xref: /dragonfly/sys/netgraph/netgraph/ng_base.c (revision 28c26f7e)
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 1.28 2008/09/24 14:26:39 sephe Exp $
42  * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
43  */
44 
45 /*
46  * This file implements the base netgraph code.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/errno.h>
52 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/syslog.h>
55 #include <sys/linker.h>
56 #include <sys/queue.h>
57 #include <sys/mbuf.h>
58 #include <sys/ctype.h>
59 #include <sys/sysctl.h>
60 #include <sys/vnode.h>
61 #include <machine/limits.h>
62 
63 #include <sys/thread2.h>
64 #include <sys/msgport2.h>
65 
66 #include <net/netisr.h>
67 
68 #include <netgraph/ng_message.h>
69 #include <netgraph/netgraph.h>
70 #include <netgraph/ng_parse.h>
71 
72 MODULE_VERSION(netgraph, NG_ABI_VERSION);
73 
74 /* List of all nodes */
75 static LIST_HEAD(, ng_node) nodelist;
76 
77 /* List of installed types */
78 static LIST_HEAD(, ng_type) typelist;
79 
80 /* Hash releted definitions */
81 #define ID_HASH_SIZE 32 /* most systems wont need even this many */
82 static LIST_HEAD(, ng_node) ID_hash[ID_HASH_SIZE];
83 /* Don't nead to initialise them because it's a LIST */
84 
85 /* Internal functions */
86 static int	ng_add_hook(node_p node, const char *name, hook_p * hookp);
87 static int	ng_connect(hook_p hook1, hook_p hook2);
88 static void	ng_disconnect_hook(hook_p hook);
89 static int	ng_generic_msg(node_p here, struct ng_mesg *msg,
90 			const char *retaddr, struct ng_mesg ** resp);
91 static ng_ID_t	ng_decodeidname(const char *name);
92 static int	ngb_mod_event(module_t mod, int event, void *data);
93 static void	ngintr(struct netmsg *);
94 static int	ng_load_module(const char *);
95 static int	ng_unload_module(const char *);
96 
97 /* Our own netgraph malloc type */
98 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
99 
100 /* Set this to Debugger("X") to catch all errors as they occur */
101 #ifndef TRAP_ERROR
102 #define TRAP_ERROR
103 #endif
104 
105 static	ng_ID_t nextID = 1;
106 
107 #ifdef INVARIANTS
108 #define CHECK_DATA_MBUF(m)	do {					\
109 		struct mbuf *n;						\
110 		int total;						\
111 									\
112 		if (((m)->m_flags & M_PKTHDR) == 0)			\
113 			panic("%s: !PKTHDR", __func__);		\
114 		for (total = 0, n = (m); n != NULL; n = n->m_next)	\
115 			total += n->m_len;				\
116 		if ((m)->m_pkthdr.len != total) {			\
117 			panic("%s: %d != %d",				\
118 			    __func__, (m)->m_pkthdr.len, total);	\
119 		}							\
120 	} while (0)
121 #else
122 #define CHECK_DATA_MBUF(m)
123 #endif
124 
125 
126 /************************************************************************
127 	Parse type definitions for generic messages
128 ************************************************************************/
129 
130 /* Handy structure parse type defining macro */
131 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args)				\
132 static const struct ng_parse_struct_field				\
133 	ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args;	\
134 static const struct ng_parse_type ng_generic_ ## lo ## _type = {	\
135 	&ng_parse_struct_type,						\
136 	&ng_ ## lo ## _type_fields					\
137 }
138 
139 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
140 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
141 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
142 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
143 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
144 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
145 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
146 
147 /* Get length of an array when the length is stored as a 32 bit
148    value immediately preceeding the array -- as with struct namelist
149    and struct typelist. */
150 static int
151 ng_generic_list_getLength(const struct ng_parse_type *type,
152 	const u_char *start, const u_char *buf)
153 {
154 	return *((const u_int32_t *)(buf - 4));
155 }
156 
157 /* Get length of the array of struct linkinfo inside a struct hooklist */
158 static int
159 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
160 	const u_char *start, const u_char *buf)
161 {
162 	const struct hooklist *hl = (const struct hooklist *)start;
163 
164 	return hl->nodeinfo.hooks;
165 }
166 
167 /* Array type for a variable length array of struct namelist */
168 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
169 	&ng_generic_nodeinfo_type,
170 	&ng_generic_list_getLength
171 };
172 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
173 	&ng_parse_array_type,
174 	&ng_nodeinfoarray_type_info
175 };
176 
177 /* Array type for a variable length array of struct typelist */
178 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
179 	&ng_generic_typeinfo_type,
180 	&ng_generic_list_getLength
181 };
182 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
183 	&ng_parse_array_type,
184 	&ng_typeinfoarray_type_info
185 };
186 
187 /* Array type for array of struct linkinfo in struct hooklist */
188 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
189 	&ng_generic_linkinfo_type,
190 	&ng_generic_linkinfo_getLength
191 };
192 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
193 	&ng_parse_array_type,
194 	&ng_generic_linkinfo_array_type_info
195 };
196 
197 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
198 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
199 	(&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
200 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
201 	(&ng_generic_nodeinfoarray_type));
202 
203 /* List of commands and how to convert arguments to/from ASCII */
204 static const struct ng_cmdlist ng_generic_cmds[] = {
205 	{
206 	  NGM_GENERIC_COOKIE,
207 	  NGM_SHUTDOWN,
208 	  "shutdown",
209 	  NULL,
210 	  NULL
211 	},
212 	{
213 	  NGM_GENERIC_COOKIE,
214 	  NGM_MKPEER,
215 	  "mkpeer",
216 	  &ng_generic_mkpeer_type,
217 	  NULL
218 	},
219 	{
220 	  NGM_GENERIC_COOKIE,
221 	  NGM_CONNECT,
222 	  "connect",
223 	  &ng_generic_connect_type,
224 	  NULL
225 	},
226 	{
227 	  NGM_GENERIC_COOKIE,
228 	  NGM_NAME,
229 	  "name",
230 	  &ng_generic_name_type,
231 	  NULL
232 	},
233 	{
234 	  NGM_GENERIC_COOKIE,
235 	  NGM_RMHOOK,
236 	  "rmhook",
237 	  &ng_generic_rmhook_type,
238 	  NULL
239 	},
240 	{
241 	  NGM_GENERIC_COOKIE,
242 	  NGM_NODEINFO,
243 	  "nodeinfo",
244 	  NULL,
245 	  &ng_generic_nodeinfo_type
246 	},
247 	{
248 	  NGM_GENERIC_COOKIE,
249 	  NGM_LISTHOOKS,
250 	  "listhooks",
251 	  NULL,
252 	  &ng_generic_hooklist_type
253 	},
254 	{
255 	  NGM_GENERIC_COOKIE,
256 	  NGM_LISTNAMES,
257 	  "listnames",
258 	  NULL,
259 	  &ng_generic_listnodes_type	/* same as NGM_LISTNODES */
260 	},
261 	{
262 	  NGM_GENERIC_COOKIE,
263 	  NGM_LISTNODES,
264 	  "listnodes",
265 	  NULL,
266 	  &ng_generic_listnodes_type
267 	},
268 	{
269 	  NGM_GENERIC_COOKIE,
270 	  NGM_LISTTYPES,
271 	  "listtypes",
272 	  NULL,
273 	  &ng_generic_typeinfo_type
274 	},
275 	{
276 	  NGM_GENERIC_COOKIE,
277 	  NGM_TEXT_CONFIG,
278 	  "textconfig",
279 	  NULL,
280 	  &ng_parse_string_type
281 	},
282 	{
283 	  NGM_GENERIC_COOKIE,
284 	  NGM_TEXT_STATUS,
285 	  "textstatus",
286 	  NULL,
287 	  &ng_parse_string_type
288 	},
289 	{
290 	  NGM_GENERIC_COOKIE,
291 	  NGM_ASCII2BINARY,
292 	  "ascii2binary",
293 	  &ng_parse_ng_mesg_type,
294 	  &ng_parse_ng_mesg_type
295 	},
296 	{
297 	  NGM_GENERIC_COOKIE,
298 	  NGM_BINARY2ASCII,
299 	  "binary2ascii",
300 	  &ng_parse_ng_mesg_type,
301 	  &ng_parse_ng_mesg_type
302 	},
303 	{ 0 }
304 };
305 
306 /************************************************************************
307 			Node routines
308 ************************************************************************/
309 
310 static int
311 linker_api_available(void)
312 {
313 	/* linker_* API won't work without a process context */
314 	if (curproc == NULL)
315 		return 0;
316 	/*
317 	 * nlookup_init() relies on namei_oc to be initialized,
318 	 * but it's not when the netgraph module is loaded during boot.
319 	 */
320 	if (namei_oc == NULL)
321 		return 0;
322 	return 1;
323 }
324 
325 static int
326 ng_load_module(const char *name)
327 {
328 	char *path, filename[NG_TYPESIZ + 3];
329 	linker_file_t lf;
330 	int error;
331 
332 	if (!linker_api_available())
333 		return (ENXIO);
334 
335 	/* Not found, try to load it as a loadable module */
336 	ksnprintf(filename, sizeof(filename), "ng_%s.ko", name);
337 	if ((path = linker_search_path(filename)) == NULL)
338 		return (ENXIO);
339 	error = linker_load_file(path, &lf);
340 	FREE(path, M_LINKER);
341 	if (error == 0)
342 		lf->userrefs++;		/* pretend kldload'ed */
343 	return (error);
344 }
345 
346 static int
347 ng_unload_module(const char *name)
348 {
349 	char filename[NG_TYPESIZ + 3];
350 	linker_file_t lf;
351 	int error;
352 
353 	if (!linker_api_available())
354 		return (ENXIO);
355 
356 	/* Not found, try to load it as a loadable module */
357 	ksnprintf(filename, sizeof(filename), "ng_%s.ko", name);
358 	if ((lf = linker_find_file_by_name(filename)) == NULL)
359 		return (ENXIO);
360 	lf->userrefs--;		/* pretend kldunload'ed */
361 	error = linker_file_unload(lf);
362 	if (error)
363 		lf->userrefs++;
364 
365 	return (error);
366 }
367 
368 /*
369  * Instantiate a node of the requested type
370  */
371 int
372 ng_make_node(const char *typename, node_p *nodepp)
373 {
374 	struct ng_type *type;
375 
376 	/* Check that the type makes sense */
377 	if (typename == NULL) {
378 		TRAP_ERROR;
379 		return (EINVAL);
380 	}
381 
382 	/* Locate the node type */
383 	if ((type = ng_findtype(typename)) == NULL)
384 		return (ENXIO);
385 
386 	/* Call the constructor */
387 	if (type->constructor != NULL)
388 		return ((*type->constructor)(nodepp));
389 	else
390 		return (ng_make_node_common(type, nodepp));
391 }
392 
393 /*
394  * Generic node creation. Called by node constructors.
395  * The returned node has a reference count of 1.
396  */
397 int
398 ng_make_node_common(struct ng_type *type, node_p *nodepp)
399 {
400 	node_p node;
401 
402 	/* Require the node type to have been already installed */
403 	if (ng_findtype(type->name) == NULL) {
404 		TRAP_ERROR;
405 		return (EINVAL);
406 	}
407 
408 	/* Make a node and try attach it to the type */
409 	MALLOC(node, node_p, sizeof(*node), M_NETGRAPH, M_NOWAIT | M_ZERO);
410 	if (node == NULL) {
411 		TRAP_ERROR;
412 		return (ENOMEM);
413 	}
414 	node->type = type;
415 	node->refs++;				/* note reference */
416 	type->refs++;
417 
418 	/* Link us into the node linked list */
419 	LIST_INSERT_HEAD(&nodelist, node, nodes);
420 
421 	/* Initialize hook list for new node */
422 	LIST_INIT(&node->hooks);
423 
424 	/* get an ID and put us in the hash chain */
425 	node->ID = nextID++; /* 137 per second for 1 year before wrap */
426 	LIST_INSERT_HEAD(&ID_hash[node->ID % ID_HASH_SIZE], node, idnodes);
427 
428 	/* Done */
429 	*nodepp = node;
430 	return (0);
431 }
432 
433 /*
434  * Forceably start the shutdown process on a node. Either call
435  * it's shutdown method, or do the default shutdown if there is
436  * no type-specific method.
437  *
438  * Persistent nodes must have a type-specific method which
439  * resets the NG_INVALID flag.
440  */
441 void
442 ng_rmnode(node_p node)
443 {
444 	/* Check if it's already shutting down */
445 	if ((node->flags & NG_INVALID) != 0)
446 		return;
447 
448 	/* Add an extra reference so it doesn't go away during this */
449 	node->refs++;
450 
451 	/* Mark it invalid so any newcomers know not to try use it */
452 	node->flags |= NG_INVALID;
453 
454 	/* Ask the type if it has anything to do in this case */
455 	if (node->type && node->type->shutdown)
456 		(*node->type->shutdown)(node);
457 	else {				/* do the default thing */
458 		ng_unname(node);
459 		ng_cutlinks(node);
460 		ng_unref(node);
461 	}
462 
463 	/* Remove extra reference, possibly the last */
464 	ng_unref(node);
465 }
466 
467 /*
468  * Called by the destructor to remove any STANDARD external references
469  */
470 void
471 ng_cutlinks(node_p node)
472 {
473 	hook_p  hook;
474 
475 	/* Make sure that this is set to stop infinite loops */
476 	node->flags |= NG_INVALID;
477 
478 	/* If we have sleepers, wake them up; they'll see NG_INVALID */
479 	if (node->sleepers)
480 		wakeup(node);
481 
482 	/* Notify all remaining connected nodes to disconnect */
483 	while ((hook = LIST_FIRST(&node->hooks)) != NULL)
484 		ng_destroy_hook(hook);
485 }
486 
487 /*
488  * Remove a reference to the node, possibly the last
489  */
490 void
491 ng_unref(node_p node)
492 {
493 	crit_enter();
494 	if (--node->refs <= 0) {
495 		node->type->refs--;
496 		LIST_REMOVE(node, nodes);
497 		LIST_REMOVE(node, idnodes);
498 		FREE(node, M_NETGRAPH);
499 	}
500 	crit_exit();
501 }
502 
503 /*
504  * Wait for a node to come ready. Returns a node with a reference count;
505  * don't forget to drop it when we are done with it using ng_release_node().
506  */
507 int
508 ng_wait_node(node_p node, char *msg)
509 {
510 	int error = 0;
511 
512 	if (msg == NULL)
513 		msg = "netgraph";
514 	crit_enter();
515 	node->sleepers++;
516 	node->refs++;		/* the sleeping process counts as a reference */
517 	while ((node->flags & (NG_BUSY | NG_INVALID)) == NG_BUSY)
518 		error = tsleep(node, PCATCH, msg, 0);
519 	node->sleepers--;
520 	if (node->flags & NG_INVALID) {
521 		TRAP_ERROR;
522 		error = ENXIO;
523 	} else {
524 		KASSERT(node->refs > 1,
525 		    ("%s: refs=%d", __func__, node->refs));
526 		node->flags |= NG_BUSY;
527 	}
528 	crit_exit();
529 
530 	/* Release the reference we had on it */
531 	if (error != 0)
532 		ng_unref(node);
533 	return error;
534 }
535 
536 /*
537  * Release a node acquired via ng_wait_node()
538  */
539 void
540 ng_release_node(node_p node)
541 {
542 	/* Declare that we don't want it */
543 	node->flags &= ~NG_BUSY;
544 
545 	/* If we have sleepers, then wake them up */
546 	if (node->sleepers)
547 		wakeup(node);
548 
549 	/* We also have a reference.. drop it too */
550 	ng_unref(node);
551 }
552 
553 /************************************************************************
554 			Node ID handling
555 ************************************************************************/
556 static node_p
557 ng_ID2node(ng_ID_t ID)
558 {
559 	node_p np;
560 	LIST_FOREACH(np, &ID_hash[ID % ID_HASH_SIZE], idnodes) {
561 		if ((np->flags & NG_INVALID) == 0 && np->ID == ID)
562 			break;
563 	}
564 	return(np);
565 }
566 
567 ng_ID_t
568 ng_node2ID(node_p node)
569 {
570 	return (node->ID);
571 }
572 
573 /************************************************************************
574 			Node name handling
575 ************************************************************************/
576 
577 /*
578  * Assign a node a name. Once assigned, the name cannot be changed.
579  */
580 int
581 ng_name_node(node_p node, const char *name)
582 {
583 	int i;
584 
585 	/* Check the name is valid */
586 	for (i = 0; i < NG_NODESIZ; i++) {
587 		if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
588 			break;
589 	}
590 	if (i == 0 || name[i] != '\0') {
591 		TRAP_ERROR;
592 		return (EINVAL);
593 	}
594 	if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
595 		TRAP_ERROR;
596 		return (EINVAL);
597 	}
598 
599 	/* Check the node isn't already named */
600 	if (node->name != NULL) {
601 		TRAP_ERROR;
602 		return (EISCONN);
603 	}
604 
605 	/* Check the name isn't already being used */
606 	if (ng_findname(node, name) != NULL) {
607 		TRAP_ERROR;
608 		return (EADDRINUSE);
609 	}
610 
611 	/* Allocate space and copy it */
612 	MALLOC(node->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
613 	if (node->name == NULL) {
614 		TRAP_ERROR;
615 		return (ENOMEM);
616 	}
617 	strcpy(node->name, name);
618 
619 	/* The name counts as a reference */
620 	node->refs++;
621 	return (0);
622 }
623 
624 /*
625  * Find a node by absolute name. The name should NOT end with ':'
626  * The name "." means "this node" and "[xxx]" means "the node
627  * with ID (ie, at address) xxx".
628  *
629  * Returns the node if found, else NULL.
630  */
631 node_p
632 ng_findname(node_p this, const char *name)
633 {
634 	node_p node;
635 	ng_ID_t temp;
636 
637 	/* "." means "this node" */
638 	if (strcmp(name, ".") == 0)
639 		return(this);
640 
641 	/* Check for name-by-ID */
642 	if ((temp = ng_decodeidname(name)) != 0) {
643 		return (ng_ID2node(temp));
644 	}
645 
646 	/* Find node by name */
647 	LIST_FOREACH(node, &nodelist, nodes) {
648 		if ((node->name != NULL)
649 		&& (strcmp(node->name, name) == 0)
650 		&& ((node->flags & NG_INVALID) == 0))
651 			break;
652 	}
653 	return (node);
654 }
655 
656 /*
657  * Decode a ID name, eg. "[f03034de]". Returns 0 if the
658  * string is not valid, otherwise returns the value.
659  */
660 static ng_ID_t
661 ng_decodeidname(const char *name)
662 {
663 	const int len = strlen(name);
664 	char *eptr;
665 	u_long val;
666 
667 	/* Check for proper length, brackets, no leading junk */
668 	if (len < 3 || name[0] != '[' || name[len - 1] != ']'
669 	    || !isxdigit(name[1]))
670 		return (0);
671 
672 	/* Decode number */
673 	val = strtoul(name + 1, &eptr, 16);
674 	if (eptr - name != len - 1 || val == ULONG_MAX || val == 0)
675 		return ((ng_ID_t)0);
676 	return (ng_ID_t)val;
677 }
678 
679 /*
680  * Remove a name from a node. This should only be called
681  * when shutting down and removing the node.
682  */
683 void
684 ng_unname(node_p node)
685 {
686 	if (node->name) {
687 		FREE(node->name, M_NETGRAPH);
688 		node->name = NULL;
689 		ng_unref(node);
690 	}
691 }
692 
693 /************************************************************************
694 			Hook routines
695 
696  Names are not optional. Hooks are always connected, except for a
697  brief moment within these routines.
698 
699 ************************************************************************/
700 
701 /*
702  * Remove a hook reference
703  */
704 void
705 ng_unref_hook(hook_p hook)
706 {
707 	crit_enter();
708 	if (--hook->refs == 0)
709 		FREE(hook, M_NETGRAPH);
710 	crit_exit();
711 }
712 
713 /*
714  * Add an unconnected hook to a node. Only used internally.
715  */
716 static int
717 ng_add_hook(node_p node, const char *name, hook_p *hookp)
718 {
719 	hook_p hook;
720 	int error = 0;
721 
722 	/* Check that the given name is good */
723 	if (name == NULL) {
724 		TRAP_ERROR;
725 		return (EINVAL);
726 	}
727 	if (ng_findhook(node, name) != NULL) {
728 		TRAP_ERROR;
729 		return (EEXIST);
730 	}
731 
732 	/* Allocate the hook and link it up */
733 	MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH, M_NOWAIT | M_ZERO);
734 	if (hook == NULL) {
735 		TRAP_ERROR;
736 		return (ENOMEM);
737 	}
738 	hook->refs = 1;
739 	hook->flags = HK_INVALID;
740 	hook->node = node;
741 	node->refs++;		/* each hook counts as a reference */
742 
743 	/* Check if the node type code has something to say about it */
744 	if (node->type->newhook != NULL)
745 		if ((error = (*node->type->newhook)(node, hook, name)) != 0)
746 			goto fail;
747 
748 	/*
749 	 * The 'type' agrees so far, so go ahead and link it in.
750 	 * We'll ask again later when we actually connect the hooks.
751 	 */
752 	LIST_INSERT_HEAD(&node->hooks, hook, hooks);
753 	node->numhooks++;
754 
755 	/* Set hook name */
756 	MALLOC(hook->name, char *, strlen(name) + 1, M_NETGRAPH, M_NOWAIT);
757 	if (hook->name == NULL) {
758 		error = ENOMEM;
759 		LIST_REMOVE(hook, hooks);
760 		node->numhooks--;
761 fail:
762 		hook->node = NULL;
763 		ng_unref(node);
764 		ng_unref_hook(hook);	/* this frees the hook */
765 		return (error);
766 	}
767 	strcpy(hook->name, name);
768 	if (hookp)
769 		*hookp = hook;
770 	return (error);
771 }
772 
773 /*
774  * Connect a pair of hooks. Only used internally.
775  */
776 static int
777 ng_connect(hook_p hook1, hook_p hook2)
778 {
779 	int     error;
780 
781 	hook1->peer = hook2;
782 	hook2->peer = hook1;
783 
784 	/* Give each node the opportunity to veto the impending connection */
785 	if (hook1->node->type->connect) {
786 		if ((error = (*hook1->node->type->connect) (hook1))) {
787 			ng_destroy_hook(hook1);	/* also zaps hook2 */
788 			return (error);
789 		}
790 	}
791 	if (hook2->node->type->connect) {
792 		if ((error = (*hook2->node->type->connect) (hook2))) {
793 			ng_destroy_hook(hook2);	/* also zaps hook1 */
794 			return (error);
795 		}
796 	}
797 	hook1->flags &= ~HK_INVALID;
798 	hook2->flags &= ~HK_INVALID;
799 	return (0);
800 }
801 
802 /*
803  * Find a hook
804  *
805  * Node types may supply their own optimized routines for finding
806  * hooks.  If none is supplied, we just do a linear search.
807  */
808 hook_p
809 ng_findhook(node_p node, const char *name)
810 {
811 	hook_p hook;
812 
813 	if (node->type->findhook != NULL)
814 		return (*node->type->findhook)(node, name);
815 	LIST_FOREACH(hook, &node->hooks, hooks) {
816 		if (hook->name != NULL
817 		    && strcmp(hook->name, name) == 0
818 		    && (hook->flags & HK_INVALID) == 0)
819 			return (hook);
820 	}
821 	return (NULL);
822 }
823 
824 /*
825  * Destroy a hook
826  *
827  * As hooks are always attached, this really destroys two hooks.
828  * The one given, and the one attached to it. Disconnect the hooks
829  * from each other first.
830  */
831 void
832 ng_destroy_hook(hook_p hook)
833 {
834 	hook_p peer = hook->peer;
835 
836 	hook->flags |= HK_INVALID;		/* as soon as possible */
837 	if (peer) {
838 		peer->flags |= HK_INVALID;	/* as soon as possible */
839 		hook->peer = NULL;
840 		peer->peer = NULL;
841 		ng_disconnect_hook(peer);
842 	}
843 	ng_disconnect_hook(hook);
844 }
845 
846 /*
847  * Notify the node of the hook's demise. This may result in more actions
848  * (e.g. shutdown) but we don't do that ourselves and don't know what
849  * happens there. If there is no appropriate handler, then just remove it
850  * (and decrement the reference count of it's node which in turn might
851  * make something happen).
852  */
853 static void
854 ng_disconnect_hook(hook_p hook)
855 {
856 	node_p node = hook->node;
857 
858 	/*
859 	 * Remove the hook from the node's list to avoid possible recursion
860 	 * in case the disconnection results in node shutdown.
861 	 */
862 	LIST_REMOVE(hook, hooks);
863 	node->numhooks--;
864 	if (node->type->disconnect) {
865 		/*
866 		 * The type handler may elect to destroy the peer so don't
867 		 * trust its existance after this point.
868 		 */
869 		(*node->type->disconnect) (hook);
870 	}
871 	ng_unref(node);		/* might be the last reference */
872 	if (hook->name)
873 		FREE(hook->name, M_NETGRAPH);
874 	hook->node = NULL;	/* may still be referenced elsewhere */
875 	ng_unref_hook(hook);
876 }
877 
878 /*
879  * Take two hooks on a node and merge the connection so that the given node
880  * is effectively bypassed.
881  */
882 int
883 ng_bypass(hook_p hook1, hook_p hook2)
884 {
885 	if (hook1->node != hook2->node)
886 		return (EINVAL);
887 	hook1->peer->peer = hook2->peer;
888 	hook2->peer->peer = hook1->peer;
889 
890 	/* XXX If we ever cache methods on hooks update them as well */
891 	hook1->peer = NULL;
892 	hook2->peer = NULL;
893 	ng_destroy_hook(hook1);
894 	ng_destroy_hook(hook2);
895 	return (0);
896 }
897 
898 /*
899  * Install a new netgraph type
900  */
901 int
902 ng_newtype(struct ng_type *tp)
903 {
904 	const size_t namelen = strlen(tp->name);
905 
906 	/* Check version and type name fields */
907 	if (tp->version != NG_VERSION || namelen == 0 || namelen >= NG_TYPESIZ) {
908 		TRAP_ERROR;
909 		return (EINVAL);
910 	}
911 
912 	/* Check for name collision */
913 	if (ng_findtype(tp->name) != NULL) {
914 		TRAP_ERROR;
915 		return (EEXIST);
916 	}
917 
918 	/* Link in new type */
919 	LIST_INSERT_HEAD(&typelist, tp, types);
920 	tp->refs = 1;	/* first ref is linked list */
921 	return (0);
922 }
923 
924 /*
925  * Look for a type of the name given
926  */
927 struct ng_type *
928 ng_findtype(const char *typename)
929 {
930 	struct ng_type *type;
931 
932 	LIST_FOREACH(type, &typelist, types) {
933 		if (strcmp(type->name, typename) == 0)
934 			break;
935 	}
936 	return (type);
937 }
938 
939 
940 /************************************************************************
941 			Composite routines
942 ************************************************************************/
943 
944 /*
945  * Make a peer and connect. The order is arranged to minimise
946  * the work needed to back out in case of error.
947  */
948 int
949 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
950 {
951 	node_p  node2;
952 	hook_p  hook;
953 	hook_p  hook2;
954 	int     error;
955 
956 	if ((error = ng_add_hook(node, name, &hook)))
957 		return (error);
958 
959 	/* make sure we have the module needed */
960 	if (ng_findtype(type) == NULL) {
961 		/* Not found, try to load it as a loadable module */
962 		error = ng_load_module(type);
963 		if (error != 0) {
964 			kprintf("required netgraph module ng_%s not loaded\n",
965 			    type);
966 			return (error);
967 		}
968 	}
969 	if ((error = ng_make_node(type, &node2))) {
970 		ng_destroy_hook(hook);
971 		return (error);
972 	}
973 	if ((error = ng_add_hook(node2, name2, &hook2))) {
974 		ng_rmnode(node2);
975 		ng_destroy_hook(hook);
976 		return (error);
977 	}
978 
979 	/*
980 	 * Actually link the two hooks together.. on failure they are
981 	 * destroyed so we don't have to do that here.
982 	 */
983 	if ((error = ng_connect(hook, hook2)))
984 		ng_rmnode(node2);
985 	return (error);
986 }
987 
988 /*
989  * Connect two nodes using the specified hooks
990  */
991 int
992 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
993 {
994 	int     error;
995 	hook_p  hook;
996 	hook_p  hook2;
997 
998 	if ((error = ng_add_hook(node, name, &hook)))
999 		return (error);
1000 	if ((error = ng_add_hook(node2, name2, &hook2))) {
1001 		ng_destroy_hook(hook);
1002 		return (error);
1003 	}
1004 	return (ng_connect(hook, hook2));
1005 }
1006 
1007 /*
1008  * Parse and verify a string of the form:  <NODE:><PATH>
1009  *
1010  * Such a string can refer to a specific node or a specific hook
1011  * on a specific node, depending on how you look at it. In the
1012  * latter case, the PATH component must not end in a dot.
1013  *
1014  * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1015  * of hook names separated by dots. This breaks out the original
1016  * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1017  * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1018  * the final hook component of <PATH>, if any, otherwise NULL.
1019  *
1020  * This returns -1 if the path is malformed. The char ** are optional.
1021  */
1022 
1023 int
1024 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1025 {
1026 	char   *node, *path, *hook;
1027 	int     k;
1028 
1029 	/*
1030 	 * Extract absolute NODE, if any
1031 	 */
1032 	for (path = addr; *path && *path != ':'; path++);
1033 	if (*path) {
1034 		node = addr;	/* Here's the NODE */
1035 		*path++ = '\0';	/* Here's the PATH */
1036 
1037 		/* Node name must not be empty */
1038 		if (!*node)
1039 			return -1;
1040 
1041 		/* A name of "." is OK; otherwise '.' not allowed */
1042 		if (strcmp(node, ".") != 0) {
1043 			for (k = 0; node[k]; k++)
1044 				if (node[k] == '.')
1045 					return -1;
1046 		}
1047 	} else {
1048 		node = NULL;	/* No absolute NODE */
1049 		path = addr;	/* Here's the PATH */
1050 	}
1051 
1052 	/* Snoop for illegal characters in PATH */
1053 	for (k = 0; path[k]; k++)
1054 		if (path[k] == ':')
1055 			return -1;
1056 
1057 	/* Check for no repeated dots in PATH */
1058 	for (k = 0; path[k]; k++)
1059 		if (path[k] == '.' && path[k + 1] == '.')
1060 			return -1;
1061 
1062 	/* Remove extra (degenerate) dots from beginning or end of PATH */
1063 	if (path[0] == '.')
1064 		path++;
1065 	if (*path && path[strlen(path) - 1] == '.')
1066 		path[strlen(path) - 1] = 0;
1067 
1068 	/* If PATH has a dot, then we're not talking about a hook */
1069 	if (*path) {
1070 		for (hook = path, k = 0; path[k]; k++)
1071 			if (path[k] == '.') {
1072 				hook = NULL;
1073 				break;
1074 			}
1075 	} else
1076 		path = hook = NULL;
1077 
1078 	/* Done */
1079 	if (nodep)
1080 		*nodep = node;
1081 	if (pathp)
1082 		*pathp = path;
1083 	if (hookp)
1084 		*hookp = hook;
1085 	return (0);
1086 }
1087 
1088 /*
1089  * Given a path, which may be absolute or relative, and a starting node,
1090  * return the destination node. Compute the "return address" if desired.
1091  */
1092 int
1093 ng_path2node(node_p here, const char *address, node_p *destp, char **rtnp)
1094 {
1095 	const	node_p start = here;
1096 	char    fullpath[NG_PATHSIZ];
1097 	char   *nodename, *path, pbuf[2];
1098 	node_p  node;
1099 	char   *cp;
1100 
1101 	/* Initialize */
1102 	if (rtnp)
1103 		*rtnp = NULL;
1104 	if (destp == NULL)
1105 		return EINVAL;
1106 	*destp = NULL;
1107 
1108 	/* Make a writable copy of address for ng_path_parse() */
1109 	strncpy(fullpath, address, sizeof(fullpath) - 1);
1110 	fullpath[sizeof(fullpath) - 1] = '\0';
1111 
1112 	/* Parse out node and sequence of hooks */
1113 	if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1114 		TRAP_ERROR;
1115 		return EINVAL;
1116 	}
1117 	if (path == NULL) {
1118 		pbuf[0] = '.';	/* Needs to be writable */
1119 		pbuf[1] = '\0';
1120 		path = pbuf;
1121 	}
1122 
1123 	/* For an absolute address, jump to the starting node */
1124 	if (nodename) {
1125 		node = ng_findname(here, nodename);
1126 		if (node == NULL) {
1127 			TRAP_ERROR;
1128 			return (ENOENT);
1129 		}
1130 	} else
1131 		node = here;
1132 
1133 	/* Now follow the sequence of hooks */
1134 	for (cp = path; node != NULL && *cp != '\0'; ) {
1135 		hook_p hook;
1136 		char *segment;
1137 
1138 		/*
1139 		 * Break out the next path segment. Replace the dot we just
1140 		 * found with a NUL; "cp" points to the next segment (or the
1141 		 * NUL at the end).
1142 		 */
1143 		for (segment = cp; *cp != '\0'; cp++) {
1144 			if (*cp == '.') {
1145 				*cp++ = '\0';
1146 				break;
1147 			}
1148 		}
1149 
1150 		/* Empty segment */
1151 		if (*segment == '\0')
1152 			continue;
1153 
1154 		/* We have a segment, so look for a hook by that name */
1155 		hook = ng_findhook(node, segment);
1156 
1157 		/* Can't get there from here... */
1158 		if (hook == NULL
1159 		    || hook->peer == NULL
1160 		    || (hook->flags & HK_INVALID) != 0) {
1161 			TRAP_ERROR;
1162 			return (ENOENT);
1163 		}
1164 
1165 		/* Hop on over to the next node */
1166 		node = hook->peer->node;
1167 	}
1168 
1169 	/* If node somehow missing, fail here (probably this is not needed) */
1170 	if (node == NULL) {
1171 		TRAP_ERROR;
1172 		return (ENXIO);
1173 	}
1174 
1175 	/* Now compute return address, i.e., the path to the sender */
1176 	if (rtnp != NULL) {
1177 		MALLOC(*rtnp, char *, NG_NODESIZ + 1, M_NETGRAPH, M_NOWAIT);
1178 		if (*rtnp == NULL) {
1179 			TRAP_ERROR;
1180 			return (ENOMEM);
1181 		}
1182 		if (start->name != NULL)
1183 			ksprintf(*rtnp, "%s:", start->name);
1184 		else
1185 			ksprintf(*rtnp, "[%x]:", ng_node2ID(start));
1186 	}
1187 
1188 	/* Done */
1189 	*destp = node;
1190 	return (0);
1191 }
1192 
1193 /*
1194  * Call the appropriate message handler for the object.
1195  * It is up to the message handler to free the message.
1196  * If it's a generic message, handle it generically, otherwise
1197  * call the type's message handler (if it exists)
1198  * XXX (race). Remember that a queued message may reference a node
1199  * or hook that has just been invalidated. It will exist
1200  * as the queue code is holding a reference, but..
1201  */
1202 
1203 #define CALL_MSG_HANDLER(error, node, msg, retaddr, resp)		\
1204 do {									\
1205 	if((msg)->header.typecookie == NGM_GENERIC_COOKIE) {		\
1206 		(error) = ng_generic_msg((node), (msg),			\
1207 				(retaddr), (resp));			\
1208 	} else {							\
1209 		if ((node)->type->rcvmsg != NULL) {			\
1210 			(error) = (*(node)->type->rcvmsg)((node),	\
1211 					(msg), (retaddr), (resp));	\
1212 		} else {						\
1213 			TRAP_ERROR;					\
1214 			FREE((msg), M_NETGRAPH);			\
1215 			(error) = EINVAL;				\
1216 		}							\
1217 	}								\
1218 } while (0)
1219 
1220 
1221 /*
1222  * Send a control message to a node
1223  */
1224 int
1225 ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
1226 	    struct ng_mesg **rptr)
1227 {
1228 	node_p  dest = NULL;
1229 	char   *retaddr = NULL;
1230 	int     error;
1231 
1232 	/* Find the target node */
1233 	error = ng_path2node(here, address, &dest, &retaddr);
1234 	if (error) {
1235 		FREE(msg, M_NETGRAPH);
1236 		return error;
1237 	}
1238 
1239 	/* Make sure the resp field is null before we start */
1240 	if (rptr != NULL)
1241 		*rptr = NULL;
1242 
1243 	CALL_MSG_HANDLER(error, dest, msg, retaddr, rptr);
1244 
1245 	/* Make sure that if there is a response, it has the RESP bit set */
1246 	if ((error == 0) && rptr && *rptr)
1247 		(*rptr)->header.flags |= NGF_RESP;
1248 
1249 	/*
1250 	 * If we had a return address it is up to us to free it. They should
1251 	 * have taken a copy if they needed to make a delayed response.
1252 	 */
1253 	if (retaddr)
1254 		FREE(retaddr, M_NETGRAPH);
1255 	return (error);
1256 }
1257 
1258 /*
1259  * Implement the 'generic' control messages
1260  */
1261 static int
1262 ng_generic_msg(node_p here, struct ng_mesg *msg, const char *retaddr,
1263 	       struct ng_mesg **resp)
1264 {
1265 	int error = 0;
1266 
1267 	if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
1268 		TRAP_ERROR;
1269 		FREE(msg, M_NETGRAPH);
1270 		return (EINVAL);
1271 	}
1272 	switch (msg->header.cmd) {
1273 	case NGM_SHUTDOWN:
1274 		ng_rmnode(here);
1275 		break;
1276 	case NGM_MKPEER:
1277 	    {
1278 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
1279 
1280 		if (msg->header.arglen != sizeof(*mkp)) {
1281 			TRAP_ERROR;
1282 			return (EINVAL);
1283 		}
1284 		mkp->type[sizeof(mkp->type) - 1] = '\0';
1285 		mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
1286 		mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
1287 		error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
1288 		break;
1289 	    }
1290 	case NGM_CONNECT:
1291 	    {
1292 		struct ngm_connect *const con =
1293 			(struct ngm_connect *) msg->data;
1294 		node_p node2;
1295 
1296 		if (msg->header.arglen != sizeof(*con)) {
1297 			TRAP_ERROR;
1298 			return (EINVAL);
1299 		}
1300 		con->path[sizeof(con->path) - 1] = '\0';
1301 		con->ourhook[sizeof(con->ourhook) - 1] = '\0';
1302 		con->peerhook[sizeof(con->peerhook) - 1] = '\0';
1303 		error = ng_path2node(here, con->path, &node2, NULL);
1304 		if (error)
1305 			break;
1306 		error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
1307 		break;
1308 	    }
1309 	case NGM_NAME:
1310 	    {
1311 		struct ngm_name *const nam = (struct ngm_name *) msg->data;
1312 
1313 		if (msg->header.arglen != sizeof(*nam)) {
1314 			TRAP_ERROR;
1315 			return (EINVAL);
1316 		}
1317 		nam->name[sizeof(nam->name) - 1] = '\0';
1318 		error = ng_name_node(here, nam->name);
1319 		break;
1320 	    }
1321 	case NGM_RMHOOK:
1322 	    {
1323 		struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
1324 		hook_p hook;
1325 
1326 		if (msg->header.arglen != sizeof(*rmh)) {
1327 			TRAP_ERROR;
1328 			return (EINVAL);
1329 		}
1330 		rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
1331 		if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
1332 			ng_destroy_hook(hook);
1333 		break;
1334 	    }
1335 	case NGM_NODEINFO:
1336 	    {
1337 		struct nodeinfo *ni;
1338 		struct ng_mesg *rp;
1339 
1340 		/* Get response struct */
1341 		if (resp == NULL) {
1342 			error = EINVAL;
1343 			break;
1344 		}
1345 		NG_MKRESPONSE(rp, msg, sizeof(*ni), M_NOWAIT);
1346 		if (rp == NULL) {
1347 			error = ENOMEM;
1348 			break;
1349 		}
1350 
1351 		/* Fill in node info */
1352 		ni = (struct nodeinfo *) rp->data;
1353 		if (here->name != NULL)
1354 			strlcpy(ni->name, here->name, NG_NODESIZ);
1355 		strlcpy(ni->type, here->type->name, NG_TYPESIZ);
1356 		ni->id = ng_node2ID(here);
1357 		ni->hooks = here->numhooks;
1358 		*resp = rp;
1359 		break;
1360 	    }
1361 	case NGM_LISTHOOKS:
1362 	    {
1363 		const int nhooks = here->numhooks;
1364 		struct hooklist *hl;
1365 		struct nodeinfo *ni;
1366 		struct ng_mesg *rp;
1367 		hook_p hook;
1368 
1369 		/* Get response struct */
1370 		if (resp == NULL) {
1371 			error = EINVAL;
1372 			break;
1373 		}
1374 		NG_MKRESPONSE(rp, msg, sizeof(*hl)
1375 		    + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
1376 		if (rp == NULL) {
1377 			error = ENOMEM;
1378 			break;
1379 		}
1380 		hl = (struct hooklist *) rp->data;
1381 		ni = &hl->nodeinfo;
1382 
1383 		/* Fill in node info */
1384 		if (here->name)
1385 			strlcpy(ni->name, here->name, NG_NODESIZ);
1386 		strlcpy(ni->type, here->type->name, NG_TYPESIZ);
1387 		ni->id = ng_node2ID(here);
1388 
1389 		/* Cycle through the linked list of hooks */
1390 		ni->hooks = 0;
1391 		LIST_FOREACH(hook, &here->hooks, hooks) {
1392 			struct linkinfo *const link = &hl->link[ni->hooks];
1393 
1394 			if (ni->hooks >= nhooks) {
1395 				log(LOG_ERR, "%s: number of %s changed\n",
1396 				    __func__, "hooks");
1397 				break;
1398 			}
1399 			if ((hook->flags & HK_INVALID) != 0)
1400 				continue;
1401 			strlcpy(link->ourhook, hook->name, NG_HOOKSIZ);
1402 			strlcpy(link->peerhook, hook->peer->name, NG_HOOKSIZ);
1403 			if (hook->peer->node->name != NULL)
1404 				strlcpy(link->nodeinfo.name,
1405 				    hook->peer->node->name, NG_NODESIZ);
1406 			strlcpy(link->nodeinfo.type,
1407 			   hook->peer->node->type->name, NG_TYPESIZ);
1408 			link->nodeinfo.id = ng_node2ID(hook->peer->node);
1409 			link->nodeinfo.hooks = hook->peer->node->numhooks;
1410 			ni->hooks++;
1411 		}
1412 		*resp = rp;
1413 		break;
1414 	    }
1415 
1416 	case NGM_LISTNAMES:
1417 	case NGM_LISTNODES:
1418 	    {
1419 		const int unnamed = (msg->header.cmd == NGM_LISTNODES);
1420 		struct namelist *nl;
1421 		struct ng_mesg *rp;
1422 		node_p node;
1423 		int num = 0;
1424 
1425 		if (resp == NULL) {
1426 			error = EINVAL;
1427 			break;
1428 		}
1429 
1430 		/* Count number of nodes */
1431 		LIST_FOREACH(node, &nodelist, nodes) {
1432 			if ((node->flags & NG_INVALID) == 0
1433 			    && (unnamed || node->name != NULL))
1434 				num++;
1435 		}
1436 
1437 		/* Get response struct */
1438 		if (resp == NULL) {
1439 			error = EINVAL;
1440 			break;
1441 		}
1442 		NG_MKRESPONSE(rp, msg, sizeof(*nl)
1443 		    + (num * sizeof(struct nodeinfo)), M_NOWAIT);
1444 		if (rp == NULL) {
1445 			error = ENOMEM;
1446 			break;
1447 		}
1448 		nl = (struct namelist *) rp->data;
1449 
1450 		/* Cycle through the linked list of nodes */
1451 		nl->numnames = 0;
1452 		LIST_FOREACH(node, &nodelist, nodes) {
1453 			struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
1454 
1455 			if (nl->numnames >= num) {
1456 				log(LOG_ERR, "%s: number of %s changed\n",
1457 				    __func__, "nodes");
1458 				break;
1459 			}
1460 			if ((node->flags & NG_INVALID) != 0)
1461 				continue;
1462 			if (!unnamed && node->name == NULL)
1463 				continue;
1464 			if (node->name != NULL)
1465 				strlcpy(np->name, node->name, NG_NODESIZ);
1466 			strlcpy(np->type, node->type->name, NG_TYPESIZ);
1467 			np->id = ng_node2ID(node);
1468 			np->hooks = node->numhooks;
1469 			nl->numnames++;
1470 		}
1471 		*resp = rp;
1472 		break;
1473 	    }
1474 
1475 	case NGM_LISTTYPES:
1476 	    {
1477 		struct typelist *tl;
1478 		struct ng_mesg *rp;
1479 		struct ng_type *type;
1480 		int num = 0;
1481 
1482 		if (resp == NULL) {
1483 			error = EINVAL;
1484 			break;
1485 		}
1486 
1487 		/* Count number of types */
1488 		LIST_FOREACH(type, &typelist, types)
1489 			num++;
1490 
1491 		/* Get response struct */
1492 		if (resp == NULL) {
1493 			error = EINVAL;
1494 			break;
1495 		}
1496 		NG_MKRESPONSE(rp, msg, sizeof(*tl)
1497 		    + (num * sizeof(struct typeinfo)), M_NOWAIT);
1498 		if (rp == NULL) {
1499 			error = ENOMEM;
1500 			break;
1501 		}
1502 		tl = (struct typelist *) rp->data;
1503 
1504 		/* Cycle through the linked list of types */
1505 		tl->numtypes = 0;
1506 		LIST_FOREACH(type, &typelist, types) {
1507 			struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
1508 
1509 			if (tl->numtypes >= num) {
1510 				log(LOG_ERR, "%s: number of %s changed\n",
1511 				    __func__, "types");
1512 				break;
1513 			}
1514 			strlcpy(tp->type_name, type->name, NG_TYPESIZ);
1515 			tp->numnodes = type->refs - 1; /* don't count list */
1516 			tl->numtypes++;
1517 		}
1518 		*resp = rp;
1519 		break;
1520 	    }
1521 
1522 	case NGM_BINARY2ASCII:
1523 	    {
1524 		int bufSize = 20 * 1024;	/* XXX hard coded constant */
1525 		const struct ng_parse_type *argstype;
1526 		const struct ng_cmdlist *c;
1527 		struct ng_mesg *rp, *binary, *ascii;
1528 
1529 		/* Data area must contain a valid netgraph message */
1530 		binary = (struct ng_mesg *)msg->data;
1531 		if (msg->header.arglen < sizeof(struct ng_mesg)
1532 		    || msg->header.arglen - sizeof(struct ng_mesg)
1533 		      < binary->header.arglen) {
1534 			error = EINVAL;
1535 			break;
1536 		}
1537 
1538 		/* Get a response message with lots of room */
1539 		NG_MKRESPONSE(rp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
1540 		if (rp == NULL) {
1541 			error = ENOMEM;
1542 			break;
1543 		}
1544 		ascii = (struct ng_mesg *)rp->data;
1545 
1546 		/* Copy binary message header to response message payload */
1547 		bcopy(binary, ascii, sizeof(*binary));
1548 
1549 		/* Find command by matching typecookie and command number */
1550 		for (c = here->type->cmdlist;
1551 		    c != NULL && c->name != NULL; c++) {
1552 			if (binary->header.typecookie == c->cookie
1553 			    && binary->header.cmd == c->cmd)
1554 				break;
1555 		}
1556 		if (c == NULL || c->name == NULL) {
1557 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1558 				if (binary->header.typecookie == c->cookie
1559 				    && binary->header.cmd == c->cmd)
1560 					break;
1561 			}
1562 			if (c->name == NULL) {
1563 				FREE(rp, M_NETGRAPH);
1564 				error = ENOSYS;
1565 				break;
1566 			}
1567 		}
1568 
1569 		/* Convert command name to ASCII */
1570 		ksnprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
1571 		    "%s", c->name);
1572 
1573 		/* Convert command arguments to ASCII */
1574 		argstype = (binary->header.flags & NGF_RESP) ?
1575 		    c->respType : c->mesgType;
1576 		if (argstype == NULL)
1577 			*ascii->data = '\0';
1578 		else {
1579 			if ((error = ng_unparse(argstype,
1580 			    (u_char *)binary->data,
1581 			    ascii->data, bufSize)) != 0) {
1582 				FREE(rp, M_NETGRAPH);
1583 				break;
1584 			}
1585 		}
1586 
1587 		/* Return the result as struct ng_mesg plus ASCII string */
1588 		bufSize = strlen(ascii->data) + 1;
1589 		ascii->header.arglen = bufSize;
1590 		rp->header.arglen = sizeof(*ascii) + bufSize;
1591 		*resp = rp;
1592 		break;
1593 	    }
1594 
1595 	case NGM_ASCII2BINARY:
1596 	    {
1597 		int bufSize = 2000;	/* XXX hard coded constant */
1598 		const struct ng_cmdlist *c;
1599 		const struct ng_parse_type *argstype;
1600 		struct ng_mesg *rp, *ascii, *binary;
1601 		int off = 0;
1602 
1603 		/* Data area must contain at least a struct ng_mesg + '\0' */
1604 		ascii = (struct ng_mesg *)msg->data;
1605 		if (msg->header.arglen < sizeof(*ascii) + 1
1606 		    || ascii->header.arglen < 1
1607 		    || msg->header.arglen
1608 		      < sizeof(*ascii) + ascii->header.arglen) {
1609 			error = EINVAL;
1610 			break;
1611 		}
1612 		ascii->data[ascii->header.arglen - 1] = '\0';
1613 
1614 		/* Get a response message with lots of room */
1615 		NG_MKRESPONSE(rp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
1616 		if (rp == NULL) {
1617 			error = ENOMEM;
1618 			break;
1619 		}
1620 		binary = (struct ng_mesg *)rp->data;
1621 
1622 		/* Copy ASCII message header to response message payload */
1623 		bcopy(ascii, binary, sizeof(*ascii));
1624 
1625 		/* Find command by matching ASCII command string */
1626 		for (c = here->type->cmdlist;
1627 		    c != NULL && c->name != NULL; c++) {
1628 			if (strcmp(ascii->header.cmdstr, c->name) == 0)
1629 				break;
1630 		}
1631 		if (c == NULL || c->name == NULL) {
1632 			for (c = ng_generic_cmds; c->name != NULL; c++) {
1633 				if (strcmp(ascii->header.cmdstr, c->name) == 0)
1634 					break;
1635 			}
1636 			if (c->name == NULL) {
1637 				FREE(rp, M_NETGRAPH);
1638 				error = ENOSYS;
1639 				break;
1640 			}
1641 		}
1642 
1643 		/* Convert command name to binary */
1644 		binary->header.cmd = c->cmd;
1645 		binary->header.typecookie = c->cookie;
1646 
1647 		/* Convert command arguments to binary */
1648 		argstype = (binary->header.flags & NGF_RESP) ?
1649 		    c->respType : c->mesgType;
1650 		if (argstype == NULL)
1651 			bufSize = 0;
1652 		else {
1653 			if ((error = ng_parse(argstype, ascii->data,
1654 			    &off, (u_char *)binary->data, &bufSize)) != 0) {
1655 				FREE(rp, M_NETGRAPH);
1656 				break;
1657 			}
1658 		}
1659 
1660 		/* Return the result */
1661 		binary->header.arglen = bufSize;
1662 		rp->header.arglen = sizeof(*binary) + bufSize;
1663 		*resp = rp;
1664 		break;
1665 	    }
1666 
1667 	case NGM_TEXT_CONFIG:
1668 	case NGM_TEXT_STATUS:
1669 		/*
1670 		 * This one is tricky as it passes the command down to the
1671 		 * actual node, even though it is a generic type command.
1672 		 * This means we must assume that the msg is already freed
1673 		 * when control passes back to us.
1674 		 */
1675 		if (resp == NULL) {
1676 			error = EINVAL;
1677 			break;
1678 		}
1679 		if (here->type->rcvmsg != NULL)
1680 			return((*here->type->rcvmsg)(here, msg, retaddr, resp));
1681 		/* Fall through if rcvmsg not supported */
1682 	default:
1683 		TRAP_ERROR;
1684 		error = EINVAL;
1685 	}
1686 	FREE(msg, M_NETGRAPH);
1687 	return (error);
1688 }
1689 
1690 /*
1691  * Send a data packet to a node. If the recipient has no
1692  * 'receive data' method, then silently discard the packet.
1693  */
1694 int
1695 ng_send_data(hook_p hook, struct mbuf *m, meta_p meta)
1696 {
1697 	int (*rcvdata)(hook_p, struct mbuf *, meta_p);
1698 	int error;
1699 
1700 	CHECK_DATA_MBUF(m);
1701 	if (hook && (hook->flags & HK_INVALID) == 0) {
1702 		rcvdata = hook->peer->node->type->rcvdata;
1703 		if (rcvdata != NULL)
1704 			error = (*rcvdata)(hook->peer, m, meta);
1705 		else {
1706 			error = 0;
1707 			NG_FREE_DATA(m, meta);
1708 		}
1709 	} else {
1710 		TRAP_ERROR;
1711 		error = ENOTCONN;
1712 		NG_FREE_DATA(m, meta);
1713 	}
1714 	return (error);
1715 }
1716 
1717 /*
1718  * Send a queued data packet to a node. If the recipient has no
1719  * 'receive queued data' method, then try the 'receive data' method above.
1720  */
1721 int
1722 ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta)
1723 {
1724 	int (*rcvdataq)(hook_p, struct mbuf *, meta_p);
1725 	int error;
1726 
1727 	CHECK_DATA_MBUF(m);
1728 	if (hook && (hook->flags & HK_INVALID) == 0) {
1729 		rcvdataq = hook->peer->node->type->rcvdataq;
1730 		if (rcvdataq != NULL)
1731 			error = (*rcvdataq)(hook->peer, m, meta);
1732 		else {
1733 			error = ng_send_data(hook, m, meta);
1734 		}
1735 	} else {
1736 		TRAP_ERROR;
1737 		error = ENOTCONN;
1738 		NG_FREE_DATA(m, meta);
1739 	}
1740 	return (error);
1741 }
1742 
1743 /*
1744  * Copy a 'meta'.
1745  *
1746  * Returns new meta, or NULL if original meta is NULL or ENOMEM.
1747  */
1748 meta_p
1749 ng_copy_meta(meta_p meta)
1750 {
1751 	meta_p meta2;
1752 
1753 	if (meta == NULL)
1754 		return (NULL);
1755 	MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH, M_NOWAIT);
1756 	if (meta2 == NULL)
1757 		return (NULL);
1758 	meta2->allocated_len = meta->used_len;
1759 	bcopy(meta, meta2, meta->used_len);
1760 	return (meta2);
1761 }
1762 
1763 /************************************************************************
1764 			Module routines
1765 ************************************************************************/
1766 
1767 /*
1768  * Handle the loading/unloading of a netgraph node type module
1769  */
1770 int
1771 ng_mod_event(module_t mod, int event, void *data)
1772 {
1773 	struct ng_type *const type = data;
1774 	int error = 0;
1775 
1776 	switch (event) {
1777 	case MOD_LOAD:
1778 
1779 		/* Register new netgraph node type */
1780 		crit_enter();
1781 		if ((error = ng_newtype(type)) != 0) {
1782 			crit_exit();
1783 			break;
1784 		}
1785 
1786 		/* Call type specific code */
1787 		if (type->mod_event != NULL)
1788 			if ((error = (*type->mod_event)(mod, event, data))) {
1789 				type->refs--;	/* undo it */
1790 				LIST_REMOVE(type, types);
1791 			}
1792 		crit_exit();
1793 		break;
1794 
1795 	case MOD_UNLOAD:
1796 		crit_enter();
1797 		if (type->refs > 1) {		/* make sure no nodes exist! */
1798 			error = EBUSY;
1799 		} else {
1800 			if (type->refs == 0) {
1801 				/* failed load, nothing to undo */
1802 				crit_exit();
1803 				break;
1804 			}
1805 			if (type->mod_event != NULL) {	/* check with type */
1806 				error = (*type->mod_event)(mod, event, data);
1807 				if (error != 0) {	/* type refuses.. */
1808 					crit_exit();
1809 					break;
1810 				}
1811 			}
1812 			LIST_REMOVE(type, types);
1813 		}
1814 		crit_exit();
1815 		break;
1816 
1817 	default:
1818 		if (type->mod_event != NULL)
1819 			error = (*type->mod_event)(mod, event, data);
1820 		else
1821 			error = 0;		/* XXX ? */
1822 		break;
1823 	}
1824 	return (error);
1825 }
1826 
1827 /*
1828  * Handle loading and unloading for this code.
1829  * The only thing we need to link into is the NETISR strucure.
1830  */
1831 static int
1832 ngb_mod_event(module_t mod, int event, void *data)
1833 {
1834 	int error = 0;
1835 
1836 	switch (event) {
1837 	case MOD_LOAD:
1838 		/* Register line discipline */
1839 		crit_enter();
1840 		error = ng_load_module("ksocket");
1841 		if (error != 0) {
1842 			crit_exit();
1843 			break;
1844 		}
1845 		netisr_register(NETISR_NETGRAPH, cpu0_portfn,
1846 				pktinfo_portfn_notsupp, ngintr,
1847 				NETISR_FLAG_NOTMPSAFE);
1848 		error = 0;
1849 		crit_exit();
1850 		break;
1851 	case MOD_UNLOAD:
1852 		ng_unload_module("ksocket");
1853 		/* You cant unload it because an interface may be using it.  */
1854 		error = EBUSY;
1855 		break;
1856 	default:
1857 		error = EOPNOTSUPP;
1858 		break;
1859 	}
1860 	return (error);
1861 }
1862 
1863 static moduledata_t netgraph_mod = {
1864 	"netgraph",
1865 	ngb_mod_event,
1866 	(NULL)
1867 };
1868 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1869 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
1870 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
1871 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
1872 
1873 /************************************************************************
1874 			Queueing routines
1875 ************************************************************************/
1876 
1877 /* The structure for queueing across ISR switches */
1878 struct ng_queue_entry {
1879 	u_long	flags;
1880 	struct ng_queue_entry *next;
1881 	union {
1882 		struct {
1883 			hook_p		da_hook;	/*  target hook */
1884 			struct mbuf	*da_m;
1885 			meta_p		da_meta;
1886 		} data;
1887 		struct {
1888 			struct ng_mesg	*msg_msg;
1889 			node_p		msg_node;
1890 			void		*msg_retaddr;
1891 		} msg;
1892 	} body;
1893 };
1894 #define NGQF_DATA	0x01		/* the queue element is data */
1895 #define NGQF_MESG	0x02		/* the queue element is a message */
1896 
1897 static struct ng_queue_entry   *ngqbase;	/* items to be unqueued */
1898 static struct ng_queue_entry   *ngqlast;	/* last item queued */
1899 static const int		ngqroom = 256;	/* max items to queue */
1900 static int			ngqsize;	/* number of items in queue */
1901 
1902 static struct ng_queue_entry   *ngqfree;	/* free ones */
1903 static const int		ngqfreemax = 256;/* cache at most this many */
1904 static int			ngqfreesize;	/* number of cached entries */
1905 
1906 /*
1907  * Get a queue entry
1908  */
1909 static struct ng_queue_entry *
1910 ng_getqblk(void)
1911 {
1912 	struct ng_queue_entry *q;
1913 
1914 	/* Could be guarding against tty ints or whatever */
1915 	crit_enter();
1916 
1917 	/* Try get a cached queue block, or else allocate a new one */
1918 	if ((q = ngqfree) == NULL) {
1919 		crit_exit();
1920 		if (ngqsize < ngqroom) {	/* don't worry about races */
1921 			MALLOC(q, struct ng_queue_entry *,
1922 			    sizeof(*q), M_NETGRAPH, M_NOWAIT);
1923 		}
1924 	} else {
1925 		ngqfree = q->next;
1926 		ngqfreesize--;
1927 		crit_exit();
1928 	}
1929 	return (q);
1930 }
1931 
1932 /*
1933  * Release a queue entry
1934  */
1935 #define RETURN_QBLK(q)							\
1936 do {									\
1937 	if (ngqfreesize < ngqfreemax) { /* don't worry about races */ 	\
1938 		crit_enter();						\
1939 		(q)->next = ngqfree;					\
1940 		ngqfree = (q);						\
1941 		ngqfreesize++;						\
1942 		crit_exit();						\
1943 	} else {							\
1944 		FREE((q), M_NETGRAPH);					\
1945 	}								\
1946 } while (0)
1947 
1948 /*
1949  * Running at a raised (but we don't know which) processor priority level,
1950  * put the data onto a queue to be picked up by another PPL (probably splnet)
1951  */
1952 int
1953 ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta)
1954 {
1955 	struct ng_queue_entry *q;
1956 
1957 	if (hook == NULL) {
1958 		NG_FREE_DATA(m, meta);
1959 		return (0);
1960 	}
1961 	if ((q = ng_getqblk()) == NULL) {
1962 		NG_FREE_DATA(m, meta);
1963 		return (ENOBUFS);
1964 	}
1965 
1966 	/* Fill out the contents */
1967 	q->flags = NGQF_DATA;
1968 	q->next = NULL;
1969 	q->body.data.da_hook = hook;
1970 	q->body.data.da_m = m;
1971 	q->body.data.da_meta = meta;
1972 	crit_enter();		/* protect refs and queue */
1973 	hook->refs++;		/* don't let it go away while on the queue */
1974 
1975 	/* Put it on the queue */
1976 	if (ngqbase) {
1977 		ngqlast->next = q;
1978 	} else {
1979 		ngqbase = q;
1980 	}
1981 	ngqlast = q;
1982 	ngqsize++;
1983 	crit_exit();
1984 
1985 	/* Schedule software interrupt to handle it later */
1986 	schednetisr(NETISR_NETGRAPH);
1987 	return (0);
1988 }
1989 
1990 /*
1991  * Running at a raised (but we don't know which) processor priority level,
1992  * put the msg onto a queue to be picked up by another PPL (probably splnet)
1993  */
1994 int
1995 ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address)
1996 {
1997 	struct ng_queue_entry *q;
1998 	node_p  dest = NULL;
1999 	char   *retaddr = NULL;
2000 	int     error;
2001 
2002 	/* Find the target node. */
2003 	error = ng_path2node(here, address, &dest, &retaddr);
2004 	if (error) {
2005 		FREE(msg, M_NETGRAPH);
2006 		return (error);
2007 	}
2008 	if ((q = ng_getqblk()) == NULL) {
2009 		FREE(msg, M_NETGRAPH);
2010 		if (retaddr)
2011 			FREE(retaddr, M_NETGRAPH);
2012 		return (ENOBUFS);
2013 	}
2014 
2015 	/* Fill out the contents */
2016 	q->flags = NGQF_MESG;
2017 	q->next = NULL;
2018 	q->body.msg.msg_node = dest;
2019 	q->body.msg.msg_msg = msg;
2020 	q->body.msg.msg_retaddr = retaddr;
2021 	crit_enter();		/* protect refs and queue */
2022 	dest->refs++;		/* don't let it go away while on the queue */
2023 
2024 	/* Put it on the queue */
2025 	if (ngqbase) {
2026 		ngqlast->next = q;
2027 	} else {
2028 		ngqbase = q;
2029 	}
2030 	ngqlast = q;
2031 	ngqsize++;
2032 	crit_exit();
2033 
2034 	/* Schedule software interrupt to handle it later */
2035 	schednetisr(NETISR_NETGRAPH);
2036 	return (0);
2037 }
2038 
2039 /*
2040  * Pick an item off the queue, process it, and dispose of the queue entry.
2041  */
2042 static void
2043 ngintr(struct netmsg *pmsg)
2044 {
2045 	hook_p  hook;
2046 	struct mbuf *m;
2047 	struct ng_queue_entry *ngq;
2048 	meta_p  meta;
2049 	void   *retaddr;
2050 	struct ng_mesg *msg;
2051 	node_p  node;
2052 	int     error = 0;
2053 
2054 	/*
2055 	 * Packets are never sent to this netisr so the message must always
2056 	 * be replied.  Interlock processing and notification by replying
2057 	 * the message first.
2058 	 */
2059 	lwkt_replymsg(&pmsg->nm_lmsg, 0);
2060 
2061 	while (1) {
2062 		crit_enter();
2063 		if ((ngq = ngqbase)) {
2064 			ngqbase = ngq->next;
2065 			ngqsize--;
2066 		}
2067 		crit_exit();
2068 		if (ngq == NULL)
2069 			goto out;
2070 		switch (ngq->flags) {
2071 		case NGQF_DATA:
2072 			hook = ngq->body.data.da_hook;
2073 			m = ngq->body.data.da_m;
2074 			meta = ngq->body.data.da_meta;
2075 			RETURN_QBLK(ngq);
2076 			NG_SEND_DATAQ(error, hook, m, meta);
2077 			ng_unref_hook(hook);
2078 			break;
2079 		case NGQF_MESG:
2080 			node = ngq->body.msg.msg_node;
2081 			msg = ngq->body.msg.msg_msg;
2082 			retaddr = ngq->body.msg.msg_retaddr;
2083 			RETURN_QBLK(ngq);
2084 			if (node->flags & NG_INVALID) {
2085 				FREE(msg, M_NETGRAPH);
2086 			} else {
2087 				CALL_MSG_HANDLER(error, node, msg,
2088 						 retaddr, NULL);
2089 			}
2090 			ng_unref(node);
2091 			if (retaddr)
2092 				FREE(retaddr, M_NETGRAPH);
2093 			break;
2094 		default:
2095 			RETURN_QBLK(ngq);
2096 		}
2097 	}
2098 out:
2099 	;
2100 }
2101 
2102 
2103