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