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 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 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/jail.h> 40 #include <sys/uuid.h> 41 42 #include <net/if.h> 43 #include <net/if_dl.h> 44 #include <net/if_types.h> 45 #include <net/vnet.h> 46 47 /* 48 * See also: 49 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 50 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm 51 * 52 * Note that the generator state is itself an UUID, but the time and clock 53 * sequence fields are written in the native byte order. 54 */ 55 56 CTASSERT(sizeof(struct uuid) == 16); 57 58 /* We use an alternative, more convenient representation in the generator. */ 59 struct uuid_private { 60 union { 61 uint64_t ll; /* internal. */ 62 struct { 63 uint32_t low; 64 uint16_t mid; 65 uint16_t hi; 66 } x; 67 } time; 68 uint16_t seq; /* Big-endian. */ 69 uint16_t node[UUID_NODE_LEN>>1]; 70 }; 71 72 CTASSERT(sizeof(struct uuid_private) == 16); 73 74 static struct uuid_private uuid_last; 75 76 static struct mtx uuid_mutex; 77 MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF); 78 79 /* 80 * Return the first MAC address we encounter or, if none was found, 81 * construct a sufficiently random multicast address. We don't try 82 * to return the same MAC address as previously returned. We always 83 * generate a new multicast address if no MAC address exists in the 84 * system. 85 * It would be nice to know if 'ifnet' or any of its sub-structures 86 * has been changed in any way. If not, we could simply skip the 87 * scan and safely return the MAC address we returned before. 88 */ 89 static void 90 uuid_node(uint16_t *node) 91 { 92 struct ifnet *ifp; 93 struct ifaddr *ifa; 94 struct sockaddr_dl *sdl; 95 int i; 96 97 CURVNET_SET(TD_TO_VNET(curthread)); 98 IFNET_RLOCK_NOSLEEP(); 99 TAILQ_FOREACH(ifp, &V_ifnet, if_link) { 100 /* Walk the address list */ 101 IF_ADDR_LOCK(ifp); 102 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 103 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 104 if (sdl != NULL && sdl->sdl_family == AF_LINK && 105 sdl->sdl_type == IFT_ETHER) { 106 /* Got a MAC address. */ 107 bcopy(LLADDR(sdl), node, UUID_NODE_LEN); 108 IF_ADDR_UNLOCK(ifp); 109 IFNET_RUNLOCK_NOSLEEP(); 110 CURVNET_RESTORE(); 111 return; 112 } 113 } 114 IF_ADDR_UNLOCK(ifp); 115 } 116 IFNET_RUNLOCK_NOSLEEP(); 117 118 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 119 node[i] = (uint16_t)arc4random(); 120 *((uint8_t*)node) |= 0x01; 121 CURVNET_RESTORE(); 122 } 123 124 /* 125 * Get the current time as a 60 bit count of 100-nanosecond intervals 126 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 127 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 128 * Gregorian reform to the Christian calendar. 129 */ 130 static uint64_t 131 uuid_time(void) 132 { 133 struct bintime bt; 134 uint64_t time = 0x01B21DD213814000LL; 135 136 bintime(&bt); 137 time += (uint64_t)bt.sec * 10000000LL; 138 time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32; 139 return (time & ((1LL << 60) - 1LL)); 140 } 141 142 struct uuid * 143 kern_uuidgen(struct uuid *store, size_t count) 144 { 145 struct uuid_private uuid; 146 uint64_t time; 147 size_t n; 148 149 mtx_lock(&uuid_mutex); 150 151 uuid_node(uuid.node); 152 time = uuid_time(); 153 154 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] || 155 uuid_last.node[1] != uuid.node[1] || 156 uuid_last.node[2] != uuid.node[2]) 157 uuid.seq = (uint16_t)arc4random() & 0x3fff; 158 else if (uuid_last.time.ll >= time) 159 uuid.seq = (uuid_last.seq + 1) & 0x3fff; 160 else 161 uuid.seq = uuid_last.seq; 162 163 uuid_last = uuid; 164 uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL); 165 166 mtx_unlock(&uuid_mutex); 167 168 /* Set sequence and variant and deal with byte order. */ 169 uuid.seq = htobe16(uuid.seq | 0x8000); 170 171 for (n = 0; n < count; n++) { 172 /* Set time and version (=1). */ 173 uuid.time.x.low = (uint32_t)time; 174 uuid.time.x.mid = (uint16_t)(time >> 32); 175 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12); 176 store[n] = *(struct uuid *)&uuid; 177 time++; 178 } 179 180 return (store); 181 } 182 183 #ifndef _SYS_SYSPROTO_H_ 184 struct uuidgen_args { 185 struct uuid *store; 186 int count; 187 }; 188 #endif 189 int 190 uuidgen(struct thread *td, struct uuidgen_args *uap) 191 { 192 struct uuid *store; 193 size_t count; 194 int error; 195 196 /* 197 * Limit the number of UUIDs that can be created at the same time 198 * to some arbitrary number. This isn't really necessary, but I 199 * like to have some sort of upper-bound that's less than 2G :-) 200 * XXX probably needs to be tunable. 201 */ 202 if (uap->count < 1 || uap->count > 2048) 203 return (EINVAL); 204 205 count = uap->count; 206 store = malloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK); 207 kern_uuidgen(store, count); 208 error = copyout(store, uap->store, count * sizeof(struct uuid)); 209 free(store, M_TEMP); 210 return (error); 211 } 212 213 int 214 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid) 215 { 216 struct uuid_private *id; 217 int cnt; 218 219 id = (struct uuid_private *)uuid; 220 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 221 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 222 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 223 return (cnt); 224 } 225 226 int 227 printf_uuid(struct uuid *uuid) 228 { 229 char buf[38]; 230 231 snprintf_uuid(buf, sizeof(buf), uuid); 232 return (printf("%s", buf)); 233 } 234 235 int 236 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid) 237 { 238 char buf[38]; 239 240 snprintf_uuid(buf, sizeof(buf), uuid); 241 return (sbuf_printf(sb, "%s", buf)); 242 } 243 244 /* 245 * Encode/Decode UUID into byte-stream. 246 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 247 * 248 * 0 1 2 3 249 * 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 1 250 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 * | time_low | 252 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 * | time_mid | time_hi_and_version | 254 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 256 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 * | node (2-5) | 258 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 */ 260 261 void 262 le_uuid_enc(void *buf, struct uuid const *uuid) 263 { 264 u_char *p; 265 int i; 266 267 p = buf; 268 le32enc(p, uuid->time_low); 269 le16enc(p + 4, uuid->time_mid); 270 le16enc(p + 6, uuid->time_hi_and_version); 271 p[8] = uuid->clock_seq_hi_and_reserved; 272 p[9] = uuid->clock_seq_low; 273 for (i = 0; i < _UUID_NODE_LEN; i++) 274 p[10 + i] = uuid->node[i]; 275 } 276 277 void 278 le_uuid_dec(void const *buf, struct uuid *uuid) 279 { 280 u_char const *p; 281 int i; 282 283 p = buf; 284 uuid->time_low = le32dec(p); 285 uuid->time_mid = le16dec(p + 4); 286 uuid->time_hi_and_version = le16dec(p + 6); 287 uuid->clock_seq_hi_and_reserved = p[8]; 288 uuid->clock_seq_low = p[9]; 289 for (i = 0; i < _UUID_NODE_LEN; i++) 290 uuid->node[i] = p[10 + i]; 291 } 292 293 void 294 be_uuid_enc(void *buf, struct uuid const *uuid) 295 { 296 u_char *p; 297 int i; 298 299 p = buf; 300 be32enc(p, uuid->time_low); 301 be16enc(p + 4, uuid->time_mid); 302 be16enc(p + 6, uuid->time_hi_and_version); 303 p[8] = uuid->clock_seq_hi_and_reserved; 304 p[9] = uuid->clock_seq_low; 305 for (i = 0; i < _UUID_NODE_LEN; i++) 306 p[10 + i] = uuid->node[i]; 307 } 308 309 void 310 be_uuid_dec(void const *buf, struct uuid *uuid) 311 { 312 u_char const *p; 313 int i; 314 315 p = buf; 316 uuid->time_low = be32dec(p); 317 uuid->time_mid = le16dec(p + 4); 318 uuid->time_hi_and_version = be16dec(p + 6); 319 uuid->clock_seq_hi_and_reserved = p[8]; 320 uuid->clock_seq_low = p[9]; 321 for (i = 0; i < _UUID_NODE_LEN; i++) 322 uuid->node[i] = p[10 + i]; 323 } 324 325 int 326 parse_uuid(const char *str, struct uuid *uuid) 327 { 328 u_int c[11]; 329 int n; 330 331 /* An empty string represents a nil UUID. */ 332 if (*str == '\0') { 333 bzero(uuid, sizeof(*uuid)); 334 return (0); 335 } 336 337 /* The UUID string representation has a fixed length. */ 338 if (strlen(str) != 36) 339 return (EINVAL); 340 341 /* 342 * We only work with "new" UUIDs. New UUIDs have the form: 343 * 01234567-89ab-cdef-0123-456789abcdef 344 * The so called "old" UUIDs, which we don't support, have the form: 345 * 0123456789ab.cd.ef.01.23.45.67.89.ab 346 */ 347 if (str[8] != '-') 348 return (EINVAL); 349 350 n = sscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1, 351 c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10); 352 /* Make sure we have all conversions. */ 353 if (n != 11) 354 return (EINVAL); 355 356 /* Successful scan. Build the UUID. */ 357 uuid->time_low = c[0]; 358 uuid->time_mid = c[1]; 359 uuid->time_hi_and_version = c[2]; 360 uuid->clock_seq_hi_and_reserved = c[3]; 361 uuid->clock_seq_low = c[4]; 362 for (n = 0; n < 6; n++) 363 uuid->node[n] = c[n + 5]; 364 365 /* Check semantics... */ 366 return (((c[3] & 0x80) != 0x00 && /* variant 0? */ 367 (c[3] & 0xc0) != 0x80 && /* variant 1? */ 368 (c[3] & 0xe0) != 0xc0) ? EINVAL : 0); /* variant 2? */ 369 } 370