1/*-
2 * Copyright (c) 2006 Vadim Goncharov <vadimnuclight@tpu.ru>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * Portions Copyright (c) 1999 Whistle Communications, Inc.
28 * (ng_bpf by Archie Cobbs <archie@freebsd.org>)
29 *
30 * $FreeBSD$
31 */
32
33/*
34 * TAG NETGRAPH NODE TYPE
35 *
36 * This node type accepts an arbitrary number of hooks. Each hook can be
37 * configured for an mbuf_tags(9) definition and two hook names: a hook
38 * for matched packets, and a hook for packets, that didn't match. Incoming
39 * packets are examined for configured tag, matched packets are delivered
40 * out via first hook, and not matched out via second. If corresponding hook
41 * is not configured, packets are dropped.
42 *
43 * A hook can also have an outgoing tag definition configured, so that
44 * all packets leaving the hook will be unconditionally appended with newly
45 * allocated tag.
46 *
47 * Both hooks can be set to null tag definitions (that is, with zeroed
48 * fields), so that packet tags are unmodified on output or all packets
49 * are unconditionally forwarded to non-matching hook on input.  There is
50 * also a possibility to replace tags by specifying strip flag on input
51 * and replacing tag on corresponding output tag (or simply remove tag if
52 * no tag specified on output).
53 *
54 * If compiled with NG_TAG_DEBUG, each hook also keeps statistics about
55 * how many packets have matched, etc.
56 */
57
58#include <sys/param.h>
59#include <sys/systm.h>
60#include <sys/errno.h>
61#include <sys/kernel.h>
62#include <sys/malloc.h>
63#include <sys/mbuf.h>
64#include <sys/stddef.h>
65
66#include <netgraph/ng_message.h>
67#include <netgraph/netgraph.h>
68#include <netgraph/ng_parse.h>
69#include <netgraph/ng_tag.h>
70
71#ifdef NG_SEPARATE_MALLOC
72static MALLOC_DEFINE(M_NETGRAPH_TAG, "netgraph_tag", "netgraph tag node");
73#else
74#define M_NETGRAPH_TAG M_NETGRAPH
75#endif
76
77#define ERROUT(x)	do { error = (x); goto done; } while (0)
78
79/*
80 * Per hook private info.
81 *
82 * We've separated API and ABI here, to make easier changes in this node,
83 * if needed. If you want to change representation, please do not break API.
84 * We still keep API structures in memory to simplify access to them for
85 * GET* messages, but most of data is accessed in internal representation
86 * only.  The reason for this is to speed things up - if data will be
87 * accessed from API structures, there would be double pointer dereferencing
88 * in the code, which almost necessarily leads to CPU cache misses and
89 * reloads.
90 *
91 * We also do another optimization by using resolved pointers to
92 * destination hooks instead of expensive ng_findhook().
93 */
94struct ng_tag_hookinfo {
95	hook_p			hi_match;	/* matching hook pointer */
96	hook_p			hi_nonmatch;	/* non-matching hook pointer */
97	uint32_t		in_tag_cookie;
98	uint32_t		out_tag_cookie;
99	uint16_t		in_tag_id;
100	uint16_t		in_tag_len;
101	uint16_t		out_tag_id;
102	uint16_t		out_tag_len;
103	uint8_t			strip;
104	void			*in_tag_data;
105	void			*out_tag_data;
106	struct ng_tag_hookin	*in;
107	struct ng_tag_hookout	*out;
108#ifdef NG_TAG_DEBUG
109	struct ng_tag_hookstat	stats;
110#endif
111};
112typedef struct ng_tag_hookinfo *hinfo_p;
113
114/* Netgraph methods. */
115static ng_constructor_t	ng_tag_constructor;
116static ng_rcvmsg_t	ng_tag_rcvmsg;
117static ng_shutdown_t	ng_tag_shutdown;
118static ng_newhook_t	ng_tag_newhook;
119static ng_rcvdata_t	ng_tag_rcvdata;
120static ng_disconnect_t	ng_tag_disconnect;
121
122/* Internal helper functions. */
123static int	ng_tag_setdata_in(hook_p hook, const struct ng_tag_hookin *hp);
124static int	ng_tag_setdata_out(hook_p hook, const struct ng_tag_hookout *hp);
125
126/* Parse types for the field 'tag_data' in structs ng_tag_hookin and out. */
127static int
128ng_tag_hookinary_getLength(const struct ng_parse_type *type,
129	const u_char *start, const u_char *buf)
130{
131	const struct ng_tag_hookin *hp;
132
133	hp = (const struct ng_tag_hookin *)
134	    (buf - offsetof(struct ng_tag_hookin, tag_data));
135	return (hp->tag_len);
136}
137
138static int
139ng_tag_hookoutary_getLength(const struct ng_parse_type *type,
140	const u_char *start, const u_char *buf)
141{
142	const struct ng_tag_hookout *hp;
143
144	hp = (const struct ng_tag_hookout *)
145	    (buf - offsetof(struct ng_tag_hookout, tag_data));
146	return (hp->tag_len);
147}
148
149static const struct ng_parse_type ng_tag_hookinary_type = {
150	&ng_parse_bytearray_type,
151	&ng_tag_hookinary_getLength
152};
153
154static const struct ng_parse_type ng_tag_hookoutary_type = {
155	&ng_parse_bytearray_type,
156	&ng_tag_hookoutary_getLength
157};
158
159/* Parse type for struct ng_tag_hookin. */
160static const struct ng_parse_struct_field ng_tag_hookin_type_fields[]
161	= NG_TAG_HOOKIN_TYPE_INFO(&ng_tag_hookinary_type);
162static const struct ng_parse_type ng_tag_hookin_type = {
163	&ng_parse_struct_type,
164	&ng_tag_hookin_type_fields
165};
166
167/* Parse type for struct ng_tag_hookout. */
168static const struct ng_parse_struct_field ng_tag_hookout_type_fields[]
169	= NG_TAG_HOOKOUT_TYPE_INFO(&ng_tag_hookoutary_type);
170static const struct ng_parse_type ng_tag_hookout_type = {
171	&ng_parse_struct_type,
172	&ng_tag_hookout_type_fields
173};
174
175#ifdef NG_TAG_DEBUG
176/* Parse type for struct ng_tag_hookstat. */
177static const struct ng_parse_struct_field ng_tag_hookstat_type_fields[]
178	= NG_TAG_HOOKSTAT_TYPE_INFO;
179static const struct ng_parse_type ng_tag_hookstat_type = {
180	&ng_parse_struct_type,
181	&ng_tag_hookstat_type_fields
182};
183#endif
184
185/* List of commands and how to convert arguments to/from ASCII. */
186static const struct ng_cmdlist ng_tag_cmdlist[] = {
187	{
188	  NGM_TAG_COOKIE,
189	  NGM_TAG_SET_HOOKIN,
190	  "sethookin",
191	  &ng_tag_hookin_type,
192	  NULL
193	},
194	{
195	  NGM_TAG_COOKIE,
196	  NGM_TAG_GET_HOOKIN,
197	  "gethookin",
198	  &ng_parse_hookbuf_type,
199	  &ng_tag_hookin_type
200	},
201	{
202	  NGM_TAG_COOKIE,
203	  NGM_TAG_SET_HOOKOUT,
204	  "sethookout",
205	  &ng_tag_hookout_type,
206	  NULL
207	},
208	{
209	  NGM_TAG_COOKIE,
210	  NGM_TAG_GET_HOOKOUT,
211	  "gethookout",
212	  &ng_parse_hookbuf_type,
213	  &ng_tag_hookout_type
214	},
215#ifdef NG_TAG_DEBUG
216	{
217	  NGM_TAG_COOKIE,
218	  NGM_TAG_GET_STATS,
219	  "getstats",
220	  &ng_parse_hookbuf_type,
221	  &ng_tag_hookstat_type
222	},
223	{
224	  NGM_TAG_COOKIE,
225	  NGM_TAG_CLR_STATS,
226	  "clrstats",
227	  &ng_parse_hookbuf_type,
228	  NULL
229	},
230	{
231	  NGM_TAG_COOKIE,
232	  NGM_TAG_GETCLR_STATS,
233	  "getclrstats",
234	  &ng_parse_hookbuf_type,
235	  &ng_tag_hookstat_type
236	},
237#endif
238	{ 0 }
239};
240
241/* Netgraph type descriptor. */
242static struct ng_type typestruct = {
243	.version =	NG_ABI_VERSION,
244	.name =		NG_TAG_NODE_TYPE,
245	.constructor =	ng_tag_constructor,
246	.rcvmsg =	ng_tag_rcvmsg,
247	.shutdown =	ng_tag_shutdown,
248	.newhook =	ng_tag_newhook,
249	.rcvdata =	ng_tag_rcvdata,
250	.disconnect =	ng_tag_disconnect,
251	.cmdlist =	ng_tag_cmdlist,
252};
253NETGRAPH_INIT(tag, &typestruct);
254
255/*
256 * This are default API structures (initialized to zeroes) which are
257 * returned in response to GET* messages when no configuration was made.
258 * One could ask why to have this structures at all when we have
259 * ng_tag_hookinfo initialized to zero and don't need in and out structures
260 * at all to operate.  Unfortunatelly, we have to return thisHook field
261 * in response to messages so the fastest and simpliest way is to have
262 * this default structures and initialize thisHook once at hook creation
263 * rather than to do it on every response.
264 */
265
266/* Default tag values for a hook that matches nothing. */
267static const struct ng_tag_hookin ng_tag_default_in = {
268	{ '\0' },		/* to be filled in at hook creation time */
269	{ '\0' },
270	{ '\0' },
271	0,
272	0,
273	0,
274	0
275};
276
277/* Default tag values for a hook that adds nothing */
278static const struct ng_tag_hookout ng_tag_default_out = {
279	{ '\0' },		/* to be filled in at hook creation time */
280	0,
281	0,
282	0
283};
284
285/*
286 * Node constructor.
287 *
288 * We don't keep any per-node private data - we do it on per-hook basis.
289 */
290static int
291ng_tag_constructor(node_p node)
292{
293	return (0);
294}
295
296/*
297 * Add a hook.
298 */
299static int
300ng_tag_newhook(node_p node, hook_p hook, const char *name)
301{
302	hinfo_p hip;
303	int error;
304
305	/* Create hook private structure. */
306	hip = malloc(sizeof(*hip), M_NETGRAPH_TAG, M_NOWAIT | M_ZERO);
307	if (hip == NULL)
308		return (ENOMEM);
309	NG_HOOK_SET_PRIVATE(hook, hip);
310
311	/*
312	 * After M_ZERO both in and out hook pointers are set to NULL,
313	 * as well as all members and pointers to in and out API
314	 * structures, so we need to set explicitly only thisHook field
315	 * in that structures (after allocating them, of course).
316	 */
317
318	/* Attach the default IN data. */
319	if ((error = ng_tag_setdata_in(hook, &ng_tag_default_in)) != 0) {
320		free(hip, M_NETGRAPH_TAG);
321		return (error);
322	}
323
324	/* Attach the default OUT data. */
325	if ((error = ng_tag_setdata_out(hook, &ng_tag_default_out)) != 0) {
326		free(hip, M_NETGRAPH_TAG);
327		return (error);
328	}
329
330	/*
331	 * Set hook name.  This is done only once at hook creation time
332	 * since hook name can't change, rather than to do it on every
333	 * response to messages requesting API structures with data who
334	 * we are etc.
335	 */
336	strncpy(hip->in->thisHook, name, sizeof(hip->in->thisHook) - 1);
337	hip->in->thisHook[sizeof(hip->in->thisHook) - 1] = '\0';
338	strncpy(hip->out->thisHook, name, sizeof(hip->out->thisHook) - 1);
339	hip->out->thisHook[sizeof(hip->out->thisHook) - 1] = '\0';
340	return (0);
341}
342
343/*
344 * Receive a control message.
345 */
346static int
347ng_tag_rcvmsg(node_p node, item_p item, hook_p lasthook)
348{
349	struct ng_mesg *msg;
350	struct ng_mesg *resp = NULL;
351	int error = 0;
352
353	NGI_GET_MSG(item, msg);
354	switch (msg->header.typecookie) {
355	case NGM_TAG_COOKIE:
356		switch (msg->header.cmd) {
357		case NGM_TAG_SET_HOOKIN:
358		    {
359			struct ng_tag_hookin *const
360			    hp = (struct ng_tag_hookin *)msg->data;
361			hook_p hook;
362
363			/* Sanity check. */
364			if (msg->header.arglen < sizeof(*hp)
365			    || msg->header.arglen !=
366			    NG_TAG_HOOKIN_SIZE(hp->tag_len))
367				ERROUT(EINVAL);
368
369			/* Find hook. */
370			if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
371				ERROUT(ENOENT);
372
373			/* Set new tag values. */
374			if ((error = ng_tag_setdata_in(hook, hp)) != 0)
375				ERROUT(error);
376			break;
377		    }
378
379		case NGM_TAG_SET_HOOKOUT:
380		    {
381			struct ng_tag_hookout *const
382			    hp = (struct ng_tag_hookout *)msg->data;
383			hook_p hook;
384
385			/* Sanity check. */
386			if (msg->header.arglen < sizeof(*hp)
387			    || msg->header.arglen !=
388			    NG_TAG_HOOKOUT_SIZE(hp->tag_len))
389				ERROUT(EINVAL);
390
391			/* Find hook. */
392			if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
393				ERROUT(ENOENT);
394
395			/* Set new tag values. */
396			if ((error = ng_tag_setdata_out(hook, hp)) != 0)
397				ERROUT(error);
398			break;
399		    }
400
401		case NGM_TAG_GET_HOOKIN:
402		    {
403			struct ng_tag_hookin *hp;
404			hook_p hook;
405
406			/* Sanity check. */
407			if (msg->header.arglen == 0)
408				ERROUT(EINVAL);
409			msg->data[msg->header.arglen - 1] = '\0';
410
411			/* Find hook. */
412			if ((hook = ng_findhook(node, msg->data)) == NULL)
413				ERROUT(ENOENT);
414
415			/* Build response. */
416			hp = ((hinfo_p)NG_HOOK_PRIVATE(hook))->in;
417			NG_MKRESPONSE(resp, msg,
418			    NG_TAG_HOOKIN_SIZE(hp->tag_len), M_WAITOK);
419			/* M_WAITOK can't return NULL. */
420			bcopy(hp, resp->data,
421			   NG_TAG_HOOKIN_SIZE(hp->tag_len));
422			break;
423		    }
424
425		case NGM_TAG_GET_HOOKOUT:
426		    {
427			struct ng_tag_hookout *hp;
428			hook_p hook;
429
430			/* Sanity check. */
431			if (msg->header.arglen == 0)
432				ERROUT(EINVAL);
433			msg->data[msg->header.arglen - 1] = '\0';
434
435			/* Find hook. */
436			if ((hook = ng_findhook(node, msg->data)) == NULL)
437				ERROUT(ENOENT);
438
439			/* Build response. */
440			hp = ((hinfo_p)NG_HOOK_PRIVATE(hook))->out;
441			NG_MKRESPONSE(resp, msg,
442			    NG_TAG_HOOKOUT_SIZE(hp->tag_len), M_WAITOK);
443			/* M_WAITOK can't return NULL. */
444			bcopy(hp, resp->data,
445			   NG_TAG_HOOKOUT_SIZE(hp->tag_len));
446			break;
447		    }
448
449#ifdef NG_TAG_DEBUG
450		case NGM_TAG_GET_STATS:
451		case NGM_TAG_CLR_STATS:
452		case NGM_TAG_GETCLR_STATS:
453		    {
454			struct ng_tag_hookstat *stats;
455			hook_p hook;
456
457			/* Sanity check. */
458			if (msg->header.arglen == 0)
459				ERROUT(EINVAL);
460			msg->data[msg->header.arglen - 1] = '\0';
461
462			/* Find hook. */
463			if ((hook = ng_findhook(node, msg->data)) == NULL)
464				ERROUT(ENOENT);
465			stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
466
467			/* Build response (if desired). */
468			if (msg->header.cmd != NGM_TAG_CLR_STATS) {
469				NG_MKRESPONSE(resp,
470				    msg, sizeof(*stats), M_WAITOK);
471				/* M_WAITOK can't return NULL. */
472				bcopy(stats, resp->data, sizeof(*stats));
473			}
474
475			/* Clear stats (if desired). */
476			if (msg->header.cmd != NGM_TAG_GET_STATS)
477				bzero(stats, sizeof(*stats));
478			break;
479		    }
480#endif /* NG_TAG_DEBUG */
481
482		default:
483			error = EINVAL;
484			break;
485		}
486		break;
487	default:
488		error = EINVAL;
489		break;
490	}
491done:
492	NG_RESPOND_MSG(error, node, item, resp);
493	NG_FREE_MSG(msg);
494	return (error);
495}
496
497/*
498 * Receive data on a hook.
499 *
500 * Apply the filter, and then drop or forward packet as appropriate.
501 */
502static int
503ng_tag_rcvdata(hook_p hook, item_p item)
504{
505	struct mbuf *m;
506	struct m_tag *tag = NULL;
507	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
508	uint16_t type, tag_len;
509	uint32_t cookie;
510	hinfo_p dhip;
511	hook_p dest;
512	int totlen;
513	int found = 0, error = 0;
514
515	m = NGI_M(item);	/* 'item' still owns it.. we are peeking */
516	totlen = m->m_pkthdr.len;
517
518#ifdef NG_TAG_DEBUG
519	hip->stats.recvFrames++;
520	hip->stats.recvOctets += totlen;
521#endif
522
523	/* Looking up incoming tag. */
524	cookie = hip->in_tag_cookie;
525	type = hip->in_tag_id;
526	tag_len = hip->in_tag_len;
527
528	/*
529	 * We treat case of all zeroes specially (that is, cookie and
530	 * type are equal to zero), as we assume that such tag
531	 * can never occur in the wild.  So we don't waste time trying
532	 * to find such tag (for example, these are zeroes after hook
533	 * creation in default structures).
534	 */
535	if ((cookie != 0) || (type != 0)) {
536		tag = m_tag_locate(m, cookie, type, NULL);
537		while (tag != NULL) {
538			if (memcmp((void *)(tag + 1),
539			    hip->in_tag_data, tag_len) == 0) {
540				found = 1;
541				break;
542			}
543			tag = m_tag_locate(m, cookie, type, tag);
544		}
545	}
546
547	/* See if we got a match and find destination hook. */
548	if (found) {
549#ifdef NG_TAG_DEBUG
550		hip->stats.recvMatchFrames++;
551		hip->stats.recvMatchOctets += totlen;
552#endif
553		if (hip->strip)
554			m_tag_delete(m, tag);
555		dest = hip->hi_match;
556	} else
557		dest = hip->hi_nonmatch;
558	if (dest == NULL) {
559		NG_FREE_ITEM(item);
560		return (0);
561	}
562
563	/* Deliver frame out destination hook. */
564	dhip = NG_HOOK_PRIVATE(dest);
565
566#ifdef NG_TAG_DEBUG
567	dhip->stats.xmitOctets += totlen;
568	dhip->stats.xmitFrames++;
569#endif
570
571	cookie = dhip->out_tag_cookie;
572	type = dhip->out_tag_id;
573	tag_len = dhip->out_tag_len;
574
575	if ((cookie != 0) || (type != 0)) {
576		tag = m_tag_alloc(cookie, type, tag_len, M_NOWAIT);
577		/* XXX may be free the mbuf if tag allocation failed? */
578		if (tag != NULL) {
579			if (tag_len != 0) {
580				/* copy tag data to its place */
581				memcpy((void *)(tag + 1),
582				    dhip->out_tag_data, tag_len);
583			}
584			m_tag_prepend(m, tag);
585		}
586	}
587
588	NG_FWD_ITEM_HOOK(error, item, dest);
589	return (error);
590}
591
592/*
593 * Shutdown processing.
594 */
595static int
596ng_tag_shutdown(node_p node)
597{
598	NG_NODE_UNREF(node);
599	return (0);
600}
601
602/*
603 * Hook disconnection.
604 *
605 * We must check all hooks, since they may reference this one.
606 */
607static int
608ng_tag_disconnect(hook_p hook)
609{
610	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
611	node_p node = NG_HOOK_NODE(hook);
612	hook_p hook2;
613
614	KASSERT(hip != NULL, ("%s: null info", __func__));
615
616	LIST_FOREACH(hook2, &node->nd_hooks, hk_hooks) {
617		hinfo_p priv = NG_HOOK_PRIVATE(hook2);
618
619		if (priv->hi_match == hook)
620			priv->hi_match = NULL;
621		if (priv->hi_nonmatch == hook)
622			priv->hi_nonmatch = NULL;
623	}
624
625	free(hip->in, M_NETGRAPH_TAG);
626	free(hip->out, M_NETGRAPH_TAG);
627	free(hip, M_NETGRAPH_TAG);
628	NG_HOOK_SET_PRIVATE(hook, NULL);			/* for good measure */
629	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
630	    (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
631		ng_rmnode_self(NG_HOOK_NODE(hook));
632	}
633	return (0);
634}
635
636/************************************************************************
637			HELPER STUFF
638 ************************************************************************/
639
640/*
641 * Set the IN tag values associated with a hook.
642 */
643static int
644ng_tag_setdata_in(hook_p hook, const struct ng_tag_hookin *hp0)
645{
646	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
647	struct ng_tag_hookin *hp;
648	int size;
649
650	/* Make a copy of the tag values and data. */
651	size = NG_TAG_HOOKIN_SIZE(hp0->tag_len);
652	hp = malloc(size, M_NETGRAPH_TAG, M_WAITOK);
653	/* M_WAITOK can't return NULL. */
654	bcopy(hp0, hp, size);
655
656	/* Free previous tag, if any, and assign new one. */
657	if (hip->in != NULL)
658		free(hip->in, M_NETGRAPH_TAG);
659	hip->in = hp;
660
661	/*
662	 * Resolve hook names to pointers.
663	 *
664	 * As ng_findhook() is expensive operation to do it on every packet
665	 * after tag matching check, we do it here and use resolved pointers
666	 * where appropriate.
667	 *
668	 * XXX The drawback is that user can configure a hook to use
669	 * ifMatch/ifNotMatch hooks that do not yet exist and will be added
670	 * by user later, so that resolved pointers will be NULL even
671	 * if the hook already exists, causing node to drop packets and
672	 * user to report bugs.  We could do check for this situation on
673	 * every hook creation with pointers correction, but that involves
674	 * re-resolving for all pointers in all hooks, up to O(n^2) operations,
675	 * so we better document this in man page for user not to do
676	 * configuration before creating all hooks.
677	 */
678	hip->hi_match = ng_findhook(NG_HOOK_NODE(hook), hip->in->ifMatch);
679	hip->hi_nonmatch = ng_findhook(NG_HOOK_NODE(hook), hip->in->ifNotMatch);
680
681	/* Fill internal values from API structures. */
682	hip->in_tag_cookie = hip->in->tag_cookie;
683	hip->in_tag_id = hip->in->tag_id;
684	hip->in_tag_len = hip->in->tag_len;
685	hip->strip = hip->in->strip;
686	hip->in_tag_data = (void*)(hip->in->tag_data);
687	return (0);
688}
689
690/*
691 * Set the OUT tag values associated with a hook.
692 */
693static int
694ng_tag_setdata_out(hook_p hook, const struct ng_tag_hookout *hp0)
695{
696	const hinfo_p hip = NG_HOOK_PRIVATE(hook);
697	struct ng_tag_hookout *hp;
698	int size;
699
700	/* Make a copy of the tag values and data. */
701	size = NG_TAG_HOOKOUT_SIZE(hp0->tag_len);
702	hp = malloc(size, M_NETGRAPH_TAG, M_WAITOK);
703	/* M_WAITOK can't return NULL. */
704	bcopy(hp0, hp, size);
705
706	/* Free previous tag, if any, and assign new one. */
707	if (hip->out != NULL)
708		free(hip->out, M_NETGRAPH_TAG);
709	hip->out = hp;
710
711	/* Fill internal values from API structures. */
712	hip->out_tag_cookie = hip->out->tag_cookie;
713	hip->out_tag_id = hip->out->tag_id;
714	hip->out_tag_len = hip->out->tag_len;
715	hip->out_tag_data = (void*)(hip->out->tag_data);
716	return (0);
717}
718
719