summaryrefslogtreecommitdiffstats
path: root/sys/kern/kern_uuid.c
blob: 14ace891b60958bd6bcdae39dc531557f5181e0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
/*-
 * Copyright (c) 2002 Marcel Moolenaar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sbuf.h>
#include <sys/socket.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/jail.h>
#include <sys/uuid.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/vnet.h>

/*
 * See also:
 *	http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
 *	http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
 *
 * Note that the generator state is itself an UUID, but the time and clock
 * sequence fields are written in the native byte order.
 */

CTASSERT(sizeof(struct uuid) == 16);

/* We use an alternative, more convenient representation in the generator. */
struct uuid_private {
	union {
		uint64_t	ll;		/* internal. */
		struct {
			uint32_t	low;
			uint16_t	mid;
			uint16_t	hi;
		} x;
	} time;
	uint16_t	seq;			/* Big-endian. */
	uint16_t	node[UUID_NODE_LEN>>1];
};

CTASSERT(sizeof(struct uuid_private) == 16);

static struct uuid_private uuid_last;

static struct mtx uuid_mutex;
MTX_SYSINIT(uuid_lock, &uuid_mutex, "UUID generator mutex lock", MTX_DEF);

/*
 * Return the first MAC address we encounter or, if none was found,
 * construct a sufficiently random multicast address. We don't try
 * to return the same MAC address as previously returned. We always
 * generate a new multicast address if no MAC address exists in the
 * system.
 * It would be nice to know if 'ifnet' or any of its sub-structures
 * has been changed in any way. If not, we could simply skip the
 * scan and safely return the MAC address we returned before.
 */
static void
uuid_node(uint16_t *node)
{
	struct ifnet *ifp;
	struct ifaddr *ifa;
	struct sockaddr_dl *sdl;
	int i;

	CURVNET_SET(TD_TO_VNET(curthread));
	IFNET_RLOCK_NOSLEEP();
	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
		/* Walk the address list */
		IF_ADDR_RLOCK(ifp);
		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
			sdl = (struct sockaddr_dl*)ifa->ifa_addr;
			if (sdl != NULL && sdl->sdl_family == AF_LINK &&
			    sdl->sdl_type == IFT_ETHER) {
				/* Got a MAC address. */
				bcopy(LLADDR(sdl), node, UUID_NODE_LEN);
				IF_ADDR_RUNLOCK(ifp);
				IFNET_RUNLOCK_NOSLEEP();
				CURVNET_RESTORE();
				return;
			}
		}
		IF_ADDR_RUNLOCK(ifp);
	}
	IFNET_RUNLOCK_NOSLEEP();

	for (i = 0; i < (UUID_NODE_LEN>>1); i++)
		node[i] = (uint16_t)arc4random();
	*((uint8_t*)node) |= 0x01;
	CURVNET_RESTORE();
}

/*
 * Get the current time as a 60 bit count of 100-nanosecond intervals
 * since 00:00:00.00, October 15,1582. We apply a magic offset to convert
 * the Unix time since 00:00:00.00, January 1, 1970 to the date of the
 * Gregorian reform to the Christian calendar.
 */
static uint64_t
uuid_time(void)
{
	struct bintime bt;
	uint64_t time = 0x01B21DD213814000LL;

	bintime(&bt);
	time += (uint64_t)bt.sec * 10000000LL;
	time += (10000000LL * (uint32_t)(bt.frac >> 32)) >> 32;
	return (time & ((1LL << 60) - 1LL));
}

struct uuid *
kern_uuidgen(struct uuid *store, size_t count)
{
	struct uuid_private uuid;
	uint64_t time;
	size_t n;

	mtx_lock(&uuid_mutex);

	uuid_node(uuid.node);
	time = uuid_time();

	if (uuid_last.time.ll == 0LL || uuid_last.node[0] != uuid.node[0] ||
	    uuid_last.node[1] != uuid.node[1] ||
	    uuid_last.node[2] != uuid.node[2])
		uuid.seq = (uint16_t)arc4random() & 0x3fff;
	else if (uuid_last.time.ll >= time)
		uuid.seq = (uuid_last.seq + 1) & 0x3fff;
	else
		uuid.seq = uuid_last.seq;

	uuid_last = uuid;
	uuid_last.time.ll = (time + count - 1) & ((1LL << 60) - 1LL);

	mtx_unlock(&uuid_mutex);

	/* Set sequence and variant and deal with byte order. */
	uuid.seq = htobe16(uuid.seq | 0x8000);

	for (n = 0; n < count; n++) {
		/* Set time and version (=1). */
		uuid.time.x.low = (uint32_t)time;
		uuid.time.x.mid = (uint16_t)(time >> 32);
		uuid.time.x.hi = ((uint16_t)(time >> 48) & 0xfff) | (1 << 12);
		store[n] = *(struct uuid *)&uuid;
		time++;
	}

	return (store);
}

#ifndef _SYS_SYSPROTO_H_
struct uuidgen_args {
	struct uuid *store;
	int	count;
};
#endif
int
sys_uuidgen(struct thread *td, struct uuidgen_args *uap)
{
	struct uuid *store;
	size_t count;
	int error;

	/*
	 * Limit the number of UUIDs that can be created at the same time
	 * to some arbitrary number. This isn't really necessary, but I
	 * like to have some sort of upper-bound that's less than 2G :-)
	 * XXX probably needs to be tunable.
	 */
	if (uap->count < 1 || uap->count > 2048)
		return (EINVAL);

	count = uap->count;
	store = malloc(count * sizeof(struct uuid), M_TEMP, M_WAITOK);
	kern_uuidgen(store, count);
	error = copyout(store, uap->store, count * sizeof(struct uuid));
	free(store, M_TEMP);
	return (error);
}

int
snprintf_uuid(char *buf, size_t sz, struct uuid *uuid)
{
	struct uuid_private *id;
	int cnt;

	id = (struct uuid_private *)uuid;
	cnt = snprintf(buf, sz, "%08x-%04x-%04x-%04x-%04x%04x%04x",
	    id->time.x.low, id->time.x.mid, id->time.x.hi, be16toh(id->seq),
	    be16toh(id->node[0]), be16toh(id->node[1]), be16toh(id->node[2]));
	return (cnt);
}

int
printf_uuid(struct uuid *uuid)
{
	char buf[38];

	snprintf_uuid(buf, sizeof(buf), uuid);
	return (printf("%s", buf));
}

int
sbuf_printf_uuid(struct sbuf *sb, struct uuid *uuid)
{
	char buf[38];

	snprintf_uuid(buf, sizeof(buf), uuid);
	return (sbuf_printf(sb, "%s", buf));
}

/*
 * Encode/Decode UUID into byte-stream.
 *   http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt
 *
 * 0                   1                   2                   3
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                          time_low                             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |       time_mid                |         time_hi_and_version   |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                         node (2-5)                            |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */

void
le_uuid_enc(void *buf, struct uuid const *uuid)
{
	u_char *p;
	int i;

	p = buf;
	le32enc(p, uuid->time_low);
	le16enc(p + 4, uuid->time_mid);
	le16enc(p + 6, uuid->time_hi_and_version);
	p[8] = uuid->clock_seq_hi_and_reserved;
	p[9] = uuid->clock_seq_low;
	for (i = 0; i < _UUID_NODE_LEN; i++)
		p[10 + i] = uuid->node[i];
}

void
le_uuid_dec(void const *buf, struct uuid *uuid)
{
	u_char const *p;
	int i;

	p = buf;
	uuid->time_low = le32dec(p);
	uuid->time_mid = le16dec(p + 4);
	uuid->time_hi_and_version = le16dec(p + 6);
	uuid->clock_seq_hi_and_reserved = p[8];
	uuid->clock_seq_low = p[9];
	for (i = 0; i < _UUID_NODE_LEN; i++)
		uuid->node[i] = p[10 + i];
}

void
be_uuid_enc(void *buf, struct uuid const *uuid)
{
	u_char *p;
	int i;

	p = buf;
	be32enc(p, uuid->time_low);
	be16enc(p + 4, uuid->time_mid);
	be16enc(p + 6, uuid->time_hi_and_version);
	p[8] = uuid->clock_seq_hi_and_reserved;
	p[9] = uuid->clock_seq_low;
	for (i = 0; i < _UUID_NODE_LEN; i++)
		p[10 + i] = uuid->node[i];
}

void
be_uuid_dec(void const *buf, struct uuid *uuid)
{
	u_char const *p;
	int i;

	p = buf;
	uuid->time_low = be32dec(p);
	uuid->time_mid = le16dec(p + 4);
	uuid->time_hi_and_version = be16dec(p + 6);
	uuid->clock_seq_hi_and_reserved = p[8];
	uuid->clock_seq_low = p[9];
	for (i = 0; i < _UUID_NODE_LEN; i++)
		uuid->node[i] = p[10 + i];
}

int
parse_uuid(const char *str, struct uuid *uuid)
{
	u_int c[11];
	int n;

	/* An empty string represents a nil UUID. */
	if (*str == '\0') {
		bzero(uuid, sizeof(*uuid));
		return (0);
	}

	/* The UUID string representation has a fixed length. */
	if (strlen(str) != 36)
		return (EINVAL);

	/*
	 * We only work with "new" UUIDs. New UUIDs have the form:
	 *      01234567-89ab-cdef-0123-456789abcdef
	 * The so called "old" UUIDs, which we don't support, have the form:
	 *      0123456789ab.cd.ef.01.23.45.67.89.ab
	 */
	if (str[8] != '-')
		return (EINVAL);

	n = sscanf(str, "%8x-%4x-%4x-%2x%2x-%2x%2x%2x%2x%2x%2x", c + 0, c + 1,
	    c + 2, c + 3, c + 4, c + 5, c + 6, c + 7, c + 8, c + 9, c + 10);
	/* Make sure we have all conversions. */
	if (n != 11)
		return (EINVAL);

	/* Successful scan. Build the UUID. */
	uuid->time_low = c[0];
	uuid->time_mid = c[1];
	uuid->time_hi_and_version = c[2];
	uuid->clock_seq_hi_and_reserved = c[3];
	uuid->clock_seq_low = c[4];
	for (n = 0; n < 6; n++)
		uuid->node[n] = c[n + 5];

	/* Check semantics... */
	return (((c[3] & 0x80) != 0x00 &&		/* variant 0? */
	    (c[3] & 0xc0) != 0x80 &&			/* variant 1? */
	    (c[3] & 0xe0) != 0xc0) ? EINVAL : 0);	/* variant 2? */
}
OpenPOWER on IntegriCloud