_and_version,
uuid.clock_seq >> 8, uuid.clock_seq & 0xFF,
uuid.node[0], uuid.node[1], uuid.node[2],
uuid.node[3], uuid.node[4], uuid.node[5]);
}
QString createUUID() {
char s[37];
uuid_t uu;
uuid_generate_time(uu);
uuid_unparse(uu, s);
return QString(s);
}
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