aarp.c revision 1.22 1 /* $NetBSD: aarp.c,v 1.22 2007/02/17 22:34:10 dyoung Exp $ */
2
3 /*
4 * Copyright (c) 1990,1991 Regents of The University of Michigan.
5 * All Rights Reserved.
6 *
7 * Permission to use, copy, modify, and distribute this software and
8 * its documentation for any purpose and without fee is hereby granted,
9 * provided that the above copyright notice appears in all copies and
10 * that both that copyright notice and this permission notice appear
11 * in supporting documentation, and that the name of The University
12 * of Michigan not be used in advertising or publicity pertaining to
13 * distribution of the software without specific, written prior
14 * permission. This software is supplied as is without expressed or
15 * implied warranties of any kind.
16 *
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 *
20 * Research Systems Unix Group
21 * The University of Michigan
22 * c/o Wesley Craig
23 * 535 W. William Street
24 * Ann Arbor, Michigan
25 * +1-313-764-2278
26 * netatalk (at) umich.edu
27 */
28
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: aarp.c,v 1.22 2007/02/17 22:34:10 dyoung Exp $");
31
32 #include "opt_mbuftrace.h"
33
34 #include <sys/param.h>
35 #include <sys/socket.h>
36 #include <sys/syslog.h>
37 #include <sys/systm.h>
38 #include <sys/callout.h>
39 #include <sys/proc.h>
40 #include <sys/mbuf.h>
41 #include <sys/time.h>
42 #include <sys/kernel.h>
43 #include <net/if.h>
44 #include <net/route.h>
45 #include <net/if_ether.h>
46 #include <net/if_dl.h>
47 #include <netinet/in.h>
48 #undef s_net
49
50 #include <netatalk/at.h>
51 #include <netatalk/at_var.h>
52 #include <netatalk/aarp.h>
53 #include <netatalk/ddp_var.h>
54 #include <netatalk/phase2.h>
55 #include <netatalk/at_extern.h>
56
57 static struct aarptab *aarptnew(const struct at_addr *);
58 static void aarptfree(struct aarptab *);
59 static void at_aarpinput(struct ifnet *, struct mbuf *);
60 static void aarptimer(void *);
61 static void aarpwhohas(struct ifnet *, const struct sockaddr_at *);
62
63 #define AARPTAB_BSIZ 9
64 #define AARPTAB_NB 19
65 #define AARPTAB_SIZE (AARPTAB_BSIZ * AARPTAB_NB)
66 struct aarptab aarptab[AARPTAB_SIZE];
67
68 #define AARPTAB_HASH(a) \
69 ((((a).s_net << 8 ) + (a).s_node ) % AARPTAB_NB )
70
71 #define AARPTAB_LOOK(aat,addr) { \
72 int n; \
73 aat = &aarptab[ AARPTAB_HASH(addr) * AARPTAB_BSIZ ]; \
74 for ( n = 0; n < AARPTAB_BSIZ; n++, aat++ ) \
75 if ( aat->aat_ataddr.s_net == (addr).s_net && \
76 aat->aat_ataddr.s_node == (addr).s_node ) \
77 break; \
78 if ( n >= AARPTAB_BSIZ ) \
79 aat = 0; \
80 }
81
82 #define AARPT_AGE (60 * 1)
83 #define AARPT_KILLC 20
84 #define AARPT_KILLI 3
85
86 const u_char atmulticastaddr[6] = {
87 0x09, 0x00, 0x07, 0xff, 0xff, 0xff
88 };
89
90 const u_char at_org_code[3] = {
91 0x08, 0x00, 0x07
92 };
93 const u_char aarp_org_code[3] = {
94 0x00, 0x00, 0x00
95 };
96
97 struct callout aarptimer_callout;
98 #ifdef MBUFTRACE
99 struct mowner aarp_mowner = MOWNER_INIT("atalk", "arp");
100 #endif
101
102 /*ARGSUSED*/
103 static void
104 aarptimer(void *ignored)
105 {
106 struct aarptab *aat;
107 int i, s;
108
109 callout_reset(&aarptimer_callout, AARPT_AGE * hz, aarptimer, NULL);
110 aat = aarptab;
111 for (i = 0; i < AARPTAB_SIZE; i++, aat++) {
112 int killtime = (aat->aat_flags & ATF_COM) ? AARPT_KILLC :
113 AARPT_KILLI;
114 if (aat->aat_flags == 0 || (aat->aat_flags & ATF_PERM))
115 continue;
116 if (++aat->aat_timer < killtime)
117 continue;
118 s = splnet();
119 aarptfree(aat);
120 splx(s);
121 }
122 }
123
124 /*
125 * search through the network addresses to find one that includes the given
126 * network.. remember to take netranges into consideration.
127 */
128 struct ifaddr *
129 at_ifawithnet(sat, ifp)
130 const struct sockaddr_at *sat;
131 struct ifnet *ifp;
132 {
133 struct ifaddr *ifa;
134 struct sockaddr_at *sat2;
135 struct netrange *nr;
136
137 for (ifa = ifp->if_addrlist.tqh_first; ifa;
138 ifa = ifa->ifa_list.tqe_next) {
139 if (ifa->ifa_addr->sa_family != AF_APPLETALK)
140 continue;
141
142 sat2 = satosat(ifa->ifa_addr);
143 if (sat2->sat_addr.s_net == sat->sat_addr.s_net)
144 break;
145
146 nr = (struct netrange *) (sat2->sat_zero);
147 if ((nr->nr_phase == 2)
148 && (ntohs(nr->nr_firstnet) <= ntohs(sat->sat_addr.s_net))
149 && (ntohs(nr->nr_lastnet) >= ntohs(sat->sat_addr.s_net)))
150 break;
151 }
152 return ifa;
153 }
154
155 static void
156 aarpwhohas(ifp, sat)
157 struct ifnet *ifp;
158 const struct sockaddr_at *sat;
159 {
160 struct mbuf *m;
161 struct ether_header *eh;
162 struct ether_aarp *ea;
163 struct at_ifaddr *aa;
164 struct llc *llc;
165 struct sockaddr sa;
166
167 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
168 return;
169
170 MCLAIM(m, &aarp_mowner);
171 m->m_len = sizeof(*ea);
172 m->m_pkthdr.len = sizeof(*ea);
173 MH_ALIGN(m, sizeof(*ea));
174
175 ea = mtod(m, struct ether_aarp *);
176 bzero(ea, sizeof(*ea));
177
178 ea->aarp_hrd = htons(AARPHRD_ETHER);
179 ea->aarp_pro = htons(ETHERTYPE_ATALK);
180 ea->aarp_hln = sizeof(ea->aarp_sha);
181 ea->aarp_pln = sizeof(ea->aarp_spu);
182 ea->aarp_op = htons(AARPOP_REQUEST);
183 bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
184
185 /*
186 * We need to check whether the output ethernet type should
187 * be phase 1 or 2. We have the interface that we'll be sending
188 * the aarp out. We need to find an AppleTalk network on that
189 * interface with the same address as we're looking for. If the
190 * net is phase 2, generate an 802.2 and SNAP header.
191 */
192 if ((aa = (struct at_ifaddr *) at_ifawithnet(sat, ifp)) == NULL) {
193 m_freem(m);
194 return;
195 }
196 eh = (struct ether_header *) sa.sa_data;
197
198 if (aa->aa_flags & AFA_PHASE2) {
199 bcopy(atmulticastaddr, eh->ether_dhost,
200 sizeof(eh->ether_dhost));
201 eh->ether_type = 0; /* if_output will treat as 802 */
202 M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
203 if (!m)
204 return;
205
206 llc = mtod(m, struct llc *);
207 llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
208 llc->llc_control = LLC_UI;
209 bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
210 llc->llc_ether_type = htons(ETHERTYPE_AARP);
211
212 bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
213 sizeof(ea->aarp_spnet));
214 bcopy(&sat->sat_addr.s_net, ea->aarp_tpnet,
215 sizeof(ea->aarp_tpnet));
216 ea->aarp_spnode = AA_SAT(aa)->sat_addr.s_node;
217 ea->aarp_tpnode = sat->sat_addr.s_node;
218 } else {
219 bcopy(etherbroadcastaddr, eh->ether_dhost,
220 sizeof(eh->ether_dhost));
221 eh->ether_type = htons(ETHERTYPE_AARP);
222
223 ea->aarp_spa = AA_SAT(aa)->sat_addr.s_node;
224 ea->aarp_tpa = sat->sat_addr.s_node;
225 }
226
227 #ifdef NETATALKDEBUG
228 printf("aarp: sending request via %u.%u seaking %u.%u\n",
229 ntohs(AA_SAT(aa)->sat_addr.s_net), AA_SAT(aa)->sat_addr.s_node,
230 ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
231 #endif /* NETATALKDEBUG */
232
233 sa.sa_len = sizeof(struct sockaddr);
234 sa.sa_family = AF_UNSPEC;
235 (*ifp->if_output) (ifp, m, &sa, NULL); /* XXX NULL should be routing */
236 /* information */
237 }
238
239 int
240 aarpresolve(struct ifnet *ifp, struct mbuf *m,
241 const struct sockaddr_at *destsat, u_char *desten)
242 {
243 struct at_ifaddr *aa;
244 struct aarptab *aat;
245 int s;
246
247 if (at_broadcast(destsat)) {
248 aa = (struct at_ifaddr *) at_ifawithnet(destsat, ifp);
249 if (aa == NULL) {
250 m_freem(m);
251 return (0);
252 }
253 if (aa->aa_flags & AFA_PHASE2)
254 bcopy(atmulticastaddr, desten,
255 sizeof(atmulticastaddr));
256 else
257 bcopy(etherbroadcastaddr, desten,
258 sizeof(etherbroadcastaddr));
259 return 1;
260 }
261 s = splnet();
262 AARPTAB_LOOK(aat, destsat->sat_addr);
263 if (aat == 0) { /* No entry */
264 aat = aarptnew(&destsat->sat_addr);
265 if (aat == 0)
266 panic("aarpresolve: no free entry");
267
268 aat->aat_hold = m;
269 aarpwhohas(ifp, destsat);
270 splx(s);
271 return 0;
272 }
273
274 /* found an entry */
275 aat->aat_timer = 0;
276 if (aat->aat_flags & ATF_COM) { /* entry is COMplete */
277 bcopy(aat->aat_enaddr, desten, sizeof(aat->aat_enaddr));
278 splx(s);
279 return 1;
280 }
281
282 /* entry has not completed */
283 if (aat->aat_hold)
284 m_freem(aat->aat_hold);
285 aat->aat_hold = m;
286 aarpwhohas(ifp, destsat);
287 splx(s);
288
289 return 0;
290 }
291
292 void
293 aarpinput(ifp, m)
294 struct ifnet *ifp;
295 struct mbuf *m;
296 {
297 struct arphdr *ar;
298
299 if (ifp->if_flags & IFF_NOARP)
300 goto out;
301
302 if (m->m_len < sizeof(struct arphdr))
303 goto out;
304
305 ar = mtod(m, struct arphdr *);
306 if (ntohs(ar->ar_hrd) != AARPHRD_ETHER)
307 goto out;
308
309 if (m->m_len < sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
310 goto out;
311
312 switch (ntohs(ar->ar_pro)) {
313 case ETHERTYPE_ATALK:
314 at_aarpinput(ifp, m);
315 return;
316
317 default:
318 break;
319 }
320
321 out:
322 m_freem(m);
323 }
324
325 static void
326 at_aarpinput(ifp, m)
327 struct ifnet *ifp;
328 struct mbuf *m;
329 {
330 struct ether_aarp *ea;
331 struct at_ifaddr *aa;
332 struct aarptab *aat;
333 struct ether_header *eh;
334 struct llc *llc;
335 struct sockaddr_at sat;
336 struct sockaddr sa;
337 struct at_addr spa, tpa, ma;
338 int op;
339 u_int16_t net;
340
341 ea = mtod(m, struct ether_aarp *);
342
343 /* Check to see if from my hardware address */
344 if (!bcmp(ea->aarp_sha, LLADDR(ifp->if_sadl), sizeof(ea->aarp_sha))) {
345 m_freem(m);
346 return;
347 }
348 op = ntohs(ea->aarp_op);
349 bcopy(ea->aarp_tpnet, &net, sizeof(net));
350
351 if (net != 0) { /* should be ATADDR_ANYNET? */
352 sat.sat_len = sizeof(struct sockaddr_at);
353 sat.sat_family = AF_APPLETALK;
354 sat.sat_addr.s_net = net;
355 aa = (struct at_ifaddr *) at_ifawithnet(&sat, ifp);
356 if (aa == NULL) {
357 m_freem(m);
358 return;
359 }
360 bcopy(ea->aarp_spnet, &spa.s_net, sizeof(spa.s_net));
361 bcopy(ea->aarp_tpnet, &tpa.s_net, sizeof(tpa.s_net));
362 } else {
363 /*
364 * Since we don't know the net, we just look for the first
365 * phase 1 address on the interface.
366 */
367 for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
368 aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
369 if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
370 (aa->aa_flags & AFA_PHASE2) == 0)
371 break;
372 }
373 if (aa == NULL) {
374 m_freem(m);
375 return;
376 }
377 tpa.s_net = spa.s_net = AA_SAT(aa)->sat_addr.s_net;
378 }
379
380 spa.s_node = ea->aarp_spnode;
381 tpa.s_node = ea->aarp_tpnode;
382 ma.s_net = AA_SAT(aa)->sat_addr.s_net;
383 ma.s_node = AA_SAT(aa)->sat_addr.s_node;
384
385 /*
386 * This looks like it's from us.
387 */
388 if (spa.s_net == ma.s_net && spa.s_node == ma.s_node) {
389 if (aa->aa_flags & AFA_PROBING) {
390 /*
391 * We're probing, someone either responded to our
392 * probe, or probed for the same address we'd like
393 * to use. Change the address we're probing for.
394 */
395 callout_stop(&aa->aa_probe_ch);
396 wakeup(aa);
397 m_freem(m);
398 return;
399 } else if (op != AARPOP_PROBE) {
400 /*
401 * This is not a probe, and we're not probing.
402 * This means that someone's saying they have the same
403 * source address as the one we're using. Get upset...
404 */
405 log(LOG_ERR, "aarp: duplicate AT address!! %s\n",
406 ether_sprintf(ea->aarp_sha));
407 m_freem(m);
408 return;
409 }
410 }
411 AARPTAB_LOOK(aat, spa);
412 if (aat) {
413 if (op == AARPOP_PROBE) {
414 /*
415 * Someone's probing for spa, deallocate the one we've
416 * got, so that if the prober keeps the address, we'll
417 * be able to arp for him.
418 */
419 aarptfree(aat);
420 m_freem(m);
421 return;
422 }
423 bcopy(ea->aarp_sha, aat->aat_enaddr, sizeof(ea->aarp_sha));
424 aat->aat_flags |= ATF_COM;
425 if (aat->aat_hold) {
426 sat.sat_len = sizeof(struct sockaddr_at);
427 sat.sat_family = AF_APPLETALK;
428 sat.sat_addr = spa;
429 (*ifp->if_output)(ifp, aat->aat_hold,
430 (struct sockaddr *) & sat, NULL); /* XXX */
431 aat->aat_hold = 0;
432 }
433 }
434 if (aat == 0 && tpa.s_net == ma.s_net && tpa.s_node == ma.s_node
435 && op != AARPOP_PROBE) {
436 if ((aat = aarptnew(&spa)) != NULL) {
437 bcopy(ea->aarp_sha, aat->aat_enaddr,
438 sizeof(ea->aarp_sha));
439 aat->aat_flags |= ATF_COM;
440 }
441 }
442 /*
443 * Don't respond to responses, and never respond if we're
444 * still probing.
445 */
446 if (tpa.s_net != ma.s_net || tpa.s_node != ma.s_node ||
447 op == AARPOP_RESPONSE || (aa->aa_flags & AFA_PROBING)) {
448 m_freem(m);
449 return;
450 }
451 bcopy(ea->aarp_sha, ea->aarp_tha, sizeof(ea->aarp_sha));
452 bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
453
454 /* XXX */
455 eh = (struct ether_header *) sa.sa_data;
456 bcopy(ea->aarp_tha, eh->ether_dhost, sizeof(eh->ether_dhost));
457
458 if (aa->aa_flags & AFA_PHASE2) {
459 M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
460 if (m == NULL)
461 return;
462
463 llc = mtod(m, struct llc *);
464 llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
465 llc->llc_control = LLC_UI;
466 bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
467 llc->llc_ether_type = htons(ETHERTYPE_AARP);
468
469 bcopy(ea->aarp_spnet, ea->aarp_tpnet, sizeof(ea->aarp_tpnet));
470 bcopy(&ma.s_net, ea->aarp_spnet, sizeof(ea->aarp_spnet));
471 eh->ether_type = 0; /* if_output will treat as 802 */
472 } else {
473 eh->ether_type = htons(ETHERTYPE_AARP);
474 }
475
476 ea->aarp_tpnode = ea->aarp_spnode;
477 ea->aarp_spnode = ma.s_node;
478 ea->aarp_op = htons(AARPOP_RESPONSE);
479
480 sa.sa_len = sizeof(struct sockaddr);
481 sa.sa_family = AF_UNSPEC;
482 (*ifp->if_output) (ifp, m, &sa, NULL); /* XXX */
483 return;
484 }
485
486 static void
487 aarptfree(aat)
488 struct aarptab *aat;
489 {
490
491 if (aat->aat_hold)
492 m_freem(aat->aat_hold);
493 aat->aat_hold = 0;
494 aat->aat_timer = aat->aat_flags = 0;
495 aat->aat_ataddr.s_net = 0;
496 aat->aat_ataddr.s_node = 0;
497 }
498
499 static struct aarptab *
500 aarptnew(const struct at_addr *addr)
501 {
502 int n;
503 int oldest = -1;
504 struct aarptab *aat, *aato = NULL;
505 static int first = 1;
506
507 if (first) {
508 first = 0;
509 callout_init(&aarptimer_callout);
510 callout_reset(&aarptimer_callout, hz, aarptimer, NULL);
511 MOWNER_ATTACH(&aarp_mowner);
512 }
513 aat = &aarptab[AARPTAB_HASH(*addr) * AARPTAB_BSIZ];
514 for (n = 0; n < AARPTAB_BSIZ; n++, aat++) {
515 if (aat->aat_flags == 0)
516 goto out;
517 if (aat->aat_flags & ATF_PERM)
518 continue;
519 if ((int) aat->aat_timer > oldest) {
520 oldest = aat->aat_timer;
521 aato = aat;
522 }
523 }
524 if (aato == NULL)
525 return (NULL);
526 aat = aato;
527 aarptfree(aat);
528 out:
529 aat->aat_ataddr = *addr;
530 aat->aat_flags = ATF_INUSE;
531 return (aat);
532 }
533
534
535 void
536 aarpprobe(arp)
537 void *arp;
538 {
539 struct mbuf *m;
540 struct ether_header *eh;
541 struct ether_aarp *ea;
542 struct at_ifaddr *aa;
543 struct llc *llc;
544 struct sockaddr sa;
545 struct ifnet *ifp = arp;
546
547 /*
548 * We need to check whether the output ethernet type should
549 * be phase 1 or 2. We have the interface that we'll be sending
550 * the aarp out. We need to find an AppleTalk network on that
551 * interface with the same address as we're looking for. If the
552 * net is phase 2, generate an 802.2 and SNAP header.
553 */
554 for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
555 aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
556 if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
557 (aa->aa_flags & AFA_PROBING))
558 break;
559 }
560 if (aa == NULL) { /* serious error XXX */
561 printf("aarpprobe why did this happen?!\n");
562 return;
563 }
564 if (aa->aa_probcnt <= 0) {
565 aa->aa_flags &= ~AFA_PROBING;
566 wakeup(aa);
567 return;
568 } else {
569 callout_reset(&aa->aa_probe_ch, hz / 5, aarpprobe, arp);
570 }
571
572 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
573 return;
574
575 MCLAIM(m, &aarp_mowner);
576 m->m_len = sizeof(*ea);
577 m->m_pkthdr.len = sizeof(*ea);
578 MH_ALIGN(m, sizeof(*ea));
579
580 ea = mtod(m, struct ether_aarp *);
581 bzero(ea, sizeof(*ea));
582
583 ea->aarp_hrd = htons(AARPHRD_ETHER);
584 ea->aarp_pro = htons(ETHERTYPE_ATALK);
585 ea->aarp_hln = sizeof(ea->aarp_sha);
586 ea->aarp_pln = sizeof(ea->aarp_spu);
587 ea->aarp_op = htons(AARPOP_PROBE);
588 bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
589
590 eh = (struct ether_header *) sa.sa_data;
591
592 if (aa->aa_flags & AFA_PHASE2) {
593 bcopy(atmulticastaddr, eh->ether_dhost,
594 sizeof(eh->ether_dhost));
595 eh->ether_type = 0; /* if_output will treat as 802 */
596 M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
597 if (!m)
598 return;
599
600 llc = mtod(m, struct llc *);
601 llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
602 llc->llc_control = LLC_UI;
603 bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
604 llc->llc_ether_type = htons(ETHERTYPE_AARP);
605
606 bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
607 sizeof(ea->aarp_spnet));
608 bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_tpnet,
609 sizeof(ea->aarp_tpnet));
610 ea->aarp_spnode = ea->aarp_tpnode =
611 AA_SAT(aa)->sat_addr.s_node;
612 } else {
613 bcopy(etherbroadcastaddr, eh->ether_dhost,
614 sizeof(eh->ether_dhost));
615 eh->ether_type = htons(ETHERTYPE_AARP);
616 ea->aarp_spa = ea->aarp_tpa = AA_SAT(aa)->sat_addr.s_node;
617 }
618
619 #ifdef NETATALKDEBUG
620 printf("aarp: sending probe for %u.%u\n",
621 ntohs(AA_SAT(aa)->sat_addr.s_net),
622 AA_SAT(aa)->sat_addr.s_node);
623 #endif /* NETATALKDEBUG */
624
625 sa.sa_len = sizeof(struct sockaddr);
626 sa.sa_family = AF_UNSPEC;
627 (*ifp->if_output) (ifp, m, &sa, NULL); /* XXX */
628 aa->aa_probcnt--;
629 }
630
631 void
632 aarp_clean()
633 {
634 struct aarptab *aat;
635 int i;
636
637 callout_stop(&aarptimer_callout);
638 for (i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++)
639 if (aat->aat_hold)
640 m_freem(aat->aat_hold);
641 }
642