xref: /dragonfly/sys/netgraph/netgraph/ng_base.c (revision cc93b0eb)
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 1.26 2008/01/05 14:02:39 swildner 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 <sys/vnode.h>
61 #include <machine/limits.h>
62 
63 #include <sys/thread2.h>
64 #include <sys/msgport2.h>
65 
66 #include <net/netisr.h>
67 
68 #include <netgraph/ng_message.h>
69 #include <netgraph/netgraph.h>
70 #include <netgraph/ng_parse.h>
71 
72 /* List of all nodes */
73 static LIST_HEAD(, ng_node) nodelist;
74 
75 /* List of installed types */
76 static LIST_HEAD(, ng_type) typelist;
77 
78 /* Hash releted definitions */
79 #define ID_HASH_SIZE 32 /* most systems wont need even this many */
80 static LIST_HEAD(, ng_node) ID_hash[ID_HASH_SIZE];
81 /* Don't nead to initialise them because it's a LIST */
82 
83 /* Internal functions */
84 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
85 static int	ng_connect(hook_p hook1, hook_p hook2);
86 static void	ng_disconnect_hook(hook_p hook);
87 static int	ng_generic_msg(node_p here, struct ng_mesg *msg,
88 			const char *retaddr, struct ng_mesg ** resp);
89 static ng_ID_t	ng_decodeidname(const char *name);
90 static int	ngb_mod_event(module_t mod, int event, void *data);
91 static void	ngintr(struct netmsg *);
92 static int	ng_load_module(const char *);
93 static int	ng_unload_module(const char *);
94 
95 /* Our own netgraph malloc type */
96 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
97 
98 /* Set this to Debugger("X") to catch all errors as they occur */
99 #ifndef TRAP_ERROR
100 #define TRAP_ERROR
101 #endif
102 
103 static	ng_ID_t nextID = 1;
104 
105 #ifdef INVARIANTS
106 #define CHECK_DATA_MBUF(m)	do {					\
107 		struct mbuf *n;						\
108 		int total;						\
109 									\
110 		if (((m)->m_flags & M_PKTHDR) == 0)			\
111 			panic("%s: !PKTHDR", __func__);		\
112 		for (total = 0, n = (m); n != NULL; n = n->m_next)	\
113 			total += n->m_len;				\
114 		if ((m)->m_pkthdr.len != total) {			\
115 			panic("%s: %d != %d",				\
116 			    __func__, (m)->m_pkthdr.len, total);	\
117 		}							\
118 	} while (0)
119 #else
120 #define CHECK_DATA_MBUF(m)
121 #endif
122 
123 
124 /************************************************************************
125 	Parse type definitions for generic messages
126 ************************************************************************/
127 
128 /* Handy structure parse type defining macro */
129 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
130 static const struct ng_parse_struct_field				\
131 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
132 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
133 	&ng_parse_struct_type,						\
134 	&ng_ ## lo ## _type_fields					\
135 }
136 
137 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
138 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
139 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
140 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
141 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
142 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
143 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
144 
145 /* Get length of an array when the length is stored as a 32 bit
146    value immediately preceeding the array -- as with struct namelist
147    and struct typelist. */
148 static int
149 ng_generic_list_getLength(const struct ng_parse_type *type,
150 	const u_char *start, const u_char *buf)
151 {
152 	return *((const u_int32_t *)(buf - 4));
153 }
154 
155 /* Get length of the array of struct linkinfo inside a struct hooklist */
156 static int
157 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
158 	const u_char *start, const u_char *buf)
159 {
160 	const struct hooklist *hl = (const struct hooklist *)start;
161 
162 	return hl->nodeinfo.hooks;
163 }
164 
165 /* Array type for a variable length array of struct namelist */
166 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
167 	&ng_generic_nodeinfo_type,
168 	&ng_generic_list_getLength
169 };
170 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
171 	&ng_parse_array_type,
172 	&ng_nodeinfoarray_type_info
173 };
174 
175 /* Array type for a variable length array of struct typelist */
176 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
177 	&ng_generic_typeinfo_type,
178 	&ng_generic_list_getLength
179 };
180 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
181 	&ng_parse_array_type,
182 	&ng_typeinfoarray_type_info
183 };
184 
185 /* Array type for array of struct linkinfo in struct hooklist */
186 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
187 	&ng_generic_linkinfo_type,
188 	&ng_generic_linkinfo_getLength
189 };
190 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
191 	&ng_parse_array_type,
192 	&ng_generic_linkinfo_array_type_info
193 };
194 
195 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
196 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
197 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
198 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
199 	(&ng_generic_nodeinfoarray_type));
200 
201 /* List of commands and how to convert arguments to/from ASCII */
202 static const struct ng_cmdlist ng_generic_cmds[] = {
203 	{
204 	  NGM_GENERIC_COOKIE,
205 	  NGM_SHUTDOWN,
206 	  "shutdown",
207 	  NULL,
208 	  NULL
209 	},
210 	{
211 	  NGM_GENERIC_COOKIE,
212 	  NGM_MKPEER,
213 	  "mkpeer",
214 	  &ng_generic_mkpeer_type,
215 	  NULL
216 	},
217 	{
218 	  NGM_GENERIC_COOKIE,
219 	  NGM_CONNECT,
220 	  "connect",
221 	  &ng_generic_connect_type,
222 	  NULL
223 	},
224 	{
225 	  NGM_GENERIC_COOKIE,
226 	  NGM_NAME,
227 	  "name",
228 	  &ng_generic_name_type,
229 	  NULL
230 	},
231 	{
232 	  NGM_GENERIC_COOKIE,
233 	  NGM_RMHOOK,
234 	  "rmhook",
235 	  &ng_generic_rmhook_type,
236 	  NULL
237 	},
238 	{
239 	  NGM_GENERIC_COOKIE,
240 	  NGM_NODEINFO,
241 	  "nodeinfo",
242 	  NULL,
243 	  &ng_generic_nodeinfo_type
244 	},
245 	{
246 	  NGM_GENERIC_COOKIE,
247 	  NGM_LISTHOOKS,
248 	  "listhooks",
249 	  NULL,
250 	  &ng_generic_hooklist_type
251 	},
252 	{
253 	  NGM_GENERIC_COOKIE,
254 	  NGM_LISTNAMES,
255 	  "listnames",
256 	  NULL,
257 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
258 	},
259 	{
260 	  NGM_GENERIC_COOKIE,
261 	  NGM_LISTNODES,
262 	  "listnodes",
263 	  NULL,
264 	  &ng_generic_listnodes_type
265 	},
266 	{
267 	  NGM_GENERIC_COOKIE,
268 	  NGM_LISTTYPES,
269 	  "listtypes",
270 	  NULL,
271 	  &ng_generic_typeinfo_type
272 	},
273 	{
274 	  NGM_GENERIC_COOKIE,
275 	  NGM_TEXT_CONFIG,
276 	  "textconfig",
277 	  NULL,
278 	  &ng_parse_string_type
279 	},
280 	{
281 	  NGM_GENERIC_COOKIE,
282 	  NGM_TEXT_STATUS,
283 	  "textstatus",
284 	  NULL,
285 	  &ng_parse_string_type
286 	},
287 	{
288 	  NGM_GENERIC_COOKIE,
289 	  NGM_ASCII2BINARY,
290 	  "ascii2binary",
291 	  &ng_parse_ng_mesg_type,
292 	  &ng_parse_ng_mesg_type
293 	},
294 	{
295 	  NGM_GENERIC_COOKIE,
296 	  NGM_BINARY2ASCII,
297 	  "binary2ascii",
298 	  &ng_parse_ng_mesg_type,
299 	  &ng_parse_ng_mesg_type
300 	},
301 	{ 0 }
302 };
303 
304 /************************************************************************
305 			Node routines
306 ************************************************************************/
307 
308 static int
309 linker_api_available(void)
310 {
311 	/* linker_* API won't work without a process context */
312 	if (curproc == NULL)
313 		return 0;
314 	/*
315 	 * nlookup_init() relies on namei_oc to be initialized,
316 	 * but it's not when the netgraph module is loaded during boot.
317 	 */
318 	if (namei_oc == NULL)
319 		return 0;
320 	return 1;
321 }
322 
323 static int
324 ng_load_module(const char *name)
325 {
326 	char *path, filename[NG_TYPESIZ + 3];
327 	linker_file_t lf;
328 	int error;
329 
330 	if (!linker_api_available())
331 		return (ENXIO);
332 
333 	/* Not found, try to load it as a loadable module */
334 	ksnprintf(filename, sizeof(filename), "ng_%s.ko", name);
335 	if ((path = linker_search_path(filename)) == NULL)
336 		return (ENXIO);
337 	error = linker_load_file(path, &lf);
338 	FREE(path, M_LINKER);
339 	if (error == 0)
340 		lf->userrefs++;		/* pretend kldload'ed */
341 	return (error);
342 }
343 
344 static int
345 ng_unload_module(const char *name)
346 {
347 	char filename[NG_TYPESIZ + 3];
348 	linker_file_t lf;
349 	int error;
350 
351 	if (!linker_api_available())
352 		return (ENXIO);
353 
354 	/* Not found, try to load it as a loadable module */
355 	ksnprintf(filename, sizeof(filename), "ng_%s.ko", name);
356 	if ((lf = linker_find_file_by_name(filename)) == NULL)
357 		return (ENXIO);
358 	error = linker_file_unload(lf);
359 
360 	if (error == 0)
361 		lf->userrefs--;		/* pretend kldunload'ed */
362 	return (error);
363 }
364 
365 /*
366  * Instantiate a node of the requested type
367  */
368 int
369 ng_make_node(const char *typename, node_p *nodepp)
370 {
371 	struct ng_type *type;
372 
373 	/* Check that the type makes sense */
374 	if (typename == NULL) {
375 		TRAP_ERROR;
376 		return (EINVAL);
377 	}
378 
379 	/* Locate the node type */
380 	if ((type = ng_findtype(typename)) == NULL)
381 		return (ENXIO);
382 
383 	/* Call the constructor */
384 	if (type->constructor != NULL)
385 		return ((*type->constructor)(nodepp));
386 	else
387 		return (ng_make_node_common(type, nodepp));
388 }
389 
390 /*
391  * Generic node creation. Called by node constructors.
392  * The returned node has a reference count of 1.
393  */
394 int
395 ng_make_node_common(struct ng_type *type, node_p *nodepp)
396 {
397 	node_p node;
398 
399 	/* Require the node type to have been already installed */
400 	if (ng_findtype(type->name) == NULL) {
401 		TRAP_ERROR;
402 		return (EINVAL);
403 	}
404 
405 	/* Make a node and try attach it to the type */
406 	MALLOC(node, node_p, sizeof(*node), M_NETGRAPH, M_NOWAIT | M_ZERO);
407 	if (node == NULL) {
408 		TRAP_ERROR;
409 		return (ENOMEM);
410 	}
411 	node->type = type;
412 	node->refs++;				/* note reference */
413 	type->refs++;
414 
415 	/* Link us into the node linked list */
416 	LIST_INSERT_HEAD(&nodelist, node, nodes);
417 
418 	/* Initialize hook list for new node */
419 	LIST_INIT(&node->hooks);
420 
421 	/* get an ID and put us in the hash chain */
422 	node->ID = nextID++; /* 137 per second for 1 year before wrap */
423 	LIST_INSERT_HEAD(&ID_hash[node->ID % ID_HASH_SIZE], node, idnodes);
424 
425 	/* Done */
426 	*nodepp = node;
427 	return (0);
428 }
429 
430 /*
431  * Forceably start the shutdown process on a node. Either call
432  * it's shutdown method, or do the default shutdown if there is
433  * no type-specific method.
434  *
435  * Persistent nodes must have a type-specific method which
436  * resets the NG_INVALID flag.
437  */
438 void
439 ng_rmnode(node_p node)
440 {
441 	/* Check if it's already shutting down */
442 	if ((node->flags & NG_INVALID) != 0)
443 		return;
444 
445 	/* Add an extra reference so it doesn't go away during this */
446 	node->refs++;
447 
448 	/* Mark it invalid so any newcomers know not to try use it */
449 	node->flags |= NG_INVALID;
450 
451 	/* Ask the type if it has anything to do in this case */
452 	if (node->type && node->type->shutdown)
453 		(*node->type->shutdown)(node);
454 	else {				/* do the default thing */
455 		ng_unname(node);
456 		ng_cutlinks(node);
457 		ng_unref(node);
458 	}
459 
460 	/* Remove extra reference, possibly the last */
461 	ng_unref(node);
462 }
463 
464 /*
465  * Called by the destructor to remove any STANDARD external references
466  */
467 void
468 ng_cutlinks(node_p node)
469 {
470 	hook_p  hook;
471 
472 	/* Make sure that this is set to stop infinite loops */
473 	node->flags |= NG_INVALID;
474 
475 	/* If we have sleepers, wake them up; they'll see NG_INVALID */
476 	if (node->sleepers)
477 		wakeup(node);
478 
479 	/* Notify all remaining connected nodes to disconnect */
480 	while ((hook = LIST_FIRST(&node->hooks)) != NULL)
481 		ng_destroy_hook(hook);
482 }
483 
484 /*
485  * Remove a reference to the node, possibly the last
486  */
487 void
488 ng_unref(node_p node)
489 {
490 	crit_enter();
491 	if (--node->refs <= 0) {
492 		node->type->refs--;
493 		LIST_REMOVE(node, nodes);
494 		LIST_REMOVE(node, idnodes);
495 		FREE(node, M_NETGRAPH);
496 	}
497 	crit_exit();
498 }
499 
500 /*
501  * Wait for a node to come ready. Returns a node with a reference count;
502  * don't forget to drop it when we are done with it using ng_release_node().
503  */
504 int
505 ng_wait_node(node_p node, char *msg)
506 {
507 	int error = 0;
508 
509 	if (msg == NULL)
510 		msg = "netgraph";
511 	crit_enter();
512 	node->sleepers++;
513 	node->refs++;		/* the sleeping process counts as a reference */
514 	while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
515 		error = tsleep(node, PCATCH, msg, 0);
516 	node->sleepers--;
517 	if (node->flags & NG_INVALID) {
518 		TRAP_ERROR;
519 		error = ENXIO;
520 	} else {
521 		KASSERT(node->refs > 1,
522 		    ("%s: refs=%d", __func__, node->refs));
523 		node->flags |= NG_BUSY;
524 	}
525 	crit_exit();
526 
527 	/* Release the reference we had on it */
528 	if (error != 0)
529 		ng_unref(node);
530 	return error;
531 }
532 
533 /*
534  * Release a node acquired via ng_wait_node()
535  */
536 void
537 ng_release_node(node_p node)
538 {
539 	/* Declare that we don't want it */
540 	node->flags &= ~NG_BUSY;
541 
542 	/* If we have sleepers, then wake them up */
543 	if (node->sleepers)
544 		wakeup(node);
545 
546 	/* We also have a reference.. drop it too */
547 	ng_unref(node);
548 }
549 
550 /************************************************************************
551 			Node ID handling
552 ************************************************************************/
553 static node_p
554 ng_ID2node(ng_ID_t ID)
555 {
556 	node_p np;
557 	LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
558 		if ((np->flags & NG_INVALID) == 0 && np->ID == ID)
559 			break;
560 	}
561 	return(np);
562 }
563 
564 ng_ID_t
565 ng_node2ID(node_p node)
566 {
567 	return (node->ID);
568 }
569 
570 /************************************************************************
571 			Node name handling
572 ************************************************************************/
573 
574 /*
575  * Assign a node a name. Once assigned, the name cannot be changed.
576  */
577 int
578 ng_name_node(node_p node, const char *name)
579 {
580 	int i;
581 
582 	/* Check the name is valid */
583 	for (i = 0; i < NG_NODESIZ; i++) {
584 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
585 			break;
586 	}
587 	if (i == 0 || name[i] != '\0') {
588 		TRAP_ERROR;
589 		return (EINVAL);
590 	}
591 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
592 		TRAP_ERROR;
593 		return (EINVAL);
594 	}
595 
596 	/* Check the node isn't already named */
597 	if (node->name != NULL) {
598 		TRAP_ERROR;
599 		return (EISCONN);
600 	}
601 
602 	/* Check the name isn't already being used */
603 	if (ng_findname(node, name) != NULL) {
604 		TRAP_ERROR;
605 		return (EADDRINUSE);
606 	}
607 
608 	/* Allocate space and copy it */
609 	MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
610 	if (node->name == NULL) {
611 		TRAP_ERROR;
612 		return (ENOMEM);
613 	}
614 	strcpy(node->name, name);
615 
616 	/* The name counts as a reference */
617 	node->refs++;
618 	return (0);
619 }
620 
621 /*
622  * Find a node by absolute name. The name should NOT end with ':'
623  * The name "." means "this node" and "[xxx]" means "the node
624  * with ID (ie, at address) xxx".
625  *
626  * Returns the node if found, else NULL.
627  */
628 node_p
629 ng_findname(node_p this, const char *name)
630 {
631 	node_p node;
632 	ng_ID_t temp;
633 
634 	/* "." means "this node" */
635 	if (strcmp(name, ".") == 0)
636 		return(this);
637 
638 	/* Check for name-by-ID */
639 	if ((temp = ng_decodeidname(name)) != 0) {
640 		return (ng_ID2node(temp));
641 	}
642 
643 	/* Find node by name */
644 	LIST_FOREACH(node, &nodelist, nodes) {
645 		if ((node->name != NULL)
646 		&& (strcmp(node->name, name) == 0)
647 		&& ((node->flags & NG_INVALID) == 0))
648 			break;
649 	}
650 	return (node);
651 }
652 
653 /*
654  * Decode a ID name, eg. "[f03034de]". Returns 0 if the
655  * string is not valid, otherwise returns the value.
656  */
657 static ng_ID_t
658 ng_decodeidname(const char *name)
659 {
660 	const int len = strlen(name);
661 	char *eptr;
662 	u_long val;
663 
664 	/* Check for proper length, brackets, no leading junk */
665 	if (len < 3 || name[0] != '[' || name[len - 1] != ']'
666 	    || !isxdigit(name[1]))
667 		return (0);
668 
669 	/* Decode number */
670 	val = strtoul(name + 1, &eptr, 16);
671 	if (eptr - name != len - 1 || val == ULONG_MAX || val == 0)
672 		return ((ng_ID_t)0);
673 	return (ng_ID_t)val;
674 }
675 
676 /*
677  * Remove a name from a node. This should only be called
678  * when shutting down and removing the node.
679  */
680 void
681 ng_unname(node_p node)
682 {
683 	if (node->name) {
684 		FREE(node->name, M_NETGRAPH);
685 		node->name = NULL;
686 		ng_unref(node);
687 	}
688 }
689 
690 /************************************************************************
691 			Hook routines
692 
693  Names are not optional. Hooks are always connected, except for a
694  brief moment within these routines.
695 
696 ************************************************************************/
697 
698 /*
699  * Remove a hook reference
700  */
701 void
702 ng_unref_hook(hook_p hook)
703 {
704 	crit_enter();
705 	if (--hook->refs == 0)
706 		FREE(hook, M_NETGRAPH);
707 	crit_exit();
708 }
709 
710 /*
711  * Add an unconnected hook to a node. Only used internally.
712  */
713 static int
714 ng_add_hook(node_p node, const char *name, hook_p *hookp)
715 {
716 	hook_p hook;
717 	int error = 0;
718 
719 	/* Check that the given name is good */
720 	if (name == NULL) {
721 		TRAP_ERROR;
722 		return (EINVAL);
723 	}
724 	if (ng_findhook(node, name) != NULL) {
725 		TRAP_ERROR;
726 		return (EEXIST);
727 	}
728 
729 	/* Allocate the hook and link it up */
730 	MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_NOWAIT | M_ZERO);
731 	if (hook == NULL) {
732 		TRAP_ERROR;
733 		return (ENOMEM);
734 	}
735 	hook->refs = 1;
736 	hook->flags = HK_INVALID;
737 	hook->node = node;
738 	node->refs++;		/* each hook counts as a reference */
739 
740 	/* Check if the node type code has something to say about it */
741 	if (node->type->newhook != NULL)
742 		if ((error = (*node->type->newhook)(node, hook, name)) != 0)
743 			goto fail;
744 
745 	/*
746 	 * The 'type' agrees so far, so go ahead and link it in.
747 	 * We'll ask again later when we actually connect the hooks.
748 	 */
749 	LIST_INSERT_HEAD(&node->hooks, hook, hooks);
750 	node->numhooks++;
751 
752 	/* Set hook name */
753 	MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
754 	if (hook->name == NULL) {
755 		error = ENOMEM;
756 		LIST_REMOVE(hook, hooks);
757 		node->numhooks--;
758 fail:
759 		hook->node = NULL;
760 		ng_unref(node);
761 		ng_unref_hook(hook);	/* this frees the hook */
762 		return (error);
763 	}
764 	strcpy(hook->name, name);
765 	if (hookp)
766 		*hookp = hook;
767 	return (error);
768 }
769 
770 /*
771  * Connect a pair of hooks. Only used internally.
772  */
773 static int
774 ng_connect(hook_p hook1, hook_p hook2)
775 {
776 	int     error;
777 
778 	hook1->peer = hook2;
779 	hook2->peer = hook1;
780 
781 	/* Give each node the opportunity to veto the impending connection */
782 	if (hook1->node->type->connect) {
783 		if ((error = (*hook1->node->type->connect) (hook1))) {
784 			ng_destroy_hook(hook1);	/* also zaps hook2 */
785 			return (error);
786 		}
787 	}
788 	if (hook2->node->type->connect) {
789 		if ((error = (*hook2->node->type->connect) (hook2))) {
790 			ng_destroy_hook(hook2);	/* also zaps hook1 */
791 			return (error);
792 		}
793 	}
794 	hook1->flags &= ~HK_INVALID;
795 	hook2->flags &= ~HK_INVALID;
796 	return (0);
797 }
798 
799 /*
800  * Find a hook
801  *
802  * Node types may supply their own optimized routines for finding
803  * hooks.  If none is supplied, we just do a linear search.
804  */
805 hook_p
806 ng_findhook(node_p node, const char *name)
807 {
808 	hook_p hook;
809 
810 	if (node->type->findhook != NULL)
811 		return (*node->type->findhook)(node, name);
812 	LIST_FOREACH(hook, &node->hooks, hooks) {
813 		if (hook->name != NULL
814 		    && strcmp(hook->name, name) == 0
815 		    && (hook->flags & HK_INVALID) == 0)
816 			return (hook);
817 	}
818 	return (NULL);
819 }
820 
821 /*
822  * Destroy a hook
823  *
824  * As hooks are always attached, this really destroys two hooks.
825  * The one given, and the one attached to it. Disconnect the hooks
826  * from each other first.
827  */
828 void
829 ng_destroy_hook(hook_p hook)
830 {
831 	hook_p peer = hook->peer;
832 
833 	hook->flags |= HK_INVALID;		/* as soon as possible */
834 	if (peer) {
835 		peer->flags |= HK_INVALID;	/* as soon as possible */
836 		hook->peer = NULL;
837 		peer->peer = NULL;
838 		ng_disconnect_hook(peer);
839 	}
840 	ng_disconnect_hook(hook);
841 }
842 
843 /*
844  * Notify the node of the hook's demise. This may result in more actions
845  * (e.g. shutdown) but we don't do that ourselves and don't know what
846  * happens there. If there is no appropriate handler, then just remove it
847  * (and decrement the reference count of it's node which in turn might
848  * make something happen).
849  */
850 static void
851 ng_disconnect_hook(hook_p hook)
852 {
853 	node_p node = hook->node;
854 
855 	/*
856 	 * Remove the hook from the node's list to avoid possible recursion
857 	 * in case the disconnection results in node shutdown.
858 	 */
859 	LIST_REMOVE(hook, hooks);
860 	node->numhooks--;
861 	if (node->type->disconnect) {
862 		/*
863 		 * The type handler may elect to destroy the peer so don't
864 		 * trust its existance after this point.
865 		 */
866 		(*node->type->disconnect) (hook);
867 	}
868 	ng_unref(node);		/* might be the last reference */
869 	if (hook->name)
870 		FREE(hook->name, M_NETGRAPH);
871 	hook->node = NULL;	/* may still be referenced elsewhere */
872 	ng_unref_hook(hook);
873 }
874 
875 /*
876  * Take two hooks on a node and merge the connection so that the given node
877  * is effectively bypassed.
878  */
879 int
880 ng_bypass(hook_p hook1, hook_p hook2)
881 {
882 	if (hook1->node != hook2->node)
883 		return (EINVAL);
884 	hook1->peer->peer = hook2->peer;
885 	hook2->peer->peer = hook1->peer;
886 
887 	/* XXX If we ever cache methods on hooks update them as well */
888 	hook1->peer = NULL;
889 	hook2->peer = NULL;
890 	ng_destroy_hook(hook1);
891 	ng_destroy_hook(hook2);
892 	return (0);
893 }
894 
895 /*
896  * Install a new netgraph type
897  */
898 int
899 ng_newtype(struct ng_type *tp)
900 {
901 	const size_t namelen = strlen(tp->name);
902 
903 	/* Check version and type name fields */
904 	if (tp->version != NG_VERSION || namelen == 0 || namelen >= NG_TYPESIZ) {
905 		TRAP_ERROR;
906 		return (EINVAL);
907 	}
908 
909 	/* Check for name collision */
910 	if (ng_findtype(tp->name) != NULL) {
911 		TRAP_ERROR;
912 		return (EEXIST);
913 	}
914 
915 	/* Link in new type */
916 	LIST_INSERT_HEAD(&typelist, tp, types);
917 	tp->refs = 1;	/* first ref is linked list */
918 	return (0);
919 }
920 
921 /*
922  * Look for a type of the name given
923  */
924 struct ng_type *
925 ng_findtype(const char *typename)
926 {
927 	struct ng_type *type;
928 
929 	LIST_FOREACH(type, &typelist, types) {
930 		if (strcmp(type->name, typename) == 0)
931 			break;
932 	}
933 	return (type);
934 }
935 
936 
937 /************************************************************************
938 			Composite routines
939 ************************************************************************/
940 
941 /*
942  * Make a peer and connect. The order is arranged to minimise
943  * the work needed to back out in case of error.
944  */
945 int
946 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
947 {
948 	node_p  node2;
949 	hook_p  hook;
950 	hook_p  hook2;
951 	int     error;
952 
953 	if ((error = ng_add_hook(node, name, &hook)))
954 		return (error);
955 
956 	/* make sure we have the module needed */
957 	if (ng_findtype(type) == NULL) {
958 		/* Not found, try to load it as a loadable module */
959 		error = ng_load_module(type);
960 		if (error != 0) {
961 			kprintf("required netgraph module ng_%s not loaded\n",
962 			    type);
963 			return (error);
964 		}
965 	}
966 	if ((error = ng_make_node(type, &node2))) {
967 		ng_destroy_hook(hook);
968 		return (error);
969 	}
970 	if ((error = ng_add_hook(node2, name2, &hook2))) {
971 		ng_rmnode(node2);
972 		ng_destroy_hook(hook);
973 		return (error);
974 	}
975 
976 	/*
977 	 * Actually link the two hooks together.. on failure they are
978 	 * destroyed so we don't have to do that here.
979 	 */
980 	if ((error = ng_connect(hook, hook2)))
981 		ng_rmnode(node2);
982 	return (error);
983 }
984 
985 /*
986  * Connect two nodes using the specified hooks
987  */
988 int
989 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
990 {
991 	int     error;
992 	hook_p  hook;
993 	hook_p  hook2;
994 
995 	if ((error = ng_add_hook(node, name, &hook)))
996 		return (error);
997 	if ((error = ng_add_hook(node2, name2, &hook2))) {
998 		ng_destroy_hook(hook);
999 		return (error);
1000 	}
1001 	return (ng_connect(hook, hook2));
1002 }
1003 
1004 /*
1005  * Parse and verify a string of the form:  <NODE:><PATH>
1006  *
1007  * Such a string can refer to a specific node or a specific hook
1008  * on a specific node, depending on how you look at it. In the
1009  * latter case, the PATH component must not end in a dot.
1010  *
1011  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1012  * of hook names separated by dots. This breaks out the original
1013  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1014  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1015  * the final hook component of <PATH>, if any, otherwise NULL.
1016  *
1017  * This returns -1 if the path is malformed. The char ** are optional.
1018  */
1019 
1020 int
1021 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1022 {
1023 	char   *node, *path, *hook;
1024 	int     k;
1025 
1026 	/*
1027 	 * Extract absolute NODE, if any
1028 	 */
1029 	for (path = addr; *path && *path != ':'; path++);
1030 	if (*path) {
1031 		node = addr;	/* Here's the NODE */
1032 		*path++ = '\0';	/* Here's the PATH */
1033 
1034 		/* Node name must not be empty */
1035 		if (!*node)
1036 			return -1;
1037 
1038 		/* A name of "." is OK; otherwise '.' not allowed */
1039 		if (strcmp(node, ".") != 0) {
1040 			for (k = 0; node[k]; k++)
1041 				if (node[k] == '.')
1042 					return -1;
1043 		}
1044 	} else {
1045 		node = NULL;	/* No absolute NODE */
1046 		path = addr;	/* Here's the PATH */
1047 	}
1048 
1049 	/* Snoop for illegal characters in PATH */
1050 	for (k = 0; path[k]; k++)
1051 		if (path[k] == ':')
1052 			return -1;
1053 
1054 	/* Check for no repeated dots in PATH */
1055 	for (k = 0; path[k]; k++)
1056 		if (path[k] == '.' && path[k + 1] == '.')
1057 			return -1;
1058 
1059 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1060 	if (path[0] == '.')
1061 		path++;
1062 	if (*path && path[strlen(path) - 1] == '.')
1063 		path[strlen(path) - 1] = 0;
1064 
1065 	/* If PATH has a dot, then we're not talking about a hook */
1066 	if (*path) {
1067 		for (hook = path, k = 0; path[k]; k++)
1068 			if (path[k] == '.') {
1069 				hook = NULL;
1070 				break;
1071 			}
1072 	} else
1073 		path = hook = NULL;
1074 
1075 	/* Done */
1076 	if (nodep)
1077 		*nodep = node;
1078 	if (pathp)
1079 		*pathp = path;
1080 	if (hookp)
1081 		*hookp = hook;
1082 	return (0);
1083 }
1084 
1085 /*
1086  * Given a path, which may be absolute or relative, and a starting node,
1087  * return the destination node. Compute the "return address" if desired.
1088  */
1089 int
1090 ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
1091 {
1092 	const	node_p start = here;
1093 	char    fullpath[NG_PATHSIZ];
1094 	char   *nodename, *path, pbuf[2];
1095 	node_p  node;
1096 	char   *cp;
1097 
1098 	/* Initialize */
1099 	if (rtnp)
1100 		*rtnp = NULL;
1101 	if (destp == NULL)
1102 		return EINVAL;
1103 	*destp = NULL;
1104 
1105 	/* Make a writable copy of address for ng_path_parse() */
1106 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1107 	fullpath[sizeof(fullpath) - 1] = '\0';
1108 
1109 	/* Parse out node and sequence of hooks */
1110 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1111 		TRAP_ERROR;
1112 		return EINVAL;
1113 	}
1114 	if (path == NULL) {
1115 		pbuf[0] = '.';	/* Needs to be writable */
1116 		pbuf[1] = '\0';
1117 		path = pbuf;
1118 	}
1119 
1120 	/* For an absolute address, jump to the starting node */
1121 	if (nodename) {
1122 		node = ng_findname(here, nodename);
1123 		if (node == NULL) {
1124 			TRAP_ERROR;
1125 			return (ENOENT);
1126 		}
1127 	} else
1128 		node = here;
1129 
1130 	/* Now follow the sequence of hooks */
1131 	for (cp = path; node != NULL && *cp != '\0'; ) {
1132 		hook_p hook;
1133 		char *segment;
1134 
1135 		/*
1136 		 * Break out the next path segment. Replace the dot we just
1137 		 * found with a NUL; "cp" points to the next segment (or the
1138 		 * NUL at the end).
1139 		 */
1140 		for (segment = cp; *cp != '\0'; cp++) {
1141 			if (*cp == '.') {
1142 				*cp++ = '\0';
1143 				break;
1144 			}
1145 		}
1146 
1147 		/* Empty segment */
1148 		if (*segment == '\0')
1149 			continue;
1150 
1151 		/* We have a segment, so look for a hook by that name */
1152 		hook = ng_findhook(node, segment);
1153 
1154 		/* Can't get there from here... */
1155 		if (hook == NULL
1156 		    || hook->peer == NULL
1157 		    || (hook->flags & HK_INVALID) != 0) {
1158 			TRAP_ERROR;
1159 			return (ENOENT);
1160 		}
1161 
1162 		/* Hop on over to the next node */
1163 		node = hook->peer->node;
1164 	}
1165 
1166 	/* If node somehow missing, fail here (probably this is not needed) */
1167 	if (node == NULL) {
1168 		TRAP_ERROR;
1169 		return (ENXIO);
1170 	}
1171 
1172 	/* Now compute return address, i.e., the path to the sender */
1173 	if (rtnp != NULL) {
1174 		MALLOC(*rtnp, char *, NG_NODESIZ + 1, M_NETGRAPH, M_NOWAIT);
1175 		if (*rtnp == NULL) {
1176 			TRAP_ERROR;
1177 			return (ENOMEM);
1178 		}
1179 		if (start->name != NULL)
1180 			ksprintf(*rtnp, "%s:", start->name);
1181 		else
1182 			ksprintf(*rtnp, "[%x]:", ng_node2ID(start));
1183 	}
1184 
1185 	/* Done */
1186 	*destp = node;
1187 	return (0);
1188 }
1189 
1190 /*
1191  * Call the appropriate message handler for the object.
1192  * It is up to the message handler to free the message.
1193  * If it's a generic message, handle it generically, otherwise
1194  * call the type's message handler (if it exists)
1195  * XXX (race). Remember that a queued message may reference a node
1196  * or hook that has just been invalidated. It will exist
1197  * as the queue code is holding a reference, but..
1198  */
1199 
1200 #define CALL_MSG_HANDLER(error, node, msg, retaddr, resp)		\
1201 do {									\
1202 	if((msg)->header.typecookie == NGM_GENERIC_COOKIE) {		\
1203 		(error) = ng_generic_msg((node), (msg),			\
1204 				(retaddr), (resp));			\
1205 	} else {							\
1206 		if ((node)->type->rcvmsg != NULL) {			\
1207 			(error) = (*(node)->type->rcvmsg)((node),	\
1208 					(msg), (retaddr), (resp));	\
1209 		} else {						\
1210 			TRAP_ERROR;					\
1211 			FREE((msg), M_NETGRAPH);			\
1212 			(error) = EINVAL;				\
1213 		}							\
1214 	}								\
1215 } while (0)
1216 
1217 
1218 /*
1219  * Send a control message to a node
1220  */
1221 int
1222 ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
1223 	    struct ng_mesg **rptr)
1224 {
1225 	node_p  dest = NULL;
1226 	char   *retaddr = NULL;
1227 	int     error;
1228 
1229 	/* Find the target node */
1230 	error = ng_path2node(here, address, &dest, &retaddr);
1231 	if (error) {
1232 		FREE(msg, M_NETGRAPH);
1233 		return error;
1234 	}
1235 
1236 	/* Make sure the resp field is null before we start */
1237 	if (rptr != NULL)
1238 		*rptr = NULL;
1239 
1240 	CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
1241 
1242 	/* Make sure that if there is a response, it has the RESP bit set */
1243 	if ((error == 0) && rptr && *rptr)
1244 		(*rptr)->header.flags |= NGF_RESP;
1245 
1246 	/*
1247 	 * If we had a return address it is up to us to free it. They should
1248 	 * have taken a copy if they needed to make a delayed response.
1249 	 */
1250 	if (retaddr)
1251 		FREE(retaddr, M_NETGRAPH);
1252 	return (error);
1253 }
1254 
1255 /*
1256  * Implement the 'generic' control messages
1257  */
1258 static int
1259 ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
1260 	       struct ng_mesg **resp)
1261 {
1262 	int error = 0;
1263 
1264 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
1265 		TRAP_ERROR;
1266 		FREE(msg, M_NETGRAPH);
1267 		return (EINVAL);
1268 	}
1269 	switch (msg->header.cmd) {
1270 	case NGM_SHUTDOWN:
1271 		ng_rmnode(here);
1272 		break;
1273 	case NGM_MKPEER:
1274 	    {
1275 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
1276 
1277 		if (msg->header.arglen != sizeof(*mkp)) {
1278 			TRAP_ERROR;
1279 			return (EINVAL);
1280 		}
1281 		mkp->type[sizeof(mkp->type) - 1] = '\0';
1282 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
1283 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
1284 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
1285 		break;
1286 	    }
1287 	case NGM_CONNECT:
1288 	    {
1289 		struct ngm_connect *const con =
1290 			(struct ngm_connect *) msg->data;
1291 		node_p node2;
1292 
1293 		if (msg->header.arglen != sizeof(*con)) {
1294 			TRAP_ERROR;
1295 			return (EINVAL);
1296 		}
1297 		con->path[sizeof(con->path) - 1] = '\0';
1298 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
1299 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
1300 		error = ng_path2node(here, con->path, &node2, NULL);
1301 		if (error)
1302 			break;
1303 		error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
1304 		break;
1305 	    }
1306 	case NGM_NAME:
1307 	    {
1308 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
1309 
1310 		if (msg->header.arglen != sizeof(*nam)) {
1311 			TRAP_ERROR;
1312 			return (EINVAL);
1313 		}
1314 		nam->name[sizeof(nam->name) - 1] = '\0';
1315 		error = ng_name_node(here, nam->name);
1316 		break;
1317 	    }
1318 	case NGM_RMHOOK:
1319 	    {
1320 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
1321 		hook_p hook;
1322 
1323 		if (msg->header.arglen != sizeof(*rmh)) {
1324 			TRAP_ERROR;
1325 			return (EINVAL);
1326 		}
1327 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
1328 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
1329 			ng_destroy_hook(hook);
1330 		break;
1331 	    }
1332 	case NGM_NODEINFO:
1333 	    {
1334 		struct nodeinfo *ni;
1335 		struct ng_mesg *rp;
1336 
1337 		/* Get response struct */
1338 		if (resp == NULL) {
1339 			error = EINVAL;
1340 			break;
1341 		}
1342 		NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
1343 		if (rp == NULL) {
1344 			error = ENOMEM;
1345 			break;
1346 		}
1347 
1348 		/* Fill in node info */
1349 		ni = (struct nodeinfo *) rp->data;
1350 		if (here->name != NULL)
1351 			strlcpy(ni->name, here->name, NG_NODESIZ);
1352 		strlcpy(ni->type, here->type->name, NG_TYPESIZ);
1353 		ni->id = ng_node2ID(here);
1354 		ni->hooks = here->numhooks;
1355 		*resp = rp;
1356 		break;
1357 	    }
1358 	case NGM_LISTHOOKS:
1359 	    {
1360 		const int nhooks = here->numhooks;
1361 		struct hooklist *hl;
1362 		struct nodeinfo *ni;
1363 		struct ng_mesg *rp;
1364 		hook_p hook;
1365 
1366 		/* Get response struct */
1367 		if (resp == NULL) {
1368 			error = EINVAL;
1369 			break;
1370 		}
1371 		NG_MKRESPONSE(rp, msg, sizeof(*hl)
1372 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
1373 		if (rp == NULL) {
1374 			error = ENOMEM;
1375 			break;
1376 		}
1377 		hl = (struct hooklist *) rp->data;
1378 		ni = &hl->nodeinfo;
1379 
1380 		/* Fill in node info */
1381 		if (here->name)
1382 			strlcpy(ni->name, here->name, NG_NODESIZ);
1383 		strlcpy(ni->type, here->type->name, NG_TYPESIZ);
1384 		ni->id = ng_node2ID(here);
1385 
1386 		/* Cycle through the linked list of hooks */
1387 		ni->hooks = 0;
1388 		LIST_FOREACH(hook, &here->hooks, hooks) {
1389 			struct linkinfo *const link = &hl->link[ni->hooks];
1390 
1391 			if (ni->hooks >= nhooks) {
1392 				log(LOG_ERR, "%s: number of %s changed\n",
1393 				    __func__, "hooks");
1394 				break;
1395 			}
1396 			if ((hook->flags & HK_INVALID) != 0)
1397 				continue;
1398 			strlcpy(link->ourhook, hook->name, NG_HOOKSIZ);
1399 			strlcpy(link->peerhook, hook->peer->name, NG_HOOKSIZ);
1400 			if (hook->peer->node->name != NULL)
1401 				strlcpy(link->nodeinfo.name,
1402 				    hook->peer->node->name, NG_NODESIZ);
1403 			strlcpy(link->nodeinfo.type,
1404 			   hook->peer->node->type->name, NG_TYPESIZ);
1405 			link->nodeinfo.id = ng_node2ID(hook->peer->node);
1406 			link->nodeinfo.hooks = hook->peer->node->numhooks;
1407 			ni->hooks++;
1408 		}
1409 		*resp = rp;
1410 		break;
1411 	    }
1412 
1413 	case NGM_LISTNAMES:
1414 	case NGM_LISTNODES:
1415 	    {
1416 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
1417 		struct namelist *nl;
1418 		struct ng_mesg *rp;
1419 		node_p node;
1420 		int num = 0;
1421 
1422 		if (resp == NULL) {
1423 			error = EINVAL;
1424 			break;
1425 		}
1426 
1427 		/* Count number of nodes */
1428 		LIST_FOREACH(node, &nodelist, nodes) {
1429 			if ((node->flags & NG_INVALID) == 0
1430 			    && (unnamed || node->name != NULL))
1431 				num++;
1432 		}
1433 
1434 		/* Get response struct */
1435 		if (resp == NULL) {
1436 			error = EINVAL;
1437 			break;
1438 		}
1439 		NG_MKRESPONSE(rp, msg, sizeof(*nl)
1440 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
1441 		if (rp == NULL) {
1442 			error = ENOMEM;
1443 			break;
1444 		}
1445 		nl = (struct namelist *) rp->data;
1446 
1447 		/* Cycle through the linked list of nodes */
1448 		nl->numnames = 0;
1449 		LIST_FOREACH(node, &nodelist, nodes) {
1450 			struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
1451 
1452 			if (nl->numnames >= num) {
1453 				log(LOG_ERR, "%s: number of %s changed\n",
1454 				    __func__, "nodes");
1455 				break;
1456 			}
1457 			if ((node->flags & NG_INVALID) != 0)
1458 				continue;
1459 			if (!unnamed && node->name == NULL)
1460 				continue;
1461 			if (node->name != NULL)
1462 				strlcpy(np->name, node->name, NG_NODESIZ);
1463 			strlcpy(np->type, node->type->name, NG_TYPESIZ);
1464 			np->id = ng_node2ID(node);
1465 			np->hooks = node->numhooks;
1466 			nl->numnames++;
1467 		}
1468 		*resp = rp;
1469 		break;
1470 	    }
1471 
1472 	case NGM_LISTTYPES:
1473 	    {
1474 		struct typelist *tl;
1475 		struct ng_mesg *rp;
1476 		struct ng_type *type;
1477 		int num = 0;
1478 
1479 		if (resp == NULL) {
1480 			error = EINVAL;
1481 			break;
1482 		}
1483 
1484 		/* Count number of types */
1485 		LIST_FOREACH(type, &typelist, types)
1486 			num++;
1487 
1488 		/* Get response struct */
1489 		if (resp == NULL) {
1490 			error = EINVAL;
1491 			break;
1492 		}
1493 		NG_MKRESPONSE(rp, msg, sizeof(*tl)
1494 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
1495 		if (rp == NULL) {
1496 			error = ENOMEM;
1497 			break;
1498 		}
1499 		tl = (struct typelist *) rp->data;
1500 
1501 		/* Cycle through the linked list of types */
1502 		tl->numtypes = 0;
1503 		LIST_FOREACH(type, &typelist, types) {
1504 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
1505 
1506 			if (tl->numtypes >= num) {
1507 				log(LOG_ERR, "%s: number of %s changed\n",
1508 				    __func__, "types");
1509 				break;
1510 			}
1511 			strlcpy(tp->type_name, type->name, NG_TYPESIZ);
1512 			tp->numnodes = type->refs - 1; /* don't count list */
1513 			tl->numtypes++;
1514 		}
1515 		*resp = rp;
1516 		break;
1517 	    }
1518 
1519 	case NGM_BINARY2ASCII:
1520 	    {
1521 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
1522 		const struct ng_parse_type *argstype;
1523 		const struct ng_cmdlist *c;
1524 		struct ng_mesg *rp, *binary, *ascii;
1525 
1526 		/* Data area must contain a valid netgraph message */
1527 		binary = (struct ng_mesg *)msg->data;
1528 		if (msg->header.arglen < sizeof(struct ng_mesg)
1529 		    || msg->header.arglen - sizeof(struct ng_mesg)
1530 		      < binary->header.arglen) {
1531 			error = EINVAL;
1532 			break;
1533 		}
1534 
1535 		/* Get a response message with lots of room */
1536 		NG_MKRESPONSE(rp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
1537 		if (rp == NULL) {
1538 			error = ENOMEM;
1539 			break;
1540 		}
1541 		ascii = (struct ng_mesg *)rp->data;
1542 
1543 		/* Copy binary message header to response message payload */
1544 		bcopy(binary, ascii, sizeof(*binary));
1545 
1546 		/* Find command by matching typecookie and command number */
1547 		for (c = here->type->cmdlist;
1548 		    c != NULL && c->name != NULL; c++) {
1549 			if (binary->header.typecookie == c->cookie
1550 			    && binary->header.cmd == c->cmd)
1551 				break;
1552 		}
1553 		if (c == NULL || c->name == NULL) {
1554 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1555 				if (binary->header.typecookie == c->cookie
1556 				    && binary->header.cmd == c->cmd)
1557 					break;
1558 			}
1559 			if (c->name == NULL) {
1560 				FREE(rp, M_NETGRAPH);
1561 				error = ENOSYS;
1562 				break;
1563 			}
1564 		}
1565 
1566 		/* Convert command name to ASCII */
1567 		ksnprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
1568 		    "%s", c->name);
1569 
1570 		/* Convert command arguments to ASCII */
1571 		argstype = (binary->header.flags & NGF_RESP) ?
1572 		    c->respType : c->mesgType;
1573 		if (argstype == NULL)
1574 			*ascii->data = '\0';
1575 		else {
1576 			if ((error = ng_unparse(argstype,
1577 			    (u_char *)binary->data,
1578 			    ascii->data, bufSize)) != 0) {
1579 				FREE(rp, M_NETGRAPH);
1580 				break;
1581 			}
1582 		}
1583 
1584 		/* Return the result as struct ng_mesg plus ASCII string */
1585 		bufSize = strlen(ascii->data) + 1;
1586 		ascii->header.arglen = bufSize;
1587 		rp->header.arglen = sizeof(*ascii) + bufSize;
1588 		*resp = rp;
1589 		break;
1590 	    }
1591 
1592 	case NGM_ASCII2BINARY:
1593 	    {
1594 		int bufSize = 2000;	/* XXX hard coded constant */
1595 		const struct ng_cmdlist *c;
1596 		const struct ng_parse_type *argstype;
1597 		struct ng_mesg *rp, *ascii, *binary;
1598 		int off = 0;
1599 
1600 		/* Data area must contain at least a struct ng_mesg + '\0' */
1601 		ascii = (struct ng_mesg *)msg->data;
1602 		if (msg->header.arglen < sizeof(*ascii) + 1
1603 		    || ascii->header.arglen < 1
1604 		    || msg->header.arglen
1605 		      < sizeof(*ascii) + ascii->header.arglen) {
1606 			error = EINVAL;
1607 			break;
1608 		}
1609 		ascii->data[ascii->header.arglen - 1] = '\0';
1610 
1611 		/* Get a response message with lots of room */
1612 		NG_MKRESPONSE(rp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
1613 		if (rp == NULL) {
1614 			error = ENOMEM;
1615 			break;
1616 		}
1617 		binary = (struct ng_mesg *)rp->data;
1618 
1619 		/* Copy ASCII message header to response message payload */
1620 		bcopy(ascii, binary, sizeof(*ascii));
1621 
1622 		/* Find command by matching ASCII command string */
1623 		for (c = here->type->cmdlist;
1624 		    c != NULL && c->name != NULL; c++) {
1625 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
1626 				break;
1627 		}
1628 		if (c == NULL || c->name == NULL) {
1629 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1630 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
1631 					break;
1632 			}
1633 			if (c->name == NULL) {
1634 				FREE(rp, M_NETGRAPH);
1635 				error = ENOSYS;
1636 				break;
1637 			}
1638 		}
1639 
1640 		/* Convert command name to binary */
1641 		binary->header.cmd = c->cmd;
1642 		binary->header.typecookie = c->cookie;
1643 
1644 		/* Convert command arguments to binary */
1645 		argstype = (binary->header.flags & NGF_RESP) ?
1646 		    c->respType : c->mesgType;
1647 		if (argstype == NULL)
1648 			bufSize = 0;
1649 		else {
1650 			if ((error = ng_parse(argstype, ascii->data,
1651 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
1652 				FREE(rp, M_NETGRAPH);
1653 				break;
1654 			}
1655 		}
1656 
1657 		/* Return the result */
1658 		binary->header.arglen = bufSize;
1659 		rp->header.arglen = sizeof(*binary) + bufSize;
1660 		*resp = rp;
1661 		break;
1662 	    }
1663 
1664 	case NGM_TEXT_CONFIG:
1665 	case NGM_TEXT_STATUS:
1666 		/*
1667 		 * This one is tricky as it passes the command down to the
1668 		 * actual node, even though it is a generic type command.
1669 		 * This means we must assume that the msg is already freed
1670 		 * when control passes back to us.
1671 		 */
1672 		if (resp == NULL) {
1673 			error = EINVAL;
1674 			break;
1675 		}
1676 		if (here->type->rcvmsg != NULL)
1677 			return((*here->type->rcvmsg)(here, msg, retaddr, resp));
1678 		/* Fall through if rcvmsg not supported */
1679 	default:
1680 		TRAP_ERROR;
1681 		error = EINVAL;
1682 	}
1683 	FREE(msg, M_NETGRAPH);
1684 	return (error);
1685 }
1686 
1687 /*
1688  * Send a data packet to a node. If the recipient has no
1689  * 'receive data' method, then silently discard the packet.
1690  */
1691 int
1692 ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
1693 {
1694 	int (*rcvdata)(hook_p, struct mbuf *, meta_p);
1695 	int error;
1696 
1697 	CHECK_DATA_MBUF(m);
1698 	if (hook && (hook->flags & HK_INVALID) == 0) {
1699 		rcvdata = hook->peer->node->type->rcvdata;
1700 		if (rcvdata != NULL)
1701 			error = (*rcvdata)(hook->peer, m, meta);
1702 		else {
1703 			error = 0;
1704 			NG_FREE_DATA(m, meta);
1705 		}
1706 	} else {
1707 		TRAP_ERROR;
1708 		error = ENOTCONN;
1709 		NG_FREE_DATA(m, meta);
1710 	}
1711 	return (error);
1712 }
1713 
1714 /*
1715  * Send a queued data packet to a node. If the recipient has no
1716  * 'receive queued data' method, then try the 'receive data' method above.
1717  */
1718 int
1719 ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
1720 {
1721 	int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
1722 	int error;
1723 
1724 	CHECK_DATA_MBUF(m);
1725 	if (hook && (hook->flags & HK_INVALID) == 0) {
1726 		rcvdataq = hook->peer->node->type->rcvdataq;
1727 		if (rcvdataq != NULL)
1728 			error = (*rcvdataq)(hook->peer, m, meta);
1729 		else {
1730 			error = ng_send_data(hook, m, meta);
1731 		}
1732 	} else {
1733 		TRAP_ERROR;
1734 		error = ENOTCONN;
1735 		NG_FREE_DATA(m, meta);
1736 	}
1737 	return (error);
1738 }
1739 
1740 /*
1741  * Copy a 'meta'.
1742  *
1743  * Returns new meta, or NULL if original meta is NULL or ENOMEM.
1744  */
1745 meta_p
1746 ng_copy_meta(meta_p meta)
1747 {
1748 	meta_p meta2;
1749 
1750 	if (meta == NULL)
1751 		return (NULL);
1752 	MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH, M_NOWAIT);
1753 	if (meta2 == NULL)
1754 		return (NULL);
1755 	meta2->allocated_len = meta->used_len;
1756 	bcopy(meta, meta2, meta->used_len);
1757 	return (meta2);
1758 }
1759 
1760 /************************************************************************
1761 			Module routines
1762 ************************************************************************/
1763 
1764 /*
1765  * Handle the loading/unloading of a netgraph node type module
1766  */
1767 int
1768 ng_mod_event(module_t mod, int event, void *data)
1769 {
1770 	struct ng_type *const type = data;
1771 	int error = 0;
1772 
1773 	switch (event) {
1774 	case MOD_LOAD:
1775 
1776 		/* Register new netgraph node type */
1777 		crit_enter();
1778 		if ((error = ng_newtype(type)) != 0) {
1779 			crit_exit();
1780 			break;
1781 		}
1782 
1783 		/* Call type specific code */
1784 		if (type->mod_event != NULL)
1785 			if ((error = (*type->mod_event)(mod, event, data))) {
1786 				type->refs--;	/* undo it */
1787 				LIST_REMOVE(type, types);
1788 			}
1789 		crit_exit();
1790 		break;
1791 
1792 	case MOD_UNLOAD:
1793 		crit_enter();
1794 		if (type->refs > 1) {		/* make sure no nodes exist! */
1795 			error = EBUSY;
1796 		} else {
1797 			if (type->refs == 0) {
1798 				/* failed load, nothing to undo */
1799 				crit_exit();
1800 				break;
1801 			}
1802 			if (type->mod_event != NULL) {	/* check with type */
1803 				error = (*type->mod_event)(mod, event, data);
1804 				if (error != 0) {	/* type refuses.. */
1805 					crit_exit();
1806 					break;
1807 				}
1808 			}
1809 			LIST_REMOVE(type, types);
1810 		}
1811 		crit_exit();
1812 		break;
1813 
1814 	default:
1815 		if (type->mod_event != NULL)
1816 			error = (*type->mod_event)(mod, event, data);
1817 		else
1818 			error = 0;		/* XXX ? */
1819 		break;
1820 	}
1821 	return (error);
1822 }
1823 
1824 /*
1825  * Handle loading and unloading for this code.
1826  * The only thing we need to link into is the NETISR strucure.
1827  */
1828 static int
1829 ngb_mod_event(module_t mod, int event, void *data)
1830 {
1831 	int error = 0;
1832 
1833 	switch (event) {
1834 	case MOD_LOAD:
1835 		/* Register line discipline */
1836 		crit_enter();
1837 		error = ng_load_module("ksocket");
1838 		if (error != 0) {
1839 			crit_exit();
1840 			break;
1841 		}
1842 		netisr_register(NETISR_NETGRAPH, cpu0_portfn, ngintr);
1843 		error = 0;
1844 		crit_exit();
1845 		break;
1846 	case MOD_UNLOAD:
1847 		ng_unload_module("ksocket");
1848 		/* You cant unload it because an interface may be using it.  */
1849 		error = EBUSY;
1850 		break;
1851 	default:
1852 		error = EOPNOTSUPP;
1853 		break;
1854 	}
1855 	return (error);
1856 }
1857 
1858 static moduledata_t netgraph_mod = {
1859 	"netgraph",
1860 	ngb_mod_event,
1861 	(NULL)
1862 };
1863 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1864 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
1865 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
1866 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
1867 
1868 /************************************************************************
1869 			Queueing routines
1870 ************************************************************************/
1871 
1872 /* The structure for queueing across ISR switches */
1873 struct ng_queue_entry {
1874 	u_long	flags;
1875 	struct ng_queue_entry *next;
1876 	union {
1877 		struct {
1878 			hook_p		da_hook;	/*  target hook */
1879 			struct mbuf	*da_m;
1880 			meta_p		da_meta;
1881 		} data;
1882 		struct {
1883 			struct ng_mesg	*msg_msg;
1884 			node_p		msg_node;
1885 			void		*msg_retaddr;
1886 		} msg;
1887 	} body;
1888 };
1889 #define NGQF_DATA	0x01		/* the queue element is data */
1890 #define NGQF_MESG	0x02		/* the queue element is a message */
1891 
1892 static struct ng_queue_entry   *ngqbase;	/* items to be unqueued */
1893 static struct ng_queue_entry   *ngqlast;	/* last item queued */
1894 static const int		ngqroom = 256;	/* max items to queue */
1895 static int			ngqsize;	/* number of items in queue */
1896 
1897 static struct ng_queue_entry   *ngqfree;	/* free ones */
1898 static const int		ngqfreemax = 256;/* cache at most this many */
1899 static int			ngqfreesize;	/* number of cached entries */
1900 
1901 /*
1902  * Get a queue entry
1903  */
1904 static struct ng_queue_entry *
1905 ng_getqblk(void)
1906 {
1907 	struct ng_queue_entry *q;
1908 
1909 	/* Could be guarding against tty ints or whatever */
1910 	crit_enter();
1911 
1912 	/* Try get a cached queue block, or else allocate a new one */
1913 	if ((q = ngqfree) == NULL) {
1914 		crit_exit();
1915 		if (ngqsize < ngqroom) {	/* don't worry about races */
1916 			MALLOC(q, struct ng_queue_entry *,
1917 			    sizeof(*q), M_NETGRAPH, M_NOWAIT);
1918 		}
1919 	} else {
1920 		ngqfree = q->next;
1921 		ngqfreesize--;
1922 		crit_exit();
1923 	}
1924 	return (q);
1925 }
1926 
1927 /*
1928  * Release a queue entry
1929  */
1930 #define RETURN_QBLK(q)							\
1931 do {									\
1932 	if (ngqfreesize < ngqfreemax) { /* don't worry about races */ 	\
1933 		crit_enter();						\
1934 		(q)->next = ngqfree;					\
1935 		ngqfree = (q);						\
1936 		ngqfreesize++;						\
1937 		crit_exit();						\
1938 	} else {							\
1939 		FREE((q), M_NETGRAPH);					\
1940 	}								\
1941 } while (0)
1942 
1943 /*
1944  * Running at a raised (but we don't know which) processor priority level,
1945  * put the data onto a queue to be picked up by another PPL (probably splnet)
1946  */
1947 int
1948 ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
1949 {
1950 	struct ng_queue_entry *q;
1951 
1952 	if (hook == NULL) {
1953 		NG_FREE_DATA(m, meta);
1954 		return (0);
1955 	}
1956 	if ((q = ng_getqblk()) == NULL) {
1957 		NG_FREE_DATA(m, meta);
1958 		return (ENOBUFS);
1959 	}
1960 
1961 	/* Fill out the contents */
1962 	q->flags = NGQF_DATA;
1963 	q->next = NULL;
1964 	q->body.data.da_hook = hook;
1965 	q->body.data.da_m = m;
1966 	q->body.data.da_meta = meta;
1967 	crit_enter();		/* protect refs and queue */
1968 	hook->refs++;		/* don't let it go away while on the queue */
1969 
1970 	/* Put it on the queue */
1971 	if (ngqbase) {
1972 		ngqlast->next = q;
1973 	} else {
1974 		ngqbase = q;
1975 	}
1976 	ngqlast = q;
1977 	ngqsize++;
1978 	crit_exit();
1979 
1980 	/* Schedule software interrupt to handle it later */
1981 	schednetisr(NETISR_NETGRAPH);
1982 	return (0);
1983 }
1984 
1985 /*
1986  * Running at a raised (but we don't know which) processor priority level,
1987  * put the msg onto a queue to be picked up by another PPL (probably splnet)
1988  */
1989 int
1990 ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address)
1991 {
1992 	struct ng_queue_entry *q;
1993 	node_p  dest = NULL;
1994 	char   *retaddr = NULL;
1995 	int     error;
1996 
1997 	/* Find the target node. */
1998 	error = ng_path2node(here, address, &dest, &retaddr);
1999 	if (error) {
2000 		FREE(msg, M_NETGRAPH);
2001 		return (error);
2002 	}
2003 	if ((q = ng_getqblk()) == NULL) {
2004 		FREE(msg, M_NETGRAPH);
2005 		if (retaddr)
2006 			FREE(retaddr, M_NETGRAPH);
2007 		return (ENOBUFS);
2008 	}
2009 
2010 	/* Fill out the contents */
2011 	q->flags = NGQF_MESG;
2012 	q->next = NULL;
2013 	q->body.msg.msg_node = dest;
2014 	q->body.msg.msg_msg = msg;
2015 	q->body.msg.msg_retaddr = retaddr;
2016 	crit_enter();		/* protect refs and queue */
2017 	dest->refs++;		/* don't let it go away while on the queue */
2018 
2019 	/* Put it on the queue */
2020 	if (ngqbase) {
2021 		ngqlast->next = q;
2022 	} else {
2023 		ngqbase = q;
2024 	}
2025 	ngqlast = q;
2026 	ngqsize++;
2027 	crit_exit();
2028 
2029 	/* Schedule software interrupt to handle it later */
2030 	schednetisr(NETISR_NETGRAPH);
2031 	return (0);
2032 }
2033 
2034 /*
2035  * Pick an item off the queue, process it, and dispose of the queue entry.
2036  */
2037 static void
2038 ngintr(struct netmsg *pmsg)
2039 {
2040 	hook_p  hook;
2041 	struct mbuf *m;
2042 	struct ng_queue_entry *ngq;
2043 	meta_p  meta;
2044 	void   *retaddr;
2045 	struct ng_mesg *msg;
2046 	node_p  node;
2047 	int     error = 0;
2048 
2049 	/*
2050 	 * Packets are never sent to this netisr so the message must always
2051 	 * be replied.  Interlock processing and notification by replying
2052 	 * the message first.
2053 	 */
2054 	lwkt_replymsg(&pmsg->nm_lmsg, 0);
2055 
2056 	while (1) {
2057 		crit_enter();
2058 		if ((ngq = ngqbase)) {
2059 			ngqbase = ngq->next;
2060 			ngqsize--;
2061 		}
2062 		crit_exit();
2063 		if (ngq == NULL)
2064 			goto out;
2065 		switch (ngq->flags) {
2066 		case NGQF_DATA:
2067 			hook = ngq->body.data.da_hook;
2068 			m = ngq->body.data.da_m;
2069 			meta = ngq->body.data.da_meta;
2070 			RETURN_QBLK(ngq);
2071 			NG_SEND_DATAQ(error, hook, m, meta);
2072 			ng_unref_hook(hook);
2073 			break;
2074 		case NGQF_MESG:
2075 			node = ngq->body.msg.msg_node;
2076 			msg = ngq->body.msg.msg_msg;
2077 			retaddr = ngq->body.msg.msg_retaddr;
2078 			RETURN_QBLK(ngq);
2079 			if (node->flags & NG_INVALID) {
2080 				FREE(msg, M_NETGRAPH);
2081 			} else {
2082 				CALL_MSG_HANDLER(error, node, msg,
2083 						 retaddr, NULL);
2084 			}
2085 			ng_unref(node);
2086 			if (retaddr)
2087 				FREE(retaddr, M_NETGRAPH);
2088 			break;
2089 		default:
2090 			RETURN_QBLK(ngq);
2091 		}
2092 	}
2093 out:
2094 	;
2095 }
2096 
2097 
2098