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 1.1 2007/06/16 18:55:27 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/sbuf.h>
  36 #include <sys/socket.h>
  37 #include <sys/sysproto.h>
  38 #include <sys/uuid.h>
  39
  40 /*
  41  * See also:
  42  *      http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
  43  *      http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
  44  *
  45  * Note that the generator state is itself an UUID, but the time and clock
  46  * sequence fields are written in the native byte order.
  47  */
  48
  49 /* We use an alternative, more convenient representation in the generator. */
  50 struct uuid_private {
  51         union {
  52                 uint64_t        ll;             /* internal. */
  53                 struct {
  54                         uint32_t        low;
  55                         uint16_t        mid;
  56                         uint16_t        hi;
  57                 } x;
  58         } time;
  59         uint16_t        seq;                    /* Big-endian. */
  60         uint16_t        node[UUID_NODE_LEN>>1];
  61 };
  62
  63 #if 0   /* NOT YET */
  64
  65 static struct uuid_private uuid_last;
  66
  67 static struct mtx uuid_mutex;
  68 MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF);
  69
  70 /*
  71  * Return the first MAC address we encounter or, if none was found,
  72  * construct a sufficiently random multicast address. We don't try
  73  * to return the same MAC address as previously returned. We always
  74  * generate a new multicast address if no MAC address exists in the
  75  * system.
  76  * It would be nice to know if 'ifnet' or any of its sub-structures
  77  * has been changed in any way. If not, we could simply skip the
  78  * scan and safely return the MAC address we returned before.
  79  */
  80 static void
  81 uuid_node(uint16_t *node)
  82 {
  83         struct ifnet *ifp;
  84         struct ifaddr *ifa;
  85         struct sockaddr_dl *sdl;
  86         int i;
  87
  88         IFNET_RLOCK();
  89         TAILQ_FOREACH(ifp, &ifnet, if_link) {
  90                 /* Walk the address list */
  91                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  92                         sdl = (struct sockaddr_dl*)ifa->ifa_addr;
  93                         if (sdl != NULL && sdl->sdl_family == AF_LINK &&
  94                             sdl->sdl_type == IFT_ETHER) {
  95                                 /* Got a MAC address. */
  96                                 bcopy(LLADDR(sdl), node, UUID_NODE_LEN);
  97                                 IFNET_RUNLOCK();
  98                                 return;
  99                         }
 100                 }
 101         }
 102         IFNET_RUNLOCK();
 103
 104         for (i = 0; i < (UUID_NODE_LEN>>1); i++)
 105                 node[i] = (uint16_t)arc4random();
 106         *((uint8_t*)node) |= 0x01;
 107 }
 108
 109 /*
 110  * Get the current time as a 60 bit count of 100-nanosecond intervals
 111  * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
 112  * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
 113  * Gregorian reform to the Christian calendar.
 114  */
 115 static uint64_t
 116 uuid_time(void)
 117 {
 118         struct bintime bt;
 119         uint64_t time = 0x01B21DD213814000LL;
 120
 121         bintime(&bt);
 122         time += (uint64_t)bt.sec * 10000000LL;
 123         time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32;
 124         return (time & ((1LL << 60) - 1LL));
 125 }
 126
 127 struct uuid *
 128 kern_uuidgen(struct uuid *store, size_t count)
 129 {
 130         struct uuid_private uuid;
 131         uint64_t time;
 132         size_t n;
 133
 134         mtx_lock(&uuid_mutex);
 135
 136         uuid_node(uuid.node);
 137         time = uuid_time();
 138
 139         if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
 140             uuid_last.node[1] != uuid.node[1] ||
 141             uuid_last.node[2] != uuid.node[2])
 142                 uuid.seq = (uint16_t)arc4random() & 0x3fff;
 143         else if (uuid_last.time.ll >= time)
 144                 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
 145         else
 146                 uuid.seq = uuid_last.seq;
 147
 148         uuid_last = uuid;
 149         uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);
 150
 151         mtx_unlock(&uuid_mutex);
 152
 153         /* Set sequence and variant and deal with byte order. */
 154         uuid.seq = htobe16(uuid.seq | 0x8000);
 155
 156         for (n = 0; n < count; n++) {
 157                 /* Set time and version (=1). */
 158                 uuid.time.x.low = (uint32_t)time;
 159                 uuid.time.x.mid = (uint16_t)(time >> 32);
 160                 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
 161                 store[n] = *(struct uuid *)&uuid;
 162                 time++;
 163         }
 164
 165         return (store);
 166 }
 167
 168 #ifndef _SYS_SYSPROTO_H_
 169 struct uuidgen_args {
 170         struct uuid *store;
 171         int     count;
 172 };
 173 #endif
 174 int
 175 uuidgen(struct thread *td, struct uuidgen_args *uap)
 176 {
 177         struct uuid *store;
 178         size_t count;
 179         int error;
 180
 181         /*
 182          * Limit the number of UUIDs that can be created at the same time
 183          * to some arbitrary number. This isn't really necessary, but I
 184          * like to have some sort of upper-bound that's less than 2G :-)
 185          * XXX probably needs to be tunable.
 186          */
 187         if (uap->count < 1 || uap->count > 2048)
 188                 return (EINVAL);
 189
 190         count = uap->count;
 191         store = malloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK);
 192         kern_uuidgen(store, count);
 193         error = copyout(store, uap->store, count * sizeof(struct uuid));
 194         free(store, M_TEMP);
 195         return (error);
 196 }
 197
 198 #endif  /* NOT YET */
 199
 200 int
 201 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
 202 {
 203         struct uuid_private *id;
 204         int cnt;
 205
 206         id = (struct uuid_private *)uuid;
 207         cnt = ksnprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
 208             id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
 209             be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
 210         return (cnt);
 211 }
 212
 213 int
 214 printf_uuid(struct uuid *uuid)
 215 {
 216         char buf[38];
 217
 218         snprintf_uuid(buf, sizeof(buf), uuid);
 219         return (kprintf("%s", buf));
 220 }
 221
 222 int
 223 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
 224 {
 225         char buf[38];
 226
 227         snprintf_uuid(buf, sizeof(buf), uuid);
 228         return (sbuf_printf(sb, "%s", buf));
 229 }
 230
 231 /*
 232  * Encode/Decode UUID into byte-stream.
 233  *   http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
 234  *
 235  * 0                   1                   2                   3
 236  *   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
 237  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 238  *  |                          time_low                             |
 239  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 240  *  |       time_mid                |         time_hi_and_version   |
 241  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 242  *  |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
 243  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 244  *  |                         node (2-5)                            |
 245  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 246  */
 247
 248 void
 249 le_uuid_enc(void *buf, struct uuid const *uuid)
 250 {
 251         u_char *p;
 252         int i;
 253
 254         p = buf;
 255         le32enc(p, uuid->time_low);
 256         le16enc(p + 4, uuid->time_mid);
 257         le16enc(p + 6, uuid->time_hi_and_version);
 258         p[8] = uuid->clock_seq_hi_and_reserved;
 259         p[9] = uuid->clock_seq_low;
 260         for (i = 0; i < _UUID_NODE_LEN; i++)
 261                 p[10 + i] = uuid->node[i];
 262 }
 263
 264 void
 265 le_uuid_dec(void const *buf, struct uuid *uuid)
 266 {
 267         u_char const *p;
 268         int i;
 269
 270         p = buf;
 271         uuid->time_low = le32dec(p);
 272         uuid->time_mid = le16dec(p + 4);
 273         uuid->time_hi_and_version = le16dec(p + 6);
 274         uuid->clock_seq_hi_and_reserved = p[8];
 275         uuid->clock_seq_low = p[9];
 276         for (i = 0; i < _UUID_NODE_LEN; i++)
 277                 uuid->node[i] = p[10 + i];
 278 }
 279
 280 void
 281 be_uuid_enc(void *buf, struct uuid const *uuid)
 282 {
 283         u_char *p;
 284         int i;
 285
 286         p = buf;
 287         be32enc(p, uuid->time_low);
 288         be16enc(p + 4, uuid->time_mid);
 289         be16enc(p + 6, uuid->time_hi_and_version);
 290         p[8] = uuid->clock_seq_hi_and_reserved;
 291         p[9] = uuid->clock_seq_low;
 292         for (i = 0; i < _UUID_NODE_LEN; i++)
 293                 p[10 + i] = uuid->node[i];
 294 }
 295
 296 void
 297 be_uuid_dec(void const *buf, struct uuid *uuid)
 298 {
 299         u_char const *p;
 300         int i;
 301
 302         p = buf;
 303         uuid->time_low = be32dec(p);
 304         uuid->time_mid = le16dec(p + 4);
 305         uuid->time_hi_and_version = be16dec(p + 6);
 306         uuid->clock_seq_hi_and_reserved = p[8];
 307         uuid->clock_seq_low = p[9];
 308         for (i = 0; i < _UUID_NODE_LEN; i++)
 309                 uuid->node[i] = p[10 + i];
 310 }
 311
 312 int
 313 parse_uuid(const char *str, struct uuid *uuid)
 314 {
 315         u_int c[11];
 316         int n;
 317
 318         /* An empty string represents a nil UUID. */
 319         if (*str == '\0') {
 320                 bzero(uuid, sizeof(*uuid));
 321                 return (0);
 322         }
 323
 324         /* The UUID string representation has a fixed length. */
 325         if (strlen(str) != 36)
 326                 return (EINVAL);
 327
 328         /*
 329          * We only work with "new" UUIDs. New UUIDs have the form:
 330          *      01234567-89ab-cdef-0123-456789abcdef
 331          * The so called "old" UUIDs, which we don't support, have the form:
 332          *      0123456789ab.cd.ef.01.23.45.67.89.ab
 333          */
 334         if (str[8] != '-')
 335                 return (EINVAL);
 336
 337         n = ksscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
 338             c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
 339         /* Make sure we have all conversions. */
 340         if (n != 11)
 341                 return (EINVAL);
 342
 343         /* Successful scan. Build the UUID. */
 344         uuid->time_low = c[0];
 345         uuid->time_mid = c[1];
 346         uuid->time_hi_and_version = c[2];
 347         uuid->clock_seq_hi_and_reserved = c[3];
 348         uuid->clock_seq_low = c[4];
 349         for (n = 0; n < 6; n++)
 350                 uuid->node[n] = c[n + 5];
 351
 352         /* Check semantics... */
 353         return (((c[3] & 0x80) != 0x00 &&               /* variant 0? */
 354             (c[3] & 0xc0) != 0x80 &&                    /* variant 1? */
 355             (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);       /* variant 2? */
 356 }