xref: /dragonfly/sys/netgraph/netgraph/ng_base.c (revision 2cd2d2b5)
1 
2 /*
3  * ng_base.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Authors: Julian Elischer <julian@freebsd.org>
38  *          Archie Cobbs <archie@freebsd.org>
39  *
40  * $FreeBSD: src/sys/netgraph/ng_base.c,v 1.11.2.17 2002/07/02 23:44:02 archie Exp $
41  * $DragonFly: src/sys/netgraph/netgraph/ng_base.c,v 1.13 2004/04/21 18:13:54 dillon Exp $
42  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
43  */
44 
45 /*
46  * This file implements the base netgraph code.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/errno.h>
52 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/syslog.h>
55 #include <sys/linker.h>
56 #include <sys/queue.h>
57 #include <sys/mbuf.h>
58 #include <sys/ctype.h>
59 #include <sys/sysctl.h>
60 #include <machine/limits.h>
61 
62 #include <sys/thread2.h>
63 #include <sys/msgport2.h>
64 
65 #include <net/netisr.h>
66 
67 #include <netgraph/ng_message.h>
68 #include <netgraph/netgraph.h>
69 #include <netgraph/ng_parse.h>
70 
71 /* List of all nodes */
72 static LIST_HEAD(, ng_node) nodelist;
73 
74 /* List of installed types */
75 static LIST_HEAD(, ng_type) typelist;
76 
77 /* Hash releted definitions */
78 #define ID_HASH_SIZE 32 /* most systems wont need even this many */
79 static LIST_HEAD(, ng_node) ID_hash[ID_HASH_SIZE];
80 /* Don't nead to initialise them because it's a LIST */
81 
82 /* Internal functions */
83 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
84 static int	ng_connect(hook_p hook1, hook_p hook2);
85 static void	ng_disconnect_hook(hook_p hook);
86 static int	ng_generic_msg(node_p here, struct ng_mesg *msg,
87 			const char *retaddr, struct ng_mesg ** resp);
88 static ng_ID_t	ng_decodeidname(const char *name);
89 static int	ngb_mod_event(module_t mod, int event, void *data);
90 static int	ngintr(struct netmsg *);
91 
92 /* Our own netgraph malloc type */
93 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
94 
95 /* Set this to Debugger("X") to catch all errors as they occur */
96 #ifndef TRAP_ERROR
97 #define TRAP_ERROR
98 #endif
99 
100 static	ng_ID_t nextID = 1;
101 
102 #ifdef INVARIANTS
103 #define CHECK_DATA_MBUF(m)	do {					\
104 		struct mbuf *n;						\
105 		int total;						\
106 									\
107 		if (((m)->m_flags & M_PKTHDR) == 0)			\
108 			panic("%s: !PKTHDR", __FUNCTION__);		\
109 		for (total = 0, n = (m); n != NULL; n = n->m_next)	\
110 			total += n->m_len;				\
111 		if ((m)->m_pkthdr.len != total) {			\
112 			panic("%s: %d != %d",				\
113 			    __FUNCTION__, (m)->m_pkthdr.len, total);	\
114 		}							\
115 	} while (0)
116 #else
117 #define CHECK_DATA_MBUF(m)
118 #endif
119 
120 
121 /************************************************************************
122 	Parse type definitions for generic messages
123 ************************************************************************/
124 
125 /* Handy structure parse type defining macro */
126 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
127 static const struct ng_parse_struct_field				\
128 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
129 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
130 	&ng_parse_struct_type,						\
131 	&ng_ ## lo ## _type_fields					\
132 }
133 
134 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
135 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
136 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
137 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
138 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
139 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
140 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
141 
142 /* Get length of an array when the length is stored as a 32 bit
143    value immediately preceeding the array -- as with struct namelist
144    and struct typelist. */
145 static int
146 ng_generic_list_getLength(const struct ng_parse_type *type,
147 	const u_char *start, const u_char *buf)
148 {
149 	return *((const u_int32_t *)(buf - 4));
150 }
151 
152 /* Get length of the array of struct linkinfo inside a struct hooklist */
153 static int
154 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
155 	const u_char *start, const u_char *buf)
156 {
157 	const struct hooklist *hl = (const struct hooklist *)start;
158 
159 	return hl->nodeinfo.hooks;
160 }
161 
162 /* Array type for a variable length array of struct namelist */
163 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
164 	&ng_generic_nodeinfo_type,
165 	&ng_generic_list_getLength
166 };
167 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
168 	&ng_parse_array_type,
169 	&ng_nodeinfoarray_type_info
170 };
171 
172 /* Array type for a variable length array of struct typelist */
173 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
174 	&ng_generic_typeinfo_type,
175 	&ng_generic_list_getLength
176 };
177 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
178 	&ng_parse_array_type,
179 	&ng_typeinfoarray_type_info
180 };
181 
182 /* Array type for array of struct linkinfo in struct hooklist */
183 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
184 	&ng_generic_linkinfo_type,
185 	&ng_generic_linkinfo_getLength
186 };
187 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
188 	&ng_parse_array_type,
189 	&ng_generic_linkinfo_array_type_info
190 };
191 
192 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
193 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
194 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
195 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
196 	(&ng_generic_nodeinfoarray_type));
197 
198 /* List of commands and how to convert arguments to/from ASCII */
199 static const struct ng_cmdlist ng_generic_cmds[] = {
200 	{
201 	  NGM_GENERIC_COOKIE,
202 	  NGM_SHUTDOWN,
203 	  "shutdown",
204 	  NULL,
205 	  NULL
206 	},
207 	{
208 	  NGM_GENERIC_COOKIE,
209 	  NGM_MKPEER,
210 	  "mkpeer",
211 	  &ng_generic_mkpeer_type,
212 	  NULL
213 	},
214 	{
215 	  NGM_GENERIC_COOKIE,
216 	  NGM_CONNECT,
217 	  "connect",
218 	  &ng_generic_connect_type,
219 	  NULL
220 	},
221 	{
222 	  NGM_GENERIC_COOKIE,
223 	  NGM_NAME,
224 	  "name",
225 	  &ng_generic_name_type,
226 	  NULL
227 	},
228 	{
229 	  NGM_GENERIC_COOKIE,
230 	  NGM_RMHOOK,
231 	  "rmhook",
232 	  &ng_generic_rmhook_type,
233 	  NULL
234 	},
235 	{
236 	  NGM_GENERIC_COOKIE,
237 	  NGM_NODEINFO,
238 	  "nodeinfo",
239 	  NULL,
240 	  &ng_generic_nodeinfo_type
241 	},
242 	{
243 	  NGM_GENERIC_COOKIE,
244 	  NGM_LISTHOOKS,
245 	  "listhooks",
246 	  NULL,
247 	  &ng_generic_hooklist_type
248 	},
249 	{
250 	  NGM_GENERIC_COOKIE,
251 	  NGM_LISTNAMES,
252 	  "listnames",
253 	  NULL,
254 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
255 	},
256 	{
257 	  NGM_GENERIC_COOKIE,
258 	  NGM_LISTNODES,
259 	  "listnodes",
260 	  NULL,
261 	  &ng_generic_listnodes_type
262 	},
263 	{
264 	  NGM_GENERIC_COOKIE,
265 	  NGM_LISTTYPES,
266 	  "listtypes",
267 	  NULL,
268 	  &ng_generic_typeinfo_type
269 	},
270 	{
271 	  NGM_GENERIC_COOKIE,
272 	  NGM_TEXT_CONFIG,
273 	  "textconfig",
274 	  NULL,
275 	  &ng_parse_string_type
276 	},
277 	{
278 	  NGM_GENERIC_COOKIE,
279 	  NGM_TEXT_STATUS,
280 	  "textstatus",
281 	  NULL,
282 	  &ng_parse_string_type
283 	},
284 	{
285 	  NGM_GENERIC_COOKIE,
286 	  NGM_ASCII2BINARY,
287 	  "ascii2binary",
288 	  &ng_parse_ng_mesg_type,
289 	  &ng_parse_ng_mesg_type
290 	},
291 	{
292 	  NGM_GENERIC_COOKIE,
293 	  NGM_BINARY2ASCII,
294 	  "binary2ascii",
295 	  &ng_parse_ng_mesg_type,
296 	  &ng_parse_ng_mesg_type
297 	},
298 	{ 0 }
299 };
300 
301 /************************************************************************
302 			Node routines
303 ************************************************************************/
304 
305 /*
306  * Instantiate a node of the requested type
307  */
308 int
309 ng_make_node(const char *typename, node_p *nodepp)
310 {
311 	struct ng_type *type;
312 
313 	/* Check that the type makes sense */
314 	if (typename == NULL) {
315 		TRAP_ERROR;
316 		return (EINVAL);
317 	}
318 
319 	/* Locate the node type */
320 	if ((type = ng_findtype(typename)) == NULL) {
321 		char *path, filename[NG_TYPELEN + 4];
322 		linker_file_t lf;
323 		int error;
324 
325 		/* Not found, try to load it as a loadable module */
326 		snprintf(filename, sizeof(filename), "ng_%s.ko", typename);
327 		if ((path = linker_search_path(filename)) == NULL)
328 			return (ENXIO);
329 		error = linker_load_file(path, &lf);
330 		FREE(path, M_LINKER);
331 		if (error != 0)
332 			return (error);
333 		lf->userrefs++;		/* pretend loaded by the syscall */
334 
335 		/* Try again, as now the type should have linked itself in */
336 		if ((type = ng_findtype(typename)) == NULL)
337 			return (ENXIO);
338 	}
339 
340 	/* Call the constructor */
341 	if (type->constructor != NULL)
342 		return ((*type->constructor)(nodepp));
343 	else
344 		return (ng_make_node_common(type, nodepp));
345 }
346 
347 /*
348  * Generic node creation. Called by node constructors.
349  * The returned node has a reference count of 1.
350  */
351 int
352 ng_make_node_common(struct ng_type *type, node_p *nodepp)
353 {
354 	node_p node;
355 
356 	/* Require the node type to have been already installed */
357 	if (ng_findtype(type->name) == NULL) {
358 		TRAP_ERROR;
359 		return (EINVAL);
360 	}
361 
362 	/* Make a node and try attach it to the type */
363 	MALLOC(node, node_p, sizeof(*node), M_NETGRAPH, M_NOWAIT);
364 	if (node == NULL) {
365 		TRAP_ERROR;
366 		return (ENOMEM);
367 	}
368 	bzero(node, sizeof(*node));
369 	node->type = type;
370 	node->refs++;				/* note reference */
371 	type->refs++;
372 
373 	/* Link us into the node linked list */
374 	LIST_INSERT_HEAD(&nodelist, node, nodes);
375 
376 	/* Initialize hook list for new node */
377 	LIST_INIT(&node->hooks);
378 
379 	/* get an ID and put us in the hash chain */
380 	node->ID = nextID++; /* 137 per second for 1 year before wrap */
381 	LIST_INSERT_HEAD(&ID_hash[node->ID % ID_HASH_SIZE], node, idnodes);
382 
383 	/* Done */
384 	*nodepp = node;
385 	return (0);
386 }
387 
388 /*
389  * Forceably start the shutdown process on a node. Either call
390  * it's shutdown method, or do the default shutdown if there is
391  * no type-specific method.
392  *
393  * Persistent nodes must have a type-specific method which
394  * resets the NG_INVALID flag.
395  */
396 void
397 ng_rmnode(node_p node)
398 {
399 	/* Check if it's already shutting down */
400 	if ((node->flags & NG_INVALID) != 0)
401 		return;
402 
403 	/* Add an extra reference so it doesn't go away during this */
404 	node->refs++;
405 
406 	/* Mark it invalid so any newcomers know not to try use it */
407 	node->flags |= NG_INVALID;
408 
409 	/* Ask the type if it has anything to do in this case */
410 	if (node->type && node->type->shutdown)
411 		(*node->type->shutdown)(node);
412 	else {				/* do the default thing */
413 		ng_unname(node);
414 		ng_cutlinks(node);
415 		ng_unref(node);
416 	}
417 
418 	/* Remove extra reference, possibly the last */
419 	ng_unref(node);
420 }
421 
422 /*
423  * Called by the destructor to remove any STANDARD external references
424  */
425 void
426 ng_cutlinks(node_p node)
427 {
428 	hook_p  hook;
429 
430 	/* Make sure that this is set to stop infinite loops */
431 	node->flags |= NG_INVALID;
432 
433 	/* If we have sleepers, wake them up; they'll see NG_INVALID */
434 	if (node->sleepers)
435 		wakeup(node);
436 
437 	/* Notify all remaining connected nodes to disconnect */
438 	while ((hook = LIST_FIRST(&node->hooks)) != NULL)
439 		ng_destroy_hook(hook);
440 }
441 
442 /*
443  * Remove a reference to the node, possibly the last
444  */
445 void
446 ng_unref(node_p node)
447 {
448 	int	s;
449 
450 	s = splhigh();
451 	if (--node->refs <= 0) {
452 		node->type->refs--;
453 		LIST_REMOVE(node, nodes);
454 		LIST_REMOVE(node, idnodes);
455 		FREE(node, M_NETGRAPH);
456 	}
457 	splx(s);
458 }
459 
460 /*
461  * Wait for a node to come ready. Returns a node with a reference count;
462  * don't forget to drop it when we are done with it using ng_release_node().
463  */
464 int
465 ng_wait_node(node_p node, char *msg)
466 {
467 	int s, error = 0;
468 
469 	if (msg == NULL)
470 		msg = "netgraph";
471 	s = splnet();
472 	node->sleepers++;
473 	node->refs++;		/* the sleeping process counts as a reference */
474 	while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
475 		error = tsleep(node, PCATCH, msg, 0);
476 	node->sleepers--;
477 	if (node->flags & NG_INVALID) {
478 		TRAP_ERROR;
479 		error = ENXIO;
480 	} else {
481 		KASSERT(node->refs > 1,
482 		    ("%s: refs=%d", __FUNCTION__, node->refs));
483 		node->flags |= NG_BUSY;
484 	}
485 	splx(s);
486 
487 	/* Release the reference we had on it */
488 	if (error != 0)
489 		ng_unref(node);
490 	return error;
491 }
492 
493 /*
494  * Release a node acquired via ng_wait_node()
495  */
496 void
497 ng_release_node(node_p node)
498 {
499 	/* Declare that we don't want it */
500 	node->flags &= ~NG_BUSY;
501 
502 	/* If we have sleepers, then wake them up */
503 	if (node->sleepers)
504 		wakeup(node);
505 
506 	/* We also have a reference.. drop it too */
507 	ng_unref(node);
508 }
509 
510 /************************************************************************
511 			Node ID handling
512 ************************************************************************/
513 static node_p
514 ng_ID2node(ng_ID_t ID)
515 {
516 	node_p np;
517 	LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
518 		if ((np->flags & NG_INVALID) == 0 && np->ID == ID)
519 			break;
520 	}
521 	return(np);
522 }
523 
524 ng_ID_t
525 ng_node2ID(node_p node)
526 {
527 	return (node->ID);
528 }
529 
530 /************************************************************************
531 			Node name handling
532 ************************************************************************/
533 
534 /*
535  * Assign a node a name. Once assigned, the name cannot be changed.
536  */
537 int
538 ng_name_node(node_p node, const char *name)
539 {
540 	int i;
541 
542 	/* Check the name is valid */
543 	for (i = 0; i < NG_NODELEN + 1; i++) {
544 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
545 			break;
546 	}
547 	if (i == 0 || name[i] != '\0') {
548 		TRAP_ERROR;
549 		return (EINVAL);
550 	}
551 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
552 		TRAP_ERROR;
553 		return (EINVAL);
554 	}
555 
556 	/* Check the node isn't already named */
557 	if (node->name != NULL) {
558 		TRAP_ERROR;
559 		return (EISCONN);
560 	}
561 
562 	/* Check the name isn't already being used */
563 	if (ng_findname(node, name) != NULL) {
564 		TRAP_ERROR;
565 		return (EADDRINUSE);
566 	}
567 
568 	/* Allocate space and copy it */
569 	MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
570 	if (node->name == NULL) {
571 		TRAP_ERROR;
572 		return (ENOMEM);
573 	}
574 	strcpy(node->name, name);
575 
576 	/* The name counts as a reference */
577 	node->refs++;
578 	return (0);
579 }
580 
581 /*
582  * Find a node by absolute name. The name should NOT end with ':'
583  * The name "." means "this node" and "[xxx]" means "the node
584  * with ID (ie, at address) xxx".
585  *
586  * Returns the node if found, else NULL.
587  */
588 node_p
589 ng_findname(node_p this, const char *name)
590 {
591 	node_p node;
592 	ng_ID_t temp;
593 
594 	/* "." means "this node" */
595 	if (strcmp(name, ".") == 0)
596 		return(this);
597 
598 	/* Check for name-by-ID */
599 	if ((temp = ng_decodeidname(name)) != 0) {
600 		return (ng_ID2node(temp));
601 	}
602 
603 	/* Find node by name */
604 	LIST_FOREACH(node, &nodelist, nodes) {
605 		if ((node->name != NULL)
606 		&& (strcmp(node->name, name) == 0)
607 		&& ((node->flags & NG_INVALID) == 0))
608 			break;
609 	}
610 	return (node);
611 }
612 
613 /*
614  * Decode a ID name, eg. "[f03034de]". Returns 0 if the
615  * string is not valid, otherwise returns the value.
616  */
617 static ng_ID_t
618 ng_decodeidname(const char *name)
619 {
620 	const int len = strlen(name);
621 	char *eptr;
622 	u_long val;
623 
624 	/* Check for proper length, brackets, no leading junk */
625 	if (len < 3 || name[0] != '[' || name[len - 1] != ']'
626 	    || !isxdigit(name[1]))
627 		return (0);
628 
629 	/* Decode number */
630 	val = strtoul(name + 1, &eptr, 16);
631 	if (eptr - name != len - 1 || val == ULONG_MAX || val == 0)
632 		return ((ng_ID_t)0);
633 	return (ng_ID_t)val;
634 }
635 
636 /*
637  * Remove a name from a node. This should only be called
638  * when shutting down and removing the node.
639  */
640 void
641 ng_unname(node_p node)
642 {
643 	if (node->name) {
644 		FREE(node->name, M_NETGRAPH);
645 		node->name = NULL;
646 		ng_unref(node);
647 	}
648 }
649 
650 /************************************************************************
651 			Hook routines
652 
653  Names are not optional. Hooks are always connected, except for a
654  brief moment within these routines.
655 
656 ************************************************************************/
657 
658 /*
659  * Remove a hook reference
660  */
661 void
662 ng_unref_hook(hook_p hook)
663 {
664 	int	s;
665 
666 	s = splhigh();
667 	if (--hook->refs == 0)
668 		FREE(hook, M_NETGRAPH);
669 	splx(s);
670 }
671 
672 /*
673  * Add an unconnected hook to a node. Only used internally.
674  */
675 static int
676 ng_add_hook(node_p node, const char *name, hook_p *hookp)
677 {
678 	hook_p hook;
679 	int error = 0;
680 
681 	/* Check that the given name is good */
682 	if (name == NULL) {
683 		TRAP_ERROR;
684 		return (EINVAL);
685 	}
686 	if (ng_findhook(node, name) != NULL) {
687 		TRAP_ERROR;
688 		return (EEXIST);
689 	}
690 
691 	/* Allocate the hook and link it up */
692 	MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_NOWAIT);
693 	if (hook == NULL) {
694 		TRAP_ERROR;
695 		return (ENOMEM);
696 	}
697 	bzero(hook, sizeof(*hook));
698 	hook->refs = 1;
699 	hook->flags = HK_INVALID;
700 	hook->node = node;
701 	node->refs++;		/* each hook counts as a reference */
702 
703 	/* Check if the node type code has something to say about it */
704 	if (node->type->newhook != NULL)
705 		if ((error = (*node->type->newhook)(node, hook, name)) != 0)
706 			goto fail;
707 
708 	/*
709 	 * The 'type' agrees so far, so go ahead and link it in.
710 	 * We'll ask again later when we actually connect the hooks.
711 	 */
712 	LIST_INSERT_HEAD(&node->hooks, hook, hooks);
713 	node->numhooks++;
714 
715 	/* Set hook name */
716 	MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
717 	if (hook->name == NULL) {
718 		error = ENOMEM;
719 		LIST_REMOVE(hook, hooks);
720 		node->numhooks--;
721 fail:
722 		hook->node = NULL;
723 		ng_unref(node);
724 		ng_unref_hook(hook);	/* this frees the hook */
725 		return (error);
726 	}
727 	strcpy(hook->name, name);
728 	if (hookp)
729 		*hookp = hook;
730 	return (error);
731 }
732 
733 /*
734  * Connect a pair of hooks. Only used internally.
735  */
736 static int
737 ng_connect(hook_p hook1, hook_p hook2)
738 {
739 	int     error;
740 
741 	hook1->peer = hook2;
742 	hook2->peer = hook1;
743 
744 	/* Give each node the opportunity to veto the impending connection */
745 	if (hook1->node->type->connect) {
746 		if ((error = (*hook1->node->type->connect) (hook1))) {
747 			ng_destroy_hook(hook1);	/* also zaps hook2 */
748 			return (error);
749 		}
750 	}
751 	if (hook2->node->type->connect) {
752 		if ((error = (*hook2->node->type->connect) (hook2))) {
753 			ng_destroy_hook(hook2);	/* also zaps hook1 */
754 			return (error);
755 		}
756 	}
757 	hook1->flags &= ~HK_INVALID;
758 	hook2->flags &= ~HK_INVALID;
759 	return (0);
760 }
761 
762 /*
763  * Find a hook
764  *
765  * Node types may supply their own optimized routines for finding
766  * hooks.  If none is supplied, we just do a linear search.
767  */
768 hook_p
769 ng_findhook(node_p node, const char *name)
770 {
771 	hook_p hook;
772 
773 	if (node->type->findhook != NULL)
774 		return (*node->type->findhook)(node, name);
775 	LIST_FOREACH(hook, &node->hooks, hooks) {
776 		if (hook->name != NULL
777 		    && strcmp(hook->name, name) == 0
778 		    && (hook->flags & HK_INVALID) == 0)
779 			return (hook);
780 	}
781 	return (NULL);
782 }
783 
784 /*
785  * Destroy a hook
786  *
787  * As hooks are always attached, this really destroys two hooks.
788  * The one given, and the one attached to it. Disconnect the hooks
789  * from each other first.
790  */
791 void
792 ng_destroy_hook(hook_p hook)
793 {
794 	hook_p peer = hook->peer;
795 
796 	hook->flags |= HK_INVALID;		/* as soon as possible */
797 	if (peer) {
798 		peer->flags |= HK_INVALID;	/* as soon as possible */
799 		hook->peer = NULL;
800 		peer->peer = NULL;
801 		ng_disconnect_hook(peer);
802 	}
803 	ng_disconnect_hook(hook);
804 }
805 
806 /*
807  * Notify the node of the hook's demise. This may result in more actions
808  * (e.g. shutdown) but we don't do that ourselves and don't know what
809  * happens there. If there is no appropriate handler, then just remove it
810  * (and decrement the reference count of it's node which in turn might
811  * make something happen).
812  */
813 static void
814 ng_disconnect_hook(hook_p hook)
815 {
816 	node_p node = hook->node;
817 
818 	/*
819 	 * Remove the hook from the node's list to avoid possible recursion
820 	 * in case the disconnection results in node shutdown.
821 	 */
822 	LIST_REMOVE(hook, hooks);
823 	node->numhooks--;
824 	if (node->type->disconnect) {
825 		/*
826 		 * The type handler may elect to destroy the peer so don't
827 		 * trust its existance after this point.
828 		 */
829 		(*node->type->disconnect) (hook);
830 	}
831 	ng_unref(node);		/* might be the last reference */
832 	if (hook->name)
833 		FREE(hook->name, M_NETGRAPH);
834 	hook->node = NULL;	/* may still be referenced elsewhere */
835 	ng_unref_hook(hook);
836 }
837 
838 /*
839  * Take two hooks on a node and merge the connection so that the given node
840  * is effectively bypassed.
841  */
842 int
843 ng_bypass(hook_p hook1, hook_p hook2)
844 {
845 	if (hook1->node != hook2->node)
846 		return (EINVAL);
847 	hook1->peer->peer = hook2->peer;
848 	hook2->peer->peer = hook1->peer;
849 
850 	/* XXX If we ever cache methods on hooks update them as well */
851 	hook1->peer = NULL;
852 	hook2->peer = NULL;
853 	ng_destroy_hook(hook1);
854 	ng_destroy_hook(hook2);
855 	return (0);
856 }
857 
858 /*
859  * Install a new netgraph type
860  */
861 int
862 ng_newtype(struct ng_type *tp)
863 {
864 	const size_t namelen = strlen(tp->name);
865 
866 	/* Check version and type name fields */
867 	if (tp->version != NG_VERSION || namelen == 0 || namelen > NG_TYPELEN) {
868 		TRAP_ERROR;
869 		return (EINVAL);
870 	}
871 
872 	/* Check for name collision */
873 	if (ng_findtype(tp->name) != NULL) {
874 		TRAP_ERROR;
875 		return (EEXIST);
876 	}
877 
878 	/* Link in new type */
879 	LIST_INSERT_HEAD(&typelist, tp, types);
880 	tp->refs = 1;	/* first ref is linked list */
881 	return (0);
882 }
883 
884 /*
885  * Look for a type of the name given
886  */
887 struct ng_type *
888 ng_findtype(const char *typename)
889 {
890 	struct ng_type *type;
891 
892 	LIST_FOREACH(type, &typelist, types) {
893 		if (strcmp(type->name, typename) == 0)
894 			break;
895 	}
896 	return (type);
897 }
898 
899 
900 /************************************************************************
901 			Composite routines
902 ************************************************************************/
903 
904 /*
905  * Make a peer and connect. The order is arranged to minimise
906  * the work needed to back out in case of error.
907  */
908 int
909 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
910 {
911 	node_p  node2;
912 	hook_p  hook;
913 	hook_p  hook2;
914 	int     error;
915 
916 	if ((error = ng_add_hook(node, name, &hook)))
917 		return (error);
918 	if ((error = ng_make_node(type, &node2))) {
919 		ng_destroy_hook(hook);
920 		return (error);
921 	}
922 	if ((error = ng_add_hook(node2, name2, &hook2))) {
923 		ng_rmnode(node2);
924 		ng_destroy_hook(hook);
925 		return (error);
926 	}
927 
928 	/*
929 	 * Actually link the two hooks together.. on failure they are
930 	 * destroyed so we don't have to do that here.
931 	 */
932 	if ((error = ng_connect(hook, hook2)))
933 		ng_rmnode(node2);
934 	return (error);
935 }
936 
937 /*
938  * Connect two nodes using the specified hooks
939  */
940 int
941 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
942 {
943 	int     error;
944 	hook_p  hook;
945 	hook_p  hook2;
946 
947 	if ((error = ng_add_hook(node, name, &hook)))
948 		return (error);
949 	if ((error = ng_add_hook(node2, name2, &hook2))) {
950 		ng_destroy_hook(hook);
951 		return (error);
952 	}
953 	return (ng_connect(hook, hook2));
954 }
955 
956 /*
957  * Parse and verify a string of the form:  <NODE:><PATH>
958  *
959  * Such a string can refer to a specific node or a specific hook
960  * on a specific node, depending on how you look at it. In the
961  * latter case, the PATH component must not end in a dot.
962  *
963  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
964  * of hook names separated by dots. This breaks out the original
965  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
966  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
967  * the final hook component of <PATH>, if any, otherwise NULL.
968  *
969  * This returns -1 if the path is malformed. The char ** are optional.
970  */
971 
972 int
973 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
974 {
975 	char   *node, *path, *hook;
976 	int     k;
977 
978 	/*
979 	 * Extract absolute NODE, if any
980 	 */
981 	for (path = addr; *path && *path != ':'; path++);
982 	if (*path) {
983 		node = addr;	/* Here's the NODE */
984 		*path++ = '\0';	/* Here's the PATH */
985 
986 		/* Node name must not be empty */
987 		if (!*node)
988 			return -1;
989 
990 		/* A name of "." is OK; otherwise '.' not allowed */
991 		if (strcmp(node, ".") != 0) {
992 			for (k = 0; node[k]; k++)
993 				if (node[k] == '.')
994 					return -1;
995 		}
996 	} else {
997 		node = NULL;	/* No absolute NODE */
998 		path = addr;	/* Here's the PATH */
999 	}
1000 
1001 	/* Snoop for illegal characters in PATH */
1002 	for (k = 0; path[k]; k++)
1003 		if (path[k] == ':')
1004 			return -1;
1005 
1006 	/* Check for no repeated dots in PATH */
1007 	for (k = 0; path[k]; k++)
1008 		if (path[k] == '.' && path[k + 1] == '.')
1009 			return -1;
1010 
1011 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1012 	if (path[0] == '.')
1013 		path++;
1014 	if (*path && path[strlen(path) - 1] == '.')
1015 		path[strlen(path) - 1] = 0;
1016 
1017 	/* If PATH has a dot, then we're not talking about a hook */
1018 	if (*path) {
1019 		for (hook = path, k = 0; path[k]; k++)
1020 			if (path[k] == '.') {
1021 				hook = NULL;
1022 				break;
1023 			}
1024 	} else
1025 		path = hook = NULL;
1026 
1027 	/* Done */
1028 	if (nodep)
1029 		*nodep = node;
1030 	if (pathp)
1031 		*pathp = path;
1032 	if (hookp)
1033 		*hookp = hook;
1034 	return (0);
1035 }
1036 
1037 /*
1038  * Given a path, which may be absolute or relative, and a starting node,
1039  * return the destination node. Compute the "return address" if desired.
1040  */
1041 int
1042 ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
1043 {
1044 	const	node_p start = here;
1045 	char    fullpath[NG_PATHLEN + 1];
1046 	char   *nodename, *path, pbuf[2];
1047 	node_p  node;
1048 	char   *cp;
1049 
1050 	/* Initialize */
1051 	if (rtnp)
1052 		*rtnp = NULL;
1053 	if (destp == NULL)
1054 		return EINVAL;
1055 	*destp = NULL;
1056 
1057 	/* Make a writable copy of address for ng_path_parse() */
1058 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1059 	fullpath[sizeof(fullpath) - 1] = '\0';
1060 
1061 	/* Parse out node and sequence of hooks */
1062 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1063 		TRAP_ERROR;
1064 		return EINVAL;
1065 	}
1066 	if (path == NULL) {
1067 		pbuf[0] = '.';	/* Needs to be writable */
1068 		pbuf[1] = '\0';
1069 		path = pbuf;
1070 	}
1071 
1072 	/* For an absolute address, jump to the starting node */
1073 	if (nodename) {
1074 		node = ng_findname(here, nodename);
1075 		if (node == NULL) {
1076 			TRAP_ERROR;
1077 			return (ENOENT);
1078 		}
1079 	} else
1080 		node = here;
1081 
1082 	/* Now follow the sequence of hooks */
1083 	for (cp = path; node != NULL && *cp != '\0'; ) {
1084 		hook_p hook;
1085 		char *segment;
1086 
1087 		/*
1088 		 * Break out the next path segment. Replace the dot we just
1089 		 * found with a NUL; "cp" points to the next segment (or the
1090 		 * NUL at the end).
1091 		 */
1092 		for (segment = cp; *cp != '\0'; cp++) {
1093 			if (*cp == '.') {
1094 				*cp++ = '\0';
1095 				break;
1096 			}
1097 		}
1098 
1099 		/* Empty segment */
1100 		if (*segment == '\0')
1101 			continue;
1102 
1103 		/* We have a segment, so look for a hook by that name */
1104 		hook = ng_findhook(node, segment);
1105 
1106 		/* Can't get there from here... */
1107 		if (hook == NULL
1108 		    || hook->peer == NULL
1109 		    || (hook->flags & HK_INVALID) != 0) {
1110 			TRAP_ERROR;
1111 			return (ENOENT);
1112 		}
1113 
1114 		/* Hop on over to the next node */
1115 		node = hook->peer->node;
1116 	}
1117 
1118 	/* If node somehow missing, fail here (probably this is not needed) */
1119 	if (node == NULL) {
1120 		TRAP_ERROR;
1121 		return (ENXIO);
1122 	}
1123 
1124 	/* Now compute return address, i.e., the path to the sender */
1125 	if (rtnp != NULL) {
1126 		MALLOC(*rtnp, char *, NG_NODELEN + 2, M_NETGRAPH, M_NOWAIT);
1127 		if (*rtnp == NULL) {
1128 			TRAP_ERROR;
1129 			return (ENOMEM);
1130 		}
1131 		if (start->name != NULL)
1132 			sprintf(*rtnp, "%s:", start->name);
1133 		else
1134 			sprintf(*rtnp, "[%x]:", ng_node2ID(start));
1135 	}
1136 
1137 	/* Done */
1138 	*destp = node;
1139 	return (0);
1140 }
1141 
1142 /*
1143  * Call the appropriate message handler for the object.
1144  * It is up to the message handler to free the message.
1145  * If it's a generic message, handle it generically, otherwise
1146  * call the type's message handler (if it exists)
1147  * XXX (race). Remember that a queued message may reference a node
1148  * or hook that has just been invalidated. It will exist
1149  * as the queue code is holding a reference, but..
1150  */
1151 
1152 #define CALL_MSG_HANDLER(error, node, msg, retaddr, resp)		\
1153 do {									\
1154 	if((msg)->header.typecookie == NGM_GENERIC_COOKIE) {		\
1155 		(error) = ng_generic_msg((node), (msg),			\
1156 				(retaddr), (resp));			\
1157 	} else {							\
1158 		if ((node)->type->rcvmsg != NULL) {			\
1159 			(error) = (*(node)->type->rcvmsg)((node),	\
1160 					(msg), (retaddr), (resp));	\
1161 		} else {						\
1162 			TRAP_ERROR;					\
1163 			FREE((msg), M_NETGRAPH);			\
1164 			(error) = EINVAL;				\
1165 		}							\
1166 	}								\
1167 } while (0)
1168 
1169 
1170 /*
1171  * Send a control message to a node
1172  */
1173 int
1174 ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
1175 	    struct ng_mesg **rptr)
1176 {
1177 	node_p  dest = NULL;
1178 	char   *retaddr = NULL;
1179 	int     error;
1180 
1181 	/* Find the target node */
1182 	error = ng_path2node(here, address, &dest, &retaddr);
1183 	if (error) {
1184 		FREE(msg, M_NETGRAPH);
1185 		return error;
1186 	}
1187 
1188 	/* Make sure the resp field is null before we start */
1189 	if (rptr != NULL)
1190 		*rptr = NULL;
1191 
1192 	CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
1193 
1194 	/* Make sure that if there is a response, it has the RESP bit set */
1195 	if ((error == 0) && rptr && *rptr)
1196 		(*rptr)->header.flags |= NGF_RESP;
1197 
1198 	/*
1199 	 * If we had a return address it is up to us to free it. They should
1200 	 * have taken a copy if they needed to make a delayed response.
1201 	 */
1202 	if (retaddr)
1203 		FREE(retaddr, M_NETGRAPH);
1204 	return (error);
1205 }
1206 
1207 /*
1208  * Implement the 'generic' control messages
1209  */
1210 static int
1211 ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
1212 	       struct ng_mesg **resp)
1213 {
1214 	int error = 0;
1215 
1216 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
1217 		TRAP_ERROR;
1218 		FREE(msg, M_NETGRAPH);
1219 		return (EINVAL);
1220 	}
1221 	switch (msg->header.cmd) {
1222 	case NGM_SHUTDOWN:
1223 		ng_rmnode(here);
1224 		break;
1225 	case NGM_MKPEER:
1226 	    {
1227 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
1228 
1229 		if (msg->header.arglen != sizeof(*mkp)) {
1230 			TRAP_ERROR;
1231 			return (EINVAL);
1232 		}
1233 		mkp->type[sizeof(mkp->type) - 1] = '\0';
1234 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
1235 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
1236 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
1237 		break;
1238 	    }
1239 	case NGM_CONNECT:
1240 	    {
1241 		struct ngm_connect *const con =
1242 			(struct ngm_connect *) msg->data;
1243 		node_p node2;
1244 
1245 		if (msg->header.arglen != sizeof(*con)) {
1246 			TRAP_ERROR;
1247 			return (EINVAL);
1248 		}
1249 		con->path[sizeof(con->path) - 1] = '\0';
1250 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
1251 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
1252 		error = ng_path2node(here, con->path, &node2, NULL);
1253 		if (error)
1254 			break;
1255 		error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
1256 		break;
1257 	    }
1258 	case NGM_NAME:
1259 	    {
1260 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
1261 
1262 		if (msg->header.arglen != sizeof(*nam)) {
1263 			TRAP_ERROR;
1264 			return (EINVAL);
1265 		}
1266 		nam->name[sizeof(nam->name) - 1] = '\0';
1267 		error = ng_name_node(here, nam->name);
1268 		break;
1269 	    }
1270 	case NGM_RMHOOK:
1271 	    {
1272 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
1273 		hook_p hook;
1274 
1275 		if (msg->header.arglen != sizeof(*rmh)) {
1276 			TRAP_ERROR;
1277 			return (EINVAL);
1278 		}
1279 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
1280 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
1281 			ng_destroy_hook(hook);
1282 		break;
1283 	    }
1284 	case NGM_NODEINFO:
1285 	    {
1286 		struct nodeinfo *ni;
1287 		struct ng_mesg *rp;
1288 
1289 		/* Get response struct */
1290 		if (resp == NULL) {
1291 			error = EINVAL;
1292 			break;
1293 		}
1294 		NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
1295 		if (rp == NULL) {
1296 			error = ENOMEM;
1297 			break;
1298 		}
1299 
1300 		/* Fill in node info */
1301 		ni = (struct nodeinfo *) rp->data;
1302 		if (here->name != NULL)
1303 			strncpy(ni->name, here->name, NG_NODELEN);
1304 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1305 		ni->id = ng_node2ID(here);
1306 		ni->hooks = here->numhooks;
1307 		*resp = rp;
1308 		break;
1309 	    }
1310 	case NGM_LISTHOOKS:
1311 	    {
1312 		const int nhooks = here->numhooks;
1313 		struct hooklist *hl;
1314 		struct nodeinfo *ni;
1315 		struct ng_mesg *rp;
1316 		hook_p hook;
1317 
1318 		/* Get response struct */
1319 		if (resp == NULL) {
1320 			error = EINVAL;
1321 			break;
1322 		}
1323 		NG_MKRESPONSE(rp, msg, sizeof(*hl)
1324 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
1325 		if (rp == NULL) {
1326 			error = ENOMEM;
1327 			break;
1328 		}
1329 		hl = (struct hooklist *) rp->data;
1330 		ni = &hl->nodeinfo;
1331 
1332 		/* Fill in node info */
1333 		if (here->name)
1334 			strncpy(ni->name, here->name, NG_NODELEN);
1335 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1336 		ni->id = ng_node2ID(here);
1337 
1338 		/* Cycle through the linked list of hooks */
1339 		ni->hooks = 0;
1340 		LIST_FOREACH(hook, &here->hooks, hooks) {
1341 			struct linkinfo *const link = &hl->link[ni->hooks];
1342 
1343 			if (ni->hooks >= nhooks) {
1344 				log(LOG_ERR, "%s: number of %s changed\n",
1345 				    __FUNCTION__, "hooks");
1346 				break;
1347 			}
1348 			if ((hook->flags & HK_INVALID) != 0)
1349 				continue;
1350 			strncpy(link->ourhook, hook->name, NG_HOOKLEN);
1351 			strncpy(link->peerhook, hook->peer->name, NG_HOOKLEN);
1352 			if (hook->peer->node->name != NULL)
1353 				strncpy(link->nodeinfo.name,
1354 				    hook->peer->node->name, NG_NODELEN);
1355 			strncpy(link->nodeinfo.type,
1356 			   hook->peer->node->type->name, NG_TYPELEN);
1357 			link->nodeinfo.id = ng_node2ID(hook->peer->node);
1358 			link->nodeinfo.hooks = hook->peer->node->numhooks;
1359 			ni->hooks++;
1360 		}
1361 		*resp = rp;
1362 		break;
1363 	    }
1364 
1365 	case NGM_LISTNAMES:
1366 	case NGM_LISTNODES:
1367 	    {
1368 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
1369 		struct namelist *nl;
1370 		struct ng_mesg *rp;
1371 		node_p node;
1372 		int num = 0;
1373 
1374 		if (resp == NULL) {
1375 			error = EINVAL;
1376 			break;
1377 		}
1378 
1379 		/* Count number of nodes */
1380 		LIST_FOREACH(node, &nodelist, nodes) {
1381 			if ((node->flags & NG_INVALID) == 0
1382 			    && (unnamed || node->name != NULL))
1383 				num++;
1384 		}
1385 
1386 		/* Get response struct */
1387 		if (resp == NULL) {
1388 			error = EINVAL;
1389 			break;
1390 		}
1391 		NG_MKRESPONSE(rp, msg, sizeof(*nl)
1392 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
1393 		if (rp == NULL) {
1394 			error = ENOMEM;
1395 			break;
1396 		}
1397 		nl = (struct namelist *) rp->data;
1398 
1399 		/* Cycle through the linked list of nodes */
1400 		nl->numnames = 0;
1401 		LIST_FOREACH(node, &nodelist, nodes) {
1402 			struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
1403 
1404 			if (nl->numnames >= num) {
1405 				log(LOG_ERR, "%s: number of %s changed\n",
1406 				    __FUNCTION__, "nodes");
1407 				break;
1408 			}
1409 			if ((node->flags & NG_INVALID) != 0)
1410 				continue;
1411 			if (!unnamed && node->name == NULL)
1412 				continue;
1413 			if (node->name != NULL)
1414 				strncpy(np->name, node->name, NG_NODELEN);
1415 			strncpy(np->type, node->type->name, NG_TYPELEN);
1416 			np->id = ng_node2ID(node);
1417 			np->hooks = node->numhooks;
1418 			nl->numnames++;
1419 		}
1420 		*resp = rp;
1421 		break;
1422 	    }
1423 
1424 	case NGM_LISTTYPES:
1425 	    {
1426 		struct typelist *tl;
1427 		struct ng_mesg *rp;
1428 		struct ng_type *type;
1429 		int num = 0;
1430 
1431 		if (resp == NULL) {
1432 			error = EINVAL;
1433 			break;
1434 		}
1435 
1436 		/* Count number of types */
1437 		LIST_FOREACH(type, &typelist, types)
1438 			num++;
1439 
1440 		/* Get response struct */
1441 		if (resp == NULL) {
1442 			error = EINVAL;
1443 			break;
1444 		}
1445 		NG_MKRESPONSE(rp, msg, sizeof(*tl)
1446 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
1447 		if (rp == NULL) {
1448 			error = ENOMEM;
1449 			break;
1450 		}
1451 		tl = (struct typelist *) rp->data;
1452 
1453 		/* Cycle through the linked list of types */
1454 		tl->numtypes = 0;
1455 		LIST_FOREACH(type, &typelist, types) {
1456 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
1457 
1458 			if (tl->numtypes >= num) {
1459 				log(LOG_ERR, "%s: number of %s changed\n",
1460 				    __FUNCTION__, "types");
1461 				break;
1462 			}
1463 			strncpy(tp->type_name, type->name, NG_TYPELEN);
1464 			tp->numnodes = type->refs - 1; /* don't count list */
1465 			tl->numtypes++;
1466 		}
1467 		*resp = rp;
1468 		break;
1469 	    }
1470 
1471 	case NGM_BINARY2ASCII:
1472 	    {
1473 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
1474 		const struct ng_parse_type *argstype;
1475 		const struct ng_cmdlist *c;
1476 		struct ng_mesg *rp, *binary, *ascii;
1477 
1478 		/* Data area must contain a valid netgraph message */
1479 		binary = (struct ng_mesg *)msg->data;
1480 		if (msg->header.arglen < sizeof(struct ng_mesg)
1481 		    || msg->header.arglen - sizeof(struct ng_mesg)
1482 		      < binary->header.arglen) {
1483 			error = EINVAL;
1484 			break;
1485 		}
1486 
1487 		/* Get a response message with lots of room */
1488 		NG_MKRESPONSE(rp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
1489 		if (rp == NULL) {
1490 			error = ENOMEM;
1491 			break;
1492 		}
1493 		ascii = (struct ng_mesg *)rp->data;
1494 
1495 		/* Copy binary message header to response message payload */
1496 		bcopy(binary, ascii, sizeof(*binary));
1497 
1498 		/* Find command by matching typecookie and command number */
1499 		for (c = here->type->cmdlist;
1500 		    c != NULL && c->name != NULL; c++) {
1501 			if (binary->header.typecookie == c->cookie
1502 			    && binary->header.cmd == c->cmd)
1503 				break;
1504 		}
1505 		if (c == NULL || c->name == NULL) {
1506 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1507 				if (binary->header.typecookie == c->cookie
1508 				    && binary->header.cmd == c->cmd)
1509 					break;
1510 			}
1511 			if (c->name == NULL) {
1512 				FREE(rp, M_NETGRAPH);
1513 				error = ENOSYS;
1514 				break;
1515 			}
1516 		}
1517 
1518 		/* Convert command name to ASCII */
1519 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
1520 		    "%s", c->name);
1521 
1522 		/* Convert command arguments to ASCII */
1523 		argstype = (binary->header.flags & NGF_RESP) ?
1524 		    c->respType : c->mesgType;
1525 		if (argstype == NULL)
1526 			*ascii->data = '\0';
1527 		else {
1528 			if ((error = ng_unparse(argstype,
1529 			    (u_char *)binary->data,
1530 			    ascii->data, bufSize)) != 0) {
1531 				FREE(rp, M_NETGRAPH);
1532 				break;
1533 			}
1534 		}
1535 
1536 		/* Return the result as struct ng_mesg plus ASCII string */
1537 		bufSize = strlen(ascii->data) + 1;
1538 		ascii->header.arglen = bufSize;
1539 		rp->header.arglen = sizeof(*ascii) + bufSize;
1540 		*resp = rp;
1541 		break;
1542 	    }
1543 
1544 	case NGM_ASCII2BINARY:
1545 	    {
1546 		int bufSize = 2000;	/* XXX hard coded constant */
1547 		const struct ng_cmdlist *c;
1548 		const struct ng_parse_type *argstype;
1549 		struct ng_mesg *rp, *ascii, *binary;
1550 		int off = 0;
1551 
1552 		/* Data area must contain at least a struct ng_mesg + '\0' */
1553 		ascii = (struct ng_mesg *)msg->data;
1554 		if (msg->header.arglen < sizeof(*ascii) + 1
1555 		    || ascii->header.arglen < 1
1556 		    || msg->header.arglen
1557 		      < sizeof(*ascii) + ascii->header.arglen) {
1558 			error = EINVAL;
1559 			break;
1560 		}
1561 		ascii->data[ascii->header.arglen - 1] = '\0';
1562 
1563 		/* Get a response message with lots of room */
1564 		NG_MKRESPONSE(rp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
1565 		if (rp == NULL) {
1566 			error = ENOMEM;
1567 			break;
1568 		}
1569 		binary = (struct ng_mesg *)rp->data;
1570 
1571 		/* Copy ASCII message header to response message payload */
1572 		bcopy(ascii, binary, sizeof(*ascii));
1573 
1574 		/* Find command by matching ASCII command string */
1575 		for (c = here->type->cmdlist;
1576 		    c != NULL && c->name != NULL; c++) {
1577 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
1578 				break;
1579 		}
1580 		if (c == NULL || c->name == NULL) {
1581 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1582 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
1583 					break;
1584 			}
1585 			if (c->name == NULL) {
1586 				FREE(rp, M_NETGRAPH);
1587 				error = ENOSYS;
1588 				break;
1589 			}
1590 		}
1591 
1592 		/* Convert command name to binary */
1593 		binary->header.cmd = c->cmd;
1594 		binary->header.typecookie = c->cookie;
1595 
1596 		/* Convert command arguments to binary */
1597 		argstype = (binary->header.flags & NGF_RESP) ?
1598 		    c->respType : c->mesgType;
1599 		if (argstype == NULL)
1600 			bufSize = 0;
1601 		else {
1602 			if ((error = ng_parse(argstype, ascii->data,
1603 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
1604 				FREE(rp, M_NETGRAPH);
1605 				break;
1606 			}
1607 		}
1608 
1609 		/* Return the result */
1610 		binary->header.arglen = bufSize;
1611 		rp->header.arglen = sizeof(*binary) + bufSize;
1612 		*resp = rp;
1613 		break;
1614 	    }
1615 
1616 	case NGM_TEXT_CONFIG:
1617 	case NGM_TEXT_STATUS:
1618 		/*
1619 		 * This one is tricky as it passes the command down to the
1620 		 * actual node, even though it is a generic type command.
1621 		 * This means we must assume that the msg is already freed
1622 		 * when control passes back to us.
1623 		 */
1624 		if (resp == NULL) {
1625 			error = EINVAL;
1626 			break;
1627 		}
1628 		if (here->type->rcvmsg != NULL)
1629 			return((*here->type->rcvmsg)(here, msg, retaddr, resp));
1630 		/* Fall through if rcvmsg not supported */
1631 	default:
1632 		TRAP_ERROR;
1633 		error = EINVAL;
1634 	}
1635 	FREE(msg, M_NETGRAPH);
1636 	return (error);
1637 }
1638 
1639 /*
1640  * Send a data packet to a node. If the recipient has no
1641  * 'receive data' method, then silently discard the packet.
1642  */
1643 int
1644 ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
1645 {
1646 	int (*rcvdata)(hook_p, struct mbuf *, meta_p);
1647 	int error;
1648 
1649 	CHECK_DATA_MBUF(m);
1650 	if (hook && (hook->flags & HK_INVALID) == 0) {
1651 		rcvdata = hook->peer->node->type->rcvdata;
1652 		if (rcvdata != NULL)
1653 			error = (*rcvdata)(hook->peer, m, meta);
1654 		else {
1655 			error = 0;
1656 			NG_FREE_DATA(m, meta);
1657 		}
1658 	} else {
1659 		TRAP_ERROR;
1660 		error = ENOTCONN;
1661 		NG_FREE_DATA(m, meta);
1662 	}
1663 	return (error);
1664 }
1665 
1666 /*
1667  * Send a queued data packet to a node. If the recipient has no
1668  * 'receive queued data' method, then try the 'receive data' method above.
1669  */
1670 int
1671 ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
1672 {
1673 	int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
1674 	int error;
1675 
1676 	CHECK_DATA_MBUF(m);
1677 	if (hook && (hook->flags & HK_INVALID) == 0) {
1678 		rcvdataq = hook->peer->node->type->rcvdataq;
1679 		if (rcvdataq != NULL)
1680 			error = (*rcvdataq)(hook->peer, m, meta);
1681 		else {
1682 			error = ng_send_data(hook, m, meta);
1683 		}
1684 	} else {
1685 		TRAP_ERROR;
1686 		error = ENOTCONN;
1687 		NG_FREE_DATA(m, meta);
1688 	}
1689 	return (error);
1690 }
1691 
1692 /*
1693  * Copy a 'meta'.
1694  *
1695  * Returns new meta, or NULL if original meta is NULL or ENOMEM.
1696  */
1697 meta_p
1698 ng_copy_meta(meta_p meta)
1699 {
1700 	meta_p meta2;
1701 
1702 	if (meta == NULL)
1703 		return (NULL);
1704 	MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH, M_NOWAIT);
1705 	if (meta2 == NULL)
1706 		return (NULL);
1707 	meta2->allocated_len = meta->used_len;
1708 	bcopy(meta, meta2, meta->used_len);
1709 	return (meta2);
1710 }
1711 
1712 /************************************************************************
1713 			Module routines
1714 ************************************************************************/
1715 
1716 /*
1717  * Handle the loading/unloading of a netgraph node type module
1718  */
1719 int
1720 ng_mod_event(module_t mod, int event, void *data)
1721 {
1722 	struct ng_type *const type = data;
1723 	int s, error = 0;
1724 
1725 	switch (event) {
1726 	case MOD_LOAD:
1727 
1728 		/* Register new netgraph node type */
1729 		s = splnet();
1730 		if ((error = ng_newtype(type)) != 0) {
1731 			splx(s);
1732 			break;
1733 		}
1734 
1735 		/* Call type specific code */
1736 		if (type->mod_event != NULL)
1737 			if ((error = (*type->mod_event)(mod, event, data))) {
1738 				type->refs--;	/* undo it */
1739 				LIST_REMOVE(type, types);
1740 			}
1741 		splx(s);
1742 		break;
1743 
1744 	case MOD_UNLOAD:
1745 		s = splnet();
1746 		if (type->refs > 1) {		/* make sure no nodes exist! */
1747 			error = EBUSY;
1748 		} else {
1749 			if (type->refs == 0) {
1750 				/* failed load, nothing to undo */
1751 				splx(s);
1752 				break;
1753 			}
1754 			if (type->mod_event != NULL) {	/* check with type */
1755 				error = (*type->mod_event)(mod, event, data);
1756 				if (error != 0) {	/* type refuses.. */
1757 					splx(s);
1758 					break;
1759 				}
1760 			}
1761 			LIST_REMOVE(type, types);
1762 		}
1763 		splx(s);
1764 		break;
1765 
1766 	default:
1767 		if (type->mod_event != NULL)
1768 			error = (*type->mod_event)(mod, event, data);
1769 		else
1770 			error = 0;		/* XXX ? */
1771 		break;
1772 	}
1773 	return (error);
1774 }
1775 
1776 /*
1777  * Handle loading and unloading for this code.
1778  * The only thing we need to link into is the NETISR strucure.
1779  */
1780 static int
1781 ngb_mod_event(module_t mod, int event, void *data)
1782 {
1783 	int s, error = 0;
1784 
1785 	switch (event) {
1786 	case MOD_LOAD:
1787 		/* Register line discipline */
1788 		s = splimp();
1789 		netisr_register(NETISR_NETGRAPH, cpu0_portfn, ngintr);
1790 		error = 0;
1791 		splx(s);
1792 		break;
1793 	case MOD_UNLOAD:
1794 		/* You cant unload it because an interface may be using it.  */
1795 		error = EBUSY;
1796 		break;
1797 	default:
1798 		error = EOPNOTSUPP;
1799 		break;
1800 	}
1801 	return (error);
1802 }
1803 
1804 static moduledata_t netgraph_mod = {
1805 	"netgraph",
1806 	ngb_mod_event,
1807 	(NULL)
1808 };
1809 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1810 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
1811 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
1812 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
1813 
1814 /************************************************************************
1815 			Queueing routines
1816 ************************************************************************/
1817 
1818 /* The structure for queueing across ISR switches */
1819 struct ng_queue_entry {
1820 	u_long	flags;
1821 	struct ng_queue_entry *next;
1822 	union {
1823 		struct {
1824 			hook_p		da_hook;	/*  target hook */
1825 			struct mbuf	*da_m;
1826 			meta_p		da_meta;
1827 		} data;
1828 		struct {
1829 			struct ng_mesg	*msg_msg;
1830 			node_p		msg_node;
1831 			void		*msg_retaddr;
1832 		} msg;
1833 	} body;
1834 };
1835 #define NGQF_DATA	0x01		/* the queue element is data */
1836 #define NGQF_MESG	0x02		/* the queue element is a message */
1837 
1838 static struct ng_queue_entry   *ngqbase;	/* items to be unqueued */
1839 static struct ng_queue_entry   *ngqlast;	/* last item queued */
1840 static const int		ngqroom = 256;	/* max items to queue */
1841 static int			ngqsize;	/* number of items in queue */
1842 
1843 static struct ng_queue_entry   *ngqfree;	/* free ones */
1844 static const int		ngqfreemax = 256;/* cache at most this many */
1845 static int			ngqfreesize;	/* number of cached entries */
1846 
1847 /*
1848  * Get a queue entry
1849  */
1850 static struct ng_queue_entry *
1851 ng_getqblk(void)
1852 {
1853 	struct ng_queue_entry *q;
1854 	int s;
1855 
1856 	/* Could be guarding against tty ints or whatever */
1857 	s = splhigh();
1858 
1859 	/* Try get a cached queue block, or else allocate a new one */
1860 	if ((q = ngqfree) == NULL) {
1861 		splx(s);
1862 		if (ngqsize < ngqroom) {	/* don't worry about races */
1863 			MALLOC(q, struct ng_queue_entry *,
1864 			    sizeof(*q), M_NETGRAPH, M_NOWAIT);
1865 		}
1866 	} else {
1867 		ngqfree = q->next;
1868 		ngqfreesize--;
1869 		splx(s);
1870 	}
1871 	return (q);
1872 }
1873 
1874 /*
1875  * Release a queue entry
1876  */
1877 #define RETURN_QBLK(q)							\
1878 do {									\
1879 	int s;								\
1880 	if (ngqfreesize < ngqfreemax) { /* don't worry about races */ 	\
1881 		s = splhigh();						\
1882 		(q)->next = ngqfree;					\
1883 		ngqfree = (q);						\
1884 		ngqfreesize++;						\
1885 		splx(s);						\
1886 	} else {							\
1887 		FREE((q), M_NETGRAPH);					\
1888 	}								\
1889 } while (0)
1890 
1891 /*
1892  * Running at a raised (but we don't know which) processor priority level,
1893  * put the data onto a queue to be picked up by another PPL (probably splnet)
1894  */
1895 int
1896 ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
1897 {
1898 	struct ng_queue_entry *q;
1899 	int s;
1900 
1901 	if (hook == NULL) {
1902 		NG_FREE_DATA(m, meta);
1903 		return (0);
1904 	}
1905 	if ((q = ng_getqblk()) == NULL) {
1906 		NG_FREE_DATA(m, meta);
1907 		return (ENOBUFS);
1908 	}
1909 
1910 	/* Fill out the contents */
1911 	q->flags = NGQF_DATA;
1912 	q->next = NULL;
1913 	q->body.data.da_hook = hook;
1914 	q->body.data.da_m = m;
1915 	q->body.data.da_meta = meta;
1916 	s = splhigh();		/* protect refs and queue */
1917 	hook->refs++;		/* don't let it go away while on the queue */
1918 
1919 	/* Put it on the queue */
1920 	if (ngqbase) {
1921 		ngqlast->next = q;
1922 	} else {
1923 		ngqbase = q;
1924 	}
1925 	ngqlast = q;
1926 	ngqsize++;
1927 	splx(s);
1928 
1929 	/* Schedule software interrupt to handle it later */
1930 	schednetisr(NETISR_NETGRAPH);
1931 	return (0);
1932 }
1933 
1934 /*
1935  * Running at a raised (but we don't know which) processor priority level,
1936  * put the msg onto a queue to be picked up by another PPL (probably splnet)
1937  */
1938 int
1939 ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address)
1940 {
1941 	struct ng_queue_entry *q;
1942 	int     s;
1943 	node_p  dest = NULL;
1944 	char   *retaddr = NULL;
1945 	int     error;
1946 
1947 	/* Find the target node. */
1948 	error = ng_path2node(here, address, &dest, &retaddr);
1949 	if (error) {
1950 		FREE(msg, M_NETGRAPH);
1951 		return (error);
1952 	}
1953 	if ((q = ng_getqblk()) == NULL) {
1954 		FREE(msg, M_NETGRAPH);
1955 		if (retaddr)
1956 			FREE(retaddr, M_NETGRAPH);
1957 		return (ENOBUFS);
1958 	}
1959 
1960 	/* Fill out the contents */
1961 	q->flags = NGQF_MESG;
1962 	q->next = NULL;
1963 	q->body.msg.msg_node = dest;
1964 	q->body.msg.msg_msg = msg;
1965 	q->body.msg.msg_retaddr = retaddr;
1966 	s = splhigh();		/* protect refs and queue */
1967 	dest->refs++;		/* don't let it go away while on the queue */
1968 
1969 	/* Put it on the queue */
1970 	if (ngqbase) {
1971 		ngqlast->next = q;
1972 	} else {
1973 		ngqbase = q;
1974 	}
1975 	ngqlast = q;
1976 	ngqsize++;
1977 	splx(s);
1978 
1979 	/* Schedule software interrupt to handle it later */
1980 	schednetisr(NETISR_NETGRAPH);
1981 	return (0);
1982 }
1983 
1984 /*
1985  * Pick an item off the queue, process it, and dispose of the queue entry.
1986  * Should be running at splnet.
1987  */
1988 static int
1989 ngintr(struct netmsg *pmsg)
1990 {
1991 	struct mbuf *m = ((struct netmsg_packet *)pmsg)->nm_packet;
1992 	hook_p  hook;
1993 	struct ng_queue_entry *ngq;
1994 	meta_p  meta;
1995 	void   *retaddr;
1996 	struct ng_mesg *msg;
1997 	node_p  node;
1998 	int     error = 0;
1999 	int     s;
2000 
2001 	while (1) {
2002 		s = splhigh();
2003 		if ((ngq = ngqbase)) {
2004 			ngqbase = ngq->next;
2005 			ngqsize--;
2006 		}
2007 		splx(s);
2008 		if (ngq == NULL)
2009 			goto out;
2010 		switch (ngq->flags) {
2011 		case NGQF_DATA:
2012 			hook = ngq->body.data.da_hook;
2013 			m = ngq->body.data.da_m;
2014 			meta = ngq->body.data.da_meta;
2015 			RETURN_QBLK(ngq);
2016 			NG_SEND_DATAQ(error, hook, m, meta);
2017 			ng_unref_hook(hook);
2018 			break;
2019 		case NGQF_MESG:
2020 			node = ngq->body.msg.msg_node;
2021 			msg = ngq->body.msg.msg_msg;
2022 			retaddr = ngq->body.msg.msg_retaddr;
2023 			RETURN_QBLK(ngq);
2024 			if (node->flags & NG_INVALID) {
2025 				FREE(msg, M_NETGRAPH);
2026 			} else {
2027 				CALL_MSG_HANDLER(error, node, msg,
2028 						 retaddr, NULL);
2029 			}
2030 			ng_unref(node);
2031 			if (retaddr)
2032 				FREE(retaddr, M_NETGRAPH);
2033 			break;
2034 		default:
2035 			RETURN_QBLK(ngq);
2036 		}
2037 	}
2038 out:
2039 	lwkt_replymsg(&pmsg->nm_lmsg, 0);
2040 	return(EASYNC);
2041 }
2042 
2043 
2044