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 1.4 2007/06/19 06:07:57 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 <sys/gpt.h>
  42 #include <net/if.h>
  43 #include <net/if_var.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 /* We use an alternative, more convenient representation in the generator. */
  55 struct uuid_private {
  56         union {
  57                 uint64_t        ll;             /* internal. */
  58                 struct {
  59                         uint32_t        low;
  60                         uint16_t        mid;
  61                         uint16_t        hi;
  62                 } x;
  63         } time;
  64         uint16_t        seq;                    /* Big-endian. */
  65         uint16_t        node[UUID_NODE_LEN>>1];
  66 };
  67
  68 static struct uuid_private uuid_last;
  69
  70 static struct lock uuid_lock;
  71
  72 static
  73 void
  74 uuid_lock_init(void *arg __unused)
  75 {
  76         lockinit(&uuid_lock, "uuid", 0, 0);
  77 }
  78 SYSINIT(uuid_lock, SI_BOOT1_POST, SI_ORDER_ANY, uuid_lock_init, NULL);
  79
  80 /*
  81  * Ask the network subsystem for a real MAC address from any of the
  82  * system interfaces.  If we can't find one, generate a random multicast
  83  * MAC address.
  84  */
  85 static void
  86 uuid_node(uint16_t *node)
  87 {
  88         if (if_getanyethermac(node, UUID_NODE_LEN) != 0)
  89                 read_random(node, UUID_NODE_LEN);
  90         *((uint8_t*)node) |= 0x01;
  91 }
  92
  93 /*
  94  * Get the current time as a 60 bit count of 100-nanosecond intervals
  95  * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
  96  * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
  97  * Gregorian reform to the Christian calendar.
  98  */
  99 static uint64_t
 100 uuid_time(void)
 101 {
 102         struct timespec ts;
 103         uint64_t time = 0x01B21DD213814000LL;
 104
 105         nanotime(&ts);
 106         time += ts.tv_sec * 10000000LL;         /* 100 ns increments */
 107         time += ts.tv_nsec / 100;               /* 100 ns increments */
 108         return (time & ((1LL << 60) - 1LL));    /* limit to 60 bits */
 109 }
 110
 111 struct uuid *
 112 kern_uuidgen(struct uuid *store, size_t count)
 113 {
 114         struct uuid_private uuid;
 115         uint64_t time;
 116         size_t n;
 117
 118         lockmgr(&uuid_lock, LK_EXCLUSIVE | LK_RETRY);
 119
 120         uuid_node(uuid.node);
 121         time = uuid_time();
 122
 123         if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
 124             uuid_last.node[1] != uuid.node[1] ||
 125             uuid_last.node[2] != uuid.node[2]) {
 126                 read_random(&uuid.seq, sizeof(uuid.seq));
 127                 uuid.seq &= 0x3fff;
 128         } else if (uuid_last.time.ll >= time) {
 129                 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
 130         } else {
 131                 uuid.seq = uuid_last.seq;
 132         }
 133
 134         uuid_last = uuid;
 135         uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);
 136
 137         lockmgr(&uuid_lock, LK_RELEASE);
 138
 139         /* Set sequence and variant and deal with byte order. */
 140         uuid.seq = htobe16(uuid.seq | 0x8000);
 141
 142         for (n = 0; n < count; n++) {
 143                 /* Set time and version (=1). */
 144                 uuid.time.x.low = (uint32_t)time;
 145                 uuid.time.x.mid = (uint16_t)(time >> 32);
 146                 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
 147                 store[n] = *(struct uuid *)&uuid;
 148                 time++;
 149         }
 150
 151         return (store);
 152 }
 153
 154 /*
 155  * uuidgen(struct uuid *store, int count)
 156  *
 157  * Generate an array of new UUIDs
 158  */
 159 int
 160 sys_uuidgen(struct uuidgen_args *uap)
 161 {
 162         struct uuid *store;
 163         size_t count;
 164         int error;
 165
 166         /*
 167          * Limit the number of UUIDs that can be created at the same time
 168          * to some arbitrary number. This isn't really necessary, but I
 169          * like to have some sort of upper-bound that's less than 2G :-)
 170          * XXX probably needs to be tunable.
 171          */
 172         if (uap->count < 1 || uap->count > 2048)
 173                 return (EINVAL);
 174
 175         count = uap->count;
 176         store = kmalloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK|M_NULLOK);
 177         if (store == NULL)
 178                 return (ENOSPC);
 179         kern_uuidgen(store, count);
 180         error = copyout(store, uap->store, count * sizeof(struct uuid));
 181         kfree(store, M_TEMP);
 182         return (error);
 183 }
 184
 185 int
 186 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
 187 {
 188         struct uuid_private *id;
 189         int cnt;
 190
 191         id = (struct uuid_private *)uuid;
 192         cnt = ksnprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
 193             id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
 194             be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
 195         return (cnt);
 196 }
 197
 198 int
 199 printf_uuid(struct uuid *uuid)
 200 {
 201         char buf[38];
 202
 203         snprintf_uuid(buf, sizeof(buf), uuid);
 204         return (kprintf("%s", buf));
 205 }
 206
 207 int
 208 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
 209 {
 210         char buf[38];
 211
 212         snprintf_uuid(buf, sizeof(buf), uuid);
 213         return (sbuf_printf(sb, "%s", buf));
 214 }
 215
 216 /*
 217  * Test functions
 218  */
 219
 220 /* A macro used to improve the readability of uuid_compare(). */
 221 #define DIFF_RETURN(a, b, field)        do {                    \
 222         if ((a)->field != (b)->field)                           \
 223                 return (((a)->field < (b)->field) ? -1 : 1);    \
 224 } while (0)
 225
 226 /*
 227  * kuuid_compare() - compare two UUIDs.
 228  * See also:
 229  *      http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
 230  *
 231  * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
 232  *       than any non-nil UUID.
 233  */
 234 int
 235 kuuid_compare(const struct uuid *a, const struct uuid *b)
 236 {
 237         int     res;
 238
 239         /* Deal with NULL or equal pointers. */
 240         if (a == b)
 241                 return (0);
 242         if (a == NULL)
 243                 return ((kuuid_is_nil(b)) ? 0 : -1);
 244         if (b == NULL)
 245                 return ((kuuid_is_nil(a)) ? 0 : 1);
 246
 247         /* We have to compare the hard way. */
 248         DIFF_RETURN(a, b, time_low);
 249         DIFF_RETURN(a, b, time_mid);
 250         DIFF_RETURN(a, b, time_hi_and_version);
 251         DIFF_RETURN(a, b, clock_seq_hi_and_reserved);
 252         DIFF_RETURN(a, b, clock_seq_low);
 253
 254         res = bcmp(a->node, b->node, sizeof(a->node));
 255         if (res)
 256                 return ((res < 0) ? -1 : 1);
 257         return (0);
 258 }
 259
 260 #undef DIFF_RETURN
 261
 262 int
 263 kuuid_is_nil(const struct uuid *uuid)
 264 {
 265         int i;
 266
 267         for (i = 0; i < sizeof(*uuid); i += sizeof(int)) {
 268                 if (*(const int *)((const char *)uuid + i) != 0)
 269                         return(0);
 270         }
 271         return(1);
 272 }
 273
 274 int
 275 kuuid_is_ccd(const struct uuid *uuid)
 276 {
 277         static struct uuid ccd_uuid = GPT_ENT_TYPE_DRAGONFLY_CCD;
 278         return(kuuid_compare(uuid, &ccd_uuid) == 0);
 279 }
 280
 281 int
 282 kuuid_is_vinum(const struct uuid *uuid)
 283 {
 284         static struct uuid vinum_uuid = GPT_ENT_TYPE_DRAGONFLY_VINUM;
 285         return(kuuid_compare(uuid, &vinum_uuid) == 0);
 286 }
 287
 288 /*
 289  * Encode/Decode UUID into byte-stream.
 290  *   http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
 291  *
 292  * 0                   1                   2                   3
 293  *   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
 294  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 295  *  |                          time_low                             |
 296  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 297  *  |       time_mid                |         time_hi_and_version   |
 298  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 299  *  |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
 300  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 301  *  |                         node (2-5)                            |
 302  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 303  */
 304
 305 void
 306 le_uuid_enc(void *buf, struct uuid const *uuid)
 307 {
 308         u_char *p;
 309         int i;
 310
 311         p = buf;
 312         le32enc(p, uuid->time_low);
 313         le16enc(p + 4, uuid->time_mid);
 314         le16enc(p + 6, uuid->time_hi_and_version);
 315         p[8] = uuid->clock_seq_hi_and_reserved;
 316         p[9] = uuid->clock_seq_low;
 317         for (i = 0; i < _UUID_NODE_LEN; i++)
 318                 p[10 + i] = uuid->node[i];
 319 }
 320
 321 void
 322 le_uuid_dec(void const *buf, struct uuid *uuid)
 323 {
 324         u_char const *p;
 325         int i;
 326
 327         p = buf;
 328         uuid->time_low = le32dec(p);
 329         uuid->time_mid = le16dec(p + 4);
 330         uuid->time_hi_and_version = le16dec(p + 6);
 331         uuid->clock_seq_hi_and_reserved = p[8];
 332         uuid->clock_seq_low = p[9];
 333         for (i = 0; i < _UUID_NODE_LEN; i++)
 334                 uuid->node[i] = p[10 + i];
 335 }
 336
 337 void
 338 be_uuid_enc(void *buf, struct uuid const *uuid)
 339 {
 340         u_char *p;
 341         int i;
 342
 343         p = buf;
 344         be32enc(p, uuid->time_low);
 345         be16enc(p + 4, uuid->time_mid);
 346         be16enc(p + 6, uuid->time_hi_and_version);
 347         p[8] = uuid->clock_seq_hi_and_reserved;
 348         p[9] = uuid->clock_seq_low;
 349         for (i = 0; i < _UUID_NODE_LEN; i++)
 350                 p[10 + i] = uuid->node[i];
 351 }
 352
 353 void
 354 be_uuid_dec(void const *buf, struct uuid *uuid)
 355 {
 356         u_char const *p;
 357         int i;
 358
 359         p = buf;
 360         uuid->time_low = be32dec(p);
 361         uuid->time_mid = le16dec(p + 4);
 362         uuid->time_hi_and_version = be16dec(p + 6);
 363         uuid->clock_seq_hi_and_reserved = p[8];
 364         uuid->clock_seq_low = p[9];
 365         for (i = 0; i < _UUID_NODE_LEN; i++)
 366                 uuid->node[i] = p[10 + i];
 367 }
 368
 369 int
 370 parse_uuid(const char *str, struct uuid *uuid)
 371 {
 372         u_int c[11];
 373         int n;
 374
 375         /* An empty string represents a nil UUID. */
 376         if (*str == '\0') {
 377                 bzero(uuid, sizeof(*uuid));
 378                 return (0);
 379         }
 380
 381         /* The UUID string representation has a fixed length. */
 382         if (strlen(str) != 36)
 383                 return (EINVAL);
 384
 385         /*
 386          * We only work with "new" UUIDs. New UUIDs have the form:
 387          *      01234567-89ab-cdef-0123-456789abcdef
 388          * The so called "old" UUIDs, which we don't support, have the form:
 389          *      0123456789ab.cd.ef.01.23.45.67.89.ab
 390          */
 391         if (str[8] != '-')
 392                 return (EINVAL);
 393
 394         n = ksscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
 395             c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
 396         /* Make sure we have all conversions. */
 397         if (n != 11)
 398                 return (EINVAL);
 399
 400         /* Successful scan. Build the UUID. */
 401         uuid->time_low = c[0];
 402         uuid->time_mid = c[1];
 403         uuid->time_hi_and_version = c[2];
 404         uuid->clock_seq_hi_and_reserved = c[3];
 405         uuid->clock_seq_low = c[4];
 406         for (n = 0; n < 6; n++)
 407                 uuid->node[n] = c[n + 5];
 408
 409         /* Check semantics... */
 410         return (((c[3] & 0x80) != 0x00 &&               /* variant 0? */
 411             (c[3] & 0xc0) != 0x80 &&                    /* variant 1? */
 412             (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);       /* variant 2? */
 413 }