1 /* 2 * Copyright (c) 2002 Marcel Moolenaar 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/endian.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/mutex.h> 35 #include <sys/sbuf.h> 36 #include <sys/socket.h> 37 #include <sys/sysproto.h> 38 #include <sys/systm.h> 39 #include <sys/uuid.h> 40 41 #include <net/if.h> 42 #include <net/if_dl.h> 43 #include <net/if_types.h> 44 45 /* 46 * See also: 47 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 48 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm 49 * 50 * Note that the generator state is itself an UUID, but the time and clock 51 * sequence fields are written in the native byte order. 52 */ 53 54 CTASSERT(sizeof(struct uuid) == 16); 55 56 /* We use an alternative, more convenient representation in the generator. */ 57 struct uuid_private { 58 union { 59 uint64_t ll; /* internal. */ 60 struct { 61 uint32_t low; 62 uint16_t mid; 63 uint16_t hi; 64 } x; 65 } time; 66 uint16_t seq; /* Big-endian. */ 67 uint16_t node[UUID_NODE_LEN>>1]; 68 }; 69 70 CTASSERT(sizeof(struct uuid_private) == 16); 71 72 static struct uuid_private uuid_last; 73 74 static struct mtx uuid_mutex; 75 MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF); 76 77 /* 78 * Return the first MAC address we encounter or, if none was found, 79 * construct a sufficiently random multicast address. We don't try 80 * to return the same MAC address as previously returned. We always 81 * generate a new multicast address if no MAC address exists in the 82 * system. 83 * It would be nice to know if 'ifnet' or any of its sub-structures 84 * has been changed in any way. If not, we could simply skip the 85 * scan and safely return the MAC address we returned before. 86 */ 87 static void 88 uuid_node(uint16_t *node) 89 { 90 struct ifnet *ifp; 91 struct ifaddr *ifa; 92 struct sockaddr_dl *sdl; 93 int i; 94 95 IFNET_RLOCK(); 96 TAILQ_FOREACH(ifp, &ifnet, if_link) { 97 /* Walk the address list */ 98 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 99 sdl = (struct sockaddr_dl*)ifa->ifa_addr; 100 if (sdl != NULL && sdl->sdl_family == AF_LINK && 101 sdl->sdl_type == IFT_ETHER) { 102 /* Got a MAC address. */ 103 bcopy(LLADDR(sdl), node, UUID_NODE_LEN); 104 IFNET_RUNLOCK(); 105 return; 106 } 107 } 108 } 109 IFNET_RUNLOCK(); 110 111 for (i = 0; i < (UUID_NODE_LEN>>1); i++) 112 node[i] = (uint16_t)arc4random(); 113 *((uint8_t*)node) |= 0x01; 114 } 115 116 /* 117 * Get the current time as a 60 bit count of 100-nanosecond intervals 118 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert 119 * the Unix time since 00:00:00.00, Januari 1, 1970 to the date of the 120 * Gregorian reform to the Christian calendar. 121 */ 122 static uint64_t 123 uuid_time(void) 124 { 125 struct bintime bt; 126 uint64_t time = 0x01B21DD213814000LL; 127 128 bintime(&bt); 129 time += (uint64_t)bt.sec * 10000000LL; 130 time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32; 131 return (time & ((1LL << 60) - 1LL)); 132 } 133 134 #ifndef _SYS_SYSPROTO_H_ 135 struct uuidgen_args { 136 struct uuid *store; 137 int count; 138 }; 139 #endif 140 141 int 142 uuidgen(struct thread *td, struct uuidgen_args *uap) 143 { 144 struct uuid_private uuid; 145 uint64_t time; 146 int error; 147 148 /* 149 * Limit the number of UUIDs that can be created at the same time 150 * to some arbitrary number. This isn't really necessary, but I 151 * like to have some sort of upper-bound that's less than 2G :-) 152 * XXX needs to be tunable. 153 */ 154 if (uap->count < 1 || uap->count > 2048) 155 return (EINVAL); 156 157 /* XXX: pre-validate accessibility to the whole of the UUID store? */ 158 159 mtx_lock(&uuid_mutex); 160 161 uuid_node(uuid.node); 162 time = uuid_time(); 163 164 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] || 165 uuid_last.node[1] != uuid.node[1] || 166 uuid_last.node[2] != uuid.node[2]) 167 uuid.seq = (uint16_t)arc4random() & 0x3fff; 168 else if (uuid_last.time.ll >= time) 169 uuid.seq = (uuid_last.seq + 1) & 0x3fff; 170 else 171 uuid.seq = uuid_last.seq; 172 173 uuid_last = uuid; 174 uuid_last.time.ll = (time + uap->count - 1) & ((1LL << 60) - 1LL); 175 176 mtx_unlock(&uuid_mutex); 177 178 /* Set sequence and variant and deal with byte order. */ 179 uuid.seq = htobe16(uuid.seq | 0x8000); 180 181 /* XXX: this should copyout larger chunks at a time. */ 182 do { 183 /* Set time and version (=1) and deal with byte order. */ 184 uuid.time.x.low = (uint32_t)time; 185 uuid.time.x.mid = (uint16_t)(time >> 32); 186 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12); 187 error = copyout(&uuid, uap->store, sizeof(uuid)); 188 uap->store++; 189 uap->count--; 190 time++; 191 } while (uap->count > 0 && !error); 192 193 return (error); 194 } 195 196 int 197 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid) 198 { 199 struct uuid_private *id; 200 int cnt; 201 202 id = (struct uuid_private *)uuid; 203 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x", 204 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq), 205 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2])); 206 return (cnt); 207 } 208 209 int 210 printf_uuid(struct uuid *uuid) 211 { 212 char buf[38]; 213 214 snprintf_uuid(buf, sizeof(buf), uuid); 215 return (printf("%s", buf)); 216 } 217 218 int 219 sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid) 220 { 221 char buf[38]; 222 223 snprintf_uuid(buf, sizeof(buf), uuid); 224 return (sbuf_printf(sb, "%s", buf)); 225 } 226 227 /* 228 * Encode/Decode UUID into byte-stream. 229 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt 230 * 231 * 0 1 2 3 232 * 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 1 233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 234 * | time_low | 235 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 236 * | time_mid | time_hi_and_version | 237 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 * |clk_seq_hi_res | clk_seq_low | node (0-1) | 239 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 240 * | node (2-5) | 241 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 */ 243 244 void 245 le_uuid_enc(void *buf, struct uuid const *uuid) 246 { 247 u_char *p; 248 int i; 249 250 p = buf; 251 le32enc(p, uuid->time_low); 252 le16enc(p + 4, uuid->time_mid); 253 le16enc(p + 6, uuid->time_hi_and_version); 254 p[8] = uuid->clock_seq_hi_and_reserved; 255 p[9] = uuid->clock_seq_low; 256 for (i = 0; i < _UUID_NODE_LEN; i++) 257 p[10 + i] = uuid->node[i]; 258 } 259 260 void 261 le_uuid_dec(void const *buf, struct uuid *uuid) 262 { 263 u_char const *p; 264 int i; 265 266 p = buf; 267 uuid->time_low = le32dec(p); 268 uuid->time_mid = le16dec(p + 4); 269 uuid->time_hi_and_version = le16dec(p + 6); 270 uuid->clock_seq_hi_and_reserved = p[8]; 271 uuid->clock_seq_low = p[9]; 272 for (i = 0; i < _UUID_NODE_LEN; i++) 273 uuid->node[i] = p[10 + i]; 274 } 275 void 276 be_uuid_enc(void *buf, struct uuid const *uuid) 277 { 278 u_char *p; 279 int i; 280 281 p = buf; 282 be32enc(p, uuid->time_low); 283 be16enc(p + 4, uuid->time_mid); 284 be16enc(p + 6, uuid->time_hi_and_version); 285 p[8] = uuid->clock_seq_hi_and_reserved; 286 p[9] = uuid->clock_seq_low; 287 for (i = 0; i < _UUID_NODE_LEN; i++) 288 p[10 + i] = uuid->node[i]; 289 } 290 291 void 292 be_uuid_dec(void const *buf, struct uuid *uuid) 293 { 294 u_char const *p; 295 int i; 296 297 p = buf; 298 uuid->time_low = be32dec(p); 299 uuid->time_mid = le16dec(p + 4); 300 uuid->time_hi_and_version = be16dec(p + 6); 301 uuid->clock_seq_hi_and_reserved = p[8]; 302 uuid->clock_seq_low = p[9]; 303 for (i = 0; i < _UUID_NODE_LEN; i++) 304 uuid->node[i] = p[10 + i]; 305 } 306