The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

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

Cache object: 97867ce0054734ebbcce3c3b01681abe


[ 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.