xref: /freebsd/sys/netgraph/ng_one2many.c (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*
2  * ng_one2many.c
3  */
4 
5 /*-
6  * Copyright (c) 2000 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Archie Cobbs <archie@freebsd.org>
39  */
40 
41 /*
42  * ng_one2many(4) netgraph node type
43  *
44  * Packets received on the "one" hook are sent out each of the
45  * "many" hooks according to an algorithm. Packets received on any
46  * "many" hook are always delivered to the "one" hook.
47  */
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/ctype.h>
54 #include <sys/mbuf.h>
55 #include <sys/errno.h>
56 
57 #include <netgraph/ng_message.h>
58 #include <netgraph/netgraph.h>
59 #include <netgraph/ng_parse.h>
60 #include <netgraph/ng_one2many.h>
61 
62 /* Per-link private data */
63 struct ng_one2many_link {
64 	hook_p				hook;	/* netgraph hook */
65 	struct ng_one2many_link_stats	stats;	/* link stats */
66 };
67 
68 /* Per-node private data */
69 struct ng_one2many_private {
70 	node_p				node;		/* link to node */
71 	struct ng_one2many_config	conf;		/* node configuration */
72 	struct ng_one2many_link		one;		/* "one" hook */
73 	struct ng_one2many_link		many[NG_ONE2MANY_MAX_LINKS];
74 	u_int16_t			nextMany;	/* next round-robin */
75 	u_int16_t			numActiveMany;	/* # active "many" */
76 	u_int16_t			activeMany[NG_ONE2MANY_MAX_LINKS];
77 };
78 typedef struct ng_one2many_private *priv_p;
79 
80 /* Netgraph node methods */
81 static ng_constructor_t	ng_one2many_constructor;
82 static ng_rcvmsg_t	ng_one2many_rcvmsg;
83 static ng_shutdown_t	ng_one2many_shutdown;
84 static ng_newhook_t	ng_one2many_newhook;
85 static ng_rcvdata_t	ng_one2many_rcvdata;
86 static ng_disconnect_t	ng_one2many_disconnect;
87 
88 /* Other functions */
89 static void		ng_one2many_update_many(priv_p priv);
90 static void		ng_one2many_notify(priv_p priv, uint32_t cmd);
91 
92 /******************************************************************
93 		    NETGRAPH PARSE TYPES
94 ******************************************************************/
95 
96 /* Parse type for struct ng_one2many_config */
97 static const struct ng_parse_fixedarray_info
98     ng_one2many_enableLinks_array_type_info = {
99 	&ng_parse_uint8_type,
100 	NG_ONE2MANY_MAX_LINKS
101 };
102 static const struct ng_parse_type ng_one2many_enableLinks_array_type = {
103 	&ng_parse_fixedarray_type,
104 	&ng_one2many_enableLinks_array_type_info,
105 };
106 static const struct ng_parse_struct_field ng_one2many_config_type_fields[]
107 	= NG_ONE2MANY_CONFIG_TYPE_INFO(&ng_one2many_enableLinks_array_type);
108 static const struct ng_parse_type ng_one2many_config_type = {
109 	&ng_parse_struct_type,
110 	&ng_one2many_config_type_fields
111 };
112 
113 /* Parse type for struct ng_one2many_link_stats */
114 static const struct ng_parse_struct_field ng_one2many_link_stats_type_fields[]
115 	= NG_ONE2MANY_LINK_STATS_TYPE_INFO;
116 static const struct ng_parse_type ng_one2many_link_stats_type = {
117 	&ng_parse_struct_type,
118 	&ng_one2many_link_stats_type_fields
119 };
120 
121 /* List of commands and how to convert arguments to/from ASCII */
122 static const struct ng_cmdlist ng_one2many_cmdlist[] = {
123 	{
124 	  NGM_ONE2MANY_COOKIE,
125 	  NGM_ONE2MANY_SET_CONFIG,
126 	  "setconfig",
127 	  &ng_one2many_config_type,
128 	  NULL
129 	},
130 	{
131 	  NGM_ONE2MANY_COOKIE,
132 	  NGM_ONE2MANY_GET_CONFIG,
133 	  "getconfig",
134 	  NULL,
135 	  &ng_one2many_config_type
136 	},
137 	{
138 	  NGM_ONE2MANY_COOKIE,
139 	  NGM_ONE2MANY_GET_STATS,
140 	  "getstats",
141 	  &ng_parse_int32_type,
142 	  &ng_one2many_link_stats_type
143 	},
144 	{
145 	  NGM_ONE2MANY_COOKIE,
146 	  NGM_ONE2MANY_CLR_STATS,
147 	  "clrstats",
148 	  &ng_parse_int32_type,
149 	  NULL,
150 	},
151 	{
152 	  NGM_ONE2MANY_COOKIE,
153 	  NGM_ONE2MANY_GETCLR_STATS,
154 	  "getclrstats",
155 	  &ng_parse_int32_type,
156 	  &ng_one2many_link_stats_type
157 	},
158 	{ 0 }
159 };
160 
161 /* Node type descriptor */
162 static struct ng_type ng_one2many_typestruct = {
163 	.version =	NG_ABI_VERSION,
164 	.name =		NG_ONE2MANY_NODE_TYPE,
165 	.constructor =	ng_one2many_constructor,
166 	.rcvmsg =	ng_one2many_rcvmsg,
167 	.shutdown =	ng_one2many_shutdown,
168 	.newhook =	ng_one2many_newhook,
169 	.rcvdata =	ng_one2many_rcvdata,
170 	.disconnect =	ng_one2many_disconnect,
171 	.cmdlist =	ng_one2many_cmdlist,
172 };
173 NETGRAPH_INIT(one2many, &ng_one2many_typestruct);
174 
175 /******************************************************************
176 		    NETGRAPH NODE METHODS
177 ******************************************************************/
178 
179 /*
180  * Node constructor
181  */
182 static int
ng_one2many_constructor(node_p node)183 ng_one2many_constructor(node_p node)
184 {
185 	priv_p priv;
186 
187 	/* Allocate and initialize private info */
188 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
189 	priv->conf.xmitAlg = NG_ONE2MANY_XMIT_ROUNDROBIN;
190 	priv->conf.failAlg = NG_ONE2MANY_FAIL_MANUAL;
191 
192 	/* cross reference */
193 	NG_NODE_SET_PRIVATE(node, priv);
194 	priv->node = node;
195 
196 	/* Done */
197 	return (0);
198 }
199 
200 /*
201  * Method for attaching a new hook
202  */
203 static	int
ng_one2many_newhook(node_p node,hook_p hook,const char * name)204 ng_one2many_newhook(node_p node, hook_p hook, const char *name)
205 {
206 	const priv_p priv = NG_NODE_PRIVATE(node);
207 	struct ng_one2many_link *link;
208 	int linkNum;
209 	u_long i;
210 
211 	/* Which hook? */
212 	if (strncmp(name, NG_ONE2MANY_HOOK_MANY_PREFIX,
213 	    strlen(NG_ONE2MANY_HOOK_MANY_PREFIX)) == 0) {
214 		const char *cp;
215 		char *eptr;
216 
217 		cp = name + strlen(NG_ONE2MANY_HOOK_MANY_PREFIX);
218 		if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
219 			return (EINVAL);
220 		i = strtoul(cp, &eptr, 10);
221 		if (*eptr != '\0' || i >= NG_ONE2MANY_MAX_LINKS)
222 			return (EINVAL);
223 		linkNum = (int)i;
224 		link = &priv->many[linkNum];
225 	} else if (strcmp(name, NG_ONE2MANY_HOOK_ONE) == 0) {
226 		linkNum = NG_ONE2MANY_ONE_LINKNUM;
227 		link = &priv->one;
228 	} else
229 		return (EINVAL);
230 
231 	/* Is hook already connected? (should never happen) */
232 	if (link->hook != NULL)
233 		return (EISCONN);
234 
235 	/* Setup private info for this link */
236 	NG_HOOK_SET_PRIVATE(hook, (void *)(intptr_t)linkNum);
237 	link->hook = hook;
238 	bzero(&link->stats, sizeof(link->stats));
239 	if (linkNum != NG_ONE2MANY_ONE_LINKNUM) {
240 		priv->conf.enabledLinks[linkNum] = 1;	/* auto-enable link */
241 		ng_one2many_update_many(priv);
242 	}
243 
244 	/* Done */
245 	return (0);
246 }
247 
248 /*
249  * Receive a control message
250  */
251 static int
ng_one2many_rcvmsg(node_p node,item_p item,hook_p lasthook)252 ng_one2many_rcvmsg(node_p node, item_p item, hook_p lasthook)
253 {
254 	const priv_p priv = NG_NODE_PRIVATE(node);
255 	struct ng_mesg *resp = NULL;
256 	int error = 0;
257 	struct ng_mesg *msg;
258 
259 	NGI_GET_MSG(item, msg);
260 	switch (msg->header.typecookie) {
261 	case NGM_ONE2MANY_COOKIE:
262 		switch (msg->header.cmd) {
263 		case NGM_ONE2MANY_SET_CONFIG:
264 		    {
265 			struct ng_one2many_config *conf;
266 			int i;
267 
268 			/* Check that new configuration is valid */
269 			if (msg->header.arglen != sizeof(*conf)) {
270 				error = EINVAL;
271 				break;
272 			}
273 			conf = (struct ng_one2many_config *)msg->data;
274 			switch (conf->xmitAlg) {
275 			case NG_ONE2MANY_XMIT_ROUNDROBIN:
276 			case NG_ONE2MANY_XMIT_ALL:
277 			case NG_ONE2MANY_XMIT_FAILOVER:
278 				break;
279 			default:
280 				error = EINVAL;
281 				break;
282 			}
283 			switch (conf->failAlg) {
284 			case NG_ONE2MANY_FAIL_MANUAL:
285 			case NG_ONE2MANY_FAIL_NOTIFY:
286 				break;
287 			default:
288 				error = EINVAL;
289 				break;
290 			}
291 			if (error != 0)
292 				break;
293 
294 			/* Normalized many link enabled bits */
295 			for (i = 0; i < NG_ONE2MANY_MAX_LINKS; i++)
296 				conf->enabledLinks[i] = !!conf->enabledLinks[i];
297 
298 			/* Copy config and reset */
299 			bcopy(conf, &priv->conf, sizeof(*conf));
300 			ng_one2many_update_many(priv);
301 			break;
302 		    }
303 		case NGM_ONE2MANY_GET_CONFIG:
304 		    {
305 			struct ng_one2many_config *conf;
306 
307 			NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
308 			if (resp == NULL) {
309 				error = ENOMEM;
310 				break;
311 			}
312 			conf = (struct ng_one2many_config *)resp->data;
313 			bcopy(&priv->conf, conf, sizeof(priv->conf));
314 			break;
315 		    }
316 		case NGM_ONE2MANY_GET_STATS:
317 		case NGM_ONE2MANY_CLR_STATS:
318 		case NGM_ONE2MANY_GETCLR_STATS:
319 		    {
320 			struct ng_one2many_link *link;
321 			int linkNum;
322 
323 			/* Get link */
324 			if (msg->header.arglen != sizeof(int32_t)) {
325 				error = EINVAL;
326 				break;
327 			}
328 			linkNum = *((int32_t *)msg->data);
329 			if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
330 				link = &priv->one;
331 			else if (linkNum >= 0
332 			    && linkNum < NG_ONE2MANY_MAX_LINKS) {
333 				link = &priv->many[linkNum];
334 			} else {
335 				error = EINVAL;
336 				break;
337 			}
338 
339 			/* Get/clear stats */
340 			if (msg->header.cmd != NGM_ONE2MANY_CLR_STATS) {
341 				NG_MKRESPONSE(resp, msg,
342 				    sizeof(link->stats), M_NOWAIT);
343 				if (resp == NULL) {
344 					error = ENOMEM;
345 					break;
346 				}
347 				bcopy(&link->stats,
348 				    resp->data, sizeof(link->stats));
349 			}
350 			if (msg->header.cmd != NGM_ONE2MANY_GET_STATS)
351 				bzero(&link->stats, sizeof(link->stats));
352 			break;
353 		    }
354 		default:
355 			error = EINVAL;
356 			break;
357 		}
358 		break;
359 	/*
360 	 * One of our downstreams notifies us of link change. If we are
361 	 * configured to listen to these message, then we remove/add
362 	 * this hook from array of active hooks.
363 	 */
364 	case NGM_FLOW_COOKIE:
365 	    {
366 		int linkNum;
367 
368 		if (priv->conf.failAlg != NG_ONE2MANY_FAIL_NOTIFY)
369 			break;
370 
371 		if (lasthook == NULL)
372 			break;
373 
374 		linkNum = (intptr_t)NG_HOOK_PRIVATE(lasthook);
375 		if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
376 			break;
377 
378 		KASSERT((linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
379 		    ("%s: linkNum=%d", __func__, linkNum));
380 
381 		switch (msg->header.cmd) {
382 		case NGM_LINK_IS_UP:
383 			priv->conf.enabledLinks[linkNum] = 1;
384 			ng_one2many_update_many(priv);
385 			break;
386 		case NGM_LINK_IS_DOWN:
387 			priv->conf.enabledLinks[linkNum] = 0;
388 			ng_one2many_update_many(priv);
389 			break;
390 		default:
391 			break;
392 		}
393 		break;
394 	    }
395 	default:
396 		error = EINVAL;
397 		break;
398 	}
399 
400 	/* Done */
401 	NG_RESPOND_MSG(error, node, item, resp);
402 	NG_FREE_MSG(msg);
403 	return (error);
404 }
405 
406 /*
407  * Receive data on a hook
408  */
409 static int
ng_one2many_rcvdata(hook_p hook,item_p item)410 ng_one2many_rcvdata(hook_p hook, item_p item)
411 {
412 	const node_p node = NG_HOOK_NODE(hook);
413 	const priv_p priv = NG_NODE_PRIVATE(node);
414 	struct ng_one2many_link *src;
415 	struct ng_one2many_link *dst = NULL;
416 	int error = 0;
417 	int linkNum;
418 	int i;
419 	struct mbuf *m;
420 
421 	m = NGI_M(item); /* just peaking, mbuf still owned by item */
422 	/* Get link number */
423 	linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
424 	KASSERT(linkNum == NG_ONE2MANY_ONE_LINKNUM
425 	    || (linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
426 	    ("%s: linkNum=%d", __func__, linkNum));
427 
428 	/* Figure out source link */
429 	src = (linkNum == NG_ONE2MANY_ONE_LINKNUM) ?
430 	    &priv->one : &priv->many[linkNum];
431 	KASSERT(src->hook != NULL, ("%s: no src%d", __func__, linkNum));
432 
433 	/* Update receive stats */
434 	src->stats.recvPackets++;
435 	src->stats.recvOctets += m->m_pkthdr.len;
436 
437 	/* Figure out destination link */
438 	if (linkNum == NG_ONE2MANY_ONE_LINKNUM) {
439 		if (priv->numActiveMany == 0) {
440 			NG_FREE_ITEM(item);
441 			return (ENOTCONN);
442 		}
443 		switch(priv->conf.xmitAlg) {
444 		case NG_ONE2MANY_XMIT_ROUNDROBIN:
445 			dst = &priv->many[priv->activeMany[priv->nextMany]];
446 			priv->nextMany = (priv->nextMany + 1) % priv->numActiveMany;
447 			break;
448 		case NG_ONE2MANY_XMIT_ALL:
449 			/* no need to copy data for the 1st one */
450 			dst = &priv->many[priv->activeMany[0]];
451 
452 			/* make modifiable copies of data and send for all
453 			 * links except the first one, which we'll do last
454 			 */
455 			for (i = 1; i < priv->numActiveMany; i++) {
456 				struct mbuf *m2;
457 				struct ng_one2many_link *mdst;
458 
459 				mdst = &priv->many[priv->activeMany[i]];
460 				m2 = m_dup(m, M_NOWAIT);
461 				if (m2 == NULL) {
462 					mdst->stats.memoryFailures++;
463 					NG_FREE_ITEM(item);
464 					NG_FREE_M(m);
465 					return (ENOBUFS);
466 				}
467 				/* Update transmit stats */
468 				mdst->stats.xmitPackets++;
469 				mdst->stats.xmitOctets += m->m_pkthdr.len;
470 				NG_SEND_DATA_ONLY(error, mdst->hook, m2);
471 			}
472 			break;
473 		case NG_ONE2MANY_XMIT_FAILOVER:
474 			dst = &priv->many[priv->activeMany[0]];
475 			break;
476 #ifdef INVARIANTS
477 		default:
478 			panic("%s: invalid xmitAlg", __func__);
479 #endif
480 		}
481 	} else {
482 		dst = &priv->one;
483 	}
484 
485 	/* Update transmit stats */
486 	dst->stats.xmitPackets++;
487 	dst->stats.xmitOctets += m->m_pkthdr.len;
488 
489 	/* Deliver packet */
490 	NG_FWD_ITEM_HOOK(error, item, dst->hook);
491 	return (error);
492 }
493 
494 /*
495  * Shutdown node
496  */
497 static int
ng_one2many_shutdown(node_p node)498 ng_one2many_shutdown(node_p node)
499 {
500 	const priv_p priv = NG_NODE_PRIVATE(node);
501 
502 	KASSERT(priv->numActiveMany == 0,
503 	    ("%s: numActiveMany=%d", __func__, priv->numActiveMany));
504 	free(priv, M_NETGRAPH);
505 	NG_NODE_SET_PRIVATE(node, NULL);
506 	NG_NODE_UNREF(node);
507 	return (0);
508 }
509 
510 /*
511  * Hook disconnection.
512  */
513 static int
ng_one2many_disconnect(hook_p hook)514 ng_one2many_disconnect(hook_p hook)
515 {
516 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
517 	int linkNum;
518 
519 	/* Get link number */
520 	linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
521 	KASSERT(linkNum == NG_ONE2MANY_ONE_LINKNUM
522 	    || (linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
523 	    ("%s: linkNum=%d", __func__, linkNum));
524 
525 	/* Nuke the link */
526 	if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
527 		priv->one.hook = NULL;
528 	else {
529 		priv->many[linkNum].hook = NULL;
530 		priv->conf.enabledLinks[linkNum] = 0;
531 		ng_one2many_update_many(priv);
532 	}
533 
534 	/* If no hooks left, go away */
535 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
536 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
537 		ng_rmnode_self(NG_HOOK_NODE(hook));
538 	return (0);
539 }
540 
541 /******************************************************************
542 		    	OTHER FUNCTIONS
543 ******************************************************************/
544 
545 /*
546  * Update internal state after the addition or removal of a "many" link
547  */
548 static void
ng_one2many_update_many(priv_p priv)549 ng_one2many_update_many(priv_p priv)
550 {
551 	uint16_t saveActive = priv->numActiveMany;
552 	int linkNum;
553 
554 	/* Update list of which "many" links are up */
555 	priv->numActiveMany = 0;
556 	for (linkNum = 0; linkNum < NG_ONE2MANY_MAX_LINKS; linkNum++) {
557 		switch (priv->conf.failAlg) {
558 		case NG_ONE2MANY_FAIL_MANUAL:
559 		case NG_ONE2MANY_FAIL_NOTIFY:
560 			if (priv->many[linkNum].hook != NULL
561 			    && priv->conf.enabledLinks[linkNum]) {
562 				priv->activeMany[priv->numActiveMany] = linkNum;
563 				priv->numActiveMany++;
564 			}
565 			break;
566 #ifdef INVARIANTS
567 		default:
568 			panic("%s: invalid failAlg", __func__);
569 #endif
570 		}
571 	}
572 
573 	if (priv->numActiveMany == 0 && saveActive > 0)
574 		ng_one2many_notify(priv, NGM_LINK_IS_DOWN);
575 
576 	if (saveActive == 0 && priv->numActiveMany > 0)
577 		ng_one2many_notify(priv, NGM_LINK_IS_UP);
578 
579 	/* Update transmit algorithm state */
580 	switch (priv->conf.xmitAlg) {
581 	case NG_ONE2MANY_XMIT_ROUNDROBIN:
582 		if (priv->numActiveMany > 0)
583 			priv->nextMany %= priv->numActiveMany;
584 		break;
585 	case NG_ONE2MANY_XMIT_ALL:
586 	case NG_ONE2MANY_XMIT_FAILOVER:
587 		break;
588 #ifdef INVARIANTS
589 	default:
590 		panic("%s: invalid xmitAlg", __func__);
591 #endif
592 	}
593 }
594 
595 /*
596  * Notify upstream if we are out of links, or we have at least one link.
597  */
598 static void
ng_one2many_notify(priv_p priv,uint32_t cmd)599 ng_one2many_notify(priv_p priv, uint32_t cmd)
600 {
601 	struct ng_mesg *msg;
602 	int dummy_error = 0;
603 
604 	if (priv->one.hook == NULL)
605 		return;
606 
607 	NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
608 	if (msg != NULL)
609 		NG_SEND_MSG_HOOK(dummy_error, priv->node, msg, priv->one.hook, 0);
610 }
611