xref: /freebsd/sys/netgraph/ng_base.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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  * $FreeBSD$
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/hash.h>
49 #include <sys/kdb.h>
50 #include <sys/kernel.h>
51 #include <sys/kthread.h>
52 #include <sys/ktr.h>
53 #include <sys/limits.h>
54 #include <sys/lock.h>
55 #include <sys/malloc.h>
56 #include <sys/mbuf.h>
57 #include <sys/proc.h>
58 #include <sys/epoch.h>
59 #include <sys/queue.h>
60 #include <sys/refcount.h>
61 #include <sys/rwlock.h>
62 #include <sys/smp.h>
63 #include <sys/sysctl.h>
64 #include <sys/syslog.h>
65 #include <sys/unistd.h>
66 #include <machine/cpu.h>
67 #include <vm/uma.h>
68 
69 #include <net/netisr.h>
70 #include <net/vnet.h>
71 
72 #include <netgraph/ng_message.h>
73 #include <netgraph/netgraph.h>
74 #include <netgraph/ng_parse.h>
75 
76 MODULE_VERSION(netgraph, NG_ABI_VERSION);
77 
78 /* Mutex to protect topology events. */
79 static struct rwlock	ng_topo_lock;
80 #define	TOPOLOGY_RLOCK()	rw_rlock(&ng_topo_lock)
81 #define	TOPOLOGY_RUNLOCK()	rw_runlock(&ng_topo_lock)
82 #define	TOPOLOGY_WLOCK()	rw_wlock(&ng_topo_lock)
83 #define	TOPOLOGY_WUNLOCK()	rw_wunlock(&ng_topo_lock)
84 #define	TOPOLOGY_NOTOWNED()	rw_assert(&ng_topo_lock, RA_UNLOCKED)
85 
86 #ifdef	NETGRAPH_DEBUG
87 static struct mtx	ng_nodelist_mtx; /* protects global node/hook lists */
88 static struct mtx	ngq_mtx;	/* protects the queue item list */
89 
90 static SLIST_HEAD(, ng_node) ng_allnodes;
91 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
92 static SLIST_HEAD(, ng_hook) ng_allhooks;
93 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
94 
95 static void ng_dumpitems(void);
96 static void ng_dumpnodes(void);
97 static void ng_dumphooks(void);
98 
99 #endif	/* NETGRAPH_DEBUG */
100 /*
101  * DEAD versions of the structures.
102  * In order to avoid races, it is sometimes necessary to point
103  * at SOMETHING even though theoretically, the current entity is
104  * INVALID. Use these to avoid these races.
105  */
106 struct ng_type ng_deadtype = {
107 	NG_ABI_VERSION,
108 	"dead",
109 	NULL,	/* modevent */
110 	NULL,	/* constructor */
111 	NULL,	/* rcvmsg */
112 	NULL,	/* shutdown */
113 	NULL,	/* newhook */
114 	NULL,	/* findhook */
115 	NULL,	/* connect */
116 	NULL,	/* rcvdata */
117 	NULL,	/* disconnect */
118 	NULL, 	/* cmdlist */
119 };
120 
121 struct ng_node ng_deadnode = {
122 	"dead",
123 	&ng_deadtype,
124 	NGF_INVALID,
125 	0,	/* numhooks */
126 	NULL,	/* private */
127 	0,	/* ID */
128 	LIST_HEAD_INITIALIZER(ng_deadnode.nd_hooks),
129 	{},	/* all_nodes list entry */
130 	{},	/* id hashtable list entry */
131 	{	0,
132 		0,
133 		{}, /* should never use! (should hang) */
134 		{}, /* workqueue entry */
135 		STAILQ_HEAD_INITIALIZER(ng_deadnode.nd_input_queue.queue),
136 	},
137 	1,	/* refs */
138 	NULL,	/* vnet */
139 #ifdef	NETGRAPH_DEBUG
140 	ND_MAGIC,
141 	__FILE__,
142 	__LINE__,
143 	{NULL}
144 #endif	/* NETGRAPH_DEBUG */
145 };
146 
147 struct ng_hook ng_deadhook = {
148 	"dead",
149 	NULL,		/* private */
150 	HK_INVALID | HK_DEAD,
151 	0,		/* undefined data link type */
152 	&ng_deadhook,	/* Peer is self */
153 	&ng_deadnode,	/* attached to deadnode */
154 	{},		/* hooks list */
155 	NULL,		/* override rcvmsg() */
156 	NULL,		/* override rcvdata() */
157 	1,		/* refs always >= 1 */
158 #ifdef	NETGRAPH_DEBUG
159 	HK_MAGIC,
160 	__FILE__,
161 	__LINE__,
162 	{NULL}
163 #endif	/* NETGRAPH_DEBUG */
164 };
165 
166 /*
167  * END DEAD STRUCTURES
168  */
169 /* List nodes with unallocated work */
170 static STAILQ_HEAD(, ng_node) ng_worklist = STAILQ_HEAD_INITIALIZER(ng_worklist);
171 static struct mtx	ng_worklist_mtx;   /* MUST LOCK NODE FIRST */
172 
173 /* List of installed types */
174 static LIST_HEAD(, ng_type) ng_typelist;
175 static struct rwlock	ng_typelist_lock;
176 #define	TYPELIST_RLOCK()	rw_rlock(&ng_typelist_lock)
177 #define	TYPELIST_RUNLOCK()	rw_runlock(&ng_typelist_lock)
178 #define	TYPELIST_WLOCK()	rw_wlock(&ng_typelist_lock)
179 #define	TYPELIST_WUNLOCK()	rw_wunlock(&ng_typelist_lock)
180 
181 /* Hash related definitions. */
182 LIST_HEAD(nodehash, ng_node);
183 VNET_DEFINE_STATIC(struct nodehash *, ng_ID_hash);
184 VNET_DEFINE_STATIC(u_long, ng_ID_hmask);
185 VNET_DEFINE_STATIC(u_long, ng_nodes);
186 VNET_DEFINE_STATIC(struct nodehash *, ng_name_hash);
187 VNET_DEFINE_STATIC(u_long, ng_name_hmask);
188 VNET_DEFINE_STATIC(u_long, ng_named_nodes);
189 #define	V_ng_ID_hash		VNET(ng_ID_hash)
190 #define	V_ng_ID_hmask		VNET(ng_ID_hmask)
191 #define	V_ng_nodes		VNET(ng_nodes)
192 #define	V_ng_name_hash		VNET(ng_name_hash)
193 #define	V_ng_name_hmask		VNET(ng_name_hmask)
194 #define	V_ng_named_nodes	VNET(ng_named_nodes)
195 
196 static struct rwlock	ng_idhash_lock;
197 #define	IDHASH_RLOCK()		rw_rlock(&ng_idhash_lock)
198 #define	IDHASH_RUNLOCK()	rw_runlock(&ng_idhash_lock)
199 #define	IDHASH_WLOCK()		rw_wlock(&ng_idhash_lock)
200 #define	IDHASH_WUNLOCK()	rw_wunlock(&ng_idhash_lock)
201 
202 /* Method to find a node.. used twice so do it here */
203 #define NG_IDHASH_FN(ID) ((ID) % (V_ng_ID_hmask + 1))
204 #define NG_IDHASH_FIND(ID, node)					\
205 	do { 								\
206 		rw_assert(&ng_idhash_lock, RA_LOCKED);			\
207 		LIST_FOREACH(node, &V_ng_ID_hash[NG_IDHASH_FN(ID)],	\
208 						nd_idnodes) {		\
209 			if (NG_NODE_IS_VALID(node)			\
210 			&& (NG_NODE_ID(node) == ID)) {			\
211 				break;					\
212 			}						\
213 		}							\
214 	} while (0)
215 
216 static struct rwlock	ng_namehash_lock;
217 #define	NAMEHASH_RLOCK()	rw_rlock(&ng_namehash_lock)
218 #define	NAMEHASH_RUNLOCK()	rw_runlock(&ng_namehash_lock)
219 #define	NAMEHASH_WLOCK()	rw_wlock(&ng_namehash_lock)
220 #define	NAMEHASH_WUNLOCK()	rw_wunlock(&ng_namehash_lock)
221 
222 /* Internal functions */
223 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
224 static int	ng_generic_msg(node_p here, item_p item, hook_p lasthook);
225 static ng_ID_t	ng_decodeidname(const char *name);
226 static int	ngb_mod_event(module_t mod, int event, void *data);
227 static void	ng_worklist_add(node_p node);
228 static void	ngthread(void *);
229 static int	ng_apply_item(node_p node, item_p item, int rw);
230 static void	ng_flush_input_queue(node_p node);
231 static node_p	ng_ID2noderef(ng_ID_t ID);
232 static int	ng_con_nodes(item_p item, node_p node, const char *name,
233 		    node_p node2, const char *name2);
234 static int	ng_con_part2(node_p node, item_p item, hook_p hook);
235 static int	ng_con_part3(node_p node, item_p item, hook_p hook);
236 static int	ng_mkpeer(node_p node, const char *name, const char *name2,
237 		    char *type);
238 static void	ng_name_rehash(void);
239 static void	ng_ID_rehash(void);
240 
241 /* Imported, these used to be externally visible, some may go back. */
242 void	ng_destroy_hook(hook_p hook);
243 int	ng_path2noderef(node_p here, const char *path,
244 	node_p *dest, hook_p *lasthook);
245 int	ng_make_node(const char *type, node_p *nodepp);
246 int	ng_path_parse(char *addr, char **node, char **path, char **hook);
247 void	ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
248 void	ng_unname(node_p node);
249 
250 /* Our own netgraph malloc type */
251 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
252 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
253 static MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook",
254     "netgraph hook structures");
255 static MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node",
256     "netgraph node structures");
257 static MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item",
258     "netgraph item structures");
259 
260 /* Should not be visible outside this file */
261 
262 #define _NG_ALLOC_HOOK(hook) \
263 	hook = malloc(sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
264 #define _NG_ALLOC_NODE(node) \
265 	node = malloc(sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
266 
267 #define	NG_QUEUE_LOCK_INIT(n)			\
268 	mtx_init(&(n)->q_mtx, "ng_node", NULL, MTX_DEF)
269 #define	NG_QUEUE_LOCK(n)			\
270 	mtx_lock(&(n)->q_mtx)
271 #define	NG_QUEUE_UNLOCK(n)			\
272 	mtx_unlock(&(n)->q_mtx)
273 #define	NG_WORKLIST_LOCK_INIT()			\
274 	mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_DEF)
275 #define	NG_WORKLIST_LOCK()			\
276 	mtx_lock(&ng_worklist_mtx)
277 #define	NG_WORKLIST_UNLOCK()			\
278 	mtx_unlock(&ng_worklist_mtx)
279 #define	NG_WORKLIST_SLEEP()			\
280 	mtx_sleep(&ng_worklist, &ng_worklist_mtx, PI_NET, "sleep", 0)
281 #define	NG_WORKLIST_WAKEUP()			\
282 	wakeup_one(&ng_worklist)
283 
284 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
285 /*
286  * In debug mode:
287  * In an attempt to help track reference count screwups
288  * we do not free objects back to the malloc system, but keep them
289  * in a local cache where we can examine them and keep information safely
290  * after they have been freed.
291  * We use this scheme for nodes and hooks, and to some extent for items.
292  */
293 static __inline hook_p
294 ng_alloc_hook(void)
295 {
296 	hook_p hook;
297 	SLIST_ENTRY(ng_hook) temp;
298 	mtx_lock(&ng_nodelist_mtx);
299 	hook = LIST_FIRST(&ng_freehooks);
300 	if (hook) {
301 		LIST_REMOVE(hook, hk_hooks);
302 		bcopy(&hook->hk_all, &temp, sizeof(temp));
303 		bzero(hook, sizeof(struct ng_hook));
304 		bcopy(&temp, &hook->hk_all, sizeof(temp));
305 		mtx_unlock(&ng_nodelist_mtx);
306 		hook->hk_magic = HK_MAGIC;
307 	} else {
308 		mtx_unlock(&ng_nodelist_mtx);
309 		_NG_ALLOC_HOOK(hook);
310 		if (hook) {
311 			hook->hk_magic = HK_MAGIC;
312 			mtx_lock(&ng_nodelist_mtx);
313 			SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
314 			mtx_unlock(&ng_nodelist_mtx);
315 		}
316 	}
317 	return (hook);
318 }
319 
320 static __inline node_p
321 ng_alloc_node(void)
322 {
323 	node_p node;
324 	SLIST_ENTRY(ng_node) temp;
325 	mtx_lock(&ng_nodelist_mtx);
326 	node = LIST_FIRST(&ng_freenodes);
327 	if (node) {
328 		LIST_REMOVE(node, nd_nodes);
329 		bcopy(&node->nd_all, &temp, sizeof(temp));
330 		bzero(node, sizeof(struct ng_node));
331 		bcopy(&temp, &node->nd_all, sizeof(temp));
332 		mtx_unlock(&ng_nodelist_mtx);
333 		node->nd_magic = ND_MAGIC;
334 	} else {
335 		mtx_unlock(&ng_nodelist_mtx);
336 		_NG_ALLOC_NODE(node);
337 		if (node) {
338 			node->nd_magic = ND_MAGIC;
339 			mtx_lock(&ng_nodelist_mtx);
340 			SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
341 			mtx_unlock(&ng_nodelist_mtx);
342 		}
343 	}
344 	return (node);
345 }
346 
347 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
348 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
349 
350 #define NG_FREE_HOOK(hook)						\
351 	do {								\
352 		mtx_lock(&ng_nodelist_mtx);				\
353 		LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks);	\
354 		hook->hk_magic = 0;					\
355 		mtx_unlock(&ng_nodelist_mtx);				\
356 	} while (0)
357 
358 #define NG_FREE_NODE(node)						\
359 	do {								\
360 		mtx_lock(&ng_nodelist_mtx);				\
361 		LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes);	\
362 		node->nd_magic = 0;					\
363 		mtx_unlock(&ng_nodelist_mtx);				\
364 	} while (0)
365 
366 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
367 
368 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
369 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
370 
371 #define NG_FREE_HOOK(hook) do { free((hook), M_NETGRAPH_HOOK); } while (0)
372 #define NG_FREE_NODE(node) do { free((node), M_NETGRAPH_NODE); } while (0)
373 
374 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
375 
376 /* Set this to kdb_enter("X") to catch all errors as they occur */
377 #ifndef TRAP_ERROR
378 #define TRAP_ERROR()
379 #endif
380 
381 VNET_DEFINE_STATIC(ng_ID_t, nextID) = 1;
382 #define	V_nextID			VNET(nextID)
383 
384 #ifdef INVARIANTS
385 #define CHECK_DATA_MBUF(m)	do {					\
386 		struct mbuf *n;						\
387 		int total;						\
388 									\
389 		M_ASSERTPKTHDR(m);					\
390 		for (total = 0, n = (m); n != NULL; n = n->m_next) {	\
391 			total += n->m_len;				\
392 			if (n->m_nextpkt != NULL)			\
393 				panic("%s: m_nextpkt", __func__);	\
394 		}							\
395 									\
396 		if ((m)->m_pkthdr.len != total) {			\
397 			panic("%s: %d != %d",				\
398 			    __func__, (m)->m_pkthdr.len, total);	\
399 		}							\
400 	} while (0)
401 #else
402 #define CHECK_DATA_MBUF(m)
403 #endif
404 
405 #define ERROUT(x)	do { error = (x); goto done; } while (0)
406 
407 /************************************************************************
408 	Parse type definitions for generic messages
409 ************************************************************************/
410 
411 /* Handy structure parse type defining macro */
412 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
413 static const struct ng_parse_struct_field				\
414 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
415 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
416 	&ng_parse_struct_type,						\
417 	&ng_ ## lo ## _type_fields					\
418 }
419 
420 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
421 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
422 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
423 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
424 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
425 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
426 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
427 
428 /* Get length of an array when the length is stored as a 32 bit
429    value immediately preceding the array -- as with struct namelist
430    and struct typelist. */
431 static int
432 ng_generic_list_getLength(const struct ng_parse_type *type,
433 	const u_char *start, const u_char *buf)
434 {
435 	return *((const u_int32_t *)(buf - 4));
436 }
437 
438 /* Get length of the array of struct linkinfo inside a struct hooklist */
439 static int
440 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
441 	const u_char *start, const u_char *buf)
442 {
443 	const struct hooklist *hl = (const struct hooklist *)start;
444 
445 	return hl->nodeinfo.hooks;
446 }
447 
448 /* Array type for a variable length array of struct namelist */
449 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
450 	&ng_generic_nodeinfo_type,
451 	&ng_generic_list_getLength
452 };
453 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
454 	&ng_parse_array_type,
455 	&ng_nodeinfoarray_type_info
456 };
457 
458 /* Array type for a variable length array of struct typelist */
459 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
460 	&ng_generic_typeinfo_type,
461 	&ng_generic_list_getLength
462 };
463 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
464 	&ng_parse_array_type,
465 	&ng_typeinfoarray_type_info
466 };
467 
468 /* Array type for array of struct linkinfo in struct hooklist */
469 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
470 	&ng_generic_linkinfo_type,
471 	&ng_generic_linkinfo_getLength
472 };
473 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
474 	&ng_parse_array_type,
475 	&ng_generic_linkinfo_array_type_info
476 };
477 
478 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_typeinfoarray_type));
479 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
480 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
481 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
482 	(&ng_generic_nodeinfoarray_type));
483 
484 /* List of commands and how to convert arguments to/from ASCII */
485 static const struct ng_cmdlist ng_generic_cmds[] = {
486 	{
487 	  NGM_GENERIC_COOKIE,
488 	  NGM_SHUTDOWN,
489 	  "shutdown",
490 	  NULL,
491 	  NULL
492 	},
493 	{
494 	  NGM_GENERIC_COOKIE,
495 	  NGM_MKPEER,
496 	  "mkpeer",
497 	  &ng_generic_mkpeer_type,
498 	  NULL
499 	},
500 	{
501 	  NGM_GENERIC_COOKIE,
502 	  NGM_CONNECT,
503 	  "connect",
504 	  &ng_generic_connect_type,
505 	  NULL
506 	},
507 	{
508 	  NGM_GENERIC_COOKIE,
509 	  NGM_NAME,
510 	  "name",
511 	  &ng_generic_name_type,
512 	  NULL
513 	},
514 	{
515 	  NGM_GENERIC_COOKIE,
516 	  NGM_RMHOOK,
517 	  "rmhook",
518 	  &ng_generic_rmhook_type,
519 	  NULL
520 	},
521 	{
522 	  NGM_GENERIC_COOKIE,
523 	  NGM_NODEINFO,
524 	  "nodeinfo",
525 	  NULL,
526 	  &ng_generic_nodeinfo_type
527 	},
528 	{
529 	  NGM_GENERIC_COOKIE,
530 	  NGM_LISTHOOKS,
531 	  "listhooks",
532 	  NULL,
533 	  &ng_generic_hooklist_type
534 	},
535 	{
536 	  NGM_GENERIC_COOKIE,
537 	  NGM_LISTNAMES,
538 	  "listnames",
539 	  NULL,
540 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
541 	},
542 	{
543 	  NGM_GENERIC_COOKIE,
544 	  NGM_LISTNODES,
545 	  "listnodes",
546 	  NULL,
547 	  &ng_generic_listnodes_type
548 	},
549 	{
550 	  NGM_GENERIC_COOKIE,
551 	  NGM_LISTTYPES,
552 	  "listtypes",
553 	  NULL,
554 	  &ng_generic_typelist_type
555 	},
556 	{
557 	  NGM_GENERIC_COOKIE,
558 	  NGM_TEXT_CONFIG,
559 	  "textconfig",
560 	  NULL,
561 	  &ng_parse_string_type
562 	},
563 	{
564 	  NGM_GENERIC_COOKIE,
565 	  NGM_TEXT_STATUS,
566 	  "textstatus",
567 	  NULL,
568 	  &ng_parse_string_type
569 	},
570 	{
571 	  NGM_GENERIC_COOKIE,
572 	  NGM_ASCII2BINARY,
573 	  "ascii2binary",
574 	  &ng_parse_ng_mesg_type,
575 	  &ng_parse_ng_mesg_type
576 	},
577 	{
578 	  NGM_GENERIC_COOKIE,
579 	  NGM_BINARY2ASCII,
580 	  "binary2ascii",
581 	  &ng_parse_ng_mesg_type,
582 	  &ng_parse_ng_mesg_type
583 	},
584 	{ 0 }
585 };
586 
587 /************************************************************************
588 			Node routines
589 ************************************************************************/
590 
591 /*
592  * Instantiate a node of the requested type
593  */
594 int
595 ng_make_node(const char *typename, node_p *nodepp)
596 {
597 	struct ng_type *type;
598 	int	error;
599 
600 	/* Check that the type makes sense */
601 	if (typename == NULL) {
602 		TRAP_ERROR();
603 		return (EINVAL);
604 	}
605 
606 	/* Locate the node type. If we fail we return. Do not try to load
607 	 * module.
608 	 */
609 	if ((type = ng_findtype(typename)) == NULL)
610 		return (ENXIO);
611 
612 	/*
613 	 * If we have a constructor, then make the node and
614 	 * call the constructor to do type specific initialisation.
615 	 */
616 	if (type->constructor != NULL) {
617 		if ((error = ng_make_node_common(type, nodepp)) == 0) {
618 			if ((error = ((*type->constructor)(*nodepp))) != 0) {
619 				NG_NODE_UNREF(*nodepp);
620 			}
621 		}
622 	} else {
623 		/*
624 		 * Node has no constructor. We cannot ask for one
625 		 * to be made. It must be brought into existence by
626 		 * some external agency. The external agency should
627 		 * call ng_make_node_common() directly to get the
628 		 * netgraph part initialised.
629 		 */
630 		TRAP_ERROR();
631 		error = EINVAL;
632 	}
633 	return (error);
634 }
635 
636 /*
637  * Generic node creation. Called by node initialisation for externally
638  * instantiated nodes (e.g. hardware, sockets, etc ).
639  * The returned node has a reference count of 1.
640  */
641 int
642 ng_make_node_common(struct ng_type *type, node_p *nodepp)
643 {
644 	node_p node;
645 
646 	/* Require the node type to have been already installed */
647 	if (ng_findtype(type->name) == NULL) {
648 		TRAP_ERROR();
649 		return (EINVAL);
650 	}
651 
652 	/* Make a node and try attach it to the type */
653 	NG_ALLOC_NODE(node);
654 	if (node == NULL) {
655 		TRAP_ERROR();
656 		return (ENOMEM);
657 	}
658 	node->nd_type = type;
659 #ifdef VIMAGE
660 	node->nd_vnet = curvnet;
661 #endif
662 	NG_NODE_REF(node);				/* note reference */
663 	type->refs++;
664 
665 	NG_QUEUE_LOCK_INIT(&node->nd_input_queue);
666 	STAILQ_INIT(&node->nd_input_queue.queue);
667 	node->nd_input_queue.q_flags = 0;
668 
669 	/* Initialize hook list for new node */
670 	LIST_INIT(&node->nd_hooks);
671 
672 	/* Get an ID and put us in the hash chain. */
673 	IDHASH_WLOCK();
674 	for (;;) { /* wrap protection, even if silly */
675 		node_p node2 = NULL;
676 		node->nd_ID = V_nextID++; /* 137/sec for 1 year before wrap */
677 
678 		/* Is there a problem with the new number? */
679 		NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
680 		if ((node->nd_ID != 0) && (node2 == NULL)) {
681 			break;
682 		}
683 	}
684 	V_ng_nodes++;
685 	if (V_ng_nodes * 2 > V_ng_ID_hmask)
686 		ng_ID_rehash();
687 	LIST_INSERT_HEAD(&V_ng_ID_hash[NG_IDHASH_FN(node->nd_ID)], node,
688 	    nd_idnodes);
689 	IDHASH_WUNLOCK();
690 
691 	/* Done */
692 	*nodepp = node;
693 	return (0);
694 }
695 
696 /*
697  * Forceably start the shutdown process on a node. Either call
698  * its shutdown method, or do the default shutdown if there is
699  * no type-specific method.
700  *
701  * We can only be called from a shutdown message, so we know we have
702  * a writer lock, and therefore exclusive access. It also means
703  * that we should not be on the work queue, but we check anyhow.
704  *
705  * Persistent node types must have a type-specific method which
706  * allocates a new node in which case, this one is irretrievably going away,
707  * or cleans up anything it needs, and just makes the node valid again,
708  * in which case we allow the node to survive.
709  *
710  * XXX We need to think of how to tell a persistent node that we
711  * REALLY need to go away because the hardware has gone or we
712  * are rebooting.... etc.
713  */
714 void
715 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
716 {
717 	hook_p hook;
718 
719 	/* Check if it's already shutting down */
720 	if ((node->nd_flags & NGF_CLOSING) != 0)
721 		return;
722 
723 	if (node == &ng_deadnode) {
724 		printf ("shutdown called on deadnode\n");
725 		return;
726 	}
727 
728 	/* Add an extra reference so it doesn't go away during this */
729 	NG_NODE_REF(node);
730 
731 	/*
732 	 * Mark it invalid so any newcomers know not to try use it
733 	 * Also add our own mark so we can't recurse
734 	 * note that NGF_INVALID does not do this as it's also set during
735 	 * creation
736 	 */
737 	node->nd_flags |= NGF_INVALID|NGF_CLOSING;
738 
739 	/* If node has its pre-shutdown method, then call it first*/
740 	if (node->nd_type && node->nd_type->close)
741 		(*node->nd_type->close)(node);
742 
743 	/* Notify all remaining connected nodes to disconnect */
744 	while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
745 		ng_destroy_hook(hook);
746 
747 	/*
748 	 * Drain the input queue forceably.
749 	 * it has no hooks so what's it going to do, bleed on someone?
750 	 * Theoretically we came here from a queue entry that was added
751 	 * Just before the queue was closed, so it should be empty anyway.
752 	 * Also removes us from worklist if needed.
753 	 */
754 	ng_flush_input_queue(node);
755 
756 	/* Ask the type if it has anything to do in this case */
757 	if (node->nd_type && node->nd_type->shutdown) {
758 		(*node->nd_type->shutdown)(node);
759 		if (NG_NODE_IS_VALID(node)) {
760 			/*
761 			 * Well, blow me down if the node code hasn't declared
762 			 * that it doesn't want to die.
763 			 * Presumably it is a persistent node.
764 			 * If we REALLY want it to go away,
765 			 *  e.g. hardware going away,
766 			 * Our caller should set NGF_REALLY_DIE in nd_flags.
767 			 */
768 			node->nd_flags &= ~(NGF_INVALID|NGF_CLOSING);
769 			NG_NODE_UNREF(node); /* Assume they still have theirs */
770 			return;
771 		}
772 	} else {				/* do the default thing */
773 		NG_NODE_UNREF(node);
774 	}
775 
776 	ng_unname(node); /* basically a NOP these days */
777 
778 	/*
779 	 * Remove extra reference, possibly the last
780 	 * Possible other holders of references may include
781 	 * timeout callouts, but theoretically the node's supposed to
782 	 * have cancelled them. Possibly hardware dependencies may
783 	 * force a driver to 'linger' with a reference.
784 	 */
785 	NG_NODE_UNREF(node);
786 }
787 
788 /*
789  * Remove a reference to the node, possibly the last.
790  * deadnode always acts as it it were the last.
791  */
792 void
793 ng_unref_node(node_p node)
794 {
795 
796 	if (node == &ng_deadnode)
797 		return;
798 
799 	CURVNET_SET(node->nd_vnet);
800 
801 	if (refcount_release(&node->nd_refs)) { /* we were the last */
802 
803 		node->nd_type->refs--; /* XXX maybe should get types lock? */
804 		NAMEHASH_WLOCK();
805 		if (NG_NODE_HAS_NAME(node)) {
806 			V_ng_named_nodes--;
807 			LIST_REMOVE(node, nd_nodes);
808 		}
809 		NAMEHASH_WUNLOCK();
810 
811 		IDHASH_WLOCK();
812 		V_ng_nodes--;
813 		LIST_REMOVE(node, nd_idnodes);
814 		IDHASH_WUNLOCK();
815 
816 		mtx_destroy(&node->nd_input_queue.q_mtx);
817 		NG_FREE_NODE(node);
818 	}
819 	CURVNET_RESTORE();
820 }
821 
822 /************************************************************************
823 			Node ID handling
824 ************************************************************************/
825 static node_p
826 ng_ID2noderef(ng_ID_t ID)
827 {
828 	node_p node;
829 
830 	IDHASH_RLOCK();
831 	NG_IDHASH_FIND(ID, node);
832 	if (node)
833 		NG_NODE_REF(node);
834 	IDHASH_RUNLOCK();
835 	return(node);
836 }
837 
838 ng_ID_t
839 ng_node2ID(node_p node)
840 {
841 	return (node ? NG_NODE_ID(node) : 0);
842 }
843 
844 /************************************************************************
845 			Node name handling
846 ************************************************************************/
847 
848 /*
849  * Assign a node a name.
850  */
851 int
852 ng_name_node(node_p node, const char *name)
853 {
854 	uint32_t hash;
855 	node_p node2;
856 	int i;
857 
858 	/* Check the name is valid */
859 	for (i = 0; i < NG_NODESIZ; i++) {
860 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
861 			break;
862 	}
863 	if (i == 0 || name[i] != '\0') {
864 		TRAP_ERROR();
865 		return (EINVAL);
866 	}
867 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
868 		TRAP_ERROR();
869 		return (EINVAL);
870 	}
871 
872 	NAMEHASH_WLOCK();
873 	if (V_ng_named_nodes * 2 > V_ng_name_hmask)
874 		ng_name_rehash();
875 
876 	hash = hash32_str(name, HASHINIT) & V_ng_name_hmask;
877 	/* Check the name isn't already being used. */
878 	LIST_FOREACH(node2, &V_ng_name_hash[hash], nd_nodes)
879 		if (NG_NODE_IS_VALID(node2) &&
880 		    (strcmp(NG_NODE_NAME(node2), name) == 0)) {
881 			NAMEHASH_WUNLOCK();
882 			return (EADDRINUSE);
883 		}
884 
885 	if (NG_NODE_HAS_NAME(node))
886 		LIST_REMOVE(node, nd_nodes);
887 	else
888 		V_ng_named_nodes++;
889 	/* Copy it. */
890 	strlcpy(NG_NODE_NAME(node), name, NG_NODESIZ);
891 	/* Update name hash. */
892 	LIST_INSERT_HEAD(&V_ng_name_hash[hash], node, nd_nodes);
893 	NAMEHASH_WUNLOCK();
894 
895 	return (0);
896 }
897 
898 /*
899  * Find a node by absolute name. The name should NOT end with ':'
900  * The name "." means "this node" and "[xxx]" means "the node
901  * with ID (ie, at address) xxx".
902  *
903  * Returns the node if found, else NULL.
904  * Eventually should add something faster than a sequential search.
905  * Note it acquires a reference on the node so you can be sure it's still
906  * there.
907  */
908 node_p
909 ng_name2noderef(node_p here, const char *name)
910 {
911 	node_p node;
912 	ng_ID_t temp;
913 	int	hash;
914 
915 	/* "." means "this node" */
916 	if (strcmp(name, ".") == 0) {
917 		NG_NODE_REF(here);
918 		return(here);
919 	}
920 
921 	/* Check for name-by-ID */
922 	if ((temp = ng_decodeidname(name)) != 0) {
923 		return (ng_ID2noderef(temp));
924 	}
925 
926 	/* Find node by name. */
927 	hash = hash32_str(name, HASHINIT) & V_ng_name_hmask;
928 	NAMEHASH_RLOCK();
929 	LIST_FOREACH(node, &V_ng_name_hash[hash], nd_nodes)
930 		if (NG_NODE_IS_VALID(node) &&
931 		    (strcmp(NG_NODE_NAME(node), name) == 0)) {
932 			NG_NODE_REF(node);
933 			break;
934 		}
935 	NAMEHASH_RUNLOCK();
936 
937 	return (node);
938 }
939 
940 /*
941  * Decode an ID name, eg. "[f03034de]". Returns 0 if the
942  * string is not valid, otherwise returns the value.
943  */
944 static ng_ID_t
945 ng_decodeidname(const char *name)
946 {
947 	const int len = strlen(name);
948 	char *eptr;
949 	u_long val;
950 
951 	/* Check for proper length, brackets, no leading junk */
952 	if ((len < 3) || (name[0] != '[') || (name[len - 1] != ']') ||
953 	    (!isxdigit(name[1])))
954 		return ((ng_ID_t)0);
955 
956 	/* Decode number */
957 	val = strtoul(name + 1, &eptr, 16);
958 	if ((eptr - name != len - 1) || (val == ULONG_MAX) || (val == 0))
959 		return ((ng_ID_t)0);
960 
961 	return ((ng_ID_t)val);
962 }
963 
964 /*
965  * Remove a name from a node. This should only be called
966  * when shutting down and removing the node.
967  */
968 void
969 ng_unname(node_p node)
970 {
971 }
972 
973 /*
974  * Allocate a bigger name hash.
975  */
976 static void
977 ng_name_rehash()
978 {
979 	struct nodehash *new;
980 	uint32_t hash;
981 	u_long hmask;
982 	node_p node, node2;
983 	int i;
984 
985 	new = hashinit_flags((V_ng_name_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask,
986 	    HASH_NOWAIT);
987 	if (new == NULL)
988 		return;
989 
990 	for (i = 0; i <= V_ng_name_hmask; i++)
991 		LIST_FOREACH_SAFE(node, &V_ng_name_hash[i], nd_nodes, node2) {
992 #ifdef INVARIANTS
993 			LIST_REMOVE(node, nd_nodes);
994 #endif
995 			hash = hash32_str(NG_NODE_NAME(node), HASHINIT) & hmask;
996 			LIST_INSERT_HEAD(&new[hash], node, nd_nodes);
997 		}
998 
999 	hashdestroy(V_ng_name_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
1000 	V_ng_name_hash = new;
1001 	V_ng_name_hmask = hmask;
1002 }
1003 
1004 /*
1005  * Allocate a bigger ID hash.
1006  */
1007 static void
1008 ng_ID_rehash()
1009 {
1010 	struct nodehash *new;
1011 	uint32_t hash;
1012 	u_long hmask;
1013 	node_p node, node2;
1014 	int i;
1015 
1016 	new = hashinit_flags((V_ng_ID_hmask + 1) * 2, M_NETGRAPH_NODE, &hmask,
1017 	    HASH_NOWAIT);
1018 	if (new == NULL)
1019 		return;
1020 
1021 	for (i = 0; i <= V_ng_ID_hmask; i++)
1022 		LIST_FOREACH_SAFE(node, &V_ng_ID_hash[i], nd_idnodes, node2) {
1023 #ifdef INVARIANTS
1024 			LIST_REMOVE(node, nd_idnodes);
1025 #endif
1026 			hash = (node->nd_ID % (hmask + 1));
1027 			LIST_INSERT_HEAD(&new[hash], node, nd_idnodes);
1028 		}
1029 
1030 	hashdestroy(V_ng_ID_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
1031 	V_ng_ID_hash = new;
1032 	V_ng_ID_hmask = hmask;
1033 }
1034 
1035 /************************************************************************
1036 			Hook routines
1037  Names are not optional. Hooks are always connected, except for a
1038  brief moment within these routines. On invalidation or during creation
1039  they are connected to the 'dead' hook.
1040 ************************************************************************/
1041 
1042 /*
1043  * Remove a hook reference
1044  */
1045 void
1046 ng_unref_hook(hook_p hook)
1047 {
1048 
1049 	if (hook == &ng_deadhook)
1050 		return;
1051 
1052 	if (refcount_release(&hook->hk_refs)) { /* we were the last */
1053 		if (_NG_HOOK_NODE(hook)) /* it'll probably be ng_deadnode */
1054 			_NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
1055 		NG_FREE_HOOK(hook);
1056 	}
1057 }
1058 
1059 /*
1060  * Add an unconnected hook to a node. Only used internally.
1061  * Assumes node is locked. (XXX not yet true )
1062  */
1063 static int
1064 ng_add_hook(node_p node, const char *name, hook_p *hookp)
1065 {
1066 	hook_p hook;
1067 	int error = 0;
1068 
1069 	/* Check that the given name is good */
1070 	if (name == NULL) {
1071 		TRAP_ERROR();
1072 		return (EINVAL);
1073 	}
1074 	if (ng_findhook(node, name) != NULL) {
1075 		TRAP_ERROR();
1076 		return (EEXIST);
1077 	}
1078 
1079 	/* Allocate the hook and link it up */
1080 	NG_ALLOC_HOOK(hook);
1081 	if (hook == NULL) {
1082 		TRAP_ERROR();
1083 		return (ENOMEM);
1084 	}
1085 	hook->hk_refs = 1;		/* add a reference for us to return */
1086 	hook->hk_flags = HK_INVALID;
1087 	hook->hk_peer = &ng_deadhook;	/* start off this way */
1088 	hook->hk_node = node;
1089 	NG_NODE_REF(node);		/* each hook counts as a reference */
1090 
1091 	/* Set hook name */
1092 	strlcpy(NG_HOOK_NAME(hook), name, NG_HOOKSIZ);
1093 
1094 	/*
1095 	 * Check if the node type code has something to say about it
1096 	 * If it fails, the unref of the hook will also unref the node.
1097 	 */
1098 	if (node->nd_type->newhook != NULL) {
1099 		if ((error = (*node->nd_type->newhook)(node, hook, name))) {
1100 			NG_HOOK_UNREF(hook);	/* this frees the hook */
1101 			return (error);
1102 		}
1103 	}
1104 	/*
1105 	 * The 'type' agrees so far, so go ahead and link it in.
1106 	 * We'll ask again later when we actually connect the hooks.
1107 	 */
1108 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1109 	node->nd_numhooks++;
1110 	NG_HOOK_REF(hook);	/* one for the node */
1111 
1112 	if (hookp)
1113 		*hookp = hook;
1114 	return (0);
1115 }
1116 
1117 /*
1118  * Find a hook
1119  *
1120  * Node types may supply their own optimized routines for finding
1121  * hooks.  If none is supplied, we just do a linear search.
1122  * XXX Possibly we should add a reference to the hook?
1123  */
1124 hook_p
1125 ng_findhook(node_p node, const char *name)
1126 {
1127 	hook_p hook;
1128 
1129 	if (node->nd_type->findhook != NULL)
1130 		return (*node->nd_type->findhook)(node, name);
1131 	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
1132 		if (NG_HOOK_IS_VALID(hook) &&
1133 		    (strcmp(NG_HOOK_NAME(hook), name) == 0))
1134 			return (hook);
1135 	}
1136 	return (NULL);
1137 }
1138 
1139 /*
1140  * Destroy a hook
1141  *
1142  * As hooks are always attached, this really destroys two hooks.
1143  * The one given, and the one attached to it. Disconnect the hooks
1144  * from each other first. We reconnect the peer hook to the 'dead'
1145  * hook so that it can still exist after we depart. We then
1146  * send the peer its own destroy message. This ensures that we only
1147  * interact with the peer's structures when it is locked processing that
1148  * message. We hold a reference to the peer hook so we are guaranteed that
1149  * the peer hook and node are still going to exist until
1150  * we are finished there as the hook holds a ref on the node.
1151  * We run this same code again on the peer hook, but that time it is already
1152  * attached to the 'dead' hook.
1153  *
1154  * This routine is called at all stages of hook creation
1155  * on error detection and must be able to handle any such stage.
1156  */
1157 void
1158 ng_destroy_hook(hook_p hook)
1159 {
1160 	hook_p peer;
1161 	node_p node;
1162 
1163 	if (hook == &ng_deadhook) {	/* better safe than sorry */
1164 		printf("ng_destroy_hook called on deadhook\n");
1165 		return;
1166 	}
1167 
1168 	/*
1169 	 * Protect divorce process with mutex, to avoid races on
1170 	 * simultaneous disconnect.
1171 	 */
1172 	TOPOLOGY_WLOCK();
1173 
1174 	hook->hk_flags |= HK_INVALID;
1175 
1176 	peer = NG_HOOK_PEER(hook);
1177 	node = NG_HOOK_NODE(hook);
1178 
1179 	if (peer && (peer != &ng_deadhook)) {
1180 		/*
1181 		 * Set the peer to point to ng_deadhook
1182 		 * from this moment on we are effectively independent it.
1183 		 * send it an rmhook message of its own.
1184 		 */
1185 		peer->hk_peer = &ng_deadhook;	/* They no longer know us */
1186 		hook->hk_peer = &ng_deadhook;	/* Nor us, them */
1187 		if (NG_HOOK_NODE(peer) == &ng_deadnode) {
1188 			/*
1189 			 * If it's already divorced from a node,
1190 			 * just free it.
1191 			 */
1192 			TOPOLOGY_WUNLOCK();
1193 		} else {
1194 			TOPOLOGY_WUNLOCK();
1195 			ng_rmhook_self(peer); 	/* Send it a surprise */
1196 		}
1197 		NG_HOOK_UNREF(peer);		/* account for peer link */
1198 		NG_HOOK_UNREF(hook);		/* account for peer link */
1199 	} else
1200 		TOPOLOGY_WUNLOCK();
1201 
1202 	TOPOLOGY_NOTOWNED();
1203 
1204 	/*
1205 	 * Remove the hook from the node's list to avoid possible recursion
1206 	 * in case the disconnection results in node shutdown.
1207 	 */
1208 	if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
1209 		return;
1210 	}
1211 	LIST_REMOVE(hook, hk_hooks);
1212 	node->nd_numhooks--;
1213 	if (node->nd_type->disconnect) {
1214 		/*
1215 		 * The type handler may elect to destroy the node so don't
1216 		 * trust its existence after this point. (except
1217 		 * that we still hold a reference on it. (which we
1218 		 * inherrited from the hook we are destroying)
1219 		 */
1220 		(*node->nd_type->disconnect) (hook);
1221 	}
1222 
1223 	/*
1224 	 * Note that because we will point to ng_deadnode, the original node
1225 	 * is not decremented automatically so we do that manually.
1226 	 */
1227 	_NG_HOOK_NODE(hook) = &ng_deadnode;
1228 	NG_NODE_UNREF(node);	/* We no longer point to it so adjust count */
1229 	NG_HOOK_UNREF(hook);	/* Account for linkage (in list) to node */
1230 }
1231 
1232 /*
1233  * Take two hooks on a node and merge the connection so that the given node
1234  * is effectively bypassed.
1235  */
1236 int
1237 ng_bypass(hook_p hook1, hook_p hook2)
1238 {
1239 	if (hook1->hk_node != hook2->hk_node) {
1240 		TRAP_ERROR();
1241 		return (EINVAL);
1242 	}
1243 	TOPOLOGY_WLOCK();
1244 	if (NG_HOOK_NOT_VALID(hook1) || NG_HOOK_NOT_VALID(hook2)) {
1245 		TOPOLOGY_WUNLOCK();
1246 		return (EINVAL);
1247 	}
1248 	hook1->hk_peer->hk_peer = hook2->hk_peer;
1249 	hook2->hk_peer->hk_peer = hook1->hk_peer;
1250 
1251 	hook1->hk_peer = &ng_deadhook;
1252 	hook2->hk_peer = &ng_deadhook;
1253 	TOPOLOGY_WUNLOCK();
1254 
1255 	NG_HOOK_UNREF(hook1);
1256 	NG_HOOK_UNREF(hook2);
1257 
1258 	/* XXX If we ever cache methods on hooks update them as well */
1259 	ng_destroy_hook(hook1);
1260 	ng_destroy_hook(hook2);
1261 	return (0);
1262 }
1263 
1264 /*
1265  * Install a new netgraph type
1266  */
1267 int
1268 ng_newtype(struct ng_type *tp)
1269 {
1270 	const size_t namelen = strlen(tp->name);
1271 
1272 	/* Check version and type name fields */
1273 	if ((tp->version != NG_ABI_VERSION) || (namelen == 0) ||
1274 	    (namelen >= NG_TYPESIZ)) {
1275 		TRAP_ERROR();
1276 		if (tp->version != NG_ABI_VERSION) {
1277 			printf("Netgraph: Node type rejected. ABI mismatch. "
1278 			    "Suggest recompile\n");
1279 		}
1280 		return (EINVAL);
1281 	}
1282 
1283 	/* Check for name collision */
1284 	if (ng_findtype(tp->name) != NULL) {
1285 		TRAP_ERROR();
1286 		return (EEXIST);
1287 	}
1288 
1289 	/* Link in new type */
1290 	TYPELIST_WLOCK();
1291 	LIST_INSERT_HEAD(&ng_typelist, tp, types);
1292 	tp->refs = 1;	/* first ref is linked list */
1293 	TYPELIST_WUNLOCK();
1294 	return (0);
1295 }
1296 
1297 /*
1298  * unlink a netgraph type
1299  * If no examples exist
1300  */
1301 int
1302 ng_rmtype(struct ng_type *tp)
1303 {
1304 	/* Check for name collision */
1305 	if (tp->refs != 1) {
1306 		TRAP_ERROR();
1307 		return (EBUSY);
1308 	}
1309 
1310 	/* Unlink type */
1311 	TYPELIST_WLOCK();
1312 	LIST_REMOVE(tp, types);
1313 	TYPELIST_WUNLOCK();
1314 	return (0);
1315 }
1316 
1317 /*
1318  * Look for a type of the name given
1319  */
1320 struct ng_type *
1321 ng_findtype(const char *typename)
1322 {
1323 	struct ng_type *type;
1324 
1325 	TYPELIST_RLOCK();
1326 	LIST_FOREACH(type, &ng_typelist, types) {
1327 		if (strcmp(type->name, typename) == 0)
1328 			break;
1329 	}
1330 	TYPELIST_RUNLOCK();
1331 	return (type);
1332 }
1333 
1334 /************************************************************************
1335 			Composite routines
1336 ************************************************************************/
1337 /*
1338  * Connect two nodes using the specified hooks, using queued functions.
1339  */
1340 static int
1341 ng_con_part3(node_p node, item_p item, hook_p hook)
1342 {
1343 	int	error = 0;
1344 
1345 	/*
1346 	 * When we run, we know that the node 'node' is locked for us.
1347 	 * Our caller has a reference on the hook.
1348 	 * Our caller has a reference on the node.
1349 	 * (In this case our caller is ng_apply_item() ).
1350 	 * The peer hook has a reference on the hook.
1351 	 * We are all set up except for the final call to the node, and
1352 	 * the clearing of the INVALID flag.
1353 	 */
1354 	if (NG_HOOK_NODE(hook) == &ng_deadnode) {
1355 		/*
1356 		 * The node must have been freed again since we last visited
1357 		 * here. ng_destry_hook() has this effect but nothing else does.
1358 		 * We should just release our references and
1359 		 * free anything we can think of.
1360 		 * Since we know it's been destroyed, and it's our caller
1361 		 * that holds the references, just return.
1362 		 */
1363 		ERROUT(ENOENT);
1364 	}
1365 	if (hook->hk_node->nd_type->connect) {
1366 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1367 			ng_destroy_hook(hook);	/* also zaps peer */
1368 			printf("failed in ng_con_part3()\n");
1369 			ERROUT(error);
1370 		}
1371 	}
1372 	/*
1373 	 *  XXX this is wrong for SMP. Possibly we need
1374 	 * to separate out 'create' and 'invalid' flags.
1375 	 * should only set flags on hooks we have locked under our node.
1376 	 */
1377 	hook->hk_flags &= ~HK_INVALID;
1378 done:
1379 	NG_FREE_ITEM(item);
1380 	return (error);
1381 }
1382 
1383 static int
1384 ng_con_part2(node_p node, item_p item, hook_p hook)
1385 {
1386 	hook_p	peer;
1387 	int	error = 0;
1388 
1389 	/*
1390 	 * When we run, we know that the node 'node' is locked for us.
1391 	 * Our caller has a reference on the hook.
1392 	 * Our caller has a reference on the node.
1393 	 * (In this case our caller is ng_apply_item() ).
1394 	 * The peer hook has a reference on the hook.
1395 	 * our node pointer points to the 'dead' node.
1396 	 * First check the hook name is unique.
1397 	 * Should not happen because we checked before queueing this.
1398 	 */
1399 	if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
1400 		TRAP_ERROR();
1401 		ng_destroy_hook(hook); /* should destroy peer too */
1402 		printf("failed in ng_con_part2()\n");
1403 		ERROUT(EEXIST);
1404 	}
1405 	/*
1406 	 * Check if the node type code has something to say about it
1407 	 * If it fails, the unref of the hook will also unref the attached node,
1408 	 * however since that node is 'ng_deadnode' this will do nothing.
1409 	 * The peer hook will also be destroyed.
1410 	 */
1411 	if (node->nd_type->newhook != NULL) {
1412 		if ((error = (*node->nd_type->newhook)(node, hook,
1413 		    hook->hk_name))) {
1414 			ng_destroy_hook(hook); /* should destroy peer too */
1415 			printf("failed in ng_con_part2()\n");
1416 			ERROUT(error);
1417 		}
1418 	}
1419 
1420 	/*
1421 	 * The 'type' agrees so far, so go ahead and link it in.
1422 	 * We'll ask again later when we actually connect the hooks.
1423 	 */
1424 	hook->hk_node = node;		/* just overwrite ng_deadnode */
1425 	NG_NODE_REF(node);		/* each hook counts as a reference */
1426 	LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1427 	node->nd_numhooks++;
1428 	NG_HOOK_REF(hook);	/* one for the node */
1429 
1430 	/*
1431 	 * We now have a symmetrical situation, where both hooks have been
1432 	 * linked to their nodes, the newhook methods have been called
1433 	 * And the references are all correct. The hooks are still marked
1434 	 * as invalid, as we have not called the 'connect' methods
1435 	 * yet.
1436 	 * We can call the local one immediately as we have the
1437 	 * node locked, but we need to queue the remote one.
1438 	 */
1439 	if (hook->hk_node->nd_type->connect) {
1440 		if ((error = (*hook->hk_node->nd_type->connect) (hook))) {
1441 			ng_destroy_hook(hook);	/* also zaps peer */
1442 			printf("failed in ng_con_part2(A)\n");
1443 			ERROUT(error);
1444 		}
1445 	}
1446 
1447 	/*
1448 	 * Acquire topo mutex to avoid race with ng_destroy_hook().
1449 	 */
1450 	TOPOLOGY_RLOCK();
1451 	peer = hook->hk_peer;
1452 	if (peer == &ng_deadhook) {
1453 		TOPOLOGY_RUNLOCK();
1454 		printf("failed in ng_con_part2(B)\n");
1455 		ng_destroy_hook(hook);
1456 		ERROUT(ENOENT);
1457 	}
1458 	TOPOLOGY_RUNLOCK();
1459 
1460 	if ((error = ng_send_fn2(peer->hk_node, peer, item, &ng_con_part3,
1461 	    NULL, 0, NG_REUSE_ITEM))) {
1462 		printf("failed in ng_con_part2(C)\n");
1463 		ng_destroy_hook(hook);	/* also zaps peer */
1464 		return (error);		/* item was consumed. */
1465 	}
1466 	hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
1467 	return (0);			/* item was consumed. */
1468 done:
1469 	NG_FREE_ITEM(item);
1470 	return (error);
1471 }
1472 
1473 /*
1474  * Connect this node with another node. We assume that this node is
1475  * currently locked, as we are only called from an NGM_CONNECT message.
1476  */
1477 static int
1478 ng_con_nodes(item_p item, node_p node, const char *name,
1479     node_p node2, const char *name2)
1480 {
1481 	int	error;
1482 	hook_p	hook;
1483 	hook_p	hook2;
1484 
1485 	if (ng_findhook(node2, name2) != NULL) {
1486 		return(EEXIST);
1487 	}
1488 	if ((error = ng_add_hook(node, name, &hook)))  /* gives us a ref */
1489 		return (error);
1490 	/* Allocate the other hook and link it up */
1491 	NG_ALLOC_HOOK(hook2);
1492 	if (hook2 == NULL) {
1493 		TRAP_ERROR();
1494 		ng_destroy_hook(hook);	/* XXX check ref counts so far */
1495 		NG_HOOK_UNREF(hook);	/* including our ref */
1496 		return (ENOMEM);
1497 	}
1498 	hook2->hk_refs = 1;		/* start with a reference for us. */
1499 	hook2->hk_flags = HK_INVALID;
1500 	hook2->hk_peer = hook;		/* Link the two together */
1501 	hook->hk_peer = hook2;
1502 	NG_HOOK_REF(hook);		/* Add a ref for the peer to each*/
1503 	NG_HOOK_REF(hook2);
1504 	hook2->hk_node = &ng_deadnode;
1505 	strlcpy(NG_HOOK_NAME(hook2), name2, NG_HOOKSIZ);
1506 
1507 	/*
1508 	 * Queue the function above.
1509 	 * Procesing continues in that function in the lock context of
1510 	 * the other node.
1511 	 */
1512 	if ((error = ng_send_fn2(node2, hook2, item, &ng_con_part2, NULL, 0,
1513 	    NG_NOFLAGS))) {
1514 		printf("failed in ng_con_nodes(): %d\n", error);
1515 		ng_destroy_hook(hook);	/* also zaps peer */
1516 	}
1517 
1518 	NG_HOOK_UNREF(hook);		/* Let each hook go if it wants to */
1519 	NG_HOOK_UNREF(hook2);
1520 	return (error);
1521 }
1522 
1523 /*
1524  * Make a peer and connect.
1525  * We assume that the local node is locked.
1526  * The new node probably doesn't need a lock until
1527  * it has a hook, because it cannot really have any work until then,
1528  * but we should think about it a bit more.
1529  *
1530  * The problem may come if the other node also fires up
1531  * some hardware or a timer or some other source of activation,
1532  * also it may already get a command msg via it's ID.
1533  *
1534  * We could use the same method as ng_con_nodes() but we'd have
1535  * to add ability to remove the node when failing. (Not hard, just
1536  * make arg1 point to the node to remove).
1537  * Unless of course we just ignore failure to connect and leave
1538  * an unconnected node?
1539  */
1540 static int
1541 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
1542 {
1543 	node_p	node2;
1544 	hook_p	hook1, hook2;
1545 	int	error;
1546 
1547 	if ((error = ng_make_node(type, &node2))) {
1548 		return (error);
1549 	}
1550 
1551 	if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
1552 		ng_rmnode(node2, NULL, NULL, 0);
1553 		return (error);
1554 	}
1555 
1556 	if ((error = ng_add_hook(node2, name2, &hook2))) {
1557 		ng_rmnode(node2, NULL, NULL, 0);
1558 		ng_destroy_hook(hook1);
1559 		NG_HOOK_UNREF(hook1);
1560 		return (error);
1561 	}
1562 
1563 	/*
1564 	 * Actually link the two hooks together.
1565 	 */
1566 	hook1->hk_peer = hook2;
1567 	hook2->hk_peer = hook1;
1568 
1569 	/* Each hook is referenced by the other */
1570 	NG_HOOK_REF(hook1);
1571 	NG_HOOK_REF(hook2);
1572 
1573 	/* Give each node the opportunity to veto the pending connection */
1574 	if (hook1->hk_node->nd_type->connect) {
1575 		error = (*hook1->hk_node->nd_type->connect) (hook1);
1576 	}
1577 
1578 	if ((error == 0) && hook2->hk_node->nd_type->connect) {
1579 		error = (*hook2->hk_node->nd_type->connect) (hook2);
1580 
1581 	}
1582 
1583 	/*
1584 	 * drop the references we were holding on the two hooks.
1585 	 */
1586 	if (error) {
1587 		ng_destroy_hook(hook2);	/* also zaps hook1 */
1588 		ng_rmnode(node2, NULL, NULL, 0);
1589 	} else {
1590 		/* As a last act, allow the hooks to be used */
1591 		hook1->hk_flags &= ~HK_INVALID;
1592 		hook2->hk_flags &= ~HK_INVALID;
1593 	}
1594 	NG_HOOK_UNREF(hook1);
1595 	NG_HOOK_UNREF(hook2);
1596 	return (error);
1597 }
1598 
1599 /************************************************************************
1600 		Utility routines to send self messages
1601 ************************************************************************/
1602 
1603 /* Shut this node down as soon as everyone is clear of it */
1604 /* Should add arg "immediately" to jump the queue */
1605 int
1606 ng_rmnode_self(node_p node)
1607 {
1608 	int		error;
1609 
1610 	if (node == &ng_deadnode)
1611 		return (0);
1612 	node->nd_flags |= NGF_INVALID;
1613 	if (node->nd_flags & NGF_CLOSING)
1614 		return (0);
1615 
1616 	error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
1617 	return (error);
1618 }
1619 
1620 static void
1621 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
1622 {
1623 	ng_destroy_hook(hook);
1624 	return ;
1625 }
1626 
1627 int
1628 ng_rmhook_self(hook_p hook)
1629 {
1630 	int		error;
1631 	node_p node = NG_HOOK_NODE(hook);
1632 
1633 	if (node == &ng_deadnode)
1634 		return (0);
1635 
1636 	error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
1637 	return (error);
1638 }
1639 
1640 /***********************************************************************
1641  * Parse and verify a string of the form:  <NODE:><PATH>
1642  *
1643  * Such a string can refer to a specific node or a specific hook
1644  * on a specific node, depending on how you look at it. In the
1645  * latter case, the PATH component must not end in a dot.
1646  *
1647  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1648  * of hook names separated by dots. This breaks out the original
1649  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1650  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1651  * the final hook component of <PATH>, if any, otherwise NULL.
1652  *
1653  * This returns -1 if the path is malformed. The char ** are optional.
1654  ***********************************************************************/
1655 int
1656 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1657 {
1658 	char	*node, *path, *hook;
1659 	int	k;
1660 
1661 	/*
1662 	 * Extract absolute NODE, if any
1663 	 */
1664 	for (path = addr; *path && *path != ':'; path++);
1665 	if (*path) {
1666 		node = addr;	/* Here's the NODE */
1667 		*path++ = '\0';	/* Here's the PATH */
1668 
1669 		/* Node name must not be empty */
1670 		if (!*node)
1671 			return -1;
1672 
1673 		/* A name of "." is OK; otherwise '.' not allowed */
1674 		if (strcmp(node, ".") != 0) {
1675 			for (k = 0; node[k]; k++)
1676 				if (node[k] == '.')
1677 					return -1;
1678 		}
1679 	} else {
1680 		node = NULL;	/* No absolute NODE */
1681 		path = addr;	/* Here's the PATH */
1682 	}
1683 
1684 	/* Snoop for illegal characters in PATH */
1685 	for (k = 0; path[k]; k++)
1686 		if (path[k] == ':')
1687 			return -1;
1688 
1689 	/* Check for no repeated dots in PATH */
1690 	for (k = 0; path[k]; k++)
1691 		if (path[k] == '.' && path[k + 1] == '.')
1692 			return -1;
1693 
1694 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1695 	if (path[0] == '.')
1696 		path++;
1697 	if (*path && path[strlen(path) - 1] == '.')
1698 		path[strlen(path) - 1] = 0;
1699 
1700 	/* If PATH has a dot, then we're not talking about a hook */
1701 	if (*path) {
1702 		for (hook = path, k = 0; path[k]; k++)
1703 			if (path[k] == '.') {
1704 				hook = NULL;
1705 				break;
1706 			}
1707 	} else
1708 		path = hook = NULL;
1709 
1710 	/* Done */
1711 	if (nodep)
1712 		*nodep = node;
1713 	if (pathp)
1714 		*pathp = path;
1715 	if (hookp)
1716 		*hookp = hook;
1717 	return (0);
1718 }
1719 
1720 /*
1721  * Given a path, which may be absolute or relative, and a starting node,
1722  * return the destination node.
1723  */
1724 int
1725 ng_path2noderef(node_p here, const char *address, node_p *destp,
1726     hook_p *lasthook)
1727 {
1728 	char    fullpath[NG_PATHSIZ];
1729 	char   *nodename, *path;
1730 	node_p  node, oldnode;
1731 
1732 	/* Initialize */
1733 	if (destp == NULL) {
1734 		TRAP_ERROR();
1735 		return EINVAL;
1736 	}
1737 	*destp = NULL;
1738 
1739 	/* Make a writable copy of address for ng_path_parse() */
1740 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1741 	fullpath[sizeof(fullpath) - 1] = '\0';
1742 
1743 	/* Parse out node and sequence of hooks */
1744 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1745 		TRAP_ERROR();
1746 		return EINVAL;
1747 	}
1748 
1749 	/*
1750 	 * For an absolute address, jump to the starting node.
1751 	 * Note that this holds a reference on the node for us.
1752 	 * Don't forget to drop the reference if we don't need it.
1753 	 */
1754 	if (nodename) {
1755 		node = ng_name2noderef(here, nodename);
1756 		if (node == NULL) {
1757 			TRAP_ERROR();
1758 			return (ENOENT);
1759 		}
1760 	} else {
1761 		if (here == NULL) {
1762 			TRAP_ERROR();
1763 			return (EINVAL);
1764 		}
1765 		node = here;
1766 		NG_NODE_REF(node);
1767 	}
1768 
1769 	if (path == NULL) {
1770 		if (lasthook != NULL)
1771 			*lasthook = NULL;
1772 		*destp = node;
1773 		return (0);
1774 	}
1775 
1776 	/*
1777 	 * Now follow the sequence of hooks
1778 	 *
1779 	 * XXXGL: The path may demolish as we go the sequence, but if
1780 	 * we hold the topology mutex at critical places, then, I hope,
1781 	 * we would always have valid pointers in hand, although the
1782 	 * path behind us may no longer exist.
1783 	 */
1784 	for (;;) {
1785 		hook_p hook;
1786 		char *segment;
1787 
1788 		/*
1789 		 * Break out the next path segment. Replace the dot we just
1790 		 * found with a NUL; "path" points to the next segment (or the
1791 		 * NUL at the end).
1792 		 */
1793 		for (segment = path; *path != '\0'; path++) {
1794 			if (*path == '.') {
1795 				*path++ = '\0';
1796 				break;
1797 			}
1798 		}
1799 
1800 		/* We have a segment, so look for a hook by that name */
1801 		hook = ng_findhook(node, segment);
1802 
1803 		TOPOLOGY_WLOCK();
1804 		/* Can't get there from here... */
1805 		if (hook == NULL || NG_HOOK_PEER(hook) == NULL ||
1806 		    NG_HOOK_NOT_VALID(hook) ||
1807 		    NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
1808 			TRAP_ERROR();
1809 			NG_NODE_UNREF(node);
1810 			TOPOLOGY_WUNLOCK();
1811 			return (ENOENT);
1812 		}
1813 
1814 		/*
1815 		 * Hop on over to the next node
1816 		 * XXX
1817 		 * Big race conditions here as hooks and nodes go away
1818 		 * *** Idea.. store an ng_ID_t in each hook and use that
1819 		 * instead of the direct hook in this crawl?
1820 		 */
1821 		oldnode = node;
1822 		if ((node = NG_PEER_NODE(hook)))
1823 			NG_NODE_REF(node);	/* XXX RACE */
1824 		NG_NODE_UNREF(oldnode);	/* XXX another race */
1825 		if (NG_NODE_NOT_VALID(node)) {
1826 			NG_NODE_UNREF(node);	/* XXX more races */
1827 			TOPOLOGY_WUNLOCK();
1828 			TRAP_ERROR();
1829 			return (ENXIO);
1830 		}
1831 
1832 		if (*path == '\0') {
1833 			if (lasthook != NULL) {
1834 				if (hook != NULL) {
1835 					*lasthook = NG_HOOK_PEER(hook);
1836 					NG_HOOK_REF(*lasthook);
1837 				} else
1838 					*lasthook = NULL;
1839 			}
1840 			TOPOLOGY_WUNLOCK();
1841 			*destp = node;
1842 			return (0);
1843 		}
1844 		TOPOLOGY_WUNLOCK();
1845 	}
1846 }
1847 
1848 /***************************************************************\
1849 * Input queue handling.
1850 * All activities are submitted to the node via the input queue
1851 * which implements a multiple-reader/single-writer gate.
1852 * Items which cannot be handled immediately are queued.
1853 *
1854 * read-write queue locking inline functions			*
1855 \***************************************************************/
1856 
1857 static __inline void	ng_queue_rw(node_p node, item_p  item, int rw);
1858 static __inline item_p	ng_dequeue(node_p node, int *rw);
1859 static __inline item_p	ng_acquire_read(node_p node, item_p  item);
1860 static __inline item_p	ng_acquire_write(node_p node, item_p  item);
1861 static __inline void	ng_leave_read(node_p node);
1862 static __inline void	ng_leave_write(node_p node);
1863 
1864 /*
1865  * Definition of the bits fields in the ng_queue flag word.
1866  * Defined here rather than in netgraph.h because no-one should fiddle
1867  * with them.
1868  *
1869  * The ordering here may be important! don't shuffle these.
1870  */
1871 /*-
1872  Safety Barrier--------+ (adjustable to suit taste) (not used yet)
1873                        |
1874                        V
1875 +-------+-------+-------+-------+-------+-------+-------+-------+
1876   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
1877   | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |P|A|
1878   | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |O|W|
1879 +-------+-------+-------+-------+-------+-------+-------+-------+
1880   \___________________________ ____________________________/ | |
1881                             V                                | |
1882                   [active reader count]                      | |
1883                                                              | |
1884             Operation Pending -------------------------------+ |
1885                                                                |
1886           Active Writer ---------------------------------------+
1887 
1888 Node queue has such semantics:
1889 - All flags modifications are atomic.
1890 - Reader count can be incremented only if there is no writer or pending flags.
1891   As soon as this can't be done with single operation, it is implemented with
1892   spin loop and atomic_cmpset().
1893 - Writer flag can be set only if there is no any bits set.
1894   It is implemented with atomic_cmpset().
1895 - Pending flag can be set any time, but to avoid collision on queue processing
1896   all queue fields are protected by the mutex.
1897 - Queue processing thread reads queue holding the mutex, but releases it while
1898   processing. When queue is empty pending flag is removed.
1899 */
1900 
1901 #define WRITER_ACTIVE	0x00000001
1902 #define OP_PENDING	0x00000002
1903 #define READER_INCREMENT 0x00000004
1904 #define READER_MASK	0xfffffffc	/* Not valid if WRITER_ACTIVE is set */
1905 #define SAFETY_BARRIER	0x00100000	/* 128K items queued should be enough */
1906 
1907 /* Defines of more elaborate states on the queue */
1908 /* Mask of bits a new read cares about */
1909 #define NGQ_RMASK	(WRITER_ACTIVE|OP_PENDING)
1910 
1911 /* Mask of bits a new write cares about */
1912 #define NGQ_WMASK	(NGQ_RMASK|READER_MASK)
1913 
1914 /* Test to decide if there is something on the queue. */
1915 #define QUEUE_ACTIVE(QP) ((QP)->q_flags & OP_PENDING)
1916 
1917 /* How to decide what the next queued item is. */
1918 #define HEAD_IS_READER(QP)  NGI_QUEUED_READER(STAILQ_FIRST(&(QP)->queue))
1919 #define HEAD_IS_WRITER(QP)  NGI_QUEUED_WRITER(STAILQ_FIRST(&(QP)->queue)) /* notused */
1920 
1921 /* Read the status to decide if the next item on the queue can now run. */
1922 #define QUEUED_READER_CAN_PROCEED(QP)			\
1923 		(((QP)->q_flags & (NGQ_RMASK & ~OP_PENDING)) == 0)
1924 #define QUEUED_WRITER_CAN_PROCEED(QP)			\
1925 		(((QP)->q_flags & (NGQ_WMASK & ~OP_PENDING)) == 0)
1926 
1927 /* Is there a chance of getting ANY work off the queue? */
1928 #define NEXT_QUEUED_ITEM_CAN_PROCEED(QP)				\
1929 	((HEAD_IS_READER(QP)) ? QUEUED_READER_CAN_PROCEED(QP) :		\
1930 				QUEUED_WRITER_CAN_PROCEED(QP))
1931 
1932 #define NGQRW_R 0
1933 #define NGQRW_W 1
1934 
1935 #define NGQ2_WORKQ	0x00000001
1936 
1937 /*
1938  * Taking into account the current state of the queue and node, possibly take
1939  * the next entry off the queue and return it. Return NULL if there was
1940  * nothing we could return, either because there really was nothing there, or
1941  * because the node was in a state where it cannot yet process the next item
1942  * on the queue.
1943  */
1944 static __inline item_p
1945 ng_dequeue(node_p node, int *rw)
1946 {
1947 	item_p item;
1948 	struct ng_queue *ngq = &node->nd_input_queue;
1949 
1950 	/* This MUST be called with the mutex held. */
1951 	mtx_assert(&ngq->q_mtx, MA_OWNED);
1952 
1953 	/* If there is nothing queued, then just return. */
1954 	if (!QUEUE_ACTIVE(ngq)) {
1955 		CTR4(KTR_NET, "%20s: node [%x] (%p) queue empty; "
1956 		    "queue flags 0x%lx", __func__,
1957 		    node->nd_ID, node, ngq->q_flags);
1958 		return (NULL);
1959 	}
1960 
1961 	/*
1962 	 * From here, we can assume there is a head item.
1963 	 * We need to find out what it is and if it can be dequeued, given
1964 	 * the current state of the node.
1965 	 */
1966 	if (HEAD_IS_READER(ngq)) {
1967 		while (1) {
1968 			long t = ngq->q_flags;
1969 			if (t & WRITER_ACTIVE) {
1970 				/* There is writer, reader can't proceed. */
1971 				CTR4(KTR_NET, "%20s: node [%x] (%p) queued "
1972 				    "reader can't proceed; queue flags 0x%lx",
1973 				    __func__, node->nd_ID, node, t);
1974 				return (NULL);
1975 			}
1976 			if (atomic_cmpset_acq_int(&ngq->q_flags, t,
1977 			    t + READER_INCREMENT))
1978 				break;
1979 			cpu_spinwait();
1980 		}
1981 		/* We have got reader lock for the node. */
1982 		*rw = NGQRW_R;
1983 	} else if (atomic_cmpset_acq_int(&ngq->q_flags, OP_PENDING,
1984 	    OP_PENDING + WRITER_ACTIVE)) {
1985 		/* We have got writer lock for the node. */
1986 		*rw = NGQRW_W;
1987 	} else {
1988 		/* There is somebody other, writer can't proceed. */
1989 		CTR4(KTR_NET, "%20s: node [%x] (%p) queued writer can't "
1990 		    "proceed; queue flags 0x%lx", __func__, node->nd_ID, node,
1991 		    ngq->q_flags);
1992 		return (NULL);
1993 	}
1994 
1995 	/*
1996 	 * Now we dequeue the request (whatever it may be) and correct the
1997 	 * pending flags and the next and last pointers.
1998 	 */
1999 	item = STAILQ_FIRST(&ngq->queue);
2000 	STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
2001 	if (STAILQ_EMPTY(&ngq->queue))
2002 		atomic_clear_int(&ngq->q_flags, OP_PENDING);
2003 	CTR6(KTR_NET, "%20s: node [%x] (%p) returning item %p as %s; queue "
2004 	    "flags 0x%lx", __func__, node->nd_ID, node, item, *rw ? "WRITER" :
2005 	    "READER", ngq->q_flags);
2006 	return (item);
2007 }
2008 
2009 /*
2010  * Queue a packet to be picked up later by someone else.
2011  * If the queue could be run now, add node to the queue handler's worklist.
2012  */
2013 static __inline void
2014 ng_queue_rw(node_p node, item_p  item, int rw)
2015 {
2016 	struct ng_queue *ngq = &node->nd_input_queue;
2017 	if (rw == NGQRW_W)
2018 		NGI_SET_WRITER(item);
2019 	else
2020 		NGI_SET_READER(item);
2021 	item->depth = 1;
2022 
2023 	NG_QUEUE_LOCK(ngq);
2024 	/* Set OP_PENDING flag and enqueue the item. */
2025 	atomic_set_int(&ngq->q_flags, OP_PENDING);
2026 	STAILQ_INSERT_TAIL(&ngq->queue, item, el_next);
2027 
2028 	CTR5(KTR_NET, "%20s: node [%x] (%p) queued item %p as %s", __func__,
2029 	    node->nd_ID, node, item, rw ? "WRITER" : "READER" );
2030 
2031 	/*
2032 	 * We can take the worklist lock with the node locked
2033 	 * BUT NOT THE REVERSE!
2034 	 */
2035 	if (NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2036 		ng_worklist_add(node);
2037 	NG_QUEUE_UNLOCK(ngq);
2038 }
2039 
2040 /* Acquire reader lock on node. If node is busy, queue the packet. */
2041 static __inline item_p
2042 ng_acquire_read(node_p node, item_p item)
2043 {
2044 	KASSERT(node != &ng_deadnode,
2045 	    ("%s: working on deadnode", __func__));
2046 
2047 	/* Reader needs node without writer and pending items. */
2048 	for (;;) {
2049 		long t = node->nd_input_queue.q_flags;
2050 		if (t & NGQ_RMASK)
2051 			break; /* Node is not ready for reader. */
2052 		if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags, t,
2053 		    t + READER_INCREMENT)) {
2054 	    		/* Successfully grabbed node */
2055 			CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
2056 			    __func__, node->nd_ID, node, item);
2057 			return (item);
2058 		}
2059 		cpu_spinwait();
2060 	}
2061 
2062 	/* Queue the request for later. */
2063 	ng_queue_rw(node, item, NGQRW_R);
2064 
2065 	return (NULL);
2066 }
2067 
2068 /* Acquire writer lock on node. If node is busy, queue the packet. */
2069 static __inline item_p
2070 ng_acquire_write(node_p node, item_p item)
2071 {
2072 	KASSERT(node != &ng_deadnode,
2073 	    ("%s: working on deadnode", __func__));
2074 
2075 	/* Writer needs completely idle node. */
2076 	if (atomic_cmpset_acq_int(&node->nd_input_queue.q_flags, 0,
2077 	    WRITER_ACTIVE)) {
2078 	    	/* Successfully grabbed node */
2079 		CTR4(KTR_NET, "%20s: node [%x] (%p) acquired item %p",
2080 		    __func__, node->nd_ID, node, item);
2081 		return (item);
2082 	}
2083 
2084 	/* Queue the request for later. */
2085 	ng_queue_rw(node, item, NGQRW_W);
2086 
2087 	return (NULL);
2088 }
2089 
2090 #if 0
2091 static __inline item_p
2092 ng_upgrade_write(node_p node, item_p item)
2093 {
2094 	struct ng_queue *ngq = &node->nd_input_queue;
2095 	KASSERT(node != &ng_deadnode,
2096 	    ("%s: working on deadnode", __func__));
2097 
2098 	NGI_SET_WRITER(item);
2099 
2100 	NG_QUEUE_LOCK(ngq);
2101 
2102 	/*
2103 	 * There will never be no readers as we are there ourselves.
2104 	 * Set the WRITER_ACTIVE flags ASAP to block out fast track readers.
2105 	 * The caller we are running from will call ng_leave_read()
2106 	 * soon, so we must account for that. We must leave again with the
2107 	 * READER lock. If we find other readers, then
2108 	 * queue the request for later. However "later" may be rignt now
2109 	 * if there are no readers. We don't really care if there are queued
2110 	 * items as we will bypass them anyhow.
2111 	 */
2112 	atomic_add_int(&ngq->q_flags, WRITER_ACTIVE - READER_INCREMENT);
2113 	if ((ngq->q_flags & (NGQ_WMASK & ~OP_PENDING)) == WRITER_ACTIVE) {
2114 		NG_QUEUE_UNLOCK(ngq);
2115 
2116 		/* It's just us, act on the item. */
2117 		/* will NOT drop writer lock when done */
2118 		ng_apply_item(node, item, 0);
2119 
2120 		/*
2121 		 * Having acted on the item, atomically
2122 		 * downgrade back to READER and finish up.
2123 	 	 */
2124 		atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
2125 
2126 		/* Our caller will call ng_leave_read() */
2127 		return;
2128 	}
2129 	/*
2130 	 * It's not just us active, so queue us AT THE HEAD.
2131 	 * "Why?" I hear you ask.
2132 	 * Put us at the head of the queue as we've already been
2133 	 * through it once. If there is nothing else waiting,
2134 	 * set the correct flags.
2135 	 */
2136 	if (STAILQ_EMPTY(&ngq->queue)) {
2137 		/* We've gone from, 0 to 1 item in the queue */
2138 		atomic_set_int(&ngq->q_flags, OP_PENDING);
2139 
2140 		CTR3(KTR_NET, "%20s: node [%x] (%p) set OP_PENDING", __func__,
2141 		    node->nd_ID, node);
2142 	};
2143 	STAILQ_INSERT_HEAD(&ngq->queue, item, el_next);
2144 	CTR4(KTR_NET, "%20s: node [%x] (%p) requeued item %p as WRITER",
2145 	    __func__, node->nd_ID, node, item );
2146 
2147 	/* Reverse what we did above. That downgrades us back to reader */
2148 	atomic_add_int(&ngq->q_flags, READER_INCREMENT - WRITER_ACTIVE);
2149 	if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2150 		ng_worklist_add(node);
2151 	NG_QUEUE_UNLOCK(ngq);
2152 
2153 	return;
2154 }
2155 #endif
2156 
2157 /* Release reader lock. */
2158 static __inline void
2159 ng_leave_read(node_p node)
2160 {
2161 	atomic_subtract_rel_int(&node->nd_input_queue.q_flags, READER_INCREMENT);
2162 }
2163 
2164 /* Release writer lock. */
2165 static __inline void
2166 ng_leave_write(node_p node)
2167 {
2168 	atomic_clear_rel_int(&node->nd_input_queue.q_flags, WRITER_ACTIVE);
2169 }
2170 
2171 /* Purge node queue. Called on node shutdown. */
2172 static void
2173 ng_flush_input_queue(node_p node)
2174 {
2175 	struct ng_queue *ngq = &node->nd_input_queue;
2176 	item_p item;
2177 
2178 	NG_QUEUE_LOCK(ngq);
2179 	while ((item = STAILQ_FIRST(&ngq->queue)) != NULL) {
2180 		STAILQ_REMOVE_HEAD(&ngq->queue, el_next);
2181 		if (STAILQ_EMPTY(&ngq->queue))
2182 			atomic_clear_int(&ngq->q_flags, OP_PENDING);
2183 		NG_QUEUE_UNLOCK(ngq);
2184 
2185 		/* If the item is supplying a callback, call it with an error */
2186 		if (item->apply != NULL) {
2187 			if (item->depth == 1)
2188 				item->apply->error = ENOENT;
2189 			if (refcount_release(&item->apply->refs)) {
2190 				(*item->apply->apply)(item->apply->context,
2191 				    item->apply->error);
2192 			}
2193 		}
2194 		NG_FREE_ITEM(item);
2195 		NG_QUEUE_LOCK(ngq);
2196 	}
2197 	NG_QUEUE_UNLOCK(ngq);
2198 }
2199 
2200 /***********************************************************************
2201 * Externally visible method for sending or queueing messages or data.
2202 ***********************************************************************/
2203 
2204 /*
2205  * The module code should have filled out the item correctly by this stage:
2206  * Common:
2207  *    reference to destination node.
2208  *    Reference to destination rcv hook if relevant.
2209  *    apply pointer must be or NULL or reference valid struct ng_apply_info.
2210  * Data:
2211  *    pointer to mbuf
2212  * Control_Message:
2213  *    pointer to msg.
2214  *    ID of original sender node. (return address)
2215  * Function:
2216  *    Function pointer
2217  *    void * argument
2218  *    integer argument
2219  *
2220  * The nodes have several routines and macros to help with this task:
2221  */
2222 
2223 int
2224 ng_snd_item(item_p item, int flags)
2225 {
2226 	hook_p hook;
2227 	node_p node;
2228 	int queue, rw;
2229 	struct ng_queue *ngq;
2230 	int error = 0;
2231 
2232 	/* We are sending item, so it must be present! */
2233 	KASSERT(item != NULL, ("ng_snd_item: item is NULL"));
2234 
2235 #ifdef	NETGRAPH_DEBUG
2236 	_ngi_check(item, __FILE__, __LINE__);
2237 #endif
2238 
2239 	/* Item was sent once more, postpone apply() call. */
2240 	if (item->apply)
2241 		refcount_acquire(&item->apply->refs);
2242 
2243 	node = NGI_NODE(item);
2244 	/* Node is never optional. */
2245 	KASSERT(node != NULL, ("ng_snd_item: node is NULL"));
2246 
2247 	hook = NGI_HOOK(item);
2248 	/* Valid hook and mbuf are mandatory for data. */
2249 	if ((item->el_flags & NGQF_TYPE) == NGQF_DATA) {
2250 		KASSERT(hook != NULL, ("ng_snd_item: hook for data is NULL"));
2251 		if (NGI_M(item) == NULL)
2252 			ERROUT(EINVAL);
2253 		CHECK_DATA_MBUF(NGI_M(item));
2254 	}
2255 
2256 	/*
2257 	 * If the item or the node specifies single threading, force
2258 	 * writer semantics. Similarly, the node may say one hook always
2259 	 * produces writers. These are overrides.
2260 	 */
2261 	if (((item->el_flags & NGQF_RW) == NGQF_WRITER) ||
2262 	    (node->nd_flags & NGF_FORCE_WRITER) ||
2263 	    (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
2264 		rw = NGQRW_W;
2265 	} else {
2266 		rw = NGQRW_R;
2267 	}
2268 
2269 	/*
2270 	 * If sender or receiver requests queued delivery, or call graph
2271 	 * loops back from outbound to inbound path, or stack usage
2272 	 * level is dangerous - enqueue message.
2273 	 */
2274 	if ((flags & NG_QUEUE) || (hook && (hook->hk_flags & HK_QUEUE))) {
2275 		queue = 1;
2276 	} else if (hook && (hook->hk_flags & HK_TO_INBOUND) &&
2277 	    curthread->td_ng_outbound) {
2278 		queue = 1;
2279 	} else {
2280 		queue = 0;
2281 #ifdef GET_STACK_USAGE
2282 		/*
2283 		 * Most of netgraph nodes have small stack consumption and
2284 		 * for them 25% of free stack space is more than enough.
2285 		 * Nodes/hooks with higher stack usage should be marked as
2286 		 * HI_STACK. For them 50% of stack will be guaranteed then.
2287 		 * XXX: Values 25% and 50% are completely empirical.
2288 		 */
2289 		size_t	st, su, sl;
2290 		GET_STACK_USAGE(st, su);
2291 		sl = st - su;
2292 		if ((sl * 4 < st) || ((sl * 2 < st) &&
2293 		    ((node->nd_flags & NGF_HI_STACK) || (hook &&
2294 		    (hook->hk_flags & HK_HI_STACK)))))
2295 			queue = 1;
2296 #endif
2297 	}
2298 
2299 	if (queue) {
2300 		/* Put it on the queue for that node*/
2301 		ng_queue_rw(node, item, rw);
2302 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2303 	}
2304 
2305 	/*
2306 	 * We already decided how we will be queueud or treated.
2307 	 * Try get the appropriate operating permission.
2308 	 */
2309  	if (rw == NGQRW_R)
2310 		item = ng_acquire_read(node, item);
2311 	else
2312 		item = ng_acquire_write(node, item);
2313 
2314 	/* Item was queued while trying to get permission. */
2315 	if (item == NULL)
2316 		return ((flags & NG_PROGRESS) ? EINPROGRESS : 0);
2317 
2318 	NGI_GET_NODE(item, node); /* zaps stored node */
2319 
2320 	item->depth++;
2321 	error = ng_apply_item(node, item, rw); /* drops r/w lock when done */
2322 
2323 	/* If something is waiting on queue and ready, schedule it. */
2324 	ngq = &node->nd_input_queue;
2325 	if (QUEUE_ACTIVE(ngq)) {
2326 		NG_QUEUE_LOCK(ngq);
2327 		if (QUEUE_ACTIVE(ngq) && NEXT_QUEUED_ITEM_CAN_PROCEED(ngq))
2328 			ng_worklist_add(node);
2329 		NG_QUEUE_UNLOCK(ngq);
2330 	}
2331 
2332 	/*
2333 	 * Node may go away as soon as we remove the reference.
2334 	 * Whatever we do, DO NOT access the node again!
2335 	 */
2336 	NG_NODE_UNREF(node);
2337 
2338 	return (error);
2339 
2340 done:
2341 	/* If was not sent, apply callback here. */
2342 	if (item->apply != NULL) {
2343 		if (item->depth == 0 && error != 0)
2344 			item->apply->error = error;
2345 		if (refcount_release(&item->apply->refs)) {
2346 			(*item->apply->apply)(item->apply->context,
2347 			    item->apply->error);
2348 		}
2349 	}
2350 
2351 	NG_FREE_ITEM(item);
2352 	return (error);
2353 }
2354 
2355 /*
2356  * We have an item that was possibly queued somewhere.
2357  * It should contain all the information needed
2358  * to run it on the appropriate node/hook.
2359  * If there is apply pointer and we own the last reference, call apply().
2360  */
2361 static int
2362 ng_apply_item(node_p node, item_p item, int rw)
2363 {
2364 	hook_p  hook;
2365 	ng_rcvdata_t *rcvdata;
2366 	ng_rcvmsg_t *rcvmsg;
2367 	struct ng_apply_info *apply;
2368 	int	error = 0, depth;
2369 
2370 	/* Node and item are never optional. */
2371 	KASSERT(node != NULL, ("ng_apply_item: node is NULL"));
2372 	KASSERT(item != NULL, ("ng_apply_item: item is NULL"));
2373 
2374 	NGI_GET_HOOK(item, hook); /* clears stored hook */
2375 #ifdef	NETGRAPH_DEBUG
2376 	_ngi_check(item, __FILE__, __LINE__);
2377 #endif
2378 
2379 	apply = item->apply;
2380 	depth = item->depth;
2381 
2382 	switch (item->el_flags & NGQF_TYPE) {
2383 	case NGQF_DATA:
2384 		/*
2385 		 * Check things are still ok as when we were queued.
2386 		 */
2387 		KASSERT(hook != NULL, ("ng_apply_item: hook for data is NULL"));
2388 		if (NG_HOOK_NOT_VALID(hook) ||
2389 		    NG_NODE_NOT_VALID(node)) {
2390 			error = EIO;
2391 			NG_FREE_ITEM(item);
2392 			break;
2393 		}
2394 		/*
2395 		 * If no receive method, just silently drop it.
2396 		 * Give preference to the hook over-ride method.
2397 		 */
2398 		if ((!(rcvdata = hook->hk_rcvdata)) &&
2399 		    (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
2400 			error = 0;
2401 			NG_FREE_ITEM(item);
2402 			break;
2403 		}
2404 		error = (*rcvdata)(hook, item);
2405 		break;
2406 	case NGQF_MESG:
2407 		if (hook && NG_HOOK_NOT_VALID(hook)) {
2408 			/*
2409 			 * The hook has been zapped then we can't use it.
2410 			 * Immediately drop its reference.
2411 			 * The message may not need it.
2412 			 */
2413 			NG_HOOK_UNREF(hook);
2414 			hook = NULL;
2415 		}
2416 		/*
2417 		 * Similarly, if the node is a zombie there is
2418 		 * nothing we can do with it, drop everything.
2419 		 */
2420 		if (NG_NODE_NOT_VALID(node)) {
2421 			TRAP_ERROR();
2422 			error = EINVAL;
2423 			NG_FREE_ITEM(item);
2424 			break;
2425 		}
2426 		/*
2427 		 * Call the appropriate message handler for the object.
2428 		 * It is up to the message handler to free the message.
2429 		 * If it's a generic message, handle it generically,
2430 		 * otherwise call the type's message handler (if it exists).
2431 		 * XXX (race). Remember that a queued message may
2432 		 * reference a node or hook that has just been
2433 		 * invalidated. It will exist as the queue code
2434 		 * is holding a reference, but..
2435 		 */
2436 		if ((NGI_MSG(item)->header.typecookie == NGM_GENERIC_COOKIE) &&
2437 		    ((NGI_MSG(item)->header.flags & NGF_RESP) == 0)) {
2438 			error = ng_generic_msg(node, item, hook);
2439 			break;
2440 		}
2441 		if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg))) &&
2442 		    (!(rcvmsg = node->nd_type->rcvmsg))) {
2443 			TRAP_ERROR();
2444 			error = 0;
2445 			NG_FREE_ITEM(item);
2446 			break;
2447 		}
2448 		error = (*rcvmsg)(node, item, hook);
2449 		break;
2450 	case NGQF_FN:
2451 	case NGQF_FN2:
2452 		/*
2453 		 * In the case of the shutdown message we allow it to hit
2454 		 * even if the node is invalid.
2455 		 */
2456 		if (NG_NODE_NOT_VALID(node) &&
2457 		    NGI_FN(item) != &ng_rmnode) {
2458 			TRAP_ERROR();
2459 			error = EINVAL;
2460 			NG_FREE_ITEM(item);
2461 			break;
2462 		}
2463 		/* Same is about some internal functions and invalid hook. */
2464 		if (hook && NG_HOOK_NOT_VALID(hook) &&
2465 		    NGI_FN2(item) != &ng_con_part2 &&
2466 		    NGI_FN2(item) != &ng_con_part3 &&
2467 		    NGI_FN(item) != &ng_rmhook_part2) {
2468 			TRAP_ERROR();
2469 			error = EINVAL;
2470 			NG_FREE_ITEM(item);
2471 			break;
2472 		}
2473 
2474 		if ((item->el_flags & NGQF_TYPE) == NGQF_FN) {
2475 			(*NGI_FN(item))(node, hook, NGI_ARG1(item),
2476 			    NGI_ARG2(item));
2477 			NG_FREE_ITEM(item);
2478 		} else	/* it is NGQF_FN2 */
2479 			error = (*NGI_FN2(item))(node, item, hook);
2480 		break;
2481 	}
2482 	/*
2483 	 * We held references on some of the resources
2484 	 * that we took from the item. Now that we have
2485 	 * finished doing everything, drop those references.
2486 	 */
2487 	if (hook)
2488 		NG_HOOK_UNREF(hook);
2489 
2490  	if (rw == NGQRW_R)
2491 		ng_leave_read(node);
2492 	else
2493 		ng_leave_write(node);
2494 
2495 	/* Apply callback. */
2496 	if (apply != NULL) {
2497 		if (depth == 1 && error != 0)
2498 			apply->error = error;
2499 		if (refcount_release(&apply->refs))
2500 			(*apply->apply)(apply->context, apply->error);
2501 	}
2502 
2503 	return (error);
2504 }
2505 
2506 /***********************************************************************
2507  * Implement the 'generic' control messages
2508  ***********************************************************************/
2509 static int
2510 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
2511 {
2512 	int error = 0;
2513 	struct ng_mesg *msg;
2514 	struct ng_mesg *resp = NULL;
2515 
2516 	NGI_GET_MSG(item, msg);
2517 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
2518 		TRAP_ERROR();
2519 		error = EINVAL;
2520 		goto out;
2521 	}
2522 	switch (msg->header.cmd) {
2523 	case NGM_SHUTDOWN:
2524 		ng_rmnode(here, NULL, NULL, 0);
2525 		break;
2526 	case NGM_MKPEER:
2527 	    {
2528 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
2529 
2530 		if (msg->header.arglen != sizeof(*mkp)) {
2531 			TRAP_ERROR();
2532 			error = EINVAL;
2533 			break;
2534 		}
2535 		mkp->type[sizeof(mkp->type) - 1] = '\0';
2536 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
2537 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
2538 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
2539 		break;
2540 	    }
2541 	case NGM_CONNECT:
2542 	    {
2543 		struct ngm_connect *const con =
2544 			(struct ngm_connect *) msg->data;
2545 		node_p node2;
2546 
2547 		if (msg->header.arglen != sizeof(*con)) {
2548 			TRAP_ERROR();
2549 			error = EINVAL;
2550 			break;
2551 		}
2552 		con->path[sizeof(con->path) - 1] = '\0';
2553 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
2554 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
2555 		/* Don't forget we get a reference.. */
2556 		error = ng_path2noderef(here, con->path, &node2, NULL);
2557 		if (error)
2558 			break;
2559 		error = ng_con_nodes(item, here, con->ourhook,
2560 		    node2, con->peerhook);
2561 		NG_NODE_UNREF(node2);
2562 		break;
2563 	    }
2564 	case NGM_NAME:
2565 	    {
2566 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
2567 
2568 		if (msg->header.arglen != sizeof(*nam)) {
2569 			TRAP_ERROR();
2570 			error = EINVAL;
2571 			break;
2572 		}
2573 		nam->name[sizeof(nam->name) - 1] = '\0';
2574 		error = ng_name_node(here, nam->name);
2575 		break;
2576 	    }
2577 	case NGM_RMHOOK:
2578 	    {
2579 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
2580 		hook_p hook;
2581 
2582 		if (msg->header.arglen != sizeof(*rmh)) {
2583 			TRAP_ERROR();
2584 			error = EINVAL;
2585 			break;
2586 		}
2587 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
2588 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
2589 			ng_destroy_hook(hook);
2590 		break;
2591 	    }
2592 	case NGM_NODEINFO:
2593 	    {
2594 		struct nodeinfo *ni;
2595 
2596 		NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
2597 		if (resp == NULL) {
2598 			error = ENOMEM;
2599 			break;
2600 		}
2601 
2602 		/* Fill in node info */
2603 		ni = (struct nodeinfo *) resp->data;
2604 		if (NG_NODE_HAS_NAME(here))
2605 			strcpy(ni->name, NG_NODE_NAME(here));
2606 		strcpy(ni->type, here->nd_type->name);
2607 		ni->id = ng_node2ID(here);
2608 		ni->hooks = here->nd_numhooks;
2609 		break;
2610 	    }
2611 	case NGM_LISTHOOKS:
2612 	    {
2613 		const int nhooks = here->nd_numhooks;
2614 		struct hooklist *hl;
2615 		struct nodeinfo *ni;
2616 		hook_p hook;
2617 
2618 		/* Get response struct */
2619 		NG_MKRESPONSE(resp, msg, sizeof(*hl) +
2620 		    (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
2621 		if (resp == NULL) {
2622 			error = ENOMEM;
2623 			break;
2624 		}
2625 		hl = (struct hooklist *) resp->data;
2626 		ni = &hl->nodeinfo;
2627 
2628 		/* Fill in node info */
2629 		if (NG_NODE_HAS_NAME(here))
2630 			strcpy(ni->name, NG_NODE_NAME(here));
2631 		strcpy(ni->type, here->nd_type->name);
2632 		ni->id = ng_node2ID(here);
2633 
2634 		/* Cycle through the linked list of hooks */
2635 		ni->hooks = 0;
2636 		LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
2637 			struct linkinfo *const link = &hl->link[ni->hooks];
2638 
2639 			if (ni->hooks >= nhooks) {
2640 				log(LOG_ERR, "%s: number of %s changed\n",
2641 				    __func__, "hooks");
2642 				break;
2643 			}
2644 			if (NG_HOOK_NOT_VALID(hook))
2645 				continue;
2646 			strcpy(link->ourhook, NG_HOOK_NAME(hook));
2647 			strcpy(link->peerhook, NG_PEER_HOOK_NAME(hook));
2648 			if (NG_PEER_NODE_NAME(hook)[0] != '\0')
2649 				strcpy(link->nodeinfo.name,
2650 				    NG_PEER_NODE_NAME(hook));
2651 			strcpy(link->nodeinfo.type,
2652 			   NG_PEER_NODE(hook)->nd_type->name);
2653 			link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
2654 			link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
2655 			ni->hooks++;
2656 		}
2657 		break;
2658 	    }
2659 
2660 	case NGM_LISTNODES:
2661 	    {
2662 		struct namelist *nl;
2663 		node_p node;
2664 		int i;
2665 
2666 		IDHASH_RLOCK();
2667 		/* Get response struct. */
2668 		NG_MKRESPONSE(resp, msg, sizeof(*nl) +
2669 		    (V_ng_nodes * sizeof(struct nodeinfo)), M_NOWAIT);
2670 		if (resp == NULL) {
2671 			IDHASH_RUNLOCK();
2672 			error = ENOMEM;
2673 			break;
2674 		}
2675 		nl = (struct namelist *) resp->data;
2676 
2677 		/* Cycle through the lists of nodes. */
2678 		nl->numnames = 0;
2679 		for (i = 0; i <= V_ng_ID_hmask; i++) {
2680 			LIST_FOREACH(node, &V_ng_ID_hash[i], nd_idnodes) {
2681 				struct nodeinfo *const np =
2682 				    &nl->nodeinfo[nl->numnames];
2683 
2684 				if (NG_NODE_NOT_VALID(node))
2685 					continue;
2686 				if (NG_NODE_HAS_NAME(node))
2687 					strcpy(np->name, NG_NODE_NAME(node));
2688 				strcpy(np->type, node->nd_type->name);
2689 				np->id = ng_node2ID(node);
2690 				np->hooks = node->nd_numhooks;
2691 				KASSERT(nl->numnames < V_ng_nodes,
2692 				    ("%s: no space", __func__));
2693 				nl->numnames++;
2694 			}
2695 		}
2696 		IDHASH_RUNLOCK();
2697 		break;
2698 	    }
2699 	case NGM_LISTNAMES:
2700 	    {
2701 		struct namelist *nl;
2702 		node_p node;
2703 		int i;
2704 
2705 		NAMEHASH_RLOCK();
2706 		/* Get response struct. */
2707 		NG_MKRESPONSE(resp, msg, sizeof(*nl) +
2708 		    (V_ng_named_nodes * sizeof(struct nodeinfo)), M_NOWAIT);
2709 		if (resp == NULL) {
2710 			NAMEHASH_RUNLOCK();
2711 			error = ENOMEM;
2712 			break;
2713 		}
2714 		nl = (struct namelist *) resp->data;
2715 
2716 		/* Cycle through the lists of nodes. */
2717 		nl->numnames = 0;
2718 		for (i = 0; i <= V_ng_name_hmask; i++) {
2719 			LIST_FOREACH(node, &V_ng_name_hash[i], nd_nodes) {
2720 				struct nodeinfo *const np =
2721 				    &nl->nodeinfo[nl->numnames];
2722 
2723 				if (NG_NODE_NOT_VALID(node))
2724 					continue;
2725 				strcpy(np->name, NG_NODE_NAME(node));
2726 				strcpy(np->type, node->nd_type->name);
2727 				np->id = ng_node2ID(node);
2728 				np->hooks = node->nd_numhooks;
2729 				KASSERT(nl->numnames < V_ng_named_nodes,
2730 				    ("%s: no space", __func__));
2731 				nl->numnames++;
2732 			}
2733 		}
2734 		NAMEHASH_RUNLOCK();
2735 		break;
2736 	    }
2737 
2738 	case NGM_LISTTYPES:
2739 	    {
2740 		struct typelist *tl;
2741 		struct ng_type *type;
2742 		int num = 0;
2743 
2744 		TYPELIST_RLOCK();
2745 		/* Count number of types */
2746 		LIST_FOREACH(type, &ng_typelist, types)
2747 			num++;
2748 
2749 		/* Get response struct */
2750 		NG_MKRESPONSE(resp, msg, sizeof(*tl) +
2751 		    (num * sizeof(struct typeinfo)), M_NOWAIT);
2752 		if (resp == NULL) {
2753 			TYPELIST_RUNLOCK();
2754 			error = ENOMEM;
2755 			break;
2756 		}
2757 		tl = (struct typelist *) resp->data;
2758 
2759 		/* Cycle through the linked list of types */
2760 		tl->numtypes = 0;
2761 		LIST_FOREACH(type, &ng_typelist, types) {
2762 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
2763 
2764 			strcpy(tp->type_name, type->name);
2765 			tp->numnodes = type->refs - 1; /* don't count list */
2766 			KASSERT(tl->numtypes < num, ("%s: no space", __func__));
2767 			tl->numtypes++;
2768 		}
2769 		TYPELIST_RUNLOCK();
2770 		break;
2771 	    }
2772 
2773 	case NGM_BINARY2ASCII:
2774 	    {
2775 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2776 		const struct ng_parse_type *argstype;
2777 		const struct ng_cmdlist *c;
2778 		struct ng_mesg *binary, *ascii;
2779 
2780 		/* Data area must contain a valid netgraph message */
2781 		binary = (struct ng_mesg *)msg->data;
2782 		if (msg->header.arglen < sizeof(struct ng_mesg) ||
2783 		    (msg->header.arglen - sizeof(struct ng_mesg) <
2784 		    binary->header.arglen)) {
2785 			TRAP_ERROR();
2786 			error = EINVAL;
2787 			break;
2788 		}
2789 
2790 		/* Get a response message with lots of room */
2791 		NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
2792 		if (resp == NULL) {
2793 			error = ENOMEM;
2794 			break;
2795 		}
2796 		ascii = (struct ng_mesg *)resp->data;
2797 
2798 		/* Copy binary message header to response message payload */
2799 		bcopy(binary, ascii, sizeof(*binary));
2800 
2801 		/* Find command by matching typecookie and command number */
2802 		for (c = here->nd_type->cmdlist; c != NULL && c->name != NULL;
2803 		    c++) {
2804 			if (binary->header.typecookie == c->cookie &&
2805 			    binary->header.cmd == c->cmd)
2806 				break;
2807 		}
2808 		if (c == NULL || c->name == NULL) {
2809 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2810 				if (binary->header.typecookie == c->cookie &&
2811 				    binary->header.cmd == c->cmd)
2812 					break;
2813 			}
2814 			if (c->name == NULL) {
2815 				NG_FREE_MSG(resp);
2816 				error = ENOSYS;
2817 				break;
2818 			}
2819 		}
2820 
2821 		/* Convert command name to ASCII */
2822 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
2823 		    "%s", c->name);
2824 
2825 		/* Convert command arguments to ASCII */
2826 		argstype = (binary->header.flags & NGF_RESP) ?
2827 		    c->respType : c->mesgType;
2828 		if (argstype == NULL) {
2829 			*ascii->data = '\0';
2830 		} else {
2831 			if ((error = ng_unparse(argstype,
2832 			    (u_char *)binary->data,
2833 			    ascii->data, bufSize)) != 0) {
2834 				NG_FREE_MSG(resp);
2835 				break;
2836 			}
2837 		}
2838 
2839 		/* Return the result as struct ng_mesg plus ASCII string */
2840 		bufSize = strlen(ascii->data) + 1;
2841 		ascii->header.arglen = bufSize;
2842 		resp->header.arglen = sizeof(*ascii) + bufSize;
2843 		break;
2844 	    }
2845 
2846 	case NGM_ASCII2BINARY:
2847 	    {
2848 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
2849 		const struct ng_cmdlist *c;
2850 		const struct ng_parse_type *argstype;
2851 		struct ng_mesg *ascii, *binary;
2852 		int off = 0;
2853 
2854 		/* Data area must contain at least a struct ng_mesg + '\0' */
2855 		ascii = (struct ng_mesg *)msg->data;
2856 		if ((msg->header.arglen < sizeof(*ascii) + 1) ||
2857 		    (ascii->header.arglen < 1) ||
2858 		    (msg->header.arglen < sizeof(*ascii) +
2859 		    ascii->header.arglen)) {
2860 			TRAP_ERROR();
2861 			error = EINVAL;
2862 			break;
2863 		}
2864 		ascii->data[ascii->header.arglen - 1] = '\0';
2865 
2866 		/* Get a response message with lots of room */
2867 		NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
2868 		if (resp == NULL) {
2869 			error = ENOMEM;
2870 			break;
2871 		}
2872 		binary = (struct ng_mesg *)resp->data;
2873 
2874 		/* Copy ASCII message header to response message payload */
2875 		bcopy(ascii, binary, sizeof(*ascii));
2876 
2877 		/* Find command by matching ASCII command string */
2878 		for (c = here->nd_type->cmdlist;
2879 		    c != NULL && c->name != NULL; c++) {
2880 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
2881 				break;
2882 		}
2883 		if (c == NULL || c->name == NULL) {
2884 			for (c = ng_generic_cmds; c->name != NULL; c++) {
2885 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
2886 					break;
2887 			}
2888 			if (c->name == NULL) {
2889 				NG_FREE_MSG(resp);
2890 				error = ENOSYS;
2891 				break;
2892 			}
2893 		}
2894 
2895 		/* Convert command name to binary */
2896 		binary->header.cmd = c->cmd;
2897 		binary->header.typecookie = c->cookie;
2898 
2899 		/* Convert command arguments to binary */
2900 		argstype = (binary->header.flags & NGF_RESP) ?
2901 		    c->respType : c->mesgType;
2902 		if (argstype == NULL) {
2903 			bufSize = 0;
2904 		} else {
2905 			if ((error = ng_parse(argstype, ascii->data, &off,
2906 			    (u_char *)binary->data, &bufSize)) != 0) {
2907 				NG_FREE_MSG(resp);
2908 				break;
2909 			}
2910 		}
2911 
2912 		/* Return the result */
2913 		binary->header.arglen = bufSize;
2914 		resp->header.arglen = sizeof(*binary) + bufSize;
2915 		break;
2916 	    }
2917 
2918 	case NGM_TEXT_CONFIG:
2919 	case NGM_TEXT_STATUS:
2920 		/*
2921 		 * This one is tricky as it passes the command down to the
2922 		 * actual node, even though it is a generic type command.
2923 		 * This means we must assume that the item/msg is already freed
2924 		 * when control passes back to us.
2925 		 */
2926 		if (here->nd_type->rcvmsg != NULL) {
2927 			NGI_MSG(item) = msg; /* put it back as we found it */
2928 			return((*here->nd_type->rcvmsg)(here, item, lasthook));
2929 		}
2930 		/* Fall through if rcvmsg not supported */
2931 	default:
2932 		TRAP_ERROR();
2933 		error = EINVAL;
2934 	}
2935 	/*
2936 	 * Sometimes a generic message may be statically allocated
2937 	 * to avoid problems with allocating when in tight memory situations.
2938 	 * Don't free it if it is so.
2939 	 * I break them apart here, because erros may cause a free if the item
2940 	 * in which case we'd be doing it twice.
2941 	 * they are kept together above, to simplify freeing.
2942 	 */
2943 out:
2944 	NG_RESPOND_MSG(error, here, item, resp);
2945 	NG_FREE_MSG(msg);
2946 	return (error);
2947 }
2948 
2949 /************************************************************************
2950 			Queue element get/free routines
2951 ************************************************************************/
2952 
2953 uma_zone_t			ng_qzone;
2954 uma_zone_t			ng_qdzone;
2955 static int			numthreads = 0; /* number of queue threads */
2956 static int			maxalloc = 4096;/* limit the damage of a leak */
2957 static int			maxdata = 4096;	/* limit the damage of a DoS */
2958 
2959 SYSCTL_INT(_net_graph, OID_AUTO, threads, CTLFLAG_RDTUN, &numthreads,
2960     0, "Number of queue processing threads");
2961 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RDTUN, &maxalloc,
2962     0, "Maximum number of non-data queue items to allocate");
2963 SYSCTL_INT(_net_graph, OID_AUTO, maxdata, CTLFLAG_RDTUN, &maxdata,
2964     0, "Maximum number of data queue items to allocate");
2965 
2966 #ifdef	NETGRAPH_DEBUG
2967 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
2968 static int allocated;	/* number of items malloc'd */
2969 #endif
2970 
2971 /*
2972  * Get a queue entry.
2973  * This is usually called when a packet first enters netgraph.
2974  * By definition, this is usually from an interrupt, or from a user.
2975  * Users are not so important, but try be quick for the times that it's
2976  * an interrupt.
2977  */
2978 static __inline item_p
2979 ng_alloc_item(int type, int flags)
2980 {
2981 	item_p item;
2982 
2983 	KASSERT(((type & ~NGQF_TYPE) == 0),
2984 	    ("%s: incorrect item type: %d", __func__, type));
2985 
2986 	item = uma_zalloc((type == NGQF_DATA) ? ng_qdzone : ng_qzone,
2987 	    ((flags & NG_WAITOK) ? M_WAITOK : M_NOWAIT) | M_ZERO);
2988 
2989 	if (item) {
2990 		item->el_flags = type;
2991 #ifdef	NETGRAPH_DEBUG
2992 		mtx_lock(&ngq_mtx);
2993 		TAILQ_INSERT_TAIL(&ng_itemlist, item, all);
2994 		allocated++;
2995 		mtx_unlock(&ngq_mtx);
2996 #endif
2997 	}
2998 
2999 	return (item);
3000 }
3001 
3002 /*
3003  * Release a queue entry
3004  */
3005 void
3006 ng_free_item(item_p item)
3007 {
3008 	/*
3009 	 * The item may hold resources on its own. We need to free
3010 	 * these before we can free the item. What they are depends upon
3011 	 * what kind of item it is. it is important that nodes zero
3012 	 * out pointers to resources that they remove from the item
3013 	 * or we release them again here.
3014 	 */
3015 	switch (item->el_flags & NGQF_TYPE) {
3016 	case NGQF_DATA:
3017 		/* If we have an mbuf still attached.. */
3018 		NG_FREE_M(_NGI_M(item));
3019 		break;
3020 	case NGQF_MESG:
3021 		_NGI_RETADDR(item) = 0;
3022 		NG_FREE_MSG(_NGI_MSG(item));
3023 		break;
3024 	case NGQF_FN:
3025 	case NGQF_FN2:
3026 		/* nothing to free really, */
3027 		_NGI_FN(item) = NULL;
3028 		_NGI_ARG1(item) = NULL;
3029 		_NGI_ARG2(item) = 0;
3030 		break;
3031 	}
3032 	/* If we still have a node or hook referenced... */
3033 	_NGI_CLR_NODE(item);
3034 	_NGI_CLR_HOOK(item);
3035 
3036 #ifdef	NETGRAPH_DEBUG
3037 	mtx_lock(&ngq_mtx);
3038 	TAILQ_REMOVE(&ng_itemlist, item, all);
3039 	allocated--;
3040 	mtx_unlock(&ngq_mtx);
3041 #endif
3042 	uma_zfree(((item->el_flags & NGQF_TYPE) == NGQF_DATA) ?
3043 	    ng_qdzone : ng_qzone, item);
3044 }
3045 
3046 /*
3047  * Change type of the queue entry.
3048  * Possibly reallocates it from another UMA zone.
3049  */
3050 static __inline item_p
3051 ng_realloc_item(item_p pitem, int type, int flags)
3052 {
3053 	item_p item;
3054 	int from, to;
3055 
3056 	KASSERT((pitem != NULL), ("%s: can't reallocate NULL", __func__));
3057 	KASSERT(((type & ~NGQF_TYPE) == 0),
3058 	    ("%s: incorrect item type: %d", __func__, type));
3059 
3060 	from = ((pitem->el_flags & NGQF_TYPE) == NGQF_DATA);
3061 	to = (type == NGQF_DATA);
3062 	if (from != to) {
3063 		/* If reallocation is required do it and copy item. */
3064 		if ((item = ng_alloc_item(type, flags)) == NULL) {
3065 			ng_free_item(pitem);
3066 			return (NULL);
3067 		}
3068 		*item = *pitem;
3069 		ng_free_item(pitem);
3070 	} else
3071 		item = pitem;
3072 	item->el_flags = (item->el_flags & ~NGQF_TYPE) | type;
3073 
3074 	return (item);
3075 }
3076 
3077 /************************************************************************
3078 			Module routines
3079 ************************************************************************/
3080 
3081 /*
3082  * Handle the loading/unloading of a netgraph node type module
3083  */
3084 int
3085 ng_mod_event(module_t mod, int event, void *data)
3086 {
3087 	struct ng_type *const type = data;
3088 	int error = 0;
3089 
3090 	switch (event) {
3091 	case MOD_LOAD:
3092 
3093 		/* Register new netgraph node type */
3094 		if ((error = ng_newtype(type)) != 0)
3095 			break;
3096 
3097 		/* Call type specific code */
3098 		if (type->mod_event != NULL)
3099 			if ((error = (*type->mod_event)(mod, event, data))) {
3100 				TYPELIST_WLOCK();
3101 				type->refs--;	/* undo it */
3102 				LIST_REMOVE(type, types);
3103 				TYPELIST_WUNLOCK();
3104 			}
3105 		break;
3106 
3107 	case MOD_UNLOAD:
3108 		if (type->refs > 1) {		/* make sure no nodes exist! */
3109 			error = EBUSY;
3110 		} else {
3111 			if (type->refs == 0) /* failed load, nothing to undo */
3112 				break;
3113 			if (type->mod_event != NULL) {	/* check with type */
3114 				error = (*type->mod_event)(mod, event, data);
3115 				if (error != 0)	/* type refuses.. */
3116 					break;
3117 			}
3118 			TYPELIST_WLOCK();
3119 			LIST_REMOVE(type, types);
3120 			TYPELIST_WUNLOCK();
3121 		}
3122 		break;
3123 
3124 	default:
3125 		if (type->mod_event != NULL)
3126 			error = (*type->mod_event)(mod, event, data);
3127 		else
3128 			error = EOPNOTSUPP;		/* XXX ? */
3129 		break;
3130 	}
3131 	return (error);
3132 }
3133 
3134 static void
3135 vnet_netgraph_init(const void *unused __unused)
3136 {
3137 
3138 	/* We start with small hashes, but they can grow. */
3139 	V_ng_ID_hash = hashinit(16, M_NETGRAPH_NODE, &V_ng_ID_hmask);
3140 	V_ng_name_hash = hashinit(16, M_NETGRAPH_NODE, &V_ng_name_hmask);
3141 }
3142 VNET_SYSINIT(vnet_netgraph_init, SI_SUB_NETGRAPH, SI_ORDER_FIRST,
3143     vnet_netgraph_init, NULL);
3144 
3145 #ifdef VIMAGE
3146 static void
3147 vnet_netgraph_uninit(const void *unused __unused)
3148 {
3149 	node_p node = NULL, last_killed = NULL;
3150 	int i;
3151 
3152 	do {
3153 		/* Find a node to kill */
3154 		IDHASH_RLOCK();
3155 		for (i = 0; i <= V_ng_ID_hmask; i++) {
3156 			LIST_FOREACH(node, &V_ng_ID_hash[i], nd_idnodes) {
3157 				if (node != &ng_deadnode) {
3158 					NG_NODE_REF(node);
3159 					break;
3160 				}
3161 			}
3162 			if (node != NULL)
3163 				break;
3164 		}
3165 		IDHASH_RUNLOCK();
3166 
3167 		/* Attempt to kill it only if it is a regular node */
3168 		if (node != NULL) {
3169 			if (node == last_killed) {
3170 				/* This should never happen */
3171 				printf("ng node %s needs NGF_REALLY_DIE\n",
3172 				    node->nd_name);
3173 				if (node->nd_flags & NGF_REALLY_DIE)
3174 					panic("ng node %s won't die",
3175 					    node->nd_name);
3176 				node->nd_flags |= NGF_REALLY_DIE;
3177 			}
3178 			ng_rmnode(node, NULL, NULL, 0);
3179 			NG_NODE_UNREF(node);
3180 			last_killed = node;
3181 		}
3182 	} while (node != NULL);
3183 
3184 	hashdestroy(V_ng_name_hash, M_NETGRAPH_NODE, V_ng_name_hmask);
3185 	hashdestroy(V_ng_ID_hash, M_NETGRAPH_NODE, V_ng_ID_hmask);
3186 }
3187 VNET_SYSUNINIT(vnet_netgraph_uninit, SI_SUB_NETGRAPH, SI_ORDER_FIRST,
3188     vnet_netgraph_uninit, NULL);
3189 #endif /* VIMAGE */
3190 
3191 /*
3192  * Handle loading and unloading for this code.
3193  * The only thing we need to link into is the NETISR strucure.
3194  */
3195 static int
3196 ngb_mod_event(module_t mod, int event, void *data)
3197 {
3198 	struct proc *p;
3199 	struct thread *td;
3200 	int i, error = 0;
3201 
3202 	switch (event) {
3203 	case MOD_LOAD:
3204 		/* Initialize everything. */
3205 		NG_WORKLIST_LOCK_INIT();
3206 		rw_init(&ng_typelist_lock, "netgraph types");
3207 		rw_init(&ng_idhash_lock, "netgraph idhash");
3208 		rw_init(&ng_namehash_lock, "netgraph namehash");
3209 		rw_init(&ng_topo_lock, "netgraph topology mutex");
3210 #ifdef	NETGRAPH_DEBUG
3211 		mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL,
3212 		    MTX_DEF);
3213 		mtx_init(&ngq_mtx, "netgraph item list mutex", NULL,
3214 		    MTX_DEF);
3215 #endif
3216 		ng_qzone = uma_zcreate("NetGraph items", sizeof(struct ng_item),
3217 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
3218 		uma_zone_set_max(ng_qzone, maxalloc);
3219 		ng_qdzone = uma_zcreate("NetGraph data items",
3220 		    sizeof(struct ng_item), NULL, NULL, NULL, NULL,
3221 		    UMA_ALIGN_CACHE, 0);
3222 		uma_zone_set_max(ng_qdzone, maxdata);
3223 		/* Autoconfigure number of threads. */
3224 		if (numthreads <= 0)
3225 			numthreads = mp_ncpus;
3226 		/* Create threads. */
3227     		p = NULL; /* start with no process */
3228 		for (i = 0; i < numthreads; i++) {
3229 			if (kproc_kthread_add(ngthread, NULL, &p, &td,
3230 			    RFHIGHPID, 0, "ng_queue", "ng_queue%d", i)) {
3231 				numthreads = i;
3232 				break;
3233 			}
3234 		}
3235 		break;
3236 	case MOD_UNLOAD:
3237 		/* You can't unload it because an interface may be using it. */
3238 		error = EBUSY;
3239 		break;
3240 	default:
3241 		error = EOPNOTSUPP;
3242 		break;
3243 	}
3244 	return (error);
3245 }
3246 
3247 static moduledata_t netgraph_mod = {
3248 	"netgraph",
3249 	ngb_mod_event,
3250 	(NULL)
3251 };
3252 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_NETGRAPH, SI_ORDER_FIRST);
3253 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
3254     "netgraph Family");
3255 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_ABI_VERSION,"");
3256 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_VERSION, "");
3257 
3258 #ifdef	NETGRAPH_DEBUG
3259 void
3260 dumphook (hook_p hook, char *file, int line)
3261 {
3262 	printf("hook: name %s, %d refs, Last touched:\n",
3263 		_NG_HOOK_NAME(hook), hook->hk_refs);
3264 	printf("	Last active @ %s, line %d\n",
3265 		hook->lastfile, hook->lastline);
3266 	if (line) {
3267 		printf(" problem discovered at file %s, line %d\n", file, line);
3268 #ifdef KDB
3269 		kdb_backtrace();
3270 #endif
3271 	}
3272 }
3273 
3274 void
3275 dumpnode(node_p node, char *file, int line)
3276 {
3277 	printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
3278 		_NG_NODE_ID(node), node->nd_type->name,
3279 		node->nd_numhooks, node->nd_flags,
3280 		node->nd_refs, node->nd_name);
3281 	printf("	Last active @ %s, line %d\n",
3282 		node->lastfile, node->lastline);
3283 	if (line) {
3284 		printf(" problem discovered at file %s, line %d\n", file, line);
3285 #ifdef KDB
3286 		kdb_backtrace();
3287 #endif
3288 	}
3289 }
3290 
3291 void
3292 dumpitem(item_p item, char *file, int line)
3293 {
3294 	printf(" ACTIVE item, last used at %s, line %d",
3295 		item->lastfile, item->lastline);
3296 	switch(item->el_flags & NGQF_TYPE) {
3297 	case NGQF_DATA:
3298 		printf(" - [data]\n");
3299 		break;
3300 	case NGQF_MESG:
3301 		printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
3302 		break;
3303 	case NGQF_FN:
3304 		printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
3305 			_NGI_FN(item),
3306 			_NGI_NODE(item),
3307 			_NGI_HOOK(item),
3308 			item->body.fn.fn_arg1,
3309 			item->body.fn.fn_arg2,
3310 			item->body.fn.fn_arg2);
3311 		break;
3312 	case NGQF_FN2:
3313 		printf(" - fn2@%p (%p, %p, %p, %d (%x))\n",
3314 			_NGI_FN2(item),
3315 			_NGI_NODE(item),
3316 			_NGI_HOOK(item),
3317 			item->body.fn.fn_arg1,
3318 			item->body.fn.fn_arg2,
3319 			item->body.fn.fn_arg2);
3320 		break;
3321 	}
3322 	if (line) {
3323 		printf(" problem discovered at file %s, line %d\n", file, line);
3324 		if (_NGI_NODE(item)) {
3325 			printf("node %p ([%x])\n",
3326 				_NGI_NODE(item), ng_node2ID(_NGI_NODE(item)));
3327 		}
3328 	}
3329 }
3330 
3331 static void
3332 ng_dumpitems(void)
3333 {
3334 	item_p item;
3335 	int i = 1;
3336 	TAILQ_FOREACH(item, &ng_itemlist, all) {
3337 		printf("[%d] ", i++);
3338 		dumpitem(item, NULL, 0);
3339 	}
3340 }
3341 
3342 static void
3343 ng_dumpnodes(void)
3344 {
3345 	node_p node;
3346 	int i = 1;
3347 	mtx_lock(&ng_nodelist_mtx);
3348 	SLIST_FOREACH(node, &ng_allnodes, nd_all) {
3349 		printf("[%d] ", i++);
3350 		dumpnode(node, NULL, 0);
3351 	}
3352 	mtx_unlock(&ng_nodelist_mtx);
3353 }
3354 
3355 static void
3356 ng_dumphooks(void)
3357 {
3358 	hook_p hook;
3359 	int i = 1;
3360 	mtx_lock(&ng_nodelist_mtx);
3361 	SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
3362 		printf("[%d] ", i++);
3363 		dumphook(hook, NULL, 0);
3364 	}
3365 	mtx_unlock(&ng_nodelist_mtx);
3366 }
3367 
3368 static int
3369 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
3370 {
3371 	int error;
3372 	int val;
3373 	int i;
3374 
3375 	val = allocated;
3376 	i = 1;
3377 	error = sysctl_handle_int(oidp, &val, 0, req);
3378 	if (error != 0 || req->newptr == NULL)
3379 		return (error);
3380 	if (val == 42) {
3381 		ng_dumpitems();
3382 		ng_dumpnodes();
3383 		ng_dumphooks();
3384 	}
3385 	return (0);
3386 }
3387 
3388 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items,
3389     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int),
3390     sysctl_debug_ng_dump_items, "I",
3391     "Number of allocated items");
3392 #endif	/* NETGRAPH_DEBUG */
3393 
3394 /***********************************************************************
3395 * Worklist routines
3396 **********************************************************************/
3397 /*
3398  * Pick a node off the list of nodes with work,
3399  * try get an item to process off it. Remove the node from the list.
3400  */
3401 static void
3402 ngthread(void *arg)
3403 {
3404 	for (;;) {
3405 		struct epoch_tracker et;
3406 		node_p  node;
3407 
3408 		/* Get node from the worklist. */
3409 		NG_WORKLIST_LOCK();
3410 		while ((node = STAILQ_FIRST(&ng_worklist)) == NULL)
3411 			NG_WORKLIST_SLEEP();
3412 		STAILQ_REMOVE_HEAD(&ng_worklist, nd_input_queue.q_work);
3413 		NG_WORKLIST_UNLOCK();
3414 		CURVNET_SET(node->nd_vnet);
3415 		CTR3(KTR_NET, "%20s: node [%x] (%p) taken off worklist",
3416 		    __func__, node->nd_ID, node);
3417 		/*
3418 		 * We have the node. We also take over the reference
3419 		 * that the list had on it.
3420 		 * Now process as much as you can, until it won't
3421 		 * let you have another item off the queue.
3422 		 * All this time, keep the reference
3423 		 * that lets us be sure that the node still exists.
3424 		 * Let the reference go at the last minute.
3425 		 */
3426 		NET_EPOCH_ENTER(et);
3427 		for (;;) {
3428 			item_p item;
3429 			int rw;
3430 
3431 			NG_QUEUE_LOCK(&node->nd_input_queue);
3432 			item = ng_dequeue(node, &rw);
3433 			if (item == NULL) {
3434 				node->nd_input_queue.q_flags2 &= ~NGQ2_WORKQ;
3435 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3436 				break; /* go look for another node */
3437 			} else {
3438 				NG_QUEUE_UNLOCK(&node->nd_input_queue);
3439 				NGI_GET_NODE(item, node); /* zaps stored node */
3440 				ng_apply_item(node, item, rw);
3441 				NG_NODE_UNREF(node);
3442 			}
3443 		}
3444 		NET_EPOCH_EXIT(et);
3445 		NG_NODE_UNREF(node);
3446 		CURVNET_RESTORE();
3447 	}
3448 }
3449 
3450 /*
3451  * XXX
3452  * It's posible that a debugging NG_NODE_REF may need
3453  * to be outside the mutex zone
3454  */
3455 static void
3456 ng_worklist_add(node_p node)
3457 {
3458 
3459 	mtx_assert(&node->nd_input_queue.q_mtx, MA_OWNED);
3460 
3461 	if ((node->nd_input_queue.q_flags2 & NGQ2_WORKQ) == 0) {
3462 		/*
3463 		 * If we are not already on the work queue,
3464 		 * then put us on.
3465 		 */
3466 		node->nd_input_queue.q_flags2 |= NGQ2_WORKQ;
3467 		NG_NODE_REF(node); /* XXX safe in mutex? */
3468 		NG_WORKLIST_LOCK();
3469 		STAILQ_INSERT_TAIL(&ng_worklist, node, nd_input_queue.q_work);
3470 		NG_WORKLIST_UNLOCK();
3471 		CTR3(KTR_NET, "%20s: node [%x] (%p) put on worklist", __func__,
3472 		    node->nd_ID, node);
3473 		NG_WORKLIST_WAKEUP();
3474 	} else {
3475 		CTR3(KTR_NET, "%20s: node [%x] (%p) already on worklist",
3476 		    __func__, node->nd_ID, node);
3477 	}
3478 }
3479 
3480 /***********************************************************************
3481 * Externally useable functions to set up a queue item ready for sending
3482 ***********************************************************************/
3483 
3484 #ifdef	NETGRAPH_DEBUG
3485 #define	ITEM_DEBUG_CHECKS						\
3486 	do {								\
3487 		if (NGI_NODE(item) ) {					\
3488 			printf("item already has node");		\
3489 			kdb_enter(KDB_WHY_NETGRAPH, "has node");	\
3490 			NGI_CLR_NODE(item);				\
3491 		}							\
3492 		if (NGI_HOOK(item) ) {					\
3493 			printf("item already has hook");		\
3494 			kdb_enter(KDB_WHY_NETGRAPH, "has hook");	\
3495 			NGI_CLR_HOOK(item);				\
3496 		}							\
3497 	} while (0)
3498 #else
3499 #define ITEM_DEBUG_CHECKS
3500 #endif
3501 
3502 /*
3503  * Put mbuf into the item.
3504  * Hook and node references will be removed when the item is dequeued.
3505  * (or equivalent)
3506  * (XXX) Unsafe because no reference held by peer on remote node.
3507  * remote node might go away in this timescale.
3508  * We know the hooks can't go away because that would require getting
3509  * a writer item on both nodes and we must have at least a  reader
3510  * here to be able to do this.
3511  * Note that the hook loaded is the REMOTE hook.
3512  *
3513  * This is possibly in the critical path for new data.
3514  */
3515 item_p
3516 ng_package_data(struct mbuf *m, int flags)
3517 {
3518 	item_p item;
3519 
3520 	if ((item = ng_alloc_item(NGQF_DATA, flags)) == NULL) {
3521 		NG_FREE_M(m);
3522 		return (NULL);
3523 	}
3524 	ITEM_DEBUG_CHECKS;
3525 	item->el_flags |= NGQF_READER;
3526 	NGI_M(item) = m;
3527 	return (item);
3528 }
3529 
3530 /*
3531  * Allocate a queue item and put items into it..
3532  * Evaluate the address as this will be needed to queue it and
3533  * to work out what some of the fields should be.
3534  * Hook and node references will be removed when the item is dequeued.
3535  * (or equivalent)
3536  */
3537 item_p
3538 ng_package_msg(struct ng_mesg *msg, int flags)
3539 {
3540 	item_p item;
3541 
3542 	if ((item = ng_alloc_item(NGQF_MESG, flags)) == NULL) {
3543 		NG_FREE_MSG(msg);
3544 		return (NULL);
3545 	}
3546 	ITEM_DEBUG_CHECKS;
3547 	/* Messages items count as writers unless explicitly exempted. */
3548 	if (msg->header.cmd & NGM_READONLY)
3549 		item->el_flags |= NGQF_READER;
3550 	else
3551 		item->el_flags |= NGQF_WRITER;
3552 	/*
3553 	 * Set the current lasthook into the queue item
3554 	 */
3555 	NGI_MSG(item) = msg;
3556 	NGI_RETADDR(item) = 0;
3557 	return (item);
3558 }
3559 
3560 #define SET_RETADDR(item, here, retaddr)				\
3561 	do {	/* Data or fn items don't have retaddrs */		\
3562 		if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) {	\
3563 			if (retaddr) {					\
3564 				NGI_RETADDR(item) = retaddr;		\
3565 			} else {					\
3566 				/*					\
3567 				 * The old return address should be ok.	\
3568 				 * If there isn't one, use the address	\
3569 				 * here.				\
3570 				 */					\
3571 				if (NGI_RETADDR(item) == 0) {		\
3572 					NGI_RETADDR(item)		\
3573 						= ng_node2ID(here);	\
3574 				}					\
3575 			}						\
3576 		}							\
3577 	} while (0)
3578 
3579 int
3580 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
3581 {
3582 	hook_p peer;
3583 	node_p peernode;
3584 	ITEM_DEBUG_CHECKS;
3585 	/*
3586 	 * Quick sanity check..
3587 	 * Since a hook holds a reference on its node, once we know
3588 	 * that the peer is still connected (even if invalid,) we know
3589 	 * that the peer node is present, though maybe invalid.
3590 	 */
3591 	TOPOLOGY_RLOCK();
3592 	if ((hook == NULL) || NG_HOOK_NOT_VALID(hook) ||
3593 	    NG_HOOK_NOT_VALID(peer = NG_HOOK_PEER(hook)) ||
3594 	    NG_NODE_NOT_VALID(peernode = NG_PEER_NODE(hook))) {
3595 		NG_FREE_ITEM(item);
3596 		TRAP_ERROR();
3597 		TOPOLOGY_RUNLOCK();
3598 		return (ENETDOWN);
3599 	}
3600 
3601 	/*
3602 	 * Transfer our interest to the other (peer) end.
3603 	 */
3604 	NG_HOOK_REF(peer);
3605 	NG_NODE_REF(peernode);
3606 	NGI_SET_HOOK(item, peer);
3607 	NGI_SET_NODE(item, peernode);
3608 	SET_RETADDR(item, here, retaddr);
3609 
3610 	TOPOLOGY_RUNLOCK();
3611 
3612 	return (0);
3613 }
3614 
3615 int
3616 ng_address_path(node_p here, item_p item, const char *address, ng_ID_t retaddr)
3617 {
3618 	node_p	dest = NULL;
3619 	hook_p	hook = NULL;
3620 	int	error;
3621 
3622 	ITEM_DEBUG_CHECKS;
3623 	/*
3624 	 * Note that ng_path2noderef increments the reference count
3625 	 * on the node for us if it finds one. So we don't have to.
3626 	 */
3627 	error = ng_path2noderef(here, address, &dest, &hook);
3628 	if (error) {
3629 		NG_FREE_ITEM(item);
3630 		return (error);
3631 	}
3632 	NGI_SET_NODE(item, dest);
3633 	if (hook)
3634 		NGI_SET_HOOK(item, hook);
3635 
3636 	SET_RETADDR(item, here, retaddr);
3637 	return (0);
3638 }
3639 
3640 int
3641 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
3642 {
3643 	node_p dest;
3644 
3645 	ITEM_DEBUG_CHECKS;
3646 	/*
3647 	 * Find the target node.
3648 	 */
3649 	dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
3650 	if (dest == NULL) {
3651 		NG_FREE_ITEM(item);
3652 		TRAP_ERROR();
3653 		return(EINVAL);
3654 	}
3655 	/* Fill out the contents */
3656 	NGI_SET_NODE(item, dest);
3657 	NGI_CLR_HOOK(item);
3658 	SET_RETADDR(item, here, retaddr);
3659 	return (0);
3660 }
3661 
3662 /*
3663  * special case to send a message to self (e.g. destroy node)
3664  * Possibly indicate an arrival hook too.
3665  * Useful for removing that hook :-)
3666  */
3667 item_p
3668 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
3669 {
3670 	item_p item;
3671 
3672 	/*
3673 	 * Find the target node.
3674 	 * If there is a HOOK argument, then use that in preference
3675 	 * to the address.
3676 	 */
3677 	if ((item = ng_alloc_item(NGQF_MESG, NG_NOFLAGS)) == NULL) {
3678 		NG_FREE_MSG(msg);
3679 		return (NULL);
3680 	}
3681 
3682 	/* Fill out the contents */
3683 	item->el_flags |= NGQF_WRITER;
3684 	NG_NODE_REF(here);
3685 	NGI_SET_NODE(item, here);
3686 	if (hook) {
3687 		NG_HOOK_REF(hook);
3688 		NGI_SET_HOOK(item, hook);
3689 	}
3690 	NGI_MSG(item) = msg;
3691 	NGI_RETADDR(item) = ng_node2ID(here);
3692 	return (item);
3693 }
3694 
3695 /*
3696  * Send ng_item_fn function call to the specified node.
3697  */
3698 
3699 int
3700 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
3701 {
3702 
3703 	return ng_send_fn1(node, hook, fn, arg1, arg2, NG_NOFLAGS);
3704 }
3705 
3706 int
3707 ng_send_fn1(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2,
3708 	int flags)
3709 {
3710 	item_p item;
3711 
3712 	if ((item = ng_alloc_item(NGQF_FN, flags)) == NULL) {
3713 		return (ENOMEM);
3714 	}
3715 	item->el_flags |= NGQF_WRITER;
3716 	NG_NODE_REF(node); /* and one for the item */
3717 	NGI_SET_NODE(item, node);
3718 	if (hook) {
3719 		NG_HOOK_REF(hook);
3720 		NGI_SET_HOOK(item, hook);
3721 	}
3722 	NGI_FN(item) = fn;
3723 	NGI_ARG1(item) = arg1;
3724 	NGI_ARG2(item) = arg2;
3725 	return(ng_snd_item(item, flags));
3726 }
3727 
3728 /*
3729  * Send ng_item_fn2 function call to the specified node.
3730  *
3731  * If an optional pitem parameter is supplied, its apply
3732  * callback will be copied to the new item. If also NG_REUSE_ITEM
3733  * flag is set, no new item will be allocated, but pitem will
3734  * be used.
3735  */
3736 int
3737 ng_send_fn2(node_p node, hook_p hook, item_p pitem, ng_item_fn2 *fn, void *arg1,
3738 	int arg2, int flags)
3739 {
3740 	item_p item;
3741 
3742 	KASSERT((pitem != NULL || (flags & NG_REUSE_ITEM) == 0),
3743 	    ("%s: NG_REUSE_ITEM but no pitem", __func__));
3744 
3745 	/*
3746 	 * Allocate a new item if no supplied or
3747 	 * if we can't use supplied one.
3748 	 */
3749 	if (pitem == NULL || (flags & NG_REUSE_ITEM) == 0) {
3750 		if ((item = ng_alloc_item(NGQF_FN2, flags)) == NULL)
3751 			return (ENOMEM);
3752 		if (pitem != NULL)
3753 			item->apply = pitem->apply;
3754 	} else {
3755 		if ((item = ng_realloc_item(pitem, NGQF_FN2, flags)) == NULL)
3756 			return (ENOMEM);
3757 	}
3758 
3759 	item->el_flags = (item->el_flags & ~NGQF_RW) | NGQF_WRITER;
3760 	NG_NODE_REF(node); /* and one for the item */
3761 	NGI_SET_NODE(item, node);
3762 	if (hook) {
3763 		NG_HOOK_REF(hook);
3764 		NGI_SET_HOOK(item, hook);
3765 	}
3766 	NGI_FN2(item) = fn;
3767 	NGI_ARG1(item) = arg1;
3768 	NGI_ARG2(item) = arg2;
3769 	return(ng_snd_item(item, flags));
3770 }
3771 
3772 /*
3773  * Official timeout routines for Netgraph nodes.
3774  */
3775 static void
3776 ng_callout_trampoline(void *arg)
3777 {
3778 	struct epoch_tracker et;
3779 	item_p item = arg;
3780 
3781 	NET_EPOCH_ENTER(et);
3782 	CURVNET_SET(NGI_NODE(item)->nd_vnet);
3783 	ng_snd_item(item, 0);
3784 	CURVNET_RESTORE();
3785 	NET_EPOCH_EXIT(et);
3786 }
3787 
3788 int
3789 ng_callout(struct callout *c, node_p node, hook_p hook, int ticks,
3790     ng_item_fn *fn, void * arg1, int arg2)
3791 {
3792 	item_p item, oitem;
3793 
3794 	if ((item = ng_alloc_item(NGQF_FN, NG_NOFLAGS)) == NULL)
3795 		return (ENOMEM);
3796 
3797 	item->el_flags |= NGQF_WRITER;
3798 	NG_NODE_REF(node);		/* and one for the item */
3799 	NGI_SET_NODE(item, node);
3800 	if (hook) {
3801 		NG_HOOK_REF(hook);
3802 		NGI_SET_HOOK(item, hook);
3803 	}
3804 	NGI_FN(item) = fn;
3805 	NGI_ARG1(item) = arg1;
3806 	NGI_ARG2(item) = arg2;
3807 	oitem = c->c_arg;
3808 	if (callout_reset(c, ticks, &ng_callout_trampoline, item) == 1 &&
3809 	    oitem != NULL)
3810 		NG_FREE_ITEM(oitem);
3811 	return (0);
3812 }
3813 
3814 /* A special modified version of callout_stop() */
3815 int
3816 ng_uncallout(struct callout *c, node_p node)
3817 {
3818 	item_p item;
3819 	int rval;
3820 
3821 	KASSERT(c != NULL, ("ng_uncallout: NULL callout"));
3822 	KASSERT(node != NULL, ("ng_uncallout: NULL node"));
3823 
3824 	rval = callout_stop(c);
3825 	item = c->c_arg;
3826 	/* Do an extra check */
3827 	if ((rval > 0) && (c->c_func == &ng_callout_trampoline) &&
3828 	    (item != NULL) && (NGI_NODE(item) == node)) {
3829 		/*
3830 		 * We successfully removed it from the queue before it ran
3831 		 * So now we need to unreference everything that was
3832 		 * given extra references. (NG_FREE_ITEM does this).
3833 		 */
3834 		NG_FREE_ITEM(item);
3835 	}
3836 	c->c_arg = NULL;
3837 
3838 	/*
3839 	 * Callers only want to know if the callout was cancelled and
3840 	 * not draining or stopped.
3841 	 */
3842 	return (rval > 0);
3843 }
3844 
3845 /*
3846  * Set the address, if none given, give the node here.
3847  */
3848 void
3849 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
3850 {
3851 	if (retaddr) {
3852 		NGI_RETADDR(item) = retaddr;
3853 	} else {
3854 		/*
3855 		 * The old return address should be ok.
3856 		 * If there isn't one, use the address here.
3857 		 */
3858 		NGI_RETADDR(item) = ng_node2ID(here);
3859 	}
3860 }
3861