kern_uuid.c revision 1.1.4.3
1 /* $FreeBSD: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $ */ 2 /* $NetBSD: kern_uuid.c,v 1.1.4.3 2004/09/03 12:45:39 skrll Exp $ */ 3 4 /* 5 * Copyright (c) 2002 Marcel Moolenaar 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.1.4.3 2004/09/03 12:45:39 skrll Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/endian.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/socket.h> 40 #include <sys/systm.h> 41 #include <sys/uuid.h> 42 43 /* NetBSD */ 44 #include <sys/proc.h> 45 #include <sys/sa.h> 46 #include <sys/mount.h> 47 #include <sys/syscallargs.h> 48 #include <sys/uio.h> 49 50 #include <net/if.h> 51 #include <net/if_dl.h> 52 #include <net/if_types.h> 53 54 /* 55 * See also: 56 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 57 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm 58 * 59 * Note that the generator state is itself an UUID, but the time and clock 60 * sequence fields are written in the native byte order. 61 */ 62 63 /* XXX Do we have a similar ASSERT()? */ 64 #define CTASSERT(x) 65 66 CTASSERT(sizeof(struct uuid) == 16); 67 68 /* We use an alternative, more convenient representation in the generator. */ 69 struct uuid_private { 70 union { 71 uint64_t ll; /* internal. */ 72 struct { 73 uint32_t low; 74 uint16_t mid; 75 uint16_t hi; 76 } x; 77 } time; 78 uint16_t seq; /* Big-endian. */ 79 uint16_t node[UUID_NODE_LEN>>1]; 80 }; 81 82 CTASSERT(sizeof(struct uuid_private) == 16); 83 84 static struct uuid_private uuid_last; 85 86 /* "UUID generator mutex lock" */ 87 static struct simplelock uuid_mutex = SIMPLELOCK_INITIALIZER; 88 89 /* 90 * Return the first MAC address we encounter or, if none was found, 91 * construct a sufficiently random multicast address. We don't try 92 * to return the same MAC address as previously returned. We always 93 * generate a new multicast address if no MAC address exists in the 94 * system. 95 * It would be nice to know if 'ifnet' or any of its sub-structures 96 * has been changed in any way. If not, we could simply skip the 97 * scan and safely return the MAC address we returned before. 98 */ 99 static void 100 uuid_node(uint16_t *node) 101 { 102 struct ifnet *ifp; 103 struct ifaddr *ifa; 104 struct sockaddr_dl *sdl; 105 int i, s; 106 107 s = splnet(); 108 TAILQ_FOREACH(ifp, &ifnet, if_list) { 109 /* Walk the address list */ 110 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 111 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 112 if (sdl != NULL && sdl->sdl_family == AF_LINK && 113 sdl->sdl_type == IFT_ETHER) { 114 /* Got a MAC address. */ 115 memcpy(node, LLADDR(sdl), UUID_NODE_LEN); 116 splx(s); 117 return; 118 } 119 } 120 } 121 splx(s); 122 123 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 124 node[i] = (uint16_t)arc4random(); 125 *((uint8_t*)node) |= 0x01; 126 } 127 128 /* 129 * Get the current time as a 60 bit count of 100-nanosecond intervals 130 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 131 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 132 * Gregorian reform to the Christian calendar. 133 */ 134 /* 135 * At present, NetBSD has no timespec source, only timeval sources. So, 136 * we use timeval. 137 */ 138 static uint64_t 139 uuid_time(void) 140 { 141 struct timeval tv; 142 uint64_t time = 0x01B21DD213814000LL; 143 144 microtime(&tv); 145 time += (uint64_t)tv.tv_sec * 10000000LL; 146 time += (uint64_t)(10 * tv.tv_usec); 147 return (time & ((1LL << 60) - 1LL)); 148 } 149 150 /* 151 * Internal routine to actually generate the UUID. 152 */ 153 static void 154 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 155 { 156 uint64_t time; 157 158 simple_lock(&uuid_mutex); 159 160 uuid_node(uuid->node); 161 time = uuid_time(); 162 *timep = time; 163 164 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 165 uuid_last.node[1] != uuid->node[1] || 166 uuid_last.node[2] != uuid->node[2]) 167 uuid->seq = (uint16_t)arc4random() & 0x3fff; 168 else if (uuid_last.time.ll >= time) 169 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 170 else 171 uuid->seq = uuid_last.seq; 172 173 uuid_last = *uuid; 174 uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL); 175 176 simple_unlock(&uuid_mutex); 177 } 178 179 int 180 sys_uuidgen(struct lwp *l, void *v, register_t *retval) 181 { 182 struct sys_uuidgen_args *uap = v; 183 struct uuid_private uuid; 184 uint64_t time; 185 int error; 186 187 /* 188 * Limit the number of UUIDs that can be created at the same time 189 * to some arbitrary number. This isn't really necessary, but I 190 * like to have some sort of upper-bound that's less than 2G :-) 191 * XXX needs to be tunable. 192 */ 193 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 194 return (EINVAL); 195 196 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 197 198 /* Generate the base UUID. */ 199 uuid_generate(&uuid, &time, SCARG(uap, count)); 200 201 /* Set sequence and variant and deal with byte order. */ 202 uuid.seq = htobe16(uuid.seq | 0x8000); 203 204 /* XXX: this should copyout larger chunks at a time. */ 205 do { 206 /* Set time and version (=1) and deal with byte order. */ 207 uuid.time.x.low = (uint32_t)time; 208 uuid.time.x.mid = (uint16_t)(time >> 32); 209 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12); 210 error = copyout(&uuid, SCARG(uap,store), sizeof(uuid)); 211 SCARG(uap, store)++; 212 SCARG(uap, count)--; 213 time++; 214 } while (SCARG(uap, count) > 0 && error == 0); 215 216 return (error); 217 } 218 219 int 220 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 221 { 222 const struct uuid_private *id; 223 int cnt; 224 225 id = (const struct uuid_private *)uuid; 226 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 227 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 228 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 229 return (cnt); 230 } 231 232 int 233 uuid_printf(const struct uuid *uuid) 234 { 235 char buf[UUID_STR_LEN]; 236 237 (void) uuid_snprintf(buf, sizeof(buf), uuid); 238 printf("%s", buf); 239 return (0); 240 } 241 242 /* 243 * Encode/Decode UUID into octet-stream. 244 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 245 * 246 * 0 1 2 3 247 * 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 1 248 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 * | time_low | 250 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 * | time_mid | time_hi_and_version | 252 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 254 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 * | node (2-5) | 256 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 */ 258 259 static void 260 be16enc(void *buf, uint16_t u) 261 { 262 uint8_t *p = buf; 263 264 p[0] = (u >> 8) & 0xff; 265 p[1] = u & 0xff; 266 } 267 268 static void 269 le16enc(void *buf, uint16_t u) 270 { 271 uint8_t *p = buf; 272 273 p[0] = u & 0xff; 274 p[1] = (u >> 8) & 0xff; 275 } 276 277 static uint16_t 278 be16dec(const void *buf) 279 { 280 const uint8_t *p = buf; 281 282 return ((p[0] << 8) | p[1]); 283 } 284 285 static uint16_t 286 le16dec(const void *buf) 287 { 288 const uint8_t *p = buf; 289 290 return ((p[1] << 8) | p[0]); 291 } 292 293 static void 294 be32enc(void *buf, uint32_t u) 295 { 296 uint8_t *p = buf; 297 298 p[0] = (u >> 24) & 0xff; 299 p[1] = (u >> 16) & 0xff; 300 p[2] = (u >> 8) & 0xff; 301 p[3] = u & 0xff; 302 } 303 304 static void 305 le32enc(void *buf, uint32_t u) 306 { 307 uint8_t *p = buf; 308 309 p[0] = u & 0xff; 310 p[1] = (u >> 8) & 0xff; 311 p[2] = (u >> 16) & 0xff; 312 p[3] = (u >> 24) & 0xff; 313 } 314 315 static uint32_t 316 be32dec(const void *buf) 317 { 318 const uint8_t *p = buf; 319 320 return ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]); 321 } 322 323 static uint32_t 324 le32dec(const void *buf) 325 { 326 const uint8_t *p = buf; 327 328 return ((p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0]); 329 } 330 331 void 332 uuid_enc_le(void *buf, const struct uuid *uuid) 333 { 334 uint8_t *p = buf; 335 int i; 336 337 le32enc(p, uuid->time_low); 338 le16enc(p + 4, uuid->time_mid); 339 le16enc(p + 6, uuid->time_hi_and_version); 340 p[8] = uuid->clock_seq_hi_and_reserved; 341 p[9] = uuid->clock_seq_low; 342 for (i = 0; i < _UUID_NODE_LEN; i++) 343 p[10 + i] = uuid->node[i]; 344 } 345 346 void 347 uuid_dec_le(void const *buf, struct uuid *uuid) 348 { 349 const uint8_t *p = buf; 350 int i; 351 352 uuid->time_low = le32dec(p); 353 uuid->time_mid = le16dec(p + 4); 354 uuid->time_hi_and_version = le16dec(p + 6); 355 uuid->clock_seq_hi_and_reserved = p[8]; 356 uuid->clock_seq_low = p[9]; 357 for (i = 0; i < _UUID_NODE_LEN; i++) 358 uuid->node[i] = p[10 + i]; 359 } 360 361 void 362 uuid_enc_be(void *buf, const struct uuid *uuid) 363 { 364 uint8_t *p = buf; 365 int i; 366 367 be32enc(p, uuid->time_low); 368 be16enc(p + 4, uuid->time_mid); 369 be16enc(p + 6, uuid->time_hi_and_version); 370 p[8] = uuid->clock_seq_hi_and_reserved; 371 p[9] = uuid->clock_seq_low; 372 for (i = 0; i < _UUID_NODE_LEN; i++) 373 p[10 + i] = uuid->node[i]; 374 } 375 376 void 377 uuid_dec_be(void const *buf, struct uuid *uuid) 378 { 379 const uint8_t *p = buf; 380 int i; 381 382 uuid->time_low = be32dec(p); 383 uuid->time_mid = le16dec(p + 4); 384 uuid->time_hi_and_version = be16dec(p + 6); 385 uuid->clock_seq_hi_and_reserved = p[8]; 386 uuid->clock_seq_low = p[9]; 387 for (i = 0; i < _UUID_NODE_LEN; i++) 388 uuid->node[i] = p[10 + i]; 389 } 390
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