blob: 3d1655f983887593e8541994c17b59e502446667 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * AARP: An implementation of the AppleTalk AARP protocol for
3 * Ethernet 'ELAP'.
4 *
5 * Alan Cox <Alan.Cox@linux.org>
6 *
7 * This doesn't fit cleanly with the IP arp. Potentially we can use
8 * the generic neighbour discovery code to clean this up.
9 *
10 * FIXME:
11 * We ought to handle the retransmits with a single list and a
12 * separate fast timer for when it is needed.
13 * Use neighbour discovery code.
14 * Token Ring Support.
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
20 *
21 *
22 * References:
23 * Inside AppleTalk (2nd Ed).
24 * Fixes:
25 * Jaume Grau - flush caches on AARP_PROBE
26 * Rob Newberry - Added proxy AARP and AARP proc fs,
27 * moved probing from DDP module.
28 * Arnaldo C. Melo - don't mangle rx packets
29 *
30 */
31
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/if_arp.h>
33#include <net/sock.h>
34#include <net/datalink.h>
35#include <net/psnap.h>
36#include <linux/atalk.h>
Nishanth Aravamudan285b3af2005-06-22 22:11:44 -070037#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/init.h>
39#include <linux/proc_fs.h>
40#include <linux/seq_file.h>
41
42int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME;
43int sysctl_aarp_tick_time = AARP_TICK_TIME;
44int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT;
45int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME;
46
47/* Lists of aarp entries */
48/**
49 * struct aarp_entry - AARP entry
50 * @last_sent - Last time we xmitted the aarp request
51 * @packet_queue - Queue of frames wait for resolution
52 * @status - Used for proxy AARP
53 * expires_at - Entry expiry time
54 * target_addr - DDP Address
55 * dev - Device to use
56 * hwaddr - Physical i/f address of target/router
57 * xmit_count - When this hits 10 we give up
58 * next - Next entry in chain
59 */
60struct aarp_entry {
61 /* These first two are only used for unresolved entries */
62 unsigned long last_sent;
63 struct sk_buff_head packet_queue;
64 int status;
65 unsigned long expires_at;
66 struct atalk_addr target_addr;
67 struct net_device *dev;
68 char hwaddr[6];
69 unsigned short xmit_count;
70 struct aarp_entry *next;
71};
72
73/* Hashed list of resolved, unresolved and proxy entries */
74static struct aarp_entry *resolved[AARP_HASH_SIZE];
75static struct aarp_entry *unresolved[AARP_HASH_SIZE];
76static struct aarp_entry *proxies[AARP_HASH_SIZE];
77static int unresolved_count;
78
79/* One lock protects it all. */
80static DEFINE_RWLOCK(aarp_lock);
81
82/* Used to walk the list and purge/kick entries. */
83static struct timer_list aarp_timer;
84
85/*
86 * Delete an aarp queue
87 *
88 * Must run under aarp_lock.
89 */
90static void __aarp_expire(struct aarp_entry *a)
91{
92 skb_queue_purge(&a->packet_queue);
93 kfree(a);
94}
95
96/*
97 * Send an aarp queue entry request
98 *
99 * Must run under aarp_lock.
100 */
101static void __aarp_send_query(struct aarp_entry *a)
102{
103 static unsigned char aarp_eth_multicast[ETH_ALEN] =
104 { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
105 struct net_device *dev = a->dev;
106 struct elapaarp *eah;
107 int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
108 struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
109 struct atalk_addr *sat = atalk_find_dev_addr(dev);
110
111 if (!skb)
112 return;
113
114 if (!sat) {
115 kfree_skb(skb);
116 return;
117 }
118
119 /* Set up the buffer */
120 skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300121 skb_reset_network_header(skb);
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -0300122 skb_reset_transport_header(skb);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300123 skb_put(skb, sizeof(*eah));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 skb->protocol = htons(ETH_P_ATALK);
125 skb->dev = dev;
126 eah = aarp_hdr(skb);
127
128 /* Set up the ARP */
129 eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
130 eah->pa_type = htons(ETH_P_ATALK);
131 eah->hw_len = ETH_ALEN;
132 eah->pa_len = AARP_PA_ALEN;
133 eah->function = htons(AARP_REQUEST);
134
135 memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
136
137 eah->pa_src_zero = 0;
138 eah->pa_src_net = sat->s_net;
139 eah->pa_src_node = sat->s_node;
140
141 memset(eah->hw_dst, '\0', ETH_ALEN);
142
143 eah->pa_dst_zero = 0;
144 eah->pa_dst_net = a->target_addr.s_net;
145 eah->pa_dst_node = a->target_addr.s_node;
146
147 /* Send it */
148 aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
149 /* Update the sending count */
150 a->xmit_count++;
151 a->last_sent = jiffies;
152}
153
154/* This runs under aarp_lock and in softint context, so only atomic memory
155 * allocations can be used. */
156static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us,
157 struct atalk_addr *them, unsigned char *sha)
158{
159 struct elapaarp *eah;
160 int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
161 struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
162
163 if (!skb)
164 return;
165
166 /* Set up the buffer */
167 skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300168 skb_reset_network_header(skb);
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -0300169 skb_reset_transport_header(skb);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300170 skb_put(skb, sizeof(*eah));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 skb->protocol = htons(ETH_P_ATALK);
172 skb->dev = dev;
173 eah = aarp_hdr(skb);
174
175 /* Set up the ARP */
176 eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
177 eah->pa_type = htons(ETH_P_ATALK);
178 eah->hw_len = ETH_ALEN;
179 eah->pa_len = AARP_PA_ALEN;
180 eah->function = htons(AARP_REPLY);
181
182 memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
183
184 eah->pa_src_zero = 0;
185 eah->pa_src_net = us->s_net;
186 eah->pa_src_node = us->s_node;
187
188 if (!sha)
189 memset(eah->hw_dst, '\0', ETH_ALEN);
190 else
191 memcpy(eah->hw_dst, sha, ETH_ALEN);
192
193 eah->pa_dst_zero = 0;
194 eah->pa_dst_net = them->s_net;
195 eah->pa_dst_node = them->s_node;
196
197 /* Send it */
198 aarp_dl->request(aarp_dl, skb, sha);
199}
200
201/*
202 * Send probe frames. Called from aarp_probe_network and
203 * aarp_proxy_probe_network.
204 */
205
206static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us)
207{
208 struct elapaarp *eah;
209 int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length;
210 struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC);
211 static unsigned char aarp_eth_multicast[ETH_ALEN] =
212 { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
213
214 if (!skb)
215 return;
216
217 /* Set up the buffer */
218 skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300219 skb_reset_network_header(skb);
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -0300220 skb_reset_transport_header(skb);
Arnaldo Carvalho de Melo7e28ecc2007-03-10 18:40:59 -0300221 skb_put(skb, sizeof(*eah));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 skb->protocol = htons(ETH_P_ATALK);
223 skb->dev = dev;
224 eah = aarp_hdr(skb);
225
226 /* Set up the ARP */
227 eah->hw_type = htons(AARP_HW_TYPE_ETHERNET);
228 eah->pa_type = htons(ETH_P_ATALK);
229 eah->hw_len = ETH_ALEN;
230 eah->pa_len = AARP_PA_ALEN;
231 eah->function = htons(AARP_PROBE);
232
233 memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN);
234
235 eah->pa_src_zero = 0;
236 eah->pa_src_net = us->s_net;
237 eah->pa_src_node = us->s_node;
238
239 memset(eah->hw_dst, '\0', ETH_ALEN);
240
241 eah->pa_dst_zero = 0;
242 eah->pa_dst_net = us->s_net;
243 eah->pa_dst_node = us->s_node;
244
245 /* Send it */
246 aarp_dl->request(aarp_dl, skb, aarp_eth_multicast);
247}
248
249/*
250 * Handle an aarp timer expire
251 *
252 * Must run under the aarp_lock.
253 */
254
255static void __aarp_expire_timer(struct aarp_entry **n)
256{
257 struct aarp_entry *t;
258
259 while (*n)
260 /* Expired ? */
261 if (time_after(jiffies, (*n)->expires_at)) {
262 t = *n;
263 *n = (*n)->next;
264 __aarp_expire(t);
265 } else
266 n = &((*n)->next);
267}
268
269/*
270 * Kick all pending requests 5 times a second.
271 *
272 * Must run under the aarp_lock.
273 */
274static void __aarp_kick(struct aarp_entry **n)
275{
276 struct aarp_entry *t;
277
278 while (*n)
279 /* Expired: if this will be the 11th tx, we delete instead. */
280 if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) {
281 t = *n;
282 *n = (*n)->next;
283 __aarp_expire(t);
284 } else {
285 __aarp_send_query(*n);
286 n = &((*n)->next);
287 }
288}
289
290/*
291 * A device has gone down. Take all entries referring to the device
292 * and remove them.
293 *
294 * Must run under the aarp_lock.
295 */
296static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev)
297{
298 struct aarp_entry *t;
299
300 while (*n)
301 if ((*n)->dev == dev) {
302 t = *n;
303 *n = (*n)->next;
304 __aarp_expire(t);
305 } else
306 n = &((*n)->next);
307}
308
309/* Handle the timer event */
310static void aarp_expire_timeout(unsigned long unused)
311{
312 int ct;
313
314 write_lock_bh(&aarp_lock);
315
316 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
317 __aarp_expire_timer(&resolved[ct]);
318 __aarp_kick(&unresolved[ct]);
319 __aarp_expire_timer(&unresolved[ct]);
320 __aarp_expire_timer(&proxies[ct]);
321 }
322
323 write_unlock_bh(&aarp_lock);
324 mod_timer(&aarp_timer, jiffies +
325 (unresolved_count ? sysctl_aarp_tick_time :
326 sysctl_aarp_expiry_time));
327}
328
329/* Network device notifier chain handler. */
330static int aarp_device_event(struct notifier_block *this, unsigned long event,
331 void *ptr)
332{
333 int ct;
334
335 if (event == NETDEV_DOWN) {
336 write_lock_bh(&aarp_lock);
337
338 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
339 __aarp_expire_device(&resolved[ct], ptr);
340 __aarp_expire_device(&unresolved[ct], ptr);
341 __aarp_expire_device(&proxies[ct], ptr);
342 }
343
344 write_unlock_bh(&aarp_lock);
345 }
346 return NOTIFY_DONE;
347}
348
349/* Expire all entries in a hash chain */
350static void __aarp_expire_all(struct aarp_entry **n)
351{
352 struct aarp_entry *t;
353
354 while (*n) {
355 t = *n;
356 *n = (*n)->next;
357 __aarp_expire(t);
358 }
359}
360
361/* Cleanup all hash chains -- module unloading */
362static void aarp_purge(void)
363{
364 int ct;
365
366 write_lock_bh(&aarp_lock);
367 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
368 __aarp_expire_all(&resolved[ct]);
369 __aarp_expire_all(&unresolved[ct]);
370 __aarp_expire_all(&proxies[ct]);
371 }
372 write_unlock_bh(&aarp_lock);
373}
374
375/*
376 * Create a new aarp entry. This must use GFP_ATOMIC because it
377 * runs while holding spinlocks.
378 */
379static struct aarp_entry *aarp_alloc(void)
380{
381 struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC);
382
383 if (a)
384 skb_queue_head_init(&a->packet_queue);
385 return a;
386}
387
388/*
389 * Find an entry. We might return an expired but not yet purged entry. We
390 * don't care as it will do no harm.
391 *
392 * This must run under the aarp_lock.
393 */
394static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list,
395 struct net_device *dev,
396 struct atalk_addr *sat)
397{
398 while (list) {
399 if (list->target_addr.s_net == sat->s_net &&
400 list->target_addr.s_node == sat->s_node &&
401 list->dev == dev)
402 break;
403 list = list->next;
404 }
405
406 return list;
407}
408
409/* Called from the DDP code, and thus must be exported. */
410void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa)
411{
412 int hash = sa->s_node % (AARP_HASH_SIZE - 1);
413 struct aarp_entry *a;
414
415 write_lock_bh(&aarp_lock);
416
417 a = __aarp_find_entry(proxies[hash], dev, sa);
418 if (a)
419 a->expires_at = jiffies - 1;
420
421 write_unlock_bh(&aarp_lock);
422}
423
424/* This must run under aarp_lock. */
425static struct atalk_addr *__aarp_proxy_find(struct net_device *dev,
426 struct atalk_addr *sa)
427{
428 int hash = sa->s_node % (AARP_HASH_SIZE - 1);
429 struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa);
430
431 return a ? sa : NULL;
432}
433
434/*
435 * Probe a Phase 1 device or a device that requires its Net:Node to
436 * be set via an ioctl.
437 */
438static void aarp_send_probe_phase1(struct atalk_iface *iface)
439{
440 struct ifreq atreq;
441 struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr;
442
443 sa->sat_addr.s_node = iface->address.s_node;
444 sa->sat_addr.s_net = ntohs(iface->address.s_net);
445
446 /* We pass the Net:Node to the drivers/cards by a Device ioctl. */
447 if (!(iface->dev->do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
448 (void)iface->dev->do_ioctl(iface->dev, &atreq, SIOCGIFADDR);
449 if (iface->address.s_net != htons(sa->sat_addr.s_net) ||
450 iface->address.s_node != sa->sat_addr.s_node)
451 iface->status |= ATIF_PROBE_FAIL;
452
453 iface->address.s_net = htons(sa->sat_addr.s_net);
454 iface->address.s_node = sa->sat_addr.s_node;
455 }
456}
457
458
459void aarp_probe_network(struct atalk_iface *atif)
460{
461 if (atif->dev->type == ARPHRD_LOCALTLK ||
462 atif->dev->type == ARPHRD_PPP)
463 aarp_send_probe_phase1(atif);
464 else {
465 unsigned int count;
466
467 for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
468 aarp_send_probe(atif->dev, &atif->address);
469
470 /* Defer 1/10th */
Nishanth Aravamudan285b3af2005-06-22 22:11:44 -0700471 msleep(100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 if (atif->status & ATIF_PROBE_FAIL)
474 break;
475 }
476 }
477}
478
479int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa)
480{
481 int hash, retval = -EPROTONOSUPPORT;
482 struct aarp_entry *entry;
483 unsigned int count;
484
485 /*
486 * we don't currently support LocalTalk or PPP for proxy AARP;
487 * if someone wants to try and add it, have fun
488 */
489 if (atif->dev->type == ARPHRD_LOCALTLK ||
490 atif->dev->type == ARPHRD_PPP)
491 goto out;
492
493 /*
494 * create a new AARP entry with the flags set to be published --
495 * we need this one to hang around even if it's in use
496 */
497 entry = aarp_alloc();
498 retval = -ENOMEM;
499 if (!entry)
500 goto out;
501
502 entry->expires_at = -1;
503 entry->status = ATIF_PROBE;
504 entry->target_addr.s_node = sa->s_node;
505 entry->target_addr.s_net = sa->s_net;
506 entry->dev = atif->dev;
507
508 write_lock_bh(&aarp_lock);
509
510 hash = sa->s_node % (AARP_HASH_SIZE - 1);
511 entry->next = proxies[hash];
512 proxies[hash] = entry;
513
514 for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
515 aarp_send_probe(atif->dev, sa);
516
517 /* Defer 1/10th */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 write_unlock_bh(&aarp_lock);
Nishanth Aravamudan285b3af2005-06-22 22:11:44 -0700519 msleep(100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 write_lock_bh(&aarp_lock);
521
522 if (entry->status & ATIF_PROBE_FAIL)
523 break;
524 }
525
526 if (entry->status & ATIF_PROBE_FAIL) {
527 entry->expires_at = jiffies - 1; /* free the entry */
528 retval = -EADDRINUSE; /* return network full */
529 } else { /* clear the probing flag */
530 entry->status &= ~ATIF_PROBE;
531 retval = 1;
532 }
533
534 write_unlock_bh(&aarp_lock);
535out:
536 return retval;
537}
538
539/* Send a DDP frame */
540int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb,
541 struct atalk_addr *sa, void *hwaddr)
542{
543 static char ddp_eth_multicast[ETH_ALEN] =
544 { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
545 int hash;
546 struct aarp_entry *a;
547
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700548 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 /* Check for LocalTalk first */
551 if (dev->type == ARPHRD_LOCALTLK) {
552 struct atalk_addr *at = atalk_find_dev_addr(dev);
553 struct ddpehdr *ddp = (struct ddpehdr *)skb->data;
554 int ft = 2;
555
556 /*
557 * Compressible ?
558 *
559 * IFF: src_net == dest_net == device_net
560 * (zero matches anything)
561 */
562
563 if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) &&
564 (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) {
565 skb_pull(skb, sizeof(*ddp) - 4);
566
567 /*
568 * The upper two remaining bytes are the port
569 * numbers we just happen to need. Now put the
570 * length in the lower two.
571 */
Alexey Dobriyanf6e276ee2005-06-20 13:32:05 -0700572 *((__be16 *)skb->data) = htons(skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 ft = 1;
574 }
575 /*
576 * Nice and easy. No AARP type protocols occur here so we can
577 * just shovel it out with a 3 byte LLAP header
578 */
579
580 skb_push(skb, 3);
581 skb->data[0] = sa->s_node;
582 skb->data[1] = at->s_node;
583 skb->data[2] = ft;
584 skb->dev = dev;
585 goto sendit;
586 }
587
588 /* On a PPP link we neither compress nor aarp. */
589 if (dev->type == ARPHRD_PPP) {
590 skb->protocol = htons(ETH_P_PPPTALK);
591 skb->dev = dev;
592 goto sendit;
593 }
594
595 /* Non ELAP we cannot do. */
596 if (dev->type != ARPHRD_ETHER)
597 return -1;
598
599 skb->dev = dev;
600 skb->protocol = htons(ETH_P_ATALK);
601 hash = sa->s_node % (AARP_HASH_SIZE - 1);
602
603 /* Do we have a resolved entry? */
604 if (sa->s_node == ATADDR_BCAST) {
605 /* Send it */
606 ddp_dl->request(ddp_dl, skb, ddp_eth_multicast);
607 goto sent;
608 }
609
610 write_lock_bh(&aarp_lock);
611 a = __aarp_find_entry(resolved[hash], dev, sa);
612
613 if (a) { /* Return 1 and fill in the address */
614 a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10);
615 ddp_dl->request(ddp_dl, skb, a->hwaddr);
616 write_unlock_bh(&aarp_lock);
617 goto sent;
618 }
619
620 /* Do we have an unresolved entry: This is the less common path */
621 a = __aarp_find_entry(unresolved[hash], dev, sa);
622 if (a) { /* Queue onto the unresolved queue */
623 skb_queue_tail(&a->packet_queue, skb);
624 goto out_unlock;
625 }
626
627 /* Allocate a new entry */
628 a = aarp_alloc();
629 if (!a) {
630 /* Whoops slipped... good job it's an unreliable protocol 8) */
631 write_unlock_bh(&aarp_lock);
632 return -1;
633 }
634
635 /* Set up the queue */
636 skb_queue_tail(&a->packet_queue, skb);
637 a->expires_at = jiffies + sysctl_aarp_resolve_time;
638 a->dev = dev;
639 a->next = unresolved[hash];
640 a->target_addr = *sa;
641 a->xmit_count = 0;
642 unresolved[hash] = a;
643 unresolved_count++;
644
645 /* Send an initial request for the address */
646 __aarp_send_query(a);
647
648 /*
649 * Switch to fast timer if needed (That is if this is the first
650 * unresolved entry to get added)
651 */
652
653 if (unresolved_count == 1)
654 mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time);
655
656 /* Now finally, it is safe to drop the lock. */
657out_unlock:
658 write_unlock_bh(&aarp_lock);
659
660 /* Tell the ddp layer we have taken over for this frame. */
661 return 0;
662
663sendit:
664 if (skb->sk)
665 skb->priority = skb->sk->sk_priority;
666 dev_queue_xmit(skb);
667sent:
668 return 1;
669}
670
671/*
672 * An entry in the aarp unresolved queue has become resolved. Send
673 * all the frames queued under it.
674 *
675 * Must run under aarp_lock.
676 */
677static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a,
678 int hash)
679{
680 struct sk_buff *skb;
681
682 while (*list)
683 if (*list == a) {
684 unresolved_count--;
685 *list = a->next;
686
687 /* Move into the resolved list */
688 a->next = resolved[hash];
689 resolved[hash] = a;
690
691 /* Kick frames off */
692 while ((skb = skb_dequeue(&a->packet_queue)) != NULL) {
693 a->expires_at = jiffies +
694 sysctl_aarp_expiry_time * 10;
695 ddp_dl->request(ddp_dl, skb, a->hwaddr);
696 }
697 } else
698 list = &((*list)->next);
699}
700
701/*
702 * This is called by the SNAP driver whenever we see an AARP SNAP
703 * frame. We currently only support Ethernet.
704 */
705static int aarp_rcv(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -0700706 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707{
708 struct elapaarp *ea = aarp_hdr(skb);
709 int hash, ret = 0;
710 __u16 function;
711 struct aarp_entry *a;
712 struct atalk_addr sa, *ma, da;
713 struct atalk_iface *ifa;
714
715 /* We only do Ethernet SNAP AARP. */
716 if (dev->type != ARPHRD_ETHER)
717 goto out0;
718
719 /* Frame size ok? */
720 if (!skb_pull(skb, sizeof(*ea)))
721 goto out0;
722
723 function = ntohs(ea->function);
724
725 /* Sanity check fields. */
726 if (function < AARP_REQUEST || function > AARP_PROBE ||
727 ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN ||
728 ea->pa_src_zero || ea->pa_dst_zero)
729 goto out0;
730
731 /* Looks good. */
732 hash = ea->pa_src_node % (AARP_HASH_SIZE - 1);
733
734 /* Build an address. */
735 sa.s_node = ea->pa_src_node;
736 sa.s_net = ea->pa_src_net;
737
738 /* Process the packet. Check for replies of me. */
739 ifa = atalk_find_dev(dev);
740 if (!ifa)
741 goto out1;
742
743 if (ifa->status & ATIF_PROBE &&
744 ifa->address.s_node == ea->pa_dst_node &&
745 ifa->address.s_net == ea->pa_dst_net) {
746 ifa->status |= ATIF_PROBE_FAIL; /* Fail the probe (in use) */
747 goto out1;
748 }
749
750 /* Check for replies of proxy AARP entries */
751 da.s_node = ea->pa_dst_node;
752 da.s_net = ea->pa_dst_net;
753
754 write_lock_bh(&aarp_lock);
755 a = __aarp_find_entry(proxies[hash], dev, &da);
756
757 if (a && a->status & ATIF_PROBE) {
758 a->status |= ATIF_PROBE_FAIL;
759 /*
760 * we do not respond to probe or request packets for
761 * this address while we are probing this address
762 */
763 goto unlock;
764 }
765
766 switch (function) {
767 case AARP_REPLY:
768 if (!unresolved_count) /* Speed up */
769 break;
770
771 /* Find the entry. */
772 a = __aarp_find_entry(unresolved[hash], dev, &sa);
773 if (!a || dev != a->dev)
774 break;
775
776 /* We can fill one in - this is good. */
777 memcpy(a->hwaddr, ea->hw_src, ETH_ALEN);
778 __aarp_resolved(&unresolved[hash], a, hash);
779 if (!unresolved_count)
780 mod_timer(&aarp_timer,
781 jiffies + sysctl_aarp_expiry_time);
782 break;
783
784 case AARP_REQUEST:
785 case AARP_PROBE:
786
787 /*
788 * If it is my address set ma to my address and reply.
789 * We can treat probe and request the same. Probe
790 * simply means we shouldn't cache the querying host,
791 * as in a probe they are proposing an address not
792 * using one.
793 *
794 * Support for proxy-AARP added. We check if the
795 * address is one of our proxies before we toss the
796 * packet out.
797 */
798
799 sa.s_node = ea->pa_dst_node;
800 sa.s_net = ea->pa_dst_net;
801
802 /* See if we have a matching proxy. */
803 ma = __aarp_proxy_find(dev, &sa);
804 if (!ma)
805 ma = &ifa->address;
806 else { /* We need to make a copy of the entry. */
807 da.s_node = sa.s_node;
808 da.s_net = da.s_net;
809 ma = &da;
810 }
811
812 if (function == AARP_PROBE) {
813 /*
814 * A probe implies someone trying to get an
815 * address. So as a precaution flush any
816 * entries we have for this address.
817 */
818 struct aarp_entry *a;
819
820 a = __aarp_find_entry(resolved[sa.s_node %
821 (AARP_HASH_SIZE - 1)],
822 skb->dev, &sa);
823
824 /*
825 * Make it expire next tick - that avoids us
826 * getting into a probe/flush/learn/probe/
827 * flush/learn cycle during probing of a slow
828 * to respond host addr.
829 */
830 if (a) {
831 a->expires_at = jiffies - 1;
832 mod_timer(&aarp_timer, jiffies +
833 sysctl_aarp_tick_time);
834 }
835 }
836
837 if (sa.s_node != ma->s_node)
838 break;
839
840 if (sa.s_net && ma->s_net && sa.s_net != ma->s_net)
841 break;
842
843 sa.s_node = ea->pa_src_node;
844 sa.s_net = ea->pa_src_net;
845
846 /* aarp_my_address has found the address to use for us.
847 */
848 aarp_send_reply(dev, ma, &sa, ea->hw_src);
849 break;
850 }
851
852unlock:
853 write_unlock_bh(&aarp_lock);
854out1:
855 ret = 1;
856out0:
857 kfree_skb(skb);
858 return ret;
859}
860
861static struct notifier_block aarp_notifier = {
862 .notifier_call = aarp_device_event,
863};
864
865static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 };
866
867void __init aarp_proto_init(void)
868{
869 aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv);
870 if (!aarp_dl)
871 printk(KERN_CRIT "Unable to register AARP with SNAP.\n");
872 init_timer(&aarp_timer);
873 aarp_timer.function = aarp_expire_timeout;
874 aarp_timer.data = 0;
875 aarp_timer.expires = jiffies + sysctl_aarp_expiry_time;
876 add_timer(&aarp_timer);
877 register_netdevice_notifier(&aarp_notifier);
878}
879
880/* Remove the AARP entries associated with a device. */
881void aarp_device_down(struct net_device *dev)
882{
883 int ct;
884
885 write_lock_bh(&aarp_lock);
886
887 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
888 __aarp_expire_device(&resolved[ct], dev);
889 __aarp_expire_device(&unresolved[ct], dev);
890 __aarp_expire_device(&proxies[ct], dev);
891 }
892
893 write_unlock_bh(&aarp_lock);
894}
895
896#ifdef CONFIG_PROC_FS
897struct aarp_iter_state {
898 int bucket;
899 struct aarp_entry **table;
900};
901
902/*
903 * Get the aarp entry that is in the chain described
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900904 * by the iterator.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 * If pos is set then skip till that index.
906 * pos = 1 is the first entry
907 */
908static struct aarp_entry *iter_next(struct aarp_iter_state *iter, loff_t *pos)
909{
910 int ct = iter->bucket;
911 struct aarp_entry **table = iter->table;
912 loff_t off = 0;
913 struct aarp_entry *entry;
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900914
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 rescan:
916 while(ct < AARP_HASH_SIZE) {
917 for (entry = table[ct]; entry; entry = entry->next) {
918 if (!pos || ++off == *pos) {
919 iter->table = table;
920 iter->bucket = ct;
921 return entry;
922 }
923 }
924 ++ct;
925 }
926
927 if (table == resolved) {
928 ct = 0;
929 table = unresolved;
930 goto rescan;
931 }
932 if (table == unresolved) {
933 ct = 0;
934 table = proxies;
935 goto rescan;
936 }
937 return NULL;
938}
939
940static void *aarp_seq_start(struct seq_file *seq, loff_t *pos)
941{
942 struct aarp_iter_state *iter = seq->private;
943
944 read_lock_bh(&aarp_lock);
945 iter->table = resolved;
946 iter->bucket = 0;
947
948 return *pos ? iter_next(iter, pos) : SEQ_START_TOKEN;
949}
950
951static void *aarp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
952{
953 struct aarp_entry *entry = v;
954 struct aarp_iter_state *iter = seq->private;
955
956 ++*pos;
957
958 /* first line after header */
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900959 if (v == SEQ_START_TOKEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 entry = iter_next(iter, NULL);
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900961
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 /* next entry in current bucket */
963 else if (entry->next)
964 entry = entry->next;
965
966 /* next bucket or table */
967 else {
968 ++iter->bucket;
969 entry = iter_next(iter, NULL);
970 }
971 return entry;
972}
973
974static void aarp_seq_stop(struct seq_file *seq, void *v)
975{
976 read_unlock_bh(&aarp_lock);
977}
978
979static const char *dt2str(unsigned long ticks)
980{
981 static char buf[32];
982
983 sprintf(buf, "%ld.%02ld", ticks / HZ, ((ticks % HZ) * 100 ) / HZ);
984
985 return buf;
986}
987
988static int aarp_seq_show(struct seq_file *seq, void *v)
989{
990 struct aarp_iter_state *iter = seq->private;
991 struct aarp_entry *entry = v;
992 unsigned long now = jiffies;
993
994 if (v == SEQ_START_TOKEN)
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900995 seq_puts(seq,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 "Address Interface Hardware Address"
997 " Expires LastSend Retry Status\n");
998 else {
999 seq_printf(seq, "%04X:%02X %-12s",
1000 ntohs(entry->target_addr.s_net),
1001 (unsigned int) entry->target_addr.s_node,
1002 entry->dev ? entry->dev->name : "????");
1003 seq_printf(seq, "%02X:%02X:%02X:%02X:%02X:%02X",
1004 entry->hwaddr[0] & 0xFF,
1005 entry->hwaddr[1] & 0xFF,
1006 entry->hwaddr[2] & 0xFF,
1007 entry->hwaddr[3] & 0xFF,
1008 entry->hwaddr[4] & 0xFF,
1009 entry->hwaddr[5] & 0xFF);
1010 seq_printf(seq, " %8s",
1011 dt2str((long)entry->expires_at - (long)now));
1012 if (iter->table == unresolved)
1013 seq_printf(seq, " %8s %6hu",
1014 dt2str(now - entry->last_sent),
1015 entry->xmit_count);
1016 else
1017 seq_puts(seq, " ");
1018 seq_printf(seq, " %s\n",
1019 (iter->table == resolved) ? "resolved"
1020 : (iter->table == unresolved) ? "unresolved"
1021 : (iter->table == proxies) ? "proxies"
1022 : "unknown");
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +09001023 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 return 0;
1025}
1026
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001027static const struct seq_operations aarp_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 .start = aarp_seq_start,
1029 .next = aarp_seq_next,
1030 .stop = aarp_seq_stop,
1031 .show = aarp_seq_show,
1032};
1033
1034static int aarp_seq_open(struct inode *inode, struct file *file)
1035{
1036 struct seq_file *seq;
1037 int rc = -ENOMEM;
1038 struct aarp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +09001039
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 if (!s)
1041 goto out;
1042
1043 rc = seq_open(file, &aarp_seq_ops);
1044 if (rc)
1045 goto out_kfree;
1046
1047 seq = file->private_data;
1048 seq->private = s;
1049 memset(s, 0, sizeof(*s));
1050out:
1051 return rc;
1052out_kfree:
1053 kfree(s);
1054 goto out;
1055}
1056
Arjan van de Ven9a321442007-02-12 00:55:35 -08001057const struct file_operations atalk_seq_arp_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 .owner = THIS_MODULE,
1059 .open = aarp_seq_open,
1060 .read = seq_read,
1061 .llseek = seq_lseek,
1062 .release = seq_release_private,
1063};
1064#endif
1065
1066/* General module cleanup. Called from cleanup_module() in ddp.c. */
1067void aarp_cleanup_module(void)
1068{
1069 del_timer_sync(&aarp_timer);
1070 unregister_netdevice_notifier(&aarp_notifier);
1071 unregister_snap_client(aarp_dl);
1072 aarp_purge();
1073}