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/*
* Copyright (c) 2002 Marcel Moolenaar
* All rights reserved.
*
* 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, this list of conditions and the following disclaimer.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 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 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sbuf.h>
#include <sys/socket.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/uuid.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
/*
* See also:
* http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
* http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
*
* Note that the generator state is itself an UUID, but the time and clock
* sequence fields are written in the native byte order.
*/
CTASSERT(sizeof(struct uuid) == 16);
/* We use an alternative, more convenient representation in the generator. */
struct uuid_private {
union {
uint64_t ll; /* internal. */
struct {
uint32_t low;
uint16_t mid;
uint16_t hi;
} x;
} time;
uint16_t seq; /* Big-endian. */
uint16_t node[UUID_NODE_LEN>>1];
};
CTASSERT(sizeof(struct uuid_private) == 16);
static struct uuid_private uuid_last;
static struct mtx uuid_mutex;
MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF);
/*
* Return the first MAC address we encounter or, if none was found,
* construct a sufficiently random multicast address. We don't try
* to return the same MAC address as previously returned. We always
* generate a new multicast address if no MAC address exists in the
* system.
* It would be nice to know if 'ifnet' or any of its sub-structures
* has been changed in any way. If not, we could simply skip the
* scan and safely return the MAC address we returned before.
*/
static void
uuid_node(uint16_t *node)
{
struct ifnet *ifp;
struct ifaddr *ifa;
struct sockaddr_dl *sdl;
int i;
/* XXX: lock ifnet. */
TAILQ_FOREACH(ifp, &ifnet, if_link) {
/* Walk the address list */
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
sdl = (struct sockaddr_dl*)ifa->ifa_addr;
if (sdl != NULL && sdl->sdl_family == AF_LINK &&
sdl->sdl_type == IFT_ETHER) {
/* Got a MAC address. */
bcopy(LLADDR(sdl), node, UUID_NODE_LEN);
/* XXX: unlock ifnet. */
return;
}
}
}
/* XXX: unlock ifnet. */
for (i = 0; i < (UUID_NODE_LEN>>1); i++)
node[i] = (uint16_t)arc4random();
*((uint8_t*)node) |= 0x80;
}
/*
* Get the current time as a 60 bit count of 100-nanosecond intervals
* since 00:00:00.00, October 15,1582. We apply a magic offset to convert
* the Unix time since 00:00:00.00, Januari 1, 1970 to the date of the
* Gregorian reform to the Christian calendar.
*/
static uint64_t
uuid_time(void)
{
struct bintime bt;
uint64_t time = 0x01B21DD213814000LL;
bintime(&bt);
time += (uint64_t)bt.sec * 10000000LL;
time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32;
return (time & ((1LL << 60) - 1LL));
}
#ifndef _SYS_SYSPROTO_H_
struct uuidgen_args {
struct uuid *store;
int count;
};
#endif
int
uuidgen(struct thread *td, struct uuidgen_args *uap)
{
struct uuid_private uuid;
uint64_t time;
int error;
/*
* Limit the number of UUIDs that can be created at the same time
* to some arbitrary number. This isn't really necessary, but I
* like to have some sort of upper-bound that's less than 2G :-)
* XXX needs to be tunable.
*/
if (uap->count < 1 || uap->count > 2048)
return (EINVAL);
/* XXX: pre-validate accessibility to the whole of the UUID store? */
mtx_lock(&uuid_mutex);
uuid_node(uuid.node);
time = uuid_time();
if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
uuid_last.node[1] != uuid.node[1] ||
uuid_last.node[2] != uuid.node[2])
uuid.seq = (uint16_t)arc4random() & 0x3fff;
else if (uuid_last.time.ll >= time)
uuid.seq = (uuid_last.seq + 1) & 0x3fff;
else
uuid.seq = uuid_last.seq;
uuid_last = uuid;
uuid_last.time.ll = (time + uap->count - 1) & ((1LL << 60) - 1LL);
mtx_unlock(&uuid_mutex);
/* Set sequence and variant and deal with byte order. */
uuid.seq = htobe16(uuid.seq | 0x8000);
/* XXX: this should copyout larger chunks at a time. */
do {
/* Set time and version (=1) and deal with byte order. */
uuid.time.x.low = (uint32_t)time;
uuid.time.x.mid = (uint16_t)(time >> 32);
uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
error = copyout(&uuid, uap->store, sizeof(uuid));
uap->store++;
uap->count--;
time++;
} while (uap->count > 0 && !error);
return (error);
}
int
snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
{
struct uuid_private *id;
int cnt;
id = (struct uuid_private *)uuid;
cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
return (cnt);
}
int
printf_uuid(struct uuid *uuid)
{
char buf[38];
snprintf_uuid(buf, sizeof(buf), uuid);
return (printf("%s", buf));
}
int
sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
{
char buf[38];
snprintf_uuid(buf, sizeof(buf), uuid);
return (sbuf_printf(sb, "%s", buf));
}
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