kern_uuid.c revision 1.5.2.1
1 /* $NetBSD: kern_uuid.c,v 1.5.2.1 2007/02/26 09:11:13 yamt 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 1.5.2.1 2007/02/26 09:11:13 yamt Exp $"); 33 34 #include <sys/param.h> 35 #include <sys/endian.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.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 /* XXX Do we have a similar ASSERT()? */ 62 #define CTASSERT(x) 63 64 CTASSERT(sizeof(struct uuid) == 16); 65 66 /* We use an alternative, more convenient representation in the generator. */ 67 struct uuid_private { 68 union { 69 uint64_t ll; /* internal. */ 70 struct { 71 uint32_t low; 72 uint16_t mid; 73 uint16_t hi; 74 } x; 75 } time; 76 uint16_t seq; /* Big-endian. */ 77 uint16_t node[UUID_NODE_LEN>>1]; 78 }; 79 80 CTASSERT(sizeof(struct uuid_private) == 16); 81 82 static struct uuid_private uuid_last; 83 84 /* "UUID generator mutex lock" */ 85 static struct simplelock uuid_mutex = SIMPLELOCK_INITIALIZER; 86 87 /* 88 * Return the first MAC address we encounter or, if none was found, 89 * construct a sufficiently random multicast address. We don't try 90 * to return the same MAC address as previously returned. We always 91 * generate a new multicast address if no MAC address exists in the 92 * system. 93 * It would be nice to know if 'ifnet' or any of its sub-structures 94 * has been changed in any way. If not, we could simply skip the 95 * scan and safely return the MAC address we returned before. 96 */ 97 static void 98 uuid_node(uint16_t *node) 99 { 100 struct ifnet *ifp; 101 struct ifaddr *ifa; 102 struct sockaddr_dl *sdl; 103 int i, s; 104 105 s = splnet(); 106 IFNET_FOREACH(ifp) { 107 /* Walk the address list */ 108 IFADDR_FOREACH(ifa, ifp) { 109 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 110 if (sdl != NULL && sdl->sdl_family == AF_LINK && 111 sdl->sdl_type == IFT_ETHER) { 112 /* Got a MAC address. */ 113 memcpy(node, LLADDR(sdl), UUID_NODE_LEN); 114 splx(s); 115 return; 116 } 117 } 118 } 119 splx(s); 120 121 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 122 node[i] = (uint16_t)arc4random(); 123 *((uint8_t*)node) |= 0x01; 124 } 125 126 /* 127 * Get the current time as a 60 bit count of 100-nanosecond intervals 128 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 129 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 130 * Gregorian reform to the Christian calendar. 131 */ 132 /* 133 * At present, NetBSD has no timespec source, only timeval sources. So, 134 * we use timeval. 135 */ 136 static uint64_t 137 uuid_time(void) 138 { 139 struct timeval tv; 140 uint64_t xtime = 0x01B21DD213814000LL; 141 142 microtime(&tv); 143 xtime += (uint64_t)tv.tv_sec * 10000000LL; 144 xtime += (uint64_t)(10 * tv.tv_usec); 145 return (xtime & ((1LL << 60) - 1LL)); 146 } 147 148 /* 149 * Internal routine to actually generate the UUID. 150 */ 151 static void 152 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 153 { 154 uint64_t xtime; 155 156 simple_lock(&uuid_mutex); 157 158 uuid_node(uuid->node); 159 xtime = uuid_time(); 160 *timep = xtime; 161 162 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 163 uuid_last.node[1] != uuid->node[1] || 164 uuid_last.node[2] != uuid->node[2]) 165 uuid->seq = (uint16_t)arc4random() & 0x3fff; 166 else if (uuid_last.time.ll >= xtime) 167 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 168 else 169 uuid->seq = uuid_last.seq; 170 171 uuid_last = *uuid; 172 uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL); 173 174 simple_unlock(&uuid_mutex); 175 } 176 177 int 178 sys_uuidgen(struct lwp *l, void *v, register_t *retval) 179 { 180 struct sys_uuidgen_args *uap = v; 181 struct uuid_private uuid; 182 uint64_t xtime; 183 int error; 184 185 /* 186 * Limit the number of UUIDs that can be created at the same time 187 * to some arbitrary number. This isn't really necessary, but I 188 * like to have some sort of upper-bound that's less than 2G :-) 189 * XXX needs to be tunable. 190 */ 191 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 192 return (EINVAL); 193 194 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 195 196 /* Generate the base UUID. */ 197 uuid_generate(&uuid, &xtime, SCARG(uap, count)); 198 199 /* Set sequence and variant and deal with byte order. */ 200 uuid.seq = htobe16(uuid.seq | 0x8000); 201 202 /* XXX: this should copyout larger chunks at a time. */ 203 do { 204 /* Set time and version (=1) and deal with byte order. */ 205 uuid.time.x.low = (uint32_t)xtime; 206 uuid.time.x.mid = (uint16_t)(xtime >> 32); 207 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12); 208 error = copyout(&uuid, SCARG(uap,store), sizeof(uuid)); 209 SCARG(uap, store)++; 210 SCARG(uap, count)--; 211 xtime++; 212 } while (SCARG(uap, count) > 0 && error == 0); 213 214 return (error); 215 } 216 217 int 218 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 219 { 220 const struct uuid_private *id; 221 int cnt; 222 223 id = (const struct uuid_private *)uuid; 224 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 225 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 226 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 227 return (cnt); 228 } 229 230 int 231 uuid_printf(const struct uuid *uuid) 232 { 233 char buf[UUID_STR_LEN]; 234 235 (void) uuid_snprintf(buf, sizeof(buf), uuid); 236 printf("%s", buf); 237 return (0); 238 } 239 240 /* 241 * Encode/Decode UUID into octet-stream. 242 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 243 * 244 * 0 1 2 3 245 * 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 1 246 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 247 * | time_low | 248 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 * | time_mid | time_hi_and_version | 250 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 252 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 * | node (2-5) | 254 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 */ 256 257 void 258 uuid_enc_le(void *buf, const struct uuid *uuid) 259 { 260 uint8_t *p = buf; 261 int i; 262 263 le32enc(p, uuid->time_low); 264 le16enc(p + 4, uuid->time_mid); 265 le16enc(p + 6, uuid->time_hi_and_version); 266 p[8] = uuid->clock_seq_hi_and_reserved; 267 p[9] = uuid->clock_seq_low; 268 for (i = 0; i < _UUID_NODE_LEN; i++) 269 p[10 + i] = uuid->node[i]; 270 } 271 272 void 273 uuid_dec_le(void const *buf, struct uuid *uuid) 274 { 275 const uint8_t *p = buf; 276 int i; 277 278 uuid->time_low = le32dec(p); 279 uuid->time_mid = le16dec(p + 4); 280 uuid->time_hi_and_version = le16dec(p + 6); 281 uuid->clock_seq_hi_and_reserved = p[8]; 282 uuid->clock_seq_low = p[9]; 283 for (i = 0; i < _UUID_NODE_LEN; i++) 284 uuid->node[i] = p[10 + i]; 285 } 286 287 void 288 uuid_enc_be(void *buf, const struct uuid *uuid) 289 { 290 uint8_t *p = buf; 291 int i; 292 293 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 } 301 302 void 303 uuid_dec_be(void const *buf, struct uuid *uuid) 304 { 305 const uint8_t *p = buf; 306 int i; 307 308 uuid->time_low = be32dec(p); 309 uuid->time_mid = le16dec(p + 4); 310 uuid->time_hi_and_version = be16dec(p + 6); 311 uuid->clock_seq_hi_and_reserved = p[8]; 312 uuid->clock_seq_low = p[9]; 313 for (i = 0; i < _UUID_NODE_LEN; i++) 314 uuid->node[i] = p[10 + i]; 315 } 316
Indexes created Sat Sep 27 14:09:57 GMT 2025