1
2 /*
3 * ng_bridge.c
4 *
5 * Copyright (c) 2000 Whistle Communications, Inc.
6 * All rights reserved.
7 *
8 * Subject to the following obligations and disclaimer of warranty, use and
9 * redistribution of this software, in source or object code forms, with or
10 * without modifications are expressly permitted by Whistle Communications;
11 * provided, however, that:
12 * 1. Any and all reproductions of the source or object code must include the
13 * copyright notice above and the following disclaimer of warranties; and
14 * 2. No rights are granted, in any manner or form, to use Whistle
15 * Communications, Inc. trademarks, including the mark "WHISTLE
16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17 * such appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35 * OF SUCH DAMAGE.
36 *
37 * Author: Archie Cobbs <archie@freebsd.org>
38 *
39 * $FreeBSD: releng/5.3/sys/netgraph/ng_bridge.c 136588 2004-10-16 08:43:07Z cvs2svn $
40 */
41
42 /*
43 * ng_bridge(4) netgraph node type
44 *
45 * The node performs standard intelligent Ethernet bridging over
46 * each of its connected hooks, or links. A simple loop detection
47 * algorithm is included which disables a link for priv->conf.loopTimeout
48 * seconds when a host is seen to have jumped from one link to
49 * another within priv->conf.minStableAge seconds.
50 *
51 * We keep a hashtable that maps Ethernet addresses to host info,
52 * which is contained in struct ng_bridge_host's. These structures
53 * tell us on which link the host may be found. A host's entry will
54 * expire after priv->conf.maxStaleness seconds.
55 *
56 * This node is optimzed for stable networks, where machines jump
57 * from one port to the other only rarely.
58 */
59
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/kernel.h>
63 #include <sys/malloc.h>
64 #include <sys/mbuf.h>
65 #include <sys/errno.h>
66 #include <sys/syslog.h>
67 #include <sys/socket.h>
68 #include <sys/ctype.h>
69
70 #include <net/if.h>
71 #include <net/ethernet.h>
72
73 #include <netinet/in.h>
74 #include <netinet/ip_fw.h>
75
76 #include <netgraph/ng_message.h>
77 #include <netgraph/netgraph.h>
78 #include <netgraph/ng_parse.h>
79 #include <netgraph/ng_bridge.h>
80
81 #ifdef NG_SEPARATE_MALLOC
82 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node ");
83 #else
84 #define M_NETGRAPH_BRIDGE M_NETGRAPH
85 #endif
86
87 /* Per-link private data */
88 struct ng_bridge_link {
89 hook_p hook; /* netgraph hook */
90 u_int16_t loopCount; /* loop ignore timer */
91 struct ng_bridge_link_stats stats; /* link stats */
92 };
93
94 /* Per-node private data */
95 struct ng_bridge_private {
96 struct ng_bridge_bucket *tab; /* hash table bucket array */
97 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
98 struct ng_bridge_config conf; /* node configuration */
99 node_p node; /* netgraph node */
100 u_int numHosts; /* num entries in table */
101 u_int numBuckets; /* num buckets in table */
102 u_int hashMask; /* numBuckets - 1 */
103 int numLinks; /* num connected links */
104 struct callout timer; /* one second periodic timer */
105 };
106 typedef struct ng_bridge_private *priv_p;
107
108 /* Information about a host, stored in a hash table entry */
109 struct ng_bridge_hent {
110 struct ng_bridge_host host; /* actual host info */
111 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
112 };
113
114 /* Hash table bucket declaration */
115 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
116
117 /* Netgraph node methods */
118 static ng_constructor_t ng_bridge_constructor;
119 static ng_rcvmsg_t ng_bridge_rcvmsg;
120 static ng_shutdown_t ng_bridge_shutdown;
121 static ng_newhook_t ng_bridge_newhook;
122 static ng_rcvdata_t ng_bridge_rcvdata;
123 static ng_disconnect_t ng_bridge_disconnect;
124
125 /* Other internal functions */
126 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
127 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
128 static void ng_bridge_rehash(priv_p priv);
129 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
130 static void ng_bridge_timeout(void *arg);
131 static const char *ng_bridge_nodename(node_p node);
132
133 /* Ethernet broadcast */
134 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
135 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
136
137 /* Store each hook's link number in the private field */
138 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
139
140 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
141 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
142 == ((const u_int32_t *)(b))[0] \
143 && ((const u_int16_t *)(a))[2] \
144 == ((const u_int16_t *)(b))[2])
145
146 /* Minimum and maximum number of hash buckets. Must be a power of two. */
147 #define MIN_BUCKETS (1 << 5) /* 32 */
148 #define MAX_BUCKETS (1 << 14) /* 16384 */
149
150 /* Configuration default values */
151 #define DEFAULT_LOOP_TIMEOUT 60
152 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
153 #define DEFAULT_MIN_STABLE_AGE 1
154
155 /******************************************************************
156 NETGRAPH PARSE TYPES
157 ******************************************************************/
158
159 /*
160 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
161 */
162 static int
163 ng_bridge_getTableLength(const struct ng_parse_type *type,
164 const u_char *start, const u_char *buf)
165 {
166 const struct ng_bridge_host_ary *const hary
167 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
168
169 return hary->numHosts;
170 }
171
172 /* Parse type for struct ng_bridge_host_ary */
173 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
174 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
175 static const struct ng_parse_type ng_bridge_host_type = {
176 &ng_parse_struct_type,
177 &ng_bridge_host_type_fields
178 };
179 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
180 &ng_bridge_host_type,
181 ng_bridge_getTableLength
182 };
183 static const struct ng_parse_type ng_bridge_hary_type = {
184 &ng_parse_array_type,
185 &ng_bridge_hary_type_info
186 };
187 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
188 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
189 static const struct ng_parse_type ng_bridge_host_ary_type = {
190 &ng_parse_struct_type,
191 &ng_bridge_host_ary_type_fields
192 };
193
194 /* Parse type for struct ng_bridge_config */
195 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
196 &ng_parse_uint8_type,
197 NG_BRIDGE_MAX_LINKS
198 };
199 static const struct ng_parse_type ng_bridge_ipfwary_type = {
200 &ng_parse_fixedarray_type,
201 &ng_bridge_ipfwary_type_info
202 };
203 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
204 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
205 static const struct ng_parse_type ng_bridge_config_type = {
206 &ng_parse_struct_type,
207 &ng_bridge_config_type_fields
208 };
209
210 /* Parse type for struct ng_bridge_link_stat */
211 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
212 = NG_BRIDGE_STATS_TYPE_INFO;
213 static const struct ng_parse_type ng_bridge_stats_type = {
214 &ng_parse_struct_type,
215 &ng_bridge_stats_type_fields
216 };
217
218 /* List of commands and how to convert arguments to/from ASCII */
219 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
220 {
221 NGM_BRIDGE_COOKIE,
222 NGM_BRIDGE_SET_CONFIG,
223 "setconfig",
224 &ng_bridge_config_type,
225 NULL
226 },
227 {
228 NGM_BRIDGE_COOKIE,
229 NGM_BRIDGE_GET_CONFIG,
230 "getconfig",
231 NULL,
232 &ng_bridge_config_type
233 },
234 {
235 NGM_BRIDGE_COOKIE,
236 NGM_BRIDGE_RESET,
237 "reset",
238 NULL,
239 NULL
240 },
241 {
242 NGM_BRIDGE_COOKIE,
243 NGM_BRIDGE_GET_STATS,
244 "getstats",
245 &ng_parse_uint32_type,
246 &ng_bridge_stats_type
247 },
248 {
249 NGM_BRIDGE_COOKIE,
250 NGM_BRIDGE_CLR_STATS,
251 "clrstats",
252 &ng_parse_uint32_type,
253 NULL
254 },
255 {
256 NGM_BRIDGE_COOKIE,
257 NGM_BRIDGE_GETCLR_STATS,
258 "getclrstats",
259 &ng_parse_uint32_type,
260 &ng_bridge_stats_type
261 },
262 {
263 NGM_BRIDGE_COOKIE,
264 NGM_BRIDGE_GET_TABLE,
265 "gettable",
266 NULL,
267 &ng_bridge_host_ary_type
268 },
269 { 0 }
270 };
271
272 /* Node type descriptor */
273 static struct ng_type ng_bridge_typestruct = {
274 .version = NG_ABI_VERSION,
275 .name = NG_BRIDGE_NODE_TYPE,
276 .constructor = ng_bridge_constructor,
277 .rcvmsg = ng_bridge_rcvmsg,
278 .shutdown = ng_bridge_shutdown,
279 .newhook = ng_bridge_newhook,
280 .rcvdata = ng_bridge_rcvdata,
281 .disconnect = ng_bridge_disconnect,
282 .cmdlist = ng_bridge_cmdlist,
283 };
284 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
285
286 /******************************************************************
287 NETGRAPH NODE METHODS
288 ******************************************************************/
289
290 /*
291 * Node constructor
292 */
293 static int
294 ng_bridge_constructor(node_p node)
295 {
296 priv_p priv;
297
298 /* Allocate and initialize private info */
299 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
300 if (priv == NULL)
301 return (ENOMEM);
302 callout_init(&priv->timer, 0);
303
304 /* Allocate and initialize hash table, etc. */
305 MALLOC(priv->tab, struct ng_bridge_bucket *,
306 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
307 if (priv->tab == NULL) {
308 FREE(priv, M_NETGRAPH_BRIDGE);
309 return (ENOMEM);
310 }
311 priv->numBuckets = MIN_BUCKETS;
312 priv->hashMask = MIN_BUCKETS - 1;
313 priv->conf.debugLevel = 1;
314 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
315 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
316 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
317
318 /*
319 * This node has all kinds of stuff that could be screwed by SMP.
320 * Until it gets it's own internal protection, we go through in
321 * single file. This could hurt a machine bridging beteen two
322 * GB ethernets so it should be fixed.
323 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
324 * (and atomic ops )
325 */
326 NG_NODE_FORCE_WRITER(node);
327 NG_NODE_SET_PRIVATE(node, priv);
328 priv->node = node;
329
330 /* Start timer; timer is always running while node is alive */
331 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node);
332
333 /* Done */
334 return (0);
335 }
336
337 /*
338 * Method for attaching a new hook
339 */
340 static int
341 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
342 {
343 const priv_p priv = NG_NODE_PRIVATE(node);
344
345 /* Check for a link hook */
346 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
347 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
348 const char *cp;
349 char *eptr;
350 u_long linkNum;
351
352 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
353 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
354 return (EINVAL);
355 linkNum = strtoul(cp, &eptr, 10);
356 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
357 return (EINVAL);
358 if (priv->links[linkNum] != NULL)
359 return (EISCONN);
360 MALLOC(priv->links[linkNum], struct ng_bridge_link *,
361 sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
362 if (priv->links[linkNum] == NULL)
363 return (ENOMEM);
364 priv->links[linkNum]->hook = hook;
365 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
366 priv->numLinks++;
367 return (0);
368 }
369
370 /* Unknown hook name */
371 return (EINVAL);
372 }
373
374 /*
375 * Receive a control message
376 */
377 static int
378 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
379 {
380 const priv_p priv = NG_NODE_PRIVATE(node);
381 struct ng_mesg *resp = NULL;
382 int error = 0;
383 struct ng_mesg *msg;
384
385 NGI_GET_MSG(item, msg);
386 switch (msg->header.typecookie) {
387 case NGM_BRIDGE_COOKIE:
388 switch (msg->header.cmd) {
389 case NGM_BRIDGE_GET_CONFIG:
390 {
391 struct ng_bridge_config *conf;
392
393 NG_MKRESPONSE(resp, msg,
394 sizeof(struct ng_bridge_config), M_NOWAIT);
395 if (resp == NULL) {
396 error = ENOMEM;
397 break;
398 }
399 conf = (struct ng_bridge_config *)resp->data;
400 *conf = priv->conf; /* no sanity checking needed */
401 break;
402 }
403 case NGM_BRIDGE_SET_CONFIG:
404 {
405 struct ng_bridge_config *conf;
406 int i;
407
408 if (msg->header.arglen
409 != sizeof(struct ng_bridge_config)) {
410 error = EINVAL;
411 break;
412 }
413 conf = (struct ng_bridge_config *)msg->data;
414 priv->conf = *conf;
415 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
416 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
417 break;
418 }
419 case NGM_BRIDGE_RESET:
420 {
421 int i;
422
423 /* Flush all entries in the hash table */
424 ng_bridge_remove_hosts(priv, -1);
425
426 /* Reset all loop detection counters and stats */
427 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
428 if (priv->links[i] == NULL)
429 continue;
430 priv->links[i]->loopCount = 0;
431 bzero(&priv->links[i]->stats,
432 sizeof(priv->links[i]->stats));
433 }
434 break;
435 }
436 case NGM_BRIDGE_GET_STATS:
437 case NGM_BRIDGE_CLR_STATS:
438 case NGM_BRIDGE_GETCLR_STATS:
439 {
440 struct ng_bridge_link *link;
441 int linkNum;
442
443 /* Get link number */
444 if (msg->header.arglen != sizeof(u_int32_t)) {
445 error = EINVAL;
446 break;
447 }
448 linkNum = *((u_int32_t *)msg->data);
449 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
450 error = EINVAL;
451 break;
452 }
453 if ((link = priv->links[linkNum]) == NULL) {
454 error = ENOTCONN;
455 break;
456 }
457
458 /* Get/clear stats */
459 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
460 NG_MKRESPONSE(resp, msg,
461 sizeof(link->stats), M_NOWAIT);
462 if (resp == NULL) {
463 error = ENOMEM;
464 break;
465 }
466 bcopy(&link->stats,
467 resp->data, sizeof(link->stats));
468 }
469 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
470 bzero(&link->stats, sizeof(link->stats));
471 break;
472 }
473 case NGM_BRIDGE_GET_TABLE:
474 {
475 struct ng_bridge_host_ary *ary;
476 struct ng_bridge_hent *hent;
477 int i = 0, bucket;
478
479 NG_MKRESPONSE(resp, msg, sizeof(*ary)
480 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
481 if (resp == NULL) {
482 error = ENOMEM;
483 break;
484 }
485 ary = (struct ng_bridge_host_ary *)resp->data;
486 ary->numHosts = priv->numHosts;
487 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
488 SLIST_FOREACH(hent, &priv->tab[bucket], next)
489 ary->hosts[i++] = hent->host;
490 }
491 break;
492 }
493 default:
494 error = EINVAL;
495 break;
496 }
497 break;
498 default:
499 error = EINVAL;
500 break;
501 }
502
503 /* Done */
504 NG_RESPOND_MSG(error, node, item, resp);
505 NG_FREE_MSG(msg);
506 return (error);
507 }
508
509 /*
510 * Receive data on a hook
511 */
512 static int
513 ng_bridge_rcvdata(hook_p hook, item_p item)
514 {
515 const node_p node = NG_HOOK_NODE(hook);
516 const priv_p priv = NG_NODE_PRIVATE(node);
517 struct ng_bridge_host *host;
518 struct ng_bridge_link *link;
519 struct ether_header *eh;
520 int error = 0, linkNum, linksSeen;
521 int manycast;
522 struct mbuf *m;
523 struct ng_bridge_link *firstLink;
524
525 NGI_GET_M(item, m);
526 /* Get link number */
527 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
528 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
529 ("%s: linkNum=%u", __func__, linkNum));
530 link = priv->links[linkNum];
531 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
532
533 /* Sanity check packet and pull up header */
534 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
535 link->stats.recvRunts++;
536 NG_FREE_ITEM(item);
537 NG_FREE_M(m);
538 return (EINVAL);
539 }
540 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
541 link->stats.memoryFailures++;
542 NG_FREE_ITEM(item);
543 return (ENOBUFS);
544 }
545 eh = mtod(m, struct ether_header *);
546 if ((eh->ether_shost[0] & 1) != 0) {
547 link->stats.recvInvalid++;
548 NG_FREE_ITEM(item);
549 NG_FREE_M(m);
550 return (EINVAL);
551 }
552
553 /* Is link disabled due to a loopback condition? */
554 if (link->loopCount != 0) {
555 link->stats.loopDrops++;
556 NG_FREE_ITEM(item);
557 NG_FREE_M(m);
558 return (ELOOP); /* XXX is this an appropriate error? */
559 }
560
561 /* Update stats */
562 link->stats.recvPackets++;
563 link->stats.recvOctets += m->m_pkthdr.len;
564 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
565 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
566 link->stats.recvBroadcasts++;
567 manycast = 2;
568 } else
569 link->stats.recvMulticasts++;
570 }
571
572 /* Look up packet's source Ethernet address in hashtable */
573 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
574
575 /* Update time since last heard from this host */
576 host->staleness = 0;
577
578 /* Did host jump to a different link? */
579 if (host->linkNum != linkNum) {
580
581 /*
582 * If the host's old link was recently established
583 * on the old link and it's already jumped to a new
584 * link, declare a loopback condition.
585 */
586 if (host->age < priv->conf.minStableAge) {
587
588 /* Log the problem */
589 if (priv->conf.debugLevel >= 2) {
590 struct ifnet *ifp = m->m_pkthdr.rcvif;
591 char suffix[32];
592
593 if (ifp != NULL)
594 snprintf(suffix, sizeof(suffix),
595 " (%s)", ifp->if_xname);
596 else
597 *suffix = '\0';
598 log(LOG_WARNING, "ng_bridge: %s:"
599 " loopback detected on %s%s\n",
600 ng_bridge_nodename(node),
601 NG_HOOK_NAME(hook), suffix);
602 }
603
604 /* Mark link as linka non grata */
605 link->loopCount = priv->conf.loopTimeout;
606 link->stats.loopDetects++;
607
608 /* Forget all hosts on this link */
609 ng_bridge_remove_hosts(priv, linkNum);
610
611 /* Drop packet */
612 link->stats.loopDrops++;
613 NG_FREE_ITEM(item);
614 NG_FREE_M(m);
615 return (ELOOP); /* XXX appropriate? */
616 }
617
618 /* Move host over to new link */
619 host->linkNum = linkNum;
620 host->age = 0;
621 }
622 } else {
623 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
624 link->stats.memoryFailures++;
625 NG_FREE_ITEM(item);
626 NG_FREE_M(m);
627 return (ENOMEM);
628 }
629 }
630
631 /* Run packet through ipfw processing, if enabled */
632 #if 0
633 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) {
634 /* XXX not implemented yet */
635 }
636 #endif
637
638 /*
639 * If unicast and destination host known, deliver to host's link,
640 * unless it is the same link as the packet came in on.
641 */
642 if (!manycast) {
643
644 /* Determine packet destination link */
645 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
646 struct ng_bridge_link *const destLink
647 = priv->links[host->linkNum];
648
649 /* If destination same as incoming link, do nothing */
650 KASSERT(destLink != NULL,
651 ("%s: link%d null", __func__, host->linkNum));
652 if (destLink == link) {
653 NG_FREE_ITEM(item);
654 NG_FREE_M(m);
655 return (0);
656 }
657
658 /* Deliver packet out the destination link */
659 destLink->stats.xmitPackets++;
660 destLink->stats.xmitOctets += m->m_pkthdr.len;
661 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
662 return (error);
663 }
664
665 /* Destination host is not known */
666 link->stats.recvUnknown++;
667 }
668
669 /* Distribute unknown, multicast, broadcast pkts to all other links */
670 firstLink = NULL;
671 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
672 struct ng_bridge_link *destLink;
673 struct mbuf *m2 = NULL;
674
675 /*
676 * If we have checked all the links then now
677 * send the original on its reserved link
678 */
679 if (linksSeen == priv->numLinks) {
680 /* If we never saw a good link, leave. */
681 if (firstLink == NULL) {
682 NG_FREE_ITEM(item);
683 NG_FREE_M(m);
684 return (0);
685 }
686 destLink = firstLink;
687 } else {
688 destLink = priv->links[linkNum];
689 if (destLink != NULL)
690 linksSeen++;
691 /* Skip incoming link and disconnected links */
692 if (destLink == NULL || destLink == link) {
693 continue;
694 }
695 if (firstLink == NULL) {
696 /*
697 * This is the first usable link we have found.
698 * Reserve it for the originals.
699 * If we never find another we save a copy.
700 */
701 firstLink = destLink;
702 continue;
703 }
704
705 /*
706 * It's usable link but not the reserved (first) one.
707 * Copy mbuf info for sending.
708 */
709 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */
710 if (m2 == NULL) {
711 link->stats.memoryFailures++;
712 NG_FREE_ITEM(item);
713 NG_FREE_M(m);
714 return (ENOBUFS);
715 }
716 }
717
718 /* Update stats */
719 destLink->stats.xmitPackets++;
720 destLink->stats.xmitOctets += m->m_pkthdr.len;
721 switch (manycast) {
722 case 0: /* unicast */
723 break;
724 case 1: /* multicast */
725 destLink->stats.xmitMulticasts++;
726 break;
727 case 2: /* broadcast */
728 destLink->stats.xmitBroadcasts++;
729 break;
730 }
731
732 /* Send packet */
733 if (destLink == firstLink) {
734 /*
735 * If we've sent all the others, send the original
736 * on the first link we found.
737 */
738 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
739 break; /* always done last - not really needed. */
740 } else {
741 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
742 }
743 }
744 return (error);
745 }
746
747 /*
748 * Shutdown node
749 */
750 static int
751 ng_bridge_shutdown(node_p node)
752 {
753 const priv_p priv = NG_NODE_PRIVATE(node);
754
755 /*
756 * Shut down everything except the timer. There's no way to
757 * avoid another possible timeout event (it may have already
758 * been dequeued), so we can't free the node yet.
759 */
760 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
761 ("%s: numLinks=%d numHosts=%d",
762 __func__, priv->numLinks, priv->numHosts));
763 FREE(priv->tab, M_NETGRAPH_BRIDGE);
764
765 /* NGF_INVALID flag is now set so node will be freed at next timeout */
766 return (0);
767 }
768
769 /*
770 * Hook disconnection.
771 */
772 static int
773 ng_bridge_disconnect(hook_p hook)
774 {
775 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
776 int linkNum;
777
778 /* Get link number */
779 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
780 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
781 ("%s: linkNum=%u", __func__, linkNum));
782
783 /* Remove all hosts associated with this link */
784 ng_bridge_remove_hosts(priv, linkNum);
785
786 /* Free associated link information */
787 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
788 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE);
789 priv->links[linkNum] = NULL;
790 priv->numLinks--;
791
792 /* If no more hooks, go away */
793 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
794 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
795 ng_rmnode_self(NG_HOOK_NODE(hook));
796 }
797 return (0);
798 }
799
800 /******************************************************************
801 HASH TABLE FUNCTIONS
802 ******************************************************************/
803
804 /*
805 * Hash algorithm
806 */
807 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
808 ^ ((const u_int16_t *)(addr))[1] \
809 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
810
811 /*
812 * Find a host entry in the table.
813 */
814 static struct ng_bridge_host *
815 ng_bridge_get(priv_p priv, const u_char *addr)
816 {
817 const int bucket = HASH(addr, priv->hashMask);
818 struct ng_bridge_hent *hent;
819
820 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
821 if (ETHER_EQUAL(hent->host.addr, addr))
822 return (&hent->host);
823 }
824 return (NULL);
825 }
826
827 /*
828 * Add a new host entry to the table. This assumes the host doesn't
829 * already exist in the table. Returns 1 on success, 0 if there
830 * was a memory allocation failure.
831 */
832 static int
833 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
834 {
835 const int bucket = HASH(addr, priv->hashMask);
836 struct ng_bridge_hent *hent;
837
838 #ifdef INVARIANTS
839 /* Assert that entry does not already exist in hashtable */
840 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
841 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
842 ("%s: entry %6D exists in table", __func__, addr, ":"));
843 }
844 #endif
845
846 /* Allocate and initialize new hashtable entry */
847 MALLOC(hent, struct ng_bridge_hent *,
848 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
849 if (hent == NULL)
850 return (0);
851 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
852 hent->host.linkNum = linkNum;
853 hent->host.staleness = 0;
854 hent->host.age = 0;
855
856 /* Add new element to hash bucket */
857 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
858 priv->numHosts++;
859
860 /* Resize table if necessary */
861 ng_bridge_rehash(priv);
862 return (1);
863 }
864
865 /*
866 * Resize the hash table. We try to maintain the number of buckets
867 * such that the load factor is in the range 0.25 to 1.0.
868 *
869 * If we can't get the new memory then we silently fail. This is OK
870 * because things will still work and we'll try again soon anyway.
871 */
872 static void
873 ng_bridge_rehash(priv_p priv)
874 {
875 struct ng_bridge_bucket *newTab;
876 int oldBucket, newBucket;
877 int newNumBuckets;
878 u_int newMask;
879
880 /* Is table too full or too empty? */
881 if (priv->numHosts > priv->numBuckets
882 && (priv->numBuckets << 1) <= MAX_BUCKETS)
883 newNumBuckets = priv->numBuckets << 1;
884 else if (priv->numHosts < (priv->numBuckets >> 2)
885 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
886 newNumBuckets = priv->numBuckets >> 2;
887 else
888 return;
889 newMask = newNumBuckets - 1;
890
891 /* Allocate and initialize new table */
892 MALLOC(newTab, struct ng_bridge_bucket *,
893 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
894 if (newTab == NULL)
895 return;
896
897 /* Move all entries from old table to new table */
898 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
899 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
900
901 while (!SLIST_EMPTY(oldList)) {
902 struct ng_bridge_hent *const hent
903 = SLIST_FIRST(oldList);
904
905 SLIST_REMOVE_HEAD(oldList, next);
906 newBucket = HASH(hent->host.addr, newMask);
907 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
908 }
909 }
910
911 /* Replace old table with new one */
912 if (priv->conf.debugLevel >= 3) {
913 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
914 ng_bridge_nodename(priv->node),
915 priv->numBuckets, newNumBuckets);
916 }
917 FREE(priv->tab, M_NETGRAPH_BRIDGE);
918 priv->numBuckets = newNumBuckets;
919 priv->hashMask = newMask;
920 priv->tab = newTab;
921 return;
922 }
923
924 /******************************************************************
925 MISC FUNCTIONS
926 ******************************************************************/
927
928 /*
929 * Remove all hosts associated with a specific link from the hashtable.
930 * If linkNum == -1, then remove all hosts in the table.
931 */
932 static void
933 ng_bridge_remove_hosts(priv_p priv, int linkNum)
934 {
935 int bucket;
936
937 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
938 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
939
940 while (*hptr != NULL) {
941 struct ng_bridge_hent *const hent = *hptr;
942
943 if (linkNum == -1 || hent->host.linkNum == linkNum) {
944 *hptr = SLIST_NEXT(hent, next);
945 FREE(hent, M_NETGRAPH_BRIDGE);
946 priv->numHosts--;
947 } else
948 hptr = &SLIST_NEXT(hent, next);
949 }
950 }
951 }
952
953 /*
954 * Handle our once-per-second timeout event. We do two things:
955 * we decrement link->loopCount for those links being muted due to
956 * a detected loopback condition, and we remove any hosts from
957 * the hashtable whom we haven't heard from in a long while.
958 *
959 * If the node has the NGF_INVALID flag set, our job is to kill it.
960 */
961 static void
962 ng_bridge_timeout(void *arg)
963 {
964 const node_p node = arg;
965 const priv_p priv = NG_NODE_PRIVATE(node);
966 int s, bucket;
967 int counter = 0;
968 int linkNum;
969
970 /* If node was shut down, this is the final lingering timeout */
971 s = splnet();
972 if (NG_NODE_NOT_VALID(node)) {
973 FREE(priv, M_NETGRAPH_BRIDGE);
974 NG_NODE_SET_PRIVATE(node, NULL);
975 NG_NODE_UNREF(node);
976 splx(s);
977 return;
978 }
979
980 /* Register a new timeout, keeping the existing node reference */
981 callout_reset(&priv->timer, hz, ng_bridge_timeout, node);
982
983 /* Update host time counters and remove stale entries */
984 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
985 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
986
987 while (*hptr != NULL) {
988 struct ng_bridge_hent *const hent = *hptr;
989
990 /* Make sure host's link really exists */
991 KASSERT(priv->links[hent->host.linkNum] != NULL,
992 ("%s: host %6D on nonexistent link %d\n",
993 __func__, hent->host.addr, ":",
994 hent->host.linkNum));
995
996 /* Remove hosts we haven't heard from in a while */
997 if (++hent->host.staleness >= priv->conf.maxStaleness) {
998 *hptr = SLIST_NEXT(hent, next);
999 FREE(hent, M_NETGRAPH_BRIDGE);
1000 priv->numHosts--;
1001 } else {
1002 if (hent->host.age < 0xffff)
1003 hent->host.age++;
1004 hptr = &SLIST_NEXT(hent, next);
1005 counter++;
1006 }
1007 }
1008 }
1009 KASSERT(priv->numHosts == counter,
1010 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1011
1012 /* Decrease table size if necessary */
1013 ng_bridge_rehash(priv);
1014
1015 /* Decrease loop counter on muted looped back links */
1016 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
1017 struct ng_bridge_link *const link = priv->links[linkNum];
1018
1019 if (link != NULL) {
1020 if (link->loopCount != 0) {
1021 link->loopCount--;
1022 if (link->loopCount == 0
1023 && priv->conf.debugLevel >= 2) {
1024 log(LOG_INFO, "ng_bridge: %s:"
1025 " restoring looped back link%d\n",
1026 ng_bridge_nodename(node), linkNum);
1027 }
1028 }
1029 counter++;
1030 }
1031 }
1032 KASSERT(priv->numLinks == counter,
1033 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1034
1035 /* Done */
1036 splx(s);
1037 }
1038
1039 /*
1040 * Return node's "name", even if it doesn't have one.
1041 */
1042 static const char *
1043 ng_bridge_nodename(node_p node)
1044 {
1045 static char name[NG_NODESIZ];
1046
1047 if (NG_NODE_NAME(node) != NULL)
1048 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1049 else
1050 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1051 return name;
1052 }
1053
Cache object: 29a3249cf511d31c593e09827d4e2e4f
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