xref: /freebsd/sys/netgraph/ng_bridge.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2000 Whistle Communications, Inc.
3  * All rights reserved.
4  *
5  * Subject to the following obligations and disclaimer of warranty, use and
6  * redistribution of this software, in source or object code forms, with or
7  * without modifications are expressly permitted by Whistle Communications;
8  * provided, however, that:
9  * 1. Any and all reproductions of the source or object code must include the
10  *    copyright notice above and the following disclaimer of warranties; and
11  * 2. No rights are granted, in any manner or form, to use Whistle
12  *    Communications, Inc. trademarks, including the mark "WHISTLE
13  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
14  *    such appears in the above copyright notice or in the software.
15  *
16  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
17  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
18  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
19  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
21  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
22  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
23  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
24  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
25  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
26  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
27  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
28  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
32  * OF SUCH DAMAGE.
33  *
34  * Author: Archie Cobbs <archie@freebsd.org>
35  *
36  * $FreeBSD$
37  */
38 
39 /*
40  * ng_bridge(4) netgraph node type
41  *
42  * The node performs standard intelligent Ethernet bridging over
43  * each of its connected hooks, or links.  A simple loop detection
44  * algorithm is included which disables a link for priv->conf.loopTimeout
45  * seconds when a host is seen to have jumped from one link to
46  * another within priv->conf.minStableAge seconds.
47  *
48  * We keep a hashtable that maps Ethernet addresses to host info,
49  * which is contained in struct ng_bridge_host's. These structures
50  * tell us on which link the host may be found. A host's entry will
51  * expire after priv->conf.maxStaleness seconds.
52  *
53  * This node is optimzed for stable networks, where machines jump
54  * from one port to the other only rarely.
55  */
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/kernel.h>
60 #include <sys/lock.h>
61 #include <sys/malloc.h>
62 #include <sys/mbuf.h>
63 #include <sys/errno.h>
64 #include <sys/rwlock.h>
65 #include <sys/syslog.h>
66 #include <sys/socket.h>
67 #include <sys/ctype.h>
68 #include <sys/types.h>
69 #include <sys/counter.h>
70 
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/ethernet.h>
74 #include <net/vnet.h>
75 
76 #include <netinet/in.h>
77 #if 0	/* not used yet */
78 #include <netinet/ip_fw.h>
79 #endif
80 #include <netgraph/ng_message.h>
81 #include <netgraph/netgraph.h>
82 #include <netgraph/ng_parse.h>
83 #include <netgraph/ng_bridge.h>
84 
85 #ifdef NG_SEPARATE_MALLOC
86 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
87     "netgraph bridge node");
88 #else
89 #define M_NETGRAPH_BRIDGE M_NETGRAPH
90 #endif
91 
92 /* Counter based stats */
93 struct ng_bridge_link_kernel_stats {
94 	counter_u64_t	recvOctets;	/* total octets rec'd on link */
95 	counter_u64_t	recvPackets;	/* total pkts rec'd on link */
96 	counter_u64_t	recvMulticasts;	/* multicast pkts rec'd on link */
97 	counter_u64_t	recvBroadcasts;	/* broadcast pkts rec'd on link */
98 	counter_u64_t	recvUnknown;	/* pkts rec'd with unknown dest addr */
99 	counter_u64_t	recvRunts;	/* pkts rec'd less than 14 bytes */
100 	counter_u64_t	recvInvalid;	/* pkts rec'd with bogus source addr */
101 	counter_u64_t	xmitOctets;	/* total octets xmit'd on link */
102 	counter_u64_t	xmitPackets;	/* total pkts xmit'd on link */
103 	counter_u64_t	xmitMulticasts;	/* multicast pkts xmit'd on link */
104 	counter_u64_t	xmitBroadcasts;	/* broadcast pkts xmit'd on link */
105 	counter_u64_t	loopDrops;	/* pkts dropped due to loopback */
106 	u_int64_t	loopDetects;	/* number of loop detections */
107 	counter_u64_t	memoryFailures;	/* times couldn't get mem or mbuf */
108 };
109 
110 /* Per-link private data */
111 struct ng_bridge_link {
112 	hook_p				hook;		/* netgraph hook */
113 	u_int16_t			loopCount;	/* loop ignore timer */
114 	unsigned int			learnMac : 1,   /* autolearn macs */
115 					sendUnknown : 1;/* send unknown macs out */
116 	struct ng_bridge_link_kernel_stats stats;	/* link stats */
117 };
118 typedef struct ng_bridge_link const *link_cp;	/* read only access */
119 
120 /* Per-node private data */
121 struct ng_bridge_private {
122 	struct ng_bridge_bucket	*tab;		/* hash table bucket array */
123 	struct ng_bridge_config	conf;		/* node configuration */
124 	node_p			node;		/* netgraph node */
125 	u_int			numHosts;	/* num entries in table */
126 	u_int			numBuckets;	/* num buckets in table */
127 	u_int			hashMask;	/* numBuckets - 1 */
128 	int			numLinks;	/* num connected links */
129 	unsigned int		persistent : 1,	/* can exist w/o hooks */
130 				sendUnknown : 1;/* links receive unknowns by default */
131 	struct callout		timer;		/* one second periodic timer */
132 };
133 typedef struct ng_bridge_private *priv_p;
134 typedef struct ng_bridge_private const *priv_cp;	/* read only access */
135 
136 /* Information about a host, stored in a hash table entry */
137 struct ng_bridge_host {
138 	u_char		addr[6];	/* ethernet address */
139 	link_p		link;		/* link where addr can be found */
140 	u_int16_t	age;		/* seconds ago entry was created */
141 	u_int16_t	staleness;	/* seconds ago host last heard from */
142 	SLIST_ENTRY(ng_bridge_host)	next;	/* next entry in bucket */
143 };
144 
145 /* Hash table bucket declaration */
146 SLIST_HEAD(ng_bridge_bucket, ng_bridge_host);
147 
148 /* Netgraph node methods */
149 static ng_constructor_t	ng_bridge_constructor;
150 static ng_rcvmsg_t	ng_bridge_rcvmsg;
151 static ng_shutdown_t	ng_bridge_shutdown;
152 static ng_newhook_t	ng_bridge_newhook;
153 static ng_rcvdata_t	ng_bridge_rcvdata;
154 static ng_disconnect_t	ng_bridge_disconnect;
155 
156 /* Other internal functions */
157 static struct	ng_bridge_host *ng_bridge_get(priv_cp priv, const u_char *addr);
158 static int	ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
159 static void	ng_bridge_rehash(priv_p priv);
160 static void	ng_bridge_remove_hosts(priv_p priv, link_p link);
161 static void	ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
162 static const	char *ng_bridge_nodename(node_cp node);
163 
164 /* Ethernet broadcast */
165 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
166     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
167 
168 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
169 #define ETHER_EQUAL(a,b)	(((const u_int32_t *)(a))[0] \
170 					== ((const u_int32_t *)(b))[0] \
171 				    && ((const u_int16_t *)(a))[2] \
172 					== ((const u_int16_t *)(b))[2])
173 
174 /* Minimum and maximum number of hash buckets. Must be a power of two. */
175 #define MIN_BUCKETS		(1 << 5)	/* 32 */
176 #define MAX_BUCKETS		(1 << 14)	/* 16384 */
177 
178 /* Configuration default values */
179 #define DEFAULT_LOOP_TIMEOUT	60
180 #define DEFAULT_MAX_STALENESS	(15 * 60)	/* same as ARP timeout */
181 #define DEFAULT_MIN_STABLE_AGE	1
182 
183 /******************************************************************
184 		    NETGRAPH PARSE TYPES
185 ******************************************************************/
186 
187 /*
188  * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
189  */
190 static int
191 ng_bridge_getTableLength(const struct ng_parse_type *type,
192 	const u_char *start, const u_char *buf)
193 {
194 	const struct ng_bridge_host_ary *const hary
195 	    = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
196 
197 	return hary->numHosts;
198 }
199 
200 /* Parse type for struct ng_bridge_host_ary */
201 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
202 	= NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
203 static const struct ng_parse_type ng_bridge_host_type = {
204 	&ng_parse_struct_type,
205 	&ng_bridge_host_type_fields
206 };
207 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
208 	&ng_bridge_host_type,
209 	ng_bridge_getTableLength
210 };
211 static const struct ng_parse_type ng_bridge_hary_type = {
212 	&ng_parse_array_type,
213 	&ng_bridge_hary_type_info
214 };
215 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
216 	= NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
217 static const struct ng_parse_type ng_bridge_host_ary_type = {
218 	&ng_parse_struct_type,
219 	&ng_bridge_host_ary_type_fields
220 };
221 
222 /* Parse type for struct ng_bridge_config */
223 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
224 	= NG_BRIDGE_CONFIG_TYPE_INFO;
225 static const struct ng_parse_type ng_bridge_config_type = {
226 	&ng_parse_struct_type,
227 	&ng_bridge_config_type_fields
228 };
229 
230 /* Parse type for struct ng_bridge_link_stat */
231 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
232 	= NG_BRIDGE_STATS_TYPE_INFO;
233 static const struct ng_parse_type ng_bridge_stats_type = {
234 	&ng_parse_struct_type,
235 	&ng_bridge_stats_type_fields
236 };
237 /* Parse type for struct ng_bridge_move_host */
238 static const struct ng_parse_struct_field ng_bridge_move_host_type_fields[]
239 	= NG_BRIDGE_MOVE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
240 static const struct ng_parse_type ng_bridge_move_host_type = {
241 	&ng_parse_struct_type,
242 	&ng_bridge_move_host_type_fields
243 };
244 
245 /* List of commands and how to convert arguments to/from ASCII */
246 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
247 	{
248 	  NGM_BRIDGE_COOKIE,
249 	  NGM_BRIDGE_SET_CONFIG,
250 	  "setconfig",
251 	  &ng_bridge_config_type,
252 	  NULL
253 	},
254 	{
255 	  NGM_BRIDGE_COOKIE,
256 	  NGM_BRIDGE_GET_CONFIG,
257 	  "getconfig",
258 	  NULL,
259 	  &ng_bridge_config_type
260 	},
261 	{
262 	  NGM_BRIDGE_COOKIE,
263 	  NGM_BRIDGE_RESET,
264 	  "reset",
265 	  NULL,
266 	  NULL
267 	},
268 	{
269 	  NGM_BRIDGE_COOKIE,
270 	  NGM_BRIDGE_GET_STATS,
271 	  "getstats",
272 	  &ng_parse_uint32_type,
273 	  &ng_bridge_stats_type
274 	},
275 	{
276 	  NGM_BRIDGE_COOKIE,
277 	  NGM_BRIDGE_CLR_STATS,
278 	  "clrstats",
279 	  &ng_parse_uint32_type,
280 	  NULL
281 	},
282 	{
283 	  NGM_BRIDGE_COOKIE,
284 	  NGM_BRIDGE_GETCLR_STATS,
285 	  "getclrstats",
286 	  &ng_parse_uint32_type,
287 	  &ng_bridge_stats_type
288 	},
289 	{
290 	  NGM_BRIDGE_COOKIE,
291 	  NGM_BRIDGE_GET_TABLE,
292 	  "gettable",
293 	  NULL,
294 	  &ng_bridge_host_ary_type
295 	},
296 	{
297 	  NGM_BRIDGE_COOKIE,
298 	  NGM_BRIDGE_SET_PERSISTENT,
299 	  "setpersistent",
300 	  NULL,
301 	  NULL
302 	},
303 	{
304 	  NGM_BRIDGE_COOKIE,
305 	  NGM_BRIDGE_MOVE_HOST,
306 	  "movehost",
307 	  &ng_bridge_move_host_type,
308 	  NULL
309 	},
310 	{ 0 }
311 };
312 
313 /* Node type descriptor */
314 static struct ng_type ng_bridge_typestruct = {
315 	.version =	NG_ABI_VERSION,
316 	.name =		NG_BRIDGE_NODE_TYPE,
317 	.constructor =	ng_bridge_constructor,
318 	.rcvmsg =	ng_bridge_rcvmsg,
319 	.shutdown =	ng_bridge_shutdown,
320 	.newhook =	ng_bridge_newhook,
321 	.rcvdata =	ng_bridge_rcvdata,
322 	.disconnect =	ng_bridge_disconnect,
323 	.cmdlist =	ng_bridge_cmdlist,
324 };
325 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
326 
327 /******************************************************************
328 		    NETGRAPH NODE METHODS
329 ******************************************************************/
330 
331 /*
332  * Node constructor
333  */
334 static int
335 ng_bridge_constructor(node_p node)
336 {
337 	priv_p priv;
338 
339 	/* Allocate and initialize private info */
340 	priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
341 	ng_callout_init(&priv->timer);
342 
343 	/* Allocate and initialize hash table, etc. */
344 	priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
345 	    M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
346 	priv->numBuckets = MIN_BUCKETS;
347 	priv->hashMask = MIN_BUCKETS - 1;
348 	priv->conf.debugLevel = 1;
349 	priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
350 	priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
351 	priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
352 	priv->sendUnknown = 1;	       /* classic bridge */
353 
354 	NG_NODE_SET_PRIVATE(node, priv);
355 	priv->node = node;
356 
357 	/* Start timer; timer is always running while node is alive */
358 	ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
359 
360 	/* Done */
361 	return (0);
362 }
363 
364 /*
365  * Method for attaching a new hook
366  */
367 static	int
368 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
369 {
370 	const priv_p priv = NG_NODE_PRIVATE(node);
371 	char linkName[NG_HOOKSIZ];
372 	u_int32_t linkNum;
373 	link_p link;
374 	const char *prefix = NG_BRIDGE_HOOK_LINK_PREFIX;
375 	bool isUplink;
376 
377 	/* Check for a link hook */
378 	if (strlen(name) <= strlen(prefix))
379 		return (EINVAL);       /* Unknown hook name */
380 
381 	isUplink = (name[0] == 'u');
382 	if (isUplink)
383 		prefix = NG_BRIDGE_HOOK_UPLINK_PREFIX;
384 
385 	/* primitive parsing */
386 	linkNum = strtoul(name + strlen(prefix), NULL, 10);
387 	/* validation by comparing against the reconstucted name  */
388 	snprintf(linkName, sizeof(linkName), "%s%u", prefix, linkNum);
389 	if (strcmp(linkName, name) != 0)
390 		return (EINVAL);
391 
392 	if (linkNum == 0 && isUplink)
393 		return (EINVAL);
394 
395 	if(NG_PEER_NODE(hook) == node)
396 	        return (ELOOP);
397 
398 	link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE, M_ZERO);
399 	if (link == NULL)
400 		return (ENOMEM);
401 
402 	link->stats.recvOctets = counter_u64_alloc(M_WAITOK);
403 	link->stats.recvPackets = counter_u64_alloc(M_WAITOK);
404 	link->stats.recvMulticasts = counter_u64_alloc(M_WAITOK);
405 	link->stats.recvBroadcasts = counter_u64_alloc(M_WAITOK);
406 	link->stats.recvUnknown = counter_u64_alloc(M_WAITOK);
407 	link->stats.recvRunts = counter_u64_alloc(M_WAITOK);
408 	link->stats.recvInvalid = counter_u64_alloc(M_WAITOK);
409 	link->stats.xmitOctets = counter_u64_alloc(M_WAITOK);
410 	link->stats.xmitPackets = counter_u64_alloc(M_WAITOK);
411 	link->stats.xmitMulticasts = counter_u64_alloc(M_WAITOK);
412 	link->stats.xmitBroadcasts = counter_u64_alloc(M_WAITOK);
413 	link->stats.loopDrops = counter_u64_alloc(M_WAITOK);
414 	link->stats.memoryFailures = counter_u64_alloc(M_WAITOK);
415 
416 	link->hook = hook;
417 	if (isUplink) {
418 		link->learnMac = 0;
419 		link->sendUnknown = 1;
420 		if (priv->numLinks == 0)	/* if the first link is an uplink */
421 		    priv->sendUnknown = 0;	/* switch to restrictive mode */
422 	} else {
423 		link->learnMac = 1;
424 		link->sendUnknown = priv->sendUnknown;
425 	}
426 
427 	NG_HOOK_SET_PRIVATE(hook, link);
428 	priv->numLinks++;
429 	return (0);
430 }
431 
432 /*
433  * Receive a control message
434  */
435 static void ng_bridge_clear_link_stats(struct ng_bridge_link_kernel_stats * p)
436 {
437 	counter_u64_zero(p->recvOctets);
438 	counter_u64_zero(p->recvPackets);
439 	counter_u64_zero(p->recvMulticasts);
440 	counter_u64_zero(p->recvBroadcasts);
441 	counter_u64_zero(p->recvUnknown);
442 	counter_u64_zero(p->recvRunts);
443 	counter_u64_zero(p->recvInvalid);
444 	counter_u64_zero(p->xmitOctets);
445 	counter_u64_zero(p->xmitPackets);
446 	counter_u64_zero(p->xmitMulticasts);
447 	counter_u64_zero(p->xmitBroadcasts);
448 	counter_u64_zero(p->loopDrops);
449 	p->loopDetects = 0;
450 	counter_u64_zero(p->memoryFailures);
451 };
452 
453 static int
454 ng_bridge_reset_link(hook_p hook, void *arg __unused)
455 {
456 	link_p priv = NG_HOOK_PRIVATE(hook);
457 
458 	priv->loopCount = 0;
459 	ng_bridge_clear_link_stats(&priv->stats);
460 	return (1);
461 }
462 
463 static int
464 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
465 {
466 	const priv_p priv = NG_NODE_PRIVATE(node);
467 	struct ng_mesg *resp = NULL;
468 	int error = 0;
469 	struct ng_mesg *msg;
470 
471 	NGI_GET_MSG(item, msg);
472 	switch (msg->header.typecookie) {
473 	case NGM_BRIDGE_COOKIE:
474 		switch (msg->header.cmd) {
475 		case NGM_BRIDGE_GET_CONFIG:
476 		    {
477 			struct ng_bridge_config *conf;
478 
479 			NG_MKRESPONSE(resp, msg,
480 			    sizeof(struct ng_bridge_config), M_NOWAIT);
481 			if (resp == NULL) {
482 				error = ENOMEM;
483 				break;
484 			}
485 			conf = (struct ng_bridge_config *)resp->data;
486 			*conf = priv->conf;	/* no sanity checking needed */
487 			break;
488 		    }
489 		case NGM_BRIDGE_SET_CONFIG:
490 		    {
491 			struct ng_bridge_config *conf;
492 
493 			if (msg->header.arglen
494 			    != sizeof(struct ng_bridge_config)) {
495 				error = EINVAL;
496 				break;
497 			}
498 			conf = (struct ng_bridge_config *)msg->data;
499 			priv->conf = *conf;
500 			break;
501 		    }
502 		case NGM_BRIDGE_RESET:
503 		    {
504 			hook_p rethook;
505 
506 			/* Flush all entries in the hash table */
507 			ng_bridge_remove_hosts(priv, NULL);
508 
509 			/* Reset all loop detection counters and stats */
510 			NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
511 			    rethook);
512 			break;
513 		    }
514 		case NGM_BRIDGE_GET_STATS:
515 		case NGM_BRIDGE_CLR_STATS:
516 		case NGM_BRIDGE_GETCLR_STATS:
517 		    {
518 			hook_p hook;
519 			link_p link;
520 			char linkName[NG_HOOKSIZ];
521 			int linkNum;
522 
523 			/* Get link number */
524 			if (msg->header.arglen != sizeof(u_int32_t)) {
525 				error = EINVAL;
526 				break;
527 			}
528 			linkNum = *((int32_t *)msg->data);
529 			if (linkNum < 0)
530 				snprintf(linkName, sizeof(linkName),
531 				    "%s%u", NG_BRIDGE_HOOK_UPLINK_PREFIX, -linkNum);
532 			else
533 				snprintf(linkName, sizeof(linkName),
534 				    "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX, linkNum);
535 
536 			if ((hook = ng_findhook(node, linkName)) == NULL) {
537 				error = ENOTCONN;
538 				break;
539 			}
540 			link = NG_HOOK_PRIVATE(hook);
541 
542 			/* Get/clear stats */
543 			if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
544 				struct ng_bridge_link_stats *rs;
545 
546 				NG_MKRESPONSE(resp, msg,
547 				    sizeof(link->stats), M_NOWAIT);
548 				if (resp == NULL) {
549 					error = ENOMEM;
550 					break;
551 				}
552 				rs = (struct ng_bridge_link_stats *)resp->data;
553 #define FETCH(x)	rs->x = counter_u64_fetch(link->stats.x)
554 				FETCH(recvOctets);
555 				FETCH(recvPackets);
556 				FETCH(recvMulticasts);
557 				FETCH(recvBroadcasts);
558 				FETCH(recvUnknown);
559 				FETCH(recvRunts);
560 				FETCH(recvInvalid);
561 				FETCH(xmitOctets);
562 				FETCH(xmitPackets);
563 				FETCH(xmitMulticasts);
564 				FETCH(xmitBroadcasts);
565 				FETCH(loopDrops);
566 				rs->loopDetects = link->stats.loopDetects;
567 				FETCH(memoryFailures);
568 #undef FETCH
569 			}
570 			if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
571 				ng_bridge_clear_link_stats(&link->stats);
572 			break;
573 		    }
574 		case NGM_BRIDGE_GET_TABLE:
575 		    {
576 			struct ng_bridge_host_ary *ary;
577 			struct ng_bridge_host *host;
578 			int i = 0, bucket;
579 
580 			NG_MKRESPONSE(resp, msg, sizeof(*ary)
581 			    + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
582 			if (resp == NULL) {
583 				error = ENOMEM;
584 				break;
585 			}
586 			ary = (struct ng_bridge_host_ary *)resp->data;
587 			ary->numHosts = priv->numHosts;
588 			for (bucket = 0; bucket < priv->numBuckets; bucket++) {
589 				SLIST_FOREACH(host, &priv->tab[bucket], next) {
590 					memcpy(ary->hosts[i].addr,
591 					       host->addr,
592 					       sizeof(ary->hosts[i].addr));
593 					ary->hosts[i].age       = host->age;
594 					ary->hosts[i].staleness = host->staleness;
595 					strncpy(ary->hosts[i].hook,
596 						NG_HOOK_NAME(host->link->hook),
597 						sizeof(ary->hosts[i].hook));
598 					i++;
599 				}
600 			}
601 			break;
602 		    }
603 		case NGM_BRIDGE_SET_PERSISTENT:
604 		    {
605 			priv->persistent = 1;
606 			break;
607 		    }
608 		case NGM_BRIDGE_MOVE_HOST:
609 		{
610 			struct ng_bridge_move_host *mh;
611 			hook_p hook;
612 
613 			if (msg->header.arglen < sizeof(*mh)) {
614 				error = EINVAL;
615 				break;
616 			}
617 			mh = (struct ng_bridge_move_host *)msg->data;
618 			hook = (mh->hook[0] == 0)
619 			    ? lasthook
620 			    : ng_findhook(node, mh->hook);
621 			if (hook == NULL) {
622 				error = ENOENT;
623 				break;
624 			}
625 			error = ng_bridge_put(priv, mh->addr, NG_HOOK_PRIVATE(hook));
626 			break;
627 		}
628 		default:
629 			error = EINVAL;
630 			break;
631 		}
632 		break;
633 	default:
634 		error = EINVAL;
635 		break;
636 	}
637 
638 	/* Done */
639 	NG_RESPOND_MSG(error, node, item, resp);
640 	NG_FREE_MSG(msg);
641 	return (error);
642 }
643 
644 /*
645  * Receive data on a hook
646  */
647 struct ng_bridge_send_ctx {
648 	link_p foundFirst, incoming;
649 	struct mbuf * m;
650 	int manycast, error;
651 };
652 
653 /*
654  * Update stats and send out
655  */
656 static inline int
657 ng_bridge_send_data(link_cp dst, int manycast, struct mbuf *m, item_p item) {
658 	int error = 0;
659 	size_t len = m->m_pkthdr.len;
660 
661 	if(item != NULL)
662 		NG_FWD_NEW_DATA(error, item, dst->hook, m);
663 	else
664 		NG_SEND_DATA_ONLY(error, dst->hook, m);
665 
666 	if (error) {
667 		/* The packet is still ours */
668 		if (item != NULL)
669 			NG_FREE_ITEM(item);
670 		if (m != NULL)
671 			NG_FREE_M(m);
672 		return (error);
673 	}
674 
675 	counter_u64_add(dst->stats.xmitPackets, 1);
676 	counter_u64_add(dst->stats.xmitOctets, len);
677 	switch (manycast) {
678 	default:		       /* unknown unicast */
679 		break;
680 	case 1:			       /* multicast */
681 		counter_u64_add(dst->stats.xmitMulticasts, 1);
682 		break;
683 	case 2:			       /* broadcast */
684 		counter_u64_add(dst->stats.xmitBroadcasts, 1);
685 		break;
686 	}
687 	return (0);
688 }
689 
690 /*
691  * Loop body for sending to multiple destinations
692  * return 0 to stop looping
693  */
694 static int
695 ng_bridge_send_ctx(hook_p dst, void *arg)
696 {
697 	struct ng_bridge_send_ctx *ctx = arg;
698 	link_p destLink = NG_HOOK_PRIVATE(dst);
699 	struct mbuf *m2 = NULL;
700 	int error = 0;
701 
702 	/* Skip incoming link */
703 	if (destLink == ctx->incoming) {
704 		return (1);
705 	}
706 
707 	/* Skip sending unknowns to undesired links  */
708 	if (!ctx->manycast && !destLink->sendUnknown)
709 		return (1);
710 
711 	if (ctx->foundFirst == NULL) {
712 		/*
713 		 * This is the first usable link we have found.
714 		 * Reserve it for the originals.
715 		 * If we never find another we save a copy.
716 		 */
717 		ctx->foundFirst = destLink;
718 		return (1);
719 	}
720 
721 	/*
722 	 * It's usable link but not the reserved (first) one.
723 	 * Copy mbuf info for sending.
724 	 */
725 	m2 = m_dup(ctx->m, M_NOWAIT);
726 	if (m2 == NULL) {
727 		counter_u64_add(ctx->incoming->stats.memoryFailures, 1);
728 		ctx->error = ENOBUFS;
729 		return (0);	       /* abort loop, do not try again and again */
730 	}
731 
732 	/* Send packet */
733 	error = ng_bridge_send_data(destLink, ctx->manycast, m2, NULL);
734 	if (error)
735 	  ctx->error = error;
736 	return (1);
737 }
738 
739 static int
740 ng_bridge_rcvdata(hook_p hook, item_p item)
741 {
742 	const node_p node = NG_HOOK_NODE(hook);
743 	const priv_p priv = NG_NODE_PRIVATE(node);
744 	struct ng_bridge_host *host;
745 	struct ether_header *eh;
746 	struct ng_bridge_send_ctx ctx = { 0 };
747 	hook_p ret;
748 
749 	NGI_GET_M(item, ctx.m);
750 
751 	ctx.incoming = NG_HOOK_PRIVATE(hook);
752 	/* Sanity check packet and pull up header */
753 	if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
754 		counter_u64_add(ctx.incoming->stats.recvRunts, 1);
755 		NG_FREE_ITEM(item);
756 		NG_FREE_M(ctx.m);
757 		return (EINVAL);
758 	}
759 	if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
760 		counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
761 		NG_FREE_ITEM(item);
762 		return (ENOBUFS);
763 	}
764 	eh = mtod(ctx.m, struct ether_header *);
765 	if ((eh->ether_shost[0] & 1) != 0) {
766 		counter_u64_add(ctx.incoming->stats.recvInvalid, 1);
767 		NG_FREE_ITEM(item);
768 		NG_FREE_M(ctx.m);
769 		return (EINVAL);
770 	}
771 
772 	/* Is link disabled due to a loopback condition? */
773 	if (ctx.incoming->loopCount != 0) {
774 		counter_u64_add(ctx.incoming->stats.loopDrops, 1);
775 		NG_FREE_ITEM(item);
776 		NG_FREE_M(ctx.m);
777 		return (ELOOP);
778 	}
779 
780 	/* Update stats */
781 	counter_u64_add(ctx.incoming->stats.recvPackets, 1);
782 	counter_u64_add(ctx.incoming->stats.recvOctets, ctx.m->m_pkthdr.len);
783 	if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
784 		if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
785 			counter_u64_add(ctx.incoming->stats.recvBroadcasts, 1);
786 			ctx.manycast = 2;
787 		} else
788 			counter_u64_add(ctx.incoming->stats.recvMulticasts, 1);
789 	}
790 
791 	/* Look up packet's source Ethernet address in hashtable */
792 	if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL)
793 		/* Update time since last heard from this host.
794 		 * This is safe without locking, because it's
795 		 * the only operation during shared access.
796 		 */
797 		if (__predict_false(host->staleness > 0))
798 			host->staleness = 0;
799 
800 	if ((host == NULL && ctx.incoming->learnMac) ||
801 	    (host != NULL && host->link != ctx.incoming)) {
802 		struct ng_mesg *msg;
803 		struct ng_bridge_move_host *mh;
804 		int error = 0;
805 
806 		NG_MKMESSAGE(msg, NGM_BRIDGE_COOKIE, NGM_BRIDGE_MOVE_HOST,
807 		    sizeof(*mh), M_NOWAIT);
808 		if (msg == NULL) {
809 			counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
810 			NG_FREE_ITEM(item);
811 			NG_FREE_M(ctx.m);
812 			return (ENOMEM);
813 		}
814 		mh = (struct ng_bridge_move_host *)msg->data;
815 		strncpy(mh->hook, NG_HOOK_NAME(ctx.incoming->hook),
816 		    sizeof(mh->hook));
817 		memcpy(mh->addr, eh->ether_shost, sizeof(mh->addr));
818 		NG_SEND_MSG_ID(error, node, msg, NG_NODE_ID(node),
819 		    NG_NODE_ID(node));
820 		if (error)
821 			counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
822 	}
823 
824 	if (host != NULL && host->link != ctx.incoming) {
825 		if (host->age < priv->conf.minStableAge) {
826 			/* Drop packet on instable links */
827 			counter_u64_add(ctx.incoming->stats.loopDrops, 1);
828 			NG_FREE_ITEM(item);
829 			NG_FREE_M(ctx.m);
830 			return (ELOOP);
831 		}
832 	}
833 
834 	/* Run packet through ipfw processing, if enabled */
835 #if 0
836 	if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
837 		/* XXX not implemented yet */
838 	}
839 #endif
840 
841 	/*
842 	 * If unicast and destination host known, deliver to host's link,
843 	 * unless it is the same link as the packet came in on.
844 	 */
845 	if (!ctx.manycast) {
846 		/* Determine packet destination link */
847 		if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
848 			link_p destLink = host->link;
849 
850 			/* If destination same as incoming link, do nothing */
851 			if (destLink == ctx.incoming) {
852 				NG_FREE_ITEM(item);
853 				NG_FREE_M(ctx.m);
854 				return (0);
855 			}
856 
857 			/* Deliver packet out the destination link */
858 			return (ng_bridge_send_data(destLink, ctx.manycast, ctx.m, item));
859 		}
860 
861 		/* Destination host is not known */
862 		counter_u64_add(ctx.incoming->stats.recvUnknown, 1);
863 	}
864 
865 	/* Distribute unknown, multicast, broadcast pkts to all other links */
866 	NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
867 
868 	/* Finally send out on the first link found */
869 	if (ctx.foundFirst != NULL) {
870 		int error = ng_bridge_send_data(ctx.foundFirst, ctx.manycast, ctx.m, item);
871 		if (error)
872 			ctx.error = error;
873 	} else {		       /* nothing to send at all */
874 		NG_FREE_ITEM(item);
875 		NG_FREE_M(ctx.m);
876 	}
877 
878 	return (ctx.error);
879 }
880 
881 /*
882  * Shutdown node
883  */
884 static int
885 ng_bridge_shutdown(node_p node)
886 {
887 	const priv_p priv = NG_NODE_PRIVATE(node);
888 
889 	/*
890 	 * Shut down everything including the timer.  Even if the
891 	 * callout has already been dequeued and is about to be
892 	 * run, ng_bridge_timeout() won't be fired as the node
893 	 * is already marked NGF_INVALID, so we're safe to free
894 	 * the node now.
895 	 */
896 	KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
897 	    ("%s: numLinks=%d numHosts=%d",
898 	    __func__, priv->numLinks, priv->numHosts));
899 	ng_uncallout(&priv->timer, node);
900 	NG_NODE_SET_PRIVATE(node, NULL);
901 	NG_NODE_UNREF(node);
902 	free(priv->tab, M_NETGRAPH_BRIDGE);
903 	free(priv, M_NETGRAPH_BRIDGE);
904 	return (0);
905 }
906 
907 /*
908  * Hook disconnection.
909  */
910 static int
911 ng_bridge_disconnect(hook_p hook)
912 {
913 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
914 	link_p link = NG_HOOK_PRIVATE(hook);
915 
916 	/* Remove all hosts associated with this link */
917 	ng_bridge_remove_hosts(priv, link);
918 
919 	/* Free associated link information */
920 	counter_u64_free(link->stats.recvOctets);
921 	counter_u64_free(link->stats.recvPackets);
922 	counter_u64_free(link->stats.recvMulticasts);
923 	counter_u64_free(link->stats.recvBroadcasts);
924 	counter_u64_free(link->stats.recvUnknown);
925 	counter_u64_free(link->stats.recvRunts);
926 	counter_u64_free(link->stats.recvInvalid);
927 	counter_u64_free(link->stats.xmitOctets);
928 	counter_u64_free(link->stats.xmitPackets);
929 	counter_u64_free(link->stats.xmitMulticasts);
930 	counter_u64_free(link->stats.xmitBroadcasts);
931 	counter_u64_free(link->stats.loopDrops);
932 	counter_u64_free(link->stats.memoryFailures);
933 	free(link, M_NETGRAPH_BRIDGE);
934 	priv->numLinks--;
935 
936 	/* If no more hooks, go away */
937 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
938 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
939 	    && !priv->persistent) {
940 		ng_rmnode_self(NG_HOOK_NODE(hook));
941 	}
942 	return (0);
943 }
944 
945 /******************************************************************
946 		    HASH TABLE FUNCTIONS
947 ******************************************************************/
948 
949 /*
950  * Hash algorithm
951  */
952 #define HASH(addr,mask)		( (((const u_int16_t *)(addr))[0] 	\
953 				 ^ ((const u_int16_t *)(addr))[1] 	\
954 				 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
955 
956 /*
957  * Find a host entry in the table.
958  */
959 static struct ng_bridge_host *
960 ng_bridge_get(priv_cp priv, const u_char *addr)
961 {
962 	const int bucket = HASH(addr, priv->hashMask);
963 	struct ng_bridge_host *host;
964 
965 	SLIST_FOREACH(host, &priv->tab[bucket], next) {
966 		if (ETHER_EQUAL(host->addr, addr))
967 			return (host);
968 	}
969 	return (NULL);
970 }
971 
972 /*
973  * Add a host entry to the table. If it already exists, move it
974  * to the new link. Returns 0 on success.
975  */
976 static int
977 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
978 {
979 	const int bucket = HASH(addr, priv->hashMask);
980 	struct ng_bridge_host *host;
981 
982 	if ((host = ng_bridge_get(priv, addr)) != NULL) {
983 		/* Host already on the correct link? */
984 		if (host->link == link)
985 			return 0;
986 
987 		/* Move old host over to new link */
988 		if (host->age >= priv->conf.minStableAge) {
989 			host->link = link;
990 			host->age = 0;
991 			return (0);
992 		}
993 		/*
994 		 * If the host was recently moved to the old link and
995 		 * it's now jumping to a new link, declare a loopback
996 		 * condition.
997 		 */
998 		if (priv->conf.debugLevel >= 2)
999 		    log(LOG_WARNING, "ng_bridge: %s:"
1000 			" loopback detected on %s\n",
1001 			ng_bridge_nodename(priv->node),
1002 			NG_HOOK_NAME(link->hook));
1003 
1004 		/* Mark link as linka non grata */
1005 		link->loopCount = priv->conf.loopTimeout;
1006 		link->stats.loopDetects++;
1007 
1008 		/* Forget all hosts on this link */
1009 		ng_bridge_remove_hosts(priv, link);
1010 		return (ELOOP);
1011 	}
1012 
1013 	/* Allocate and initialize new hashtable entry */
1014 	host = malloc(sizeof(*host), M_NETGRAPH_BRIDGE, M_NOWAIT);
1015 	if (host == NULL)
1016 		return (ENOMEM);
1017 	bcopy(addr, host->addr, ETHER_ADDR_LEN);
1018 	host->link = link;
1019 	host->staleness = 0;
1020 	host->age = 0;
1021 
1022 	/* Add new element to hash bucket */
1023 	SLIST_INSERT_HEAD(&priv->tab[bucket], host, next);
1024 	priv->numHosts++;
1025 
1026 	/* Resize table if necessary */
1027 	ng_bridge_rehash(priv);
1028 	return (0);
1029 }
1030 
1031 /*
1032  * Resize the hash table. We try to maintain the number of buckets
1033  * such that the load factor is in the range 0.25 to 1.0.
1034  *
1035  * If we can't get the new memory then we silently fail. This is OK
1036  * because things will still work and we'll try again soon anyway.
1037  */
1038 static void
1039 ng_bridge_rehash(priv_p priv)
1040 {
1041 	struct ng_bridge_bucket *newTab;
1042 	int oldBucket, newBucket;
1043 	int newNumBuckets;
1044 	u_int newMask;
1045 
1046 	/* Is table too full or too empty? */
1047 	if (priv->numHosts > priv->numBuckets
1048 	    && (priv->numBuckets << 1) <= MAX_BUCKETS)
1049 		newNumBuckets = priv->numBuckets << 1;
1050 	else if (priv->numHosts < (priv->numBuckets >> 2)
1051 	    && (priv->numBuckets >> 2) >= MIN_BUCKETS)
1052 		newNumBuckets = priv->numBuckets >> 2;
1053 	else
1054 		return;
1055 	newMask = newNumBuckets - 1;
1056 
1057 	/* Allocate and initialize new table */
1058 	newTab = malloc(newNumBuckets * sizeof(*newTab),
1059 	    M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
1060 	if (newTab == NULL)
1061 		return;
1062 
1063 	/* Move all entries from old table to new table */
1064 	for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
1065 		struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
1066 
1067 		while (!SLIST_EMPTY(oldList)) {
1068 			struct ng_bridge_host *const host
1069 			    = SLIST_FIRST(oldList);
1070 
1071 			SLIST_REMOVE_HEAD(oldList, next);
1072 			newBucket = HASH(host->addr, newMask);
1073 			SLIST_INSERT_HEAD(&newTab[newBucket], host, next);
1074 		}
1075 	}
1076 
1077 	/* Replace old table with new one */
1078 	if (priv->conf.debugLevel >= 3) {
1079 		log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
1080 		    ng_bridge_nodename(priv->node),
1081 		    priv->numBuckets, newNumBuckets);
1082 	}
1083 	free(priv->tab, M_NETGRAPH_BRIDGE);
1084 	priv->numBuckets = newNumBuckets;
1085 	priv->hashMask = newMask;
1086 	priv->tab = newTab;
1087 	return;
1088 }
1089 
1090 /******************************************************************
1091 		    MISC FUNCTIONS
1092 ******************************************************************/
1093 
1094 /*
1095  * Remove all hosts associated with a specific link from the hashtable.
1096  * If linkNum == -1, then remove all hosts in the table.
1097  */
1098 static void
1099 ng_bridge_remove_hosts(priv_p priv, link_p link)
1100 {
1101 	int bucket;
1102 
1103 	for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1104 		struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1105 
1106 		while (*hptr != NULL) {
1107 			struct ng_bridge_host *const host = *hptr;
1108 
1109 			if (link == NULL || host->link == link) {
1110 				*hptr = SLIST_NEXT(host, next);
1111 				free(host, M_NETGRAPH_BRIDGE);
1112 				priv->numHosts--;
1113 			} else
1114 				hptr = &SLIST_NEXT(host, next);
1115 		}
1116 	}
1117 }
1118 
1119 /*
1120  * Handle our once-per-second timeout event. We do two things:
1121  * we decrement link->loopCount for those links being muted due to
1122  * a detected loopback condition, and we remove any hosts from
1123  * the hashtable whom we haven't heard from in a long while.
1124  */
1125 static int
1126 ng_bridge_unmute(hook_p hook, void *arg)
1127 {
1128 	link_p link = NG_HOOK_PRIVATE(hook);
1129 	node_p node = NG_HOOK_NODE(hook);
1130 	priv_p priv = NG_NODE_PRIVATE(node);
1131 	int *counter = arg;
1132 
1133 	if (link->loopCount != 0) {
1134 		link->loopCount--;
1135 		if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1136 			log(LOG_INFO, "ng_bridge: %s:"
1137 			    " restoring looped back %s\n",
1138 			    ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1139 		}
1140 	}
1141 	(*counter)++;
1142 	return (1);
1143 }
1144 
1145 static void
1146 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1147 {
1148 	const priv_p priv = NG_NODE_PRIVATE(node);
1149 	int bucket;
1150 	int counter = 0;
1151 	hook_p ret;
1152 
1153 	/* Update host time counters and remove stale entries */
1154 	for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1155 		struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1156 
1157 		while (*hptr != NULL) {
1158 			struct ng_bridge_host *const host = *hptr;
1159 
1160 			/* Remove hosts we haven't heard from in a while */
1161 			if (++host->staleness >= priv->conf.maxStaleness) {
1162 				*hptr = SLIST_NEXT(host, next);
1163 				free(host, M_NETGRAPH_BRIDGE);
1164 				priv->numHosts--;
1165 			} else {
1166 				if (host->age < 0xffff)
1167 					host->age++;
1168 				hptr = &SLIST_NEXT(host, next);
1169 				counter++;
1170 			}
1171 		}
1172 	}
1173 	KASSERT(priv->numHosts == counter,
1174 	    ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1175 
1176 	/* Decrease table size if necessary */
1177 	ng_bridge_rehash(priv);
1178 
1179 	/* Decrease loop counter on muted looped back links */
1180 	counter = 0;
1181 	NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1182 	KASSERT(priv->numLinks == counter,
1183 	    ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1184 
1185 	/* Register a new timeout, keeping the existing node reference */
1186 	ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1187 }
1188 
1189 /*
1190  * Return node's "name", even if it doesn't have one.
1191  */
1192 static const char *
1193 ng_bridge_nodename(node_cp node)
1194 {
1195 	static char name[NG_NODESIZ];
1196 
1197 	if (NG_NODE_HAS_NAME(node))
1198 		snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1199 	else
1200 		snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1201 	return name;
1202 }
1203