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/10.2/sys/netgraph/ng_bridge.c 243882 2012-12-05 08:04:20Z 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 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
88 "netgraph bridge node");
89 #else
90 #define M_NETGRAPH_BRIDGE M_NETGRAPH
91 #endif
92
93 /* Per-link private data */
94 struct ng_bridge_link {
95 hook_p hook; /* netgraph hook */
96 u_int16_t loopCount; /* loop ignore timer */
97 struct ng_bridge_link_stats stats; /* link stats */
98 };
99
100 /* Per-node private data */
101 struct ng_bridge_private {
102 struct ng_bridge_bucket *tab; /* hash table bucket array */
103 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
104 struct ng_bridge_config conf; /* node configuration */
105 node_p node; /* netgraph node */
106 u_int numHosts; /* num entries in table */
107 u_int numBuckets; /* num buckets in table */
108 u_int hashMask; /* numBuckets - 1 */
109 int numLinks; /* num connected links */
110 int persistent; /* can exist w/o hooks */
111 struct callout timer; /* one second periodic timer */
112 };
113 typedef struct ng_bridge_private *priv_p;
114
115 /* Information about a host, stored in a hash table entry */
116 struct ng_bridge_hent {
117 struct ng_bridge_host host; /* actual host info */
118 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
119 };
120
121 /* Hash table bucket declaration */
122 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
123
124 /* Netgraph node methods */
125 static ng_constructor_t ng_bridge_constructor;
126 static ng_rcvmsg_t ng_bridge_rcvmsg;
127 static ng_shutdown_t ng_bridge_shutdown;
128 static ng_newhook_t ng_bridge_newhook;
129 static ng_rcvdata_t ng_bridge_rcvdata;
130 static ng_disconnect_t ng_bridge_disconnect;
131
132 /* Other internal functions */
133 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
134 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
135 static void ng_bridge_rehash(priv_p priv);
136 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
137 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
138 static const char *ng_bridge_nodename(node_p node);
139
140 /* Ethernet broadcast */
141 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
142 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
143
144 /* Store each hook's link number in the private field */
145 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
146
147 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
148 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
149 == ((const u_int32_t *)(b))[0] \
150 && ((const u_int16_t *)(a))[2] \
151 == ((const u_int16_t *)(b))[2])
152
153 /* Minimum and maximum number of hash buckets. Must be a power of two. */
154 #define MIN_BUCKETS (1 << 5) /* 32 */
155 #define MAX_BUCKETS (1 << 14) /* 16384 */
156
157 /* Configuration default values */
158 #define DEFAULT_LOOP_TIMEOUT 60
159 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
160 #define DEFAULT_MIN_STABLE_AGE 1
161
162 /******************************************************************
163 NETGRAPH PARSE TYPES
164 ******************************************************************/
165
166 /*
167 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
168 */
169 static int
170 ng_bridge_getTableLength(const struct ng_parse_type *type,
171 const u_char *start, const u_char *buf)
172 {
173 const struct ng_bridge_host_ary *const hary
174 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
175
176 return hary->numHosts;
177 }
178
179 /* Parse type for struct ng_bridge_host_ary */
180 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
181 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
182 static const struct ng_parse_type ng_bridge_host_type = {
183 &ng_parse_struct_type,
184 &ng_bridge_host_type_fields
185 };
186 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
187 &ng_bridge_host_type,
188 ng_bridge_getTableLength
189 };
190 static const struct ng_parse_type ng_bridge_hary_type = {
191 &ng_parse_array_type,
192 &ng_bridge_hary_type_info
193 };
194 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
195 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
196 static const struct ng_parse_type ng_bridge_host_ary_type = {
197 &ng_parse_struct_type,
198 &ng_bridge_host_ary_type_fields
199 };
200
201 /* Parse type for struct ng_bridge_config */
202 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
203 &ng_parse_uint8_type,
204 NG_BRIDGE_MAX_LINKS
205 };
206 static const struct ng_parse_type ng_bridge_ipfwary_type = {
207 &ng_parse_fixedarray_type,
208 &ng_bridge_ipfwary_type_info
209 };
210 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
211 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
212 static const struct ng_parse_type ng_bridge_config_type = {
213 &ng_parse_struct_type,
214 &ng_bridge_config_type_fields
215 };
216
217 /* Parse type for struct ng_bridge_link_stat */
218 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
219 = NG_BRIDGE_STATS_TYPE_INFO;
220 static const struct ng_parse_type ng_bridge_stats_type = {
221 &ng_parse_struct_type,
222 &ng_bridge_stats_type_fields
223 };
224
225 /* List of commands and how to convert arguments to/from ASCII */
226 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
227 {
228 NGM_BRIDGE_COOKIE,
229 NGM_BRIDGE_SET_CONFIG,
230 "setconfig",
231 &ng_bridge_config_type,
232 NULL
233 },
234 {
235 NGM_BRIDGE_COOKIE,
236 NGM_BRIDGE_GET_CONFIG,
237 "getconfig",
238 NULL,
239 &ng_bridge_config_type
240 },
241 {
242 NGM_BRIDGE_COOKIE,
243 NGM_BRIDGE_RESET,
244 "reset",
245 NULL,
246 NULL
247 },
248 {
249 NGM_BRIDGE_COOKIE,
250 NGM_BRIDGE_GET_STATS,
251 "getstats",
252 &ng_parse_uint32_type,
253 &ng_bridge_stats_type
254 },
255 {
256 NGM_BRIDGE_COOKIE,
257 NGM_BRIDGE_CLR_STATS,
258 "clrstats",
259 &ng_parse_uint32_type,
260 NULL
261 },
262 {
263 NGM_BRIDGE_COOKIE,
264 NGM_BRIDGE_GETCLR_STATS,
265 "getclrstats",
266 &ng_parse_uint32_type,
267 &ng_bridge_stats_type
268 },
269 {
270 NGM_BRIDGE_COOKIE,
271 NGM_BRIDGE_GET_TABLE,
272 "gettable",
273 NULL,
274 &ng_bridge_host_ary_type
275 },
276 {
277 NGM_BRIDGE_COOKIE,
278 NGM_BRIDGE_SET_PERSISTENT,
279 "setpersistent",
280 NULL,
281 NULL
282 },
283 { 0 }
284 };
285
286 /* Node type descriptor */
287 static struct ng_type ng_bridge_typestruct = {
288 .version = NG_ABI_VERSION,
289 .name = NG_BRIDGE_NODE_TYPE,
290 .constructor = ng_bridge_constructor,
291 .rcvmsg = ng_bridge_rcvmsg,
292 .shutdown = ng_bridge_shutdown,
293 .newhook = ng_bridge_newhook,
294 .rcvdata = ng_bridge_rcvdata,
295 .disconnect = ng_bridge_disconnect,
296 .cmdlist = ng_bridge_cmdlist,
297 };
298 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
299
300 /******************************************************************
301 NETGRAPH NODE METHODS
302 ******************************************************************/
303
304 /*
305 * Node constructor
306 */
307 static int
308 ng_bridge_constructor(node_p node)
309 {
310 priv_p priv;
311
312 /* Allocate and initialize private info */
313 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
314 ng_callout_init(&priv->timer);
315
316 /* Allocate and initialize hash table, etc. */
317 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
318 M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
319 priv->numBuckets = MIN_BUCKETS;
320 priv->hashMask = MIN_BUCKETS - 1;
321 priv->conf.debugLevel = 1;
322 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
323 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
324 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
325
326 /*
327 * This node has all kinds of stuff that could be screwed by SMP.
328 * Until it gets it's own internal protection, we go through in
329 * single file. This could hurt a machine bridging beteen two
330 * GB ethernets so it should be fixed.
331 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
332 * (and atomic ops )
333 */
334 NG_NODE_FORCE_WRITER(node);
335 NG_NODE_SET_PRIVATE(node, priv);
336 priv->node = node;
337
338 /* Start timer; timer is always running while node is alive */
339 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
340
341 /* Done */
342 return (0);
343 }
344
345 /*
346 * Method for attaching a new hook
347 */
348 static int
349 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
350 {
351 const priv_p priv = NG_NODE_PRIVATE(node);
352
353 /* Check for a link hook */
354 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
355 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
356 const char *cp;
357 char *eptr;
358 u_long linkNum;
359
360 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
361 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
362 return (EINVAL);
363 linkNum = strtoul(cp, &eptr, 10);
364 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
365 return (EINVAL);
366 if (priv->links[linkNum] != NULL)
367 return (EISCONN);
368 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]),
369 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
370 if (priv->links[linkNum] == NULL)
371 return (ENOMEM);
372 priv->links[linkNum]->hook = hook;
373 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
374 priv->numLinks++;
375 return (0);
376 }
377
378 /* Unknown hook name */
379 return (EINVAL);
380 }
381
382 /*
383 * Receive a control message
384 */
385 static int
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 case NGM_BRIDGE_COOKIE:
396 switch (msg->header.cmd) {
397 case NGM_BRIDGE_GET_CONFIG:
398 {
399 struct ng_bridge_config *conf;
400
401 NG_MKRESPONSE(resp, msg,
402 sizeof(struct ng_bridge_config), M_NOWAIT);
403 if (resp == NULL) {
404 error = ENOMEM;
405 break;
406 }
407 conf = (struct ng_bridge_config *)resp->data;
408 *conf = priv->conf; /* no sanity checking needed */
409 break;
410 }
411 case NGM_BRIDGE_SET_CONFIG:
412 {
413 struct ng_bridge_config *conf;
414 int i;
415
416 if (msg->header.arglen
417 != sizeof(struct ng_bridge_config)) {
418 error = EINVAL;
419 break;
420 }
421 conf = (struct ng_bridge_config *)msg->data;
422 priv->conf = *conf;
423 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
424 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
425 break;
426 }
427 case NGM_BRIDGE_RESET:
428 {
429 int i;
430
431 /* Flush all entries in the hash table */
432 ng_bridge_remove_hosts(priv, -1);
433
434 /* Reset all loop detection counters and stats */
435 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
436 if (priv->links[i] == NULL)
437 continue;
438 priv->links[i]->loopCount = 0;
439 bzero(&priv->links[i]->stats,
440 sizeof(priv->links[i]->stats));
441 }
442 break;
443 }
444 case NGM_BRIDGE_GET_STATS:
445 case NGM_BRIDGE_CLR_STATS:
446 case NGM_BRIDGE_GETCLR_STATS:
447 {
448 struct ng_bridge_link *link;
449 int linkNum;
450
451 /* Get link number */
452 if (msg->header.arglen != sizeof(u_int32_t)) {
453 error = EINVAL;
454 break;
455 }
456 linkNum = *((u_int32_t *)msg->data);
457 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
458 error = EINVAL;
459 break;
460 }
461 if ((link = priv->links[linkNum]) == NULL) {
462 error = ENOTCONN;
463 break;
464 }
465
466 /* Get/clear stats */
467 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
468 NG_MKRESPONSE(resp, msg,
469 sizeof(link->stats), M_NOWAIT);
470 if (resp == NULL) {
471 error = ENOMEM;
472 break;
473 }
474 bcopy(&link->stats,
475 resp->data, sizeof(link->stats));
476 }
477 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
478 bzero(&link->stats, sizeof(link->stats));
479 break;
480 }
481 case NGM_BRIDGE_GET_TABLE:
482 {
483 struct ng_bridge_host_ary *ary;
484 struct ng_bridge_hent *hent;
485 int i = 0, bucket;
486
487 NG_MKRESPONSE(resp, msg, sizeof(*ary)
488 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
489 if (resp == NULL) {
490 error = ENOMEM;
491 break;
492 }
493 ary = (struct ng_bridge_host_ary *)resp->data;
494 ary->numHosts = priv->numHosts;
495 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
496 SLIST_FOREACH(hent, &priv->tab[bucket], next)
497 ary->hosts[i++] = hent->host;
498 }
499 break;
500 }
501 case NGM_BRIDGE_SET_PERSISTENT:
502 {
503 priv->persistent = 1;
504 break;
505 }
506 default:
507 error = EINVAL;
508 break;
509 }
510 break;
511 default:
512 error = EINVAL;
513 break;
514 }
515
516 /* Done */
517 NG_RESPOND_MSG(error, node, item, resp);
518 NG_FREE_MSG(msg);
519 return (error);
520 }
521
522 /*
523 * Receive data on a hook
524 */
525 static int
526 ng_bridge_rcvdata(hook_p hook, item_p item)
527 {
528 const node_p node = NG_HOOK_NODE(hook);
529 const priv_p priv = NG_NODE_PRIVATE(node);
530 struct ng_bridge_host *host;
531 struct ng_bridge_link *link;
532 struct ether_header *eh;
533 int error = 0, linkNum, linksSeen;
534 int manycast;
535 struct mbuf *m;
536 struct ng_bridge_link *firstLink;
537
538 NGI_GET_M(item, m);
539 /* Get link number */
540 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
541 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
542 ("%s: linkNum=%u", __func__, linkNum));
543 link = priv->links[linkNum];
544 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
545
546 /* Sanity check packet and pull up header */
547 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
548 link->stats.recvRunts++;
549 NG_FREE_ITEM(item);
550 NG_FREE_M(m);
551 return (EINVAL);
552 }
553 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
554 link->stats.memoryFailures++;
555 NG_FREE_ITEM(item);
556 return (ENOBUFS);
557 }
558 eh = mtod(m, struct ether_header *);
559 if ((eh->ether_shost[0] & 1) != 0) {
560 link->stats.recvInvalid++;
561 NG_FREE_ITEM(item);
562 NG_FREE_M(m);
563 return (EINVAL);
564 }
565
566 /* Is link disabled due to a loopback condition? */
567 if (link->loopCount != 0) {
568 link->stats.loopDrops++;
569 NG_FREE_ITEM(item);
570 NG_FREE_M(m);
571 return (ELOOP); /* XXX is this an appropriate error? */
572 }
573
574 /* Update stats */
575 link->stats.recvPackets++;
576 link->stats.recvOctets += m->m_pkthdr.len;
577 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
578 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
579 link->stats.recvBroadcasts++;
580 manycast = 2;
581 } else
582 link->stats.recvMulticasts++;
583 }
584
585 /* Look up packet's source Ethernet address in hashtable */
586 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
587
588 /* Update time since last heard from this host */
589 host->staleness = 0;
590
591 /* Did host jump to a different link? */
592 if (host->linkNum != linkNum) {
593
594 /*
595 * If the host's old link was recently established
596 * on the old link and it's already jumped to a new
597 * link, declare a loopback condition.
598 */
599 if (host->age < priv->conf.minStableAge) {
600
601 /* Log the problem */
602 if (priv->conf.debugLevel >= 2) {
603 struct ifnet *ifp = m->m_pkthdr.rcvif;
604 char suffix[32];
605
606 if (ifp != NULL)
607 snprintf(suffix, sizeof(suffix),
608 " (%s)", ifp->if_xname);
609 else
610 *suffix = '\0';
611 log(LOG_WARNING, "ng_bridge: %s:"
612 " loopback detected on %s%s\n",
613 ng_bridge_nodename(node),
614 NG_HOOK_NAME(hook), suffix);
615 }
616
617 /* Mark link as linka non grata */
618 link->loopCount = priv->conf.loopTimeout;
619 link->stats.loopDetects++;
620
621 /* Forget all hosts on this link */
622 ng_bridge_remove_hosts(priv, linkNum);
623
624 /* Drop packet */
625 link->stats.loopDrops++;
626 NG_FREE_ITEM(item);
627 NG_FREE_M(m);
628 return (ELOOP); /* XXX appropriate? */
629 }
630
631 /* Move host over to new link */
632 host->linkNum = linkNum;
633 host->age = 0;
634 }
635 } else {
636 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
637 link->stats.memoryFailures++;
638 NG_FREE_ITEM(item);
639 NG_FREE_M(m);
640 return (ENOMEM);
641 }
642 }
643
644 /* Run packet through ipfw processing, if enabled */
645 #if 0
646 if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
647 /* XXX not implemented yet */
648 }
649 #endif
650
651 /*
652 * If unicast and destination host known, deliver to host's link,
653 * unless it is the same link as the packet came in on.
654 */
655 if (!manycast) {
656
657 /* Determine packet destination link */
658 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
659 struct ng_bridge_link *const destLink
660 = priv->links[host->linkNum];
661
662 /* If destination same as incoming link, do nothing */
663 KASSERT(destLink != NULL,
664 ("%s: link%d null", __func__, host->linkNum));
665 if (destLink == link) {
666 NG_FREE_ITEM(item);
667 NG_FREE_M(m);
668 return (0);
669 }
670
671 /* Deliver packet out the destination link */
672 destLink->stats.xmitPackets++;
673 destLink->stats.xmitOctets += m->m_pkthdr.len;
674 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
675 return (error);
676 }
677
678 /* Destination host is not known */
679 link->stats.recvUnknown++;
680 }
681
682 /* Distribute unknown, multicast, broadcast pkts to all other links */
683 firstLink = NULL;
684 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
685 struct ng_bridge_link *destLink;
686 struct mbuf *m2 = NULL;
687
688 /*
689 * If we have checked all the links then now
690 * send the original on its reserved link
691 */
692 if (linksSeen == priv->numLinks) {
693 /* If we never saw a good link, leave. */
694 if (firstLink == NULL) {
695 NG_FREE_ITEM(item);
696 NG_FREE_M(m);
697 return (0);
698 }
699 destLink = firstLink;
700 } else {
701 destLink = priv->links[linkNum];
702 if (destLink != NULL)
703 linksSeen++;
704 /* Skip incoming link and disconnected links */
705 if (destLink == NULL || destLink == link) {
706 continue;
707 }
708 if (firstLink == NULL) {
709 /*
710 * This is the first usable link we have found.
711 * Reserve it for the originals.
712 * If we never find another we save a copy.
713 */
714 firstLink = destLink;
715 continue;
716 }
717
718 /*
719 * It's usable link but not the reserved (first) one.
720 * Copy mbuf info for sending.
721 */
722 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */
723 if (m2 == NULL) {
724 link->stats.memoryFailures++;
725 NG_FREE_ITEM(item);
726 NG_FREE_M(m);
727 return (ENOBUFS);
728 }
729 }
730
731 /* Update stats */
732 destLink->stats.xmitPackets++;
733 destLink->stats.xmitOctets += m->m_pkthdr.len;
734 switch (manycast) {
735 case 0: /* unicast */
736 break;
737 case 1: /* multicast */
738 destLink->stats.xmitMulticasts++;
739 break;
740 case 2: /* broadcast */
741 destLink->stats.xmitBroadcasts++;
742 break;
743 }
744
745 /* Send packet */
746 if (destLink == firstLink) {
747 /*
748 * If we've sent all the others, send the original
749 * on the first link we found.
750 */
751 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
752 break; /* always done last - not really needed. */
753 } else {
754 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
755 }
756 }
757 return (error);
758 }
759
760 /*
761 * Shutdown node
762 */
763 static int
764 ng_bridge_shutdown(node_p node)
765 {
766 const priv_p priv = NG_NODE_PRIVATE(node);
767
768 /*
769 * Shut down everything including the timer. Even if the
770 * callout has already been dequeued and is about to be
771 * run, ng_bridge_timeout() won't be fired as the node
772 * is already marked NGF_INVALID, so we're safe to free
773 * the node now.
774 */
775 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
776 ("%s: numLinks=%d numHosts=%d",
777 __func__, priv->numLinks, priv->numHosts));
778 ng_uncallout(&priv->timer, node);
779 NG_NODE_SET_PRIVATE(node, NULL);
780 NG_NODE_UNREF(node);
781 free(priv->tab, M_NETGRAPH_BRIDGE);
782 free(priv, M_NETGRAPH_BRIDGE);
783 return (0);
784 }
785
786 /*
787 * Hook disconnection.
788 */
789 static int
790 ng_bridge_disconnect(hook_p hook)
791 {
792 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
793 int linkNum;
794
795 /* Get link number */
796 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
797 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
798 ("%s: linkNum=%u", __func__, linkNum));
799
800 /* Remove all hosts associated with this link */
801 ng_bridge_remove_hosts(priv, linkNum);
802
803 /* Free associated link information */
804 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
805 free(priv->links[linkNum], M_NETGRAPH_BRIDGE);
806 priv->links[linkNum] = NULL;
807 priv->numLinks--;
808
809 /* If no more hooks, go away */
810 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
811 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
812 && !priv->persistent) {
813 ng_rmnode_self(NG_HOOK_NODE(hook));
814 }
815 return (0);
816 }
817
818 /******************************************************************
819 HASH TABLE FUNCTIONS
820 ******************************************************************/
821
822 /*
823 * Hash algorithm
824 */
825 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
826 ^ ((const u_int16_t *)(addr))[1] \
827 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
828
829 /*
830 * Find a host entry in the table.
831 */
832 static struct ng_bridge_host *
833 ng_bridge_get(priv_p priv, const u_char *addr)
834 {
835 const int bucket = HASH(addr, priv->hashMask);
836 struct ng_bridge_hent *hent;
837
838 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
839 if (ETHER_EQUAL(hent->host.addr, addr))
840 return (&hent->host);
841 }
842 return (NULL);
843 }
844
845 /*
846 * Add a new host entry to the table. This assumes the host doesn't
847 * already exist in the table. Returns 1 on success, 0 if there
848 * was a memory allocation failure.
849 */
850 static int
851 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
852 {
853 const int bucket = HASH(addr, priv->hashMask);
854 struct ng_bridge_hent *hent;
855
856 #ifdef INVARIANTS
857 /* Assert that entry does not already exist in hashtable */
858 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
859 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
860 ("%s: entry %6D exists in table", __func__, addr, ":"));
861 }
862 #endif
863
864 /* Allocate and initialize new hashtable entry */
865 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
866 if (hent == NULL)
867 return (0);
868 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
869 hent->host.linkNum = linkNum;
870 hent->host.staleness = 0;
871 hent->host.age = 0;
872
873 /* Add new element to hash bucket */
874 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
875 priv->numHosts++;
876
877 /* Resize table if necessary */
878 ng_bridge_rehash(priv);
879 return (1);
880 }
881
882 /*
883 * Resize the hash table. We try to maintain the number of buckets
884 * such that the load factor is in the range 0.25 to 1.0.
885 *
886 * If we can't get the new memory then we silently fail. This is OK
887 * because things will still work and we'll try again soon anyway.
888 */
889 static void
890 ng_bridge_rehash(priv_p priv)
891 {
892 struct ng_bridge_bucket *newTab;
893 int oldBucket, newBucket;
894 int newNumBuckets;
895 u_int newMask;
896
897 /* Is table too full or too empty? */
898 if (priv->numHosts > priv->numBuckets
899 && (priv->numBuckets << 1) <= MAX_BUCKETS)
900 newNumBuckets = priv->numBuckets << 1;
901 else if (priv->numHosts < (priv->numBuckets >> 2)
902 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
903 newNumBuckets = priv->numBuckets >> 2;
904 else
905 return;
906 newMask = newNumBuckets - 1;
907
908 /* Allocate and initialize new table */
909 newTab = malloc(newNumBuckets * sizeof(*newTab),
910 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
911 if (newTab == NULL)
912 return;
913
914 /* Move all entries from old table to new table */
915 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
916 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
917
918 while (!SLIST_EMPTY(oldList)) {
919 struct ng_bridge_hent *const hent
920 = SLIST_FIRST(oldList);
921
922 SLIST_REMOVE_HEAD(oldList, next);
923 newBucket = HASH(hent->host.addr, newMask);
924 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
925 }
926 }
927
928 /* Replace old table with new one */
929 if (priv->conf.debugLevel >= 3) {
930 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
931 ng_bridge_nodename(priv->node),
932 priv->numBuckets, newNumBuckets);
933 }
934 free(priv->tab, M_NETGRAPH_BRIDGE);
935 priv->numBuckets = newNumBuckets;
936 priv->hashMask = newMask;
937 priv->tab = newTab;
938 return;
939 }
940
941 /******************************************************************
942 MISC FUNCTIONS
943 ******************************************************************/
944
945 /*
946 * Remove all hosts associated with a specific link from the hashtable.
947 * If linkNum == -1, then remove all hosts in the table.
948 */
949 static void
950 ng_bridge_remove_hosts(priv_p priv, int linkNum)
951 {
952 int bucket;
953
954 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
955 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
956
957 while (*hptr != NULL) {
958 struct ng_bridge_hent *const hent = *hptr;
959
960 if (linkNum == -1 || hent->host.linkNum == linkNum) {
961 *hptr = SLIST_NEXT(hent, next);
962 free(hent, M_NETGRAPH_BRIDGE);
963 priv->numHosts--;
964 } else
965 hptr = &SLIST_NEXT(hent, next);
966 }
967 }
968 }
969
970 /*
971 * Handle our once-per-second timeout event. We do two things:
972 * we decrement link->loopCount for those links being muted due to
973 * a detected loopback condition, and we remove any hosts from
974 * the hashtable whom we haven't heard from in a long while.
975 */
976 static void
977 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
978 {
979 const priv_p priv = NG_NODE_PRIVATE(node);
980 int bucket;
981 int counter = 0;
982 int linkNum;
983
984 /* Update host time counters and remove stale entries */
985 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
986 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
987
988 while (*hptr != NULL) {
989 struct ng_bridge_hent *const hent = *hptr;
990
991 /* Make sure host's link really exists */
992 KASSERT(priv->links[hent->host.linkNum] != NULL,
993 ("%s: host %6D on nonexistent link %d\n",
994 __func__, hent->host.addr, ":",
995 hent->host.linkNum));
996
997 /* Remove hosts we haven't heard from in a while */
998 if (++hent->host.staleness >= priv->conf.maxStaleness) {
999 *hptr = SLIST_NEXT(hent, next);
1000 free(hent, M_NETGRAPH_BRIDGE);
1001 priv->numHosts--;
1002 } else {
1003 if (hent->host.age < 0xffff)
1004 hent->host.age++;
1005 hptr = &SLIST_NEXT(hent, next);
1006 counter++;
1007 }
1008 }
1009 }
1010 KASSERT(priv->numHosts == counter,
1011 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1012
1013 /* Decrease table size if necessary */
1014 ng_bridge_rehash(priv);
1015
1016 /* Decrease loop counter on muted looped back links */
1017 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
1018 struct ng_bridge_link *const link = priv->links[linkNum];
1019
1020 if (link != NULL) {
1021 if (link->loopCount != 0) {
1022 link->loopCount--;
1023 if (link->loopCount == 0
1024 && priv->conf.debugLevel >= 2) {
1025 log(LOG_INFO, "ng_bridge: %s:"
1026 " restoring looped back link%d\n",
1027 ng_bridge_nodename(node), linkNum);
1028 }
1029 }
1030 counter++;
1031 }
1032 }
1033 KASSERT(priv->numLinks == counter,
1034 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1035
1036 /* Register a new timeout, keeping the existing node reference */
1037 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1038 }
1039
1040 /*
1041 * Return node's "name", even if it doesn't have one.
1042 */
1043 static const char *
1044 ng_bridge_nodename(node_p node)
1045 {
1046 static char name[NG_NODESIZ];
1047
1048 if (NG_NODE_NAME(node) != NULL)
1049 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1050 else
1051 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1052 return name;
1053 }
1054
Cache object: c06845d017bc6b1ced2ba8c7ffe9706d
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