1 /*
2 * ng_bridge.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 * $FreeBSD: src/sys/netgraph/ng_bridge.c,v 1.34 2008/10/23 20:26:15 des Exp $
41 */
42
43 /*
44 * ng_bridge(4) netgraph node type
45 *
46 * The node performs standard intelligent Ethernet bridging over
47 * each of its connected hooks, or links. A simple loop detection
48 * algorithm is included which disables a link for priv->conf.loopTimeout
49 * seconds when a host is seen to have jumped from one link to
50 * another within priv->conf.minStableAge seconds.
51 *
52 * We keep a hashtable that maps Ethernet addresses to host info,
53 * which is contained in struct ng_bridge_host's. These structures
54 * tell us on which link the host may be found. A host's entry will
55 * expire after priv->conf.maxStaleness seconds.
56 *
57 * This node is optimzed for stable networks, where machines jump
58 * from one port to the other only rarely.
59 */
60
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/kernel.h>
64 #include <sys/malloc.h>
65 #include <sys/mbuf.h>
66 #include <sys/errno.h>
67 #include <sys/syslog.h>
68 #include <sys/socket.h>
69 #include <sys/ctype.h>
70 #include <sys/vimage.h>
71
72 #include <net/if.h>
73 #include <net/ethernet.h>
74
75 #include <netinet/in.h>
76 #include <netinet/ip_fw.h>
77
78 #include <netgraph/ng_message.h>
79 #include <netgraph/netgraph.h>
80 #include <netgraph/ng_parse.h>
81 #include <netgraph/ng_bridge.h>
82
83 #ifdef NG_SEPARATE_MALLOC
84 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node ");
85 #else
86 #define M_NETGRAPH_BRIDGE M_NETGRAPH
87 #endif
88
89 /* Per-link private data */
90 struct ng_bridge_link {
91 hook_p hook; /* netgraph hook */
92 u_int16_t loopCount; /* loop ignore timer */
93 struct ng_bridge_link_stats stats; /* link stats */
94 };
95
96 /* Per-node private data */
97 struct ng_bridge_private {
98 struct ng_bridge_bucket *tab; /* hash table bucket array */
99 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
100 struct ng_bridge_config conf; /* node configuration */
101 node_p node; /* netgraph node */
102 u_int numHosts; /* num entries in table */
103 u_int numBuckets; /* num buckets in table */
104 u_int hashMask; /* numBuckets - 1 */
105 int numLinks; /* num connected links */
106 struct callout timer; /* one second periodic timer */
107 };
108 typedef struct ng_bridge_private *priv_p;
109
110 /* Information about a host, stored in a hash table entry */
111 struct ng_bridge_hent {
112 struct ng_bridge_host host; /* actual host info */
113 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
114 };
115
116 /* Hash table bucket declaration */
117 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
118
119 /* Netgraph node methods */
120 static ng_constructor_t ng_bridge_constructor;
121 static ng_rcvmsg_t ng_bridge_rcvmsg;
122 static ng_shutdown_t ng_bridge_shutdown;
123 static ng_newhook_t ng_bridge_newhook;
124 static ng_rcvdata_t ng_bridge_rcvdata;
125 static ng_disconnect_t ng_bridge_disconnect;
126
127 /* Other internal functions */
128 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
129 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
130 static void ng_bridge_rehash(priv_p priv);
131 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
132 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
133 static const char *ng_bridge_nodename(node_p node);
134
135 /* Ethernet broadcast */
136 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
137 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
138
139 /* Store each hook's link number in the private field */
140 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
141
142 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
143 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
144 == ((const u_int32_t *)(b))[0] \
145 && ((const u_int16_t *)(a))[2] \
146 == ((const u_int16_t *)(b))[2])
147
148 /* Minimum and maximum number of hash buckets. Must be a power of two. */
149 #define MIN_BUCKETS (1 << 5) /* 32 */
150 #define MAX_BUCKETS (1 << 14) /* 16384 */
151
152 /* Configuration default values */
153 #define DEFAULT_LOOP_TIMEOUT 60
154 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
155 #define DEFAULT_MIN_STABLE_AGE 1
156
157 /******************************************************************
158 NETGRAPH PARSE TYPES
159 ******************************************************************/
160
161 /*
162 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
163 */
164 static int
165 ng_bridge_getTableLength(const struct ng_parse_type *type,
166 const u_char *start, const u_char *buf)
167 {
168 const struct ng_bridge_host_ary *const hary
169 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
170
171 return hary->numHosts;
172 }
173
174 /* Parse type for struct ng_bridge_host_ary */
175 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
176 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
177 static const struct ng_parse_type ng_bridge_host_type = {
178 &ng_parse_struct_type,
179 &ng_bridge_host_type_fields
180 };
181 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
182 &ng_bridge_host_type,
183 ng_bridge_getTableLength
184 };
185 static const struct ng_parse_type ng_bridge_hary_type = {
186 &ng_parse_array_type,
187 &ng_bridge_hary_type_info
188 };
189 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
190 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
191 static const struct ng_parse_type ng_bridge_host_ary_type = {
192 &ng_parse_struct_type,
193 &ng_bridge_host_ary_type_fields
194 };
195
196 /* Parse type for struct ng_bridge_config */
197 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
198 &ng_parse_uint8_type,
199 NG_BRIDGE_MAX_LINKS
200 };
201 static const struct ng_parse_type ng_bridge_ipfwary_type = {
202 &ng_parse_fixedarray_type,
203 &ng_bridge_ipfwary_type_info
204 };
205 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
206 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
207 static const struct ng_parse_type ng_bridge_config_type = {
208 &ng_parse_struct_type,
209 &ng_bridge_config_type_fields
210 };
211
212 /* Parse type for struct ng_bridge_link_stat */
213 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
214 = NG_BRIDGE_STATS_TYPE_INFO;
215 static const struct ng_parse_type ng_bridge_stats_type = {
216 &ng_parse_struct_type,
217 &ng_bridge_stats_type_fields
218 };
219
220 /* List of commands and how to convert arguments to/from ASCII */
221 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
222 {
223 NGM_BRIDGE_COOKIE,
224 NGM_BRIDGE_SET_CONFIG,
225 "setconfig",
226 &ng_bridge_config_type,
227 NULL
228 },
229 {
230 NGM_BRIDGE_COOKIE,
231 NGM_BRIDGE_GET_CONFIG,
232 "getconfig",
233 NULL,
234 &ng_bridge_config_type
235 },
236 {
237 NGM_BRIDGE_COOKIE,
238 NGM_BRIDGE_RESET,
239 "reset",
240 NULL,
241 NULL
242 },
243 {
244 NGM_BRIDGE_COOKIE,
245 NGM_BRIDGE_GET_STATS,
246 "getstats",
247 &ng_parse_uint32_type,
248 &ng_bridge_stats_type
249 },
250 {
251 NGM_BRIDGE_COOKIE,
252 NGM_BRIDGE_CLR_STATS,
253 "clrstats",
254 &ng_parse_uint32_type,
255 NULL
256 },
257 {
258 NGM_BRIDGE_COOKIE,
259 NGM_BRIDGE_GETCLR_STATS,
260 "getclrstats",
261 &ng_parse_uint32_type,
262 &ng_bridge_stats_type
263 },
264 {
265 NGM_BRIDGE_COOKIE,
266 NGM_BRIDGE_GET_TABLE,
267 "gettable",
268 NULL,
269 &ng_bridge_host_ary_type
270 },
271 { 0 }
272 };
273
274 /* Node type descriptor */
275 static struct ng_type ng_bridge_typestruct = {
276 .version = NG_ABI_VERSION,
277 .name = NG_BRIDGE_NODE_TYPE,
278 .constructor = ng_bridge_constructor,
279 .rcvmsg = ng_bridge_rcvmsg,
280 .shutdown = ng_bridge_shutdown,
281 .newhook = ng_bridge_newhook,
282 .rcvdata = ng_bridge_rcvdata,
283 .disconnect = ng_bridge_disconnect,
284 .cmdlist = ng_bridge_cmdlist,
285 };
286 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
287
288 /******************************************************************
289 NETGRAPH NODE METHODS
290 ******************************************************************/
291
292 /*
293 * Node constructor
294 */
295 static int
296 ng_bridge_constructor(node_p node)
297 {
298 priv_p priv;
299
300 /* Allocate and initialize private info */
301 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
302 if (priv == NULL)
303 return (ENOMEM);
304 ng_callout_init(&priv->timer);
305
306 /* Allocate and initialize hash table, etc. */
307 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
308 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
309 if (priv->tab == NULL) {
310 free(priv, M_NETGRAPH_BRIDGE);
311 return (ENOMEM);
312 }
313 priv->numBuckets = MIN_BUCKETS;
314 priv->hashMask = MIN_BUCKETS - 1;
315 priv->conf.debugLevel = 1;
316 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
317 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
318 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
319
320 /*
321 * This node has all kinds of stuff that could be screwed by SMP.
322 * Until it gets it's own internal protection, we go through in
323 * single file. This could hurt a machine bridging beteen two
324 * GB ethernets so it should be fixed.
325 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
326 * (and atomic ops )
327 */
328 NG_NODE_FORCE_WRITER(node);
329 NG_NODE_SET_PRIVATE(node, priv);
330 priv->node = node;
331
332 /* Start timer; timer is always running while node is alive */
333 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
334
335 /* Done */
336 return (0);
337 }
338
339 /*
340 * Method for attaching a new hook
341 */
342 static int
343 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
344 {
345 const priv_p priv = NG_NODE_PRIVATE(node);
346
347 /* Check for a link hook */
348 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
349 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
350 const char *cp;
351 char *eptr;
352 u_long linkNum;
353
354 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
355 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
356 return (EINVAL);
357 linkNum = strtoul(cp, &eptr, 10);
358 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
359 return (EINVAL);
360 if (priv->links[linkNum] != NULL)
361 return (EISCONN);
362 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]),
363 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
364 if (priv->links[linkNum] == NULL)
365 return (ENOMEM);
366 priv->links[linkNum]->hook = hook;
367 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
368 priv->numLinks++;
369 return (0);
370 }
371
372 /* Unknown hook name */
373 return (EINVAL);
374 }
375
376 /*
377 * Receive a control message
378 */
379 static int
380 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
381 {
382 const priv_p priv = NG_NODE_PRIVATE(node);
383 struct ng_mesg *resp = NULL;
384 int error = 0;
385 struct ng_mesg *msg;
386
387 NGI_GET_MSG(item, msg);
388 switch (msg->header.typecookie) {
389 case NGM_BRIDGE_COOKIE:
390 switch (msg->header.cmd) {
391 case NGM_BRIDGE_GET_CONFIG:
392 {
393 struct ng_bridge_config *conf;
394
395 NG_MKRESPONSE(resp, msg,
396 sizeof(struct ng_bridge_config), M_NOWAIT);
397 if (resp == NULL) {
398 error = ENOMEM;
399 break;
400 }
401 conf = (struct ng_bridge_config *)resp->data;
402 *conf = priv->conf; /* no sanity checking needed */
403 break;
404 }
405 case NGM_BRIDGE_SET_CONFIG:
406 {
407 struct ng_bridge_config *conf;
408 int i;
409
410 if (msg->header.arglen
411 != sizeof(struct ng_bridge_config)) {
412 error = EINVAL;
413 break;
414 }
415 conf = (struct ng_bridge_config *)msg->data;
416 priv->conf = *conf;
417 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
418 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
419 break;
420 }
421 case NGM_BRIDGE_RESET:
422 {
423 int i;
424
425 /* Flush all entries in the hash table */
426 ng_bridge_remove_hosts(priv, -1);
427
428 /* Reset all loop detection counters and stats */
429 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
430 if (priv->links[i] == NULL)
431 continue;
432 priv->links[i]->loopCount = 0;
433 bzero(&priv->links[i]->stats,
434 sizeof(priv->links[i]->stats));
435 }
436 break;
437 }
438 case NGM_BRIDGE_GET_STATS:
439 case NGM_BRIDGE_CLR_STATS:
440 case NGM_BRIDGE_GETCLR_STATS:
441 {
442 struct ng_bridge_link *link;
443 int linkNum;
444
445 /* Get link number */
446 if (msg->header.arglen != sizeof(u_int32_t)) {
447 error = EINVAL;
448 break;
449 }
450 linkNum = *((u_int32_t *)msg->data);
451 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
452 error = EINVAL;
453 break;
454 }
455 if ((link = priv->links[linkNum]) == NULL) {
456 error = ENOTCONN;
457 break;
458 }
459
460 /* Get/clear stats */
461 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
462 NG_MKRESPONSE(resp, msg,
463 sizeof(link->stats), M_NOWAIT);
464 if (resp == NULL) {
465 error = ENOMEM;
466 break;
467 }
468 bcopy(&link->stats,
469 resp->data, sizeof(link->stats));
470 }
471 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
472 bzero(&link->stats, sizeof(link->stats));
473 break;
474 }
475 case NGM_BRIDGE_GET_TABLE:
476 {
477 struct ng_bridge_host_ary *ary;
478 struct ng_bridge_hent *hent;
479 int i = 0, bucket;
480
481 NG_MKRESPONSE(resp, msg, sizeof(*ary)
482 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
483 if (resp == NULL) {
484 error = ENOMEM;
485 break;
486 }
487 ary = (struct ng_bridge_host_ary *)resp->data;
488 ary->numHosts = priv->numHosts;
489 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
490 SLIST_FOREACH(hent, &priv->tab[bucket], next)
491 ary->hosts[i++] = hent->host;
492 }
493 break;
494 }
495 default:
496 error = EINVAL;
497 break;
498 }
499 break;
500 default:
501 error = EINVAL;
502 break;
503 }
504
505 /* Done */
506 NG_RESPOND_MSG(error, node, item, resp);
507 NG_FREE_MSG(msg);
508 return (error);
509 }
510
511 /*
512 * Receive data on a hook
513 */
514 static int
515 ng_bridge_rcvdata(hook_p hook, item_p item)
516 {
517 const node_p node = NG_HOOK_NODE(hook);
518 const priv_p priv = NG_NODE_PRIVATE(node);
519 struct ng_bridge_host *host;
520 struct ng_bridge_link *link;
521 struct ether_header *eh;
522 int error = 0, linkNum, linksSeen;
523 int manycast;
524 struct mbuf *m;
525 struct ng_bridge_link *firstLink;
526
527 NGI_GET_M(item, m);
528 /* Get link number */
529 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
530 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
531 ("%s: linkNum=%u", __func__, linkNum));
532 link = priv->links[linkNum];
533 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
534
535 /* Sanity check packet and pull up header */
536 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
537 link->stats.recvRunts++;
538 NG_FREE_ITEM(item);
539 NG_FREE_M(m);
540 return (EINVAL);
541 }
542 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
543 link->stats.memoryFailures++;
544 NG_FREE_ITEM(item);
545 return (ENOBUFS);
546 }
547 eh = mtod(m, struct ether_header *);
548 if ((eh->ether_shost[0] & 1) != 0) {
549 link->stats.recvInvalid++;
550 NG_FREE_ITEM(item);
551 NG_FREE_M(m);
552 return (EINVAL);
553 }
554
555 /* Is link disabled due to a loopback condition? */
556 if (link->loopCount != 0) {
557 link->stats.loopDrops++;
558 NG_FREE_ITEM(item);
559 NG_FREE_M(m);
560 return (ELOOP); /* XXX is this an appropriate error? */
561 }
562
563 /* Update stats */
564 link->stats.recvPackets++;
565 link->stats.recvOctets += m->m_pkthdr.len;
566 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
567 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
568 link->stats.recvBroadcasts++;
569 manycast = 2;
570 } else
571 link->stats.recvMulticasts++;
572 }
573
574 /* Look up packet's source Ethernet address in hashtable */
575 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
576
577 /* Update time since last heard from this host */
578 host->staleness = 0;
579
580 /* Did host jump to a different link? */
581 if (host->linkNum != linkNum) {
582
583 /*
584 * If the host's old link was recently established
585 * on the old link and it's already jumped to a new
586 * link, declare a loopback condition.
587 */
588 if (host->age < priv->conf.minStableAge) {
589
590 /* Log the problem */
591 if (priv->conf.debugLevel >= 2) {
592 struct ifnet *ifp = m->m_pkthdr.rcvif;
593 char suffix[32];
594
595 if (ifp != NULL)
596 snprintf(suffix, sizeof(suffix),
597 " (%s)", ifp->if_xname);
598 else
599 *suffix = '\0';
600 log(LOG_WARNING, "ng_bridge: %s:"
601 " loopback detected on %s%s\n",
602 ng_bridge_nodename(node),
603 NG_HOOK_NAME(hook), suffix);
604 }
605
606 /* Mark link as linka non grata */
607 link->loopCount = priv->conf.loopTimeout;
608 link->stats.loopDetects++;
609
610 /* Forget all hosts on this link */
611 ng_bridge_remove_hosts(priv, linkNum);
612
613 /* Drop packet */
614 link->stats.loopDrops++;
615 NG_FREE_ITEM(item);
616 NG_FREE_M(m);
617 return (ELOOP); /* XXX appropriate? */
618 }
619
620 /* Move host over to new link */
621 host->linkNum = linkNum;
622 host->age = 0;
623 }
624 } else {
625 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
626 link->stats.memoryFailures++;
627 NG_FREE_ITEM(item);
628 NG_FREE_M(m);
629 return (ENOMEM);
630 }
631 }
632
633 /* Run packet through ipfw processing, if enabled */
634 #if 0
635 if (priv->conf.ipfw[linkNum] && V_fw_enable && ip_fw_chk_ptr != NULL) {
636 /* XXX not implemented yet */
637 }
638 #endif
639
640 /*
641 * If unicast and destination host known, deliver to host's link,
642 * unless it is the same link as the packet came in on.
643 */
644 if (!manycast) {
645
646 /* Determine packet destination link */
647 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
648 struct ng_bridge_link *const destLink
649 = priv->links[host->linkNum];
650
651 /* If destination same as incoming link, do nothing */
652 KASSERT(destLink != NULL,
653 ("%s: link%d null", __func__, host->linkNum));
654 if (destLink == link) {
655 NG_FREE_ITEM(item);
656 NG_FREE_M(m);
657 return (0);
658 }
659
660 /* Deliver packet out the destination link */
661 destLink->stats.xmitPackets++;
662 destLink->stats.xmitOctets += m->m_pkthdr.len;
663 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
664 return (error);
665 }
666
667 /* Destination host is not known */
668 link->stats.recvUnknown++;
669 }
670
671 /* Distribute unknown, multicast, broadcast pkts to all other links */
672 firstLink = NULL;
673 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
674 struct ng_bridge_link *destLink;
675 struct mbuf *m2 = NULL;
676
677 /*
678 * If we have checked all the links then now
679 * send the original on its reserved link
680 */
681 if (linksSeen == priv->numLinks) {
682 /* If we never saw a good link, leave. */
683 if (firstLink == NULL) {
684 NG_FREE_ITEM(item);
685 NG_FREE_M(m);
686 return (0);
687 }
688 destLink = firstLink;
689 } else {
690 destLink = priv->links[linkNum];
691 if (destLink != NULL)
692 linksSeen++;
693 /* Skip incoming link and disconnected links */
694 if (destLink == NULL || destLink == link) {
695 continue;
696 }
697 if (firstLink == NULL) {
698 /*
699 * This is the first usable link we have found.
700 * Reserve it for the originals.
701 * If we never find another we save a copy.
702 */
703 firstLink = destLink;
704 continue;
705 }
706
707 /*
708 * It's usable link but not the reserved (first) one.
709 * Copy mbuf info for sending.
710 */
711 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */
712 if (m2 == NULL) {
713 link->stats.memoryFailures++;
714 NG_FREE_ITEM(item);
715 NG_FREE_M(m);
716 return (ENOBUFS);
717 }
718 }
719
720 /* Update stats */
721 destLink->stats.xmitPackets++;
722 destLink->stats.xmitOctets += m->m_pkthdr.len;
723 switch (manycast) {
724 case 0: /* unicast */
725 break;
726 case 1: /* multicast */
727 destLink->stats.xmitMulticasts++;
728 break;
729 case 2: /* broadcast */
730 destLink->stats.xmitBroadcasts++;
731 break;
732 }
733
734 /* Send packet */
735 if (destLink == firstLink) {
736 /*
737 * If we've sent all the others, send the original
738 * on the first link we found.
739 */
740 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
741 break; /* always done last - not really needed. */
742 } else {
743 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
744 }
745 }
746 return (error);
747 }
748
749 /*
750 * Shutdown node
751 */
752 static int
753 ng_bridge_shutdown(node_p node)
754 {
755 const priv_p priv = NG_NODE_PRIVATE(node);
756
757 /*
758 * Shut down everything including the timer. Even if the
759 * callout has already been dequeued and is about to be
760 * run, ng_bridge_timeout() won't be fired as the node
761 * is already marked NGF_INVALID, so we're safe to free
762 * the node now.
763 */
764 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
765 ("%s: numLinks=%d numHosts=%d",
766 __func__, priv->numLinks, priv->numHosts));
767 ng_uncallout(&priv->timer, node);
768 NG_NODE_SET_PRIVATE(node, NULL);
769 NG_NODE_UNREF(node);
770 free(priv->tab, M_NETGRAPH_BRIDGE);
771 free(priv, M_NETGRAPH_BRIDGE);
772 return (0);
773 }
774
775 /*
776 * Hook disconnection.
777 */
778 static int
779 ng_bridge_disconnect(hook_p hook)
780 {
781 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
782 int linkNum;
783
784 /* Get link number */
785 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
786 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
787 ("%s: linkNum=%u", __func__, linkNum));
788
789 /* Remove all hosts associated with this link */
790 ng_bridge_remove_hosts(priv, linkNum);
791
792 /* Free associated link information */
793 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
794 free(priv->links[linkNum], M_NETGRAPH_BRIDGE);
795 priv->links[linkNum] = NULL;
796 priv->numLinks--;
797
798 /* If no more hooks, go away */
799 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
800 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
801 ng_rmnode_self(NG_HOOK_NODE(hook));
802 }
803 return (0);
804 }
805
806 /******************************************************************
807 HASH TABLE FUNCTIONS
808 ******************************************************************/
809
810 /*
811 * Hash algorithm
812 */
813 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
814 ^ ((const u_int16_t *)(addr))[1] \
815 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
816
817 /*
818 * Find a host entry in the table.
819 */
820 static struct ng_bridge_host *
821 ng_bridge_get(priv_p priv, const u_char *addr)
822 {
823 const int bucket = HASH(addr, priv->hashMask);
824 struct ng_bridge_hent *hent;
825
826 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
827 if (ETHER_EQUAL(hent->host.addr, addr))
828 return (&hent->host);
829 }
830 return (NULL);
831 }
832
833 /*
834 * Add a new host entry to the table. This assumes the host doesn't
835 * already exist in the table. Returns 1 on success, 0 if there
836 * was a memory allocation failure.
837 */
838 static int
839 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
840 {
841 const int bucket = HASH(addr, priv->hashMask);
842 struct ng_bridge_hent *hent;
843
844 #ifdef INVARIANTS
845 /* Assert that entry does not already exist in hashtable */
846 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
847 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
848 ("%s: entry %6D exists in table", __func__, addr, ":"));
849 }
850 #endif
851
852 /* Allocate and initialize new hashtable entry */
853 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
854 if (hent == NULL)
855 return (0);
856 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
857 hent->host.linkNum = linkNum;
858 hent->host.staleness = 0;
859 hent->host.age = 0;
860
861 /* Add new element to hash bucket */
862 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
863 priv->numHosts++;
864
865 /* Resize table if necessary */
866 ng_bridge_rehash(priv);
867 return (1);
868 }
869
870 /*
871 * Resize the hash table. We try to maintain the number of buckets
872 * such that the load factor is in the range 0.25 to 1.0.
873 *
874 * If we can't get the new memory then we silently fail. This is OK
875 * because things will still work and we'll try again soon anyway.
876 */
877 static void
878 ng_bridge_rehash(priv_p priv)
879 {
880 struct ng_bridge_bucket *newTab;
881 int oldBucket, newBucket;
882 int newNumBuckets;
883 u_int newMask;
884
885 /* Is table too full or too empty? */
886 if (priv->numHosts > priv->numBuckets
887 && (priv->numBuckets << 1) <= MAX_BUCKETS)
888 newNumBuckets = priv->numBuckets << 1;
889 else if (priv->numHosts < (priv->numBuckets >> 2)
890 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
891 newNumBuckets = priv->numBuckets >> 2;
892 else
893 return;
894 newMask = newNumBuckets - 1;
895
896 /* Allocate and initialize new table */
897 newTab = malloc(newNumBuckets * sizeof(*newTab),
898 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
899 if (newTab == NULL)
900 return;
901
902 /* Move all entries from old table to new table */
903 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
904 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
905
906 while (!SLIST_EMPTY(oldList)) {
907 struct ng_bridge_hent *const hent
908 = SLIST_FIRST(oldList);
909
910 SLIST_REMOVE_HEAD(oldList, next);
911 newBucket = HASH(hent->host.addr, newMask);
912 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
913 }
914 }
915
916 /* Replace old table with new one */
917 if (priv->conf.debugLevel >= 3) {
918 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
919 ng_bridge_nodename(priv->node),
920 priv->numBuckets, newNumBuckets);
921 }
922 free(priv->tab, M_NETGRAPH_BRIDGE);
923 priv->numBuckets = newNumBuckets;
924 priv->hashMask = newMask;
925 priv->tab = newTab;
926 return;
927 }
928
929 /******************************************************************
930 MISC FUNCTIONS
931 ******************************************************************/
932
933 /*
934 * Remove all hosts associated with a specific link from the hashtable.
935 * If linkNum == -1, then remove all hosts in the table.
936 */
937 static void
938 ng_bridge_remove_hosts(priv_p priv, int linkNum)
939 {
940 int bucket;
941
942 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
943 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
944
945 while (*hptr != NULL) {
946 struct ng_bridge_hent *const hent = *hptr;
947
948 if (linkNum == -1 || hent->host.linkNum == linkNum) {
949 *hptr = SLIST_NEXT(hent, next);
950 free(hent, M_NETGRAPH_BRIDGE);
951 priv->numHosts--;
952 } else
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