summaryrefslogtreecommitdiffstats
path: root/sys/net/vnet.c
blob: 298ffb28457f108296e6623b568359692d0cd39f (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
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
/*-
 * Copyright (c) 2004-2009 University of Zagreb
 * Copyright (c) 2006-2009 FreeBSD Foundation
 * All rights reserved.
 *
 * This software was developed by the University of Zagreb and the
 * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
 * FreeBSD Foundation.
 *
 * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
 * Copyright (c) 2009 Robert N. M. Watson
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 "opt_ddb.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/jail.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/linker_set.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/sx.h>
#include <sys/sysctl.h>

#ifdef DDB
#include <ddb/ddb.h>
#endif

#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>

/*-
 * This file implements core functions for virtual network stacks:
 *
 * - Virtual network stack management functions.
 *
 * - Virtual network stack memory allocator, which virtualizes global
 *   variables in the network stack
 *
 * - Virtualized SYSINIT's/SYSUNINIT's, which allow network stack subsystems
 *   to register startup/shutdown events to be run for each virtual network
 *   stack instance.
 */

MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");

/*
 * The virtual network stack list has two read-write locks, one sleepable and
 * the other not, so that the list can be stablized and walked in a variety
 * of network stack contexts.  Both must be acquired exclusively to modify
 * the list, but a read lock of either lock is sufficient to walk the list.
 */
struct rwlock		vnet_rwlock;
struct sx		vnet_sxlock;

#define	VNET_LIST_WLOCK() do {						\
	sx_xlock(&vnet_sxlock);						\
	rw_wlock(&vnet_rwlock);						\
} while (0)

#define	VNET_LIST_WUNLOCK() do {					\
	rw_wunlock(&vnet_rwlock);					\
	sx_xunlock(&vnet_sxlock);					\
} while (0)

struct vnet_list_head vnet_head;
struct vnet *vnet0;

/*
 * The virtual network stack allocator provides storage for virtualized
 * global variables.  These variables are defined/declared using the
 * VNET_DEFINE()/VNET_DECLARE() macros, which place them in the 'set_vnet'
 * linker set.  The details of the implementation are somewhat subtle, but
 * allow the majority of most network subsystems to maintain
 * virtualization-agnostic.
 *
 * The virtual network stack allocator handles variables in the base kernel
 * vs. modules in similar but different ways.  In both cases, virtualized
 * global variables are marked as such by being declared to be part of the
 * vnet linker set.  These "master" copies of global variables serve two
 * functions:
 *
 * (1) They contain static initialization or "default" values for global
 *     variables which will be propagated to each virtual network stack
 *     instance when created.  As with normal global variables, they default
 *     to zero-filled.
 *
 * (2) They act as unique global names by which the variable can be referred
 *     to, regardless of network stack instance.  The single global symbol
 *     will be used to calculate the location of a per-virtual instance
 *     variable at run-time.
 *
 * Each virtual network stack instance has a complete copy of each
 * virtualized global variable, stored in a malloc'd block of memory
 * referred to by vnet->vnet_data_mem.  Critical to the design is that each
 * per-instance memory block is laid out identically to the master block so
 * that the offset of each global variable is the same across all blocks.  To
 * optimize run-time access, a precalculated 'base' address,
 * vnet->vnet_data_base, is stored in each vnet, and is the amount that can
 * be added to the address of a 'master' instance of a variable to get to the
 * per-vnet instance.
 *
 * Virtualized global variables are handled in a similar manner, but as each
 * module has its own 'set_vnet' linker set, and we want to keep all
 * virtualized globals togther, we reserve space in the kernel's linker set
 * for potential module variables using a per-vnet character array,
 * 'modspace'.  The virtual network stack allocator maintains a free list to
 * track what space in the array is free (all, initially) and as modules are
 * linked, allocates portions of the space to specific globals.  The kernel
 * module linker queries the virtual network stack allocator and will
 * bind references of the global to the location during linking.  It also
 * calls into the virtual network stack allocator, once the memory is
 * initialized, in order to propagate the new static initializations to all
 * existing virtual network stack instances so that the soon-to-be executing
 * module will find every network stack instance with proper default values.
 */

/*
 * Location of the kernel's 'set_vnet' linker set.
 */
extern uintptr_t	*__start_set_vnet;
extern uintptr_t	*__stop_set_vnet;

#define	VNET_START	(uintptr_t)&__start_set_vnet
#define	VNET_STOP	(uintptr_t)&__stop_set_vnet

/*
 * Number of bytes of data in the 'set_vnet' linker set, and hence the total
 * size of all kernel virtualized global variables, and the malloc(9) type
 * that will be used to allocate it.
 */
#define	VNET_BYTES	(VNET_STOP - VNET_START)

MALLOC_DEFINE(M_VNET_DATA, "vnet_data", "VNET data");

/*
 * VNET_MODMIN is the minimum number of bytes we will reserve for the sum of
 * global variables across all loaded modules.  As this actually sizes an
 * array declared as a virtualized global variable in the kernel itself, and
 * we want the virtualized global variable space to be page-sized, we may
 * have more space than that in practice.
 */
#define	VNET_MODMIN	8192
#define	VNET_SIZE	roundup2(VNET_BYTES, PAGE_SIZE)
#define	VNET_MODSIZE	(VNET_SIZE - (VNET_BYTES - VNET_MODMIN))

/*
 * Space to store virtualized global variables from loadable kernel modules,
 * and the free list to manage it.
 */
static VNET_DEFINE(char, modspace[VNET_MODMIN]);

/*
 * Global lists of subsystem constructor and destructors for vnets.  They are
 * registered via VNET_SYSINIT() and VNET_SYSUNINIT().  Both lists are
 * protected by the vnet_sysinit_sxlock global lock.
 */
static TAILQ_HEAD(vnet_sysinit_head, vnet_sysinit) vnet_constructors =
	TAILQ_HEAD_INITIALIZER(vnet_constructors);
static TAILQ_HEAD(vnet_sysuninit_head, vnet_sysinit) vnet_destructors =
	TAILQ_HEAD_INITIALIZER(vnet_destructors);

struct sx		vnet_sysinit_sxlock;

#define	VNET_SYSINIT_WLOCK()	sx_xlock(&vnet_sysinit_sxlock);
#define	VNET_SYSINIT_WUNLOCK()	sx_xunlock(&vnet_sysinit_sxlock);
#define	VNET_SYSINIT_RLOCK()	sx_slock(&vnet_sysinit_sxlock);
#define	VNET_SYSINIT_RUNLOCK()	sx_sunlock(&vnet_sysinit_sxlock);

struct vnet_data_free {
	uintptr_t	vnd_start;
	int		vnd_len;
	TAILQ_ENTRY(vnet_data_free) vnd_link;
};

MALLOC_DEFINE(M_VNET_DATA_FREE, "vnet_data_free", "VNET resource accounting");
static TAILQ_HEAD(, vnet_data_free) vnet_data_free_head =
	    TAILQ_HEAD_INITIALIZER(vnet_data_free_head);
static struct sx vnet_data_free_lock;

/*
 * Allocate a virtual network stack.
 */
struct vnet *
vnet_alloc(void)
{
	struct vnet *vnet;

	vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
	vnet->vnet_magic_n = VNET_MAGIC_N;

	/*
	 * Allocate storage for virtualized global variables and copy in
	 * initial values form our 'master' copy.
	 */
	vnet->vnet_data_mem = malloc(VNET_SIZE, M_VNET_DATA, M_WAITOK);
	memcpy(vnet->vnet_data_mem, (void *)VNET_START, VNET_BYTES);

	/*
	 * All use of vnet-specific data will immediately subtract VNET_START
	 * from the base memory pointer, so pre-calculate that now to avoid
	 * it on each use.
	 */
	vnet->vnet_data_base = (uintptr_t)vnet->vnet_data_mem - VNET_START;

	/* Initialize / attach vnet module instances. */
	CURVNET_SET_QUIET(vnet);
	vnet_sysinit();
	CURVNET_RESTORE();

	VNET_LIST_WLOCK();
	LIST_INSERT_HEAD(&vnet_head, vnet, vnet_le);
	VNET_LIST_WUNLOCK();

	return (vnet);
}

/*
 * Destroy a virtual network stack.
 */
void
vnet_destroy(struct vnet *vnet)
{
	struct ifnet *ifp, *nifp;

	KASSERT(vnet->vnet_sockcnt == 0,
	    ("%s: vnet still has sockets", __func__));

	VNET_LIST_WLOCK();
	LIST_REMOVE(vnet, vnet_le);
	VNET_LIST_WUNLOCK();

	CURVNET_SET_QUIET(vnet);

	/* Return all inherited interfaces to their parent vnets. */
	TAILQ_FOREACH_SAFE(ifp, &V_ifnet, if_link, nifp) {
		if (ifp->if_home_vnet != ifp->if_vnet)
			if_vmove(ifp, ifp->if_home_vnet);
	}

	vnet_sysuninit();
	CURVNET_RESTORE();

	/*
	 * Release storage for the virtual network stack instance.
	 */
	free(vnet->vnet_data_mem, M_VNET_DATA);
	vnet->vnet_data_mem = NULL;
	vnet->vnet_data_base = 0;
	vnet->vnet_magic_n = 0xdeadbeef;
	free(vnet, M_VNET);
}

/*
 * Boot time initialization and allocation of virtual network stacks.
 */
static void
vnet_init_prelink(void *arg)
{

	rw_init(&vnet_rwlock, "vnet_rwlock");
	sx_init(&vnet_sxlock, "vnet_sxlock");
	sx_init(&vnet_sysinit_sxlock, "vnet_sysinit_sxlock");
	LIST_INIT(&vnet_head);
}
SYSINIT(vnet_init_prelink, SI_SUB_VNET_PRELINK, SI_ORDER_FIRST,
    vnet_init_prelink, NULL);

static void
vnet0_init(void *arg)
{

	/* Warn people before take off - in case we crash early. */
	printf("WARNING: VIMAGE (virtualized network stack) is a highly "
	    "experimental feature.\n");

	/*
	 * We MUST clear curvnet in vi_init_done() before going SMP,
	 * otherwise CURVNET_SET() macros would scream about unnecessary
	 * curvnet recursions.
	 */
	curvnet = prison0.pr_vnet = vnet0 = vnet_alloc();
}
SYSINIT(vnet0_init, SI_SUB_VNET, SI_ORDER_FIRST, vnet0_init, NULL);

static void
vnet_init_done(void *unused)
{

	curvnet = NULL;
}

SYSINIT(vnet_init_done, SI_SUB_VNET_DONE, SI_ORDER_FIRST, vnet_init_done,
    NULL);

/*
 * Once on boot, initialize the modspace freelist to entirely cover modspace.
 */
static void
vnet_data_startup(void *dummy __unused)
{
	struct vnet_data_free *df;

	df = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
	df->vnd_start = (uintptr_t)&VNET_NAME(modspace);
	df->vnd_len = VNET_MODSIZE;
	TAILQ_INSERT_HEAD(&vnet_data_free_head, df, vnd_link);
	sx_init(&vnet_data_free_lock, "vnet_data alloc lock");
}
SYSINIT(vnet_data, SI_SUB_KLD, SI_ORDER_FIRST, vnet_data_startup, 0);

/*
 * When a module is loaded and requires storage for a virtualized global
 * variable, allocate space from the modspace free list.  This interface
 * should be used only by the kernel linker.
 */
void *
vnet_data_alloc(int size)
{
	struct vnet_data_free *df;
	void *s;

	s = NULL;
	size = roundup2(size, sizeof(void *));
	sx_xlock(&vnet_data_free_lock);
	TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
		if (df->vnd_len < size)
			continue;
		if (df->vnd_len == size) {
			s = (void *)df->vnd_start;
			TAILQ_REMOVE(&vnet_data_free_head, df, vnd_link);
			free(df, M_VNET_DATA_FREE);
			break;
		}
		s = (void *)df->vnd_start;
		df->vnd_len -= size;
		df->vnd_start = df->vnd_start + size;
		break;
	}
	sx_xunlock(&vnet_data_free_lock);

	return (s);
}

/*
 * Free space for a virtualized global variable on module unload.
 */
void
vnet_data_free(void *start_arg, int size)
{
	struct vnet_data_free *df;
	struct vnet_data_free *dn;
	uintptr_t start;
	uintptr_t end;

	size = roundup2(size, sizeof(void *));
	start = (uintptr_t)start_arg;
	end = start + size;
	/*
	 * Free a region of space and merge it with as many neighbors as
	 * possible.  Keeping the list sorted simplifies this operation.
	 */
	sx_xlock(&vnet_data_free_lock);
	TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
		if (df->vnd_start > end)
			break;
		/*
		 * If we expand at the end of an entry we may have to merge
		 * it with the one following it as well.
		 */
		if (df->vnd_start + df->vnd_len == start) {
			df->vnd_len += size;
			dn = TAILQ_NEXT(df, vnd_link);
			if (df->vnd_start + df->vnd_len == dn->vnd_start) {
				df->vnd_len += dn->vnd_len;
				TAILQ_REMOVE(&vnet_data_free_head, dn,
				    vnd_link);
				free(dn, M_VNET_DATA_FREE);
			}
			sx_xunlock(&vnet_data_free_lock);
			return;
		}
		if (df->vnd_start == end) {
			df->vnd_start = start;
			df->vnd_len += size;
			sx_xunlock(&vnet_data_free_lock);
			return;
		}
	}
	dn = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
	dn->vnd_start = start;
	dn->vnd_len = size;
	if (df)
		TAILQ_INSERT_BEFORE(df, dn, vnd_link);
	else
		TAILQ_INSERT_TAIL(&vnet_data_free_head, dn, vnd_link);
	sx_xunlock(&vnet_data_free_lock);
}

/*
 * When a new virtualized global variable has been allocated, propagate its
 * initial value to each already-allocated virtual network stack instance.
 */
void
vnet_data_copy(void *start, int size)
{
	struct vnet *vnet;

	VNET_LIST_RLOCK();
	LIST_FOREACH(vnet, &vnet_head, vnet_le)
		memcpy((void *)((uintptr_t)vnet->vnet_data_base +
		    (uintptr_t)start), start, size);
	VNET_LIST_RUNLOCK();
}

/*
 * Variants on sysctl_handle_foo that know how to handle virtualized global
 * variables: if 'arg1' is a pointer, then we transform it to the local vnet
 * offset.
 */
int
vnet_sysctl_handle_int(SYSCTL_HANDLER_ARGS)
{

	if (arg1 != NULL)
		arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
	return (sysctl_handle_int(oidp, arg1, arg2, req));
}

int
vnet_sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
{

	if (arg1 != NULL)
		arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
	return (sysctl_handle_opaque(oidp, arg1, arg2, req));
}

int
vnet_sysctl_handle_string(SYSCTL_HANDLER_ARGS)
{

	if (arg1 != NULL)
		arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
	return (sysctl_handle_string(oidp, arg1, arg2, req));
}

int
vnet_sysctl_handle_uint(SYSCTL_HANDLER_ARGS)
{

	if (arg1 != NULL)
		arg1 = (void *)(curvnet->vnet_data_base + (uintptr_t)arg1);
	return (sysctl_handle_int(oidp, arg1, arg2, req));
}

/*
 * Support for special SYSINIT handlers registered via VNET_SYSINIT()
 * and VNET_SYSUNINIT().
 */
void
vnet_register_sysinit(void *arg)
{
	struct vnet_sysinit *vs, *vs2;	
	struct vnet *vnet;

	vs = arg;
	KASSERT(vs->subsystem > SI_SUB_VNET, ("vnet sysinit too early"));

	/* Add the constructor to the global list of vnet constructors. */
	VNET_SYSINIT_WLOCK();
	TAILQ_FOREACH(vs2, &vnet_constructors, link) {
		if (vs2->subsystem > vs->subsystem)
			break;
		if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
			break;
	}
	if (vs2 != NULL)
		TAILQ_INSERT_BEFORE(vs2, vs, link);
	else
		TAILQ_INSERT_TAIL(&vnet_constructors, vs, link);

	/*
	 * Invoke the constructor on all the existing vnets when it is
	 * registered.
	 */
	VNET_FOREACH(vnet) {
		CURVNET_SET_QUIET(vnet);
		vs->func(vs->arg);
		CURVNET_RESTORE();
	}
	VNET_SYSINIT_WUNLOCK();
}

void
vnet_deregister_sysinit(void *arg)
{
	struct vnet_sysinit *vs;

	vs = arg;

	/* Remove the constructor from the global list of vnet constructors. */
	VNET_SYSINIT_WLOCK();
	TAILQ_REMOVE(&vnet_constructors, vs, link);
	VNET_SYSINIT_WUNLOCK();
}

void
vnet_register_sysuninit(void *arg)
{
	struct vnet_sysinit *vs, *vs2;

	vs = arg;

	/* Add the destructor to the global list of vnet destructors. */
	VNET_SYSINIT_WLOCK();
	TAILQ_FOREACH(vs2, &vnet_destructors, link) {
		if (vs2->subsystem > vs->subsystem)
			break;
		if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
			break;
	}
	if (vs2 != NULL)
		TAILQ_INSERT_BEFORE(vs2, vs, link);
	else
		TAILQ_INSERT_TAIL(&vnet_destructors, vs, link);
	VNET_SYSINIT_WUNLOCK();
}

void
vnet_deregister_sysuninit(void *arg)
{
	struct vnet_sysinit *vs;
	struct vnet *vnet;

	vs = arg;

	/*
	 * Invoke the destructor on all the existing vnets when it is
	 * deregistered.
	 */
	VNET_SYSINIT_WLOCK();
	VNET_FOREACH(vnet) {
		CURVNET_SET_QUIET(vnet);
		vs->func(vs->arg);
		CURVNET_RESTORE();
	}

	/* Remove the destructor from the global list of vnet destructors. */
	TAILQ_REMOVE(&vnet_destructors, vs, link);
	VNET_SYSINIT_WUNLOCK();
}

/*
 * Invoke all registered vnet constructors on the current vnet.  Used during
 * vnet construction.  The caller is responsible for ensuring the new vnet is
 * the current vnet and that the vnet_sysinit_sxlock lock is locked.
 */
void
vnet_sysinit(void)
{
	struct vnet_sysinit *vs;

	VNET_SYSINIT_RLOCK();
	TAILQ_FOREACH(vs, &vnet_constructors, link) {
		vs->func(vs->arg);
	}
	VNET_SYSINIT_RUNLOCK();
}

/*
 * Invoke all registered vnet destructors on the current vnet.  Used during
 * vnet destruction.  The caller is responsible for ensuring the dying vnet
 * the current vnet and that the vnet_sysinit_sxlock lock is locked.
 */
void
vnet_sysuninit(void)
{
	struct vnet_sysinit *vs;

	VNET_SYSINIT_RLOCK();
	TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
	    link) {
		vs->func(vs->arg);
	}
	VNET_SYSINIT_RUNLOCK();
}

#ifdef DDB
DB_SHOW_COMMAND(vnets, db_show_vnets)
{
	VNET_ITERATOR_DECL(vnet_iter);

	VNET_FOREACH(vnet_iter) {
		db_printf("vnet            = %p\n", vnet_iter);
		db_printf(" vnet_magic_n   = 0x%x (%s, orig 0x%x)\n",
		    vnet_iter->vnet_magic_n,
		    (vnet_iter->vnet_magic_n == VNET_MAGIC_N) ?
			"ok" : "mismatch", VNET_MAGIC_N);
		db_printf(" vnet_ifcnt     = %u\n", vnet_iter->vnet_ifcnt);
		db_printf(" vnet_sockcnt   = %u\n", vnet_iter->vnet_sockcnt);
		db_printf(" vnet_data_mem  = %p\n", vnet_iter->vnet_data_mem);
		db_printf(" vnet_data_base = 0x%jx\n",
		    (uintmax_t)vnet_iter->vnet_data_base);
		db_printf("\n");
		if (db_pager_quit)
			break;
	}
}
#endif
OpenPOWER on IntegriCloud