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f30c2269 | 1 | /* linux/net/ipv4/arp.c |
1da177e4 LT |
2 | * |
3 | * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $ | |
4 | * | |
5 | * Copyright (C) 1994 by Florian La Roche | |
6 | * | |
7 | * This module implements the Address Resolution Protocol ARP (RFC 826), | |
8 | * which is used to convert IP addresses (or in the future maybe other | |
9 | * high-level addresses) into a low-level hardware address (like an Ethernet | |
10 | * address). | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * Fixes: | |
e905a9ed | 18 | * Alan Cox : Removed the Ethernet assumptions in |
1da177e4 | 19 | * Florian's code |
e905a9ed | 20 | * Alan Cox : Fixed some small errors in the ARP |
1da177e4 LT |
21 | * logic |
22 | * Alan Cox : Allow >4K in /proc | |
23 | * Alan Cox : Make ARP add its own protocol entry | |
24 | * Ross Martin : Rewrote arp_rcv() and arp_get_info() | |
25 | * Stephen Henson : Add AX25 support to arp_get_info() | |
26 | * Alan Cox : Drop data when a device is downed. | |
27 | * Alan Cox : Use init_timer(). | |
28 | * Alan Cox : Double lock fixes. | |
29 | * Martin Seine : Move the arphdr structure | |
30 | * to if_arp.h for compatibility. | |
31 | * with BSD based programs. | |
32 | * Andrew Tridgell : Added ARP netmask code and | |
33 | * re-arranged proxy handling. | |
34 | * Alan Cox : Changed to use notifiers. | |
35 | * Niibe Yutaka : Reply for this device or proxies only. | |
36 | * Alan Cox : Don't proxy across hardware types! | |
37 | * Jonathan Naylor : Added support for NET/ROM. | |
38 | * Mike Shaver : RFC1122 checks. | |
39 | * Jonathan Naylor : Only lookup the hardware address for | |
40 | * the correct hardware type. | |
41 | * Germano Caronni : Assorted subtle races. | |
e905a9ed | 42 | * Craig Schlenter : Don't modify permanent entry |
1da177e4 LT |
43 | * during arp_rcv. |
44 | * Russ Nelson : Tidied up a few bits. | |
45 | * Alexey Kuznetsov: Major changes to caching and behaviour, | |
e905a9ed | 46 | * eg intelligent arp probing and |
1da177e4 LT |
47 | * generation |
48 | * of host down events. | |
49 | * Alan Cox : Missing unlock in device events. | |
50 | * Eckes : ARP ioctl control errors. | |
51 | * Alexey Kuznetsov: Arp free fix. | |
52 | * Manuel Rodriguez: Gratuitous ARP. | |
e905a9ed | 53 | * Jonathan Layes : Added arpd support through kerneld |
1da177e4 LT |
54 | * message queue (960314) |
55 | * Mike Shaver : /proc/sys/net/ipv4/arp_* support | |
56 | * Mike McLagan : Routing by source | |
57 | * Stuart Cheshire : Metricom and grat arp fixes | |
58 | * *** FOR 2.1 clean this up *** | |
59 | * Lawrence V. Stefani: (08/12/96) Added FDDI support. | |
60 | * Alan Cox : Took the AP1000 nasty FDDI hack and | |
61 | * folded into the mainstream FDDI code. | |
62 | * Ack spit, Linus how did you allow that | |
63 | * one in... | |
64 | * Jes Sorensen : Make FDDI work again in 2.1.x and | |
65 | * clean up the APFDDI & gen. FDDI bits. | |
66 | * Alexey Kuznetsov: new arp state machine; | |
67 | * now it is in net/core/neighbour.c. | |
68 | * Krzysztof Halasa: Added Frame Relay ARP support. | |
69 | * Arnaldo C. Melo : convert /proc/net/arp to seq_file | |
70 | * Shmulik Hen: Split arp_send to arp_create and | |
71 | * arp_xmit so intermediate drivers like | |
72 | * bonding can change the skb before | |
73 | * sending (e.g. insert 8021q tag). | |
74 | * Harald Welte : convert to make use of jenkins hash | |
75 | */ | |
76 | ||
77 | #include <linux/module.h> | |
78 | #include <linux/types.h> | |
79 | #include <linux/string.h> | |
80 | #include <linux/kernel.h> | |
4fc268d2 | 81 | #include <linux/capability.h> |
1da177e4 LT |
82 | #include <linux/socket.h> |
83 | #include <linux/sockios.h> | |
84 | #include <linux/errno.h> | |
85 | #include <linux/in.h> | |
86 | #include <linux/mm.h> | |
87 | #include <linux/inet.h> | |
14c85021 | 88 | #include <linux/inetdevice.h> |
1da177e4 LT |
89 | #include <linux/netdevice.h> |
90 | #include <linux/etherdevice.h> | |
91 | #include <linux/fddidevice.h> | |
92 | #include <linux/if_arp.h> | |
93 | #include <linux/trdevice.h> | |
94 | #include <linux/skbuff.h> | |
95 | #include <linux/proc_fs.h> | |
96 | #include <linux/seq_file.h> | |
97 | #include <linux/stat.h> | |
98 | #include <linux/init.h> | |
99 | #include <linux/net.h> | |
100 | #include <linux/rcupdate.h> | |
101 | #include <linux/jhash.h> | |
102 | #ifdef CONFIG_SYSCTL | |
103 | #include <linux/sysctl.h> | |
104 | #endif | |
105 | ||
457c4cbc | 106 | #include <net/net_namespace.h> |
1da177e4 LT |
107 | #include <net/ip.h> |
108 | #include <net/icmp.h> | |
109 | #include <net/route.h> | |
110 | #include <net/protocol.h> | |
111 | #include <net/tcp.h> | |
112 | #include <net/sock.h> | |
113 | #include <net/arp.h> | |
1da177e4 | 114 | #include <net/ax25.h> |
1da177e4 | 115 | #include <net/netrom.h> |
1da177e4 LT |
116 | #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) |
117 | #include <net/atmclip.h> | |
118 | struct neigh_table *clip_tbl_hook; | |
119 | #endif | |
120 | ||
121 | #include <asm/system.h> | |
122 | #include <asm/uaccess.h> | |
123 | ||
124 | #include <linux/netfilter_arp.h> | |
125 | ||
126 | /* | |
127 | * Interface to generic neighbour cache. | |
128 | */ | |
129 | static u32 arp_hash(const void *pkey, const struct net_device *dev); | |
130 | static int arp_constructor(struct neighbour *neigh); | |
131 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); | |
132 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); | |
133 | static void parp_redo(struct sk_buff *skb); | |
134 | ||
135 | static struct neigh_ops arp_generic_ops = { | |
136 | .family = AF_INET, | |
137 | .solicit = arp_solicit, | |
138 | .error_report = arp_error_report, | |
139 | .output = neigh_resolve_output, | |
140 | .connected_output = neigh_connected_output, | |
141 | .hh_output = dev_queue_xmit, | |
142 | .queue_xmit = dev_queue_xmit, | |
143 | }; | |
144 | ||
145 | static struct neigh_ops arp_hh_ops = { | |
146 | .family = AF_INET, | |
147 | .solicit = arp_solicit, | |
148 | .error_report = arp_error_report, | |
149 | .output = neigh_resolve_output, | |
150 | .connected_output = neigh_resolve_output, | |
151 | .hh_output = dev_queue_xmit, | |
152 | .queue_xmit = dev_queue_xmit, | |
153 | }; | |
154 | ||
155 | static struct neigh_ops arp_direct_ops = { | |
156 | .family = AF_INET, | |
157 | .output = dev_queue_xmit, | |
158 | .connected_output = dev_queue_xmit, | |
159 | .hh_output = dev_queue_xmit, | |
160 | .queue_xmit = dev_queue_xmit, | |
161 | }; | |
162 | ||
163 | struct neigh_ops arp_broken_ops = { | |
164 | .family = AF_INET, | |
165 | .solicit = arp_solicit, | |
166 | .error_report = arp_error_report, | |
167 | .output = neigh_compat_output, | |
168 | .connected_output = neigh_compat_output, | |
169 | .hh_output = dev_queue_xmit, | |
170 | .queue_xmit = dev_queue_xmit, | |
171 | }; | |
172 | ||
173 | struct neigh_table arp_tbl = { | |
174 | .family = AF_INET, | |
175 | .entry_size = sizeof(struct neighbour) + 4, | |
176 | .key_len = 4, | |
177 | .hash = arp_hash, | |
178 | .constructor = arp_constructor, | |
179 | .proxy_redo = parp_redo, | |
180 | .id = "arp_cache", | |
181 | .parms = { | |
182 | .tbl = &arp_tbl, | |
183 | .base_reachable_time = 30 * HZ, | |
184 | .retrans_time = 1 * HZ, | |
185 | .gc_staletime = 60 * HZ, | |
186 | .reachable_time = 30 * HZ, | |
187 | .delay_probe_time = 5 * HZ, | |
188 | .queue_len = 3, | |
189 | .ucast_probes = 3, | |
190 | .mcast_probes = 3, | |
191 | .anycast_delay = 1 * HZ, | |
192 | .proxy_delay = (8 * HZ) / 10, | |
193 | .proxy_qlen = 64, | |
194 | .locktime = 1 * HZ, | |
195 | }, | |
196 | .gc_interval = 30 * HZ, | |
197 | .gc_thresh1 = 128, | |
198 | .gc_thresh2 = 512, | |
199 | .gc_thresh3 = 1024, | |
200 | }; | |
201 | ||
714e85be | 202 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
1da177e4 LT |
203 | { |
204 | switch (dev->type) { | |
205 | case ARPHRD_ETHER: | |
206 | case ARPHRD_FDDI: | |
207 | case ARPHRD_IEEE802: | |
208 | ip_eth_mc_map(addr, haddr); | |
e905a9ed | 209 | return 0; |
1da177e4 LT |
210 | case ARPHRD_IEEE802_TR: |
211 | ip_tr_mc_map(addr, haddr); | |
212 | return 0; | |
213 | case ARPHRD_INFINIBAND: | |
a9e527e3 | 214 | ip_ib_mc_map(addr, dev->broadcast, haddr); |
1da177e4 LT |
215 | return 0; |
216 | default: | |
217 | if (dir) { | |
218 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
219 | return 0; | |
220 | } | |
221 | } | |
222 | return -EINVAL; | |
223 | } | |
224 | ||
225 | ||
226 | static u32 arp_hash(const void *pkey, const struct net_device *dev) | |
227 | { | |
228 | return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); | |
229 | } | |
230 | ||
231 | static int arp_constructor(struct neighbour *neigh) | |
232 | { | |
fd683222 | 233 | __be32 addr = *(__be32*)neigh->primary_key; |
1da177e4 LT |
234 | struct net_device *dev = neigh->dev; |
235 | struct in_device *in_dev; | |
236 | struct neigh_parms *parms; | |
237 | ||
1da177e4 | 238 | rcu_read_lock(); |
e5ed6399 | 239 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
240 | if (in_dev == NULL) { |
241 | rcu_read_unlock(); | |
242 | return -EINVAL; | |
243 | } | |
244 | ||
a79878f0 DL |
245 | neigh->type = inet_addr_type(&init_net, addr); |
246 | ||
1da177e4 LT |
247 | parms = in_dev->arp_parms; |
248 | __neigh_parms_put(neigh->parms); | |
249 | neigh->parms = neigh_parms_clone(parms); | |
250 | rcu_read_unlock(); | |
251 | ||
3b04ddde | 252 | if (!dev->header_ops) { |
1da177e4 LT |
253 | neigh->nud_state = NUD_NOARP; |
254 | neigh->ops = &arp_direct_ops; | |
255 | neigh->output = neigh->ops->queue_xmit; | |
256 | } else { | |
257 | /* Good devices (checked by reading texts, but only Ethernet is | |
258 | tested) | |
259 | ||
260 | ARPHRD_ETHER: (ethernet, apfddi) | |
261 | ARPHRD_FDDI: (fddi) | |
262 | ARPHRD_IEEE802: (tr) | |
263 | ARPHRD_METRICOM: (strip) | |
264 | ARPHRD_ARCNET: | |
265 | etc. etc. etc. | |
266 | ||
267 | ARPHRD_IPDDP will also work, if author repairs it. | |
268 | I did not it, because this driver does not work even | |
269 | in old paradigm. | |
270 | */ | |
271 | ||
272 | #if 1 | |
273 | /* So... these "amateur" devices are hopeless. | |
274 | The only thing, that I can say now: | |
275 | It is very sad that we need to keep ugly obsolete | |
276 | code to make them happy. | |
277 | ||
278 | They should be moved to more reasonable state, now | |
279 | they use rebuild_header INSTEAD OF hard_start_xmit!!! | |
280 | Besides that, they are sort of out of date | |
281 | (a lot of redundant clones/copies, useless in 2.1), | |
282 | I wonder why people believe that they work. | |
283 | */ | |
284 | switch (dev->type) { | |
285 | default: | |
286 | break; | |
e905a9ed | 287 | case ARPHRD_ROSE: |
1da177e4 LT |
288 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) |
289 | case ARPHRD_AX25: | |
290 | #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) | |
291 | case ARPHRD_NETROM: | |
292 | #endif | |
293 | neigh->ops = &arp_broken_ops; | |
294 | neigh->output = neigh->ops->output; | |
295 | return 0; | |
296 | #endif | |
297 | ;} | |
298 | #endif | |
299 | if (neigh->type == RTN_MULTICAST) { | |
300 | neigh->nud_state = NUD_NOARP; | |
301 | arp_mc_map(addr, neigh->ha, dev, 1); | |
302 | } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { | |
303 | neigh->nud_state = NUD_NOARP; | |
304 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); | |
305 | } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { | |
306 | neigh->nud_state = NUD_NOARP; | |
307 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); | |
308 | } | |
3b04ddde SH |
309 | |
310 | if (dev->header_ops->cache) | |
1da177e4 LT |
311 | neigh->ops = &arp_hh_ops; |
312 | else | |
313 | neigh->ops = &arp_generic_ops; | |
3b04ddde | 314 | |
1da177e4 LT |
315 | if (neigh->nud_state&NUD_VALID) |
316 | neigh->output = neigh->ops->connected_output; | |
317 | else | |
318 | neigh->output = neigh->ops->output; | |
319 | } | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) | |
324 | { | |
325 | dst_link_failure(skb); | |
326 | kfree_skb(skb); | |
327 | } | |
328 | ||
329 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) | |
330 | { | |
a61ced5d | 331 | __be32 saddr = 0; |
1da177e4 LT |
332 | u8 *dst_ha = NULL; |
333 | struct net_device *dev = neigh->dev; | |
a61ced5d | 334 | __be32 target = *(__be32*)neigh->primary_key; |
1da177e4 LT |
335 | int probes = atomic_read(&neigh->probes); |
336 | struct in_device *in_dev = in_dev_get(dev); | |
337 | ||
338 | if (!in_dev) | |
339 | return; | |
340 | ||
341 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { | |
342 | default: | |
343 | case 0: /* By default announce any local IP */ | |
6b175b26 | 344 | if (skb && inet_addr_type(&init_net, ip_hdr(skb)->saddr) == RTN_LOCAL) |
eddc9ec5 | 345 | saddr = ip_hdr(skb)->saddr; |
1da177e4 LT |
346 | break; |
347 | case 1: /* Restrict announcements of saddr in same subnet */ | |
348 | if (!skb) | |
349 | break; | |
eddc9ec5 | 350 | saddr = ip_hdr(skb)->saddr; |
6b175b26 | 351 | if (inet_addr_type(&init_net, saddr) == RTN_LOCAL) { |
1da177e4 LT |
352 | /* saddr should be known to target */ |
353 | if (inet_addr_onlink(in_dev, target, saddr)) | |
354 | break; | |
355 | } | |
356 | saddr = 0; | |
357 | break; | |
358 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ | |
359 | break; | |
360 | } | |
361 | ||
362 | if (in_dev) | |
363 | in_dev_put(in_dev); | |
364 | if (!saddr) | |
365 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); | |
366 | ||
367 | if ((probes -= neigh->parms->ucast_probes) < 0) { | |
368 | if (!(neigh->nud_state&NUD_VALID)) | |
369 | printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); | |
370 | dst_ha = neigh->ha; | |
1da177e4 LT |
371 | } else if ((probes -= neigh->parms->app_probes) < 0) { |
372 | #ifdef CONFIG_ARPD | |
373 | neigh_app_ns(neigh); | |
374 | #endif | |
375 | return; | |
376 | } | |
377 | ||
378 | arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, | |
379 | dst_ha, dev->dev_addr, NULL); | |
1da177e4 LT |
380 | } |
381 | ||
9bd85e32 | 382 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
1da177e4 LT |
383 | { |
384 | int scope; | |
385 | ||
386 | switch (IN_DEV_ARP_IGNORE(in_dev)) { | |
387 | case 0: /* Reply, the tip is already validated */ | |
388 | return 0; | |
389 | case 1: /* Reply only if tip is configured on the incoming interface */ | |
390 | sip = 0; | |
391 | scope = RT_SCOPE_HOST; | |
392 | break; | |
393 | case 2: /* | |
394 | * Reply only if tip is configured on the incoming interface | |
395 | * and is in same subnet as sip | |
396 | */ | |
397 | scope = RT_SCOPE_HOST; | |
398 | break; | |
399 | case 3: /* Do not reply for scope host addresses */ | |
400 | sip = 0; | |
401 | scope = RT_SCOPE_LINK; | |
1da177e4 LT |
402 | break; |
403 | case 4: /* Reserved */ | |
404 | case 5: | |
405 | case 6: | |
406 | case 7: | |
407 | return 0; | |
408 | case 8: /* Do not reply */ | |
409 | return 1; | |
410 | default: | |
411 | return 0; | |
412 | } | |
9bd85e32 | 413 | return !inet_confirm_addr(in_dev, sip, tip, scope); |
1da177e4 LT |
414 | } |
415 | ||
ed9bad06 | 416 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
1da177e4 LT |
417 | { |
418 | struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, | |
419 | .saddr = tip } } }; | |
420 | struct rtable *rt; | |
e905a9ed | 421 | int flag = 0; |
1da177e4 LT |
422 | /*unsigned long now; */ |
423 | ||
f206351a | 424 | if (ip_route_output_key(&init_net, &rt, &fl) < 0) |
1da177e4 | 425 | return 1; |
e905a9ed | 426 | if (rt->u.dst.dev != dev) { |
1da177e4 LT |
427 | NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); |
428 | flag = 1; | |
e905a9ed YH |
429 | } |
430 | ip_rt_put(rt); | |
431 | return flag; | |
432 | } | |
1da177e4 LT |
433 | |
434 | /* OBSOLETE FUNCTIONS */ | |
435 | ||
436 | /* | |
437 | * Find an arp mapping in the cache. If not found, post a request. | |
438 | * | |
439 | * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, | |
440 | * even if it exists. It is supposed that skb->dev was mangled | |
441 | * by a virtual device (eql, shaper). Nobody but broken devices | |
442 | * is allowed to use this function, it is scheduled to be removed. --ANK | |
443 | */ | |
444 | ||
ed9bad06 | 445 | static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) |
1da177e4 LT |
446 | { |
447 | switch (addr_hint) { | |
448 | case RTN_LOCAL: | |
449 | printk(KERN_DEBUG "ARP: arp called for own IP address\n"); | |
450 | memcpy(haddr, dev->dev_addr, dev->addr_len); | |
451 | return 1; | |
452 | case RTN_MULTICAST: | |
453 | arp_mc_map(paddr, haddr, dev, 1); | |
454 | return 1; | |
455 | case RTN_BROADCAST: | |
456 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
457 | return 1; | |
458 | } | |
459 | return 0; | |
460 | } | |
461 | ||
462 | ||
463 | int arp_find(unsigned char *haddr, struct sk_buff *skb) | |
464 | { | |
465 | struct net_device *dev = skb->dev; | |
fd683222 | 466 | __be32 paddr; |
1da177e4 LT |
467 | struct neighbour *n; |
468 | ||
469 | if (!skb->dst) { | |
470 | printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); | |
471 | kfree_skb(skb); | |
472 | return 1; | |
473 | } | |
474 | ||
475 | paddr = ((struct rtable*)skb->dst)->rt_gateway; | |
476 | ||
6b175b26 | 477 | if (arp_set_predefined(inet_addr_type(&init_net, paddr), haddr, paddr, dev)) |
1da177e4 LT |
478 | return 0; |
479 | ||
480 | n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); | |
481 | ||
482 | if (n) { | |
483 | n->used = jiffies; | |
484 | if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { | |
485 | read_lock_bh(&n->lock); | |
e905a9ed | 486 | memcpy(haddr, n->ha, dev->addr_len); |
1da177e4 LT |
487 | read_unlock_bh(&n->lock); |
488 | neigh_release(n); | |
489 | return 0; | |
490 | } | |
491 | neigh_release(n); | |
492 | } else | |
493 | kfree_skb(skb); | |
494 | return 1; | |
495 | } | |
496 | ||
497 | /* END OF OBSOLETE FUNCTIONS */ | |
498 | ||
499 | int arp_bind_neighbour(struct dst_entry *dst) | |
500 | { | |
501 | struct net_device *dev = dst->dev; | |
502 | struct neighbour *n = dst->neighbour; | |
503 | ||
504 | if (dev == NULL) | |
505 | return -EINVAL; | |
506 | if (n == NULL) { | |
ed9bad06 | 507 | __be32 nexthop = ((struct rtable*)dst)->rt_gateway; |
1da177e4 LT |
508 | if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) |
509 | nexthop = 0; | |
510 | n = __neigh_lookup_errno( | |
511 | #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) | |
512 | dev->type == ARPHRD_ATM ? clip_tbl_hook : | |
513 | #endif | |
514 | &arp_tbl, &nexthop, dev); | |
515 | if (IS_ERR(n)) | |
516 | return PTR_ERR(n); | |
517 | dst->neighbour = n; | |
518 | } | |
519 | return 0; | |
520 | } | |
521 | ||
522 | /* | |
523 | * Check if we can use proxy ARP for this path | |
524 | */ | |
525 | ||
526 | static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) | |
527 | { | |
528 | struct in_device *out_dev; | |
529 | int imi, omi = -1; | |
530 | ||
531 | if (!IN_DEV_PROXY_ARP(in_dev)) | |
532 | return 0; | |
533 | ||
534 | if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) | |
535 | return 1; | |
536 | if (imi == -1) | |
537 | return 0; | |
538 | ||
539 | /* place to check for proxy_arp for routes */ | |
540 | ||
541 | if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { | |
542 | omi = IN_DEV_MEDIUM_ID(out_dev); | |
543 | in_dev_put(out_dev); | |
544 | } | |
545 | return (omi != imi && omi != -1); | |
546 | } | |
547 | ||
548 | /* | |
549 | * Interface to link layer: send routine and receive handler. | |
550 | */ | |
551 | ||
552 | /* | |
553 | * Create an arp packet. If (dest_hw == NULL), we create a broadcast | |
554 | * message. | |
555 | */ | |
ed9bad06 AV |
556 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
557 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
558 | const unsigned char *dest_hw, |
559 | const unsigned char *src_hw, | |
560 | const unsigned char *target_hw) | |
1da177e4 LT |
561 | { |
562 | struct sk_buff *skb; | |
563 | struct arphdr *arp; | |
564 | unsigned char *arp_ptr; | |
565 | ||
566 | /* | |
567 | * Allocate a buffer | |
568 | */ | |
e905a9ed | 569 | |
1da177e4 LT |
570 | skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) |
571 | + LL_RESERVED_SPACE(dev), GFP_ATOMIC); | |
572 | if (skb == NULL) | |
573 | return NULL; | |
574 | ||
575 | skb_reserve(skb, LL_RESERVED_SPACE(dev)); | |
c1d2bbe1 | 576 | skb_reset_network_header(skb); |
1da177e4 LT |
577 | arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); |
578 | skb->dev = dev; | |
579 | skb->protocol = htons(ETH_P_ARP); | |
580 | if (src_hw == NULL) | |
581 | src_hw = dev->dev_addr; | |
582 | if (dest_hw == NULL) | |
583 | dest_hw = dev->broadcast; | |
584 | ||
585 | /* | |
586 | * Fill the device header for the ARP frame | |
587 | */ | |
0c4e8581 | 588 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
1da177e4 LT |
589 | goto out; |
590 | ||
591 | /* | |
592 | * Fill out the arp protocol part. | |
593 | * | |
594 | * The arp hardware type should match the device type, except for FDDI, | |
595 | * which (according to RFC 1390) should always equal 1 (Ethernet). | |
596 | */ | |
597 | /* | |
598 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the | |
599 | * DIX code for the protocol. Make these device structure fields. | |
600 | */ | |
601 | switch (dev->type) { | |
602 | default: | |
603 | arp->ar_hrd = htons(dev->type); | |
604 | arp->ar_pro = htons(ETH_P_IP); | |
605 | break; | |
606 | ||
607 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
608 | case ARPHRD_AX25: | |
609 | arp->ar_hrd = htons(ARPHRD_AX25); | |
610 | arp->ar_pro = htons(AX25_P_IP); | |
611 | break; | |
612 | ||
613 | #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) | |
614 | case ARPHRD_NETROM: | |
615 | arp->ar_hrd = htons(ARPHRD_NETROM); | |
616 | arp->ar_pro = htons(AX25_P_IP); | |
617 | break; | |
618 | #endif | |
619 | #endif | |
620 | ||
621 | #ifdef CONFIG_FDDI | |
622 | case ARPHRD_FDDI: | |
623 | arp->ar_hrd = htons(ARPHRD_ETHER); | |
624 | arp->ar_pro = htons(ETH_P_IP); | |
625 | break; | |
626 | #endif | |
627 | #ifdef CONFIG_TR | |
628 | case ARPHRD_IEEE802_TR: | |
629 | arp->ar_hrd = htons(ARPHRD_IEEE802); | |
630 | arp->ar_pro = htons(ETH_P_IP); | |
631 | break; | |
632 | #endif | |
633 | } | |
634 | ||
635 | arp->ar_hln = dev->addr_len; | |
636 | arp->ar_pln = 4; | |
637 | arp->ar_op = htons(type); | |
638 | ||
639 | arp_ptr=(unsigned char *)(arp+1); | |
640 | ||
641 | memcpy(arp_ptr, src_hw, dev->addr_len); | |
642 | arp_ptr+=dev->addr_len; | |
643 | memcpy(arp_ptr, &src_ip,4); | |
644 | arp_ptr+=4; | |
645 | if (target_hw != NULL) | |
646 | memcpy(arp_ptr, target_hw, dev->addr_len); | |
647 | else | |
648 | memset(arp_ptr, 0, dev->addr_len); | |
649 | arp_ptr+=dev->addr_len; | |
650 | memcpy(arp_ptr, &dest_ip, 4); | |
651 | ||
652 | return skb; | |
653 | ||
654 | out: | |
655 | kfree_skb(skb); | |
656 | return NULL; | |
657 | } | |
658 | ||
659 | /* | |
660 | * Send an arp packet. | |
661 | */ | |
662 | void arp_xmit(struct sk_buff *skb) | |
663 | { | |
664 | /* Send it off, maybe filter it using firewalling first. */ | |
665 | NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); | |
666 | } | |
667 | ||
668 | /* | |
669 | * Create and send an arp packet. | |
670 | */ | |
ed9bad06 AV |
671 | void arp_send(int type, int ptype, __be32 dest_ip, |
672 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
673 | const unsigned char *dest_hw, const unsigned char *src_hw, |
674 | const unsigned char *target_hw) | |
1da177e4 LT |
675 | { |
676 | struct sk_buff *skb; | |
677 | ||
678 | /* | |
679 | * No arp on this interface. | |
680 | */ | |
e905a9ed | 681 | |
1da177e4 LT |
682 | if (dev->flags&IFF_NOARP) |
683 | return; | |
684 | ||
685 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, | |
686 | dest_hw, src_hw, target_hw); | |
687 | if (skb == NULL) { | |
688 | return; | |
689 | } | |
690 | ||
691 | arp_xmit(skb); | |
692 | } | |
693 | ||
1da177e4 LT |
694 | /* |
695 | * Process an arp request. | |
696 | */ | |
697 | ||
698 | static int arp_process(struct sk_buff *skb) | |
699 | { | |
700 | struct net_device *dev = skb->dev; | |
701 | struct in_device *in_dev = in_dev_get(dev); | |
702 | struct arphdr *arp; | |
703 | unsigned char *arp_ptr; | |
704 | struct rtable *rt; | |
e0260fed | 705 | unsigned char *sha; |
9e12bb22 | 706 | __be32 sip, tip; |
1da177e4 LT |
707 | u16 dev_type = dev->type; |
708 | int addr_type; | |
709 | struct neighbour *n; | |
710 | ||
711 | /* arp_rcv below verifies the ARP header and verifies the device | |
712 | * is ARP'able. | |
713 | */ | |
714 | ||
715 | if (in_dev == NULL) | |
716 | goto out; | |
717 | ||
d0a92be0 | 718 | arp = arp_hdr(skb); |
1da177e4 LT |
719 | |
720 | switch (dev_type) { | |
e905a9ed | 721 | default: |
1da177e4 LT |
722 | if (arp->ar_pro != htons(ETH_P_IP) || |
723 | htons(dev_type) != arp->ar_hrd) | |
724 | goto out; | |
725 | break; | |
1da177e4 | 726 | case ARPHRD_ETHER: |
1da177e4 | 727 | case ARPHRD_IEEE802_TR: |
1da177e4 | 728 | case ARPHRD_FDDI: |
1da177e4 | 729 | case ARPHRD_IEEE802: |
1da177e4 LT |
730 | /* |
731 | * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 | |
732 | * devices, according to RFC 2625) devices will accept ARP | |
733 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). | |
734 | * This is the case also of FDDI, where the RFC 1390 says that | |
735 | * FDDI devices should accept ARP hardware of (1) Ethernet, | |
736 | * however, to be more robust, we'll accept both 1 (Ethernet) | |
737 | * or 6 (IEEE 802.2) | |
738 | */ | |
739 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && | |
740 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || | |
741 | arp->ar_pro != htons(ETH_P_IP)) | |
742 | goto out; | |
743 | break; | |
1da177e4 LT |
744 | case ARPHRD_AX25: |
745 | if (arp->ar_pro != htons(AX25_P_IP) || | |
746 | arp->ar_hrd != htons(ARPHRD_AX25)) | |
747 | goto out; | |
748 | break; | |
1da177e4 LT |
749 | case ARPHRD_NETROM: |
750 | if (arp->ar_pro != htons(AX25_P_IP) || | |
751 | arp->ar_hrd != htons(ARPHRD_NETROM)) | |
752 | goto out; | |
753 | break; | |
1da177e4 LT |
754 | } |
755 | ||
756 | /* Understand only these message types */ | |
757 | ||
758 | if (arp->ar_op != htons(ARPOP_REPLY) && | |
759 | arp->ar_op != htons(ARPOP_REQUEST)) | |
760 | goto out; | |
761 | ||
762 | /* | |
763 | * Extract fields | |
764 | */ | |
765 | arp_ptr= (unsigned char *)(arp+1); | |
766 | sha = arp_ptr; | |
767 | arp_ptr += dev->addr_len; | |
768 | memcpy(&sip, arp_ptr, 4); | |
769 | arp_ptr += 4; | |
1da177e4 LT |
770 | arp_ptr += dev->addr_len; |
771 | memcpy(&tip, arp_ptr, 4); | |
e905a9ed | 772 | /* |
1da177e4 LT |
773 | * Check for bad requests for 127.x.x.x and requests for multicast |
774 | * addresses. If this is one such, delete it. | |
775 | */ | |
f97c1e0c | 776 | if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) |
1da177e4 LT |
777 | goto out; |
778 | ||
779 | /* | |
780 | * Special case: We must set Frame Relay source Q.922 address | |
781 | */ | |
782 | if (dev_type == ARPHRD_DLCI) | |
783 | sha = dev->broadcast; | |
784 | ||
785 | /* | |
786 | * Process entry. The idea here is we want to send a reply if it is a | |
787 | * request for us or if it is a request for someone else that we hold | |
788 | * a proxy for. We want to add an entry to our cache if it is a reply | |
e905a9ed YH |
789 | * to us or if it is a request for our address. |
790 | * (The assumption for this last is that if someone is requesting our | |
791 | * address, they are probably intending to talk to us, so it saves time | |
792 | * if we cache their address. Their address is also probably not in | |
1da177e4 | 793 | * our cache, since ours is not in their cache.) |
e905a9ed | 794 | * |
1da177e4 LT |
795 | * Putting this another way, we only care about replies if they are to |
796 | * us, in which case we add them to the cache. For requests, we care | |
797 | * about those for us and those for our proxies. We reply to both, | |
e905a9ed | 798 | * and in the case of requests for us we add the requester to the arp |
1da177e4 LT |
799 | * cache. |
800 | */ | |
801 | ||
802 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ | |
803 | if (sip == 0) { | |
804 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
6b175b26 | 805 | inet_addr_type(&init_net, tip) == RTN_LOCAL && |
9bd85e32 | 806 | !arp_ignore(in_dev, sip, tip)) |
b4a9811c JD |
807 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, |
808 | dev->dev_addr, sha); | |
1da177e4 LT |
809 | goto out; |
810 | } | |
811 | ||
812 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
813 | ip_route_input(skb, tip, sip, 0, dev) == 0) { | |
814 | ||
815 | rt = (struct rtable*)skb->dst; | |
816 | addr_type = rt->rt_type; | |
817 | ||
818 | if (addr_type == RTN_LOCAL) { | |
819 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
820 | if (n) { | |
821 | int dont_send = 0; | |
822 | ||
823 | if (!dont_send) | |
9bd85e32 | 824 | dont_send |= arp_ignore(in_dev,sip,tip); |
1da177e4 | 825 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
e905a9ed | 826 | dont_send |= arp_filter(sip,tip,dev); |
1da177e4 LT |
827 | if (!dont_send) |
828 | arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); | |
829 | ||
830 | neigh_release(n); | |
831 | } | |
832 | goto out; | |
833 | } else if (IN_DEV_FORWARD(in_dev)) { | |
cb7928a5 RR |
834 | if (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && |
835 | (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &init_net, &tip, dev, 0))) { | |
1da177e4 LT |
836 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
837 | if (n) | |
838 | neigh_release(n); | |
839 | ||
e905a9ed | 840 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
1da177e4 LT |
841 | skb->pkt_type == PACKET_HOST || |
842 | in_dev->arp_parms->proxy_delay == 0) { | |
843 | arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); | |
844 | } else { | |
845 | pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); | |
846 | in_dev_put(in_dev); | |
847 | return 0; | |
848 | } | |
849 | goto out; | |
850 | } | |
851 | } | |
852 | } | |
853 | ||
854 | /* Update our ARP tables */ | |
855 | ||
856 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); | |
857 | ||
586f1211 | 858 | if (IPV4_DEVCONF_ALL(dev->nd_net, ARP_ACCEPT)) { |
abd596a4 NH |
859 | /* Unsolicited ARP is not accepted by default. |
860 | It is possible, that this option should be enabled for some | |
861 | devices (strip is candidate) | |
862 | */ | |
863 | if (n == NULL && | |
864 | arp->ar_op == htons(ARPOP_REPLY) && | |
6b175b26 | 865 | inet_addr_type(&init_net, sip) == RTN_UNICAST) |
1b1ac759 | 866 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
abd596a4 | 867 | } |
1da177e4 LT |
868 | |
869 | if (n) { | |
870 | int state = NUD_REACHABLE; | |
871 | int override; | |
872 | ||
873 | /* If several different ARP replies follows back-to-back, | |
874 | use the FIRST one. It is possible, if several proxy | |
875 | agents are active. Taking the first reply prevents | |
876 | arp trashing and chooses the fastest router. | |
877 | */ | |
878 | override = time_after(jiffies, n->updated + n->parms->locktime); | |
879 | ||
880 | /* Broadcast replies and request packets | |
881 | do not assert neighbour reachability. | |
882 | */ | |
883 | if (arp->ar_op != htons(ARPOP_REPLY) || | |
884 | skb->pkt_type != PACKET_HOST) | |
885 | state = NUD_STALE; | |
886 | neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); | |
887 | neigh_release(n); | |
888 | } | |
889 | ||
890 | out: | |
891 | if (in_dev) | |
892 | in_dev_put(in_dev); | |
893 | kfree_skb(skb); | |
894 | return 0; | |
895 | } | |
896 | ||
444fc8fc HX |
897 | static void parp_redo(struct sk_buff *skb) |
898 | { | |
899 | arp_process(skb); | |
900 | } | |
901 | ||
1da177e4 LT |
902 | |
903 | /* | |
904 | * Receive an arp request from the device layer. | |
905 | */ | |
906 | ||
6c97e72a AB |
907 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
908 | struct packet_type *pt, struct net_device *orig_dev) | |
1da177e4 LT |
909 | { |
910 | struct arphdr *arp; | |
911 | ||
e730c155 EB |
912 | if (dev->nd_net != &init_net) |
913 | goto freeskb; | |
914 | ||
1da177e4 LT |
915 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ |
916 | if (!pskb_may_pull(skb, (sizeof(struct arphdr) + | |
917 | (2 * dev->addr_len) + | |
918 | (2 * sizeof(u32))))) | |
919 | goto freeskb; | |
920 | ||
d0a92be0 | 921 | arp = arp_hdr(skb); |
1da177e4 LT |
922 | if (arp->ar_hln != dev->addr_len || |
923 | dev->flags & IFF_NOARP || | |
924 | skb->pkt_type == PACKET_OTHERHOST || | |
925 | skb->pkt_type == PACKET_LOOPBACK || | |
926 | arp->ar_pln != 4) | |
927 | goto freeskb; | |
928 | ||
929 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) | |
930 | goto out_of_mem; | |
931 | ||
a61bbcf2 PM |
932 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
933 | ||
1da177e4 LT |
934 | return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); |
935 | ||
936 | freeskb: | |
937 | kfree_skb(skb); | |
938 | out_of_mem: | |
939 | return 0; | |
940 | } | |
941 | ||
942 | /* | |
943 | * User level interface (ioctl) | |
944 | */ | |
945 | ||
946 | /* | |
947 | * Set (create) an ARP cache entry. | |
948 | */ | |
949 | ||
32e569b7 | 950 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
f8b33fdf PE |
951 | { |
952 | if (dev == NULL) { | |
586f1211 | 953 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
f8b33fdf PE |
954 | return 0; |
955 | } | |
956 | if (__in_dev_get_rtnl(dev)) { | |
957 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); | |
958 | return 0; | |
959 | } | |
960 | return -ENXIO; | |
961 | } | |
962 | ||
32e569b7 PE |
963 | static int arp_req_set_public(struct net *net, struct arpreq *r, |
964 | struct net_device *dev) | |
43dc1701 PE |
965 | { |
966 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
967 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
968 | ||
969 | if (mask && mask != htonl(0xFFFFFFFF)) | |
970 | return -EINVAL; | |
971 | if (!dev && (r->arp_flags & ATF_COM)) { | |
2db82b53 | 972 | dev = dev_getbyhwaddr(net, r->arp_ha.sa_family, |
43dc1701 PE |
973 | r->arp_ha.sa_data); |
974 | if (!dev) | |
975 | return -ENODEV; | |
976 | } | |
977 | if (mask) { | |
2db82b53 | 978 | if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) |
43dc1701 PE |
979 | return -ENOBUFS; |
980 | return 0; | |
981 | } | |
f8b33fdf | 982 | |
32e569b7 | 983 | return arp_req_set_proxy(net, dev, 1); |
43dc1701 PE |
984 | } |
985 | ||
32e569b7 PE |
986 | static int arp_req_set(struct net *net, struct arpreq *r, |
987 | struct net_device * dev) | |
1da177e4 | 988 | { |
43dc1701 | 989 | __be32 ip; |
1da177e4 LT |
990 | struct neighbour *neigh; |
991 | int err; | |
992 | ||
43dc1701 | 993 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 994 | return arp_req_set_public(net, r, dev); |
1da177e4 | 995 | |
43dc1701 | 996 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
997 | if (r->arp_flags & ATF_PERM) |
998 | r->arp_flags |= ATF_COM; | |
999 | if (dev == NULL) { | |
1000 | struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, | |
1001 | .tos = RTO_ONLINK } } }; | |
1002 | struct rtable * rt; | |
f206351a | 1003 | if ((err = ip_route_output_key(net, &rt, &fl)) != 0) |
1da177e4 LT |
1004 | return err; |
1005 | dev = rt->u.dst.dev; | |
1006 | ip_rt_put(rt); | |
1007 | if (!dev) | |
1008 | return -EINVAL; | |
1009 | } | |
1010 | switch (dev->type) { | |
1011 | #ifdef CONFIG_FDDI | |
1012 | case ARPHRD_FDDI: | |
1013 | /* | |
1014 | * According to RFC 1390, FDDI devices should accept ARP | |
1015 | * hardware types of 1 (Ethernet). However, to be more | |
1016 | * robust, we'll accept hardware types of either 1 (Ethernet) | |
1017 | * or 6 (IEEE 802.2). | |
1018 | */ | |
1019 | if (r->arp_ha.sa_family != ARPHRD_FDDI && | |
1020 | r->arp_ha.sa_family != ARPHRD_ETHER && | |
1021 | r->arp_ha.sa_family != ARPHRD_IEEE802) | |
1022 | return -EINVAL; | |
1023 | break; | |
1024 | #endif | |
1025 | default: | |
1026 | if (r->arp_ha.sa_family != dev->type) | |
1027 | return -EINVAL; | |
1028 | break; | |
1029 | } | |
1030 | ||
1031 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); | |
1032 | err = PTR_ERR(neigh); | |
1033 | if (!IS_ERR(neigh)) { | |
1034 | unsigned state = NUD_STALE; | |
1035 | if (r->arp_flags & ATF_PERM) | |
1036 | state = NUD_PERMANENT; | |
1037 | err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? | |
e905a9ed | 1038 | r->arp_ha.sa_data : NULL, state, |
1da177e4 LT |
1039 | NEIGH_UPDATE_F_OVERRIDE| |
1040 | NEIGH_UPDATE_F_ADMIN); | |
1041 | neigh_release(neigh); | |
1042 | } | |
1043 | return err; | |
1044 | } | |
1045 | ||
1046 | static unsigned arp_state_to_flags(struct neighbour *neigh) | |
1047 | { | |
1048 | unsigned flags = 0; | |
1049 | if (neigh->nud_state&NUD_PERMANENT) | |
1050 | flags = ATF_PERM|ATF_COM; | |
1051 | else if (neigh->nud_state&NUD_VALID) | |
1052 | flags = ATF_COM; | |
1053 | return flags; | |
1054 | } | |
1055 | ||
1056 | /* | |
1057 | * Get an ARP cache entry. | |
1058 | */ | |
1059 | ||
1060 | static int arp_req_get(struct arpreq *r, struct net_device *dev) | |
1061 | { | |
ed9bad06 | 1062 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1063 | struct neighbour *neigh; |
1064 | int err = -ENXIO; | |
1065 | ||
1066 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1067 | if (neigh) { | |
1068 | read_lock_bh(&neigh->lock); | |
1069 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); | |
1070 | r->arp_flags = arp_state_to_flags(neigh); | |
1071 | read_unlock_bh(&neigh->lock); | |
1072 | r->arp_ha.sa_family = dev->type; | |
1073 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); | |
1074 | neigh_release(neigh); | |
1075 | err = 0; | |
1076 | } | |
1077 | return err; | |
1078 | } | |
1079 | ||
32e569b7 PE |
1080 | static int arp_req_delete_public(struct net *net, struct arpreq *r, |
1081 | struct net_device *dev) | |
46479b43 PE |
1082 | { |
1083 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1084 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1085 | ||
1086 | if (mask == htonl(0xFFFFFFFF)) | |
2db82b53 | 1087 | return pneigh_delete(&arp_tbl, net, &ip, dev); |
46479b43 | 1088 | |
f8b33fdf PE |
1089 | if (mask) |
1090 | return -EINVAL; | |
1091 | ||
32e569b7 | 1092 | return arp_req_set_proxy(net, dev, 0); |
46479b43 PE |
1093 | } |
1094 | ||
32e569b7 PE |
1095 | static int arp_req_delete(struct net *net, struct arpreq *r, |
1096 | struct net_device * dev) | |
1da177e4 LT |
1097 | { |
1098 | int err; | |
46479b43 | 1099 | __be32 ip; |
1da177e4 LT |
1100 | struct neighbour *neigh; |
1101 | ||
46479b43 | 1102 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1103 | return arp_req_delete_public(net, r, dev); |
1da177e4 | 1104 | |
46479b43 | 1105 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1106 | if (dev == NULL) { |
1107 | struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, | |
1108 | .tos = RTO_ONLINK } } }; | |
1109 | struct rtable * rt; | |
f206351a | 1110 | if ((err = ip_route_output_key(net, &rt, &fl)) != 0) |
1da177e4 LT |
1111 | return err; |
1112 | dev = rt->u.dst.dev; | |
1113 | ip_rt_put(rt); | |
1114 | if (!dev) | |
1115 | return -EINVAL; | |
1116 | } | |
1117 | err = -ENXIO; | |
1118 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1119 | if (neigh) { | |
1120 | if (neigh->nud_state&~NUD_NOARP) | |
e905a9ed | 1121 | err = neigh_update(neigh, NULL, NUD_FAILED, |
1da177e4 LT |
1122 | NEIGH_UPDATE_F_OVERRIDE| |
1123 | NEIGH_UPDATE_F_ADMIN); | |
1124 | neigh_release(neigh); | |
1125 | } | |
1126 | return err; | |
1127 | } | |
1128 | ||
1129 | /* | |
1130 | * Handle an ARP layer I/O control request. | |
1131 | */ | |
1132 | ||
32e569b7 | 1133 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
1da177e4 LT |
1134 | { |
1135 | int err; | |
1136 | struct arpreq r; | |
1137 | struct net_device *dev = NULL; | |
1138 | ||
1139 | switch (cmd) { | |
1140 | case SIOCDARP: | |
1141 | case SIOCSARP: | |
1142 | if (!capable(CAP_NET_ADMIN)) | |
1143 | return -EPERM; | |
1144 | case SIOCGARP: | |
1145 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); | |
1146 | if (err) | |
1147 | return -EFAULT; | |
1148 | break; | |
1149 | default: | |
1150 | return -EINVAL; | |
1151 | } | |
1152 | ||
1153 | if (r.arp_pa.sa_family != AF_INET) | |
1154 | return -EPFNOSUPPORT; | |
1155 | ||
1156 | if (!(r.arp_flags & ATF_PUBL) && | |
1157 | (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) | |
1158 | return -EINVAL; | |
1159 | if (!(r.arp_flags & ATF_NETMASK)) | |
1160 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = | |
1161 | htonl(0xFFFFFFFFUL); | |
1162 | rtnl_lock(); | |
1163 | if (r.arp_dev[0]) { | |
1164 | err = -ENODEV; | |
2db82b53 | 1165 | if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL) |
1da177e4 LT |
1166 | goto out; |
1167 | ||
1168 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ | |
1169 | if (!r.arp_ha.sa_family) | |
1170 | r.arp_ha.sa_family = dev->type; | |
1171 | err = -EINVAL; | |
1172 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) | |
1173 | goto out; | |
1174 | } else if (cmd == SIOCGARP) { | |
1175 | err = -ENODEV; | |
1176 | goto out; | |
1177 | } | |
1178 | ||
132adf54 | 1179 | switch (cmd) { |
1da177e4 | 1180 | case SIOCDARP: |
32e569b7 | 1181 | err = arp_req_delete(net, &r, dev); |
1da177e4 LT |
1182 | break; |
1183 | case SIOCSARP: | |
32e569b7 | 1184 | err = arp_req_set(net, &r, dev); |
1da177e4 LT |
1185 | break; |
1186 | case SIOCGARP: | |
1187 | err = arp_req_get(&r, dev); | |
1188 | if (!err && copy_to_user(arg, &r, sizeof(r))) | |
1189 | err = -EFAULT; | |
1190 | break; | |
1191 | } | |
1192 | out: | |
1193 | rtnl_unlock(); | |
1194 | return err; | |
1195 | } | |
1196 | ||
1197 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) | |
1198 | { | |
1199 | struct net_device *dev = ptr; | |
1200 | ||
e9dc8653 EB |
1201 | if (dev->nd_net != &init_net) |
1202 | return NOTIFY_DONE; | |
1203 | ||
1da177e4 LT |
1204 | switch (event) { |
1205 | case NETDEV_CHANGEADDR: | |
1206 | neigh_changeaddr(&arp_tbl, dev); | |
1207 | rt_cache_flush(0); | |
1208 | break; | |
1209 | default: | |
1210 | break; | |
1211 | } | |
1212 | ||
1213 | return NOTIFY_DONE; | |
1214 | } | |
1215 | ||
1216 | static struct notifier_block arp_netdev_notifier = { | |
1217 | .notifier_call = arp_netdev_event, | |
1218 | }; | |
1219 | ||
1220 | /* Note, that it is not on notifier chain. | |
1221 | It is necessary, that this routine was called after route cache will be | |
1222 | flushed. | |
1223 | */ | |
1224 | void arp_ifdown(struct net_device *dev) | |
1225 | { | |
1226 | neigh_ifdown(&arp_tbl, dev); | |
1227 | } | |
1228 | ||
1229 | ||
1230 | /* | |
1231 | * Called once on startup. | |
1232 | */ | |
1233 | ||
1234 | static struct packet_type arp_packet_type = { | |
1235 | .type = __constant_htons(ETH_P_ARP), | |
1236 | .func = arp_rcv, | |
1237 | }; | |
1238 | ||
1239 | static int arp_proc_init(void); | |
1240 | ||
1241 | void __init arp_init(void) | |
1242 | { | |
1243 | neigh_table_init(&arp_tbl); | |
1244 | ||
1245 | dev_add_pack(&arp_packet_type); | |
1246 | arp_proc_init(); | |
1247 | #ifdef CONFIG_SYSCTL | |
1248 | neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, | |
1249 | NET_IPV4_NEIGH, "ipv4", NULL, NULL); | |
1250 | #endif | |
1251 | register_netdevice_notifier(&arp_netdev_notifier); | |
1252 | } | |
1253 | ||
1254 | #ifdef CONFIG_PROC_FS | |
1255 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
1256 | ||
1257 | /* ------------------------------------------------------------------------ */ | |
1258 | /* | |
1259 | * ax25 -> ASCII conversion | |
1260 | */ | |
1261 | static char *ax2asc2(ax25_address *a, char *buf) | |
1262 | { | |
1263 | char c, *s; | |
1264 | int n; | |
1265 | ||
1266 | for (n = 0, s = buf; n < 6; n++) { | |
1267 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
1268 | ||
1269 | if (c != ' ') *s++ = c; | |
1270 | } | |
e905a9ed | 1271 | |
1da177e4 LT |
1272 | *s++ = '-'; |
1273 | ||
1274 | if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { | |
1275 | *s++ = '1'; | |
1276 | n -= 10; | |
1277 | } | |
e905a9ed | 1278 | |
1da177e4 LT |
1279 | *s++ = n + '0'; |
1280 | *s++ = '\0'; | |
1281 | ||
1282 | if (*buf == '\0' || *buf == '-') | |
1283 | return "*"; | |
1284 | ||
1285 | return buf; | |
1286 | ||
1287 | } | |
1288 | #endif /* CONFIG_AX25 */ | |
1289 | ||
1290 | #define HBUFFERLEN 30 | |
1291 | ||
1292 | static void arp_format_neigh_entry(struct seq_file *seq, | |
1293 | struct neighbour *n) | |
1294 | { | |
1295 | char hbuffer[HBUFFERLEN]; | |
1296 | const char hexbuf[] = "0123456789ABCDEF"; | |
1297 | int k, j; | |
1298 | char tbuf[16]; | |
1299 | struct net_device *dev = n->dev; | |
1300 | int hatype = dev->type; | |
1301 | ||
1302 | read_lock(&n->lock); | |
1303 | /* Convert hardware address to XX:XX:XX:XX ... form. */ | |
1304 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
1305 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) | |
1306 | ax2asc2((ax25_address *)n->ha, hbuffer); | |
1307 | else { | |
1308 | #endif | |
1309 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { | |
1310 | hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; | |
1311 | hbuffer[k++] = hexbuf[n->ha[j] & 15]; | |
1312 | hbuffer[k++] = ':'; | |
1313 | } | |
1314 | hbuffer[--k] = 0; | |
1315 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
1316 | } | |
1317 | #endif | |
1318 | sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); | |
1319 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", | |
1320 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); | |
1321 | read_unlock(&n->lock); | |
1322 | } | |
1323 | ||
1324 | static void arp_format_pneigh_entry(struct seq_file *seq, | |
1325 | struct pneigh_entry *n) | |
1326 | { | |
1327 | struct net_device *dev = n->dev; | |
1328 | int hatype = dev ? dev->type : 0; | |
1329 | char tbuf[16]; | |
1330 | ||
1331 | sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); | |
1332 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", | |
1333 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", | |
1334 | dev ? dev->name : "*"); | |
1335 | } | |
1336 | ||
1337 | static int arp_seq_show(struct seq_file *seq, void *v) | |
1338 | { | |
1339 | if (v == SEQ_START_TOKEN) { | |
1340 | seq_puts(seq, "IP address HW type Flags " | |
1341 | "HW address Mask Device\n"); | |
1342 | } else { | |
1343 | struct neigh_seq_state *state = seq->private; | |
1344 | ||
1345 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) | |
1346 | arp_format_pneigh_entry(seq, v); | |
1347 | else | |
1348 | arp_format_neigh_entry(seq, v); | |
1349 | } | |
1350 | ||
1351 | return 0; | |
1352 | } | |
1353 | ||
1354 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) | |
1355 | { | |
1356 | /* Don't want to confuse "arp -a" w/ magic entries, | |
1357 | * so we tell the generic iterator to skip NUD_NOARP. | |
1358 | */ | |
1359 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); | |
1360 | } | |
1361 | ||
1362 | /* ------------------------------------------------------------------------ */ | |
1363 | ||
f690808e | 1364 | static const struct seq_operations arp_seq_ops = { |
1da177e4 LT |
1365 | .start = arp_seq_start, |
1366 | .next = neigh_seq_next, | |
1367 | .stop = neigh_seq_stop, | |
1368 | .show = arp_seq_show, | |
1369 | }; | |
1370 | ||
1371 | static int arp_seq_open(struct inode *inode, struct file *file) | |
1372 | { | |
426b5303 EB |
1373 | return seq_open_net(inode, file, &arp_seq_ops, |
1374 | sizeof(struct neigh_seq_state)); | |
1da177e4 LT |
1375 | } |
1376 | ||
9a32144e | 1377 | static const struct file_operations arp_seq_fops = { |
1da177e4 LT |
1378 | .owner = THIS_MODULE, |
1379 | .open = arp_seq_open, | |
1380 | .read = seq_read, | |
1381 | .llseek = seq_lseek, | |
426b5303 | 1382 | .release = seq_release_net, |
1da177e4 LT |
1383 | }; |
1384 | ||
1385 | static int __init arp_proc_init(void) | |
1386 | { | |
457c4cbc | 1387 | if (!proc_net_fops_create(&init_net, "arp", S_IRUGO, &arp_seq_fops)) |
1da177e4 LT |
1388 | return -ENOMEM; |
1389 | return 0; | |
1390 | } | |
1391 | ||
1392 | #else /* CONFIG_PROC_FS */ | |
1393 | ||
1394 | static int __init arp_proc_init(void) | |
1395 | { | |
1396 | return 0; | |
1397 | } | |
1398 | ||
1399 | #endif /* CONFIG_PROC_FS */ | |
1400 | ||
1401 | EXPORT_SYMBOL(arp_broken_ops); | |
1402 | EXPORT_SYMBOL(arp_find); | |
1da177e4 LT |
1403 | EXPORT_SYMBOL(arp_create); |
1404 | EXPORT_SYMBOL(arp_xmit); | |
1405 | EXPORT_SYMBOL(arp_send); | |
1406 | EXPORT_SYMBOL(arp_tbl); | |
1407 | ||
1408 | #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) | |
1409 | EXPORT_SYMBOL(clip_tbl_hook); | |
1410 | #endif |