FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_uuid.c
1 /* $NetBSD: kern_uuid.c,v 1.1 2004/01/29 02:00:03 tsarna Exp $ */
2 /* $FreeBSD: /repoman/r/ncvs/src/sys/kern/kern_uuid.c,v 1.7 2004/01/12 13:34:11 rse Exp $ */
3
4 /*
5 * Copyright (c) 2002 Marcel Moolenaar
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: kern_uuid.c,v 1.1 2004/01/29 02:00:03 tsarna Exp $");
32
33 #include <sys/param.h>
34 #include <sys/endian.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/socket.h>
38 #include <sys/systm.h>
39 #include <sys/uuid.h>
40
41 /* NetBSD */
42 #include <sys/proc.h>
43 #include <sys/sa.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 int sys_uuidgen(struct lwp *, void *, register_t *);
54
55 /*
56 * See also:
57 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
58 * http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
59 *
60 * Note that the generator state is itself an UUID, but the time and clock
61 * sequence fields are written in the native byte order.
62 */
63
64 /* XXX Do we have a similar ASSERT()? */
65 #define CTASSERT(x)
66
67 CTASSERT(sizeof(struct uuid) == 16);
68
69 /* We use an alternative, more convenient representation in the generator. */
70 struct uuid_private {
71 union {
72 uint64_t ll; /* internal. */
73 struct {
74 uint32_t low;
75 uint16_t mid;
76 uint16_t hi;
77 } x;
78 } time;
79 uint16_t seq; /* Big-endian. */
80 uint16_t node[UUID_NODE_LEN>>1];
81 };
82
83 CTASSERT(sizeof(struct uuid_private) == 16);
84
85 static struct uuid_private uuid_last;
86
87 /* "UUID generator mutex lock" */
88 static struct simplelock uuid_mutex = SIMPLELOCK_INITIALIZER;
89
90 /*
91 * Return the first MAC address we encounter or, if none was found,
92 * construct a sufficiently random multicast address. We don't try
93 * to return the same MAC address as previously returned. We always
94 * generate a new multicast address if no MAC address exists in the
95 * system.
96 * It would be nice to know if 'ifnet' or any of its sub-structures
97 * has been changed in any way. If not, we could simply skip the
98 * scan and safely return the MAC address we returned before.
99 */
100 static void
101 uuid_node(uint16_t *node)
102 {
103 struct ifnet *ifp;
104 struct ifaddr *ifa;
105 struct sockaddr_dl *sdl;
106 int i, s;
107
108 s = splnet();
109 TAILQ_FOREACH(ifp, &ifnet, if_list) {
110 /* Walk the address list */
111 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
112 sdl = (struct sockaddr_dl*)ifa->ifa_addr;
113 if (sdl != NULL && sdl->sdl_family == AF_LINK &&
114 sdl->sdl_type == IFT_ETHER) {
115 /* Got a MAC address. */
116 memcpy(node, LLADDR(sdl), UUID_NODE_LEN);
117 splx(s);
118 return;
119 }
120 }
121 }
122 splx(s);
123
124 for (i = 0; i < (UUID_NODE_LEN>>1); i++)
125 node[i] = (uint16_t)arc4random();
126 *((uint8_t*)node) |= 0x01;
127 }
128
129 /*
130 * Get the current time as a 60 bit count of 100-nanosecond intervals
131 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
132 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
133 * Gregorian reform to the Christian calendar.
134 */
135 /*
136 * At present, NetBSD has no timespec source, only timeval sources. So,
137 * we use timeval.
138 */
139 static uint64_t
140 uuid_time(void)
141 {
142 struct timeval tv;
143 uint64_t time = 0x01B21DD213814000LL;
144
145 microtime(&tv);
146 time += (uint64_t)tv.tv_sec * 10000000LL;
147 time += (uint64_t)(10 * tv.tv_usec);
148 return (time & ((1LL << 60) - 1LL));
149 }
150
151 int
152 sys_uuidgen(struct lwp *l, void *v, register_t *retval)
153 {
154 struct sys_uuidgen_args *uap = v;
155 struct uuid_private uuid;
156 uint64_t time;
157 int error;
158
159 /*
160 * Limit the number of UUIDs that can be created at the same time
161 * to some arbitrary number. This isn't really necessary, but I
162 * like to have some sort of upper-bound that's less than 2G :-)
163 * XXX needs to be tunable.
164 */
165 if (SCARG(uap,count) < 1 || SCARG(uap,count) > 2048)
166 return (EINVAL);
167
168 /* XXX: pre-validate accessibility to the whole of the UUID store? */
169
170 simple_lock(&uuid_mutex);
171
172 uuid_node(uuid.node);
173 time = uuid_time();
174
175 if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
176 uuid_last.node[1] != uuid.node[1] ||
177 uuid_last.node[2] != uuid.node[2])
178 uuid.seq = (uint16_t)arc4random() & 0x3fff;
179 else if (uuid_last.time.ll >= time)
180 uuid.seq = (uuid_last.seq + 1) & 0x3fff;
181 else
182 uuid.seq = uuid_last.seq;
183
184 uuid_last = uuid;
185 uuid_last.time.ll = (time + SCARG(uap,count) - 1) & ((1LL << 60) - 1LL);
186
187 simple_unlock(&uuid_mutex);
188
189 /* Set sequence and variant and deal with byte order. */
190 uuid.seq = htobe16(uuid.seq | 0x8000);
191
192 /* XXX: this should copyout larger chunks at a time. */
193 do {
194 /* Set time and version (=1) and deal with byte order. */
195 uuid.time.x.low = (uint32_t)time;
196 uuid.time.x.mid = (uint16_t)(time >> 32);
197 uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
198 error = copyout(&uuid, SCARG(uap,store), sizeof(uuid));
199 SCARG(uap,store)++;
200 SCARG(uap,count)--;
201 time++;
202 } while (SCARG(uap,count) > 0 && !error);
203
204 return (error);
205 }
206
207 #ifdef notyet
208 int
209 snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
210 {
211 struct uuid_private *id;
212 int cnt;
213
214 id = (struct uuid_private *)uuid;
215 cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
216 id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
217 be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
218 return (cnt);
219 }
220
221 int
222 printf_uuid(struct uuid *uuid)
223 {
224 char buf[38];
225
226 snprintf_uuid(buf, sizeof(buf), uuid);
227 printf("%s", buf);
228 return 0;
229 }
230
231 /*
232 * Encode/Decode UUID into byte-stream.
233 * http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
234 *
235 * 0 1 2 3
236 * 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
237 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
238 * | time_low |
239 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
240 * | time_mid | time_hi_and_version |
241 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
242 * |clk_seq_hi_res | clk_seq_low | node (0-1) |
243 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
244 * | node (2-5) |
245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
246 */
247
248 void
249 le_uuid_enc(void *buf, struct uuid const *uuid)
250 {
251 u_char *p;
252 int i;
253
254 p = buf;
255 le32enc(p, uuid->time_low);
256 le16enc(p + 4, uuid->time_mid);
257 le16enc(p + 6, uuid->time_hi_and_version);
258 p[8] = uuid->clock_seq_hi_and_reserved;
259 p[9] = uuid->clock_seq_low;
260 for (i = 0; i < _UUID_NODE_LEN; i++)
261 p[10 + i] = uuid->node[i];
262 }
263
264 void
265 le_uuid_dec(void const *buf, struct uuid *uuid)
266 {
267 u_char const *p;
268 int i;
269
270 p = buf;
271 uuid->time_low = le32dec(p);
272 uuid->time_mid = le16dec(p + 4);
273 uuid->time_hi_and_version = le16dec(p + 6);
274 uuid->clock_seq_hi_and_reserved = p[8];
275 uuid->clock_seq_low = p[9];
276 for (i = 0; i < _UUID_NODE_LEN; i++)
277 uuid->node[i] = p[10 + i];
278 }
279 void
280 be_uuid_enc(void *buf, struct uuid const *uuid)
281 {
282 u_char *p;
283 int i;
284
285 p = buf;
286 be32enc(p, uuid->time_low);
287 be16enc(p + 4, uuid->time_mid);
288 be16enc(p + 6, uuid->time_hi_and_version);
289 p[8] = uuid->clock_seq_hi_and_reserved;
290 p[9] = uuid->clock_seq_low;
291 for (i = 0; i < _UUID_NODE_LEN; i++)
292 p[10 + i] = uuid->node[i];
293 }
294
295 void
296 be_uuid_dec(void const *buf, struct uuid *uuid)
297 {
298 u_char const *p;
299 int i;
300
301 p = buf;
302 uuid->time_low = be32dec(p);
303 uuid->time_mid = le16dec(p + 4);
304 uuid->time_hi_and_version = be16dec(p + 6);
305 uuid->clock_seq_hi_and_reserved = p[8];
306 uuid->clock_seq_low = p[9];
307 for (i = 0; i < _UUID_NODE_LEN; i++)
308 uuid->node[i] = p[10 + i];
309 }
310 #endif
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