1 /* $NetBSD: kern_uuid.c,v 1.18 2011/11/19 22:51:25 tls Exp $ */ 2 3 /* 4 * Copyright (c) 2002 Marcel Moolenaar 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $ 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.18 2011/11/19 22:51:25 tls Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/endian.h> 36 #include <sys/kernel.h> 37 #include <sys/mutex.h> 38 #include <sys/socket.h> 39 #include <sys/systm.h> 40 #include <sys/uuid.h> 41 42 /* NetBSD */ 43 #include <sys/proc.h> 44 #include <sys/mount.h> 45 #include <sys/syscallargs.h> 46 #include <sys/uio.h> 47 #include <sys/cprng.h> 48 49 #include <net/if.h> 50 #include <net/if_dl.h> 51 #include <net/if_types.h> 52 53 /* 54 * See also: 55 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 56 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm 57 * 58 * Note that the generator state is itself an UUID, but the time and clock 59 * sequence fields are written in the native byte order. 60 */ 61 62 CTASSERT(sizeof(struct uuid) == 16); 63 64 /* We use an alternative, more convenient representation in the generator. */ 65 struct uuid_private { 66 union { 67 uint64_t ll; /* internal. */ 68 struct { 69 uint32_t low; 70 uint16_t mid; 71 uint16_t hi; 72 } x; 73 } time; 74 uint16_t seq; /* Big-endian. */ 75 uint16_t node[UUID_NODE_LEN>>1]; 76 }; 77 78 CTASSERT(sizeof(struct uuid_private) == 16); 79 80 static struct uuid_private uuid_last; 81 82 /* "UUID generator mutex lock" */ 83 static kmutex_t uuid_mutex; 84 85 void 86 uuid_init(void) 87 { 88 89 mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE); 90 } 91 92 /* 93 * Return the first MAC address we encounter or, if none was found, 94 * construct a sufficiently random multicast address. We don't try 95 * to return the same MAC address as previously returned. We always 96 * generate a new multicast address if no MAC address exists in the 97 * system. 98 * It would be nice to know if 'ifnet' or any of its sub-structures 99 * has been changed in any way. If not, we could simply skip the 100 * scan and safely return the MAC address we returned before. 101 */ 102 static void 103 uuid_node(uint16_t *node) 104 { 105 struct ifnet *ifp; 106 struct ifaddr *ifa; 107 struct sockaddr_dl *sdl; 108 int i, s; 109 110 s = splnet(); 111 KERNEL_LOCK(1, NULL); 112 IFNET_FOREACH(ifp) { 113 /* Walk the address list */ 114 IFADDR_FOREACH(ifa, ifp) { 115 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 116 if (sdl != NULL && sdl->sdl_family == AF_LINK && 117 sdl->sdl_type == IFT_ETHER) { 118 /* Got a MAC address. */ 119 memcpy(node, CLLADDR(sdl), UUID_NODE_LEN); 120 KERNEL_UNLOCK_ONE(NULL); 121 splx(s); 122 return; 123 } 124 } 125 } 126 KERNEL_UNLOCK_ONE(NULL); 127 splx(s); 128 129 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 130 node[i] = (uint16_t)cprng_fast32(); 131 *((uint8_t*)node) |= 0x01; 132 } 133 134 /* 135 * Get the current time as a 60 bit count of 100-nanosecond intervals 136 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 137 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 138 * Gregorian reform to the Christian calendar. 139 */ 140 static uint64_t 141 uuid_time(void) 142 { 143 struct timespec tsp; 144 uint64_t xtime = 0x01B21DD213814000LL; 145 146 nanotime(&tsp); 147 xtime += (uint64_t)tsp.tv_sec * 10000000LL; 148 xtime += (uint64_t)(tsp.tv_nsec / 100); 149 return (xtime & ((1LL << 60) - 1LL)); 150 } 151 152 /* 153 * Internal routine to actually generate the UUID. 154 */ 155 static void 156 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 157 { 158 uint64_t xtime; 159 160 mutex_enter(&uuid_mutex); 161 162 uuid_node(uuid->node); 163 xtime = uuid_time(); 164 *timep = xtime; 165 166 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 167 uuid_last.node[1] != uuid->node[1] || 168 uuid_last.node[2] != uuid->node[2]) 169 uuid->seq = (uint16_t)cprng_fast32() & 0x3fff; 170 else if (uuid_last.time.ll >= xtime) 171 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 172 else 173 uuid->seq = uuid_last.seq; 174 175 uuid_last = *uuid; 176 uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL); 177 178 mutex_exit(&uuid_mutex); 179 } 180 181 static int 182 kern_uuidgen(struct uuid *store, int count, bool to_user) 183 { 184 struct uuid_private uuid; 185 uint64_t xtime; 186 int error = 0, i; 187 188 KASSERT(count >= 1); 189 190 /* Generate the base UUID. */ 191 uuid_generate(&uuid, &xtime, count); 192 193 /* Set sequence and variant and deal with byte order. */ 194 uuid.seq = htobe16(uuid.seq | 0x8000); 195 196 for (i = 0; i < count; xtime++, i++) { 197 /* Set time and version (=1) and deal with byte order. */ 198 uuid.time.x.low = (uint32_t)xtime; 199 uuid.time.x.mid = (uint16_t)(xtime >> 32); 200 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12); 201 if (to_user) { 202 error = copyout(&uuid, store + i, sizeof(uuid)); 203 if (error != 0) 204 break; 205 } else { 206 memcpy(store + i, &uuid, sizeof(uuid)); 207 } 208 } 209 210 return error; 211 } 212 213 int 214 sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval) 215 { 216 /* 217 * Limit the number of UUIDs that can be created at the same time 218 * to some arbitrary number. This isn't really necessary, but I 219 * like to have some sort of upper-bound that's less than 2G :-) 220 * XXX needs to be tunable. 221 */ 222 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 223 return (EINVAL); 224 225 return kern_uuidgen(SCARG(uap, store), SCARG(uap,count), true); 226 } 227 228 int 229 uuidgen(struct uuid *store, int count) 230 { 231 return kern_uuidgen(store,count, false); 232 } 233 234 int 235 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 236 { 237 const struct uuid_private *id; 238 int cnt; 239 240 id = (const struct uuid_private *)uuid; 241 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 242 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 243 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 244 return (cnt); 245 } 246 247 int 248 uuid_printf(const struct uuid *uuid) 249 { 250 char buf[UUID_STR_LEN]; 251 252 (void) uuid_snprintf(buf, sizeof(buf), uuid); 253 printf("%s", buf); 254 return (0); 255 } 256 257 /* 258 * Encode/Decode UUID into octet-stream. 259 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 260 * 261 * 0 1 2 3 262 * 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 1 263 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 264 * | time_low | 265 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 266 * | time_mid | time_hi_and_version | 267 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 268 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 269 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 270 * | node (2-5) | 271 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 272 */ 273 274 void 275 uuid_enc_le(void *buf, const struct uuid *uuid) 276 { 277 uint8_t *p = buf; 278 int i; 279 280 le32enc(p, uuid->time_low); 281 le16enc(p + 4, uuid->time_mid); 282 le16enc(p + 6, uuid->time_hi_and_version); 283 p[8] = uuid->clock_seq_hi_and_reserved; 284 p[9] = uuid->clock_seq_low; 285 for (i = 0; i < _UUID_NODE_LEN; i++) 286 p[10 + i] = uuid->node[i]; 287 } 288 289 void 290 uuid_dec_le(void const *buf, struct uuid *uuid) 291 { 292 const uint8_t *p = buf; 293 int i; 294 295 uuid->time_low = le32dec(p); 296 uuid->time_mid = le16dec(p + 4); 297 uuid->time_hi_and_version = le16dec(p + 6); 298 uuid->clock_seq_hi_and_reserved = p[8]; 299 uuid->clock_seq_low = p[9]; 300 for (i = 0; i < _UUID_NODE_LEN; i++) 301 uuid->node[i] = p[10 + i]; 302 } 303 304 void 305 uuid_enc_be(void *buf, const struct uuid *uuid) 306 { 307 uint8_t *p = buf; 308 int i; 309 310 be32enc(p, uuid->time_low); 311 be16enc(p + 4, uuid->time_mid); 312 be16enc(p + 6, uuid->time_hi_and_version); 313 p[8] = uuid->clock_seq_hi_and_reserved; 314 p[9] = uuid->clock_seq_low; 315 for (i = 0; i < _UUID_NODE_LEN; i++) 316 p[10 + i] = uuid->node[i]; 317 } 318 319 void 320 uuid_dec_be(void const *buf, struct uuid *uuid) 321 { 322 const uint8_t *p = buf; 323 int i; 324 325 uuid->time_low = be32dec(p); 326 uuid->time_mid = be16dec(p + 4); 327 uuid->time_hi_and_version = be16dec(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