1 /* $NetBSD: kern_uuid.c,v 1.3 2004/09/12 23:17:37 thorpej 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 1.3 2004/09/12 23:17:37 thorpej 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/sa.h> 45 #include <sys/mount.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 struct simplelock uuid_mutex = SIMPLELOCK_INITIALIZER; 87 88 /* 89 * Return the first MAC address we encounter or, if none was found, 90 * construct a sufficiently random multicast address. We don't try 91 * to return the same MAC address as previously returned. We always 92 * generate a new multicast address if no MAC address exists in the 93 * system. 94 * It would be nice to know if 'ifnet' or any of its sub-structures 95 * has been changed in any way. If not, we could simply skip the 96 * scan and safely return the MAC address we returned before. 97 */ 98 static void 99 uuid_node(uint16_t *node) 100 { 101 struct ifnet *ifp; 102 struct ifaddr *ifa; 103 struct sockaddr_dl *sdl; 104 int i, s; 105 106 s = splnet(); 107 TAILQ_FOREACH(ifp, &ifnet, if_list) { 108 /* Walk the address list */ 109 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) { 110 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 111 if (sdl != NULL && sdl->sdl_family == AF_LINK && 112 sdl->sdl_type == IFT_ETHER) { 113 /* Got a MAC address. */ 114 memcpy(node, LLADDR(sdl), UUID_NODE_LEN); 115 splx(s); 116 return; 117 } 118 } 119 } 120 splx(s); 121 122 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 123 node[i] = (uint16_t)arc4random(); 124 *((uint8_t*)node) |= 0x01; 125 } 126 127 /* 128 * Get the current time as a 60 bit count of 100-nanosecond intervals 129 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 130 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the 131 * Gregorian reform to the Christian calendar. 132 */ 133 /* 134 * At present, NetBSD has no timespec source, only timeval sources. So, 135 * we use timeval. 136 */ 137 static uint64_t 138 uuid_time(void) 139 { 140 struct timeval tv; 141 uint64_t time = 0x01B21DD213814000LL; 142 143 microtime(&tv); 144 time += (uint64_t)tv.tv_sec * 10000000LL; 145 time += (uint64_t)(10 * tv.tv_usec); 146 return (time & ((1LL << 60) - 1LL)); 147 } 148 149 /* 150 * Internal routine to actually generate the UUID. 151 */ 152 static void 153 uuid_generate(struct uuid_private *uuid, uint64_t *timep, int count) 154 { 155 uint64_t time; 156 157 simple_lock(&uuid_mutex); 158 159 uuid_node(uuid->node); 160 time = uuid_time(); 161 *timep = time; 162 163 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid->node[0] || 164 uuid_last.node[1] != uuid->node[1] || 165 uuid_last.node[2] != uuid->node[2]) 166 uuid->seq = (uint16_t)arc4random() & 0x3fff; 167 else if (uuid_last.time.ll >= time) 168 uuid->seq = (uuid_last.seq + 1) & 0x3fff; 169 else 170 uuid->seq = uuid_last.seq; 171 172 uuid_last = *uuid; 173 uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL); 174 175 simple_unlock(&uuid_mutex); 176 } 177 178 int 179 sys_uuidgen(struct lwp *l, void *v, register_t *retval) 180 { 181 struct sys_uuidgen_args *uap = v; 182 struct uuid_private uuid; 183 uint64_t time; 184 int error; 185 186 /* 187 * Limit the number of UUIDs that can be created at the same time 188 * to some arbitrary number. This isn't really necessary, but I 189 * like to have some sort of upper-bound that's less than 2G :-) 190 * XXX needs to be tunable. 191 */ 192 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048) 193 return (EINVAL); 194 195 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 196 197 /* Generate the base UUID. */ 198 uuid_generate(&uuid, &time, SCARG(uap, count)); 199 200 /* Set sequence and variant and deal with byte order. */ 201 uuid.seq = htobe16(uuid.seq | 0x8000); 202 203 /* XXX: this should copyout larger chunks at a time. */ 204 do { 205 /* Set time and version (=1) and deal with byte order. */ 206 uuid.time.x.low = (uint32_t)time; 207 uuid.time.x.mid = (uint16_t)(time >> 32); 208 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12); 209 error = copyout(&uuid, SCARG(uap,store), sizeof(uuid)); 210 SCARG(uap, store)++; 211 SCARG(uap, count)--; 212 time++; 213 } while (SCARG(uap, count) > 0 && error == 0); 214 215 return (error); 216 } 217 218 int 219 uuid_snprintf(char *buf, size_t sz, const struct uuid *uuid) 220 { 221 const struct uuid_private *id; 222 int cnt; 223 224 id = (const struct uuid_private *)uuid; 225 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 226 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 227 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 228 return (cnt); 229 } 230 231 int 232 uuid_printf(const struct uuid *uuid) 233 { 234 char buf[UUID_STR_LEN]; 235 236 (void) uuid_snprintf(buf, sizeof(buf), uuid); 237 printf("%s", buf); 238 return (0); 239 } 240 241 /* 242 * Encode/Decode UUID into octet-stream. 243 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 244 * 245 * 0 1 2 3 246 * 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 1 247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 * | time_low | 249 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 250 * | time_mid | time_hi_and_version | 251 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 252 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 253 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 254 * | node (2-5) | 255 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 256 */ 257 258 void 259 uuid_enc_le(void *buf, const struct uuid *uuid) 260 { 261 uint8_t *p = buf; 262 int i; 263 264 le32enc(p, uuid->time_low); 265 le16enc(p + 4, uuid->time_mid); 266 le16enc(p + 6, uuid->time_hi_and_version); 267 p[8] = uuid->clock_seq_hi_and_reserved; 268 p[9] = uuid->clock_seq_low; 269 for (i = 0; i < _UUID_NODE_LEN; i++) 270 p[10 + i] = uuid->node[i]; 271 } 272 273 void 274 uuid_dec_le(void const *buf, struct uuid *uuid) 275 { 276 const uint8_t *p = buf; 277 int i; 278 279 uuid->time_low = le32dec(p); 280 uuid->time_mid = le16dec(p + 4); 281 uuid->time_hi_and_version = le16dec(p + 6); 282 uuid->clock_seq_hi_and_reserved = p[8]; 283 uuid->clock_seq_low = p[9]; 284 for (i = 0; i < _UUID_NODE_LEN; i++) 285 uuid->node[i] = p[10 + i]; 286 } 287 288 void 289 uuid_enc_be(void *buf, const struct uuid *uuid) 290 { 291 uint8_t *p = buf; 292 int i; 293 294 be32enc(p, uuid->time_low); 295 be16enc(p + 4, uuid->time_mid); 296 be16enc(p + 6, uuid->time_hi_and_version); 297 p[8] = uuid->clock_seq_hi_and_reserved; 298 p[9] = uuid->clock_seq_low; 299 for (i = 0; i < _UUID_NODE_LEN; i++) 300 p[10 + i] = uuid->node[i]; 301 } 302 303 void 304 uuid_dec_be(void const *buf, struct uuid *uuid) 305 { 306 const uint8_t *p = buf; 307 int i; 308 309 uuid->time_low = be32dec(p); 310 uuid->time_mid = le16dec(p + 4); 311 uuid->time_hi_and_version = be16dec(p + 6); 312 uuid->clock_seq_hi_and_reserved = p[8]; 313 uuid->clock_seq_low = p[9]; 314 for (i = 0; i < _UUID_NODE_LEN; i++) 315 uuid->node[i] = p[10 + i]; 316 } 317