1
2 /*
3 * ng_bridge.c
4 *
5 * Copyright (c) 2000 Whistle Communications, Inc.
6 * All rights reserved.
7 *
8 * Subject to the following obligations and disclaimer of warranty, use and
9 * redistribution of this software, in source or object code forms, with or
10 * without modifications are expressly permitted by Whistle Communications;
11 * provided, however, that:
12 * 1. Any and all reproductions of the source or object code must include the
13 * copyright notice above and the following disclaimer of warranties; and
14 * 2. No rights are granted, in any manner or form, to use Whistle
15 * Communications, Inc. trademarks, including the mark "WHISTLE
16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17 * such appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35 * OF SUCH DAMAGE.
36 *
37 * Author: Archie Cobbs <archie@freebsd.org>
38 *
39 * $FreeBSD: src/sys/netgraph/ng_bridge.c,v 1.1.2.5 2002/07/02 23:44:02 archie Exp $
40 */
41
42 /*
43 * ng_bridge(4) netgraph node type
44 *
45 * The node performs standard intelligent Ethernet bridging over
46 * each of its connected hooks, or links. A simple loop detection
47 * algorithm is included which disables a link for priv->conf.loopTimeout
48 * seconds when a host is seen to have jumped from one link to
49 * another within priv->conf.minStableAge seconds.
50 *
51 * We keep a hashtable that maps Ethernet addresses to host info,
52 * which is contained in struct ng_bridge_host's. These structures
53 * tell us on which link the host may be found. A host's entry will
54 * expire after priv->conf.maxStaleness seconds.
55 *
56 * This node is optimzed for stable networks, where machines jump
57 * from one port to the other only rarely.
58 */
59
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/kernel.h>
63 #include <sys/malloc.h>
64 #include <sys/mbuf.h>
65 #include <sys/errno.h>
66 #include <sys/syslog.h>
67 #include <sys/socket.h>
68 #include <sys/ctype.h>
69 #include <sys/thread2.h>
70
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/ethernet.h>
74
75 #include <netinet/in.h>
76 #include <net/ipfw/ip_fw.h>
77
78 #include <netgraph/ng_message.h>
79 #include <netgraph/netgraph.h>
80 #include <netgraph/ng_parse.h>
81 #include "ng_bridge.h"
82 #include <netgraph/ether/ng_ether.h>
83
84 /* Per-link private data */
85 struct ng_bridge_link {
86 hook_p hook; /* netgraph hook */
87 u_int16_t loopCount; /* loop ignore timer */
88 struct ng_bridge_link_stats stats; /* link stats */
89 };
90
91 /* Per-node private data */
92 struct ng_bridge_private {
93 struct ng_bridge_bucket *tab; /* hash table bucket array */
94 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS];
95 struct ng_bridge_config conf; /* node configuration */
96 node_p node; /* netgraph node */
97 u_int numHosts; /* num entries in table */
98 u_int numBuckets; /* num buckets in table */
99 u_int hashMask; /* numBuckets - 1 */
100 int numLinks; /* num connected links */
101 struct callout timer; /* one second periodic timer */
102 };
103 typedef struct ng_bridge_private *priv_p;
104
105 /* Information about a host, stored in a hash table entry */
106 struct ng_bridge_hent {
107 struct ng_bridge_host host; /* actual host info */
108 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */
109 };
110
111 /* Hash table bucket declaration */
112 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
113
114 /* Netgraph node methods */
115 static ng_constructor_t ng_bridge_constructor;
116 static ng_rcvmsg_t ng_bridge_rcvmsg;
117 static ng_shutdown_t ng_bridge_rmnode;
118 static ng_newhook_t ng_bridge_newhook;
119 static ng_rcvdata_t ng_bridge_rcvdata;
120 static ng_disconnect_t ng_bridge_disconnect;
121
122 /* Other internal functions */
123 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
124 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum);
125 static void ng_bridge_rehash(priv_p priv);
126 static void ng_bridge_remove_hosts(priv_p priv, int linkNum);
127 static void ng_bridge_timeout(void *arg);
128 static const char *ng_bridge_nodename(node_p node);
129
130 /* Ethernet broadcast */
131 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
132 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
133
134 /* Store each hook's link number in the private field */
135 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private))
136
137 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
138 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \
139 == ((const u_int32_t *)(b))[0] \
140 && ((const u_int16_t *)(a))[2] \
141 == ((const u_int16_t *)(b))[2])
142
143 /* Minimum and maximum number of hash buckets. Must be a power of two. */
144 #define MIN_BUCKETS (1 << 5) /* 32 */
145 #define MAX_BUCKETS (1 << 14) /* 16384 */
146
147 /* Configuration default values */
148 #define DEFAULT_LOOP_TIMEOUT 60
149 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */
150 #define DEFAULT_MIN_STABLE_AGE 1
151
152 /******************************************************************
153 NETGRAPH PARSE TYPES
154 ******************************************************************/
155
156 /*
157 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
158 */
159 static int
ng_bridge_getTableLength(const struct ng_parse_type * type,const u_char * start,const u_char * buf)160 ng_bridge_getTableLength(const struct ng_parse_type *type,
161 const u_char *start, const u_char *buf)
162 {
163 const struct ng_bridge_host_ary *const hary
164 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
165
166 return hary->numHosts;
167 }
168
169 /* Parse type for struct ng_bridge_host_ary */
170 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
171 = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type);
172 static const struct ng_parse_type ng_bridge_host_type = {
173 &ng_parse_struct_type,
174 &ng_bridge_host_type_fields
175 };
176 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
177 &ng_bridge_host_type,
178 ng_bridge_getTableLength
179 };
180 static const struct ng_parse_type ng_bridge_hary_type = {
181 &ng_parse_array_type,
182 &ng_bridge_hary_type_info
183 };
184 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
185 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
186 static const struct ng_parse_type ng_bridge_host_ary_type = {
187 &ng_parse_struct_type,
188 &ng_bridge_host_ary_type_fields
189 };
190
191 /* Parse type for struct ng_bridge_config */
192 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = {
193 &ng_parse_uint8_type,
194 NG_BRIDGE_MAX_LINKS
195 };
196 static const struct ng_parse_type ng_bridge_ipfwary_type = {
197 &ng_parse_fixedarray_type,
198 &ng_bridge_ipfwary_type_info
199 };
200 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
201 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type);
202 static const struct ng_parse_type ng_bridge_config_type = {
203 &ng_parse_struct_type,
204 &ng_bridge_config_type_fields
205 };
206
207 /* Parse type for struct ng_bridge_link_stat */
208 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
209 = NG_BRIDGE_STATS_TYPE_INFO;
210 static const struct ng_parse_type ng_bridge_stats_type = {
211 &ng_parse_struct_type,
212 &ng_bridge_stats_type_fields
213 };
214
215 /* List of commands and how to convert arguments to/from ASCII */
216 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
217 {
218 NGM_BRIDGE_COOKIE,
219 NGM_BRIDGE_SET_CONFIG,
220 "setconfig",
221 &ng_bridge_config_type,
222 NULL
223 },
224 {
225 NGM_BRIDGE_COOKIE,
226 NGM_BRIDGE_GET_CONFIG,
227 "getconfig",
228 NULL,
229 &ng_bridge_config_type
230 },
231 {
232 NGM_BRIDGE_COOKIE,
233 NGM_BRIDGE_RESET,
234 "reset",
235 NULL,
236 NULL
237 },
238 {
239 NGM_BRIDGE_COOKIE,
240 NGM_BRIDGE_GET_STATS,
241 "getstats",
242 &ng_parse_uint32_type,
243 &ng_bridge_stats_type
244 },
245 {
246 NGM_BRIDGE_COOKIE,
247 NGM_BRIDGE_CLR_STATS,
248 "clrstats",
249 &ng_parse_uint32_type,
250 NULL
251 },
252 {
253 NGM_BRIDGE_COOKIE,
254 NGM_BRIDGE_GETCLR_STATS,
255 "getclrstats",
256 &ng_parse_uint32_type,
257 &ng_bridge_stats_type
258 },
259 {
260 NGM_BRIDGE_COOKIE,
261 NGM_BRIDGE_GET_TABLE,
262 "gettable",
263 NULL,
264 &ng_bridge_host_ary_type
265 },
266 { 0 }
267 };
268
269 /* Node type descriptor */
270 static struct ng_type ng_bridge_typestruct = {
271 NG_VERSION,
272 NG_BRIDGE_NODE_TYPE,
273 NULL,
274 ng_bridge_constructor,
275 ng_bridge_rcvmsg,
276 ng_bridge_rmnode,
277 ng_bridge_newhook,
278 NULL,
279 NULL,
280 ng_bridge_rcvdata,
281 ng_bridge_rcvdata,
282 ng_bridge_disconnect,
283 ng_bridge_cmdlist,
284 };
285 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
286
287 /* Depend on ng_ether so we can use the Ethernet parse type */
288 MODULE_DEPEND(ng_bridge, ng_ether, NG_ABI_VERSION, NG_ABI_VERSION, NG_ABI_VERSION);
289
290 /******************************************************************
291 NETGRAPH NODE METHODS
292 ******************************************************************/
293
294 /*
295 * Node constructor
296 */
297 static int
ng_bridge_constructor(node_p * nodep)298 ng_bridge_constructor(node_p *nodep)
299 {
300 priv_p priv;
301 int error;
302
303 /* Allocate and initialize private info */
304 priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
305 if (priv == NULL)
306 return (ENOMEM);
307 callout_init(&priv->timer);
308
309 /* Allocate and initialize hash table, etc. */
310 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH,
311 M_NOWAIT | M_ZERO);
312 if (priv->tab == NULL) {
313 kfree(priv, M_NETGRAPH);
314 return (ENOMEM);
315 }
316 priv->numBuckets = MIN_BUCKETS;
317 priv->hashMask = MIN_BUCKETS - 1;
318 priv->conf.debugLevel = 1;
319 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
320 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
321 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
322
323 /* Call superclass constructor */
324 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) {
325 kfree(priv, M_NETGRAPH);
326 return (error);
327 }
328 (*nodep)->private = priv;
329 priv->node = *nodep;
330
331 /* Start timer; timer is always running while node is alive */
332 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node);
333
334 /* Done */
335 return (0);
336 }
337
338 /*
339 * Method for attaching a new hook
340 */
341 static int
ng_bridge_newhook(node_p node,hook_p hook,const char * name)342 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
343 {
344 const priv_p priv = node->private;
345
346 /* Check for a link hook */
347 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX,
348 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) {
349 const char *cp;
350 char *eptr;
351 u_long linkNum;
352
353 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX);
354 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
355 return (EINVAL);
356 linkNum = strtoul(cp, &eptr, 10);
357 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS)
358 return (EINVAL);
359 if (priv->links[linkNum] != NULL)
360 return (EISCONN);
361 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]),
362 M_NETGRAPH, M_NOWAIT);
363 if (priv->links[linkNum] == NULL)
364 return (ENOMEM);
365 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum]));
366 priv->links[linkNum]->hook = hook;
367 LINK_NUM(hook) = linkNum;
368 priv->numLinks++;
369 return (0);
370 }
371
372 /* Unknown hook name */
373 return (EINVAL);
374 }
375
376 /*
377 * Receive a control message
378 */
379 static int
ng_bridge_rcvmsg(node_p node,struct ng_mesg * msg,const char * retaddr,struct ng_mesg ** rptr)380 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg,
381 const char *retaddr, struct ng_mesg **rptr)
382 {
383 const priv_p priv = node->private;
384 struct ng_mesg *resp = NULL;
385 int error = 0;
386
387 switch (msg->header.typecookie) {
388 case NGM_BRIDGE_COOKIE:
389 switch (msg->header.cmd) {
390 case NGM_BRIDGE_GET_CONFIG:
391 {
392 struct ng_bridge_config *conf;
393
394 NG_MKRESPONSE(resp, msg,
395 sizeof(struct ng_bridge_config), M_NOWAIT);
396 if (resp == NULL) {
397 error = ENOMEM;
398 break;
399 }
400 conf = (struct ng_bridge_config *)resp->data;
401 *conf = priv->conf; /* no sanity checking needed */
402 break;
403 }
404 case NGM_BRIDGE_SET_CONFIG:
405 {
406 struct ng_bridge_config *conf;
407 int i;
408
409 if (msg->header.arglen
410 != sizeof(struct ng_bridge_config)) {
411 error = EINVAL;
412 break;
413 }
414 conf = (struct ng_bridge_config *)msg->data;
415 priv->conf = *conf;
416 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++)
417 priv->conf.ipfw[i] = !!priv->conf.ipfw[i];
418 break;
419 }
420 case NGM_BRIDGE_RESET:
421 {
422 int i;
423
424 /* Flush all entries in the hash table */
425 ng_bridge_remove_hosts(priv, -1);
426
427 /* Reset all loop detection counters and stats */
428 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) {
429 if (priv->links[i] == NULL)
430 continue;
431 priv->links[i]->loopCount = 0;
432 bzero(&priv->links[i]->stats,
433 sizeof(priv->links[i]->stats));
434 }
435 break;
436 }
437 case NGM_BRIDGE_GET_STATS:
438 case NGM_BRIDGE_CLR_STATS:
439 case NGM_BRIDGE_GETCLR_STATS:
440 {
441 struct ng_bridge_link *link;
442 int linkNum;
443
444 /* Get link number */
445 if (msg->header.arglen != sizeof(u_int32_t)) {
446 error = EINVAL;
447 break;
448 }
449 linkNum = *((u_int32_t *)msg->data);
450 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) {
451 error = EINVAL;
452 break;
453 }
454 if ((link = priv->links[linkNum]) == NULL) {
455 error = ENOTCONN;
456 break;
457 }
458
459 /* Get/clear stats */
460 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
461 NG_MKRESPONSE(resp, msg,
462 sizeof(link->stats), M_NOWAIT);
463 if (resp == NULL) {
464 error = ENOMEM;
465 break;
466 }
467 bcopy(&link->stats,
468 resp->data, sizeof(link->stats));
469 }
470 if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
471 bzero(&link->stats, sizeof(link->stats));
472 break;
473 }
474 case NGM_BRIDGE_GET_TABLE:
475 {
476 struct ng_bridge_host_ary *ary;
477 struct ng_bridge_hent *hent;
478 int i = 0, bucket;
479
480 NG_MKRESPONSE(resp, msg, sizeof(*ary)
481 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
482 if (resp == NULL) {
483 error = ENOMEM;
484 break;
485 }
486 ary = (struct ng_bridge_host_ary *)resp->data;
487 ary->numHosts = priv->numHosts;
488 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
489 SLIST_FOREACH(hent, &priv->tab[bucket], next)
490 ary->hosts[i++] = hent->host;
491 }
492 break;
493 }
494 default:
495 error = EINVAL;
496 break;
497 }
498 break;
499 default:
500 error = EINVAL;
501 break;
502 }
503
504 /* Done */
505 if (rptr)
506 *rptr = resp;
507 else if (resp != NULL)
508 kfree(resp, M_NETGRAPH);
509 kfree(msg, M_NETGRAPH);
510 return (error);
511 }
512
513 /*
514 * Receive data on a hook
515 */
516 static int
ng_bridge_rcvdata(hook_p hook,struct mbuf * m,meta_p meta)517 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
518 {
519 const node_p node = hook->node;
520 const priv_p priv = node->private;
521 struct ng_bridge_host *host;
522 struct ng_bridge_link *link;
523 struct ether_header *eh;
524 int error = 0, linkNum;
525 int i, manycast;
526
527 /* Get link number */
528 linkNum = LINK_NUM(hook);
529 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
530 ("%s: linkNum=%u", __func__, linkNum));
531 link = priv->links[linkNum];
532 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum));
533
534 /* Sanity check packet and pull up header */
535 if (m->m_pkthdr.len < ETHER_HDR_LEN) {
536 link->stats.recvRunts++;
537 NG_FREE_DATA(m, meta);
538 return (EINVAL);
539 }
540 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) {
541 link->stats.memoryFailures++;
542 NG_FREE_META(meta);
543 return (ENOBUFS);
544 }
545 eh = mtod(m, struct ether_header *);
546 if ((eh->ether_shost[0] & 1) != 0) {
547 link->stats.recvInvalid++;
548 NG_FREE_DATA(m, meta);
549 return (EINVAL);
550 }
551
552 /* Is link disabled due to a loopback condition? */
553 if (link->loopCount != 0) {
554 link->stats.loopDrops++;
555 NG_FREE_DATA(m, meta);
556 return (ELOOP); /* XXX is this an appropriate error? */
557 }
558
559 /* Update stats */
560 link->stats.recvPackets++;
561 link->stats.recvOctets += m->m_pkthdr.len;
562 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) {
563 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
564 link->stats.recvBroadcasts++;
565 manycast = 2;
566 } else
567 link->stats.recvMulticasts++;
568 }
569
570 /* Look up packet's source Ethernet address in hashtable */
571 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
572
573 /* Update time since last heard from this host */
574 host->staleness = 0;
575
576 /* Did host jump to a different link? */
577 if (host->linkNum != linkNum) {
578
579 /*
580 * If the host's old link was recently established
581 * on the old link and it's already jumped to a new
582 * link, declare a loopback condition.
583 */
584 if (host->age < priv->conf.minStableAge) {
585
586 /* Log the problem */
587 if (priv->conf.debugLevel >= 2) {
588 struct ifnet *ifp = m->m_pkthdr.rcvif;
589 char suffix[32];
590
591 if (ifp != NULL)
592 ksnprintf(suffix, sizeof(suffix),
593 " (%s)", ifp->if_xname);
594 else
595 *suffix = '\0';
596 log(LOG_WARNING, "ng_bridge: %s:"
597 " loopback detected on %s%s\n",
598 ng_bridge_nodename(node),
599 hook->name, suffix);
600 }
601
602 /* Mark link as linka non grata */
603 link->loopCount = priv->conf.loopTimeout;
604 link->stats.loopDetects++;
605
606 /* Forget all hosts on this link */
607 ng_bridge_remove_hosts(priv, linkNum);
608
609 /* Drop packet */
610 link->stats.loopDrops++;
611 NG_FREE_DATA(m, meta);
612 return (ELOOP); /* XXX appropriate? */
613 }
614
615 /* Move host over to new link */
616 host->linkNum = linkNum;
617 host->age = 0;
618 }
619 } else {
620 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) {
621 link->stats.memoryFailures++;
622 NG_FREE_DATA(m, meta);
623 return (ENOMEM);
624 }
625 }
626
627 /* Run packet through ipfw processing, if enabled */
628 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) {
629 /* XXX not implemented yet */
630 }
631
632 /*
633 * If unicast and destination host known, deliver to host's link,
634 * unless it is the same link as the packet came in on.
635 */
636 if (!manycast) {
637
638 /* Determine packet destination link */
639 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
640 struct ng_bridge_link *const destLink
641 = priv->links[host->linkNum];
642
643 /* If destination same as incoming link, do nothing */
644 KASSERT(destLink != NULL,
645 ("%s: link%d null", __func__, host->linkNum));
646 if (destLink == link) {
647 NG_FREE_DATA(m, meta);
648 return (0);
649 }
650
651 /* Deliver packet out the destination link */
652 destLink->stats.xmitPackets++;
653 destLink->stats.xmitOctets += m->m_pkthdr.len;
654 NG_SEND_DATA(error, destLink->hook, m, meta);
655 return (error);
656 }
657
658 /* Destination host is not known */
659 link->stats.recvUnknown++;
660 }
661
662 /* Distribute unknown, multicast, broadcast pkts to all other links */
663 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) {
664 struct ng_bridge_link *const destLink = priv->links[linkNum];
665 meta_p meta2 = NULL;
666 struct mbuf *m2;
667
668 /* Skip incoming link and disconnected links */
669 if (destLink == NULL || destLink == link)
670 continue;
671
672 /* Copy mbuf and meta info */
673 if (++i == priv->numLinks - 1) { /* last link */
674 m2 = m;
675 meta2 = meta;
676 } else {
677 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */
678 if (m2 == NULL) {
679 link->stats.memoryFailures++;
680 NG_FREE_DATA(m, meta);
681 return (ENOBUFS);
682 }
683 if (meta != NULL
684 && (meta2 = ng_copy_meta(meta)) == NULL) {
685 link->stats.memoryFailures++;
686 m_freem(m2);
687 NG_FREE_DATA(m, meta);
688 return (ENOMEM);
689 }
690 }
691
692 /* Update stats */
693 destLink->stats.xmitPackets++;
694 destLink->stats.xmitOctets += m->m_pkthdr.len;
695 switch (manycast) {
696 case 0: /* unicast */
697 break;
698 case 1: /* multicast */
699 destLink->stats.xmitMulticasts++;
700 break;
701 case 2: /* broadcast */
702 destLink->stats.xmitBroadcasts++;
703 break;
704 }
705
706 /* Send packet */
707 NG_SEND_DATA(error, destLink->hook, m2, meta2);
708 }
709 return (error);
710 }
711
712 /*
713 * Shutdown node
714 */
715 static int
ng_bridge_rmnode(node_p node)716 ng_bridge_rmnode(node_p node)
717 {
718 const priv_p priv = node->private;
719
720 /*
721 * Shut down everything except the timer. There's no way to
722 * avoid another possible timeout event (it may have already
723 * been dequeued), so we can't free the node yet.
724 */
725 ng_unname(node);
726 ng_cutlinks(node); /* frees all link and host info */
727 KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
728 ("%s: numLinks=%d numHosts=%d",
729 __func__, priv->numLinks, priv->numHosts));
730 kfree(priv->tab, M_NETGRAPH);
731
732 /* NG_INVALID flag is now set so node will be freed at next timeout */
733 return (0);
734 }
735
736 /*
737 * Hook disconnection.
738 */
739 static int
ng_bridge_disconnect(hook_p hook)740 ng_bridge_disconnect(hook_p hook)
741 {
742 const priv_p priv = hook->node->private;
743 int linkNum;
744
745 /* Get link number */
746 linkNum = LINK_NUM(hook);
747 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS,
748 ("%s: linkNum=%u", __func__, linkNum));
749
750 /* Remove all hosts associated with this link */
751 ng_bridge_remove_hosts(priv, linkNum);
752
753 /* Free associated link information */
754 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__));
755 kfree(priv->links[linkNum], M_NETGRAPH);
756 priv->links[linkNum] = NULL;
757 priv->numLinks--;
758
759 /* If no more hooks, go away */
760 if (hook->node->numhooks == 0)
761 ng_rmnode(hook->node);
762 return (0);
763 }
764
765 /******************************************************************
766 HASH TABLE FUNCTIONS
767 ******************************************************************/
768
769 /*
770 * Hash algorithm
771 *
772 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast.
773 */
774 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \
775 ^ ((const u_int16_t *)(addr))[1] \
776 ^ ((const u_int16_t *)(addr))[2]) & (mask) )
777
778 /*
779 * Find a host entry in the table.
780 */
781 static struct ng_bridge_host *
ng_bridge_get(priv_p priv,const u_char * addr)782 ng_bridge_get(priv_p priv, const u_char *addr)
783 {
784 const int bucket = HASH(addr, priv->hashMask);
785 struct ng_bridge_hent *hent;
786
787 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
788 if (ETHER_EQUAL(hent->host.addr, addr))
789 return (&hent->host);
790 }
791 return (NULL);
792 }
793
794 /*
795 * Add a new host entry to the table. This assumes the host doesn't
796 * already exist in the table. Returns 1 on success, 0 if there
797 * was a memory allocation failure.
798 */
799 static int
ng_bridge_put(priv_p priv,const u_char * addr,int linkNum)800 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum)
801 {
802 const int bucket = HASH(addr, priv->hashMask);
803 struct ng_bridge_hent *hent;
804
805 #ifdef INVARIANTS
806 char ethstr[ETHER_ADDRSTRLEN + 1];
807
808 /* Assert that entry does not already exist in hashtable */
809 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
810 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
811 ("%s: entry %s exists in table", __func__, kether_ntoa(addr, ethstr)));
812 }
813 #endif
814
815 /* Allocate and initialize new hashtable entry */
816 hent = kmalloc(sizeof(*hent), M_NETGRAPH, M_NOWAIT);
817 if (hent == NULL)
818 return (0);
819 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
820 hent->host.linkNum = linkNum;
821 hent->host.staleness = 0;
822 hent->host.age = 0;
823
824 /* Add new element to hash bucket */
825 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
826 priv->numHosts++;
827
828 /* Resize table if necessary */
829 ng_bridge_rehash(priv);
830 return (1);
831 }
832
833 /*
834 * Resize the hash table. We try to maintain the number of buckets
835 * such that the load factor is in the range 0.25 to 1.0.
836 *
837 * If we can't get the new memory then we silently fail. This is OK
838 * because things will still work and we'll try again soon anyway.
839 */
840 static void
ng_bridge_rehash(priv_p priv)841 ng_bridge_rehash(priv_p priv)
842 {
843 struct ng_bridge_bucket *newTab;
844 int oldBucket, newBucket;
845 int newNumBuckets;
846 u_int newMask;
847
848 /* Is table too full or too empty? */
849 if (priv->numHosts > priv->numBuckets
850 && (priv->numBuckets << 1) <= MAX_BUCKETS)
851 newNumBuckets = priv->numBuckets << 1;
852 else if (priv->numHosts < (priv->numBuckets >> 2)
853 && (priv->numBuckets >> 2) >= MIN_BUCKETS)
854 newNumBuckets = priv->numBuckets >> 2;
855 else
856 return;
857 newMask = newNumBuckets - 1;
858
859 /* Allocate and initialize new table */
860 newTab = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH,
861 M_NOWAIT | M_ZERO);
862 if (newTab == NULL)
863 return;
864
865 /* Move all entries from old table to new table */
866 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
867 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
868
869 while (!SLIST_EMPTY(oldList)) {
870 struct ng_bridge_hent *const hent
871 = SLIST_FIRST(oldList);
872
873 SLIST_REMOVE_HEAD(oldList, next);
874 newBucket = HASH(hent->host.addr, newMask);
875 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
876 }
877 }
878
879 /* Replace old table with new one */
880 if (priv->conf.debugLevel >= 3) {
881 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
882 ng_bridge_nodename(priv->node),
883 priv->numBuckets, newNumBuckets);
884 }
885 kfree(priv->tab, M_NETGRAPH);
886 priv->numBuckets = newNumBuckets;
887 priv->hashMask = newMask;
888 priv->tab = newTab;
889 return;
890 }
891
892 /******************************************************************
893 MISC FUNCTIONS
894 ******************************************************************/
895
896 /*
897 * Remove all hosts associated with a specific link from the hashtable.
898 * If linkNum == -1, then remove all hosts in the table.
899 */
900 static void
ng_bridge_remove_hosts(priv_p priv,int linkNum)901 ng_bridge_remove_hosts(priv_p priv, int linkNum)
902 {
903 int bucket;
904
905 for (bucket = 0; bucket < priv->numBuckets; bucket++) {
906 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
907
908 while (*hptr != NULL) {
909 struct ng_bridge_hent *const hent = *hptr;
910
911 if (linkNum == -1 || hent->host.linkNum == linkNum) {
912 *hptr = SLIST_NEXT(hent, next);
913 kfree(hent, M_NETGRAPH);
914 priv->numHosts--;
915 } else
916 hptr = &SLIST_NEXT(hent, next);
917 }
918 }
919 }
920
921 /*
922 * Handle our once-per-second timeout event. We do two things:
923 * we decrement link->loopCount for those links being muted due to
924 * a detected loopback condition, and we remove any hosts from
925 * the hashtable whom we haven't heard from in a long while.
926 *
927 * If the node has the NG_INVALID flag set, our job is to kill it.
928 */
929 static void
ng_bridge_timeout(void * arg)930 ng_bridge_timeout(void *arg)
931 {
932 const node_p node = arg;
933 const priv_p priv = node->private;
934 int bucket;
935 int counter = 0;
936 int linkNum;
937 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar;
938
939 /* If node was shut down, this is the final lingering timeout */
940 crit_enter();
941 if ((node->flags & NG_INVALID) != 0) {
942 kfree(priv, M_NETGRAPH);
943 node->private = NULL;
944 ng_unref(node);
945 crit_exit();
946 return;
947 }
948
949 /* Register a new timeout, keeping the existing node reference */
950 callout_reset(&priv->timer, hz, ng_bridge_timeout, node);
951
952 /* Update host time counters and remove stale entries */
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 /* Make sure host's link really exists */
960 KASSERT(priv->links[hent->host.linkNum] != NULL,
961 ("%s: host %s on nonexistent link %d",
962 __func__, kether_ntoa(hent->host.addr, ethstr),
963 hent->host.linkNum));
964
965 /* Remove hosts we haven't heard from in a while */
966 if (++hent->host.staleness >= priv->conf.maxStaleness) {
967 *hptr = SLIST_NEXT(hent, next);
968 kfree(hent, M_NETGRAPH);
969 priv->numHosts--;
970 } else {
971 if (hent->host.age < 0xffff)
972 hent->host.age++;
973 hptr = &SLIST_NEXT(hent, next);
974 counter++;
975 }
976 }
977 }
978 KASSERT(priv->numHosts == counter,
979 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
980
981 /* Decrease table size if necessary */
982 ng_bridge_rehash(priv);
983
984 /* Decrease loop counter on muted looped back links */
985 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) {
986 struct ng_bridge_link *const link = priv->links[linkNum];
987
988 if (link != NULL) {
989 if (link->loopCount != 0) {
990 link->loopCount--;
991 if (link->loopCount == 0
992 && priv->conf.debugLevel >= 2) {
993 log(LOG_INFO, "ng_bridge: %s:"
994 " restoring looped back link%d\n",
995 ng_bridge_nodename(node), linkNum);
996 }
997 }
998 counter++;
999 }
1000 }
1001 KASSERT(priv->numLinks == counter,
1002 ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1003
1004 /* Done */
1005 crit_exit();
1006 }
1007
1008 /*
1009 * Return node's "name", even if it doesn't have one.
1010 */
1011 static const char *
ng_bridge_nodename(node_p node)1012 ng_bridge_nodename(node_p node)
1013 {
1014 static char name[NG_NODESIZ];
1015
1016 if (node->name != NULL)
1017 ksnprintf(name, sizeof(name), "%s", node->name);
1018 else
1019 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1020 return name;
1021 }
1022
1023