xref: /dragonfly/sys/netgraph/netgraph/ng_base.c (revision b1e9d17a)
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 1.17 2005/08/30 14:22:05 y0netan1 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 static int	ng_load_module(const char *);
92 static int	ng_unload_module(const char *);
93 
94 /* Our own netgraph malloc type */
95 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
96 
97 /* Set this to Debugger("X") to catch all errors as they occur */
98 #ifndef TRAP_ERROR
99 #define TRAP_ERROR
100 #endif
101 
102 static	ng_ID_t nextID = 1;
103 
104 #ifdef INVARIANTS
105 #define CHECK_DATA_MBUF(m)	do {					\
106 		struct mbuf *n;						\
107 		int total;						\
108 									\
109 		if (((m)->m_flags & M_PKTHDR) == 0)			\
110 			panic("%s: !PKTHDR", __func__);		\
111 		for (total = 0, n = (m); n != NULL; n = n->m_next)	\
112 			total += n->m_len;				\
113 		if ((m)->m_pkthdr.len != total) {			\
114 			panic("%s: %d != %d",				\
115 			    __func__, (m)->m_pkthdr.len, total);	\
116 		}							\
117 	} while (0)
118 #else
119 #define CHECK_DATA_MBUF(m)
120 #endif
121 
122 
123 /************************************************************************
124 	Parse type definitions for generic messages
125 ************************************************************************/
126 
127 /* Handy structure parse type defining macro */
128 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
129 static const struct ng_parse_struct_field				\
130 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
131 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
132 	&ng_parse_struct_type,						\
133 	&ng_ ## lo ## _type_fields					\
134 }
135 
136 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
137 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
138 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
139 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
140 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
141 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
142 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
143 
144 /* Get length of an array when the length is stored as a 32 bit
145    value immediately preceeding the array -- as with struct namelist
146    and struct typelist. */
147 static int
148 ng_generic_list_getLength(const struct ng_parse_type *type,
149 	const u_char *start, const u_char *buf)
150 {
151 	return *((const u_int32_t *)(buf - 4));
152 }
153 
154 /* Get length of the array of struct linkinfo inside a struct hooklist */
155 static int
156 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
157 	const u_char *start, const u_char *buf)
158 {
159 	const struct hooklist *hl = (const struct hooklist *)start;
160 
161 	return hl->nodeinfo.hooks;
162 }
163 
164 /* Array type for a variable length array of struct namelist */
165 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
166 	&ng_generic_nodeinfo_type,
167 	&ng_generic_list_getLength
168 };
169 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
170 	&ng_parse_array_type,
171 	&ng_nodeinfoarray_type_info
172 };
173 
174 /* Array type for a variable length array of struct typelist */
175 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
176 	&ng_generic_typeinfo_type,
177 	&ng_generic_list_getLength
178 };
179 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
180 	&ng_parse_array_type,
181 	&ng_typeinfoarray_type_info
182 };
183 
184 /* Array type for array of struct linkinfo in struct hooklist */
185 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
186 	&ng_generic_linkinfo_type,
187 	&ng_generic_linkinfo_getLength
188 };
189 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
190 	&ng_parse_array_type,
191 	&ng_generic_linkinfo_array_type_info
192 };
193 
194 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
195 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
196 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
197 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
198 	(&ng_generic_nodeinfoarray_type));
199 
200 /* List of commands and how to convert arguments to/from ASCII */
201 static const struct ng_cmdlist ng_generic_cmds[] = {
202 	{
203 	  NGM_GENERIC_COOKIE,
204 	  NGM_SHUTDOWN,
205 	  "shutdown",
206 	  NULL,
207 	  NULL
208 	},
209 	{
210 	  NGM_GENERIC_COOKIE,
211 	  NGM_MKPEER,
212 	  "mkpeer",
213 	  &ng_generic_mkpeer_type,
214 	  NULL
215 	},
216 	{
217 	  NGM_GENERIC_COOKIE,
218 	  NGM_CONNECT,
219 	  "connect",
220 	  &ng_generic_connect_type,
221 	  NULL
222 	},
223 	{
224 	  NGM_GENERIC_COOKIE,
225 	  NGM_NAME,
226 	  "name",
227 	  &ng_generic_name_type,
228 	  NULL
229 	},
230 	{
231 	  NGM_GENERIC_COOKIE,
232 	  NGM_RMHOOK,
233 	  "rmhook",
234 	  &ng_generic_rmhook_type,
235 	  NULL
236 	},
237 	{
238 	  NGM_GENERIC_COOKIE,
239 	  NGM_NODEINFO,
240 	  "nodeinfo",
241 	  NULL,
242 	  &ng_generic_nodeinfo_type
243 	},
244 	{
245 	  NGM_GENERIC_COOKIE,
246 	  NGM_LISTHOOKS,
247 	  "listhooks",
248 	  NULL,
249 	  &ng_generic_hooklist_type
250 	},
251 	{
252 	  NGM_GENERIC_COOKIE,
253 	  NGM_LISTNAMES,
254 	  "listnames",
255 	  NULL,
256 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
257 	},
258 	{
259 	  NGM_GENERIC_COOKIE,
260 	  NGM_LISTNODES,
261 	  "listnodes",
262 	  NULL,
263 	  &ng_generic_listnodes_type
264 	},
265 	{
266 	  NGM_GENERIC_COOKIE,
267 	  NGM_LISTTYPES,
268 	  "listtypes",
269 	  NULL,
270 	  &ng_generic_typeinfo_type
271 	},
272 	{
273 	  NGM_GENERIC_COOKIE,
274 	  NGM_TEXT_CONFIG,
275 	  "textconfig",
276 	  NULL,
277 	  &ng_parse_string_type
278 	},
279 	{
280 	  NGM_GENERIC_COOKIE,
281 	  NGM_TEXT_STATUS,
282 	  "textstatus",
283 	  NULL,
284 	  &ng_parse_string_type
285 	},
286 	{
287 	  NGM_GENERIC_COOKIE,
288 	  NGM_ASCII2BINARY,
289 	  "ascii2binary",
290 	  &ng_parse_ng_mesg_type,
291 	  &ng_parse_ng_mesg_type
292 	},
293 	{
294 	  NGM_GENERIC_COOKIE,
295 	  NGM_BINARY2ASCII,
296 	  "binary2ascii",
297 	  &ng_parse_ng_mesg_type,
298 	  &ng_parse_ng_mesg_type
299 	},
300 	{ 0 }
301 };
302 
303 /************************************************************************
304 			Node routines
305 ************************************************************************/
306 
307 static int
308 ng_load_module(const char *name)
309 {
310 	char *path, filename[NG_TYPELEN + 4];
311 	linker_file_t lf;
312 	int error;
313 
314 	/* linker_* API won't work without a process context */
315 	if (curproc == NULL)
316 		return (ENXIO);
317 
318 	/* Not found, try to load it as a loadable module */
319 	snprintf(filename, sizeof(filename), "ng_%s.ko", name);
320 	if ((path = linker_search_path(filename)) == NULL)
321 		return (ENXIO);
322 	error = linker_load_file(path, &lf);
323 	FREE(path, M_LINKER);
324 	if (error == 0)
325 		lf->userrefs++;		/* pretend kldload'ed */
326 	return (error);
327 }
328 
329 static int
330 ng_unload_module(const char *name)
331 {
332 	char filename[NG_TYPELEN + 4];
333 	linker_file_t lf;
334 	int error;
335 
336 	/* linker_* API won't work without a process context */
337 	if (curproc == NULL)
338 		return (ENXIO);
339 
340 	/* Not found, try to load it as a loadable module */
341 	snprintf(filename, sizeof(filename), "ng_%s.ko", name);
342 	if ((lf = linker_find_file_by_name(filename)) == NULL)
343 		return (ENXIO);
344 	error = linker_file_unload(lf);
345 
346 	if (error == 0)
347 		lf->userrefs--;		/* pretend kldunload'ed */
348 	return (error);
349 }
350 
351 /*
352  * Instantiate a node of the requested type
353  */
354 int
355 ng_make_node(const char *typename, node_p *nodepp)
356 {
357 	struct ng_type *type;
358 
359 	/* Check that the type makes sense */
360 	if (typename == NULL) {
361 		TRAP_ERROR;
362 		return (EINVAL);
363 	}
364 
365 	/* Locate the node type */
366 	if ((type = ng_findtype(typename)) == NULL)
367 		return (ENXIO);
368 
369 	/* Call the constructor */
370 	if (type->constructor != NULL)
371 		return ((*type->constructor)(nodepp));
372 	else
373 		return (ng_make_node_common(type, nodepp));
374 }
375 
376 /*
377  * Generic node creation. Called by node constructors.
378  * The returned node has a reference count of 1.
379  */
380 int
381 ng_make_node_common(struct ng_type *type, node_p *nodepp)
382 {
383 	node_p node;
384 
385 	/* Require the node type to have been already installed */
386 	if (ng_findtype(type->name) == NULL) {
387 		TRAP_ERROR;
388 		return (EINVAL);
389 	}
390 
391 	/* Make a node and try attach it to the type */
392 	MALLOC(node, node_p, sizeof(*node), M_NETGRAPH, M_NOWAIT);
393 	if (node == NULL) {
394 		TRAP_ERROR;
395 		return (ENOMEM);
396 	}
397 	bzero(node, sizeof(*node));
398 	node->type = type;
399 	node->refs++;				/* note reference */
400 	type->refs++;
401 
402 	/* Link us into the node linked list */
403 	LIST_INSERT_HEAD(&nodelist, node, nodes);
404 
405 	/* Initialize hook list for new node */
406 	LIST_INIT(&node->hooks);
407 
408 	/* get an ID and put us in the hash chain */
409 	node->ID = nextID++; /* 137 per second for 1 year before wrap */
410 	LIST_INSERT_HEAD(&ID_hash[node->ID % ID_HASH_SIZE], node, idnodes);
411 
412 	/* Done */
413 	*nodepp = node;
414 	return (0);
415 }
416 
417 /*
418  * Forceably start the shutdown process on a node. Either call
419  * it's shutdown method, or do the default shutdown if there is
420  * no type-specific method.
421  *
422  * Persistent nodes must have a type-specific method which
423  * resets the NG_INVALID flag.
424  */
425 void
426 ng_rmnode(node_p node)
427 {
428 	/* Check if it's already shutting down */
429 	if ((node->flags & NG_INVALID) != 0)
430 		return;
431 
432 	/* Add an extra reference so it doesn't go away during this */
433 	node->refs++;
434 
435 	/* Mark it invalid so any newcomers know not to try use it */
436 	node->flags |= NG_INVALID;
437 
438 	/* Ask the type if it has anything to do in this case */
439 	if (node->type && node->type->shutdown)
440 		(*node->type->shutdown)(node);
441 	else {				/* do the default thing */
442 		ng_unname(node);
443 		ng_cutlinks(node);
444 		ng_unref(node);
445 	}
446 
447 	/* Remove extra reference, possibly the last */
448 	ng_unref(node);
449 }
450 
451 /*
452  * Called by the destructor to remove any STANDARD external references
453  */
454 void
455 ng_cutlinks(node_p node)
456 {
457 	hook_p  hook;
458 
459 	/* Make sure that this is set to stop infinite loops */
460 	node->flags |= NG_INVALID;
461 
462 	/* If we have sleepers, wake them up; they'll see NG_INVALID */
463 	if (node->sleepers)
464 		wakeup(node);
465 
466 	/* Notify all remaining connected nodes to disconnect */
467 	while ((hook = LIST_FIRST(&node->hooks)) != NULL)
468 		ng_destroy_hook(hook);
469 }
470 
471 /*
472  * Remove a reference to the node, possibly the last
473  */
474 void
475 ng_unref(node_p node)
476 {
477 	crit_enter();
478 	if (--node->refs <= 0) {
479 		node->type->refs--;
480 		LIST_REMOVE(node, nodes);
481 		LIST_REMOVE(node, idnodes);
482 		FREE(node, M_NETGRAPH);
483 	}
484 	crit_exit();
485 }
486 
487 /*
488  * Wait for a node to come ready. Returns a node with a reference count;
489  * don't forget to drop it when we are done with it using ng_release_node().
490  */
491 int
492 ng_wait_node(node_p node, char *msg)
493 {
494 	int error = 0;
495 
496 	if (msg == NULL)
497 		msg = "netgraph";
498 	crit_enter();
499 	node->sleepers++;
500 	node->refs++;		/* the sleeping process counts as a reference */
501 	while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
502 		error = tsleep(node, PCATCH, msg, 0);
503 	node->sleepers--;
504 	if (node->flags & NG_INVALID) {
505 		TRAP_ERROR;
506 		error = ENXIO;
507 	} else {
508 		KASSERT(node->refs > 1,
509 		    ("%s: refs=%d", __func__, node->refs));
510 		node->flags |= NG_BUSY;
511 	}
512 	crit_exit();
513 
514 	/* Release the reference we had on it */
515 	if (error != 0)
516 		ng_unref(node);
517 	return error;
518 }
519 
520 /*
521  * Release a node acquired via ng_wait_node()
522  */
523 void
524 ng_release_node(node_p node)
525 {
526 	/* Declare that we don't want it */
527 	node->flags &= ~NG_BUSY;
528 
529 	/* If we have sleepers, then wake them up */
530 	if (node->sleepers)
531 		wakeup(node);
532 
533 	/* We also have a reference.. drop it too */
534 	ng_unref(node);
535 }
536 
537 /************************************************************************
538 			Node ID handling
539 ************************************************************************/
540 static node_p
541 ng_ID2node(ng_ID_t ID)
542 {
543 	node_p np;
544 	LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
545 		if ((np->flags & NG_INVALID) == 0 && np->ID == ID)
546 			break;
547 	}
548 	return(np);
549 }
550 
551 ng_ID_t
552 ng_node2ID(node_p node)
553 {
554 	return (node->ID);
555 }
556 
557 /************************************************************************
558 			Node name handling
559 ************************************************************************/
560 
561 /*
562  * Assign a node a name. Once assigned, the name cannot be changed.
563  */
564 int
565 ng_name_node(node_p node, const char *name)
566 {
567 	int i;
568 
569 	/* Check the name is valid */
570 	for (i = 0; i < NG_NODELEN + 1; i++) {
571 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
572 			break;
573 	}
574 	if (i == 0 || name[i] != '\0') {
575 		TRAP_ERROR;
576 		return (EINVAL);
577 	}
578 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
579 		TRAP_ERROR;
580 		return (EINVAL);
581 	}
582 
583 	/* Check the node isn't already named */
584 	if (node->name != NULL) {
585 		TRAP_ERROR;
586 		return (EISCONN);
587 	}
588 
589 	/* Check the name isn't already being used */
590 	if (ng_findname(node, name) != NULL) {
591 		TRAP_ERROR;
592 		return (EADDRINUSE);
593 	}
594 
595 	/* Allocate space and copy it */
596 	MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
597 	if (node->name == NULL) {
598 		TRAP_ERROR;
599 		return (ENOMEM);
600 	}
601 	strcpy(node->name, name);
602 
603 	/* The name counts as a reference */
604 	node->refs++;
605 	return (0);
606 }
607 
608 /*
609  * Find a node by absolute name. The name should NOT end with ':'
610  * The name "." means "this node" and "[xxx]" means "the node
611  * with ID (ie, at address) xxx".
612  *
613  * Returns the node if found, else NULL.
614  */
615 node_p
616 ng_findname(node_p this, const char *name)
617 {
618 	node_p node;
619 	ng_ID_t temp;
620 
621 	/* "." means "this node" */
622 	if (strcmp(name, ".") == 0)
623 		return(this);
624 
625 	/* Check for name-by-ID */
626 	if ((temp = ng_decodeidname(name)) != 0) {
627 		return (ng_ID2node(temp));
628 	}
629 
630 	/* Find node by name */
631 	LIST_FOREACH(node, &nodelist, nodes) {
632 		if ((node->name != NULL)
633 		&& (strcmp(node->name, name) == 0)
634 		&& ((node->flags & NG_INVALID) == 0))
635 			break;
636 	}
637 	return (node);
638 }
639 
640 /*
641  * Decode a ID name, eg. "[f03034de]". Returns 0 if the
642  * string is not valid, otherwise returns the value.
643  */
644 static ng_ID_t
645 ng_decodeidname(const char *name)
646 {
647 	const int len = strlen(name);
648 	char *eptr;
649 	u_long val;
650 
651 	/* Check for proper length, brackets, no leading junk */
652 	if (len < 3 || name[0] != '[' || name[len - 1] != ']'
653 	    || !isxdigit(name[1]))
654 		return (0);
655 
656 	/* Decode number */
657 	val = strtoul(name + 1, &eptr, 16);
658 	if (eptr - name != len - 1 || val == ULONG_MAX || val == 0)
659 		return ((ng_ID_t)0);
660 	return (ng_ID_t)val;
661 }
662 
663 /*
664  * Remove a name from a node. This should only be called
665  * when shutting down and removing the node.
666  */
667 void
668 ng_unname(node_p node)
669 {
670 	if (node->name) {
671 		FREE(node->name, M_NETGRAPH);
672 		node->name = NULL;
673 		ng_unref(node);
674 	}
675 }
676 
677 /************************************************************************
678 			Hook routines
679 
680  Names are not optional. Hooks are always connected, except for a
681  brief moment within these routines.
682 
683 ************************************************************************/
684 
685 /*
686  * Remove a hook reference
687  */
688 void
689 ng_unref_hook(hook_p hook)
690 {
691 	crit_enter();
692 	if (--hook->refs == 0)
693 		FREE(hook, M_NETGRAPH);
694 	crit_exit();
695 }
696 
697 /*
698  * Add an unconnected hook to a node. Only used internally.
699  */
700 static int
701 ng_add_hook(node_p node, const char *name, hook_p *hookp)
702 {
703 	hook_p hook;
704 	int error = 0;
705 
706 	/* Check that the given name is good */
707 	if (name == NULL) {
708 		TRAP_ERROR;
709 		return (EINVAL);
710 	}
711 	if (ng_findhook(node, name) != NULL) {
712 		TRAP_ERROR;
713 		return (EEXIST);
714 	}
715 
716 	/* Allocate the hook and link it up */
717 	MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_NOWAIT);
718 	if (hook == NULL) {
719 		TRAP_ERROR;
720 		return (ENOMEM);
721 	}
722 	bzero(hook, sizeof(*hook));
723 	hook->refs = 1;
724 	hook->flags = HK_INVALID;
725 	hook->node = node;
726 	node->refs++;		/* each hook counts as a reference */
727 
728 	/* Check if the node type code has something to say about it */
729 	if (node->type->newhook != NULL)
730 		if ((error = (*node->type->newhook)(node, hook, name)) != 0)
731 			goto fail;
732 
733 	/*
734 	 * The 'type' agrees so far, so go ahead and link it in.
735 	 * We'll ask again later when we actually connect the hooks.
736 	 */
737 	LIST_INSERT_HEAD(&node->hooks, hook, hooks);
738 	node->numhooks++;
739 
740 	/* Set hook name */
741 	MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
742 	if (hook->name == NULL) {
743 		error = ENOMEM;
744 		LIST_REMOVE(hook, hooks);
745 		node->numhooks--;
746 fail:
747 		hook->node = NULL;
748 		ng_unref(node);
749 		ng_unref_hook(hook);	/* this frees the hook */
750 		return (error);
751 	}
752 	strcpy(hook->name, name);
753 	if (hookp)
754 		*hookp = hook;
755 	return (error);
756 }
757 
758 /*
759  * Connect a pair of hooks. Only used internally.
760  */
761 static int
762 ng_connect(hook_p hook1, hook_p hook2)
763 {
764 	int     error;
765 
766 	hook1->peer = hook2;
767 	hook2->peer = hook1;
768 
769 	/* Give each node the opportunity to veto the impending connection */
770 	if (hook1->node->type->connect) {
771 		if ((error = (*hook1->node->type->connect) (hook1))) {
772 			ng_destroy_hook(hook1);	/* also zaps hook2 */
773 			return (error);
774 		}
775 	}
776 	if (hook2->node->type->connect) {
777 		if ((error = (*hook2->node->type->connect) (hook2))) {
778 			ng_destroy_hook(hook2);	/* also zaps hook1 */
779 			return (error);
780 		}
781 	}
782 	hook1->flags &= ~HK_INVALID;
783 	hook2->flags &= ~HK_INVALID;
784 	return (0);
785 }
786 
787 /*
788  * Find a hook
789  *
790  * Node types may supply their own optimized routines for finding
791  * hooks.  If none is supplied, we just do a linear search.
792  */
793 hook_p
794 ng_findhook(node_p node, const char *name)
795 {
796 	hook_p hook;
797 
798 	if (node->type->findhook != NULL)
799 		return (*node->type->findhook)(node, name);
800 	LIST_FOREACH(hook, &node->hooks, hooks) {
801 		if (hook->name != NULL
802 		    && strcmp(hook->name, name) == 0
803 		    && (hook->flags & HK_INVALID) == 0)
804 			return (hook);
805 	}
806 	return (NULL);
807 }
808 
809 /*
810  * Destroy a hook
811  *
812  * As hooks are always attached, this really destroys two hooks.
813  * The one given, and the one attached to it. Disconnect the hooks
814  * from each other first.
815  */
816 void
817 ng_destroy_hook(hook_p hook)
818 {
819 	hook_p peer = hook->peer;
820 
821 	hook->flags |= HK_INVALID;		/* as soon as possible */
822 	if (peer) {
823 		peer->flags |= HK_INVALID;	/* as soon as possible */
824 		hook->peer = NULL;
825 		peer->peer = NULL;
826 		ng_disconnect_hook(peer);
827 	}
828 	ng_disconnect_hook(hook);
829 }
830 
831 /*
832  * Notify the node of the hook's demise. This may result in more actions
833  * (e.g. shutdown) but we don't do that ourselves and don't know what
834  * happens there. If there is no appropriate handler, then just remove it
835  * (and decrement the reference count of it's node which in turn might
836  * make something happen).
837  */
838 static void
839 ng_disconnect_hook(hook_p hook)
840 {
841 	node_p node = hook->node;
842 
843 	/*
844 	 * Remove the hook from the node's list to avoid possible recursion
845 	 * in case the disconnection results in node shutdown.
846 	 */
847 	LIST_REMOVE(hook, hooks);
848 	node->numhooks--;
849 	if (node->type->disconnect) {
850 		/*
851 		 * The type handler may elect to destroy the peer so don't
852 		 * trust its existance after this point.
853 		 */
854 		(*node->type->disconnect) (hook);
855 	}
856 	ng_unref(node);		/* might be the last reference */
857 	if (hook->name)
858 		FREE(hook->name, M_NETGRAPH);
859 	hook->node = NULL;	/* may still be referenced elsewhere */
860 	ng_unref_hook(hook);
861 }
862 
863 /*
864  * Take two hooks on a node and merge the connection so that the given node
865  * is effectively bypassed.
866  */
867 int
868 ng_bypass(hook_p hook1, hook_p hook2)
869 {
870 	if (hook1->node != hook2->node)
871 		return (EINVAL);
872 	hook1->peer->peer = hook2->peer;
873 	hook2->peer->peer = hook1->peer;
874 
875 	/* XXX If we ever cache methods on hooks update them as well */
876 	hook1->peer = NULL;
877 	hook2->peer = NULL;
878 	ng_destroy_hook(hook1);
879 	ng_destroy_hook(hook2);
880 	return (0);
881 }
882 
883 /*
884  * Install a new netgraph type
885  */
886 int
887 ng_newtype(struct ng_type *tp)
888 {
889 	const size_t namelen = strlen(tp->name);
890 
891 	/* Check version and type name fields */
892 	if (tp->version != NG_VERSION || namelen == 0 || namelen > NG_TYPELEN) {
893 		TRAP_ERROR;
894 		return (EINVAL);
895 	}
896 
897 	/* Check for name collision */
898 	if (ng_findtype(tp->name) != NULL) {
899 		TRAP_ERROR;
900 		return (EEXIST);
901 	}
902 
903 	/* Link in new type */
904 	LIST_INSERT_HEAD(&typelist, tp, types);
905 	tp->refs = 1;	/* first ref is linked list */
906 	return (0);
907 }
908 
909 /*
910  * Look for a type of the name given
911  */
912 struct ng_type *
913 ng_findtype(const char *typename)
914 {
915 	struct ng_type *type;
916 
917 	LIST_FOREACH(type, &typelist, types) {
918 		if (strcmp(type->name, typename) == 0)
919 			break;
920 	}
921 	return (type);
922 }
923 
924 
925 /************************************************************************
926 			Composite routines
927 ************************************************************************/
928 
929 /*
930  * Make a peer and connect. The order is arranged to minimise
931  * the work needed to back out in case of error.
932  */
933 int
934 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
935 {
936 	node_p  node2;
937 	hook_p  hook;
938 	hook_p  hook2;
939 	int     error;
940 
941 	if ((error = ng_add_hook(node, name, &hook)))
942 		return (error);
943 
944 	/* make sure we have the module needed */
945 	if (ng_findtype(type) == NULL) {
946 		/* Not found, try to load it as a loadable module */
947 		error = ng_load_module(type);
948 		if (error != 0) {
949 			printf("required netgraph module ng_%s not loaded\n",
950 			    type);
951 			return (error);
952 		}
953 	}
954 	if ((error = ng_make_node(type, &node2))) {
955 		ng_destroy_hook(hook);
956 		return (error);
957 	}
958 	if ((error = ng_add_hook(node2, name2, &hook2))) {
959 		ng_rmnode(node2);
960 		ng_destroy_hook(hook);
961 		return (error);
962 	}
963 
964 	/*
965 	 * Actually link the two hooks together.. on failure they are
966 	 * destroyed so we don't have to do that here.
967 	 */
968 	if ((error = ng_connect(hook, hook2)))
969 		ng_rmnode(node2);
970 	return (error);
971 }
972 
973 /*
974  * Connect two nodes using the specified hooks
975  */
976 int
977 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
978 {
979 	int     error;
980 	hook_p  hook;
981 	hook_p  hook2;
982 
983 	if ((error = ng_add_hook(node, name, &hook)))
984 		return (error);
985 	if ((error = ng_add_hook(node2, name2, &hook2))) {
986 		ng_destroy_hook(hook);
987 		return (error);
988 	}
989 	return (ng_connect(hook, hook2));
990 }
991 
992 /*
993  * Parse and verify a string of the form:  <NODE:><PATH>
994  *
995  * Such a string can refer to a specific node or a specific hook
996  * on a specific node, depending on how you look at it. In the
997  * latter case, the PATH component must not end in a dot.
998  *
999  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1000  * of hook names separated by dots. This breaks out the original
1001  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1002  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1003  * the final hook component of <PATH>, if any, otherwise NULL.
1004  *
1005  * This returns -1 if the path is malformed. The char ** are optional.
1006  */
1007 
1008 int
1009 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1010 {
1011 	char   *node, *path, *hook;
1012 	int     k;
1013 
1014 	/*
1015 	 * Extract absolute NODE, if any
1016 	 */
1017 	for (path = addr; *path && *path != ':'; path++);
1018 	if (*path) {
1019 		node = addr;	/* Here's the NODE */
1020 		*path++ = '\0';	/* Here's the PATH */
1021 
1022 		/* Node name must not be empty */
1023 		if (!*node)
1024 			return -1;
1025 
1026 		/* A name of "." is OK; otherwise '.' not allowed */
1027 		if (strcmp(node, ".") != 0) {
1028 			for (k = 0; node[k]; k++)
1029 				if (node[k] == '.')
1030 					return -1;
1031 		}
1032 	} else {
1033 		node = NULL;	/* No absolute NODE */
1034 		path = addr;	/* Here's the PATH */
1035 	}
1036 
1037 	/* Snoop for illegal characters in PATH */
1038 	for (k = 0; path[k]; k++)
1039 		if (path[k] == ':')
1040 			return -1;
1041 
1042 	/* Check for no repeated dots in PATH */
1043 	for (k = 0; path[k]; k++)
1044 		if (path[k] == '.' && path[k + 1] == '.')
1045 			return -1;
1046 
1047 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1048 	if (path[0] == '.')
1049 		path++;
1050 	if (*path && path[strlen(path) - 1] == '.')
1051 		path[strlen(path) - 1] = 0;
1052 
1053 	/* If PATH has a dot, then we're not talking about a hook */
1054 	if (*path) {
1055 		for (hook = path, k = 0; path[k]; k++)
1056 			if (path[k] == '.') {
1057 				hook = NULL;
1058 				break;
1059 			}
1060 	} else
1061 		path = hook = NULL;
1062 
1063 	/* Done */
1064 	if (nodep)
1065 		*nodep = node;
1066 	if (pathp)
1067 		*pathp = path;
1068 	if (hookp)
1069 		*hookp = hook;
1070 	return (0);
1071 }
1072 
1073 /*
1074  * Given a path, which may be absolute or relative, and a starting node,
1075  * return the destination node. Compute the "return address" if desired.
1076  */
1077 int
1078 ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
1079 {
1080 	const	node_p start = here;
1081 	char    fullpath[NG_PATHLEN + 1];
1082 	char   *nodename, *path, pbuf[2];
1083 	node_p  node;
1084 	char   *cp;
1085 
1086 	/* Initialize */
1087 	if (rtnp)
1088 		*rtnp = NULL;
1089 	if (destp == NULL)
1090 		return EINVAL;
1091 	*destp = NULL;
1092 
1093 	/* Make a writable copy of address for ng_path_parse() */
1094 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1095 	fullpath[sizeof(fullpath) - 1] = '\0';
1096 
1097 	/* Parse out node and sequence of hooks */
1098 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1099 		TRAP_ERROR;
1100 		return EINVAL;
1101 	}
1102 	if (path == NULL) {
1103 		pbuf[0] = '.';	/* Needs to be writable */
1104 		pbuf[1] = '\0';
1105 		path = pbuf;
1106 	}
1107 
1108 	/* For an absolute address, jump to the starting node */
1109 	if (nodename) {
1110 		node = ng_findname(here, nodename);
1111 		if (node == NULL) {
1112 			TRAP_ERROR;
1113 			return (ENOENT);
1114 		}
1115 	} else
1116 		node = here;
1117 
1118 	/* Now follow the sequence of hooks */
1119 	for (cp = path; node != NULL && *cp != '\0'; ) {
1120 		hook_p hook;
1121 		char *segment;
1122 
1123 		/*
1124 		 * Break out the next path segment. Replace the dot we just
1125 		 * found with a NUL; "cp" points to the next segment (or the
1126 		 * NUL at the end).
1127 		 */
1128 		for (segment = cp; *cp != '\0'; cp++) {
1129 			if (*cp == '.') {
1130 				*cp++ = '\0';
1131 				break;
1132 			}
1133 		}
1134 
1135 		/* Empty segment */
1136 		if (*segment == '\0')
1137 			continue;
1138 
1139 		/* We have a segment, so look for a hook by that name */
1140 		hook = ng_findhook(node, segment);
1141 
1142 		/* Can't get there from here... */
1143 		if (hook == NULL
1144 		    || hook->peer == NULL
1145 		    || (hook->flags & HK_INVALID) != 0) {
1146 			TRAP_ERROR;
1147 			return (ENOENT);
1148 		}
1149 
1150 		/* Hop on over to the next node */
1151 		node = hook->peer->node;
1152 	}
1153 
1154 	/* If node somehow missing, fail here (probably this is not needed) */
1155 	if (node == NULL) {
1156 		TRAP_ERROR;
1157 		return (ENXIO);
1158 	}
1159 
1160 	/* Now compute return address, i.e., the path to the sender */
1161 	if (rtnp != NULL) {
1162 		MALLOC(*rtnp, char *, NG_NODELEN + 2, M_NETGRAPH, M_NOWAIT);
1163 		if (*rtnp == NULL) {
1164 			TRAP_ERROR;
1165 			return (ENOMEM);
1166 		}
1167 		if (start->name != NULL)
1168 			sprintf(*rtnp, "%s:", start->name);
1169 		else
1170 			sprintf(*rtnp, "[%x]:", ng_node2ID(start));
1171 	}
1172 
1173 	/* Done */
1174 	*destp = node;
1175 	return (0);
1176 }
1177 
1178 /*
1179  * Call the appropriate message handler for the object.
1180  * It is up to the message handler to free the message.
1181  * If it's a generic message, handle it generically, otherwise
1182  * call the type's message handler (if it exists)
1183  * XXX (race). Remember that a queued message may reference a node
1184  * or hook that has just been invalidated. It will exist
1185  * as the queue code is holding a reference, but..
1186  */
1187 
1188 #define CALL_MSG_HANDLER(error, node, msg, retaddr, resp)		\
1189 do {									\
1190 	if((msg)->header.typecookie == NGM_GENERIC_COOKIE) {		\
1191 		(error) = ng_generic_msg((node), (msg),			\
1192 				(retaddr), (resp));			\
1193 	} else {							\
1194 		if ((node)->type->rcvmsg != NULL) {			\
1195 			(error) = (*(node)->type->rcvmsg)((node),	\
1196 					(msg), (retaddr), (resp));	\
1197 		} else {						\
1198 			TRAP_ERROR;					\
1199 			FREE((msg), M_NETGRAPH);			\
1200 			(error) = EINVAL;				\
1201 		}							\
1202 	}								\
1203 } while (0)
1204 
1205 
1206 /*
1207  * Send a control message to a node
1208  */
1209 int
1210 ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
1211 	    struct ng_mesg **rptr)
1212 {
1213 	node_p  dest = NULL;
1214 	char   *retaddr = NULL;
1215 	int     error;
1216 
1217 	/* Find the target node */
1218 	error = ng_path2node(here, address, &dest, &retaddr);
1219 	if (error) {
1220 		FREE(msg, M_NETGRAPH);
1221 		return error;
1222 	}
1223 
1224 	/* Make sure the resp field is null before we start */
1225 	if (rptr != NULL)
1226 		*rptr = NULL;
1227 
1228 	CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
1229 
1230 	/* Make sure that if there is a response, it has the RESP bit set */
1231 	if ((error == 0) && rptr && *rptr)
1232 		(*rptr)->header.flags |= NGF_RESP;
1233 
1234 	/*
1235 	 * If we had a return address it is up to us to free it. They should
1236 	 * have taken a copy if they needed to make a delayed response.
1237 	 */
1238 	if (retaddr)
1239 		FREE(retaddr, M_NETGRAPH);
1240 	return (error);
1241 }
1242 
1243 /*
1244  * Implement the 'generic' control messages
1245  */
1246 static int
1247 ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
1248 	       struct ng_mesg **resp)
1249 {
1250 	int error = 0;
1251 
1252 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
1253 		TRAP_ERROR;
1254 		FREE(msg, M_NETGRAPH);
1255 		return (EINVAL);
1256 	}
1257 	switch (msg->header.cmd) {
1258 	case NGM_SHUTDOWN:
1259 		ng_rmnode(here);
1260 		break;
1261 	case NGM_MKPEER:
1262 	    {
1263 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
1264 
1265 		if (msg->header.arglen != sizeof(*mkp)) {
1266 			TRAP_ERROR;
1267 			return (EINVAL);
1268 		}
1269 		mkp->type[sizeof(mkp->type) - 1] = '\0';
1270 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
1271 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
1272 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
1273 		break;
1274 	    }
1275 	case NGM_CONNECT:
1276 	    {
1277 		struct ngm_connect *const con =
1278 			(struct ngm_connect *) msg->data;
1279 		node_p node2;
1280 
1281 		if (msg->header.arglen != sizeof(*con)) {
1282 			TRAP_ERROR;
1283 			return (EINVAL);
1284 		}
1285 		con->path[sizeof(con->path) - 1] = '\0';
1286 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
1287 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
1288 		error = ng_path2node(here, con->path, &node2, NULL);
1289 		if (error)
1290 			break;
1291 		error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
1292 		break;
1293 	    }
1294 	case NGM_NAME:
1295 	    {
1296 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
1297 
1298 		if (msg->header.arglen != sizeof(*nam)) {
1299 			TRAP_ERROR;
1300 			return (EINVAL);
1301 		}
1302 		nam->name[sizeof(nam->name) - 1] = '\0';
1303 		error = ng_name_node(here, nam->name);
1304 		break;
1305 	    }
1306 	case NGM_RMHOOK:
1307 	    {
1308 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
1309 		hook_p hook;
1310 
1311 		if (msg->header.arglen != sizeof(*rmh)) {
1312 			TRAP_ERROR;
1313 			return (EINVAL);
1314 		}
1315 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
1316 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
1317 			ng_destroy_hook(hook);
1318 		break;
1319 	    }
1320 	case NGM_NODEINFO:
1321 	    {
1322 		struct nodeinfo *ni;
1323 		struct ng_mesg *rp;
1324 
1325 		/* Get response struct */
1326 		if (resp == NULL) {
1327 			error = EINVAL;
1328 			break;
1329 		}
1330 		NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
1331 		if (rp == NULL) {
1332 			error = ENOMEM;
1333 			break;
1334 		}
1335 
1336 		/* Fill in node info */
1337 		ni = (struct nodeinfo *) rp->data;
1338 		if (here->name != NULL)
1339 			strncpy(ni->name, here->name, NG_NODELEN);
1340 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1341 		ni->id = ng_node2ID(here);
1342 		ni->hooks = here->numhooks;
1343 		*resp = rp;
1344 		break;
1345 	    }
1346 	case NGM_LISTHOOKS:
1347 	    {
1348 		const int nhooks = here->numhooks;
1349 		struct hooklist *hl;
1350 		struct nodeinfo *ni;
1351 		struct ng_mesg *rp;
1352 		hook_p hook;
1353 
1354 		/* Get response struct */
1355 		if (resp == NULL) {
1356 			error = EINVAL;
1357 			break;
1358 		}
1359 		NG_MKRESPONSE(rp, msg, sizeof(*hl)
1360 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
1361 		if (rp == NULL) {
1362 			error = ENOMEM;
1363 			break;
1364 		}
1365 		hl = (struct hooklist *) rp->data;
1366 		ni = &hl->nodeinfo;
1367 
1368 		/* Fill in node info */
1369 		if (here->name)
1370 			strncpy(ni->name, here->name, NG_NODELEN);
1371 		strncpy(ni->type, here->type->name, NG_TYPELEN);
1372 		ni->id = ng_node2ID(here);
1373 
1374 		/* Cycle through the linked list of hooks */
1375 		ni->hooks = 0;
1376 		LIST_FOREACH(hook, &here->hooks, hooks) {
1377 			struct linkinfo *const link = &hl->link[ni->hooks];
1378 
1379 			if (ni->hooks >= nhooks) {
1380 				log(LOG_ERR, "%s: number of %s changed\n",
1381 				    __func__, "hooks");
1382 				break;
1383 			}
1384 			if ((hook->flags & HK_INVALID) != 0)
1385 				continue;
1386 			strncpy(link->ourhook, hook->name, NG_HOOKLEN);
1387 			strncpy(link->peerhook, hook->peer->name, NG_HOOKLEN);
1388 			if (hook->peer->node->name != NULL)
1389 				strncpy(link->nodeinfo.name,
1390 				    hook->peer->node->name, NG_NODELEN);
1391 			strncpy(link->nodeinfo.type,
1392 			   hook->peer->node->type->name, NG_TYPELEN);
1393 			link->nodeinfo.id = ng_node2ID(hook->peer->node);
1394 			link->nodeinfo.hooks = hook->peer->node->numhooks;
1395 			ni->hooks++;
1396 		}
1397 		*resp = rp;
1398 		break;
1399 	    }
1400 
1401 	case NGM_LISTNAMES:
1402 	case NGM_LISTNODES:
1403 	    {
1404 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
1405 		struct namelist *nl;
1406 		struct ng_mesg *rp;
1407 		node_p node;
1408 		int num = 0;
1409 
1410 		if (resp == NULL) {
1411 			error = EINVAL;
1412 			break;
1413 		}
1414 
1415 		/* Count number of nodes */
1416 		LIST_FOREACH(node, &nodelist, nodes) {
1417 			if ((node->flags & NG_INVALID) == 0
1418 			    && (unnamed || node->name != NULL))
1419 				num++;
1420 		}
1421 
1422 		/* Get response struct */
1423 		if (resp == NULL) {
1424 			error = EINVAL;
1425 			break;
1426 		}
1427 		NG_MKRESPONSE(rp, msg, sizeof(*nl)
1428 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
1429 		if (rp == NULL) {
1430 			error = ENOMEM;
1431 			break;
1432 		}
1433 		nl = (struct namelist *) rp->data;
1434 
1435 		/* Cycle through the linked list of nodes */
1436 		nl->numnames = 0;
1437 		LIST_FOREACH(node, &nodelist, nodes) {
1438 			struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
1439 
1440 			if (nl->numnames >= num) {
1441 				log(LOG_ERR, "%s: number of %s changed\n",
1442 				    __func__, "nodes");
1443 				break;
1444 			}
1445 			if ((node->flags & NG_INVALID) != 0)
1446 				continue;
1447 			if (!unnamed && node->name == NULL)
1448 				continue;
1449 			if (node->name != NULL)
1450 				strncpy(np->name, node->name, NG_NODELEN);
1451 			strncpy(np->type, node->type->name, NG_TYPELEN);
1452 			np->id = ng_node2ID(node);
1453 			np->hooks = node->numhooks;
1454 			nl->numnames++;
1455 		}
1456 		*resp = rp;
1457 		break;
1458 	    }
1459 
1460 	case NGM_LISTTYPES:
1461 	    {
1462 		struct typelist *tl;
1463 		struct ng_mesg *rp;
1464 		struct ng_type *type;
1465 		int num = 0;
1466 
1467 		if (resp == NULL) {
1468 			error = EINVAL;
1469 			break;
1470 		}
1471 
1472 		/* Count number of types */
1473 		LIST_FOREACH(type, &typelist, types)
1474 			num++;
1475 
1476 		/* Get response struct */
1477 		if (resp == NULL) {
1478 			error = EINVAL;
1479 			break;
1480 		}
1481 		NG_MKRESPONSE(rp, msg, sizeof(*tl)
1482 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
1483 		if (rp == NULL) {
1484 			error = ENOMEM;
1485 			break;
1486 		}
1487 		tl = (struct typelist *) rp->data;
1488 
1489 		/* Cycle through the linked list of types */
1490 		tl->numtypes = 0;
1491 		LIST_FOREACH(type, &typelist, types) {
1492 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
1493 
1494 			if (tl->numtypes >= num) {
1495 				log(LOG_ERR, "%s: number of %s changed\n",
1496 				    __func__, "types");
1497 				break;
1498 			}
1499 			strncpy(tp->type_name, type->name, NG_TYPELEN);
1500 			tp->numnodes = type->refs - 1; /* don't count list */
1501 			tl->numtypes++;
1502 		}
1503 		*resp = rp;
1504 		break;
1505 	    }
1506 
1507 	case NGM_BINARY2ASCII:
1508 	    {
1509 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
1510 		const struct ng_parse_type *argstype;
1511 		const struct ng_cmdlist *c;
1512 		struct ng_mesg *rp, *binary, *ascii;
1513 
1514 		/* Data area must contain a valid netgraph message */
1515 		binary = (struct ng_mesg *)msg->data;
1516 		if (msg->header.arglen < sizeof(struct ng_mesg)
1517 		    || msg->header.arglen - sizeof(struct ng_mesg)
1518 		      < binary->header.arglen) {
1519 			error = EINVAL;
1520 			break;
1521 		}
1522 
1523 		/* Get a response message with lots of room */
1524 		NG_MKRESPONSE(rp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
1525 		if (rp == NULL) {
1526 			error = ENOMEM;
1527 			break;
1528 		}
1529 		ascii = (struct ng_mesg *)rp->data;
1530 
1531 		/* Copy binary message header to response message payload */
1532 		bcopy(binary, ascii, sizeof(*binary));
1533 
1534 		/* Find command by matching typecookie and command number */
1535 		for (c = here->type->cmdlist;
1536 		    c != NULL && c->name != NULL; c++) {
1537 			if (binary->header.typecookie == c->cookie
1538 			    && binary->header.cmd == c->cmd)
1539 				break;
1540 		}
1541 		if (c == NULL || c->name == NULL) {
1542 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1543 				if (binary->header.typecookie == c->cookie
1544 				    && binary->header.cmd == c->cmd)
1545 					break;
1546 			}
1547 			if (c->name == NULL) {
1548 				FREE(rp, M_NETGRAPH);
1549 				error = ENOSYS;
1550 				break;
1551 			}
1552 		}
1553 
1554 		/* Convert command name to ASCII */
1555 		snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
1556 		    "%s", c->name);
1557 
1558 		/* Convert command arguments to ASCII */
1559 		argstype = (binary->header.flags & NGF_RESP) ?
1560 		    c->respType : c->mesgType;
1561 		if (argstype == NULL)
1562 			*ascii->data = '\0';
1563 		else {
1564 			if ((error = ng_unparse(argstype,
1565 			    (u_char *)binary->data,
1566 			    ascii->data, bufSize)) != 0) {
1567 				FREE(rp, M_NETGRAPH);
1568 				break;
1569 			}
1570 		}
1571 
1572 		/* Return the result as struct ng_mesg plus ASCII string */
1573 		bufSize = strlen(ascii->data) + 1;
1574 		ascii->header.arglen = bufSize;
1575 		rp->header.arglen = sizeof(*ascii) + bufSize;
1576 		*resp = rp;
1577 		break;
1578 	    }
1579 
1580 	case NGM_ASCII2BINARY:
1581 	    {
1582 		int bufSize = 2000;	/* XXX hard coded constant */
1583 		const struct ng_cmdlist *c;
1584 		const struct ng_parse_type *argstype;
1585 		struct ng_mesg *rp, *ascii, *binary;
1586 		int off = 0;
1587 
1588 		/* Data area must contain at least a struct ng_mesg + '\0' */
1589 		ascii = (struct ng_mesg *)msg->data;
1590 		if (msg->header.arglen < sizeof(*ascii) + 1
1591 		    || ascii->header.arglen < 1
1592 		    || msg->header.arglen
1593 		      < sizeof(*ascii) + ascii->header.arglen) {
1594 			error = EINVAL;
1595 			break;
1596 		}
1597 		ascii->data[ascii->header.arglen - 1] = '\0';
1598 
1599 		/* Get a response message with lots of room */
1600 		NG_MKRESPONSE(rp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
1601 		if (rp == NULL) {
1602 			error = ENOMEM;
1603 			break;
1604 		}
1605 		binary = (struct ng_mesg *)rp->data;
1606 
1607 		/* Copy ASCII message header to response message payload */
1608 		bcopy(ascii, binary, sizeof(*ascii));
1609 
1610 		/* Find command by matching ASCII command string */
1611 		for (c = here->type->cmdlist;
1612 		    c != NULL && c->name != NULL; c++) {
1613 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
1614 				break;
1615 		}
1616 		if (c == NULL || c->name == NULL) {
1617 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1618 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
1619 					break;
1620 			}
1621 			if (c->name == NULL) {
1622 				FREE(rp, M_NETGRAPH);
1623 				error = ENOSYS;
1624 				break;
1625 			}
1626 		}
1627 
1628 		/* Convert command name to binary */
1629 		binary->header.cmd = c->cmd;
1630 		binary->header.typecookie = c->cookie;
1631 
1632 		/* Convert command arguments to binary */
1633 		argstype = (binary->header.flags & NGF_RESP) ?
1634 		    c->respType : c->mesgType;
1635 		if (argstype == NULL)
1636 			bufSize = 0;
1637 		else {
1638 			if ((error = ng_parse(argstype, ascii->data,
1639 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
1640 				FREE(rp, M_NETGRAPH);
1641 				break;
1642 			}
1643 		}
1644 
1645 		/* Return the result */
1646 		binary->header.arglen = bufSize;
1647 		rp->header.arglen = sizeof(*binary) + bufSize;
1648 		*resp = rp;
1649 		break;
1650 	    }
1651 
1652 	case NGM_TEXT_CONFIG:
1653 	case NGM_TEXT_STATUS:
1654 		/*
1655 		 * This one is tricky as it passes the command down to the
1656 		 * actual node, even though it is a generic type command.
1657 		 * This means we must assume that the msg is already freed
1658 		 * when control passes back to us.
1659 		 */
1660 		if (resp == NULL) {
1661 			error = EINVAL;
1662 			break;
1663 		}
1664 		if (here->type->rcvmsg != NULL)
1665 			return((*here->type->rcvmsg)(here, msg, retaddr, resp));
1666 		/* Fall through if rcvmsg not supported */
1667 	default:
1668 		TRAP_ERROR;
1669 		error = EINVAL;
1670 	}
1671 	FREE(msg, M_NETGRAPH);
1672 	return (error);
1673 }
1674 
1675 /*
1676  * Send a data packet to a node. If the recipient has no
1677  * 'receive data' method, then silently discard the packet.
1678  */
1679 int
1680 ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
1681 {
1682 	int (*rcvdata)(hook_p, struct mbuf *, meta_p);
1683 	int error;
1684 
1685 	CHECK_DATA_MBUF(m);
1686 	if (hook && (hook->flags & HK_INVALID) == 0) {
1687 		rcvdata = hook->peer->node->type->rcvdata;
1688 		if (rcvdata != NULL)
1689 			error = (*rcvdata)(hook->peer, m, meta);
1690 		else {
1691 			error = 0;
1692 			NG_FREE_DATA(m, meta);
1693 		}
1694 	} else {
1695 		TRAP_ERROR;
1696 		error = ENOTCONN;
1697 		NG_FREE_DATA(m, meta);
1698 	}
1699 	return (error);
1700 }
1701 
1702 /*
1703  * Send a queued data packet to a node. If the recipient has no
1704  * 'receive queued data' method, then try the 'receive data' method above.
1705  */
1706 int
1707 ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
1708 {
1709 	int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
1710 	int error;
1711 
1712 	CHECK_DATA_MBUF(m);
1713 	if (hook && (hook->flags & HK_INVALID) == 0) {
1714 		rcvdataq = hook->peer->node->type->rcvdataq;
1715 		if (rcvdataq != NULL)
1716 			error = (*rcvdataq)(hook->peer, m, meta);
1717 		else {
1718 			error = ng_send_data(hook, m, meta);
1719 		}
1720 	} else {
1721 		TRAP_ERROR;
1722 		error = ENOTCONN;
1723 		NG_FREE_DATA(m, meta);
1724 	}
1725 	return (error);
1726 }
1727 
1728 /*
1729  * Copy a 'meta'.
1730  *
1731  * Returns new meta, or NULL if original meta is NULL or ENOMEM.
1732  */
1733 meta_p
1734 ng_copy_meta(meta_p meta)
1735 {
1736 	meta_p meta2;
1737 
1738 	if (meta == NULL)
1739 		return (NULL);
1740 	MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH, M_NOWAIT);
1741 	if (meta2 == NULL)
1742 		return (NULL);
1743 	meta2->allocated_len = meta->used_len;
1744 	bcopy(meta, meta2, meta->used_len);
1745 	return (meta2);
1746 }
1747 
1748 /************************************************************************
1749 			Module routines
1750 ************************************************************************/
1751 
1752 /*
1753  * Handle the loading/unloading of a netgraph node type module
1754  */
1755 int
1756 ng_mod_event(module_t mod, int event, void *data)
1757 {
1758 	struct ng_type *const type = data;
1759 	int error = 0;
1760 
1761 	switch (event) {
1762 	case MOD_LOAD:
1763 
1764 		/* Register new netgraph node type */
1765 		crit_enter();
1766 		if ((error = ng_newtype(type)) != 0) {
1767 			crit_exit();
1768 			break;
1769 		}
1770 
1771 		/* Call type specific code */
1772 		if (type->mod_event != NULL)
1773 			if ((error = (*type->mod_event)(mod, event, data))) {
1774 				type->refs--;	/* undo it */
1775 				LIST_REMOVE(type, types);
1776 			}
1777 		crit_exit();
1778 		break;
1779 
1780 	case MOD_UNLOAD:
1781 		crit_enter();
1782 		if (type->refs > 1) {		/* make sure no nodes exist! */
1783 			error = EBUSY;
1784 		} else {
1785 			if (type->refs == 0) {
1786 				/* failed load, nothing to undo */
1787 				crit_exit();
1788 				break;
1789 			}
1790 			if (type->mod_event != NULL) {	/* check with type */
1791 				error = (*type->mod_event)(mod, event, data);
1792 				if (error != 0) {	/* type refuses.. */
1793 					crit_exit();
1794 					break;
1795 				}
1796 			}
1797 			LIST_REMOVE(type, types);
1798 		}
1799 		crit_exit();
1800 		break;
1801 
1802 	default:
1803 		if (type->mod_event != NULL)
1804 			error = (*type->mod_event)(mod, event, data);
1805 		else
1806 			error = 0;		/* XXX ? */
1807 		break;
1808 	}
1809 	return (error);
1810 }
1811 
1812 /*
1813  * Handle loading and unloading for this code.
1814  * The only thing we need to link into is the NETISR strucure.
1815  */
1816 static int
1817 ngb_mod_event(module_t mod, int event, void *data)
1818 {
1819 	int error = 0;
1820 
1821 	switch (event) {
1822 	case MOD_LOAD:
1823 		/* Register line discipline */
1824 		crit_enter();
1825 		error = ng_load_module("ksocket");
1826 		if (error != 0) {
1827 			crit_exit();
1828 			break;
1829 		}
1830 		netisr_register(NETISR_NETGRAPH, cpu0_portfn, ngintr);
1831 		error = 0;
1832 		crit_exit();
1833 		break;
1834 	case MOD_UNLOAD:
1835 		ng_unload_module("ksocket");
1836 		/* You cant unload it because an interface may be using it.  */
1837 		error = EBUSY;
1838 		break;
1839 	default:
1840 		error = EOPNOTSUPP;
1841 		break;
1842 	}
1843 	return (error);
1844 }
1845 
1846 static moduledata_t netgraph_mod = {
1847 	"netgraph",
1848 	ngb_mod_event,
1849 	(NULL)
1850 };
1851 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1852 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
1853 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
1854 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
1855 
1856 /************************************************************************
1857 			Queueing routines
1858 ************************************************************************/
1859 
1860 /* The structure for queueing across ISR switches */
1861 struct ng_queue_entry {
1862 	u_long	flags;
1863 	struct ng_queue_entry *next;
1864 	union {
1865 		struct {
1866 			hook_p		da_hook;	/*  target hook */
1867 			struct mbuf	*da_m;
1868 			meta_p		da_meta;
1869 		} data;
1870 		struct {
1871 			struct ng_mesg	*msg_msg;
1872 			node_p		msg_node;
1873 			void		*msg_retaddr;
1874 		} msg;
1875 	} body;
1876 };
1877 #define NGQF_DATA	0x01		/* the queue element is data */
1878 #define NGQF_MESG	0x02		/* the queue element is a message */
1879 
1880 static struct ng_queue_entry   *ngqbase;	/* items to be unqueued */
1881 static struct ng_queue_entry   *ngqlast;	/* last item queued */
1882 static const int		ngqroom = 256;	/* max items to queue */
1883 static int			ngqsize;	/* number of items in queue */
1884 
1885 static struct ng_queue_entry   *ngqfree;	/* free ones */
1886 static const int		ngqfreemax = 256;/* cache at most this many */
1887 static int			ngqfreesize;	/* number of cached entries */
1888 
1889 /*
1890  * Get a queue entry
1891  */
1892 static struct ng_queue_entry *
1893 ng_getqblk(void)
1894 {
1895 	struct ng_queue_entry *q;
1896 
1897 	/* Could be guarding against tty ints or whatever */
1898 	crit_enter();
1899 
1900 	/* Try get a cached queue block, or else allocate a new one */
1901 	if ((q = ngqfree) == NULL) {
1902 		crit_exit();
1903 		if (ngqsize < ngqroom) {	/* don't worry about races */
1904 			MALLOC(q, struct ng_queue_entry *,
1905 			    sizeof(*q), M_NETGRAPH, M_NOWAIT);
1906 		}
1907 	} else {
1908 		ngqfree = q->next;
1909 		ngqfreesize--;
1910 		crit_exit();
1911 	}
1912 	return (q);
1913 }
1914 
1915 /*
1916  * Release a queue entry
1917  */
1918 #define RETURN_QBLK(q)							\
1919 do {									\
1920 	if (ngqfreesize < ngqfreemax) { /* don't worry about races */ 	\
1921 		crit_enter();						\
1922 		(q)->next = ngqfree;					\
1923 		ngqfree = (q);						\
1924 		ngqfreesize++;						\
1925 		crit_exit();						\
1926 	} else {							\
1927 		FREE((q), M_NETGRAPH);					\
1928 	}								\
1929 } while (0)
1930 
1931 /*
1932  * Running at a raised (but we don't know which) processor priority level,
1933  * put the data onto a queue to be picked up by another PPL (probably splnet)
1934  */
1935 int
1936 ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
1937 {
1938 	struct ng_queue_entry *q;
1939 
1940 	if (hook == NULL) {
1941 		NG_FREE_DATA(m, meta);
1942 		return (0);
1943 	}
1944 	if ((q = ng_getqblk()) == NULL) {
1945 		NG_FREE_DATA(m, meta);
1946 		return (ENOBUFS);
1947 	}
1948 
1949 	/* Fill out the contents */
1950 	q->flags = NGQF_DATA;
1951 	q->next = NULL;
1952 	q->body.data.da_hook = hook;
1953 	q->body.data.da_m = m;
1954 	q->body.data.da_meta = meta;
1955 	crit_enter();		/* protect refs and queue */
1956 	hook->refs++;		/* don't let it go away while on the queue */
1957 
1958 	/* Put it on the queue */
1959 	if (ngqbase) {
1960 		ngqlast->next = q;
1961 	} else {
1962 		ngqbase = q;
1963 	}
1964 	ngqlast = q;
1965 	ngqsize++;
1966 	crit_exit();
1967 
1968 	/* Schedule software interrupt to handle it later */
1969 	schednetisr(NETISR_NETGRAPH);
1970 	return (0);
1971 }
1972 
1973 /*
1974  * Running at a raised (but we don't know which) processor priority level,
1975  * put the msg onto a queue to be picked up by another PPL (probably splnet)
1976  */
1977 int
1978 ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address)
1979 {
1980 	struct ng_queue_entry *q;
1981 	node_p  dest = NULL;
1982 	char   *retaddr = NULL;
1983 	int     error;
1984 
1985 	/* Find the target node. */
1986 	error = ng_path2node(here, address, &dest, &retaddr);
1987 	if (error) {
1988 		FREE(msg, M_NETGRAPH);
1989 		return (error);
1990 	}
1991 	if ((q = ng_getqblk()) == NULL) {
1992 		FREE(msg, M_NETGRAPH);
1993 		if (retaddr)
1994 			FREE(retaddr, M_NETGRAPH);
1995 		return (ENOBUFS);
1996 	}
1997 
1998 	/* Fill out the contents */
1999 	q->flags = NGQF_MESG;
2000 	q->next = NULL;
2001 	q->body.msg.msg_node = dest;
2002 	q->body.msg.msg_msg = msg;
2003 	q->body.msg.msg_retaddr = retaddr;
2004 	crit_enter();		/* protect refs and queue */
2005 	dest->refs++;		/* don't let it go away while on the queue */
2006 
2007 	/* Put it on the queue */
2008 	if (ngqbase) {
2009 		ngqlast->next = q;
2010 	} else {
2011 		ngqbase = q;
2012 	}
2013 	ngqlast = q;
2014 	ngqsize++;
2015 	crit_exit();
2016 
2017 	/* Schedule software interrupt to handle it later */
2018 	schednetisr(NETISR_NETGRAPH);
2019 	return (0);
2020 }
2021 
2022 /*
2023  * Pick an item off the queue, process it, and dispose of the queue entry.
2024  * Should be running at splnet.
2025  */
2026 static int
2027 ngintr(struct netmsg *pmsg)
2028 {
2029 	struct mbuf *m = ((struct netmsg_packet *)pmsg)->nm_packet;
2030 	hook_p  hook;
2031 	struct ng_queue_entry *ngq;
2032 	meta_p  meta;
2033 	void   *retaddr;
2034 	struct ng_mesg *msg;
2035 	node_p  node;
2036 	int     error = 0;
2037 
2038 	while (1) {
2039 		crit_enter();
2040 		if ((ngq = ngqbase)) {
2041 			ngqbase = ngq->next;
2042 			ngqsize--;
2043 		}
2044 		crit_exit();
2045 		if (ngq == NULL)
2046 			goto out;
2047 		switch (ngq->flags) {
2048 		case NGQF_DATA:
2049 			hook = ngq->body.data.da_hook;
2050 			m = ngq->body.data.da_m;
2051 			meta = ngq->body.data.da_meta;
2052 			RETURN_QBLK(ngq);
2053 			NG_SEND_DATAQ(error, hook, m, meta);
2054 			ng_unref_hook(hook);
2055 			break;
2056 		case NGQF_MESG:
2057 			node = ngq->body.msg.msg_node;
2058 			msg = ngq->body.msg.msg_msg;
2059 			retaddr = ngq->body.msg.msg_retaddr;
2060 			RETURN_QBLK(ngq);
2061 			if (node->flags & NG_INVALID) {
2062 				FREE(msg, M_NETGRAPH);
2063 			} else {
2064 				CALL_MSG_HANDLER(error, node, msg,
2065 						 retaddr, NULL);
2066 			}
2067 			ng_unref(node);
2068 			if (retaddr)
2069 				FREE(retaddr, M_NETGRAPH);
2070 			break;
2071 		default:
2072 			RETURN_QBLK(ngq);
2073 		}
2074 	}
2075 out:
2076 	lwkt_replymsg(&pmsg->nm_lmsg, 0);
2077 	return(EASYNC);
2078 }
2079 
2080 
2081