kern_uuid.c revision 1.14.4.1
1 /* $NetBSD: kern_uuid.c,v 1.14.4.1 2008/05/10 23:49:05 wrstuden 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 1.14.4.1 2008/05/10 23:49:05 wrstuden 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/sa.h> 46 #include <sys/syscallargs.h> 47 #include <sys/uio.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 /* XXX Do we have a similar ASSERT()? */ 63 #define CTASSERT(x) 64 65 CTASSERT(sizeof(struct uuid) == 16); 66 67 /* We use an alternative, more convenient representation in the generator. */ 68 struct uuid_private { 69 union { 70 uint64_t ll; /* internal. */ 71 struct { 72 uint32_t low; 73 uint16_t mid; 74 uint16_t hi; 75 } x; 76 } time; 77 uint16_t seq; /* Big-endian. */ 78 uint16_t node[UUID_NODE_LEN>>1]; 79 }; 80 81 CTASSERT(sizeof(struct uuid_private) == 16); 82 83 static struct uuid_private uuid_last; 84 85 /* "UUID generator mutex lock" */ 86 static kmutex_t uuid_mutex; 87 88 void 89 uuid_init(void) 90 { 91 92 mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE); 93 } 94 95 /* 96 * Return the first MAC address we encounter or, if none was found, 97 * construct a sufficiently random multicast address. We don't try 98 * to return the same MAC address as previously returned. We always 99 * generate a new multicast address if no MAC address exists in the 100 * system. 101 * It would be nice to know if 'ifnet' or any of its sub-structures 102 * has been changed in any way. If not, we could simply skip the 103 * scan and safely return the MAC address we returned before. 104 */ 105 static void 106 uuid_node(uint16_t *node) 107 { 108 struct ifnet *ifp; 109 struct ifaddr *ifa; 110 struct sockaddr_dl *sdl; 111 int i, s; 112 113 s = splnet(); 114 KERNEL_LOCK(1, NULL); 115 IFNET_FOREACH(ifp) { 116 /* Walk the address list */ 117 IFADDR_FOREACH(ifa, ifp) { 118 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 119 if (sdl != NULL && sdl->sdl_family == AF_LINK && 120 sdl->sdl_type == IFT_ETHER) { 121 /* Got a MAC address. */ 122 memcpy(node, CLLADDR(sdl), UUID_NODE_LEN); 123 KERNEL_UNLOCK_ONE(NULL); 124 splx(s); 125 return; 126 } 127 } 128 } 129 KERNEL_UNLOCK_ONE(NULL); 130 splx(s); 131 132 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 133 node[i] = (uint16_t)arc4random(); 134 *((uint8_t*)node) |= 0x01; 135 } 136 137 /* 138 * Get the current time as a 60 bit count of 100-nanosecond intervals 139 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 140 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 141 * Gregorian reform to the Christian calendar. 142 */ 143 /* 144 * At present, NetBSD has no timespec source, only timeval sources. So, 145 * we use timeval. 146 */ 147 static uint64_t 148 uuid_time(void) 149 { 150 struct timeval tv; 151 uint64_t xtime = 0x01B21DD213814000LL; 152 153 microtime(&tv); 154 xtime += (uint64_t)tv.tv_sec * 10000000LL; 155 xtime += (uint64_t)(10 * tv.tv_usec); 156 return (xtime & ((1LL << 60) - 1LL)); 157 } 158 159 /* 160 * Internal routine to actually generate the UUID. 161 */ 162 static void 163 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 164 { 165 uint64_t xtime; 166 167 mutex_enter(&uuid_mutex); 168 169 uuid_node(uuid->node); 170 xtime = uuid_time(); 171 *timep = xtime; 172 173 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 174 uuid_last.node[1] != uuid->node[1] || 175 uuid_last.node[2] != uuid->node[2]) 176 uuid->seq = (uint16_t)arc4random() & 0x3fff; 177 else if (uuid_last.time.ll >= xtime) 178 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 179 else 180 uuid->seq = uuid_last.seq; 181 182 uuid_last = *uuid; 183 uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL); 184 185 mutex_exit(&uuid_mutex); 186 } 187 188 int 189 sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval) 190 { 191 struct uuid_private uuid; 192 uint64_t xtime; 193 int error; 194 int i; 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 needs to be tunable. 201 */ 202 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 203 return (EINVAL); 204 205 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 206 207 /* Generate the base UUID. */ 208 uuid_generate(&uuid, &xtime, SCARG(uap, count)); 209 210 /* Set sequence and variant and deal with byte order. */ 211 uuid.seq = htobe16(uuid.seq | 0x8000); 212 213 /* XXX: this should copyout larger chunks at a time. */ 214 for (i = 0; i < SCARG(uap, count); xtime++, i++) { 215 /* Set time and version (=1) and deal with byte order. */ 216 uuid.time.x.low = (uint32_t)xtime; 217 uuid.time.x.mid = (uint16_t)(xtime >> 32); 218 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12); 219 error = copyout(&uuid, SCARG(uap,store) + i, sizeof(uuid)); 220 if (error != 0) 221 return error; 222 } 223 224 return 0; 225 } 226 227 int 228 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 229 { 230 const struct uuid_private *id; 231 int cnt; 232 233 id = (const struct uuid_private *)uuid; 234 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 235 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 236 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 237 return (cnt); 238 } 239 240 int 241 uuid_printf(const struct uuid *uuid) 242 { 243 char buf[UUID_STR_LEN]; 244 245 (void) uuid_snprintf(buf, sizeof(buf), uuid); 246 printf("%s", buf); 247 return (0); 248 } 249 250 /* 251 * Encode/Decode UUID into octet-stream. 252 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 253 * 254 * 0 1 2 3 255 * 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 1 256 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 * | time_low | 258 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 * | time_mid | time_hi_and_version | 260 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 261 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 262 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 263 * | node (2-5) | 264 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 265 */ 266 267 void 268 uuid_enc_le(void *buf, const struct uuid *uuid) 269 { 270 uint8_t *p = buf; 271 int i; 272 273 le32enc(p, uuid->time_low); 274 le16enc(p + 4, uuid->time_mid); 275 le16enc(p + 6, uuid->time_hi_and_version); 276 p[8] = uuid->clock_seq_hi_and_reserved; 277 p[9] = uuid->clock_seq_low; 278 for (i = 0; i < _UUID_NODE_LEN; i++) 279 p[10 + i] = uuid->node[i]; 280 } 281 282 void 283 uuid_dec_le(void const *buf, struct uuid *uuid) 284 { 285 const uint8_t *p = buf; 286 int i; 287 288 uuid->time_low = le32dec(p); 289 uuid->time_mid = le16dec(p + 4); 290 uuid->time_hi_and_version = le16dec(p + 6); 291 uuid->clock_seq_hi_and_reserved = p[8]; 292 uuid->clock_seq_low = p[9]; 293 for (i = 0; i < _UUID_NODE_LEN; i++) 294 uuid->node[i] = p[10 + i]; 295 } 296 297 void 298 uuid_enc_be(void *buf, const struct uuid *uuid) 299 { 300 uint8_t *p = buf; 301 int i; 302 303 be32enc(p, uuid->time_low); 304 be16enc(p + 4, uuid->time_mid); 305 be16enc(p + 6, uuid->time_hi_and_version); 306 p[8] = uuid->clock_seq_hi_and_reserved; 307 p[9] = uuid->clock_seq_low; 308 for (i = 0; i < _UUID_NODE_LEN; i++) 309 p[10 + i] = uuid->node[i]; 310 } 311 312 void 313 uuid_dec_be(void const *buf, struct uuid *uuid) 314 { 315 const uint8_t *p = buf; 316 int i; 317 318 uuid->time_low = be32dec(p); 319 uuid->time_mid = be16dec(p + 4); 320 uuid->time_hi_and_version = be16dec(p + 6); 321 uuid->clock_seq_hi_and_reserved = p[8]; 322 uuid->clock_seq_low = p[9]; 323 for (i = 0; i < _UUID_NODE_LEN; i++) 324 uuid->node[i] = p[10 + i]; 325 } 326
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