kern_uuid.c revision 181803
1140089Sdas/*- 2140089Sdas * Copyright (c) 2002 Marcel Moolenaar 3140089Sdas * All rights reserved. 4140089Sdas * 5140089Sdas * Redistribution and use in source and binary forms, with or without 6140089Sdas * modification, are permitted provided that the following conditions 7140089Sdas * are met: 8140089Sdas * 9140089Sdas * 1. Redistributions of source code must retain the above copyright 10140089Sdas * 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 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/kern_uuid.c 181803 2008-08-17 23:27:27Z bz $"); 29 30#include <sys/param.h> 31#include <sys/endian.h> 32#include <sys/kernel.h> 33#include <sys/lock.h> 34#include <sys/mutex.h> 35#include <sys/sbuf.h> 36#include <sys/socket.h> 37#include <sys/sysproto.h> 38#include <sys/systm.h> 39#include <sys/uuid.h> 40#include <sys/vimage.h> 41 42#include <net/if.h> 43#include <net/if_dl.h> 44#include <net/if_types.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 55CTASSERT(sizeof(struct uuid) == 16); 56 57/* We use an alternative, more convenient representation in the generator. */ 58struct uuid_private { 59 union { 60 uint64_t ll; /* internal. */ 61 struct { 62 uint32_t low; 63 uint16_t mid; 64 uint16_t hi; 65 } x; 66 } time; 67 uint16_t seq; /* Big-endian. */ 68 uint16_t node[UUID_NODE_LEN>>1]; 69}; 70 71CTASSERT(sizeof(struct uuid_private) == 16); 72 73static struct uuid_private uuid_last; 74 75static struct mtx uuid_mutex; 76MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF); 77 78/* 79 * Return the first MAC address we encounter or, if none was found, 80 * construct a sufficiently random multicast address. We don't try 81 * to return the same MAC address as previously returned. We always 82 * generate a new multicast address if no MAC address exists in the 83 * system. 84 * It would be nice to know if 'ifnet' or any of its sub-structures 85 * has been changed in any way. If not, we could simply skip the 86 * scan and safely return the MAC address we returned before. 87 */ 88static void 89uuid_node(uint16_t *node) 90{ 91 struct ifnet *ifp; 92 struct ifaddr *ifa; 93 struct sockaddr_dl *sdl; 94 int i; 95 96 IFNET_RLOCK(); 97 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 98 /* Walk the address list */ 99 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 100 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 101 if (sdl != NULL && sdl->sdl_family == AF_LINK && 102 sdl->sdl_type == IFT_ETHER) { 103 /* Got a MAC address. */ 104 bcopy(LLADDR(sdl), node, UUID_NODE_LEN); 105 IFNET_RUNLOCK(); 106 return; 107 } 108 } 109 } 110 IFNET_RUNLOCK(); 111 112 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 113 node[i] = (uint16_t)arc4random(); 114 *((uint8_t*)node) |= 0x01; 115} 116 117/* 118 * Get the current time as a 60 bit count of 100-nanosecond intervals 119 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 120 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 121 * Gregorian reform to the Christian calendar. 122 */ 123static uint64_t 124uuid_time(void) 125{ 126 struct bintime bt; 127 uint64_t time = 0x01B21DD213814000LL; 128 129 bintime(&bt); 130 time += (uint64_t)bt.sec * 10000000LL; 131 time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32; 132 return (time & ((1LL << 60) - 1LL)); 133} 134 135struct uuid * 136kern_uuidgen(struct uuid *store, size_t count) 137{ 138 struct uuid_private uuid; 139 uint64_t time; 140 size_t n; 141 142 mtx_lock(&uuid_mutex); 143 144 uuid_node(uuid.node); 145 time = uuid_time(); 146 147 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] || 148 uuid_last.node[1] != uuid.node[1] || 149 uuid_last.node[2] != uuid.node[2]) 150 uuid.seq = (uint16_t)arc4random() & 0x3fff; 151 else if (uuid_last.time.ll >= time) 152 uuid.seq = (uuid_last.seq + 1) & 0x3fff; 153 else 154 uuid.seq = uuid_last.seq; 155 156 uuid_last = uuid; 157 uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL); 158 159 mtx_unlock(&uuid_mutex); 160 161 /* Set sequence and variant and deal with byte order. */ 162 uuid.seq = htobe16(uuid.seq | 0x8000); 163 164 for (n = 0; n < count; n++) { 165 /* Set time and version (=1). */ 166 uuid.time.x.low = (uint32_t)time; 167 uuid.time.x.mid = (uint16_t)(time >> 32); 168 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12); 169 store[n] = *(struct uuid *)&uuid; 170 time++; 171 } 172 173 return (store); 174} 175 176#ifndef _SYS_SYSPROTO_H_ 177struct uuidgen_args { 178 struct uuid *store; 179 int count; 180}; 181#endif 182int 183uuidgen(struct thread *td, struct uuidgen_args *uap) 184{ 185 struct uuid *store; 186 size_t count; 187 int error; 188 189 /* 190 * Limit the number of UUIDs that can be created at the same time 191 * to some arbitrary number. This isn't really necessary, but I 192 * like to have some sort of upper-bound that's less than 2G :-) 193 * XXX probably needs to be tunable. 194 */ 195 if (uap->count < 1 || uap->count > 2048) 196 return (EINVAL); 197 198 count = uap->count; 199 store = malloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK); 200 kern_uuidgen(store, count); 201 error = copyout(store, uap->store, count * sizeof(struct uuid)); 202 free(store, M_TEMP); 203 return (error); 204} 205 206int 207snprintf_uuid(char *buf, size_t sz, struct uuid *uuid) 208{ 209 struct uuid_private *id; 210 int cnt; 211 212 id = (struct uuid_private *)uuid; 213 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 214 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 215 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 216 return (cnt); 217} 218 219int 220printf_uuid(struct uuid *uuid) 221{ 222 char buf[38]; 223 224 snprintf_uuid(buf, sizeof(buf), uuid); 225 return (printf("%s", buf)); 226} 227 228int 229sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid) 230{ 231 char buf[38]; 232 233 snprintf_uuid(buf, sizeof(buf), uuid); 234 return (sbuf_printf(sb, "%s", buf)); 235} 236 237/* 238 * Encode/Decode UUID into byte-stream. 239 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 240 * 241 * 0 1 2 3 242 * 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 1 243 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 * | time_low | 245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 * | time_mid | time_hi_and_version | 247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 249 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 * | node (2-5) | 251 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 252 */ 253 254void 255le_uuid_enc(void *buf, struct uuid const *uuid) 256{ 257 u_char *p; 258 int i; 259 260 p = buf; 261 le32enc(p, uuid->time_low); 262 le16enc(p + 4, uuid->time_mid); 263 le16enc(p + 6, uuid->time_hi_and_version); 264 p[8] = uuid->clock_seq_hi_and_reserved; 265 p[9] = uuid->clock_seq_low; 266 for (i = 0; i < _UUID_NODE_LEN; i++) 267 p[10 + i] = uuid->node[i]; 268} 269 270void 271le_uuid_dec(void const *buf, struct uuid *uuid) 272{ 273 u_char const *p; 274 int i; 275 276 p = buf; 277 uuid->time_low = le32dec(p); 278 uuid->time_mid = le16dec(p + 4); 279 uuid->time_hi_and_version = le16dec(p + 6); 280 uuid->clock_seq_hi_and_reserved = p[8]; 281 uuid->clock_seq_low = p[9]; 282 for (i = 0; i < _UUID_NODE_LEN; i++) 283 uuid->node[i] = p[10 + i]; 284} 285 286void 287be_uuid_enc(void *buf, struct uuid const *uuid) 288{ 289 u_char *p; 290 int i; 291 292 p = buf; 293 be32enc(p, uuid->time_low); 294 be16enc(p + 4, uuid->time_mid); 295 be16enc(p + 6, uuid->time_hi_and_version); 296 p[8] = uuid->clock_seq_hi_and_reserved; 297 p[9] = uuid->clock_seq_low; 298 for (i = 0; i < _UUID_NODE_LEN; i++) 299 p[10 + i] = uuid->node[i]; 300} 301 302void 303be_uuid_dec(void const *buf, struct uuid *uuid) 304{ 305 u_char const *p; 306 int i; 307 308 p = buf; 309 uuid->time_low = be32dec(p); 310 uuid->time_mid = le16dec(p + 4); 311 uuid->time_hi_and_version = be16dec(p + 6); 312 uuid->clock_seq_hi_and_reserved = p[8]; 313 uuid->clock_seq_low = p[9]; 314 for (i = 0; i < _UUID_NODE_LEN; i++) 315 uuid->node[i] = p[10 + i]; 316} 317 318int 319parse_uuid(const char *str, struct uuid *uuid) 320{ 321 u_int c[11]; 322 int n; 323 324 /* An empty string represents a nil UUID. */ 325 if (*str == '\0') { 326 bzero(uuid, sizeof(*uuid)); 327 return (0); 328 } 329 330 /* The UUID string representation has a fixed length. */ 331 if (strlen(str) != 36) 332 return (EINVAL); 333 334 /* 335 * We only work with "new" UUIDs. New UUIDs have the form: 336 * 01234567-89ab-cdef-0123-456789abcdef 337 * The so called "old" UUIDs, which we don't support, have the form: 338 * 0123456789ab.cd.ef.01.23.45.67.89.ab 339 */ 340 if (str[8] != '-') 341 return (EINVAL); 342 343 n = sscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1, 344 c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10); 345 /* Make sure we have all conversions. */ 346 if (n != 11) 347 return (EINVAL); 348 349 /* Successful scan. Build the UUID. */ 350 uuid->time_low = c[0]; 351 uuid->time_mid = c[1]; 352 uuid->time_hi_and_version = c[2]; 353 uuid->clock_seq_hi_and_reserved = c[3]; 354 uuid->clock_seq_low = c[4]; 355 for (n = 0; n < 6; n++) 356 uuid->node[n] = c[n + 5]; 357 358 /* Check semantics... */ 359 return (((c[3] & 0x80) != 0x00 && /* variant 0? */ 360 (c[3] & 0xc0) != 0x80 && /* variant 1? */ 361 (c[3] & 0xe0) != 0xc0) ? EINVAL : 0); /* variant 2? */ 362} 363