311 lines
7.7 KiB
C
311 lines
7.7 KiB
C
/*
|
|
* gen_uuid.c --- generate a DCE-compatible uuid
|
|
*
|
|
* Copyright (C) 1996, 1997, 1998, 1999 Theodore Ts'o.
|
|
*
|
|
* %Begin-Header%
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, and the entire permission notice in its entirety,
|
|
* including the disclaimer of warranties.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. The name of the author may not be used to endorse or promote
|
|
* products derived from this software without specific prior
|
|
* written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
|
|
* WHICH ARE HEREBY DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
|
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
|
|
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
|
|
* USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
|
|
* DAMAGE.
|
|
* %End-Header%
|
|
*/
|
|
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
#ifdef HAVE_STDLIB_H
|
|
#include <stdlib.h>
|
|
#endif
|
|
#include <string.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <sys/types.h>
|
|
#include <sys/time.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/file.h>
|
|
#ifdef HAVE_SYS_IOCTL_H
|
|
#include <sys/ioctl.h>
|
|
#endif
|
|
#ifdef HAVE_SYS_SOCKET_H
|
|
#include <sys/socket.h>
|
|
#endif
|
|
#ifdef HAVE_SYS_SOCKIO_H
|
|
#include <sys/sockio.h>
|
|
#endif
|
|
#ifdef HAVE_NET_IF_H
|
|
#include <net/if.h>
|
|
#endif
|
|
#ifdef HAVE_NETINET_IN_H
|
|
#include <netinet/in.h>
|
|
#endif
|
|
#ifdef HAVE_NET_IF_DL_H
|
|
#include <net/if_dl.h>
|
|
#endif
|
|
|
|
#include "uuidP.h"
|
|
|
|
#ifdef HAVE_SRANDOM
|
|
#define srand(x) srandom(x)
|
|
#define rand() random()
|
|
#endif
|
|
|
|
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, n = nbytes, fd = get_random_fd();
|
|
int lose_counter = 0;
|
|
unsigned char *cp = (unsigned char *) buf;
|
|
|
|
if (fd >= 0) {
|
|
while (n > 0) {
|
|
i = read(fd, cp, n);
|
|
if (i <= 0) {
|
|
if (lose_counter++ > 16)
|
|
break;
|
|
continue;
|
|
}
|
|
n -= i;
|
|
cp += i;
|
|
lose_counter = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We do this all the time, but this is the only source of
|
|
* randomness if /dev/random/urandom is out to lunch.
|
|
*/
|
|
for (cp = buf, i = 0; i < nbytes; i++)
|
|
*cp++ ^= (rand() >> 7) & 0xFF;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Get the ethernet hardware address, if we can find it...
|
|
*/
|
|
static int get_node_id(unsigned char *node_id)
|
|
{
|
|
#ifdef HAVE_NET_IF_H
|
|
int sd;
|
|
struct ifreq ifr, *ifrp;
|
|
struct ifconf ifc;
|
|
char buf[1024];
|
|
int n, i;
|
|
unsigned char *a;
|
|
#ifdef HAVE_NET_IF_DL_H
|
|
struct sockaddr_dl *sdlp;
|
|
#endif
|
|
|
|
/*
|
|
* BSD 4.4 defines the size of an ifreq to be
|
|
* max(sizeof(ifreq), sizeof(ifreq.ifr_name)+ifreq.ifr_addr.sa_len
|
|
* However, under earlier systems, sa_len isn't present, so the size is
|
|
* just sizeof(struct ifreq)
|
|
*/
|
|
#ifdef HAVE_SA_LEN
|
|
#ifndef max
|
|
#define max(a,b) ((a) > (b) ? (a) : (b))
|
|
#endif
|
|
#define ifreq_size(i) max(sizeof(struct ifreq),\
|
|
sizeof((i).ifr_name)+(i).ifr_addr.sa_len)
|
|
#else
|
|
#define ifreq_size(i) sizeof(struct ifreq)
|
|
#endif /* HAVE_SA_LEN*/
|
|
|
|
sd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
|
|
if (sd < 0) {
|
|
return -1;
|
|
}
|
|
memset(buf, 0, sizeof(buf));
|
|
ifc.ifc_len = sizeof(buf);
|
|
ifc.ifc_buf = buf;
|
|
if (ioctl (sd, SIOCGIFCONF, (char *)&ifc) < 0) {
|
|
close(sd);
|
|
return -1;
|
|
}
|
|
n = ifc.ifc_len;
|
|
for (i = 0; i < n; i+= ifreq_size(*ifrp) ) {
|
|
ifrp = (struct ifreq *)((char *) ifc.ifc_buf+i);
|
|
strncpy(ifr.ifr_name, ifrp->ifr_name, IFNAMSIZ);
|
|
#ifdef SIOCGIFHWADDR
|
|
if (ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)
|
|
continue;
|
|
a = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
|
|
#else
|
|
#ifdef SIOCGENADDR
|
|
if (ioctl(sd, SIOCGENADDR, &ifr) < 0)
|
|
continue;
|
|
a = (unsigned char *) ifr.ifr_enaddr;
|
|
#else
|
|
#ifdef HAVE_NET_IF_DL_H
|
|
sdlp = (struct sockaddr_dl *) &ifrp->ifr_addr;
|
|
if ((sdlp->sdl_family != AF_LINK) || (sdlp->sdl_alen != 6))
|
|
continue;
|
|
a = (unsigned char *) &sdlp->sdl_data[sdlp->sdl_nlen];
|
|
#else
|
|
/*
|
|
* XXX we don't have a way of getting the hardware
|
|
* address
|
|
*/
|
|
close(sd);
|
|
return 0;
|
|
#endif /* HAVE_NET_IF_DL_H */
|
|
#endif /* SIOCGENADDR */
|
|
#endif /* SIOCGIFHWADDR */
|
|
if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5])
|
|
continue;
|
|
if (node_id) {
|
|
memcpy(node_id, a, 6);
|
|
close(sd);
|
|
return 1;
|
|
}
|
|
}
|
|
close(sd);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* Assume that the gettimeofday() has microsecond granularity */
|
|
#define MAX_ADJUSTMENT 10
|
|
|
|
static int get_clock(uint32_t *clock_high, uint32_t *clock_low, uint16_t *ret_clock_seq)
|
|
{
|
|
static int adjustment = 0;
|
|
static struct timeval last = {0, 0};
|
|
static uint16_t 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 &= 0x3FFF;
|
|
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) & 0x3FFF;
|
|
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;
|
|
}
|
|
|
|
void uuid_generate_time(uuid_t out)
|
|
{
|
|
static unsigned char node_id[6];
|
|
static int has_init = 0;
|
|
struct uuid uu;
|
|
uint32_t clock_mid;
|
|
|
|
if (!has_init) {
|
|
if (get_node_id(node_id) <= 0) {
|
|
get_random_bytes(node_id, 6);
|
|
/*
|
|
* Set multicast bit, to prevent conflicts
|
|
* with IEEE 802 addresses obtained from
|
|
* network cards
|
|
*/
|
|
node_id[0] |= 0x01;
|
|
}
|
|
has_init = 1;
|
|
}
|
|
get_clock(&clock_mid, &uu.time_low, &uu.clock_seq);
|
|
uu.clock_seq |= 0x8000;
|
|
uu.time_mid = (uint16_t) clock_mid;
|
|
uu.time_hi_and_version = ((clock_mid >> 16) & 0x0FFF) | 0x1000;
|
|
memcpy(uu.node, node_id, 6);
|
|
uuid_pack(&uu, out);
|
|
}
|
|
|
|
void uuid_generate_random(uuid_t out)
|
|
{
|
|
uuid_t buf;
|
|
struct uuid uu;
|
|
|
|
get_random_bytes(buf, sizeof(buf));
|
|
uuid_unpack(buf, &uu);
|
|
|
|
uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
|
|
uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x4000;
|
|
uuid_pack(&uu, out);
|
|
}
|
|
|
|
/*
|
|
* This is the generic front-end to uuid_generate_random and
|
|
* uuid_generate_time. It uses uuid_generate_random only if
|
|
* /dev/urandom is available, since otherwise we won't have
|
|
* high-quality randomness.
|
|
*/
|
|
void uuid_generate(uuid_t out)
|
|
{
|
|
if (get_random_fd() >= 0)
|
|
uuid_generate_random(out);
|
|
else
|
|
uuid_generate_time(out);
|
|
}
|