1 /* $NetBSD: kern_uuid.c,v 1.17 2010/05/04 19:23:56 kardel 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 1.17 2010/05/04 19:23:56 kardel 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 48 #include <net/if.h> 49 #include <net/if_dl.h> 50 #include <net/if_types.h> 51 52 /* 53 * See also: 54 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 55 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm 56 * 57 * Note that the generator state is itself an UUID, but the time and clock 58 * sequence fields are written in the native byte order. 59 */ 60 61 CTASSERT(sizeof(struct uuid) == 16); 62 63 /* We use an alternative, more convenient representation in the generator. */ 64 struct uuid_private { 65 union { 66 uint64_t ll; /* internal. */ 67 struct { 68 uint32_t low; 69 uint16_t mid; 70 uint16_t hi; 71 } x; 72 } time; 73 uint16_t seq; /* Big-endian. */ 74 uint16_t node[UUID_NODE_LEN>>1]; 75 }; 76 77 CTASSERT(sizeof(struct uuid_private) == 16); 78 79 static struct uuid_private uuid_last; 80 81 /* "UUID generator mutex lock" */ 82 static kmutex_t uuid_mutex; 83 84 void 85 uuid_init(void) 86 { 87 88 mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE); 89 } 90 91 /* 92 * Return the first MAC address we encounter or, if none was found, 93 * construct a sufficiently random multicast address. We don't try 94 * to return the same MAC address as previously returned. We always 95 * generate a new multicast address if no MAC address exists in the 96 * system. 97 * It would be nice to know if 'ifnet' or any of its sub-structures 98 * has been changed in any way. If not, we could simply skip the 99 * scan and safely return the MAC address we returned before. 100 */ 101 static void 102 uuid_node(uint16_t *node) 103 { 104 struct ifnet *ifp; 105 struct ifaddr *ifa; 106 struct sockaddr_dl *sdl; 107 int i, s; 108 109 s = splnet(); 110 KERNEL_LOCK(1, NULL); 111 IFNET_FOREACH(ifp) { 112 /* Walk the address list */ 113 IFADDR_FOREACH(ifa, ifp) { 114 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 115 if (sdl != NULL && sdl->sdl_family == AF_LINK && 116 sdl->sdl_type == IFT_ETHER) { 117 /* Got a MAC address. */ 118 memcpy(node, CLLADDR(sdl), UUID_NODE_LEN); 119 KERNEL_UNLOCK_ONE(NULL); 120 splx(s); 121 return; 122 } 123 } 124 } 125 KERNEL_UNLOCK_ONE(NULL); 126 splx(s); 127 128 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 129 node[i] = (uint16_t)arc4random(); 130 *((uint8_t*)node) |= 0x01; 131 } 132 133 /* 134 * Get the current time as a 60 bit count of 100-nanosecond intervals 135 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 136 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 137 * Gregorian reform to the Christian calendar. 138 */ 139 static uint64_t 140 uuid_time(void) 141 { 142 struct timespec tsp; 143 uint64_t xtime = 0x01B21DD213814000LL; 144 145 nanotime(&tsp); 146 xtime += (uint64_t)tsp.tv_sec * 10000000LL; 147 xtime += (uint64_t)(tsp.tv_nsec / 100); 148 return (xtime & ((1LL << 60) - 1LL)); 149 } 150 151 /* 152 * Internal routine to actually generate the UUID. 153 */ 154 static void 155 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 156 { 157 uint64_t xtime; 158 159 mutex_enter(&uuid_mutex); 160 161 uuid_node(uuid->node); 162 xtime = uuid_time(); 163 *timep = xtime; 164 165 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 166 uuid_last.node[1] != uuid->node[1] || 167 uuid_last.node[2] != uuid->node[2]) 168 uuid->seq = (uint16_t)arc4random() & 0x3fff; 169 else if (uuid_last.time.ll >= xtime) 170 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 171 else 172 uuid->seq = uuid_last.seq; 173 174 uuid_last = *uuid; 175 uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL); 176 177 mutex_exit(&uuid_mutex); 178 } 179 180 static int 181 kern_uuidgen(struct uuid *store, int count, bool to_user) 182 { 183 struct uuid_private uuid; 184 uint64_t xtime; 185 int error = 0, i; 186 187 KASSERT(count >= 1); 188 189 /* Generate the base UUID. */ 190 uuid_generate(&uuid, &xtime, count); 191 192 /* Set sequence and variant and deal with byte order. */ 193 uuid.seq = htobe16(uuid.seq | 0x8000); 194 195 for (i = 0; i < count; xtime++, i++) { 196 /* Set time and version (=1) and deal with byte order. */ 197 uuid.time.x.low = (uint32_t)xtime; 198 uuid.time.x.mid = (uint16_t)(xtime >> 32); 199 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12); 200 if (to_user) { 201 error = copyout(&uuid, store + i, sizeof(uuid)); 202 if (error != 0) 203 break; 204 } else { 205 memcpy(store + i, &uuid, sizeof(uuid)); 206 } 207 } 208 209 return error; 210 } 211 212 int 213 sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval) 214 { 215 /* 216 * Limit the number of UUIDs that can be created at the same time 217 * to some arbitrary number. This isn't really necessary, but I 218 * like to have some sort of upper-bound that's less than 2G :-) 219 * XXX needs to be tunable. 220 */ 221 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 222 return (EINVAL); 223 224 return kern_uuidgen(SCARG(uap, store), SCARG(uap,count), true); 225 } 226 227 int 228 uuidgen(struct uuid *store, int count) 229 { 230 return kern_uuidgen(store,count, false); 231 } 232 233 int 234 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 235 { 236 const struct uuid_private *id; 237 int cnt; 238 239 id = (const struct uuid_private *)uuid; 240 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 241 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 242 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 243 return (cnt); 244 } 245 246 int 247 uuid_printf(const struct uuid *uuid) 248 { 249 char buf[UUID_STR_LEN]; 250 251 (void) uuid_snprintf(buf, sizeof(buf), uuid); 252 printf("%s", buf); 253 return (0); 254 } 255 256 /* 257 * Encode/Decode UUID into octet-stream. 258 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 259 * 260 * 0 1 2 3 261 * 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 1 262 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 * | time_low | 264 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 * | time_mid | time_hi_and_version | 266 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 267 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 268 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 269 * | node (2-5) | 270 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 271 */ 272 273 void 274 uuid_enc_le(void *buf, const struct uuid *uuid) 275 { 276 uint8_t *p = buf; 277 int i; 278 279 le32enc(p, uuid->time_low); 280 le16enc(p + 4, uuid->time_mid); 281 le16enc(p + 6, uuid->time_hi_and_version); 282 p[8] = uuid->clock_seq_hi_and_reserved; 283 p[9] = uuid->clock_seq_low; 284 for (i = 0; i < _UUID_NODE_LEN; i++) 285 p[10 + i] = uuid->node[i]; 286 } 287 288 void 289 uuid_dec_le(void const *buf, struct uuid *uuid) 290 { 291 const uint8_t *p = buf; 292 int i; 293 294 uuid->time_low = le32dec(p); 295 uuid->time_mid = le16dec(p + 4); 296 uuid->time_hi_and_version = le16dec(p + 6); 297 uuid->clock_seq_hi_and_reserved = p[8]; 298 uuid->clock_seq_low = p[9]; 299 for (i = 0; i < _UUID_NODE_LEN; i++) 300 uuid->node[i] = p[10 + i]; 301 } 302 303 void 304 uuid_enc_be(void *buf, const struct uuid *uuid) 305 { 306 uint8_t *p = buf; 307 int i; 308 309 be32enc(p, uuid->time_low); 310 be16enc(p + 4, uuid->time_mid); 311 be16enc(p + 6, uuid->time_hi_and_version); 312 p[8] = uuid->clock_seq_hi_and_reserved; 313 p[9] = uuid->clock_seq_low; 314 for (i = 0; i < _UUID_NODE_LEN; i++) 315 p[10 + i] = uuid->node[i]; 316 } 317 318 void 319 uuid_dec_be(void const *buf, struct uuid *uuid) 320 { 321 const uint8_t *p = buf; 322 int i; 323 324 uuid->time_low = be32dec(p); 325 uuid->time_mid = be16dec(p + 4); 326 uuid->time_hi_and_version = be16dec(p + 6); 327 uuid->clock_seq_hi_and_reserved = p[8]; 328 uuid->clock_seq_low = p[9]; 329 for (i = 0; i < _UUID_NODE_LEN; i++) 330 uuid->node[i] = p[10 + i]; 331 } 332