xref: /dflybsd-src/sys/netgraph7/netgraph/ng_base.c (revision a62226e46c982d037de05e1bb0894805c0b7a32f)
1 /*-
2  * Copyright (c) 1996-1999 Whistle Communications, Inc.
3  * All rights reserved.
4  *
5  * Subject to the following obligations and disclaimer of warranty, use and
6  * redistribution of this software, in source or object code forms, with or
7  * without modifications are expressly permitted by Whistle Communications;
8  * provided, however, that:
9  * 1. Any and all reproductions of the source or object code must include the
10  *    copyright notice above and the following disclaimer of warranties; and
11  * 2. No rights are granted, in any manner or form, to use Whistle
12  *    Communications, Inc. trademarks, including the mark "WHISTLE
13  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
14  *    such appears in the above copyright notice or in the software.
15  *
16  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
17  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
18  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
19  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
21  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
22  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
23  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
24  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
25  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
26  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
27  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
28  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
32  * OF SUCH DAMAGE.
33  *
34  * Authors: Julian Elischer <julian@freebsd.org>
35  *          Archie Cobbs <archie@freebsd.org>
36  *
37  * $FreeBSD: src/sys/netgraph/ng_base.c,v 1.159 2008/04/19 05:30:49 mav Exp $
38  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
39  */
40 
41 /*
42  * This file implements the base netgraph code.
43  */
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/ctype.h>
48 #include <sys/errno.h>
49 #include <sys/hash.h>
50 /*#include <sys/kdb.h>*/
51 #include <sys/kernel.h>
52 #include <sys/limits.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/msgport2.h>
56 #include <sys/mutex2.h>
57 #include <sys/objcache.h>
58 #include <sys/proc.h>
59 #include <sys/queue.h>
60 #include <sys/refcount.h>
61 #include <sys/sysctl.h>
62 #include <sys/syslog.h>
63 #include <machine/cpu.h>
64 
65 #include <netgraph7/netgraph.h>
66 #include <netgraph7/netgraph2.h>
67 #include <netgraph7/ng_parse.h>
68 
69 MODULE_VERSION(netgraph, NG_ABI_VERSION);
70 
71 /* Token to protect topology events. */
72 static struct lwkt_token	ng_topo_token;
73 #define	TOPOLOGY_RLOCK()	lwkt_gettoken_shared(&ng_topo_token)
74 #define	TOPOLOGY_RUNLOCK()	lwkt_reltoken(&ng_topo_token)
75 #define	TOPOLOGY_WLOCK()	lwkt_gettoken(&ng_topo_token)
76 #define	TOPOLOGY_WUNLOCK()	lwkt_reltoken(&ng_topo_token)
77 #define	TOPOLOGY_NOTOWNED()	KKASSERT(!LWKT_TOKEN_HELD_ANY(&ng_topo_token))
78 
79 #ifdef	NETGRAPH_DEBUG
80 static struct mtx	ng_nodelist_mtx; /* protects global node/hook lists */
81 static struct mtx	ngq_mtx;	/* protects the queue item list */
82 
83 static SLIST_HEAD(, ng_node) ng_allnodes;
84 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
85 static SLIST_HEAD(, ng_hook) ng_allhooks;
86 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
87 
88 static void ng_dumpitems(void);
89 static void ng_dumpnodes(void);
90 static void ng_dumphooks(void);
91 
92 #endif	/* NETGRAPH_DEBUG */
93 /*
94  * DEAD versions of the structures.
95  * In order to avoid races, it is sometimes necessary to point
96  * at SOMETHING even though theoretically, the current entity is
97  * INVALID. Use these to avoid these races.
98  */
99 struct ng_type ng_deadtype = {
100 	NG_ABI_VERSION,
101 	"dead",
102 	NULL,	/* modevent */
103 	NULL,	/* constructor */
104 	NULL,	/* rcvmsg */
105 	NULL,	/* shutdown */
106 	NULL,	/* newhook */
107 	NULL,	/* findhook */
108 	NULL,	/* connect */
109 	NULL,	/* rcvdata */
110 	NULL,	/* disconnect */
111 	NULL, 	/* cmdlist */
112 };
113 
114 struct ng_node ng_deadnode = {
115 	"dead",
116 	&ng_deadtype,
117 	NGF_INVALID,
118 	0,	/* numhooks */
119 	NULL,	/* private */
120 	0,	/* ID */
121 	LIST_HEAD_INITIALIZER(ng_deadnode.hooks),
122 	{},	/* all_nodes list entry */
123 	{},	/* id hashtable list entry */
124 	{
125 		0,
126 		NULL,
127 		0,
128 		NULL,
129 	},	/* token */
130 	1,	/* refs */
131 #ifdef	NETGRAPH_DEBUG
132 	ND_MAGIC,
133 	__FILE__,
134 	__LINE__,
135 	{NULL}
136 #endif	/* NETGRAPH_DEBUG */
137 };
138 
139 struct ng_hook ng_deadhook = {
140 	"dead",
141 	NULL,		/* private */
142 	HK_INVALID | HK_DEAD,
143 	0,		/* undefined data link type */
144 	&ng_deadhook,	/* Peer is self */
145 	&ng_deadnode,	/* attached to deadnode */
146 	{},		/* hooks list */
147 	NULL,		/* override rcvmsg() */
148 	NULL,		/* override rcvdata() */
149 	1,		/* refs always >= 1 */
150 #ifdef	NETGRAPH_DEBUG
151 	HK_MAGIC,
152 	__FILE__,
153 	__LINE__,
154 	{NULL}
155 #endif	/* NETGRAPH_DEBUG */
156 };
157 
158 /*
159  * END DEAD STRUCTURES
160  */
161 
162 /* We don't want our messages to be replied. This is our panic reply port. */
163 static struct lwkt_port ng_panic_reply_port;
164 
165 /* Array of per-CPU target ports */
166 struct lwkt_port *ng_msgport[MAXCPU];
167 
168 /* List of installed types */
169 static LIST_HEAD(, ng_type) ng_typelist;
170 static struct lwkt_token	ng_typelist_token;
171 #define	TYPELIST_RLOCK()	lwkt_gettoken_shared(&ng_typelist_token)
172 #define	TYPELIST_RUNLOCK()	lwkt_reltoken(&ng_typelist_token)
173 #define	TYPELIST_WLOCK()	lwkt_gettoken(&ng_typelist_token)
174 #define	TYPELIST_WUNLOCK()	lwkt_reltoken(&ng_typelist_token)
175 
176 /* Hash related definitions */
177 LIST_HEAD(nodehash, ng_node);
178 static struct nodehash		*ng_ID_hash;
179 static u_long			 ng_ID_hmask;
180 static u_long			 ng_nodes;
181 static struct nodehash		*ng_name_hash;
182 static u_long			 ng_name_hmask;
183 static u_long			 ng_named_nodes;
184 static struct lwkt_token	 ng_idhash_token;
185 #define	IDHASH_RLOCK()		lwkt_gettoken_shared(&ng_idhash_token)
186 #define	IDHASH_RUNLOCK()	lwkt_reltoken(&ng_idhash_token)
187 #define	IDHASH_WLOCK()		lwkt_gettoken(&ng_idhash_token)
188 #define	IDHASH_WUNLOCK()	lwkt_reltoken(&ng_idhash_token)
189 #define	IDHASH_ASSERT_LOCKED()	KKASSERT(LWKT_TOKEN_HELD_ANY(&ng_idhash_token));
190 /* Method to find a node.. used twice so do it here */
191 #define NG_IDHASH_FN(ID) ((ID) % (ng_ID_hmask + 1))
192 #define NG_IDHASH_FIND(ID, node)					\
193 	do { 								\
194 		IDHASH_ASSERT_LOCKED();					\
195 		LIST_FOREACH(node, &ng_ID_hash[NG_IDHASH_FN(ID)],	\
196 						nd_idnodes) {		\
197 			if (NG_NODE_IS_VALID(node)			\
198 			&& (NG_NODE_ID(node) == ID)) {			\
199 				break;					\
200 			}						\
201 		}							\
202 	} while (0)
203 
204 static struct lwkt_token		ng_namehash_token;
205 #define	NAMEHASH_RLOCK()		lwkt_gettoken_shared(&ng_namehash_token)
206 #define	NAMEHASH_RUNLOCK()		lwkt_reltoken(&ng_namehash_token)
207 #define	NAMEHASH_WLOCK()		lwkt_gettoken(&ng_namehash_token)
208 #define	NAMEHASH_WUNLOCK()		lwkt_reltoken(&ng_namehash_token)
209 #define	NAMEHASH_ASSERT_LOCKED()	KKASSERT(LWKT_TOKEN_HELD_ANY(&ng_namehash_token));
210 
211 /* Internal functions */
212 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
213 static int	ng_generic_msg(node_p here, item_p item, hook_p lasthook);
214 static ng_ID_t	ng_decodeidname(const char *name);
215 static int	ngb_mod_event(module_t mod, int event, void *data);
216 static void	ngthread(void *dummy);
217 static int	ng_apply_item(item_p item);
218 static node_p	ng_ID2noderef(ng_ID_t ID);
219 static int	ng_con_nodes(item_p item, node_p node, const char *name,
220 		    node_p node2, const char *name2);
221 static int	ng_con_part2(node_p node, item_p item, hook_p hook);
222 static int	ng_con_part3(node_p node, item_p item, hook_p hook);
223 static int	ng_mkpeer(node_p node, const char *name, const char *name2,
224 		    char *type);
225 static void	ng_name_rehash(void);
226 static void	ng_ID_rehash(void);
227 static void	ng_check_apply(item_p item, int error);
228 static boolean_t	bzero_ctor(void *obj, void *private, int ocflags);
229 
230 /* Imported, these used to be externally visible, some may go back. */
231 void	ng_destroy_hook(hook_p hook);
232 node_p	ng_name2noderef(node_p node, const char *name);
233 int	ng_path2noderef(node_p here, const char *path,
234 	node_p *dest, hook_p *lasthook);
235 int	ng_make_node(const char *type, node_p *nodepp);
236 int	ng_path_parse(char *addr, char **node, char **path, char **hook);
237 void	ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
238 void	ng_unname(node_p node);
239 
240 
241 /* Our own netgraph malloc type */
242 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
243 MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
244 MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
245 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
246 MALLOC_DEFINE(M_NETGRAPH_APPLY, "netgraph_apply", "netgraph apply_info structures");
247 
248 /* Should not be visible outside this file */
249 
250 #define _NG_ALLOC_HOOK(hook) \
251 	hook = kmalloc(sizeof(*hook), M_NETGRAPH_HOOK, \
252 	    M_WAITOK | M_NULLOK | M_ZERO)
253 #define _NG_ALLOC_NODE(node) \
254 	node = kmalloc(sizeof(*node), M_NETGRAPH_NODE, \
255 	    M_WAITOK | M_NULLOK | M_ZERO)
256 
257 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
258 /*
259  * In debug mode:
260  * In an attempt to help track reference count screwups
261  * we do not free objects back to the malloc system, but keep them
262  * in a local cache where we can examine them and keep information safely
263  * after they have been freed.
264  * We use this scheme for nodes and hooks, and to some extent for items.
265  */
266 static __inline hook_p
267 ng_alloc_hook(void)
268 {
269 	hook_p hook;
270 	SLIST_ENTRY(ng_hook) temp;
271 	mtx_lock(&ng_nodelist_mtx);
272 	hook = LIST_FIRST(&ng_freehooks);
273 	if (hook) {
274 		LIST_REMOVE(hook, hk_hooks);
275 		bcopy(&hook->hk_all, &temp, sizeof(temp));
276 		bzero(hook, sizeof(struct ng_hook));
277 		bcopy(&temp, &hook->hk_all, sizeof(temp));
278 		mtx_unlock(&ng_nodelist_mtx);
279 		hook->hk_magic = HK_MAGIC;
280 	} else {
281 		mtx_unlock(&ng_nodelist_mtx);
282 		_NG_ALLOC_HOOK(hook);
283 		if (hook) {
284 			hook->hk_magic = HK_MAGIC;
285 			mtx_lock(&ng_nodelist_mtx);
286 			SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
287 			mtx_unlock(&ng_nodelist_mtx);
288 		}
289 	}
290 	return (hook);
291 }
292 
293 static __inline node_p
294 ng_alloc_node(void)
295 {
296 	node_p node;
297 	SLIST_ENTRY(ng_node) temp;
298 	mtx_lock(&ng_nodelist_mtx);
299 	node = LIST_FIRST(&ng_freenodes);
300 	if (node) {
301 		LIST_REMOVE(node, nd_nodes);
302 		bcopy(&node->nd_all, &temp, sizeof(temp));
303 		bzero(node, sizeof(struct ng_node));
304 		bcopy(&temp, &node->nd_all, sizeof(temp));
305 		mtx_unlock(&ng_nodelist_mtx);
306 		node->nd_magic = ND_MAGIC;
307 	} else {
308 		mtx_unlock(&ng_nodelist_mtx);
309 		_NG_ALLOC_NODE(node);
310 		if (node) {
311 			node->nd_magic = ND_MAGIC;
312 			mtx_lock(&ng_nodelist_mtx);
313 			SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
314 			mtx_unlock(&ng_nodelist_mtx);
315 		}
316 	}
317 	return (node);
318 }
319 
320 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
321 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
322 
323 
324 #define NG_FREE_HOOK(hook)						\
325 	do {								\
326 		mtx_lock(&ng_nodelist_mtx);			\
327 		LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);	\
328 		hook->hk_magic = 0;					\
329 		mtx_unlock(&ng_nodelist_mtx);			\
330 	} while (0)
331 
332 #define NG_FREE_NODE(node)						\
333 	do {								\
334 		mtx_lock(&ng_nodelist_mtx);			\
335 		LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);	\
336 		node->nd_magic = 0;					\
337 		mtx_unlock(&ng_nodelist_mtx);			\
338 	} while (0)
339 
340 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
341 
342 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
343 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
344 
345 #define NG_FREE_HOOK(hook) do { kfree((hook), M_NETGRAPH_HOOK); } while (0)
346 #define NG_FREE_NODE(node) do { kfree((node), M_NETGRAPH_NODE); } while (0)
347 
348 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
349 
350 /* Set this to kdb_enter("X") to catch all errors as they occur */
351 #ifndef TRAP_ERROR
352 #define TRAP_ERROR()
353 #endif
354 
355 static	ng_ID_t nextID = 1;
356 
357 #ifdef INVARIANTS
358 #define CHECK_DATA_MBUF(m)	do {					\
359 		struct mbuf *n;						\
360 		int total;						\
361 									\
362 		M_ASSERTPKTHDR(m);					\
363 		for (total = 0, n = (m); n != NULL; n = n->m_next) {	\
364 			total += n->m_len;				\
365 			if (n->m_nextpkt != NULL)			\
366 				panic("%s: m_nextpkt", __func__);	\
367 		}							\
368 									\
369 		if ((m)->m_pkthdr.len != total) {			\
370 			panic("%s: %d != %d",				\
371 			    __func__, (m)->m_pkthdr.len, total);	\
372 		}							\
373 	} while (0)
374 #else
375 #define CHECK_DATA_MBUF(m)
376 #endif
377 
378 #define ERROUT(x)	do { error = (x); goto done; } while (0)
379 
380 /************************************************************************
381 	Parse type definitions for generic messages
382 ************************************************************************/
383 
384 /* Handy structure parse type defining macro */
385 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
386 static const struct ng_parse_struct_field				\
387 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
388 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
389 	&ng_parse_struct_type,						\
390 	&ng_ ## lo ## _type_fields					\
391 }
392 
393 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
394 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
395 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
396 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
397 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
398 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
399 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
400 
401 /* Get length of an array when the length is stored as a 32 bit
402    value immediately preceding the array -- as with struct namelist
403    and struct typelist. */
404 static int
405 ng_generic_list_getLength(const struct ng_parse_type *type,
406 	const u_char *start, const u_char *buf)
407 {
408 	return *((const u_int32_t *)(buf - 4));
409 }
410 
411 /* Get length of the array of struct linkinfo inside a struct hooklist */
412 static int
413 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
414 	const u_char *start, const u_char *buf)
415 {
416 	const struct hooklist *hl = (const struct hooklist *)start;
417 
418 	return hl->nodeinfo.hooks;
419 }
420 
421 /* Array type for a variable length array of struct namelist */
422 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
423 	&ng_generic_nodeinfo_type,
424 	&ng_generic_list_getLength
425 };
426 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
427 	&ng_parse_array_type,
428 	&ng_nodeinfoarray_type_info
429 };
430 
431 /* Array type for a variable length array of struct typelist */
432 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
433 	&ng_generic_typeinfo_type,
434 	&ng_generic_list_getLength
435 };
436 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
437 	&ng_parse_array_type,
438 	&ng_typeinfoarray_type_info
439 };
440 
441 /* Array type for array of struct linkinfo in struct hooklist */
442 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
443 	&ng_generic_linkinfo_type,
444 	&ng_generic_linkinfo_getLength
445 };
446 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
447 	&ng_parse_array_type,
448 	&ng_generic_linkinfo_array_type_info
449 };
450 
451 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_typeinfoarray_type));
452 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
453 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
454 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
455 	(&ng_generic_nodeinfoarray_type));
456 
457 /* List of commands and how to convert arguments to/from ASCII */
458 static const struct ng_cmdlist ng_generic_cmds[] = {
459 	{
460 	  NGM_GENERIC_COOKIE,
461 	  NGM_SHUTDOWN,
462 	  "shutdown",
463 	  NULL,
464 	  NULL
465 	},
466 	{
467 	  NGM_GENERIC_COOKIE,
468 	  NGM_MKPEER,
469 	  "mkpeer",
470 	  &ng_generic_mkpeer_type,
471 	  NULL
472 	},
473 	{
474 	  NGM_GENERIC_COOKIE,
475 	  NGM_CONNECT,
476 	  "connect",
477 	  &ng_generic_connect_type,
478 	  NULL
479 	},
480 	{
481 	  NGM_GENERIC_COOKIE,
482 	  NGM_NAME,
483 	  "name",
484 	  &ng_generic_name_type,
485 	  NULL
486 	},
487 	{
488 	  NGM_GENERIC_COOKIE,
489 	  NGM_RMHOOK,
490 	  "rmhook",
491 	  &ng_generic_rmhook_type,
492 	  NULL
493 	},
494 	{
495 	  NGM_GENERIC_COOKIE,
496 	  NGM_NODEINFO,
497 	  "nodeinfo",
498 	  NULL,
499 	  &ng_generic_nodeinfo_type
500 	},
501 	{
502 	  NGM_GENERIC_COOKIE,
503 	  NGM_LISTHOOKS,
504 	  "listhooks",
505 	  NULL,
506 	  &ng_generic_hooklist_type
507 	},
508 	{
509 	  NGM_GENERIC_COOKIE,
510 	  NGM_LISTNAMES,
511 	  "listnames",
512 	  NULL,
513 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
514 	},
515 	{
516 	  NGM_GENERIC_COOKIE,
517 	  NGM_LISTNODES,
518 	  "listnodes",
519 	  NULL,
520 	  &ng_generic_listnodes_type
521 	},
522 	{
523 	  NGM_GENERIC_COOKIE,
524 	  NGM_LISTTYPES,
525 	  "listtypes",
526 	  NULL,
527 	  &ng_generic_typeinfo_type
528 	},
529 	{
530 	  NGM_GENERIC_COOKIE,
531 	  NGM_TEXT_CONFIG,
532 	  "textconfig",
533 	  NULL,
534 	  &ng_parse_string_type
535 	},
536 	{
537 	  NGM_GENERIC_COOKIE,
538 	  NGM_TEXT_STATUS,
539 	  "textstatus",
540 	  NULL,
541 	  &ng_parse_string_type
542 	},
543 	{
544 	  NGM_GENERIC_COOKIE,
545 	  NGM_ASCII2BINARY,
546 	  "ascii2binary",
547 	  &ng_parse_ng_mesg_type,
548 	  &ng_parse_ng_mesg_type
549 	},
550 	{
551 	  NGM_GENERIC_COOKIE,
552 	  NGM_BINARY2ASCII,
553 	  "binary2ascii",
554 	  &ng_parse_ng_mesg_type,
555 	  &ng_parse_ng_mesg_type
556 	},
557 	{ 0 }
558 };
559 
560 /************************************************************************
561 			Node routines
562 ************************************************************************/
563 
564 /*
565  * Instantiate a node of the requested type
566  */
567 int
568 ng_make_node(const char *typename, node_p *nodepp)
569 {
570 	struct ng_type *type;
571 	int	error;
572 
573 	/* Check that the type makes sense */
574 	if (typename == NULL) {
575 		TRAP_ERROR();
576 		return (EINVAL);
577 	}
578 
579 	/* Locate the node type. If we fail we return. Do not try to load
580 	 * module.
581 	 */
582 	if ((type = ng_findtype(typename)) == NULL)
583 		return (ENXIO);
584 
585 	/*
586 	 * If we have a constructor, then make the node and
587 	 * call the constructor to do type specific initialisation.
588 	 */
589 	if (type->constructor != NULL) {
590 		if ((error = ng_make_node_common(type, nodepp)) == 0) {
591 			if ((error = ((*type->constructor)(*nodepp)) != 0)) {
592 				NG_NODE_UNREF(*nodepp);
593 			}
594 		}
595 	} else {
596 		/*
597 		 * Node has no constructor. We cannot ask for one
598 		 * to be made. It must be brought into existence by
599 		 * some external agency. The external agency should
600 		 * call ng_make_node_common() directly to get the
601 		 * netgraph part initialised.
602 		 */
603 		TRAP_ERROR();
604 		error = EINVAL;
605 	}
606 	return (error);
607 }
608 
609 /*
610  * Generic node creation. Called by node initialisation for externally
611  * instantiated nodes (e.g. hardware, sockets, etc ).
612  * The returned node has a reference count of 1.
613  */
614 int
615 ng_make_node_common(struct ng_type *type, node_p *nodepp)
616 {
617 	node_p node;
618 
619 	/* Require the node type to have been already installed */
620 	if (ng_findtype(type->name) == NULL) {
621 		TRAP_ERROR();
622 		return (EINVAL);
623 	}
624 
625 	/* Make a node and try attach it to the type */
626 	NG_ALLOC_NODE(node);
627 	if (node == NULL) {
628 		TRAP_ERROR();
629 		return (ENOMEM);
630 	}
631 	node->nd_type = type;
632 	NG_NODE_REF(node);				/* note reference */
633 	type->refs++;
634 
635 	/* Initialize the reader/writer shared token */
636 	lwkt_token_init(&node->nd_token, type->name);
637 
638 	/* Initialize hook list for new node */
639 	LIST_INIT(&node->nd_hooks);
640 
641 	/* Get an ID and put us in the hash chain. */
642 	IDHASH_WLOCK();
643 	for (;;) { /* wrap protection, even if silly */
644 		node_p node2 = NULL;
645 		node->nd_ID = nextID++; /* 137/second for 1 year before wrap */
646 
647 		/* Is there a problem with the new number? */
648 		NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
649 		if ((node->nd_ID != 0) && (node2 == NULL)) {
650 			break;
651 		}
652 	}
653 	ng_nodes++;
654 	if (ng_nodes * 2 > ng_ID_hmask)
655 		ng_ID_rehash();
656 	LIST_INSERT_HEAD(&ng_ID_hash[NG_IDHASH_FN(node->nd_ID)], node,
657 	    nd_idnodes);
658 	IDHASH_WUNLOCK();
659 
660 	/* Done */
661 	*nodepp = node;
662 	return (0);
663 }
664 
665 /*
666  * Forceably start the shutdown process on a node. Either call
667  * its shutdown method, or do the default shutdown if there is
668  * no type-specific method.
669  *
670  * We can only be called from a shutdown message, so we know we have
671  * a writer lock, and therefore exclusive access.
672  *
673  * Persistent node types must have a type-specific method which
674  * allocates a new node in which case, this one is irretrievably going away,
675  * or cleans up anything it needs, and just makes the node valid again,
676  * in which case we allow the node to survive.
677  *
678  * XXX We need to think of how to tell a persistent node that we
679  * REALLY need to go away because the hardware has gone or we
680  * are rebooting.... etc.
681  */
682 void
683 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
684 {
685 	hook_p hook;
686 
687 	/* Check if it's already shutting down */
688 	if ((node->nd_flags & NGF_CLOSING) != 0)
689 		return;
690 
691 	if (node == &ng_deadnode) {
692 		kprintf ("shutdown called on deadnode\n");
693 		return;
694 	}
695 
696 	/* Add an extra reference so it doesn't go away during this */
697 	NG_NODE_REF(node);
698 
699 	/*
700 	 * Mark it invalid so any newcomers know not to try use it
701 	 * Also add our own mark so we can't recurse
702 	 * note that NGF_INVALID does not do this as it's also set during
703 	 * creation
704 	 */
705 	node->nd_flags |= NGF_INVALID|NGF_CLOSING;
706 
707 	/* If node has its pre-shutdown method, then call it first*/
708 	if (node->nd_type && node->nd_type->close)
709 		(*node->nd_type->close)(node);
710 
711 	/* Notify all remaining connected nodes to disconnect */
712 	while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
713 		ng_destroy_hook(hook);
714 
715 	/* Ask the type if it has anything to do in this case */
716 	if (node->nd_type && node->nd_type->shutdown) {
717 		(*node->nd_type->shutdown)(node);
718 		if (NG_NODE_IS_VALID(node)) {
719 			/*
720 			 * Well, blow me down if the node code hasn't declared
721 			 * that it doesn't want to die.
722 			 * Presumably it is a persistant node.
723 			 * If we REALLY want it to go away,
724 			 *  e.g. hardware going away,
725 			 * Our caller should set NGF_REALLY_DIE in nd_flags.
726 			 */
727 			node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
728 			NG_NODE_UNREF(node); /* Assume they still have theirs */
729 			return;
730 		}
731 	} else {				/* do the default thing */
732 		NG_NODE_UNREF(node);
733 	}
734 
735 	ng_unname(node); /* basically a NOP these days */
736 
737 	/*
738 	 * Remove extra reference, possibly the last
739 	 * Possible other holders of references may include
740 	 * timeout callouts, but theoretically the node's supposed to
741 	 * have cancelled them. Possibly hardware dependencies may
742 	 * force a driver to 'linger' with a reference.
743 	 */
744 	NG_NODE_UNREF(node);
745 }
746 
747 /*
748  * Remove a reference to the node, possibly the last.
749  * deadnode always acts as it it were the last.
750  */
751 void
752 ng_unref_node(node_p node)
753 {
754 
755 	if (node == &ng_deadnode)
756 		return;
757 
758 
759 	if (refcount_release(&node->nd_refs)) { /* we were the last */
760 
761 		node->nd_type->refs--; /* XXX maybe should get types lock? */
762 		NAMEHASH_WLOCK();
763 		if (NG_NODE_HAS_NAME(node)) {
764 			ng_named_nodes--;
765 			LIST_REMOVE(node, nd_nodes);
766 		}
767 		NAMEHASH_WUNLOCK();
768 
769 		IDHASH_WLOCK();
770 		ng_nodes--;
771 		LIST_REMOVE(node, nd_idnodes);
772 		IDHASH_WUNLOCK();
773 
774 		NG_FREE_NODE(node);
775 	}
776 }
777 
778 /************************************************************************
779 			Node ID handling
780 ************************************************************************/
781 static node_p
782 ng_ID2noderef(ng_ID_t ID)
783 {
784 	node_p node;
785 
786 	IDHASH_RLOCK();
787 	NG_IDHASH_FIND(ID, node);
788 	if (node)
789 		NG_NODE_REF(node);
790 	IDHASH_RUNLOCK();
791 	return(node);
792 }
793 
794 ng_ID_t
795 ng_node2ID(node_p node)
796 {
797 	return (node ? NG_NODE_ID(node) : 0);
798 }
799 
800 /************************************************************************
801 			Node name handling
802 ************************************************************************/
803 
804 /*
805  * Assign a node a name.
806  */
807 int
808 ng_name_node(node_p node, const char *name)
809 {
810 	uint32_t hash;
811 	node_p node2;
812 	int i;
813 
814 	/* Check the name is valid */
815 	for (i = 0; i < NG_NODESIZ; i++) {
816 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
817 			break;
818 	}
819 	if (i == 0 || name[i] != '\0') {
820 		TRAP_ERROR();
821 		return (EINVAL);
822 	}
823 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
824 		TRAP_ERROR();
825 		return (EINVAL);
826 	}
827 
828 	NAMEHASH_WLOCK();
829 	if (ng_named_nodes * 2 > ng_name_hmask)
830 		ng_name_rehash();
831 
832 	hash = hash32_str(name, HASHINIT) & ng_name_hmask;
833 	/* Check the name isn't already being used. */
834 	LIST_FOREACH(node2, &ng_name_hash[hash], nd_nodes)
835 		if (NG_NODE_IS_VALID(node2) &&
836 		    (strcmp(NG_NODE_NAME(node2), name) == 0)) {
837 			NAMEHASH_WUNLOCK();
838 			return (EADDRINUSE);
839 		}
840 
841 	if (NG_NODE_HAS_NAME(node))
842 		LIST_REMOVE(node, nd_nodes);
843 	else
844 		ng_named_nodes++;
845 	/* Copy it. */
846 	strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
847 
848 	/* Update name hash. */
849 	LIST_INSERT_HEAD(&ng_name_hash[hash], node, nd_nodes);
850 	NAMEHASH_WUNLOCK();
851 
852 	return (0);
853 }
854 
855 /*
856  * Find a node by absolute name. The name should NOT end with ':'
857  * The name "." means "this node" and "[xxx]" means "the node
858  * with ID (ie, at address) xxx".
859  *
860  * Returns the node if found, else NULL.
861  * Eventually should add something faster than a sequential search.
862  * Note it acquires a reference on the node so you can be sure it's still
863  * there.
864  */
865 node_p
866 ng_name2noderef(node_p here, const char *name)
867 {
868 	node_p node;
869 	ng_ID_t temp;
870 	int	hash;
871 
872 	/* "." means "this node" */
873 	if (strcmp(name, ".") == 0) {
874 		NG_NODE_REF(here);
875 		return(here);
876 	}
877 
878 	/* Check for name-by-ID */
879 	if ((temp = ng_decodeidname(name)) != 0) {
880 		return (ng_ID2noderef(temp));
881 	}
882 
883 	/* Find node by name. */
884 	hash = hash32_str(name, HASHINIT) & ng_name_hmask;
885 	NAMEHASH_RLOCK();
886 	LIST_FOREACH(node, &ng_name_hash[hash], nd_nodes)
887 		if (NG_NODE_IS_VALID(node) &&
888 		    (strcmp(NG_NODE_NAME(node), name) == 0)) {
889 			NG_NODE_REF(node);
890 			break;
891 		}
892 	NAMEHASH_RUNLOCK();
893 
894 	return (node);
895 }
896 
897 /*
898  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
899  * string is not valid, otherwise returns the value.
900  */
901 static ng_ID_t
902 ng_decodeidname(const char *name)
903 {
904 	const int len = strlen(name);
905 	char *eptr;
906 	u_long val;
907 
908 	/* Check for proper length, brackets, no leading junk */
909 	if ((len < 3)
910 	|| (name[0] != '[')
911 	|| (name[len - 1] != ']')
912 	|| (!isxdigit(name[1]))) {
913 		return ((ng_ID_t)0);
914 	}
915 
916 	/* Decode number */
917 	val = strtoul(name + 1, &eptr, 16);
918 	if ((eptr - name != len - 1)
919 	|| (val == ULONG_MAX)
920 	|| (val == 0)) {
921 		return ((ng_ID_t)0);
922 	}
923 	return (ng_ID_t)val;
924 }
925 
926 /*
927  * Remove a name from a node. This should only be called
928  * when shutting down and removing the node.
929  */
930 void
931 ng_unname(node_p node)
932 {
933 }
934 
935 /*
936  * Allocate a bigger name hash.
937  */
938 static void
939 ng_name_rehash(void)
940 {
941 	struct nodehash *new;
942 	uint32_t hash;
943 	u_long hmask;
944 	node_p node, node2;
945 	int i;
946 
947 	NAMEHASH_ASSERT_LOCKED();
948 	new = hashinit((ng_name_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask);
949 	if (new == NULL)
950 		return;
951 
952 	for (i = 0; i <= ng_name_hmask; i++) {
953 		LIST_FOREACH_MUTABLE(node, &ng_name_hash[i], nd_nodes, node2) {
954 #ifdef INVARIANTS
955 			LIST_REMOVE(node, nd_nodes);
956 #endif
957 			hash = hash32_str(NG_NODE_NAME(node), HASHINIT) & hmask;
958 			LIST_INSERT_HEAD(&new[hash], node, nd_nodes);
959 		}
960 	}
961 
962 	hashdestroy(ng_name_hash, M_NETGRAPH_NODE, ng_name_hmask);
963 	ng_name_hash = new;
964 	ng_name_hmask = hmask;
965 }
966 
967 /*
968  * Allocate a bigger ID hash.
969  */
970 static void
971 ng_ID_rehash(void)
972 {
973 	struct nodehash *new;
974 	uint32_t hash;
975 	u_long hmask;
976 	node_p node, node2;
977 	int i;
978 
979 	IDHASH_ASSERT_LOCKED();
980 	new = hashinit((ng_ID_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask);
981 	if (new == NULL)
982 		return;
983 
984 	for (i = 0; i <= ng_ID_hmask; i++) {
985 		LIST_FOREACH_MUTABLE(node, &ng_ID_hash[i], nd_idnodes, node2) {
986 #ifdef INVARIANTS
987 			LIST_REMOVE(node, nd_idnodes);
988 #endif
989 			hash = (node->nd_ID % (hmask + 1));
990 			LIST_INSERT_HEAD(&new[hash], node, nd_idnodes);
991 		}
992 	}
993 
994 	hashdestroy(ng_ID_hash, M_NETGRAPH_NODE, ng_name_hmask);
995 	ng_ID_hash = new;
996 	ng_ID_hmask = hmask;
997 }
998 
999 /************************************************************************
1000 			Hook routines
1001  Names are not optional. Hooks are always connected, except for a
1002  brief moment within these routines. On invalidation or during creation
1003  they are connected to the 'dead' hook.
1004 ************************************************************************/
1005 
1006 /*
1007  * Remove a hook reference
1008  */
1009 void
1010 ng_unref_hook(hook_p hook)
1011 {
1012 	int v;
1013 
1014 	if (hook == &ng_deadhook) {
1015 		return;
1016 	}
1017 
1018 	v = atomic_fetchadd_int(&hook->hk_refs, -1);
1019 
1020 	if (v == 1) { /* we were the last */
1021 		if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
1022 			_NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
1023 		NG_FREE_HOOK(hook);
1024 	}
1025 }
1026 
1027 /*
1028  * Add an unconnected hook to a node. Only used internally.
1029  * Assumes node is locked. (XXX not yet true )
1030  */
1031 static int
1032 ng_add_hook(node_p node, const char *name, hook_p *hookp)
1033 {
1034 	hook_p hook;
1035 	int error = 0;
1036 
1037 	/* Check that the given name is good */
1038 	if (name == NULL) {
1039 		TRAP_ERROR();
1040 		return (EINVAL);
1041 	}
1042 	if (ng_findhook(node, name) != NULL) {
1043 		TRAP_ERROR();
1044 		return (EEXIST);
1045 	}
1046 
1047 	/* Allocate the hook and link it up */
1048 	NG_ALLOC_HOOK(hook);
1049 	if (hook == NULL) {
1050 		TRAP_ERROR();
1051 		return (ENOMEM);
1052 	}
1053 	hook->hk_refs = 1;		/* add a reference for us to return */
1054 	hook->hk_flags = HK_INVALID;
1055 	hook->hk_peer = &ng_deadhook;	/* start off this way */
1056 	hook->hk_node = node;
1057 	NG_NODE_REF(node);		/* each hook counts as a reference */
1058 
1059 	/* Set hook name */
1060 	strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
1061 
1062 	/*
1063 	 * Check if the node type code has something to say about it
1064 	 * If it fails, the unref of the hook will also unref the node.
1065 	 */
1066 	if (node->nd_type->newhook != NULL) {
1067 		if ((error = (*node->nd_type->newhook)(node, hook, name))) {
1068 			NG_HOOK_UNREF(hook);	/* this frees the hook */
1069 			return (error);
1070 		}
1071 	}
1072 	/*
1073 	 * The 'type' agrees so far, so go ahead and link it in.
1074 	 * We'll ask again later when we actually connect the hooks.
1075 	 */
1076 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1077 	node->nd_numhooks++;
1078 	NG_HOOK_REF(hook);	/* one for the node */
1079 
1080 	if (hookp)
1081 		*hookp = hook;
1082 	return (0);
1083 }
1084 
1085 /*
1086  * Find a hook
1087  *
1088  * Node types may supply their own optimized routines for finding
1089  * hooks.  If none is supplied, we just do a linear search.
1090  * XXX Possibly we should add a reference to the hook?
1091  */
1092 hook_p
1093 ng_findhook(node_p node, const char *name)
1094 {
1095 	hook_p hook;
1096 
1097 	if (node->nd_type->findhook != NULL)
1098 		return (*node->nd_type->findhook)(node, name);
1099 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
1100 		if (NG_HOOK_IS_VALID(hook)
1101 		&& (strcmp(NG_HOOK_NAME(hook), name) == 0))
1102 			return (hook);
1103 	}
1104 	return (NULL);
1105 }
1106 
1107 /*
1108  * Destroy a hook
1109  *
1110  * As hooks are always attached, this really destroys two hooks.
1111  * The one given, and the one attached to it. Disconnect the hooks
1112  * from each other first. We reconnect the peer hook to the 'dead'
1113  * hook so that it can still exist after we depart. We then
1114  * send the peer its own destroy message. This ensures that we only
1115  * interact with the peer's structures when it is locked processing that
1116  * message. We hold a reference to the peer hook so we are guaranteed that
1117  * the peer hook and node are still going to exist until
1118  * we are finished there as the hook holds a ref on the node.
1119  * We run this same code again on the peer hook, but that time it is already
1120  * attached to the 'dead' hook.
1121  *
1122  * This routine is called at all stages of hook creation
1123  * on error detection and must be able to handle any such stage.
1124  */
1125 void
1126 ng_destroy_hook(hook_p hook)
1127 {
1128 	hook_p peer;
1129 	node_p node;
1130 
1131 	if (hook == &ng_deadhook) {	/* better safe than sorry */
1132 		kprintf("ng_destroy_hook called on deadhook\n");
1133 		return;
1134 	}
1135 
1136 	/*
1137 	 * Protect divorce process with mutex, to avoid races on
1138 	 * simultaneous disconnect.
1139 	 */
1140 	TOPOLOGY_WLOCK();
1141 
1142 	hook->hk_flags |= HK_INVALID;
1143 
1144 	peer = NG_HOOK_PEER(hook);
1145 	node = NG_HOOK_NODE(hook);
1146 
1147 	if (peer && (peer != &ng_deadhook)) {
1148 		/*
1149 		 * Set the peer to point to ng_deadhook
1150 		 * from this moment on we are effectively independent it.
1151 		 * send it an rmhook message of it's own.
1152 		 */
1153 		peer->hk_peer = &ng_deadhook;	/* They no longer know us */
1154 		hook->hk_peer = &ng_deadhook;	/* Nor us, them */
1155 		if (NG_HOOK_NODE(peer) == &ng_deadnode) {
1156 			/*
1157 			 * If it's already divorced from a node,
1158 			 * just free it.
1159 			 */
1160 			TOPOLOGY_WUNLOCK();
1161 		} else {
1162 			TOPOLOGY_WUNLOCK();
1163 			ng_rmhook_self(peer); 	/* Send it a surprise */
1164 		}
1165 		NG_HOOK_UNREF(peer);		/* account for peer link */
1166 		NG_HOOK_UNREF(hook);		/* account for peer link */
1167 	} else
1168 		TOPOLOGY_WUNLOCK();
1169 
1170 	TOPOLOGY_NOTOWNED();
1171 
1172 	/*
1173 	 * Remove the hook from the node's list to avoid possible recursion
1174 	 * in case the disconnection results in node shutdown.
1175 	 */
1176 	if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
1177 		return;
1178 	}
1179 	LIST_REMOVE(hook, hk_hooks);
1180 	node->nd_numhooks--;
1181 	if (node->nd_type->disconnect) {
1182 		/*
1183 		 * The type handler may elect to destroy the node so don't
1184 		 * trust its existence after this point. (except
1185 		 * that we still hold a reference on it. (which we
1186 		 * inherrited from the hook we are destroying)
1187 		 */
1188 		(*node->nd_type->disconnect) (hook);
1189 	}
1190 
1191 	/*
1192 	 * Note that because we will point to ng_deadnode, the original node
1193 	 * is not decremented automatically so we do that manually.
1194 	 */
1195 	_NG_HOOK_NODE(hook) = &ng_deadnode;
1196 	NG_NODE_UNREF(node);	/* We no longer point to it so adjust count */
1197 	NG_HOOK_UNREF(hook);	/* Account for linkage (in list) to node */
1198 }
1199 
1200 /*
1201  * Take two hooks on a node and merge the connection so that the given node
1202  * is effectively bypassed.
1203  */
1204 int
1205 ng_bypass(hook_p hook1, hook_p hook2)
1206 {
1207 	if (hook1->hk_node != hook2->hk_node) {
1208 		TRAP_ERROR();
1209 		return (EINVAL);
1210 	}
1211 	hook1->hk_peer->hk_peer = hook2->hk_peer;
1212 	hook2->hk_peer->hk_peer = hook1->hk_peer;
1213 
1214 	hook1->hk_peer = &ng_deadhook;
1215 	hook2->hk_peer = &ng_deadhook;
1216 
1217 	NG_HOOK_UNREF(hook1);
1218 	NG_HOOK_UNREF(hook2);
1219 
1220 	/* XXX If we ever cache methods on hooks update them as well */
1221 	ng_destroy_hook(hook1);
1222 	ng_destroy_hook(hook2);
1223 	return (0);
1224 }
1225 
1226 /*
1227  * Install a new netgraph type
1228  */
1229 int
1230 ng_newtype(struct ng_type *tp)
1231 {
1232 	const size_t namelen = strlen(tp->name);
1233 
1234 	/* Check version and type name fields */
1235 	if ((tp->version != NG_ABI_VERSION)
1236 	|| (namelen == 0)
1237 	|| (namelen >= NG_TYPESIZ)) {
1238 		TRAP_ERROR();
1239 		if (tp->version != NG_ABI_VERSION) {
1240 			kprintf("Netgraph: Node type rejected. ABI mismatch. Suggest recompile\n");
1241 		}
1242 		return (EINVAL);
1243 	}
1244 
1245 	/* Check for name collision */
1246 	if (ng_findtype(tp->name) != NULL) {
1247 		TRAP_ERROR();
1248 		return (EEXIST);
1249 	}
1250 
1251 	/* Link in new type */
1252 	TYPELIST_WLOCK();
1253 	LIST_INSERT_HEAD(&ng_typelist, tp, types);
1254 	tp->refs = 1;	/* first ref is linked list */
1255 	TYPELIST_WUNLOCK();
1256 	return (0);
1257 }
1258 
1259 /*
1260  * unlink a netgraph type
1261  * If no examples exist
1262  */
1263 int
1264 ng_rmtype(struct ng_type *tp)
1265 {
1266 	/* Check for name collision */
1267 	if (tp->refs != 1) {
1268 		TRAP_ERROR();
1269 		return (EBUSY);
1270 	}
1271 
1272 	/* Unlink type */
1273 	TYPELIST_WLOCK();
1274 	LIST_REMOVE(tp, types);
1275 	TYPELIST_WUNLOCK();
1276 	return (0);
1277 }
1278 
1279 /*
1280  * Look for a type of the name given
1281  */
1282 struct ng_type *
1283 ng_findtype(const char *typename)
1284 {
1285 	struct ng_type *type;
1286 
1287 	TYPELIST_RLOCK();
1288 	LIST_FOREACH(type, &ng_typelist, types) {
1289 		if (strcmp(type->name, typename) == 0)
1290 			break;
1291 	}
1292 	TYPELIST_RUNLOCK();
1293 	return (type);
1294 }
1295 
1296 /************************************************************************
1297 			Composite routines
1298 ************************************************************************/
1299 /*
1300  * Connect two nodes using the specified hooks, using queued functions.
1301  */
1302 static int
1303 ng_con_part3(node_p node, item_p item, hook_p hook)
1304 {
1305 	int	error = 0;
1306 
1307 	/*
1308 	 * When we run, we know that the node 'node' is locked for us.
1309 	 * Our caller has a reference on the hook.
1310 	 * Our caller has a reference on the node.
1311 	 * (In this case our caller is ng_apply_item() ).
1312 	 * The peer hook has a reference on the hook.
1313 	 * We are all set up except for the final call to the node, and
1314 	 * the clearing of the INVALID flag.
1315 	 */
1316 	if (NG_HOOK_NODE(hook) == &ng_deadnode) {
1317 		/*
1318 		 * The node must have been freed again since we last visited
1319 		 * here. ng_destry_hook() has this effect but nothing else does.
1320 		 * We should just release our references and
1321 		 * free anything we can think of.
1322 		 * Since we know it's been destroyed, and it's our caller
1323 		 * that holds the references, just return.
1324 		 */
1325 		ERROUT(ENOENT);
1326 	}
1327 	if (hook->hk_node->nd_type->connect) {
1328 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1329 			ng_destroy_hook(hook);	/* also zaps peer */
1330 			kprintf("failed in ng_con_part3()\n");
1331 			ERROUT(error);
1332 		}
1333 	}
1334 	/*
1335 	 *  XXX this is wrong for SMP. Possibly we need
1336 	 * to separate out 'create' and 'invalid' flags.
1337 	 * should only set flags on hooks we have locked under our node.
1338 	 */
1339 	hook->hk_flags &= ~HK_INVALID;
1340 done:
1341 	NG_FREE_ITEM(item);
1342 	return (error);
1343 }
1344 
1345 static int
1346 ng_con_part2(node_p node, item_p item, hook_p hook)
1347 {
1348 	hook_p	peer;
1349 	int	error = 0;
1350 
1351 	/*
1352 	 * When we run, we know that the node 'node' is locked for us.
1353 	 * Our caller has a reference on the hook.
1354 	 * Our caller has a reference on the node.
1355 	 * (In this case our caller is ng_apply_item() ).
1356 	 * The peer hook has a reference on the hook.
1357 	 * our node pointer points to the 'dead' node.
1358 	 * First check the hook name is unique.
1359 	 * Should not happen because we checked before queueing this.
1360 	 */
1361 	if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
1362 		TRAP_ERROR();
1363 		ng_destroy_hook(hook); /* should destroy peer too */
1364 		kprintf("failed in ng_con_part2()\n");
1365 		ERROUT(EEXIST);
1366 	}
1367 	/*
1368 	 * Check if the node type code has something to say about it
1369 	 * If it fails, the unref of the hook will also unref the attached node,
1370 	 * however since that node is 'ng_deadnode' this will do nothing.
1371 	 * The peer hook will also be destroyed.
1372 	 */
1373 	if (node->nd_type->newhook != NULL) {
1374 		if ((error = (*node->nd_type->newhook)(node, hook,
1375 		    hook->hk_name))) {
1376 			ng_destroy_hook(hook); /* should destroy peer too */
1377 			kprintf("failed in ng_con_part2()\n");
1378 			ERROUT(error);
1379 		}
1380 	}
1381 
1382 	/*
1383 	 * The 'type' agrees so far, so go ahead and link it in.
1384 	 * We'll ask again later when we actually connect the hooks.
1385 	 */
1386 	hook->hk_node = node;		/* just overwrite ng_deadnode */
1387 	NG_NODE_REF(node);		/* each hook counts as a reference */
1388 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1389 	node->nd_numhooks++;
1390 	NG_HOOK_REF(hook);	/* one for the node */
1391 
1392 	/*
1393 	 * We now have a symmetrical situation, where both hooks have been
1394 	 * linked to their nodes, the newhook methods have been called
1395 	 * And the references are all correct. The hooks are still marked
1396 	 * as invalid, as we have not called the 'connect' methods
1397 	 * yet.
1398 	 * We can call the local one immediately as we have the
1399 	 * node locked, but we need to queue the remote one.
1400 	 */
1401 	if (hook->hk_node->nd_type->connect) {
1402 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1403 			ng_destroy_hook(hook);	/* also zaps peer */
1404 			kprintf("failed in ng_con_part2(A)\n");
1405 			ERROUT(error);
1406 		}
1407 	}
1408 
1409 	/*
1410 	 * Acquire topo token to avoid race with ng_destroy_hook().
1411 	 */
1412 	TOPOLOGY_RLOCK();
1413 	peer = hook->hk_peer;
1414 	if (peer == &ng_deadhook) {
1415 		TOPOLOGY_RUNLOCK();
1416 		kprintf("failed in ng_con_part2(B)\n");
1417 		ng_destroy_hook(hook);
1418 		ERROUT(ENOENT);
1419 	}
1420 	TOPOLOGY_RUNLOCK();
1421 
1422 	if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
1423 	    NULL, 0, NG_REUSE_ITEM))) {
1424 		kprintf("failed in ng_con_part2(C)\n");
1425 		ng_destroy_hook(hook);	/* also zaps peer */
1426 		return (error);		/* item was consumed. */
1427 	}
1428 	hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
1429 	return (0);			/* item was consumed. */
1430 done:
1431 	NG_FREE_ITEM(item);
1432 	return (error);
1433 }
1434 
1435 /*
1436  * Connect this node with another node. We assume that this node is
1437  * currently locked, as we are only called from an NGM_CONNECT message.
1438  */
1439 static int
1440 ng_con_nodes(item_p item, node_p node, const char *name,
1441     node_p node2, const char *name2)
1442 {
1443 	int	error;
1444 	hook_p	hook;
1445 	hook_p	hook2;
1446 
1447 	if (ng_findhook(node2, name2) != NULL) {
1448 		return(EEXIST);
1449 	}
1450 	if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
1451 		return (error);
1452 	/* Allocate the other hook and link it up */
1453 	NG_ALLOC_HOOK(hook2);
1454 	if (hook2 == NULL) {
1455 		TRAP_ERROR();
1456 		ng_destroy_hook(hook);	/* XXX check ref counts so far */
1457 		NG_HOOK_UNREF(hook);	/* including our ref */
1458 		return (ENOMEM);
1459 	}
1460 	hook2->hk_refs = 1;		/* start with a reference for us. */
1461 	hook2->hk_flags = HK_INVALID;
1462 	hook2->hk_peer = hook;		/* Link the two together */
1463 	hook->hk_peer = hook2;
1464 	NG_HOOK_REF(hook);		/* Add a ref for the peer to each*/
1465 	NG_HOOK_REF(hook2);
1466 	hook2->hk_node = &ng_deadnode;
1467 	strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
1468 
1469 	/*
1470 	 * Queue the function above.
1471 	 * Procesing continues in that function in the lock context of
1472 	 * the other node.
1473 	 */
1474 	if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
1475 	    NG_NOFLAGS))) {
1476 		kprintf("failed in ng_con_nodes(): %d\n", error);
1477 		ng_destroy_hook(hook);	/* also zaps peer */
1478 	}
1479 
1480 	NG_HOOK_UNREF(hook);		/* Let each hook go if it wants to */
1481 	NG_HOOK_UNREF(hook2);
1482 	return (error);
1483 }
1484 
1485 /*
1486  * Make a peer and connect.
1487  * We assume that the local node is locked.
1488  * The new node probably doesn't need a lock until
1489  * it has a hook, because it cannot really have any work until then,
1490  * but we should think about it a bit more.
1491  *
1492  * The problem may come if the other node also fires up
1493  * some hardware or a timer or some other source of activation,
1494  * also it may already get a command msg via it's ID.
1495  *
1496  * We could use the same method as ng_con_nodes() but we'd have
1497  * to add ability to remove the node when failing. (Not hard, just
1498  * make arg1 point to the node to remove).
1499  * Unless of course we just ignore failure to connect and leave
1500  * an unconnected node?
1501  */
1502 static int
1503 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
1504 {
1505 	node_p	node2;
1506 	hook_p	hook1, hook2;
1507 	int	error;
1508 
1509 	if ((error = ng_make_node(type, &node2))) {
1510 		return (error);
1511 	}
1512 
1513 	if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
1514 		ng_rmnode(node2, NULL, NULL, 0);
1515 		return (error);
1516 	}
1517 
1518 	if ((error = ng_add_hook(node2, name2, &hook2))) {
1519 		ng_rmnode(node2, NULL, NULL, 0);
1520 		ng_destroy_hook(hook1);
1521 		NG_HOOK_UNREF(hook1);
1522 		return (error);
1523 	}
1524 
1525 	/*
1526 	 * Actually link the two hooks together.
1527 	 */
1528 	hook1->hk_peer = hook2;
1529 	hook2->hk_peer = hook1;
1530 
1531 	/* Each hook is referenced by the other */
1532 	NG_HOOK_REF(hook1);
1533 	NG_HOOK_REF(hook2);
1534 
1535 	/* Give each node the opportunity to veto the pending connection */
1536 	if (hook1->hk_node->nd_type->connect) {
1537 		error = (*hook1->hk_node->nd_type->connect) (hook1);
1538 	}
1539 
1540 	if ((error == 0) && hook2->hk_node->nd_type->connect) {
1541 		error = (*hook2->hk_node->nd_type->connect) (hook2);
1542 
1543 	}
1544 
1545 	/*
1546 	 * drop the references we were holding on the two hooks.
1547 	 */
1548 	if (error) {
1549 		ng_destroy_hook(hook2);	/* also zaps hook1 */
1550 		ng_rmnode(node2, NULL, NULL, 0);
1551 	} else {
1552 		/* As a last act, allow the hooks to be used */
1553 		hook1->hk_flags &= ~HK_INVALID;
1554 		hook2->hk_flags &= ~HK_INVALID;
1555 	}
1556 	NG_HOOK_UNREF(hook1);
1557 	NG_HOOK_UNREF(hook2);
1558 	return (error);
1559 }
1560 
1561 /************************************************************************
1562 		Utility routines to send self messages
1563 ************************************************************************/
1564 
1565 /* Shut this node down as soon as everyone is clear of it */
1566 /* Should add arg "immediately" to jump the queue */
1567 int
1568 ng_rmnode_self(node_p node)
1569 {
1570 	int		error;
1571 
1572 	if (node == &ng_deadnode)
1573 		return (0);
1574 	node->nd_flags |= NGF_INVALID;
1575 	if (node->nd_flags & NGF_CLOSING)
1576 		return (0);
1577 
1578 	error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
1579 	return (error);
1580 }
1581 
1582 static void
1583 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
1584 {
1585 	ng_destroy_hook(hook);
1586 	return ;
1587 }
1588 
1589 int
1590 ng_rmhook_self(hook_p hook)
1591 {
1592 	int		error;
1593 	node_p node = NG_HOOK_NODE(hook);
1594 
1595 	if (node == &ng_deadnode)
1596 		return (0);
1597 
1598 	error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
1599 	return (error);
1600 }
1601 
1602 /***********************************************************************
1603  * Parse and verify a string of the form:  <NODE:><PATH>
1604  *
1605  * Such a string can refer to a specific node or a specific hook
1606  * on a specific node, depending on how you look at it. In the
1607  * latter case, the PATH component must not end in a dot.
1608  *
1609  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1610  * of hook names separated by dots. This breaks out the original
1611  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1612  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1613  * the final hook component of <PATH>, if any, otherwise NULL.
1614  *
1615  * This returns -1 if the path is malformed. The char ** are optional.
1616  ***********************************************************************/
1617 int
1618 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1619 {
1620 	char	*node, *path, *hook;
1621 	int	k;
1622 
1623 	/*
1624 	 * Extract absolute NODE, if any
1625 	 */
1626 	for (path = addr; *path && *path != ':'; path++);
1627 	if (*path) {
1628 		node = addr;	/* Here's the NODE */
1629 		*path++ = '\0';	/* Here's the PATH */
1630 
1631 		/* Node name must not be empty */
1632 		if (!*node)
1633 			return -1;
1634 
1635 		/* A name of "." is OK; otherwise '.' not allowed */
1636 		if (strcmp(node, ".") != 0) {
1637 			for (k = 0; node[k]; k++)
1638 				if (node[k] == '.')
1639 					return -1;
1640 		}
1641 	} else {
1642 		node = NULL;	/* No absolute NODE */
1643 		path = addr;	/* Here's the PATH */
1644 	}
1645 
1646 	/* Snoop for illegal characters in PATH */
1647 	for (k = 0; path[k]; k++)
1648 		if (path[k] == ':')
1649 			return -1;
1650 
1651 	/* Check for no repeated dots in PATH */
1652 	for (k = 0; path[k]; k++)
1653 		if (path[k] == '.' && path[k + 1] == '.')
1654 			return -1;
1655 
1656 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1657 	if (path[0] == '.')
1658 		path++;
1659 	if (*path && path[strlen(path) - 1] == '.')
1660 		path[strlen(path) - 1] = 0;
1661 
1662 	/* If PATH has a dot, then we're not talking about a hook */
1663 	if (*path) {
1664 		for (hook = path, k = 0; path[k]; k++)
1665 			if (path[k] == '.') {
1666 				hook = NULL;
1667 				break;
1668 			}
1669 	} else
1670 		path = hook = NULL;
1671 
1672 	/* Done */
1673 	if (nodep)
1674 		*nodep = node;
1675 	if (pathp)
1676 		*pathp = path;
1677 	if (hookp)
1678 		*hookp = hook;
1679 	return (0);
1680 }
1681 
1682 /*
1683  * Given a path, which may be absolute or relative, and a starting node,
1684  * return the destination node.
1685  */
1686 int
1687 ng_path2noderef(node_p here, const char *address,
1688 				node_p *destp, hook_p *lasthook)
1689 {
1690 	char    fullpath[NG_PATHSIZ];
1691 	char   *nodename, *path, pbuf[2];
1692 	node_p  node, oldnode;
1693 	char   *cp;
1694 	hook_p hook = NULL;
1695 
1696 	/* Initialize */
1697 	if (destp == NULL) {
1698 		TRAP_ERROR();
1699 		return EINVAL;
1700 	}
1701 	*destp = NULL;
1702 
1703 	/* Make a writable copy of address for ng_path_parse() */
1704 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1705 	fullpath[sizeof(fullpath) - 1] = '\0';
1706 
1707 	/* Parse out node and sequence of hooks */
1708 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1709 		TRAP_ERROR();
1710 		return EINVAL;
1711 	}
1712 	if (path == NULL) {
1713 		pbuf[0] = '.';	/* Needs to be writable */
1714 		pbuf[1] = '\0';
1715 		path = pbuf;
1716 	}
1717 
1718 	/*
1719 	 * For an absolute address, jump to the starting node.
1720 	 * Note that this holds a reference on the node for us.
1721 	 * Don't forget to drop the reference if we don't need it.
1722 	 */
1723 	if (nodename) {
1724 		node = ng_name2noderef(here, nodename);
1725 		if (node == NULL) {
1726 			TRAP_ERROR();
1727 			return (ENOENT);
1728 		}
1729 	} else {
1730 		if (here == NULL) {
1731 			TRAP_ERROR();
1732 			return (EINVAL);
1733 		}
1734 		node = here;
1735 		NG_NODE_REF(node);
1736 	}
1737 
1738 	/*
1739 	 * Now follow the sequence of hooks
1740 	 * XXX
1741 	 * We actually cannot guarantee that the sequence
1742 	 * is not being demolished as we crawl along it
1743 	 * without extra-ordinary locking etc.
1744 	 * So this is a bit dodgy to say the least.
1745 	 * We can probably hold up some things by holding
1746 	 * the nodelist mutex for the time of this
1747 	 * crawl if we wanted.. At least that way we wouldn't have to
1748 	 * worry about the nodes disappearing, but the hooks would still
1749 	 * be a problem.
1750 	 */
1751 	for (cp = path; node != NULL && *cp != '\0'; ) {
1752 		char *segment;
1753 
1754 		/*
1755 		 * Break out the next path segment. Replace the dot we just
1756 		 * found with a NUL; "cp" points to the next segment (or the
1757 		 * NUL at the end).
1758 		 */
1759 		for (segment = cp; *cp != '\0'; cp++) {
1760 			if (*cp == '.') {
1761 				*cp++ = '\0';
1762 				break;
1763 			}
1764 		}
1765 
1766 		/* Empty segment */
1767 		if (*segment == '\0')
1768 			continue;
1769 
1770 		/* We have a segment, so look for a hook by that name */
1771 		hook = ng_findhook(node, segment);
1772 
1773 		/* Can't get there from here... */
1774 		if (hook == NULL
1775 		    || NG_HOOK_PEER(hook) == NULL
1776 		    || NG_HOOK_NOT_VALID(hook)
1777 		    || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
1778 			TRAP_ERROR();
1779 			NG_NODE_UNREF(node);
1780 #if 0
1781 			kprintf("hooknotvalid %s %s %d %d %d %d ",
1782 					path,
1783 					segment,
1784 					hook == NULL,
1785 					NG_HOOK_PEER(hook) == NULL,
1786 					NG_HOOK_NOT_VALID(hook),
1787 					NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook)));
1788 #endif
1789 			return (ENOENT);
1790 		}
1791 
1792 		/*
1793 		 * Hop on over to the next node
1794 		 * XXX
1795 		 * Big race conditions here as hooks and nodes go away
1796 		 * *** Idea.. store an ng_ID_t in each hook and use that
1797 		 * instead of the direct hook in this crawl?
1798 		 */
1799 		oldnode = node;
1800 		if ((node = NG_PEER_NODE(hook)))
1801 			NG_NODE_REF(node);	/* XXX RACE */
1802 		NG_NODE_UNREF(oldnode);	/* XXX another race */
1803 		if (NG_NODE_NOT_VALID(node)) {
1804 			NG_NODE_UNREF(node);	/* XXX more races */
1805 			node = NULL;
1806 		}
1807 	}
1808 
1809 	/* If node somehow missing, fail here (probably this is not needed) */
1810 	if (node == NULL) {
1811 		TRAP_ERROR();
1812 		return (ENXIO);
1813 	}
1814 
1815 	/* Done */
1816 	*destp = node;
1817 	if (lasthook != NULL)
1818 		*lasthook = (hook ? NG_HOOK_PEER(hook) : NULL);
1819 	return (0);
1820 }
1821 
1822 /*********************************************************************\
1823 * Inter-CPU node synchronization
1824 *
1825 * All activities are submitted to one of the netgraph per-CPU threads.
1826 * There is one item input queue per CPU, not one per node as in
1827 * FreeBSD.  If the item is entering netgraph for the first time, it is
1828 * queued to the thread's msgport.  Otherwise it is applied directly.
1829 * From start to finish, the item is processed on the same CPU.  Items
1830 * are distributed based on the ingress node, to keep item ordering.
1831 \***************************************************************/
1832 
1833 static __inline void	ng_acquire_read(node_p node);
1834 static __inline void	ng_acquire_write(node_p node);
1835 static __inline void	ng_leave_readwrite(node_p node);
1836 
1837 static __inline void
1838 ng_acquire_read(node_p node)
1839 {
1840 	KASSERT(node != &ng_deadnode,
1841 	    ("%s: working on deadnode", __func__));
1842 
1843 	lwkt_gettoken_shared(&node->nd_token);
1844 }
1845 
1846 /* Acquire writer lock on node. If node is busy, sleep. */
1847 static __inline void
1848 ng_acquire_write(node_p node)
1849 {
1850 	KASSERT(node != &ng_deadnode,
1851 	    ("%s: working on deadnode", __func__));
1852 
1853 	lwkt_gettoken(&node->nd_token);
1854 }
1855 
1856 /* Release reader or writer lock. */
1857 static __inline void
1858 ng_leave_readwrite(node_p node)
1859 {
1860 	lwkt_reltoken(&node->nd_token);
1861 }
1862 
1863 /***********************************************************************
1864 * Worklist routines
1865 **********************************************************************/
1866 /* NETGRAPH thread routine
1867  *
1868  * Pick an item from our thread's queue and apply it.
1869  */
1870 static void
1871 ngthread(void *dummy __unused)
1872 {
1873 	lwkt_msg_t msg;
1874 
1875 	while ((msg = lwkt_waitport(&curthread->td_msgport, 0)) != NULL) {
1876 		item_p  item = (void *)msg;
1877 
1878 		ng_apply_item(item);
1879 		/* Do not reply to the message */
1880 	}
1881 }
1882 
1883 /***********************************************************************
1884 * Externally visible method for sending or queueing messages or data.
1885 ***********************************************************************/
1886 
1887 /*
1888  * The module code should have filled out the item correctly by this stage:
1889  * Common:
1890  *    reference to destination node.
1891  *    Reference to destination rcv hook if relevant.
1892  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
1893  * Data:
1894  *    pointer to mbuf
1895  * Control_Message:
1896  *    pointer to msg.
1897  *    ID of original sender node. (return address)
1898  * Function:
1899  *    Function pointer
1900  *    void * argument
1901  *    integer argument
1902  *
1903  * The nodes have several routines and macros to help with this task:
1904  */
1905 
1906 int
1907 ng_snd_item(item_p item, int flags)
1908 {
1909 	hook_p hook;
1910 	node_p node;
1911 	int error = 0;
1912 
1913 	/* We are sending item, so it must be present! */
1914 	KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
1915 
1916 #ifdef	NETGRAPH_DEBUG
1917 	_ngi_check(item, __FILE__, __LINE__);
1918 #endif
1919 
1920 	/*
1921 	 * Every time an item is sent or forwarded we hold a reference on it
1922 	 * to postone the callback (if there is one) and item freedom.
1923 	 */
1924 	refcount_acquire(&item->depth);
1925 
1926 	/*
1927 	 * Node is never optional.
1928 	 */
1929 	node = NGI_NODE(item);
1930 	KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
1931 
1932 	/*
1933 	 * Valid hook and mbuf are mandatory for data.
1934 	 */
1935 	hook = NGI_HOOK(item);
1936 	if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
1937 		KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
1938 		if (NGI_M(item) == NULL)
1939 			ERROUT(EINVAL);
1940 		CHECK_DATA_MBUF(NGI_M(item));
1941 	}
1942 
1943 	/*
1944 	 * Always queue items entering netgraph for the first time.
1945 	 */
1946 	if (item->depth == 1) {
1947 		struct lwkt_msg *msg = &item->el_lmsg;
1948 
1949 		lwkt_initmsg(msg, &ng_panic_reply_port, 0);
1950 		/* Always send to cpu0 for now */
1951 		lwkt_sendmsg(ng_cpuport(0), msg);
1952 
1953 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
1954 	}
1955 
1956 	/*
1957 	 * The item wasn't queued.  Process it synchronously.
1958 	 */
1959 	error = ng_apply_item(item);
1960 
1961 done:
1962 	return (error);
1963 }
1964 
1965 /*
1966  * We have an item that was possibly queued somewhere.
1967  * It should contain all the information needed
1968  * to run it on the appropriate node/hook.
1969  * If there is apply pointer and we own the last reference, call apply().
1970  */
1971 static int
1972 ng_apply_item(item_p item)
1973 {
1974 	hook_p  hook;
1975 	node_p	node;
1976 	ng_rcvdata_t *rcvdata;
1977 	ng_rcvmsg_t *rcvmsg;
1978 	int	error = 0;
1979 
1980 	/* Node and item are never optional. */
1981 	KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
1982 	NGI_GET_NODE(item, node);		/* zaps stored node */
1983 	KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
1984 	NGI_GET_HOOK(item, hook);		/* clears stored hook */
1985 
1986 	/*
1987 	 * If the item or the node specifies single threading, force
1988 	 * writer semantics. Similarly, the node may say one hook always
1989 	 * produces writers. These are overrides.
1990 	 */
1991 	if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
1992 	    (node->nd_flags & NGF_FORCE_WRITER) ||
1993 	    (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
1994 		ng_acquire_write(node);
1995 	} else {
1996 		ng_acquire_read(node);
1997 	}
1998 
1999 #ifdef	NETGRAPH_DEBUG
2000 	_ngi_check(item, __FILE__, __LINE__);
2001 #endif
2002 
2003 	switch (item->el_flags & NGQF_TYPE) {
2004 	case NGQF_DATA:
2005 		/*
2006 		 * Check things are still ok as when we were queued.
2007 		 */
2008 		KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
2009 		if (NG_HOOK_NOT_VALID(hook) ||
2010 		    NG_NODE_NOT_VALID(node)) {
2011 			error = EIO;
2012 			NG_FREE_ITEM(item);
2013 			break;
2014 		}
2015 		/*
2016 		 * If no receive method, just silently drop it.
2017 		 * Give preference to the hook over-ride method
2018 		 */
2019 		if ((!(rcvdata = hook->hk_rcvdata))
2020 		&& (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
2021 			error = 0;
2022 			NG_FREE_ITEM(item);
2023 			break;
2024 		}
2025 		error = (*rcvdata)(hook, item);
2026 		break;
2027 	case NGQF_MESG:
2028 		if (hook && NG_HOOK_NOT_VALID(hook)) {
2029 			/*
2030 			 * The hook has been zapped then we can't use it.
2031 			 * Immediately drop its reference.
2032 			 * The message may not need it.
2033 			 */
2034 			NG_HOOK_UNREF(hook);
2035 			hook = NULL;
2036 		}
2037 		/*
2038 		 * Similarly, if the node is a zombie there is
2039 		 * nothing we can do with it, drop everything.
2040 		 */
2041 		if (NG_NODE_NOT_VALID(node)) {
2042 			TRAP_ERROR();
2043 			error = EINVAL;
2044 			NG_FREE_ITEM(item);
2045 			break;
2046 		}
2047 		/*
2048 		 * Call the appropriate message handler for the object.
2049 		 * It is up to the message handler to free the message.
2050 		 * If it's a generic message, handle it generically,
2051 		 * otherwise call the type's message handler (if it exists).
2052 		 * XXX (race). Remember that a queued message may
2053 		 * reference a node or hook that has just been
2054 		 * invalidated. It will exist as the queue code
2055 		 * is holding a reference, but..
2056 		 */
2057 		if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
2058 		    ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
2059 			error = ng_generic_msg(node, item, hook);
2060 			break;
2061 		}
2062 		if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
2063 		    (!(rcvmsg = node->nd_type->rcvmsg))) {
2064 			TRAP_ERROR();
2065 			error = 0;
2066 			NG_FREE_ITEM(item);
2067 			break;
2068 		}
2069 		error = (*rcvmsg)(node, item, hook);
2070 		break;
2071 	case NGQF_FN:
2072 	case NGQF_FN2:
2073 		/*
2074 		 *  We have to implicitly trust the hook,
2075 		 * as some of these are used for system purposes
2076 		 * where the hook is invalid. In the case of
2077 		 * the shutdown message we allow it to hit
2078 		 * even if the node is invalid.
2079 		 */
2080 		if ((NG_NODE_NOT_VALID(node))
2081 		&& (NGI_FN(item) != &ng_rmnode)) {
2082 			TRAP_ERROR();
2083 			error = EINVAL;
2084 			NG_FREE_ITEM(item);
2085 			break;
2086 		}
2087 		if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
2088 			(*NGI_FN(item))(node, hook, NGI_ARG1(item),
2089 			    NGI_ARG2(item));
2090 			NG_FREE_ITEM(item);
2091 		} else	/* it is NGQF_FN2 */
2092 			error = (*NGI_FN2(item))(node, item, hook);
2093 		break;
2094 	}
2095 	/*
2096 	 * We held references on some of the resources
2097 	 * that we took from the item. Now that we have
2098 	 * finished doing everything, drop those references.
2099 	 */
2100 	if (hook)
2101 		NG_HOOK_UNREF(hook);
2102 
2103 	/* Release our node's token */
2104 	ng_leave_readwrite(node);
2105 
2106 	/* Free the item if we own the last reference to it. */
2107 	if (refcount_release(&item->depth)) {
2108 		ng_check_apply(item, error);
2109 		ng_free_item(item);
2110 	}
2111 	NG_NODE_UNREF(node);
2112 
2113 	return (error);
2114 }
2115 
2116 /***********************************************************************
2117  * Implement the 'generic' control messages
2118  ***********************************************************************/
2119 static int
2120 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
2121 {
2122 	int error = 0;
2123 	struct ng_mesg *msg;
2124 	struct ng_mesg *resp = NULL;
2125 
2126 	NGI_GET_MSG(item, msg);
2127 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
2128 		TRAP_ERROR();
2129 		error = EINVAL;
2130 		goto out;
2131 	}
2132 	switch (msg->header.cmd) {
2133 	case NGM_SHUTDOWN:
2134 		ng_rmnode(here, NULL, NULL, 0);
2135 		break;
2136 	case NGM_MKPEER:
2137 	    {
2138 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
2139 
2140 		if (msg->header.arglen != sizeof(*mkp)) {
2141 			TRAP_ERROR();
2142 			error = EINVAL;
2143 			break;
2144 		}
2145 		mkp->type[sizeof(mkp->type) - 1] = '\0';
2146 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
2147 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
2148 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
2149 		break;
2150 	    }
2151 	case NGM_CONNECT:
2152 	    {
2153 		struct ngm_connect *const con =
2154 			(struct ngm_connect *) msg->data;
2155 		node_p node2;
2156 
2157 		if (msg->header.arglen != sizeof(*con)) {
2158 			TRAP_ERROR();
2159 			error = EINVAL;
2160 			break;
2161 		}
2162 		con->path[sizeof(con->path) - 1] = '\0';
2163 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
2164 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
2165 		/* Don't forget we get a reference.. */
2166 		error = ng_path2noderef(here, con->path, &node2, NULL);
2167 		if (error)
2168 			break;
2169 		error = ng_con_nodes(item, here, con->ourhook,
2170 		    node2, con->peerhook);
2171 		NG_NODE_UNREF(node2);
2172 		break;
2173 	    }
2174 	case NGM_NAME:
2175 	    {
2176 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
2177 
2178 		if (msg->header.arglen != sizeof(*nam)) {
2179 			TRAP_ERROR();
2180 			error = EINVAL;
2181 			break;
2182 		}
2183 		nam->name[sizeof(nam->name) - 1] = '\0';
2184 		error = ng_name_node(here, nam->name);
2185 		break;
2186 	    }
2187 	case NGM_RMHOOK:
2188 	    {
2189 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
2190 		hook_p hook;
2191 
2192 		if (msg->header.arglen != sizeof(*rmh)) {
2193 			TRAP_ERROR();
2194 			error = EINVAL;
2195 			break;
2196 		}
2197 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
2198 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
2199 			ng_destroy_hook(hook);
2200 		break;
2201 	    }
2202 	case NGM_NODEINFO:
2203 	    {
2204 		struct nodeinfo *ni;
2205 
2206 		NG_MKRESPONSE(resp, msg, sizeof(*ni), M_WAITOK | M_NULLOK);
2207 		if (resp == NULL) {
2208 			error = ENOMEM;
2209 			break;
2210 		}
2211 
2212 		/* Fill in node info */
2213 		ni = (struct nodeinfo *) resp->data;
2214 		if (NG_NODE_HAS_NAME(here))
2215 			strcpy(ni->name, NG_NODE_NAME(here));
2216 		strcpy(ni->type, here->nd_type->name);
2217 		ni->id = ng_node2ID(here);
2218 		ni->hooks = here->nd_numhooks;
2219 		break;
2220 	    }
2221 	case NGM_LISTHOOKS:
2222 	    {
2223 		const int nhooks = here->nd_numhooks;
2224 		struct hooklist *hl;
2225 		struct nodeinfo *ni;
2226 		hook_p hook;
2227 
2228 		/* Get response struct */
2229 		NG_MKRESPONSE(resp, msg, sizeof(*hl)
2230 		    + (nhooks * sizeof(struct linkinfo)), M_WAITOK | M_NULLOK);
2231 		if (resp == NULL) {
2232 			error = ENOMEM;
2233 			break;
2234 		}
2235 		hl = (struct hooklist *) resp->data;
2236 		ni = &hl->nodeinfo;
2237 
2238 		/* Fill in node info */
2239 		if (NG_NODE_HAS_NAME(here))
2240 			strcpy(ni->name, NG_NODE_NAME(here));
2241 		strcpy(ni->type, here->nd_type->name);
2242 		ni->id = ng_node2ID(here);
2243 
2244 		/* Cycle through the linked list of hooks */
2245 		ni->hooks = 0;
2246 		LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
2247 			struct linkinfo *const link = &hl->link[ni->hooks];
2248 
2249 			if (ni->hooks >= nhooks) {
2250 				log(LOG_ERR, "%s: number of %s changed\n",
2251 				    __func__, "hooks");
2252 				break;
2253 			}
2254 			if (NG_HOOK_NOT_VALID(hook))
2255 				continue;
2256 			strcpy(link->ourhook, NG_HOOK_NAME(hook));
2257 			strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
2258 			if (NG_PEER_NODE_NAME(hook)[0] != '\0')
2259 				strcpy(link->nodeinfo.name,
2260 				    NG_PEER_NODE_NAME(hook));
2261 			strcpy(link->nodeinfo.type,
2262 			   NG_PEER_NODE(hook)->nd_type->name);
2263 			link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
2264 			link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
2265 			ni->hooks++;
2266 		}
2267 		break;
2268 	    }
2269 
2270 	case NGM_LISTNODES:
2271 	    {
2272 		struct namelist *nl;
2273 		node_p node;
2274 		int i;
2275 
2276 		IDHASH_RLOCK();
2277 		/* Get response struct. */
2278 		NG_MKRESPONSE(resp, msg, sizeof(*nl) +
2279 		    (ng_nodes * sizeof(struct nodeinfo)), M_NOWAIT | M_ZERO);
2280 		if (resp == NULL) {
2281 			IDHASH_RUNLOCK();
2282 			error = ENOMEM;
2283 			break;
2284 		}
2285 		nl = (struct namelist *) resp->data;
2286 
2287 		/* Cycle through the lists of nodes. */
2288 		nl->numnames = 0;
2289 		for (i = 0; i <= ng_ID_hmask; i++) {
2290 			LIST_FOREACH(node, &ng_ID_hash[i], nd_idnodes) {
2291 				struct nodeinfo *const np =
2292 				    &nl->nodeinfo[nl->numnames];
2293 
2294 				if (NG_NODE_NOT_VALID(node))
2295 					continue;
2296 				if (NG_NODE_HAS_NAME(node))
2297 					strcpy(np->name, NG_NODE_NAME(node));
2298 				strcpy(np->type, node->nd_type->name);
2299 				np->id = ng_node2ID(node);
2300 				np->hooks = node->nd_numhooks;
2301 				KASSERT(nl->numnames < ng_nodes,
2302 				    ("%s: no space", __func__));
2303 				nl->numnames++;
2304 			}
2305 		}
2306 		IDHASH_RUNLOCK();
2307 		break;
2308 	    }
2309 	case NGM_LISTNAMES:
2310 	    {
2311 		struct namelist *nl;
2312 		node_p node;
2313 		int i;
2314 
2315 		NAMEHASH_RLOCK();
2316 		/* Get response struct. */
2317 		NG_MKRESPONSE(resp, msg, sizeof(*nl) +
2318 		    (ng_named_nodes * sizeof(struct nodeinfo)), M_NOWAIT);
2319 		if (resp == NULL) {
2320 			NAMEHASH_RUNLOCK();
2321 			error = ENOMEM;
2322 			break;
2323 		}
2324 		nl = (struct namelist *) resp->data;
2325 
2326 		/* Cycle through the lists of nodes. */
2327 		nl->numnames = 0;
2328 		for (i = 0; i <= ng_name_hmask; i++) {
2329 			LIST_FOREACH(node, &ng_name_hash[i], nd_nodes) {
2330 				struct nodeinfo *const np =
2331 				    &nl->nodeinfo[nl->numnames];
2332 
2333 				if (NG_NODE_NOT_VALID(node))
2334 					continue;
2335 				strcpy(np->name, NG_NODE_NAME(node));
2336 				strcpy(np->type, node->nd_type->name);
2337 				np->id = ng_node2ID(node);
2338 				np->hooks = node->nd_numhooks;
2339 				KASSERT(nl->numnames < ng_named_nodes,
2340 				    ("%s: no space", __func__));
2341 				nl->numnames++;
2342 			}
2343 		}
2344 		NAMEHASH_RUNLOCK();
2345 		break;
2346 	    }
2347 
2348 	case NGM_LISTTYPES:
2349 	    {
2350 		struct typelist *tl;
2351 		struct ng_type *type;
2352 		int num = 0;
2353 
2354 		TYPELIST_RLOCK();
2355 		/* Count number of types */
2356 		LIST_FOREACH(type, &ng_typelist, types)
2357 			num++;
2358 
2359 		/* Get response struct */
2360 		NG_MKRESPONSE(resp, msg, sizeof(*tl)
2361 		    + (num * sizeof(struct typeinfo)), M_WAITOK | M_NULLOK);
2362 		if (resp == NULL) {
2363 			TYPELIST_RUNLOCK();
2364 			error = ENOMEM;
2365 			break;
2366 		}
2367 		tl = (struct typelist *) resp->data;
2368 
2369 		/* Cycle through the linked list of types */
2370 		tl->numtypes = 0;
2371 		LIST_FOREACH(type, &ng_typelist, types) {
2372 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
2373 
2374 			strcpy(tp->type_name, type->name);
2375 			tp->numnodes = type->refs - 1; /* don't count list */
2376 			KASSERT(tl->numtypes < num, ("%s: no space", __func__));
2377 			tl->numtypes++;
2378 		}
2379 		TYPELIST_RUNLOCK();
2380 		break;
2381 	    }
2382 
2383 	case NGM_BINARY2ASCII:
2384 	    {
2385 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2386 		const struct ng_parse_type *argstype;
2387 		const struct ng_cmdlist *c;
2388 		struct ng_mesg *binary, *ascii;
2389 
2390 		/* Data area must contain a valid netgraph message */
2391 		binary = (struct ng_mesg *)msg->data;
2392 		if (msg->header.arglen < sizeof(struct ng_mesg) ||
2393 		    (msg->header.arglen - sizeof(struct ng_mesg) <
2394 		    binary->header.arglen)) {
2395 			TRAP_ERROR();
2396 			error = EINVAL;
2397 			break;
2398 		}
2399 
2400 		/* Get a response message with lots of room */
2401 		NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_WAITOK | M_NULLOK);
2402 		if (resp == NULL) {
2403 			error = ENOMEM;
2404 			break;
2405 		}
2406 		ascii = (struct ng_mesg *)resp->data;
2407 
2408 		/* Copy binary message header to response message payload */
2409 		bcopy(binary, ascii, sizeof(*binary));
2410 
2411 		/* Find command by matching typecookie and command number */
2412 		for (c = here->nd_type->cmdlist;
2413 		    c != NULL && c->name != NULL; c++) {
2414 			if (binary->header.typecookie == c->cookie
2415 			    && binary->header.cmd == c->cmd)
2416 				break;
2417 		}
2418 		if (c == NULL || c->name == NULL) {
2419 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2420 				if (binary->header.typecookie == c->cookie
2421 				    && binary->header.cmd == c->cmd)
2422 					break;
2423 			}
2424 			if (c->name == NULL) {
2425 				NG_FREE_MSG(resp);
2426 				error = ENOSYS;
2427 				break;
2428 			}
2429 		}
2430 
2431 		/* Convert command name to ASCII */
2432 		ksnprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
2433 		    "%s", c->name);
2434 
2435 		/* Convert command arguments to ASCII */
2436 		argstype = (binary->header.flags & NGF_RESP) ?
2437 		    c->respType : c->mesgType;
2438 		if (argstype == NULL) {
2439 			*ascii->data = '\0';
2440 		} else {
2441 			if ((error = ng_unparse(argstype,
2442 			    (u_char *)binary->data,
2443 			    ascii->data, bufSize)) != 0) {
2444 				NG_FREE_MSG(resp);
2445 				break;
2446 			}
2447 		}
2448 
2449 		/* Return the result as struct ng_mesg plus ASCII string */
2450 		bufSize = strlen(ascii->data) + 1;
2451 		ascii->header.arglen = bufSize;
2452 		resp->header.arglen = sizeof(*ascii) + bufSize;
2453 		break;
2454 	    }
2455 
2456 	case NGM_ASCII2BINARY:
2457 	    {
2458 		int bufSize = 2000;	/* XXX hard coded constant */
2459 		const struct ng_cmdlist *c;
2460 		const struct ng_parse_type *argstype;
2461 		struct ng_mesg *ascii, *binary;
2462 		int off = 0;
2463 
2464 		/* Data area must contain at least a struct ng_mesg + '\0' */
2465 		ascii = (struct ng_mesg *)msg->data;
2466 		if ((msg->header.arglen < sizeof(*ascii) + 1) ||
2467 		    (ascii->header.arglen < 1) ||
2468 		    (msg->header.arglen < sizeof(*ascii) +
2469 		    ascii->header.arglen)) {
2470 			TRAP_ERROR();
2471 			error = EINVAL;
2472 			break;
2473 		}
2474 		ascii->data[ascii->header.arglen - 1] = '\0';
2475 
2476 		/* Get a response message with lots of room */
2477 		NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_WAITOK | M_NULLOK);
2478 		if (resp == NULL) {
2479 			error = ENOMEM;
2480 			break;
2481 		}
2482 		binary = (struct ng_mesg *)resp->data;
2483 
2484 		/* Copy ASCII message header to response message payload */
2485 		bcopy(ascii, binary, sizeof(*ascii));
2486 
2487 		/* Find command by matching ASCII command string */
2488 		for (c = here->nd_type->cmdlist;
2489 		    c != NULL && c->name != NULL; c++) {
2490 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
2491 				break;
2492 		}
2493 		if (c == NULL || c->name == NULL) {
2494 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2495 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
2496 					break;
2497 			}
2498 			if (c->name == NULL) {
2499 				NG_FREE_MSG(resp);
2500 				error = ENOSYS;
2501 				break;
2502 			}
2503 		}
2504 
2505 		/* Convert command name to binary */
2506 		binary->header.cmd = c->cmd;
2507 		binary->header.typecookie = c->cookie;
2508 
2509 		/* Convert command arguments to binary */
2510 		argstype = (binary->header.flags & NGF_RESP) ?
2511 		    c->respType : c->mesgType;
2512 		if (argstype == NULL) {
2513 			bufSize = 0;
2514 		} else {
2515 			if ((error = ng_parse(argstype, ascii->data,
2516 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
2517 				NG_FREE_MSG(resp);
2518 				break;
2519 			}
2520 		}
2521 
2522 		/* Return the result */
2523 		binary->header.arglen = bufSize;
2524 		resp->header.arglen = sizeof(*binary) + bufSize;
2525 		break;
2526 	    }
2527 
2528 	case NGM_TEXT_CONFIG:
2529 	case NGM_TEXT_STATUS:
2530 		/*
2531 		 * This one is tricky as it passes the command down to the
2532 		 * actual node, even though it is a generic type command.
2533 		 * This means we must assume that the item/msg is already freed
2534 		 * when control passes back to us.
2535 		 */
2536 		if (here->nd_type->rcvmsg != NULL) {
2537 			NGI_MSG(item) = msg; /* put it back as we found it */
2538 			return((*here->nd_type->rcvmsg)(here, item, lasthook));
2539 		}
2540 		/* Fall through if rcvmsg not supported */
2541 	default:
2542 		TRAP_ERROR();
2543 		error = EINVAL;
2544 	}
2545 	/*
2546 	 * Sometimes a generic message may be statically allocated
2547 	 * to avoid problems with allocating when in tight memeory situations.
2548 	 * Don't free it if it is so.
2549 	 * I break them appart here, because erros may cause a free if the item
2550 	 * in which case we'd be doing it twice.
2551 	 * they are kept together above, to simplify freeing.
2552 	 */
2553 out:
2554 	NG_RESPOND_MSG(error, here, item, resp);
2555 	if (msg)
2556 		NG_FREE_MSG(msg);
2557 	return (error);
2558 }
2559 
2560 /************************************************************************
2561 			Queue element get/free routines
2562 ************************************************************************/
2563 
2564 static struct objcache	*ng_oc;
2565 static struct objcache	*ng_apply_oc;
2566 static int		 maxalloc = 4096; /* limit the damage of a leak */
2567 
2568 TUNABLE_INT("net.graph.maxalloc", &maxalloc);
2569 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RD, &maxalloc,
2570     0, "Maximum number of queue items to allocate");
2571 
2572 #ifdef	NETGRAPH_DEBUG
2573 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
2574 static int			allocated;	/* number of items malloc'd */
2575 #endif
2576 
2577 /*
2578  * Get a queue entry.
2579  * This is usually called when a packet first enters netgraph.
2580  * By definition, this is usually from an interrupt, or from a user.
2581  * Users are not so important, but try be quick for the times that it's
2582  * an interrupt.
2583  */
2584 static __inline item_p
2585 ng_alloc_item(int type, int flags)
2586 {
2587 	item_p item;
2588 
2589 	KASSERT(((type & ~NGQF_TYPE) == 0),
2590 	    ("%s: incorrect item type: %d", __func__, type));
2591 
2592 	item = objcache_get(ng_oc,
2593 	    (flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT );
2594 
2595 	if (item) {
2596 		item->el_flags = type;
2597 #ifdef	NETGRAPH_DEBUG
2598 		mtx_lock(&ngq_mtx);
2599 		TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
2600 		allocated++;
2601 		mtx_unlock(&ngq_mtx);
2602 #endif
2603 	}
2604 
2605 	return (item);
2606 }
2607 
2608 /*
2609  * Release a queue entry
2610  */
2611 void
2612 ng_free_item(item_p item)
2613 {
2614 	/*
2615 	 * If the item still has an apply callback registered, it is
2616 	 * being freed too early.
2617 	 */
2618 	KASSERT(item->apply == NULL, ("freeing item with registered callback"));
2619 
2620 	/*
2621 	 * The item may hold resources on it's own. We need to free
2622 	 * these before we can free the item. What they are depends upon
2623 	 * what kind of item it is. it is important that nodes zero
2624 	 * out pointers to resources that they remove from the item
2625 	 * or we release them again here.
2626 	 */
2627 	switch (item->el_flags & NGQF_TYPE) {
2628 	case NGQF_DATA:
2629 		/* If we have an mbuf still attached.. */
2630 		NG_FREE_M(_NGI_M(item));
2631 		break;
2632 	case NGQF_MESG:
2633 		_NGI_RETADDR(item) = 0;
2634 		NG_FREE_MSG(_NGI_MSG(item));
2635 		break;
2636 	case NGQF_FN:
2637 	case NGQF_FN2:
2638 		/* nothing to free really, */
2639 		_NGI_FN(item) = NULL;
2640 		_NGI_ARG1(item) = NULL;
2641 		_NGI_ARG2(item) = 0;
2642 		break;
2643 	}
2644 	/* If we still have a node or hook referenced... */
2645 	_NGI_CLR_NODE(item);
2646 	_NGI_CLR_HOOK(item);
2647 
2648 #ifdef	NETGRAPH_DEBUG
2649 	mtx_lock(&ngq_mtx);
2650 	TAILQ_REMOVE(&ng_itemlist, item, all);
2651 	allocated--;
2652 	mtx_unlock(&ngq_mtx);
2653 #endif
2654 	/* Object must be initialized before returning to objcache */
2655 	bzero(item, sizeof(struct ng_item));
2656 	objcache_put(ng_oc, item);
2657 }
2658 
2659 /*
2660  * Change type of the queue entry.
2661  */
2662 static __inline item_p
2663 ng_realloc_item(item_p item, int type, int flags)
2664 {
2665 
2666 	KASSERT((item != NULL), ("%s: can't reallocate NULL", __func__));
2667 	KASSERT(((type & ~NGQF_TYPE) == 0),
2668 	    ("%s: incorrect item type: %d", __func__, type));
2669 
2670 	item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
2671 
2672 	return (item);
2673 }
2674 
2675 __inline apply_p
2676 ng_alloc_apply(void)
2677 {
2678 	return (objcache_get(ng_apply_oc, M_WAITOK));
2679 }
2680 
2681 __inline void
2682 ng_free_apply(apply_p apply)
2683 {
2684 	objcache_put(ng_apply_oc, apply);
2685 }
2686 
2687 static void
2688 ng_check_apply(item_p item, int error)
2689 {
2690 	if (item->apply == NULL)
2691 		return;
2692 
2693 	KKASSERT(item->apply->apply != NULL);
2694 	(*item->apply->apply)(item->apply->context, error);
2695 	ng_free_apply(item->apply);
2696 	item->apply = NULL;
2697 }
2698 
2699 /************************************************************************
2700 			Module routines
2701 ************************************************************************/
2702 
2703 /*
2704  * Handle the loading/unloading of a netgraph node type module
2705  */
2706 int
2707 ng_mod_event(module_t mod, int event, void *data)
2708 {
2709 	struct ng_type *const type = data;
2710 	int error = 0;
2711 
2712 	switch (event) {
2713 	case MOD_LOAD:
2714 
2715 		/* Register new netgraph node type */
2716 		if ((error = ng_newtype(type)) != 0) {
2717 			break;
2718 		}
2719 
2720 		/* Call type specific code */
2721 		if (type->mod_event != NULL)
2722 			if ((error = (*type->mod_event)(mod, event, data))) {
2723 				TYPELIST_WLOCK();
2724 				type->refs--;	/* undo it */
2725 				LIST_REMOVE(type, types);
2726 				TYPELIST_WUNLOCK();
2727 			}
2728 		break;
2729 
2730 	case MOD_UNLOAD:
2731 		if (type->refs > 1) {		/* make sure no nodes exist! */
2732 			error = EBUSY;
2733 		} else {
2734 			if (type->refs == 0) {
2735 				/* failed load, nothing to undo */
2736 				break;
2737 			}
2738 			if (type->mod_event != NULL) {	/* check with type */
2739 				error = (*type->mod_event)(mod, event, data);
2740 				if (error != 0) {	/* type refuses.. */
2741 					break;
2742 				}
2743 			}
2744 			TYPELIST_WLOCK();
2745 			LIST_REMOVE(type, types);
2746 			TYPELIST_WUNLOCK();
2747 		}
2748 		break;
2749 
2750 	default:
2751 		if (type->mod_event != NULL)
2752 			error = (*type->mod_event)(mod, event, data);
2753 		else
2754 			error = EOPNOTSUPP;		/* XXX ? */
2755 		break;
2756 	}
2757 	return (error);
2758 }
2759 
2760 /*
2761  * Handle loading and unloading for this code.
2762  */
2763 static int
2764 ngb_mod_event(module_t mod, int event, void *data)
2765 {
2766 	int i, error = 0;
2767 
2768 	switch (event) {
2769 	case MOD_LOAD:
2770 		/* Initialize everything. */
2771 		lwkt_token_init(&ng_typelist_token, "ng typelist");
2772 		lwkt_token_init(&ng_idhash_token, "ng idhash");
2773 		lwkt_token_init(&ng_namehash_token, "ng namehash");
2774 		lwkt_token_init(&ng_topo_token, "ng topology");
2775 #ifdef	NETGRAPH_DEBUG
2776 		mtx_init(&ng_nodelist_mtx);
2777 		mtx_init(&ngq_mtx);
2778 #endif
2779 		ng_oc = objcache_create_mbacked(M_NETGRAPH,
2780 			    sizeof(struct ng_item), maxalloc, 0, bzero_ctor,
2781 			    NULL, NULL);
2782 		ng_apply_oc = objcache_create_mbacked(M_NETGRAPH_APPLY,
2783 			    sizeof(struct ng_apply_info), 0, 0, bzero_ctor,
2784 			    NULL, NULL);
2785 
2786 		/* We start with small hashes, but they can grow. */
2787 		ng_ID_hash = hashinit(16, M_NETGRAPH_NODE, &ng_ID_hmask);
2788 		ng_name_hash = hashinit(16, M_NETGRAPH_NODE, &ng_name_hmask);
2789 
2790 		lwkt_initport_panic(&ng_panic_reply_port);
2791 		for (i = 0; i < ncpus; ++i) {
2792 			thread_t td;
2793 
2794 			lwkt_create(ngthread, NULL, &td,
2795 			   NULL, 0, i, "netgraph %d", i);
2796 			ng_msgport[i] = &td->td_msgport;
2797 		}
2798 		break;
2799 	case MOD_UNLOAD:
2800 #if 0
2801 		hashdestroy(V_ng_name_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
2802 		hashdestroy(V_ng_ID_hash, M_NETGRAPH_NODE, V_ng_ID_hmask);
2803 
2804 		/* Destroy the lwkt threads too */
2805 
2806 		objcache_destroy(ng_apply_oc);
2807 		objcache_destroy(ng_oc);
2808 #endif
2809 		/* You can't unload it because an interface may be using it. */
2810 		error = EBUSY;
2811 		break;
2812 	default:
2813 		error = EOPNOTSUPP;
2814 		break;
2815 	}
2816 	return (error);
2817 }
2818 
2819 static moduledata_t netgraph_mod = {
2820 	"netgraph",
2821 	ngb_mod_event,
2822 	(NULL)
2823 };
2824 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_MIDDLE);
2825 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
2826 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
2827 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
2828 
2829 #ifdef	NETGRAPH_DEBUG
2830 void
2831 dumphook (hook_p hook, char *file, int line)
2832 {
2833 	kprintf("hook: name %s, %d refs, Last touched:\n",
2834 		_NG_HOOK_NAME(hook), hook->hk_refs);
2835 	kprintf("	Last active @ %s, line %d\n",
2836 		hook->lastfile, hook->lastline);
2837 	if (line) {
2838 		kprintf(" problem discovered at file %s, line %d\n", file, line);
2839 	}
2840 }
2841 
2842 void
2843 dumpnode(node_p node, char *file, int line)
2844 {
2845 	kprintf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
2846 		_NG_NODE_ID(node), node->nd_type->name,
2847 		node->nd_numhooks, node->nd_flags,
2848 		node->nd_refs, node->nd_name);
2849 	kprintf("	Last active @ %s, line %d\n",
2850 		node->lastfile, node->lastline);
2851 	if (line) {
2852 		kprintf(" problem discovered at file %s, line %d\n", file, line);
2853 	}
2854 }
2855 
2856 void
2857 dumpitem(item_p item, char *file, int line)
2858 {
2859 	kprintf(" ACTIVE item, last used at %s, line %d",
2860 		item->lastfile, item->lastline);
2861 	switch(item->el_flags & NGQF_TYPE) {
2862 	case NGQF_DATA:
2863 		kprintf(" - [data]\n");
2864 		break;
2865 	case NGQF_MESG:
2866 		kprintf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
2867 		break;
2868 	case NGQF_FN:
2869 		kprintf(" - fn@%p (%p, %p, %p, %d (%x))\n",
2870 			_NGI_FN(item),
2871 			_NGI_NODE(item),
2872 			_NGI_HOOK(item),
2873 			item->body.fn.fn_arg1,
2874 			item->body.fn.fn_arg2,
2875 			item->body.fn.fn_arg2);
2876 		break;
2877 	case NGQF_FN2:
2878 		kprintf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
2879 			_NGI_FN2(item),
2880 			_NGI_NODE(item),
2881 			_NGI_HOOK(item),
2882 			item->body.fn.fn_arg1,
2883 			item->body.fn.fn_arg2,
2884 			item->body.fn.fn_arg2);
2885 		break;
2886 	}
2887 	if (line) {
2888 		kprintf(" problem discovered at file %s, line %d\n", file, line);
2889 		if (_NGI_NODE(item)) {
2890 			kprintf("node %p ([%x])\n",
2891 				_NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
2892 		}
2893 	}
2894 }
2895 
2896 static void
2897 ng_dumpitems(void)
2898 {
2899 	item_p item;
2900 	int i = 1;
2901 	TAILQ_FOREACH(item, &ng_itemlist, all) {
2902 		kprintf("[%d] ", i++);
2903 		dumpitem(item, NULL, 0);
2904 	}
2905 }
2906 
2907 static void
2908 ng_dumpnodes(void)
2909 {
2910 	node_p node;
2911 	int i = 1;
2912 	mtx_lock(&ng_nodelist_mtx);
2913 	SLIST_FOREACH(node, &ng_allnodes, nd_all) {
2914 		kprintf("[%d] ", i++);
2915 		dumpnode(node, NULL, 0);
2916 	}
2917 	mtx_unlock(&ng_nodelist_mtx);
2918 }
2919 
2920 static void
2921 ng_dumphooks(void)
2922 {
2923 	hook_p hook;
2924 	int i = 1;
2925 	mtx_lock(&ng_nodelist_mtx);
2926 	SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
2927 		kprintf("[%d] ", i++);
2928 		dumphook(hook, NULL, 0);
2929 	}
2930 	mtx_unlock(&ng_nodelist_mtx);
2931 }
2932 
2933 static int
2934 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
2935 {
2936 	int error;
2937 	int val;
2938 
2939 	val = allocated;
2940 	error = sysctl_handle_int(oidp, &val, 0, req);
2941 	if (error != 0 || req->newptr == NULL)
2942 		return (error);
2943 	if (val == 42) {
2944 		ng_dumpitems();
2945 		ng_dumpnodes();
2946 		ng_dumphooks();
2947 	}
2948 	return (0);
2949 }
2950 
2951 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
2952     0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
2953 #endif	/* NETGRAPH_DEBUG */
2954 
2955 
2956 /***********************************************************************
2957 * Externally useable functions to set up a queue item ready for sending
2958 ***********************************************************************/
2959 
2960 #ifdef	NETGRAPH_DEBUG
2961 #define	ITEM_DEBUG_CHECKS						\
2962 	do {								\
2963 		if (NGI_NODE(item) ) {					\
2964 			kprintf("item already has node");		\
2965 			kdb_enter(KDB_WHY_NETGRAPH, "has node");	\
2966 			NGI_CLR_NODE(item);				\
2967 		}							\
2968 		if (NGI_HOOK(item) ) {					\
2969 			kprintf("item already has hook");		\
2970 			kdb_enter(KDB_WHY_NETGRAPH, "has hook");	\
2971 			NGI_CLR_HOOK(item);				\
2972 		}							\
2973 	} while (0)
2974 #else
2975 #define ITEM_DEBUG_CHECKS
2976 #endif
2977 
2978 /*
2979  * Put mbuf into the item.
2980  * Hook and node references will be removed when the item is dequeued.
2981  * (or equivalent)
2982  * (XXX) Unsafe because no reference held by peer on remote node.
2983  * remote node might go away in this timescale.
2984  * We know the hooks can't go away because that would require getting
2985  * a writer item on both nodes and we must have at least a  reader
2986  * here to be able to do this.
2987  * Note that the hook loaded is the REMOTE hook.
2988  *
2989  * This is possibly in the critical path for new data.
2990  */
2991 item_p
2992 ng_package_data(struct mbuf *m, int flags)
2993 {
2994 	item_p item;
2995 
2996 	if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
2997 		NG_FREE_M(m);
2998 		return (NULL);
2999 	}
3000 	ITEM_DEBUG_CHECKS;
3001 	item->el_flags |= NGQF_READER;
3002 	NGI_M(item) = m;
3003 	return (item);
3004 }
3005 
3006 /*
3007  * Allocate a queue item and put items into it..
3008  * Evaluate the address as this will be needed to queue it and
3009  * to work out what some of the fields should be.
3010  * Hook and node references will be removed when the item is dequeued.
3011  * (or equivalent)
3012  */
3013 item_p
3014 ng_package_msg(struct ng_mesg *msg, int flags)
3015 {
3016 	item_p item;
3017 
3018 	if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
3019 		NG_FREE_MSG(msg);
3020 		return (NULL);
3021 	}
3022 	ITEM_DEBUG_CHECKS;
3023 	/* Messages items count as writers unless explicitly exempted. */
3024 	if (msg->header.cmd & NGM_READONLY)
3025 		item->el_flags |= NGQF_READER;
3026 	else
3027 		item->el_flags |= NGQF_WRITER;
3028 	/*
3029 	 * Set the current lasthook into the queue item
3030 	 */
3031 	NGI_MSG(item) = msg;
3032 	NGI_RETADDR(item) = 0;
3033 	return (item);
3034 }
3035 
3036 
3037 
3038 #define SET_RETADDR(item, here, retaddr)				\
3039 	do {	/* Data or fn items don't have retaddrs */		\
3040 		if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {	\
3041 			if (retaddr) {					\
3042 				NGI_RETADDR(item) = retaddr;		\
3043 			} else {					\
3044 				/*					\
3045 				 * The old return address should be ok.	\
3046 				 * If there isn't one, use the address	\
3047 				 * here.				\
3048 				 */					\
3049 				if (NGI_RETADDR(item) == 0) {		\
3050 					NGI_RETADDR(item)		\
3051 						= ng_node2ID(here);	\
3052 				}					\
3053 			}						\
3054 		}							\
3055 	} while (0)
3056 
3057 int
3058 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
3059 {
3060 	hook_p peer;
3061 	node_p peernode;
3062 	ITEM_DEBUG_CHECKS;
3063 	/*
3064 	 * Quick sanity check..
3065 	 * Since a hook holds a reference on it's node, once we know
3066 	 * that the peer is still connected (even if invalid,) we know
3067 	 * that the peer node is present, though maybe invalid.
3068 	 */
3069 	if ((hook == NULL) ||
3070 	    NG_HOOK_NOT_VALID(hook) ||
3071 	    NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
3072 	    NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
3073 		NG_FREE_ITEM(item);
3074 		TRAP_ERROR();
3075 		return (ENETDOWN);
3076 	}
3077 
3078 	/*
3079 	 * Transfer our interest to the other (peer) end.
3080 	 */
3081 	NG_HOOK_REF(peer);
3082 	NG_NODE_REF(peernode);
3083 	NGI_SET_HOOK(item, peer);
3084 	NGI_SET_NODE(item, peernode);
3085 	SET_RETADDR(item, here, retaddr);
3086 	return (0);
3087 }
3088 
3089 int
3090 ng_address_path(node_p here, item_p item, char *address, ng_ID_t retaddr)
3091 {
3092 	node_p	dest = NULL;
3093 	hook_p	hook = NULL;
3094 	int	error;
3095 
3096 	ITEM_DEBUG_CHECKS;
3097 	/*
3098 	 * Note that ng_path2noderef increments the reference count
3099 	 * on the node for us if it finds one. So we don't have to.
3100 	 */
3101 	error = ng_path2noderef(here, address, &dest, &hook);
3102 	if (error) {
3103 		NG_FREE_ITEM(item);
3104 		return (error);
3105 	}
3106 	NGI_SET_NODE(item, dest);
3107 	if ( hook) {
3108 		NG_HOOK_REF(hook);	/* don't let it go while on the queue */
3109 		NGI_SET_HOOK(item, hook);
3110 	}
3111 	SET_RETADDR(item, here, retaddr);
3112 	return (0);
3113 }
3114 
3115 int
3116 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
3117 {
3118 	node_p dest;
3119 
3120 	ITEM_DEBUG_CHECKS;
3121 	/*
3122 	 * Find the target node.
3123 	 */
3124 	dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
3125 	if (dest == NULL) {
3126 		NG_FREE_ITEM(item);
3127 		TRAP_ERROR();
3128 		return(EINVAL);
3129 	}
3130 	/* Fill out the contents */
3131 	NGI_SET_NODE(item, dest);
3132 	NGI_CLR_HOOK(item);
3133 	SET_RETADDR(item, here, retaddr);
3134 	return (0);
3135 }
3136 
3137 /*
3138  * special case to send a message to self (e.g. destroy node)
3139  * Possibly indicate an arrival hook too.
3140  * Useful for removing that hook :-)
3141  */
3142 item_p
3143 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
3144 {
3145 	item_p item;
3146 
3147 	/*
3148 	 * Find the target node.
3149 	 * If there is a HOOK argument, then use that in preference
3150 	 * to the address.
3151 	 */
3152 	if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
3153 		NG_FREE_MSG(msg);
3154 		return (NULL);
3155 	}
3156 
3157 	/* Fill out the contents */
3158 	item->el_flags |= NGQF_WRITER;
3159 	NG_NODE_REF(here);
3160 	NGI_SET_NODE(item, here);
3161 	if (hook) {
3162 		NG_HOOK_REF(hook);
3163 		NGI_SET_HOOK(item, hook);
3164 	}
3165 	NGI_MSG(item) = msg;
3166 	NGI_RETADDR(item) = ng_node2ID(here);
3167 	return (item);
3168 }
3169 
3170 /*
3171  * Send ng_item_fn function call to the specified node.
3172  */
3173 
3174 int
3175 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
3176 {
3177 	return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
3178 }
3179 
3180 int
3181 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
3182 	int flags)
3183 {
3184 	item_p item;
3185 
3186 	if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
3187 		return (ENOMEM);
3188 	}
3189 	item->el_flags |= NGQF_WRITER;
3190 	NG_NODE_REF(node); /* and one for the item */
3191 	NGI_SET_NODE(item, node);
3192 	if (hook) {
3193 		NG_HOOK_REF(hook);
3194 		NGI_SET_HOOK(item, hook);
3195 	}
3196 	NGI_FN(item) = fn;
3197 	NGI_ARG1(item) = arg1;
3198 	NGI_ARG2(item) = arg2;
3199 	return(ng_snd_item(item, flags));
3200 }
3201 
3202 /*
3203  * Send ng_item_fn2 function call to the specified node.
3204  *
3205  * If NG_REUSE_ITEM flag is set, no new item will be allocated,
3206  * pitem will be used instead.
3207  */
3208 int
3209 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
3210 	int arg2, int flags)
3211 {
3212 	item_p item;
3213 
3214 	KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
3215 	    ("%s: NG_REUSE_ITEM but no pitem", __func__));
3216 
3217 	/*
3218 	 * Allocate a new item if no supplied or
3219 	 * if we can't use supplied one.
3220 	 */
3221 	if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
3222 		if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
3223 			return (ENOMEM);
3224 	} else {
3225 		if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
3226 			return (ENOMEM);
3227 	}
3228 
3229 	item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
3230 	NG_NODE_REF(node); /* and one for the item */
3231 	NGI_SET_NODE(item, node);
3232 	if (hook) {
3233 		NG_HOOK_REF(hook);
3234 		NGI_SET_HOOK(item, hook);
3235 	}
3236 	NGI_FN2(item) = fn;
3237 	NGI_ARG1(item) = arg1;
3238 	NGI_ARG2(item) = arg2;
3239 	return(ng_snd_item(item, flags));
3240 }
3241 
3242 /*
3243  * Official timeout routines for Netgraph nodes.
3244  */
3245 static void
3246 ng_callout_trampoline(void *arg)
3247 {
3248 	item_p item = arg;
3249 
3250 	ng_snd_item(item, 0);
3251 }
3252 
3253 
3254 int
3255 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
3256     ng_item_fn *fn, void * arg1, int arg2)
3257 {
3258 	item_p item, oitem;
3259 
3260 	if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
3261 		return (ENOMEM);
3262 
3263 	item->el_flags |= NGQF_WRITER;
3264 	NG_NODE_REF(node);		/* and one for the item */
3265 	NGI_SET_NODE(item, node);
3266 	if (hook) {
3267 		NG_HOOK_REF(hook);
3268 		NGI_SET_HOOK(item, hook);
3269 	}
3270 	NGI_FN(item) = fn;
3271 	NGI_ARG1(item) = arg1;
3272 	NGI_ARG2(item) = arg2;
3273 	oitem = c->c_arg;
3274 	callout_reset(c, ticks, &ng_callout_trampoline, item);
3275 	return (0);
3276 }
3277 
3278 /* A special modified version of untimeout() */
3279 int
3280 ng_uncallout(struct callout *c, node_p node)
3281 {
3282 	item_p item;
3283 	int rval;
3284 
3285 	KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
3286 	KASSERT(node != NULL, ("ng_uncallout: NULL node"));
3287 
3288 	rval = callout_stop(c);
3289 	item = c->c_arg;
3290 	/* Do an extra check */
3291 	if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
3292 	    (NGI_NODE(item) == node)) {
3293 		/*
3294 		 * We successfully removed it from the queue before it ran
3295 		 * So now we need to unreference everything that was
3296 		 * given extra references. (NG_FREE_ITEM does this).
3297 		 */
3298 		NG_FREE_ITEM(item);
3299 	}
3300 	c->c_arg = NULL;
3301 
3302 	return (rval);
3303 }
3304 
3305 /*
3306  * Set the address, if none given, give the node here.
3307  */
3308 void
3309 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
3310 {
3311 	if (retaddr) {
3312 		NGI_RETADDR(item) = retaddr;
3313 	} else {
3314 		/*
3315 		 * The old return address should be ok.
3316 		 * If there isn't one, use the address here.
3317 		 */
3318 		NGI_RETADDR(item) = ng_node2ID(here);
3319 	}
3320 }
3321 
3322 static boolean_t
3323 bzero_ctor(void *obj, void *private, int ocflags)
3324 {
3325 	struct ng_item *i = obj;
3326 
3327 	bzero(i, sizeof(struct ng_item));
3328 	return(TRUE);
3329 }
3330 
3331 #define TESTING
3332 #ifdef TESTING
3333 /* just test all the macros */
3334 void
3335 ng_macro_test(item_p item);
3336 void
3337 ng_macro_test(item_p item)
3338 {
3339 	node_p node = NULL;
3340 	hook_p hook = NULL;
3341 	struct mbuf *m;
3342 	struct ng_mesg *msg;
3343 	ng_ID_t retaddr;
3344 	int	error;
3345 
3346 	NGI_GET_M(item, m);
3347 	NGI_GET_MSG(item, msg);
3348 	retaddr = NGI_RETADDR(item);
3349 	NG_SEND_DATA(error, hook, m, NULL);
3350 	NG_SEND_DATA_ONLY(error, hook, m);
3351 	NG_FWD_NEW_DATA(error, item, hook, m);
3352 	NG_FWD_ITEM_HOOK(error, item, hook);
3353 	NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
3354 	NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
3355 	NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
3356 	NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
3357 }
3358 #endif /* TESTING */
3359 
3360