FreeBSD/Linux Kernel Cross Reference
sys/net/bridge.c
1 /*
2 * Copyright (c) 1998-2002 Luigi Rizzo
3 *
4 * Work partly supported by: Cisco Systems, Inc. - NSITE lab, RTP, NC
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: releng/5.2/sys/net/bridge.c 121816 2003-10-31 18:32:15Z brooks $
28 */
29
30 /*
31 * This code implements bridging in FreeBSD. It only acts on ethernet
32 * interfaces, including VLANs (others are still usable for routing).
33 * A FreeBSD host can implement multiple logical bridges, called
34 * "clusters". Each cluster is made of a set of interfaces, and
35 * identified by a "cluster-id" which is a number in the range 1..2^16-1.
36 *
37 * Bridging is enabled by the sysctl variable
38 * net.link.ether.bridge.enable
39 * the grouping of interfaces into clusters is done with
40 * net.link.ether.bridge.config
41 * containing a list of interfaces each optionally followed by
42 * a colon and the cluster it belongs to (1 is the default).
43 * Separators can be * spaces, commas or tabs, e.g.
44 * net.link.ether.bridge.config="fxp0:2 fxp1:2 dc0 dc1:1"
45 * Optionally bridged packets can be passed through the firewall,
46 * this is controlled by the variable
47 * net.link.ether.bridge.ipfw
48 *
49 * For each cluster there is a descriptor (cluster_softc) storing
50 * the following data structures:
51 * - a hash table with the MAC address and destination interface for each
52 * known node. The table is indexed using a hash of the source address.
53 * - an array with the MAC addresses of the interfaces used in the cluster.
54 *
55 * Input packets are tapped near the beginning of ether_input(), and
56 * analysed by bridge_in(). Depending on the result, the packet
57 * can be forwarded to one or more output interfaces using bdg_forward(),
58 * and/or sent to the upper layer (e.g. in case of multicast).
59 *
60 * Output packets are intercepted near the end of ether_output().
61 * The correct destination is selected by bridge_dst_lookup(),
62 * and then forwarding is done by bdg_forward().
63 *
64 * The arp code is also modified to let a machine answer to requests
65 * irrespective of the port the request came from.
66 *
67 * In case of loops in the bridging topology, the bridge detects this
68 * event and temporarily mutes output bridging on one of the ports.
69 * Periodically, interfaces are unmuted by bdg_timeout().
70 * Muting is only implemented as a safety measure, and also as
71 * a mechanism to support a user-space implementation of the spanning
72 * tree algorithm.
73 *
74 * To build a bridging kernel, use the following option
75 * option BRIDGE
76 * and then at runtime set the sysctl variable to enable bridging.
77 *
78 * Only one interface per cluster is supposed to have addresses set (but
79 * there are no substantial problems if you set addresses for none or
80 * for more than one interface).
81 * Bridging will act before routing, but nothing prevents a machine
82 * from doing both (modulo bugs in the implementation...).
83 *
84 * THINGS TO REMEMBER
85 * - bridging is incompatible with multicast routing on the same
86 * machine. There is not an easy fix to this.
87 * - be very careful when bridging VLANs
88 * - loop detection is still not very robust.
89 */
90 #include "opt_pfil_hooks.h"
91
92 #include <sys/param.h>
93 #include <sys/mbuf.h>
94 #include <sys/malloc.h>
95 #include <sys/protosw.h>
96 #include <sys/systm.h>
97 #include <sys/socket.h> /* for net/if.h */
98 #include <sys/ctype.h> /* string functions */
99 #include <sys/kernel.h>
100 #include <sys/sysctl.h>
101
102 #include <net/if.h>
103 #include <net/if_types.h>
104 #include <net/if_var.h>
105
106 #include <netinet/in.h> /* for struct arpcom */
107 #include <netinet/in_systm.h>
108 #include <netinet/in_var.h>
109 #include <netinet/ip.h>
110 #include <netinet/if_ether.h> /* for struct arpcom */
111
112 #ifdef PFIL_HOOKS
113 #include <net/pfil.h>
114 #include <netinet/ip_var.h>
115 #endif
116
117 #include <net/route.h>
118 #include <netinet/ip_fw.h>
119 #include <netinet/ip_dummynet.h>
120 #include <net/bridge.h>
121
122 /*--------------------*/
123
124 #define ETHER_ADDR_COPY(_dst,_src) bcopy(_src, _dst, ETHER_ADDR_LEN)
125 #define ETHER_ADDR_EQ(_a1,_a2) (bcmp(_a1, _a2, ETHER_ADDR_LEN) == 0)
126
127 /*
128 * For each cluster, source MAC addresses are stored into a hash
129 * table which locates the port they reside on.
130 */
131 #define HASH_SIZE 8192 /* Table size, must be a power of 2 */
132
133 typedef struct hash_table { /* each entry. */
134 struct ifnet * name;
135 u_char etheraddr[ETHER_ADDR_LEN];
136 u_int16_t used; /* also, padding */
137 } bdg_hash_table ;
138
139 /*
140 * The hash function applied to MAC addresses. Out of the 6 bytes,
141 * the last ones tend to vary more. Since we are on a little endian machine,
142 * we have to do some gimmick...
143 */
144 #define HASH_FN(addr) ( \
145 ntohs( ((u_int16_t *)addr)[1] ^ ((u_int16_t *)addr)[2] ) & (HASH_SIZE -1))
146
147 /*
148 * This is the data structure where local addresses are stored.
149 */
150 struct bdg_addr {
151 u_char etheraddr[ETHER_ADDR_LEN];
152 u_int16_t _padding;
153 };
154
155 /*
156 * The configuration of each cluster includes the cluster id, a pointer to
157 * the hash table, and an array of local MAC addresses (of size "ports").
158 */
159 struct cluster_softc {
160 u_int16_t cluster_id;
161 u_int16_t ports;
162 bdg_hash_table *ht;
163 struct bdg_addr *my_macs; /* local MAC addresses */
164 };
165
166
167 extern struct protosw inetsw[]; /* from netinet/ip_input.c */
168
169 static int n_clusters; /* number of clusters */
170 static struct cluster_softc *clusters;
171
172 static struct mtx bdg_mtx;
173 #define BDG_LOCK_INIT() mtx_init(&bdg_mtx, "bridge", NULL, MTX_DEF)
174 #define BDG_LOCK_DESTROY() mtx_destroy(&bdg_mtx)
175 #define BDG_LOCK() mtx_lock(&bdg_mtx)
176 #define BDG_UNLOCK() mtx_unlock(&bdg_mtx)
177 #define BDG_LOCK_ASSERT() mtx_assert(&bdg_mtx, MA_OWNED)
178
179 #define BDG_MUTED(ifp) (ifp2sc[ifp->if_index].flags & IFF_MUTE)
180 #define BDG_MUTE(ifp) ifp2sc[ifp->if_index].flags |= IFF_MUTE
181 #define BDG_CLUSTER(ifp) (ifp2sc[ifp->if_index].cluster)
182
183 #define BDG_SAMECLUSTER(ifp,src) \
184 (src == NULL || BDG_CLUSTER(ifp) == BDG_CLUSTER(src) )
185
186 #ifdef __i386__
187 #define BDG_MATCH(a,b) ( \
188 ((u_int16_t *)(a))[2] == ((u_int16_t *)(b))[2] && \
189 *((u_int32_t *)(a)) == *((u_int32_t *)(b)) )
190 #define IS_ETHER_BROADCAST(a) ( \
191 *((u_int32_t *)(a)) == 0xffffffff && \
192 ((u_int16_t *)(a))[2] == 0xffff )
193 #else
194 /* for machines that do not support unaligned access */
195 #define BDG_MATCH(a,b) ETHER_ADDR_EQ(a,b)
196 #define IS_ETHER_BROADCAST(a) ETHER_ADDR_EQ(a,"\377\377\377\377\377\377")
197 #endif
198
199 SYSCTL_DECL(_net_link_ether);
200 SYSCTL_NODE(_net_link_ether, OID_AUTO, bridge, CTLFLAG_RD, 0,
201 "Bridge parameters");
202 static char bridge_version[] = "$Revision$ $Date$";
203 SYSCTL_STRING(_net_link_ether_bridge, OID_AUTO, version, CTLFLAG_RD,
204 bridge_version, 0, "software version");
205
206 #define BRIDGE_DEBUG
207 #ifdef BRIDGE_DEBUG
208 int bridge_debug = 0;
209 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, debug, CTLFLAG_RW, &bridge_debug,
210 0, "control debugging printfs");
211 #define DPRINTF(X) if (bridge_debug) printf X
212 #else
213 #define DPRINTF(X)
214 #endif
215
216 #ifdef BRIDGE_TIMING
217 /*
218 * For timing-related debugging, you can use the following macros.
219 * remember, rdtsc() only works on Pentium-class machines
220
221 quad_t ticks;
222 DDB(ticks = rdtsc();)
223 ... interesting code ...
224 DDB(bdg_fw_ticks += (u_long)(rdtsc() - ticks) ; bdg_fw_count++ ;)
225
226 *
227 */
228 #define DDB(x) x
229
230 static int bdg_fw_avg;
231 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, fw_avg, CTLFLAG_RW,
232 &bdg_fw_avg, 0,"Cycle counter avg");
233 static int bdg_fw_ticks;
234 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, fw_ticks, CTLFLAG_RW,
235 &bdg_fw_ticks, 0,"Cycle counter item");
236 static int bdg_fw_count;
237 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, fw_count, CTLFLAG_RW,
238 &bdg_fw_count, 0,"Cycle counter count");
239 #else
240 #define DDB(x)
241 #endif
242
243 static int bdginit(void);
244 static void parse_bdg_cfg(void);
245
246 static int bdg_ipf; /* IPFilter enabled in bridge */
247 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, ipf, CTLFLAG_RW,
248 &bdg_ipf, 0,"Pass bridged pkts through IPFilter");
249 static int bdg_ipfw;
250 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, ipfw, CTLFLAG_RW,
251 &bdg_ipfw,0,"Pass bridged pkts through firewall");
252
253 static int bdg_copy;
254 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, copy, CTLFLAG_RW,
255 &bdg_copy, 0, "Force packet copy in bdg_forward");
256
257 int bdg_ipfw_drops;
258 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, ipfw_drop,
259 CTLFLAG_RW, &bdg_ipfw_drops,0,"");
260 int bdg_ipfw_colls;
261 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, ipfw_collisions,
262 CTLFLAG_RW, &bdg_ipfw_colls,0,"");
263
264 static int bdg_thru;
265 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, packets, CTLFLAG_RW,
266 &bdg_thru, 0, "Packets through bridge");
267 static int bdg_dropped;
268 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, dropped, CTLFLAG_RW,
269 &bdg_dropped, 0, "Packets dropped in bdg_forward");
270 static int bdg_predict;
271 SYSCTL_INT(_net_link_ether_bridge, OID_AUTO, predict, CTLFLAG_RW,
272 &bdg_predict, 0, "Correctly predicted header location");
273
274 #ifdef BRIDGE_DEBUG
275 static char *bdg_dst_names[] = {
276 "BDG_NULL ",
277 "BDG_BCAST ",
278 "BDG_MCAST ",
279 "BDG_LOCAL ",
280 "BDG_DROP ",
281 "BDG_UNKNOWN ",
282 "BDG_IN ",
283 "BDG_OUT ",
284 "BDG_FORWARD " };
285 #endif /* BRIDGE_DEBUG */
286
287 /*
288 * System initialization
289 */
290 static struct bdg_stats bdg_stats ;
291 SYSCTL_STRUCT(_net_link_ether_bridge, OID_AUTO, stats, CTLFLAG_RD,
292 &bdg_stats, bdg_stats, "bridge statistics");
293
294 static struct callout bdg_callout;
295
296 /*
297 * Add an interface to a cluster, possibly creating a new entry in
298 * the cluster table. This requires reallocation of the table and
299 * updating pointers in ifp2sc.
300 */
301 static struct cluster_softc *
302 add_cluster(u_int16_t cluster_id, struct arpcom *ac)
303 {
304 struct cluster_softc *c = NULL;
305 int i;
306
307 BDG_LOCK_ASSERT();
308
309 for (i = 0; i < n_clusters ; i++)
310 if (clusters[i].cluster_id == cluster_id)
311 goto found;
312
313 /* Not found, need to reallocate */
314 c = malloc((1+n_clusters) * sizeof (*c), M_IFADDR, M_NOWAIT | M_ZERO);
315 if (c == NULL) {/* malloc failure */
316 printf("-- bridge: cannot add new cluster\n");
317 goto bad;
318 }
319 c[n_clusters].ht = (struct hash_table *)
320 malloc(HASH_SIZE * sizeof(struct hash_table),
321 M_IFADDR, M_NOWAIT | M_ZERO);
322 if (c[n_clusters].ht == NULL) {
323 printf("-- bridge: cannot allocate hash table for new cluster\n");
324 goto bad;
325 }
326 c[n_clusters].my_macs = (struct bdg_addr *)
327 malloc(BDG_MAX_PORTS * sizeof(struct bdg_addr),
328 M_IFADDR, M_NOWAIT | M_ZERO);
329 if (c[n_clusters].my_macs == NULL) {
330 printf("-- bridge: cannot allocate mac addr table for new cluster\n");
331 free(c[n_clusters].ht, M_IFADDR);
332 goto bad;
333 }
334
335 c[n_clusters].cluster_id = cluster_id;
336 c[n_clusters].ports = 0;
337 /*
338 * now copy old descriptors here
339 */
340 if (n_clusters > 0) {
341 for (i=0; i < n_clusters; i++)
342 c[i] = clusters[i];
343 /*
344 * and finally update pointers in ifp2sc
345 */
346 for (i = 0 ; i < if_index && i < BDG_MAX_PORTS; i++)
347 if (ifp2sc[i].cluster != NULL)
348 ifp2sc[i].cluster = c + (ifp2sc[i].cluster - clusters);
349 free(clusters, M_IFADDR);
350 }
351 clusters = c;
352 i = n_clusters; /* index of cluster entry */
353 n_clusters++;
354 found:
355 c = clusters + i; /* the right cluster ... */
356 ETHER_ADDR_COPY(c->my_macs[c->ports].etheraddr, ac->ac_enaddr);
357 c->ports++;
358 return c;
359 bad:
360 if (c)
361 free(c, M_IFADDR);
362 return NULL;
363 }
364
365
366 /*
367 * Turn off bridging, by clearing promisc mode on the interface,
368 * marking the interface as unused, and clearing the name in the
369 * stats entry.
370 * Also dispose the hash tables associated with the clusters.
371 */
372 static void
373 bridge_off(void)
374 {
375 struct ifnet *ifp ;
376 int i;
377
378 BDG_LOCK_ASSERT();
379
380 DPRINTF(("%s: n_clusters %d\n", __func__, n_clusters));
381
382 IFNET_RLOCK();
383 TAILQ_FOREACH(ifp, &ifnet, if_link) {
384 struct bdg_softc *b;
385
386 if (ifp->if_index >= BDG_MAX_PORTS)
387 continue; /* make sure we do not go beyond the end */
388 b = &ifp2sc[ifp->if_index];
389
390 if ( b->flags & IFF_BDG_PROMISC ) {
391 ifpromisc(ifp, 0);
392 b->flags &= ~(IFF_BDG_PROMISC|IFF_MUTE) ;
393 DPRINTF(("%s: %s promisc OFF if_flags 0x%x "
394 "bdg_flags 0x%x\n", __func__, ifp->if_xname,
395 ifp->if_flags, b->flags));
396 }
397 b->flags &= ~(IFF_USED) ;
398 b->cluster = NULL;
399 bdg_stats.s[ifp->if_index].name[0] = '\0';
400 }
401 IFNET_RUNLOCK();
402 /* flush_tables */
403
404 for (i=0; i < n_clusters; i++) {
405 free(clusters[i].ht, M_IFADDR);
406 free(clusters[i].my_macs, M_IFADDR);
407 }
408 if (clusters != NULL)
409 free(clusters, M_IFADDR);
410 clusters = NULL;
411 n_clusters =0;
412 }
413
414 /*
415 * set promisc mode on the interfaces we use.
416 */
417 static void
418 bridge_on(void)
419 {
420 struct ifnet *ifp ;
421
422 BDG_LOCK_ASSERT();
423
424 IFNET_RLOCK();
425 TAILQ_FOREACH(ifp, &ifnet, if_link) {
426 struct bdg_softc *b = &ifp2sc[ifp->if_index];
427
428 if ( !(b->flags & IFF_USED) )
429 continue ;
430 if ( !( ifp->if_flags & IFF_UP) ) {
431 if_up(ifp);
432 }
433 if ( !(b->flags & IFF_BDG_PROMISC) ) {
434 (void) ifpromisc(ifp, 1);
435 b->flags |= IFF_BDG_PROMISC ;
436 DPRINTF(("%s: %s promisc ON if_flags 0x%x bdg_flags 0x%x\n",
437 __func__, ifp->if_xname, ifp->if_flags, b->flags));
438 }
439 if (b->flags & IFF_MUTE) {
440 DPRINTF(("%s: unmuting %s\n", __func__, ifp->if_xname));
441 b->flags &= ~IFF_MUTE;
442 }
443 }
444 IFNET_RUNLOCK();
445 }
446
447 static char bridge_cfg[1024]; /* NB: in BSS so initialized to zero */
448
449 /**
450 * reconfigure bridge.
451 * This is also done every time we attach or detach an interface.
452 * Main use is to make sure that we do not bridge on some old
453 * (ejected) device. So, it would be really useful to have a
454 * pointer to the modified device as an argument. Without it, we
455 * have to scan all interfaces.
456 */
457 static void
458 reconfigure_bridge_locked(void)
459 {
460 BDG_LOCK_ASSERT();
461
462 bridge_off();
463 if (do_bridge) {
464 if (if_index >= BDG_MAX_PORTS) {
465 printf("-- sorry too many interfaces (%d, max is %d),"
466 " disabling bridging\n", if_index, BDG_MAX_PORTS);
467 do_bridge = 0;
468 return;
469 }
470 parse_bdg_cfg();
471 bridge_on();
472 }
473 }
474
475 static void
476 reconfigure_bridge(void)
477 {
478 BDG_LOCK();
479 reconfigure_bridge_locked();
480 BDG_UNLOCK();
481 }
482
483 /*
484 * parse the config string, set IFF_USED, name and cluster_id
485 * for all interfaces found.
486 * The config string is a list of "if[:cluster]" with
487 * a number of possible separators (see "sep"). In particular the
488 * use of the space lets you set bridge_cfg with the output from
489 * "ifconfig -l"
490 */
491 static void
492 parse_bdg_cfg(void)
493 {
494 char *p, *beg;
495 int l, cluster;
496 static const char *sep = ", \t";
497
498 BDG_LOCK_ASSERT();
499
500 for (p = bridge_cfg; *p ; p++) {
501 struct ifnet *ifp;
502 int found = 0;
503 char c;
504
505 if (index(sep, *p)) /* skip separators */
506 continue ;
507 /* names are lowercase and digits */
508 for ( beg = p ; islower(*p) || isdigit(*p) ; p++ )
509 ;
510 l = p - beg ; /* length of name string */
511 if (l == 0) /* invalid name */
512 break ;
513 if ( *p != ':' ) /* no ':', assume default cluster 1 */
514 cluster = 1 ;
515 else /* fetch cluster */
516 cluster = strtoul( p+1, &p, 10);
517 c = *p;
518 *p = '\0';
519 /*
520 * now search in interface list for a matching name
521 */
522 IFNET_RLOCK(); /* could sleep XXX */
523 TAILQ_FOREACH(ifp, &ifnet, if_link) {
524
525 if (!strncmp(beg, ifp->if_xname, max(l, strlen(ifp->if_xname)))) {
526 struct bdg_softc *b = &ifp2sc[ifp->if_index];
527 if (ifp->if_type != IFT_ETHER && ifp->if_type != IFT_L2VLAN) {
528 printf("%s is not an ethernet, continue\n", ifp->if_xname);
529 continue;
530 }
531 if (b->flags & IFF_USED) {
532 printf("%s already used, skipping\n", ifp->if_xname);
533 break;
534 }
535 b->cluster = add_cluster(htons(cluster), (struct arpcom *)ifp);
536 b->flags |= IFF_USED ;
537 snprintf(bdg_stats.s[ifp->if_index].name,
538 sizeof(bdg_stats.s[ifp->if_index].name),
539 "%s:%d", ifp->if_xname, cluster);
540
541 DPRINTF(("%s: found %s next c %d\n", __func__,
542 bdg_stats.s[ifp->if_index].name, c));
543 found = 1;
544 break ;
545 }
546 }
547 IFNET_RUNLOCK();
548 if (!found)
549 printf("interface %s Not found in bridge\n", beg);
550 *p = c;
551 if (c == '\0')
552 break; /* no more */
553 }
554 }
555
556 /*
557 * handler for net.link.ether.bridge
558 */
559 static int
560 sysctl_bdg(SYSCTL_HANDLER_ARGS)
561 {
562 int enable = do_bridge;
563 int error;
564
565 error = sysctl_handle_int(oidp, &enable, 0, req);
566 BDG_LOCK();
567 if (enable != do_bridge) {
568 do_bridge = enable;
569 reconfigure_bridge_locked();
570 }
571 BDG_UNLOCK();
572 return error ;
573 }
574 SYSCTL_PROC(_net_link_ether_bridge, OID_AUTO, enable, CTLTYPE_INT|CTLFLAG_RW,
575 &do_bridge, 0, &sysctl_bdg, "I", "Bridging");
576
577 /*
578 * handler for net.link.ether.bridge_cfg
579 */
580 static int
581 sysctl_bdg_cfg(SYSCTL_HANDLER_ARGS)
582 {
583 int error;
584 char *new_cfg;
585
586 new_cfg = malloc(sizeof(bridge_cfg), M_TEMP, M_WAITOK);
587 bcopy(bridge_cfg, new_cfg, sizeof(bridge_cfg));
588
589 error = sysctl_handle_string(oidp, new_cfg, oidp->oid_arg2, req);
590 if (error == 0) {
591 BDG_LOCK();
592 if (strcmp(new_cfg, bridge_cfg)) {
593 bcopy(new_cfg, bridge_cfg, sizeof(bridge_cfg));
594 reconfigure_bridge_locked();
595 }
596 BDG_UNLOCK();
597 }
598
599 free(new_cfg, M_TEMP);
600
601 return error;
602 }
603 SYSCTL_PROC(_net_link_ether_bridge, OID_AUTO, config, CTLTYPE_STRING|CTLFLAG_RW,
604 &bridge_cfg, sizeof(bridge_cfg), &sysctl_bdg_cfg, "A",
605 "Bridge configuration");
606
607 static int
608 sysctl_refresh(SYSCTL_HANDLER_ARGS)
609 {
610 if (req->newptr)
611 reconfigure_bridge();
612
613 return 0;
614 }
615 SYSCTL_PROC(_net_link_ether_bridge, OID_AUTO, refresh, CTLTYPE_INT|CTLFLAG_WR,
616 NULL, 0, &sysctl_refresh, "I", "iface refresh");
617
618 #ifndef BURN_BRIDGES
619 #define SYSCTL_OID_COMPAT(parent, nbr, name, kind, a1, a2, handler, fmt, descr)\
620 static struct sysctl_oid sysctl__##parent##_##name##_compat = { \
621 &sysctl_##parent##_children, { 0 }, \
622 nbr, kind, a1, a2, #name, handler, fmt, 0, descr }; \
623 DATA_SET(sysctl_set, sysctl__##parent##_##name##_compat)
624 #define SYSCTL_INT_COMPAT(parent, nbr, name, access, ptr, val, descr) \
625 SYSCTL_OID_COMPAT(parent, nbr, name, CTLTYPE_INT|(access), \
626 ptr, val, sysctl_handle_int, "I", descr)
627 #define SYSCTL_STRUCT_COMPAT(parent, nbr, name, access, ptr, type, descr)\
628 SYSCTL_OID_COMPAT(parent, nbr, name, CTLTYPE_OPAQUE|(access), \
629 ptr, sizeof(struct type), sysctl_handle_opaque, \
630 "S," #type, descr)
631 #define SYSCTL_PROC_COMPAT(parent, nbr, name, access, ptr, arg, handler, fmt, descr) \
632 SYSCTL_OID_COMPAT(parent, nbr, name, (access), \
633 ptr, arg, handler, fmt, descr)
634
635 SYSCTL_INT_COMPAT(_net_link_ether, OID_AUTO, bridge_ipf, CTLFLAG_RW,
636 &bdg_ipf, 0,"Pass bridged pkts through IPFilter");
637 SYSCTL_INT_COMPAT(_net_link_ether, OID_AUTO, bridge_ipfw, CTLFLAG_RW,
638 &bdg_ipfw,0,"Pass bridged pkts through firewall");
639 SYSCTL_STRUCT_COMPAT(_net_link_ether, PF_BDG, bdgstats, CTLFLAG_RD,
640 &bdg_stats, bdg_stats, "bridge statistics");
641 SYSCTL_PROC_COMPAT(_net_link_ether, OID_AUTO, bridge_cfg,
642 CTLTYPE_STRING|CTLFLAG_RW,
643 &bridge_cfg, sizeof(bridge_cfg), &sysctl_bdg_cfg, "A",
644 "Bridge configuration");
645 SYSCTL_PROC_COMPAT(_net_link_ether, OID_AUTO, bridge_refresh,
646 CTLTYPE_INT|CTLFLAG_WR,
647 NULL, 0, &sysctl_refresh, "I", "iface refresh");
648 #endif
649
650 static int bdg_loops;
651 static int bdg_slowtimer = 0;
652 static int bdg_age_index = 0; /* index of table position to age */
653
654 /*
655 * called periodically to flush entries etc.
656 */
657 static void
658 bdg_timeout(void *dummy)
659 {
660 if (do_bridge) {
661 int l, i;
662
663 BDG_LOCK();
664 /*
665 * age entries in the forwarding table.
666 */
667 l = bdg_age_index + HASH_SIZE/4 ;
668 if (l > HASH_SIZE)
669 l = HASH_SIZE;
670
671 for (i = 0; i < n_clusters; i++) {
672 bdg_hash_table *bdg_table = clusters[i].ht;
673 for (; bdg_age_index < l; bdg_age_index++)
674 if (bdg_table[bdg_age_index].used)
675 bdg_table[bdg_age_index].used = 0;
676 else if (bdg_table[bdg_age_index].name) {
677 DPRINTF(("%s: flushing stale entry %d\n",
678 __func__, bdg_age_index));
679 bdg_table[bdg_age_index].name = NULL;
680 }
681 }
682 if (bdg_age_index >= HASH_SIZE)
683 bdg_age_index = 0;
684
685 if (--bdg_slowtimer <= 0 ) {
686 bdg_slowtimer = 5;
687
688 bridge_on(); /* we just need unmute, really */
689 bdg_loops = 0;
690 }
691 BDG_UNLOCK();
692 }
693 callout_reset(&bdg_callout, 2*hz, bdg_timeout, NULL);
694 }
695
696 /*
697 * Find the right pkt destination:
698 * BDG_BCAST is a broadcast
699 * BDG_MCAST is a multicast
700 * BDG_LOCAL is for a local address
701 * BDG_DROP must be dropped
702 * other ifp of the dest. interface (incl.self)
703 *
704 * We assume this is only called for interfaces for which bridging
705 * is enabled, i.e. BDG_USED(ifp) is true.
706 */
707 static __inline struct ifnet *
708 bridge_dst_lookup(struct ether_header *eh, struct cluster_softc *c)
709 {
710 bdg_hash_table *bt; /* pointer to entry in hash table */
711
712 BDG_LOCK_ASSERT();
713
714 if (ETHER_IS_MULTICAST(eh->ether_dhost))
715 return IS_ETHER_BROADCAST(eh->ether_dhost) ? BDG_BCAST : BDG_MCAST;
716 /*
717 * Lookup local addresses in case one matches. We optimize
718 * for the common case of two interfaces.
719 */
720 KASSERT(c->ports != 0, ("lookup with no ports!"));
721 switch (c->ports) {
722 int i;
723 default:
724 for (i = c->ports-1; i > 1; i--) {
725 if (ETHER_ADDR_EQ(c->my_macs[i].etheraddr, eh->ether_dhost))
726 return BDG_LOCAL;
727 }
728 /* fall thru... */
729 case 2:
730 if (ETHER_ADDR_EQ(c->my_macs[1].etheraddr, eh->ether_dhost))
731 return BDG_LOCAL;
732 case 1:
733 if (ETHER_ADDR_EQ(c->my_macs[0].etheraddr, eh->ether_dhost))
734 return BDG_LOCAL;
735 }
736 /*
737 * Look for a possible destination in table
738 */
739 bt = &c->ht[HASH_FN(eh->ether_dhost)];
740 if (bt->name && ETHER_ADDR_EQ(bt->etheraddr, eh->ether_dhost))
741 return bt->name;
742 else
743 return BDG_UNKNOWN;
744 }
745
746 /**
747 * bridge_in() is invoked to perform bridging decision on input packets.
748 *
749 * On Input:
750 * eh Ethernet header of the incoming packet.
751 * ifp interface the packet is coming from.
752 *
753 * On Return: destination of packet, one of
754 * BDG_BCAST broadcast
755 * BDG_MCAST multicast
756 * BDG_LOCAL is only for a local address (do not forward)
757 * BDG_DROP drop the packet
758 * ifp ifp of the destination interface.
759 *
760 * Forwarding is not done directly to give a chance to some drivers
761 * to fetch more of the packet, or simply drop it completely.
762 */
763
764 static struct ifnet *
765 bridge_in(struct ifnet *ifp, struct ether_header *eh)
766 {
767 int index;
768 struct ifnet *dst, *old;
769 bdg_hash_table *bt; /* location in hash table */
770 int dropit = BDG_MUTED(ifp);
771
772 /*
773 * hash the source address
774 */
775 BDG_LOCK();
776 index = HASH_FN(eh->ether_shost);
777 bt = &BDG_CLUSTER(ifp)->ht[index];
778 bt->used = 1;
779 old = bt->name;
780 if (old) { /* the entry is valid */
781 if (!ETHER_ADDR_EQ(eh->ether_shost, bt->etheraddr)) {
782 bdg_ipfw_colls++;
783 bt->name = NULL; /* NB: will overwrite below */
784 } else if (old != ifp) {
785 /*
786 * Found a loop. Either a machine has moved, or there
787 * is a misconfiguration/reconfiguration of the network.
788 * First, do not forward this packet!
789 * Record the relocation anyways; then, if loops persist,
790 * suspect a reconfiguration and disable forwarding
791 * from the old interface.
792 */
793 bt->name = ifp; /* relocate address */
794 printf("-- loop (%d) %6D to %s from %s (%s)\n",
795 bdg_loops, eh->ether_shost, ".",
796 ifp->if_xname, old->if_xname,
797 BDG_MUTED(old) ? "muted":"active");
798 dropit = 1;
799 if (!BDG_MUTED(old)) {
800 if (bdg_loops++ > 10)
801 BDG_MUTE(old);
802 }
803 }
804 }
805
806 /*
807 * now write the source address into the table
808 */
809 if (bt->name == NULL) {
810 DPRINTF(("%s: new addr %6D at %d for %s\n",
811 __func__, eh->ether_shost, ".", index, ifp->if_xname));
812 ETHER_ADDR_COPY(bt->etheraddr, eh->ether_shost);
813 bt->name = ifp;
814 }
815 dst = bridge_dst_lookup(eh, BDG_CLUSTER(ifp));
816 BDG_UNLOCK();
817
818 /*
819 * bridge_dst_lookup can return the following values:
820 * BDG_BCAST, BDG_MCAST, BDG_LOCAL, BDG_UNKNOWN, BDG_DROP, ifp.
821 * For muted interfaces, or when we detect a loop, the first 3 are
822 * changed in BDG_LOCAL (we still listen to incoming traffic),
823 * and others to BDG_DROP (no use for the local host).
824 * Also, for incoming packets, ifp is changed to BDG_DROP if ifp == src.
825 * These changes are not necessary for outgoing packets from ether_output().
826 */
827 BDG_STAT(ifp, BDG_IN);
828 switch ((uintptr_t)dst) {
829 case (uintptr_t)BDG_BCAST:
830 case (uintptr_t)BDG_MCAST:
831 case (uintptr_t)BDG_LOCAL:
832 case (uintptr_t)BDG_UNKNOWN:
833 case (uintptr_t)BDG_DROP:
834 BDG_STAT(ifp, dst);
835 break;
836 default:
837 if (dst == ifp || dropit)
838 BDG_STAT(ifp, BDG_DROP);
839 else
840 BDG_STAT(ifp, BDG_FORWARD);
841 break;
842 }
843
844 if (dropit) {
845 if (dst == BDG_BCAST || dst == BDG_MCAST || dst == BDG_LOCAL)
846 dst = BDG_LOCAL;
847 else
848 dst = BDG_DROP;
849 } else {
850 if (dst == ifp)
851 dst = BDG_DROP;
852 }
853 DPRINTF(("%s: %6D ->%6D ty 0x%04x dst %s\n", __func__,
854 eh->ether_shost, ".",
855 eh->ether_dhost, ".",
856 ntohs(eh->ether_type),
857 (dst <= BDG_FORWARD) ? bdg_dst_names[(uintptr_t)dst] :
858 dst->if_xname));
859
860 return dst;
861 }
862
863 /*
864 * Return 1 if it's ok to send a packet out the specified interface.
865 * The interface must be:
866 * used for bridging,
867 * not muted,
868 * not full,
869 * up and running,
870 * not the source interface, and
871 * belong to the same cluster as the 'real_dst'.
872 */
873 static __inline int
874 bridge_ifok(struct ifnet *ifp, struct ifnet *src, struct ifnet *dst)
875 {
876 return (BDG_USED(ifp)
877 && !BDG_MUTED(ifp)
878 && !_IF_QFULL(&ifp->if_snd)
879 && (ifp->if_flags & (IFF_UP|IFF_RUNNING)) == (IFF_UP|IFF_RUNNING)
880 && ifp != src
881 && BDG_SAMECLUSTER(ifp, dst));
882 }
883
884 /*
885 * Forward a packet to dst -- which can be a single interface or
886 * an entire cluster. The src port and muted interfaces are excluded.
887 *
888 * If src == NULL, the pkt comes from ether_output, and dst is the real
889 * interface the packet is originally sent to. In this case, we must forward
890 * it to the whole cluster.
891 * We never call bdg_forward from ether_output on interfaces which are
892 * not part of a cluster.
893 *
894 * If possible (i.e. we can determine that the caller does not need
895 * a copy), the packet is consumed here, and bdg_forward returns NULL.
896 * Otherwise, a pointer to a copy of the packet is returned.
897 */
898 static struct mbuf *
899 bdg_forward(struct mbuf *m0, struct ifnet *dst)
900 {
901 #define EH_RESTORE(_m) do { \
902 M_PREPEND((_m), ETHER_HDR_LEN, M_DONTWAIT); \
903 if ((_m) == NULL) { \
904 bdg_dropped++; \
905 return NULL; \
906 } \
907 if (eh != mtod((_m), struct ether_header *)) \
908 bcopy(&save_eh, mtod((_m), struct ether_header *), ETHER_HDR_LEN); \
909 else \
910 bdg_predict++; \
911 } while (0);
912 struct ether_header *eh;
913 struct ifnet *src;
914 struct ifnet *ifp, *last;
915 int shared = bdg_copy; /* someone else is using the mbuf */
916 struct ifnet *real_dst = dst; /* real dst from ether_output */
917 struct ip_fw_args args;
918 struct ether_header save_eh;
919 struct mbuf *m;
920
921 DDB(quad_t ticks; ticks = rdtsc();)
922
923 args.rule = NULL; /* did we match a firewall rule ? */
924 /* Fetch state from dummynet tag, ignore others */
925 for (;m0->m_type == MT_TAG; m0 = m0->m_next)
926 if (m0->_m_tag_id == PACKET_TAG_DUMMYNET) {
927 args.rule = ((struct dn_pkt *)m0)->rule;
928 shared = 0; /* For sure this is our own mbuf. */
929 }
930 if (args.rule == NULL)
931 bdg_thru++; /* count 1st time through bdg_forward */
932
933 /*
934 * The packet arrives with the Ethernet header at the front.
935 */
936 eh = mtod(m0, struct ether_header *);
937
938 src = m0->m_pkthdr.rcvif;
939 if (src == NULL) { /* packet from ether_output */
940 BDG_LOCK();
941 dst = bridge_dst_lookup(eh, BDG_CLUSTER(real_dst));
942 BDG_UNLOCK();
943 }
944
945 if (dst == BDG_DROP) { /* this should not happen */
946 printf("xx bdg_forward for BDG_DROP\n");
947 m_freem(m0);
948 bdg_dropped++;
949 return NULL;
950 }
951 if (dst == BDG_LOCAL) { /* this should not happen as well */
952 printf("xx ouch, bdg_forward for local pkt\n");
953 return m0;
954 }
955 if (dst == BDG_BCAST || dst == BDG_MCAST) {
956 /* need a copy for the local stack */
957 shared = 1;
958 }
959
960 /*
961 * Do filtering in a very similar way to what is done in ip_output.
962 * Only if firewall is loaded, enabled, and the packet is not
963 * from ether_output() (src==NULL, or we would filter it twice).
964 * Additional restrictions may apply e.g. non-IP, short packets,
965 * and pkts already gone through a pipe.
966 */
967 if (src != NULL && (
968 #ifdef PFIL_HOOKS
969 (inet_pfil_hook.ph_busy_count >= 0 && bdg_ipf != 0) ||
970 #endif
971 (IPFW_LOADED && bdg_ipfw != 0))) {
972
973 int i;
974
975 if (args.rule != NULL && fw_one_pass)
976 goto forward; /* packet already partially processed */
977 /*
978 * i need some amt of data to be contiguous, and in case others need
979 * the packet (shared==1) also better be in the first mbuf.
980 */
981 i = min(m0->m_pkthdr.len, max_protohdr) ;
982 if (shared || m0->m_len < i) {
983 m0 = m_pullup(m0, i);
984 if (m0 == NULL) {
985 printf("%s: m_pullup failed\n", __func__); /* XXXDPRINTF*/
986 bdg_dropped++;
987 return NULL;
988 }
989 eh = mtod(m0, struct ether_header *);
990 }
991
992 /*
993 * Processing below expects the Ethernet header is stripped.
994 * Furthermore, the mbuf chain might be replaced at various
995 * places. To deal with this we copy the header to a temporary
996 * location, strip the header, and restore it as needed.
997 */
998 bcopy(eh, &save_eh, ETHER_HDR_LEN); /* local copy for restore */
999 m_adj(m0, ETHER_HDR_LEN); /* temporarily strip header */
1000
1001 #ifdef PFIL_HOOKS
1002 /*
1003 * NetBSD-style generic packet filter, pfil(9), hooks.
1004 * Enables ipf(8) in bridging.
1005 */
1006 if (inet_pfil_hook.ph_busy_count >= 0 &&
1007 m0->m_pkthdr.len >= sizeof(struct ip) &&
1008 ntohs(save_eh.ether_type) == ETHERTYPE_IP) {
1009 /*
1010 * before calling the firewall, swap fields the same as IP does.
1011 * here we assume the pkt is an IP one and the header is contiguous
1012 */
1013 struct ip *ip = mtod(m0, struct ip *);
1014
1015 ip->ip_len = ntohs(ip->ip_len);
1016 ip->ip_off = ntohs(ip->ip_off);
1017
1018 if (pfil_run_hooks(&inet_pfil_hook, &m0, src, PFIL_IN) != 0) {
1019 /* NB: hook should consume packet */
1020 return NULL;
1021 }
1022 if (m0 == NULL) /* consumed by filter */
1023 return m0;
1024 /*
1025 * If we get here, the firewall has passed the pkt, but the mbuf
1026 * pointer might have changed. Restore ip and the fields ntohs()'d.
1027 */
1028 ip = mtod(m0, struct ip *);
1029 ip->ip_len = htons(ip->ip_len);
1030 ip->ip_off = htons(ip->ip_off);
1031 }
1032 #endif /* PFIL_HOOKS */
1033
1034 /*
1035 * Prepare arguments and call the firewall.
1036 */
1037 if (!IPFW_LOADED || bdg_ipfw == 0) {
1038 EH_RESTORE(m0); /* restore Ethernet header */
1039 goto forward; /* not using ipfw, accept the packet */
1040 }
1041
1042 /*
1043 * XXX The following code is very similar to the one in
1044 * if_ethersubr.c:ether_ipfw_chk()
1045 */
1046
1047 args.m = m0; /* the packet we are looking at */
1048 args.oif = NULL; /* this is an input packet */
1049 args.divert_rule = 0; /* we do not support divert yet */
1050 args.next_hop = NULL; /* we do not support forward yet */
1051 args.eh = &save_eh; /* MAC header for bridged/MAC packets */
1052 i = ip_fw_chk_ptr(&args);
1053 m0 = args.m; /* in case the firewall used the mbuf */
1054
1055 if (m0 != NULL)
1056 EH_RESTORE(m0); /* restore Ethernet header */
1057
1058 if ( (i & IP_FW_PORT_DENY_FLAG) || m0 == NULL) /* drop */
1059 return m0;
1060
1061 if (i == 0) /* a PASS rule. */
1062 goto forward;
1063 if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG)) {
1064 /*
1065 * Pass the pkt to dummynet, which consumes it.
1066 * If shared, make a copy and keep the original.
1067 */
1068 if (shared) {
1069 m = m_copypacket(m0, M_DONTWAIT);
1070 if (m == NULL) { /* copy failed, give up */
1071 bdg_dropped++;
1072 return NULL;
1073 }
1074 } else {
1075 m = m0 ; /* pass the original to dummynet */
1076 m0 = NULL ; /* and nothing back to the caller */
1077 }
1078
1079 args.oif = real_dst;
1080 ip_dn_io_ptr(m, (i & 0xffff),DN_TO_BDG_FWD, &args);
1081 return m0;
1082 }
1083 /*
1084 * XXX at some point, add support for divert/forward actions.
1085 * If none of the above matches, we have to drop the packet.
1086 */
1087 bdg_ipfw_drops++;
1088 return m0;
1089 }
1090 forward:
1091 /*
1092 * Again, bring up the headers in case of shared bufs to avoid
1093 * corruptions in the future.
1094 */
1095 if (shared) {
1096 int i = min(m0->m_pkthdr.len, max_protohdr);
1097
1098 m0 = m_pullup(m0, i);
1099 if (m0 == NULL) {
1100 bdg_dropped++;
1101 return NULL;
1102 }
1103 /* NB: eh is not used below; no need to recalculate it */
1104 }
1105
1106 /*
1107 * now real_dst is used to determine the cluster where to forward.
1108 * For packets coming from ether_input, this is the one of the 'src'
1109 * interface, whereas for locally generated packets (src==NULL) it
1110 * is the cluster of the original destination interface, which
1111 * was already saved into real_dst.
1112 */
1113 if (src != NULL)
1114 real_dst = src;
1115
1116 last = NULL;
1117 if (dst == BDG_BCAST || dst == BDG_MCAST || dst == BDG_UNKNOWN) {
1118 /*
1119 * Scan all ports and send copies to all but the last.
1120 */
1121 IFNET_RLOCK(); /* XXX replace with generation # */
1122 TAILQ_FOREACH(ifp, &ifnet, if_link) {
1123 if (bridge_ifok(ifp, src, real_dst)) {
1124 if (last) {
1125 /*
1126 * At this point we know two interfaces need a copy
1127 * of the packet (last + ifp) so we must create a
1128 * copy to handoff to last.
1129 */
1130 m = m_copypacket(m0, M_DONTWAIT);
1131 if (m == NULL) {
1132 IFNET_RUNLOCK();
1133 printf("%s: , m_copypacket failed!\n", __func__);
1134 bdg_dropped++;
1135 return m0; /* the original is still there... */
1136 }
1137 if (IF_HANDOFF(&last->if_snd, m, last))
1138 BDG_STAT(last, BDG_OUT);
1139 else
1140 bdg_dropped++;
1141 }
1142 last = ifp;
1143 }
1144 }
1145 IFNET_RUNLOCK();
1146 } else {
1147 if (bridge_ifok(dst, src, real_dst))
1148 last = dst;
1149 }
1150 if (last) {
1151 if (shared) { /* need to copy */
1152 m = m_copypacket(m0, M_DONTWAIT);
1153 if (m == NULL) {
1154 printf("%s: sorry, m_copypacket failed!\n", __func__);
1155 bdg_dropped++ ;
1156 return m0; /* the original is still there... */
1157 }
1158 } else { /* consume original */
1159 m = m0, m0 = NULL;
1160 }
1161 if (IF_HANDOFF(&last->if_snd, m, last))
1162 BDG_STAT(last, BDG_OUT);
1163 else
1164 bdg_dropped++;
1165 }
1166
1167 DDB(bdg_fw_ticks += (u_long)(rdtsc() - ticks) ; bdg_fw_count++ ;
1168 if (bdg_fw_count != 0) bdg_fw_avg = bdg_fw_ticks/bdg_fw_count; )
1169 return m0;
1170 #undef EH_RESTORE
1171 }
1172
1173 /*
1174 * initialization of bridge code.
1175 */
1176 static int
1177 bdginit(void)
1178 {
1179 if (bootverbose)
1180 printf("BRIDGE %s loaded\n", bridge_version);
1181
1182 ifp2sc = malloc(BDG_MAX_PORTS * sizeof(struct bdg_softc),
1183 M_IFADDR, M_WAITOK | M_ZERO );
1184 if (ifp2sc == NULL)
1185 return ENOMEM;
1186
1187 BDG_LOCK_INIT();
1188
1189 n_clusters = 0;
1190 clusters = NULL;
1191 do_bridge = 0;
1192
1193 bzero(&bdg_stats, sizeof(bdg_stats));
1194
1195 bridge_in_ptr = bridge_in;
1196 bdg_forward_ptr = bdg_forward;
1197 bdgtakeifaces_ptr = reconfigure_bridge;
1198
1199 bdgtakeifaces_ptr(); /* XXX does this do anything? */
1200
1201 callout_init(&bdg_callout, CALLOUT_MPSAFE);
1202 bdg_timeout(0);
1203 return 0 ;
1204 }
1205
1206 static void
1207 bdgdestroy(void)
1208 {
1209 bridge_in_ptr = NULL;
1210 bdg_forward_ptr = NULL;
1211 bdgtakeifaces_ptr = NULL;
1212
1213 callout_stop(&bdg_callout);
1214 BDG_LOCK();
1215 bridge_off();
1216
1217 if (ifp2sc) {
1218 free(ifp2sc, M_IFADDR);
1219 ifp2sc = NULL;
1220 }
1221 BDG_LOCK_DESTROY();
1222 }
1223
1224 /*
1225 * initialization code, both for static and dynamic loading.
1226 */
1227 static int
1228 bridge_modevent(module_t mod, int type, void *unused)
1229 {
1230 int err;
1231
1232 switch (type) {
1233 case MOD_LOAD:
1234 if (BDG_LOADED)
1235 err = EEXIST;
1236 else
1237 err = bdginit();
1238 break;
1239 case MOD_UNLOAD:
1240 do_bridge = 0;
1241 bdgdestroy();
1242 err = 0;
1243 break;
1244 default:
1245 err = EINVAL;
1246 break;
1247 }
1248 return err;
1249 }
1250
1251 static moduledata_t bridge_mod = {
1252 "bridge",
1253 bridge_modevent,
1254 0
1255 };
1256
1257 DECLARE_MODULE(bridge, bridge_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1258 MODULE_VERSION(bridge, 1);
Cache object: c1a8bcb0b59f02d13b16ff97bba47d8c
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