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/11.2/sys/netgraph/ng_bridge.c 298813 2016-04-29 21:25:05Z pfg $
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/if_var.h>
75 #include <net/ethernet.h>
76 #include <net/vnet.h>
77
78 #include <netinet/in.h>
79 #if 0 /* not used yet */
80 #include <netinet/ip_fw.h>
81 #endif
82 #include <netgraph/ng_message.h>
83 #include <netgraph/netgraph.h>
84 #include <netgraph/ng_parse.h>
85 #include <netgraph/ng_bridge.h>
86
87 #ifdef NG_SEPARATE_MALLOC
88 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
89 "netgraph bridge node");
90 #else
91 #define M_NETGRAPH_BRIDGE M_NETGRAPH
92 #endif
93
94 /* Per-link private data */
95 struct ng_bridge_link {
96 hook_p hook; /* netgraph hook */
97 u_int16_t loopCount; /* loop ignore timer */
98 struct ng_bridge_link_stats stats; /* link stats */
99 };
100
101 /* Per-node private data */
102 struct ng_bridge_private {
103 struct ng_bridge_bucket *tab; /* hash table bucket array */
104 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
105 struct ng_bridge_config conf; /* node configuration */
106 node_p node; /* netgraph node */
107 u_int numHosts; /* num entries in table */
108 u_int numBuckets; /* num buckets in table */
109 u_int hashMask; /* numBuckets - 1 */
110 int numLinks; /* num connected links */
111 int persistent; /* can exist w/o hooks */
112 struct callout timer; /* one second periodic timer */
113 };
114 typedef struct ng_bridge_private *priv_p;
115
116 /* Information about a host, stored in a hash table entry */
117 struct ng_bridge_hent {
118 struct ng_bridge_host host; /* actual host info */
119 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
120 };
121
122 /* Hash table bucket declaration */
123 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
124
125 /* Netgraph node methods */
126 static ng_constructor_t ng_bridge_constructor;
127 static ng_rcvmsg_t ng_bridge_rcvmsg;
128 static ng_shutdown_t ng_bridge_shutdown;
129 static ng_newhook_t ng_bridge_newhook;
130 static ng_rcvdata_t ng_bridge_rcvdata;
131 static ng_disconnect_t ng_bridge_disconnect;
132
133 /* Other internal functions */
134 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
135 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
136 static void ng_bridge_rehash(priv_p priv);
137 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
138 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
139 static const char *ng_bridge_nodename(node_p node);
140
141 /* Ethernet broadcast */
142 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
143 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
144
145 /* Store each hook's link number in the private field */
146 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
147
148 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
149 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
150 == ((const u_int32_t *)(b))[0] \
151 && ((const u_int16_t *)(a))[2] \
152 == ((const u_int16_t *)(b))[2])
153
154 /* Minimum and maximum number of hash buckets. Must be a power of two. */
155 #define MIN_BUCKETS (1 << 5) /* 32 */
156 #define MAX_BUCKETS (1 << 14) /* 16384 */
157
158 /* Configuration default values */
159 #define DEFAULT_LOOP_TIMEOUT 60
160 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
161 #define DEFAULT_MIN_STABLE_AGE 1
162
163 /******************************************************************
164 NETGRAPH PARSE TYPES
165 ******************************************************************/
166
167 /*
168 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
169 */
170 static int
171 ng_bridge_getTableLength(const struct ng_parse_type *type,
172 const u_char *start, const u_char *buf)
173 {
174 const struct ng_bridge_host_ary *const hary
175 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
176
177 return hary->numHosts;
178 }
179
180 /* Parse type for struct ng_bridge_host_ary */
181 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
182 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
183 static const struct ng_parse_type ng_bridge_host_type = {
184 &ng_parse_struct_type,
185 &ng_bridge_host_type_fields
186 };
187 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
188 &ng_bridge_host_type,
189 ng_bridge_getTableLength
190 };
191 static const struct ng_parse_type ng_bridge_hary_type = {
192 &ng_parse_array_type,
193 &ng_bridge_hary_type_info
194 };
195 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
196 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
197 static const struct ng_parse_type ng_bridge_host_ary_type = {
198 &ng_parse_struct_type,
199 &ng_bridge_host_ary_type_fields
200 };
201
202 /* Parse type for struct ng_bridge_config */
203 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
204 &ng_parse_uint8_type,
205 NG_BRIDGE_MAX_LINKS
206 };
207 static const struct ng_parse_type ng_bridge_ipfwary_type = {
208 &ng_parse_fixedarray_type,
209 &ng_bridge_ipfwary_type_info
210 };
211 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
212 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
213 static const struct ng_parse_type ng_bridge_config_type = {
214 &ng_parse_struct_type,
215 &ng_bridge_config_type_fields
216 };
217
218 /* Parse type for struct ng_bridge_link_stat */
219 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
220 = NG_BRIDGE_STATS_TYPE_INFO;
221 static const struct ng_parse_type ng_bridge_stats_type = {
222 &ng_parse_struct_type,
223 &ng_bridge_stats_type_fields
224 };
225
226 /* List of commands and how to convert arguments to/from ASCII */
227 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
228 {
229 NGM_BRIDGE_COOKIE,
230 NGM_BRIDGE_SET_CONFIG,
231 "setconfig",
232 &ng_bridge_config_type,
233 NULL
234 },
235 {
236 NGM_BRIDGE_COOKIE,
237 NGM_BRIDGE_GET_CONFIG,
238 "getconfig",
239 NULL,
240 &ng_bridge_config_type
241 },
242 {
243 NGM_BRIDGE_COOKIE,
244 NGM_BRIDGE_RESET,
245 "reset",
246 NULL,
247 NULL
248 },
249 {
250 NGM_BRIDGE_COOKIE,
251 NGM_BRIDGE_GET_STATS,
252 "getstats",
253 &ng_parse_uint32_type,
254 &ng_bridge_stats_type
255 },
256 {
257 NGM_BRIDGE_COOKIE,
258 NGM_BRIDGE_CLR_STATS,
259 "clrstats",
260 &ng_parse_uint32_type,
261 NULL
262 },
263 {
264 NGM_BRIDGE_COOKIE,
265 NGM_BRIDGE_GETCLR_STATS,
266 "getclrstats",
267 &ng_parse_uint32_type,
268 &ng_bridge_stats_type
269 },
270 {
271 NGM_BRIDGE_COOKIE,
272 NGM_BRIDGE_GET_TABLE,
273 "gettable",
274 NULL,
275 &ng_bridge_host_ary_type
276 },
277 {
278 NGM_BRIDGE_COOKIE,
279 NGM_BRIDGE_SET_PERSISTENT,
280 "setpersistent",
281 NULL,
282 NULL
283 },
284 { 0 }
285 };
286
287 /* Node type descriptor */
288 static struct ng_type ng_bridge_typestruct = {
289 .version = NG_ABI_VERSION,
290 .name = NG_BRIDGE_NODE_TYPE,
291 .constructor = ng_bridge_constructor,
292 .rcvmsg = ng_bridge_rcvmsg,
293 .shutdown = ng_bridge_shutdown,
294 .newhook = ng_bridge_newhook,
295 .rcvdata = ng_bridge_rcvdata,
296 .disconnect = ng_bridge_disconnect,
297 .cmdlist = ng_bridge_cmdlist,
298 };
299 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
300
301 /******************************************************************
302 NETGRAPH NODE METHODS
303 ******************************************************************/
304
305 /*
306 * Node constructor
307 */
308 static int
309 ng_bridge_constructor(node_p node)
310 {
311 priv_p priv;
312
313 /* Allocate and initialize private info */
314 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
315 ng_callout_init(&priv->timer);
316
317 /* Allocate and initialize hash table, etc. */
318 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
319 M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
320 priv->numBuckets = MIN_BUCKETS;
321 priv->hashMask = MIN_BUCKETS - 1;
322 priv->conf.debugLevel = 1;
323 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
324 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
325 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
326
327 /*
328 * This node has all kinds of stuff that could be screwed by SMP.
329 * Until it gets it's own internal protection, we go through in
330 * single file. This could hurt a machine bridging between two
331 * GB ethernets so it should be fixed.
332 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
333 * (and atomic ops )
334 */
335 NG_NODE_FORCE_WRITER(node);
336 NG_NODE_SET_PRIVATE(node, priv);
337 priv->node = node;
338
339 /* Start timer; timer is always running while node is alive */
340 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
341
342 /* Done */
343 return (0);
344 }
345
346 /*
347 * Method for attaching a new hook
348 */
349 static int
350 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
351 {
352 const priv_p priv = NG_NODE_PRIVATE(node);
353
354 /* Check for a link hook */
355 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
356 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
357 const char *cp;
358 char *eptr;
359 u_long linkNum;
360
361 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
362 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
363 return (EINVAL);
364 linkNum = strtoul(cp, &eptr, 10);
365 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
366 return (EINVAL);
367 if (priv->links[linkNum] != NULL)
368 return (EISCONN);
369 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]),
370 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO);
371 if (priv->links[linkNum] == NULL)
372 return (ENOMEM);
373 priv->links[linkNum]->hook = hook;
374 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum);
375 priv->numLinks++;
376 return (0);
377 }
378
379 /* Unknown hook name */
380 return (EINVAL);
381 }
382
383 /*
384 * Receive a control message
385 */
386 static int
387 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
388 {
389 const priv_p priv = NG_NODE_PRIVATE(node);
390 struct ng_mesg *resp = NULL;
391 int error = 0;
392 struct ng_mesg *msg;
393
394 NGI_GET_MSG(item, msg);
395 switch (msg->header.typecookie) {
396 case NGM_BRIDGE_COOKIE:
397 switch (msg->header.cmd) {
398 case NGM_BRIDGE_GET_CONFIG:
399 {
400 struct ng_bridge_config *conf;
401
402 NG_MKRESPONSE(resp, msg,
403 sizeof(struct ng_bridge_config), M_NOWAIT);
404 if (resp == NULL) {
405 error = ENOMEM;
406 break;
407 }
408 conf = (struct ng_bridge_config *)resp->data;
409 *conf = priv->conf; /* no sanity checking needed */
410 break;
411 }
412 case NGM_BRIDGE_SET_CONFIG:
413 {
414 struct ng_bridge_config *conf;
415 int i;
416
417 if (msg->header.arglen
418 != sizeof(struct ng_bridge_config)) {
419 error = EINVAL;
420 break;
421 }
422 conf = (struct ng_bridge_config *)msg->data;
423 priv->conf = *conf;
424 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
425 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
426 break;
427 }
428 case NGM_BRIDGE_RESET:
429 {
430 int i;
431
432 /* Flush all entries in the hash table */
433 ng_bridge_remove_hosts(priv, -1);
434
435 /* Reset all loop detection counters and stats */
436 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
437 if (priv->links[i] == NULL)
438 continue;
439 priv->links[i]->loopCount = 0;
440 bzero(&priv->links[i]->stats,
441 sizeof(priv->links[i]->stats));
442 }
443 break;
444 }
445 case NGM_BRIDGE_GET_STATS:
446 case NGM_BRIDGE_CLR_STATS:
447 case NGM_BRIDGE_GETCLR_STATS:
448 {
449 struct ng_bridge_link *link;
450 int linkNum;
451
452 /* Get link number */
453 if (msg->header.arglen != sizeof(u_int32_t)) {
454 error = EINVAL;
455 break;
456 }
457 linkNum = *((u_int32_t *)msg->data);
458 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
459 error = EINVAL;
460 break;
461 }
462 if ((link = priv->links[linkNum]) == NULL) {
463 error = ENOTCONN;
464 break;
465 }
466
467 /* Get/clear stats */
468 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
469 NG_MKRESPONSE(resp, msg,
470 sizeof(link->stats), M_NOWAIT);
471 if (resp == NULL) {
472 error = ENOMEM;
473 break;
474 }
475 bcopy(&link->stats,
476 resp->data, sizeof(link->stats));
477 }
478 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
479 bzero(&link->stats, sizeof(link->stats));
480 break;
481 }
482 case NGM_BRIDGE_GET_TABLE:
483 {
484 struct ng_bridge_host_ary *ary;
485 struct ng_bridge_hent *hent;
486 int i = 0, bucket;
487
488 NG_MKRESPONSE(resp, msg, sizeof(*ary)
489 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
490 if (resp == NULL) {
491 error = ENOMEM;
492 break;
493 }
494 ary = (struct ng_bridge_host_ary *)resp->data;
495 ary->numHosts = priv->numHosts;
496 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
497 SLIST_FOREACH(hent, &priv->tab[bucket], next)
498 ary->hosts[i++] = hent->host;
499 }
500 break;
501 }
502 case NGM_BRIDGE_SET_PERSISTENT:
503 {
504 priv->persistent = 1;
505 break;
506 }
507 default:
508 error = EINVAL;
509 break;
510 }
511 break;
512 default:
513 error = EINVAL;
514 break;
515 }
516
517 /* Done */
518 NG_RESPOND_MSG(error, node, item, resp);
519 NG_FREE_MSG(msg);
520 return (error);
521 }
522
523 /*
524 * Receive data on a hook
525 */
526 static int
527 ng_bridge_rcvdata(hook_p hook, item_p item)
528 {
529 const node_p node = NG_HOOK_NODE(hook);
530 const priv_p priv = NG_NODE_PRIVATE(node);
531 struct ng_bridge_host *host;
532 struct ng_bridge_link *link;
533 struct ether_header *eh;
534 int error = 0, linkNum, linksSeen;
535 int manycast;
536 struct mbuf *m;
537 struct ng_bridge_link *firstLink;
538
539 NGI_GET_M(item, m);
540 /* Get link number */
541 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
542 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
543 ("%s: linkNum=%u", __func__, linkNum));
544 link = priv->links[linkNum];
545 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
546
547 /* Sanity check packet and pull up header */
548 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
549 link->stats.recvRunts++;
550 NG_FREE_ITEM(item);
551 NG_FREE_M(m);
552 return (EINVAL);
553 }
554 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
555 link->stats.memoryFailures++;
556 NG_FREE_ITEM(item);
557 return (ENOBUFS);
558 }
559 eh = mtod(m, struct ether_header *);
560 if ((eh->ether_shost[0] & 1) != 0) {
561 link->stats.recvInvalid++;
562 NG_FREE_ITEM(item);
563 NG_FREE_M(m);
564 return (EINVAL);
565 }
566
567 /* Is link disabled due to a loopback condition? */
568 if (link->loopCount != 0) {
569 link->stats.loopDrops++;
570 NG_FREE_ITEM(item);
571 NG_FREE_M(m);
572 return (ELOOP); /* XXX is this an appropriate error? */
573 }
574
575 /* Update stats */
576 link->stats.recvPackets++;
577 link->stats.recvOctets += m->m_pkthdr.len;
578 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
579 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
580 link->stats.recvBroadcasts++;
581 manycast = 2;
582 } else
583 link->stats.recvMulticasts++;
584 }
585
586 /* Look up packet's source Ethernet address in hashtable */
587 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
588
589 /* Update time since last heard from this host */
590 host->staleness = 0;
591
592 /* Did host jump to a different link? */
593 if (host->linkNum != linkNum) {
594
595 /*
596 * If the host's old link was recently established
597 * on the old link and it's already jumped to a new
598 * link, declare a loopback condition.
599 */
600 if (host->age < priv->conf.minStableAge) {
601
602 /* Log the problem */
603 if (priv->conf.debugLevel >= 2) {
604 struct ifnet *ifp = m->m_pkthdr.rcvif;
605 char suffix[32];
606
607 if (ifp != NULL)
608 snprintf(suffix, sizeof(suffix),
609 " (%s)", ifp->if_xname);
610 else
611 *suffix = '\0';
612 log(LOG_WARNING, "ng_bridge: %s:"
613 " loopback detected on %s%s\n",
614 ng_bridge_nodename(node),
615 NG_HOOK_NAME(hook), suffix);
616 }
617
618 /* Mark link as linka non grata */
619 link->loopCount = priv->conf.loopTimeout;
620 link->stats.loopDetects++;
621
622 /* Forget all hosts on this link */
623 ng_bridge_remove_hosts(priv, linkNum);
624
625 /* Drop packet */
626 link->stats.loopDrops++;
627 NG_FREE_ITEM(item);
628 NG_FREE_M(m);
629 return (ELOOP); /* XXX appropriate? */
630 }
631
632 /* Move host over to new link */
633 host->linkNum = linkNum;
634 host->age = 0;
635 }
636 } else {
637 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
638 link->stats.memoryFailures++;
639 NG_FREE_ITEM(item);
640 NG_FREE_M(m);
641 return (ENOMEM);
642 }
643 }
644
645 /* Run packet through ipfw processing, if enabled */
646 #if 0
647 if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
648 /* XXX not implemented yet */
649 }
650 #endif
651
652 /*
653 * If unicast and destination host known, deliver to host's link,
654 * unless it is the same link as the packet came in on.
655 */
656 if (!manycast) {
657
658 /* Determine packet destination link */
659 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
660 struct ng_bridge_link *const destLink
661 = priv->links[host->linkNum];
662
663 /* If destination same as incoming link, do nothing */
664 KASSERT(destLink != NULL,
665 ("%s: link%d null", __func__, host->linkNum));
666 if (destLink == link) {
667 NG_FREE_ITEM(item);
668 NG_FREE_M(m);
669 return (0);
670 }
671
672 /* Deliver packet out the destination link */
673 destLink->stats.xmitPackets++;
674 destLink->stats.xmitOctets += m->m_pkthdr.len;
675 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
676 return (error);
677 }
678
679 /* Destination host is not known */
680 link->stats.recvUnknown++;
681 }
682
683 /* Distribute unknown, multicast, broadcast pkts to all other links */
684 firstLink = NULL;
685 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) {
686 struct ng_bridge_link *destLink;
687 struct mbuf *m2 = NULL;
688
689 /*
690 * If we have checked all the links then now
691 * send the original on its reserved link
692 */
693 if (linksSeen == priv->numLinks) {
694 /* If we never saw a good link, leave. */
695 if (firstLink == NULL) {
696 NG_FREE_ITEM(item);
697 NG_FREE_M(m);
698 return (0);
699 }
700 destLink = firstLink;
701 } else {
702 destLink = priv->links[linkNum];
703 if (destLink != NULL)
704 linksSeen++;
705 /* Skip incoming link and disconnected links */
706 if (destLink == NULL || destLink == link) {
707 continue;
708 }
709 if (firstLink == NULL) {
710 /*
711 * This is the first usable link we have found.
712 * Reserve it for the originals.
713 * If we never find another we save a copy.
714 */
715 firstLink = destLink;
716 continue;
717 }
718
719 /*
720 * It's usable link but not the reserved (first) one.
721 * Copy mbuf info for sending.
722 */
723 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */
724 if (m2 == NULL) {
725 link->stats.memoryFailures++;
726 NG_FREE_ITEM(item);
727 NG_FREE_M(m);
728 return (ENOBUFS);
729 }
730 }
731
732 /* Update stats */
733 destLink->stats.xmitPackets++;
734 destLink->stats.xmitOctets += m->m_pkthdr.len;
735 switch (manycast) {
736 case 0: /* unicast */
737 break;
738 case 1: /* multicast */
739 destLink->stats.xmitMulticasts++;
740 break;
741 case 2: /* broadcast */
742 destLink->stats.xmitBroadcasts++;
743 break;
744 }
745
746 /* Send packet */
747 if (destLink == firstLink) {
748 /*
749 * If we've sent all the others, send the original
750 * on the first link we found.
751 */
752 NG_FWD_NEW_DATA(error, item, destLink->hook, m);
753 break; /* always done last - not really needed. */
754 } else {
755 NG_SEND_DATA_ONLY(error, destLink->hook, m2);
756 }
757 }
758 return (error);
759 }
760
761 /*
762 * Shutdown node
763 */
764 static int
765 ng_bridge_shutdown(node_p node)
766 {
767 const priv_p priv = NG_NODE_PRIVATE(node);
768
769 /*
770 * Shut down everything including the timer. Even if the
771 * callout has already been dequeued and is about to be
772 * run, ng_bridge_timeout() won't be fired as the node
773 * is already marked NGF_INVALID, so we're safe to free
774 * the node now.
775 */
776 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
777 ("%s: numLinks=%d numHosts=%d",
778 __func__, priv->numLinks, priv->numHosts));
779 ng_uncallout(&priv->timer, node);
780 NG_NODE_SET_PRIVATE(node, NULL);
781 NG_NODE_UNREF(node);
782 free(priv->tab, M_NETGRAPH_BRIDGE);
783 free(priv, M_NETGRAPH_BRIDGE);
784 return (0);
785 }
786
787 /*
788 * Hook disconnection.
789 */
790 static int
791 ng_bridge_disconnect(hook_p hook)
792 {
793 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
794 int linkNum;
795
796 /* Get link number */
797 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
798 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
799 ("%s: linkNum=%u", __func__, linkNum));
800
801 /* Remove all hosts associated with this link */
802 ng_bridge_remove_hosts(priv, linkNum);
803
804 /* Free associated link information */
805 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
806 free(priv->links[linkNum], M_NETGRAPH_BRIDGE);
807 priv->links[linkNum] = NULL;
808 priv->numLinks--;
809
810 /* If no more hooks, go away */
811 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
812 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
813 && !priv->persistent) {
814 ng_rmnode_self(NG_HOOK_NODE(hook));
815 }
816 return (0);
817 }
818
819 /******************************************************************
820 HASH TABLE FUNCTIONS
821 ******************************************************************/
822
823 /*
824 * Hash algorithm
825 */
826 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
827 ^ ((const u_int16_t *)(addr))[1] \
828 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
829
830 /*
831 * Find a host entry in the table.
832 */
833 static struct ng_bridge_host *
834 ng_bridge_get(priv_p priv, const u_char *addr)
835 {
836 const int bucket = HASH(addr, priv->hashMask);
837 struct ng_bridge_hent *hent;
838
839 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
840 if (ETHER_EQUAL(hent->host.addr, addr))
841 return (&hent->host);
842 }
843 return (NULL);
844 }
845
846 /*
847 * Add a new host entry to the table. This assumes the host doesn't
848 * already exist in the table. Returns 1 on success, 0 if there
849 * was a memory allocation failure.
850 */
851 static int
852 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
853 {
854 const int bucket = HASH(addr, priv->hashMask);
855 struct ng_bridge_hent *hent;
856
857 #ifdef INVARIANTS
858 /* Assert that entry does not already exist in hashtable */
859 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
860 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
861 ("%s: entry %6D exists in table", __func__, addr, ":"));
862 }
863 #endif
864
865 /* Allocate and initialize new hashtable entry */
866 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
867 if (hent == NULL)
868 return (0);
869 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
870 hent->host.linkNum = linkNum;
871 hent->host.staleness = 0;
872 hent->host.age = 0;
873
874 /* Add new element to hash bucket */
875 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
876 priv->numHosts++;
877
878 /* Resize table if necessary */
879 ng_bridge_rehash(priv);
880 return (1);
881 }
882
883 /*
884 * Resize the hash table. We try to maintain the number of buckets
885 * such that the load factor is in the range 0.25 to 1.0.
886 *
887 * If we can't get the new memory then we silently fail. This is OK
888 * because things will still work and we'll try again soon anyway.
889 */
890 static void
891 ng_bridge_rehash(priv_p priv)
892 {
893 struct ng_bridge_bucket *newTab;
894 int oldBucket, newBucket;
895 int newNumBuckets;
896 u_int newMask;
897
898 /* Is table too full or too empty? */
899 if (priv->numHosts > priv->numBuckets
900 && (priv->numBuckets << 1) <= MAX_BUCKETS)
901 newNumBuckets = priv->numBuckets << 1;
902 else if (priv->numHosts < (priv->numBuckets >> 2)
903 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
904 newNumBuckets = priv->numBuckets >> 2;
905 else
906 return;
907 newMask = newNumBuckets - 1;
908
909 /* Allocate and initialize new table */
910 newTab = malloc(newNumBuckets * sizeof(*newTab),
911 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
912 if (newTab == NULL)
913 return;
914
915 /* Move all entries from old table to new table */
916 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
917 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
918
919 while (!SLIST_EMPTY(oldList)) {
920 struct ng_bridge_hent *const hent
921 = SLIST_FIRST(oldList);
922
923 SLIST_REMOVE_HEAD(oldList, next);
924 newBucket = HASH(hent->host.addr, newMask);
925 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
926 }
927 }
928
929 /* Replace old table with new one */
930 if (priv->conf.debugLevel >= 3) {
931 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
932 ng_bridge_nodename(priv->node),
933 priv->numBuckets, newNumBuckets);
934 }
935 free(priv->tab, M_NETGRAPH_BRIDGE);
936 priv->numBuckets = newNumBuckets;
937 priv->hashMask = newMask;
938 priv->tab = newTab;
939 return;
940 }
941
942 /******************************************************************
943 MISC FUNCTIONS
944 ******************************************************************/
945
946 /*
947 * Remove all hosts associated with a specific link from the hashtable.
948 * If linkNum == -1, then remove all hosts in the table.
949 */
950 static void
951 ng_bridge_remove_hosts(priv_p priv, int linkNum)
952 {
953 int bucket;
954
955 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
956 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
957
958 while (*hptr != NULL) {
959 struct ng_bridge_hent *const hent = *hptr;
960
961 if (linkNum == -1 || hent->host.linkNum == linkNum) {
962 *hptr = SLIST_NEXT(hent, next);
963 free(hent, M_NETGRAPH_BRIDGE);
964 priv->numHosts--;
965 } else
966 hptr = &SLIST_NEXT(hent, next);
967 }
968 }
969 }
970
971 /*
972 * Handle our once-per-second timeout event. We do two things:
973 * we decrement link->loopCount for those links being muted due to
974 * a detected loopback condition, and we remove any hosts from
975 * the hashtable whom we haven't heard from in a long while.
976 */
977 static void
978 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
979 {
980 const priv_p priv = NG_NODE_PRIVATE(node);
981 int bucket;
982 int counter = 0;
983 int linkNum;
984
985 /* Update host time counters and remove stale entries */
986 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
987 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
988
989 while (*hptr != NULL) {
990 struct ng_bridge_hent *const hent = *hptr;
991
992 /* Make sure host's link really exists */
993 KASSERT(priv->links[hent->host.linkNum] != NULL,
994 ("%s: host %6D on nonexistent link %d\n",
995 __func__, hent->host.addr, ":",
996 hent->host.linkNum));
997
998 /* Remove hosts we haven't heard from in a while */
999 if (++hent->host.staleness >= priv->conf.maxStaleness) {
1000 *hptr = SLIST_NEXT(hent, next);
1001 free(hent, M_NETGRAPH_BRIDGE);
1002 priv->numHosts--;
1003 } else {
1004 if (hent->host.age < 0xffff)
1005 hent->host.age++;
1006 hptr = &SLIST_NEXT(hent, next);
1007 counter++;
1008 }
1009 }
1010 }
1011 KASSERT(priv->numHosts == counter,
1012 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1013
1014 /* Decrease table size if necessary */
1015 ng_bridge_rehash(priv);
1016
1017 /* Decrease loop counter on muted looped back links */
1018 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
1019 struct ng_bridge_link *const link = priv->links[linkNum];
1020
1021 if (link != NULL) {
1022 if (link->loopCount != 0) {
1023 link->loopCount--;
1024 if (link->loopCount == 0
1025 && priv->conf.debugLevel >= 2) {
1026 log(LOG_INFO, "ng_bridge: %s:"
1027 " restoring looped back link%d\n",
1028 ng_bridge_nodename(node), linkNum);
1029 }
1030 }
1031 counter++;
1032 }
1033 }
1034 KASSERT(priv->numLinks == counter,
1035 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1036
1037 /* Register a new timeout, keeping the existing node reference */
1038 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1039 }
1040
1041 /*
1042 * Return node's "name", even if it doesn't have one.
1043 */
1044 static const char *
1045 ng_bridge_nodename(node_p node)
1046 {
1047 static char name[NG_NODESIZ];
1048
1049 if (NG_NODE_HAS_NAME(node))
1050 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1051 else
1052 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1053 return name;
1054 }
1055
Cache object: b782d1a4963831adc444d1da2a86f141
|