xref: /freebsd/sys/netgraph/ng_bridge.c (revision 77013d11e6483b970af25e13c9b892075742f7e5)
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_WAITOK | M_ZERO);
399 
400 	link->stats.recvOctets = counter_u64_alloc(M_WAITOK);
401 	link->stats.recvPackets = counter_u64_alloc(M_WAITOK);
402 	link->stats.recvMulticasts = counter_u64_alloc(M_WAITOK);
403 	link->stats.recvBroadcasts = counter_u64_alloc(M_WAITOK);
404 	link->stats.recvUnknown = counter_u64_alloc(M_WAITOK);
405 	link->stats.recvRunts = counter_u64_alloc(M_WAITOK);
406 	link->stats.recvInvalid = counter_u64_alloc(M_WAITOK);
407 	link->stats.xmitOctets = counter_u64_alloc(M_WAITOK);
408 	link->stats.xmitPackets = counter_u64_alloc(M_WAITOK);
409 	link->stats.xmitMulticasts = counter_u64_alloc(M_WAITOK);
410 	link->stats.xmitBroadcasts = counter_u64_alloc(M_WAITOK);
411 	link->stats.loopDrops = counter_u64_alloc(M_WAITOK);
412 	link->stats.memoryFailures = counter_u64_alloc(M_WAITOK);
413 
414 	link->hook = hook;
415 	if (isUplink) {
416 		link->learnMac = 0;
417 		link->sendUnknown = 1;
418 		if (priv->numLinks == 0)	/* if the first link is an uplink */
419 		    priv->sendUnknown = 0;	/* switch to restrictive mode */
420 	} else {
421 		link->learnMac = 1;
422 		link->sendUnknown = priv->sendUnknown;
423 	}
424 
425 	NG_HOOK_SET_PRIVATE(hook, link);
426 	priv->numLinks++;
427 	return (0);
428 }
429 
430 /*
431  * Receive a control message
432  */
433 static void ng_bridge_clear_link_stats(struct ng_bridge_link_kernel_stats * p)
434 {
435 	counter_u64_zero(p->recvOctets);
436 	counter_u64_zero(p->recvPackets);
437 	counter_u64_zero(p->recvMulticasts);
438 	counter_u64_zero(p->recvBroadcasts);
439 	counter_u64_zero(p->recvUnknown);
440 	counter_u64_zero(p->recvRunts);
441 	counter_u64_zero(p->recvInvalid);
442 	counter_u64_zero(p->xmitOctets);
443 	counter_u64_zero(p->xmitPackets);
444 	counter_u64_zero(p->xmitMulticasts);
445 	counter_u64_zero(p->xmitBroadcasts);
446 	counter_u64_zero(p->loopDrops);
447 	p->loopDetects = 0;
448 	counter_u64_zero(p->memoryFailures);
449 };
450 
451 static int
452 ng_bridge_reset_link(hook_p hook, void *arg __unused)
453 {
454 	link_p priv = NG_HOOK_PRIVATE(hook);
455 
456 	priv->loopCount = 0;
457 	ng_bridge_clear_link_stats(&priv->stats);
458 	return (1);
459 }
460 
461 static int
462 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
463 {
464 	const priv_p priv = NG_NODE_PRIVATE(node);
465 	struct ng_mesg *resp = NULL;
466 	int error = 0;
467 	struct ng_mesg *msg;
468 
469 	NGI_GET_MSG(item, msg);
470 	switch (msg->header.typecookie) {
471 	case NGM_BRIDGE_COOKIE:
472 		switch (msg->header.cmd) {
473 		case NGM_BRIDGE_GET_CONFIG:
474 		    {
475 			struct ng_bridge_config *conf;
476 
477 			NG_MKRESPONSE(resp, msg,
478 			    sizeof(struct ng_bridge_config), M_NOWAIT);
479 			if (resp == NULL) {
480 				error = ENOMEM;
481 				break;
482 			}
483 			conf = (struct ng_bridge_config *)resp->data;
484 			*conf = priv->conf;	/* no sanity checking needed */
485 			break;
486 		    }
487 		case NGM_BRIDGE_SET_CONFIG:
488 		    {
489 			struct ng_bridge_config *conf;
490 
491 			if (msg->header.arglen
492 			    != sizeof(struct ng_bridge_config)) {
493 				error = EINVAL;
494 				break;
495 			}
496 			conf = (struct ng_bridge_config *)msg->data;
497 			priv->conf = *conf;
498 			break;
499 		    }
500 		case NGM_BRIDGE_RESET:
501 		    {
502 			hook_p rethook;
503 
504 			/* Flush all entries in the hash table */
505 			ng_bridge_remove_hosts(priv, NULL);
506 
507 			/* Reset all loop detection counters and stats */
508 			NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
509 			    rethook);
510 			break;
511 		    }
512 		case NGM_BRIDGE_GET_STATS:
513 		case NGM_BRIDGE_CLR_STATS:
514 		case NGM_BRIDGE_GETCLR_STATS:
515 		    {
516 			hook_p hook;
517 			link_p link;
518 			char linkName[NG_HOOKSIZ];
519 			int linkNum;
520 
521 			/* Get link number */
522 			if (msg->header.arglen != sizeof(u_int32_t)) {
523 				error = EINVAL;
524 				break;
525 			}
526 			linkNum = *((int32_t *)msg->data);
527 			if (linkNum < 0)
528 				snprintf(linkName, sizeof(linkName),
529 				    "%s%u", NG_BRIDGE_HOOK_UPLINK_PREFIX, -linkNum);
530 			else
531 				snprintf(linkName, sizeof(linkName),
532 				    "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX, linkNum);
533 
534 			if ((hook = ng_findhook(node, linkName)) == NULL) {
535 				error = ENOTCONN;
536 				break;
537 			}
538 			link = NG_HOOK_PRIVATE(hook);
539 
540 			/* Get/clear stats */
541 			if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
542 				struct ng_bridge_link_stats *rs;
543 
544 				NG_MKRESPONSE(resp, msg,
545 				    sizeof(link->stats), M_NOWAIT);
546 				if (resp == NULL) {
547 					error = ENOMEM;
548 					break;
549 				}
550 				rs = (struct ng_bridge_link_stats *)resp->data;
551 #define FETCH(x)	rs->x = counter_u64_fetch(link->stats.x)
552 				FETCH(recvOctets);
553 				FETCH(recvPackets);
554 				FETCH(recvMulticasts);
555 				FETCH(recvBroadcasts);
556 				FETCH(recvUnknown);
557 				FETCH(recvRunts);
558 				FETCH(recvInvalid);
559 				FETCH(xmitOctets);
560 				FETCH(xmitPackets);
561 				FETCH(xmitMulticasts);
562 				FETCH(xmitBroadcasts);
563 				FETCH(loopDrops);
564 				rs->loopDetects = link->stats.loopDetects;
565 				FETCH(memoryFailures);
566 #undef FETCH
567 			}
568 			if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
569 				ng_bridge_clear_link_stats(&link->stats);
570 			break;
571 		    }
572 		case NGM_BRIDGE_GET_TABLE:
573 		    {
574 			struct ng_bridge_host_ary *ary;
575 			struct ng_bridge_host *host;
576 			int i = 0, bucket;
577 
578 			NG_MKRESPONSE(resp, msg, sizeof(*ary)
579 			    + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
580 			if (resp == NULL) {
581 				error = ENOMEM;
582 				break;
583 			}
584 			ary = (struct ng_bridge_host_ary *)resp->data;
585 			ary->numHosts = priv->numHosts;
586 			for (bucket = 0; bucket < priv->numBuckets; bucket++) {
587 				SLIST_FOREACH(host, &priv->tab[bucket], next) {
588 					memcpy(ary->hosts[i].addr,
589 					       host->addr,
590 					       sizeof(ary->hosts[i].addr));
591 					ary->hosts[i].age       = host->age;
592 					ary->hosts[i].staleness = host->staleness;
593 					strncpy(ary->hosts[i].hook,
594 						NG_HOOK_NAME(host->link->hook),
595 						sizeof(ary->hosts[i].hook));
596 					i++;
597 				}
598 			}
599 			break;
600 		    }
601 		case NGM_BRIDGE_SET_PERSISTENT:
602 		    {
603 			priv->persistent = 1;
604 			break;
605 		    }
606 		case NGM_BRIDGE_MOVE_HOST:
607 		{
608 			struct ng_bridge_move_host *mh;
609 			hook_p hook;
610 
611 			if (msg->header.arglen < sizeof(*mh)) {
612 				error = EINVAL;
613 				break;
614 			}
615 			mh = (struct ng_bridge_move_host *)msg->data;
616 			hook = (mh->hook[0] == 0)
617 			    ? lasthook
618 			    : ng_findhook(node, mh->hook);
619 			if (hook == NULL) {
620 				error = ENOENT;
621 				break;
622 			}
623 			error = ng_bridge_put(priv, mh->addr, NG_HOOK_PRIVATE(hook));
624 			break;
625 		}
626 		default:
627 			error = EINVAL;
628 			break;
629 		}
630 		break;
631 	default:
632 		error = EINVAL;
633 		break;
634 	}
635 
636 	/* Done */
637 	NG_RESPOND_MSG(error, node, item, resp);
638 	NG_FREE_MSG(msg);
639 	return (error);
640 }
641 
642 /*
643  * Receive data on a hook
644  */
645 struct ng_bridge_send_ctx {
646 	link_p foundFirst, incoming;
647 	struct mbuf * m;
648 	int manycast, error;
649 };
650 
651 /*
652  * Update stats and send out
653  */
654 static inline int
655 ng_bridge_send_data(link_cp dst, int manycast, struct mbuf *m, item_p item) {
656 	int error = 0;
657 	size_t len = m->m_pkthdr.len;
658 
659 	if(item != NULL)
660 		NG_FWD_NEW_DATA(error, item, dst->hook, m);
661 	else
662 		NG_SEND_DATA_ONLY(error, dst->hook, m);
663 
664 	if (error) {
665 		/* The packet is still ours */
666 		if (item != NULL)
667 			NG_FREE_ITEM(item);
668 		if (m != NULL)
669 			NG_FREE_M(m);
670 		return (error);
671 	}
672 
673 	counter_u64_add(dst->stats.xmitPackets, 1);
674 	counter_u64_add(dst->stats.xmitOctets, len);
675 	switch (manycast) {
676 	default:		       /* unknown unicast */
677 		break;
678 	case 1:			       /* multicast */
679 		counter_u64_add(dst->stats.xmitMulticasts, 1);
680 		break;
681 	case 2:			       /* broadcast */
682 		counter_u64_add(dst->stats.xmitBroadcasts, 1);
683 		break;
684 	}
685 	return (0);
686 }
687 
688 /*
689  * Loop body for sending to multiple destinations
690  * return 0 to stop looping
691  */
692 static int
693 ng_bridge_send_ctx(hook_p dst, void *arg)
694 {
695 	struct ng_bridge_send_ctx *ctx = arg;
696 	link_p destLink = NG_HOOK_PRIVATE(dst);
697 	struct mbuf *m2 = NULL;
698 	int error = 0;
699 
700 	/* Skip incoming link */
701 	if (destLink == ctx->incoming) {
702 		return (1);
703 	}
704 
705 	/* Skip sending unknowns to undesired links  */
706 	if (!ctx->manycast && !destLink->sendUnknown)
707 		return (1);
708 
709 	if (ctx->foundFirst == NULL) {
710 		/*
711 		 * This is the first usable link we have found.
712 		 * Reserve it for the originals.
713 		 * If we never find another we save a copy.
714 		 */
715 		ctx->foundFirst = destLink;
716 		return (1);
717 	}
718 
719 	/*
720 	 * It's usable link but not the reserved (first) one.
721 	 * Copy mbuf info for sending.
722 	 */
723 	m2 = m_dup(ctx->m, M_NOWAIT);
724 	if (m2 == NULL) {
725 		counter_u64_add(ctx->incoming->stats.memoryFailures, 1);
726 		ctx->error = ENOBUFS;
727 		return (0);	       /* abort loop, do not try again and again */
728 	}
729 
730 	/* Send packet */
731 	error = ng_bridge_send_data(destLink, ctx->manycast, m2, NULL);
732 	if (error)
733 	  ctx->error = error;
734 	return (1);
735 }
736 
737 static int
738 ng_bridge_rcvdata(hook_p hook, item_p item)
739 {
740 	const node_p node = NG_HOOK_NODE(hook);
741 	const priv_p priv = NG_NODE_PRIVATE(node);
742 	struct ng_bridge_host *host;
743 	struct ether_header *eh;
744 	struct ng_bridge_send_ctx ctx = { 0 };
745 	hook_p ret;
746 
747 	NGI_GET_M(item, ctx.m);
748 
749 	ctx.incoming = NG_HOOK_PRIVATE(hook);
750 	/* Sanity check packet and pull up header */
751 	if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
752 		counter_u64_add(ctx.incoming->stats.recvRunts, 1);
753 		NG_FREE_ITEM(item);
754 		NG_FREE_M(ctx.m);
755 		return (EINVAL);
756 	}
757 	if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
758 		counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
759 		NG_FREE_ITEM(item);
760 		return (ENOBUFS);
761 	}
762 	eh = mtod(ctx.m, struct ether_header *);
763 	if ((eh->ether_shost[0] & 1) != 0) {
764 		counter_u64_add(ctx.incoming->stats.recvInvalid, 1);
765 		NG_FREE_ITEM(item);
766 		NG_FREE_M(ctx.m);
767 		return (EINVAL);
768 	}
769 
770 	/* Is link disabled due to a loopback condition? */
771 	if (ctx.incoming->loopCount != 0) {
772 		counter_u64_add(ctx.incoming->stats.loopDrops, 1);
773 		NG_FREE_ITEM(item);
774 		NG_FREE_M(ctx.m);
775 		return (ELOOP);
776 	}
777 
778 	/* Update stats */
779 	counter_u64_add(ctx.incoming->stats.recvPackets, 1);
780 	counter_u64_add(ctx.incoming->stats.recvOctets, ctx.m->m_pkthdr.len);
781 	if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
782 		if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
783 			counter_u64_add(ctx.incoming->stats.recvBroadcasts, 1);
784 			ctx.manycast = 2;
785 		} else
786 			counter_u64_add(ctx.incoming->stats.recvMulticasts, 1);
787 	}
788 
789 	/* Look up packet's source Ethernet address in hashtable */
790 	if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL)
791 		/* Update time since last heard from this host.
792 		 * This is safe without locking, because it's
793 		 * the only operation during shared access.
794 		 */
795 		if (__predict_false(host->staleness > 0))
796 			host->staleness = 0;
797 
798 	if ((host == NULL && ctx.incoming->learnMac) ||
799 	    (host != NULL && host->link != ctx.incoming)) {
800 		struct ng_mesg *msg;
801 		struct ng_bridge_move_host *mh;
802 		int error = 0;
803 
804 		NG_MKMESSAGE(msg, NGM_BRIDGE_COOKIE, NGM_BRIDGE_MOVE_HOST,
805 		    sizeof(*mh), M_NOWAIT);
806 		if (msg == NULL) {
807 			counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
808 			NG_FREE_ITEM(item);
809 			NG_FREE_M(ctx.m);
810 			return (ENOMEM);
811 		}
812 		mh = (struct ng_bridge_move_host *)msg->data;
813 		strncpy(mh->hook, NG_HOOK_NAME(ctx.incoming->hook),
814 		    sizeof(mh->hook));
815 		memcpy(mh->addr, eh->ether_shost, sizeof(mh->addr));
816 		NG_SEND_MSG_ID(error, node, msg, NG_NODE_ID(node),
817 		    NG_NODE_ID(node));
818 		if (error)
819 			counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
820 	}
821 
822 	if (host != NULL && host->link != ctx.incoming) {
823 		if (host->age < priv->conf.minStableAge) {
824 			/* Drop packet on instable links */
825 			counter_u64_add(ctx.incoming->stats.loopDrops, 1);
826 			NG_FREE_ITEM(item);
827 			NG_FREE_M(ctx.m);
828 			return (ELOOP);
829 		}
830 	}
831 
832 	/* Run packet through ipfw processing, if enabled */
833 #if 0
834 	if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
835 		/* XXX not implemented yet */
836 	}
837 #endif
838 
839 	/*
840 	 * If unicast and destination host known, deliver to host's link,
841 	 * unless it is the same link as the packet came in on.
842 	 */
843 	if (!ctx.manycast) {
844 		/* Determine packet destination link */
845 		if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
846 			link_p destLink = host->link;
847 
848 			/* If destination same as incoming link, do nothing */
849 			if (destLink == ctx.incoming) {
850 				NG_FREE_ITEM(item);
851 				NG_FREE_M(ctx.m);
852 				return (0);
853 			}
854 
855 			/* Deliver packet out the destination link */
856 			return (ng_bridge_send_data(destLink, ctx.manycast, ctx.m, item));
857 		}
858 
859 		/* Destination host is not known */
860 		counter_u64_add(ctx.incoming->stats.recvUnknown, 1);
861 	}
862 
863 	/* Distribute unknown, multicast, broadcast pkts to all other links */
864 	NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
865 
866 	/* Finally send out on the first link found */
867 	if (ctx.foundFirst != NULL) {
868 		int error = ng_bridge_send_data(ctx.foundFirst, ctx.manycast, ctx.m, item);
869 		if (error)
870 			ctx.error = error;
871 	} else {		       /* nothing to send at all */
872 		NG_FREE_ITEM(item);
873 		NG_FREE_M(ctx.m);
874 	}
875 
876 	return (ctx.error);
877 }
878 
879 /*
880  * Shutdown node
881  */
882 static int
883 ng_bridge_shutdown(node_p node)
884 {
885 	const priv_p priv = NG_NODE_PRIVATE(node);
886 
887 	/*
888 	 * Shut down everything including the timer.  Even if the
889 	 * callout has already been dequeued and is about to be
890 	 * run, ng_bridge_timeout() won't be fired as the node
891 	 * is already marked NGF_INVALID, so we're safe to free
892 	 * the node now.
893 	 */
894 	KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
895 	    ("%s: numLinks=%d numHosts=%d",
896 	    __func__, priv->numLinks, priv->numHosts));
897 	ng_uncallout(&priv->timer, node);
898 	NG_NODE_SET_PRIVATE(node, NULL);
899 	NG_NODE_UNREF(node);
900 	free(priv->tab, M_NETGRAPH_BRIDGE);
901 	free(priv, M_NETGRAPH_BRIDGE);
902 	return (0);
903 }
904 
905 /*
906  * Hook disconnection.
907  */
908 static int
909 ng_bridge_disconnect(hook_p hook)
910 {
911 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
912 	link_p link = NG_HOOK_PRIVATE(hook);
913 
914 	/* Remove all hosts associated with this link */
915 	ng_bridge_remove_hosts(priv, link);
916 
917 	/* Free associated link information */
918 	counter_u64_free(link->stats.recvOctets);
919 	counter_u64_free(link->stats.recvPackets);
920 	counter_u64_free(link->stats.recvMulticasts);
921 	counter_u64_free(link->stats.recvBroadcasts);
922 	counter_u64_free(link->stats.recvUnknown);
923 	counter_u64_free(link->stats.recvRunts);
924 	counter_u64_free(link->stats.recvInvalid);
925 	counter_u64_free(link->stats.xmitOctets);
926 	counter_u64_free(link->stats.xmitPackets);
927 	counter_u64_free(link->stats.xmitMulticasts);
928 	counter_u64_free(link->stats.xmitBroadcasts);
929 	counter_u64_free(link->stats.loopDrops);
930 	counter_u64_free(link->stats.memoryFailures);
931 	free(link, M_NETGRAPH_BRIDGE);
932 	priv->numLinks--;
933 
934 	/* If no more hooks, go away */
935 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
936 	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
937 	    && !priv->persistent) {
938 		ng_rmnode_self(NG_HOOK_NODE(hook));
939 	}
940 	return (0);
941 }
942 
943 /******************************************************************
944 		    HASH TABLE FUNCTIONS
945 ******************************************************************/
946 
947 /*
948  * Hash algorithm
949  */
950 #define HASH(addr,mask)		( (((const u_int16_t *)(addr))[0] 	\
951 				 ^ ((const u_int16_t *)(addr))[1] 	\
952 				 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
953 
954 /*
955  * Find a host entry in the table.
956  */
957 static struct ng_bridge_host *
958 ng_bridge_get(priv_cp priv, const u_char *addr)
959 {
960 	const int bucket = HASH(addr, priv->hashMask);
961 	struct ng_bridge_host *host;
962 
963 	SLIST_FOREACH(host, &priv->tab[bucket], next) {
964 		if (ETHER_EQUAL(host->addr, addr))
965 			return (host);
966 	}
967 	return (NULL);
968 }
969 
970 /*
971  * Add a host entry to the table. If it already exists, move it
972  * to the new link. Returns 0 on success.
973  */
974 static int
975 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
976 {
977 	const int bucket = HASH(addr, priv->hashMask);
978 	struct ng_bridge_host *host;
979 
980 	if ((host = ng_bridge_get(priv, addr)) != NULL) {
981 		/* Host already on the correct link? */
982 		if (host->link == link)
983 			return 0;
984 
985 		/* Move old host over to new link */
986 		if (host->age >= priv->conf.minStableAge) {
987 			host->link = link;
988 			host->age = 0;
989 			return (0);
990 		}
991 		/*
992 		 * If the host was recently moved to the old link and
993 		 * it's now jumping to a new link, declare a loopback
994 		 * condition.
995 		 */
996 		if (priv->conf.debugLevel >= 2)
997 		    log(LOG_WARNING, "ng_bridge: %s:"
998 			" loopback detected on %s\n",
999 			ng_bridge_nodename(priv->node),
1000 			NG_HOOK_NAME(link->hook));
1001 
1002 		/* Mark link as linka non grata */
1003 		link->loopCount = priv->conf.loopTimeout;
1004 		link->stats.loopDetects++;
1005 
1006 		/* Forget all hosts on this link */
1007 		ng_bridge_remove_hosts(priv, link);
1008 		return (ELOOP);
1009 	}
1010 
1011 	/* Allocate and initialize new hashtable entry */
1012 	host = malloc(sizeof(*host), M_NETGRAPH_BRIDGE, M_NOWAIT);
1013 	if (host == NULL)
1014 		return (ENOMEM);
1015 	bcopy(addr, host->addr, ETHER_ADDR_LEN);
1016 	host->link = link;
1017 	host->staleness = 0;
1018 	host->age = 0;
1019 
1020 	/* Add new element to hash bucket */
1021 	SLIST_INSERT_HEAD(&priv->tab[bucket], host, next);
1022 	priv->numHosts++;
1023 
1024 	/* Resize table if necessary */
1025 	ng_bridge_rehash(priv);
1026 	return (0);
1027 }
1028 
1029 /*
1030  * Resize the hash table. We try to maintain the number of buckets
1031  * such that the load factor is in the range 0.25 to 1.0.
1032  *
1033  * If we can't get the new memory then we silently fail. This is OK
1034  * because things will still work and we'll try again soon anyway.
1035  */
1036 static void
1037 ng_bridge_rehash(priv_p priv)
1038 {
1039 	struct ng_bridge_bucket *newTab;
1040 	int oldBucket, newBucket;
1041 	int newNumBuckets;
1042 	u_int newMask;
1043 
1044 	/* Is table too full or too empty? */
1045 	if (priv->numHosts > priv->numBuckets
1046 	    && (priv->numBuckets << 1) <= MAX_BUCKETS)
1047 		newNumBuckets = priv->numBuckets << 1;
1048 	else if (priv->numHosts < (priv->numBuckets >> 2)
1049 	    && (priv->numBuckets >> 2) >= MIN_BUCKETS)
1050 		newNumBuckets = priv->numBuckets >> 2;
1051 	else
1052 		return;
1053 	newMask = newNumBuckets - 1;
1054 
1055 	/* Allocate and initialize new table */
1056 	newTab = malloc(newNumBuckets * sizeof(*newTab),
1057 	    M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
1058 	if (newTab == NULL)
1059 		return;
1060 
1061 	/* Move all entries from old table to new table */
1062 	for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
1063 		struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
1064 
1065 		while (!SLIST_EMPTY(oldList)) {
1066 			struct ng_bridge_host *const host
1067 			    = SLIST_FIRST(oldList);
1068 
1069 			SLIST_REMOVE_HEAD(oldList, next);
1070 			newBucket = HASH(host->addr, newMask);
1071 			SLIST_INSERT_HEAD(&newTab[newBucket], host, next);
1072 		}
1073 	}
1074 
1075 	/* Replace old table with new one */
1076 	if (priv->conf.debugLevel >= 3) {
1077 		log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
1078 		    ng_bridge_nodename(priv->node),
1079 		    priv->numBuckets, newNumBuckets);
1080 	}
1081 	free(priv->tab, M_NETGRAPH_BRIDGE);
1082 	priv->numBuckets = newNumBuckets;
1083 	priv->hashMask = newMask;
1084 	priv->tab = newTab;
1085 	return;
1086 }
1087 
1088 /******************************************************************
1089 		    MISC FUNCTIONS
1090 ******************************************************************/
1091 
1092 /*
1093  * Remove all hosts associated with a specific link from the hashtable.
1094  * If linkNum == -1, then remove all hosts in the table.
1095  */
1096 static void
1097 ng_bridge_remove_hosts(priv_p priv, link_p link)
1098 {
1099 	int bucket;
1100 
1101 	for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1102 		struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1103 
1104 		while (*hptr != NULL) {
1105 			struct ng_bridge_host *const host = *hptr;
1106 
1107 			if (link == NULL || host->link == link) {
1108 				*hptr = SLIST_NEXT(host, next);
1109 				free(host, M_NETGRAPH_BRIDGE);
1110 				priv->numHosts--;
1111 			} else
1112 				hptr = &SLIST_NEXT(host, next);
1113 		}
1114 	}
1115 }
1116 
1117 /*
1118  * Handle our once-per-second timeout event. We do two things:
1119  * we decrement link->loopCount for those links being muted due to
1120  * a detected loopback condition, and we remove any hosts from
1121  * the hashtable whom we haven't heard from in a long while.
1122  */
1123 static int
1124 ng_bridge_unmute(hook_p hook, void *arg)
1125 {
1126 	link_p link = NG_HOOK_PRIVATE(hook);
1127 	node_p node = NG_HOOK_NODE(hook);
1128 	priv_p priv = NG_NODE_PRIVATE(node);
1129 	int *counter = arg;
1130 
1131 	if (link->loopCount != 0) {
1132 		link->loopCount--;
1133 		if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1134 			log(LOG_INFO, "ng_bridge: %s:"
1135 			    " restoring looped back %s\n",
1136 			    ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1137 		}
1138 	}
1139 	(*counter)++;
1140 	return (1);
1141 }
1142 
1143 static void
1144 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1145 {
1146 	const priv_p priv = NG_NODE_PRIVATE(node);
1147 	int bucket;
1148 	int counter = 0;
1149 	hook_p ret;
1150 
1151 	/* Update host time counters and remove stale entries */
1152 	for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1153 		struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1154 
1155 		while (*hptr != NULL) {
1156 			struct ng_bridge_host *const host = *hptr;
1157 
1158 			/* Remove hosts we haven't heard from in a while */
1159 			if (++host->staleness >= priv->conf.maxStaleness) {
1160 				*hptr = SLIST_NEXT(host, next);
1161 				free(host, M_NETGRAPH_BRIDGE);
1162 				priv->numHosts--;
1163 			} else {
1164 				if (host->age < 0xffff)
1165 					host->age++;
1166 				hptr = &SLIST_NEXT(host, next);
1167 				counter++;
1168 			}
1169 		}
1170 	}
1171 	KASSERT(priv->numHosts == counter,
1172 	    ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1173 
1174 	/* Decrease table size if necessary */
1175 	ng_bridge_rehash(priv);
1176 
1177 	/* Decrease loop counter on muted looped back links */
1178 	counter = 0;
1179 	NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1180 	KASSERT(priv->numLinks == counter,
1181 	    ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1182 
1183 	/* Register a new timeout, keeping the existing node reference */
1184 	ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1185 }
1186 
1187 /*
1188  * Return node's "name", even if it doesn't have one.
1189  */
1190 static const char *
1191 ng_bridge_nodename(node_cp node)
1192 {
1193 	static char name[NG_NODESIZ];
1194 
1195 	if (NG_NODE_HAS_NAME(node))
1196 		snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1197 	else
1198 		snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1199 	return name;
1200 }
1201