diff options
Diffstat (limited to 'sys/kern/kern_uuid.c')
| -rw-r--r-- | sys/kern/kern_uuid.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/sys/kern/kern_uuid.c b/sys/kern/kern_uuid.c new file mode 100644 index 0000000..ba5faa5 --- /dev/null +++ b/sys/kern/kern_uuid.c @@ -0,0 +1,222 @@ +/* + * 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/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)); +} |
