sys/kern/kern_uuid.c

   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  * $FreeBSD: src/sys/kern/kern_uuid.c,v 1.13 2007/04/23 12:53:00 pjd Exp $
  27  * $DragonFly: src/sys/kern/kern_uuid.c,v 1.3 2007/06/17 03:51:10 dillon Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/endian.h>
  32 #include <sys/systm.h>
  33 #include <sys/kernel.h>
  34 #include <sys/lock.h>
  35 #include <sys/kern_syscall.h>
  36 #include <sys/random.h>
  37 #include <sys/sbuf.h>
  38 #include <sys/socket.h>
  39 #include <sys/sysproto.h>
  40 #include <sys/uuid.h>
  41 #include <net/if_var.h>
  42
  43 /*
  44  * See also:
  45  *      http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
  46  *      http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
  47  *
  48  * Note that the generator state is itself an UUID, but the time and clock
  49  * sequence fields are written in the native byte order.
  50  */
  51
  52 /* We use an alternative, more convenient representation in the generator. */
  53 struct uuid_private {
  54         union {
  55                 uint64_t        ll;             /* internal. */
  56                 struct {
  57                         uint32_t        low;
  58                         uint16_t        mid;
  59                         uint16_t        hi;
  60                 } x;
  61         } time;
  62         uint16_t        seq;                    /* Big-endian. */
  63         uint16_t        node[UUID_NODE_LEN>>1];
  64 };
  65
  66 static struct uuid_private uuid_last;
  67
  68 static struct lock uuid_lock;
  69
  70 static
  71 void
  72 uuid_lock_init(void *arg __unused)
  73 {
  74         lockinit(&uuid_lock, "uuid", 0, 0);
  75 }
  76 SYSINIT(uuid_lock, SI_BOOT1_POST, SI_ORDER_ANY, uuid_lock_init, NULL);
  77
  78 /*
  79  * Ask the network subsystem for a real MAC address from any of the
  80  * system interfaces.  If we can't find one, generate a random multicast
  81  * MAC address.
  82  */
  83 static void
  84 uuid_node(uint16_t *node)
  85 {
  86         if (if_getanyethermac(node, UUID_NODE_LEN) != 0)
  87                 read_random(node, UUID_NODE_LEN);
  88         *((uint8_t*)node) |= 0x01;
  89 }
  90
  91 /*
  92  * Get the current time as a 60 bit count of 100-nanosecond intervals
  93  * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
  94  * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
  95  * Gregorian reform to the Christian calendar.
  96  */
  97 static uint64_t
  98 uuid_time(void)
  99 {
 100         struct timespec ts;
 101         uint64_t time = 0x01B21DD213814000LL;
 102
 103         nanotime(&ts);
 104         time += ts.tv_sec * 10000000LL;         /* 100 ns increments */
 105         time += ts.tv_nsec / 100;               /* 100 ns increments */
 106         return (time & ((1LL << 60) - 1LL));    /* limit to 60 bits */
 107 }
 108
 109 struct uuid *
 110 kern_uuidgen(struct uuid *store, size_t count)
 111 {
 112         struct uuid_private uuid;
 113         uint64_t time;
 114         size_t n;
 115
 116         lockmgr(&uuid_lock, LK_EXCLUSIVE | LK_RETRY);
 117
 118         uuid_node(uuid.node);
 119         time = uuid_time();
 120
 121         if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
 122             uuid_last.node[1] != uuid.node[1] ||
 123             uuid_last.node[2] != uuid.node[2]) {
 124                 read_random(&uuid.seq, sizeof(uuid.seq));
 125                 uuid.seq &= 0x3fff;
 126         } else if (uuid_last.time.ll >= time) {
 127                 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
 128         } else {
 129                 uuid.seq = uuid_last.seq;
 130         }
 131
 132         uuid_last = uuid;
 133         uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);
 134
 135         lockmgr(&uuid_lock, LK_RELEASE);
 136
 137         /* Set sequence and variant and deal with byte order. */
 138         uuid.seq = htobe16(uuid.seq | 0x8000);
 139
 140         for (n = 0; n < count; n++) {
 141                 /* Set time and version (=1). */
 142                 uuid.time.x.low = (uint32_t)time;
 143                 uuid.time.x.mid = (uint16_t)(time >> 32);
 144                 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
 145                 store[n] = *(struct uuid *)&uuid;
 146                 time++;
 147         }
 148
 149         return (store);
 150 }
 151
 152 /*
 153  * uuidgen(struct uuid *store, int count)
 154  *
 155  * Generate an array of new UUIDs
 156  */
 157 int
 158 sys_uuidgen(struct uuidgen_args *uap)
 159 {
 160         struct uuid *store;
 161         size_t count;
 162         int error;
 163
 164         /*
 165          * Limit the number of UUIDs that can be created at the same time
 166          * to some arbitrary number. This isn't really necessary, but I
 167          * like to have some sort of upper-bound that's less than 2G :-)
 168          * XXX probably needs to be tunable.
 169          */
 170         if (uap->count < 1 || uap->count > 2048)
 171                 return (EINVAL);
 172
 173         count = uap->count;
 174         store = kmalloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK);
 175         kern_uuidgen(store, count);
 176         error = copyout(store, uap->store, count * sizeof(struct uuid));
 177         kfree(store, M_TEMP);
 178         return (error);
 179 }
 180
 181 int
 182 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
 183 {
 184         struct uuid_private *id;
 185         int cnt;
 186
 187         id = (struct uuid_private *)uuid;
 188         cnt = ksnprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
 189             id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
 190             be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
 191         return (cnt);
 192 }
 193
 194 int
 195 printf_uuid(struct uuid *uuid)
 196 {
 197         char buf[38];
 198
 199         snprintf_uuid(buf, sizeof(buf), uuid);
 200         return (kprintf("%s", buf));
 201 }
 202
 203 int
 204 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
 205 {
 206         char buf[38];
 207
 208         snprintf_uuid(buf, sizeof(buf), uuid);
 209         return (sbuf_printf(sb, "%s", buf));
 210 }
 211
 212 /*
 213  * Test functions
 214  */
 215 int
 216 kuuid_is_nil(struct uuid *uuid)
 217 {
 218         int i;
 219
 220         for (i = 0; i < sizeof(*uuid); i += sizeof(int)) {
 221                 if (*(int *)((char *)uuid + i) != 0)
 222                         return(0);
 223         }
 224         return(1);
 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
 276 void
 277 be_uuid_enc(void *buf, struct uuid const *uuid)
 278 {
 279         u_char *p;
 280         int i;
 281
 282         p = buf;
 283         be32enc(p, uuid->time_low);
 284         be16enc(p + 4, uuid->time_mid);
 285         be16enc(p + 6, uuid->time_hi_and_version);
 286         p[8] = uuid->clock_seq_hi_and_reserved;
 287         p[9] = uuid->clock_seq_low;
 288         for (i = 0; i < _UUID_NODE_LEN; i++)
 289                 p[10 + i] = uuid->node[i];
 290 }
 291
 292 void
 293 be_uuid_dec(void const *buf, struct uuid *uuid)
 294 {
 295         u_char const *p;
 296         int i;
 297
 298         p = buf;
 299         uuid->time_low = be32dec(p);
 300         uuid->time_mid = le16dec(p + 4);
 301         uuid->time_hi_and_version = be16dec(p + 6);
 302         uuid->clock_seq_hi_and_reserved = p[8];
 303         uuid->clock_seq_low = p[9];
 304         for (i = 0; i < _UUID_NODE_LEN; i++)
 305                 uuid->node[i] = p[10 + i];
 306 }
 307
 308 int
 309 parse_uuid(const char *str, struct uuid *uuid)
 310 {
 311         u_int c[11];
 312         int n;
 313
 314         /* An empty string represents a nil UUID. */
 315         if (*str == '\0') {
 316                 bzero(uuid, sizeof(*uuid));
 317                 return (0);
 318         }
 319
 320         /* The UUID string representation has a fixed length. */
 321         if (strlen(str) != 36)
 322                 return (EINVAL);
 323
 324         /*
 325          * We only work with "new" UUIDs. New UUIDs have the form:
 326          *      01234567-89ab-cdef-0123-456789abcdef
 327          * The so called "old" UUIDs, which we don't support, have the form:
 328          *      0123456789ab.cd.ef.01.23.45.67.89.ab
 329          */
 330         if (str[8] != '-')
 331                 return (EINVAL);
 332
 333         n = ksscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
 334             c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
 335         /* Make sure we have all conversions. */
 336         if (n != 11)
 337                 return (EINVAL);
 338
 339         /* Successful scan. Build the UUID. */
 340         uuid->time_low = c[0];
 341         uuid->time_mid = c[1];
 342         uuid->time_hi_and_version = c[2];
 343         uuid->clock_seq_hi_and_reserved = c[3];
 344         uuid->clock_seq_low = c[4];
 345         for (n = 0; n < 6; n++)
 346                 uuid->node[n] = c[n + 5];
 347
 348         /* Check semantics... */
 349         return (((c[3] & 0x80) != 0x00 &&               /* variant 0? */
 350             (c[3] & 0xc0) != 0x80 &&                    /* variant 1? */
 351             (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);       /* variant 2? */
 352 }