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 <[email protected]>
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
69 #include <net/if.h>
70 #include <net/if_var.h>
71 #include <net/ethernet.h>
72 #include <net/vnet.h>
73
74 #include <netinet/in.h>
75 #if 0 /* not used yet */
76 #include <netinet/ip_fw.h>
77 #endif
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 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
85 "netgraph bridge node");
86 #else
87 #define M_NETGRAPH_BRIDGE M_NETGRAPH
88 #endif
89
90 /* Per-link private data */
91 struct ng_bridge_link {
92 hook_p hook; /* netgraph hook */
93 u_int16_t loopCount; /* loop ignore timer */
94 struct ng_bridge_link_stats stats; /* link stats */
95 };
96
97 /* Per-node private data */
98 struct ng_bridge_private {
99 struct ng_bridge_bucket *tab; /* hash table bucket array */
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 int persistent; /* can exist w/o hooks */
107 struct callout timer; /* one second periodic timer */
108 };
109 typedef struct ng_bridge_private *priv_p;
110
111 /* Information about a host, stored in a hash table entry */
112 struct ng_bridge_hent {
113 struct ng_bridge_host host; /* actual host info */
114 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
115 };
116
117 /* Hash table bucket declaration */
118 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
119
120 /* Netgraph node methods */
121 static ng_constructor_t ng_bridge_constructor;
122 static ng_rcvmsg_t ng_bridge_rcvmsg;
123 static ng_shutdown_t ng_bridge_shutdown;
124 static ng_newhook_t ng_bridge_newhook;
125 static ng_rcvdata_t ng_bridge_rcvdata;
126 static ng_disconnect_t ng_bridge_disconnect;
127
128 /* Other internal functions */
129 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
130 static int ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
131 static void ng_bridge_rehash(priv_p priv);
132 static void ng_bridge_remove_hosts(priv_p priv, link_p link);
133 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
134 static const char *ng_bridge_nodename(node_p node);
135
136 /* Ethernet broadcast */
137 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
138 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
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
ng_bridge_getTableLength(const struct ng_parse_type * type,const u_char * start,const u_char * buf)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_struct_field ng_bridge_config_type_fields[]
196 = NG_BRIDGE_CONFIG_TYPE_INFO;
197 static const struct ng_parse_type ng_bridge_config_type = {
198 &ng_parse_struct_type,
199 &ng_bridge_config_type_fields
200 };
201
202 /* Parse type for struct ng_bridge_link_stat */
203 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
204 = NG_BRIDGE_STATS_TYPE_INFO;
205 static const struct ng_parse_type ng_bridge_stats_type = {
206 &ng_parse_struct_type,
207 &ng_bridge_stats_type_fields
208 };
209
210 /* List of commands and how to convert arguments to/from ASCII */
211 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
212 {
213 NGM_BRIDGE_COOKIE,
214 NGM_BRIDGE_SET_CONFIG,
215 "setconfig",
216 &ng_bridge_config_type,
217 NULL
218 },
219 {
220 NGM_BRIDGE_COOKIE,
221 NGM_BRIDGE_GET_CONFIG,
222 "getconfig",
223 NULL,
224 &ng_bridge_config_type
225 },
226 {
227 NGM_BRIDGE_COOKIE,
228 NGM_BRIDGE_RESET,
229 "reset",
230 NULL,
231 NULL
232 },
233 {
234 NGM_BRIDGE_COOKIE,
235 NGM_BRIDGE_GET_STATS,
236 "getstats",
237 &ng_parse_uint32_type,
238 &ng_bridge_stats_type
239 },
240 {
241 NGM_BRIDGE_COOKIE,
242 NGM_BRIDGE_CLR_STATS,
243 "clrstats",
244 &ng_parse_uint32_type,
245 NULL
246 },
247 {
248 NGM_BRIDGE_COOKIE,
249 NGM_BRIDGE_GETCLR_STATS,
250 "getclrstats",
251 &ng_parse_uint32_type,
252 &ng_bridge_stats_type
253 },
254 {
255 NGM_BRIDGE_COOKIE,
256 NGM_BRIDGE_GET_TABLE,
257 "gettable",
258 NULL,
259 &ng_bridge_host_ary_type
260 },
261 {
262 NGM_BRIDGE_COOKIE,
263 NGM_BRIDGE_SET_PERSISTENT,
264 "setpersistent",
265 NULL,
266 NULL
267 },
268 { 0 }
269 };
270
271 /* Node type descriptor */
272 static struct ng_type ng_bridge_typestruct = {
273 .version = NG_ABI_VERSION,
274 .name = NG_BRIDGE_NODE_TYPE,
275 .constructor = ng_bridge_constructor,
276 .rcvmsg = ng_bridge_rcvmsg,
277 .shutdown = ng_bridge_shutdown,
278 .newhook = ng_bridge_newhook,
279 .rcvdata = ng_bridge_rcvdata,
280 .disconnect = ng_bridge_disconnect,
281 .cmdlist = ng_bridge_cmdlist,
282 };
283 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
284
285 /******************************************************************
286 NETGRAPH NODE METHODS
287 ******************************************************************/
288
289 /*
290 * Node constructor
291 */
292 static int
ng_bridge_constructor(node_p node)293 ng_bridge_constructor(node_p node)
294 {
295 priv_p priv;
296
297 /* Allocate and initialize private info */
298 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
299 ng_callout_init(&priv->timer);
300
301 /* Allocate and initialize hash table, etc. */
302 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
303 M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
304 priv->numBuckets = MIN_BUCKETS;
305 priv->hashMask = MIN_BUCKETS - 1;
306 priv->conf.debugLevel = 1;
307 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
308 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
309 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
310
311 /*
312 * This node has all kinds of stuff that could be screwed by SMP.
313 * Until it gets it's own internal protection, we go through in
314 * single file. This could hurt a machine bridging between two
315 * GB ethernets so it should be fixed.
316 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
317 * (and atomic ops )
318 */
319 NG_NODE_FORCE_WRITER(node);
320 NG_NODE_SET_PRIVATE(node, priv);
321 priv->node = node;
322
323 /* Start timer; timer is always running while node is alive */
324 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
325
326 /* Done */
327 return (0);
328 }
329
330 /*
331 * Method for attaching a new hook
332 */
333 static int
ng_bridge_newhook(node_p node,hook_p hook,const char * name)334 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
335 {
336 const priv_p priv = NG_NODE_PRIVATE(node);
337
338 /* Check for a link hook */
339 if (strlen(name) > strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) {
340 char linkName[NG_HOOKSIZ];
341 u_int32_t linkNum;
342 link_p link;
343
344 /* primitive parsing */
345 linkNum = strtoul(name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
346 NULL, 10);
347 /* validation by comparing against the reconstucted name */
348 snprintf(linkName, sizeof(linkName),
349 "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
350 linkNum);
351 if (strcmp(linkName, name) != 0)
352 return (EINVAL);
353
354 if(NG_PEER_NODE(hook) == node)
355 return (ELOOP);
356
357 link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE,
358 M_WAITOK|M_ZERO);
359 if (link == NULL)
360 return (ENOMEM);
361 link->hook = hook;
362 NG_HOOK_SET_PRIVATE(hook, link);
363 priv->numLinks++;
364 return (0);
365 }
366
367 /* Unknown hook name */
368 return (EINVAL);
369 }
370
371 /*
372 * Receive a control message
373 */
374 static int
ng_bridge_reset_link(hook_p hook,void * arg __unused)375 ng_bridge_reset_link(hook_p hook, void *arg __unused)
376 {
377 link_p priv = NG_HOOK_PRIVATE(hook);
378
379 priv->loopCount = 0;
380 bzero(&priv->stats, sizeof(priv->stats));
381
382 return (1);
383 }
384
385 static int
ng_bridge_rcvmsg(node_p node,item_p item,hook_p lasthook)386 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
387 {
388 const priv_p priv = NG_NODE_PRIVATE(node);
389 struct ng_mesg *resp = NULL;
390 int error = 0;
391 struct ng_mesg *msg;
392
393 NGI_GET_MSG(item, msg);
394 switch (msg->header.typecookie) {
395 #ifdef NGM_BRIDGE_TABLE_ABI
396 case NGM_BRIDGE_COOKIE_TBL:
397 switch (msg->header.cmd) {
398 case NGM_BRIDGE_GET_CONFIG:
399 {
400 struct ng_bridge_config_tbl *conf;
401
402 NG_MKRESPONSE(resp, msg, sizeof(*conf),
403 M_NOWAIT|M_ZERO);
404 if (resp == NULL) {
405 error = ENOMEM;
406 break;
407 }
408 conf = (struct ng_bridge_config_tbl *)resp->data;
409 conf->cfg = priv->conf;
410 break;
411 }
412 case NGM_BRIDGE_SET_CONFIG:
413 {
414 struct ng_bridge_config_tbl *conf;
415
416 if (msg->header.arglen != sizeof(*conf)) {
417 error = EINVAL;
418 break;
419 }
420 conf = (struct ng_bridge_config_tbl *)msg->data;
421 priv->conf = conf->cfg;
422 break;
423 }
424 case NGM_BRIDGE_GET_TABLE:
425 {
426 struct ng_bridge_host_tbl_ary *ary;
427 struct ng_bridge_hent *hent;
428 int i, bucket;
429
430 NG_MKRESPONSE(resp, msg, sizeof(*ary) +
431 (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
432 if (resp == NULL) {
433 error = ENOMEM;
434 break;
435 }
436 ary = (struct ng_bridge_host_tbl_ary *)resp->data;
437 ary->numHosts = priv->numHosts;
438 i = 0;
439 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
440 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
441 memcpy(ary->hosts[i].addr,
442 hent->host.addr,
443 sizeof(ary->hosts[i].addr));
444 ary->hosts[i].age = hent->host.age;
445 ary->hosts[i].staleness =
446 hent->host.staleness;
447 ary->hosts[i].linkNum = strtol(
448 NG_HOOK_NAME(hent->host.link->hook) +
449 strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
450 NULL, 10);
451 i++;
452 }
453 }
454 break;
455 }
456 }
457 /* If already handled break, otherwise use new ABI. */
458 if (resp != NULL || error != 0)
459 break;
460 #endif /* NGM_BRIDGE_TABLE_ABI */
461 case NGM_BRIDGE_COOKIE:
462 switch (msg->header.cmd) {
463 case NGM_BRIDGE_GET_CONFIG:
464 {
465 struct ng_bridge_config *conf;
466
467 NG_MKRESPONSE(resp, msg,
468 sizeof(struct ng_bridge_config), M_NOWAIT);
469 if (resp == NULL) {
470 error = ENOMEM;
471 break;
472 }
473 conf = (struct ng_bridge_config *)resp->data;
474 *conf = priv->conf; /* no sanity checking needed */
475 break;
476 }
477 case NGM_BRIDGE_SET_CONFIG:
478 {
479 struct ng_bridge_config *conf;
480
481 if (msg->header.arglen
482 != sizeof(struct ng_bridge_config)) {
483 error = EINVAL;
484 break;
485 }
486 conf = (struct ng_bridge_config *)msg->data;
487 priv->conf = *conf;
488 break;
489 }
490 case NGM_BRIDGE_RESET:
491 {
492 hook_p rethook;
493
494 /* Flush all entries in the hash table */
495 ng_bridge_remove_hosts(priv, NULL);
496
497 /* Reset all loop detection counters and stats */
498 NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
499 rethook);
500 break;
501 }
502 case NGM_BRIDGE_GET_STATS:
503 case NGM_BRIDGE_CLR_STATS:
504 case NGM_BRIDGE_GETCLR_STATS:
505 {
506 hook_p hook;
507 link_p link;
508 char linkName[NG_HOOKSIZ];
509
510 /* Get link number */
511 if (msg->header.arglen != sizeof(u_int32_t)) {
512 error = EINVAL;
513 break;
514 }
515 snprintf(linkName, sizeof(linkName),
516 "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
517 *((u_int32_t *)msg->data));
518
519 if ((hook = ng_findhook(node, linkName)) == NULL) {
520 error = ENOTCONN;
521 break;
522 }
523 link = NG_HOOK_PRIVATE(hook);
524
525 /* Get/clear stats */
526 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
527 NG_MKRESPONSE(resp, msg,
528 sizeof(link->stats), M_NOWAIT);
529 if (resp == NULL) {
530 error = ENOMEM;
531 break;
532 }
533 bcopy(&link->stats,
534 resp->data, sizeof(link->stats));
535 }
536 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
537 bzero(&link->stats, sizeof(link->stats));
538 break;
539 }
540 case NGM_BRIDGE_GET_TABLE:
541 {
542 struct ng_bridge_host_ary *ary;
543 struct ng_bridge_hent *hent;
544 int i = 0, bucket;
545
546 NG_MKRESPONSE(resp, msg, sizeof(*ary)
547 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
548 if (resp == NULL) {
549 error = ENOMEM;
550 break;
551 }
552 ary = (struct ng_bridge_host_ary *)resp->data;
553 ary->numHosts = priv->numHosts;
554 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
555 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
556 memcpy(ary->hosts[i].addr,
557 hent->host.addr,
558 sizeof(ary->hosts[i].addr));
559 ary->hosts[i].age = hent->host.age;
560 ary->hosts[i].staleness = hent->host.staleness;
561 strncpy(ary->hosts[i].hook,
562 NG_HOOK_NAME(hent->host.link->hook),
563 sizeof(ary->hosts[i].hook));
564 i++;
565 }
566 }
567 break;
568 }
569 case NGM_BRIDGE_SET_PERSISTENT:
570 {
571 priv->persistent = 1;
572 break;
573 }
574 default:
575 error = EINVAL;
576 break;
577 }
578 break;
579 default:
580 error = EINVAL;
581 break;
582 }
583
584 /* Done */
585 NG_RESPOND_MSG(error, node, item, resp);
586 NG_FREE_MSG(msg);
587 return (error);
588 }
589
590 /*
591 * Receive data on a hook
592 */
593 struct ng_bridge_send_ctx {
594 link_p foundFirst, incoming;
595 struct mbuf * m;
596 int manycast, error;
597 };
598
599 static int
ng_bridge_send_ctx(hook_p dst,void * arg)600 ng_bridge_send_ctx(hook_p dst, void *arg)
601 {
602 struct ng_bridge_send_ctx *ctx = arg;
603 link_p destLink = NG_HOOK_PRIVATE(dst);
604 struct mbuf *m2 = NULL;
605 int error = 0;
606
607 /* Skip incoming link */
608 if (destLink == ctx->incoming) {
609 return (1);
610 }
611
612 if (ctx->foundFirst == NULL) {
613 /*
614 * This is the first usable link we have found.
615 * Reserve it for the originals.
616 * If we never find another we save a copy.
617 */
618 ctx->foundFirst = destLink;
619 return (1);
620 }
621
622 /*
623 * It's usable link but not the reserved (first) one.
624 * Copy mbuf info for sending.
625 */
626 m2 = m_dup(ctx->m, M_NOWAIT); /* XXX m_copypacket() */
627 if (m2 == NULL) {
628 ctx->incoming->stats.memoryFailures++;
629 ctx->error = ENOBUFS;
630 return (0); /* abort loop */
631 }
632
633 /* Update stats */
634 destLink->stats.xmitPackets++;
635 destLink->stats.xmitOctets += m2->m_pkthdr.len;
636 switch (ctx->manycast) {
637 default: /* unknown unicast */
638 break;
639 case 1: /* multicast */
640 destLink->stats.xmitMulticasts++;
641 break;
642 case 2: /* broadcast */
643 destLink->stats.xmitBroadcasts++;
644 break;
645 }
646
647 /* Send packet */
648 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
649 if(error)
650 ctx->error = error;
651 return (1);
652 }
653
654 static int
ng_bridge_rcvdata(hook_p hook,item_p item)655 ng_bridge_rcvdata(hook_p hook, item_p item)
656 {
657 const node_p node = NG_HOOK_NODE(hook);
658 const priv_p priv = NG_NODE_PRIVATE(node);
659 struct ng_bridge_host *host;
660 struct ether_header *eh;
661 struct ng_bridge_send_ctx ctx = { 0 };
662 hook_p ret;
663
664 NGI_GET_M(item, ctx.m);
665
666 ctx.incoming = NG_HOOK_PRIVATE(hook);
667 /* Sanity check packet and pull up header */
668 if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
669 ctx.incoming->stats.recvRunts++;
670 NG_FREE_ITEM(item);
671 NG_FREE_M(ctx.m);
672 return (EINVAL);
673 }
674 if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
675 ctx.incoming->stats.memoryFailures++;
676 NG_FREE_ITEM(item);
677 return (ENOBUFS);
678 }
679 eh = mtod(ctx.m, struct ether_header *);
680 if ((eh->ether_shost[0] & 1) != 0) {
681 ctx.incoming->stats.recvInvalid++;
682 NG_FREE_ITEM(item);
683 NG_FREE_M(ctx.m);
684 return (EINVAL);
685 }
686
687 /* Is link disabled due to a loopback condition? */
688 if (ctx.incoming->loopCount != 0) {
689 ctx.incoming->stats.loopDrops++;
690 NG_FREE_ITEM(item);
691 NG_FREE_M(ctx.m);
692 return (ELOOP); /* XXX is this an appropriate error? */
693 }
694
695 /* Update stats */
696 ctx.incoming->stats.recvPackets++;
697 ctx.incoming->stats.recvOctets += ctx.m->m_pkthdr.len;
698 if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
699 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
700 ctx.incoming->stats.recvBroadcasts++;
701 ctx.manycast = 2;
702 } else
703 ctx.incoming->stats.recvMulticasts++;
704 }
705
706 /* Look up packet's source Ethernet address in hashtable */
707 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
708 /* Update time since last heard from this host */
709 host->staleness = 0;
710
711 /* Did host jump to a different link? */
712 if (host->link != ctx.incoming) {
713 /*
714 * If the host's old link was recently established
715 * on the old link and it's already jumped to a new
716 * link, declare a loopback condition.
717 */
718 if (host->age < priv->conf.minStableAge) {
719 /* Log the problem */
720 if (priv->conf.debugLevel >= 2) {
721 struct ifnet *ifp = ctx.m->m_pkthdr.rcvif;
722 char suffix[32];
723
724 if (ifp != NULL)
725 snprintf(suffix, sizeof(suffix),
726 " (%s)", ifp->if_xname);
727 else
728 *suffix = '\0';
729 log(LOG_WARNING, "ng_bridge: %s:"
730 " loopback detected on %s%s\n",
731 ng_bridge_nodename(node),
732 NG_HOOK_NAME(hook), suffix);
733 }
734
735 /* Mark link as linka non grata */
736 ctx.incoming->loopCount = priv->conf.loopTimeout;
737 ctx.incoming->stats.loopDetects++;
738
739 /* Forget all hosts on this link */
740 ng_bridge_remove_hosts(priv, ctx.incoming);
741
742 /* Drop packet */
743 ctx.incoming->stats.loopDrops++;
744 NG_FREE_ITEM(item);
745 NG_FREE_M(ctx.m);
746 return (ELOOP); /* XXX appropriate? */
747 }
748
749 /* Move host over to new link */
750 host->link = ctx.incoming;
751 host->age = 0;
752 }
753 } else {
754 if (!ng_bridge_put(priv, eh->ether_shost, ctx.incoming)) {
755 ctx.incoming->stats.memoryFailures++;
756 NG_FREE_ITEM(item);
757 NG_FREE_M(ctx.m);
758 return (ENOMEM);
759 }
760 }
761
762 /* Run packet through ipfw processing, if enabled */
763 #if 0
764 if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
765 /* XXX not implemented yet */
766 }
767 #endif
768
769 /*
770 * If unicast and destination host known, deliver to host's link,
771 * unless it is the same link as the packet came in on.
772 */
773 if (!ctx.manycast) {
774 /* Determine packet destination link */
775 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
776 link_p destLink = host->link;
777
778 /* If destination same as incoming link, do nothing */
779 if (destLink == ctx.incoming) {
780 NG_FREE_ITEM(item);
781 NG_FREE_M(ctx.m);
782 return (0);
783 }
784
785 /* Deliver packet out the destination link */
786 destLink->stats.xmitPackets++;
787 destLink->stats.xmitOctets += ctx.m->m_pkthdr.len;
788 NG_FWD_NEW_DATA(ctx.error, item, destLink->hook, ctx.m);
789 return (ctx.error);
790 }
791
792 /* Destination host is not known */
793 ctx.incoming->stats.recvUnknown++;
794 }
795
796 /* Distribute unknown, multicast, broadcast pkts to all other links */
797 NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
798
799 /* If we never saw a good link, leave. */
800 if (ctx.foundFirst == NULL || ctx.error != 0) {
801 NG_FREE_ITEM(item);
802 NG_FREE_M(ctx.m);
803 return (ctx.error);
804 }
805
806 /*
807 * If we've sent all the others, send the original
808 * on the first link we found.
809 */
810 NG_FWD_NEW_DATA(ctx.error, item, ctx.foundFirst->hook, ctx.m);
811 return (ctx.error);
812 }
813
814 /*
815 * Shutdown node
816 */
817 static int
ng_bridge_shutdown(node_p node)818 ng_bridge_shutdown(node_p node)
819 {
820 const priv_p priv = NG_NODE_PRIVATE(node);
821
822 /*
823 * Shut down everything including the timer. Even if the
824 * callout has already been dequeued and is about to be
825 * run, ng_bridge_timeout() won't be fired as the node
826 * is already marked NGF_INVALID, so we're safe to free
827 * the node now.
828 */
829 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
830 ("%s: numLinks=%d numHosts=%d",
831 __func__, priv->numLinks, priv->numHosts));
832 ng_uncallout(&priv->timer, node);
833 NG_NODE_SET_PRIVATE(node, NULL);
834 NG_NODE_UNREF(node);
835 free(priv->tab, M_NETGRAPH_BRIDGE);
836 free(priv, M_NETGRAPH_BRIDGE);
837 return (0);
838 }
839
840 /*
841 * Hook disconnection.
842 */
843 static int
ng_bridge_disconnect(hook_p hook)844 ng_bridge_disconnect(hook_p hook)
845 {
846 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
847 link_p link = NG_HOOK_PRIVATE(hook);
848
849 /* Remove all hosts associated with this link */
850 ng_bridge_remove_hosts(priv, link);
851
852 /* Free associated link information */
853 free(link, M_NETGRAPH_BRIDGE);
854 priv->numLinks--;
855
856 /* If no more hooks, go away */
857 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
858 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
859 && !priv->persistent) {
860 ng_rmnode_self(NG_HOOK_NODE(hook));
861 }
862 return (0);
863 }
864
865 /******************************************************************
866 HASH TABLE FUNCTIONS
867 ******************************************************************/
868
869 /*
870 * Hash algorithm
871 */
872 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
873 ^ ((const u_int16_t *)(addr))[1] \
874 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
875
876 /*
877 * Find a host entry in the table.
878 */
879 static struct ng_bridge_host *
ng_bridge_get(priv_p priv,const u_char * addr)880 ng_bridge_get(priv_p priv, const u_char *addr)
881 {
882 const int bucket = HASH(addr, priv->hashMask);
883 struct ng_bridge_hent *hent;
884
885 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
886 if (ETHER_EQUAL(hent->host.addr, addr))
887 return (&hent->host);
888 }
889 return (NULL);
890 }
891
892 /*
893 * Add a new host entry to the table. This assumes the host doesn't
894 * already exist in the table. Returns 1 on success, 0 if there
895 * was a memory allocation failure.
896 */
897 static int
ng_bridge_put(priv_p priv,const u_char * addr,link_p link)898 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
899 {
900 const int bucket = HASH(addr, priv->hashMask);
901 struct ng_bridge_hent *hent;
902
903 #ifdef INVARIANTS
904 /* Assert that entry does not already exist in hashtable */
905 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
906 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
907 ("%s: entry %6D exists in table", __func__, addr, ":"));
908 }
909 #endif
910
911 /* Allocate and initialize new hashtable entry */
912 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
913 if (hent == NULL)
914 return (0);
915 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
916 hent->host.link = link;
917 hent->host.staleness = 0;
918 hent->host.age = 0;
919
920 /* Add new element to hash bucket */
921 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
922 priv->numHosts++;
923
924 /* Resize table if necessary */
925 ng_bridge_rehash(priv);
926 return (1);
927 }
928
929 /*
930 * Resize the hash table. We try to maintain the number of buckets
931 * such that the load factor is in the range 0.25 to 1.0.
932 *
933 * If we can't get the new memory then we silently fail. This is OK
934 * because things will still work and we'll try again soon anyway.
935 */
936 static void
ng_bridge_rehash(priv_p priv)937 ng_bridge_rehash(priv_p priv)
938 {
939 struct ng_bridge_bucket *newTab;
940 int oldBucket, newBucket;
941 int newNumBuckets;
942 u_int newMask;
943
944 /* Is table too full or too empty? */
945 if (priv->numHosts > priv->numBuckets
946 && (priv->numBuckets << 1) <= MAX_BUCKETS)
947 newNumBuckets = priv->numBuckets << 1;
948 else if (priv->numHosts < (priv->numBuckets >> 2)
949 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
950 newNumBuckets = priv->numBuckets >> 2;
951 else
952 return;
953 newMask = newNumBuckets - 1;
954
955 /* Allocate and initialize new table */
956 newTab = malloc(newNumBuckets * sizeof(*newTab),
957 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
958 if (newTab == NULL)
959 return;
960
961 /* Move all entries from old table to new table */
962 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
963 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
964
965 while (!SLIST_EMPTY(oldList)) {
966 struct ng_bridge_hent *const hent
967 = SLIST_FIRST(oldList);
968
969 SLIST_REMOVE_HEAD(oldList, next);
970 newBucket = HASH(hent->host.addr, newMask);
971 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
972 }
973 }
974
975 /* Replace old table with new one */
976 if (priv->conf.debugLevel >= 3) {
977 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
978 ng_bridge_nodename(priv->node),
979 priv->numBuckets, newNumBuckets);
980 }
981 free(priv->tab, M_NETGRAPH_BRIDGE);
982 priv->numBuckets = newNumBuckets;
983 priv->hashMask = newMask;
984 priv->tab = newTab;
985 return;
986 }
987
988 /******************************************************************
989 MISC FUNCTIONS
990 ******************************************************************/
991
992 /*
993 * Remove all hosts associated with a specific link from the hashtable.
994 * If linkNum == -1, then remove all hosts in the table.
995 */
996 static void
ng_bridge_remove_hosts(priv_p priv,link_p link)997 ng_bridge_remove_hosts(priv_p priv, link_p link)
998 {
999 int bucket;
1000
1001 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1002 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1003
1004 while (*hptr != NULL) {
1005 struct ng_bridge_hent *const hent = *hptr;
1006
1007 if (link == NULL || hent->host.link == link) {
1008 *hptr = SLIST_NEXT(hent, next);
1009 free(hent, M_NETGRAPH_BRIDGE);
1010 priv->numHosts--;
1011 } else
1012 hptr = &SLIST_NEXT(hent, next);
1013 }
1014 }
1015 }
1016
1017 /*
1018 * Handle our once-per-second timeout event. We do two things:
1019 * we decrement link->loopCount for those links being muted due to
1020 * a detected loopback condition, and we remove any hosts from
1021 * the hashtable whom we haven't heard from in a long while.
1022 */
1023 static int
ng_bridge_unmute(hook_p hook,void * arg)1024 ng_bridge_unmute(hook_p hook, void *arg)
1025 {
1026 link_p link = NG_HOOK_PRIVATE(hook);
1027 node_p node = NG_HOOK_NODE(hook);
1028 priv_p priv = NG_NODE_PRIVATE(node);
1029 int *counter = arg;
1030
1031 if (link->loopCount != 0) {
1032 link->loopCount--;
1033 if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1034 log(LOG_INFO, "ng_bridge: %s:"
1035 " restoring looped back %s\n",
1036 ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1037 }
1038 }
1039 (*counter)++;
1040 return (1);
1041 }
1042
1043 static void
ng_bridge_timeout(node_p node,hook_p hook,void * arg1,int arg2)1044 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1045 {
1046 const priv_p priv = NG_NODE_PRIVATE(node);
1047 int bucket;
1048 int counter = 0;
1049 hook_p ret;
1050
1051 /* Update host time counters and remove stale entries */
1052 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1053 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1054
1055 while (*hptr != NULL) {
1056 struct ng_bridge_hent *const hent = *hptr;
1057
1058 /* Remove hosts we haven't heard from in a while */
1059 if (++hent->host.staleness >= priv->conf.maxStaleness) {
1060 *hptr = SLIST_NEXT(hent, next);
1061 free(hent, M_NETGRAPH_BRIDGE);
1062 priv->numHosts--;
1063 } else {
1064 if (hent->host.age < 0xffff)
1065 hent->host.age++;
1066 hptr = &SLIST_NEXT(hent, next);
1067 counter++;
1068 }
1069 }
1070 }
1071 KASSERT(priv->numHosts == counter,
1072 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1073
1074 /* Decrease table size if necessary */
1075 ng_bridge_rehash(priv);
1076
1077 /* Decrease loop counter on muted looped back links */
1078 counter = 0;
1079 NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1080 KASSERT(priv->numLinks == counter,
1081 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1082
1083 /* Register a new timeout, keeping the existing node reference */
1084 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1085 }
1086
1087 /*
1088 * Return node's "name", even if it doesn't have one.
1089 */
1090 static const char *
ng_bridge_nodename(node_p node)1091 ng_bridge_nodename(node_p node)
1092 {
1093 static char name[NG_NODESIZ];
1094
1095 if (NG_NODE_HAS_NAME(node))
1096 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1097 else
1098 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1099 return name;
1100 }
1101