xref: /freebsd/sys/netgraph/ng_base.c (revision 5861f9665471e98e544f6fa3ce73c4912229ff82)
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/vimage.h>
65 #include <sys/unistd.h>
66 #include <sys/kthread.h>
67 #include <sys/smp.h>
68 #include <machine/cpu.h>
69 
70 #include <net/netisr.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 #ifndef VIMAGE
79 #ifndef VIMAGE_GLOBALS
80 struct vnet_netgraph vnet_netgraph_0;
81 #endif
82 #endif
83 
84 /* Mutex to protect topology events. */
85 static struct mtx	ng_topo_mtx;
86 
87 static vnet_attach_fn vnet_netgraph_iattach;
88 #ifdef VIMAGE
89 static vnet_detach_fn vnet_netgraph_idetach;
90 #endif
91 
92 #ifdef	NETGRAPH_DEBUG
93 static struct mtx	ng_nodelist_mtx; /* protects global node/hook lists */
94 static struct mtx	ngq_mtx;	/* protects the queue item list */
95 
96 static SLIST_HEAD(, ng_node) ng_allnodes;
97 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
98 static SLIST_HEAD(, ng_hook) ng_allhooks;
99 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
100 
101 static void ng_dumpitems(void);
102 static void ng_dumpnodes(void);
103 static void ng_dumphooks(void);
104 
105 #endif	/* NETGRAPH_DEBUG */
106 /*
107  * DEAD versions of the structures.
108  * In order to avoid races, it is sometimes neccesary to point
109  * at SOMETHING even though theoretically, the current entity is
110  * INVALID. Use these to avoid these races.
111  */
112 struct ng_type ng_deadtype = {
113 	NG_ABI_VERSION,
114 	"dead",
115 	NULL,	/* modevent */
116 	NULL,	/* constructor */
117 	NULL,	/* rcvmsg */
118 	NULL,	/* shutdown */
119 	NULL,	/* newhook */
120 	NULL,	/* findhook */
121 	NULL,	/* connect */
122 	NULL,	/* rcvdata */
123 	NULL,	/* disconnect */
124 	NULL, 	/* cmdlist */
125 };
126 
127 struct ng_node ng_deadnode = {
128 	"dead",
129 	&ng_deadtype,
130 	NGF_INVALID,
131 	0,	/* numhooks */
132 	NULL,	/* private */
133 	0,	/* ID */
134 	LIST_HEAD_INITIALIZER(ng_deadnode.hooks),
135 	{},	/* all_nodes list entry */
136 	{},	/* id hashtable list entry */
137 	{	0,
138 		0,
139 		{}, /* should never use! (should hang) */
140 		{}, /* workqueue entry */
141 		STAILQ_HEAD_INITIALIZER(ng_deadnode.nd_input_queue.queue),
142 	},
143 	1,	/* refs */
144 	NULL,	/* vnet */
145 #ifdef	NETGRAPH_DEBUG
146 	ND_MAGIC,
147 	__FILE__,
148 	__LINE__,
149 	{NULL}
150 #endif	/* NETGRAPH_DEBUG */
151 };
152 
153 struct ng_hook ng_deadhook = {
154 	"dead",
155 	NULL,		/* private */
156 	HK_INVALID | HK_DEAD,
157 	0,		/* undefined data link type */
158 	&ng_deadhook,	/* Peer is self */
159 	&ng_deadnode,	/* attached to deadnode */
160 	{},		/* hooks list */
161 	NULL,		/* override rcvmsg() */
162 	NULL,		/* override rcvdata() */
163 	1,		/* refs always >= 1 */
164 #ifdef	NETGRAPH_DEBUG
165 	HK_MAGIC,
166 	__FILE__,
167 	__LINE__,
168 	{NULL}
169 #endif	/* NETGRAPH_DEBUG */
170 };
171 
172 /*
173  * END DEAD STRUCTURES
174  */
175 /* List nodes with unallocated work */
176 static STAILQ_HEAD(, ng_node) ng_worklist = STAILQ_HEAD_INITIALIZER(ng_worklist);
177 static struct mtx	ng_worklist_mtx;   /* MUST LOCK NODE FIRST */
178 
179 /* List of installed types */
180 static LIST_HEAD(, ng_type) ng_typelist;
181 static struct mtx	ng_typelist_mtx;
182 
183 /* Hash related definitions */
184 /* XXX Don't need to initialise them because it's a LIST */
185 #ifdef VIMAGE_GLOBALS
186 static LIST_HEAD(, ng_node) ng_ID_hash[NG_ID_HASH_SIZE];
187 #endif
188 static struct mtx	ng_idhash_mtx;
189 /* Method to find a node.. used twice so do it here */
190 #define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
191 #define NG_IDHASH_FIND(ID, node)					\
192 	do { 								\
193 		mtx_assert(&ng_idhash_mtx, MA_OWNED);			\
194 		LIST_FOREACH(node, &V_ng_ID_hash[NG_IDHASH_FN(ID)],	\
195 						nd_idnodes) {		\
196 			if (NG_NODE_IS_VALID(node)			\
197 			&& (NG_NODE_ID(node) == ID)) {			\
198 				break;					\
199 			}						\
200 		}							\
201 	} while (0)
202 
203 #ifdef VIMAGE_GLOBALS
204 static LIST_HEAD(, ng_node) ng_name_hash[NG_NAME_HASH_SIZE];
205 #endif
206 static struct mtx	ng_namehash_mtx;
207 #define NG_NAMEHASH(NAME, HASH)				\
208 	do {						\
209 		u_char	h = 0;				\
210 		const u_char	*c;			\
211 		for (c = (const u_char*)(NAME); *c; c++)\
212 			h += *c;			\
213 		(HASH) = h % (NG_NAME_HASH_SIZE);	\
214 	} while (0)
215 
216 
217 /* Internal functions */
218 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
219 static int	ng_generic_msg(node_p here, item_p item, hook_p lasthook);
220 static ng_ID_t	ng_decodeidname(const char *name);
221 static int	ngb_mod_event(module_t mod, int event, void *data);
222 static void	ng_worklist_add(node_p node);
223 static void	ngthread(void *);
224 static int	ng_apply_item(node_p node, item_p item, int rw);
225 static void	ng_flush_input_queue(node_p node);
226 static node_p	ng_ID2noderef(ng_ID_t ID);
227 static int	ng_con_nodes(item_p item, node_p node, const char *name,
228 		    node_p node2, const char *name2);
229 static int	ng_con_part2(node_p node, item_p item, hook_p hook);
230 static int	ng_con_part3(node_p node, item_p item, hook_p hook);
231 static int	ng_mkpeer(node_p node, const char *name,
232 						const char *name2, char *type);
233 
234 /* Imported, these used to be externally visible, some may go back. */
235 void	ng_destroy_hook(hook_p hook);
236 int	ng_path2noderef(node_p here, const char *path,
237 	node_p *dest, hook_p *lasthook);
238 int	ng_make_node(const char *type, node_p *nodepp);
239 int	ng_path_parse(char *addr, char **node, char **path, char **hook);
240 void	ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
241 void	ng_unname(node_p node);
242 
243 
244 /* Our own netgraph malloc type */
245 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
246 MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
247 MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
248 MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item", "netgraph item structures");
249 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
250 
251 /* Should not be visible outside this file */
252 
253 #define _NG_ALLOC_HOOK(hook) \
254 	hook = malloc(sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
255 #define _NG_ALLOC_NODE(node) \
256 	node = malloc(sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
257 
258 #define	NG_QUEUE_LOCK_INIT(n)			\
259 	mtx_init(&(n)->q_mtx, "ng_node", NULL, MTX_DEF)
260 #define	NG_QUEUE_LOCK(n)			\
261 	mtx_lock(&(n)->q_mtx)
262 #define	NG_QUEUE_UNLOCK(n)			\
263 	mtx_unlock(&(n)->q_mtx)
264 #define	NG_WORKLIST_LOCK_INIT()			\
265 	mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_DEF)
266 #define	NG_WORKLIST_LOCK()			\
267 	mtx_lock(&ng_worklist_mtx)
268 #define	NG_WORKLIST_UNLOCK()			\
269 	mtx_unlock(&ng_worklist_mtx)
270 #define	NG_WORKLIST_SLEEP()			\
271 	mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
272 #define	NG_WORKLIST_WAKEUP()			\
273 	wakeup_one(&ng_worklist)
274 
275 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
276 /*
277  * In debug mode:
278  * In an attempt to help track reference count screwups
279  * we do not free objects back to the malloc system, but keep them
280  * in a local cache where we can examine them and keep information safely
281  * after they have been freed.
282  * We use this scheme for nodes and hooks, and to some extent for items.
283  */
284 static __inline hook_p
285 ng_alloc_hook(void)
286 {
287 	hook_p hook;
288 	SLIST_ENTRY(ng_hook) temp;
289 	mtx_lock(&ng_nodelist_mtx);
290 	hook = LIST_FIRST(&ng_freehooks);
291 	if (hook) {
292 		LIST_REMOVE(hook, hk_hooks);
293 		bcopy(&hook->hk_all, &temp, sizeof(temp));
294 		bzero(hook, sizeof(struct ng_hook));
295 		bcopy(&temp, &hook->hk_all, sizeof(temp));
296 		mtx_unlock(&ng_nodelist_mtx);
297 		hook->hk_magic = HK_MAGIC;
298 	} else {
299 		mtx_unlock(&ng_nodelist_mtx);
300 		_NG_ALLOC_HOOK(hook);
301 		if (hook) {
302 			hook->hk_magic = HK_MAGIC;
303 			mtx_lock(&ng_nodelist_mtx);
304 			SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
305 			mtx_unlock(&ng_nodelist_mtx);
306 		}
307 	}
308 	return (hook);
309 }
310 
311 static __inline node_p
312 ng_alloc_node(void)
313 {
314 	node_p node;
315 	SLIST_ENTRY(ng_node) temp;
316 	mtx_lock(&ng_nodelist_mtx);
317 	node = LIST_FIRST(&ng_freenodes);
318 	if (node) {
319 		LIST_REMOVE(node, nd_nodes);
320 		bcopy(&node->nd_all, &temp, sizeof(temp));
321 		bzero(node, sizeof(struct ng_node));
322 		bcopy(&temp, &node->nd_all, sizeof(temp));
323 		mtx_unlock(&ng_nodelist_mtx);
324 		node->nd_magic = ND_MAGIC;
325 	} else {
326 		mtx_unlock(&ng_nodelist_mtx);
327 		_NG_ALLOC_NODE(node);
328 		if (node) {
329 			node->nd_magic = ND_MAGIC;
330 			mtx_lock(&ng_nodelist_mtx);
331 			SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
332 			mtx_unlock(&ng_nodelist_mtx);
333 		}
334 	}
335 	return (node);
336 }
337 
338 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
339 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
340 
341 
342 #define NG_FREE_HOOK(hook)						\
343 	do {								\
344 		mtx_lock(&ng_nodelist_mtx);			\
345 		LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);	\
346 		hook->hk_magic = 0;					\
347 		mtx_unlock(&ng_nodelist_mtx);			\
348 	} while (0)
349 
350 #define NG_FREE_NODE(node)						\
351 	do {								\
352 		mtx_lock(&ng_nodelist_mtx);			\
353 		LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);	\
354 		node->nd_magic = 0;					\
355 		mtx_unlock(&ng_nodelist_mtx);			\
356 	} while (0)
357 
358 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
359 
360 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
361 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
362 
363 #define NG_FREE_HOOK(hook) do { free((hook), M_NETGRAPH_HOOK); } while (0)
364 #define NG_FREE_NODE(node) do { free((node), M_NETGRAPH_NODE); } while (0)
365 
366 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
367 
368 /* Set this to kdb_enter("X") to catch all errors as they occur */
369 #ifndef TRAP_ERROR
370 #define TRAP_ERROR()
371 #endif
372 
373 #ifdef VIMAGE_GLOBALS
374 static	ng_ID_t nextID;
375 #endif
376 
377 #ifdef INVARIANTS
378 #define CHECK_DATA_MBUF(m)	do {					\
379 		struct mbuf *n;						\
380 		int total;						\
381 									\
382 		M_ASSERTPKTHDR(m);					\
383 		for (total = 0, n = (m); n != NULL; n = n->m_next) {	\
384 			total += n->m_len;				\
385 			if (n->m_nextpkt != NULL)			\
386 				panic("%s: m_nextpkt", __func__);	\
387 		}							\
388 									\
389 		if ((m)->m_pkthdr.len != total) {			\
390 			panic("%s: %d != %d",				\
391 			    __func__, (m)->m_pkthdr.len, total);	\
392 		}							\
393 	} while (0)
394 #else
395 #define CHECK_DATA_MBUF(m)
396 #endif
397 
398 #define ERROUT(x)	do { error = (x); goto done; } while (0)
399 
400 /************************************************************************
401 	Parse type definitions for generic messages
402 ************************************************************************/
403 
404 /* Handy structure parse type defining macro */
405 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
406 static const struct ng_parse_struct_field				\
407 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
408 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
409 	&ng_parse_struct_type,						\
410 	&ng_ ## lo ## _type_fields					\
411 }
412 
413 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
414 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
415 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
416 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
417 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
418 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
419 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
420 
421 /* Get length of an array when the length is stored as a 32 bit
422    value immediately preceding the array -- as with struct namelist
423    and struct typelist. */
424 static int
425 ng_generic_list_getLength(const struct ng_parse_type *type,
426 	const u_char *start, const u_char *buf)
427 {
428 	return *((const u_int32_t *)(buf - 4));
429 }
430 
431 /* Get length of the array of struct linkinfo inside a struct hooklist */
432 static int
433 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
434 	const u_char *start, const u_char *buf)
435 {
436 	const struct hooklist *hl = (const struct hooklist *)start;
437 
438 	return hl->nodeinfo.hooks;
439 }
440 
441 /* Array type for a variable length array of struct namelist */
442 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
443 	&ng_generic_nodeinfo_type,
444 	&ng_generic_list_getLength
445 };
446 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
447 	&ng_parse_array_type,
448 	&ng_nodeinfoarray_type_info
449 };
450 
451 /* Array type for a variable length array of struct typelist */
452 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
453 	&ng_generic_typeinfo_type,
454 	&ng_generic_list_getLength
455 };
456 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
457 	&ng_parse_array_type,
458 	&ng_typeinfoarray_type_info
459 };
460 
461 /* Array type for array of struct linkinfo in struct hooklist */
462 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
463 	&ng_generic_linkinfo_type,
464 	&ng_generic_linkinfo_getLength
465 };
466 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
467 	&ng_parse_array_type,
468 	&ng_generic_linkinfo_array_type_info
469 };
470 
471 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
472 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
473 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
474 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
475 	(&ng_generic_nodeinfoarray_type));
476 
477 /* List of commands and how to convert arguments to/from ASCII */
478 static const struct ng_cmdlist ng_generic_cmds[] = {
479 	{
480 	  NGM_GENERIC_COOKIE,
481 	  NGM_SHUTDOWN,
482 	  "shutdown",
483 	  NULL,
484 	  NULL
485 	},
486 	{
487 	  NGM_GENERIC_COOKIE,
488 	  NGM_MKPEER,
489 	  "mkpeer",
490 	  &ng_generic_mkpeer_type,
491 	  NULL
492 	},
493 	{
494 	  NGM_GENERIC_COOKIE,
495 	  NGM_CONNECT,
496 	  "connect",
497 	  &ng_generic_connect_type,
498 	  NULL
499 	},
500 	{
501 	  NGM_GENERIC_COOKIE,
502 	  NGM_NAME,
503 	  "name",
504 	  &ng_generic_name_type,
505 	  NULL
506 	},
507 	{
508 	  NGM_GENERIC_COOKIE,
509 	  NGM_RMHOOK,
510 	  "rmhook",
511 	  &ng_generic_rmhook_type,
512 	  NULL
513 	},
514 	{
515 	  NGM_GENERIC_COOKIE,
516 	  NGM_NODEINFO,
517 	  "nodeinfo",
518 	  NULL,
519 	  &ng_generic_nodeinfo_type
520 	},
521 	{
522 	  NGM_GENERIC_COOKIE,
523 	  NGM_LISTHOOKS,
524 	  "listhooks",
525 	  NULL,
526 	  &ng_generic_hooklist_type
527 	},
528 	{
529 	  NGM_GENERIC_COOKIE,
530 	  NGM_LISTNAMES,
531 	  "listnames",
532 	  NULL,
533 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
534 	},
535 	{
536 	  NGM_GENERIC_COOKIE,
537 	  NGM_LISTNODES,
538 	  "listnodes",
539 	  NULL,
540 	  &ng_generic_listnodes_type
541 	},
542 	{
543 	  NGM_GENERIC_COOKIE,
544 	  NGM_LISTTYPES,
545 	  "listtypes",
546 	  NULL,
547 	  &ng_generic_typeinfo_type
548 	},
549 	{
550 	  NGM_GENERIC_COOKIE,
551 	  NGM_TEXT_CONFIG,
552 	  "textconfig",
553 	  NULL,
554 	  &ng_parse_string_type
555 	},
556 	{
557 	  NGM_GENERIC_COOKIE,
558 	  NGM_TEXT_STATUS,
559 	  "textstatus",
560 	  NULL,
561 	  &ng_parse_string_type
562 	},
563 	{
564 	  NGM_GENERIC_COOKIE,
565 	  NGM_ASCII2BINARY,
566 	  "ascii2binary",
567 	  &ng_parse_ng_mesg_type,
568 	  &ng_parse_ng_mesg_type
569 	},
570 	{
571 	  NGM_GENERIC_COOKIE,
572 	  NGM_BINARY2ASCII,
573 	  "binary2ascii",
574 	  &ng_parse_ng_mesg_type,
575 	  &ng_parse_ng_mesg_type
576 	},
577 	{ 0 }
578 };
579 
580 /************************************************************************
581 			Node routines
582 ************************************************************************/
583 
584 /*
585  * Instantiate a node of the requested type
586  */
587 int
588 ng_make_node(const char *typename, node_p *nodepp)
589 {
590 	struct ng_type *type;
591 	int	error;
592 
593 	/* Check that the type makes sense */
594 	if (typename == NULL) {
595 		TRAP_ERROR();
596 		return (EINVAL);
597 	}
598 
599 	/* Locate the node type. If we fail we return. Do not try to load
600 	 * module.
601 	 */
602 	if ((type = ng_findtype(typename)) == NULL)
603 		return (ENXIO);
604 
605 	/*
606 	 * If we have a constructor, then make the node and
607 	 * call the constructor to do type specific initialisation.
608 	 */
609 	if (type->constructor != NULL) {
610 		if ((error = ng_make_node_common(type, nodepp)) == 0) {
611 			if ((error = ((*type->constructor)(*nodepp)) != 0)) {
612 				NG_NODE_UNREF(*nodepp);
613 			}
614 		}
615 	} else {
616 		/*
617 		 * Node has no constructor. We cannot ask for one
618 		 * to be made. It must be brought into existence by
619 		 * some external agency. The external agency should
620 		 * call ng_make_node_common() directly to get the
621 		 * netgraph part initialised.
622 		 */
623 		TRAP_ERROR();
624 		error = EINVAL;
625 	}
626 	return (error);
627 }
628 
629 /*
630  * Generic node creation. Called by node initialisation for externally
631  * instantiated nodes (e.g. hardware, sockets, etc ).
632  * The returned node has a reference count of 1.
633  */
634 int
635 ng_make_node_common(struct ng_type *type, node_p *nodepp)
636 {
637 	INIT_VNET_NETGRAPH(curvnet);
638 	node_p node;
639 
640 	/* Require the node type to have been already installed */
641 	if (ng_findtype(type->name) == NULL) {
642 		TRAP_ERROR();
643 		return (EINVAL);
644 	}
645 
646 	/* Make a node and try attach it to the type */
647 	NG_ALLOC_NODE(node);
648 	if (node == NULL) {
649 		TRAP_ERROR();
650 		return (ENOMEM);
651 	}
652 	node->nd_type = type;
653 #ifdef VIMAGE
654 	node->nd_vnet = curvnet;
655 #endif
656 	NG_NODE_REF(node);				/* note reference */
657 	type->refs++;
658 
659 	NG_QUEUE_LOCK_INIT(&node->nd_input_queue);
660 	STAILQ_INIT(&node->nd_input_queue.queue);
661 	node->nd_input_queue.q_flags = 0;
662 
663 	/* Initialize hook list for new node */
664 	LIST_INIT(&node->nd_hooks);
665 
666 	/* Link us into the name hash. */
667 	mtx_lock(&ng_namehash_mtx);
668 	LIST_INSERT_HEAD(&V_ng_name_hash[0], node, nd_nodes);
669 	mtx_unlock(&ng_namehash_mtx);
670 
671 	/* get an ID and put us in the hash chain */
672 	mtx_lock(&ng_idhash_mtx);
673 	for (;;) { /* wrap protection, even if silly */
674 		node_p node2 = NULL;
675 		node->nd_ID = V_nextID++; /* 137/sec for 1 year before wrap */
676 
677 		/* Is there a problem with the new number? */
678 		NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
679 		if ((node->nd_ID != 0) && (node2 == NULL)) {
680 			break;
681 		}
682 	}
683 	LIST_INSERT_HEAD(&V_ng_ID_hash[NG_IDHASH_FN(node->nd_ID)],
684 							node, nd_idnodes);
685 	mtx_unlock(&ng_idhash_mtx);
686 
687 	/* Done */
688 	*nodepp = node;
689 	return (0);
690 }
691 
692 /*
693  * Forceably start the shutdown process on a node. Either call
694  * its shutdown method, or do the default shutdown if there is
695  * no type-specific method.
696  *
697  * We can only be called from a shutdown message, so we know we have
698  * a writer lock, and therefore exclusive access. It also means
699  * that we should not be on the work queue, but we check anyhow.
700  *
701  * Persistent node types must have a type-specific method which
702  * allocates a new node in which case, this one is irretrievably going away,
703  * or cleans up anything it needs, and just makes the node valid again,
704  * in which case we allow the node to survive.
705  *
706  * XXX We need to think of how to tell a persistent node that we
707  * REALLY need to go away because the hardware has gone or we
708  * are rebooting.... etc.
709  */
710 void
711 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
712 {
713 	hook_p hook;
714 
715 	/* Check if it's already shutting down */
716 	if ((node->nd_flags & NGF_CLOSING) != 0)
717 		return;
718 
719 	if (node == &ng_deadnode) {
720 		printf ("shutdown called on deadnode\n");
721 		return;
722 	}
723 
724 	/* Add an extra reference so it doesn't go away during this */
725 	NG_NODE_REF(node);
726 
727 	/*
728 	 * Mark it invalid so any newcomers know not to try use it
729 	 * Also add our own mark so we can't recurse
730 	 * note that NGF_INVALID does not do this as it's also set during
731 	 * creation
732 	 */
733 	node->nd_flags |= NGF_INVALID|NGF_CLOSING;
734 
735 	/* If node has its pre-shutdown method, then call it first*/
736 	if (node->nd_type && node->nd_type->close)
737 		(*node->nd_type->close)(node);
738 
739 	/* Notify all remaining connected nodes to disconnect */
740 	while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
741 		ng_destroy_hook(hook);
742 
743 	/*
744 	 * Drain the input queue forceably.
745 	 * it has no hooks so what's it going to do, bleed on someone?
746 	 * Theoretically we came here from a queue entry that was added
747 	 * Just before the queue was closed, so it should be empty anyway.
748 	 * Also removes us from worklist if needed.
749 	 */
750 	ng_flush_input_queue(node);
751 
752 	/* Ask the type if it has anything to do in this case */
753 	if (node->nd_type && node->nd_type->shutdown) {
754 		(*node->nd_type->shutdown)(node);
755 		if (NG_NODE_IS_VALID(node)) {
756 			/*
757 			 * Well, blow me down if the node code hasn't declared
758 			 * that it doesn't want to die.
759 			 * Presumably it is a persistant node.
760 			 * If we REALLY want it to go away,
761 			 *  e.g. hardware going away,
762 			 * Our caller should set NGF_REALLY_DIE in nd_flags.
763 			 */
764 			node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
765 			NG_NODE_UNREF(node); /* Assume they still have theirs */
766 			return;
767 		}
768 	} else {				/* do the default thing */
769 		NG_NODE_UNREF(node);
770 	}
771 
772 	ng_unname(node); /* basically a NOP these days */
773 
774 	/*
775 	 * Remove extra reference, possibly the last
776 	 * Possible other holders of references may include
777 	 * timeout callouts, but theoretically the node's supposed to
778 	 * have cancelled them. Possibly hardware dependencies may
779 	 * force a driver to 'linger' with a reference.
780 	 */
781 	NG_NODE_UNREF(node);
782 }
783 
784 /*
785  * Remove a reference to the node, possibly the last.
786  * deadnode always acts as it it were the last.
787  */
788 int
789 ng_unref_node(node_p node)
790 {
791 	int v;
792 
793 	if (node == &ng_deadnode) {
794 		return (0);
795 	}
796 
797 	v = atomic_fetchadd_int(&node->nd_refs, -1);
798 
799 	if (v == 1) { /* we were the last */
800 
801 		mtx_lock(&ng_namehash_mtx);
802 		node->nd_type->refs--; /* XXX maybe should get types lock? */
803 		LIST_REMOVE(node, nd_nodes);
804 		mtx_unlock(&ng_namehash_mtx);
805 
806 		mtx_lock(&ng_idhash_mtx);
807 		LIST_REMOVE(node, nd_idnodes);
808 		mtx_unlock(&ng_idhash_mtx);
809 
810 		mtx_destroy(&node->nd_input_queue.q_mtx);
811 		NG_FREE_NODE(node);
812 	}
813 	return (v - 1);
814 }
815 
816 /************************************************************************
817 			Node ID handling
818 ************************************************************************/
819 static node_p
820 ng_ID2noderef(ng_ID_t ID)
821 {
822 	INIT_VNET_NETGRAPH(curvnet);
823 	node_p node;
824 	mtx_lock(&ng_idhash_mtx);
825 	NG_IDHASH_FIND(ID, node);
826 	if(node)
827 		NG_NODE_REF(node);
828 	mtx_unlock(&ng_idhash_mtx);
829 	return(node);
830 }
831 
832 ng_ID_t
833 ng_node2ID(node_p node)
834 {
835 	return (node ? NG_NODE_ID(node) : 0);
836 }
837 
838 /************************************************************************
839 			Node name handling
840 ************************************************************************/
841 
842 /*
843  * Assign a node a name. Once assigned, the name cannot be changed.
844  */
845 int
846 ng_name_node(node_p node, const char *name)
847 {
848 	INIT_VNET_NETGRAPH(curvnet);
849 	int i, hash;
850 	node_p node2;
851 
852 	/* Check the name is valid */
853 	for (i = 0; i < NG_NODESIZ; i++) {
854 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
855 			break;
856 	}
857 	if (i == 0 || name[i] != '\0') {
858 		TRAP_ERROR();
859 		return (EINVAL);
860 	}
861 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
862 		TRAP_ERROR();
863 		return (EINVAL);
864 	}
865 
866 	/* Check the name isn't already being used */
867 	if ((node2 = ng_name2noderef(node, name)) != NULL) {
868 		NG_NODE_UNREF(node2);
869 		TRAP_ERROR();
870 		return (EADDRINUSE);
871 	}
872 
873 	/* copy it */
874 	strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
875 
876 	/* Update name hash. */
877 	NG_NAMEHASH(name, hash);
878 	mtx_lock(&ng_namehash_mtx);
879 	LIST_REMOVE(node, nd_nodes);
880 	LIST_INSERT_HEAD(&V_ng_name_hash[hash], node, nd_nodes);
881 	mtx_unlock(&ng_namehash_mtx);
882 
883 	return (0);
884 }
885 
886 /*
887  * Find a node by absolute name. The name should NOT end with ':'
888  * The name "." means "this node" and "[xxx]" means "the node
889  * with ID (ie, at address) xxx".
890  *
891  * Returns the node if found, else NULL.
892  * Eventually should add something faster than a sequential search.
893  * Note it acquires a reference on the node so you can be sure it's still
894  * there.
895  */
896 node_p
897 ng_name2noderef(node_p here, const char *name)
898 {
899 	INIT_VNET_NETGRAPH(curvnet);
900 	node_p node;
901 	ng_ID_t temp;
902 	int	hash;
903 
904 	/* "." means "this node" */
905 	if (strcmp(name, ".") == 0) {
906 		NG_NODE_REF(here);
907 		return(here);
908 	}
909 
910 	/* Check for name-by-ID */
911 	if ((temp = ng_decodeidname(name)) != 0) {
912 		return (ng_ID2noderef(temp));
913 	}
914 
915 	/* Find node by name */
916 	NG_NAMEHASH(name, hash);
917 	mtx_lock(&ng_namehash_mtx);
918 	LIST_FOREACH(node, &V_ng_name_hash[hash], nd_nodes) {
919 		if (NG_NODE_IS_VALID(node) &&
920 		    (strcmp(NG_NODE_NAME(node), name) == 0)) {
921 			break;
922 		}
923 	}
924 	if (node)
925 		NG_NODE_REF(node);
926 	mtx_unlock(&ng_namehash_mtx);
927 	return (node);
928 }
929 
930 /*
931  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
932  * string is not valid, otherwise returns the value.
933  */
934 static ng_ID_t
935 ng_decodeidname(const char *name)
936 {
937 	const int len = strlen(name);
938 	char *eptr;
939 	u_long val;
940 
941 	/* Check for proper length, brackets, no leading junk */
942 	if ((len < 3)
943 	|| (name[0] != '[')
944 	|| (name[len - 1] != ']')
945 	|| (!isxdigit(name[1]))) {
946 		return ((ng_ID_t)0);
947 	}
948 
949 	/* Decode number */
950 	val = strtoul(name + 1, &eptr, 16);
951 	if ((eptr - name != len - 1)
952 	|| (val == ULONG_MAX)
953 	|| (val == 0)) {
954 		return ((ng_ID_t)0);
955 	}
956 	return (ng_ID_t)val;
957 }
958 
959 /*
960  * Remove a name from a node. This should only be called
961  * when shutting down and removing the node.
962  * IF we allow name changing this may be more resurrected.
963  */
964 void
965 ng_unname(node_p node)
966 {
967 }
968 
969 /************************************************************************
970 			Hook routines
971  Names are not optional. Hooks are always connected, except for a
972  brief moment within these routines. On invalidation or during creation
973  they are connected to the 'dead' hook.
974 ************************************************************************/
975 
976 /*
977  * Remove a hook reference
978  */
979 void
980 ng_unref_hook(hook_p hook)
981 {
982 	int v;
983 
984 	if (hook == &ng_deadhook) {
985 		return;
986 	}
987 
988 	v = atomic_fetchadd_int(&hook->hk_refs, -1);
989 
990 	if (v == 1) { /* we were the last */
991 		if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
992 			_NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
993 		NG_FREE_HOOK(hook);
994 	}
995 }
996 
997 /*
998  * Add an unconnected hook to a node. Only used internally.
999  * Assumes node is locked. (XXX not yet true )
1000  */
1001 static int
1002 ng_add_hook(node_p node, const char *name, hook_p *hookp)
1003 {
1004 	hook_p hook;
1005 	int error = 0;
1006 
1007 	/* Check that the given name is good */
1008 	if (name == NULL) {
1009 		TRAP_ERROR();
1010 		return (EINVAL);
1011 	}
1012 	if (ng_findhook(node, name) != NULL) {
1013 		TRAP_ERROR();
1014 		return (EEXIST);
1015 	}
1016 
1017 	/* Allocate the hook and link it up */
1018 	NG_ALLOC_HOOK(hook);
1019 	if (hook == NULL) {
1020 		TRAP_ERROR();
1021 		return (ENOMEM);
1022 	}
1023 	hook->hk_refs = 1;		/* add a reference for us to return */
1024 	hook->hk_flags = HK_INVALID;
1025 	hook->hk_peer = &ng_deadhook;	/* start off this way */
1026 	hook->hk_node = node;
1027 	NG_NODE_REF(node);		/* each hook counts as a reference */
1028 
1029 	/* Set hook name */
1030 	strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
1031 
1032 	/*
1033 	 * Check if the node type code has something to say about it
1034 	 * If it fails, the unref of the hook will also unref the node.
1035 	 */
1036 	if (node->nd_type->newhook != NULL) {
1037 		if ((error = (*node->nd_type->newhook)(node, hook, name))) {
1038 			NG_HOOK_UNREF(hook);	/* this frees the hook */
1039 			return (error);
1040 		}
1041 	}
1042 	/*
1043 	 * The 'type' agrees so far, so go ahead and link it in.
1044 	 * We'll ask again later when we actually connect the hooks.
1045 	 */
1046 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1047 	node->nd_numhooks++;
1048 	NG_HOOK_REF(hook);	/* one for the node */
1049 
1050 	if (hookp)
1051 		*hookp = hook;
1052 	return (0);
1053 }
1054 
1055 /*
1056  * Find a hook
1057  *
1058  * Node types may supply their own optimized routines for finding
1059  * hooks.  If none is supplied, we just do a linear search.
1060  * XXX Possibly we should add a reference to the hook?
1061  */
1062 hook_p
1063 ng_findhook(node_p node, const char *name)
1064 {
1065 	hook_p hook;
1066 
1067 	if (node->nd_type->findhook != NULL)
1068 		return (*node->nd_type->findhook)(node, name);
1069 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
1070 		if (NG_HOOK_IS_VALID(hook)
1071 		&& (strcmp(NG_HOOK_NAME(hook), name) == 0))
1072 			return (hook);
1073 	}
1074 	return (NULL);
1075 }
1076 
1077 /*
1078  * Destroy a hook
1079  *
1080  * As hooks are always attached, this really destroys two hooks.
1081  * The one given, and the one attached to it. Disconnect the hooks
1082  * from each other first. We reconnect the peer hook to the 'dead'
1083  * hook so that it can still exist after we depart. We then
1084  * send the peer its own destroy message. This ensures that we only
1085  * interact with the peer's structures when it is locked processing that
1086  * message. We hold a reference to the peer hook so we are guaranteed that
1087  * the peer hook and node are still going to exist until
1088  * we are finished there as the hook holds a ref on the node.
1089  * We run this same code again on the peer hook, but that time it is already
1090  * attached to the 'dead' hook.
1091  *
1092  * This routine is called at all stages of hook creation
1093  * on error detection and must be able to handle any such stage.
1094  */
1095 void
1096 ng_destroy_hook(hook_p hook)
1097 {
1098 	hook_p peer;
1099 	node_p node;
1100 
1101 	if (hook == &ng_deadhook) {	/* better safe than sorry */
1102 		printf("ng_destroy_hook called on deadhook\n");
1103 		return;
1104 	}
1105 
1106 	/*
1107 	 * Protect divorce process with mutex, to avoid races on
1108 	 * simultaneous disconnect.
1109 	 */
1110 	mtx_lock(&ng_topo_mtx);
1111 
1112 	hook->hk_flags |= HK_INVALID;
1113 
1114 	peer = NG_HOOK_PEER(hook);
1115 	node = NG_HOOK_NODE(hook);
1116 
1117 	if (peer && (peer != &ng_deadhook)) {
1118 		/*
1119 		 * Set the peer to point to ng_deadhook
1120 		 * from this moment on we are effectively independent it.
1121 		 * send it an rmhook message of it's own.
1122 		 */
1123 		peer->hk_peer = &ng_deadhook;	/* They no longer know us */
1124 		hook->hk_peer = &ng_deadhook;	/* Nor us, them */
1125 		if (NG_HOOK_NODE(peer) == &ng_deadnode) {
1126 			/*
1127 			 * If it's already divorced from a node,
1128 			 * just free it.
1129 			 */
1130 			mtx_unlock(&ng_topo_mtx);
1131 		} else {
1132 			mtx_unlock(&ng_topo_mtx);
1133 			ng_rmhook_self(peer); 	/* Send it a surprise */
1134 		}
1135 		NG_HOOK_UNREF(peer);		/* account for peer link */
1136 		NG_HOOK_UNREF(hook);		/* account for peer link */
1137 	} else
1138 		mtx_unlock(&ng_topo_mtx);
1139 
1140 	mtx_assert(&ng_topo_mtx, MA_NOTOWNED);
1141 
1142 	/*
1143 	 * Remove the hook from the node's list to avoid possible recursion
1144 	 * in case the disconnection results in node shutdown.
1145 	 */
1146 	if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
1147 		return;
1148 	}
1149 	LIST_REMOVE(hook, hk_hooks);
1150 	node->nd_numhooks--;
1151 	if (node->nd_type->disconnect) {
1152 		/*
1153 		 * The type handler may elect to destroy the node so don't
1154 		 * trust its existence after this point. (except
1155 		 * that we still hold a reference on it. (which we
1156 		 * inherrited from the hook we are destroying)
1157 		 */
1158 		(*node->nd_type->disconnect) (hook);
1159 	}
1160 
1161 	/*
1162 	 * Note that because we will point to ng_deadnode, the original node
1163 	 * is not decremented automatically so we do that manually.
1164 	 */
1165 	_NG_HOOK_NODE(hook) = &ng_deadnode;
1166 	NG_NODE_UNREF(node);	/* We no longer point to it so adjust count */
1167 	NG_HOOK_UNREF(hook);	/* Account for linkage (in list) to node */
1168 }
1169 
1170 /*
1171  * Take two hooks on a node and merge the connection so that the given node
1172  * is effectively bypassed.
1173  */
1174 int
1175 ng_bypass(hook_p hook1, hook_p hook2)
1176 {
1177 	if (hook1->hk_node != hook2->hk_node) {
1178 		TRAP_ERROR();
1179 		return (EINVAL);
1180 	}
1181 	hook1->hk_peer->hk_peer = hook2->hk_peer;
1182 	hook2->hk_peer->hk_peer = hook1->hk_peer;
1183 
1184 	hook1->hk_peer = &ng_deadhook;
1185 	hook2->hk_peer = &ng_deadhook;
1186 
1187 	NG_HOOK_UNREF(hook1);
1188 	NG_HOOK_UNREF(hook2);
1189 
1190 	/* XXX If we ever cache methods on hooks update them as well */
1191 	ng_destroy_hook(hook1);
1192 	ng_destroy_hook(hook2);
1193 	return (0);
1194 }
1195 
1196 /*
1197  * Install a new netgraph type
1198  */
1199 int
1200 ng_newtype(struct ng_type *tp)
1201 {
1202 	const size_t namelen = strlen(tp->name);
1203 
1204 	/* Check version and type name fields */
1205 	if ((tp->version != NG_ABI_VERSION)
1206 	|| (namelen == 0)
1207 	|| (namelen >= NG_TYPESIZ)) {
1208 		TRAP_ERROR();
1209 		if (tp->version != NG_ABI_VERSION) {
1210 			printf("Netgraph: Node type rejected. ABI mismatch. Suggest recompile\n");
1211 		}
1212 		return (EINVAL);
1213 	}
1214 
1215 	/* Check for name collision */
1216 	if (ng_findtype(tp->name) != NULL) {
1217 		TRAP_ERROR();
1218 		return (EEXIST);
1219 	}
1220 
1221 
1222 	/* Link in new type */
1223 	mtx_lock(&ng_typelist_mtx);
1224 	LIST_INSERT_HEAD(&ng_typelist, tp, types);
1225 	tp->refs = 1;	/* first ref is linked list */
1226 	mtx_unlock(&ng_typelist_mtx);
1227 	return (0);
1228 }
1229 
1230 /*
1231  * unlink a netgraph type
1232  * If no examples exist
1233  */
1234 int
1235 ng_rmtype(struct ng_type *tp)
1236 {
1237 	/* Check for name collision */
1238 	if (tp->refs != 1) {
1239 		TRAP_ERROR();
1240 		return (EBUSY);
1241 	}
1242 
1243 	/* Unlink type */
1244 	mtx_lock(&ng_typelist_mtx);
1245 	LIST_REMOVE(tp, types);
1246 	mtx_unlock(&ng_typelist_mtx);
1247 	return (0);
1248 }
1249 
1250 /*
1251  * Look for a type of the name given
1252  */
1253 struct ng_type *
1254 ng_findtype(const char *typename)
1255 {
1256 	struct ng_type *type;
1257 
1258 	mtx_lock(&ng_typelist_mtx);
1259 	LIST_FOREACH(type, &ng_typelist, types) {
1260 		if (strcmp(type->name, typename) == 0)
1261 			break;
1262 	}
1263 	mtx_unlock(&ng_typelist_mtx);
1264 	return (type);
1265 }
1266 
1267 /************************************************************************
1268 			Composite routines
1269 ************************************************************************/
1270 /*
1271  * Connect two nodes using the specified hooks, using queued functions.
1272  */
1273 static int
1274 ng_con_part3(node_p node, item_p item, hook_p hook)
1275 {
1276 	int	error = 0;
1277 
1278 	/*
1279 	 * When we run, we know that the node 'node' is locked for us.
1280 	 * Our caller has a reference on the hook.
1281 	 * Our caller has a reference on the node.
1282 	 * (In this case our caller is ng_apply_item() ).
1283 	 * The peer hook has a reference on the hook.
1284 	 * We are all set up except for the final call to the node, and
1285 	 * the clearing of the INVALID flag.
1286 	 */
1287 	if (NG_HOOK_NODE(hook) == &ng_deadnode) {
1288 		/*
1289 		 * The node must have been freed again since we last visited
1290 		 * here. ng_destry_hook() has this effect but nothing else does.
1291 		 * We should just release our references and
1292 		 * free anything we can think of.
1293 		 * Since we know it's been destroyed, and it's our caller
1294 		 * that holds the references, just return.
1295 		 */
1296 		ERROUT(ENOENT);
1297 	}
1298 	if (hook->hk_node->nd_type->connect) {
1299 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1300 			ng_destroy_hook(hook);	/* also zaps peer */
1301 			printf("failed in ng_con_part3()\n");
1302 			ERROUT(error);
1303 		}
1304 	}
1305 	/*
1306 	 *  XXX this is wrong for SMP. Possibly we need
1307 	 * to separate out 'create' and 'invalid' flags.
1308 	 * should only set flags on hooks we have locked under our node.
1309 	 */
1310 	hook->hk_flags &= ~HK_INVALID;
1311 done:
1312 	NG_FREE_ITEM(item);
1313 	return (error);
1314 }
1315 
1316 static int
1317 ng_con_part2(node_p node, item_p item, hook_p hook)
1318 {
1319 	hook_p	peer;
1320 	int	error = 0;
1321 
1322 	/*
1323 	 * When we run, we know that the node 'node' is locked for us.
1324 	 * Our caller has a reference on the hook.
1325 	 * Our caller has a reference on the node.
1326 	 * (In this case our caller is ng_apply_item() ).
1327 	 * The peer hook has a reference on the hook.
1328 	 * our node pointer points to the 'dead' node.
1329 	 * First check the hook name is unique.
1330 	 * Should not happen because we checked before queueing this.
1331 	 */
1332 	if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
1333 		TRAP_ERROR();
1334 		ng_destroy_hook(hook); /* should destroy peer too */
1335 		printf("failed in ng_con_part2()\n");
1336 		ERROUT(EEXIST);
1337 	}
1338 	/*
1339 	 * Check if the node type code has something to say about it
1340 	 * If it fails, the unref of the hook will also unref the attached node,
1341 	 * however since that node is 'ng_deadnode' this will do nothing.
1342 	 * The peer hook will also be destroyed.
1343 	 */
1344 	if (node->nd_type->newhook != NULL) {
1345 		if ((error = (*node->nd_type->newhook)(node, hook,
1346 		    hook->hk_name))) {
1347 			ng_destroy_hook(hook); /* should destroy peer too */
1348 			printf("failed in ng_con_part2()\n");
1349 			ERROUT(error);
1350 		}
1351 	}
1352 
1353 	/*
1354 	 * The 'type' agrees so far, so go ahead and link it in.
1355 	 * We'll ask again later when we actually connect the hooks.
1356 	 */
1357 	hook->hk_node = node;		/* just overwrite ng_deadnode */
1358 	NG_NODE_REF(node);		/* each hook counts as a reference */
1359 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1360 	node->nd_numhooks++;
1361 	NG_HOOK_REF(hook);	/* one for the node */
1362 
1363 	/*
1364 	 * We now have a symmetrical situation, where both hooks have been
1365 	 * linked to their nodes, the newhook methods have been called
1366 	 * And the references are all correct. The hooks are still marked
1367 	 * as invalid, as we have not called the 'connect' methods
1368 	 * yet.
1369 	 * We can call the local one immediately as we have the
1370 	 * node locked, but we need to queue the remote one.
1371 	 */
1372 	if (hook->hk_node->nd_type->connect) {
1373 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1374 			ng_destroy_hook(hook);	/* also zaps peer */
1375 			printf("failed in ng_con_part2(A)\n");
1376 			ERROUT(error);
1377 		}
1378 	}
1379 
1380 	/*
1381 	 * Acquire topo mutex to avoid race with ng_destroy_hook().
1382 	 */
1383 	mtx_lock(&ng_topo_mtx);
1384 	peer = hook->hk_peer;
1385 	if (peer == &ng_deadhook) {
1386 		mtx_unlock(&ng_topo_mtx);
1387 		printf("failed in ng_con_part2(B)\n");
1388 		ng_destroy_hook(hook);
1389 		ERROUT(ENOENT);
1390 	}
1391 	mtx_unlock(&ng_topo_mtx);
1392 
1393 	if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
1394 	    NULL, 0, NG_REUSE_ITEM))) {
1395 		printf("failed in ng_con_part2(C)\n");
1396 		ng_destroy_hook(hook);	/* also zaps peer */
1397 		return (error);		/* item was consumed. */
1398 	}
1399 	hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
1400 	return (0);			/* item was consumed. */
1401 done:
1402 	NG_FREE_ITEM(item);
1403 	return (error);
1404 }
1405 
1406 /*
1407  * Connect this node with another node. We assume that this node is
1408  * currently locked, as we are only called from an NGM_CONNECT message.
1409  */
1410 static int
1411 ng_con_nodes(item_p item, node_p node, const char *name,
1412     node_p node2, const char *name2)
1413 {
1414 	int	error;
1415 	hook_p	hook;
1416 	hook_p	hook2;
1417 
1418 	if (ng_findhook(node2, name2) != NULL) {
1419 		return(EEXIST);
1420 	}
1421 	if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
1422 		return (error);
1423 	/* Allocate the other hook and link it up */
1424 	NG_ALLOC_HOOK(hook2);
1425 	if (hook2 == NULL) {
1426 		TRAP_ERROR();
1427 		ng_destroy_hook(hook);	/* XXX check ref counts so far */
1428 		NG_HOOK_UNREF(hook);	/* including our ref */
1429 		return (ENOMEM);
1430 	}
1431 	hook2->hk_refs = 1;		/* start with a reference for us. */
1432 	hook2->hk_flags = HK_INVALID;
1433 	hook2->hk_peer = hook;		/* Link the two together */
1434 	hook->hk_peer = hook2;
1435 	NG_HOOK_REF(hook);		/* Add a ref for the peer to each*/
1436 	NG_HOOK_REF(hook2);
1437 	hook2->hk_node = &ng_deadnode;
1438 	strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
1439 
1440 	/*
1441 	 * Queue the function above.
1442 	 * Procesing continues in that function in the lock context of
1443 	 * the other node.
1444 	 */
1445 	if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
1446 	    NG_NOFLAGS))) {
1447 		printf("failed in ng_con_nodes(): %d\n", error);
1448 		ng_destroy_hook(hook);	/* also zaps peer */
1449 	}
1450 
1451 	NG_HOOK_UNREF(hook);		/* Let each hook go if it wants to */
1452 	NG_HOOK_UNREF(hook2);
1453 	return (error);
1454 }
1455 
1456 /*
1457  * Make a peer and connect.
1458  * We assume that the local node is locked.
1459  * The new node probably doesn't need a lock until
1460  * it has a hook, because it cannot really have any work until then,
1461  * but we should think about it a bit more.
1462  *
1463  * The problem may come if the other node also fires up
1464  * some hardware or a timer or some other source of activation,
1465  * also it may already get a command msg via it's ID.
1466  *
1467  * We could use the same method as ng_con_nodes() but we'd have
1468  * to add ability to remove the node when failing. (Not hard, just
1469  * make arg1 point to the node to remove).
1470  * Unless of course we just ignore failure to connect and leave
1471  * an unconnected node?
1472  */
1473 static int
1474 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
1475 {
1476 	node_p	node2;
1477 	hook_p	hook1, hook2;
1478 	int	error;
1479 
1480 	if ((error = ng_make_node(type, &node2))) {
1481 		return (error);
1482 	}
1483 
1484 	if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
1485 		ng_rmnode(node2, NULL, NULL, 0);
1486 		return (error);
1487 	}
1488 
1489 	if ((error = ng_add_hook(node2, name2, &hook2))) {
1490 		ng_rmnode(node2, NULL, NULL, 0);
1491 		ng_destroy_hook(hook1);
1492 		NG_HOOK_UNREF(hook1);
1493 		return (error);
1494 	}
1495 
1496 	/*
1497 	 * Actually link the two hooks together.
1498 	 */
1499 	hook1->hk_peer = hook2;
1500 	hook2->hk_peer = hook1;
1501 
1502 	/* Each hook is referenced by the other */
1503 	NG_HOOK_REF(hook1);
1504 	NG_HOOK_REF(hook2);
1505 
1506 	/* Give each node the opportunity to veto the pending connection */
1507 	if (hook1->hk_node->nd_type->connect) {
1508 		error = (*hook1->hk_node->nd_type->connect) (hook1);
1509 	}
1510 
1511 	if ((error == 0) && hook2->hk_node->nd_type->connect) {
1512 		error = (*hook2->hk_node->nd_type->connect) (hook2);
1513 
1514 	}
1515 
1516 	/*
1517 	 * drop the references we were holding on the two hooks.
1518 	 */
1519 	if (error) {
1520 		ng_destroy_hook(hook2);	/* also zaps hook1 */
1521 		ng_rmnode(node2, NULL, NULL, 0);
1522 	} else {
1523 		/* As a last act, allow the hooks to be used */
1524 		hook1->hk_flags &= ~HK_INVALID;
1525 		hook2->hk_flags &= ~HK_INVALID;
1526 	}
1527 	NG_HOOK_UNREF(hook1);
1528 	NG_HOOK_UNREF(hook2);
1529 	return (error);
1530 }
1531 
1532 /************************************************************************
1533 		Utility routines to send self messages
1534 ************************************************************************/
1535 
1536 /* Shut this node down as soon as everyone is clear of it */
1537 /* Should add arg "immediately" to jump the queue */
1538 int
1539 ng_rmnode_self(node_p node)
1540 {
1541 	int		error;
1542 
1543 	if (node == &ng_deadnode)
1544 		return (0);
1545 	node->nd_flags |= NGF_INVALID;
1546 	if (node->nd_flags & NGF_CLOSING)
1547 		return (0);
1548 
1549 	error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
1550 	return (error);
1551 }
1552 
1553 static void
1554 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
1555 {
1556 	ng_destroy_hook(hook);
1557 	return ;
1558 }
1559 
1560 int
1561 ng_rmhook_self(hook_p hook)
1562 {
1563 	int		error;
1564 	node_p node = NG_HOOK_NODE(hook);
1565 
1566 	if (node == &ng_deadnode)
1567 		return (0);
1568 
1569 	error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
1570 	return (error);
1571 }
1572 
1573 /***********************************************************************
1574  * Parse and verify a string of the form:  <NODE:><PATH>
1575  *
1576  * Such a string can refer to a specific node or a specific hook
1577  * on a specific node, depending on how you look at it. In the
1578  * latter case, the PATH component must not end in a dot.
1579  *
1580  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1581  * of hook names separated by dots. This breaks out the original
1582  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1583  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1584  * the final hook component of <PATH>, if any, otherwise NULL.
1585  *
1586  * This returns -1 if the path is malformed. The char ** are optional.
1587  ***********************************************************************/
1588 int
1589 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1590 {
1591 	char	*node, *path, *hook;
1592 	int	k;
1593 
1594 	/*
1595 	 * Extract absolute NODE, if any
1596 	 */
1597 	for (path = addr; *path && *path != ':'; path++);
1598 	if (*path) {
1599 		node = addr;	/* Here's the NODE */
1600 		*path++ = '\0';	/* Here's the PATH */
1601 
1602 		/* Node name must not be empty */
1603 		if (!*node)
1604 			return -1;
1605 
1606 		/* A name of "." is OK; otherwise '.' not allowed */
1607 		if (strcmp(node, ".") != 0) {
1608 			for (k = 0; node[k]; k++)
1609 				if (node[k] == '.')
1610 					return -1;
1611 		}
1612 	} else {
1613 		node = NULL;	/* No absolute NODE */
1614 		path = addr;	/* Here's the PATH */
1615 	}
1616 
1617 	/* Snoop for illegal characters in PATH */
1618 	for (k = 0; path[k]; k++)
1619 		if (path[k] == ':')
1620 			return -1;
1621 
1622 	/* Check for no repeated dots in PATH */
1623 	for (k = 0; path[k]; k++)
1624 		if (path[k] == '.' && path[k + 1] == '.')
1625 			return -1;
1626 
1627 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1628 	if (path[0] == '.')
1629 		path++;
1630 	if (*path && path[strlen(path) - 1] == '.')
1631 		path[strlen(path) - 1] = 0;
1632 
1633 	/* If PATH has a dot, then we're not talking about a hook */
1634 	if (*path) {
1635 		for (hook = path, k = 0; path[k]; k++)
1636 			if (path[k] == '.') {
1637 				hook = NULL;
1638 				break;
1639 			}
1640 	} else
1641 		path = hook = NULL;
1642 
1643 	/* Done */
1644 	if (nodep)
1645 		*nodep = node;
1646 	if (pathp)
1647 		*pathp = path;
1648 	if (hookp)
1649 		*hookp = hook;
1650 	return (0);
1651 }
1652 
1653 /*
1654  * Given a path, which may be absolute or relative, and a starting node,
1655  * return the destination node.
1656  */
1657 int
1658 ng_path2noderef(node_p here, const char *address,
1659 				node_p *destp, hook_p *lasthook)
1660 {
1661 	char    fullpath[NG_PATHSIZ];
1662 	char   *nodename, *path, pbuf[2];
1663 	node_p  node, oldnode;
1664 	char   *cp;
1665 	hook_p hook = NULL;
1666 
1667 	/* Initialize */
1668 	if (destp == NULL) {
1669 		TRAP_ERROR();
1670 		return EINVAL;
1671 	}
1672 	*destp = NULL;
1673 
1674 	/* Make a writable copy of address for ng_path_parse() */
1675 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1676 	fullpath[sizeof(fullpath) - 1] = '\0';
1677 
1678 	/* Parse out node and sequence of hooks */
1679 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1680 		TRAP_ERROR();
1681 		return EINVAL;
1682 	}
1683 	if (path == NULL) {
1684 		pbuf[0] = '.';	/* Needs to be writable */
1685 		pbuf[1] = '\0';
1686 		path = pbuf;
1687 	}
1688 
1689 	/*
1690 	 * For an absolute address, jump to the starting node.
1691 	 * Note that this holds a reference on the node for us.
1692 	 * Don't forget to drop the reference if we don't need it.
1693 	 */
1694 	if (nodename) {
1695 		node = ng_name2noderef(here, nodename);
1696 		if (node == NULL) {
1697 			TRAP_ERROR();
1698 			return (ENOENT);
1699 		}
1700 	} else {
1701 		if (here == NULL) {
1702 			TRAP_ERROR();
1703 			return (EINVAL);
1704 		}
1705 		node = here;
1706 		NG_NODE_REF(node);
1707 	}
1708 
1709 	/*
1710 	 * Now follow the sequence of hooks
1711 	 * XXX
1712 	 * We actually cannot guarantee that the sequence
1713 	 * is not being demolished as we crawl along it
1714 	 * without extra-ordinary locking etc.
1715 	 * So this is a bit dodgy to say the least.
1716 	 * We can probably hold up some things by holding
1717 	 * the nodelist mutex for the time of this
1718 	 * crawl if we wanted.. At least that way we wouldn't have to
1719 	 * worry about the nodes disappearing, but the hooks would still
1720 	 * be a problem.
1721 	 */
1722 	for (cp = path; node != NULL && *cp != '\0'; ) {
1723 		char *segment;
1724 
1725 		/*
1726 		 * Break out the next path segment. Replace the dot we just
1727 		 * found with a NUL; "cp" points to the next segment (or the
1728 		 * NUL at the end).
1729 		 */
1730 		for (segment = cp; *cp != '\0'; cp++) {
1731 			if (*cp == '.') {
1732 				*cp++ = '\0';
1733 				break;
1734 			}
1735 		}
1736 
1737 		/* Empty segment */
1738 		if (*segment == '\0')
1739 			continue;
1740 
1741 		/* We have a segment, so look for a hook by that name */
1742 		hook = ng_findhook(node, segment);
1743 
1744 		/* Can't get there from here... */
1745 		if (hook == NULL
1746 		    || NG_HOOK_PEER(hook) == NULL
1747 		    || NG_HOOK_NOT_VALID(hook)
1748 		    || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
1749 			TRAP_ERROR();
1750 			NG_NODE_UNREF(node);
1751 #if 0
1752 			printf("hooknotvalid %s %s %d %d %d %d ",
1753 					path,
1754 					segment,
1755 					hook == NULL,
1756 					NG_HOOK_PEER(hook) == NULL,
1757 					NG_HOOK_NOT_VALID(hook),
1758 					NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook)));
1759 #endif
1760 			return (ENOENT);
1761 		}
1762 
1763 		/*
1764 		 * Hop on over to the next node
1765 		 * XXX
1766 		 * Big race conditions here as hooks and nodes go away
1767 		 * *** Idea.. store an ng_ID_t in each hook and use that
1768 		 * instead of the direct hook in this crawl?
1769 		 */
1770 		oldnode = node;
1771 		if ((node = NG_PEER_NODE(hook)))
1772 			NG_NODE_REF(node);	/* XXX RACE */
1773 		NG_NODE_UNREF(oldnode);	/* XXX another race */
1774 		if (NG_NODE_NOT_VALID(node)) {
1775 			NG_NODE_UNREF(node);	/* XXX more races */
1776 			node = NULL;
1777 		}
1778 	}
1779 
1780 	/* If node somehow missing, fail here (probably this is not needed) */
1781 	if (node == NULL) {
1782 		TRAP_ERROR();
1783 		return (ENXIO);
1784 	}
1785 
1786 	/* Done */
1787 	*destp = node;
1788 	if (lasthook != NULL)
1789 		*lasthook = (hook ? NG_HOOK_PEER(hook) : NULL);
1790 	return (0);
1791 }
1792 
1793 /***************************************************************\
1794 * Input queue handling.
1795 * All activities are submitted to the node via the input queue
1796 * which implements a multiple-reader/single-writer gate.
1797 * Items which cannot be handled immediately are queued.
1798 *
1799 * read-write queue locking inline functions			*
1800 \***************************************************************/
1801 
1802 static __inline void	ng_queue_rw(node_p node, item_p  item, int rw);
1803 static __inline item_p	ng_dequeue(node_p node, int *rw);
1804 static __inline item_p	ng_acquire_read(node_p node, item_p  item);
1805 static __inline item_p	ng_acquire_write(node_p node, item_p  item);
1806 static __inline void	ng_leave_read(node_p node);
1807 static __inline void	ng_leave_write(node_p node);
1808 
1809 /*
1810  * Definition of the bits fields in the ng_queue flag word.
1811  * Defined here rather than in netgraph.h because no-one should fiddle
1812  * with them.
1813  *
1814  * The ordering here may be important! don't shuffle these.
1815  */
1816 /*-
1817  Safety Barrier--------+ (adjustable to suit taste) (not used yet)
1818                        |
1819                        V
1820 +-------+-------+-------+-------+-------+-------+-------+-------+
1821   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
1822   | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
1823   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
1824 +-------+-------+-------+-------+-------+-------+-------+-------+
1825   \___________________________ ____________________________/ | |
1826                             V                                | |
1827                   [active reader count]                      | |
1828                                                              | |
1829             Operation Pending -------------------------------+ |
1830                                                                |
1831           Active Writer ---------------------------------------+
1832 
1833 Node queue has such semantics:
1834 - All flags modifications are atomic.
1835 - Reader count can be incremented only if there is no writer or pending flags.
1836   As soon as this can't be done with single operation, it is implemented with
1837   spin loop and atomic_cmpset().
1838 - Writer flag can be set only if there is no any bits set.
1839   It is implemented with atomic_cmpset().
1840 - Pending flag can be set any time, but to avoid collision on queue processing
1841   all queue fields are protected by the mutex.
1842 - Queue processing thread reads queue holding the mutex, but releases it while
1843   processing. When queue is empty pending flag is removed.
1844 */
1845 
1846 #define WRITER_ACTIVE	0x00000001
1847 #define OP_PENDING	0x00000002
1848 #define READER_INCREMENT 0x00000004
1849 #define READER_MASK	0xfffffffc	/* Not valid if WRITER_ACTIVE is set */
1850 #define SAFETY_BARRIER	0x00100000	/* 128K items queued should be enough */
1851 
1852 /* Defines of more elaborate states on the queue */
1853 /* Mask of bits a new read cares about */
1854 #define NGQ_RMASK	(WRITER_ACTIVE|OP_PENDING)
1855 
1856 /* Mask of bits a new write cares about */
1857 #define NGQ_WMASK	(NGQ_RMASK|READER_MASK)
1858 
1859 /* Test to decide if there is something on the queue. */
1860 #define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
1861 
1862 /* How to decide what the next queued item is. */
1863 #define HEAD_IS_READER(QP)  NGI_QUEUED_READER(STAILQ_FIRST(&(QP)->queue))
1864 #define HEAD_IS_WRITER(QP)  NGI_QUEUED_WRITER(STAILQ_FIRST(&(QP)->queue)) /* notused */
1865 
1866 /* Read the status to decide if the next item on the queue can now run. */
1867 #define QUEUED_READER_CAN_PROCEED(QP)			\
1868 		(((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
1869 #define QUEUED_WRITER_CAN_PROCEED(QP)			\
1870 		(((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
1871 
1872 /* Is there a chance of getting ANY work off the queue? */
1873 #define NEXT_QUEUED_ITEM_CAN_PROCEED(QP)				\
1874 	((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) :		\
1875 				QUEUED_WRITER_CAN_PROCEED(QP))
1876 
1877 #define NGQRW_R 0
1878 #define NGQRW_W 1
1879 
1880 #define NGQ2_WORKQ	0x00000001
1881 
1882 /*
1883  * Taking into account the current state of the queue and node, possibly take
1884  * the next entry off the queue and return it. Return NULL if there was
1885  * nothing we could return, either because there really was nothing there, or
1886  * because the node was in a state where it cannot yet process the next item
1887  * on the queue.
1888  */
1889 static __inline item_p
1890 ng_dequeue(node_p node, int *rw)
1891 {
1892 	item_p item;
1893 	struct ng_queue *ngq = &node->nd_input_queue;
1894 
1895 	/* This MUST be called with the mutex held. */
1896 	mtx_assert(&ngq->q_mtx, MA_OWNED);
1897 
1898 	/* If there is nothing queued, then just return. */
1899 	if (!QUEUE_ACTIVE(ngq)) {
1900 		CTR4(KTR_NET, "%20s: node [%x] (%p) queue empty; "
1901 		    "queue flags 0x%lx", __func__,
1902 		    node->nd_ID, node, ngq->q_flags);
1903 		return (NULL);
1904 	}
1905 
1906 	/*
1907 	 * From here, we can assume there is a head item.
1908 	 * We need to find out what it is and if it can be dequeued, given
1909 	 * the current state of the node.
1910 	 */
1911 	if (HEAD_IS_READER(ngq)) {
1912 		while (1) {
1913 			long t = ngq->q_flags;
1914 			if (t & WRITER_ACTIVE) {
1915 				/* There is writer, reader can't proceed. */
1916 				CTR4(KTR_NET, "%20s: node [%x] (%p) queued reader "
1917 				    "can't proceed; queue flags 0x%lx", __func__,
1918 				    node->nd_ID, node, t);
1919 				return (NULL);
1920 			}
1921 			if (atomic_cmpset_acq_int(&ngq->q_flags, t,
1922 			    t + READER_INCREMENT))
1923 				break;
1924 			cpu_spinwait();
1925 		}
1926 		/* We have got reader lock for the node. */
1927 		*rw = NGQRW_R;
1928 	} else if (atomic_cmpset_acq_int(&ngq->q_flags, OP_PENDING,
1929 	    OP_PENDING + WRITER_ACTIVE)) {
1930 		/* We have got writer lock for the node. */
1931 		*rw = NGQRW_W;
1932 	} else {
1933 		/* There is somebody other, writer can't proceed. */
1934 		CTR4(KTR_NET, "%20s: node [%x] (%p) queued writer "
1935 		    "can't proceed; queue flags 0x%lx", __func__,
1936 		    node->nd_ID, node, ngq->q_flags);
1937 		return (NULL);
1938 	}
1939 
1940 	/*
1941 	 * Now we dequeue the request (whatever it may be) and correct the
1942 	 * pending flags and the next and last pointers.
1943 	 */
1944 	item = STAILQ_FIRST(&ngq->queue);
1945 	STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
1946 	if (STAILQ_EMPTY(&ngq->queue))
1947 		atomic_clear_int(&ngq->q_flags, OP_PENDING);
1948 	CTR6(KTR_NET, "%20s: node [%x] (%p) returning item %p as %s; "
1949 	    "queue flags 0x%lx", __func__,
1950 	    node->nd_ID, node, item, *rw ? "WRITER" : "READER" ,
1951 	    ngq->q_flags);
1952 	return (item);
1953 }
1954 
1955 /*
1956  * Queue a packet to be picked up later by someone else.
1957  * If the queue could be run now, add node to the queue handler's worklist.
1958  */
1959 static __inline void
1960 ng_queue_rw(node_p node, item_p  item, int rw)
1961 {
1962 	struct ng_queue *ngq = &node->nd_input_queue;
1963 	if (rw == NGQRW_W)
1964 		NGI_SET_WRITER(item);
1965 	else
1966 		NGI_SET_READER(item);
1967 
1968 	NG_QUEUE_LOCK(ngq);
1969 	/* Set OP_PENDING flag and enqueue the item. */
1970 	atomic_set_int(&ngq->q_flags, OP_PENDING);
1971 	STAILQ_INSERT_TAIL(&ngq->queue, item, el_next);
1972 
1973 	CTR5(KTR_NET, "%20s: node [%x] (%p) queued item %p as %s", __func__,
1974 	    node->nd_ID, node, item, rw ? "WRITER" : "READER" );
1975 
1976 	/*
1977 	 * We can take the worklist lock with the node locked
1978 	 * BUT NOT THE REVERSE!
1979 	 */
1980 	if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
1981 		ng_worklist_add(node);
1982 	NG_QUEUE_UNLOCK(ngq);
1983 }
1984 
1985 /* Acquire reader lock on node. If node is busy, queue the packet. */
1986 static __inline item_p
1987 ng_acquire_read(node_p node, item_p item)
1988 {
1989 	KASSERT(node != &ng_deadnode,
1990 	    ("%s: working on deadnode", __func__));
1991 
1992 	/* Reader needs node without writer and pending items. */
1993 	while (1) {
1994 		long t = node->nd_input_queue.q_flags;
1995 		if (t & NGQ_RMASK)
1996 			break; /* Node is not ready for reader. */
1997 		if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
1998 		    t, t + READER_INCREMENT)) {
1999 	    		/* Successfully grabbed node */
2000 			CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
2001 			    __func__, node->nd_ID, node, item);
2002 			return (item);
2003 		}
2004 		cpu_spinwait();
2005 	};
2006 
2007 	/* Queue the request for later. */
2008 	ng_queue_rw(node, item, NGQRW_R);
2009 
2010 	return (NULL);
2011 }
2012 
2013 /* Acquire writer lock on node. If node is busy, queue the packet. */
2014 static __inline item_p
2015 ng_acquire_write(node_p node, item_p item)
2016 {
2017 	KASSERT(node != &ng_deadnode,
2018 	    ("%s: working on deadnode", __func__));
2019 
2020 	/* Writer needs completely idle node. */
2021 	if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags,
2022 	    0, WRITER_ACTIVE)) {
2023 	    	/* Successfully grabbed node */
2024 		CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
2025 		    __func__, node->nd_ID, node, item);
2026 		return (item);
2027 	}
2028 
2029 	/* Queue the request for later. */
2030 	ng_queue_rw(node, item, NGQRW_W);
2031 
2032 	return (NULL);
2033 }
2034 
2035 #if 0
2036 static __inline item_p
2037 ng_upgrade_write(node_p node, item_p item)
2038 {
2039 	struct ng_queue *ngq = &node->nd_input_queue;
2040 	KASSERT(node != &ng_deadnode,
2041 	    ("%s: working on deadnode", __func__));
2042 
2043 	NGI_SET_WRITER(item);
2044 
2045 	NG_QUEUE_LOCK(ngq);
2046 
2047 	/*
2048 	 * There will never be no readers as we are there ourselves.
2049 	 * Set the WRITER_ACTIVE flags ASAP to block out fast track readers.
2050 	 * The caller we are running from will call ng_leave_read()
2051 	 * soon, so we must account for that. We must leave again with the
2052 	 * READER lock. If we find other readers, then
2053 	 * queue the request for later. However "later" may be rignt now
2054 	 * if there are no readers. We don't really care if there are queued
2055 	 * items as we will bypass them anyhow.
2056 	 */
2057 	atomic_add_int(&ngq->q_flags, WRITER_ACTIVE - READER_INCREMENT);
2058 	if ((ngq->q_flags & (NGQ_WMASK & ~OP_PENDING)) == WRITER_ACTIVE) {
2059 		NG_QUEUE_UNLOCK(ngq);
2060 
2061 		/* It's just us, act on the item. */
2062 		/* will NOT drop writer lock when done */
2063 		ng_apply_item(node, item, 0);
2064 
2065 		/*
2066 		 * Having acted on the item, atomically
2067 		 * down grade back to READER and finish up
2068 	 	 */
2069 		atomic_add_int(&ngq->q_flags,
2070 		    READER_INCREMENT - WRITER_ACTIVE);
2071 
2072 		/* Our caller will call ng_leave_read() */
2073 		return;
2074 	}
2075 	/*
2076 	 * It's not just us active, so queue us AT THE HEAD.
2077 	 * "Why?" I hear you ask.
2078 	 * Put us at the head of the queue as we've already been
2079 	 * through it once. If there is nothing else waiting,
2080 	 * set the correct flags.
2081 	 */
2082 	if (STAILQ_EMPTY(&ngq->queue)) {
2083 		/* We've gone from, 0 to 1 item in the queue */
2084 		atomic_set_int(&ngq->q_flags, OP_PENDING);
2085 
2086 		CTR3(KTR_NET, "%20s: node [%x] (%p) set OP_PENDING", __func__,
2087 		    node->nd_ID, node);
2088 	};
2089 	STAILQ_INSERT_HEAD(&ngq->queue, item, el_next);
2090 	CTR4(KTR_NET, "%20s: node [%x] (%p) requeued item %p as WRITER",
2091 	    __func__, node->nd_ID, node, item );
2092 
2093 	/* Reverse what we did above. That downgrades us back to reader */
2094 	atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
2095 	if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2096 		ng_worklist_add(node);
2097 	NG_QUEUE_UNLOCK(ngq);
2098 
2099 	return;
2100 }
2101 #endif
2102 
2103 /* Release reader lock. */
2104 static __inline void
2105 ng_leave_read(node_p node)
2106 {
2107 	atomic_subtract_rel_int(&node->nd_input_queue.q_flags, READER_INCREMENT);
2108 }
2109 
2110 /* Release writer lock. */
2111 static __inline void
2112 ng_leave_write(node_p node)
2113 {
2114 	atomic_clear_rel_int(&node->nd_input_queue.q_flags, WRITER_ACTIVE);
2115 }
2116 
2117 /* Purge node queue. Called on node shutdown. */
2118 static void
2119 ng_flush_input_queue(node_p node)
2120 {
2121 	struct ng_queue *ngq = &node->nd_input_queue;
2122 	item_p item;
2123 
2124 	NG_QUEUE_LOCK(ngq);
2125 	while ((item = STAILQ_FIRST(&ngq->queue)) != NULL) {
2126 		STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
2127 		if (STAILQ_EMPTY(&ngq->queue))
2128 			atomic_clear_int(&ngq->q_flags, OP_PENDING);
2129 		NG_QUEUE_UNLOCK(ngq);
2130 
2131 		/* If the item is supplying a callback, call it with an error */
2132 		if (item->apply != NULL) {
2133 			if (item->depth == 1)
2134 				item->apply->error = ENOENT;
2135 			if (refcount_release(&item->apply->refs)) {
2136 				(*item->apply->apply)(item->apply->context,
2137 				    item->apply->error);
2138 			}
2139 		}
2140 		NG_FREE_ITEM(item);
2141 		NG_QUEUE_LOCK(ngq);
2142 	}
2143 	NG_QUEUE_UNLOCK(ngq);
2144 }
2145 
2146 /***********************************************************************
2147 * Externally visible method for sending or queueing messages or data.
2148 ***********************************************************************/
2149 
2150 /*
2151  * The module code should have filled out the item correctly by this stage:
2152  * Common:
2153  *    reference to destination node.
2154  *    Reference to destination rcv hook if relevant.
2155  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
2156  * Data:
2157  *    pointer to mbuf
2158  * Control_Message:
2159  *    pointer to msg.
2160  *    ID of original sender node. (return address)
2161  * Function:
2162  *    Function pointer
2163  *    void * argument
2164  *    integer argument
2165  *
2166  * The nodes have several routines and macros to help with this task:
2167  */
2168 
2169 int
2170 ng_snd_item(item_p item, int flags)
2171 {
2172 	hook_p hook;
2173 	node_p node;
2174 	int queue, rw;
2175 	struct ng_queue *ngq;
2176 	int error = 0;
2177 
2178 	/* We are sending item, so it must be present! */
2179 	KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
2180 
2181 #ifdef	NETGRAPH_DEBUG
2182 	_ngi_check(item, __FILE__, __LINE__);
2183 #endif
2184 
2185 	/* Item was sent once more, postpone apply() call. */
2186 	if (item->apply)
2187 		refcount_acquire(&item->apply->refs);
2188 
2189 	node = NGI_NODE(item);
2190 	/* Node is never optional. */
2191 	KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
2192 
2193 	hook = NGI_HOOK(item);
2194 	/* Valid hook and mbuf are mandatory for data. */
2195 	if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
2196 		KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
2197 		if (NGI_M(item) == NULL)
2198 			ERROUT(EINVAL);
2199 		CHECK_DATA_MBUF(NGI_M(item));
2200 	}
2201 
2202 	/*
2203 	 * If the item or the node specifies single threading, force
2204 	 * writer semantics. Similarly, the node may say one hook always
2205 	 * produces writers. These are overrides.
2206 	 */
2207 	if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
2208 	    (node->nd_flags & NGF_FORCE_WRITER) ||
2209 	    (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
2210 		rw = NGQRW_W;
2211 	} else {
2212 		rw = NGQRW_R;
2213 	}
2214 
2215 	/*
2216 	 * If sender or receiver requests queued delivery, or call graph
2217 	 * loops back from outbound to inbound path, or stack usage
2218 	 * level is dangerous - enqueue message.
2219 	 */
2220 	if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
2221 		queue = 1;
2222 	} else if (hook && (hook->hk_flags & HK_TO_INBOUND) &&
2223 	    curthread->td_ng_outbound) {
2224 		queue = 1;
2225 	} else {
2226 		queue = 0;
2227 #ifdef GET_STACK_USAGE
2228 		/*
2229 		 * Most of netgraph nodes have small stack consumption and
2230 		 * for them 25% of free stack space is more than enough.
2231 		 * Nodes/hooks with higher stack usage should be marked as
2232 		 * HI_STACK. For them 50% of stack will be guaranteed then.
2233 		 * XXX: Values 25% and 50% are completely empirical.
2234 		 */
2235 		size_t	st, su, sl;
2236 		GET_STACK_USAGE(st, su);
2237 		sl = st - su;
2238 		if ((sl * 4 < st) ||
2239 		    ((sl * 2 < st) && ((node->nd_flags & NGF_HI_STACK) ||
2240 		      (hook && (hook->hk_flags & HK_HI_STACK))))) {
2241 			queue = 1;
2242 		}
2243 #endif
2244 	}
2245 
2246 	if (queue) {
2247 		item->depth = 1;
2248 		/* Put it on the queue for that node*/
2249 		ng_queue_rw(node, item, rw);
2250 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2251 	}
2252 
2253 	/*
2254 	 * We already decided how we will be queueud or treated.
2255 	 * Try get the appropriate operating permission.
2256 	 */
2257  	if (rw == NGQRW_R)
2258 		item = ng_acquire_read(node, item);
2259 	else
2260 		item = ng_acquire_write(node, item);
2261 
2262 	/* Item was queued while trying to get permission. */
2263 	if (item == NULL)
2264 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2265 
2266 	NGI_GET_NODE(item, node); /* zaps stored node */
2267 
2268 	item->depth++;
2269 	error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
2270 
2271 	/* If something is waiting on queue and ready, schedule it. */
2272 	ngq = &node->nd_input_queue;
2273 	if (QUEUE_ACTIVE(ngq)) {
2274 		NG_QUEUE_LOCK(ngq);
2275 		if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2276 			ng_worklist_add(node);
2277 		NG_QUEUE_UNLOCK(ngq);
2278 	}
2279 
2280 	/*
2281 	 * Node may go away as soon as we remove the reference.
2282 	 * Whatever we do, DO NOT access the node again!
2283 	 */
2284 	NG_NODE_UNREF(node);
2285 
2286 	return (error);
2287 
2288 done:
2289 	/* If was not sent, apply callback here. */
2290 	if (item->apply != NULL) {
2291 		if (item->depth == 0 && error != 0)
2292 			item->apply->error = error;
2293 		if (refcount_release(&item->apply->refs)) {
2294 			(*item->apply->apply)(item->apply->context,
2295 			    item->apply->error);
2296 		}
2297 	}
2298 
2299 	NG_FREE_ITEM(item);
2300 	return (error);
2301 }
2302 
2303 /*
2304  * We have an item that was possibly queued somewhere.
2305  * It should contain all the information needed
2306  * to run it on the appropriate node/hook.
2307  * If there is apply pointer and we own the last reference, call apply().
2308  */
2309 static int
2310 ng_apply_item(node_p node, item_p item, int rw)
2311 {
2312 	hook_p  hook;
2313 	ng_rcvdata_t *rcvdata;
2314 	ng_rcvmsg_t *rcvmsg;
2315 	struct ng_apply_info *apply;
2316 	int	error = 0, depth;
2317 
2318 	/* Node and item are never optional. */
2319 	KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
2320 	KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
2321 
2322 	NGI_GET_HOOK(item, hook); /* clears stored hook */
2323 #ifdef	NETGRAPH_DEBUG
2324 	_ngi_check(item, __FILE__, __LINE__);
2325 #endif
2326 
2327 	apply = item->apply;
2328 	depth = item->depth;
2329 
2330 	switch (item->el_flags & NGQF_TYPE) {
2331 	case NGQF_DATA:
2332 		/*
2333 		 * Check things are still ok as when we were queued.
2334 		 */
2335 		KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
2336 		if (NG_HOOK_NOT_VALID(hook) ||
2337 		    NG_NODE_NOT_VALID(node)) {
2338 			error = EIO;
2339 			NG_FREE_ITEM(item);
2340 			break;
2341 		}
2342 		/*
2343 		 * If no receive method, just silently drop it.
2344 		 * Give preference to the hook over-ride method
2345 		 */
2346 		if ((!(rcvdata = hook->hk_rcvdata))
2347 		&& (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
2348 			error = 0;
2349 			NG_FREE_ITEM(item);
2350 			break;
2351 		}
2352 		error = (*rcvdata)(hook, item);
2353 		break;
2354 	case NGQF_MESG:
2355 		if (hook && NG_HOOK_NOT_VALID(hook)) {
2356 			/*
2357 			 * The hook has been zapped then we can't use it.
2358 			 * Immediately drop its reference.
2359 			 * The message may not need it.
2360 			 */
2361 			NG_HOOK_UNREF(hook);
2362 			hook = NULL;
2363 		}
2364 		/*
2365 		 * Similarly, if the node is a zombie there is
2366 		 * nothing we can do with it, drop everything.
2367 		 */
2368 		if (NG_NODE_NOT_VALID(node)) {
2369 			TRAP_ERROR();
2370 			error = EINVAL;
2371 			NG_FREE_ITEM(item);
2372 			break;
2373 		}
2374 		/*
2375 		 * Call the appropriate message handler for the object.
2376 		 * It is up to the message handler to free the message.
2377 		 * If it's a generic message, handle it generically,
2378 		 * otherwise call the type's message handler (if it exists).
2379 		 * XXX (race). Remember that a queued message may
2380 		 * reference a node or hook that has just been
2381 		 * invalidated. It will exist as the queue code
2382 		 * is holding a reference, but..
2383 		 */
2384 		if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
2385 		    ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
2386 			error = ng_generic_msg(node, item, hook);
2387 			break;
2388 		}
2389 		if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
2390 		    (!(rcvmsg = node->nd_type->rcvmsg))) {
2391 			TRAP_ERROR();
2392 			error = 0;
2393 			NG_FREE_ITEM(item);
2394 			break;
2395 		}
2396 		error = (*rcvmsg)(node, item, hook);
2397 		break;
2398 	case NGQF_FN:
2399 	case NGQF_FN2:
2400 		/*
2401 		 * In the case of the shutdown message we allow it to hit
2402 		 * even if the node is invalid.
2403 		 */
2404 		if (NG_NODE_NOT_VALID(node) &&
2405 		    NGI_FN(item) != &ng_rmnode) {
2406 			TRAP_ERROR();
2407 			error = EINVAL;
2408 			NG_FREE_ITEM(item);
2409 			break;
2410 		}
2411 		/* Same is about some internal functions and invalid hook. */
2412 		if (hook && NG_HOOK_NOT_VALID(hook) &&
2413 		    NGI_FN2(item) != &ng_con_part2 &&
2414 		    NGI_FN2(item) != &ng_con_part3 &&
2415 		    NGI_FN(item) != &ng_rmhook_part2) {
2416 			TRAP_ERROR();
2417 			error = EINVAL;
2418 			NG_FREE_ITEM(item);
2419 			break;
2420 		}
2421 
2422 		if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
2423 			(*NGI_FN(item))(node, hook, NGI_ARG1(item),
2424 			    NGI_ARG2(item));
2425 			NG_FREE_ITEM(item);
2426 		} else	/* it is NGQF_FN2 */
2427 			error = (*NGI_FN2(item))(node, item, hook);
2428 		break;
2429 	}
2430 	/*
2431 	 * We held references on some of the resources
2432 	 * that we took from the item. Now that we have
2433 	 * finished doing everything, drop those references.
2434 	 */
2435 	if (hook)
2436 		NG_HOOK_UNREF(hook);
2437 
2438  	if (rw == NGQRW_R)
2439 		ng_leave_read(node);
2440 	else
2441 		ng_leave_write(node);
2442 
2443 	/* Apply callback. */
2444 	if (apply != NULL) {
2445 		if (depth == 1 && error != 0)
2446 			apply->error = error;
2447 		if (refcount_release(&apply->refs))
2448 			(*apply->apply)(apply->context, apply->error);
2449 	}
2450 
2451 	return (error);
2452 }
2453 
2454 /***********************************************************************
2455  * Implement the 'generic' control messages
2456  ***********************************************************************/
2457 static int
2458 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
2459 {
2460 	INIT_VNET_NETGRAPH(curvnet);
2461 	int error = 0;
2462 	struct ng_mesg *msg;
2463 	struct ng_mesg *resp = NULL;
2464 
2465 	NGI_GET_MSG(item, msg);
2466 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
2467 		TRAP_ERROR();
2468 		error = EINVAL;
2469 		goto out;
2470 	}
2471 	switch (msg->header.cmd) {
2472 	case NGM_SHUTDOWN:
2473 		ng_rmnode(here, NULL, NULL, 0);
2474 		break;
2475 	case NGM_MKPEER:
2476 	    {
2477 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
2478 
2479 		if (msg->header.arglen != sizeof(*mkp)) {
2480 			TRAP_ERROR();
2481 			error = EINVAL;
2482 			break;
2483 		}
2484 		mkp->type[sizeof(mkp->type) - 1] = '\0';
2485 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
2486 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
2487 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
2488 		break;
2489 	    }
2490 	case NGM_CONNECT:
2491 	    {
2492 		struct ngm_connect *const con =
2493 			(struct ngm_connect *) msg->data;
2494 		node_p node2;
2495 
2496 		if (msg->header.arglen != sizeof(*con)) {
2497 			TRAP_ERROR();
2498 			error = EINVAL;
2499 			break;
2500 		}
2501 		con->path[sizeof(con->path) - 1] = '\0';
2502 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
2503 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
2504 		/* Don't forget we get a reference.. */
2505 		error = ng_path2noderef(here, con->path, &node2, NULL);
2506 		if (error)
2507 			break;
2508 		error = ng_con_nodes(item, here, con->ourhook,
2509 		    node2, con->peerhook);
2510 		NG_NODE_UNREF(node2);
2511 		break;
2512 	    }
2513 	case NGM_NAME:
2514 	    {
2515 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
2516 
2517 		if (msg->header.arglen != sizeof(*nam)) {
2518 			TRAP_ERROR();
2519 			error = EINVAL;
2520 			break;
2521 		}
2522 		nam->name[sizeof(nam->name) - 1] = '\0';
2523 		error = ng_name_node(here, nam->name);
2524 		break;
2525 	    }
2526 	case NGM_RMHOOK:
2527 	    {
2528 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
2529 		hook_p hook;
2530 
2531 		if (msg->header.arglen != sizeof(*rmh)) {
2532 			TRAP_ERROR();
2533 			error = EINVAL;
2534 			break;
2535 		}
2536 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
2537 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
2538 			ng_destroy_hook(hook);
2539 		break;
2540 	    }
2541 	case NGM_NODEINFO:
2542 	    {
2543 		struct nodeinfo *ni;
2544 
2545 		NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
2546 		if (resp == NULL) {
2547 			error = ENOMEM;
2548 			break;
2549 		}
2550 
2551 		/* Fill in node info */
2552 		ni = (struct nodeinfo *) resp->data;
2553 		if (NG_NODE_HAS_NAME(here))
2554 			strcpy(ni->name, NG_NODE_NAME(here));
2555 		strcpy(ni->type, here->nd_type->name);
2556 		ni->id = ng_node2ID(here);
2557 		ni->hooks = here->nd_numhooks;
2558 		break;
2559 	    }
2560 	case NGM_LISTHOOKS:
2561 	    {
2562 		const int nhooks = here->nd_numhooks;
2563 		struct hooklist *hl;
2564 		struct nodeinfo *ni;
2565 		hook_p hook;
2566 
2567 		/* Get response struct */
2568 		NG_MKRESPONSE(resp, msg, sizeof(*hl)
2569 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
2570 		if (resp == NULL) {
2571 			error = ENOMEM;
2572 			break;
2573 		}
2574 		hl = (struct hooklist *) resp->data;
2575 		ni = &hl->nodeinfo;
2576 
2577 		/* Fill in node info */
2578 		if (NG_NODE_HAS_NAME(here))
2579 			strcpy(ni->name, NG_NODE_NAME(here));
2580 		strcpy(ni->type, here->nd_type->name);
2581 		ni->id = ng_node2ID(here);
2582 
2583 		/* Cycle through the linked list of hooks */
2584 		ni->hooks = 0;
2585 		LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
2586 			struct linkinfo *const link = &hl->link[ni->hooks];
2587 
2588 			if (ni->hooks >= nhooks) {
2589 				log(LOG_ERR, "%s: number of %s changed\n",
2590 				    __func__, "hooks");
2591 				break;
2592 			}
2593 			if (NG_HOOK_NOT_VALID(hook))
2594 				continue;
2595 			strcpy(link->ourhook, NG_HOOK_NAME(hook));
2596 			strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
2597 			if (NG_PEER_NODE_NAME(hook)[0] != '\0')
2598 				strcpy(link->nodeinfo.name,
2599 				    NG_PEER_NODE_NAME(hook));
2600 			strcpy(link->nodeinfo.type,
2601 			   NG_PEER_NODE(hook)->nd_type->name);
2602 			link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
2603 			link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
2604 			ni->hooks++;
2605 		}
2606 		break;
2607 	    }
2608 
2609 	case NGM_LISTNAMES:
2610 	case NGM_LISTNODES:
2611 	    {
2612 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
2613 		struct namelist *nl;
2614 		node_p node;
2615 		int num = 0, i;
2616 
2617 		mtx_lock(&ng_namehash_mtx);
2618 		/* Count number of nodes */
2619 		for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
2620 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
2621 				if (NG_NODE_IS_VALID(node) &&
2622 				    (unnamed || NG_NODE_HAS_NAME(node))) {
2623 					num++;
2624 				}
2625 			}
2626 		}
2627 		mtx_unlock(&ng_namehash_mtx);
2628 
2629 		/* Get response struct */
2630 		NG_MKRESPONSE(resp, msg, sizeof(*nl)
2631 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
2632 		if (resp == NULL) {
2633 			error = ENOMEM;
2634 			break;
2635 		}
2636 		nl = (struct namelist *) resp->data;
2637 
2638 		/* Cycle through the linked list of nodes */
2639 		nl->numnames = 0;
2640 		mtx_lock(&ng_namehash_mtx);
2641 		for (i = 0; i < NG_NAME_HASH_SIZE; i++) {
2642 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
2643 				struct nodeinfo *const np =
2644 				    &nl->nodeinfo[nl->numnames];
2645 
2646 				if (NG_NODE_NOT_VALID(node))
2647 					continue;
2648 				if (!unnamed && (! NG_NODE_HAS_NAME(node)))
2649 					continue;
2650 				if (nl->numnames >= num) {
2651 					log(LOG_ERR, "%s: number of nodes changed\n",
2652 					    __func__);
2653 					break;
2654 				}
2655 				if (NG_NODE_HAS_NAME(node))
2656 					strcpy(np->name, NG_NODE_NAME(node));
2657 				strcpy(np->type, node->nd_type->name);
2658 				np->id = ng_node2ID(node);
2659 				np->hooks = node->nd_numhooks;
2660 				nl->numnames++;
2661 			}
2662 		}
2663 		mtx_unlock(&ng_namehash_mtx);
2664 		break;
2665 	    }
2666 
2667 	case NGM_LISTTYPES:
2668 	    {
2669 		struct typelist *tl;
2670 		struct ng_type *type;
2671 		int num = 0;
2672 
2673 		mtx_lock(&ng_typelist_mtx);
2674 		/* Count number of types */
2675 		LIST_FOREACH(type, &ng_typelist, types) {
2676 			num++;
2677 		}
2678 		mtx_unlock(&ng_typelist_mtx);
2679 
2680 		/* Get response struct */
2681 		NG_MKRESPONSE(resp, msg, sizeof(*tl)
2682 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
2683 		if (resp == NULL) {
2684 			error = ENOMEM;
2685 			break;
2686 		}
2687 		tl = (struct typelist *) resp->data;
2688 
2689 		/* Cycle through the linked list of types */
2690 		tl->numtypes = 0;
2691 		mtx_lock(&ng_typelist_mtx);
2692 		LIST_FOREACH(type, &ng_typelist, types) {
2693 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
2694 
2695 			if (tl->numtypes >= num) {
2696 				log(LOG_ERR, "%s: number of %s changed\n",
2697 				    __func__, "types");
2698 				break;
2699 			}
2700 			strcpy(tp->type_name, type->name);
2701 			tp->numnodes = type->refs - 1; /* don't count list */
2702 			tl->numtypes++;
2703 		}
2704 		mtx_unlock(&ng_typelist_mtx);
2705 		break;
2706 	    }
2707 
2708 	case NGM_BINARY2ASCII:
2709 	    {
2710 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2711 		const struct ng_parse_type *argstype;
2712 		const struct ng_cmdlist *c;
2713 		struct ng_mesg *binary, *ascii;
2714 
2715 		/* Data area must contain a valid netgraph message */
2716 		binary = (struct ng_mesg *)msg->data;
2717 		if (msg->header.arglen < sizeof(struct ng_mesg) ||
2718 		    (msg->header.arglen - sizeof(struct ng_mesg) <
2719 		    binary->header.arglen)) {
2720 			TRAP_ERROR();
2721 			error = EINVAL;
2722 			break;
2723 		}
2724 
2725 		/* Get a response message with lots of room */
2726 		NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
2727 		if (resp == NULL) {
2728 			error = ENOMEM;
2729 			break;
2730 		}
2731 		ascii = (struct ng_mesg *)resp->data;
2732 
2733 		/* Copy binary message header to response message payload */
2734 		bcopy(binary, ascii, sizeof(*binary));
2735 
2736 		/* Find command by matching typecookie and command number */
2737 		for (c = here->nd_type->cmdlist;
2738 		    c != NULL && c->name != NULL; c++) {
2739 			if (binary->header.typecookie == c->cookie
2740 			    && binary->header.cmd == c->cmd)
2741 				break;
2742 		}
2743 		if (c == NULL || c->name == NULL) {
2744 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2745 				if (binary->header.typecookie == c->cookie
2746 				    && binary->header.cmd == c->cmd)
2747 					break;
2748 			}
2749 			if (c->name == NULL) {
2750 				NG_FREE_MSG(resp);
2751 				error = ENOSYS;
2752 				break;
2753 			}
2754 		}
2755 
2756 		/* Convert command name to ASCII */
2757 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
2758 		    "%s", c->name);
2759 
2760 		/* Convert command arguments to ASCII */
2761 		argstype = (binary->header.flags & NGF_RESP) ?
2762 		    c->respType : c->mesgType;
2763 		if (argstype == NULL) {
2764 			*ascii->data = '\0';
2765 		} else {
2766 			if ((error = ng_unparse(argstype,
2767 			    (u_char *)binary->data,
2768 			    ascii->data, bufSize)) != 0) {
2769 				NG_FREE_MSG(resp);
2770 				break;
2771 			}
2772 		}
2773 
2774 		/* Return the result as struct ng_mesg plus ASCII string */
2775 		bufSize = strlen(ascii->data) + 1;
2776 		ascii->header.arglen = bufSize;
2777 		resp->header.arglen = sizeof(*ascii) + bufSize;
2778 		break;
2779 	    }
2780 
2781 	case NGM_ASCII2BINARY:
2782 	    {
2783 		int bufSize = 2000;	/* XXX hard coded constant */
2784 		const struct ng_cmdlist *c;
2785 		const struct ng_parse_type *argstype;
2786 		struct ng_mesg *ascii, *binary;
2787 		int off = 0;
2788 
2789 		/* Data area must contain at least a struct ng_mesg + '\0' */
2790 		ascii = (struct ng_mesg *)msg->data;
2791 		if ((msg->header.arglen < sizeof(*ascii) + 1) ||
2792 		    (ascii->header.arglen < 1) ||
2793 		    (msg->header.arglen < sizeof(*ascii) +
2794 		    ascii->header.arglen)) {
2795 			TRAP_ERROR();
2796 			error = EINVAL;
2797 			break;
2798 		}
2799 		ascii->data[ascii->header.arglen - 1] = '\0';
2800 
2801 		/* Get a response message with lots of room */
2802 		NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
2803 		if (resp == NULL) {
2804 			error = ENOMEM;
2805 			break;
2806 		}
2807 		binary = (struct ng_mesg *)resp->data;
2808 
2809 		/* Copy ASCII message header to response message payload */
2810 		bcopy(ascii, binary, sizeof(*ascii));
2811 
2812 		/* Find command by matching ASCII command string */
2813 		for (c = here->nd_type->cmdlist;
2814 		    c != NULL && c->name != NULL; c++) {
2815 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
2816 				break;
2817 		}
2818 		if (c == NULL || c->name == NULL) {
2819 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2820 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
2821 					break;
2822 			}
2823 			if (c->name == NULL) {
2824 				NG_FREE_MSG(resp);
2825 				error = ENOSYS;
2826 				break;
2827 			}
2828 		}
2829 
2830 		/* Convert command name to binary */
2831 		binary->header.cmd = c->cmd;
2832 		binary->header.typecookie = c->cookie;
2833 
2834 		/* Convert command arguments to binary */
2835 		argstype = (binary->header.flags & NGF_RESP) ?
2836 		    c->respType : c->mesgType;
2837 		if (argstype == NULL) {
2838 			bufSize = 0;
2839 		} else {
2840 			if ((error = ng_parse(argstype, ascii->data,
2841 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
2842 				NG_FREE_MSG(resp);
2843 				break;
2844 			}
2845 		}
2846 
2847 		/* Return the result */
2848 		binary->header.arglen = bufSize;
2849 		resp->header.arglen = sizeof(*binary) + bufSize;
2850 		break;
2851 	    }
2852 
2853 	case NGM_TEXT_CONFIG:
2854 	case NGM_TEXT_STATUS:
2855 		/*
2856 		 * This one is tricky as it passes the command down to the
2857 		 * actual node, even though it is a generic type command.
2858 		 * This means we must assume that the item/msg is already freed
2859 		 * when control passes back to us.
2860 		 */
2861 		if (here->nd_type->rcvmsg != NULL) {
2862 			NGI_MSG(item) = msg; /* put it back as we found it */
2863 			return((*here->nd_type->rcvmsg)(here, item, lasthook));
2864 		}
2865 		/* Fall through if rcvmsg not supported */
2866 	default:
2867 		TRAP_ERROR();
2868 		error = EINVAL;
2869 	}
2870 	/*
2871 	 * Sometimes a generic message may be statically allocated
2872 	 * to avoid problems with allocating when in tight memeory situations.
2873 	 * Don't free it if it is so.
2874 	 * I break them appart here, because erros may cause a free if the item
2875 	 * in which case we'd be doing it twice.
2876 	 * they are kept together above, to simplify freeing.
2877 	 */
2878 out:
2879 	NG_RESPOND_MSG(error, here, item, resp);
2880 	NG_FREE_MSG(msg);
2881 	return (error);
2882 }
2883 
2884 /************************************************************************
2885 			Queue element get/free routines
2886 ************************************************************************/
2887 
2888 uma_zone_t			ng_qzone;
2889 uma_zone_t			ng_qdzone;
2890 static int			numthreads = 0; /* number of queue threads */
2891 static int			maxalloc = 4096;/* limit the damage of a leak */
2892 static int			maxdata = 512;	/* limit the damage of a DoS */
2893 
2894 TUNABLE_INT("net.graph.threads", &numthreads);
2895 SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
2896     0, "Number of queue processing threads");
2897 TUNABLE_INT("net.graph.maxalloc", &maxalloc);
2898 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
2899     0, "Maximum number of non-data queue items to allocate");
2900 TUNABLE_INT("net.graph.maxdata", &maxdata);
2901 SYSCTL_INT(_net_graph, OID_AUTO, maxdata, CTLFLAG_RDTUN, &maxdata,
2902     0, "Maximum number of data queue items to allocate");
2903 
2904 #ifdef	NETGRAPH_DEBUG
2905 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
2906 static int			allocated;	/* number of items malloc'd */
2907 #endif
2908 
2909 /*
2910  * Get a queue entry.
2911  * This is usually called when a packet first enters netgraph.
2912  * By definition, this is usually from an interrupt, or from a user.
2913  * Users are not so important, but try be quick for the times that it's
2914  * an interrupt.
2915  */
2916 static __inline item_p
2917 ng_alloc_item(int type, int flags)
2918 {
2919 	item_p item;
2920 
2921 	KASSERT(((type & ~NGQF_TYPE) == 0),
2922 	    ("%s: incorrect item type: %d", __func__, type));
2923 
2924 	item = uma_zalloc((type == NGQF_DATA)?ng_qdzone:ng_qzone,
2925 	    ((flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT) | M_ZERO);
2926 
2927 	if (item) {
2928 		item->el_flags = type;
2929 #ifdef	NETGRAPH_DEBUG
2930 		mtx_lock(&ngq_mtx);
2931 		TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
2932 		allocated++;
2933 		mtx_unlock(&ngq_mtx);
2934 #endif
2935 	}
2936 
2937 	return (item);
2938 }
2939 
2940 /*
2941  * Release a queue entry
2942  */
2943 void
2944 ng_free_item(item_p item)
2945 {
2946 	/*
2947 	 * The item may hold resources on it's own. We need to free
2948 	 * these before we can free the item. What they are depends upon
2949 	 * what kind of item it is. it is important that nodes zero
2950 	 * out pointers to resources that they remove from the item
2951 	 * or we release them again here.
2952 	 */
2953 	switch (item->el_flags & NGQF_TYPE) {
2954 	case NGQF_DATA:
2955 		/* If we have an mbuf still attached.. */
2956 		NG_FREE_M(_NGI_M(item));
2957 		break;
2958 	case NGQF_MESG:
2959 		_NGI_RETADDR(item) = 0;
2960 		NG_FREE_MSG(_NGI_MSG(item));
2961 		break;
2962 	case NGQF_FN:
2963 	case NGQF_FN2:
2964 		/* nothing to free really, */
2965 		_NGI_FN(item) = NULL;
2966 		_NGI_ARG1(item) = NULL;
2967 		_NGI_ARG2(item) = 0;
2968 		break;
2969 	}
2970 	/* If we still have a node or hook referenced... */
2971 	_NGI_CLR_NODE(item);
2972 	_NGI_CLR_HOOK(item);
2973 
2974 #ifdef	NETGRAPH_DEBUG
2975 	mtx_lock(&ngq_mtx);
2976 	TAILQ_REMOVE(&ng_itemlist, item, all);
2977 	allocated--;
2978 	mtx_unlock(&ngq_mtx);
2979 #endif
2980 	uma_zfree(((item->el_flags & NGQF_TYPE) == NGQF_DATA)?
2981 	    ng_qdzone:ng_qzone, item);
2982 }
2983 
2984 /*
2985  * Change type of the queue entry.
2986  * Possibly reallocates it from another UMA zone.
2987  */
2988 static __inline item_p
2989 ng_realloc_item(item_p pitem, int type, int flags)
2990 {
2991 	item_p item;
2992 	int from, to;
2993 
2994 	KASSERT((pitem != NULL), ("%s: can't reallocate NULL", __func__));
2995 	KASSERT(((type & ~NGQF_TYPE) == 0),
2996 	    ("%s: incorrect item type: %d", __func__, type));
2997 
2998 	from = ((pitem->el_flags & NGQF_TYPE) == NGQF_DATA);
2999 	to = (type == NGQF_DATA);
3000 	if (from != to) {
3001 		/* If reallocation is required do it and copy item. */
3002 		if ((item = ng_alloc_item(type, flags)) == NULL) {
3003 			ng_free_item(pitem);
3004 			return (NULL);
3005 		}
3006 		*item = *pitem;
3007 		ng_free_item(pitem);
3008 	} else
3009 		item = pitem;
3010 	item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
3011 
3012 	return (item);
3013 }
3014 
3015 /************************************************************************
3016 			Module routines
3017 ************************************************************************/
3018 
3019 /*
3020  * Handle the loading/unloading of a netgraph node type module
3021  */
3022 int
3023 ng_mod_event(module_t mod, int event, void *data)
3024 {
3025 	struct ng_type *const type = data;
3026 	int s, error = 0;
3027 
3028 	switch (event) {
3029 	case MOD_LOAD:
3030 
3031 		/* Register new netgraph node type */
3032 		s = splnet();
3033 		if ((error = ng_newtype(type)) != 0) {
3034 			splx(s);
3035 			break;
3036 		}
3037 
3038 		/* Call type specific code */
3039 		if (type->mod_event != NULL)
3040 			if ((error = (*type->mod_event)(mod, event, data))) {
3041 				mtx_lock(&ng_typelist_mtx);
3042 				type->refs--;	/* undo it */
3043 				LIST_REMOVE(type, types);
3044 				mtx_unlock(&ng_typelist_mtx);
3045 			}
3046 		splx(s);
3047 		break;
3048 
3049 	case MOD_UNLOAD:
3050 		s = splnet();
3051 		if (type->refs > 1) {		/* make sure no nodes exist! */
3052 			error = EBUSY;
3053 		} else {
3054 			if (type->refs == 0) {
3055 				/* failed load, nothing to undo */
3056 				splx(s);
3057 				break;
3058 			}
3059 			if (type->mod_event != NULL) {	/* check with type */
3060 				error = (*type->mod_event)(mod, event, data);
3061 				if (error != 0) {	/* type refuses.. */
3062 					splx(s);
3063 					break;
3064 				}
3065 			}
3066 			mtx_lock(&ng_typelist_mtx);
3067 			LIST_REMOVE(type, types);
3068 			mtx_unlock(&ng_typelist_mtx);
3069 		}
3070 		splx(s);
3071 		break;
3072 
3073 	default:
3074 		if (type->mod_event != NULL)
3075 			error = (*type->mod_event)(mod, event, data);
3076 		else
3077 			error = EOPNOTSUPP;		/* XXX ? */
3078 		break;
3079 	}
3080 	return (error);
3081 }
3082 
3083 #ifndef VIMAGE_GLOBALS
3084 static const vnet_modinfo_t vnet_netgraph_modinfo = {
3085 	.vmi_id		= VNET_MOD_NETGRAPH,
3086 	.vmi_name	= "netgraph",
3087 	.vmi_size	= sizeof(struct vnet_netgraph),
3088 	.vmi_dependson	= VNET_MOD_LOIF,
3089 	.vmi_iattach	= vnet_netgraph_iattach,
3090 #ifdef VIMAGE
3091 	.vmi_idetach	= vnet_netgraph_idetach
3092 #endif
3093 };
3094 #endif
3095 
3096 static int
3097 vnet_netgraph_iattach(const void *unused __unused)
3098 {
3099 	INIT_VNET_NETGRAPH(curvnet);
3100 
3101 	V_nextID = 1;
3102 
3103 	return (0);
3104 }
3105 
3106 #ifdef VIMAGE
3107 static int
3108 vnet_netgraph_idetach(const void *unused __unused)
3109 {
3110 	INIT_VNET_NETGRAPH(curvnet);
3111 	node_p node, last_killed = NULL;
3112 
3113 	while ((node = LIST_FIRST(&V_ng_nodelist)) != NULL) {
3114 		if (node == last_killed) {
3115 			/* This should never happen */
3116 			node->nd_flags |= NGF_REALLY_DIE;
3117 			printf("netgraph node %s needs NGF_REALLY_DIE\n",
3118 			    node->nd_name);
3119 			ng_rmnode(node, NULL, NULL, 0);
3120 			/* This must never happen */
3121 			if (node == LIST_FIRST(&V_ng_nodelist))
3122 				panic("netgraph node %s won't die",
3123 				    node->nd_name);
3124 		}
3125 		ng_rmnode(node, NULL, NULL, 0);
3126 		last_killed = node;
3127 	}
3128 
3129 	return (0);
3130 }
3131 #endif /* VIMAGE */
3132 
3133 /*
3134  * Handle loading and unloading for this code.
3135  * The only thing we need to link into is the NETISR strucure.
3136  */
3137 static int
3138 ngb_mod_event(module_t mod, int event, void *data)
3139 {
3140 	struct proc *p;
3141 	struct thread *td;
3142 	int i, error = 0;
3143 
3144 	switch (event) {
3145 	case MOD_LOAD:
3146 		/* Initialize everything. */
3147 #ifndef VIMAGE_GLOBALS
3148 		vnet_mod_register(&vnet_netgraph_modinfo);
3149 #else
3150 		vnet_netgraph_iattach(NULL);
3151 #endif
3152 		NG_WORKLIST_LOCK_INIT();
3153 		mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL,
3154 		    MTX_DEF);
3155 		mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", NULL,
3156 		    MTX_DEF);
3157 		mtx_init(&ng_namehash_mtx, "netgraph namehash mutex", NULL,
3158 		    MTX_DEF);
3159 		mtx_init(&ng_topo_mtx, "netgraph topology mutex", NULL,
3160 		    MTX_DEF);
3161 #ifdef	NETGRAPH_DEBUG
3162 		mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
3163 		    MTX_DEF);
3164 		mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
3165 		    MTX_DEF);
3166 #endif
3167 		ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
3168 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
3169 		uma_zone_set_max(ng_qzone, maxalloc);
3170 		ng_qdzone = uma_zcreate("NetGraph data items", sizeof(struct ng_item),
3171 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
3172 		uma_zone_set_max(ng_qdzone, maxdata);
3173 		/* Autoconfigure number of threads. */
3174 		if (numthreads <= 0)
3175 			numthreads = mp_ncpus;
3176 		/* Create threads. */
3177     		p = NULL; /* start with no process */
3178 		for (i = 0; i < numthreads; i++) {
3179 			if (kproc_kthread_add(ngthread, NULL, &p, &td,
3180 			    RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
3181 				numthreads = i;
3182 				break;
3183 			}
3184 		}
3185 		break;
3186 	case MOD_UNLOAD:
3187 		/* You can't unload it because an interface may be using it. */
3188 		error = EBUSY;
3189 		break;
3190 	default:
3191 		error = EOPNOTSUPP;
3192 		break;
3193 	}
3194 	return (error);
3195 }
3196 
3197 static moduledata_t netgraph_mod = {
3198 	"netgraph",
3199 	ngb_mod_event,
3200 	(NULL)
3201 };
3202 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_MIDDLE);
3203 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
3204 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
3205 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
3206 
3207 #ifdef	NETGRAPH_DEBUG
3208 void
3209 dumphook (hook_p hook, char *file, int line)
3210 {
3211 	printf("hook: name %s, %d refs, Last touched:\n",
3212 		_NG_HOOK_NAME(hook), hook->hk_refs);
3213 	printf("	Last active @ %s, line %d\n",
3214 		hook->lastfile, hook->lastline);
3215 	if (line) {
3216 		printf(" problem discovered at file %s, line %d\n", file, line);
3217 	}
3218 }
3219 
3220 void
3221 dumpnode(node_p node, char *file, int line)
3222 {
3223 	printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
3224 		_NG_NODE_ID(node), node->nd_type->name,
3225 		node->nd_numhooks, node->nd_flags,
3226 		node->nd_refs, node->nd_name);
3227 	printf("	Last active @ %s, line %d\n",
3228 		node->lastfile, node->lastline);
3229 	if (line) {
3230 		printf(" problem discovered at file %s, line %d\n", file, line);
3231 	}
3232 }
3233 
3234 void
3235 dumpitem(item_p item, char *file, int line)
3236 {
3237 	printf(" ACTIVE item, last used at %s, line %d",
3238 		item->lastfile, item->lastline);
3239 	switch(item->el_flags & NGQF_TYPE) {
3240 	case NGQF_DATA:
3241 		printf(" - [data]\n");
3242 		break;
3243 	case NGQF_MESG:
3244 		printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
3245 		break;
3246 	case NGQF_FN:
3247 		printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
3248 			_NGI_FN(item),
3249 			_NGI_NODE(item),
3250 			_NGI_HOOK(item),
3251 			item->body.fn.fn_arg1,
3252 			item->body.fn.fn_arg2,
3253 			item->body.fn.fn_arg2);
3254 		break;
3255 	case NGQF_FN2:
3256 		printf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
3257 			_NGI_FN2(item),
3258 			_NGI_NODE(item),
3259 			_NGI_HOOK(item),
3260 			item->body.fn.fn_arg1,
3261 			item->body.fn.fn_arg2,
3262 			item->body.fn.fn_arg2);
3263 		break;
3264 	}
3265 	if (line) {
3266 		printf(" problem discovered at file %s, line %d\n", file, line);
3267 		if (_NGI_NODE(item)) {
3268 			printf("node %p ([%x])\n",
3269 				_NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
3270 		}
3271 	}
3272 }
3273 
3274 static void
3275 ng_dumpitems(void)
3276 {
3277 	item_p item;
3278 	int i = 1;
3279 	TAILQ_FOREACH(item, &ng_itemlist, all) {
3280 		printf("[%d] ", i++);
3281 		dumpitem(item, NULL, 0);
3282 	}
3283 }
3284 
3285 static void
3286 ng_dumpnodes(void)
3287 {
3288 	node_p node;
3289 	int i = 1;
3290 	mtx_lock(&ng_nodelist_mtx);
3291 	SLIST_FOREACH(node, &ng_allnodes, nd_all) {
3292 		printf("[%d] ", i++);
3293 		dumpnode(node, NULL, 0);
3294 	}
3295 	mtx_unlock(&ng_nodelist_mtx);
3296 }
3297 
3298 static void
3299 ng_dumphooks(void)
3300 {
3301 	hook_p hook;
3302 	int i = 1;
3303 	mtx_lock(&ng_nodelist_mtx);
3304 	SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
3305 		printf("[%d] ", i++);
3306 		dumphook(hook, NULL, 0);
3307 	}
3308 	mtx_unlock(&ng_nodelist_mtx);
3309 }
3310 
3311 static int
3312 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
3313 {
3314 	int error;
3315 	int val;
3316 	int i;
3317 
3318 	val = allocated;
3319 	i = 1;
3320 	error = sysctl_handle_int(oidp, &val, 0, req);
3321 	if (error != 0 || req->newptr == NULL)
3322 		return (error);
3323 	if (val == 42) {
3324 		ng_dumpitems();
3325 		ng_dumpnodes();
3326 		ng_dumphooks();
3327 	}
3328 	return (0);
3329 }
3330 
3331 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
3332     0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
3333 #endif	/* NETGRAPH_DEBUG */
3334 
3335 
3336 /***********************************************************************
3337 * Worklist routines
3338 **********************************************************************/
3339 /*
3340  * Pick a node off the list of nodes with work,
3341  * try get an item to process off it. Remove the node from the list.
3342  */
3343 static void
3344 ngthread(void *arg)
3345 {
3346 	for (;;) {
3347 		node_p  node;
3348 
3349 		/* Get node from the worklist. */
3350 		NG_WORKLIST_LOCK();
3351 		while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
3352 			NG_WORKLIST_SLEEP();
3353 		STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
3354 		NG_WORKLIST_UNLOCK();
3355 		CURVNET_SET(node->nd_vnet);
3356 		CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
3357 		    __func__, node->nd_ID, node);
3358 		/*
3359 		 * We have the node. We also take over the reference
3360 		 * that the list had on it.
3361 		 * Now process as much as you can, until it won't
3362 		 * let you have another item off the queue.
3363 		 * All this time, keep the reference
3364 		 * that lets us be sure that the node still exists.
3365 		 * Let the reference go at the last minute.
3366 		 */
3367 		for (;;) {
3368 			item_p item;
3369 			int rw;
3370 
3371 			NG_QUEUE_LOCK(&node->nd_input_queue);
3372 			item = ng_dequeue(node, &rw);
3373 			if (item == NULL) {
3374 				node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
3375 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3376 				break; /* go look for another node */
3377 			} else {
3378 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3379 				NGI_GET_NODE(item, node); /* zaps stored node */
3380 				ng_apply_item(node, item, rw);
3381 				NG_NODE_UNREF(node);
3382 			}
3383 		}
3384 		NG_NODE_UNREF(node);
3385 		CURVNET_RESTORE();
3386 	}
3387 }
3388 
3389 /*
3390  * XXX
3391  * It's posible that a debugging NG_NODE_REF may need
3392  * to be outside the mutex zone
3393  */
3394 static void
3395 ng_worklist_add(node_p node)
3396 {
3397 
3398 	mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
3399 
3400 	if ((node->nd_input_queue.q_flags2 & NGQ2_WORKQ) == 0) {
3401 		/*
3402 		 * If we are not already on the work queue,
3403 		 * then put us on.
3404 		 */
3405 		node->nd_input_queue.q_flags2 |= NGQ2_WORKQ;
3406 		NG_NODE_REF(node); /* XXX fafe in mutex? */
3407 		NG_WORKLIST_LOCK();
3408 		STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
3409 		NG_WORKLIST_UNLOCK();
3410 		CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
3411 		    node->nd_ID, node);
3412 		NG_WORKLIST_WAKEUP();
3413 	} else {
3414 		CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
3415 		    __func__, node->nd_ID, node);
3416 	}
3417 }
3418 
3419 
3420 /***********************************************************************
3421 * Externally useable functions to set up a queue item ready for sending
3422 ***********************************************************************/
3423 
3424 #ifdef	NETGRAPH_DEBUG
3425 #define	ITEM_DEBUG_CHECKS						\
3426 	do {								\
3427 		if (NGI_NODE(item) ) {					\
3428 			printf("item already has node");		\
3429 			kdb_enter(KDB_WHY_NETGRAPH, "has node");	\
3430 			NGI_CLR_NODE(item);				\
3431 		}							\
3432 		if (NGI_HOOK(item) ) {					\
3433 			printf("item already has hook");		\
3434 			kdb_enter(KDB_WHY_NETGRAPH, "has hook");	\
3435 			NGI_CLR_HOOK(item);				\
3436 		}							\
3437 	} while (0)
3438 #else
3439 #define ITEM_DEBUG_CHECKS
3440 #endif
3441 
3442 /*
3443  * Put mbuf into the item.
3444  * Hook and node references will be removed when the item is dequeued.
3445  * (or equivalent)
3446  * (XXX) Unsafe because no reference held by peer on remote node.
3447  * remote node might go away in this timescale.
3448  * We know the hooks can't go away because that would require getting
3449  * a writer item on both nodes and we must have at least a  reader
3450  * here to be able to do this.
3451  * Note that the hook loaded is the REMOTE hook.
3452  *
3453  * This is possibly in the critical path for new data.
3454  */
3455 item_p
3456 ng_package_data(struct mbuf *m, int flags)
3457 {
3458 	item_p item;
3459 
3460 	if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
3461 		NG_FREE_M(m);
3462 		return (NULL);
3463 	}
3464 	ITEM_DEBUG_CHECKS;
3465 	item->el_flags |= NGQF_READER;
3466 	NGI_M(item) = m;
3467 	return (item);
3468 }
3469 
3470 /*
3471  * Allocate a queue item and put items into it..
3472  * Evaluate the address as this will be needed to queue it and
3473  * to work out what some of the fields should be.
3474  * Hook and node references will be removed when the item is dequeued.
3475  * (or equivalent)
3476  */
3477 item_p
3478 ng_package_msg(struct ng_mesg *msg, int flags)
3479 {
3480 	item_p item;
3481 
3482 	if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
3483 		NG_FREE_MSG(msg);
3484 		return (NULL);
3485 	}
3486 	ITEM_DEBUG_CHECKS;
3487 	/* Messages items count as writers unless explicitly exempted. */
3488 	if (msg->header.cmd & NGM_READONLY)
3489 		item->el_flags |= NGQF_READER;
3490 	else
3491 		item->el_flags |= NGQF_WRITER;
3492 	/*
3493 	 * Set the current lasthook into the queue item
3494 	 */
3495 	NGI_MSG(item) = msg;
3496 	NGI_RETADDR(item) = 0;
3497 	return (item);
3498 }
3499 
3500 
3501 
3502 #define SET_RETADDR(item, here, retaddr)				\
3503 	do {	/* Data or fn items don't have retaddrs */		\
3504 		if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {	\
3505 			if (retaddr) {					\
3506 				NGI_RETADDR(item) = retaddr;		\
3507 			} else {					\
3508 				/*					\
3509 				 * The old return address should be ok.	\
3510 				 * If there isn't one, use the address	\
3511 				 * here.				\
3512 				 */					\
3513 				if (NGI_RETADDR(item) == 0) {		\
3514 					NGI_RETADDR(item)		\
3515 						= ng_node2ID(here);	\
3516 				}					\
3517 			}						\
3518 		}							\
3519 	} while (0)
3520 
3521 int
3522 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
3523 {
3524 	hook_p peer;
3525 	node_p peernode;
3526 	ITEM_DEBUG_CHECKS;
3527 	/*
3528 	 * Quick sanity check..
3529 	 * Since a hook holds a reference on it's node, once we know
3530 	 * that the peer is still connected (even if invalid,) we know
3531 	 * that the peer node is present, though maybe invalid.
3532 	 */
3533 	if ((hook == NULL) ||
3534 	    NG_HOOK_NOT_VALID(hook) ||
3535 	    NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
3536 	    NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
3537 		NG_FREE_ITEM(item);
3538 		TRAP_ERROR();
3539 		return (ENETDOWN);
3540 	}
3541 
3542 	/*
3543 	 * Transfer our interest to the other (peer) end.
3544 	 */
3545 	NG_HOOK_REF(peer);
3546 	NG_NODE_REF(peernode);
3547 	NGI_SET_HOOK(item, peer);
3548 	NGI_SET_NODE(item, peernode);
3549 	SET_RETADDR(item, here, retaddr);
3550 	return (0);
3551 }
3552 
3553 int
3554 ng_address_path(node_p here, item_p item, char *address, ng_ID_t retaddr)
3555 {
3556 	node_p	dest = NULL;
3557 	hook_p	hook = NULL;
3558 	int	error;
3559 
3560 	ITEM_DEBUG_CHECKS;
3561 	/*
3562 	 * Note that ng_path2noderef increments the reference count
3563 	 * on the node for us if it finds one. So we don't have to.
3564 	 */
3565 	error = ng_path2noderef(here, address, &dest, &hook);
3566 	if (error) {
3567 		NG_FREE_ITEM(item);
3568 		return (error);
3569 	}
3570 	NGI_SET_NODE(item, dest);
3571 	if ( hook) {
3572 		NG_HOOK_REF(hook);	/* don't let it go while on the queue */
3573 		NGI_SET_HOOK(item, hook);
3574 	}
3575 	SET_RETADDR(item, here, retaddr);
3576 	return (0);
3577 }
3578 
3579 int
3580 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
3581 {
3582 	node_p dest;
3583 
3584 	ITEM_DEBUG_CHECKS;
3585 	/*
3586 	 * Find the target node.
3587 	 */
3588 	dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
3589 	if (dest == NULL) {
3590 		NG_FREE_ITEM(item);
3591 		TRAP_ERROR();
3592 		return(EINVAL);
3593 	}
3594 	/* Fill out the contents */
3595 	NGI_SET_NODE(item, dest);
3596 	NGI_CLR_HOOK(item);
3597 	SET_RETADDR(item, here, retaddr);
3598 	return (0);
3599 }
3600 
3601 /*
3602  * special case to send a message to self (e.g. destroy node)
3603  * Possibly indicate an arrival hook too.
3604  * Useful for removing that hook :-)
3605  */
3606 item_p
3607 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
3608 {
3609 	item_p item;
3610 
3611 	/*
3612 	 * Find the target node.
3613 	 * If there is a HOOK argument, then use that in preference
3614 	 * to the address.
3615 	 */
3616 	if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
3617 		NG_FREE_MSG(msg);
3618 		return (NULL);
3619 	}
3620 
3621 	/* Fill out the contents */
3622 	item->el_flags |= NGQF_WRITER;
3623 	NG_NODE_REF(here);
3624 	NGI_SET_NODE(item, here);
3625 	if (hook) {
3626 		NG_HOOK_REF(hook);
3627 		NGI_SET_HOOK(item, hook);
3628 	}
3629 	NGI_MSG(item) = msg;
3630 	NGI_RETADDR(item) = ng_node2ID(here);
3631 	return (item);
3632 }
3633 
3634 /*
3635  * Send ng_item_fn function call to the specified node.
3636  */
3637 
3638 int
3639 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
3640 {
3641 
3642 	return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
3643 }
3644 
3645 int
3646 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
3647 	int flags)
3648 {
3649 	item_p item;
3650 
3651 	if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
3652 		return (ENOMEM);
3653 	}
3654 	item->el_flags |= NGQF_WRITER;
3655 	NG_NODE_REF(node); /* and one for the item */
3656 	NGI_SET_NODE(item, node);
3657 	if (hook) {
3658 		NG_HOOK_REF(hook);
3659 		NGI_SET_HOOK(item, hook);
3660 	}
3661 	NGI_FN(item) = fn;
3662 	NGI_ARG1(item) = arg1;
3663 	NGI_ARG2(item) = arg2;
3664 	return(ng_snd_item(item, flags));
3665 }
3666 
3667 /*
3668  * Send ng_item_fn2 function call to the specified node.
3669  *
3670  * If an optional pitem parameter is supplied, its apply
3671  * callback will be copied to the new item. If also NG_REUSE_ITEM
3672  * flag is set, no new item will be allocated, but pitem will
3673  * be used.
3674  */
3675 int
3676 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
3677 	int arg2, int flags)
3678 {
3679 	item_p item;
3680 
3681 	KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
3682 	    ("%s: NG_REUSE_ITEM but no pitem", __func__));
3683 
3684 	/*
3685 	 * Allocate a new item if no supplied or
3686 	 * if we can't use supplied one.
3687 	 */
3688 	if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
3689 		if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
3690 			return (ENOMEM);
3691 		if (pitem != NULL)
3692 			item->apply = pitem->apply;
3693 	} else {
3694 		if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
3695 			return (ENOMEM);
3696 	}
3697 
3698 	item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
3699 	NG_NODE_REF(node); /* and one for the item */
3700 	NGI_SET_NODE(item, node);
3701 	if (hook) {
3702 		NG_HOOK_REF(hook);
3703 		NGI_SET_HOOK(item, hook);
3704 	}
3705 	NGI_FN2(item) = fn;
3706 	NGI_ARG1(item) = arg1;
3707 	NGI_ARG2(item) = arg2;
3708 	return(ng_snd_item(item, flags));
3709 }
3710 
3711 /*
3712  * Official timeout routines for Netgraph nodes.
3713  */
3714 static void
3715 ng_callout_trampoline(void *arg)
3716 {
3717 	item_p item = arg;
3718 
3719 	CURVNET_SET(NGI_NODE(item)->nd_vnet);
3720 	ng_snd_item(item, 0);
3721 	CURVNET_RESTORE();
3722 }
3723 
3724 
3725 int
3726 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
3727     ng_item_fn *fn, void * arg1, int arg2)
3728 {
3729 	item_p item, oitem;
3730 
3731 	if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
3732 		return (ENOMEM);
3733 
3734 	item->el_flags |= NGQF_WRITER;
3735 	NG_NODE_REF(node);		/* and one for the item */
3736 	NGI_SET_NODE(item, node);
3737 	if (hook) {
3738 		NG_HOOK_REF(hook);
3739 		NGI_SET_HOOK(item, hook);
3740 	}
3741 	NGI_FN(item) = fn;
3742 	NGI_ARG1(item) = arg1;
3743 	NGI_ARG2(item) = arg2;
3744 	oitem = c->c_arg;
3745 	if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
3746 	    oitem != NULL)
3747 		NG_FREE_ITEM(oitem);
3748 	return (0);
3749 }
3750 
3751 /* A special modified version of untimeout() */
3752 int
3753 ng_uncallout(struct callout *c, node_p node)
3754 {
3755 	item_p item;
3756 	int rval;
3757 
3758 	KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
3759 	KASSERT(node != NULL, ("ng_uncallout: NULL node"));
3760 
3761 	rval = callout_stop(c);
3762 	item = c->c_arg;
3763 	/* Do an extra check */
3764 	if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
3765 	    (NGI_NODE(item) == node)) {
3766 		/*
3767 		 * We successfully removed it from the queue before it ran
3768 		 * So now we need to unreference everything that was
3769 		 * given extra references. (NG_FREE_ITEM does this).
3770 		 */
3771 		NG_FREE_ITEM(item);
3772 	}
3773 	c->c_arg = NULL;
3774 
3775 	return (rval);
3776 }
3777 
3778 /*
3779  * Set the address, if none given, give the node here.
3780  */
3781 void
3782 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
3783 {
3784 	if (retaddr) {
3785 		NGI_RETADDR(item) = retaddr;
3786 	} else {
3787 		/*
3788 		 * The old return address should be ok.
3789 		 * If there isn't one, use the address here.
3790 		 */
3791 		NGI_RETADDR(item) = ng_node2ID(here);
3792 	}
3793 }
3794 
3795 #define TESTING
3796 #ifdef TESTING
3797 /* just test all the macros */
3798 void
3799 ng_macro_test(item_p item);
3800 void
3801 ng_macro_test(item_p item)
3802 {
3803 	node_p node = NULL;
3804 	hook_p hook = NULL;
3805 	struct mbuf *m;
3806 	struct ng_mesg *msg;
3807 	ng_ID_t retaddr;
3808 	int	error;
3809 
3810 	NGI_GET_M(item, m);
3811 	NGI_GET_MSG(item, msg);
3812 	retaddr = NGI_RETADDR(item);
3813 	NG_SEND_DATA(error, hook, m, NULL);
3814 	NG_SEND_DATA_ONLY(error, hook, m);
3815 	NG_FWD_NEW_DATA(error, item, hook, m);
3816 	NG_FWD_ITEM_HOOK(error, item, hook);
3817 	NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
3818 	NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
3819 	NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
3820 	NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
3821 }
3822 #endif /* TESTING */
3823 
3824