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_var.h>
  43
  44 #include <sys/mplock2.h>
  45
  46 /*
  47  * See also:
  48  *      http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
  49  *      http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
  50  *
  51  * Note that the generator state is itself an UUID, but the time and clock
  52  * sequence fields are written in the native byte order.
  53  */
  54
  55 /* We use an alternative, more convenient representation in the generator. */
  56 struct uuid_private {
  57         union {
  58                 uint64_t        ll;             /* internal. */
  59                 struct {
  60                         uint32_t        low;
  61                         uint16_t        mid;
  62                         uint16_t        hi;
  63                 } x;
  64         } time;
  65         uint16_t        seq;                    /* Big-endian. */
  66         uint16_t        node[UUID_NODE_LEN>>1];
  67 };
  68
  69 static struct uuid_private uuid_last;
  70
  71 static struct lock uuid_lock;
  72
  73 static
  74 void
  75 uuid_lock_init(void *arg __unused)
  76 {
  77         lockinit(&uuid_lock, "uuid", 0, 0);
  78 }
  79 SYSINIT(uuid_lock, SI_BOOT1_POST, SI_ORDER_ANY, uuid_lock_init, NULL);
  80
  81 /*
  82  * Ask the network subsystem for a real MAC address from any of the
  83  * system interfaces.  If we can't find one, generate a random multicast
  84  * MAC address.
  85  */
  86 static void
  87 uuid_node(uint16_t *node)
  88 {
  89         if (if_getanyethermac(node, UUID_NODE_LEN) != 0)
  90                 read_random(node, UUID_NODE_LEN);
  91         *((uint8_t*)node) |= 0x01;
  92 }
  93
  94 /*
  95  * Get the current time as a 60 bit count of 100-nanosecond intervals
  96  * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
  97  * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
  98  * Gregorian reform to the Christian calendar.
  99  */
 100 static uint64_t
 101 uuid_time(void)
 102 {
 103         struct timespec ts;
 104         uint64_t time = 0x01B21DD213814000LL;
 105
 106         nanotime(&ts);
 107         time += ts.tv_sec * 10000000LL;         /* 100 ns increments */
 108         time += ts.tv_nsec / 100;               /* 100 ns increments */
 109         return (time & ((1LL << 60) - 1LL));    /* limit to 60 bits */
 110 }
 111
 112 struct uuid *
 113 kern_uuidgen(struct uuid *store, size_t count)
 114 {
 115         struct uuid_private uuid;
 116         uint64_t time;
 117         size_t n;
 118
 119         lockmgr(&uuid_lock, LK_EXCLUSIVE | LK_RETRY);
 120
 121         uuid_node(uuid.node);
 122         time = uuid_time();
 123
 124         if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
 125             uuid_last.node[1] != uuid.node[1] ||
 126             uuid_last.node[2] != uuid.node[2]) {
 127                 read_random(&uuid.seq, sizeof(uuid.seq));
 128                 uuid.seq &= 0x3fff;
 129         } else if (uuid_last.time.ll >= time) {
 130                 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
 131         } else {
 132                 uuid.seq = uuid_last.seq;
 133         }
 134
 135         uuid_last = uuid;
 136         uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);
 137
 138         lockmgr(&uuid_lock, LK_RELEASE);
 139
 140         /* Set sequence and variant and deal with byte order. */
 141         uuid.seq = htobe16(uuid.seq | 0x8000);
 142
 143         for (n = 0; n < count; n++) {
 144                 /* Set time and version (=1). */
 145                 uuid.time.x.low = (uint32_t)time;
 146                 uuid.time.x.mid = (uint16_t)(time >> 32);
 147                 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
 148                 store[n] = *(struct uuid *)&uuid;
 149                 time++;
 150         }
 151
 152         return (store);
 153 }
 154
 155 /*
 156  * uuidgen(struct uuid *store, int count)
 157  *
 158  * Generate an array of new UUIDs
 159  *
 160  * MPALMOSTSAFE
 161  */
 162 int
 163 sys_uuidgen(struct uuidgen_args *uap)
 164 {
 165         struct uuid *store;
 166         size_t count;
 167         int error;
 168
 169         /*
 170          * Limit the number of UUIDs that can be created at the same time
 171          * to some arbitrary number. This isn't really necessary, but I
 172          * like to have some sort of upper-bound that's less than 2G :-)
 173          * XXX probably needs to be tunable.
 174          */
 175         if (uap->count < 1 || uap->count > 2048)
 176                 return (EINVAL);
 177
 178         count = uap->count;
 179         store = kmalloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK);
 180         get_mplock();
 181         kern_uuidgen(store, count);
 182         rel_mplock();
 183         error = copyout(store, uap->store, count * sizeof(struct uuid));
 184         kfree(store, M_TEMP);
 185         return (error);
 186 }
 187
 188 int
 189 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
 190 {
 191         struct uuid_private *id;
 192         int cnt;
 193
 194         id = (struct uuid_private *)uuid;
 195         cnt = ksnprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
 196             id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
 197             be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
 198         return (cnt);
 199 }
 200
 201 int
 202 printf_uuid(struct uuid *uuid)
 203 {
 204         char buf[38];
 205
 206         snprintf_uuid(buf, sizeof(buf), uuid);
 207         return (kprintf("%s", buf));
 208 }
 209
 210 int
 211 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
 212 {
 213         char buf[38];
 214
 215         snprintf_uuid(buf, sizeof(buf), uuid);
 216         return (sbuf_printf(sb, "%s", buf));
 217 }
 218
 219 /*
 220  * Test functions
 221  */
 222
 223 /* A macro used to improve the readability of uuid_compare(). */
 224 #define DIFF_RETURN(a, b, field)        do {                    \
 225         if ((a)->field != (b)->field)                           \
 226                 return (((a)->field < (b)->field) ? -1 : 1);    \
 227 } while (0)
 228
 229 /*
 230  * kuuid_compare() - compare two UUIDs.
 231  * See also:
 232  *      http://www.opengroup.org/onlinepubs/009629399/uuid_compare.htm
 233  *
 234  * NOTE: Either UUID can be NULL, meaning a nil UUID. nil UUIDs are smaller
 235  *       than any non-nil UUID.
 236  */
 237 int
 238 kuuid_compare(const struct uuid *a, const struct uuid *b)
 239 {
 240         int     res;
 241
 242         /* Deal with NULL or equal pointers. */
 243         if (a == b)
 244                 return (0);
 245         if (a == NULL)
 246                 return ((kuuid_is_nil(b)) ? 0 : -1);
 247         if (b == NULL)
 248                 return ((kuuid_is_nil(a)) ? 0 : 1);
 249
 250         /* We have to compare the hard way. */
 251         DIFF_RETURN(a, b, time_low);
 252         DIFF_RETURN(a, b, time_mid);
 253         DIFF_RETURN(a, b, time_hi_and_version);
 254         DIFF_RETURN(a, b, clock_seq_hi_and_reserved);
 255         DIFF_RETURN(a, b, clock_seq_low);
 256
 257         res = bcmp(a->node, b->node, sizeof(a->node));
 258         if (res)
 259                 return ((res < 0) ? -1 : 1);
 260         return (0);
 261 }
 262
 263 #undef DIFF_RETURN
 264
 265 int
 266 kuuid_is_nil(const struct uuid *uuid)
 267 {
 268         int i;
 269
 270         for (i = 0; i < sizeof(*uuid); i += sizeof(int)) {
 271                 if (*(const int *)((const char *)uuid + i) != 0)
 272                         return(0);
 273         }
 274         return(1);
 275 }
 276
 277 int
 278 kuuid_is_ccd(const struct uuid *uuid)
 279 {
 280         static struct uuid ccd_uuid = GPT_ENT_TYPE_DRAGONFLY_CCD;
 281         return(kuuid_compare(uuid, &ccd_uuid) == 0);
 282 }
 283
 284 int
 285 kuuid_is_vinum(const struct uuid *uuid)
 286 {
 287         static struct uuid vinum_uuid = GPT_ENT_TYPE_DRAGONFLY_VINUM;
 288         return(kuuid_compare(uuid, &vinum_uuid) == 0);
 289 }
 290
 291 /*
 292  * Encode/Decode UUID into byte-stream.
 293  *   http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
 294  *
 295  * 0                   1                   2                   3
 296  *   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
 297  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 298  *  |                          time_low                             |
 299  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 300  *  |       time_mid                |         time_hi_and_version   |
 301  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 302  *  |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
 303  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 304  *  |                         node (2-5)                            |
 305  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 306  */
 307
 308 void
 309 le_uuid_enc(void *buf, struct uuid const *uuid)
 310 {
 311         u_char *p;
 312         int i;
 313
 314         p = buf;
 315         le32enc(p, uuid->time_low);
 316         le16enc(p + 4, uuid->time_mid);
 317         le16enc(p + 6, uuid->time_hi_and_version);
 318         p[8] = uuid->clock_seq_hi_and_reserved;
 319         p[9] = uuid->clock_seq_low;
 320         for (i = 0; i < _UUID_NODE_LEN; i++)
 321                 p[10 + i] = uuid->node[i];
 322 }
 323
 324 void
 325 le_uuid_dec(void const *buf, struct uuid *uuid)
 326 {
 327         u_char const *p;
 328         int i;
 329
 330         p = buf;
 331         uuid->time_low = le32dec(p);
 332         uuid->time_mid = le16dec(p + 4);
 333         uuid->time_hi_and_version = le16dec(p + 6);
 334         uuid->clock_seq_hi_and_reserved = p[8];
 335         uuid->clock_seq_low = p[9];
 336         for (i = 0; i < _UUID_NODE_LEN; i++)
 337                 uuid->node[i] = p[10 + i];
 338 }
 339
 340 void
 341 be_uuid_enc(void *buf, struct uuid const *uuid)
 342 {
 343         u_char *p;
 344         int i;
 345
 346         p = buf;
 347         be32enc(p, uuid->time_low);
 348         be16enc(p + 4, uuid->time_mid);
 349         be16enc(p + 6, uuid->time_hi_and_version);
 350         p[8] = uuid->clock_seq_hi_and_reserved;
 351         p[9] = uuid->clock_seq_low;
 352         for (i = 0; i < _UUID_NODE_LEN; i++)
 353                 p[10 + i] = uuid->node[i];
 354 }
 355
 356 void
 357 be_uuid_dec(void const *buf, struct uuid *uuid)
 358 {
 359         u_char const *p;
 360         int i;
 361
 362         p = buf;
 363         uuid->time_low = be32dec(p);
 364         uuid->time_mid = le16dec(p + 4);
 365         uuid->time_hi_and_version = be16dec(p + 6);
 366         uuid->clock_seq_hi_and_reserved = p[8];
 367         uuid->clock_seq_low = p[9];
 368         for (i = 0; i < _UUID_NODE_LEN; i++)
 369                 uuid->node[i] = p[10 + i];
 370 }
 371
 372 int
 373 parse_uuid(const char *str, struct uuid *uuid)
 374 {
 375         u_int c[11];
 376         int n;
 377
 378         /* An empty string represents a nil UUID. */
 379         if (*str == '\0') {
 380                 bzero(uuid, sizeof(*uuid));
 381                 return (0);
 382         }
 383
 384         /* The UUID string representation has a fixed length. */
 385         if (strlen(str) != 36)
 386                 return (EINVAL);
 387
 388         /*
 389          * We only work with "new" UUIDs. New UUIDs have the form:
 390          *      01234567-89ab-cdef-0123-456789abcdef
 391          * The so called "old" UUIDs, which we don't support, have the form:
 392          *      0123456789ab.cd.ef.01.23.45.67.89.ab
 393          */
 394         if (str[8] != '-')
 395                 return (EINVAL);
 396
 397         n = ksscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
 398             c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
 399         /* Make sure we have all conversions. */
 400         if (n != 11)
 401                 return (EINVAL);
 402
 403         /* Successful scan. Build the UUID. */
 404         uuid->time_low = c[0];
 405         uuid->time_mid = c[1];
 406         uuid->time_hi_and_version = c[2];
 407         uuid->clock_seq_hi_and_reserved = c[3];
 408         uuid->clock_seq_low = c[4];
 409         for (n = 0; n < 6; n++)
 410                 uuid->node[n] = c[n + 5];
 411
 412         /* Check semantics... */
 413         return (((c[3] & 0x80) != 0x00 &&               /* variant 0? */
 414             (c[3] & 0xc0) != 0x80 &&                    /* variant 1? */
 415             (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);       /* variant 2? */
 416 }