NetBSD-5.0.2/sys/kern/kern_uuid.c
/* $NetBSD: kern_uuid.c,v 1.15 2008/07/02 14:47:34 matt Exp $ */
/*
* 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: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.15 2008/07/02 14:47:34 matt Exp $");
#include <sys/param.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/uuid.h>
/* NetBSD */
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/uio.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;
/* "UUID generator mutex lock" */
static kmutex_t uuid_mutex;
void
uuid_init(void)
{
mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE);
}
/*
* 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, s;
s = splnet();
KERNEL_LOCK(1, NULL);
IFNET_FOREACH(ifp) {
/* Walk the address list */
IFADDR_FOREACH(ifa, ifp) {
sdl = (struct sockaddr_dl*)ifa->ifa_addr;
if (sdl != NULL && sdl->sdl_family == AF_LINK &&
sdl->sdl_type == IFT_ETHER) {
/* Got a MAC address. */
memcpy(node, CLLADDR(sdl), UUID_NODE_LEN);
KERNEL_UNLOCK_ONE(NULL);
splx(s);
return;
}
}
}
KERNEL_UNLOCK_ONE(NULL);
splx(s);
for (i = 0; i < (UUID_NODE_LEN>>1); i++)
node[i] = (uint16_t)arc4random();
*((uint8_t*)node) |= 0x01;
}
/*
* 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, January 1, 1970 to the date of the
* Gregorian reform to the Christian calendar.
*/
/*
* At present, NetBSD has no timespec source, only timeval sources. So,
* we use timeval.
*/
static uint64_t
uuid_time(void)
{
struct timeval tv;
uint64_t xtime = 0x01B21DD213814000LL;
microtime(&tv);
xtime += (uint64_t)tv.tv_sec * 10000000LL;
xtime += (uint64_t)(10 * tv.tv_usec);
return (xtime & ((1LL << 60) - 1LL));
}
/*
* Internal routine to actually generate the UUID.
*/
static void
uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count)
{
uint64_t xtime;
mutex_enter(&uuid_mutex);
uuid_node(uuid->node);
xtime = uuid_time();
*timep = xtime;
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 >= xtime)
uuid->seq = (uuid_last.seq + 1) & 0x3fff;
else
uuid->seq = uuid_last.seq;
uuid_last = *uuid;
uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL);
mutex_exit(&uuid_mutex);
}
int
sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval)
{
struct uuid_private uuid;
uint64_t xtime;
int error;
int i;
/*
* 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 (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048)
return (EINVAL);
/* XXX: pre-validate accessibility to the whole of the UUID store? */
/* Generate the base UUID. */
uuid_generate(&uuid, &xtime, SCARG(uap, count));
/* Set sequence and variant and deal with byte order. */
uuid.seq = htobe16(uuid.seq | 0x8000);
/* XXX: this should copyout larger chunks at a time. */
for (i = 0; i < SCARG(uap, count); xtime++, i++) {
/* Set time and version (=1) and deal with byte order. */
uuid.time.x.low = (uint32_t)xtime;
uuid.time.x.mid = (uint16_t)(xtime >> 32);
uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12);
error = copyout(&uuid, SCARG(uap,store) + i, sizeof(uuid));
if (error != 0)
return error;
}
return 0;
}
int
uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid)
{
const struct uuid_private *id;
int cnt;
id = (const 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
uuid_printf(const struct uuid *uuid)
{
char buf[UUID_STR_LEN];
(void) uuid_snprintf(buf, sizeof(buf), uuid);
printf("%s", buf);
return (0);
}
/*
* Encode/Decode UUID into octet-stream.
* http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
*
* 0 1 2 3
* 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_hi_res | clk_seq_low | node (0-1) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | node (2-5) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
void
uuid_enc_le(void *buf, const struct uuid *uuid)
{
uint8_t *p = buf;
int i;
le32enc(p, uuid->time_low);
le16enc(p + 4, uuid->time_mid);
le16enc(p + 6, uuid->time_hi_and_version);
p[8] = uuid->clock_seq_hi_and_reserved;
p[9] = uuid->clock_seq_low;
for (i = 0; i < _UUID_NODE_LEN; i++)
p[10 + i] = uuid->node[i];
}
void
uuid_dec_le(void const *buf, struct uuid *uuid)
{
const uint8_t *p = buf;
int i;
uuid->time_low = le32dec(p);
uuid->time_mid = le16dec(p + 4);
uuid->time_hi_and_version = le16dec(p + 6);
uuid->clock_seq_hi_and_reserved = p[8];
uuid->clock_seq_low = p[9];
for (i = 0; i < _UUID_NODE_LEN; i++)
uuid->node[i] = p[10 + i];
}
void
uuid_enc_be(void *buf, const struct uuid *uuid)
{
uint8_t *p = buf;
int i;
be32enc(p, uuid->time_low);
be16enc(p + 4, uuid->time_mid);
be16enc(p + 6, uuid->time_hi_and_version);
p[8] = uuid->clock_seq_hi_and_reserved;
p[9] = uuid->clock_seq_low;
for (i = 0; i < _UUID_NODE_LEN; i++)
p[10 + i] = uuid->node[i];
}
void
uuid_dec_be(void const *buf, struct uuid *uuid)
{
const uint8_t *p = buf;
int i;
uuid->time_low = be32dec(p);
uuid->time_mid = be16dec(p + 4);
uuid->time_hi_and_version = be16dec(p + 6);
uuid->clock_seq_hi_and_reserved = p[8];
uuid->clock_seq_low = p[9];
for (i = 0; i < _UUID_NODE_LEN; i++)
uuid->node[i] = p[10 + i];
}