xref: /freebsd/sys/netgraph/ng_base.c (revision 69c5bce6ee1ec42997757e7f1334767d217c5d7d)
1 /*
2  * ng_base.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Authors: Julian Elischer <julian@freebsd.org>
39  *          Archie Cobbs <archie@freebsd.org>
40  *
41  * $FreeBSD$
42  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
43  */
44 
45 /*
46  * This file implements the base netgraph code.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/ctype.h>
52 #include <sys/errno.h>
53 #include <sys/kdb.h>
54 #include <sys/kernel.h>
55 #include <sys/ktr.h>
56 #include <sys/limits.h>
57 #include <sys/malloc.h>
58 #include <sys/mbuf.h>
59 #include <sys/queue.h>
60 #include <sys/sysctl.h>
61 #include <sys/syslog.h>
62 #include <sys/refcount.h>
63 #include <sys/proc.h>
64 #include <sys/unistd.h>
65 #include <sys/kthread.h>
66 #include <sys/smp.h>
67 #include <machine/cpu.h>
68 
69 #include <net/netisr.h>
70 #include <net/vnet.h>
71 
72 #include <netgraph/ng_message.h>
73 #include <netgraph/netgraph.h>
74 #include <netgraph/ng_parse.h>
75 
76 MODULE_VERSION(netgraph, NG_ABI_VERSION);
77 
78 /* Mutex to protect topology events. */
79 static struct mtx	ng_topo_mtx;
80 
81 #ifdef	NETGRAPH_DEBUG
82 static struct mtx	ng_nodelist_mtx; /* protects global node/hook lists */
83 static struct mtx	ngq_mtx;	/* protects the queue item list */
84 
85 static SLIST_HEAD(, ng_node) ng_allnodes;
86 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
87 static SLIST_HEAD(, ng_hook) ng_allhooks;
88 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
89 
90 static void ng_dumpitems(void);
91 static void ng_dumpnodes(void);
92 static void ng_dumphooks(void);
93 
94 #endif	/* NETGRAPH_DEBUG */
95 /*
96  * DEAD versions of the structures.
97  * In order to avoid races, it is sometimes neccesary to point
98  * at SOMETHING even though theoretically, the current entity is
99  * INVALID. Use these to avoid these races.
100  */
101 struct ng_type ng_deadtype = {
102 	NG_ABI_VERSION,
103 	"dead",
104 	NULL,	/* modevent */
105 	NULL,	/* constructor */
106 	NULL,	/* rcvmsg */
107 	NULL,	/* shutdown */
108 	NULL,	/* newhook */
109 	NULL,	/* findhook */
110 	NULL,	/* connect */
111 	NULL,	/* rcvdata */
112 	NULL,	/* disconnect */
113 	NULL, 	/* cmdlist */
114 };
115 
116 struct ng_node ng_deadnode = {
117 	"dead",
118 	&ng_deadtype,
119 	NGF_INVALID,
120 	0,	/* numhooks */
121 	NULL,	/* private */
122 	0,	/* ID */
123 	LIST_HEAD_INITIALIZER(ng_deadnode.nd_hooks),
124 	{},	/* all_nodes list entry */
125 	{},	/* id hashtable list entry */
126 	{	0,
127 		0,
128 		{}, /* should never use! (should hang) */
129 		{}, /* workqueue entry */
130 		STAILQ_HEAD_INITIALIZER(ng_deadnode.nd_input_queue.queue),
131 	},
132 	1,	/* refs */
133 	NULL,	/* vnet */
134 #ifdef	NETGRAPH_DEBUG
135 	ND_MAGIC,
136 	__FILE__,
137 	__LINE__,
138 	{NULL}
139 #endif	/* NETGRAPH_DEBUG */
140 };
141 
142 struct ng_hook ng_deadhook = {
143 	"dead",
144 	NULL,		/* private */
145 	HK_INVALID | HK_DEAD,
146 	0,		/* undefined data link type */
147 	&ng_deadhook,	/* Peer is self */
148 	&ng_deadnode,	/* attached to deadnode */
149 	{},		/* hooks list */
150 	NULL,		/* override rcvmsg() */
151 	NULL,		/* override rcvdata() */
152 	1,		/* refs always >= 1 */
153 #ifdef	NETGRAPH_DEBUG
154 	HK_MAGIC,
155 	__FILE__,
156 	__LINE__,
157 	{NULL}
158 #endif	/* NETGRAPH_DEBUG */
159 };
160 
161 /*
162  * END DEAD STRUCTURES
163  */
164 /* List nodes with unallocated work */
165 static STAILQ_HEAD(, ng_node) ng_worklist = STAILQ_HEAD_INITIALIZER(ng_worklist);
166 static struct mtx	ng_worklist_mtx;   /* MUST LOCK NODE FIRST */
167 
168 /* List of installed types */
169 static LIST_HEAD(, ng_type) ng_typelist;
170 static struct mtx	ng_typelist_mtx;
171 
172 /* Hash related definitions */
173 /* XXX Don't need to initialise them because it's a LIST */
174 static VNET_DEFINE(LIST_HEAD(, ng_node), ng_ID_hash[NG_ID_HASH_SIZE]);
175 #define	V_ng_ID_hash			VNET(ng_ID_hash)
176 
177 static struct mtx	ng_idhash_mtx;
178 /* Method to find a node.. used twice so do it here */
179 #define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
180 #define NG_IDHASH_FIND(ID, node)					\
181 	do { 								\
182 		mtx_assert(&ng_idhash_mtx, MA_OWNED);			\
183 		LIST_FOREACH(node, &V_ng_ID_hash[NG_IDHASH_FN(ID)],	\
184 						nd_idnodes) {		\
185 			if (NG_NODE_IS_VALID(node)			\
186 			&& (NG_NODE_ID(node) == ID)) {			\
187 				break;					\
188 			}						\
189 		}							\
190 	} while (0)
191 
192 static VNET_DEFINE(LIST_HEAD(, ng_node), ng_name_hash[NG_NAME_HASH_SIZE]);
193 #define	V_ng_name_hash			VNET(ng_name_hash)
194 
195 static struct mtx	ng_namehash_mtx;
196 #define NG_NAMEHASH(NAME, HASH)				\
197 	do {						\
198 		u_char	h = 0;				\
199 		const u_char	*c;			\
200 		for (c = (const u_char*)(NAME); *c; c++)\
201 			h += *c;			\
202 		(HASH) = h % (NG_NAME_HASH_SIZE);	\
203 	} while (0)
204 
205 
206 /* Internal functions */
207 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
208 static int	ng_generic_msg(node_p here, item_p item, hook_p lasthook);
209 static ng_ID_t	ng_decodeidname(const char *name);
210 static int	ngb_mod_event(module_t mod, int event, void *data);
211 static void	ng_worklist_add(node_p node);
212 static void	ngthread(void *);
213 static int	ng_apply_item(node_p node, item_p item, int rw);
214 static void	ng_flush_input_queue(node_p node);
215 static node_p	ng_ID2noderef(ng_ID_t ID);
216 static int	ng_con_nodes(item_p item, node_p node, const char *name,
217 		    node_p node2, const char *name2);
218 static int	ng_con_part2(node_p node, item_p item, hook_p hook);
219 static int	ng_con_part3(node_p node, item_p item, hook_p hook);
220 static int	ng_mkpeer(node_p node, const char *name,
221 						const char *name2, char *type);
222 
223 /* Imported, these used to be externally visible, some may go back. */
224 void	ng_destroy_hook(hook_p hook);
225 int	ng_path2noderef(node_p here, const char *path,
226 	node_p *dest, hook_p *lasthook);
227 int	ng_make_node(const char *type, node_p *nodepp);
228 int	ng_path_parse(char *addr, char **node, char **path, char **hook);
229 void	ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
230 void	ng_unname(node_p node);
231 
232 
233 /* Our own netgraph malloc type */
234 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
235 MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
236 MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
237 MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item", "netgraph item structures");
238 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
239 
240 /* Should not be visible outside this file */
241 
242 #define _NG_ALLOC_HOOK(hook) \
243 	hook = malloc(sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
244 #define _NG_ALLOC_NODE(node) \
245 	node = malloc(sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
246 
247 #define	NG_QUEUE_LOCK_INIT(n)			\
248 	mtx_init(&(n)->q_mtx, "ng_node", NULL, MTX_DEF)
249 #define	NG_QUEUE_LOCK(n)			\
250 	mtx_lock(&(n)->q_mtx)
251 #define	NG_QUEUE_UNLOCK(n)			\
252 	mtx_unlock(&(n)->q_mtx)
253 #define	NG_WORKLIST_LOCK_INIT()			\
254 	mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_DEF)
255 #define	NG_WORKLIST_LOCK()			\
256 	mtx_lock(&ng_worklist_mtx)
257 #define	NG_WORKLIST_UNLOCK()			\
258 	mtx_unlock(&ng_worklist_mtx)
259 #define	NG_WORKLIST_SLEEP()			\
260 	mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
261 #define	NG_WORKLIST_WAKEUP()			\
262 	wakeup_one(&ng_worklist)
263 
264 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
265 /*
266  * In debug mode:
267  * In an attempt to help track reference count screwups
268  * we do not free objects back to the malloc system, but keep them
269  * in a local cache where we can examine them and keep information safely
270  * after they have been freed.
271  * We use this scheme for nodes and hooks, and to some extent for items.
272  */
273 static __inline hook_p
274 ng_alloc_hook(void)
275 {
276 	hook_p hook;
277 	SLIST_ENTRY(ng_hook) temp;
278 	mtx_lock(&ng_nodelist_mtx);
279 	hook = LIST_FIRST(&ng_freehooks);
280 	if (hook) {
281 		LIST_REMOVE(hook, hk_hooks);
282 		bcopy(&hook->hk_all, &temp, sizeof(temp));
283 		bzero(hook, sizeof(struct ng_hook));
284 		bcopy(&temp, &hook->hk_all, sizeof(temp));
285 		mtx_unlock(&ng_nodelist_mtx);
286 		hook->hk_magic = HK_MAGIC;
287 	} else {
288 		mtx_unlock(&ng_nodelist_mtx);
289 		_NG_ALLOC_HOOK(hook);
290 		if (hook) {
291 			hook->hk_magic = HK_MAGIC;
292 			mtx_lock(&ng_nodelist_mtx);
293 			SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
294 			mtx_unlock(&ng_nodelist_mtx);
295 		}
296 	}
297 	return (hook);
298 }
299 
300 static __inline node_p
301 ng_alloc_node(void)
302 {
303 	node_p node;
304 	SLIST_ENTRY(ng_node) temp;
305 	mtx_lock(&ng_nodelist_mtx);
306 	node = LIST_FIRST(&ng_freenodes);
307 	if (node) {
308 		LIST_REMOVE(node, nd_nodes);
309 		bcopy(&node->nd_all, &temp, sizeof(temp));
310 		bzero(node, sizeof(struct ng_node));
311 		bcopy(&temp, &node->nd_all, sizeof(temp));
312 		mtx_unlock(&ng_nodelist_mtx);
313 		node->nd_magic = ND_MAGIC;
314 	} else {
315 		mtx_unlock(&ng_nodelist_mtx);
316 		_NG_ALLOC_NODE(node);
317 		if (node) {
318 			node->nd_magic = ND_MAGIC;
319 			mtx_lock(&ng_nodelist_mtx);
320 			SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
321 			mtx_unlock(&ng_nodelist_mtx);
322 		}
323 	}
324 	return (node);
325 }
326 
327 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
328 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
329 
330 
331 #define NG_FREE_HOOK(hook)						\
332 	do {								\
333 		mtx_lock(&ng_nodelist_mtx);			\
334 		LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);	\
335 		hook->hk_magic = 0;					\
336 		mtx_unlock(&ng_nodelist_mtx);			\
337 	} while (0)
338 
339 #define NG_FREE_NODE(node)						\
340 	do {								\
341 		mtx_lock(&ng_nodelist_mtx);			\
342 		LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);	\
343 		node->nd_magic = 0;					\
344 		mtx_unlock(&ng_nodelist_mtx);			\
345 	} while (0)
346 
347 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
348 
349 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
350 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
351 
352 #define NG_FREE_HOOK(hook) do { free((hook), M_NETGRAPH_HOOK); } while (0)
353 #define NG_FREE_NODE(node) do { free((node), M_NETGRAPH_NODE); } while (0)
354 
355 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
356 
357 /* Set this to kdb_enter("X") to catch all errors as they occur */
358 #ifndef TRAP_ERROR
359 #define TRAP_ERROR()
360 #endif
361 
362 static VNET_DEFINE(ng_ID_t, nextID) = 1;
363 #define	V_nextID			VNET(nextID)
364 
365 #ifdef INVARIANTS
366 #define CHECK_DATA_MBUF(m)	do {					\
367 		struct mbuf *n;						\
368 		int total;						\
369 									\
370 		M_ASSERTPKTHDR(m);					\
371 		for (total = 0, n = (m); n != NULL; n = n->m_next) {	\
372 			total += n->m_len;				\
373 			if (n->m_nextpkt != NULL)			\
374 				panic("%s: m_nextpkt", __func__);	\
375 		}							\
376 									\
377 		if ((m)->m_pkthdr.len != total) {			\
378 			panic("%s: %d != %d",				\
379 			    __func__, (m)->m_pkthdr.len, total);	\
380 		}							\
381 	} while (0)
382 #else
383 #define CHECK_DATA_MBUF(m)
384 #endif
385 
386 #define ERROUT(x)	do { error = (x); goto done; } while (0)
387 
388 /************************************************************************
389 	Parse type definitions for generic messages
390 ************************************************************************/
391 
392 /* Handy structure parse type defining macro */
393 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
394 static const struct ng_parse_struct_field				\
395 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
396 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
397 	&ng_parse_struct_type,						\
398 	&ng_ ## lo ## _type_fields					\
399 }
400 
401 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
402 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
403 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
404 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
405 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
406 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
407 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
408 
409 /* Get length of an array when the length is stored as a 32 bit
410    value immediately preceding the array -- as with struct namelist
411    and struct typelist. */
412 static int
413 ng_generic_list_getLength(const struct ng_parse_type *type,
414 	const u_char *start, const u_char *buf)
415 {
416 	return *((const u_int32_t *)(buf - 4));
417 }
418 
419 /* Get length of the array of struct linkinfo inside a struct hooklist */
420 static int
421 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
422 	const u_char *start, const u_char *buf)
423 {
424 	const struct hooklist *hl = (const struct hooklist *)start;
425 
426 	return hl->nodeinfo.hooks;
427 }
428 
429 /* Array type for a variable length array of struct namelist */
430 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
431 	&ng_generic_nodeinfo_type,
432 	&ng_generic_list_getLength
433 };
434 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
435 	&ng_parse_array_type,
436 	&ng_nodeinfoarray_type_info
437 };
438 
439 /* Array type for a variable length array of struct typelist */
440 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
441 	&ng_generic_typeinfo_type,
442 	&ng_generic_list_getLength
443 };
444 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
445 	&ng_parse_array_type,
446 	&ng_typeinfoarray_type_info
447 };
448 
449 /* Array type for array of struct linkinfo in struct hooklist */
450 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
451 	&ng_generic_linkinfo_type,
452 	&ng_generic_linkinfo_getLength
453 };
454 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
455 	&ng_parse_array_type,
456 	&ng_generic_linkinfo_array_type_info
457 };
458 
459 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
460 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
461 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
462 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
463 	(&ng_generic_nodeinfoarray_type));
464 
465 /* List of commands and how to convert arguments to/from ASCII */
466 static const struct ng_cmdlist ng_generic_cmds[] = {
467 	{
468 	  NGM_GENERIC_COOKIE,
469 	  NGM_SHUTDOWN,
470 	  "shutdown",
471 	  NULL,
472 	  NULL
473 	},
474 	{
475 	  NGM_GENERIC_COOKIE,
476 	  NGM_MKPEER,
477 	  "mkpeer",
478 	  &ng_generic_mkpeer_type,
479 	  NULL
480 	},
481 	{
482 	  NGM_GENERIC_COOKIE,
483 	  NGM_CONNECT,
484 	  "connect",
485 	  &ng_generic_connect_type,
486 	  NULL
487 	},
488 	{
489 	  NGM_GENERIC_COOKIE,
490 	  NGM_NAME,
491 	  "name",
492 	  &ng_generic_name_type,
493 	  NULL
494 	},
495 	{
496 	  NGM_GENERIC_COOKIE,
497 	  NGM_RMHOOK,
498 	  "rmhook",
499 	  &ng_generic_rmhook_type,
500 	  NULL
501 	},
502 	{
503 	  NGM_GENERIC_COOKIE,
504 	  NGM_NODEINFO,
505 	  "nodeinfo",
506 	  NULL,
507 	  &ng_generic_nodeinfo_type
508 	},
509 	{
510 	  NGM_GENERIC_COOKIE,
511 	  NGM_LISTHOOKS,
512 	  "listhooks",
513 	  NULL,
514 	  &ng_generic_hooklist_type
515 	},
516 	{
517 	  NGM_GENERIC_COOKIE,
518 	  NGM_LISTNAMES,
519 	  "listnames",
520 	  NULL,
521 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
522 	},
523 	{
524 	  NGM_GENERIC_COOKIE,
525 	  NGM_LISTNODES,
526 	  "listnodes",
527 	  NULL,
528 	  &ng_generic_listnodes_type
529 	},
530 	{
531 	  NGM_GENERIC_COOKIE,
532 	  NGM_LISTTYPES,
533 	  "listtypes",
534 	  NULL,
535 	  &ng_generic_typeinfo_type
536 	},
537 	{
538 	  NGM_GENERIC_COOKIE,
539 	  NGM_TEXT_CONFIG,
540 	  "textconfig",
541 	  NULL,
542 	  &ng_parse_string_type
543 	},
544 	{
545 	  NGM_GENERIC_COOKIE,
546 	  NGM_TEXT_STATUS,
547 	  "textstatus",
548 	  NULL,
549 	  &ng_parse_string_type
550 	},
551 	{
552 	  NGM_GENERIC_COOKIE,
553 	  NGM_ASCII2BINARY,
554 	  "ascii2binary",
555 	  &ng_parse_ng_mesg_type,
556 	  &ng_parse_ng_mesg_type
557 	},
558 	{
559 	  NGM_GENERIC_COOKIE,
560 	  NGM_BINARY2ASCII,
561 	  "binary2ascii",
562 	  &ng_parse_ng_mesg_type,
563 	  &ng_parse_ng_mesg_type
564 	},
565 	{ 0 }
566 };
567 
568 /************************************************************************
569 			Node routines
570 ************************************************************************/
571 
572 /*
573  * Instantiate a node of the requested type
574  */
575 int
576 ng_make_node(const char *typename, node_p *nodepp)
577 {
578 	struct ng_type *type;
579 	int	error;
580 
581 	/* Check that the type makes sense */
582 	if (typename == NULL) {
583 		TRAP_ERROR();
584 		return (EINVAL);
585 	}
586 
587 	/* Locate the node type. If we fail we return. Do not try to load
588 	 * module.
589 	 */
590 	if ((type = ng_findtype(typename)) == NULL)
591 		return (ENXIO);
592 
593 	/*
594 	 * If we have a constructor, then make the node and
595 	 * call the constructor to do type specific initialisation.
596 	 */
597 	if (type->constructor != NULL) {
598 		if ((error = ng_make_node_common(type, nodepp)) == 0) {
599 			if ((error = ((*type->constructor)(*nodepp))) != 0) {
600 				NG_NODE_UNREF(*nodepp);
601 			}
602 		}
603 	} else {
604 		/*
605 		 * Node has no constructor. We cannot ask for one
606 		 * to be made. It must be brought into existence by
607 		 * some external agency. The external agency should
608 		 * call ng_make_node_common() directly to get the
609 		 * netgraph part initialised.
610 		 */
611 		TRAP_ERROR();
612 		error = EINVAL;
613 	}
614 	return (error);
615 }
616 
617 /*
618  * Generic node creation. Called by node initialisation for externally
619  * instantiated nodes (e.g. hardware, sockets, etc ).
620  * The returned node has a reference count of 1.
621  */
622 int
623 ng_make_node_common(struct ng_type *type, node_p *nodepp)
624 {
625 	node_p node;
626 
627 	/* Require the node type to have been already installed */
628 	if (ng_findtype(type->name) == NULL) {
629 		TRAP_ERROR();
630 		return (EINVAL);
631 	}
632 
633 	/* Make a node and try attach it to the type */
634 	NG_ALLOC_NODE(node);
635 	if (node == NULL) {
636 		TRAP_ERROR();
637 		return (ENOMEM);
638 	}
639 	node->nd_type = type;
640 #ifdef VIMAGE
641 	node->nd_vnet = curvnet;
642 #endif
643 	NG_NODE_REF(node);				/* note reference */
644 	type->refs++;
645 
646 	NG_QUEUE_LOCK_INIT(&node->nd_input_queue);
647 	STAILQ_INIT(&node->nd_input_queue.queue);
648 	node->nd_input_queue.q_flags = 0;
649 
650 	/* Initialize hook list for new node */
651 	LIST_INIT(&node->nd_hooks);
652 
653 	/* Link us into the name hash. */
654 	mtx_lock(&ng_namehash_mtx);
655 	LIST_INSERT_HEAD(&V_ng_name_hash[0], node, nd_nodes);
656 	mtx_unlock(&ng_namehash_mtx);
657 
658 	/* get an ID and put us in the hash chain */
659 	mtx_lock(&ng_idhash_mtx);
660 	for (;;) { /* wrap protection, even if silly */
661 		node_p node2 = NULL;
662 		node->nd_ID = V_nextID++; /* 137/sec for 1 year before wrap */
663 
664 		/* Is there a problem with the new number? */
665 		NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
666 		if ((node->nd_ID != 0) && (node2 == NULL)) {
667 			break;
668 		}
669 	}
670 	LIST_INSERT_HEAD(&V_ng_ID_hash[NG_IDHASH_FN(node->nd_ID)],
671 							node, nd_idnodes);
672 	mtx_unlock(&ng_idhash_mtx);
673 
674 	/* Done */
675 	*nodepp = node;
676 	return (0);
677 }
678 
679 /*
680  * Forceably start the shutdown process on a node. Either call
681  * its shutdown method, or do the default shutdown if there is
682  * no type-specific method.
683  *
684  * We can only be called from a shutdown message, so we know we have
685  * a writer lock, and therefore exclusive access. It also means
686  * that we should not be on the work queue, but we check anyhow.
687  *
688  * Persistent node types must have a type-specific method which
689  * allocates a new node in which case, this one is irretrievably going away,
690  * or cleans up anything it needs, and just makes the node valid again,
691  * in which case we allow the node to survive.
692  *
693  * XXX We need to think of how to tell a persistent node that we
694  * REALLY need to go away because the hardware has gone or we
695  * are rebooting.... etc.
696  */
697 void
698 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
699 {
700 	hook_p hook;
701 
702 	/* Check if it's already shutting down */
703 	if ((node->nd_flags & NGF_CLOSING) != 0)
704 		return;
705 
706 	if (node == &ng_deadnode) {
707 		printf ("shutdown called on deadnode\n");
708 		return;
709 	}
710 
711 	/* Add an extra reference so it doesn't go away during this */
712 	NG_NODE_REF(node);
713 
714 	/*
715 	 * Mark it invalid so any newcomers know not to try use it
716 	 * Also add our own mark so we can't recurse
717 	 * note that NGF_INVALID does not do this as it's also set during
718 	 * creation
719 	 */
720 	node->nd_flags |= NGF_INVALID|NGF_CLOSING;
721 
722 	/* If node has its pre-shutdown method, then call it first*/
723 	if (node->nd_type && node->nd_type->close)
724 		(*node->nd_type->close)(node);
725 
726 	/* Notify all remaining connected nodes to disconnect */
727 	while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
728 		ng_destroy_hook(hook);
729 
730 	/*
731 	 * Drain the input queue forceably.
732 	 * it has no hooks so what's it going to do, bleed on someone?
733 	 * Theoretically we came here from a queue entry that was added
734 	 * Just before the queue was closed, so it should be empty anyway.
735 	 * Also removes us from worklist if needed.
736 	 */
737 	ng_flush_input_queue(node);
738 
739 	/* Ask the type if it has anything to do in this case */
740 	if (node->nd_type && node->nd_type->shutdown) {
741 		(*node->nd_type->shutdown)(node);
742 		if (NG_NODE_IS_VALID(node)) {
743 			/*
744 			 * Well, blow me down if the node code hasn't declared
745 			 * that it doesn't want to die.
746 			 * Presumably it is a persistant node.
747 			 * If we REALLY want it to go away,
748 			 *  e.g. hardware going away,
749 			 * Our caller should set NGF_REALLY_DIE in nd_flags.
750 			 */
751 			node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
752 			NG_NODE_UNREF(node); /* Assume they still have theirs */
753 			return;
754 		}
755 	} else {				/* do the default thing */
756 		NG_NODE_UNREF(node);
757 	}
758 
759 	ng_unname(node); /* basically a NOP these days */
760 
761 	/*
762 	 * Remove extra reference, possibly the last
763 	 * Possible other holders of references may include
764 	 * timeout callouts, but theoretically the node's supposed to
765 	 * have cancelled them. Possibly hardware dependencies may
766 	 * force a driver to 'linger' with a reference.
767 	 */
768 	NG_NODE_UNREF(node);
769 }
770 
771 /*
772  * Remove a reference to the node, possibly the last.
773  * deadnode always acts as it it were the last.
774  */
775 void
776 ng_unref_node(node_p node)
777 {
778 
779 	if (node == &ng_deadnode)
780 		return;
781 
782 	if (refcount_release(&node->nd_refs)) { /* we were the last */
783 
784 		mtx_lock(&ng_namehash_mtx);
785 		node->nd_type->refs--; /* XXX maybe should get types lock? */
786 		LIST_REMOVE(node, nd_nodes);
787 		mtx_unlock(&ng_namehash_mtx);
788 
789 		mtx_lock(&ng_idhash_mtx);
790 		LIST_REMOVE(node, nd_idnodes);
791 		mtx_unlock(&ng_idhash_mtx);
792 
793 		mtx_destroy(&node->nd_input_queue.q_mtx);
794 		NG_FREE_NODE(node);
795 	}
796 }
797 
798 /************************************************************************
799 			Node ID handling
800 ************************************************************************/
801 static node_p
802 ng_ID2noderef(ng_ID_t ID)
803 {
804 	node_p node;
805 	mtx_lock(&ng_idhash_mtx);
806 	NG_IDHASH_FIND(ID, node);
807 	if(node)
808 		NG_NODE_REF(node);
809 	mtx_unlock(&ng_idhash_mtx);
810 	return(node);
811 }
812 
813 ng_ID_t
814 ng_node2ID(node_p node)
815 {
816 	return (node ? NG_NODE_ID(node) : 0);
817 }
818 
819 /************************************************************************
820 			Node name handling
821 ************************************************************************/
822 
823 /*
824  * Assign a node a name. Once assigned, the name cannot be changed.
825  */
826 int
827 ng_name_node(node_p node, const char *name)
828 {
829 	int i, hash;
830 	node_p node2;
831 
832 	/* Check the name is valid */
833 	for (i = 0; i < NG_NODESIZ; i++) {
834 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
835 			break;
836 	}
837 	if (i == 0 || name[i] != '\0') {
838 		TRAP_ERROR();
839 		return (EINVAL);
840 	}
841 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
842 		TRAP_ERROR();
843 		return (EINVAL);
844 	}
845 
846 	/* Check the name isn't already being used */
847 	if ((node2 = ng_name2noderef(node, name)) != NULL) {
848 		NG_NODE_UNREF(node2);
849 		TRAP_ERROR();
850 		return (EADDRINUSE);
851 	}
852 
853 	/* copy it */
854 	strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
855 
856 	/* Update name hash. */
857 	NG_NAMEHASH(name, hash);
858 	mtx_lock(&ng_namehash_mtx);
859 	LIST_REMOVE(node, nd_nodes);
860 	LIST_INSERT_HEAD(&V_ng_name_hash[hash], node, nd_nodes);
861 	mtx_unlock(&ng_namehash_mtx);
862 
863 	return (0);
864 }
865 
866 /*
867  * Find a node by absolute name. The name should NOT end with ':'
868  * The name "." means "this node" and "[xxx]" means "the node
869  * with ID (ie, at address) xxx".
870  *
871  * Returns the node if found, else NULL.
872  * Eventually should add something faster than a sequential search.
873  * Note it acquires a reference on the node so you can be sure it's still
874  * there.
875  */
876 node_p
877 ng_name2noderef(node_p here, const char *name)
878 {
879 	node_p node;
880 	ng_ID_t temp;
881 	int	hash;
882 
883 	/* "." means "this node" */
884 	if (strcmp(name, ".") == 0) {
885 		NG_NODE_REF(here);
886 		return(here);
887 	}
888 
889 	/* Check for name-by-ID */
890 	if ((temp = ng_decodeidname(name)) != 0) {
891 		return (ng_ID2noderef(temp));
892 	}
893 
894 	/* Find node by name */
895 	NG_NAMEHASH(name, hash);
896 	mtx_lock(&ng_namehash_mtx);
897 	LIST_FOREACH(node, &V_ng_name_hash[hash], nd_nodes) {
898 		if (NG_NODE_IS_VALID(node) &&
899 		    (strcmp(NG_NODE_NAME(node), name) == 0)) {
900 			break;
901 		}
902 	}
903 	if (node)
904 		NG_NODE_REF(node);
905 	mtx_unlock(&ng_namehash_mtx);
906 	return (node);
907 }
908 
909 /*
910  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
911  * string is not valid, otherwise returns the value.
912  */
913 static ng_ID_t
914 ng_decodeidname(const char *name)
915 {
916 	const int len = strlen(name);
917 	char *eptr;
918 	u_long val;
919 
920 	/* Check for proper length, brackets, no leading junk */
921 	if ((len < 3)
922 	|| (name[0] != '[')
923 	|| (name[len - 1] != ']')
924 	|| (!isxdigit(name[1]))) {
925 		return ((ng_ID_t)0);
926 	}
927 
928 	/* Decode number */
929 	val = strtoul(name + 1, &eptr, 16);
930 	if ((eptr - name != len - 1)
931 	|| (val == ULONG_MAX)
932 	|| (val == 0)) {
933 		return ((ng_ID_t)0);
934 	}
935 	return (ng_ID_t)val;
936 }
937 
938 /*
939  * Remove a name from a node. This should only be called
940  * when shutting down and removing the node.
941  * IF we allow name changing this may be more resurrected.
942  */
943 void
944 ng_unname(node_p node)
945 {
946 }
947 
948 /************************************************************************
949 			Hook routines
950  Names are not optional. Hooks are always connected, except for a
951  brief moment within these routines. On invalidation or during creation
952  they are connected to the 'dead' hook.
953 ************************************************************************/
954 
955 /*
956  * Remove a hook reference
957  */
958 void
959 ng_unref_hook(hook_p hook)
960 {
961 
962 	if (hook == &ng_deadhook)
963 		return;
964 
965 	if (refcount_release(&hook->hk_refs)) { /* we were the last */
966 		if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
967 			_NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
968 		NG_FREE_HOOK(hook);
969 	}
970 }
971 
972 /*
973  * Add an unconnected hook to a node. Only used internally.
974  * Assumes node is locked. (XXX not yet true )
975  */
976 static int
977 ng_add_hook(node_p node, const char *name, hook_p *hookp)
978 {
979 	hook_p hook;
980 	int error = 0;
981 
982 	/* Check that the given name is good */
983 	if (name == NULL) {
984 		TRAP_ERROR();
985 		return (EINVAL);
986 	}
987 	if (ng_findhook(node, name) != NULL) {
988 		TRAP_ERROR();
989 		return (EEXIST);
990 	}
991 
992 	/* Allocate the hook and link it up */
993 	NG_ALLOC_HOOK(hook);
994 	if (hook == NULL) {
995 		TRAP_ERROR();
996 		return (ENOMEM);
997 	}
998 	hook->hk_refs = 1;		/* add a reference for us to return */
999 	hook->hk_flags = HK_INVALID;
1000 	hook->hk_peer = &ng_deadhook;	/* start off this way */
1001 	hook->hk_node = node;
1002 	NG_NODE_REF(node);		/* each hook counts as a reference */
1003 
1004 	/* Set hook name */
1005 	strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
1006 
1007 	/*
1008 	 * Check if the node type code has something to say about it
1009 	 * If it fails, the unref of the hook will also unref the node.
1010 	 */
1011 	if (node->nd_type->newhook != NULL) {
1012 		if ((error = (*node->nd_type->newhook)(node, hook, name))) {
1013 			NG_HOOK_UNREF(hook);	/* this frees the hook */
1014 			return (error);
1015 		}
1016 	}
1017 	/*
1018 	 * The 'type' agrees so far, so go ahead and link it in.
1019 	 * We'll ask again later when we actually connect the hooks.
1020 	 */
1021 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1022 	node->nd_numhooks++;
1023 	NG_HOOK_REF(hook);	/* one for the node */
1024 
1025 	if (hookp)
1026 		*hookp = hook;
1027 	return (0);
1028 }
1029 
1030 /*
1031  * Find a hook
1032  *
1033  * Node types may supply their own optimized routines for finding
1034  * hooks.  If none is supplied, we just do a linear search.
1035  * XXX Possibly we should add a reference to the hook?
1036  */
1037 hook_p
1038 ng_findhook(node_p node, const char *name)
1039 {
1040 	hook_p hook;
1041 
1042 	if (node->nd_type->findhook != NULL)
1043 		return (*node->nd_type->findhook)(node, name);
1044 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
1045 		if (NG_HOOK_IS_VALID(hook)
1046 		&& (strcmp(NG_HOOK_NAME(hook), name) == 0))
1047 			return (hook);
1048 	}
1049 	return (NULL);
1050 }
1051 
1052 /*
1053  * Destroy a hook
1054  *
1055  * As hooks are always attached, this really destroys two hooks.
1056  * The one given, and the one attached to it. Disconnect the hooks
1057  * from each other first. We reconnect the peer hook to the 'dead'
1058  * hook so that it can still exist after we depart. We then
1059  * send the peer its own destroy message. This ensures that we only
1060  * interact with the peer's structures when it is locked processing that
1061  * message. We hold a reference to the peer hook so we are guaranteed that
1062  * the peer hook and node are still going to exist until
1063  * we are finished there as the hook holds a ref on the node.
1064  * We run this same code again on the peer hook, but that time it is already
1065  * attached to the 'dead' hook.
1066  *
1067  * This routine is called at all stages of hook creation
1068  * on error detection and must be able to handle any such stage.
1069  */
1070 void
1071 ng_destroy_hook(hook_p hook)
1072 {
1073 	hook_p peer;
1074 	node_p node;
1075 
1076 	if (hook == &ng_deadhook) {	/* better safe than sorry */
1077 		printf("ng_destroy_hook called on deadhook\n");
1078 		return;
1079 	}
1080 
1081 	/*
1082 	 * Protect divorce process with mutex, to avoid races on
1083 	 * simultaneous disconnect.
1084 	 */
1085 	mtx_lock(&ng_topo_mtx);
1086 
1087 	hook->hk_flags |= HK_INVALID;
1088 
1089 	peer = NG_HOOK_PEER(hook);
1090 	node = NG_HOOK_NODE(hook);
1091 
1092 	if (peer && (peer != &ng_deadhook)) {
1093 		/*
1094 		 * Set the peer to point to ng_deadhook
1095 		 * from this moment on we are effectively independent it.
1096 		 * send it an rmhook message of it's own.
1097 		 */
1098 		peer->hk_peer = &ng_deadhook;	/* They no longer know us */
1099 		hook->hk_peer = &ng_deadhook;	/* Nor us, them */
1100 		if (NG_HOOK_NODE(peer) == &ng_deadnode) {
1101 			/*
1102 			 * If it's already divorced from a node,
1103 			 * just free it.
1104 			 */
1105 			mtx_unlock(&ng_topo_mtx);
1106 		} else {
1107 			mtx_unlock(&ng_topo_mtx);
1108 			ng_rmhook_self(peer); 	/* Send it a surprise */
1109 		}
1110 		NG_HOOK_UNREF(peer);		/* account for peer link */
1111 		NG_HOOK_UNREF(hook);		/* account for peer link */
1112 	} else
1113 		mtx_unlock(&ng_topo_mtx);
1114 
1115 	mtx_assert(&ng_topo_mtx, MA_NOTOWNED);
1116 
1117 	/*
1118 	 * Remove the hook from the node's list to avoid possible recursion
1119 	 * in case the disconnection results in node shutdown.
1120 	 */
1121 	if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
1122 		return;
1123 	}
1124 	LIST_REMOVE(hook, hk_hooks);
1125 	node->nd_numhooks--;
1126 	if (node->nd_type->disconnect) {
1127 		/*
1128 		 * The type handler may elect to destroy the node so don't
1129 		 * trust its existence after this point. (except
1130 		 * that we still hold a reference on it. (which we
1131 		 * inherrited from the hook we are destroying)
1132 		 */
1133 		(*node->nd_type->disconnect) (hook);
1134 	}
1135 
1136 	/*
1137 	 * Note that because we will point to ng_deadnode, the original node
1138 	 * is not decremented automatically so we do that manually.
1139 	 */
1140 	_NG_HOOK_NODE(hook) = &ng_deadnode;
1141 	NG_NODE_UNREF(node);	/* We no longer point to it so adjust count */
1142 	NG_HOOK_UNREF(hook);	/* Account for linkage (in list) to node */
1143 }
1144 
1145 /*
1146  * Take two hooks on a node and merge the connection so that the given node
1147  * is effectively bypassed.
1148  */
1149 int
1150 ng_bypass(hook_p hook1, hook_p hook2)
1151 {
1152 	if (hook1->hk_node != hook2->hk_node) {
1153 		TRAP_ERROR();
1154 		return (EINVAL);
1155 	}
1156 	mtx_lock(&ng_topo_mtx);
1157 	hook1->hk_peer->hk_peer = hook2->hk_peer;
1158 	hook2->hk_peer->hk_peer = hook1->hk_peer;
1159 
1160 	hook1->hk_peer = &ng_deadhook;
1161 	hook2->hk_peer = &ng_deadhook;
1162 	mtx_unlock(&ng_topo_mtx);
1163 
1164 	NG_HOOK_UNREF(hook1);
1165 	NG_HOOK_UNREF(hook2);
1166 
1167 	/* XXX If we ever cache methods on hooks update them as well */
1168 	ng_destroy_hook(hook1);
1169 	ng_destroy_hook(hook2);
1170 	return (0);
1171 }
1172 
1173 /*
1174  * Install a new netgraph type
1175  */
1176 int
1177 ng_newtype(struct ng_type *tp)
1178 {
1179 	const size_t namelen = strlen(tp->name);
1180 
1181 	/* Check version and type name fields */
1182 	if ((tp->version != NG_ABI_VERSION)
1183 	|| (namelen == 0)
1184 	|| (namelen >= NG_TYPESIZ)) {
1185 		TRAP_ERROR();
1186 		if (tp->version != NG_ABI_VERSION) {
1187 			printf("Netgraph: Node type rejected. ABI mismatch. Suggest recompile\n");
1188 		}
1189 		return (EINVAL);
1190 	}
1191 
1192 	/* Check for name collision */
1193 	if (ng_findtype(tp->name) != NULL) {
1194 		TRAP_ERROR();
1195 		return (EEXIST);
1196 	}
1197 
1198 
1199 	/* Link in new type */
1200 	mtx_lock(&ng_typelist_mtx);
1201 	LIST_INSERT_HEAD(&ng_typelist, tp, types);
1202 	tp->refs = 1;	/* first ref is linked list */
1203 	mtx_unlock(&ng_typelist_mtx);
1204 	return (0);
1205 }
1206 
1207 /*
1208  * unlink a netgraph type
1209  * If no examples exist
1210  */
1211 int
1212 ng_rmtype(struct ng_type *tp)
1213 {
1214 	/* Check for name collision */
1215 	if (tp->refs != 1) {
1216 		TRAP_ERROR();
1217 		return (EBUSY);
1218 	}
1219 
1220 	/* Unlink type */
1221 	mtx_lock(&ng_typelist_mtx);
1222 	LIST_REMOVE(tp, types);
1223 	mtx_unlock(&ng_typelist_mtx);
1224 	return (0);
1225 }
1226 
1227 /*
1228  * Look for a type of the name given
1229  */
1230 struct ng_type *
1231 ng_findtype(const char *typename)
1232 {
1233 	struct ng_type *type;
1234 
1235 	mtx_lock(&ng_typelist_mtx);
1236 	LIST_FOREACH(type, &ng_typelist, types) {
1237 		if (strcmp(type->name, typename) == 0)
1238 			break;
1239 	}
1240 	mtx_unlock(&ng_typelist_mtx);
1241 	return (type);
1242 }
1243 
1244 /************************************************************************
1245 			Composite routines
1246 ************************************************************************/
1247 /*
1248  * Connect two nodes using the specified hooks, using queued functions.
1249  */
1250 static int
1251 ng_con_part3(node_p node, item_p item, hook_p hook)
1252 {
1253 	int	error = 0;
1254 
1255 	/*
1256 	 * When we run, we know that the node 'node' is locked for us.
1257 	 * Our caller has a reference on the hook.
1258 	 * Our caller has a reference on the node.
1259 	 * (In this case our caller is ng_apply_item() ).
1260 	 * The peer hook has a reference on the hook.
1261 	 * We are all set up except for the final call to the node, and
1262 	 * the clearing of the INVALID flag.
1263 	 */
1264 	if (NG_HOOK_NODE(hook) == &ng_deadnode) {
1265 		/*
1266 		 * The node must have been freed again since we last visited
1267 		 * here. ng_destry_hook() has this effect but nothing else does.
1268 		 * We should just release our references and
1269 		 * free anything we can think of.
1270 		 * Since we know it's been destroyed, and it's our caller
1271 		 * that holds the references, just return.
1272 		 */
1273 		ERROUT(ENOENT);
1274 	}
1275 	if (hook->hk_node->nd_type->connect) {
1276 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1277 			ng_destroy_hook(hook);	/* also zaps peer */
1278 			printf("failed in ng_con_part3()\n");
1279 			ERROUT(error);
1280 		}
1281 	}
1282 	/*
1283 	 *  XXX this is wrong for SMP. Possibly we need
1284 	 * to separate out 'create' and 'invalid' flags.
1285 	 * should only set flags on hooks we have locked under our node.
1286 	 */
1287 	hook->hk_flags &= ~HK_INVALID;
1288 done:
1289 	NG_FREE_ITEM(item);
1290 	return (error);
1291 }
1292 
1293 static int
1294 ng_con_part2(node_p node, item_p item, hook_p hook)
1295 {
1296 	hook_p	peer;
1297 	int	error = 0;
1298 
1299 	/*
1300 	 * When we run, we know that the node 'node' is locked for us.
1301 	 * Our caller has a reference on the hook.
1302 	 * Our caller has a reference on the node.
1303 	 * (In this case our caller is ng_apply_item() ).
1304 	 * The peer hook has a reference on the hook.
1305 	 * our node pointer points to the 'dead' node.
1306 	 * First check the hook name is unique.
1307 	 * Should not happen because we checked before queueing this.
1308 	 */
1309 	if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
1310 		TRAP_ERROR();
1311 		ng_destroy_hook(hook); /* should destroy peer too */
1312 		printf("failed in ng_con_part2()\n");
1313 		ERROUT(EEXIST);
1314 	}
1315 	/*
1316 	 * Check if the node type code has something to say about it
1317 	 * If it fails, the unref of the hook will also unref the attached node,
1318 	 * however since that node is 'ng_deadnode' this will do nothing.
1319 	 * The peer hook will also be destroyed.
1320 	 */
1321 	if (node->nd_type->newhook != NULL) {
1322 		if ((error = (*node->nd_type->newhook)(node, hook,
1323 		    hook->hk_name))) {
1324 			ng_destroy_hook(hook); /* should destroy peer too */
1325 			printf("failed in ng_con_part2()\n");
1326 			ERROUT(error);
1327 		}
1328 	}
1329 
1330 	/*
1331 	 * The 'type' agrees so far, so go ahead and link it in.
1332 	 * We'll ask again later when we actually connect the hooks.
1333 	 */
1334 	hook->hk_node = node;		/* just overwrite ng_deadnode */
1335 	NG_NODE_REF(node);		/* each hook counts as a reference */
1336 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1337 	node->nd_numhooks++;
1338 	NG_HOOK_REF(hook);	/* one for the node */
1339 
1340 	/*
1341 	 * We now have a symmetrical situation, where both hooks have been
1342 	 * linked to their nodes, the newhook methods have been called
1343 	 * And the references are all correct. The hooks are still marked
1344 	 * as invalid, as we have not called the 'connect' methods
1345 	 * yet.
1346 	 * We can call the local one immediately as we have the
1347 	 * node locked, but we need to queue the remote one.
1348 	 */
1349 	if (hook->hk_node->nd_type->connect) {
1350 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1351 			ng_destroy_hook(hook);	/* also zaps peer */
1352 			printf("failed in ng_con_part2(A)\n");
1353 			ERROUT(error);
1354 		}
1355 	}
1356 
1357 	/*
1358 	 * Acquire topo mutex to avoid race with ng_destroy_hook().
1359 	 */
1360 	mtx_lock(&ng_topo_mtx);
1361 	peer = hook->hk_peer;
1362 	if (peer == &ng_deadhook) {
1363 		mtx_unlock(&ng_topo_mtx);
1364 		printf("failed in ng_con_part2(B)\n");
1365 		ng_destroy_hook(hook);
1366 		ERROUT(ENOENT);
1367 	}
1368 	mtx_unlock(&ng_topo_mtx);
1369 
1370 	if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
1371 	    NULL, 0, NG_REUSE_ITEM))) {
1372 		printf("failed in ng_con_part2(C)\n");
1373 		ng_destroy_hook(hook);	/* also zaps peer */
1374 		return (error);		/* item was consumed. */
1375 	}
1376 	hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
1377 	return (0);			/* item was consumed. */
1378 done:
1379 	NG_FREE_ITEM(item);
1380 	return (error);
1381 }
1382 
1383 /*
1384  * Connect this node with another node. We assume that this node is
1385  * currently locked, as we are only called from an NGM_CONNECT message.
1386  */
1387 static int
1388 ng_con_nodes(item_p item, node_p node, const char *name,
1389     node_p node2, const char *name2)
1390 {
1391 	int	error;
1392 	hook_p	hook;
1393 	hook_p	hook2;
1394 
1395 	if (ng_findhook(node2, name2) != NULL) {
1396 		return(EEXIST);
1397 	}
1398 	if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
1399 		return (error);
1400 	/* Allocate the other hook and link it up */
1401 	NG_ALLOC_HOOK(hook2);
1402 	if (hook2 == NULL) {
1403 		TRAP_ERROR();
1404 		ng_destroy_hook(hook);	/* XXX check ref counts so far */
1405 		NG_HOOK_UNREF(hook);	/* including our ref */
1406 		return (ENOMEM);
1407 	}
1408 	hook2->hk_refs = 1;		/* start with a reference for us. */
1409 	hook2->hk_flags = HK_INVALID;
1410 	hook2->hk_peer = hook;		/* Link the two together */
1411 	hook->hk_peer = hook2;
1412 	NG_HOOK_REF(hook);		/* Add a ref for the peer to each*/
1413 	NG_HOOK_REF(hook2);
1414 	hook2->hk_node = &ng_deadnode;
1415 	strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
1416 
1417 	/*
1418 	 * Queue the function above.
1419 	 * Procesing continues in that function in the lock context of
1420 	 * the other node.
1421 	 */
1422 	if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
1423 	    NG_NOFLAGS))) {
1424 		printf("failed in ng_con_nodes(): %d\n", error);
1425 		ng_destroy_hook(hook);	/* also zaps peer */
1426 	}
1427 
1428 	NG_HOOK_UNREF(hook);		/* Let each hook go if it wants to */
1429 	NG_HOOK_UNREF(hook2);
1430 	return (error);
1431 }
1432 
1433 /*
1434  * Make a peer and connect.
1435  * We assume that the local node is locked.
1436  * The new node probably doesn't need a lock until
1437  * it has a hook, because it cannot really have any work until then,
1438  * but we should think about it a bit more.
1439  *
1440  * The problem may come if the other node also fires up
1441  * some hardware or a timer or some other source of activation,
1442  * also it may already get a command msg via it's ID.
1443  *
1444  * We could use the same method as ng_con_nodes() but we'd have
1445  * to add ability to remove the node when failing. (Not hard, just
1446  * make arg1 point to the node to remove).
1447  * Unless of course we just ignore failure to connect and leave
1448  * an unconnected node?
1449  */
1450 static int
1451 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
1452 {
1453 	node_p	node2;
1454 	hook_p	hook1, hook2;
1455 	int	error;
1456 
1457 	if ((error = ng_make_node(type, &node2))) {
1458 		return (error);
1459 	}
1460 
1461 	if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
1462 		ng_rmnode(node2, NULL, NULL, 0);
1463 		return (error);
1464 	}
1465 
1466 	if ((error = ng_add_hook(node2, name2, &hook2))) {
1467 		ng_rmnode(node2, NULL, NULL, 0);
1468 		ng_destroy_hook(hook1);
1469 		NG_HOOK_UNREF(hook1);
1470 		return (error);
1471 	}
1472 
1473 	/*
1474 	 * Actually link the two hooks together.
1475 	 */
1476 	hook1->hk_peer = hook2;
1477 	hook2->hk_peer = hook1;
1478 
1479 	/* Each hook is referenced by the other */
1480 	NG_HOOK_REF(hook1);
1481 	NG_HOOK_REF(hook2);
1482 
1483 	/* Give each node the opportunity to veto the pending connection */
1484 	if (hook1->hk_node->nd_type->connect) {
1485 		error = (*hook1->hk_node->nd_type->connect) (hook1);
1486 	}
1487 
1488 	if ((error == 0) && hook2->hk_node->nd_type->connect) {
1489 		error = (*hook2->hk_node->nd_type->connect) (hook2);
1490 
1491 	}
1492 
1493 	/*
1494 	 * drop the references we were holding on the two hooks.
1495 	 */
1496 	if (error) {
1497 		ng_destroy_hook(hook2);	/* also zaps hook1 */
1498 		ng_rmnode(node2, NULL, NULL, 0);
1499 	} else {
1500 		/* As a last act, allow the hooks to be used */
1501 		hook1->hk_flags &= ~HK_INVALID;
1502 		hook2->hk_flags &= ~HK_INVALID;
1503 	}
1504 	NG_HOOK_UNREF(hook1);
1505 	NG_HOOK_UNREF(hook2);
1506 	return (error);
1507 }
1508 
1509 /************************************************************************
1510 		Utility routines to send self messages
1511 ************************************************************************/
1512 
1513 /* Shut this node down as soon as everyone is clear of it */
1514 /* Should add arg "immediately" to jump the queue */
1515 int
1516 ng_rmnode_self(node_p node)
1517 {
1518 	int		error;
1519 
1520 	if (node == &ng_deadnode)
1521 		return (0);
1522 	node->nd_flags |= NGF_INVALID;
1523 	if (node->nd_flags & NGF_CLOSING)
1524 		return (0);
1525 
1526 	error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
1527 	return (error);
1528 }
1529 
1530 static void
1531 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
1532 {
1533 	ng_destroy_hook(hook);
1534 	return ;
1535 }
1536 
1537 int
1538 ng_rmhook_self(hook_p hook)
1539 {
1540 	int		error;
1541 	node_p node = NG_HOOK_NODE(hook);
1542 
1543 	if (node == &ng_deadnode)
1544 		return (0);
1545 
1546 	error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
1547 	return (error);
1548 }
1549 
1550 /***********************************************************************
1551  * Parse and verify a string of the form:  <NODE:><PATH>
1552  *
1553  * Such a string can refer to a specific node or a specific hook
1554  * on a specific node, depending on how you look at it. In the
1555  * latter case, the PATH component must not end in a dot.
1556  *
1557  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1558  * of hook names separated by dots. This breaks out the original
1559  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1560  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1561  * the final hook component of <PATH>, if any, otherwise NULL.
1562  *
1563  * This returns -1 if the path is malformed. The char ** are optional.
1564  ***********************************************************************/
1565 int
1566 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1567 {
1568 	char	*node, *path, *hook;
1569 	int	k;
1570 
1571 	/*
1572 	 * Extract absolute NODE, if any
1573 	 */
1574 	for (path = addr; *path && *path != ':'; path++);
1575 	if (*path) {
1576 		node = addr;	/* Here's the NODE */
1577 		*path++ = '\0';	/* Here's the PATH */
1578 
1579 		/* Node name must not be empty */
1580 		if (!*node)
1581 			return -1;
1582 
1583 		/* A name of "." is OK; otherwise '.' not allowed */
1584 		if (strcmp(node, ".") != 0) {
1585 			for (k = 0; node[k]; k++)
1586 				if (node[k] == '.')
1587 					return -1;
1588 		}
1589 	} else {
1590 		node = NULL;	/* No absolute NODE */
1591 		path = addr;	/* Here's the PATH */
1592 	}
1593 
1594 	/* Snoop for illegal characters in PATH */
1595 	for (k = 0; path[k]; k++)
1596 		if (path[k] == ':')
1597 			return -1;
1598 
1599 	/* Check for no repeated dots in PATH */
1600 	for (k = 0; path[k]; k++)
1601 		if (path[k] == '.' && path[k + 1] == '.')
1602 			return -1;
1603 
1604 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1605 	if (path[0] == '.')
1606 		path++;
1607 	if (*path && path[strlen(path) - 1] == '.')
1608 		path[strlen(path) - 1] = 0;
1609 
1610 	/* If PATH has a dot, then we're not talking about a hook */
1611 	if (*path) {
1612 		for (hook = path, k = 0; path[k]; k++)
1613 			if (path[k] == '.') {
1614 				hook = NULL;
1615 				break;
1616 			}
1617 	} else
1618 		path = hook = NULL;
1619 
1620 	/* Done */
1621 	if (nodep)
1622 		*nodep = node;
1623 	if (pathp)
1624 		*pathp = path;
1625 	if (hookp)
1626 		*hookp = hook;
1627 	return (0);
1628 }
1629 
1630 /*
1631  * Given a path, which may be absolute or relative, and a starting node,
1632  * return the destination node.
1633  */
1634 int
1635 ng_path2noderef(node_p here, const char *address,
1636 				node_p *destp, hook_p *lasthook)
1637 {
1638 	char    fullpath[NG_PATHSIZ];
1639 	char   *nodename, *path;
1640 	node_p  node, oldnode;
1641 
1642 	/* Initialize */
1643 	if (destp == NULL) {
1644 		TRAP_ERROR();
1645 		return EINVAL;
1646 	}
1647 	*destp = NULL;
1648 
1649 	/* Make a writable copy of address for ng_path_parse() */
1650 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1651 	fullpath[sizeof(fullpath) - 1] = '\0';
1652 
1653 	/* Parse out node and sequence of hooks */
1654 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1655 		TRAP_ERROR();
1656 		return EINVAL;
1657 	}
1658 
1659 	/*
1660 	 * For an absolute address, jump to the starting node.
1661 	 * Note that this holds a reference on the node for us.
1662 	 * Don't forget to drop the reference if we don't need it.
1663 	 */
1664 	if (nodename) {
1665 		node = ng_name2noderef(here, nodename);
1666 		if (node == NULL) {
1667 			TRAP_ERROR();
1668 			return (ENOENT);
1669 		}
1670 	} else {
1671 		if (here == NULL) {
1672 			TRAP_ERROR();
1673 			return (EINVAL);
1674 		}
1675 		node = here;
1676 		NG_NODE_REF(node);
1677 	}
1678 
1679 	if (path == NULL) {
1680 		if (lasthook != NULL)
1681 			*lasthook = NULL;
1682 		*destp = node;
1683 		return (0);
1684 	}
1685 
1686 	/*
1687 	 * Now follow the sequence of hooks
1688 	 *
1689 	 * XXXGL: The path may demolish as we go the sequence, but if
1690 	 * we hold the topology mutex at critical places, then, I hope,
1691 	 * we would always have valid pointers in hand, although the
1692 	 * path behind us may no longer exist.
1693 	 */
1694 	for (;;) {
1695 		hook_p hook;
1696 		char *segment;
1697 
1698 		/*
1699 		 * Break out the next path segment. Replace the dot we just
1700 		 * found with a NUL; "path" points to the next segment (or the
1701 		 * NUL at the end).
1702 		 */
1703 		for (segment = path; *path != '\0'; path++) {
1704 			if (*path == '.') {
1705 				*path++ = '\0';
1706 				break;
1707 			}
1708 		}
1709 
1710 		/* We have a segment, so look for a hook by that name */
1711 		hook = ng_findhook(node, segment);
1712 
1713 		mtx_lock(&ng_topo_mtx);
1714 		/* Can't get there from here... */
1715 		if (hook == NULL
1716 		    || NG_HOOK_PEER(hook) == NULL
1717 		    || NG_HOOK_NOT_VALID(hook)
1718 		    || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
1719 			TRAP_ERROR();
1720 			NG_NODE_UNREF(node);
1721 			mtx_unlock(&ng_topo_mtx);
1722 			return (ENOENT);
1723 		}
1724 
1725 		/*
1726 		 * Hop on over to the next node
1727 		 * XXX
1728 		 * Big race conditions here as hooks and nodes go away
1729 		 * *** Idea.. store an ng_ID_t in each hook and use that
1730 		 * instead of the direct hook in this crawl?
1731 		 */
1732 		oldnode = node;
1733 		if ((node = NG_PEER_NODE(hook)))
1734 			NG_NODE_REF(node);	/* XXX RACE */
1735 		NG_NODE_UNREF(oldnode);	/* XXX another race */
1736 		if (NG_NODE_NOT_VALID(node)) {
1737 			NG_NODE_UNREF(node);	/* XXX more races */
1738 			mtx_unlock(&ng_topo_mtx);
1739 			TRAP_ERROR();
1740 			return (ENXIO);
1741 		}
1742 
1743 		if (*path == '\0') {
1744 			if (lasthook != NULL) {
1745 				if (hook != NULL) {
1746 					*lasthook = NG_HOOK_PEER(hook);
1747 					NG_HOOK_REF(*lasthook);
1748 				} else
1749 					*lasthook = NULL;
1750 			}
1751 			mtx_unlock(&ng_topo_mtx);
1752 			*destp = node;
1753 			return (0);
1754 		}
1755 		mtx_unlock(&ng_topo_mtx);
1756 	}
1757 }
1758 
1759 /***************************************************************\
1760 * Input queue handling.
1761 * All activities are submitted to the node via the input queue
1762 * which implements a multiple-reader/single-writer gate.
1763 * Items which cannot be handled immediately are queued.
1764 *
1765 * read-write queue locking inline functions			*
1766 \***************************************************************/
1767 
1768 static __inline void	ng_queue_rw(node_p node, item_p  item, int rw);
1769 static __inline item_p	ng_dequeue(node_p node, int *rw);
1770 static __inline item_p	ng_acquire_read(node_p node, item_p  item);
1771 static __inline item_p	ng_acquire_write(node_p node, item_p  item);
1772 static __inline void	ng_leave_read(node_p node);
1773 static __inline void	ng_leave_write(node_p node);
1774 
1775 /*
1776  * Definition of the bits fields in the ng_queue flag word.
1777  * Defined here rather than in netgraph.h because no-one should fiddle
1778  * with them.
1779  *
1780  * The ordering here may be important! don't shuffle these.
1781  */
1782 /*-
1783  Safety Barrier--------+ (adjustable to suit taste) (not used yet)
1784                        |
1785                        V
1786 +-------+-------+-------+-------+-------+-------+-------+-------+
1787   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
1788   | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
1789   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
1790 +-------+-------+-------+-------+-------+-------+-------+-------+
1791   \___________________________ ____________________________/ | |
1792                             V                                | |
1793                   [active reader count]                      | |
1794                                                              | |
1795             Operation Pending -------------------------------+ |
1796                                                                |
1797           Active Writer ---------------------------------------+
1798 
1799 Node queue has such semantics:
1800 - All flags modifications are atomic.
1801 - Reader count can be incremented only if there is no writer or pending flags.
1802   As soon as this can't be done with single operation, it is implemented with
1803   spin loop and atomic_cmpset().
1804 - Writer flag can be set only if there is no any bits set.
1805   It is implemented with atomic_cmpset().
1806 - Pending flag can be set any time, but to avoid collision on queue processing
1807   all queue fields are protected by the mutex.
1808 - Queue processing thread reads queue holding the mutex, but releases it while
1809   processing. When queue is empty pending flag is removed.
1810 */
1811 
1812 #define WRITER_ACTIVE	0x00000001
1813 #define OP_PENDING	0x00000002
1814 #define READER_INCREMENT 0x00000004
1815 #define READER_MASK	0xfffffffc	/* Not valid if WRITER_ACTIVE is set */
1816 #define SAFETY_BARRIER	0x00100000	/* 128K items queued should be enough */
1817 
1818 /* Defines of more elaborate states on the queue */
1819 /* Mask of bits a new read cares about */
1820 #define NGQ_RMASK	(WRITER_ACTIVE|OP_PENDING)
1821 
1822 /* Mask of bits a new write cares about */
1823 #define NGQ_WMASK	(NGQ_RMASK|READER_MASK)
1824 
1825 /* Test to decide if there is something on the queue. */
1826 #define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
1827 
1828 /* How to decide what the next queued item is. */
1829 #define HEAD_IS_READER(QP)  NGI_QUEUED_READER(STAILQ_FIRST(&(QP)->queue))
1830 #define HEAD_IS_WRITER(QP)  NGI_QUEUED_WRITER(STAILQ_FIRST(&(QP)->queue)) /* notused */
1831 
1832 /* Read the status to decide if the next item on the queue can now run. */
1833 #define QUEUED_READER_CAN_PROCEED(QP)			\
1834 		(((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
1835 #define QUEUED_WRITER_CAN_PROCEED(QP)			\
1836 		(((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
1837 
1838 /* Is there a chance of getting ANY work off the queue? */
1839 #define NEXT_QUEUED_ITEM_CAN_PROCEED(QP)				\
1840 	((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) :		\
1841 				QUEUED_WRITER_CAN_PROCEED(QP))
1842 
1843 #define NGQRW_R 0
1844 #define NGQRW_W 1
1845 
1846 #define NGQ2_WORKQ	0x00000001
1847 
1848 /*
1849  * Taking into account the current state of the queue and node, possibly take
1850  * the next entry off the queue and return it. Return NULL if there was
1851  * nothing we could return, either because there really was nothing there, or
1852  * because the node was in a state where it cannot yet process the next item
1853  * on the queue.
1854  */
1855 static __inline item_p
1856 ng_dequeue(node_p node, int *rw)
1857 {
1858 	item_p item;
1859 	struct ng_queue *ngq = &node->nd_input_queue;
1860 
1861 	/* This MUST be called with the mutex held. */
1862 	mtx_assert(&ngq->q_mtx, MA_OWNED);
1863 
1864 	/* If there is nothing queued, then just return. */
1865 	if (!QUEUE_ACTIVE(ngq)) {
1866 		CTR4(KTR_NET, "%20s: node [%x] (%p) queue empty; "
1867 		    "queue flags 0x%lx", __func__,
1868 		    node->nd_ID, node, ngq->q_flags);
1869 		return (NULL);
1870 	}
1871 
1872 	/*
1873 	 * From here, we can assume there is a head item.
1874 	 * We need to find out what it is and if it can be dequeued, given
1875 	 * the current state of the node.
1876 	 */
1877 	if (HEAD_IS_READER(ngq)) {
1878 		while (1) {
1879 			long t = ngq->q_flags;
1880 			if (t & WRITER_ACTIVE) {
1881 				/* There is writer, reader can't proceed. */
1882 				CTR4(KTR_NET, "%20s: node [%x] (%p) queued reader "
1883 				    "can't proceed; queue flags 0x%lx", __func__,
1884 				    node->nd_ID, node, t);
1885 				return (NULL);
1886 			}
1887 			if (atomic_cmpset_acq_int(&ngq->q_flags, t,
1888 			    t + READER_INCREMENT))
1889 				break;
1890 			cpu_spinwait();
1891 		}
1892 		/* We have got reader lock for the node. */
1893 		*rw = NGQRW_R;
1894 	} else if (atomic_cmpset_acq_int(&ngq->q_flags, OP_PENDING,
1895 	    OP_PENDING + WRITER_ACTIVE)) {
1896 		/* We have got writer lock for the node. */
1897 		*rw = NGQRW_W;
1898 	} else {
1899 		/* There is somebody other, writer can't proceed. */
1900 		CTR4(KTR_NET, "%20s: node [%x] (%p) queued writer "
1901 		    "can't proceed; queue flags 0x%lx", __func__,
1902 		    node->nd_ID, node, ngq->q_flags);
1903 		return (NULL);
1904 	}
1905 
1906 	/*
1907 	 * Now we dequeue the request (whatever it may be) and correct the
1908 	 * pending flags and the next and last pointers.
1909 	 */
1910 	item = STAILQ_FIRST(&ngq->queue);
1911 	STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
1912 	if (STAILQ_EMPTY(&ngq->queue))
1913 		atomic_clear_int(&ngq->q_flags, OP_PENDING);
1914 	CTR6(KTR_NET, "%20s: node [%x] (%p) returning item %p as %s; "
1915 	    "queue flags 0x%lx", __func__,
1916 	    node->nd_ID, node, item, *rw ? "WRITER" : "READER" ,
1917 	    ngq->q_flags);
1918 	return (item);
1919 }
1920 
1921 /*
1922  * Queue a packet to be picked up later by someone else.
1923  * If the queue could be run now, add node to the queue handler's worklist.
1924  */
1925 static __inline void
1926 ng_queue_rw(node_p node, item_p  item, int rw)
1927 {
1928 	struct ng_queue *ngq = &node->nd_input_queue;
1929 	if (rw == NGQRW_W)
1930 		NGI_SET_WRITER(item);
1931 	else
1932 		NGI_SET_READER(item);
1933 
1934 	NG_QUEUE_LOCK(ngq);
1935 	/* Set OP_PENDING flag and enqueue the item. */
1936 	atomic_set_int(&ngq->q_flags, OP_PENDING);
1937 	STAILQ_INSERT_TAIL(&ngq->queue, item, el_next);
1938 
1939 	CTR5(KTR_NET, "%20s: node [%x] (%p) queued item %p as %s", __func__,
1940 	    node->nd_ID, node, item, rw ? "WRITER" : "READER" );
1941 
1942 	/*
1943 	 * We can take the worklist lock with the node locked
1944 	 * BUT NOT THE REVERSE!
1945 	 */
1946 	if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
1947 		ng_worklist_add(node);
1948 	NG_QUEUE_UNLOCK(ngq);
1949 }
1950 
1951 /* Acquire reader lock on node. If node is busy, queue the packet. */
1952 static __inline item_p
1953 ng_acquire_read(node_p node, item_p item)
1954 {
1955 	KASSERT(node != &ng_deadnode,
1956 	    ("%s: working on deadnode", __func__));
1957 
1958 	/* Reader needs node without writer and pending items. */
1959 	while (1) {
1960 		long t = node->nd_input_queue.q_flags;
1961 		if (t & NGQ_RMASK)
1962 			break; /* Node is not ready for reader. */
1963 		if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
1964 		    t, t + READER_INCREMENT)) {
1965 	    		/* Successfully grabbed node */
1966 			CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
1967 			    __func__, node->nd_ID, node, item);
1968 			return (item);
1969 		}
1970 		cpu_spinwait();
1971 	};
1972 
1973 	/* Queue the request for later. */
1974 	ng_queue_rw(node, item, NGQRW_R);
1975 
1976 	return (NULL);
1977 }
1978 
1979 /* Acquire writer lock on node. If node is busy, queue the packet. */
1980 static __inline item_p
1981 ng_acquire_write(node_p node, item_p item)
1982 {
1983 	KASSERT(node != &ng_deadnode,
1984 	    ("%s: working on deadnode", __func__));
1985 
1986 	/* Writer needs completely idle node. */
1987 	if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
1988 	    0, WRITER_ACTIVE)) {
1989 	    	/* Successfully grabbed node */
1990 		CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
1991 		    __func__, node->nd_ID, node, item);
1992 		return (item);
1993 	}
1994 
1995 	/* Queue the request for later. */
1996 	ng_queue_rw(node, item, NGQRW_W);
1997 
1998 	return (NULL);
1999 }
2000 
2001 #if 0
2002 static __inline item_p
2003 ng_upgrade_write(node_p node, item_p item)
2004 {
2005 	struct ng_queue *ngq = &node->nd_input_queue;
2006 	KASSERT(node != &ng_deadnode,
2007 	    ("%s: working on deadnode", __func__));
2008 
2009 	NGI_SET_WRITER(item);
2010 
2011 	NG_QUEUE_LOCK(ngq);
2012 
2013 	/*
2014 	 * There will never be no readers as we are there ourselves.
2015 	 * Set the WRITER_ACTIVE flags ASAP to block out fast track readers.
2016 	 * The caller we are running from will call ng_leave_read()
2017 	 * soon, so we must account for that. We must leave again with the
2018 	 * READER lock. If we find other readers, then
2019 	 * queue the request for later. However "later" may be rignt now
2020 	 * if there are no readers. We don't really care if there are queued
2021 	 * items as we will bypass them anyhow.
2022 	 */
2023 	atomic_add_int(&ngq->q_flags, WRITER_ACTIVE - READER_INCREMENT);
2024 	if ((ngq->q_flags & (NGQ_WMASK & ~OP_PENDING)) == WRITER_ACTIVE) {
2025 		NG_QUEUE_UNLOCK(ngq);
2026 
2027 		/* It's just us, act on the item. */
2028 		/* will NOT drop writer lock when done */
2029 		ng_apply_item(node, item, 0);
2030 
2031 		/*
2032 		 * Having acted on the item, atomically
2033 		 * down grade back to READER and finish up
2034 	 	 */
2035 		atomic_add_int(&ngq->q_flags,
2036 		    READER_INCREMENT - WRITER_ACTIVE);
2037 
2038 		/* Our caller will call ng_leave_read() */
2039 		return;
2040 	}
2041 	/*
2042 	 * It's not just us active, so queue us AT THE HEAD.
2043 	 * "Why?" I hear you ask.
2044 	 * Put us at the head of the queue as we've already been
2045 	 * through it once. If there is nothing else waiting,
2046 	 * set the correct flags.
2047 	 */
2048 	if (STAILQ_EMPTY(&ngq->queue)) {
2049 		/* We've gone from, 0 to 1 item in the queue */
2050 		atomic_set_int(&ngq->q_flags, OP_PENDING);
2051 
2052 		CTR3(KTR_NET, "%20s: node [%x] (%p) set OP_PENDING", __func__,
2053 		    node->nd_ID, node);
2054 	};
2055 	STAILQ_INSERT_HEAD(&ngq->queue, item, el_next);
2056 	CTR4(KTR_NET, "%20s: node [%x] (%p) requeued item %p as WRITER",
2057 	    __func__, node->nd_ID, node, item );
2058 
2059 	/* Reverse what we did above. That downgrades us back to reader */
2060 	atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
2061 	if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2062 		ng_worklist_add(node);
2063 	NG_QUEUE_UNLOCK(ngq);
2064 
2065 	return;
2066 }
2067 #endif
2068 
2069 /* Release reader lock. */
2070 static __inline void
2071 ng_leave_read(node_p node)
2072 {
2073 	atomic_subtract_rel_int(&node->nd_input_queue.q_flags, READER_INCREMENT);
2074 }
2075 
2076 /* Release writer lock. */
2077 static __inline void
2078 ng_leave_write(node_p node)
2079 {
2080 	atomic_clear_rel_int(&node->nd_input_queue.q_flags, WRITER_ACTIVE);
2081 }
2082 
2083 /* Purge node queue. Called on node shutdown. */
2084 static void
2085 ng_flush_input_queue(node_p node)
2086 {
2087 	struct ng_queue *ngq = &node->nd_input_queue;
2088 	item_p item;
2089 
2090 	NG_QUEUE_LOCK(ngq);
2091 	while ((item = STAILQ_FIRST(&ngq->queue)) != NULL) {
2092 		STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
2093 		if (STAILQ_EMPTY(&ngq->queue))
2094 			atomic_clear_int(&ngq->q_flags, OP_PENDING);
2095 		NG_QUEUE_UNLOCK(ngq);
2096 
2097 		/* If the item is supplying a callback, call it with an error */
2098 		if (item->apply != NULL) {
2099 			if (item->depth == 1)
2100 				item->apply->error = ENOENT;
2101 			if (refcount_release(&item->apply->refs)) {
2102 				(*item->apply->apply)(item->apply->context,
2103 				    item->apply->error);
2104 			}
2105 		}
2106 		NG_FREE_ITEM(item);
2107 		NG_QUEUE_LOCK(ngq);
2108 	}
2109 	NG_QUEUE_UNLOCK(ngq);
2110 }
2111 
2112 /***********************************************************************
2113 * Externally visible method for sending or queueing messages or data.
2114 ***********************************************************************/
2115 
2116 /*
2117  * The module code should have filled out the item correctly by this stage:
2118  * Common:
2119  *    reference to destination node.
2120  *    Reference to destination rcv hook if relevant.
2121  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
2122  * Data:
2123  *    pointer to mbuf
2124  * Control_Message:
2125  *    pointer to msg.
2126  *    ID of original sender node. (return address)
2127  * Function:
2128  *    Function pointer
2129  *    void * argument
2130  *    integer argument
2131  *
2132  * The nodes have several routines and macros to help with this task:
2133  */
2134 
2135 int
2136 ng_snd_item(item_p item, int flags)
2137 {
2138 	hook_p hook;
2139 	node_p node;
2140 	int queue, rw;
2141 	struct ng_queue *ngq;
2142 	int error = 0;
2143 
2144 	/* We are sending item, so it must be present! */
2145 	KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
2146 
2147 #ifdef	NETGRAPH_DEBUG
2148 	_ngi_check(item, __FILE__, __LINE__);
2149 #endif
2150 
2151 	/* Item was sent once more, postpone apply() call. */
2152 	if (item->apply)
2153 		refcount_acquire(&item->apply->refs);
2154 
2155 	node = NGI_NODE(item);
2156 	/* Node is never optional. */
2157 	KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
2158 
2159 	hook = NGI_HOOK(item);
2160 	/* Valid hook and mbuf are mandatory for data. */
2161 	if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
2162 		KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
2163 		if (NGI_M(item) == NULL)
2164 			ERROUT(EINVAL);
2165 		CHECK_DATA_MBUF(NGI_M(item));
2166 	}
2167 
2168 	/*
2169 	 * If the item or the node specifies single threading, force
2170 	 * writer semantics. Similarly, the node may say one hook always
2171 	 * produces writers. These are overrides.
2172 	 */
2173 	if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
2174 	    (node->nd_flags & NGF_FORCE_WRITER) ||
2175 	    (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
2176 		rw = NGQRW_W;
2177 	} else {
2178 		rw = NGQRW_R;
2179 	}
2180 
2181 	/*
2182 	 * If sender or receiver requests queued delivery, or call graph
2183 	 * loops back from outbound to inbound path, or stack usage
2184 	 * level is dangerous - enqueue message.
2185 	 */
2186 	if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
2187 		queue = 1;
2188 	} else if (hook && (hook->hk_flags & HK_TO_INBOUND) &&
2189 	    curthread->td_ng_outbound) {
2190 		queue = 1;
2191 	} else {
2192 		queue = 0;
2193 #ifdef GET_STACK_USAGE
2194 		/*
2195 		 * Most of netgraph nodes have small stack consumption and
2196 		 * for them 25% of free stack space is more than enough.
2197 		 * Nodes/hooks with higher stack usage should be marked as
2198 		 * HI_STACK. For them 50% of stack will be guaranteed then.
2199 		 * XXX: Values 25% and 50% are completely empirical.
2200 		 */
2201 		size_t	st, su, sl;
2202 		GET_STACK_USAGE(st, su);
2203 		sl = st - su;
2204 		if ((sl * 4 < st) ||
2205 		    ((sl * 2 < st) && ((node->nd_flags & NGF_HI_STACK) ||
2206 		      (hook && (hook->hk_flags & HK_HI_STACK))))) {
2207 			queue = 1;
2208 		}
2209 #endif
2210 	}
2211 
2212 	if (queue) {
2213 		item->depth = 1;
2214 		/* Put it on the queue for that node*/
2215 		ng_queue_rw(node, item, rw);
2216 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2217 	}
2218 
2219 	/*
2220 	 * We already decided how we will be queueud or treated.
2221 	 * Try get the appropriate operating permission.
2222 	 */
2223  	if (rw == NGQRW_R)
2224 		item = ng_acquire_read(node, item);
2225 	else
2226 		item = ng_acquire_write(node, item);
2227 
2228 	/* Item was queued while trying to get permission. */
2229 	if (item == NULL)
2230 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2231 
2232 	NGI_GET_NODE(item, node); /* zaps stored node */
2233 
2234 	item->depth++;
2235 	error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
2236 
2237 	/* If something is waiting on queue and ready, schedule it. */
2238 	ngq = &node->nd_input_queue;
2239 	if (QUEUE_ACTIVE(ngq)) {
2240 		NG_QUEUE_LOCK(ngq);
2241 		if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2242 			ng_worklist_add(node);
2243 		NG_QUEUE_UNLOCK(ngq);
2244 	}
2245 
2246 	/*
2247 	 * Node may go away as soon as we remove the reference.
2248 	 * Whatever we do, DO NOT access the node again!
2249 	 */
2250 	NG_NODE_UNREF(node);
2251 
2252 	return (error);
2253 
2254 done:
2255 	/* If was not sent, apply callback here. */
2256 	if (item->apply != NULL) {
2257 		if (item->depth == 0 && error != 0)
2258 			item->apply->error = error;
2259 		if (refcount_release(&item->apply->refs)) {
2260 			(*item->apply->apply)(item->apply->context,
2261 			    item->apply->error);
2262 		}
2263 	}
2264 
2265 	NG_FREE_ITEM(item);
2266 	return (error);
2267 }
2268 
2269 /*
2270  * We have an item that was possibly queued somewhere.
2271  * It should contain all the information needed
2272  * to run it on the appropriate node/hook.
2273  * If there is apply pointer and we own the last reference, call apply().
2274  */
2275 static int
2276 ng_apply_item(node_p node, item_p item, int rw)
2277 {
2278 	hook_p  hook;
2279 	ng_rcvdata_t *rcvdata;
2280 	ng_rcvmsg_t *rcvmsg;
2281 	struct ng_apply_info *apply;
2282 	int	error = 0, depth;
2283 
2284 	/* Node and item are never optional. */
2285 	KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
2286 	KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
2287 
2288 	NGI_GET_HOOK(item, hook); /* clears stored hook */
2289 #ifdef	NETGRAPH_DEBUG
2290 	_ngi_check(item, __FILE__, __LINE__);
2291 #endif
2292 
2293 	apply = item->apply;
2294 	depth = item->depth;
2295 
2296 	switch (item->el_flags & NGQF_TYPE) {
2297 	case NGQF_DATA:
2298 		/*
2299 		 * Check things are still ok as when we were queued.
2300 		 */
2301 		KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
2302 		if (NG_HOOK_NOT_VALID(hook) ||
2303 		    NG_NODE_NOT_VALID(node)) {
2304 			error = EIO;
2305 			NG_FREE_ITEM(item);
2306 			break;
2307 		}
2308 		/*
2309 		 * If no receive method, just silently drop it.
2310 		 * Give preference to the hook over-ride method
2311 		 */
2312 		if ((!(rcvdata = hook->hk_rcvdata))
2313 		&& (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
2314 			error = 0;
2315 			NG_FREE_ITEM(item);
2316 			break;
2317 		}
2318 		error = (*rcvdata)(hook, item);
2319 		break;
2320 	case NGQF_MESG:
2321 		if (hook && NG_HOOK_NOT_VALID(hook)) {
2322 			/*
2323 			 * The hook has been zapped then we can't use it.
2324 			 * Immediately drop its reference.
2325 			 * The message may not need it.
2326 			 */
2327 			NG_HOOK_UNREF(hook);
2328 			hook = NULL;
2329 		}
2330 		/*
2331 		 * Similarly, if the node is a zombie there is
2332 		 * nothing we can do with it, drop everything.
2333 		 */
2334 		if (NG_NODE_NOT_VALID(node)) {
2335 			TRAP_ERROR();
2336 			error = EINVAL;
2337 			NG_FREE_ITEM(item);
2338 			break;
2339 		}
2340 		/*
2341 		 * Call the appropriate message handler for the object.
2342 		 * It is up to the message handler to free the message.
2343 		 * If it's a generic message, handle it generically,
2344 		 * otherwise call the type's message handler (if it exists).
2345 		 * XXX (race). Remember that a queued message may
2346 		 * reference a node or hook that has just been
2347 		 * invalidated. It will exist as the queue code
2348 		 * is holding a reference, but..
2349 		 */
2350 		if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
2351 		    ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
2352 			error = ng_generic_msg(node, item, hook);
2353 			break;
2354 		}
2355 		if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
2356 		    (!(rcvmsg = node->nd_type->rcvmsg))) {
2357 			TRAP_ERROR();
2358 			error = 0;
2359 			NG_FREE_ITEM(item);
2360 			break;
2361 		}
2362 		error = (*rcvmsg)(node, item, hook);
2363 		break;
2364 	case NGQF_FN:
2365 	case NGQF_FN2:
2366 		/*
2367 		 * In the case of the shutdown message we allow it to hit
2368 		 * even if the node is invalid.
2369 		 */
2370 		if (NG_NODE_NOT_VALID(node) &&
2371 		    NGI_FN(item) != &ng_rmnode) {
2372 			TRAP_ERROR();
2373 			error = EINVAL;
2374 			NG_FREE_ITEM(item);
2375 			break;
2376 		}
2377 		/* Same is about some internal functions and invalid hook. */
2378 		if (hook && NG_HOOK_NOT_VALID(hook) &&
2379 		    NGI_FN2(item) != &ng_con_part2 &&
2380 		    NGI_FN2(item) != &ng_con_part3 &&
2381 		    NGI_FN(item) != &ng_rmhook_part2) {
2382 			TRAP_ERROR();
2383 			error = EINVAL;
2384 			NG_FREE_ITEM(item);
2385 			break;
2386 		}
2387 
2388 		if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
2389 			(*NGI_FN(item))(node, hook, NGI_ARG1(item),
2390 			    NGI_ARG2(item));
2391 			NG_FREE_ITEM(item);
2392 		} else	/* it is NGQF_FN2 */
2393 			error = (*NGI_FN2(item))(node, item, hook);
2394 		break;
2395 	}
2396 	/*
2397 	 * We held references on some of the resources
2398 	 * that we took from the item. Now that we have
2399 	 * finished doing everything, drop those references.
2400 	 */
2401 	if (hook)
2402 		NG_HOOK_UNREF(hook);
2403 
2404  	if (rw == NGQRW_R)
2405 		ng_leave_read(node);
2406 	else
2407 		ng_leave_write(node);
2408 
2409 	/* Apply callback. */
2410 	if (apply != NULL) {
2411 		if (depth == 1 && error != 0)
2412 			apply->error = error;
2413 		if (refcount_release(&apply->refs))
2414 			(*apply->apply)(apply->context, apply->error);
2415 	}
2416 
2417 	return (error);
2418 }
2419 
2420 /***********************************************************************
2421  * Implement the 'generic' control messages
2422  ***********************************************************************/
2423 static int
2424 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
2425 {
2426 	int error = 0;
2427 	struct ng_mesg *msg;
2428 	struct ng_mesg *resp = NULL;
2429 
2430 	NGI_GET_MSG(item, msg);
2431 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
2432 		TRAP_ERROR();
2433 		error = EINVAL;
2434 		goto out;
2435 	}
2436 	switch (msg->header.cmd) {
2437 	case NGM_SHUTDOWN:
2438 		ng_rmnode(here, NULL, NULL, 0);
2439 		break;
2440 	case NGM_MKPEER:
2441 	    {
2442 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
2443 
2444 		if (msg->header.arglen != sizeof(*mkp)) {
2445 			TRAP_ERROR();
2446 			error = EINVAL;
2447 			break;
2448 		}
2449 		mkp->type[sizeof(mkp->type) - 1] = '\0';
2450 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
2451 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
2452 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
2453 		break;
2454 	    }
2455 	case NGM_CONNECT:
2456 	    {
2457 		struct ngm_connect *const con =
2458 			(struct ngm_connect *) msg->data;
2459 		node_p node2;
2460 
2461 		if (msg->header.arglen != sizeof(*con)) {
2462 			TRAP_ERROR();
2463 			error = EINVAL;
2464 			break;
2465 		}
2466 		con->path[sizeof(con->path) - 1] = '\0';
2467 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
2468 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
2469 		/* Don't forget we get a reference.. */
2470 		error = ng_path2noderef(here, con->path, &node2, NULL);
2471 		if (error)
2472 			break;
2473 		error = ng_con_nodes(item, here, con->ourhook,
2474 		    node2, con->peerhook);
2475 		NG_NODE_UNREF(node2);
2476 		break;
2477 	    }
2478 	case NGM_NAME:
2479 	    {
2480 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
2481 
2482 		if (msg->header.arglen != sizeof(*nam)) {
2483 			TRAP_ERROR();
2484 			error = EINVAL;
2485 			break;
2486 		}
2487 		nam->name[sizeof(nam->name) - 1] = '\0';
2488 		error = ng_name_node(here, nam->name);
2489 		break;
2490 	    }
2491 	case NGM_RMHOOK:
2492 	    {
2493 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
2494 		hook_p hook;
2495 
2496 		if (msg->header.arglen != sizeof(*rmh)) {
2497 			TRAP_ERROR();
2498 			error = EINVAL;
2499 			break;
2500 		}
2501 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
2502 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
2503 			ng_destroy_hook(hook);
2504 		break;
2505 	    }
2506 	case NGM_NODEINFO:
2507 	    {
2508 		struct nodeinfo *ni;
2509 
2510 		NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
2511 		if (resp == NULL) {
2512 			error = ENOMEM;
2513 			break;
2514 		}
2515 
2516 		/* Fill in node info */
2517 		ni = (struct nodeinfo *) resp->data;
2518 		if (NG_NODE_HAS_NAME(here))
2519 			strcpy(ni->name, NG_NODE_NAME(here));
2520 		strcpy(ni->type, here->nd_type->name);
2521 		ni->id = ng_node2ID(here);
2522 		ni->hooks = here->nd_numhooks;
2523 		break;
2524 	    }
2525 	case NGM_LISTHOOKS:
2526 	    {
2527 		const int nhooks = here->nd_numhooks;
2528 		struct hooklist *hl;
2529 		struct nodeinfo *ni;
2530 		hook_p hook;
2531 
2532 		/* Get response struct */
2533 		NG_MKRESPONSE(resp, msg, sizeof(*hl)
2534 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
2535 		if (resp == NULL) {
2536 			error = ENOMEM;
2537 			break;
2538 		}
2539 		hl = (struct hooklist *) resp->data;
2540 		ni = &hl->nodeinfo;
2541 
2542 		/* Fill in node info */
2543 		if (NG_NODE_HAS_NAME(here))
2544 			strcpy(ni->name, NG_NODE_NAME(here));
2545 		strcpy(ni->type, here->nd_type->name);
2546 		ni->id = ng_node2ID(here);
2547 
2548 		/* Cycle through the linked list of hooks */
2549 		ni->hooks = 0;
2550 		LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
2551 			struct linkinfo *const link = &hl->link[ni->hooks];
2552 
2553 			if (ni->hooks >= nhooks) {
2554 				log(LOG_ERR, "%s: number of %s changed\n",
2555 				    __func__, "hooks");
2556 				break;
2557 			}
2558 			if (NG_HOOK_NOT_VALID(hook))
2559 				continue;
2560 			strcpy(link->ourhook, NG_HOOK_NAME(hook));
2561 			strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
2562 			if (NG_PEER_NODE_NAME(hook)[0] != '\0')
2563 				strcpy(link->nodeinfo.name,
2564 				    NG_PEER_NODE_NAME(hook));
2565 			strcpy(link->nodeinfo.type,
2566 			   NG_PEER_NODE(hook)->nd_type->name);
2567 			link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
2568 			link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
2569 			ni->hooks++;
2570 		}
2571 		break;
2572 	    }
2573 
2574 	case NGM_LISTNAMES:
2575 	case NGM_LISTNODES:
2576 	    {
2577 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
2578 		struct namelist *nl;
2579 		node_p node;
2580 		int num = 0, i;
2581 
2582 		mtx_lock(&ng_namehash_mtx);
2583 		/* Count number of nodes */
2584 		for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
2585 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
2586 				if (NG_NODE_IS_VALID(node) &&
2587 				    (unnamed || NG_NODE_HAS_NAME(node))) {
2588 					num++;
2589 				}
2590 			}
2591 		}
2592 		mtx_unlock(&ng_namehash_mtx);
2593 
2594 		/* Get response struct */
2595 		NG_MKRESPONSE(resp, msg, sizeof(*nl)
2596 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
2597 		if (resp == NULL) {
2598 			error = ENOMEM;
2599 			break;
2600 		}
2601 		nl = (struct namelist *) resp->data;
2602 
2603 		/* Cycle through the linked list of nodes */
2604 		nl->numnames = 0;
2605 		mtx_lock(&ng_namehash_mtx);
2606 		for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
2607 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
2608 				struct nodeinfo *const np =
2609 				    &nl->nodeinfo[nl->numnames];
2610 
2611 				if (NG_NODE_NOT_VALID(node))
2612 					continue;
2613 				if (!unnamed && (! NG_NODE_HAS_NAME(node)))
2614 					continue;
2615 				if (nl->numnames >= num) {
2616 					log(LOG_ERR, "%s: number of nodes changed\n",
2617 					    __func__);
2618 					break;
2619 				}
2620 				if (NG_NODE_HAS_NAME(node))
2621 					strcpy(np->name, NG_NODE_NAME(node));
2622 				strcpy(np->type, node->nd_type->name);
2623 				np->id = ng_node2ID(node);
2624 				np->hooks = node->nd_numhooks;
2625 				nl->numnames++;
2626 			}
2627 		}
2628 		mtx_unlock(&ng_namehash_mtx);
2629 		break;
2630 	    }
2631 
2632 	case NGM_LISTTYPES:
2633 	    {
2634 		struct typelist *tl;
2635 		struct ng_type *type;
2636 		int num = 0;
2637 
2638 		mtx_lock(&ng_typelist_mtx);
2639 		/* Count number of types */
2640 		LIST_FOREACH(type, &ng_typelist, types) {
2641 			num++;
2642 		}
2643 		mtx_unlock(&ng_typelist_mtx);
2644 
2645 		/* Get response struct */
2646 		NG_MKRESPONSE(resp, msg, sizeof(*tl)
2647 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
2648 		if (resp == NULL) {
2649 			error = ENOMEM;
2650 			break;
2651 		}
2652 		tl = (struct typelist *) resp->data;
2653 
2654 		/* Cycle through the linked list of types */
2655 		tl->numtypes = 0;
2656 		mtx_lock(&ng_typelist_mtx);
2657 		LIST_FOREACH(type, &ng_typelist, types) {
2658 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
2659 
2660 			if (tl->numtypes >= num) {
2661 				log(LOG_ERR, "%s: number of %s changed\n",
2662 				    __func__, "types");
2663 				break;
2664 			}
2665 			strcpy(tp->type_name, type->name);
2666 			tp->numnodes = type->refs - 1; /* don't count list */
2667 			tl->numtypes++;
2668 		}
2669 		mtx_unlock(&ng_typelist_mtx);
2670 		break;
2671 	    }
2672 
2673 	case NGM_BINARY2ASCII:
2674 	    {
2675 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2676 		const struct ng_parse_type *argstype;
2677 		const struct ng_cmdlist *c;
2678 		struct ng_mesg *binary, *ascii;
2679 
2680 		/* Data area must contain a valid netgraph message */
2681 		binary = (struct ng_mesg *)msg->data;
2682 		if (msg->header.arglen < sizeof(struct ng_mesg) ||
2683 		    (msg->header.arglen - sizeof(struct ng_mesg) <
2684 		    binary->header.arglen)) {
2685 			TRAP_ERROR();
2686 			error = EINVAL;
2687 			break;
2688 		}
2689 
2690 		/* Get a response message with lots of room */
2691 		NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
2692 		if (resp == NULL) {
2693 			error = ENOMEM;
2694 			break;
2695 		}
2696 		ascii = (struct ng_mesg *)resp->data;
2697 
2698 		/* Copy binary message header to response message payload */
2699 		bcopy(binary, ascii, sizeof(*binary));
2700 
2701 		/* Find command by matching typecookie and command number */
2702 		for (c = here->nd_type->cmdlist;
2703 		    c != NULL && c->name != NULL; c++) {
2704 			if (binary->header.typecookie == c->cookie
2705 			    && binary->header.cmd == c->cmd)
2706 				break;
2707 		}
2708 		if (c == NULL || c->name == NULL) {
2709 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2710 				if (binary->header.typecookie == c->cookie
2711 				    && binary->header.cmd == c->cmd)
2712 					break;
2713 			}
2714 			if (c->name == NULL) {
2715 				NG_FREE_MSG(resp);
2716 				error = ENOSYS;
2717 				break;
2718 			}
2719 		}
2720 
2721 		/* Convert command name to ASCII */
2722 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
2723 		    "%s", c->name);
2724 
2725 		/* Convert command arguments to ASCII */
2726 		argstype = (binary->header.flags & NGF_RESP) ?
2727 		    c->respType : c->mesgType;
2728 		if (argstype == NULL) {
2729 			*ascii->data = '\0';
2730 		} else {
2731 			if ((error = ng_unparse(argstype,
2732 			    (u_char *)binary->data,
2733 			    ascii->data, bufSize)) != 0) {
2734 				NG_FREE_MSG(resp);
2735 				break;
2736 			}
2737 		}
2738 
2739 		/* Return the result as struct ng_mesg plus ASCII string */
2740 		bufSize = strlen(ascii->data) + 1;
2741 		ascii->header.arglen = bufSize;
2742 		resp->header.arglen = sizeof(*ascii) + bufSize;
2743 		break;
2744 	    }
2745 
2746 	case NGM_ASCII2BINARY:
2747 	    {
2748 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2749 		const struct ng_cmdlist *c;
2750 		const struct ng_parse_type *argstype;
2751 		struct ng_mesg *ascii, *binary;
2752 		int off = 0;
2753 
2754 		/* Data area must contain at least a struct ng_mesg + '\0' */
2755 		ascii = (struct ng_mesg *)msg->data;
2756 		if ((msg->header.arglen < sizeof(*ascii) + 1) ||
2757 		    (ascii->header.arglen < 1) ||
2758 		    (msg->header.arglen < sizeof(*ascii) +
2759 		    ascii->header.arglen)) {
2760 			TRAP_ERROR();
2761 			error = EINVAL;
2762 			break;
2763 		}
2764 		ascii->data[ascii->header.arglen - 1] = '\0';
2765 
2766 		/* Get a response message with lots of room */
2767 		NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
2768 		if (resp == NULL) {
2769 			error = ENOMEM;
2770 			break;
2771 		}
2772 		binary = (struct ng_mesg *)resp->data;
2773 
2774 		/* Copy ASCII message header to response message payload */
2775 		bcopy(ascii, binary, sizeof(*ascii));
2776 
2777 		/* Find command by matching ASCII command string */
2778 		for (c = here->nd_type->cmdlist;
2779 		    c != NULL && c->name != NULL; c++) {
2780 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
2781 				break;
2782 		}
2783 		if (c == NULL || c->name == NULL) {
2784 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2785 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
2786 					break;
2787 			}
2788 			if (c->name == NULL) {
2789 				NG_FREE_MSG(resp);
2790 				error = ENOSYS;
2791 				break;
2792 			}
2793 		}
2794 
2795 		/* Convert command name to binary */
2796 		binary->header.cmd = c->cmd;
2797 		binary->header.typecookie = c->cookie;
2798 
2799 		/* Convert command arguments to binary */
2800 		argstype = (binary->header.flags & NGF_RESP) ?
2801 		    c->respType : c->mesgType;
2802 		if (argstype == NULL) {
2803 			bufSize = 0;
2804 		} else {
2805 			if ((error = ng_parse(argstype, ascii->data,
2806 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
2807 				NG_FREE_MSG(resp);
2808 				break;
2809 			}
2810 		}
2811 
2812 		/* Return the result */
2813 		binary->header.arglen = bufSize;
2814 		resp->header.arglen = sizeof(*binary) + bufSize;
2815 		break;
2816 	    }
2817 
2818 	case NGM_TEXT_CONFIG:
2819 	case NGM_TEXT_STATUS:
2820 		/*
2821 		 * This one is tricky as it passes the command down to the
2822 		 * actual node, even though it is a generic type command.
2823 		 * This means we must assume that the item/msg is already freed
2824 		 * when control passes back to us.
2825 		 */
2826 		if (here->nd_type->rcvmsg != NULL) {
2827 			NGI_MSG(item) = msg; /* put it back as we found it */
2828 			return((*here->nd_type->rcvmsg)(here, item, lasthook));
2829 		}
2830 		/* Fall through if rcvmsg not supported */
2831 	default:
2832 		TRAP_ERROR();
2833 		error = EINVAL;
2834 	}
2835 	/*
2836 	 * Sometimes a generic message may be statically allocated
2837 	 * to avoid problems with allocating when in tight memeory situations.
2838 	 * Don't free it if it is so.
2839 	 * I break them appart here, because erros may cause a free if the item
2840 	 * in which case we'd be doing it twice.
2841 	 * they are kept together above, to simplify freeing.
2842 	 */
2843 out:
2844 	NG_RESPOND_MSG(error, here, item, resp);
2845 	NG_FREE_MSG(msg);
2846 	return (error);
2847 }
2848 
2849 /************************************************************************
2850 			Queue element get/free routines
2851 ************************************************************************/
2852 
2853 uma_zone_t			ng_qzone;
2854 uma_zone_t			ng_qdzone;
2855 static int			numthreads = 0; /* number of queue threads */
2856 static int			maxalloc = 4096;/* limit the damage of a leak */
2857 static int			maxdata = 512;	/* limit the damage of a DoS */
2858 
2859 TUNABLE_INT("net.graph.threads", &numthreads);
2860 SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
2861     0, "Number of queue processing threads");
2862 TUNABLE_INT("net.graph.maxalloc", &maxalloc);
2863 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
2864     0, "Maximum number of non-data queue items to allocate");
2865 TUNABLE_INT("net.graph.maxdata", &maxdata);
2866 SYSCTL_INT(_net_graph, OID_AUTO, maxdata, CTLFLAG_RDTUN, &maxdata,
2867     0, "Maximum number of data queue items to allocate");
2868 
2869 #ifdef	NETGRAPH_DEBUG
2870 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
2871 static int			allocated;	/* number of items malloc'd */
2872 #endif
2873 
2874 /*
2875  * Get a queue entry.
2876  * This is usually called when a packet first enters netgraph.
2877  * By definition, this is usually from an interrupt, or from a user.
2878  * Users are not so important, but try be quick for the times that it's
2879  * an interrupt.
2880  */
2881 static __inline item_p
2882 ng_alloc_item(int type, int flags)
2883 {
2884 	item_p item;
2885 
2886 	KASSERT(((type & ~NGQF_TYPE) == 0),
2887 	    ("%s: incorrect item type: %d", __func__, type));
2888 
2889 	item = uma_zalloc((type == NGQF_DATA)?ng_qdzone:ng_qzone,
2890 	    ((flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT) | M_ZERO);
2891 
2892 	if (item) {
2893 		item->el_flags = type;
2894 #ifdef	NETGRAPH_DEBUG
2895 		mtx_lock(&ngq_mtx);
2896 		TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
2897 		allocated++;
2898 		mtx_unlock(&ngq_mtx);
2899 #endif
2900 	}
2901 
2902 	return (item);
2903 }
2904 
2905 /*
2906  * Release a queue entry
2907  */
2908 void
2909 ng_free_item(item_p item)
2910 {
2911 	/*
2912 	 * The item may hold resources on it's own. We need to free
2913 	 * these before we can free the item. What they are depends upon
2914 	 * what kind of item it is. it is important that nodes zero
2915 	 * out pointers to resources that they remove from the item
2916 	 * or we release them again here.
2917 	 */
2918 	switch (item->el_flags & NGQF_TYPE) {
2919 	case NGQF_DATA:
2920 		/* If we have an mbuf still attached.. */
2921 		NG_FREE_M(_NGI_M(item));
2922 		break;
2923 	case NGQF_MESG:
2924 		_NGI_RETADDR(item) = 0;
2925 		NG_FREE_MSG(_NGI_MSG(item));
2926 		break;
2927 	case NGQF_FN:
2928 	case NGQF_FN2:
2929 		/* nothing to free really, */
2930 		_NGI_FN(item) = NULL;
2931 		_NGI_ARG1(item) = NULL;
2932 		_NGI_ARG2(item) = 0;
2933 		break;
2934 	}
2935 	/* If we still have a node or hook referenced... */
2936 	_NGI_CLR_NODE(item);
2937 	_NGI_CLR_HOOK(item);
2938 
2939 #ifdef	NETGRAPH_DEBUG
2940 	mtx_lock(&ngq_mtx);
2941 	TAILQ_REMOVE(&ng_itemlist, item, all);
2942 	allocated--;
2943 	mtx_unlock(&ngq_mtx);
2944 #endif
2945 	uma_zfree(((item->el_flags & NGQF_TYPE) == NGQF_DATA)?
2946 	    ng_qdzone:ng_qzone, item);
2947 }
2948 
2949 /*
2950  * Change type of the queue entry.
2951  * Possibly reallocates it from another UMA zone.
2952  */
2953 static __inline item_p
2954 ng_realloc_item(item_p pitem, int type, int flags)
2955 {
2956 	item_p item;
2957 	int from, to;
2958 
2959 	KASSERT((pitem != NULL), ("%s: can't reallocate NULL", __func__));
2960 	KASSERT(((type & ~NGQF_TYPE) == 0),
2961 	    ("%s: incorrect item type: %d", __func__, type));
2962 
2963 	from = ((pitem->el_flags & NGQF_TYPE) == NGQF_DATA);
2964 	to = (type == NGQF_DATA);
2965 	if (from != to) {
2966 		/* If reallocation is required do it and copy item. */
2967 		if ((item = ng_alloc_item(type, flags)) == NULL) {
2968 			ng_free_item(pitem);
2969 			return (NULL);
2970 		}
2971 		*item = *pitem;
2972 		ng_free_item(pitem);
2973 	} else
2974 		item = pitem;
2975 	item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
2976 
2977 	return (item);
2978 }
2979 
2980 /************************************************************************
2981 			Module routines
2982 ************************************************************************/
2983 
2984 /*
2985  * Handle the loading/unloading of a netgraph node type module
2986  */
2987 int
2988 ng_mod_event(module_t mod, int event, void *data)
2989 {
2990 	struct ng_type *const type = data;
2991 	int s, error = 0;
2992 
2993 	switch (event) {
2994 	case MOD_LOAD:
2995 
2996 		/* Register new netgraph node type */
2997 		s = splnet();
2998 		if ((error = ng_newtype(type)) != 0) {
2999 			splx(s);
3000 			break;
3001 		}
3002 
3003 		/* Call type specific code */
3004 		if (type->mod_event != NULL)
3005 			if ((error = (*type->mod_event)(mod, event, data))) {
3006 				mtx_lock(&ng_typelist_mtx);
3007 				type->refs--;	/* undo it */
3008 				LIST_REMOVE(type, types);
3009 				mtx_unlock(&ng_typelist_mtx);
3010 			}
3011 		splx(s);
3012 		break;
3013 
3014 	case MOD_UNLOAD:
3015 		s = splnet();
3016 		if (type->refs > 1) {		/* make sure no nodes exist! */
3017 			error = EBUSY;
3018 		} else {
3019 			if (type->refs == 0) {
3020 				/* failed load, nothing to undo */
3021 				splx(s);
3022 				break;
3023 			}
3024 			if (type->mod_event != NULL) {	/* check with type */
3025 				error = (*type->mod_event)(mod, event, data);
3026 				if (error != 0) {	/* type refuses.. */
3027 					splx(s);
3028 					break;
3029 				}
3030 			}
3031 			mtx_lock(&ng_typelist_mtx);
3032 			LIST_REMOVE(type, types);
3033 			mtx_unlock(&ng_typelist_mtx);
3034 		}
3035 		splx(s);
3036 		break;
3037 
3038 	default:
3039 		if (type->mod_event != NULL)
3040 			error = (*type->mod_event)(mod, event, data);
3041 		else
3042 			error = EOPNOTSUPP;		/* XXX ? */
3043 		break;
3044 	}
3045 	return (error);
3046 }
3047 
3048 #ifdef VIMAGE
3049 static void
3050 vnet_netgraph_uninit(const void *unused __unused)
3051 {
3052 	node_p node = NULL, last_killed = NULL;
3053 	int i;
3054 
3055 	do {
3056 		/* Find a node to kill */
3057 		mtx_lock(&ng_namehash_mtx);
3058 		for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
3059 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
3060 				if (node != &ng_deadnode) {
3061 					NG_NODE_REF(node);
3062 					break;
3063 				}
3064 			}
3065 			if (node != NULL)
3066 				break;
3067 		}
3068 		mtx_unlock(&ng_namehash_mtx);
3069 
3070 		/* Attempt to kill it only if it is a regular node */
3071 		if (node != NULL) {
3072 			if (node == last_killed) {
3073 				/* This should never happen */
3074 				printf("ng node %s needs"
3075 				    "NGF_REALLY_DIE\n", node->nd_name);
3076 				if (node->nd_flags & NGF_REALLY_DIE)
3077 					panic("ng node %s won't die",
3078 					    node->nd_name);
3079 				node->nd_flags |= NGF_REALLY_DIE;
3080 			}
3081 			ng_rmnode(node, NULL, NULL, 0);
3082 			NG_NODE_UNREF(node);
3083 			last_killed = node;
3084 		}
3085 	} while (node != NULL);
3086 }
3087 VNET_SYSUNINIT(vnet_netgraph_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
3088     vnet_netgraph_uninit, NULL);
3089 #endif /* VIMAGE */
3090 
3091 /*
3092  * Handle loading and unloading for this code.
3093  * The only thing we need to link into is the NETISR strucure.
3094  */
3095 static int
3096 ngb_mod_event(module_t mod, int event, void *data)
3097 {
3098 	struct proc *p;
3099 	struct thread *td;
3100 	int i, error = 0;
3101 
3102 	switch (event) {
3103 	case MOD_LOAD:
3104 		/* Initialize everything. */
3105 		NG_WORKLIST_LOCK_INIT();
3106 		mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL,
3107 		    MTX_DEF);
3108 		mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", NULL,
3109 		    MTX_DEF);
3110 		mtx_init(&ng_namehash_mtx, "netgraph namehash mutex", NULL,
3111 		    MTX_DEF);
3112 		mtx_init(&ng_topo_mtx, "netgraph topology mutex", NULL,
3113 		    MTX_DEF);
3114 #ifdef	NETGRAPH_DEBUG
3115 		mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
3116 		    MTX_DEF);
3117 		mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
3118 		    MTX_DEF);
3119 #endif
3120 		ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
3121 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
3122 		uma_zone_set_max(ng_qzone, maxalloc);
3123 		ng_qdzone = uma_zcreate("NetGraph data items", sizeof(struct ng_item),
3124 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
3125 		uma_zone_set_max(ng_qdzone, maxdata);
3126 		/* Autoconfigure number of threads. */
3127 		if (numthreads <= 0)
3128 			numthreads = mp_ncpus;
3129 		/* Create threads. */
3130     		p = NULL; /* start with no process */
3131 		for (i = 0; i < numthreads; i++) {
3132 			if (kproc_kthread_add(ngthread, NULL, &p, &td,
3133 			    RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
3134 				numthreads = i;
3135 				break;
3136 			}
3137 		}
3138 		break;
3139 	case MOD_UNLOAD:
3140 		/* You can't unload it because an interface may be using it. */
3141 		error = EBUSY;
3142 		break;
3143 	default:
3144 		error = EOPNOTSUPP;
3145 		break;
3146 	}
3147 	return (error);
3148 }
3149 
3150 static moduledata_t netgraph_mod = {
3151 	"netgraph",
3152 	ngb_mod_event,
3153 	(NULL)
3154 };
3155 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_MIDDLE);
3156 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
3157 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
3158 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
3159 
3160 #ifdef	NETGRAPH_DEBUG
3161 void
3162 dumphook (hook_p hook, char *file, int line)
3163 {
3164 	printf("hook: name %s, %d refs, Last touched:\n",
3165 		_NG_HOOK_NAME(hook), hook->hk_refs);
3166 	printf("	Last active @ %s, line %d\n",
3167 		hook->lastfile, hook->lastline);
3168 	if (line) {
3169 		printf(" problem discovered at file %s, line %d\n", file, line);
3170 #ifdef KDB
3171 		kdb_backtrace();
3172 #endif
3173 	}
3174 }
3175 
3176 void
3177 dumpnode(node_p node, char *file, int line)
3178 {
3179 	printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
3180 		_NG_NODE_ID(node), node->nd_type->name,
3181 		node->nd_numhooks, node->nd_flags,
3182 		node->nd_refs, node->nd_name);
3183 	printf("	Last active @ %s, line %d\n",
3184 		node->lastfile, node->lastline);
3185 	if (line) {
3186 		printf(" problem discovered at file %s, line %d\n", file, line);
3187 #ifdef KDB
3188 		kdb_backtrace();
3189 #endif
3190 	}
3191 }
3192 
3193 void
3194 dumpitem(item_p item, char *file, int line)
3195 {
3196 	printf(" ACTIVE item, last used at %s, line %d",
3197 		item->lastfile, item->lastline);
3198 	switch(item->el_flags & NGQF_TYPE) {
3199 	case NGQF_DATA:
3200 		printf(" - [data]\n");
3201 		break;
3202 	case NGQF_MESG:
3203 		printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
3204 		break;
3205 	case NGQF_FN:
3206 		printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
3207 			_NGI_FN(item),
3208 			_NGI_NODE(item),
3209 			_NGI_HOOK(item),
3210 			item->body.fn.fn_arg1,
3211 			item->body.fn.fn_arg2,
3212 			item->body.fn.fn_arg2);
3213 		break;
3214 	case NGQF_FN2:
3215 		printf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
3216 			_NGI_FN2(item),
3217 			_NGI_NODE(item),
3218 			_NGI_HOOK(item),
3219 			item->body.fn.fn_arg1,
3220 			item->body.fn.fn_arg2,
3221 			item->body.fn.fn_arg2);
3222 		break;
3223 	}
3224 	if (line) {
3225 		printf(" problem discovered at file %s, line %d\n", file, line);
3226 		if (_NGI_NODE(item)) {
3227 			printf("node %p ([%x])\n",
3228 				_NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
3229 		}
3230 	}
3231 }
3232 
3233 static void
3234 ng_dumpitems(void)
3235 {
3236 	item_p item;
3237 	int i = 1;
3238 	TAILQ_FOREACH(item, &ng_itemlist, all) {
3239 		printf("[%d] ", i++);
3240 		dumpitem(item, NULL, 0);
3241 	}
3242 }
3243 
3244 static void
3245 ng_dumpnodes(void)
3246 {
3247 	node_p node;
3248 	int i = 1;
3249 	mtx_lock(&ng_nodelist_mtx);
3250 	SLIST_FOREACH(node, &ng_allnodes, nd_all) {
3251 		printf("[%d] ", i++);
3252 		dumpnode(node, NULL, 0);
3253 	}
3254 	mtx_unlock(&ng_nodelist_mtx);
3255 }
3256 
3257 static void
3258 ng_dumphooks(void)
3259 {
3260 	hook_p hook;
3261 	int i = 1;
3262 	mtx_lock(&ng_nodelist_mtx);
3263 	SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
3264 		printf("[%d] ", i++);
3265 		dumphook(hook, NULL, 0);
3266 	}
3267 	mtx_unlock(&ng_nodelist_mtx);
3268 }
3269 
3270 static int
3271 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
3272 {
3273 	int error;
3274 	int val;
3275 	int i;
3276 
3277 	val = allocated;
3278 	i = 1;
3279 	error = sysctl_handle_int(oidp, &val, 0, req);
3280 	if (error != 0 || req->newptr == NULL)
3281 		return (error);
3282 	if (val == 42) {
3283 		ng_dumpitems();
3284 		ng_dumpnodes();
3285 		ng_dumphooks();
3286 	}
3287 	return (0);
3288 }
3289 
3290 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
3291     0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
3292 #endif	/* NETGRAPH_DEBUG */
3293 
3294 
3295 /***********************************************************************
3296 * Worklist routines
3297 **********************************************************************/
3298 /*
3299  * Pick a node off the list of nodes with work,
3300  * try get an item to process off it. Remove the node from the list.
3301  */
3302 static void
3303 ngthread(void *arg)
3304 {
3305 	for (;;) {
3306 		node_p  node;
3307 
3308 		/* Get node from the worklist. */
3309 		NG_WORKLIST_LOCK();
3310 		while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
3311 			NG_WORKLIST_SLEEP();
3312 		STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
3313 		NG_WORKLIST_UNLOCK();
3314 		CURVNET_SET(node->nd_vnet);
3315 		CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
3316 		    __func__, node->nd_ID, node);
3317 		/*
3318 		 * We have the node. We also take over the reference
3319 		 * that the list had on it.
3320 		 * Now process as much as you can, until it won't
3321 		 * let you have another item off the queue.
3322 		 * All this time, keep the reference
3323 		 * that lets us be sure that the node still exists.
3324 		 * Let the reference go at the last minute.
3325 		 */
3326 		for (;;) {
3327 			item_p item;
3328 			int rw;
3329 
3330 			NG_QUEUE_LOCK(&node->nd_input_queue);
3331 			item = ng_dequeue(node, &rw);
3332 			if (item == NULL) {
3333 				node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
3334 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3335 				break; /* go look for another node */
3336 			} else {
3337 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3338 				NGI_GET_NODE(item, node); /* zaps stored node */
3339 				ng_apply_item(node, item, rw);
3340 				NG_NODE_UNREF(node);
3341 			}
3342 		}
3343 		NG_NODE_UNREF(node);
3344 		CURVNET_RESTORE();
3345 	}
3346 }
3347 
3348 /*
3349  * XXX
3350  * It's posible that a debugging NG_NODE_REF may need
3351  * to be outside the mutex zone
3352  */
3353 static void
3354 ng_worklist_add(node_p node)
3355 {
3356 
3357 	mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
3358 
3359 	if ((node->nd_input_queue.q_flags2 & NGQ2_WORKQ) == 0) {
3360 		/*
3361 		 * If we are not already on the work queue,
3362 		 * then put us on.
3363 		 */
3364 		node->nd_input_queue.q_flags2 |= NGQ2_WORKQ;
3365 		NG_NODE_REF(node); /* XXX fafe in mutex? */
3366 		NG_WORKLIST_LOCK();
3367 		STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
3368 		NG_WORKLIST_UNLOCK();
3369 		CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
3370 		    node->nd_ID, node);
3371 		NG_WORKLIST_WAKEUP();
3372 	} else {
3373 		CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
3374 		    __func__, node->nd_ID, node);
3375 	}
3376 }
3377 
3378 
3379 /***********************************************************************
3380 * Externally useable functions to set up a queue item ready for sending
3381 ***********************************************************************/
3382 
3383 #ifdef	NETGRAPH_DEBUG
3384 #define	ITEM_DEBUG_CHECKS						\
3385 	do {								\
3386 		if (NGI_NODE(item) ) {					\
3387 			printf("item already has node");		\
3388 			kdb_enter(KDB_WHY_NETGRAPH, "has node");	\
3389 			NGI_CLR_NODE(item);				\
3390 		}							\
3391 		if (NGI_HOOK(item) ) {					\
3392 			printf("item already has hook");		\
3393 			kdb_enter(KDB_WHY_NETGRAPH, "has hook");	\
3394 			NGI_CLR_HOOK(item);				\
3395 		}							\
3396 	} while (0)
3397 #else
3398 #define ITEM_DEBUG_CHECKS
3399 #endif
3400 
3401 /*
3402  * Put mbuf into the item.
3403  * Hook and node references will be removed when the item is dequeued.
3404  * (or equivalent)
3405  * (XXX) Unsafe because no reference held by peer on remote node.
3406  * remote node might go away in this timescale.
3407  * We know the hooks can't go away because that would require getting
3408  * a writer item on both nodes and we must have at least a  reader
3409  * here to be able to do this.
3410  * Note that the hook loaded is the REMOTE hook.
3411  *
3412  * This is possibly in the critical path for new data.
3413  */
3414 item_p
3415 ng_package_data(struct mbuf *m, int flags)
3416 {
3417 	item_p item;
3418 
3419 	if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
3420 		NG_FREE_M(m);
3421 		return (NULL);
3422 	}
3423 	ITEM_DEBUG_CHECKS;
3424 	item->el_flags |= NGQF_READER;
3425 	NGI_M(item) = m;
3426 	return (item);
3427 }
3428 
3429 /*
3430  * Allocate a queue item and put items into it..
3431  * Evaluate the address as this will be needed to queue it and
3432  * to work out what some of the fields should be.
3433  * Hook and node references will be removed when the item is dequeued.
3434  * (or equivalent)
3435  */
3436 item_p
3437 ng_package_msg(struct ng_mesg *msg, int flags)
3438 {
3439 	item_p item;
3440 
3441 	if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
3442 		NG_FREE_MSG(msg);
3443 		return (NULL);
3444 	}
3445 	ITEM_DEBUG_CHECKS;
3446 	/* Messages items count as writers unless explicitly exempted. */
3447 	if (msg->header.cmd & NGM_READONLY)
3448 		item->el_flags |= NGQF_READER;
3449 	else
3450 		item->el_flags |= NGQF_WRITER;
3451 	/*
3452 	 * Set the current lasthook into the queue item
3453 	 */
3454 	NGI_MSG(item) = msg;
3455 	NGI_RETADDR(item) = 0;
3456 	return (item);
3457 }
3458 
3459 
3460 
3461 #define SET_RETADDR(item, here, retaddr)				\
3462 	do {	/* Data or fn items don't have retaddrs */		\
3463 		if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {	\
3464 			if (retaddr) {					\
3465 				NGI_RETADDR(item) = retaddr;		\
3466 			} else {					\
3467 				/*					\
3468 				 * The old return address should be ok.	\
3469 				 * If there isn't one, use the address	\
3470 				 * here.				\
3471 				 */					\
3472 				if (NGI_RETADDR(item) == 0) {		\
3473 					NGI_RETADDR(item)		\
3474 						= ng_node2ID(here);	\
3475 				}					\
3476 			}						\
3477 		}							\
3478 	} while (0)
3479 
3480 int
3481 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
3482 {
3483 	hook_p peer;
3484 	node_p peernode;
3485 	ITEM_DEBUG_CHECKS;
3486 	/*
3487 	 * Quick sanity check..
3488 	 * Since a hook holds a reference on it's node, once we know
3489 	 * that the peer is still connected (even if invalid,) we know
3490 	 * that the peer node is present, though maybe invalid.
3491 	 */
3492 	mtx_lock(&ng_topo_mtx);
3493 	if ((hook == NULL) ||
3494 	    NG_HOOK_NOT_VALID(hook) ||
3495 	    NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
3496 	    NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
3497 		NG_FREE_ITEM(item);
3498 		TRAP_ERROR();
3499 		mtx_unlock(&ng_topo_mtx);
3500 		return (ENETDOWN);
3501 	}
3502 
3503 	/*
3504 	 * Transfer our interest to the other (peer) end.
3505 	 */
3506 	NG_HOOK_REF(peer);
3507 	NG_NODE_REF(peernode);
3508 	NGI_SET_HOOK(item, peer);
3509 	NGI_SET_NODE(item, peernode);
3510 	SET_RETADDR(item, here, retaddr);
3511 
3512 	mtx_unlock(&ng_topo_mtx);
3513 
3514 	return (0);
3515 }
3516 
3517 int
3518 ng_address_path(node_p here, item_p item, const char *address, ng_ID_t retaddr)
3519 {
3520 	node_p	dest = NULL;
3521 	hook_p	hook = NULL;
3522 	int	error;
3523 
3524 	ITEM_DEBUG_CHECKS;
3525 	/*
3526 	 * Note that ng_path2noderef increments the reference count
3527 	 * on the node for us if it finds one. So we don't have to.
3528 	 */
3529 	error = ng_path2noderef(here, address, &dest, &hook);
3530 	if (error) {
3531 		NG_FREE_ITEM(item);
3532 		return (error);
3533 	}
3534 	NGI_SET_NODE(item, dest);
3535 	if (hook)
3536 		NGI_SET_HOOK(item, hook);
3537 
3538 	SET_RETADDR(item, here, retaddr);
3539 	return (0);
3540 }
3541 
3542 int
3543 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
3544 {
3545 	node_p dest;
3546 
3547 	ITEM_DEBUG_CHECKS;
3548 	/*
3549 	 * Find the target node.
3550 	 */
3551 	dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
3552 	if (dest == NULL) {
3553 		NG_FREE_ITEM(item);
3554 		TRAP_ERROR();
3555 		return(EINVAL);
3556 	}
3557 	/* Fill out the contents */
3558 	NGI_SET_NODE(item, dest);
3559 	NGI_CLR_HOOK(item);
3560 	SET_RETADDR(item, here, retaddr);
3561 	return (0);
3562 }
3563 
3564 /*
3565  * special case to send a message to self (e.g. destroy node)
3566  * Possibly indicate an arrival hook too.
3567  * Useful for removing that hook :-)
3568  */
3569 item_p
3570 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
3571 {
3572 	item_p item;
3573 
3574 	/*
3575 	 * Find the target node.
3576 	 * If there is a HOOK argument, then use that in preference
3577 	 * to the address.
3578 	 */
3579 	if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
3580 		NG_FREE_MSG(msg);
3581 		return (NULL);
3582 	}
3583 
3584 	/* Fill out the contents */
3585 	item->el_flags |= NGQF_WRITER;
3586 	NG_NODE_REF(here);
3587 	NGI_SET_NODE(item, here);
3588 	if (hook) {
3589 		NG_HOOK_REF(hook);
3590 		NGI_SET_HOOK(item, hook);
3591 	}
3592 	NGI_MSG(item) = msg;
3593 	NGI_RETADDR(item) = ng_node2ID(here);
3594 	return (item);
3595 }
3596 
3597 /*
3598  * Send ng_item_fn function call to the specified node.
3599  */
3600 
3601 int
3602 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
3603 {
3604 
3605 	return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
3606 }
3607 
3608 int
3609 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
3610 	int flags)
3611 {
3612 	item_p item;
3613 
3614 	if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
3615 		return (ENOMEM);
3616 	}
3617 	item->el_flags |= NGQF_WRITER;
3618 	NG_NODE_REF(node); /* and one for the item */
3619 	NGI_SET_NODE(item, node);
3620 	if (hook) {
3621 		NG_HOOK_REF(hook);
3622 		NGI_SET_HOOK(item, hook);
3623 	}
3624 	NGI_FN(item) = fn;
3625 	NGI_ARG1(item) = arg1;
3626 	NGI_ARG2(item) = arg2;
3627 	return(ng_snd_item(item, flags));
3628 }
3629 
3630 /*
3631  * Send ng_item_fn2 function call to the specified node.
3632  *
3633  * If an optional pitem parameter is supplied, its apply
3634  * callback will be copied to the new item. If also NG_REUSE_ITEM
3635  * flag is set, no new item will be allocated, but pitem will
3636  * be used.
3637  */
3638 int
3639 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
3640 	int arg2, int flags)
3641 {
3642 	item_p item;
3643 
3644 	KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
3645 	    ("%s: NG_REUSE_ITEM but no pitem", __func__));
3646 
3647 	/*
3648 	 * Allocate a new item if no supplied or
3649 	 * if we can't use supplied one.
3650 	 */
3651 	if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
3652 		if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
3653 			return (ENOMEM);
3654 		if (pitem != NULL)
3655 			item->apply = pitem->apply;
3656 	} else {
3657 		if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
3658 			return (ENOMEM);
3659 	}
3660 
3661 	item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
3662 	NG_NODE_REF(node); /* and one for the item */
3663 	NGI_SET_NODE(item, node);
3664 	if (hook) {
3665 		NG_HOOK_REF(hook);
3666 		NGI_SET_HOOK(item, hook);
3667 	}
3668 	NGI_FN2(item) = fn;
3669 	NGI_ARG1(item) = arg1;
3670 	NGI_ARG2(item) = arg2;
3671 	return(ng_snd_item(item, flags));
3672 }
3673 
3674 /*
3675  * Official timeout routines for Netgraph nodes.
3676  */
3677 static void
3678 ng_callout_trampoline(void *arg)
3679 {
3680 	item_p item = arg;
3681 
3682 	CURVNET_SET(NGI_NODE(item)->nd_vnet);
3683 	ng_snd_item(item, 0);
3684 	CURVNET_RESTORE();
3685 }
3686 
3687 
3688 int
3689 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
3690     ng_item_fn *fn, void * arg1, int arg2)
3691 {
3692 	item_p item, oitem;
3693 
3694 	if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
3695 		return (ENOMEM);
3696 
3697 	item->el_flags |= NGQF_WRITER;
3698 	NG_NODE_REF(node);		/* and one for the item */
3699 	NGI_SET_NODE(item, node);
3700 	if (hook) {
3701 		NG_HOOK_REF(hook);
3702 		NGI_SET_HOOK(item, hook);
3703 	}
3704 	NGI_FN(item) = fn;
3705 	NGI_ARG1(item) = arg1;
3706 	NGI_ARG2(item) = arg2;
3707 	oitem = c->c_arg;
3708 	if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
3709 	    oitem != NULL)
3710 		NG_FREE_ITEM(oitem);
3711 	return (0);
3712 }
3713 
3714 /* A special modified version of untimeout() */
3715 int
3716 ng_uncallout(struct callout *c, node_p node)
3717 {
3718 	item_p item;
3719 	int rval;
3720 
3721 	KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
3722 	KASSERT(node != NULL, ("ng_uncallout: NULL node"));
3723 
3724 	rval = callout_stop(c);
3725 	item = c->c_arg;
3726 	/* Do an extra check */
3727 	if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
3728 	    (NGI_NODE(item) == node)) {
3729 		/*
3730 		 * We successfully removed it from the queue before it ran
3731 		 * So now we need to unreference everything that was
3732 		 * given extra references. (NG_FREE_ITEM does this).
3733 		 */
3734 		NG_FREE_ITEM(item);
3735 	}
3736 	c->c_arg = NULL;
3737 
3738 	return (rval);
3739 }
3740 
3741 /*
3742  * Set the address, if none given, give the node here.
3743  */
3744 void
3745 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
3746 {
3747 	if (retaddr) {
3748 		NGI_RETADDR(item) = retaddr;
3749 	} else {
3750 		/*
3751 		 * The old return address should be ok.
3752 		 * If there isn't one, use the address here.
3753 		 */
3754 		NGI_RETADDR(item) = ng_node2ID(here);
3755 	}
3756 }
3757 
3758 #define TESTING
3759 #ifdef TESTING
3760 /* just test all the macros */
3761 void
3762 ng_macro_test(item_p item);
3763 void
3764 ng_macro_test(item_p item)
3765 {
3766 	node_p node = NULL;
3767 	hook_p hook = NULL;
3768 	struct mbuf *m;
3769 	struct ng_mesg *msg;
3770 	ng_ID_t retaddr;
3771 	int	error;
3772 
3773 	NGI_GET_M(item, m);
3774 	NGI_GET_MSG(item, msg);
3775 	retaddr = NGI_RETADDR(item);
3776 	NG_SEND_DATA(error, hook, m, NULL);
3777 	NG_SEND_DATA_ONLY(error, hook, m);
3778 	NG_FWD_NEW_DATA(error, item, hook, m);
3779 	NG_FWD_ITEM_HOOK(error, item, hook);
3780 	NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
3781 	NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
3782 	NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
3783 	NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
3784 }
3785 #endif /* TESTING */
3786 
3787