FreeBSD/Linux Kernel Cross Reference
sys/net/if_llatbl.c
1 /*
2 * Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
3 * Copyright (c) 2004-2008 Qing Li. All rights reserved.
4 * Copyright (c) 2008 Kip Macy. All rights reserved.
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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR 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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/10.1/sys/net/if_llatbl.c 250300 2013-05-06 16:42:18Z andre $");
29
30 #include "opt_ddb.h"
31 #include "opt_inet.h"
32 #include "opt_inet6.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/syslog.h>
39 #include <sys/sysctl.h>
40 #include <sys/socket.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/rwlock.h>
45
46 #ifdef DDB
47 #include <ddb/ddb.h>
48 #endif
49
50 #include <vm/uma.h>
51
52 #include <netinet/in.h>
53 #include <net/if_llatbl.h>
54 #include <net/if.h>
55 #include <net/if_dl.h>
56 #include <net/if_var.h>
57 #include <net/route.h>
58 #include <net/vnet.h>
59 #include <netinet/if_ether.h>
60 #include <netinet6/in6_var.h>
61 #include <netinet6/nd6.h>
62
63 MALLOC_DEFINE(M_LLTABLE, "lltable", "link level address tables");
64
65 static VNET_DEFINE(SLIST_HEAD(, lltable), lltables);
66 #define V_lltables VNET(lltables)
67
68 static void vnet_lltable_init(void);
69
70 struct rwlock lltable_rwlock;
71 RW_SYSINIT(lltable_rwlock, &lltable_rwlock, "lltable_rwlock");
72
73 /*
74 * Dump arp state for a specific address family.
75 */
76 int
77 lltable_sysctl_dumparp(int af, struct sysctl_req *wr)
78 {
79 struct lltable *llt;
80 int error = 0;
81
82 LLTABLE_RLOCK();
83 SLIST_FOREACH(llt, &V_lltables, llt_link) {
84 if (llt->llt_af == af) {
85 error = llt->llt_dump(llt, wr);
86 if (error != 0)
87 goto done;
88 }
89 }
90 done:
91 LLTABLE_RUNLOCK();
92 return (error);
93 }
94
95 /*
96 * Deletes an address from the address table.
97 * This function is called by the timer functions
98 * such as arptimer() and nd6_llinfo_timer(), and
99 * the caller does the locking.
100 *
101 * Returns the number of held packets, if any, that were dropped.
102 */
103 size_t
104 llentry_free(struct llentry *lle)
105 {
106 size_t pkts_dropped;
107 struct mbuf *next;
108
109 IF_AFDATA_WLOCK_ASSERT(lle->lle_tbl->llt_ifp);
110 LLE_WLOCK_ASSERT(lle);
111
112 LIST_REMOVE(lle, lle_next);
113 lle->la_flags &= ~(LLE_VALID | LLE_LINKED);
114
115 pkts_dropped = 0;
116 while ((lle->la_numheld > 0) && (lle->la_hold != NULL)) {
117 next = lle->la_hold->m_nextpkt;
118 m_freem(lle->la_hold);
119 lle->la_hold = next;
120 lle->la_numheld--;
121 pkts_dropped++;
122 }
123
124 KASSERT(lle->la_numheld == 0,
125 ("%s: la_numheld %d > 0, pkts_droped %zd", __func__,
126 lle->la_numheld, pkts_dropped));
127
128 LLE_FREE_LOCKED(lle);
129
130 return (pkts_dropped);
131 }
132
133 /*
134 * (al)locate an llentry for address dst (equivalent to rtalloc for new-arp).
135 *
136 * If found the llentry * is returned referenced and unlocked.
137 */
138 struct llentry *
139 llentry_alloc(struct ifnet *ifp, struct lltable *lt,
140 struct sockaddr_storage *dst)
141 {
142 struct llentry *la;
143
144 IF_AFDATA_RLOCK(ifp);
145 la = lla_lookup(lt, LLE_EXCLUSIVE, (struct sockaddr *)dst);
146 IF_AFDATA_RUNLOCK(ifp);
147 if ((la == NULL) &&
148 (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {
149 IF_AFDATA_WLOCK(ifp);
150 la = lla_lookup(lt, (LLE_CREATE | LLE_EXCLUSIVE),
151 (struct sockaddr *)dst);
152 IF_AFDATA_WUNLOCK(ifp);
153 }
154
155 if (la != NULL) {
156 LLE_ADDREF(la);
157 LLE_WUNLOCK(la);
158 }
159
160 return (la);
161 }
162
163 /*
164 * Free all entries from given table and free itself.
165 */
166 void
167 lltable_free(struct lltable *llt)
168 {
169 struct llentry *lle, *next;
170 int i;
171
172 KASSERT(llt != NULL, ("%s: llt is NULL", __func__));
173
174 LLTABLE_WLOCK();
175 SLIST_REMOVE(&V_lltables, llt, lltable, llt_link);
176 LLTABLE_WUNLOCK();
177
178 IF_AFDATA_WLOCK(llt->llt_ifp);
179 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
180 LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
181 LLE_WLOCK(lle);
182 if (callout_stop(&lle->la_timer))
183 LLE_REMREF(lle);
184 llentry_free(lle);
185 }
186 }
187 IF_AFDATA_WUNLOCK(llt->llt_ifp);
188
189 free(llt, M_LLTABLE);
190 }
191
192 #if 0
193 void
194 lltable_drain(int af)
195 {
196 struct lltable *llt;
197 struct llentry *lle;
198 register int i;
199
200 LLTABLE_RLOCK();
201 SLIST_FOREACH(llt, &V_lltables, llt_link) {
202 if (llt->llt_af != af)
203 continue;
204
205 for (i=0; i < LLTBL_HASHTBL_SIZE; i++) {
206 LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
207 LLE_WLOCK(lle);
208 if (lle->la_hold) {
209 m_freem(lle->la_hold);
210 lle->la_hold = NULL;
211 }
212 LLE_WUNLOCK(lle);
213 }
214 }
215 }
216 LLTABLE_RUNLOCK();
217 }
218 #endif
219
220 void
221 lltable_prefix_free(int af, struct sockaddr *prefix, struct sockaddr *mask,
222 u_int flags)
223 {
224 struct lltable *llt;
225
226 LLTABLE_RLOCK();
227 SLIST_FOREACH(llt, &V_lltables, llt_link) {
228 if (llt->llt_af != af)
229 continue;
230
231 llt->llt_prefix_free(llt, prefix, mask, flags);
232 }
233 LLTABLE_RUNLOCK();
234 }
235
236
237
238 /*
239 * Create a new lltable.
240 */
241 struct lltable *
242 lltable_init(struct ifnet *ifp, int af)
243 {
244 struct lltable *llt;
245 register int i;
246
247 llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK);
248
249 llt->llt_af = af;
250 llt->llt_ifp = ifp;
251 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++)
252 LIST_INIT(&llt->lle_head[i]);
253
254 LLTABLE_WLOCK();
255 SLIST_INSERT_HEAD(&V_lltables, llt, llt_link);
256 LLTABLE_WUNLOCK();
257
258 return (llt);
259 }
260
261 /*
262 * Called in route_output when adding/deleting a route to an interface.
263 */
264 int
265 lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info)
266 {
267 struct sockaddr_dl *dl =
268 (struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY];
269 struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST];
270 struct ifnet *ifp;
271 struct lltable *llt;
272 struct llentry *lle;
273 u_int laflags = 0, flags = 0;
274 int error = 0;
275
276 KASSERT(dl != NULL && dl->sdl_family == AF_LINK,
277 ("%s: invalid dl\n", __func__));
278
279 ifp = ifnet_byindex(dl->sdl_index);
280 if (ifp == NULL) {
281 log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n",
282 __func__, dl->sdl_index);
283 return EINVAL;
284 }
285
286 switch (rtm->rtm_type) {
287 case RTM_ADD:
288 if (rtm->rtm_flags & RTF_ANNOUNCE)
289 flags |= LLE_PUB;
290 flags |= LLE_CREATE;
291 break;
292
293 case RTM_DELETE:
294 flags |= LLE_DELETE;
295 break;
296
297 case RTM_CHANGE:
298 break;
299
300 default:
301 return EINVAL; /* XXX not implemented yet */
302 }
303
304 /* XXX linked list may be too expensive */
305 LLTABLE_RLOCK();
306 SLIST_FOREACH(llt, &V_lltables, llt_link) {
307 if (llt->llt_af == dst->sa_family &&
308 llt->llt_ifp == ifp)
309 break;
310 }
311 LLTABLE_RUNLOCK();
312 KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n"));
313
314 if (flags & LLE_CREATE)
315 flags |= LLE_EXCLUSIVE;
316
317 IF_AFDATA_LOCK(ifp);
318 lle = lla_lookup(llt, flags, dst);
319 IF_AFDATA_UNLOCK(ifp);
320 if (LLE_IS_VALID(lle)) {
321 if (flags & LLE_CREATE) {
322 /*
323 * If we delay the delete, then a subsequent
324 * "arp add" should look up this entry, reset the
325 * LLE_DELETED flag, and reset the expiration timer
326 */
327 bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen);
328 lle->la_flags |= (flags & LLE_PUB);
329 lle->la_flags |= LLE_VALID;
330 lle->la_flags &= ~LLE_DELETED;
331 #ifdef INET6
332 /*
333 * ND6
334 */
335 if (dst->sa_family == AF_INET6)
336 lle->ln_state = ND6_LLINFO_REACHABLE;
337 #endif
338 /*
339 * NB: arp and ndp always set (RTF_STATIC | RTF_HOST)
340 */
341
342 if (rtm->rtm_rmx.rmx_expire == 0) {
343 lle->la_flags |= LLE_STATIC;
344 lle->la_expire = 0;
345 } else
346 lle->la_expire = rtm->rtm_rmx.rmx_expire;
347 laflags = lle->la_flags;
348 LLE_WUNLOCK(lle);
349 #ifdef INET
350 /* gratuitous ARP */
351 if ((laflags & LLE_PUB) && dst->sa_family == AF_INET)
352 arprequest(ifp,
353 &((struct sockaddr_in *)dst)->sin_addr,
354 &((struct sockaddr_in *)dst)->sin_addr,
355 (u_char *)LLADDR(dl));
356 #endif
357 } else {
358 if (flags & LLE_EXCLUSIVE)
359 LLE_WUNLOCK(lle);
360 else
361 LLE_RUNLOCK(lle);
362 }
363 } else if ((lle == NULL) && (flags & LLE_DELETE))
364 error = EINVAL;
365
366
367 return (error);
368 }
369
370 static void
371 vnet_lltable_init()
372 {
373
374 SLIST_INIT(&V_lltables);
375 }
376 VNET_SYSINIT(vnet_lltable_init, SI_SUB_PSEUDO, SI_ORDER_FIRST,
377 vnet_lltable_init, NULL);
378
379 #ifdef DDB
380 struct llentry_sa {
381 struct llentry base;
382 struct sockaddr l3_addr;
383 };
384
385 static void
386 llatbl_lle_show(struct llentry_sa *la)
387 {
388 struct llentry *lle;
389 uint8_t octet[6];
390
391 lle = &la->base;
392 db_printf("lle=%p\n", lle);
393 db_printf(" lle_next=%p\n", lle->lle_next.le_next);
394 db_printf(" lle_lock=%p\n", &lle->lle_lock);
395 db_printf(" lle_tbl=%p\n", lle->lle_tbl);
396 db_printf(" lle_head=%p\n", lle->lle_head);
397 db_printf(" la_hold=%p\n", lle->la_hold);
398 db_printf(" la_numheld=%d\n", lle->la_numheld);
399 db_printf(" la_expire=%ju\n", (uintmax_t)lle->la_expire);
400 db_printf(" la_flags=0x%04x\n", lle->la_flags);
401 db_printf(" la_asked=%u\n", lle->la_asked);
402 db_printf(" la_preempt=%u\n", lle->la_preempt);
403 db_printf(" ln_byhint=%u\n", lle->ln_byhint);
404 db_printf(" ln_state=%d\n", lle->ln_state);
405 db_printf(" ln_router=%u\n", lle->ln_router);
406 db_printf(" ln_ntick=%ju\n", (uintmax_t)lle->ln_ntick);
407 db_printf(" lle_refcnt=%d\n", lle->lle_refcnt);
408 bcopy(&lle->ll_addr.mac16, octet, sizeof(octet));
409 db_printf(" ll_addr=%02x:%02x:%02x:%02x:%02x:%02x\n",
410 octet[0], octet[1], octet[2], octet[3], octet[4], octet[5]);
411 db_printf(" la_timer=%p\n", &lle->la_timer);
412
413 switch (la->l3_addr.sa_family) {
414 #ifdef INET
415 case AF_INET:
416 {
417 struct sockaddr_in *sin;
418 char l3s[INET_ADDRSTRLEN];
419
420 sin = (struct sockaddr_in *)&la->l3_addr;
421 inet_ntoa_r(sin->sin_addr, l3s);
422 db_printf(" l3_addr=%s\n", l3s);
423 break;
424 }
425 #endif
426 #ifdef INET6
427 case AF_INET6:
428 {
429 struct sockaddr_in6 *sin6;
430 char l3s[INET6_ADDRSTRLEN];
431
432 sin6 = (struct sockaddr_in6 *)&la->l3_addr;
433 ip6_sprintf(l3s, &sin6->sin6_addr);
434 db_printf(" l3_addr=%s\n", l3s);
435 break;
436 }
437 #endif
438 default:
439 db_printf(" l3_addr=N/A (af=%d)\n", la->l3_addr.sa_family);
440 break;
441 }
442 }
443
444 DB_SHOW_COMMAND(llentry, db_show_llentry)
445 {
446
447 if (!have_addr) {
448 db_printf("usage: show llentry <struct llentry *>\n");
449 return;
450 }
451
452 llatbl_lle_show((struct llentry_sa *)addr);
453 }
454
455 static void
456 llatbl_llt_show(struct lltable *llt)
457 {
458 int i;
459 struct llentry *lle;
460
461 db_printf("llt=%p llt_af=%d llt_ifp=%p\n",
462 llt, llt->llt_af, llt->llt_ifp);
463
464 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
465 LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
466
467 llatbl_lle_show((struct llentry_sa *)lle);
468 if (db_pager_quit)
469 return;
470 }
471 }
472 }
473
474 DB_SHOW_COMMAND(lltable, db_show_lltable)
475 {
476
477 if (!have_addr) {
478 db_printf("usage: show lltable <struct lltable *>\n");
479 return;
480 }
481
482 llatbl_llt_show((struct lltable *)addr);
483 }
484
485 DB_SHOW_ALL_COMMAND(lltables, db_show_all_lltables)
486 {
487 VNET_ITERATOR_DECL(vnet_iter);
488 struct lltable *llt;
489
490 VNET_FOREACH(vnet_iter) {
491 CURVNET_SET_QUIET(vnet_iter);
492 #ifdef VIMAGE
493 db_printf("vnet=%p\n", curvnet);
494 #endif
495 SLIST_FOREACH(llt, &V_lltables, llt_link) {
496 db_printf("llt=%p llt_af=%d llt_ifp=%p(%s)\n",
497 llt, llt->llt_af, llt->llt_ifp,
498 (llt->llt_ifp != NULL) ?
499 llt->llt_ifp->if_xname : "?");
500 if (have_addr && addr != 0) /* verbose */
501 llatbl_llt_show(llt);
502 if (db_pager_quit) {
503 CURVNET_RESTORE();
504 return;
505 }
506 }
507 CURVNET_RESTORE();
508 }
509 }
510 #endif
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