kern_uuid.c revision 1.14
1 /* $NetBSD: kern_uuid.c,v 1.14 2008/04/19 18:21:38 plunky 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 2008/04/19 18:21:38 plunky 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 /* 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 kmutex_t uuid_mutex; 86 87 void 88 uuid_init(void) 89 { 90 91 mutex_init(&uuid_mutex, MUTEX_DEFAULT, IPL_NONE); 92 } 93 94 /* 95 * Return the first MAC address we encounter or, if none was found, 96 * construct a sufficiently random multicast address. We don't try 97 * to return the same MAC address as previously returned. We always 98 * generate a new multicast address if no MAC address exists in the 99 * system. 100 * It would be nice to know if 'ifnet' or any of its sub-structures 101 * has been changed in any way. If not, we could simply skip the 102 * scan and safely return the MAC address we returned before. 103 */ 104 static void 105 uuid_node(uint16_t *node) 106 { 107 struct ifnet *ifp; 108 struct ifaddr *ifa; 109 struct sockaddr_dl *sdl; 110 int i, s; 111 112 s = splnet(); 113 KERNEL_LOCK(1, NULL); 114 IFNET_FOREACH(ifp) { 115 /* Walk the address list */ 116 IFADDR_FOREACH(ifa, ifp) { 117 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 118 if (sdl != NULL && sdl->sdl_family == AF_LINK && 119 sdl->sdl_type == IFT_ETHER) { 120 /* Got a MAC address. */ 121 memcpy(node, CLLADDR(sdl), UUID_NODE_LEN); 122 KERNEL_UNLOCK_ONE(NULL); 123 splx(s); 124 return; 125 } 126 } 127 } 128 KERNEL_UNLOCK_ONE(NULL); 129 splx(s); 130 131 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 132 node[i] = (uint16_t)arc4random(); 133 *((uint8_t*)node) |= 0x01; 134 } 135 136 /* 137 * Get the current time as a 60 bit count of 100-nanosecond intervals 138 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 139 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 140 * Gregorian reform to the Christian calendar. 141 */ 142 /* 143 * At present, NetBSD has no timespec source, only timeval sources. So, 144 * we use timeval. 145 */ 146 static uint64_t 147 uuid_time(void) 148 { 149 struct timeval tv; 150 uint64_t xtime = 0x01B21DD213814000LL; 151 152 microtime(&tv); 153 xtime += (uint64_t)tv.tv_sec * 10000000LL; 154 xtime += (uint64_t)(10 * tv.tv_usec); 155 return (xtime & ((1LL << 60) - 1LL)); 156 } 157 158 /* 159 * Internal routine to actually generate the UUID. 160 */ 161 static void 162 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 163 { 164 uint64_t xtime; 165 166 mutex_enter(&uuid_mutex); 167 168 uuid_node(uuid->node); 169 xtime = uuid_time(); 170 *timep = xtime; 171 172 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 173 uuid_last.node[1] != uuid->node[1] || 174 uuid_last.node[2] != uuid->node[2]) 175 uuid->seq = (uint16_t)arc4random() & 0x3fff; 176 else if (uuid_last.time.ll >= xtime) 177 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 178 else 179 uuid->seq = uuid_last.seq; 180 181 uuid_last = *uuid; 182 uuid_last.time.ll = (xtime + count - 1) & ((1LL << 60) - 1LL); 183 184 mutex_exit(&uuid_mutex); 185 } 186 187 int 188 sys_uuidgen(struct lwp *l, const struct sys_uuidgen_args *uap, register_t *retval) 189 { 190 struct uuid_private uuid; 191 uint64_t xtime; 192 int error; 193 int i; 194 195 /* 196 * Limit the number of UUIDs that can be created at the same time 197 * to some arbitrary number. This isn't really necessary, but I 198 * like to have some sort of upper-bound that's less than 2G :-) 199 * XXX needs to be tunable. 200 */ 201 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 202 return (EINVAL); 203 204 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 205 206 /* Generate the base UUID. */ 207 uuid_generate(&uuid, &xtime, SCARG(uap, count)); 208 209 /* Set sequence and variant and deal with byte order. */ 210 uuid.seq = htobe16(uuid.seq | 0x8000); 211 212 /* XXX: this should copyout larger chunks at a time. */ 213 for (i = 0; i < SCARG(uap, count); xtime++, i++) { 214 /* Set time and version (=1) and deal with byte order. */ 215 uuid.time.x.low = (uint32_t)xtime; 216 uuid.time.x.mid = (uint16_t)(xtime >> 32); 217 uuid.time.x.hi = ((uint16_t)(xtime >> 48) & 0xfff) | (1 << 12); 218 error = copyout(&uuid, SCARG(uap,store) + i, sizeof(uuid)); 219 if (error != 0) 220 return error; 221 } 222 223 return 0; 224 } 225 226 int 227 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 228 { 229 const struct uuid_private *id; 230 int cnt; 231 232 id = (const struct uuid_private *)uuid; 233 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 234 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 235 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 236 return (cnt); 237 } 238 239 int 240 uuid_printf(const struct uuid *uuid) 241 { 242 char buf[UUID_STR_LEN]; 243 244 (void) uuid_snprintf(buf, sizeof(buf), uuid); 245 printf("%s", buf); 246 return (0); 247 } 248 249 /* 250 * Encode/Decode UUID into octet-stream. 251 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 252 * 253 * 0 1 2 3 254 * 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 1 255 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 * | time_low | 257 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 258 * | time_mid | time_hi_and_version | 259 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 260 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 261 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 262 * | node (2-5) | 263 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 264 */ 265 266 void 267 uuid_enc_le(void *buf, const struct uuid *uuid) 268 { 269 uint8_t *p = buf; 270 int i; 271 272 le32enc(p, uuid->time_low); 273 le16enc(p + 4, uuid->time_mid); 274 le16enc(p + 6, uuid->time_hi_and_version); 275 p[8] = uuid->clock_seq_hi_and_reserved; 276 p[9] = uuid->clock_seq_low; 277 for (i = 0; i < _UUID_NODE_LEN; i++) 278 p[10 + i] = uuid->node[i]; 279 } 280 281 void 282 uuid_dec_le(void const *buf, struct uuid *uuid) 283 { 284 const uint8_t *p = buf; 285 int i; 286 287 uuid->time_low = le32dec(p); 288 uuid->time_mid = le16dec(p + 4); 289 uuid->time_hi_and_version = le16dec(p + 6); 290 uuid->clock_seq_hi_and_reserved = p[8]; 291 uuid->clock_seq_low = p[9]; 292 for (i = 0; i < _UUID_NODE_LEN; i++) 293 uuid->node[i] = p[10 + i]; 294 } 295 296 void 297 uuid_enc_be(void *buf, const struct uuid *uuid) 298 { 299 uint8_t *p = buf; 300 int i; 301 302 be32enc(p, uuid->time_low); 303 be16enc(p + 4, uuid->time_mid); 304 be16enc(p + 6, uuid->time_hi_and_version); 305 p[8] = uuid->clock_seq_hi_and_reserved; 306 p[9] = uuid->clock_seq_low; 307 for (i = 0; i < _UUID_NODE_LEN; i++) 308 p[10 + i] = uuid->node[i]; 309 } 310 311 void 312 uuid_dec_be(void const *buf, struct uuid *uuid) 313 { 314 const uint8_t *p = buf; 315 int i; 316 317 uuid->time_low = be32dec(p); 318 uuid->time_mid = be16dec(p + 4); 319 uuid->time_hi_and_version = be16dec(p + 6); 320 uuid->clock_seq_hi_and_reserved = p[8]; 321 uuid->clock_seq_low = p[9]; 322 for (i = 0; i < _UUID_NODE_LEN; i++) 323 uuid->node[i] = p[10 + i]; 324 } 325
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