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: releng/9.1/sys/netgraph/ng_bridge.c 220768 2011-04-18 09:12:27Z glebius $
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/lock.h>
65 #include <sys/malloc.h>
66 #include <sys/mbuf.h>
67 #include <sys/errno.h>
68 #include <sys/rwlock.h>
69 #include <sys/syslog.h>
70 #include <sys/socket.h>
71 #include <sys/ctype.h>
72
73 #include <net/if.h>
74 #include <net/ethernet.h>
75 #include <net/vnet.h>
76
77 #include <netinet/in.h>
78 #if 0 /* not used yet */
79 #include <netinet/ip_fw.h>
80 #endif
81 #include <netgraph/ng_message.h>
82 #include <netgraph/netgraph.h>
83 #include <netgraph/ng_parse.h>
84 #include <netgraph/ng_bridge.h>
85
86 #ifdef NG_SEPARATE_MALLOC
87 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node");
88 #else
89 #define M_NETGRAPH_BRIDGE M_NETGRAPH
90 #endif
91
92 /* Per-link private data */
93 struct ng_bridge_link {
94 hook_p hook; /* netgraph hook */
95 u_int16_t loopCount; /* loop ignore timer */
96 struct ng_bridge_link_stats stats; /* link stats */
97 };
98
99 /* Per-node private data */
100 struct ng_bridge_private {
101 struct ng_bridge_bucket *tab; /* hash table bucket array */
102 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
103 struct ng_bridge_config conf; /* node configuration */
104 node_p node; /* netgraph node */
105 u_int numHosts; /* num entries in table */
106 u_int numBuckets; /* num buckets in table */
107 u_int hashMask; /* numBuckets - 1 */
108 int numLinks; /* num connected links */
109 int persistent; /* can exist w/o hooks */
110 struct callout timer; /* one second periodic timer */
111 };
112 typedef struct ng_bridge_private *priv_p;
113
114 /* Information about a host, stored in a hash table entry */
115 struct ng_bridge_hent {
116 struct ng_bridge_host host; /* actual host info */
117 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
118 };
119
120 /* Hash table bucket declaration */
121 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
122
123 /* Netgraph node methods */
124 static ng_constructor_t ng_bridge_constructor;
125 static ng_rcvmsg_t ng_bridge_rcvmsg;
126 static ng_shutdown_t ng_bridge_shutdown;
127 static ng_newhook_t ng_bridge_newhook;
128 static ng_rcvdata_t ng_bridge_rcvdata;
129 static ng_disconnect_t ng_bridge_disconnect;
130
131 /* Other internal functions */
132 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
133 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
134 static void ng_bridge_rehash(priv_p priv);
135 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
136 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
137 static const char *ng_bridge_nodename(node_p node);
138
139 /* Ethernet broadcast */
140 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
141 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
142
143 /* Store each hook's link number in the private field */
144 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
145
146 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
147 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
148 == ((const u_int32_t *)(b))[0] \
149 && ((const u_int16_t *)(a))[2] \
150 == ((const u_int16_t *)(b))[2])
151
152 /* Minimum and maximum number of hash buckets. Must be a power of two. */
153 #define MIN_BUCKETS (1 << 5) /* 32 */
154 #define MAX_BUCKETS (1 << 14) /* 16384 */
155
156 /* Configuration default values */
157 #define DEFAULT_LOOP_TIMEOUT 60
158 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
159 #define DEFAULT_MIN_STABLE_AGE 1
160
161 /******************************************************************
162 NETGRAPH PARSE TYPES
163 ******************************************************************/
164
165 /*
166 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
167 */
168 static int
169 ng_bridge_getTableLength(const struct ng_parse_type *type,
170 const u_char *start, const u_char *buf)
171 {
172 const struct ng_bridge_host_ary *const hary
173 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
174
175 return hary->numHosts;
176 }
177
178 /* Parse type for struct ng_bridge_host_ary */
179 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
180 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
181 static const struct ng_parse_type ng_bridge_host_type = {
182 &ng_parse_struct_type,
183 &ng_bridge_host_type_fields
184 };
185 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
186 &ng_bridge_host_type,
187 ng_bridge_getTableLength
188 };
189 static const struct ng_parse_type ng_bridge_hary_type = {
190 &ng_parse_array_type,
191 &ng_bridge_hary_type_info
192 };
193 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
194 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
195 static const struct ng_parse_type ng_bridge_host_ary_type = {
196 &ng_parse_struct_type,
197 &ng_bridge_host_ary_type_fields
198 };
199
200 /* Parse type for struct ng_bridge_config */
201 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
202 &ng_parse_uint8_type,
203 NG_BRIDGE_MAX_LINKS
204 };
205 static const struct ng_parse_type ng_bridge_ipfwary_type = {
206 &ng_parse_fixedarray_type,
207 &ng_bridge_ipfwary_type_info
208 };
209 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
210 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
211 static const struct ng_parse_type ng_bridge_config_type = {
212 &ng_parse_struct_type,
213 &ng_bridge_config_type_fields
214 };
215
216 /* Parse type for struct ng_bridge_link_stat */
217 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
218 = NG_BRIDGE_STATS_TYPE_INFO;
219 static const struct ng_parse_type ng_bridge_stats_type = {
220 &ng_parse_struct_type,
221 &ng_bridge_stats_type_fields
222 };
223
224 /* List of commands and how to convert arguments to/from ASCII */
225 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
226 {
227 NGM_BRIDGE_COOKIE,
228 NGM_BRIDGE_SET_CONFIG,
229 "setconfig",
230 &ng_bridge_config_type,
231 NULL
232 },
233 {
234 NGM_BRIDGE_COOKIE,
235 NGM_BRIDGE_GET_CONFIG,
236 "getconfig",
237 NULL,
238 &ng_bridge_config_type
239 },
240 {
241 NGM_BRIDGE_COOKIE,
242 NGM_BRIDGE_RESET,
243 "reset",
244 NULL,
245 NULL
246 },
247 {
248 NGM_BRIDGE_COOKIE,
249 NGM_BRIDGE_GET_STATS,
250 "getstats",
251 &ng_parse_uint32_type,
252 &ng_bridge_stats_type
253 },
254 {
255 NGM_BRIDGE_COOKIE,
256 NGM_BRIDGE_CLR_STATS,
257 "clrstats",
258 &ng_parse_uint32_type,
259 NULL
260 },
261 {
262 NGM_BRIDGE_COOKIE,
263 NGM_BRIDGE_GETCLR_STATS,
264 "getclrstats",
265 &ng_parse_uint32_type,
266 &ng_bridge_stats_type
267 },
268 {
269 NGM_BRIDGE_COOKIE,
270 NGM_BRIDGE_GET_TABLE,
271 "gettable",
272 NULL,
273 &ng_bridge_host_ary_type
274 },
275 {
276 NGM_BRIDGE_COOKIE,
277 NGM_BRIDGE_SET_PERSISTENT,
278 "setpersistent",
279 NULL,
280 NULL
281 },
282 { 0 }
283 };
284
285 /* Node type descriptor */
286 static struct ng_type ng_bridge_typestruct = {
287 .version = NG_ABI_VERSION,
288 .name = NG_BRIDGE_NODE_TYPE,
289 .constructor = ng_bridge_constructor,
290 .rcvmsg = ng_bridge_rcvmsg,
291 .shutdown = ng_bridge_shutdown,
292 .newhook = ng_bridge_newhook,
293 .rcvdata = ng_bridge_rcvdata,
294 .disconnect = ng_bridge_disconnect,
295 .cmdlist = ng_bridge_cmdlist,
296 };
297 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
298
299 /******************************************************************
300 NETGRAPH NODE METHODS
301 ******************************************************************/
302
303 /*
304 * Node constructor
305 */
306 static int
307 ng_bridge_constructor(node_p node)
308 {
309 priv_p priv;
310
311 /* Allocate and initialize private info */
312 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
313 ng_callout_init(&priv->timer);
314
315 /* Allocate and initialize hash table, etc. */
316 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
317 M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
318 priv->numBuckets = MIN_BUCKETS;
319 priv->hashMask = MIN_BUCKETS - 1;
320 priv->conf.debugLevel = 1;
321 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
322 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
323 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
324
325 /*
326 * This node has all kinds of stuff that could be screwed by SMP.
327 * Until it gets it's own internal protection, we go through in
328 * single file. This could hurt a machine bridging beteen two
329 * GB ethernets so it should be fixed.
330 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
331 * (and atomic ops )
332 */
333 NG_NODE_FORCE_WRITER(node);
334 NG_NODE_SET_PRIVATE(node, priv);
335 priv->node = node;
336
337 /* Start timer; timer is always running while node is alive */
338 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
339
340 /* Done */
341 return (0);
342 }
343
344 /*
345 * Method for attaching a new hook
346 */
347 static int
348 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
349 {
350 const priv_p priv = NG_NODE_PRIVATE(node);
351
352 /* Check for a link hook */
353 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
354 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
355 const char *cp;
356 char *eptr;
357 u_long linkNum;
358
359 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
360 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
361 return (EINVAL);
362 linkNum = strtoul(cp, &eptr, 10);
363 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
364 return (EINVAL);
365 if (priv->links[linkNum] != NULL)
366 return (EISCONN);
367 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]),
368 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
369 if (priv->links[linkNum] == NULL)
370 return (ENOMEM);
371 priv->links[linkNum]->hook = hook;
372 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
373 priv->numLinks++;
374 return (0);
375 }
376
377 /* Unknown hook name */
378 return (EINVAL);
379 }
380
381 /*
382 * Receive a control message
383 */
384 static int
385 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
386 {
387 const priv_p priv = NG_NODE_PRIVATE(node);
388 struct ng_mesg *resp = NULL;
389 int error = 0;
390 struct ng_mesg *msg;
391
392 NGI_GET_MSG(item, msg);
393 switch (msg->header.typecookie) {
394 case NGM_BRIDGE_COOKIE:
395 switch (msg->header.cmd) {
396 case NGM_BRIDGE_GET_CONFIG:
397 {
398 struct ng_bridge_config *conf;
399
400 NG_MKRESPONSE(resp, msg,
401 sizeof(struct ng_bridge_config), M_NOWAIT);
402 if (resp == NULL) {
403 error = ENOMEM;
404 break;
405 }
406 conf = (struct ng_bridge_config *)resp->data;
407 *conf = priv->conf; /* no sanity checking needed */
408 break;
409 }
410 case NGM_BRIDGE_SET_CONFIG:
411 {
412 struct ng_bridge_config *conf;
413 int i;
414
415 if (msg->header.arglen
416 != sizeof(struct ng_bridge_config)) {
417 error = EINVAL;
418 break;
419 }
420 conf = (struct ng_bridge_config *)msg->data;
421 priv->conf = *conf;
422 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
423 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
424 break;
425 }
426 case NGM_BRIDGE_RESET:
427 {
428 int i;
429
430 /* Flush all entries in the hash table */
431 ng_bridge_remove_hosts(priv, -1);
432
433 /* Reset all loop detection counters and stats */
434 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
435 if (priv->links[i] == NULL)
436 continue;
437 priv->links[i]->loopCount = 0;
438 bzero(&priv->links[i]->stats,
439 sizeof(priv->links[i]->stats));
440 }
441 break;
442 }
443 case NGM_BRIDGE_GET_STATS:
444 case NGM_BRIDGE_CLR_STATS:
445 case NGM_BRIDGE_GETCLR_STATS:
446 {
447 struct ng_bridge_link *link;
448 int linkNum;
449
450 /* Get link number */
451 if (msg->header.arglen != sizeof(u_int32_t)) {
452 error = EINVAL;
453 break;
454 }
455 linkNum = *((u_int32_t *)msg->data);
456 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
457 error = EINVAL;
458 break;
459 }
460 if ((link = priv->links[linkNum]) == NULL) {
461 error = ENOTCONN;
462 break;
463 }
464
465 /* Get/clear stats */
466 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
467 NG_MKRESPONSE(resp, msg,
468 sizeof(link->stats), M_NOWAIT);
469 if (resp == NULL) {
470 error = ENOMEM;
471 break;
472 }
473 bcopy(&link->stats,
474 resp->data, sizeof(link->stats));
475 }
476 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
477 bzero(&link->stats, sizeof(link->stats));
478 break;
479 }
480 case NGM_BRIDGE_GET_TABLE:
481 {
482 struct ng_bridge_host_ary *ary;
483 struct ng_bridge_hent *hent;
484 int i = 0, bucket;
485
486 NG_MKRESPONSE(resp, msg, sizeof(*ary)
487 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
488 if (resp == NULL) {
489 error = ENOMEM;
490 break;
491 }
492 ary = (struct ng_bridge_host_ary *)resp->data;
493 ary->numHosts = priv->numHosts;
494 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
495 SLIST_FOREACH(hent, &priv->tab[bucket], next)
496 ary->hosts[i++] = hent->host;
497 }
498 break;
499 }
500 case NGM_BRIDGE_SET_PERSISTENT:
501 {
502 priv->persistent = 1;
503 break;
504 }
505 default:
506 error = EINVAL;
507 break;
508 }
509 break;
510 default:
511 error = EINVAL;
512 break;
513 }
514
515 /* Done */
516 NG_RESPOND_MSG(error, node, item, resp);
517 NG_FREE_MSG(msg);
518 return (error);
519 }
520
521 /*
522 * Receive data on a hook
523 */
524 static int
525 ng_bridge_rcvdata(hook_p hook, item_p item)
526 {
527 const node_p node = NG_HOOK_NODE(hook);
528 const priv_p priv = NG_NODE_PRIVATE(node);
529 struct ng_bridge_host *host;
530 struct ng_bridge_link *link;
531 struct ether_header *eh;
532 int error = 0, linkNum, linksSeen;
533 int manycast;
534 struct mbuf *m;
535 struct ng_bridge_link *firstLink;
536
537 NGI_GET_M(item, m);
538 /* Get link number */
539 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
540 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
541 ("%s: linkNum=%u", __func__, linkNum));
542 link = priv->links[linkNum];
543 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
544
545 /* Sanity check packet and pull up header */
546 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
547 link->stats.recvRunts++;
548 NG_FREE_ITEM(item);
549 NG_FREE_M(m);
550 return (EINVAL);
551 }
552 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
553 link->stats.memoryFailures++;
554 NG_FREE_ITEM(item);
555 return (ENOBUFS);
556 }
557 eh = mtod(m, struct ether_header *);
558 if ((eh->ether_shost[0] & 1) != 0) {
559 link->stats.recvInvalid++;
560 NG_FREE_ITEM(item);
561 NG_FREE_M(m);
562 return (EINVAL);
563 }
564
565 /* Is link disabled due to a loopback condition? */
566 if (link->loopCount != 0) {
567 link->stats.loopDrops++;
568 NG_FREE_ITEM(item);
569 NG_FREE_M(m);
570 return (ELOOP); /* XXX is this an appropriate error? */
571 }
572
573 /* Update stats */
574 link->stats.recvPackets++;
575 link->stats.recvOctets += m->m_pkthdr.len;
576 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
577 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
578 link->stats.recvBroadcasts++;
579 manycast = 2;
580 } else
581 link->stats.recvMulticasts++;
582 }
583
584 /* Look up packet's source Ethernet address in hashtable */
585 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
586
587 /* Update time since last heard from this host */
588 host->staleness = 0;
589
590 /* Did host jump to a different link? */
591 if (host->linkNum != linkNum) {
592
593 /*
594 * If the host's old link was recently established
595 * on the old link and it's already jumped to a new
596 * link, declare a loopback condition.
597 */
598 if (host->age < priv->conf.minStableAge) {
599
600 /* Log the problem */
601 if (priv->conf.debugLevel >= 2) {
602 struct ifnet *ifp = m->m_pkthdr.rcvif;
603 char suffix[32];
604
605 if (ifp != NULL)
606 snprintf(suffix, sizeof(suffix),
607 " (%s)", ifp->if_xname);
608 else
609 *suffix = '\0';
610 log(LOG_WARNING, "ng_bridge: %s:"
611 " loopback detected on %s%s\n",
612 ng_bridge_nodename(node),
613 NG_HOOK_NAME(hook), suffix);
614 }
615
616 /* Mark link as linka non grata */
617 link->loopCount = priv->conf.loopTimeout;
618 link->stats.loopDetects++;
619
620 /* Forget all hosts on this link */
621 ng_bridge_remove_hosts(priv, linkNum);
622
623 /* Drop packet */
624 link->stats.loopDrops++;
625 NG_FREE_ITEM(item);
626 NG_FREE_M(m);
627 return (ELOOP); /* XXX appropriate? */
628 }
629
630 /* Move host over to new link */
631 host->linkNum = linkNum;
632 host->age = 0;
633 }
634 } else {
635 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
636 link->stats.memoryFailures++;
637 NG_FREE_ITEM(item);
638 NG_FREE_M(m);
639 return (ENOMEM);
640 }
641 }
642
643 /* Run packet through ipfw processing, if enabled */
644 #if 0
645 if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
646 /* XXX not implemented yet */
647 }
648 #endif
649
650 /*
651 * If unicast and destination host known, deliver to host's link,
652 * unless it is the same link as the packet came in on.
653 */
654 if (!manycast) {
655
656 /* Determine packet destination link */
657 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
658 struct ng_bridge_link *const destLink
659 = priv->links[host->linkNum];
660
661 /* If destination same as incoming link, do nothing */
662 KASSERT(destLink != NULL,
663 ("%s: link%d null", __func__, host->linkNum));
664 if (destLink == link) {
665 NG_FREE_ITEM(item);
666 NG_FREE_M(m);
667 return (0);
668 }
669
670 /* Deliver packet out the destination link */
671 destLink->stats.xmitPackets++;
672 destLink->stats.xmitOctets += m->m_pkthdr.len;
673 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
674 return (error);
675 }
676
677 /* Destination host is not known */
678 link->stats.recvUnknown++;
679 }
680
681 /* Distribute unknown, multicast, broadcast pkts to all other links */
682 firstLink = NULL;
683 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
684 struct ng_bridge_link *destLink;
685 struct mbuf *m2 = NULL;
686
687 /*
688 * If we have checked all the links then now
689 * send the original on its reserved link
690 */
691 if (linksSeen == priv->numLinks) {
692 /* If we never saw a good link, leave. */
693 if (firstLink == NULL) {
694 NG_FREE_ITEM(item);
695 NG_FREE_M(m);
696 return (0);
697 }
698 destLink = firstLink;
699 } else {
700 destLink = priv->links[linkNum];
701 if (destLink != NULL)
702 linksSeen++;
703 /* Skip incoming link and disconnected links */
704 if (destLink == NULL || destLink == link) {
705 continue;
706 }
707 if (firstLink == NULL) {
708 /*
709 * This is the first usable link we have found.
710 * Reserve it for the originals.
711 * If we never find another we save a copy.
712 */
713 firstLink = destLink;
714 continue;
715 }
716
717 /*
718 * It's usable link but not the reserved (first) one.
719 * Copy mbuf info for sending.
720 */
721 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */
722 if (m2 == NULL) {
723 link->stats.memoryFailures++;
724 NG_FREE_ITEM(item);
725 NG_FREE_M(m);
726 return (ENOBUFS);
727 }
728 }
729
730 /* Update stats */
731 destLink->stats.xmitPackets++;
732 destLink->stats.xmitOctets += m->m_pkthdr.len;
733 switch (manycast) {
734 case 0: /* unicast */
735 break;
736 case 1: /* multicast */
737 destLink->stats.xmitMulticasts++;
738 break;
739 case 2: /* broadcast */
740 destLink->stats.xmitBroadcasts++;
741 break;
742 }
743
744 /* Send packet */
745 if (destLink == firstLink) {
746 /*
747 * If we've sent all the others, send the original
748 * on the first link we found.
749 */
750 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
751 break; /* always done last - not really needed. */
752 } else {
753 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
754 }
755 }
756 return (error);
757 }
758
759 /*
760 * Shutdown node
761 */
762 static int
763 ng_bridge_shutdown(node_p node)
764 {
765 const priv_p priv = NG_NODE_PRIVATE(node);
766
767 /*
768 * Shut down everything including the timer. Even if the
769 * callout has already been dequeued and is about to be
770 * run, ng_bridge_timeout() won't be fired as the node
771 * is already marked NGF_INVALID, so we're safe to free
772 * the node now.
773 */
774 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
775 ("%s: numLinks=%d numHosts=%d",
776 __func__, priv->numLinks, priv->numHosts));
777 ng_uncallout(&priv->timer, node);
778 NG_NODE_SET_PRIVATE(node, NULL);
779 NG_NODE_UNREF(node);
780 free(priv->tab, M_NETGRAPH_BRIDGE);
781 free(priv, M_NETGRAPH_BRIDGE);
782 return (0);
783 }
784
785 /*
786 * Hook disconnection.
787 */
788 static int
789 ng_bridge_disconnect(hook_p hook)
790 {
791 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
792 int linkNum;
793
794 /* Get link number */
795 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
796 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
797 ("%s: linkNum=%u", __func__, linkNum));
798
799 /* Remove all hosts associated with this link */
800 ng_bridge_remove_hosts(priv, linkNum);
801
802 /* Free associated link information */
803 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
804 free(priv->links[linkNum], M_NETGRAPH_BRIDGE);
805 priv->links[linkNum] = NULL;
806 priv->numLinks--;
807
808 /* If no more hooks, go away */
809 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
810 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
811 && !priv->persistent) {
812 ng_rmnode_self(NG_HOOK_NODE(hook));
813 }
814 return (0);
815 }
816
817 /******************************************************************
818 HASH TABLE FUNCTIONS
819 ******************************************************************/
820
821 /*
822 * Hash algorithm
823 */
824 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
825 ^ ((const u_int16_t *)(addr))[1] \
826 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
827
828 /*
829 * Find a host entry in the table.
830 */
831 static struct ng_bridge_host *
832 ng_bridge_get(priv_p priv, const u_char *addr)
833 {
834 const int bucket = HASH(addr, priv->hashMask);
835 struct ng_bridge_hent *hent;
836
837 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
838 if (ETHER_EQUAL(hent->host.addr, addr))
839 return (&hent->host);
840 }
841 return (NULL);
842 }
843
844 /*
845 * Add a new host entry to the table. This assumes the host doesn't
846 * already exist in the table. Returns 1 on success, 0 if there
847 * was a memory allocation failure.
848 */
849 static int
850 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
851 {
852 const int bucket = HASH(addr, priv->hashMask);
853 struct ng_bridge_hent *hent;
854
855 #ifdef INVARIANTS
856 /* Assert that entry does not already exist in hashtable */
857 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
858 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
859 ("%s: entry %6D exists in table", __func__, addr, ":"));
860 }
861 #endif
862
863 /* Allocate and initialize new hashtable entry */
864 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
865 if (hent == NULL)
866 return (0);
867 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
868 hent->host.linkNum = linkNum;
869 hent->host.staleness = 0;
870 hent->host.age = 0;
871
872 /* Add new element to hash bucket */
873 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
874 priv->numHosts++;
875
876 /* Resize table if necessary */
877 ng_bridge_rehash(priv);
878 return (1);
879 }
880
881 /*
882 * Resize the hash table. We try to maintain the number of buckets
883 * such that the load factor is in the range 0.25 to 1.0.
884 *
885 * If we can't get the new memory then we silently fail. This is OK
886 * because things will still work and we'll try again soon anyway.
887 */
888 static void
889 ng_bridge_rehash(priv_p priv)
890 {
891 struct ng_bridge_bucket *newTab;
892 int oldBucket, newBucket;
893 int newNumBuckets;
894 u_int newMask;
895
896 /* Is table too full or too empty? */
897 if (priv->numHosts > priv->numBuckets
898 && (priv->numBuckets << 1) <= MAX_BUCKETS)
899 newNumBuckets = priv->numBuckets << 1;
900 else if (priv->numHosts < (priv->numBuckets >> 2)
901 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
902 newNumBuckets = priv->numBuckets >> 2;
903 else
904 return;
905 newMask = newNumBuckets - 1;
906
907 /* Allocate and initialize new table */
908 newTab = malloc(newNumBuckets * sizeof(*newTab),
909 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
910 if (newTab == NULL)
911 return;
912
913 /* Move all entries from old table to new table */
914 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
915 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
916
917 while (!SLIST_EMPTY(oldList)) {
918 struct ng_bridge_hent *const hent
919 = SLIST_FIRST(oldList);
920
921 SLIST_REMOVE_HEAD(oldList, next);
922 newBucket = HASH(hent->host.addr, newMask);
923 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
924 }
925 }
926
927 /* Replace old table with new one */
928 if (priv->conf.debugLevel >= 3) {
929 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
930 ng_bridge_nodename(priv->node),
931 priv->numBuckets, newNumBuckets);
932 }
933 free(priv->tab, M_NETGRAPH_BRIDGE);
934 priv->numBuckets = newNumBuckets;
935 priv->hashMask = newMask;
936 priv->tab = newTab;
937 return;
938 }
939
940 /******************************************************************
941 MISC FUNCTIONS
942 ******************************************************************/
943
944 /*
945 * Remove all hosts associated with a specific link from the hashtable.
946 * If linkNum == -1, then remove all hosts in the table.
947 */
948 static void
949 ng_bridge_remove_hosts(priv_p priv, int linkNum)
950 {
951 int bucket;
952
953 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
954 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
955
956 while (*hptr != NULL) {
957 struct ng_bridge_hent *const hent = *hptr;
958
959 if (linkNum == -1 || hent->host.linkNum == linkNum) {
960 *hptr = SLIST_NEXT(hent, next);
961 free(hent, M_NETGRAPH_BRIDGE);
962 priv->numHosts--;
963 } else
964 hptr = &SLIST_NEXT(hent, next);
965 }
966 }
967 }
968
969 /*
970 * Handle our once-per-second timeout event. We do two things:
971 * we decrement link->loopCount for those links being muted due to
972 * a detected loopback condition, and we remove any hosts from
973 * the hashtable whom we haven't heard from in a long while.
974 */
975 static void
976 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
977 {
978 const priv_p priv = NG_NODE_PRIVATE(node);
979 int bucket;
980 int counter = 0;
981 int linkNum;
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 /* Register a new timeout, keeping the existing node reference */
1036 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
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: 27ccd35c2bff57e525c1053ea16f9624
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