kern_uuid.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*      $NetBSD: kern_uuid.c,v 1.15 2008/07/02 14:47:34 matt Exp $      */
    2 
    3 /*
    4  * Copyright (c) 2002 Marcel Moolenaar
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  *
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   27  *
   28  * $FreeBSD: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $
   29  */
   30 
   31 #include <sys/cdefs.h>
   32 __KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.15 2008/07/02 14:47:34 matt Exp $");
   33 
   34 #include <sys/param.h>
   35 #include <sys/endian.h>
   36 #include <sys/kernel.h>
   37 #include <sys/mutex.h>
   38 #include <sys/socket.h>
   39 #include <sys/systm.h>
   40 #include <sys/uuid.h>
   41 
   42 /* NetBSD */
   43 #include <sys/proc.h>
   44 #include <sys/mount.h>
   45 #include <sys/syscallargs.h>
   46 #include <sys/uio.h>
   47 
   48 #include <net/if.h>
   49 #include <net/if_dl.h>
   50 #include <net/if_types.h>
   51 
   52 /*
   53  * See also:
   54  *      http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
   55  *      http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
   56  *
   57  * Note that the generator state is itself an UUID, but the time and clock
   58  * sequence fields are written in the native byte order.
   59  */
   60 
   61 CTASSERT(sizeof(struct uuid) == 16);
   62 
   63 /* We use an alternative, more convenient representation in the generator. */
   64 struct uuid_private {
   65         union {
   66                 uint64_t        ll;             /* internal. */
   67                 struct {
   68                         uint32_t        low;
   69                         uint16_t        mid;
   70                         uint16_t        hi;
   71                 } x;
   72         } time;
   73         uint16_t        seq;                    /* Big-endian. */
   74         uint16_t        node[UUID_NODE_LEN>>1];
   75 };
   76 
   77 CTASSERT(sizeof(struct uuid_private) == 16);
   78 
   79 static struct uuid_private uuid_last;
   80 
   81 /* "UUID generator mutex lock" */
   82 static kmutex_t uuid_mutex;
   83 
   84 void
   85 uuid_init(void)
   86 {
   87 
   88         mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE);
   89 }
   90 
   91 /*
   92  * Return the first MAC address we encounter or, if none was found,
   93  * construct a sufficiently random multicast address. We don't try
   94  * to return the same MAC address as previously returned. We always
   95  * generate a new multicast address if no MAC address exists in the
   96  * system.
   97  * It would be nice to know if 'ifnet' or any of its sub-structures
   98  * has been changed in any way. If not, we could simply skip the
   99  * scan and safely return the MAC address we returned before.
  100  */
  101 static void
  102 uuid_node(uint16_t *node)
  103 {
  104         struct ifnet *ifp;
  105         struct ifaddr *ifa;
  106         struct sockaddr_dl *sdl;
  107         int i, s;
  108 
  109         s = splnet();
  110         KERNEL_LOCK(1, NULL);
  111         IFNET_FOREACH(ifp) {
  112                 /* Walk the address list */
  113                 IFADDR_FOREACH(ifa, ifp) {
  114                         sdl = (struct sockaddr_dl*)ifa->ifa_addr;
  115                         if (sdl != NULL && sdl->sdl_family == AF_LINK &&
  116                             sdl->sdl_type == IFT_ETHER) {
  117                                 /* Got a MAC address. */
  118                                 memcpy(node, CLLADDR(sdl), UUID_NODE_LEN);
  119                                 KERNEL_UNLOCK_ONE(NULL);
  120                                 splx(s);
  121                                 return;
  122                         }
  123                 }
  124         }
  125         KERNEL_UNLOCK_ONE(NULL);
  126         splx(s);
  127 
  128         for (i = 0; i < (UUID_NODE_LEN>>1); i++)
  129                 node[i] = (uint16_t)arc4random();
  130         *((uint8_t*)node) |= 0x01;
  131 }
  132 
  133 /*
  134  * Get the current time as a 60 bit count of 100-nanosecond intervals
  135  * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
  136  * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
  137  * Gregorian reform to the Christian calendar.
  138  */
  139 /*
  140  * At present, NetBSD has no timespec source, only timeval sources.  So,
  141  * we use timeval.
  142  */
  143 static uint64_t
  144 uuid_time(void)
  145 {
  146         struct timeval tv;
  147         uint64_t xtime = 0x01B21DD213814000LL;
  148 
  149         microtime(&tv);
  150         xtime += (uint64_t)tv.tv_sec * 10000000LL;
  151         xtime += (uint64_t)(10 * tv.tv_usec);
  152         return (xtime & ((1LL << 60) - 1LL));
  153 }
  154 
  155 /*
  156  * Internal routine to actually generate the UUID.
  157  */
  158 static void
  159 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count)
  160 {
  161         uint64_t xtime;
  162 
  163         mutex_enter(&uuid_mutex);
  164 
  165         uuid_node(uuid->node);
  166         xtime = uuid_time();
  167         *timep = xtime;
  168 
  169         if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] ||
  170             uuid_last.node[1] != uuid->node[1] ||
  171             uuid_last.node[2] != uuid->node[2])
  172                 uuid->seq = (uint16_t)arc4random() & 0x3fff;
  173         else if (uuid_last.time.ll >= xtime)
  174                 uuid->seq = (uuid_last.seq + 1) & 0x3fff;
  175         else
  176                 uuid->seq = uuid_last.seq;
  177 
  178         uuid_last = *uuid;
  179         uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL);
  180 
  181         mutex_exit(&uuid_mutex);
  182 }
  183 
  184 int
  185 sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval)
  186 {
  187         struct uuid_private uuid;
  188         uint64_t xtime;
  189         int error;
  190         int i;
  191 
  192         /*
  193          * Limit the number of UUIDs that can be created at the same time
  194          * to some arbitrary number. This isn't really necessary, but I
  195          * like to have some sort of upper-bound that's less than 2G :-)
  196          * XXX needs to be tunable.
  197          */
  198         if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048)
  199                 return (EINVAL);
  200 
  201         /* XXX: pre-validate accessibility to the whole of the UUID store? */
  202 
  203         /* Generate the base UUID. */
  204         uuid_generate(&uuid, &xtime, SCARG(uap, count));
  205 
  206         /* Set sequence and variant and deal with byte order. */
  207         uuid.seq = htobe16(uuid.seq | 0x8000);
  208 
  209         /* XXX: this should copyout larger chunks at a time. */
  210         for (i = 0; i < SCARG(uap, count); xtime++, i++) {
  211                 /* Set time and version (=1) and deal with byte order. */
  212                 uuid.time.x.low = (uint32_t)xtime;
  213                 uuid.time.x.mid = (uint16_t)(xtime >> 32);
  214                 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12);
  215                 error = copyout(&uuid, SCARG(uap,store) + i, sizeof(uuid));
  216                 if (error != 0)
  217                         return error;
  218         }
  219 
  220         return 0;
  221 }
  222 
  223 int
  224 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid)
  225 {
  226         const struct uuid_private *id;
  227         int cnt;
  228 
  229         id = (const struct uuid_private *)uuid;
  230         cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
  231             id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
  232             be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
  233         return (cnt);
  234 }
  235 
  236 int
  237 uuid_printf(const struct uuid *uuid)
  238 {
  239         char buf[UUID_STR_LEN];
  240 
  241         (void) uuid_snprintf(buf, sizeof(buf), uuid);
  242         printf("%s", buf);
  243         return (0);
  244 }
  245 
  246 /*
  247  * Encode/Decode UUID into octet-stream.
  248  *   http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
  249  *
  250  * 0                   1                   2                   3
  251  *   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
  252  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  253  *  |                          time_low                             |
  254  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  255  *  |       time_mid                |         time_hi_and_version   |
  256  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  257  *  |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
  258  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  259  *  |                         node (2-5)                            |
  260  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  261  */
  262 
  263 void
  264 uuid_enc_le(void *buf, const struct uuid *uuid)
  265 {
  266         uint8_t *p = buf;
  267         int i;
  268 
  269         le32enc(p, uuid->time_low);
  270         le16enc(p + 4, uuid->time_mid);
  271         le16enc(p + 6, uuid->time_hi_and_version);
  272         p[8] = uuid->clock_seq_hi_and_reserved;
  273         p[9] = uuid->clock_seq_low;
  274         for (i = 0; i < _UUID_NODE_LEN; i++)
  275                 p[10 + i] = uuid->node[i];
  276 }
  277 
  278 void
  279 uuid_dec_le(void const *buf, struct uuid *uuid)
  280 {
  281         const uint8_t *p = buf;
  282         int i;
  283 
  284         uuid->time_low = le32dec(p);
  285         uuid->time_mid = le16dec(p + 4);
  286         uuid->time_hi_and_version = le16dec(p + 6);
  287         uuid->clock_seq_hi_and_reserved = p[8];
  288         uuid->clock_seq_low = p[9];
  289         for (i = 0; i < _UUID_NODE_LEN; i++)
  290                 uuid->node[i] = p[10 + i];
  291 }
  292 
  293 void
  294 uuid_enc_be(void *buf, const struct uuid *uuid)
  295 {
  296         uint8_t *p = buf;
  297         int i;
  298 
  299         be32enc(p, uuid->time_low);
  300         be16enc(p + 4, uuid->time_mid);
  301         be16enc(p + 6, uuid->time_hi_and_version);
  302         p[8] = uuid->clock_seq_hi_and_reserved;
  303         p[9] = uuid->clock_seq_low;
  304         for (i = 0; i < _UUID_NODE_LEN; i++)
  305                 p[10 + i] = uuid->node[i];
  306 }
  307 
  308 void
  309 uuid_dec_be(void const *buf, struct uuid *uuid)
  310 {
  311         const uint8_t *p = buf;
  312         int i;
  313 
  314         uuid->time_low = be32dec(p);
  315         uuid->time_mid = be16dec(p + 4);
  316         uuid->time_hi_and_version = be16dec(p + 6);
  317         uuid->clock_seq_hi_and_reserved = p[8];
  318         uuid->clock_seq_low = p[9];
  319         for (i = 0; i < _UUID_NODE_LEN; i++)
  320                 uuid->node[i] = p[10 + i];
  321 }
Cache object: 78f6a15c5e34cce7ad8ef48a1018e8e5
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/kern_uuid.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_uuid.c
