xref: /freebsd/sys/net/vnet.c (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
1 /*-
2  * Copyright (c) 2004-2009 University of Zagreb
3  * Copyright (c) 2006-2009 FreeBSD Foundation
4  * All rights reserved.
5  *
6  * This software was developed by the University of Zagreb and the
7  * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
8  * FreeBSD Foundation.
9  *
10  * Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
11  * Copyright (c) 2009 Robert N. M. Watson
12  * All rights reserved.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "opt_ddb.h"
40 #include "opt_kdb.h"
41 
42 #include <sys/param.h>
43 #include <sys/kdb.h>
44 #include <sys/kernel.h>
45 #include <sys/jail.h>
46 #include <sys/sdt.h>
47 #include <sys/systm.h>
48 #include <sys/sysctl.h>
49 #include <sys/eventhandler.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/proc.h>
53 #include <sys/socket.h>
54 #include <sys/sx.h>
55 #include <sys/sysctl.h>
56 
57 #include <machine/stdarg.h>
58 
59 #ifdef DDB
60 #include <ddb/ddb.h>
61 #include <ddb/db_sym.h>
62 #endif
63 
64 #include <net/if.h>
65 #include <net/if_var.h>
66 #include <net/vnet.h>
67 
68 /*-
69  * This file implements core functions for virtual network stacks:
70  *
71  * - Virtual network stack management functions.
72  *
73  * - Virtual network stack memory allocator, which virtualizes global
74  *   variables in the network stack
75  *
76  * - Virtualized SYSINIT's/SYSUNINIT's, which allow network stack subsystems
77  *   to register startup/shutdown events to be run for each virtual network
78  *   stack instance.
79  */
80 
81 FEATURE(vimage, "VIMAGE kernel virtualization");
82 
83 static MALLOC_DEFINE(M_VNET, "vnet", "network stack control block");
84 
85 /*
86  * The virtual network stack list has two read-write locks, one sleepable and
87  * the other not, so that the list can be stablized and walked in a variety
88  * of network stack contexts.  Both must be acquired exclusively to modify
89  * the list, but a read lock of either lock is sufficient to walk the list.
90  */
91 struct rwlock		vnet_rwlock;
92 struct sx		vnet_sxlock;
93 
94 #define	VNET_LIST_WLOCK() do {						\
95 	sx_xlock(&vnet_sxlock);						\
96 	rw_wlock(&vnet_rwlock);						\
97 } while (0)
98 
99 #define	VNET_LIST_WUNLOCK() do {					\
100 	rw_wunlock(&vnet_rwlock);					\
101 	sx_xunlock(&vnet_sxlock);					\
102 } while (0)
103 
104 struct vnet_list_head vnet_head;
105 struct vnet *vnet0;
106 
107 /*
108  * The virtual network stack allocator provides storage for virtualized
109  * global variables.  These variables are defined/declared using the
110  * VNET_DEFINE()/VNET_DECLARE() macros, which place them in the 'set_vnet'
111  * linker set.  The details of the implementation are somewhat subtle, but
112  * allow the majority of most network subsystems to maintain
113  * virtualization-agnostic.
114  *
115  * The virtual network stack allocator handles variables in the base kernel
116  * vs. modules in similar but different ways.  In both cases, virtualized
117  * global variables are marked as such by being declared to be part of the
118  * vnet linker set.  These "master" copies of global variables serve two
119  * functions:
120  *
121  * (1) They contain static initialization or "default" values for global
122  *     variables which will be propagated to each virtual network stack
123  *     instance when created.  As with normal global variables, they default
124  *     to zero-filled.
125  *
126  * (2) They act as unique global names by which the variable can be referred
127  *     to, regardless of network stack instance.  The single global symbol
128  *     will be used to calculate the location of a per-virtual instance
129  *     variable at run-time.
130  *
131  * Each virtual network stack instance has a complete copy of each
132  * virtualized global variable, stored in a malloc'd block of memory
133  * referred to by vnet->vnet_data_mem.  Critical to the design is that each
134  * per-instance memory block is laid out identically to the master block so
135  * that the offset of each global variable is the same across all blocks.  To
136  * optimize run-time access, a precalculated 'base' address,
137  * vnet->vnet_data_base, is stored in each vnet, and is the amount that can
138  * be added to the address of a 'master' instance of a variable to get to the
139  * per-vnet instance.
140  *
141  * Virtualized global variables are handled in a similar manner, but as each
142  * module has its own 'set_vnet' linker set, and we want to keep all
143  * virtualized globals togther, we reserve space in the kernel's linker set
144  * for potential module variables using a per-vnet character array,
145  * 'modspace'.  The virtual network stack allocator maintains a free list to
146  * track what space in the array is free (all, initially) and as modules are
147  * linked, allocates portions of the space to specific globals.  The kernel
148  * module linker queries the virtual network stack allocator and will
149  * bind references of the global to the location during linking.  It also
150  * calls into the virtual network stack allocator, once the memory is
151  * initialized, in order to propagate the new static initializations to all
152  * existing virtual network stack instances so that the soon-to-be executing
153  * module will find every network stack instance with proper default values.
154  */
155 
156 /*
157  * Number of bytes of data in the 'set_vnet' linker set, and hence the total
158  * size of all kernel virtualized global variables, and the malloc(9) type
159  * that will be used to allocate it.
160  */
161 #define	VNET_BYTES	(VNET_STOP - VNET_START)
162 
163 static MALLOC_DEFINE(M_VNET_DATA, "vnet_data", "VNET data");
164 
165 /*
166  * VNET_MODMIN is the minimum number of bytes we will reserve for the sum of
167  * global variables across all loaded modules.  As this actually sizes an
168  * array declared as a virtualized global variable in the kernel itself, and
169  * we want the virtualized global variable space to be page-sized, we may
170  * have more space than that in practice.
171  */
172 #define	VNET_MODMIN	8192
173 #define	VNET_SIZE	roundup2(VNET_BYTES, PAGE_SIZE)
174 
175 /*
176  * Space to store virtualized global variables from loadable kernel modules,
177  * and the free list to manage it.
178  */
179 static VNET_DEFINE(char, modspace[VNET_MODMIN]);
180 
181 /*
182  * Global lists of subsystem constructor and destructors for vnets.  They are
183  * registered via VNET_SYSINIT() and VNET_SYSUNINIT().  Both lists are
184  * protected by the vnet_sysinit_sxlock global lock.
185  */
186 static TAILQ_HEAD(vnet_sysinit_head, vnet_sysinit) vnet_constructors =
187 	TAILQ_HEAD_INITIALIZER(vnet_constructors);
188 static TAILQ_HEAD(vnet_sysuninit_head, vnet_sysinit) vnet_destructors =
189 	TAILQ_HEAD_INITIALIZER(vnet_destructors);
190 
191 struct sx		vnet_sysinit_sxlock;
192 
193 #define	VNET_SYSINIT_WLOCK()	sx_xlock(&vnet_sysinit_sxlock);
194 #define	VNET_SYSINIT_WUNLOCK()	sx_xunlock(&vnet_sysinit_sxlock);
195 #define	VNET_SYSINIT_RLOCK()	sx_slock(&vnet_sysinit_sxlock);
196 #define	VNET_SYSINIT_RUNLOCK()	sx_sunlock(&vnet_sysinit_sxlock);
197 
198 struct vnet_data_free {
199 	uintptr_t	vnd_start;
200 	int		vnd_len;
201 	TAILQ_ENTRY(vnet_data_free) vnd_link;
202 };
203 
204 static MALLOC_DEFINE(M_VNET_DATA_FREE, "vnet_data_free",
205     "VNET resource accounting");
206 static TAILQ_HEAD(, vnet_data_free) vnet_data_free_head =
207 	    TAILQ_HEAD_INITIALIZER(vnet_data_free_head);
208 static struct sx vnet_data_free_lock;
209 
210 SDT_PROVIDER_DEFINE(vnet);
211 SDT_PROBE_DEFINE1(vnet, functions, vnet_alloc, entry, "int");
212 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, alloc, "int",
213     "struct vnet *");
214 SDT_PROBE_DEFINE2(vnet, functions, vnet_alloc, return,
215     "int", "struct vnet *");
216 SDT_PROBE_DEFINE2(vnet, functions, vnet_destroy, entry,
217     "int", "struct vnet *");
218 SDT_PROBE_DEFINE1(vnet, functions, vnet_destroy, return,
219     "int");
220 
221 #ifdef DDB
222 static void db_show_vnet_print_vs(struct vnet_sysinit *, int);
223 #endif
224 
225 /*
226  * Allocate a virtual network stack.
227  */
228 struct vnet *
229 vnet_alloc(void)
230 {
231 	struct vnet *vnet;
232 
233 	SDT_PROBE1(vnet, functions, vnet_alloc, entry, __LINE__);
234 	vnet = malloc(sizeof(struct vnet), M_VNET, M_WAITOK | M_ZERO);
235 	vnet->vnet_magic_n = VNET_MAGIC_N;
236 	vnet->vnet_state = 0;
237 	SDT_PROBE2(vnet, functions, vnet_alloc, alloc, __LINE__, vnet);
238 
239 	/*
240 	 * Allocate storage for virtualized global variables and copy in
241 	 * initial values form our 'master' copy.
242 	 */
243 	vnet->vnet_data_mem = malloc(VNET_SIZE, M_VNET_DATA, M_WAITOK);
244 	memcpy(vnet->vnet_data_mem, (void *)VNET_START, VNET_BYTES);
245 
246 	/*
247 	 * All use of vnet-specific data will immediately subtract VNET_START
248 	 * from the base memory pointer, so pre-calculate that now to avoid
249 	 * it on each use.
250 	 */
251 	vnet->vnet_data_base = (uintptr_t)vnet->vnet_data_mem - VNET_START;
252 
253 	/* Initialize / attach vnet module instances. */
254 	CURVNET_SET_QUIET(vnet);
255 	vnet_sysinit();
256 	CURVNET_RESTORE();
257 
258 	VNET_LIST_WLOCK();
259 	LIST_INSERT_HEAD(&vnet_head, vnet, vnet_le);
260 	VNET_LIST_WUNLOCK();
261 
262 	SDT_PROBE2(vnet, functions, vnet_alloc, return, __LINE__, vnet);
263 	return (vnet);
264 }
265 
266 /*
267  * Destroy a virtual network stack.
268  */
269 void
270 vnet_destroy(struct vnet *vnet)
271 {
272 
273 	SDT_PROBE2(vnet, functions, vnet_destroy, entry, __LINE__, vnet);
274 	KASSERT(vnet->vnet_sockcnt == 0,
275 	    ("%s: vnet still has sockets", __func__));
276 
277 	VNET_LIST_WLOCK();
278 	LIST_REMOVE(vnet, vnet_le);
279 	VNET_LIST_WUNLOCK();
280 
281 	CURVNET_SET_QUIET(vnet);
282 	vnet_sysuninit();
283 	CURVNET_RESTORE();
284 
285 	/*
286 	 * Release storage for the virtual network stack instance.
287 	 */
288 	free(vnet->vnet_data_mem, M_VNET_DATA);
289 	vnet->vnet_data_mem = NULL;
290 	vnet->vnet_data_base = 0;
291 	vnet->vnet_magic_n = 0xdeadbeef;
292 	free(vnet, M_VNET);
293 	SDT_PROBE1(vnet, functions, vnet_destroy, return, __LINE__);
294 }
295 
296 /*
297  * Boot time initialization and allocation of virtual network stacks.
298  */
299 static void
300 vnet_init_prelink(void *arg __unused)
301 {
302 
303 	rw_init(&vnet_rwlock, "vnet_rwlock");
304 	sx_init(&vnet_sxlock, "vnet_sxlock");
305 	sx_init(&vnet_sysinit_sxlock, "vnet_sysinit_sxlock");
306 	LIST_INIT(&vnet_head);
307 }
308 SYSINIT(vnet_init_prelink, SI_SUB_VNET_PRELINK, SI_ORDER_FIRST,
309     vnet_init_prelink, NULL);
310 
311 static void
312 vnet0_init(void *arg __unused)
313 {
314 
315 	/* Warn people before take off - in case we crash early. */
316 	printf("WARNING: VIMAGE (virtualized network stack) is a highly "
317 	    "experimental feature.\n");
318 
319 	/*
320 	 * We MUST clear curvnet in vi_init_done() before going SMP,
321 	 * otherwise CURVNET_SET() macros would scream about unnecessary
322 	 * curvnet recursions.
323 	 */
324 	curvnet = prison0.pr_vnet = vnet0 = vnet_alloc();
325 }
326 SYSINIT(vnet0_init, SI_SUB_VNET, SI_ORDER_FIRST, vnet0_init, NULL);
327 
328 static void
329 vnet_init_done(void *unused __unused)
330 {
331 
332 	curvnet = NULL;
333 }
334 SYSINIT(vnet_init_done, SI_SUB_VNET_DONE, SI_ORDER_ANY, vnet_init_done,
335     NULL);
336 
337 /*
338  * Once on boot, initialize the modspace freelist to entirely cover modspace.
339  */
340 static void
341 vnet_data_startup(void *dummy __unused)
342 {
343 	struct vnet_data_free *df;
344 
345 	df = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
346 	df->vnd_start = (uintptr_t)&VNET_NAME(modspace);
347 	df->vnd_len = VNET_MODMIN;
348 	TAILQ_INSERT_HEAD(&vnet_data_free_head, df, vnd_link);
349 	sx_init(&vnet_data_free_lock, "vnet_data alloc lock");
350 }
351 SYSINIT(vnet_data, SI_SUB_KLD, SI_ORDER_FIRST, vnet_data_startup, 0);
352 
353 /* Dummy VNET_SYSINIT to make sure we always reach the final end state. */
354 static void
355 vnet_sysinit_done(void *unused __unused)
356 {
357 
358 	return;
359 }
360 VNET_SYSINIT(vnet_sysinit_done, SI_SUB_VNET_DONE, SI_ORDER_ANY,
361     vnet_sysinit_done, NULL);
362 
363 /*
364  * When a module is loaded and requires storage for a virtualized global
365  * variable, allocate space from the modspace free list.  This interface
366  * should be used only by the kernel linker.
367  */
368 void *
369 vnet_data_alloc(int size)
370 {
371 	struct vnet_data_free *df;
372 	void *s;
373 
374 	s = NULL;
375 	size = roundup2(size, sizeof(void *));
376 	sx_xlock(&vnet_data_free_lock);
377 	TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
378 		if (df->vnd_len < size)
379 			continue;
380 		if (df->vnd_len == size) {
381 			s = (void *)df->vnd_start;
382 			TAILQ_REMOVE(&vnet_data_free_head, df, vnd_link);
383 			free(df, M_VNET_DATA_FREE);
384 			break;
385 		}
386 		s = (void *)df->vnd_start;
387 		df->vnd_len -= size;
388 		df->vnd_start = df->vnd_start + size;
389 		break;
390 	}
391 	sx_xunlock(&vnet_data_free_lock);
392 
393 	return (s);
394 }
395 
396 /*
397  * Free space for a virtualized global variable on module unload.
398  */
399 void
400 vnet_data_free(void *start_arg, int size)
401 {
402 	struct vnet_data_free *df;
403 	struct vnet_data_free *dn;
404 	uintptr_t start;
405 	uintptr_t end;
406 
407 	size = roundup2(size, sizeof(void *));
408 	start = (uintptr_t)start_arg;
409 	end = start + size;
410 	/*
411 	 * Free a region of space and merge it with as many neighbors as
412 	 * possible.  Keeping the list sorted simplifies this operation.
413 	 */
414 	sx_xlock(&vnet_data_free_lock);
415 	TAILQ_FOREACH(df, &vnet_data_free_head, vnd_link) {
416 		if (df->vnd_start > end)
417 			break;
418 		/*
419 		 * If we expand at the end of an entry we may have to merge
420 		 * it with the one following it as well.
421 		 */
422 		if (df->vnd_start + df->vnd_len == start) {
423 			df->vnd_len += size;
424 			dn = TAILQ_NEXT(df, vnd_link);
425 			if (df->vnd_start + df->vnd_len == dn->vnd_start) {
426 				df->vnd_len += dn->vnd_len;
427 				TAILQ_REMOVE(&vnet_data_free_head, dn,
428 				    vnd_link);
429 				free(dn, M_VNET_DATA_FREE);
430 			}
431 			sx_xunlock(&vnet_data_free_lock);
432 			return;
433 		}
434 		if (df->vnd_start == end) {
435 			df->vnd_start = start;
436 			df->vnd_len += size;
437 			sx_xunlock(&vnet_data_free_lock);
438 			return;
439 		}
440 	}
441 	dn = malloc(sizeof(*df), M_VNET_DATA_FREE, M_WAITOK | M_ZERO);
442 	dn->vnd_start = start;
443 	dn->vnd_len = size;
444 	if (df)
445 		TAILQ_INSERT_BEFORE(df, dn, vnd_link);
446 	else
447 		TAILQ_INSERT_TAIL(&vnet_data_free_head, dn, vnd_link);
448 	sx_xunlock(&vnet_data_free_lock);
449 }
450 
451 /*
452  * When a new virtualized global variable has been allocated, propagate its
453  * initial value to each already-allocated virtual network stack instance.
454  */
455 void
456 vnet_data_copy(void *start, int size)
457 {
458 	struct vnet *vnet;
459 
460 	VNET_LIST_RLOCK();
461 	LIST_FOREACH(vnet, &vnet_head, vnet_le)
462 		memcpy((void *)((uintptr_t)vnet->vnet_data_base +
463 		    (uintptr_t)start), start, size);
464 	VNET_LIST_RUNLOCK();
465 }
466 
467 /*
468  * Support for special SYSINIT handlers registered via VNET_SYSINIT()
469  * and VNET_SYSUNINIT().
470  */
471 void
472 vnet_register_sysinit(void *arg)
473 {
474 	struct vnet_sysinit *vs, *vs2;
475 	struct vnet *vnet;
476 
477 	vs = arg;
478 	KASSERT(vs->subsystem > SI_SUB_VNET, ("vnet sysinit too early"));
479 
480 	/* Add the constructor to the global list of vnet constructors. */
481 	VNET_SYSINIT_WLOCK();
482 	TAILQ_FOREACH(vs2, &vnet_constructors, link) {
483 		if (vs2->subsystem > vs->subsystem)
484 			break;
485 		if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
486 			break;
487 	}
488 	if (vs2 != NULL)
489 		TAILQ_INSERT_BEFORE(vs2, vs, link);
490 	else
491 		TAILQ_INSERT_TAIL(&vnet_constructors, vs, link);
492 
493 	/*
494 	 * Invoke the constructor on all the existing vnets when it is
495 	 * registered.
496 	 */
497 	VNET_FOREACH(vnet) {
498 		CURVNET_SET_QUIET(vnet);
499 		vs->func(vs->arg);
500 		CURVNET_RESTORE();
501 	}
502 	VNET_SYSINIT_WUNLOCK();
503 }
504 
505 void
506 vnet_deregister_sysinit(void *arg)
507 {
508 	struct vnet_sysinit *vs;
509 
510 	vs = arg;
511 
512 	/* Remove the constructor from the global list of vnet constructors. */
513 	VNET_SYSINIT_WLOCK();
514 	TAILQ_REMOVE(&vnet_constructors, vs, link);
515 	VNET_SYSINIT_WUNLOCK();
516 }
517 
518 void
519 vnet_register_sysuninit(void *arg)
520 {
521 	struct vnet_sysinit *vs, *vs2;
522 
523 	vs = arg;
524 
525 	/* Add the destructor to the global list of vnet destructors. */
526 	VNET_SYSINIT_WLOCK();
527 	TAILQ_FOREACH(vs2, &vnet_destructors, link) {
528 		if (vs2->subsystem > vs->subsystem)
529 			break;
530 		if (vs2->subsystem == vs->subsystem && vs2->order > vs->order)
531 			break;
532 	}
533 	if (vs2 != NULL)
534 		TAILQ_INSERT_BEFORE(vs2, vs, link);
535 	else
536 		TAILQ_INSERT_TAIL(&vnet_destructors, vs, link);
537 	VNET_SYSINIT_WUNLOCK();
538 }
539 
540 void
541 vnet_deregister_sysuninit(void *arg)
542 {
543 	struct vnet_sysinit *vs;
544 	struct vnet *vnet;
545 
546 	vs = arg;
547 
548 	/*
549 	 * Invoke the destructor on all the existing vnets when it is
550 	 * deregistered.
551 	 */
552 	VNET_SYSINIT_WLOCK();
553 	VNET_FOREACH(vnet) {
554 		CURVNET_SET_QUIET(vnet);
555 		vs->func(vs->arg);
556 		CURVNET_RESTORE();
557 	}
558 
559 	/* Remove the destructor from the global list of vnet destructors. */
560 	TAILQ_REMOVE(&vnet_destructors, vs, link);
561 	VNET_SYSINIT_WUNLOCK();
562 }
563 
564 /*
565  * Invoke all registered vnet constructors on the current vnet.  Used during
566  * vnet construction.  The caller is responsible for ensuring the new vnet is
567  * the current vnet and that the vnet_sysinit_sxlock lock is locked.
568  */
569 void
570 vnet_sysinit(void)
571 {
572 	struct vnet_sysinit *vs;
573 
574 	VNET_SYSINIT_RLOCK();
575 	TAILQ_FOREACH(vs, &vnet_constructors, link) {
576 		curvnet->vnet_state = vs->subsystem;
577 		vs->func(vs->arg);
578 	}
579 	VNET_SYSINIT_RUNLOCK();
580 }
581 
582 /*
583  * Invoke all registered vnet destructors on the current vnet.  Used during
584  * vnet destruction.  The caller is responsible for ensuring the dying vnet
585  * the current vnet and that the vnet_sysinit_sxlock lock is locked.
586  */
587 void
588 vnet_sysuninit(void)
589 {
590 	struct vnet_sysinit *vs;
591 
592 	VNET_SYSINIT_RLOCK();
593 	TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
594 	    link) {
595 		curvnet->vnet_state = vs->subsystem;
596 		vs->func(vs->arg);
597 	}
598 	VNET_SYSINIT_RUNLOCK();
599 }
600 
601 /*
602  * EVENTHANDLER(9) extensions.
603  */
604 /*
605  * Invoke the eventhandler function originally registered with the possibly
606  * registered argument for all virtual network stack instances.
607  *
608  * This iterator can only be used for eventhandlers that do not take any
609  * additional arguments, as we do ignore the variadic arguments from the
610  * EVENTHANDLER_INVOKE() call.
611  */
612 void
613 vnet_global_eventhandler_iterator_func(void *arg, ...)
614 {
615 	VNET_ITERATOR_DECL(vnet_iter);
616 	struct eventhandler_entry_vimage *v_ee;
617 
618 	/*
619 	 * There is a bug here in that we should actually cast things to
620 	 * (struct eventhandler_entry_ ## name *)  but that's not easily
621 	 * possible in here so just re-using the variadic version we
622 	 * defined for the generic vimage case.
623 	 */
624 	v_ee = arg;
625 	VNET_LIST_RLOCK();
626 	VNET_FOREACH(vnet_iter) {
627 		CURVNET_SET(vnet_iter);
628 		((vimage_iterator_func_t)v_ee->func)(v_ee->ee_arg);
629 		CURVNET_RESTORE();
630 	}
631 	VNET_LIST_RUNLOCK();
632 }
633 
634 #ifdef VNET_DEBUG
635 struct vnet_recursion {
636 	SLIST_ENTRY(vnet_recursion)	 vnr_le;
637 	const char			*prev_fn;
638 	const char			*where_fn;
639 	int				 where_line;
640 	struct vnet			*old_vnet;
641 	struct vnet			*new_vnet;
642 };
643 
644 static SLIST_HEAD(, vnet_recursion) vnet_recursions =
645     SLIST_HEAD_INITIALIZER(vnet_recursions);
646 
647 static void
648 vnet_print_recursion(struct vnet_recursion *vnr, int brief)
649 {
650 
651 	if (!brief)
652 		printf("CURVNET_SET() recursion in ");
653 	printf("%s() line %d, prev in %s()", vnr->where_fn, vnr->where_line,
654 	    vnr->prev_fn);
655 	if (brief)
656 		printf(", ");
657 	else
658 		printf("\n    ");
659 	printf("%p -> %p\n", vnr->old_vnet, vnr->new_vnet);
660 }
661 
662 void
663 vnet_log_recursion(struct vnet *old_vnet, const char *old_fn, int line)
664 {
665 	struct vnet_recursion *vnr;
666 
667 	/* Skip already logged recursion events. */
668 	SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
669 		if (vnr->prev_fn == old_fn &&
670 		    vnr->where_fn == curthread->td_vnet_lpush &&
671 		    vnr->where_line == line &&
672 		    (vnr->old_vnet == vnr->new_vnet) == (curvnet == old_vnet))
673 			return;
674 
675 	vnr = malloc(sizeof(*vnr), M_VNET, M_NOWAIT | M_ZERO);
676 	if (vnr == NULL)
677 		panic("%s: malloc failed", __func__);
678 	vnr->prev_fn = old_fn;
679 	vnr->where_fn = curthread->td_vnet_lpush;
680 	vnr->where_line = line;
681 	vnr->old_vnet = old_vnet;
682 	vnr->new_vnet = curvnet;
683 
684 	SLIST_INSERT_HEAD(&vnet_recursions, vnr, vnr_le);
685 
686 	vnet_print_recursion(vnr, 0);
687 #ifdef KDB
688 	kdb_backtrace();
689 #endif
690 }
691 #endif /* VNET_DEBUG */
692 
693 /*
694  * DDB(4).
695  */
696 #ifdef DDB
697 static void
698 db_vnet_print(struct vnet *vnet)
699 {
700 
701 	db_printf("vnet            = %p\n", vnet);
702 	db_printf(" vnet_magic_n   = %#08x (%s, orig %#08x)\n",
703 	    vnet->vnet_magic_n,
704 	    (vnet->vnet_magic_n == VNET_MAGIC_N) ?
705 		"ok" : "mismatch", VNET_MAGIC_N);
706 	db_printf(" vnet_ifcnt     = %u\n", vnet->vnet_ifcnt);
707 	db_printf(" vnet_sockcnt   = %u\n", vnet->vnet_sockcnt);
708 	db_printf(" vnet_data_mem  = %p\n", vnet->vnet_data_mem);
709 	db_printf(" vnet_data_base = %#jx\n",
710 	    (uintmax_t)vnet->vnet_data_base);
711 	db_printf(" vnet_state     = %#08x\n", vnet->vnet_state);
712 	db_printf("\n");
713 }
714 
715 DB_SHOW_ALL_COMMAND(vnets, db_show_all_vnets)
716 {
717 	VNET_ITERATOR_DECL(vnet_iter);
718 
719 	VNET_FOREACH(vnet_iter) {
720 		db_vnet_print(vnet_iter);
721 		if (db_pager_quit)
722 			break;
723 	}
724 }
725 
726 DB_SHOW_COMMAND(vnet, db_show_vnet)
727 {
728 
729 	if (!have_addr) {
730 		db_printf("usage: show vnet <struct vnet *>\n");
731 		return;
732 	}
733 
734 	db_vnet_print((struct vnet *)addr);
735 }
736 
737 static void
738 db_show_vnet_print_vs(struct vnet_sysinit *vs, int ddb)
739 {
740 	const char *vsname, *funcname;
741 	c_db_sym_t sym;
742 	db_expr_t  offset;
743 
744 #define xprint(...)							\
745 	if (ddb)							\
746 		db_printf(__VA_ARGS__);					\
747 	else								\
748 		printf(__VA_ARGS__)
749 
750 	if (vs == NULL) {
751 		xprint("%s: no vnet_sysinit * given\n", __func__);
752 		return;
753 	}
754 
755 	sym = db_search_symbol((vm_offset_t)vs, DB_STGY_ANY, &offset);
756 	db_symbol_values(sym, &vsname, NULL);
757 	sym = db_search_symbol((vm_offset_t)vs->func, DB_STGY_PROC, &offset);
758 	db_symbol_values(sym, &funcname, NULL);
759 	xprint("%s(%p)\n", (vsname != NULL) ? vsname : "", vs);
760 	xprint("  %#08x %#08x\n", vs->subsystem, vs->order);
761 	xprint("  %p(%s)(%p)\n",
762 	    vs->func, (funcname != NULL) ? funcname : "", vs->arg);
763 #undef xprint
764 }
765 
766 DB_SHOW_COMMAND(vnet_sysinit, db_show_vnet_sysinit)
767 {
768 	struct vnet_sysinit *vs;
769 
770 	db_printf("VNET_SYSINIT vs Name(Ptr)\n");
771 	db_printf("  Subsystem  Order\n");
772 	db_printf("  Function(Name)(Arg)\n");
773 	TAILQ_FOREACH(vs, &vnet_constructors, link) {
774 		db_show_vnet_print_vs(vs, 1);
775 		if (db_pager_quit)
776 			break;
777 	}
778 }
779 
780 DB_SHOW_COMMAND(vnet_sysuninit, db_show_vnet_sysuninit)
781 {
782 	struct vnet_sysinit *vs;
783 
784 	db_printf("VNET_SYSUNINIT vs Name(Ptr)\n");
785 	db_printf("  Subsystem  Order\n");
786 	db_printf("  Function(Name)(Arg)\n");
787 	TAILQ_FOREACH_REVERSE(vs, &vnet_destructors, vnet_sysuninit_head,
788 	    link) {
789 		db_show_vnet_print_vs(vs, 1);
790 		if (db_pager_quit)
791 			break;
792 	}
793 }
794 
795 #ifdef VNET_DEBUG
796 DB_SHOW_COMMAND(vnetrcrs, db_show_vnetrcrs)
797 {
798 	struct vnet_recursion *vnr;
799 
800 	SLIST_FOREACH(vnr, &vnet_recursions, vnr_le)
801 		vnet_print_recursion(vnr, 1);
802 }
803 #endif
804 #endif /* DDB */
805