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1da177e4 LT |
1 | /* |
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 | ||
32 | #include <linux/config.h> | |
33 | #include <linux/if_arp.h> | |
34 | #include <net/sock.h> | |
35 | #include <net/datalink.h> | |
36 | #include <net/psnap.h> | |
37 | #include <linux/atalk.h> | |
285b3afe | 38 | #include <linux/delay.h> |
1da177e4 LT |
39 | #include <linux/init.h> |
40 | #include <linux/proc_fs.h> | |
41 | #include <linux/seq_file.h> | |
42 | ||
43 | int sysctl_aarp_expiry_time = AARP_EXPIRY_TIME; | |
44 | int sysctl_aarp_tick_time = AARP_TICK_TIME; | |
45 | int sysctl_aarp_retransmit_limit = AARP_RETRANSMIT_LIMIT; | |
46 | int sysctl_aarp_resolve_time = AARP_RESOLVE_TIME; | |
47 | ||
48 | /* Lists of aarp entries */ | |
49 | /** | |
50 | * struct aarp_entry - AARP entry | |
51 | * @last_sent - Last time we xmitted the aarp request | |
52 | * @packet_queue - Queue of frames wait for resolution | |
53 | * @status - Used for proxy AARP | |
54 | * expires_at - Entry expiry time | |
55 | * target_addr - DDP Address | |
56 | * dev - Device to use | |
57 | * hwaddr - Physical i/f address of target/router | |
58 | * xmit_count - When this hits 10 we give up | |
59 | * next - Next entry in chain | |
60 | */ | |
61 | struct aarp_entry { | |
62 | /* These first two are only used for unresolved entries */ | |
63 | unsigned long last_sent; | |
64 | struct sk_buff_head packet_queue; | |
65 | int status; | |
66 | unsigned long expires_at; | |
67 | struct atalk_addr target_addr; | |
68 | struct net_device *dev; | |
69 | char hwaddr[6]; | |
70 | unsigned short xmit_count; | |
71 | struct aarp_entry *next; | |
72 | }; | |
73 | ||
74 | /* Hashed list of resolved, unresolved and proxy entries */ | |
75 | static struct aarp_entry *resolved[AARP_HASH_SIZE]; | |
76 | static struct aarp_entry *unresolved[AARP_HASH_SIZE]; | |
77 | static struct aarp_entry *proxies[AARP_HASH_SIZE]; | |
78 | static int unresolved_count; | |
79 | ||
80 | /* One lock protects it all. */ | |
81 | static DEFINE_RWLOCK(aarp_lock); | |
82 | ||
83 | /* Used to walk the list and purge/kick entries. */ | |
84 | static struct timer_list aarp_timer; | |
85 | ||
86 | /* | |
87 | * Delete an aarp queue | |
88 | * | |
89 | * Must run under aarp_lock. | |
90 | */ | |
91 | static void __aarp_expire(struct aarp_entry *a) | |
92 | { | |
93 | skb_queue_purge(&a->packet_queue); | |
94 | kfree(a); | |
95 | } | |
96 | ||
97 | /* | |
98 | * Send an aarp queue entry request | |
99 | * | |
100 | * Must run under aarp_lock. | |
101 | */ | |
102 | static void __aarp_send_query(struct aarp_entry *a) | |
103 | { | |
104 | static unsigned char aarp_eth_multicast[ETH_ALEN] = | |
105 | { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; | |
106 | struct net_device *dev = a->dev; | |
107 | struct elapaarp *eah; | |
108 | int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; | |
109 | struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); | |
110 | struct atalk_addr *sat = atalk_find_dev_addr(dev); | |
111 | ||
112 | if (!skb) | |
113 | return; | |
114 | ||
115 | if (!sat) { | |
116 | kfree_skb(skb); | |
117 | return; | |
118 | } | |
119 | ||
120 | /* Set up the buffer */ | |
121 | skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); | |
122 | skb->nh.raw = skb->h.raw = skb_put(skb, sizeof(*eah)); | |
123 | skb->protocol = htons(ETH_P_ATALK); | |
124 | skb->dev = dev; | |
125 | eah = aarp_hdr(skb); | |
126 | ||
127 | /* Set up the ARP */ | |
128 | eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); | |
129 | eah->pa_type = htons(ETH_P_ATALK); | |
130 | eah->hw_len = ETH_ALEN; | |
131 | eah->pa_len = AARP_PA_ALEN; | |
132 | eah->function = htons(AARP_REQUEST); | |
133 | ||
134 | memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); | |
135 | ||
136 | eah->pa_src_zero = 0; | |
137 | eah->pa_src_net = sat->s_net; | |
138 | eah->pa_src_node = sat->s_node; | |
139 | ||
140 | memset(eah->hw_dst, '\0', ETH_ALEN); | |
141 | ||
142 | eah->pa_dst_zero = 0; | |
143 | eah->pa_dst_net = a->target_addr.s_net; | |
144 | eah->pa_dst_node = a->target_addr.s_node; | |
145 | ||
146 | /* Send it */ | |
147 | aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); | |
148 | /* Update the sending count */ | |
149 | a->xmit_count++; | |
150 | a->last_sent = jiffies; | |
151 | } | |
152 | ||
153 | /* This runs under aarp_lock and in softint context, so only atomic memory | |
154 | * allocations can be used. */ | |
155 | static void aarp_send_reply(struct net_device *dev, struct atalk_addr *us, | |
156 | struct atalk_addr *them, unsigned char *sha) | |
157 | { | |
158 | struct elapaarp *eah; | |
159 | int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; | |
160 | struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); | |
161 | ||
162 | if (!skb) | |
163 | return; | |
164 | ||
165 | /* Set up the buffer */ | |
166 | skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); | |
167 | skb->nh.raw = skb->h.raw = skb_put(skb, sizeof(*eah)); | |
168 | skb->protocol = htons(ETH_P_ATALK); | |
169 | skb->dev = dev; | |
170 | eah = aarp_hdr(skb); | |
171 | ||
172 | /* Set up the ARP */ | |
173 | eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); | |
174 | eah->pa_type = htons(ETH_P_ATALK); | |
175 | eah->hw_len = ETH_ALEN; | |
176 | eah->pa_len = AARP_PA_ALEN; | |
177 | eah->function = htons(AARP_REPLY); | |
178 | ||
179 | memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); | |
180 | ||
181 | eah->pa_src_zero = 0; | |
182 | eah->pa_src_net = us->s_net; | |
183 | eah->pa_src_node = us->s_node; | |
184 | ||
185 | if (!sha) | |
186 | memset(eah->hw_dst, '\0', ETH_ALEN); | |
187 | else | |
188 | memcpy(eah->hw_dst, sha, ETH_ALEN); | |
189 | ||
190 | eah->pa_dst_zero = 0; | |
191 | eah->pa_dst_net = them->s_net; | |
192 | eah->pa_dst_node = them->s_node; | |
193 | ||
194 | /* Send it */ | |
195 | aarp_dl->request(aarp_dl, skb, sha); | |
196 | } | |
197 | ||
198 | /* | |
199 | * Send probe frames. Called from aarp_probe_network and | |
200 | * aarp_proxy_probe_network. | |
201 | */ | |
202 | ||
203 | static void aarp_send_probe(struct net_device *dev, struct atalk_addr *us) | |
204 | { | |
205 | struct elapaarp *eah; | |
206 | int len = dev->hard_header_len + sizeof(*eah) + aarp_dl->header_length; | |
207 | struct sk_buff *skb = alloc_skb(len, GFP_ATOMIC); | |
208 | static unsigned char aarp_eth_multicast[ETH_ALEN] = | |
209 | { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; | |
210 | ||
211 | if (!skb) | |
212 | return; | |
213 | ||
214 | /* Set up the buffer */ | |
215 | skb_reserve(skb, dev->hard_header_len + aarp_dl->header_length); | |
216 | skb->nh.raw = skb->h.raw = skb_put(skb, sizeof(*eah)); | |
217 | skb->protocol = htons(ETH_P_ATALK); | |
218 | skb->dev = dev; | |
219 | eah = aarp_hdr(skb); | |
220 | ||
221 | /* Set up the ARP */ | |
222 | eah->hw_type = htons(AARP_HW_TYPE_ETHERNET); | |
223 | eah->pa_type = htons(ETH_P_ATALK); | |
224 | eah->hw_len = ETH_ALEN; | |
225 | eah->pa_len = AARP_PA_ALEN; | |
226 | eah->function = htons(AARP_PROBE); | |
227 | ||
228 | memcpy(eah->hw_src, dev->dev_addr, ETH_ALEN); | |
229 | ||
230 | eah->pa_src_zero = 0; | |
231 | eah->pa_src_net = us->s_net; | |
232 | eah->pa_src_node = us->s_node; | |
233 | ||
234 | memset(eah->hw_dst, '\0', ETH_ALEN); | |
235 | ||
236 | eah->pa_dst_zero = 0; | |
237 | eah->pa_dst_net = us->s_net; | |
238 | eah->pa_dst_node = us->s_node; | |
239 | ||
240 | /* Send it */ | |
241 | aarp_dl->request(aarp_dl, skb, aarp_eth_multicast); | |
242 | } | |
243 | ||
244 | /* | |
245 | * Handle an aarp timer expire | |
246 | * | |
247 | * Must run under the aarp_lock. | |
248 | */ | |
249 | ||
250 | static void __aarp_expire_timer(struct aarp_entry **n) | |
251 | { | |
252 | struct aarp_entry *t; | |
253 | ||
254 | while (*n) | |
255 | /* Expired ? */ | |
256 | if (time_after(jiffies, (*n)->expires_at)) { | |
257 | t = *n; | |
258 | *n = (*n)->next; | |
259 | __aarp_expire(t); | |
260 | } else | |
261 | n = &((*n)->next); | |
262 | } | |
263 | ||
264 | /* | |
265 | * Kick all pending requests 5 times a second. | |
266 | * | |
267 | * Must run under the aarp_lock. | |
268 | */ | |
269 | static void __aarp_kick(struct aarp_entry **n) | |
270 | { | |
271 | struct aarp_entry *t; | |
272 | ||
273 | while (*n) | |
274 | /* Expired: if this will be the 11th tx, we delete instead. */ | |
275 | if ((*n)->xmit_count >= sysctl_aarp_retransmit_limit) { | |
276 | t = *n; | |
277 | *n = (*n)->next; | |
278 | __aarp_expire(t); | |
279 | } else { | |
280 | __aarp_send_query(*n); | |
281 | n = &((*n)->next); | |
282 | } | |
283 | } | |
284 | ||
285 | /* | |
286 | * A device has gone down. Take all entries referring to the device | |
287 | * and remove them. | |
288 | * | |
289 | * Must run under the aarp_lock. | |
290 | */ | |
291 | static void __aarp_expire_device(struct aarp_entry **n, struct net_device *dev) | |
292 | { | |
293 | struct aarp_entry *t; | |
294 | ||
295 | while (*n) | |
296 | if ((*n)->dev == dev) { | |
297 | t = *n; | |
298 | *n = (*n)->next; | |
299 | __aarp_expire(t); | |
300 | } else | |
301 | n = &((*n)->next); | |
302 | } | |
303 | ||
304 | /* Handle the timer event */ | |
305 | static void aarp_expire_timeout(unsigned long unused) | |
306 | { | |
307 | int ct; | |
308 | ||
309 | write_lock_bh(&aarp_lock); | |
310 | ||
311 | for (ct = 0; ct < AARP_HASH_SIZE; ct++) { | |
312 | __aarp_expire_timer(&resolved[ct]); | |
313 | __aarp_kick(&unresolved[ct]); | |
314 | __aarp_expire_timer(&unresolved[ct]); | |
315 | __aarp_expire_timer(&proxies[ct]); | |
316 | } | |
317 | ||
318 | write_unlock_bh(&aarp_lock); | |
319 | mod_timer(&aarp_timer, jiffies + | |
320 | (unresolved_count ? sysctl_aarp_tick_time : | |
321 | sysctl_aarp_expiry_time)); | |
322 | } | |
323 | ||
324 | /* Network device notifier chain handler. */ | |
325 | static int aarp_device_event(struct notifier_block *this, unsigned long event, | |
326 | void *ptr) | |
327 | { | |
328 | int ct; | |
329 | ||
330 | if (event == NETDEV_DOWN) { | |
331 | write_lock_bh(&aarp_lock); | |
332 | ||
333 | for (ct = 0; ct < AARP_HASH_SIZE; ct++) { | |
334 | __aarp_expire_device(&resolved[ct], ptr); | |
335 | __aarp_expire_device(&unresolved[ct], ptr); | |
336 | __aarp_expire_device(&proxies[ct], ptr); | |
337 | } | |
338 | ||
339 | write_unlock_bh(&aarp_lock); | |
340 | } | |
341 | return NOTIFY_DONE; | |
342 | } | |
343 | ||
344 | /* Expire all entries in a hash chain */ | |
345 | static void __aarp_expire_all(struct aarp_entry **n) | |
346 | { | |
347 | struct aarp_entry *t; | |
348 | ||
349 | while (*n) { | |
350 | t = *n; | |
351 | *n = (*n)->next; | |
352 | __aarp_expire(t); | |
353 | } | |
354 | } | |
355 | ||
356 | /* Cleanup all hash chains -- module unloading */ | |
357 | static void aarp_purge(void) | |
358 | { | |
359 | int ct; | |
360 | ||
361 | write_lock_bh(&aarp_lock); | |
362 | for (ct = 0; ct < AARP_HASH_SIZE; ct++) { | |
363 | __aarp_expire_all(&resolved[ct]); | |
364 | __aarp_expire_all(&unresolved[ct]); | |
365 | __aarp_expire_all(&proxies[ct]); | |
366 | } | |
367 | write_unlock_bh(&aarp_lock); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Create a new aarp entry. This must use GFP_ATOMIC because it | |
372 | * runs while holding spinlocks. | |
373 | */ | |
374 | static struct aarp_entry *aarp_alloc(void) | |
375 | { | |
376 | struct aarp_entry *a = kmalloc(sizeof(*a), GFP_ATOMIC); | |
377 | ||
378 | if (a) | |
379 | skb_queue_head_init(&a->packet_queue); | |
380 | return a; | |
381 | } | |
382 | ||
383 | /* | |
384 | * Find an entry. We might return an expired but not yet purged entry. We | |
385 | * don't care as it will do no harm. | |
386 | * | |
387 | * This must run under the aarp_lock. | |
388 | */ | |
389 | static struct aarp_entry *__aarp_find_entry(struct aarp_entry *list, | |
390 | struct net_device *dev, | |
391 | struct atalk_addr *sat) | |
392 | { | |
393 | while (list) { | |
394 | if (list->target_addr.s_net == sat->s_net && | |
395 | list->target_addr.s_node == sat->s_node && | |
396 | list->dev == dev) | |
397 | break; | |
398 | list = list->next; | |
399 | } | |
400 | ||
401 | return list; | |
402 | } | |
403 | ||
404 | /* Called from the DDP code, and thus must be exported. */ | |
405 | void aarp_proxy_remove(struct net_device *dev, struct atalk_addr *sa) | |
406 | { | |
407 | int hash = sa->s_node % (AARP_HASH_SIZE - 1); | |
408 | struct aarp_entry *a; | |
409 | ||
410 | write_lock_bh(&aarp_lock); | |
411 | ||
412 | a = __aarp_find_entry(proxies[hash], dev, sa); | |
413 | if (a) | |
414 | a->expires_at = jiffies - 1; | |
415 | ||
416 | write_unlock_bh(&aarp_lock); | |
417 | } | |
418 | ||
419 | /* This must run under aarp_lock. */ | |
420 | static struct atalk_addr *__aarp_proxy_find(struct net_device *dev, | |
421 | struct atalk_addr *sa) | |
422 | { | |
423 | int hash = sa->s_node % (AARP_HASH_SIZE - 1); | |
424 | struct aarp_entry *a = __aarp_find_entry(proxies[hash], dev, sa); | |
425 | ||
426 | return a ? sa : NULL; | |
427 | } | |
428 | ||
429 | /* | |
430 | * Probe a Phase 1 device or a device that requires its Net:Node to | |
431 | * be set via an ioctl. | |
432 | */ | |
433 | static void aarp_send_probe_phase1(struct atalk_iface *iface) | |
434 | { | |
435 | struct ifreq atreq; | |
436 | struct sockaddr_at *sa = (struct sockaddr_at *)&atreq.ifr_addr; | |
437 | ||
438 | sa->sat_addr.s_node = iface->address.s_node; | |
439 | sa->sat_addr.s_net = ntohs(iface->address.s_net); | |
440 | ||
441 | /* We pass the Net:Node to the drivers/cards by a Device ioctl. */ | |
442 | if (!(iface->dev->do_ioctl(iface->dev, &atreq, SIOCSIFADDR))) { | |
443 | (void)iface->dev->do_ioctl(iface->dev, &atreq, SIOCGIFADDR); | |
444 | if (iface->address.s_net != htons(sa->sat_addr.s_net) || | |
445 | iface->address.s_node != sa->sat_addr.s_node) | |
446 | iface->status |= ATIF_PROBE_FAIL; | |
447 | ||
448 | iface->address.s_net = htons(sa->sat_addr.s_net); | |
449 | iface->address.s_node = sa->sat_addr.s_node; | |
450 | } | |
451 | } | |
452 | ||
453 | ||
454 | void aarp_probe_network(struct atalk_iface *atif) | |
455 | { | |
456 | if (atif->dev->type == ARPHRD_LOCALTLK || | |
457 | atif->dev->type == ARPHRD_PPP) | |
458 | aarp_send_probe_phase1(atif); | |
459 | else { | |
460 | unsigned int count; | |
461 | ||
462 | for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { | |
463 | aarp_send_probe(atif->dev, &atif->address); | |
464 | ||
465 | /* Defer 1/10th */ | |
285b3afe | 466 | msleep(100); |
1da177e4 LT |
467 | |
468 | if (atif->status & ATIF_PROBE_FAIL) | |
469 | break; | |
470 | } | |
471 | } | |
472 | } | |
473 | ||
474 | int aarp_proxy_probe_network(struct atalk_iface *atif, struct atalk_addr *sa) | |
475 | { | |
476 | int hash, retval = -EPROTONOSUPPORT; | |
477 | struct aarp_entry *entry; | |
478 | unsigned int count; | |
479 | ||
480 | /* | |
481 | * we don't currently support LocalTalk or PPP for proxy AARP; | |
482 | * if someone wants to try and add it, have fun | |
483 | */ | |
484 | if (atif->dev->type == ARPHRD_LOCALTLK || | |
485 | atif->dev->type == ARPHRD_PPP) | |
486 | goto out; | |
487 | ||
488 | /* | |
489 | * create a new AARP entry with the flags set to be published -- | |
490 | * we need this one to hang around even if it's in use | |
491 | */ | |
492 | entry = aarp_alloc(); | |
493 | retval = -ENOMEM; | |
494 | if (!entry) | |
495 | goto out; | |
496 | ||
497 | entry->expires_at = -1; | |
498 | entry->status = ATIF_PROBE; | |
499 | entry->target_addr.s_node = sa->s_node; | |
500 | entry->target_addr.s_net = sa->s_net; | |
501 | entry->dev = atif->dev; | |
502 | ||
503 | write_lock_bh(&aarp_lock); | |
504 | ||
505 | hash = sa->s_node % (AARP_HASH_SIZE - 1); | |
506 | entry->next = proxies[hash]; | |
507 | proxies[hash] = entry; | |
508 | ||
509 | for (count = 0; count < AARP_RETRANSMIT_LIMIT; count++) { | |
510 | aarp_send_probe(atif->dev, sa); | |
511 | ||
512 | /* Defer 1/10th */ | |
1da177e4 | 513 | write_unlock_bh(&aarp_lock); |
285b3afe | 514 | msleep(100); |
1da177e4 LT |
515 | write_lock_bh(&aarp_lock); |
516 | ||
517 | if (entry->status & ATIF_PROBE_FAIL) | |
518 | break; | |
519 | } | |
520 | ||
521 | if (entry->status & ATIF_PROBE_FAIL) { | |
522 | entry->expires_at = jiffies - 1; /* free the entry */ | |
523 | retval = -EADDRINUSE; /* return network full */ | |
524 | } else { /* clear the probing flag */ | |
525 | entry->status &= ~ATIF_PROBE; | |
526 | retval = 1; | |
527 | } | |
528 | ||
529 | write_unlock_bh(&aarp_lock); | |
530 | out: | |
531 | return retval; | |
532 | } | |
533 | ||
534 | /* Send a DDP frame */ | |
535 | int aarp_send_ddp(struct net_device *dev, struct sk_buff *skb, | |
536 | struct atalk_addr *sa, void *hwaddr) | |
537 | { | |
538 | static char ddp_eth_multicast[ETH_ALEN] = | |
539 | { 0x09, 0x00, 0x07, 0xFF, 0xFF, 0xFF }; | |
540 | int hash; | |
541 | struct aarp_entry *a; | |
542 | ||
543 | skb->nh.raw = skb->data; | |
544 | ||
545 | /* Check for LocalTalk first */ | |
546 | if (dev->type == ARPHRD_LOCALTLK) { | |
547 | struct atalk_addr *at = atalk_find_dev_addr(dev); | |
548 | struct ddpehdr *ddp = (struct ddpehdr *)skb->data; | |
549 | int ft = 2; | |
550 | ||
551 | /* | |
552 | * Compressible ? | |
553 | * | |
554 | * IFF: src_net == dest_net == device_net | |
555 | * (zero matches anything) | |
556 | */ | |
557 | ||
558 | if ((!ddp->deh_snet || at->s_net == ddp->deh_snet) && | |
559 | (!ddp->deh_dnet || at->s_net == ddp->deh_dnet)) { | |
560 | skb_pull(skb, sizeof(*ddp) - 4); | |
561 | ||
562 | /* | |
563 | * The upper two remaining bytes are the port | |
564 | * numbers we just happen to need. Now put the | |
565 | * length in the lower two. | |
566 | */ | |
f6e276ee | 567 | *((__be16 *)skb->data) = htons(skb->len); |
1da177e4 LT |
568 | ft = 1; |
569 | } | |
570 | /* | |
571 | * Nice and easy. No AARP type protocols occur here so we can | |
572 | * just shovel it out with a 3 byte LLAP header | |
573 | */ | |
574 | ||
575 | skb_push(skb, 3); | |
576 | skb->data[0] = sa->s_node; | |
577 | skb->data[1] = at->s_node; | |
578 | skb->data[2] = ft; | |
579 | skb->dev = dev; | |
580 | goto sendit; | |
581 | } | |
582 | ||
583 | /* On a PPP link we neither compress nor aarp. */ | |
584 | if (dev->type == ARPHRD_PPP) { | |
585 | skb->protocol = htons(ETH_P_PPPTALK); | |
586 | skb->dev = dev; | |
587 | goto sendit; | |
588 | } | |
589 | ||
590 | /* Non ELAP we cannot do. */ | |
591 | if (dev->type != ARPHRD_ETHER) | |
592 | return -1; | |
593 | ||
594 | skb->dev = dev; | |
595 | skb->protocol = htons(ETH_P_ATALK); | |
596 | hash = sa->s_node % (AARP_HASH_SIZE - 1); | |
597 | ||
598 | /* Do we have a resolved entry? */ | |
599 | if (sa->s_node == ATADDR_BCAST) { | |
600 | /* Send it */ | |
601 | ddp_dl->request(ddp_dl, skb, ddp_eth_multicast); | |
602 | goto sent; | |
603 | } | |
604 | ||
605 | write_lock_bh(&aarp_lock); | |
606 | a = __aarp_find_entry(resolved[hash], dev, sa); | |
607 | ||
608 | if (a) { /* Return 1 and fill in the address */ | |
609 | a->expires_at = jiffies + (sysctl_aarp_expiry_time * 10); | |
610 | ddp_dl->request(ddp_dl, skb, a->hwaddr); | |
611 | write_unlock_bh(&aarp_lock); | |
612 | goto sent; | |
613 | } | |
614 | ||
615 | /* Do we have an unresolved entry: This is the less common path */ | |
616 | a = __aarp_find_entry(unresolved[hash], dev, sa); | |
617 | if (a) { /* Queue onto the unresolved queue */ | |
618 | skb_queue_tail(&a->packet_queue, skb); | |
619 | goto out_unlock; | |
620 | } | |
621 | ||
622 | /* Allocate a new entry */ | |
623 | a = aarp_alloc(); | |
624 | if (!a) { | |
625 | /* Whoops slipped... good job it's an unreliable protocol 8) */ | |
626 | write_unlock_bh(&aarp_lock); | |
627 | return -1; | |
628 | } | |
629 | ||
630 | /* Set up the queue */ | |
631 | skb_queue_tail(&a->packet_queue, skb); | |
632 | a->expires_at = jiffies + sysctl_aarp_resolve_time; | |
633 | a->dev = dev; | |
634 | a->next = unresolved[hash]; | |
635 | a->target_addr = *sa; | |
636 | a->xmit_count = 0; | |
637 | unresolved[hash] = a; | |
638 | unresolved_count++; | |
639 | ||
640 | /* Send an initial request for the address */ | |
641 | __aarp_send_query(a); | |
642 | ||
643 | /* | |
644 | * Switch to fast timer if needed (That is if this is the first | |
645 | * unresolved entry to get added) | |
646 | */ | |
647 | ||
648 | if (unresolved_count == 1) | |
649 | mod_timer(&aarp_timer, jiffies + sysctl_aarp_tick_time); | |
650 | ||
651 | /* Now finally, it is safe to drop the lock. */ | |
652 | out_unlock: | |
653 | write_unlock_bh(&aarp_lock); | |
654 | ||
655 | /* Tell the ddp layer we have taken over for this frame. */ | |
656 | return 0; | |
657 | ||
658 | sendit: | |
659 | if (skb->sk) | |
660 | skb->priority = skb->sk->sk_priority; | |
661 | dev_queue_xmit(skb); | |
662 | sent: | |
663 | return 1; | |
664 | } | |
665 | ||
666 | /* | |
667 | * An entry in the aarp unresolved queue has become resolved. Send | |
668 | * all the frames queued under it. | |
669 | * | |
670 | * Must run under aarp_lock. | |
671 | */ | |
672 | static void __aarp_resolved(struct aarp_entry **list, struct aarp_entry *a, | |
673 | int hash) | |
674 | { | |
675 | struct sk_buff *skb; | |
676 | ||
677 | while (*list) | |
678 | if (*list == a) { | |
679 | unresolved_count--; | |
680 | *list = a->next; | |
681 | ||
682 | /* Move into the resolved list */ | |
683 | a->next = resolved[hash]; | |
684 | resolved[hash] = a; | |
685 | ||
686 | /* Kick frames off */ | |
687 | while ((skb = skb_dequeue(&a->packet_queue)) != NULL) { | |
688 | a->expires_at = jiffies + | |
689 | sysctl_aarp_expiry_time * 10; | |
690 | ddp_dl->request(ddp_dl, skb, a->hwaddr); | |
691 | } | |
692 | } else | |
693 | list = &((*list)->next); | |
694 | } | |
695 | ||
696 | /* | |
697 | * This is called by the SNAP driver whenever we see an AARP SNAP | |
698 | * frame. We currently only support Ethernet. | |
699 | */ | |
700 | static int aarp_rcv(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 701 | struct packet_type *pt, struct net_device *orig_dev) |
1da177e4 LT |
702 | { |
703 | struct elapaarp *ea = aarp_hdr(skb); | |
704 | int hash, ret = 0; | |
705 | __u16 function; | |
706 | struct aarp_entry *a; | |
707 | struct atalk_addr sa, *ma, da; | |
708 | struct atalk_iface *ifa; | |
709 | ||
710 | /* We only do Ethernet SNAP AARP. */ | |
711 | if (dev->type != ARPHRD_ETHER) | |
712 | goto out0; | |
713 | ||
714 | /* Frame size ok? */ | |
715 | if (!skb_pull(skb, sizeof(*ea))) | |
716 | goto out0; | |
717 | ||
718 | function = ntohs(ea->function); | |
719 | ||
720 | /* Sanity check fields. */ | |
721 | if (function < AARP_REQUEST || function > AARP_PROBE || | |
722 | ea->hw_len != ETH_ALEN || ea->pa_len != AARP_PA_ALEN || | |
723 | ea->pa_src_zero || ea->pa_dst_zero) | |
724 | goto out0; | |
725 | ||
726 | /* Looks good. */ | |
727 | hash = ea->pa_src_node % (AARP_HASH_SIZE - 1); | |
728 | ||
729 | /* Build an address. */ | |
730 | sa.s_node = ea->pa_src_node; | |
731 | sa.s_net = ea->pa_src_net; | |
732 | ||
733 | /* Process the packet. Check for replies of me. */ | |
734 | ifa = atalk_find_dev(dev); | |
735 | if (!ifa) | |
736 | goto out1; | |
737 | ||
738 | if (ifa->status & ATIF_PROBE && | |
739 | ifa->address.s_node == ea->pa_dst_node && | |
740 | ifa->address.s_net == ea->pa_dst_net) { | |
741 | ifa->status |= ATIF_PROBE_FAIL; /* Fail the probe (in use) */ | |
742 | goto out1; | |
743 | } | |
744 | ||
745 | /* Check for replies of proxy AARP entries */ | |
746 | da.s_node = ea->pa_dst_node; | |
747 | da.s_net = ea->pa_dst_net; | |
748 | ||
749 | write_lock_bh(&aarp_lock); | |
750 | a = __aarp_find_entry(proxies[hash], dev, &da); | |
751 | ||
752 | if (a && a->status & ATIF_PROBE) { | |
753 | a->status |= ATIF_PROBE_FAIL; | |
754 | /* | |
755 | * we do not respond to probe or request packets for | |
756 | * this address while we are probing this address | |
757 | */ | |
758 | goto unlock; | |
759 | } | |
760 | ||
761 | switch (function) { | |
762 | case AARP_REPLY: | |
763 | if (!unresolved_count) /* Speed up */ | |
764 | break; | |
765 | ||
766 | /* Find the entry. */ | |
767 | a = __aarp_find_entry(unresolved[hash], dev, &sa); | |
768 | if (!a || dev != a->dev) | |
769 | break; | |
770 | ||
771 | /* We can fill one in - this is good. */ | |
772 | memcpy(a->hwaddr, ea->hw_src, ETH_ALEN); | |
773 | __aarp_resolved(&unresolved[hash], a, hash); | |
774 | if (!unresolved_count) | |
775 | mod_timer(&aarp_timer, | |
776 | jiffies + sysctl_aarp_expiry_time); | |
777 | break; | |
778 | ||
779 | case AARP_REQUEST: | |
780 | case AARP_PROBE: | |
781 | ||
782 | /* | |
783 | * If it is my address set ma to my address and reply. | |
784 | * We can treat probe and request the same. Probe | |
785 | * simply means we shouldn't cache the querying host, | |
786 | * as in a probe they are proposing an address not | |
787 | * using one. | |
788 | * | |
789 | * Support for proxy-AARP added. We check if the | |
790 | * address is one of our proxies before we toss the | |
791 | * packet out. | |
792 | */ | |
793 | ||
794 | sa.s_node = ea->pa_dst_node; | |
795 | sa.s_net = ea->pa_dst_net; | |
796 | ||
797 | /* See if we have a matching proxy. */ | |
798 | ma = __aarp_proxy_find(dev, &sa); | |
799 | if (!ma) | |
800 | ma = &ifa->address; | |
801 | else { /* We need to make a copy of the entry. */ | |
802 | da.s_node = sa.s_node; | |
803 | da.s_net = da.s_net; | |
804 | ma = &da; | |
805 | } | |
806 | ||
807 | if (function == AARP_PROBE) { | |
808 | /* | |
809 | * A probe implies someone trying to get an | |
810 | * address. So as a precaution flush any | |
811 | * entries we have for this address. | |
812 | */ | |
813 | struct aarp_entry *a; | |
814 | ||
815 | a = __aarp_find_entry(resolved[sa.s_node % | |
816 | (AARP_HASH_SIZE - 1)], | |
817 | skb->dev, &sa); | |
818 | ||
819 | /* | |
820 | * Make it expire next tick - that avoids us | |
821 | * getting into a probe/flush/learn/probe/ | |
822 | * flush/learn cycle during probing of a slow | |
823 | * to respond host addr. | |
824 | */ | |
825 | if (a) { | |
826 | a->expires_at = jiffies - 1; | |
827 | mod_timer(&aarp_timer, jiffies + | |
828 | sysctl_aarp_tick_time); | |
829 | } | |
830 | } | |
831 | ||
832 | if (sa.s_node != ma->s_node) | |
833 | break; | |
834 | ||
835 | if (sa.s_net && ma->s_net && sa.s_net != ma->s_net) | |
836 | break; | |
837 | ||
838 | sa.s_node = ea->pa_src_node; | |
839 | sa.s_net = ea->pa_src_net; | |
840 | ||
841 | /* aarp_my_address has found the address to use for us. | |
842 | */ | |
843 | aarp_send_reply(dev, ma, &sa, ea->hw_src); | |
844 | break; | |
845 | } | |
846 | ||
847 | unlock: | |
848 | write_unlock_bh(&aarp_lock); | |
849 | out1: | |
850 | ret = 1; | |
851 | out0: | |
852 | kfree_skb(skb); | |
853 | return ret; | |
854 | } | |
855 | ||
856 | static struct notifier_block aarp_notifier = { | |
857 | .notifier_call = aarp_device_event, | |
858 | }; | |
859 | ||
860 | static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 }; | |
861 | ||
862 | void __init aarp_proto_init(void) | |
863 | { | |
864 | aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv); | |
865 | if (!aarp_dl) | |
866 | printk(KERN_CRIT "Unable to register AARP with SNAP.\n"); | |
867 | init_timer(&aarp_timer); | |
868 | aarp_timer.function = aarp_expire_timeout; | |
869 | aarp_timer.data = 0; | |
870 | aarp_timer.expires = jiffies + sysctl_aarp_expiry_time; | |
871 | add_timer(&aarp_timer); | |
872 | register_netdevice_notifier(&aarp_notifier); | |
873 | } | |
874 | ||
875 | /* Remove the AARP entries associated with a device. */ | |
876 | void aarp_device_down(struct net_device *dev) | |
877 | { | |
878 | int ct; | |
879 | ||
880 | write_lock_bh(&aarp_lock); | |
881 | ||
882 | for (ct = 0; ct < AARP_HASH_SIZE; ct++) { | |
883 | __aarp_expire_device(&resolved[ct], dev); | |
884 | __aarp_expire_device(&unresolved[ct], dev); | |
885 | __aarp_expire_device(&proxies[ct], dev); | |
886 | } | |
887 | ||
888 | write_unlock_bh(&aarp_lock); | |
889 | } | |
890 | ||
891 | #ifdef CONFIG_PROC_FS | |
892 | struct aarp_iter_state { | |
893 | int bucket; | |
894 | struct aarp_entry **table; | |
895 | }; | |
896 | ||
897 | /* | |
898 | * Get the aarp entry that is in the chain described | |
899 | * by the iterator. | |
900 | * If pos is set then skip till that index. | |
901 | * pos = 1 is the first entry | |
902 | */ | |
903 | static struct aarp_entry *iter_next(struct aarp_iter_state *iter, loff_t *pos) | |
904 | { | |
905 | int ct = iter->bucket; | |
906 | struct aarp_entry **table = iter->table; | |
907 | loff_t off = 0; | |
908 | struct aarp_entry *entry; | |
909 | ||
910 | rescan: | |
911 | while(ct < AARP_HASH_SIZE) { | |
912 | for (entry = table[ct]; entry; entry = entry->next) { | |
913 | if (!pos || ++off == *pos) { | |
914 | iter->table = table; | |
915 | iter->bucket = ct; | |
916 | return entry; | |
917 | } | |
918 | } | |
919 | ++ct; | |
920 | } | |
921 | ||
922 | if (table == resolved) { | |
923 | ct = 0; | |
924 | table = unresolved; | |
925 | goto rescan; | |
926 | } | |
927 | if (table == unresolved) { | |
928 | ct = 0; | |
929 | table = proxies; | |
930 | goto rescan; | |
931 | } | |
932 | return NULL; | |
933 | } | |
934 | ||
935 | static void *aarp_seq_start(struct seq_file *seq, loff_t *pos) | |
936 | { | |
937 | struct aarp_iter_state *iter = seq->private; | |
938 | ||
939 | read_lock_bh(&aarp_lock); | |
940 | iter->table = resolved; | |
941 | iter->bucket = 0; | |
942 | ||
943 | return *pos ? iter_next(iter, pos) : SEQ_START_TOKEN; | |
944 | } | |
945 | ||
946 | static void *aarp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
947 | { | |
948 | struct aarp_entry *entry = v; | |
949 | struct aarp_iter_state *iter = seq->private; | |
950 | ||
951 | ++*pos; | |
952 | ||
953 | /* first line after header */ | |
954 | if (v == SEQ_START_TOKEN) | |
955 | entry = iter_next(iter, NULL); | |
956 | ||
957 | /* next entry in current bucket */ | |
958 | else if (entry->next) | |
959 | entry = entry->next; | |
960 | ||
961 | /* next bucket or table */ | |
962 | else { | |
963 | ++iter->bucket; | |
964 | entry = iter_next(iter, NULL); | |
965 | } | |
966 | return entry; | |
967 | } | |
968 | ||
969 | static void aarp_seq_stop(struct seq_file *seq, void *v) | |
970 | { | |
971 | read_unlock_bh(&aarp_lock); | |
972 | } | |
973 | ||
974 | static const char *dt2str(unsigned long ticks) | |
975 | { | |
976 | static char buf[32]; | |
977 | ||
978 | sprintf(buf, "%ld.%02ld", ticks / HZ, ((ticks % HZ) * 100 ) / HZ); | |
979 | ||
980 | return buf; | |
981 | } | |
982 | ||
983 | static int aarp_seq_show(struct seq_file *seq, void *v) | |
984 | { | |
985 | struct aarp_iter_state *iter = seq->private; | |
986 | struct aarp_entry *entry = v; | |
987 | unsigned long now = jiffies; | |
988 | ||
989 | if (v == SEQ_START_TOKEN) | |
990 | seq_puts(seq, | |
991 | "Address Interface Hardware Address" | |
992 | " Expires LastSend Retry Status\n"); | |
993 | else { | |
994 | seq_printf(seq, "%04X:%02X %-12s", | |
995 | ntohs(entry->target_addr.s_net), | |
996 | (unsigned int) entry->target_addr.s_node, | |
997 | entry->dev ? entry->dev->name : "????"); | |
998 | seq_printf(seq, "%02X:%02X:%02X:%02X:%02X:%02X", | |
999 | entry->hwaddr[0] & 0xFF, | |
1000 | entry->hwaddr[1] & 0xFF, | |
1001 | entry->hwaddr[2] & 0xFF, | |
1002 | entry->hwaddr[3] & 0xFF, | |
1003 | entry->hwaddr[4] & 0xFF, | |
1004 | entry->hwaddr[5] & 0xFF); | |
1005 | seq_printf(seq, " %8s", | |
1006 | dt2str((long)entry->expires_at - (long)now)); | |
1007 | if (iter->table == unresolved) | |
1008 | seq_printf(seq, " %8s %6hu", | |
1009 | dt2str(now - entry->last_sent), | |
1010 | entry->xmit_count); | |
1011 | else | |
1012 | seq_puts(seq, " "); | |
1013 | seq_printf(seq, " %s\n", | |
1014 | (iter->table == resolved) ? "resolved" | |
1015 | : (iter->table == unresolved) ? "unresolved" | |
1016 | : (iter->table == proxies) ? "proxies" | |
1017 | : "unknown"); | |
1018 | } | |
1019 | return 0; | |
1020 | } | |
1021 | ||
1022 | static struct seq_operations aarp_seq_ops = { | |
1023 | .start = aarp_seq_start, | |
1024 | .next = aarp_seq_next, | |
1025 | .stop = aarp_seq_stop, | |
1026 | .show = aarp_seq_show, | |
1027 | }; | |
1028 | ||
1029 | static int aarp_seq_open(struct inode *inode, struct file *file) | |
1030 | { | |
1031 | struct seq_file *seq; | |
1032 | int rc = -ENOMEM; | |
1033 | struct aarp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL); | |
1034 | ||
1035 | if (!s) | |
1036 | goto out; | |
1037 | ||
1038 | rc = seq_open(file, &aarp_seq_ops); | |
1039 | if (rc) | |
1040 | goto out_kfree; | |
1041 | ||
1042 | seq = file->private_data; | |
1043 | seq->private = s; | |
1044 | memset(s, 0, sizeof(*s)); | |
1045 | out: | |
1046 | return rc; | |
1047 | out_kfree: | |
1048 | kfree(s); | |
1049 | goto out; | |
1050 | } | |
1051 | ||
1052 | struct file_operations atalk_seq_arp_fops = { | |
1053 | .owner = THIS_MODULE, | |
1054 | .open = aarp_seq_open, | |
1055 | .read = seq_read, | |
1056 | .llseek = seq_lseek, | |
1057 | .release = seq_release_private, | |
1058 | }; | |
1059 | #endif | |
1060 | ||
1061 | /* General module cleanup. Called from cleanup_module() in ddp.c. */ | |
1062 | void aarp_cleanup_module(void) | |
1063 | { | |
1064 | del_timer_sync(&aarp_timer); | |
1065 | unregister_netdevice_notifier(&aarp_notifier); | |
1066 | unregister_snap_client(aarp_dl); | |
1067 | aarp_purge(); | |
1068 | } |