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 1.31 2005/02/09 15:14:44 ru 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
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/ethernet.h>
74
75 #include <netinet/in.h>
76 #include <net/ipfw/ip_fw.h>
77
78 #include <netgraph7/ng_message.h>
79 #include <netgraph7/netgraph.h>
80 #include <netgraph7/ng_parse.h>
81 #include "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
ng_bridge_getTableLength(const struct ng_parse_type * type,const u_char * start,const u_char * buf)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
ng_bridge_constructor(node_p node)296 ng_bridge_constructor(node_p node)
297 {
298 priv_p priv;
299
300 /* Allocate and initialize private info */
301 priv = kmalloc(sizeof(*priv), M_NETGRAPH_BRIDGE,
302 M_WAITOK | M_NULLOK | M_ZERO);
303 if (priv == NULL)
304 return (ENOMEM);
305 ng_callout_init(&priv->timer);
306
307 /* Allocate and initialize hash table, etc. */
308 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab),
309 M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK | M_ZERO);
310 if (priv->tab == NULL) {
311 kfree(priv, M_NETGRAPH_BRIDGE);
312 return (ENOMEM);
313 }
314 priv->numBuckets = MIN_BUCKETS;
315 priv->hashMask = MIN_BUCKETS - 1;
316 priv->conf.debugLevel = 1;
317 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
318 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
319 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
320
321 /*
322 * This node has all kinds of stuff that could be screwed by SMP.
323 * Until it gets it's own internal protection, we go through in
324 * single file. This could hurt a machine bridging beteen two
325 * GB ethernets so it should be fixed.
326 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
327 * (and atomic ops )
328 */
329 NG_NODE_FORCE_WRITER(node);
330 NG_NODE_SET_PRIVATE(node, priv);
331 priv->node = node;
332
333 /* Start timer; timer is always running while node is alive */
334 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
335
336 /* Done */
337 return (0);
338 }
339
340 /*
341 * Method for attaching a new hook
342 */
343 static int
ng_bridge_newhook(node_p node,hook_p hook,const char * name)344 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
345 {
346 const priv_p priv = NG_NODE_PRIVATE(node);
347
348 /* Check for a link hook */
349 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
350 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
351 const char *cp;
352 char *eptr;
353 u_long linkNum;
354
355 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
356 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
357 return (EINVAL);
358 linkNum = strtoul(cp, &eptr, 10);
359 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
360 return (EINVAL);
361 if (priv->links[linkNum] != NULL)
362 return (EISCONN);
363 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]),
364 M_NETGRAPH_BRIDGE,
365 M_WAITOK | M_NULLOK | M_ZERO);
366 if (priv->links[linkNum] == NULL)
367 return (ENOMEM);
368 priv->links[linkNum]->hook = hook;
369 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
370 priv->numLinks++;
371 return (0);
372 }
373
374 /* Unknown hook name */
375 return (EINVAL);
376 }
377
378 /*
379 * Receive a control message
380 */
381 static int
ng_bridge_rcvmsg(node_p node,item_p item,hook_p lasthook)382 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
383 {
384 const priv_p priv = NG_NODE_PRIVATE(node);
385 struct ng_mesg *resp = NULL;
386 int error = 0;
387 struct ng_mesg *msg;
388
389 NGI_GET_MSG(item, msg);
390 switch (msg->header.typecookie) {
391 case NGM_BRIDGE_COOKIE:
392 switch (msg->header.cmd) {
393 case NGM_BRIDGE_GET_CONFIG:
394 {
395 struct ng_bridge_config *conf;
396
397 NG_MKRESPONSE(resp, msg,
398 sizeof(struct ng_bridge_config), M_WAITOK | M_NULLOK);
399 if (resp == NULL) {
400 error = ENOMEM;
401 break;
402 }
403 conf = (struct ng_bridge_config *)resp->data;
404 *conf = priv->conf; /* no sanity checking needed */
405 break;
406 }
407 case NGM_BRIDGE_SET_CONFIG:
408 {
409 struct ng_bridge_config *conf;
410 int i;
411
412 if (msg->header.arglen
413 != sizeof(struct ng_bridge_config)) {
414 error = EINVAL;
415 break;
416 }
417 conf = (struct ng_bridge_config *)msg->data;
418 priv->conf = *conf;
419 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
420 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
421 break;
422 }
423 case NGM_BRIDGE_RESET:
424 {
425 int i;
426
427 /* Flush all entries in the hash table */
428 ng_bridge_remove_hosts(priv, -1);
429
430 /* Reset all loop detection counters and stats */
431 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
432 if (priv->links[i] == NULL)
433 continue;
434 priv->links[i]->loopCount = 0;
435 bzero(&priv->links[i]->stats,
436 sizeof(priv->links[i]->stats));
437 }
438 break;
439 }
440 case NGM_BRIDGE_GET_STATS:
441 case NGM_BRIDGE_CLR_STATS:
442 case NGM_BRIDGE_GETCLR_STATS:
443 {
444 struct ng_bridge_link *link;
445 int linkNum;
446
447 /* Get link number */
448 if (msg->header.arglen != sizeof(u_int32_t)) {
449 error = EINVAL;
450 break;
451 }
452 linkNum = *((u_int32_t *)msg->data);
453 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
454 error = EINVAL;
455 break;
456 }
457 if ((link = priv->links[linkNum]) == NULL) {
458 error = ENOTCONN;
459 break;
460 }
461
462 /* Get/clear stats */
463 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
464 NG_MKRESPONSE(resp, msg,
465 sizeof(link->stats), M_WAITOK | M_NULLOK);
466 if (resp == NULL) {
467 error = ENOMEM;
468 break;
469 }
470 bcopy(&link->stats,
471 resp->data, sizeof(link->stats));
472 }
473 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
474 bzero(&link->stats, sizeof(link->stats));
475 break;
476 }
477 case NGM_BRIDGE_GET_TABLE:
478 {
479 struct ng_bridge_host_ary *ary;
480 struct ng_bridge_hent *hent;
481 int i = 0, bucket;
482
483 NG_MKRESPONSE(resp, msg, sizeof(*ary)
484 + (priv->numHosts * sizeof(*ary->hosts)), M_WAITOK | M_NULLOK);
485 if (resp == NULL) {
486 error = ENOMEM;
487 break;
488 }
489 ary = (struct ng_bridge_host_ary *)resp->data;
490 ary->numHosts = priv->numHosts;
491 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
492 SLIST_FOREACH(hent, &priv->tab[bucket], next)
493 ary->hosts[i++] = hent->host;
494 }
495 break;
496 }
497 default:
498 error = EINVAL;
499 break;
500 }
501 break;
502 default:
503 error = EINVAL;
504 break;
505 }
506
507 /* Done */
508 NG_RESPOND_MSG(error, node, item, resp);
509 NG_FREE_MSG(msg);
510 return (error);
511 }
512
513 /*
514 * Receive data on a hook
515 */
516 static int
ng_bridge_rcvdata(hook_p hook,item_p item)517 ng_bridge_rcvdata(hook_p hook, item_p item)
518 {
519 const node_p node = NG_HOOK_NODE(hook);
520 const priv_p priv = NG_NODE_PRIVATE(node);
521 struct ng_bridge_host *host;
522 struct ng_bridge_link *link;
523 struct ether_header *eh;
524 int error = 0, linkNum, linksSeen;
525 int manycast;
526 struct mbuf *m;
527 struct ng_bridge_link *firstLink;
528
529 NGI_GET_M(item, m);
530 /* Get link number */
531 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
532 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
533 ("%s: linkNum=%u", __func__, linkNum));
534 link = priv->links[linkNum];
535 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
536
537 /* Sanity check packet and pull up header */
538 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
539 link->stats.recvRunts++;
540 NG_FREE_ITEM(item);
541 NG_FREE_M(m);
542 return (EINVAL);
543 }
544 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
545 link->stats.memoryFailures++;
546 NG_FREE_ITEM(item);
547 return (ENOBUFS);
548 }
549 eh = mtod(m, struct ether_header *);
550 if ((eh->ether_shost[0] & 1) != 0) {
551 link->stats.recvInvalid++;
552 NG_FREE_ITEM(item);
553 NG_FREE_M(m);
554 return (EINVAL);
555 }
556
557 /* Is link disabled due to a loopback condition? */
558 if (link->loopCount != 0) {
559 link->stats.loopDrops++;
560 NG_FREE_ITEM(item);
561 NG_FREE_M(m);
562 return (ELOOP); /* XXX is this an appropriate error? */
563 }
564
565 /* Update stats */
566 link->stats.recvPackets++;
567 link->stats.recvOctets += m->m_pkthdr.len;
568 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
569 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
570 link->stats.recvBroadcasts++;
571 manycast = 2;
572 } else
573 link->stats.recvMulticasts++;
574 }
575
576 /* Look up packet's source Ethernet address in hashtable */
577 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
578
579 /* Update time since last heard from this host */
580 host->staleness = 0;
581
582 /* Did host jump to a different link? */
583 if (host->linkNum != linkNum) {
584
585 /*
586 * If the host's old link was recently established
587 * on the old link and it's already jumped to a new
588 * link, declare a loopback condition.
589 */
590 if (host->age < priv->conf.minStableAge) {
591
592 /* Log the problem */
593 if (priv->conf.debugLevel >= 2) {
594 struct ifnet *ifp = m->m_pkthdr.rcvif;
595 char suffix[32];
596
597 if (ifp != NULL)
598 ksnprintf(suffix, sizeof(suffix),
599 " (%s)", ifp->if_xname);
600 else
601 *suffix = '\0';
602 log(LOG_WARNING, "ng_bridge: %s:"
603 " loopback detected on %s%s\n",
604 ng_bridge_nodename(node),
605 NG_HOOK_NAME(hook), suffix);
606 }
607
608 /* Mark link as linka non grata */
609 link->loopCount = priv->conf.loopTimeout;
610 link->stats.loopDetects++;
611
612 /* Forget all hosts on this link */
613 ng_bridge_remove_hosts(priv, linkNum);
614
615 /* Drop packet */
616 link->stats.loopDrops++;
617 NG_FREE_ITEM(item);
618 NG_FREE_M(m);
619 return (ELOOP); /* XXX appropriate? */
620 }
621
622 /* Move host over to new link */
623 host->linkNum = linkNum;
624 host->age = 0;
625 }
626 } else {
627 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
628 link->stats.memoryFailures++;
629 NG_FREE_ITEM(item);
630 NG_FREE_M(m);
631 return (ENOMEM);
632 }
633 }
634
635 /* Run packet through ipfw processing, if enabled */
636 #if 0
637 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) {
638 /* XXX not implemented yet */
639 }
640 #endif
641
642 /*
643 * If unicast and destination host known, deliver to host's link,
644 * unless it is the same link as the packet came in on.
645 */
646 if (!manycast) {
647
648 /* Determine packet destination link */
649 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
650 struct ng_bridge_link *const destLink
651 = priv->links[host->linkNum];
652
653 /* If destination same as incoming link, do nothing */
654 KASSERT(destLink != NULL,
655 ("%s: link%d null", __func__, host->linkNum));
656 if (destLink == link) {
657 NG_FREE_ITEM(item);
658 NG_FREE_M(m);
659 return (0);
660 }
661
662 /* Deliver packet out the destination link */
663 destLink->stats.xmitPackets++;
664 destLink->stats.xmitOctets += m->m_pkthdr.len;
665 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
666 return (error);
667 }
668
669 /* Destination host is not known */
670 link->stats.recvUnknown++;
671 }
672
673 /* Distribute unknown, multicast, broadcast pkts to all other links */
674 firstLink = NULL;
675 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
676 struct ng_bridge_link *destLink;
677 struct mbuf *m2 = NULL;
678
679 /*
680 * If we have checked all the links then now
681 * send the original on its reserved link
682 */
683 if (linksSeen == priv->numLinks) {
684 /* If we never saw a good link, leave. */
685 if (firstLink == NULL) {
686 NG_FREE_ITEM(item);
687 NG_FREE_M(m);
688 return (0);
689 }
690 destLink = firstLink;
691 } else {
692 destLink = priv->links[linkNum];
693 if (destLink != NULL)
694 linksSeen++;
695 /* Skip incoming link and disconnected links */
696 if (destLink == NULL || destLink == link) {
697 continue;
698 }
699 if (firstLink == NULL) {
700 /*
701 * This is the first usable link we have found.
702 * Reserve it for the originals.
703 * If we never find another we save a copy.
704 */
705 firstLink = destLink;
706 continue;
707 }
708
709 /*
710 * It's usable link but not the reserved (first) one.
711 * Copy mbuf info for sending.
712 */
713 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */
714 if (m2 == NULL) {
715 link->stats.memoryFailures++;
716 NG_FREE_ITEM(item);
717 NG_FREE_M(m);
718 return (ENOBUFS);
719 }
720 }
721
722 /* Update stats */
723 destLink->stats.xmitPackets++;
724 destLink->stats.xmitOctets += m->m_pkthdr.len;
725 switch (manycast) {
726 case 0: /* unicast */
727 break;
728 case 1: /* multicast */
729 destLink->stats.xmitMulticasts++;
730 break;
731 case 2: /* broadcast */
732 destLink->stats.xmitBroadcasts++;
733 break;
734 }
735
736 /* Send packet */
737 if (destLink == firstLink) {
738 /*
739 * If we've sent all the others, send the original
740 * on the first link we found.
741 */
742 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
743 break; /* always done last - not really needed. */
744 } else {
745 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
746 }
747 }
748 return (error);
749 }
750
751 /*
752 * Shutdown node
753 */
754 static int
ng_bridge_shutdown(node_p node)755 ng_bridge_shutdown(node_p node)
756 {
757 const priv_p priv = NG_NODE_PRIVATE(node);
758
759 /*
760 * Shut down everything including the timer. Even if the
761 * callout has already been dequeued and is about to be
762 * run, ng_bridge_timeout() won't be fired as the node
763 * is already marked NGF_INVALID, so we're safe to free
764 * the node now.
765 */
766 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
767 ("%s: numLinks=%d numHosts=%d",
768 __func__, priv->numLinks, priv->numHosts));
769 ng_uncallout(&priv->timer, node);
770 NG_NODE_SET_PRIVATE(node, NULL);
771 NG_NODE_UNREF(node);
772 kfree(priv->tab, M_NETGRAPH_BRIDGE);
773 kfree(priv, M_NETGRAPH_BRIDGE);
774 return (0);
775 }
776
777 /*
778 * Hook disconnection.
779 */
780 static int
ng_bridge_disconnect(hook_p hook)781 ng_bridge_disconnect(hook_p hook)
782 {
783 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
784 int linkNum;
785
786 /* Get link number */
787 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
788 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
789 ("%s: linkNum=%u", __func__, linkNum));
790
791 /* Remove all hosts associated with this link */
792 ng_bridge_remove_hosts(priv, linkNum);
793
794 /* Free associated link information */
795 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
796 kfree(priv->links[linkNum], M_NETGRAPH_BRIDGE);
797 priv->links[linkNum] = NULL;
798 priv->numLinks--;
799
800 /* If no more hooks, go away */
801 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
802 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
803 ng_rmnode_self(NG_HOOK_NODE(hook));
804 }
805 return (0);
806 }
807
808 /******************************************************************
809 HASH TABLE FUNCTIONS
810 ******************************************************************/
811
812 /*
813 * Hash algorithm
814 */
815 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
816 ^ ((const u_int16_t *)(addr))[1] \
817 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
818
819 /*
820 * Find a host entry in the table.
821 */
822 static struct ng_bridge_host *
ng_bridge_get(priv_p priv,const u_char * addr)823 ng_bridge_get(priv_p priv, const u_char *addr)
824 {
825 const int bucket = HASH(addr, priv->hashMask);
826 struct ng_bridge_hent *hent;
827
828 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
829 if (ETHER_EQUAL(hent->host.addr, addr))
830 return (&hent->host);
831 }
832 return (NULL);
833 }
834
835 /*
836 * Add a new host entry to the table. This assumes the host doesn't
837 * already exist in the table. Returns 1 on success, 0 if there
838 * was a memory allocation failure.
839 */
840 static int
ng_bridge_put(priv_p priv,const u_char * addr,int linkNum)841 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
842 {
843 const int bucket = HASH(addr, priv->hashMask);
844 struct ng_bridge_hent *hent;
845 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar;
846
847 #ifdef INVARIANTS
848 /* Assert that entry does not already exist in hashtable */
849 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
850 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
851 ("%s: entry %s exists in table", __func__, kether_ntoa(addr, ethstr)));
852 }
853 #endif
854
855 /* Allocate and initialize new hashtable entry */
856 hent = kmalloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK);
857 if (hent == NULL)
858 return (0);
859 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
860 hent->host.linkNum = linkNum;
861 hent->host.staleness = 0;
862 hent->host.age = 0;
863
864 /* Add new element to hash bucket */
865 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
866 priv->numHosts++;
867
868 /* Resize table if necessary */
869 ng_bridge_rehash(priv);
870 return (1);
871 }
872
873 /*
874 * Resize the hash table. We try to maintain the number of buckets
875 * such that the load factor is in the range 0.25 to 1.0.
876 *
877 * If we can't get the new memory then we silently fail. This is OK
878 * because things will still work and we'll try again soon anyway.
879 */
880 static void
ng_bridge_rehash(priv_p priv)881 ng_bridge_rehash(priv_p priv)
882 {
883 struct ng_bridge_bucket *newTab;
884 int oldBucket, newBucket;
885 int newNumBuckets;
886 u_int newMask;
887
888 /* Is table too full or too empty? */
889 if (priv->numHosts > priv->numBuckets
890 && (priv->numBuckets << 1) <= MAX_BUCKETS)
891 newNumBuckets = priv->numBuckets << 1;
892 else if (priv->numHosts < (priv->numBuckets >> 2)
893 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
894 newNumBuckets = priv->numBuckets >> 2;
895 else
896 return;
897 newMask = newNumBuckets - 1;
898
899 /* Allocate and initialize new table */
900 newTab = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE,
901 M_NOWAIT | M_ZERO);
902 if (newTab == NULL)
903 return;
904
905 /* Move all entries from old table to new table */
906 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
907 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
908
909 while (!SLIST_EMPTY(oldList)) {
910 struct ng_bridge_hent *const hent
911 = SLIST_FIRST(oldList);
912
913 SLIST_REMOVE_HEAD(oldList, next);
914 newBucket = HASH(hent->host.addr, newMask);
915 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
916 }
917 }
918
919 /* Replace old table with new one */
920 if (priv->conf.debugLevel >= 3) {
921 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
922 ng_bridge_nodename(priv->node),
923 priv->numBuckets, newNumBuckets);
924 }
925 kfree(priv->tab, M_NETGRAPH_BRIDGE);
926 priv->numBuckets = newNumBuckets;
927 priv->hashMask = newMask;
928 priv->tab = newTab;
929 return;
930 }
931
932 /******************************************************************
933 MISC FUNCTIONS
934 ******************************************************************/
935
936 /*
937 * Remove all hosts associated with a specific link from the hashtable.
938 * If linkNum == -1, then remove all hosts in the table.
939 */
940 static void
ng_bridge_remove_hosts(priv_p priv,int linkNum)941 ng_bridge_remove_hosts(priv_p priv, int linkNum)
942 {
943 int bucket;
944
945 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
946 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
947
948 while (*hptr != NULL) {
949 struct ng_bridge_hent *const hent = *hptr;
950
951 if (linkNum == -1 || hent->host.linkNum == linkNum) {
952 *hptr = SLIST_NEXT(hent, next);
953 kfree(hent, M_NETGRAPH_BRIDGE);
954 priv->numHosts--;
955 } else
956 hptr = &SLIST_NEXT(hent, next);
957 }
958 }
959 }
960
961 /*
962 * Handle our once-per-second timeout event. We do two things:
963 * we decrement link->loopCount for those links being muted due to
964 * a detected loopback condition, and we remove any hosts from
965 * the hashtable whom we haven't heard from in a long while.
966 */
967 static void
ng_bridge_timeout(node_p node,hook_p hook,void * arg1,int arg2)968 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
969 {
970 const priv_p priv = NG_NODE_PRIVATE(node);
971 int bucket;
972 int counter = 0;
973 int linkNum;
974 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar;
975
976 /* Update host time counters and remove stale entries */
977 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
978 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
979
980 while (*hptr != NULL) {
981 struct ng_bridge_hent *const hent = *hptr;
982
983 /* Make sure host's link really exists */
984 KASSERT(priv->links[hent->host.linkNum] != NULL,
985 ("%s: host %s on nonexistent link %d",
986 __func__, kether_ntoa(hent->host.addr, ethstr),
987 hent->host.linkNum));
988
989 /* Remove hosts we haven't heard from in a while */
990 if (++hent->host.staleness >= priv->conf.maxStaleness) {
991 *hptr = SLIST_NEXT(hent, next);
992 kfree(hent, M_NETGRAPH_BRIDGE);
993 priv->numHosts--;
994 } else {
995 if (hent->host.age < 0xffff)
996 hent->host.age++;
997 hptr = &SLIST_NEXT(hent, next);
998 counter++;
999 }
1000 }
1001 }
1002 KASSERT(priv->numHosts == counter,
1003 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1004
1005 /* Decrease table size if necessary */
1006 ng_bridge_rehash(priv);
1007
1008 /* Decrease loop counter on muted looped back links */
1009 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
1010 struct ng_bridge_link *const link = priv->links[linkNum];
1011
1012 if (link != NULL) {
1013 if (link->loopCount != 0) {
1014 link->loopCount--;
1015 if (link->loopCount == 0
1016 && priv->conf.debugLevel >= 2) {
1017 log(LOG_INFO, "ng_bridge: %s:"
1018 " restoring looped back link%d\n",
1019 ng_bridge_nodename(node), linkNum);
1020 }
1021 }
1022 counter++;
1023 }
1024 }
1025 KASSERT(priv->numLinks == counter,
1026 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1027
1028 /* Register a new timeout, keeping the existing node reference */
1029 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1030 }
1031
1032 /*
1033 * Return node's "name", even if it doesn't have one.
1034 */
1035 static const char *
ng_bridge_nodename(node_p node)1036 ng_bridge_nodename(node_p node)
1037 {
1038 static char name[NG_NODESIZ];
1039
1040 if (NG_NODE_NAME(node) != NULL)
1041 ksnprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1042 else
1043 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1044 return name;
1045 }
1046
1047