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util-linux/libuuid/src/gen_uuid.c

610 lines
14 KiB

/*
* 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 _WIN32
#define _WIN32_WINNT 0x0500
#include <windows.h>
#define UUID MYUUID
#endif
#include <stdio.h>
#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 <limits.h>
#include <sys/types.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <sys/stat.h>
#ifdef HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_UN_H
#include <sys/un.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
#if defined(__linux__) && defined(HAVE_SYS_SYSCALL_H)
#include <sys/syscall.h>
#endif
#include "all-io.h"
#include "uuidP.h"
#include "uuidd.h"
#include "randutils.h"
#include "strutils.h"
#include "c.h"
#include "md5.h"
#include "sha1.h"
#ifdef HAVE_TLS
#define THREAD_LOCAL static __thread
#else
#define THREAD_LOCAL static
#endif
/* index with UUID_VARIANT_xxx and shift 5 bits */
static unsigned char variant_bits[] = { 0x00, 0x04, 0x06, 0x07 };
#ifdef _WIN32
static void gettimeofday (struct timeval *tv, void *dummy)
{
FILETIME ftime;
uint64_t n;
GetSystemTimeAsFileTime (&ftime);
n = (((uint64_t) ftime.dwHighDateTime << 32)
+ (uint64_t) ftime.dwLowDateTime);
if (n) {
n /= 10;
n -= ((369 * 365 + 89) * (uint64_t) 86400) * 1000000;
}
tv->tv_sec = n / 1000000;
tv->tv_usec = n % 1000000;
}
static int getuid (void)
{
return 1;
}
#endif
/*
* Get the ethernet hardware address, if we can find it...
*
* XXX for a windows version, probably should use GetAdaptersInfo:
* http://www.codeguru.com/cpp/i-n/network/networkinformation/article.php/c5451
* commenting out get_node_id just to get gen_uuid to compile under windows
* is not the right way to go!
*/
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
#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
/*
* Get clock from global sequence clock counter.
*
* Return -1 if the clock counter could not be opened/locked (in this case
* pseudorandom value is returned in @ret_clock_seq), otherwise return 0.
*/
static int get_clock(uint32_t *clock_high, uint32_t *clock_low,
uint16_t *ret_clock_seq, int *num)
{
THREAD_LOCAL int adjustment = 0;
THREAD_LOCAL struct timeval last = {0, 0};
THREAD_LOCAL int state_fd = -2;
THREAD_LOCAL FILE *state_f;
THREAD_LOCAL uint16_t clock_seq;
struct timeval tv;
uint64_t clock_reg;
mode_t save_umask;
int len;
int ret = 0;
if (state_fd == -1)
ret = -1;
if (state_fd == -2) {
save_umask = umask(0);
state_fd = open(LIBUUID_CLOCK_FILE, O_RDWR|O_CREAT|O_CLOEXEC, 0660);
(void) umask(save_umask);
if (state_fd != -1) {
state_f = fdopen(state_fd, "r+" UL_CLOEXECSTR);
if (!state_f) {
close(state_fd);
state_fd = -1;
ret = -1;
}
}
else
ret = -1;
}
if (state_fd >= 0) {
rewind(state_f);
while (flock(state_fd, LOCK_EX) < 0) {
if ((errno == EAGAIN) || (errno == EINTR))
continue;
fclose(state_f);
close(state_fd);
state_fd = -1;
ret = -1;
break;
}
}
if (state_fd >= 0) {
unsigned int cl;
unsigned long tv1, tv2;
int a;
if (fscanf(state_f, "clock: %04x tv: %lu %lu adj: %d\n",
&cl, &tv1, &tv2, &a) == 4) {
clock_seq = cl & 0x3FFF;
last.tv_sec = tv1;
last.tv_usec = tv2;
adjustment = a;
}
}
if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
random_get_bytes(&clock_seq, sizeof(clock_seq));
clock_seq &= 0x3FFF;
gettimeofday(&last, NULL);
last.tv_sec--;
}
try_again:
gettimeofday(&tv, NULL);
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 += ((uint64_t) tv.tv_sec)*10000000;
clock_reg += (((uint64_t) 0x01B21DD2) << 32) + 0x13814000;
if (num && (*num > 1)) {
adjustment += *num - 1;
last.tv_usec += adjustment / 10;
adjustment = adjustment % 10;
last.tv_sec += last.tv_usec / 1000000;
last.tv_usec = last.tv_usec % 1000000;
}
if (state_fd >= 0) {
rewind(state_f);
len = fprintf(state_f,
"clock: %04x tv: %016ld %08ld adj: %08d\n",
clock_seq, (long)last.tv_sec, (long)last.tv_usec, adjustment);
fflush(state_f);
if (ftruncate(state_fd, len) < 0) {
fprintf(state_f, " \n");
fflush(state_f);
}
rewind(state_f);
flock(state_fd, LOCK_UN);
}
*clock_high = clock_reg >> 32;
*clock_low = clock_reg;
*ret_clock_seq = clock_seq;
return ret;
}
#if defined(HAVE_UUIDD) && defined(HAVE_SYS_UN_H)
/*
* Try using the uuidd daemon to generate the UUID
*
* Returns 0 on success, non-zero on failure.
*/
static int get_uuid_via_daemon(int op, uuid_t out, int *num)
{
char op_buf[64];
int op_len;
int s;
ssize_t ret;
int32_t reply_len = 0, expected = 16;
struct sockaddr_un srv_addr;
if (sizeof(UUIDD_SOCKET_PATH) > sizeof(srv_addr.sun_path))
return -1;
if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
return -1;
srv_addr.sun_family = AF_UNIX;
xstrncpy(srv_addr.sun_path, UUIDD_SOCKET_PATH, sizeof(srv_addr.sun_path));
if (connect(s, (const struct sockaddr *) &srv_addr,
sizeof(struct sockaddr_un)) < 0)
goto fail;
op_buf[0] = op;
op_len = 1;
if (op == UUIDD_OP_BULK_TIME_UUID) {
memcpy(op_buf+1, num, sizeof(*num));
op_len += sizeof(*num);
expected += sizeof(*num);
}
ret = write(s, op_buf, op_len);
if (ret < 1)
goto fail;
ret = read_all(s, (char *) &reply_len, sizeof(reply_len));
if (ret < 0)
goto fail;
if (reply_len != expected)
goto fail;
ret = read_all(s, op_buf, reply_len);
if (op == UUIDD_OP_BULK_TIME_UUID)
memcpy(op_buf+16, num, sizeof(int));
memcpy(out, op_buf, 16);
close(s);
return ((ret == expected) ? 0 : -1);
fail:
close(s);
return -1;
}
#else /* !defined(HAVE_UUIDD) && defined(HAVE_SYS_UN_H) */
static int get_uuid_via_daemon(int op __attribute__((__unused__)),
uuid_t out __attribute__((__unused__)),
int *num __attribute__((__unused__)))
{
return -1;
}
#endif
int __uuid_generate_time(uuid_t out, int *num)
{
static unsigned char node_id[6];
static int has_init = 0;
struct uuid uu;
uint32_t clock_mid;
int ret;
if (!has_init) {
if (get_node_id(node_id) <= 0) {
random_get_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;
}
ret = get_clock(&clock_mid, &uu.time_low, &uu.clock_seq, num);
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);
return ret;
}
/*
* Generate time-based UUID and store it to @out
*
* Tries to guarantee uniqueness of the generated UUIDs by obtaining them from the uuidd daemon,
* or, if uuidd is not usable, by using the global clock state counter (see get_clock()).
* If neither of these is possible (e.g. because of insufficient permissions), it generates
* the UUID anyway, but returns -1. Otherwise, returns 0.
*/
static int uuid_generate_time_generic(uuid_t out) {
#ifdef HAVE_TLS
THREAD_LOCAL int num = 0;
THREAD_LOCAL struct uuid uu;
THREAD_LOCAL time_t last_time = 0;
time_t now;
if (num > 0) {
now = time(NULL);
if (now > last_time+1)
num = 0;
}
if (num <= 0) {
num = 1000;
if (get_uuid_via_daemon(UUIDD_OP_BULK_TIME_UUID,
out, &num) == 0) {
last_time = time(NULL);
uuid_unpack(out, &uu);
num--;
return 0;
}
num = 0;
}
if (num > 0) {
uu.time_low++;
if (uu.time_low == 0) {
uu.time_mid++;
if (uu.time_mid == 0)
uu.time_hi_and_version++;
}
num--;
uuid_pack(&uu, out);
return 0;
}
#else
if (get_uuid_via_daemon(UUIDD_OP_TIME_UUID, out, 0) == 0)
return 0;
#endif
return __uuid_generate_time(out, NULL);
}
/*
* Generate time-based UUID and store it to @out.
*
* Discards return value from uuid_generate_time_generic()
*/
void uuid_generate_time(uuid_t out)
{
(void)uuid_generate_time_generic(out);
}
int uuid_generate_time_safe(uuid_t out)
{
return uuid_generate_time_generic(out);
}
void __uuid_generate_random(uuid_t out, int *num)
{
uuid_t buf;
struct uuid uu;
int i, n;
if (!num || !*num)
n = 1;
else
n = *num;
for (i = 0; i < n; i++) {
random_get_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);
out += sizeof(uuid_t);
}
}
void uuid_generate_random(uuid_t out)
{
int num = 1;
/* No real reason to use the daemon for random uuid's -- yet */
__uuid_generate_random(out, &num);
}
/*
* Check whether good random source (/dev/random or /dev/urandom)
* is available.
*/
static int have_random_source(void)
{
return (access("/dev/random", R_OK) == 0 ||
access("/dev/urandom", R_OK) == 0);
}
/*
* 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 (have_random_source())
uuid_generate_random(out);
else
uuid_generate_time(out);
}
/*
* Generate an MD5 hashed (predictable) UUID based on a well-known UUID
* providing the namespace and an arbitrary binary string.
*/
void uuid_generate_md5(uuid_t out, const uuid_t ns, const char *name, size_t len)
{
MD5_CTX ctx;
char hash[MD5LENGTH];
MD5Init(&ctx);
/* hash concatenation of well-known UUID with name */
MD5Update(&ctx, ns, sizeof(uuid_t));
MD5Update(&ctx, (const unsigned char *)name, len);
MD5Final((unsigned char *)hash, &ctx);
memcpy(out, hash, sizeof(uuid_t));
out[6] &= ~(UUID_TYPE_MASK << UUID_TYPE_SHIFT);
out[6] |= (UUID_TYPE_DCE_MD5 << UUID_TYPE_SHIFT);
out[8] &= ~(UUID_VARIANT_MASK << UUID_VARIANT_SHIFT);
out[8] |= (variant_bits[UUID_VARIANT_DCE] << UUID_VARIANT_SHIFT);
}
/*
* Generate a SHA1 hashed (predictable) UUID based on a well-known UUID
* providing the namespace and an arbitrary binary string.
*/
void uuid_generate_sha1(uuid_t out, const uuid_t ns, const char *name, size_t len)
{
UL_SHA1_CTX ctx;
char hash[UL_SHA1LENGTH];
ul_SHA1Init(&ctx);
/* hash concatenation of well-known UUID with name */
ul_SHA1Update(&ctx, ns, sizeof(uuid_t));
ul_SHA1Update(&ctx, (const unsigned char *)name, len);
ul_SHA1Final((unsigned char *)hash, &ctx);
memcpy(out, hash, sizeof(uuid_t));
out[6] &= ~(UUID_TYPE_MASK << UUID_TYPE_SHIFT);
out[6] |= (UUID_TYPE_DCE_SHA1 << UUID_TYPE_SHIFT);
out[8] &= ~(UUID_VARIANT_MASK << UUID_VARIANT_SHIFT);
out[8] |= (variant_bits[UUID_VARIANT_DCE] << UUID_VARIANT_SHIFT);
}