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/10.3/sys/net/if_llatbl.c 294500 2016-01-21 14:04:02Z bz $");
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 SLIST_HEAD_INITIALIZER(lltables);
67 #define V_lltables VNET(lltables)
68
69 struct rwlock lltable_rwlock;
70 RW_SYSINIT(lltable_rwlock, &lltable_rwlock, "lltable_rwlock");
71
72 /*
73 * Dump arp state for a specific address family.
74 */
75 int
76 lltable_sysctl_dumparp(int af, struct sysctl_req *wr)
77 {
78 struct lltable *llt;
79 int error = 0;
80
81 LLTABLE_RLOCK();
82 SLIST_FOREACH(llt, &V_lltables, llt_link) {
83 if (llt->llt_af == af) {
84 error = llt->llt_dump(llt, wr);
85 if (error != 0)
86 goto done;
87 }
88 }
89 done:
90 LLTABLE_RUNLOCK();
91 return (error);
92 }
93
94 /*
95 * Deletes an address from the address table.
96 * This function is called by the timer functions
97 * such as arptimer() and nd6_llinfo_timer(), and
98 * the caller does the locking.
99 *
100 * Returns the number of held packets, if any, that were dropped.
101 */
102 size_t
103 llentry_free(struct llentry *lle)
104 {
105 size_t pkts_dropped;
106 struct mbuf *next;
107
108 IF_AFDATA_WLOCK_ASSERT(lle->lle_tbl->llt_ifp);
109 LLE_WLOCK_ASSERT(lle);
110
111 LIST_REMOVE(lle, lle_next);
112 lle->la_flags &= ~(LLE_VALID | LLE_LINKED);
113
114 pkts_dropped = 0;
115 while ((lle->la_numheld > 0) && (lle->la_hold != NULL)) {
116 next = lle->la_hold->m_nextpkt;
117 m_freem(lle->la_hold);
118 lle->la_hold = next;
119 lle->la_numheld--;
120 pkts_dropped++;
121 }
122
123 KASSERT(lle->la_numheld == 0,
124 ("%s: la_numheld %d > 0, pkts_droped %zd", __func__,
125 lle->la_numheld, pkts_dropped));
126
127 LLE_FREE_LOCKED(lle);
128
129 return (pkts_dropped);
130 }
131
132 /*
133 * (al)locate an llentry for address dst (equivalent to rtalloc for new-arp).
134 *
135 * If found the llentry * is returned referenced and unlocked.
136 */
137 struct llentry *
138 llentry_alloc(struct ifnet *ifp, struct lltable *lt,
139 struct sockaddr_storage *dst)
140 {
141 struct llentry *la;
142
143 IF_AFDATA_RLOCK(ifp);
144 la = lla_lookup(lt, LLE_EXCLUSIVE, (struct sockaddr *)dst);
145 IF_AFDATA_RUNLOCK(ifp);
146 if ((la == NULL) &&
147 (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {
148 IF_AFDATA_WLOCK(ifp);
149 la = lla_lookup(lt, (LLE_CREATE | LLE_EXCLUSIVE),
150 (struct sockaddr *)dst);
151 IF_AFDATA_WUNLOCK(ifp);
152 }
153
154 if (la != NULL) {
155 LLE_ADDREF(la);
156 LLE_WUNLOCK(la);
157 }
158
159 return (la);
160 }
161
162 /*
163 * Free all entries from given table and free itself.
164 */
165 void
166 lltable_free(struct lltable *llt)
167 {
168 struct llentry *lle, *next;
169 int i;
170
171 KASSERT(llt != NULL, ("%s: llt is NULL", __func__));
172
173 LLTABLE_WLOCK();
174 SLIST_REMOVE(&V_lltables, llt, lltable, llt_link);
175 LLTABLE_WUNLOCK();
176
177 IF_AFDATA_WLOCK(llt->llt_ifp);
178 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
179 LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
180 LLE_WLOCK(lle);
181 if (callout_stop(&lle->la_timer))
182 LLE_REMREF(lle);
183 llentry_free(lle);
184 }
185 }
186 IF_AFDATA_WUNLOCK(llt->llt_ifp);
187
188 free(llt, M_LLTABLE);
189 }
190
191 #if 0
192 void
193 lltable_drain(int af)
194 {
195 struct lltable *llt;
196 struct llentry *lle;
197 register int i;
198
199 LLTABLE_RLOCK();
200 SLIST_FOREACH(llt, &V_lltables, llt_link) {
201 if (llt->llt_af != af)
202 continue;
203
204 for (i=0; i < LLTBL_HASHTBL_SIZE; i++) {
205 LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
206 LLE_WLOCK(lle);
207 if (lle->la_hold) {
208 m_freem(lle->la_hold);
209 lle->la_hold = NULL;
210 }
211 LLE_WUNLOCK(lle);
212 }
213 }
214 }
215 LLTABLE_RUNLOCK();
216 }
217 #endif
218
219 void
220 lltable_prefix_free(int af, struct sockaddr *prefix, struct sockaddr *mask,
221 u_int flags)
222 {
223 struct lltable *llt;
224
225 LLTABLE_RLOCK();
226 SLIST_FOREACH(llt, &V_lltables, llt_link) {
227 if (llt->llt_af != af)
228 continue;
229
230 llt->llt_prefix_free(llt, prefix, mask, flags);
231 }
232 LLTABLE_RUNLOCK();
233 }
234
235
236
237 /*
238 * Create a new lltable.
239 */
240 struct lltable *
241 lltable_init(struct ifnet *ifp, int af)
242 {
243 struct lltable *llt;
244 register int i;
245
246 llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK);
247
248 llt->llt_af = af;
249 llt->llt_ifp = ifp;
250 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++)
251 LIST_INIT(&llt->lle_head[i]);
252
253 LLTABLE_WLOCK();
254 SLIST_INSERT_HEAD(&V_lltables, llt, llt_link);
255 LLTABLE_WUNLOCK();
256
257 return (llt);
258 }
259
260 /*
261 * Called in route_output when adding/deleting a route to an interface.
262 */
263 int
264 lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info)
265 {
266 struct sockaddr_dl *dl =
267 (struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY];
268 struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST];
269 struct ifnet *ifp;
270 struct lltable *llt;
271 struct llentry *lle;
272 u_int laflags = 0, flags = 0;
273 int error = 0;
274
275 KASSERT(dl != NULL && dl->sdl_family == AF_LINK,
276 ("%s: invalid dl\n", __func__));
277
278 ifp = ifnet_byindex(dl->sdl_index);
279 if (ifp == NULL) {
280 log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n",
281 __func__, dl->sdl_index);
282 return EINVAL;
283 }
284
285 switch (rtm->rtm_type) {
286 case RTM_ADD:
287 if (rtm->rtm_flags & RTF_ANNOUNCE)
288 flags |= LLE_PUB;
289 flags |= LLE_CREATE;
290 break;
291
292 case RTM_DELETE:
293 flags |= LLE_DELETE;
294 break;
295
296 case RTM_CHANGE:
297 break;
298
299 default:
300 return EINVAL; /* XXX not implemented yet */
301 }
302
303 /* XXX linked list may be too expensive */
304 LLTABLE_RLOCK();
305 SLIST_FOREACH(llt, &V_lltables, llt_link) {
306 if (llt->llt_af == dst->sa_family &&
307 llt->llt_ifp == ifp)
308 break;
309 }
310 LLTABLE_RUNLOCK();
311 KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n"));
312
313 if (flags & LLE_CREATE)
314 flags |= LLE_EXCLUSIVE;
315
316 IF_AFDATA_LOCK(ifp);
317 lle = lla_lookup(llt, flags, dst);
318 IF_AFDATA_UNLOCK(ifp);
319 if (LLE_IS_VALID(lle)) {
320 if (flags & LLE_CREATE) {
321 /*
322 * If we delay the delete, then a subsequent
323 * "arp add" should look up this entry, reset the
324 * LLE_DELETED flag, and reset the expiration timer
325 */
326 bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen);
327 lle->la_flags |= (flags & LLE_PUB);
328 lle->la_flags |= LLE_VALID;
329 lle->la_flags &= ~LLE_DELETED;
330 #ifdef INET6
331 /*
332 * ND6
333 */
334 if (dst->sa_family == AF_INET6)
335 lle->ln_state = ND6_LLINFO_REACHABLE;
336 #endif
337 /*
338 * NB: arp and ndp always set (RTF_STATIC | RTF_HOST)
339 */
340
341 if (rtm->rtm_rmx.rmx_expire == 0) {
342 lle->la_flags |= LLE_STATIC;
343 lle->la_expire = 0;
344 } else
345 lle->la_expire = rtm->rtm_rmx.rmx_expire;
346 laflags = lle->la_flags;
347 LLE_WUNLOCK(lle);
348 #ifdef INET
349 /* gratuitous ARP */
350 if ((laflags & LLE_PUB) && dst->sa_family == AF_INET)
351 arprequest(ifp,
352 &((struct sockaddr_in *)dst)->sin_addr,
353 &((struct sockaddr_in *)dst)->sin_addr,
354 (u_char *)LLADDR(dl));
355 #endif
356 } else {
357 if (flags & LLE_EXCLUSIVE)
358 LLE_WUNLOCK(lle);
359 else
360 LLE_RUNLOCK(lle);
361 }
362 } else if ((lle == NULL) && (flags & LLE_DELETE))
363 error = EINVAL;
364
365
366 return (error);
367 }
368
369 #ifdef DDB
370 struct llentry_sa {
371 struct llentry base;
372 struct sockaddr l3_addr;
373 };
374
375 static void
376 llatbl_lle_show(struct llentry_sa *la)
377 {
378 struct llentry *lle;
379 uint8_t octet[6];
380
381 lle = &la->base;
382 db_printf("lle=%p\n", lle);
383 db_printf(" lle_next=%p\n", lle->lle_next.le_next);
384 db_printf(" lle_lock=%p\n", &lle->lle_lock);
385 db_printf(" lle_tbl=%p\n", lle->lle_tbl);
386 db_printf(" lle_head=%p\n", lle->lle_head);
387 db_printf(" la_hold=%p\n", lle->la_hold);
388 db_printf(" la_numheld=%d\n", lle->la_numheld);
389 db_printf(" la_expire=%ju\n", (uintmax_t)lle->la_expire);
390 db_printf(" la_flags=0x%04x\n", lle->la_flags);
391 db_printf(" la_asked=%u\n", lle->la_asked);
392 db_printf(" la_preempt=%u\n", lle->la_preempt);
393 db_printf(" ln_byhint=%u\n", lle->ln_byhint);
394 db_printf(" ln_state=%d\n", lle->ln_state);
395 db_printf(" ln_router=%u\n", lle->ln_router);
396 db_printf(" ln_ntick=%ju\n", (uintmax_t)lle->ln_ntick);
397 db_printf(" lle_refcnt=%d\n", lle->lle_refcnt);
398 bcopy(&lle->ll_addr.mac16, octet, sizeof(octet));
399 db_printf(" ll_addr=%02x:%02x:%02x:%02x:%02x:%02x\n",
400 octet[0], octet[1], octet[2], octet[3], octet[4], octet[5]);
401 db_printf(" la_timer=%p\n", &lle->la_timer);
402
403 switch (la->l3_addr.sa_family) {
404 #ifdef INET
405 case AF_INET:
406 {
407 struct sockaddr_in *sin;
408 char l3s[INET_ADDRSTRLEN];
409
410 sin = (struct sockaddr_in *)&la->l3_addr;
411 inet_ntoa_r(sin->sin_addr, l3s);
412 db_printf(" l3_addr=%s\n", l3s);
413 break;
414 }
415 #endif
416 #ifdef INET6
417 case AF_INET6:
418 {
419 struct sockaddr_in6 *sin6;
420 char l3s[INET6_ADDRSTRLEN];
421
422 sin6 = (struct sockaddr_in6 *)&la->l3_addr;
423 ip6_sprintf(l3s, &sin6->sin6_addr);
424 db_printf(" l3_addr=%s\n", l3s);
425 break;
426 }
427 #endif
428 default:
429 db_printf(" l3_addr=N/A (af=%d)\n", la->l3_addr.sa_family);
430 break;
431 }
432 }
433
434 DB_SHOW_COMMAND(llentry, db_show_llentry)
435 {
436
437 if (!have_addr) {
438 db_printf("usage: show llentry <struct llentry *>\n");
439 return;
440 }
441
442 llatbl_lle_show((struct llentry_sa *)addr);
443 }
444
445 static void
446 llatbl_llt_show(struct lltable *llt)
447 {
448 int i;
449 struct llentry *lle;
450
451 db_printf("llt=%p llt_af=%d llt_ifp=%p\n",
452 llt, llt->llt_af, llt->llt_ifp);
453
454 for (i = 0; i < LLTBL_HASHTBL_SIZE; i++) {
455 LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
456
457 llatbl_lle_show((struct llentry_sa *)lle);
458 if (db_pager_quit)
459 return;
460 }
461 }
462 }
463
464 DB_SHOW_COMMAND(lltable, db_show_lltable)
465 {
466
467 if (!have_addr) {
468 db_printf("usage: show lltable <struct lltable *>\n");
469 return;
470 }
471
472 llatbl_llt_show((struct lltable *)addr);
473 }
474
475 DB_SHOW_ALL_COMMAND(lltables, db_show_all_lltables)
476 {
477 VNET_ITERATOR_DECL(vnet_iter);
478 struct lltable *llt;
479
480 VNET_FOREACH(vnet_iter) {
481 CURVNET_SET_QUIET(vnet_iter);
482 #ifdef VIMAGE
483 db_printf("vnet=%p\n", curvnet);
484 #endif
485 SLIST_FOREACH(llt, &V_lltables, llt_link) {
486 db_printf("llt=%p llt_af=%d llt_ifp=%p(%s)\n",
487 llt, llt->llt_af, llt->llt_ifp,
488 (llt->llt_ifp != NULL) ?
489 llt->llt_ifp->if_xname : "?");
490 if (have_addr && addr != 0) /* verbose */
491 llatbl_llt_show(llt);
492 if (db_pager_quit) {
493 CURVNET_RESTORE();
494 return;
495 }
496 }
497 CURVNET_RESTORE();
498 }
499 }
500 #endif
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