xref: /dragonfly/sys/netgraph/netgraph/ng_base.c (revision 2ee85085)
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 1.15 2005/06/02 22:11:46 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 <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", __func__);		\
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 			    __func__, (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 	crit_enter();
449 	if (--node->refs <= 0) {
450 		node->type->refs--;
451 		LIST_REMOVE(node, nodes);
452 		LIST_REMOVE(node, idnodes);
453 		FREE(node, M_NETGRAPH);
454 	}
455 	crit_exit();
456 }
457 
458 /*
459  * Wait for a node to come ready. Returns a node with a reference count;
460  * don't forget to drop it when we are done with it using ng_release_node().
461  */
462 int
463 ng_wait_node(node_p node, char *msg)
464 {
465 	int error = 0;
466 
467 	if (msg == NULL)
468 		msg = "netgraph";
469 	crit_enter();
470 	node->sleepers++;
471 	node->refs++;		/* the sleeping process counts as a reference */
472 	while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
473 		error = tsleep(node, PCATCH, msg, 0);
474 	node->sleepers--;
475 	if (node->flags & NG_INVALID) {
476 		TRAP_ERROR;
477 		error = ENXIO;
478 	} else {
479 		KASSERT(node->refs > 1,
480 		    ("%s: refs=%d", __func__, node->refs));
481 		node->flags |= NG_BUSY;
482 	}
483 	crit_exit();
484 
485 	/* Release the reference we had on it */
486 	if (error != 0)
487 		ng_unref(node);
488 	return error;
489 }
490 
491 /*
492  * Release a node acquired via ng_wait_node()
493  */
494 void
495 ng_release_node(node_p node)
496 {
497 	/* Declare that we don't want it */
498 	node->flags &= ~NG_BUSY;
499 
500 	/* If we have sleepers, then wake them up */
501 	if (node->sleepers)
502 		wakeup(node);
503 
504 	/* We also have a reference.. drop it too */
505 	ng_unref(node);
506 }
507 
508 /************************************************************************
509 			Node ID handling
510 ************************************************************************/
511 static node_p
512 ng_ID2node(ng_ID_t ID)
513 {
514 	node_p np;
515 	LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
516 		if ((np->flags & NG_INVALID) == 0 && np->ID == ID)
517 			break;
518 	}
519 	return(np);
520 }
521 
522 ng_ID_t
523 ng_node2ID(node_p node)
524 {
525 	return (node->ID);
526 }
527 
528 /************************************************************************
529 			Node name handling
530 ************************************************************************/
531 
532 /*
533  * Assign a node a name. Once assigned, the name cannot be changed.
534  */
535 int
536 ng_name_node(node_p node, const char *name)
537 {
538 	int i;
539 
540 	/* Check the name is valid */
541 	for (i = 0; i < NG_NODELEN + 1; i++) {
542 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
543 			break;
544 	}
545 	if (i == 0 || name[i] != '\0') {
546 		TRAP_ERROR;
547 		return (EINVAL);
548 	}
549 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
550 		TRAP_ERROR;
551 		return (EINVAL);
552 	}
553 
554 	/* Check the node isn't already named */
555 	if (node->name != NULL) {
556 		TRAP_ERROR;
557 		return (EISCONN);
558 	}
559 
560 	/* Check the name isn't already being used */
561 	if (ng_findname(node, name) != NULL) {
562 		TRAP_ERROR;
563 		return (EADDRINUSE);
564 	}
565 
566 	/* Allocate space and copy it */
567 	MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
568 	if (node->name == NULL) {
569 		TRAP_ERROR;
570 		return (ENOMEM);
571 	}
572 	strcpy(node->name, name);
573 
574 	/* The name counts as a reference */
575 	node->refs++;
576 	return (0);
577 }
578 
579 /*
580  * Find a node by absolute name. The name should NOT end with ':'
581  * The name "." means "this node" and "[xxx]" means "the node
582  * with ID (ie, at address) xxx".
583  *
584  * Returns the node if found, else NULL.
585  */
586 node_p
587 ng_findname(node_p this, const char *name)
588 {
589 	node_p node;
590 	ng_ID_t temp;
591 
592 	/* "." means "this node" */
593 	if (strcmp(name, ".") == 0)
594 		return(this);
595 
596 	/* Check for name-by-ID */
597 	if ((temp = ng_decodeidname(name)) != 0) {
598 		return (ng_ID2node(temp));
599 	}
600 
601 	/* Find node by name */
602 	LIST_FOREACH(node, &nodelist, nodes) {
603 		if ((node->name != NULL)
604 		&& (strcmp(node->name, name) == 0)
605 		&& ((node->flags & NG_INVALID) == 0))
606 			break;
607 	}
608 	return (node);
609 }
610 
611 /*
612  * Decode a ID name, eg. "[f03034de]". Returns 0 if the
613  * string is not valid, otherwise returns the value.
614  */
615 static ng_ID_t
616 ng_decodeidname(const char *name)
617 {
618 	const int len = strlen(name);
619 	char *eptr;
620 	u_long val;
621 
622 	/* Check for proper length, brackets, no leading junk */
623 	if (len < 3 || name[0] != '[' || name[len - 1] != ']'
624 	    || !isxdigit(name[1]))
625 		return (0);
626 
627 	/* Decode number */
628 	val = strtoul(name + 1, &eptr, 16);
629 	if (eptr - name != len - 1 || val == ULONG_MAX || val == 0)
630 		return ((ng_ID_t)0);
631 	return (ng_ID_t)val;
632 }
633 
634 /*
635  * Remove a name from a node. This should only be called
636  * when shutting down and removing the node.
637  */
638 void
639 ng_unname(node_p node)
640 {
641 	if (node->name) {
642 		FREE(node->name, M_NETGRAPH);
643 		node->name = NULL;
644 		ng_unref(node);
645 	}
646 }
647 
648 /************************************************************************
649 			Hook routines
650 
651  Names are not optional. Hooks are always connected, except for a
652  brief moment within these routines.
653 
654 ************************************************************************/
655 
656 /*
657  * Remove a hook reference
658  */
659 void
660 ng_unref_hook(hook_p hook)
661 {
662 	crit_enter();
663 	if (--hook->refs == 0)
664 		FREE(hook, M_NETGRAPH);
665 	crit_exit();
666 }
667 
668 /*
669  * Add an unconnected hook to a node. Only used internally.
670  */
671 static int
672 ng_add_hook(node_p node, const char *name, hook_p *hookp)
673 {
674 	hook_p hook;
675 	int error = 0;
676 
677 	/* Check that the given name is good */
678 	if (name == NULL) {
679 		TRAP_ERROR;
680 		return (EINVAL);
681 	}
682 	if (ng_findhook(node, name) != NULL) {
683 		TRAP_ERROR;
684 		return (EEXIST);
685 	}
686 
687 	/* Allocate the hook and link it up */
688 	MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_NOWAIT);
689 	if (hook == NULL) {
690 		TRAP_ERROR;
691 		return (ENOMEM);
692 	}
693 	bzero(hook, sizeof(*hook));
694 	hook->refs = 1;
695 	hook->flags = HK_INVALID;
696 	hook->node = node;
697 	node->refs++;		/* each hook counts as a reference */
698 
699 	/* Check if the node type code has something to say about it */
700 	if (node->type->newhook != NULL)
701 		if ((error = (*node->type->newhook)(node, hook, name)) != 0)
702 			goto fail;
703 
704 	/*
705 	 * The 'type' agrees so far, so go ahead and link it in.
706 	 * We'll ask again later when we actually connect the hooks.
707 	 */
708 	LIST_INSERT_HEAD(&node->hooks, hook, hooks);
709 	node->numhooks++;
710 
711 	/* Set hook name */
712 	MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
713 	if (hook->name == NULL) {
714 		error = ENOMEM;
715 		LIST_REMOVE(hook, hooks);
716 		node->numhooks--;
717 fail:
718 		hook->node = NULL;
719 		ng_unref(node);
720 		ng_unref_hook(hook);	/* this frees the hook */
721 		return (error);
722 	}
723 	strcpy(hook->name, name);
724 	if (hookp)
725 		*hookp = hook;
726 	return (error);
727 }
728 
729 /*
730  * Connect a pair of hooks. Only used internally.
731  */
732 static int
733 ng_connect(hook_p hook1, hook_p hook2)
734 {
735 	int     error;
736 
737 	hook1->peer = hook2;
738 	hook2->peer = hook1;
739 
740 	/* Give each node the opportunity to veto the impending connection */
741 	if (hook1->node->type->connect) {
742 		if ((error = (*hook1->node->type->connect) (hook1))) {
743 			ng_destroy_hook(hook1);	/* also zaps hook2 */
744 			return (error);
745 		}
746 	}
747 	if (hook2->node->type->connect) {
748 		if ((error = (*hook2->node->type->connect) (hook2))) {
749 			ng_destroy_hook(hook2);	/* also zaps hook1 */
750 			return (error);
751 		}
752 	}
753 	hook1->flags &= ~HK_INVALID;
754 	hook2->flags &= ~HK_INVALID;
755 	return (0);
756 }
757 
758 /*
759  * Find a hook
760  *
761  * Node types may supply their own optimized routines for finding
762  * hooks.  If none is supplied, we just do a linear search.
763  */
764 hook_p
765 ng_findhook(node_p node, const char *name)
766 {
767 	hook_p hook;
768 
769 	if (node->type->findhook != NULL)
770 		return (*node->type->findhook)(node, name);
771 	LIST_FOREACH(hook, &node->hooks, hooks) {
772 		if (hook->name != NULL
773 		    && strcmp(hook->name, name) == 0
774 		    && (hook->flags & HK_INVALID) == 0)
775 			return (hook);
776 	}
777 	return (NULL);
778 }
779 
780 /*
781  * Destroy a hook
782  *
783  * As hooks are always attached, this really destroys two hooks.
784  * The one given, and the one attached to it. Disconnect the hooks
785  * from each other first.
786  */
787 void
788 ng_destroy_hook(hook_p hook)
789 {
790 	hook_p peer = hook->peer;
791 
792 	hook->flags |= HK_INVALID;		/* as soon as possible */
793 	if (peer) {
794 		peer->flags |= HK_INVALID;	/* as soon as possible */
795 		hook->peer = NULL;
796 		peer->peer = NULL;
797 		ng_disconnect_hook(peer);
798 	}
799 	ng_disconnect_hook(hook);
800 }
801 
802 /*
803  * Notify the node of the hook's demise. This may result in more actions
804  * (e.g. shutdown) but we don't do that ourselves and don't know what
805  * happens there. If there is no appropriate handler, then just remove it
806  * (and decrement the reference count of it's node which in turn might
807  * make something happen).
808  */
809 static void
810 ng_disconnect_hook(hook_p hook)
811 {
812 	node_p node = hook->node;
813 
814 	/*
815 	 * Remove the hook from the node's list to avoid possible recursion
816 	 * in case the disconnection results in node shutdown.
817 	 */
818 	LIST_REMOVE(hook, hooks);
819 	node->numhooks--;
820 	if (node->type->disconnect) {
821 		/*
822 		 * The type handler may elect to destroy the peer so don't
823 		 * trust its existance after this point.
824 		 */
825 		(*node->type->disconnect) (hook);
826 	}
827 	ng_unref(node);		/* might be the last reference */
828 	if (hook->name)
829 		FREE(hook->name, M_NETGRAPH);
830 	hook->node = NULL;	/* may still be referenced elsewhere */
831 	ng_unref_hook(hook);
832 }
833 
834 /*
835  * Take two hooks on a node and merge the connection so that the given node
836  * is effectively bypassed.
837  */
838 int
839 ng_bypass(hook_p hook1, hook_p hook2)
840 {
841 	if (hook1->node != hook2->node)
842 		return (EINVAL);
843 	hook1->peer->peer = hook2->peer;
844 	hook2->peer->peer = hook1->peer;
845 
846 	/* XXX If we ever cache methods on hooks update them as well */
847 	hook1->peer = NULL;
848 	hook2->peer = NULL;
849 	ng_destroy_hook(hook1);
850 	ng_destroy_hook(hook2);
851 	return (0);
852 }
853 
854 /*
855  * Install a new netgraph type
856  */
857 int
858 ng_newtype(struct ng_type *tp)
859 {
860 	const size_t namelen = strlen(tp->name);
861 
862 	/* Check version and type name fields */
863 	if (tp->version != NG_VERSION || namelen == 0 || namelen > NG_TYPELEN) {
864 		TRAP_ERROR;
865 		return (EINVAL);
866 	}
867 
868 	/* Check for name collision */
869 	if (ng_findtype(tp->name) != NULL) {
870 		TRAP_ERROR;
871 		return (EEXIST);
872 	}
873 
874 	/* Link in new type */
875 	LIST_INSERT_HEAD(&typelist, tp, types);
876 	tp->refs = 1;	/* first ref is linked list */
877 	return (0);
878 }
879 
880 /*
881  * Look for a type of the name given
882  */
883 struct ng_type *
884 ng_findtype(const char *typename)
885 {
886 	struct ng_type *type;
887 
888 	LIST_FOREACH(type, &typelist, types) {
889 		if (strcmp(type->name, typename) == 0)
890 			break;
891 	}
892 	return (type);
893 }
894 
895 
896 /************************************************************************
897 			Composite routines
898 ************************************************************************/
899 
900 /*
901  * Make a peer and connect. The order is arranged to minimise
902  * the work needed to back out in case of error.
903  */
904 int
905 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
906 {
907 	node_p  node2;
908 	hook_p  hook;
909 	hook_p  hook2;
910 	int     error;
911 
912 	if ((error = ng_add_hook(node, name, &hook)))
913 		return (error);
914 	if ((error = ng_make_node(type, &node2))) {
915 		ng_destroy_hook(hook);
916 		return (error);
917 	}
918 	if ((error = ng_add_hook(node2, name2, &hook2))) {
919 		ng_rmnode(node2);
920 		ng_destroy_hook(hook);
921 		return (error);
922 	}
923 
924 	/*
925 	 * Actually link the two hooks together.. on failure they are
926 	 * destroyed so we don't have to do that here.
927 	 */
928 	if ((error = ng_connect(hook, hook2)))
929 		ng_rmnode(node2);
930 	return (error);
931 }
932 
933 /*
934  * Connect two nodes using the specified hooks
935  */
936 int
937 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
938 {
939 	int     error;
940 	hook_p  hook;
941 	hook_p  hook2;
942 
943 	if ((error = ng_add_hook(node, name, &hook)))
944 		return (error);
945 	if ((error = ng_add_hook(node2, name2, &hook2))) {
946 		ng_destroy_hook(hook);
947 		return (error);
948 	}
949 	return (ng_connect(hook, hook2));
950 }
951 
952 /*
953  * Parse and verify a string of the form:  <NODE:><PATH>
954  *
955  * Such a string can refer to a specific node or a specific hook
956  * on a specific node, depending on how you look at it. In the
957  * latter case, the PATH component must not end in a dot.
958  *
959  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
960  * of hook names separated by dots. This breaks out the original
961  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
962  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
963  * the final hook component of <PATH>, if any, otherwise NULL.
964  *
965  * This returns -1 if the path is malformed. The char ** are optional.
966  */
967 
968 int
969 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
970 {
971 	char   *node, *path, *hook;
972 	int     k;
973 
974 	/*
975 	 * Extract absolute NODE, if any
976 	 */
977 	for (path = addr; *path && *path != ':'; path++);
978 	if (*path) {
979 		node = addr;	/* Here's the NODE */
980 		*path++ = '\0';	/* Here's the PATH */
981 
982 		/* Node name must not be empty */
983 		if (!*node)
984 			return -1;
985 
986 		/* A name of "." is OK; otherwise '.' not allowed */
987 		if (strcmp(node, ".") != 0) {
988 			for (k = 0; node[k]; k++)
989 				if (node[k] == '.')
990 					return -1;
991 		}
992 	} else {
993 		node = NULL;	/* No absolute NODE */
994 		path = addr;	/* Here's the PATH */
995 	}
996 
997 	/* Snoop for illegal characters in PATH */
998 	for (k = 0; path[k]; k++)
999 		if (path[k] == ':')
1000 			return -1;
1001 
1002 	/* Check for no repeated dots in PATH */
1003 	for (k = 0; path[k]; k++)
1004 		if (path[k] == '.' && path[k + 1] == '.')
1005 			return -1;
1006 
1007 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1008 	if (path[0] == '.')
1009 		path++;
1010 	if (*path && path[strlen(path) - 1] == '.')
1011 		path[strlen(path) - 1] = 0;
1012 
1013 	/* If PATH has a dot, then we're not talking about a hook */
1014 	if (*path) {
1015 		for (hook = path, k = 0; path[k]; k++)
1016 			if (path[k] == '.') {
1017 				hook = NULL;
1018 				break;
1019 			}
1020 	} else
1021 		path = hook = NULL;
1022 
1023 	/* Done */
1024 	if (nodep)
1025 		*nodep = node;
1026 	if (pathp)
1027 		*pathp = path;
1028 	if (hookp)
1029 		*hookp = hook;
1030 	return (0);
1031 }
1032 
1033 /*
1034  * Given a path, which may be absolute or relative, and a starting node,
1035  * return the destination node. Compute the "return address" if desired.
1036  */
1037 int
1038 ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
1039 {
1040 	const	node_p start = here;
1041 	char    fullpath[NG_PATHLEN + 1];
1042 	char   *nodename, *path, pbuf[2];
1043 	node_p  node;
1044 	char   *cp;
1045 
1046 	/* Initialize */
1047 	if (rtnp)
1048 		*rtnp = NULL;
1049 	if (destp == NULL)
1050 		return EINVAL;
1051 	*destp = NULL;
1052 
1053 	/* Make a writable copy of address for ng_path_parse() */
1054 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1055 	fullpath[sizeof(fullpath) - 1] = '\0';
1056 
1057 	/* Parse out node and sequence of hooks */
1058 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1059 		TRAP_ERROR;
1060 		return EINVAL;
1061 	}
1062 	if (path == NULL) {
1063 		pbuf[0] = '.';	/* Needs to be writable */
1064 		pbuf[1] = '\0';
1065 		path = pbuf;
1066 	}
1067 
1068 	/* For an absolute address, jump to the starting node */
1069 	if (nodename) {
1070 		node = ng_findname(here, nodename);
1071 		if (node == NULL) {
1072 			TRAP_ERROR;
1073 			return (ENOENT);
1074 		}
1075 	} else
1076 		node = here;
1077 
1078 	/* Now follow the sequence of hooks */
1079 	for (cp = path; node != NULL && *cp != '\0'; ) {
1080 		hook_p hook;
1081 		char *segment;
1082 
1083 		/*
1084 		 * Break out the next path segment. Replace the dot we just
1085 		 * found with a NUL; "cp" points to the next segment (or the
1086 		 * NUL at the end).
1087 		 */
1088 		for (segment = cp; *cp != '\0'; cp++) {
1089 			if (*cp == '.') {
1090 				*cp++ = '\0';
1091 				break;
1092 			}
1093 		}
1094 
1095 		/* Empty segment */
1096 		if (*segment == '\0')
1097 			continue;
1098 
1099 		/* We have a segment, so look for a hook by that name */
1100 		hook = ng_findhook(node, segment);
1101 
1102 		/* Can't get there from here... */
1103 		if (hook == NULL
1104 		    || hook->peer == NULL
1105 		    || (hook->flags & HK_INVALID) != 0) {
1106 			TRAP_ERROR;
1107 			return (ENOENT);
1108 		}
1109 
1110 		/* Hop on over to the next node */
1111 		node = hook->peer->node;
1112 	}
1113 
1114 	/* If node somehow missing, fail here (probably this is not needed) */
1115 	if (node == NULL) {
1116 		TRAP_ERROR;
1117 		return (ENXIO);
1118 	}
1119 
1120 	/* Now compute return address, i.e., the path to the sender */
1121 	if (rtnp != NULL) {
1122 		MALLOC(*rtnp, char *, NG_NODELEN + 2, M_NETGRAPH, M_NOWAIT);
1123 		if (*rtnp == NULL) {
1124 			TRAP_ERROR;
1125 			return (ENOMEM);
1126 		}
1127 		if (start->name != NULL)
1128 			sprintf(*rtnp, "%s:", start->name);
1129 		else
1130 			sprintf(*rtnp, "[%x]:", ng_node2ID(start));
1131 	}
1132 
1133 	/* Done */
1134 	*destp = node;
1135 	return (0);
1136 }
1137 
1138 /*
1139  * Call the appropriate message handler for the object.
1140  * It is up to the message handler to free the message.
1141  * If it's a generic message, handle it generically, otherwise
1142  * call the type's message handler (if it exists)
1143  * XXX (race). Remember that a queued message may reference a node
1144  * or hook that has just been invalidated. It will exist
1145  * as the queue code is holding a reference, but..
1146  */
1147 
1148 #define CALL_MSG_HANDLER(error, node, msg, retaddr, resp)		\
1149 do {									\
1150 	if((msg)->header.typecookie == NGM_GENERIC_COOKIE) {		\
1151 		(error) = ng_generic_msg((node), (msg),			\
1152 				(retaddr), (resp));			\
1153 	} else {							\
1154 		if ((node)->type->rcvmsg != NULL) {			\
1155 			(error) = (*(node)->type->rcvmsg)((node),	\
1156 					(msg), (retaddr), (resp));	\
1157 		} else {						\
1158 			TRAP_ERROR;					\
1159 			FREE((msg), M_NETGRAPH);			\
1160 			(error) = EINVAL;				\
1161 		}							\
1162 	}								\
1163 } while (0)
1164 
1165 
1166 /*
1167  * Send a control message to a node
1168  */
1169 int
1170 ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
1171 	    struct ng_mesg **rptr)
1172 {
1173 	node_p  dest = NULL;
1174 	char   *retaddr = NULL;
1175 	int     error;
1176 
1177 	/* Find the target node */
1178 	error = ng_path2node(here, address, &dest, &retaddr);
1179 	if (error) {
1180 		FREE(msg, M_NETGRAPH);
1181 		return error;
1182 	}
1183 
1184 	/* Make sure the resp field is null before we start */
1185 	if (rptr != NULL)
1186 		*rptr = NULL;
1187 
1188 	CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
1189 
1190 	/* Make sure that if there is a response, it has the RESP bit set */
1191 	if ((error == 0) && rptr && *rptr)
1192 		(*rptr)->header.flags |= NGF_RESP;
1193 
1194 	/*
1195 	 * If we had a return address it is up to us to free it. They should
1196 	 * have taken a copy if they needed to make a delayed response.
1197 	 */
1198 	if (retaddr)
1199 		FREE(retaddr, M_NETGRAPH);
1200 	return (error);
1201 }
1202 
1203 /*
1204  * Implement the 'generic' control messages
1205  */
1206 static int
1207 ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
1208 	       struct ng_mesg **resp)
1209 {
1210 	int error = 0;
1211 
1212 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
1213 		TRAP_ERROR;
1214 		FREE(msg, M_NETGRAPH);
1215 		return (EINVAL);
1216 	}
1217 	switch (msg->header.cmd) {
1218 	case NGM_SHUTDOWN:
1219 		ng_rmnode(here);
1220 		break;
1221 	case NGM_MKPEER:
1222 	    {
1223 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
1224 
1225 		if (msg->header.arglen != sizeof(*mkp)) {
1226 			TRAP_ERROR;
1227 			return (EINVAL);
1228 		}
1229 		mkp->type[sizeof(mkp->type) - 1] = '\0';
1230 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
1231 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
1232 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
1233 		break;
1234 	    }
1235 	case NGM_CONNECT:
1236 	    {
1237 		struct ngm_connect *const con =
1238 			(struct ngm_connect *) msg->data;
1239 		node_p node2;
1240 
1241 		if (msg->header.arglen != sizeof(*con)) {
1242 			TRAP_ERROR;
1243 			return (EINVAL);
1244 		}
1245 		con->path[sizeof(con->path) - 1] = '\0';
1246 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
1247 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
1248 		error = ng_path2node(here, con->path, &node2, NULL);
1249 		if (error)
1250 			break;
1251 		error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
1252 		break;
1253 	    }
1254 	case NGM_NAME:
1255 	    {
1256 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
1257 
1258 		if (msg->header.arglen != sizeof(*nam)) {
1259 			TRAP_ERROR;
1260 			return (EINVAL);
1261 		}
1262 		nam->name[sizeof(nam->name) - 1] = '\0';
1263 		error = ng_name_node(here, nam->name);
1264 		break;
1265 	    }
1266 	case NGM_RMHOOK:
1267 	    {
1268 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
1269 		hook_p hook;
1270 
1271 		if (msg->header.arglen != sizeof(*rmh)) {
1272 			TRAP_ERROR;
1273 			return (EINVAL);
1274 		}
1275 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
1276 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
1277 			ng_destroy_hook(hook);
1278 		break;
1279 	    }
1280 	case NGM_NODEINFO:
1281 	    {
1282 		struct nodeinfo *ni;
1283 		struct ng_mesg *rp;
1284 
1285 		/* Get response struct */
1286 		if (resp == NULL) {
1287 			error = EINVAL;
1288 			break;
1289 		}
1290 		NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
1291 		if (rp == NULL) {
1292 			error = ENOMEM;
1293 			break;
1294 		}
1295 
1296 		/* Fill in node info */
1297 		ni = (struct nodeinfo *) rp->data;
1298 		if (here->name != NULL)
1299 			strncpy(ni->name, here->name, NG_NODELEN);
1300 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1301 		ni->id = ng_node2ID(here);
1302 		ni->hooks = here->numhooks;
1303 		*resp = rp;
1304 		break;
1305 	    }
1306 	case NGM_LISTHOOKS:
1307 	    {
1308 		const int nhooks = here->numhooks;
1309 		struct hooklist *hl;
1310 		struct nodeinfo *ni;
1311 		struct ng_mesg *rp;
1312 		hook_p hook;
1313 
1314 		/* Get response struct */
1315 		if (resp == NULL) {
1316 			error = EINVAL;
1317 			break;
1318 		}
1319 		NG_MKRESPONSE(rp, msg, sizeof(*hl)
1320 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
1321 		if (rp == NULL) {
1322 			error = ENOMEM;
1323 			break;
1324 		}
1325 		hl = (struct hooklist *) rp->data;
1326 		ni = &hl->nodeinfo;
1327 
1328 		/* Fill in node info */
1329 		if (here->name)
1330 			strncpy(ni->name, here->name, NG_NODELEN);
1331 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1332 		ni->id = ng_node2ID(here);
1333 
1334 		/* Cycle through the linked list of hooks */
1335 		ni->hooks = 0;
1336 		LIST_FOREACH(hook, &here->hooks, hooks) {
1337 			struct linkinfo *const link = &hl->link[ni->hooks];
1338 
1339 			if (ni->hooks >= nhooks) {
1340 				log(LOG_ERR, "%s: number of %s changed\n",
1341 				    __func__, "hooks");
1342 				break;
1343 			}
1344 			if ((hook->flags & HK_INVALID) != 0)
1345 				continue;
1346 			strncpy(link->ourhook, hook->name, NG_HOOKLEN);
1347 			strncpy(link->peerhook, hook->peer->name, NG_HOOKLEN);
1348 			if (hook->peer->node->name != NULL)
1349 				strncpy(link->nodeinfo.name,
1350 				    hook->peer->node->name, NG_NODELEN);
1351 			strncpy(link->nodeinfo.type,
1352 			   hook->peer->node->type->name, NG_TYPELEN);
1353 			link->nodeinfo.id = ng_node2ID(hook->peer->node);
1354 			link->nodeinfo.hooks = hook->peer->node->numhooks;
1355 			ni->hooks++;
1356 		}
1357 		*resp = rp;
1358 		break;
1359 	    }
1360 
1361 	case NGM_LISTNAMES:
1362 	case NGM_LISTNODES:
1363 	    {
1364 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
1365 		struct namelist *nl;
1366 		struct ng_mesg *rp;
1367 		node_p node;
1368 		int num = 0;
1369 
1370 		if (resp == NULL) {
1371 			error = EINVAL;
1372 			break;
1373 		}
1374 
1375 		/* Count number of nodes */
1376 		LIST_FOREACH(node, &nodelist, nodes) {
1377 			if ((node->flags & NG_INVALID) == 0
1378 			    && (unnamed || node->name != NULL))
1379 				num++;
1380 		}
1381 
1382 		/* Get response struct */
1383 		if (resp == NULL) {
1384 			error = EINVAL;
1385 			break;
1386 		}
1387 		NG_MKRESPONSE(rp, msg, sizeof(*nl)
1388 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
1389 		if (rp == NULL) {
1390 			error = ENOMEM;
1391 			break;
1392 		}
1393 		nl = (struct namelist *) rp->data;
1394 
1395 		/* Cycle through the linked list of nodes */
1396 		nl->numnames = 0;
1397 		LIST_FOREACH(node, &nodelist, nodes) {
1398 			struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
1399 
1400 			if (nl->numnames >= num) {
1401 				log(LOG_ERR, "%s: number of %s changed\n",
1402 				    __func__, "nodes");
1403 				break;
1404 			}
1405 			if ((node->flags & NG_INVALID) != 0)
1406 				continue;
1407 			if (!unnamed && node->name == NULL)
1408 				continue;
1409 			if (node->name != NULL)
1410 				strncpy(np->name, node->name, NG_NODELEN);
1411 			strncpy(np->type, node->type->name, NG_TYPELEN);
1412 			np->id = ng_node2ID(node);
1413 			np->hooks = node->numhooks;
1414 			nl->numnames++;
1415 		}
1416 		*resp = rp;
1417 		break;
1418 	    }
1419 
1420 	case NGM_LISTTYPES:
1421 	    {
1422 		struct typelist *tl;
1423 		struct ng_mesg *rp;
1424 		struct ng_type *type;
1425 		int num = 0;
1426 
1427 		if (resp == NULL) {
1428 			error = EINVAL;
1429 			break;
1430 		}
1431 
1432 		/* Count number of types */
1433 		LIST_FOREACH(type, &typelist, types)
1434 			num++;
1435 
1436 		/* Get response struct */
1437 		if (resp == NULL) {
1438 			error = EINVAL;
1439 			break;
1440 		}
1441 		NG_MKRESPONSE(rp, msg, sizeof(*tl)
1442 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
1443 		if (rp == NULL) {
1444 			error = ENOMEM;
1445 			break;
1446 		}
1447 		tl = (struct typelist *) rp->data;
1448 
1449 		/* Cycle through the linked list of types */
1450 		tl->numtypes = 0;
1451 		LIST_FOREACH(type, &typelist, types) {
1452 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
1453 
1454 			if (tl->numtypes >= num) {
1455 				log(LOG_ERR, "%s: number of %s changed\n",
1456 				    __func__, "types");
1457 				break;
1458 			}
1459 			strncpy(tp->type_name, type->name, NG_TYPELEN);
1460 			tp->numnodes = type->refs - 1; /* don't count list */
1461 			tl->numtypes++;
1462 		}
1463 		*resp = rp;
1464 		break;
1465 	    }
1466 
1467 	case NGM_BINARY2ASCII:
1468 	    {
1469 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
1470 		const struct ng_parse_type *argstype;
1471 		const struct ng_cmdlist *c;
1472 		struct ng_mesg *rp, *binary, *ascii;
1473 
1474 		/* Data area must contain a valid netgraph message */
1475 		binary = (struct ng_mesg *)msg->data;
1476 		if (msg->header.arglen < sizeof(struct ng_mesg)
1477 		    || msg->header.arglen - sizeof(struct ng_mesg)
1478 		      < binary->header.arglen) {
1479 			error = EINVAL;
1480 			break;
1481 		}
1482 
1483 		/* Get a response message with lots of room */
1484 		NG_MKRESPONSE(rp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
1485 		if (rp == NULL) {
1486 			error = ENOMEM;
1487 			break;
1488 		}
1489 		ascii = (struct ng_mesg *)rp->data;
1490 
1491 		/* Copy binary message header to response message payload */
1492 		bcopy(binary, ascii, sizeof(*binary));
1493 
1494 		/* Find command by matching typecookie and command number */
1495 		for (c = here->type->cmdlist;
1496 		    c != NULL && c->name != NULL; c++) {
1497 			if (binary->header.typecookie == c->cookie
1498 			    && binary->header.cmd == c->cmd)
1499 				break;
1500 		}
1501 		if (c == NULL || c->name == NULL) {
1502 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1503 				if (binary->header.typecookie == c->cookie
1504 				    && binary->header.cmd == c->cmd)
1505 					break;
1506 			}
1507 			if (c->name == NULL) {
1508 				FREE(rp, M_NETGRAPH);
1509 				error = ENOSYS;
1510 				break;
1511 			}
1512 		}
1513 
1514 		/* Convert command name to ASCII */
1515 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
1516 		    "%s", c->name);
1517 
1518 		/* Convert command arguments to ASCII */
1519 		argstype = (binary->header.flags & NGF_RESP) ?
1520 		    c->respType : c->mesgType;
1521 		if (argstype == NULL)
1522 			*ascii->data = '\0';
1523 		else {
1524 			if ((error = ng_unparse(argstype,
1525 			    (u_char *)binary->data,
1526 			    ascii->data, bufSize)) != 0) {
1527 				FREE(rp, M_NETGRAPH);
1528 				break;
1529 			}
1530 		}
1531 
1532 		/* Return the result as struct ng_mesg plus ASCII string */
1533 		bufSize = strlen(ascii->data) + 1;
1534 		ascii->header.arglen = bufSize;
1535 		rp->header.arglen = sizeof(*ascii) + bufSize;
1536 		*resp = rp;
1537 		break;
1538 	    }
1539 
1540 	case NGM_ASCII2BINARY:
1541 	    {
1542 		int bufSize = 2000;	/* XXX hard coded constant */
1543 		const struct ng_cmdlist *c;
1544 		const struct ng_parse_type *argstype;
1545 		struct ng_mesg *rp, *ascii, *binary;
1546 		int off = 0;
1547 
1548 		/* Data area must contain at least a struct ng_mesg + '\0' */
1549 		ascii = (struct ng_mesg *)msg->data;
1550 		if (msg->header.arglen < sizeof(*ascii) + 1
1551 		    || ascii->header.arglen < 1
1552 		    || msg->header.arglen
1553 		      < sizeof(*ascii) + ascii->header.arglen) {
1554 			error = EINVAL;
1555 			break;
1556 		}
1557 		ascii->data[ascii->header.arglen - 1] = '\0';
1558 
1559 		/* Get a response message with lots of room */
1560 		NG_MKRESPONSE(rp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
1561 		if (rp == NULL) {
1562 			error = ENOMEM;
1563 			break;
1564 		}
1565 		binary = (struct ng_mesg *)rp->data;
1566 
1567 		/* Copy ASCII message header to response message payload */
1568 		bcopy(ascii, binary, sizeof(*ascii));
1569 
1570 		/* Find command by matching ASCII command string */
1571 		for (c = here->type->cmdlist;
1572 		    c != NULL && c->name != NULL; c++) {
1573 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
1574 				break;
1575 		}
1576 		if (c == NULL || c->name == NULL) {
1577 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1578 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
1579 					break;
1580 			}
1581 			if (c->name == NULL) {
1582 				FREE(rp, M_NETGRAPH);
1583 				error = ENOSYS;
1584 				break;
1585 			}
1586 		}
1587 
1588 		/* Convert command name to binary */
1589 		binary->header.cmd = c->cmd;
1590 		binary->header.typecookie = c->cookie;
1591 
1592 		/* Convert command arguments to binary */
1593 		argstype = (binary->header.flags & NGF_RESP) ?
1594 		    c->respType : c->mesgType;
1595 		if (argstype == NULL)
1596 			bufSize = 0;
1597 		else {
1598 			if ((error = ng_parse(argstype, ascii->data,
1599 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
1600 				FREE(rp, M_NETGRAPH);
1601 				break;
1602 			}
1603 		}
1604 
1605 		/* Return the result */
1606 		binary->header.arglen = bufSize;
1607 		rp->header.arglen = sizeof(*binary) + bufSize;
1608 		*resp = rp;
1609 		break;
1610 	    }
1611 
1612 	case NGM_TEXT_CONFIG:
1613 	case NGM_TEXT_STATUS:
1614 		/*
1615 		 * This one is tricky as it passes the command down to the
1616 		 * actual node, even though it is a generic type command.
1617 		 * This means we must assume that the msg is already freed
1618 		 * when control passes back to us.
1619 		 */
1620 		if (resp == NULL) {
1621 			error = EINVAL;
1622 			break;
1623 		}
1624 		if (here->type->rcvmsg != NULL)
1625 			return((*here->type->rcvmsg)(here, msg, retaddr, resp));
1626 		/* Fall through if rcvmsg not supported */
1627 	default:
1628 		TRAP_ERROR;
1629 		error = EINVAL;
1630 	}
1631 	FREE(msg, M_NETGRAPH);
1632 	return (error);
1633 }
1634 
1635 /*
1636  * Send a data packet to a node. If the recipient has no
1637  * 'receive data' method, then silently discard the packet.
1638  */
1639 int
1640 ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
1641 {
1642 	int (*rcvdata)(hook_p, struct mbuf *, meta_p);
1643 	int error;
1644 
1645 	CHECK_DATA_MBUF(m);
1646 	if (hook && (hook->flags & HK_INVALID) == 0) {
1647 		rcvdata = hook->peer->node->type->rcvdata;
1648 		if (rcvdata != NULL)
1649 			error = (*rcvdata)(hook->peer, m, meta);
1650 		else {
1651 			error = 0;
1652 			NG_FREE_DATA(m, meta);
1653 		}
1654 	} else {
1655 		TRAP_ERROR;
1656 		error = ENOTCONN;
1657 		NG_FREE_DATA(m, meta);
1658 	}
1659 	return (error);
1660 }
1661 
1662 /*
1663  * Send a queued data packet to a node. If the recipient has no
1664  * 'receive queued data' method, then try the 'receive data' method above.
1665  */
1666 int
1667 ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
1668 {
1669 	int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
1670 	int error;
1671 
1672 	CHECK_DATA_MBUF(m);
1673 	if (hook && (hook->flags & HK_INVALID) == 0) {
1674 		rcvdataq = hook->peer->node->type->rcvdataq;
1675 		if (rcvdataq != NULL)
1676 			error = (*rcvdataq)(hook->peer, m, meta);
1677 		else {
1678 			error = ng_send_data(hook, m, meta);
1679 		}
1680 	} else {
1681 		TRAP_ERROR;
1682 		error = ENOTCONN;
1683 		NG_FREE_DATA(m, meta);
1684 	}
1685 	return (error);
1686 }
1687 
1688 /*
1689  * Copy a 'meta'.
1690  *
1691  * Returns new meta, or NULL if original meta is NULL or ENOMEM.
1692  */
1693 meta_p
1694 ng_copy_meta(meta_p meta)
1695 {
1696 	meta_p meta2;
1697 
1698 	if (meta == NULL)
1699 		return (NULL);
1700 	MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH, M_NOWAIT);
1701 	if (meta2 == NULL)
1702 		return (NULL);
1703 	meta2->allocated_len = meta->used_len;
1704 	bcopy(meta, meta2, meta->used_len);
1705 	return (meta2);
1706 }
1707 
1708 /************************************************************************
1709 			Module routines
1710 ************************************************************************/
1711 
1712 /*
1713  * Handle the loading/unloading of a netgraph node type module
1714  */
1715 int
1716 ng_mod_event(module_t mod, int event, void *data)
1717 {
1718 	struct ng_type *const type = data;
1719 	int error = 0;
1720 
1721 	switch (event) {
1722 	case MOD_LOAD:
1723 
1724 		/* Register new netgraph node type */
1725 		crit_enter();
1726 		if ((error = ng_newtype(type)) != 0) {
1727 			crit_exit();
1728 			break;
1729 		}
1730 
1731 		/* Call type specific code */
1732 		if (type->mod_event != NULL)
1733 			if ((error = (*type->mod_event)(mod, event, data))) {
1734 				type->refs--;	/* undo it */
1735 				LIST_REMOVE(type, types);
1736 			}
1737 		crit_exit();
1738 		break;
1739 
1740 	case MOD_UNLOAD:
1741 		crit_enter();
1742 		if (type->refs > 1) {		/* make sure no nodes exist! */
1743 			error = EBUSY;
1744 		} else {
1745 			if (type->refs == 0) {
1746 				/* failed load, nothing to undo */
1747 				crit_exit();
1748 				break;
1749 			}
1750 			if (type->mod_event != NULL) {	/* check with type */
1751 				error = (*type->mod_event)(mod, event, data);
1752 				if (error != 0) {	/* type refuses.. */
1753 					crit_exit();
1754 					break;
1755 				}
1756 			}
1757 			LIST_REMOVE(type, types);
1758 		}
1759 		crit_exit();
1760 		break;
1761 
1762 	default:
1763 		if (type->mod_event != NULL)
1764 			error = (*type->mod_event)(mod, event, data);
1765 		else
1766 			error = 0;		/* XXX ? */
1767 		break;
1768 	}
1769 	return (error);
1770 }
1771 
1772 /*
1773  * Handle loading and unloading for this code.
1774  * The only thing we need to link into is the NETISR strucure.
1775  */
1776 static int
1777 ngb_mod_event(module_t mod, int event, void *data)
1778 {
1779 	int error = 0;
1780 
1781 	switch (event) {
1782 	case MOD_LOAD:
1783 		/* Register line discipline */
1784 		crit_enter();
1785 		netisr_register(NETISR_NETGRAPH, cpu0_portfn, ngintr);
1786 		error = 0;
1787 		crit_exit();
1788 		break;
1789 	case MOD_UNLOAD:
1790 		/* You cant unload it because an interface may be using it.  */
1791 		error = EBUSY;
1792 		break;
1793 	default:
1794 		error = EOPNOTSUPP;
1795 		break;
1796 	}
1797 	return (error);
1798 }
1799 
1800 static moduledata_t netgraph_mod = {
1801 	"netgraph",
1802 	ngb_mod_event,
1803 	(NULL)
1804 };
1805 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1806 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
1807 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
1808 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
1809 
1810 /************************************************************************
1811 			Queueing routines
1812 ************************************************************************/
1813 
1814 /* The structure for queueing across ISR switches */
1815 struct ng_queue_entry {
1816 	u_long	flags;
1817 	struct ng_queue_entry *next;
1818 	union {
1819 		struct {
1820 			hook_p		da_hook;	/*  target hook */
1821 			struct mbuf	*da_m;
1822 			meta_p		da_meta;
1823 		} data;
1824 		struct {
1825 			struct ng_mesg	*msg_msg;
1826 			node_p		msg_node;
1827 			void		*msg_retaddr;
1828 		} msg;
1829 	} body;
1830 };
1831 #define NGQF_DATA	0x01		/* the queue element is data */
1832 #define NGQF_MESG	0x02		/* the queue element is a message */
1833 
1834 static struct ng_queue_entry   *ngqbase;	/* items to be unqueued */
1835 static struct ng_queue_entry   *ngqlast;	/* last item queued */
1836 static const int		ngqroom = 256;	/* max items to queue */
1837 static int			ngqsize;	/* number of items in queue */
1838 
1839 static struct ng_queue_entry   *ngqfree;	/* free ones */
1840 static const int		ngqfreemax = 256;/* cache at most this many */
1841 static int			ngqfreesize;	/* number of cached entries */
1842 
1843 /*
1844  * Get a queue entry
1845  */
1846 static struct ng_queue_entry *
1847 ng_getqblk(void)
1848 {
1849 	struct ng_queue_entry *q;
1850 
1851 	/* Could be guarding against tty ints or whatever */
1852 	crit_enter();
1853 
1854 	/* Try get a cached queue block, or else allocate a new one */
1855 	if ((q = ngqfree) == NULL) {
1856 		crit_exit();
1857 		if (ngqsize < ngqroom) {	/* don't worry about races */
1858 			MALLOC(q, struct ng_queue_entry *,
1859 			    sizeof(*q), M_NETGRAPH, M_NOWAIT);
1860 		}
1861 	} else {
1862 		ngqfree = q->next;
1863 		ngqfreesize--;
1864 		crit_exit();
1865 	}
1866 	return (q);
1867 }
1868 
1869 /*
1870  * Release a queue entry
1871  */
1872 #define RETURN_QBLK(q)							\
1873 do {									\
1874 	if (ngqfreesize < ngqfreemax) { /* don't worry about races */ 	\
1875 		crit_enter();						\
1876 		(q)->next = ngqfree;					\
1877 		ngqfree = (q);						\
1878 		ngqfreesize++;						\
1879 		crit_exit();						\
1880 	} else {							\
1881 		FREE((q), M_NETGRAPH);					\
1882 	}								\
1883 } while (0)
1884 
1885 /*
1886  * Running at a raised (but we don't know which) processor priority level,
1887  * put the data onto a queue to be picked up by another PPL (probably splnet)
1888  */
1889 int
1890 ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
1891 {
1892 	struct ng_queue_entry *q;
1893 
1894 	if (hook == NULL) {
1895 		NG_FREE_DATA(m, meta);
1896 		return (0);
1897 	}
1898 	if ((q = ng_getqblk()) == NULL) {
1899 		NG_FREE_DATA(m, meta);
1900 		return (ENOBUFS);
1901 	}
1902 
1903 	/* Fill out the contents */
1904 	q->flags = NGQF_DATA;
1905 	q->next = NULL;
1906 	q->body.data.da_hook = hook;
1907 	q->body.data.da_m = m;
1908 	q->body.data.da_meta = meta;
1909 	crit_enter();		/* protect refs and queue */
1910 	hook->refs++;		/* don't let it go away while on the queue */
1911 
1912 	/* Put it on the queue */
1913 	if (ngqbase) {
1914 		ngqlast->next = q;
1915 	} else {
1916 		ngqbase = q;
1917 	}
1918 	ngqlast = q;
1919 	ngqsize++;
1920 	crit_exit();
1921 
1922 	/* Schedule software interrupt to handle it later */
1923 	schednetisr(NETISR_NETGRAPH);
1924 	return (0);
1925 }
1926 
1927 /*
1928  * Running at a raised (but we don't know which) processor priority level,
1929  * put the msg onto a queue to be picked up by another PPL (probably splnet)
1930  */
1931 int
1932 ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address)
1933 {
1934 	struct ng_queue_entry *q;
1935 	node_p  dest = NULL;
1936 	char   *retaddr = NULL;
1937 	int     error;
1938 
1939 	/* Find the target node. */
1940 	error = ng_path2node(here, address, &dest, &retaddr);
1941 	if (error) {
1942 		FREE(msg, M_NETGRAPH);
1943 		return (error);
1944 	}
1945 	if ((q = ng_getqblk()) == NULL) {
1946 		FREE(msg, M_NETGRAPH);
1947 		if (retaddr)
1948 			FREE(retaddr, M_NETGRAPH);
1949 		return (ENOBUFS);
1950 	}
1951 
1952 	/* Fill out the contents */
1953 	q->flags = NGQF_MESG;
1954 	q->next = NULL;
1955 	q->body.msg.msg_node = dest;
1956 	q->body.msg.msg_msg = msg;
1957 	q->body.msg.msg_retaddr = retaddr;
1958 	crit_enter();		/* protect refs and queue */
1959 	dest->refs++;		/* don't let it go away while on the queue */
1960 
1961 	/* Put it on the queue */
1962 	if (ngqbase) {
1963 		ngqlast->next = q;
1964 	} else {
1965 		ngqbase = q;
1966 	}
1967 	ngqlast = q;
1968 	ngqsize++;
1969 	crit_exit();
1970 
1971 	/* Schedule software interrupt to handle it later */
1972 	schednetisr(NETISR_NETGRAPH);
1973 	return (0);
1974 }
1975 
1976 /*
1977  * Pick an item off the queue, process it, and dispose of the queue entry.
1978  * Should be running at splnet.
1979  */
1980 static int
1981 ngintr(struct netmsg *pmsg)
1982 {
1983 	struct mbuf *m = ((struct netmsg_packet *)pmsg)->nm_packet;
1984 	hook_p  hook;
1985 	struct ng_queue_entry *ngq;
1986 	meta_p  meta;
1987 	void   *retaddr;
1988 	struct ng_mesg *msg;
1989 	node_p  node;
1990 	int     error = 0;
1991 
1992 	while (1) {
1993 		crit_enter();
1994 		if ((ngq = ngqbase)) {
1995 			ngqbase = ngq->next;
1996 			ngqsize--;
1997 		}
1998 		crit_exit();
1999 		if (ngq == NULL)
2000 			goto out;
2001 		switch (ngq->flags) {
2002 		case NGQF_DATA:
2003 			hook = ngq->body.data.da_hook;
2004 			m = ngq->body.data.da_m;
2005 			meta = ngq->body.data.da_meta;
2006 			RETURN_QBLK(ngq);
2007 			NG_SEND_DATAQ(error, hook, m, meta);
2008 			ng_unref_hook(hook);
2009 			break;
2010 		case NGQF_MESG:
2011 			node = ngq->body.msg.msg_node;
2012 			msg = ngq->body.msg.msg_msg;
2013 			retaddr = ngq->body.msg.msg_retaddr;
2014 			RETURN_QBLK(ngq);
2015 			if (node->flags & NG_INVALID) {
2016 				FREE(msg, M_NETGRAPH);
2017 			} else {
2018 				CALL_MSG_HANDLER(error, node, msg,
2019 						 retaddr, NULL);
2020 			}
2021 			ng_unref(node);
2022 			if (retaddr)
2023 				FREE(retaddr, M_NETGRAPH);
2024 			break;
2025 		default:
2026 			RETURN_QBLK(ngq);
2027 		}
2028 	}
2029 out:
2030 	lwkt_replymsg(&pmsg->nm_lmsg, 0);
2031 	return(EASYNC);
2032 }
2033 
2034 
2035