blob: b25c1e909d14fdabadf150693dd80252345f4f26 [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{
Eric W. Biederman890d52d2007-09-12 11:26:59 +0200333 struct net_device *dev = ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 int ct;
335
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700336 if (!net_eq(dev_net(dev), &init_net))
Eric W. Biedermane9dc8652007-09-12 13:02:17 +0200337 return NOTIFY_DONE;
338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 if (event == NETDEV_DOWN) {
340 write_lock_bh(&aarp_lock);
341
342 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
Eric W. Biederman890d52d2007-09-12 11:26:59 +0200343 __aarp_expire_device(&resolved[ct], dev);
344 __aarp_expire_device(&unresolved[ct], dev);
345 __aarp_expire_device(&proxies[ct], dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 }
347
348 write_unlock_bh(&aarp_lock);
349 }
350 return NOTIFY_DONE;
351}
352
353/* Expire all entries in a hash chain */
354static void __aarp_expire_all(struct aarp_entry **n)
355{
356 struct aarp_entry *t;
357
358 while (*n) {
359 t = *n;
360 *n = (*n)->next;
361 __aarp_expire(t);
362 }
363}
364
365/* Cleanup all hash chains -- module unloading */
366static void aarp_purge(void)
367{
368 int ct;
369
370 write_lock_bh(&aarp_lock);
371 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
372 __aarp_expire_all(&resolved[ct]);
373 __aarp_expire_all(&unresolved[ct]);
374 __aarp_expire_all(&proxies[ct]);
375 }
376 write_unlock_bh(&aarp_lock);
377}
378
379/*
380 * Create a new aarp entry. This must use GFP_ATOMIC because it
381 * runs while holding spinlocks.
382 */
383static struct aarp_entry *aarp_alloc(void)
384{
385 struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC);
386
387 if (a)
388 skb_queue_head_init(&a->packet_queue);
389 return a;
390}
391
392/*
393 * Find an entry. We might return an expired but not yet purged entry. We
394 * don't care as it will do no harm.
395 *
396 * This must run under the aarp_lock.
397 */
398static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list,
399 struct net_device *dev,
400 struct atalk_addr *sat)
401{
402 while (list) {
403 if (list->target_addr.s_net == sat->s_net &&
404 list->target_addr.s_node == sat->s_node &&
405 list->dev == dev)
406 break;
407 list = list->next;
408 }
409
410 return list;
411}
412
413/* Called from the DDP code, and thus must be exported. */
414void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa)
415{
416 int hash = sa->s_node % (AARP_HASH_SIZE - 1);
417 struct aarp_entry *a;
418
419 write_lock_bh(&aarp_lock);
420
421 a = __aarp_find_entry(proxies[hash], dev, sa);
422 if (a)
423 a->expires_at = jiffies - 1;
424
425 write_unlock_bh(&aarp_lock);
426}
427
428/* This must run under aarp_lock. */
429static struct atalk_addr *__aarp_proxy_find(struct net_device *dev,
430 struct atalk_addr *sa)
431{
432 int hash = sa->s_node % (AARP_HASH_SIZE - 1);
433 struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa);
434
435 return a ? sa : NULL;
436}
437
438/*
439 * Probe a Phase 1 device or a device that requires its Net:Node to
440 * be set via an ioctl.
441 */
442static void aarp_send_probe_phase1(struct atalk_iface *iface)
443{
444 struct ifreq atreq;
445 struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr;
446
447 sa->sat_addr.s_node = iface->address.s_node;
448 sa->sat_addr.s_net = ntohs(iface->address.s_net);
449
450 /* We pass the Net:Node to the drivers/cards by a Device ioctl. */
451 if (!(iface->dev->do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) {
452 (void)iface->dev->do_ioctl(iface->dev, &atreq, SIOCGIFADDR);
453 if (iface->address.s_net != htons(sa->sat_addr.s_net) ||
454 iface->address.s_node != sa->sat_addr.s_node)
455 iface->status |= ATIF_PROBE_FAIL;
456
457 iface->address.s_net = htons(sa->sat_addr.s_net);
458 iface->address.s_node = sa->sat_addr.s_node;
459 }
460}
461
462
463void aarp_probe_network(struct atalk_iface *atif)
464{
465 if (atif->dev->type == ARPHRD_LOCALTLK ||
466 atif->dev->type == ARPHRD_PPP)
467 aarp_send_probe_phase1(atif);
468 else {
469 unsigned int count;
470
471 for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
472 aarp_send_probe(atif->dev, &atif->address);
473
474 /* Defer 1/10th */
Nishanth Aravamudan285b3af2005-06-22 22:11:44 -0700475 msleep(100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477 if (atif->status & ATIF_PROBE_FAIL)
478 break;
479 }
480 }
481}
482
483int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa)
484{
485 int hash, retval = -EPROTONOSUPPORT;
486 struct aarp_entry *entry;
487 unsigned int count;
488
489 /*
490 * we don't currently support LocalTalk or PPP for proxy AARP;
491 * if someone wants to try and add it, have fun
492 */
493 if (atif->dev->type == ARPHRD_LOCALTLK ||
494 atif->dev->type == ARPHRD_PPP)
495 goto out;
496
497 /*
498 * create a new AARP entry with the flags set to be published --
499 * we need this one to hang around even if it's in use
500 */
501 entry = aarp_alloc();
502 retval = -ENOMEM;
503 if (!entry)
504 goto out;
505
506 entry->expires_at = -1;
507 entry->status = ATIF_PROBE;
508 entry->target_addr.s_node = sa->s_node;
509 entry->target_addr.s_net = sa->s_net;
510 entry->dev = atif->dev;
511
512 write_lock_bh(&aarp_lock);
513
514 hash = sa->s_node % (AARP_HASH_SIZE - 1);
515 entry->next = proxies[hash];
516 proxies[hash] = entry;
517
518 for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) {
519 aarp_send_probe(atif->dev, sa);
520
521 /* Defer 1/10th */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 write_unlock_bh(&aarp_lock);
Nishanth Aravamudan285b3af2005-06-22 22:11:44 -0700523 msleep(100);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 write_lock_bh(&aarp_lock);
525
526 if (entry->status & ATIF_PROBE_FAIL)
527 break;
528 }
529
530 if (entry->status & ATIF_PROBE_FAIL) {
531 entry->expires_at = jiffies - 1; /* free the entry */
532 retval = -EADDRINUSE; /* return network full */
533 } else { /* clear the probing flag */
534 entry->status &= ~ATIF_PROBE;
535 retval = 1;
536 }
537
538 write_unlock_bh(&aarp_lock);
539out:
540 return retval;
541}
542
543/* Send a DDP frame */
544int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb,
545 struct atalk_addr *sa, void *hwaddr)
546{
547 static char ddp_eth_multicast[ETH_ALEN] =
548 { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF };
549 int hash;
550 struct aarp_entry *a;
551
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700552 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553
554 /* Check for LocalTalk first */
555 if (dev->type == ARPHRD_LOCALTLK) {
556 struct atalk_addr *at = atalk_find_dev_addr(dev);
557 struct ddpehdr *ddp = (struct ddpehdr *)skb->data;
558 int ft = 2;
559
560 /*
561 * Compressible ?
562 *
563 * IFF: src_net == dest_net == device_net
564 * (zero matches anything)
565 */
566
567 if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) &&
568 (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) {
569 skb_pull(skb, sizeof(*ddp) - 4);
570
571 /*
572 * The upper two remaining bytes are the port
573 * numbers we just happen to need. Now put the
574 * length in the lower two.
575 */
Alexey Dobriyanf6e276ee2005-06-20 13:32:05 -0700576 *((__be16 *)skb->data) = htons(skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 ft = 1;
578 }
579 /*
580 * Nice and easy. No AARP type protocols occur here so we can
581 * just shovel it out with a 3 byte LLAP header
582 */
583
584 skb_push(skb, 3);
585 skb->data[0] = sa->s_node;
586 skb->data[1] = at->s_node;
587 skb->data[2] = ft;
588 skb->dev = dev;
589 goto sendit;
590 }
591
592 /* On a PPP link we neither compress nor aarp. */
593 if (dev->type == ARPHRD_PPP) {
594 skb->protocol = htons(ETH_P_PPPTALK);
595 skb->dev = dev;
596 goto sendit;
597 }
598
599 /* Non ELAP we cannot do. */
600 if (dev->type != ARPHRD_ETHER)
601 return -1;
602
603 skb->dev = dev;
604 skb->protocol = htons(ETH_P_ATALK);
605 hash = sa->s_node % (AARP_HASH_SIZE - 1);
606
607 /* Do we have a resolved entry? */
608 if (sa->s_node == ATADDR_BCAST) {
609 /* Send it */
610 ddp_dl->request(ddp_dl, skb, ddp_eth_multicast);
611 goto sent;
612 }
613
614 write_lock_bh(&aarp_lock);
615 a = __aarp_find_entry(resolved[hash], dev, sa);
616
617 if (a) { /* Return 1 and fill in the address */
618 a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10);
619 ddp_dl->request(ddp_dl, skb, a->hwaddr);
620 write_unlock_bh(&aarp_lock);
621 goto sent;
622 }
623
624 /* Do we have an unresolved entry: This is the less common path */
625 a = __aarp_find_entry(unresolved[hash], dev, sa);
626 if (a) { /* Queue onto the unresolved queue */
627 skb_queue_tail(&a->packet_queue, skb);
628 goto out_unlock;
629 }
630
631 /* Allocate a new entry */
632 a = aarp_alloc();
633 if (!a) {
634 /* Whoops slipped... good job it's an unreliable protocol 8) */
635 write_unlock_bh(&aarp_lock);
636 return -1;
637 }
638
639 /* Set up the queue */
640 skb_queue_tail(&a->packet_queue, skb);
641 a->expires_at = jiffies + sysctl_aarp_resolve_time;
642 a->dev = dev;
643 a->next = unresolved[hash];
644 a->target_addr = *sa;
645 a->xmit_count = 0;
646 unresolved[hash] = a;
647 unresolved_count++;
648
649 /* Send an initial request for the address */
650 __aarp_send_query(a);
651
652 /*
653 * Switch to fast timer if needed (That is if this is the first
654 * unresolved entry to get added)
655 */
656
657 if (unresolved_count == 1)
658 mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time);
659
660 /* Now finally, it is safe to drop the lock. */
661out_unlock:
662 write_unlock_bh(&aarp_lock);
663
664 /* Tell the ddp layer we have taken over for this frame. */
665 return 0;
666
667sendit:
668 if (skb->sk)
669 skb->priority = skb->sk->sk_priority;
670 dev_queue_xmit(skb);
671sent:
672 return 1;
673}
674
675/*
676 * An entry in the aarp unresolved queue has become resolved. Send
677 * all the frames queued under it.
678 *
679 * Must run under aarp_lock.
680 */
681static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a,
682 int hash)
683{
684 struct sk_buff *skb;
685
686 while (*list)
687 if (*list == a) {
688 unresolved_count--;
689 *list = a->next;
690
691 /* Move into the resolved list */
692 a->next = resolved[hash];
693 resolved[hash] = a;
694
695 /* Kick frames off */
696 while ((skb = skb_dequeue(&a->packet_queue)) != NULL) {
697 a->expires_at = jiffies +
698 sysctl_aarp_expiry_time * 10;
699 ddp_dl->request(ddp_dl, skb, a->hwaddr);
700 }
701 } else
702 list = &((*list)->next);
703}
704
705/*
706 * This is called by the SNAP driver whenever we see an AARP SNAP
707 * frame. We currently only support Ethernet.
708 */
709static int aarp_rcv(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -0700710 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711{
712 struct elapaarp *ea = aarp_hdr(skb);
713 int hash, ret = 0;
714 __u16 function;
715 struct aarp_entry *a;
716 struct atalk_addr sa, *ma, da;
717 struct atalk_iface *ifa;
718
YOSHIFUJI Hideaki721499e2008-07-19 22:34:43 -0700719 if (!net_eq(dev_net(dev), &init_net))
Eric W. Biedermane730c152007-09-17 11:53:39 -0700720 goto out0;
721
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 /* We only do Ethernet SNAP AARP. */
723 if (dev->type != ARPHRD_ETHER)
724 goto out0;
725
726 /* Frame size ok? */
727 if (!skb_pull(skb, sizeof(*ea)))
728 goto out0;
729
730 function = ntohs(ea->function);
731
732 /* Sanity check fields. */
733 if (function < AARP_REQUEST || function > AARP_PROBE ||
734 ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN ||
735 ea->pa_src_zero || ea->pa_dst_zero)
736 goto out0;
737
738 /* Looks good. */
739 hash = ea->pa_src_node % (AARP_HASH_SIZE - 1);
740
741 /* Build an address. */
742 sa.s_node = ea->pa_src_node;
743 sa.s_net = ea->pa_src_net;
744
745 /* Process the packet. Check for replies of me. */
746 ifa = atalk_find_dev(dev);
747 if (!ifa)
748 goto out1;
749
750 if (ifa->status & ATIF_PROBE &&
751 ifa->address.s_node == ea->pa_dst_node &&
752 ifa->address.s_net == ea->pa_dst_net) {
753 ifa->status |= ATIF_PROBE_FAIL; /* Fail the probe (in use) */
754 goto out1;
755 }
756
757 /* Check for replies of proxy AARP entries */
758 da.s_node = ea->pa_dst_node;
759 da.s_net = ea->pa_dst_net;
760
761 write_lock_bh(&aarp_lock);
762 a = __aarp_find_entry(proxies[hash], dev, &da);
763
764 if (a && a->status & ATIF_PROBE) {
765 a->status |= ATIF_PROBE_FAIL;
766 /*
767 * we do not respond to probe or request packets for
768 * this address while we are probing this address
769 */
770 goto unlock;
771 }
772
773 switch (function) {
774 case AARP_REPLY:
775 if (!unresolved_count) /* Speed up */
776 break;
777
778 /* Find the entry. */
779 a = __aarp_find_entry(unresolved[hash], dev, &sa);
780 if (!a || dev != a->dev)
781 break;
782
783 /* We can fill one in - this is good. */
784 memcpy(a->hwaddr, ea->hw_src, ETH_ALEN);
785 __aarp_resolved(&unresolved[hash], a, hash);
786 if (!unresolved_count)
787 mod_timer(&aarp_timer,
788 jiffies + sysctl_aarp_expiry_time);
789 break;
790
791 case AARP_REQUEST:
792 case AARP_PROBE:
793
794 /*
795 * If it is my address set ma to my address and reply.
796 * We can treat probe and request the same. Probe
797 * simply means we shouldn't cache the querying host,
798 * as in a probe they are proposing an address not
799 * using one.
800 *
801 * Support for proxy-AARP added. We check if the
802 * address is one of our proxies before we toss the
803 * packet out.
804 */
805
806 sa.s_node = ea->pa_dst_node;
807 sa.s_net = ea->pa_dst_net;
808
809 /* See if we have a matching proxy. */
810 ma = __aarp_proxy_find(dev, &sa);
811 if (!ma)
812 ma = &ifa->address;
813 else { /* We need to make a copy of the entry. */
814 da.s_node = sa.s_node;
815 da.s_net = da.s_net;
816 ma = &da;
817 }
818
819 if (function == AARP_PROBE) {
820 /*
821 * A probe implies someone trying to get an
822 * address. So as a precaution flush any
823 * entries we have for this address.
824 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 a = __aarp_find_entry(resolved[sa.s_node %
826 (AARP_HASH_SIZE - 1)],
827 skb->dev, &sa);
828
829 /*
830 * Make it expire next tick - that avoids us
831 * getting into a probe/flush/learn/probe/
832 * flush/learn cycle during probing of a slow
833 * to respond host addr.
834 */
835 if (a) {
836 a->expires_at = jiffies - 1;
837 mod_timer(&aarp_timer, jiffies +
838 sysctl_aarp_tick_time);
839 }
840 }
841
842 if (sa.s_node != ma->s_node)
843 break;
844
845 if (sa.s_net && ma->s_net && sa.s_net != ma->s_net)
846 break;
847
848 sa.s_node = ea->pa_src_node;
849 sa.s_net = ea->pa_src_net;
850
851 /* aarp_my_address has found the address to use for us.
852 */
853 aarp_send_reply(dev, ma, &sa, ea->hw_src);
854 break;
855 }
856
857unlock:
858 write_unlock_bh(&aarp_lock);
859out1:
860 ret = 1;
861out0:
862 kfree_skb(skb);
863 return ret;
864}
865
866static struct notifier_block aarp_notifier = {
867 .notifier_call = aarp_device_event,
868};
869
870static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 };
871
872void __init aarp_proto_init(void)
873{
874 aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv);
875 if (!aarp_dl)
876 printk(KERN_CRIT "Unable to register AARP with SNAP.\n");
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800877 setup_timer(&aarp_timer, aarp_expire_timeout, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 aarp_timer.expires = jiffies + sysctl_aarp_expiry_time;
879 add_timer(&aarp_timer);
880 register_netdevice_notifier(&aarp_notifier);
881}
882
883/* Remove the AARP entries associated with a device. */
884void aarp_device_down(struct net_device *dev)
885{
886 int ct;
887
888 write_lock_bh(&aarp_lock);
889
890 for (ct = 0; ct < AARP_HASH_SIZE; ct++) {
891 __aarp_expire_device(&resolved[ct], dev);
892 __aarp_expire_device(&unresolved[ct], dev);
893 __aarp_expire_device(&proxies[ct], dev);
894 }
895
896 write_unlock_bh(&aarp_lock);
897}
898
899#ifdef CONFIG_PROC_FS
900struct aarp_iter_state {
901 int bucket;
902 struct aarp_entry **table;
903};
904
905/*
906 * Get the aarp entry that is in the chain described
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900907 * by the iterator.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 * If pos is set then skip till that index.
909 * pos = 1 is the first entry
910 */
911static struct aarp_entry *iter_next(struct aarp_iter_state *iter, loff_t *pos)
912{
913 int ct = iter->bucket;
914 struct aarp_entry **table = iter->table;
915 loff_t off = 0;
916 struct aarp_entry *entry;
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900917
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 rescan:
919 while(ct < AARP_HASH_SIZE) {
920 for (entry = table[ct]; entry; entry = entry->next) {
921 if (!pos || ++off == *pos) {
922 iter->table = table;
923 iter->bucket = ct;
924 return entry;
925 }
926 }
927 ++ct;
928 }
929
930 if (table == resolved) {
931 ct = 0;
932 table = unresolved;
933 goto rescan;
934 }
935 if (table == unresolved) {
936 ct = 0;
937 table = proxies;
938 goto rescan;
939 }
940 return NULL;
941}
942
943static void *aarp_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazetca629f242008-01-15 03:28:43 -0800944 __acquires(aarp_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945{
946 struct aarp_iter_state *iter = seq->private;
947
948 read_lock_bh(&aarp_lock);
949 iter->table = resolved;
950 iter->bucket = 0;
951
952 return *pos ? iter_next(iter, pos) : SEQ_START_TOKEN;
953}
954
955static void *aarp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
956{
957 struct aarp_entry *entry = v;
958 struct aarp_iter_state *iter = seq->private;
959
960 ++*pos;
961
962 /* first line after header */
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900963 if (v == SEQ_START_TOKEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 entry = iter_next(iter, NULL);
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +0900965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 /* next entry in current bucket */
967 else if (entry->next)
968 entry = entry->next;
969
970 /* next bucket or table */
971 else {
972 ++iter->bucket;
973 entry = iter_next(iter, NULL);
974 }
975 return entry;
976}
977
978static void aarp_seq_stop(struct seq_file *seq, void *v)
Eric Dumazetca629f242008-01-15 03:28:43 -0800979 __releases(aarp_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980{
981 read_unlock_bh(&aarp_lock);
982}
983
984static const char *dt2str(unsigned long ticks)
985{
986 static char buf[32];
987
988 sprintf(buf, "%ld.%02ld", ticks / HZ, ((ticks % HZ) * 100 ) / HZ);
989
990 return buf;
991}
992
993static int aarp_seq_show(struct seq_file *seq, void *v)
994{
995 struct aarp_iter_state *iter = seq->private;
996 struct aarp_entry *entry = v;
997 unsigned long now = jiffies;
Joe Perches0795af52007-10-03 17:59:30 -0700998 DECLARE_MAC_BUF(mac);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
1000 if (v == SEQ_START_TOKEN)
YOSHIFUJI Hideakied4477b2007-02-09 23:24:27 +09001001 seq_puts(seq,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 "Address Interface Hardware Address"
1003 " Expires LastSend Retry Status\n");
1004 else {
1005 seq_printf(seq, "%04X:%02X %-12s",
1006 ntohs(entry->target_addr.s_net),
1007 (unsigned int) entry->target_addr.s_node,
1008 entry->dev ? entry->dev->name : "????");
Joe Perches0795af52007-10-03 17:59:30 -07001009 seq_printf(seq, "%s", print_mac(mac, entry->hwaddr));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 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{
Pavel Emelyanovc20932d22008-02-29 11:38:24 -08001036 return seq_open_private(file, &aarp_seq_ops,
1037 sizeof(struct aarp_iter_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038}
1039
Arjan van de Ven9a321442007-02-12 00:55:35 -08001040const struct file_operations atalk_seq_arp_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 .owner = THIS_MODULE,
1042 .open = aarp_seq_open,
1043 .read = seq_read,
1044 .llseek = seq_lseek,
1045 .release = seq_release_private,
1046};
1047#endif
1048
1049/* General module cleanup. Called from cleanup_module() in ddp.c. */
1050void aarp_cleanup_module(void)
1051{
1052 del_timer_sync(&aarp_timer);
1053 unregister_netdevice_notifier(&aarp_notifier);
1054 unregister_snap_client(aarp_dl);
1055 aarp_purge();
1056}