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f30c2269 | 1 | /* linux/net/ipv4/arp.c |
1da177e4 LT |
2 | * |
3 | * Copyright (C) 1994 by Florian La Roche | |
4 | * | |
5 | * This module implements the Address Resolution Protocol ARP (RFC 826), | |
6 | * which is used to convert IP addresses (or in the future maybe other | |
7 | * high-level addresses) into a low-level hardware address (like an Ethernet | |
8 | * address). | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | * | |
15 | * Fixes: | |
e905a9ed | 16 | * Alan Cox : Removed the Ethernet assumptions in |
1da177e4 | 17 | * Florian's code |
e905a9ed | 18 | * Alan Cox : Fixed some small errors in the ARP |
1da177e4 LT |
19 | * logic |
20 | * Alan Cox : Allow >4K in /proc | |
21 | * Alan Cox : Make ARP add its own protocol entry | |
22 | * Ross Martin : Rewrote arp_rcv() and arp_get_info() | |
23 | * Stephen Henson : Add AX25 support to arp_get_info() | |
24 | * Alan Cox : Drop data when a device is downed. | |
25 | * Alan Cox : Use init_timer(). | |
26 | * Alan Cox : Double lock fixes. | |
27 | * Martin Seine : Move the arphdr structure | |
28 | * to if_arp.h for compatibility. | |
29 | * with BSD based programs. | |
30 | * Andrew Tridgell : Added ARP netmask code and | |
31 | * re-arranged proxy handling. | |
32 | * Alan Cox : Changed to use notifiers. | |
33 | * Niibe Yutaka : Reply for this device or proxies only. | |
34 | * Alan Cox : Don't proxy across hardware types! | |
35 | * Jonathan Naylor : Added support for NET/ROM. | |
36 | * Mike Shaver : RFC1122 checks. | |
37 | * Jonathan Naylor : Only lookup the hardware address for | |
38 | * the correct hardware type. | |
39 | * Germano Caronni : Assorted subtle races. | |
e905a9ed | 40 | * Craig Schlenter : Don't modify permanent entry |
1da177e4 LT |
41 | * during arp_rcv. |
42 | * Russ Nelson : Tidied up a few bits. | |
43 | * Alexey Kuznetsov: Major changes to caching and behaviour, | |
e905a9ed | 44 | * eg intelligent arp probing and |
1da177e4 LT |
45 | * generation |
46 | * of host down events. | |
47 | * Alan Cox : Missing unlock in device events. | |
48 | * Eckes : ARP ioctl control errors. | |
49 | * Alexey Kuznetsov: Arp free fix. | |
50 | * Manuel Rodriguez: Gratuitous ARP. | |
e905a9ed | 51 | * Jonathan Layes : Added arpd support through kerneld |
1da177e4 LT |
52 | * message queue (960314) |
53 | * Mike Shaver : /proc/sys/net/ipv4/arp_* support | |
54 | * Mike McLagan : Routing by source | |
55 | * Stuart Cheshire : Metricom and grat arp fixes | |
56 | * *** FOR 2.1 clean this up *** | |
57 | * Lawrence V. Stefani: (08/12/96) Added FDDI support. | |
deffd777 | 58 | * Alan Cox : Took the AP1000 nasty FDDI hack and |
1da177e4 LT |
59 | * folded into the mainstream FDDI code. |
60 | * Ack spit, Linus how did you allow that | |
61 | * one in... | |
62 | * Jes Sorensen : Make FDDI work again in 2.1.x and | |
63 | * clean up the APFDDI & gen. FDDI bits. | |
64 | * Alexey Kuznetsov: new arp state machine; | |
65 | * now it is in net/core/neighbour.c. | |
66 | * Krzysztof Halasa: Added Frame Relay ARP support. | |
67 | * Arnaldo C. Melo : convert /proc/net/arp to seq_file | |
68 | * Shmulik Hen: Split arp_send to arp_create and | |
69 | * arp_xmit so intermediate drivers like | |
70 | * bonding can change the skb before | |
71 | * sending (e.g. insert 8021q tag). | |
72 | * Harald Welte : convert to make use of jenkins hash | |
65324144 | 73 | * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. |
1da177e4 LT |
74 | */ |
75 | ||
76 | #include <linux/module.h> | |
77 | #include <linux/types.h> | |
78 | #include <linux/string.h> | |
79 | #include <linux/kernel.h> | |
4fc268d2 | 80 | #include <linux/capability.h> |
1da177e4 LT |
81 | #include <linux/socket.h> |
82 | #include <linux/sockios.h> | |
83 | #include <linux/errno.h> | |
84 | #include <linux/in.h> | |
85 | #include <linux/mm.h> | |
86 | #include <linux/inet.h> | |
14c85021 | 87 | #include <linux/inetdevice.h> |
1da177e4 LT |
88 | #include <linux/netdevice.h> |
89 | #include <linux/etherdevice.h> | |
90 | #include <linux/fddidevice.h> | |
91 | #include <linux/if_arp.h> | |
92 | #include <linux/trdevice.h> | |
93 | #include <linux/skbuff.h> | |
94 | #include <linux/proc_fs.h> | |
95 | #include <linux/seq_file.h> | |
96 | #include <linux/stat.h> | |
97 | #include <linux/init.h> | |
98 | #include <linux/net.h> | |
99 | #include <linux/rcupdate.h> | |
100 | #include <linux/jhash.h> | |
5a0e3ad6 | 101 | #include <linux/slab.h> |
1da177e4 LT |
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; | |
4bc2f18b | 119 | EXPORT_SYMBOL(clip_tbl_hook); |
1da177e4 LT |
120 | #endif |
121 | ||
122 | #include <asm/system.h> | |
deffd777 | 123 | #include <linux/uaccess.h> |
1da177e4 LT |
124 | |
125 | #include <linux/netfilter_arp.h> | |
126 | ||
127 | /* | |
128 | * Interface to generic neighbour cache. | |
129 | */ | |
d6bf7817 | 130 | static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 rnd); |
1da177e4 LT |
131 | static int arp_constructor(struct neighbour *neigh); |
132 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); | |
133 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); | |
134 | static void parp_redo(struct sk_buff *skb); | |
135 | ||
89d69d2b | 136 | static const struct neigh_ops arp_generic_ops = { |
1da177e4 LT |
137 | .family = AF_INET, |
138 | .solicit = arp_solicit, | |
139 | .error_report = arp_error_report, | |
140 | .output = neigh_resolve_output, | |
141 | .connected_output = neigh_connected_output, | |
142 | .hh_output = dev_queue_xmit, | |
143 | .queue_xmit = dev_queue_xmit, | |
144 | }; | |
145 | ||
89d69d2b | 146 | static const struct neigh_ops arp_hh_ops = { |
1da177e4 LT |
147 | .family = AF_INET, |
148 | .solicit = arp_solicit, | |
149 | .error_report = arp_error_report, | |
150 | .output = neigh_resolve_output, | |
151 | .connected_output = neigh_resolve_output, | |
152 | .hh_output = dev_queue_xmit, | |
153 | .queue_xmit = dev_queue_xmit, | |
154 | }; | |
155 | ||
89d69d2b | 156 | static const struct neigh_ops arp_direct_ops = { |
1da177e4 LT |
157 | .family = AF_INET, |
158 | .output = dev_queue_xmit, | |
159 | .connected_output = dev_queue_xmit, | |
160 | .hh_output = dev_queue_xmit, | |
161 | .queue_xmit = dev_queue_xmit, | |
162 | }; | |
163 | ||
a64de47c | 164 | static const struct neigh_ops arp_broken_ops = { |
1da177e4 LT |
165 | .family = AF_INET, |
166 | .solicit = arp_solicit, | |
167 | .error_report = arp_error_report, | |
168 | .output = neigh_compat_output, | |
169 | .connected_output = neigh_compat_output, | |
170 | .hh_output = dev_queue_xmit, | |
171 | .queue_xmit = dev_queue_xmit, | |
172 | }; | |
173 | ||
174 | struct neigh_table arp_tbl = { | |
deffd777 CG |
175 | .family = AF_INET, |
176 | .entry_size = sizeof(struct neighbour) + 4, | |
177 | .key_len = 4, | |
178 | .hash = arp_hash, | |
179 | .constructor = arp_constructor, | |
180 | .proxy_redo = parp_redo, | |
181 | .id = "arp_cache", | |
182 | .parms = { | |
183 | .tbl = &arp_tbl, | |
184 | .base_reachable_time = 30 * HZ, | |
185 | .retrans_time = 1 * HZ, | |
186 | .gc_staletime = 60 * HZ, | |
187 | .reachable_time = 30 * HZ, | |
188 | .delay_probe_time = 5 * HZ, | |
189 | .queue_len = 3, | |
190 | .ucast_probes = 3, | |
191 | .mcast_probes = 3, | |
192 | .anycast_delay = 1 * HZ, | |
193 | .proxy_delay = (8 * HZ) / 10, | |
194 | .proxy_qlen = 64, | |
195 | .locktime = 1 * HZ, | |
1da177e4 | 196 | }, |
deffd777 CG |
197 | .gc_interval = 30 * HZ, |
198 | .gc_thresh1 = 128, | |
199 | .gc_thresh2 = 512, | |
200 | .gc_thresh3 = 1024, | |
1da177e4 | 201 | }; |
4bc2f18b | 202 | EXPORT_SYMBOL(arp_tbl); |
1da177e4 | 203 | |
714e85be | 204 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
1da177e4 LT |
205 | { |
206 | switch (dev->type) { | |
207 | case ARPHRD_ETHER: | |
208 | case ARPHRD_FDDI: | |
209 | case ARPHRD_IEEE802: | |
210 | ip_eth_mc_map(addr, haddr); | |
e905a9ed | 211 | return 0; |
1da177e4 LT |
212 | case ARPHRD_IEEE802_TR: |
213 | ip_tr_mc_map(addr, haddr); | |
214 | return 0; | |
215 | case ARPHRD_INFINIBAND: | |
a9e527e3 | 216 | ip_ib_mc_map(addr, dev->broadcast, haddr); |
1da177e4 LT |
217 | return 0; |
218 | default: | |
219 | if (dir) { | |
220 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
221 | return 0; | |
222 | } | |
223 | } | |
224 | return -EINVAL; | |
225 | } | |
226 | ||
227 | ||
d6bf7817 ED |
228 | static u32 arp_hash(const void *pkey, |
229 | const struct net_device *dev, | |
230 | __u32 hash_rnd) | |
1da177e4 | 231 | { |
d6bf7817 | 232 | return jhash_2words(*(u32 *)pkey, dev->ifindex, hash_rnd); |
1da177e4 LT |
233 | } |
234 | ||
235 | static int arp_constructor(struct neighbour *neigh) | |
236 | { | |
deffd777 | 237 | __be32 addr = *(__be32 *)neigh->primary_key; |
1da177e4 LT |
238 | struct net_device *dev = neigh->dev; |
239 | struct in_device *in_dev; | |
240 | struct neigh_parms *parms; | |
241 | ||
1da177e4 | 242 | rcu_read_lock(); |
e5ed6399 | 243 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
244 | if (in_dev == NULL) { |
245 | rcu_read_unlock(); | |
246 | return -EINVAL; | |
247 | } | |
248 | ||
c346dca1 | 249 | neigh->type = inet_addr_type(dev_net(dev), addr); |
a79878f0 | 250 | |
1da177e4 LT |
251 | parms = in_dev->arp_parms; |
252 | __neigh_parms_put(neigh->parms); | |
253 | neigh->parms = neigh_parms_clone(parms); | |
254 | rcu_read_unlock(); | |
255 | ||
3b04ddde | 256 | if (!dev->header_ops) { |
1da177e4 LT |
257 | neigh->nud_state = NUD_NOARP; |
258 | neigh->ops = &arp_direct_ops; | |
259 | neigh->output = neigh->ops->queue_xmit; | |
260 | } else { | |
261 | /* Good devices (checked by reading texts, but only Ethernet is | |
262 | tested) | |
263 | ||
264 | ARPHRD_ETHER: (ethernet, apfddi) | |
265 | ARPHRD_FDDI: (fddi) | |
266 | ARPHRD_IEEE802: (tr) | |
267 | ARPHRD_METRICOM: (strip) | |
268 | ARPHRD_ARCNET: | |
269 | etc. etc. etc. | |
270 | ||
271 | ARPHRD_IPDDP will also work, if author repairs it. | |
272 | I did not it, because this driver does not work even | |
273 | in old paradigm. | |
274 | */ | |
275 | ||
276 | #if 1 | |
277 | /* So... these "amateur" devices are hopeless. | |
278 | The only thing, that I can say now: | |
279 | It is very sad that we need to keep ugly obsolete | |
280 | code to make them happy. | |
281 | ||
282 | They should be moved to more reasonable state, now | |
283 | they use rebuild_header INSTEAD OF hard_start_xmit!!! | |
284 | Besides that, they are sort of out of date | |
285 | (a lot of redundant clones/copies, useless in 2.1), | |
286 | I wonder why people believe that they work. | |
287 | */ | |
288 | switch (dev->type) { | |
289 | default: | |
290 | break; | |
e905a9ed | 291 | case ARPHRD_ROSE: |
1da177e4 LT |
292 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) |
293 | case ARPHRD_AX25: | |
294 | #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) | |
295 | case ARPHRD_NETROM: | |
296 | #endif | |
297 | neigh->ops = &arp_broken_ops; | |
298 | neigh->output = neigh->ops->output; | |
299 | return 0; | |
deffd777 CG |
300 | #else |
301 | break; | |
1da177e4 | 302 | #endif |
deffd777 | 303 | } |
1da177e4 LT |
304 | #endif |
305 | if (neigh->type == RTN_MULTICAST) { | |
306 | neigh->nud_state = NUD_NOARP; | |
307 | arp_mc_map(addr, neigh->ha, dev, 1); | |
deffd777 | 308 | } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { |
1da177e4 LT |
309 | neigh->nud_state = NUD_NOARP; |
310 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); | |
deffd777 CG |
311 | } else if (neigh->type == RTN_BROADCAST || |
312 | (dev->flags & IFF_POINTOPOINT)) { | |
1da177e4 LT |
313 | neigh->nud_state = NUD_NOARP; |
314 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); | |
315 | } | |
3b04ddde SH |
316 | |
317 | if (dev->header_ops->cache) | |
1da177e4 LT |
318 | neigh->ops = &arp_hh_ops; |
319 | else | |
320 | neigh->ops = &arp_generic_ops; | |
3b04ddde | 321 | |
deffd777 | 322 | if (neigh->nud_state & NUD_VALID) |
1da177e4 LT |
323 | neigh->output = neigh->ops->connected_output; |
324 | else | |
325 | neigh->output = neigh->ops->output; | |
326 | } | |
327 | return 0; | |
328 | } | |
329 | ||
330 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) | |
331 | { | |
332 | dst_link_failure(skb); | |
333 | kfree_skb(skb); | |
334 | } | |
335 | ||
336 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) | |
337 | { | |
a61ced5d | 338 | __be32 saddr = 0; |
1da177e4 LT |
339 | u8 *dst_ha = NULL; |
340 | struct net_device *dev = neigh->dev; | |
deffd777 | 341 | __be32 target = *(__be32 *)neigh->primary_key; |
1da177e4 | 342 | int probes = atomic_read(&neigh->probes); |
4b4194c4 | 343 | struct in_device *in_dev; |
1da177e4 | 344 | |
4b4194c4 ED |
345 | rcu_read_lock(); |
346 | in_dev = __in_dev_get_rcu(dev); | |
347 | if (!in_dev) { | |
348 | rcu_read_unlock(); | |
1da177e4 | 349 | return; |
4b4194c4 | 350 | } |
1da177e4 LT |
351 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { |
352 | default: | |
353 | case 0: /* By default announce any local IP */ | |
deffd777 CG |
354 | if (skb && inet_addr_type(dev_net(dev), |
355 | ip_hdr(skb)->saddr) == RTN_LOCAL) | |
eddc9ec5 | 356 | saddr = ip_hdr(skb)->saddr; |
1da177e4 LT |
357 | break; |
358 | case 1: /* Restrict announcements of saddr in same subnet */ | |
359 | if (!skb) | |
360 | break; | |
eddc9ec5 | 361 | saddr = ip_hdr(skb)->saddr; |
c346dca1 | 362 | if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { |
1da177e4 LT |
363 | /* saddr should be known to target */ |
364 | if (inet_addr_onlink(in_dev, target, saddr)) | |
365 | break; | |
366 | } | |
367 | saddr = 0; | |
368 | break; | |
369 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ | |
370 | break; | |
371 | } | |
4b4194c4 | 372 | rcu_read_unlock(); |
1da177e4 | 373 | |
1da177e4 LT |
374 | if (!saddr) |
375 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); | |
376 | ||
deffd777 CG |
377 | probes -= neigh->parms->ucast_probes; |
378 | if (probes < 0) { | |
379 | if (!(neigh->nud_state & NUD_VALID)) | |
380 | printk(KERN_DEBUG | |
381 | "trying to ucast probe in NUD_INVALID\n"); | |
1da177e4 | 382 | dst_ha = neigh->ha; |
9ff56607 | 383 | read_lock_bh(&neigh->lock); |
deffd777 CG |
384 | } else { |
385 | probes -= neigh->parms->app_probes; | |
386 | if (probes < 0) { | |
1da177e4 | 387 | #ifdef CONFIG_ARPD |
deffd777 | 388 | neigh_app_ns(neigh); |
1da177e4 | 389 | #endif |
deffd777 CG |
390 | return; |
391 | } | |
1da177e4 LT |
392 | } |
393 | ||
394 | arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, | |
395 | dst_ha, dev->dev_addr, NULL); | |
9ff56607 DM |
396 | if (dst_ha) |
397 | read_unlock_bh(&neigh->lock); | |
1da177e4 LT |
398 | } |
399 | ||
9bd85e32 | 400 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
1da177e4 LT |
401 | { |
402 | int scope; | |
403 | ||
404 | switch (IN_DEV_ARP_IGNORE(in_dev)) { | |
405 | case 0: /* Reply, the tip is already validated */ | |
406 | return 0; | |
407 | case 1: /* Reply only if tip is configured on the incoming interface */ | |
408 | sip = 0; | |
409 | scope = RT_SCOPE_HOST; | |
410 | break; | |
411 | case 2: /* | |
412 | * Reply only if tip is configured on the incoming interface | |
413 | * and is in same subnet as sip | |
414 | */ | |
415 | scope = RT_SCOPE_HOST; | |
416 | break; | |
417 | case 3: /* Do not reply for scope host addresses */ | |
418 | sip = 0; | |
419 | scope = RT_SCOPE_LINK; | |
1da177e4 LT |
420 | break; |
421 | case 4: /* Reserved */ | |
422 | case 5: | |
423 | case 6: | |
424 | case 7: | |
425 | return 0; | |
426 | case 8: /* Do not reply */ | |
427 | return 1; | |
428 | default: | |
429 | return 0; | |
430 | } | |
9bd85e32 | 431 | return !inet_confirm_addr(in_dev, sip, tip, scope); |
1da177e4 LT |
432 | } |
433 | ||
ed9bad06 | 434 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
1da177e4 | 435 | { |
5811662b CG |
436 | struct flowi fl = { .fl4_dst = sip, |
437 | .fl4_src = tip }; | |
1da177e4 | 438 | struct rtable *rt; |
e905a9ed | 439 | int flag = 0; |
1da177e4 | 440 | /*unsigned long now; */ |
ca12a1a4 | 441 | struct net *net = dev_net(dev); |
1da177e4 | 442 | |
b23dd4fe DM |
443 | rt = ip_route_output_key(net, &fl); |
444 | if (IS_ERR(rt)) | |
1da177e4 | 445 | return 1; |
d8d1f30b | 446 | if (rt->dst.dev != dev) { |
de0744af | 447 | NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); |
1da177e4 | 448 | flag = 1; |
e905a9ed YH |
449 | } |
450 | ip_rt_put(rt); | |
451 | return flag; | |
452 | } | |
1da177e4 LT |
453 | |
454 | /* OBSOLETE FUNCTIONS */ | |
455 | ||
456 | /* | |
457 | * Find an arp mapping in the cache. If not found, post a request. | |
458 | * | |
459 | * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, | |
460 | * even if it exists. It is supposed that skb->dev was mangled | |
461 | * by a virtual device (eql, shaper). Nobody but broken devices | |
462 | * is allowed to use this function, it is scheduled to be removed. --ANK | |
463 | */ | |
464 | ||
deffd777 CG |
465 | static int arp_set_predefined(int addr_hint, unsigned char *haddr, |
466 | __be32 paddr, struct net_device *dev) | |
1da177e4 LT |
467 | { |
468 | switch (addr_hint) { | |
469 | case RTN_LOCAL: | |
470 | printk(KERN_DEBUG "ARP: arp called for own IP address\n"); | |
471 | memcpy(haddr, dev->dev_addr, dev->addr_len); | |
472 | return 1; | |
473 | case RTN_MULTICAST: | |
474 | arp_mc_map(paddr, haddr, dev, 1); | |
475 | return 1; | |
476 | case RTN_BROADCAST: | |
477 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
478 | return 1; | |
479 | } | |
480 | return 0; | |
481 | } | |
482 | ||
483 | ||
484 | int arp_find(unsigned char *haddr, struct sk_buff *skb) | |
485 | { | |
486 | struct net_device *dev = skb->dev; | |
fd683222 | 487 | __be32 paddr; |
1da177e4 LT |
488 | struct neighbour *n; |
489 | ||
adf30907 | 490 | if (!skb_dst(skb)) { |
1da177e4 LT |
491 | printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); |
492 | kfree_skb(skb); | |
493 | return 1; | |
494 | } | |
495 | ||
511c3f92 | 496 | paddr = skb_rtable(skb)->rt_gateway; |
1da177e4 | 497 | |
deffd777 CG |
498 | if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, |
499 | paddr, dev)) | |
1da177e4 LT |
500 | return 0; |
501 | ||
502 | n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); | |
503 | ||
504 | if (n) { | |
505 | n->used = jiffies; | |
0ed8ddf4 ED |
506 | if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) { |
507 | neigh_ha_snapshot(haddr, n, dev); | |
1da177e4 LT |
508 | neigh_release(n); |
509 | return 0; | |
510 | } | |
511 | neigh_release(n); | |
512 | } else | |
513 | kfree_skb(skb); | |
514 | return 1; | |
515 | } | |
4bc2f18b | 516 | EXPORT_SYMBOL(arp_find); |
1da177e4 LT |
517 | |
518 | /* END OF OBSOLETE FUNCTIONS */ | |
519 | ||
520 | int arp_bind_neighbour(struct dst_entry *dst) | |
521 | { | |
522 | struct net_device *dev = dst->dev; | |
523 | struct neighbour *n = dst->neighbour; | |
524 | ||
525 | if (dev == NULL) | |
526 | return -EINVAL; | |
527 | if (n == NULL) { | |
f4cca7ff | 528 | __be32 nexthop = ((struct rtable *)dst)->rt_gateway; |
deffd777 | 529 | if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) |
1da177e4 LT |
530 | nexthop = 0; |
531 | n = __neigh_lookup_errno( | |
532 | #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) | |
deffd777 CG |
533 | dev->type == ARPHRD_ATM ? |
534 | clip_tbl_hook : | |
1da177e4 | 535 | #endif |
deffd777 | 536 | &arp_tbl, &nexthop, dev); |
1da177e4 LT |
537 | if (IS_ERR(n)) |
538 | return PTR_ERR(n); | |
539 | dst->neighbour = n; | |
540 | } | |
541 | return 0; | |
542 | } | |
543 | ||
544 | /* | |
545 | * Check if we can use proxy ARP for this path | |
546 | */ | |
65324144 JDB |
547 | static inline int arp_fwd_proxy(struct in_device *in_dev, |
548 | struct net_device *dev, struct rtable *rt) | |
1da177e4 LT |
549 | { |
550 | struct in_device *out_dev; | |
551 | int imi, omi = -1; | |
552 | ||
d8d1f30b | 553 | if (rt->dst.dev == dev) |
65324144 JDB |
554 | return 0; |
555 | ||
1da177e4 LT |
556 | if (!IN_DEV_PROXY_ARP(in_dev)) |
557 | return 0; | |
deffd777 CG |
558 | imi = IN_DEV_MEDIUM_ID(in_dev); |
559 | if (imi == 0) | |
1da177e4 LT |
560 | return 1; |
561 | if (imi == -1) | |
562 | return 0; | |
563 | ||
564 | /* place to check for proxy_arp for routes */ | |
565 | ||
d8d1f30b | 566 | out_dev = __in_dev_get_rcu(rt->dst.dev); |
faa9dcf7 | 567 | if (out_dev) |
1da177e4 | 568 | omi = IN_DEV_MEDIUM_ID(out_dev); |
faa9dcf7 | 569 | |
a02cec21 | 570 | return omi != imi && omi != -1; |
1da177e4 LT |
571 | } |
572 | ||
65324144 JDB |
573 | /* |
574 | * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) | |
575 | * | |
576 | * RFC3069 supports proxy arp replies back to the same interface. This | |
577 | * is done to support (ethernet) switch features, like RFC 3069, where | |
578 | * the individual ports are not allowed to communicate with each | |
579 | * other, BUT they are allowed to talk to the upstream router. As | |
580 | * described in RFC 3069, it is possible to allow these hosts to | |
581 | * communicate through the upstream router, by proxy_arp'ing. | |
582 | * | |
583 | * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" | |
584 | * | |
585 | * This technology is known by different names: | |
586 | * In RFC 3069 it is called VLAN Aggregation. | |
587 | * Cisco and Allied Telesyn call it Private VLAN. | |
588 | * Hewlett-Packard call it Source-Port filtering or port-isolation. | |
589 | * Ericsson call it MAC-Forced Forwarding (RFC Draft). | |
590 | * | |
591 | */ | |
592 | static inline int arp_fwd_pvlan(struct in_device *in_dev, | |
593 | struct net_device *dev, struct rtable *rt, | |
594 | __be32 sip, __be32 tip) | |
595 | { | |
596 | /* Private VLAN is only concerned about the same ethernet segment */ | |
d8d1f30b | 597 | if (rt->dst.dev != dev) |
65324144 JDB |
598 | return 0; |
599 | ||
600 | /* Don't reply on self probes (often done by windowz boxes)*/ | |
601 | if (sip == tip) | |
602 | return 0; | |
603 | ||
604 | if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) | |
605 | return 1; | |
606 | else | |
607 | return 0; | |
608 | } | |
609 | ||
1da177e4 LT |
610 | /* |
611 | * Interface to link layer: send routine and receive handler. | |
612 | */ | |
613 | ||
614 | /* | |
615 | * Create an arp packet. If (dest_hw == NULL), we create a broadcast | |
616 | * message. | |
617 | */ | |
ed9bad06 AV |
618 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
619 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
620 | const unsigned char *dest_hw, |
621 | const unsigned char *src_hw, | |
622 | const unsigned char *target_hw) | |
1da177e4 LT |
623 | { |
624 | struct sk_buff *skb; | |
625 | struct arphdr *arp; | |
626 | unsigned char *arp_ptr; | |
627 | ||
628 | /* | |
629 | * Allocate a buffer | |
630 | */ | |
e905a9ed | 631 | |
f5184d26 | 632 | skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC); |
1da177e4 LT |
633 | if (skb == NULL) |
634 | return NULL; | |
635 | ||
636 | skb_reserve(skb, LL_RESERVED_SPACE(dev)); | |
c1d2bbe1 | 637 | skb_reset_network_header(skb); |
988b7050 | 638 | arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); |
1da177e4 LT |
639 | skb->dev = dev; |
640 | skb->protocol = htons(ETH_P_ARP); | |
641 | if (src_hw == NULL) | |
642 | src_hw = dev->dev_addr; | |
643 | if (dest_hw == NULL) | |
644 | dest_hw = dev->broadcast; | |
645 | ||
646 | /* | |
647 | * Fill the device header for the ARP frame | |
648 | */ | |
0c4e8581 | 649 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
1da177e4 LT |
650 | goto out; |
651 | ||
652 | /* | |
653 | * Fill out the arp protocol part. | |
654 | * | |
655 | * The arp hardware type should match the device type, except for FDDI, | |
656 | * which (according to RFC 1390) should always equal 1 (Ethernet). | |
657 | */ | |
658 | /* | |
659 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the | |
660 | * DIX code for the protocol. Make these device structure fields. | |
661 | */ | |
662 | switch (dev->type) { | |
663 | default: | |
664 | arp->ar_hrd = htons(dev->type); | |
665 | arp->ar_pro = htons(ETH_P_IP); | |
666 | break; | |
667 | ||
668 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
669 | case ARPHRD_AX25: | |
670 | arp->ar_hrd = htons(ARPHRD_AX25); | |
671 | arp->ar_pro = htons(AX25_P_IP); | |
672 | break; | |
673 | ||
674 | #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) | |
675 | case ARPHRD_NETROM: | |
676 | arp->ar_hrd = htons(ARPHRD_NETROM); | |
677 | arp->ar_pro = htons(AX25_P_IP); | |
678 | break; | |
679 | #endif | |
680 | #endif | |
681 | ||
f0ecde14 | 682 | #if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) |
1da177e4 LT |
683 | case ARPHRD_FDDI: |
684 | arp->ar_hrd = htons(ARPHRD_ETHER); | |
685 | arp->ar_pro = htons(ETH_P_IP); | |
686 | break; | |
687 | #endif | |
f0ecde14 | 688 | #if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE) |
1da177e4 LT |
689 | case ARPHRD_IEEE802_TR: |
690 | arp->ar_hrd = htons(ARPHRD_IEEE802); | |
691 | arp->ar_pro = htons(ETH_P_IP); | |
692 | break; | |
693 | #endif | |
694 | } | |
695 | ||
696 | arp->ar_hln = dev->addr_len; | |
697 | arp->ar_pln = 4; | |
698 | arp->ar_op = htons(type); | |
699 | ||
deffd777 | 700 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
701 | |
702 | memcpy(arp_ptr, src_hw, dev->addr_len); | |
f4cca7ff JK |
703 | arp_ptr += dev->addr_len; |
704 | memcpy(arp_ptr, &src_ip, 4); | |
705 | arp_ptr += 4; | |
1da177e4 LT |
706 | if (target_hw != NULL) |
707 | memcpy(arp_ptr, target_hw, dev->addr_len); | |
708 | else | |
709 | memset(arp_ptr, 0, dev->addr_len); | |
f4cca7ff | 710 | arp_ptr += dev->addr_len; |
1da177e4 LT |
711 | memcpy(arp_ptr, &dest_ip, 4); |
712 | ||
713 | return skb; | |
714 | ||
715 | out: | |
716 | kfree_skb(skb); | |
717 | return NULL; | |
718 | } | |
4bc2f18b | 719 | EXPORT_SYMBOL(arp_create); |
1da177e4 LT |
720 | |
721 | /* | |
722 | * Send an arp packet. | |
723 | */ | |
724 | void arp_xmit(struct sk_buff *skb) | |
725 | { | |
726 | /* Send it off, maybe filter it using firewalling first. */ | |
fdc9314c | 727 | NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); |
1da177e4 | 728 | } |
4bc2f18b | 729 | EXPORT_SYMBOL(arp_xmit); |
1da177e4 LT |
730 | |
731 | /* | |
732 | * Create and send an arp packet. | |
733 | */ | |
ed9bad06 AV |
734 | void arp_send(int type, int ptype, __be32 dest_ip, |
735 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
736 | const unsigned char *dest_hw, const unsigned char *src_hw, |
737 | const unsigned char *target_hw) | |
1da177e4 LT |
738 | { |
739 | struct sk_buff *skb; | |
740 | ||
741 | /* | |
742 | * No arp on this interface. | |
743 | */ | |
e905a9ed | 744 | |
1da177e4 LT |
745 | if (dev->flags&IFF_NOARP) |
746 | return; | |
747 | ||
748 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, | |
749 | dest_hw, src_hw, target_hw); | |
deffd777 | 750 | if (skb == NULL) |
1da177e4 | 751 | return; |
1da177e4 LT |
752 | |
753 | arp_xmit(skb); | |
754 | } | |
4bc2f18b | 755 | EXPORT_SYMBOL(arp_send); |
1da177e4 | 756 | |
1da177e4 LT |
757 | /* |
758 | * Process an arp request. | |
759 | */ | |
760 | ||
761 | static int arp_process(struct sk_buff *skb) | |
762 | { | |
763 | struct net_device *dev = skb->dev; | |
faa9dcf7 | 764 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
765 | struct arphdr *arp; |
766 | unsigned char *arp_ptr; | |
767 | struct rtable *rt; | |
e0260fed | 768 | unsigned char *sha; |
9e12bb22 | 769 | __be32 sip, tip; |
1da177e4 LT |
770 | u16 dev_type = dev->type; |
771 | int addr_type; | |
772 | struct neighbour *n; | |
c346dca1 | 773 | struct net *net = dev_net(dev); |
1da177e4 LT |
774 | |
775 | /* arp_rcv below verifies the ARP header and verifies the device | |
776 | * is ARP'able. | |
777 | */ | |
778 | ||
779 | if (in_dev == NULL) | |
780 | goto out; | |
781 | ||
d0a92be0 | 782 | arp = arp_hdr(skb); |
1da177e4 LT |
783 | |
784 | switch (dev_type) { | |
e905a9ed | 785 | default: |
1da177e4 LT |
786 | if (arp->ar_pro != htons(ETH_P_IP) || |
787 | htons(dev_type) != arp->ar_hrd) | |
788 | goto out; | |
789 | break; | |
1da177e4 | 790 | case ARPHRD_ETHER: |
1da177e4 | 791 | case ARPHRD_IEEE802_TR: |
1da177e4 | 792 | case ARPHRD_FDDI: |
1da177e4 | 793 | case ARPHRD_IEEE802: |
1da177e4 LT |
794 | /* |
795 | * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 | |
796 | * devices, according to RFC 2625) devices will accept ARP | |
797 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). | |
798 | * This is the case also of FDDI, where the RFC 1390 says that | |
799 | * FDDI devices should accept ARP hardware of (1) Ethernet, | |
800 | * however, to be more robust, we'll accept both 1 (Ethernet) | |
801 | * or 6 (IEEE 802.2) | |
802 | */ | |
803 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && | |
804 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || | |
805 | arp->ar_pro != htons(ETH_P_IP)) | |
806 | goto out; | |
807 | break; | |
1da177e4 LT |
808 | case ARPHRD_AX25: |
809 | if (arp->ar_pro != htons(AX25_P_IP) || | |
810 | arp->ar_hrd != htons(ARPHRD_AX25)) | |
811 | goto out; | |
812 | break; | |
1da177e4 LT |
813 | case ARPHRD_NETROM: |
814 | if (arp->ar_pro != htons(AX25_P_IP) || | |
815 | arp->ar_hrd != htons(ARPHRD_NETROM)) | |
816 | goto out; | |
817 | break; | |
1da177e4 LT |
818 | } |
819 | ||
820 | /* Understand only these message types */ | |
821 | ||
822 | if (arp->ar_op != htons(ARPOP_REPLY) && | |
823 | arp->ar_op != htons(ARPOP_REQUEST)) | |
824 | goto out; | |
825 | ||
826 | /* | |
827 | * Extract fields | |
828 | */ | |
deffd777 | 829 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
830 | sha = arp_ptr; |
831 | arp_ptr += dev->addr_len; | |
832 | memcpy(&sip, arp_ptr, 4); | |
833 | arp_ptr += 4; | |
1da177e4 LT |
834 | arp_ptr += dev->addr_len; |
835 | memcpy(&tip, arp_ptr, 4); | |
e905a9ed | 836 | /* |
1da177e4 LT |
837 | * Check for bad requests for 127.x.x.x and requests for multicast |
838 | * addresses. If this is one such, delete it. | |
839 | */ | |
f97c1e0c | 840 | if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) |
1da177e4 LT |
841 | goto out; |
842 | ||
843 | /* | |
844 | * Special case: We must set Frame Relay source Q.922 address | |
845 | */ | |
846 | if (dev_type == ARPHRD_DLCI) | |
847 | sha = dev->broadcast; | |
848 | ||
849 | /* | |
850 | * Process entry. The idea here is we want to send a reply if it is a | |
851 | * request for us or if it is a request for someone else that we hold | |
852 | * a proxy for. We want to add an entry to our cache if it is a reply | |
e905a9ed YH |
853 | * to us or if it is a request for our address. |
854 | * (The assumption for this last is that if someone is requesting our | |
855 | * address, they are probably intending to talk to us, so it saves time | |
856 | * if we cache their address. Their address is also probably not in | |
1da177e4 | 857 | * our cache, since ours is not in their cache.) |
e905a9ed | 858 | * |
1da177e4 LT |
859 | * Putting this another way, we only care about replies if they are to |
860 | * us, in which case we add them to the cache. For requests, we care | |
861 | * about those for us and those for our proxies. We reply to both, | |
e905a9ed | 862 | * and in the case of requests for us we add the requester to the arp |
1da177e4 LT |
863 | * cache. |
864 | */ | |
865 | ||
f8a68e75 EB |
866 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ |
867 | if (sip == 0) { | |
1da177e4 | 868 | if (arp->ar_op == htons(ARPOP_REQUEST) && |
49e8a279 | 869 | inet_addr_type(net, tip) == RTN_LOCAL && |
9bd85e32 | 870 | !arp_ignore(in_dev, sip, tip)) |
b4a9811c JD |
871 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, |
872 | dev->dev_addr, sha); | |
1da177e4 LT |
873 | goto out; |
874 | } | |
875 | ||
876 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
4a94445c | 877 | ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { |
1da177e4 | 878 | |
511c3f92 | 879 | rt = skb_rtable(skb); |
1da177e4 LT |
880 | addr_type = rt->rt_type; |
881 | ||
882 | if (addr_type == RTN_LOCAL) { | |
deffd777 | 883 | int dont_send; |
8164f1b7 | 884 | |
deffd777 | 885 | dont_send = arp_ignore(in_dev, sip, tip); |
8164f1b7 | 886 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
ae9c416d | 887 | dont_send = arp_filter(sip, tip, dev); |
8164f1b7 BG |
888 | if (!dont_send) { |
889 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
890 | if (n) { | |
deffd777 CG |
891 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, |
892 | dev, tip, sha, dev->dev_addr, | |
893 | sha); | |
8164f1b7 BG |
894 | neigh_release(n); |
895 | } | |
1da177e4 LT |
896 | } |
897 | goto out; | |
898 | } else if (IN_DEV_FORWARD(in_dev)) { | |
65324144 JDB |
899 | if (addr_type == RTN_UNICAST && |
900 | (arp_fwd_proxy(in_dev, dev, rt) || | |
901 | arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || | |
deffd777 | 902 | pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) { |
1da177e4 LT |
903 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
904 | if (n) | |
905 | neigh_release(n); | |
906 | ||
e905a9ed | 907 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
1da177e4 LT |
908 | skb->pkt_type == PACKET_HOST || |
909 | in_dev->arp_parms->proxy_delay == 0) { | |
deffd777 CG |
910 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, |
911 | dev, tip, sha, dev->dev_addr, | |
912 | sha); | |
1da177e4 | 913 | } else { |
deffd777 CG |
914 | pneigh_enqueue(&arp_tbl, |
915 | in_dev->arp_parms, skb); | |
1da177e4 LT |
916 | return 0; |
917 | } | |
918 | goto out; | |
919 | } | |
920 | } | |
921 | } | |
922 | ||
923 | /* Update our ARP tables */ | |
924 | ||
925 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); | |
926 | ||
c346dca1 | 927 | if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { |
abd596a4 NH |
928 | /* Unsolicited ARP is not accepted by default. |
929 | It is possible, that this option should be enabled for some | |
930 | devices (strip is candidate) | |
931 | */ | |
932 | if (n == NULL && | |
6d955180 OP |
933 | (arp->ar_op == htons(ARPOP_REPLY) || |
934 | (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && | |
49e8a279 | 935 | inet_addr_type(net, sip) == RTN_UNICAST) |
1b1ac759 | 936 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
abd596a4 | 937 | } |
1da177e4 LT |
938 | |
939 | if (n) { | |
940 | int state = NUD_REACHABLE; | |
941 | int override; | |
942 | ||
943 | /* If several different ARP replies follows back-to-back, | |
944 | use the FIRST one. It is possible, if several proxy | |
945 | agents are active. Taking the first reply prevents | |
946 | arp trashing and chooses the fastest router. | |
947 | */ | |
948 | override = time_after(jiffies, n->updated + n->parms->locktime); | |
949 | ||
950 | /* Broadcast replies and request packets | |
951 | do not assert neighbour reachability. | |
952 | */ | |
953 | if (arp->ar_op != htons(ARPOP_REPLY) || | |
954 | skb->pkt_type != PACKET_HOST) | |
955 | state = NUD_STALE; | |
deffd777 CG |
956 | neigh_update(n, sha, state, |
957 | override ? NEIGH_UPDATE_F_OVERRIDE : 0); | |
1da177e4 LT |
958 | neigh_release(n); |
959 | } | |
960 | ||
961 | out: | |
ead2ceb0 | 962 | consume_skb(skb); |
1da177e4 LT |
963 | return 0; |
964 | } | |
965 | ||
444fc8fc HX |
966 | static void parp_redo(struct sk_buff *skb) |
967 | { | |
968 | arp_process(skb); | |
969 | } | |
970 | ||
1da177e4 LT |
971 | |
972 | /* | |
973 | * Receive an arp request from the device layer. | |
974 | */ | |
975 | ||
6c97e72a AB |
976 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
977 | struct packet_type *pt, struct net_device *orig_dev) | |
1da177e4 LT |
978 | { |
979 | struct arphdr *arp; | |
980 | ||
981 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ | |
988b7050 | 982 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) |
1da177e4 LT |
983 | goto freeskb; |
984 | ||
d0a92be0 | 985 | arp = arp_hdr(skb); |
1da177e4 LT |
986 | if (arp->ar_hln != dev->addr_len || |
987 | dev->flags & IFF_NOARP || | |
988 | skb->pkt_type == PACKET_OTHERHOST || | |
989 | skb->pkt_type == PACKET_LOOPBACK || | |
990 | arp->ar_pln != 4) | |
991 | goto freeskb; | |
992 | ||
deffd777 CG |
993 | skb = skb_share_check(skb, GFP_ATOMIC); |
994 | if (skb == NULL) | |
1da177e4 LT |
995 | goto out_of_mem; |
996 | ||
a61bbcf2 PM |
997 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
998 | ||
fdc9314c | 999 | return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); |
1da177e4 LT |
1000 | |
1001 | freeskb: | |
1002 | kfree_skb(skb); | |
1003 | out_of_mem: | |
1004 | return 0; | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * User level interface (ioctl) | |
1009 | */ | |
1010 | ||
1011 | /* | |
1012 | * Set (create) an ARP cache entry. | |
1013 | */ | |
1014 | ||
32e569b7 | 1015 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
f8b33fdf PE |
1016 | { |
1017 | if (dev == NULL) { | |
586f1211 | 1018 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
f8b33fdf PE |
1019 | return 0; |
1020 | } | |
c506653d ED |
1021 | if (__in_dev_get_rtnl(dev)) { |
1022 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); | |
f8b33fdf PE |
1023 | return 0; |
1024 | } | |
1025 | return -ENXIO; | |
1026 | } | |
1027 | ||
32e569b7 PE |
1028 | static int arp_req_set_public(struct net *net, struct arpreq *r, |
1029 | struct net_device *dev) | |
43dc1701 PE |
1030 | { |
1031 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
1032 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1033 | ||
1034 | if (mask && mask != htonl(0xFFFFFFFF)) | |
1035 | return -EINVAL; | |
1036 | if (!dev && (r->arp_flags & ATF_COM)) { | |
941666c2 | 1037 | dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, |
deffd777 | 1038 | r->arp_ha.sa_data); |
43dc1701 PE |
1039 | if (!dev) |
1040 | return -ENODEV; | |
1041 | } | |
1042 | if (mask) { | |
2db82b53 | 1043 | if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) |
43dc1701 PE |
1044 | return -ENOBUFS; |
1045 | return 0; | |
1046 | } | |
f8b33fdf | 1047 | |
32e569b7 | 1048 | return arp_req_set_proxy(net, dev, 1); |
43dc1701 PE |
1049 | } |
1050 | ||
32e569b7 | 1051 | static int arp_req_set(struct net *net, struct arpreq *r, |
deffd777 | 1052 | struct net_device *dev) |
1da177e4 | 1053 | { |
43dc1701 | 1054 | __be32 ip; |
1da177e4 LT |
1055 | struct neighbour *neigh; |
1056 | int err; | |
1057 | ||
43dc1701 | 1058 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1059 | return arp_req_set_public(net, r, dev); |
1da177e4 | 1060 | |
43dc1701 | 1061 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1062 | if (r->arp_flags & ATF_PERM) |
1063 | r->arp_flags |= ATF_COM; | |
1064 | if (dev == NULL) { | |
5811662b CG |
1065 | struct flowi fl = { .fl4_dst = ip, |
1066 | .fl4_tos = RTO_ONLINK }; | |
b23dd4fe DM |
1067 | struct rtable *rt = ip_route_output_key(net, &fl); |
1068 | ||
1069 | if (IS_ERR(rt)) | |
1070 | return PTR_ERR(rt); | |
d8d1f30b | 1071 | dev = rt->dst.dev; |
1da177e4 LT |
1072 | ip_rt_put(rt); |
1073 | if (!dev) | |
1074 | return -EINVAL; | |
1075 | } | |
1076 | switch (dev->type) { | |
f0ecde14 | 1077 | #if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) |
1da177e4 LT |
1078 | case ARPHRD_FDDI: |
1079 | /* | |
1080 | * According to RFC 1390, FDDI devices should accept ARP | |
1081 | * hardware types of 1 (Ethernet). However, to be more | |
1082 | * robust, we'll accept hardware types of either 1 (Ethernet) | |
1083 | * or 6 (IEEE 802.2). | |
1084 | */ | |
1085 | if (r->arp_ha.sa_family != ARPHRD_FDDI && | |
1086 | r->arp_ha.sa_family != ARPHRD_ETHER && | |
1087 | r->arp_ha.sa_family != ARPHRD_IEEE802) | |
1088 | return -EINVAL; | |
1089 | break; | |
1090 | #endif | |
1091 | default: | |
1092 | if (r->arp_ha.sa_family != dev->type) | |
1093 | return -EINVAL; | |
1094 | break; | |
1095 | } | |
1096 | ||
1097 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); | |
1098 | err = PTR_ERR(neigh); | |
1099 | if (!IS_ERR(neigh)) { | |
1100 | unsigned state = NUD_STALE; | |
1101 | if (r->arp_flags & ATF_PERM) | |
1102 | state = NUD_PERMANENT; | |
deffd777 | 1103 | err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? |
e905a9ed | 1104 | r->arp_ha.sa_data : NULL, state, |
deffd777 | 1105 | NEIGH_UPDATE_F_OVERRIDE | |
1da177e4 LT |
1106 | NEIGH_UPDATE_F_ADMIN); |
1107 | neigh_release(neigh); | |
1108 | } | |
1109 | return err; | |
1110 | } | |
1111 | ||
1112 | static unsigned arp_state_to_flags(struct neighbour *neigh) | |
1113 | { | |
1da177e4 | 1114 | if (neigh->nud_state&NUD_PERMANENT) |
deffd777 | 1115 | return ATF_PERM | ATF_COM; |
1da177e4 | 1116 | else if (neigh->nud_state&NUD_VALID) |
deffd777 CG |
1117 | return ATF_COM; |
1118 | else | |
1119 | return 0; | |
1da177e4 LT |
1120 | } |
1121 | ||
1122 | /* | |
1123 | * Get an ARP cache entry. | |
1124 | */ | |
1125 | ||
1126 | static int arp_req_get(struct arpreq *r, struct net_device *dev) | |
1127 | { | |
ed9bad06 | 1128 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1129 | struct neighbour *neigh; |
1130 | int err = -ENXIO; | |
1131 | ||
1132 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1133 | if (neigh) { | |
1134 | read_lock_bh(&neigh->lock); | |
1135 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); | |
1136 | r->arp_flags = arp_state_to_flags(neigh); | |
1137 | read_unlock_bh(&neigh->lock); | |
1138 | r->arp_ha.sa_family = dev->type; | |
1139 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); | |
1140 | neigh_release(neigh); | |
1141 | err = 0; | |
1142 | } | |
1143 | return err; | |
1144 | } | |
1145 | ||
545ecdc3 ML |
1146 | int arp_invalidate(struct net_device *dev, __be32 ip) |
1147 | { | |
1148 | struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1149 | int err = -ENXIO; | |
1150 | ||
1151 | if (neigh) { | |
1152 | if (neigh->nud_state & ~NUD_NOARP) | |
1153 | err = neigh_update(neigh, NULL, NUD_FAILED, | |
1154 | NEIGH_UPDATE_F_OVERRIDE| | |
1155 | NEIGH_UPDATE_F_ADMIN); | |
1156 | neigh_release(neigh); | |
1157 | } | |
1158 | ||
1159 | return err; | |
1160 | } | |
1161 | EXPORT_SYMBOL(arp_invalidate); | |
1162 | ||
32e569b7 PE |
1163 | static int arp_req_delete_public(struct net *net, struct arpreq *r, |
1164 | struct net_device *dev) | |
46479b43 PE |
1165 | { |
1166 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1167 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1168 | ||
1169 | if (mask == htonl(0xFFFFFFFF)) | |
2db82b53 | 1170 | return pneigh_delete(&arp_tbl, net, &ip, dev); |
46479b43 | 1171 | |
f8b33fdf PE |
1172 | if (mask) |
1173 | return -EINVAL; | |
1174 | ||
32e569b7 | 1175 | return arp_req_set_proxy(net, dev, 0); |
46479b43 PE |
1176 | } |
1177 | ||
32e569b7 | 1178 | static int arp_req_delete(struct net *net, struct arpreq *r, |
deffd777 | 1179 | struct net_device *dev) |
1da177e4 | 1180 | { |
46479b43 | 1181 | __be32 ip; |
1da177e4 | 1182 | |
46479b43 | 1183 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1184 | return arp_req_delete_public(net, r, dev); |
1da177e4 | 1185 | |
46479b43 | 1186 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 | 1187 | if (dev == NULL) { |
5811662b CG |
1188 | struct flowi fl = { .fl4_dst = ip, |
1189 | .fl4_tos = RTO_ONLINK }; | |
b23dd4fe DM |
1190 | struct rtable *rt = ip_route_output_key(net, &fl); |
1191 | if (IS_ERR(rt)) | |
1192 | return PTR_ERR(rt); | |
d8d1f30b | 1193 | dev = rt->dst.dev; |
1da177e4 LT |
1194 | ip_rt_put(rt); |
1195 | if (!dev) | |
1196 | return -EINVAL; | |
1197 | } | |
545ecdc3 | 1198 | return arp_invalidate(dev, ip); |
1da177e4 LT |
1199 | } |
1200 | ||
1201 | /* | |
1202 | * Handle an ARP layer I/O control request. | |
1203 | */ | |
1204 | ||
32e569b7 | 1205 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
1da177e4 LT |
1206 | { |
1207 | int err; | |
1208 | struct arpreq r; | |
1209 | struct net_device *dev = NULL; | |
1210 | ||
1211 | switch (cmd) { | |
deffd777 CG |
1212 | case SIOCDARP: |
1213 | case SIOCSARP: | |
1214 | if (!capable(CAP_NET_ADMIN)) | |
1215 | return -EPERM; | |
1216 | case SIOCGARP: | |
1217 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); | |
1218 | if (err) | |
1219 | return -EFAULT; | |
1220 | break; | |
1221 | default: | |
1222 | return -EINVAL; | |
1da177e4 LT |
1223 | } |
1224 | ||
1225 | if (r.arp_pa.sa_family != AF_INET) | |
1226 | return -EPFNOSUPPORT; | |
1227 | ||
1228 | if (!(r.arp_flags & ATF_PUBL) && | |
deffd777 | 1229 | (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) |
1da177e4 LT |
1230 | return -EINVAL; |
1231 | if (!(r.arp_flags & ATF_NETMASK)) | |
1232 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = | |
1233 | htonl(0xFFFFFFFFUL); | |
c506653d | 1234 | rtnl_lock(); |
1da177e4 LT |
1235 | if (r.arp_dev[0]) { |
1236 | err = -ENODEV; | |
c506653d | 1237 | dev = __dev_get_by_name(net, r.arp_dev); |
deffd777 | 1238 | if (dev == NULL) |
1da177e4 LT |
1239 | goto out; |
1240 | ||
1241 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ | |
1242 | if (!r.arp_ha.sa_family) | |
1243 | r.arp_ha.sa_family = dev->type; | |
1244 | err = -EINVAL; | |
1245 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) | |
1246 | goto out; | |
1247 | } else if (cmd == SIOCGARP) { | |
1248 | err = -ENODEV; | |
1249 | goto out; | |
1250 | } | |
1251 | ||
132adf54 | 1252 | switch (cmd) { |
1da177e4 | 1253 | case SIOCDARP: |
32e569b7 | 1254 | err = arp_req_delete(net, &r, dev); |
1da177e4 LT |
1255 | break; |
1256 | case SIOCSARP: | |
32e569b7 | 1257 | err = arp_req_set(net, &r, dev); |
1da177e4 LT |
1258 | break; |
1259 | case SIOCGARP: | |
1260 | err = arp_req_get(&r, dev); | |
1da177e4 LT |
1261 | break; |
1262 | } | |
1263 | out: | |
c506653d | 1264 | rtnl_unlock(); |
941666c2 ED |
1265 | if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) |
1266 | err = -EFAULT; | |
1da177e4 LT |
1267 | return err; |
1268 | } | |
1269 | ||
deffd777 CG |
1270 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, |
1271 | void *ptr) | |
1da177e4 LT |
1272 | { |
1273 | struct net_device *dev = ptr; | |
1274 | ||
1275 | switch (event) { | |
1276 | case NETDEV_CHANGEADDR: | |
1277 | neigh_changeaddr(&arp_tbl, dev); | |
76e6ebfb | 1278 | rt_cache_flush(dev_net(dev), 0); |
1da177e4 LT |
1279 | break; |
1280 | default: | |
1281 | break; | |
1282 | } | |
1283 | ||
1284 | return NOTIFY_DONE; | |
1285 | } | |
1286 | ||
1287 | static struct notifier_block arp_netdev_notifier = { | |
1288 | .notifier_call = arp_netdev_event, | |
1289 | }; | |
1290 | ||
1291 | /* Note, that it is not on notifier chain. | |
1292 | It is necessary, that this routine was called after route cache will be | |
1293 | flushed. | |
1294 | */ | |
1295 | void arp_ifdown(struct net_device *dev) | |
1296 | { | |
1297 | neigh_ifdown(&arp_tbl, dev); | |
1298 | } | |
1299 | ||
1300 | ||
1301 | /* | |
1302 | * Called once on startup. | |
1303 | */ | |
1304 | ||
7546dd97 | 1305 | static struct packet_type arp_packet_type __read_mostly = { |
09640e63 | 1306 | .type = cpu_to_be16(ETH_P_ARP), |
1da177e4 LT |
1307 | .func = arp_rcv, |
1308 | }; | |
1309 | ||
1310 | static int arp_proc_init(void); | |
1311 | ||
1312 | void __init arp_init(void) | |
1313 | { | |
1314 | neigh_table_init(&arp_tbl); | |
1315 | ||
1316 | dev_add_pack(&arp_packet_type); | |
1317 | arp_proc_init(); | |
1318 | #ifdef CONFIG_SYSCTL | |
54716e3b | 1319 | neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); |
1da177e4 LT |
1320 | #endif |
1321 | register_netdevice_notifier(&arp_netdev_notifier); | |
1322 | } | |
1323 | ||
1324 | #ifdef CONFIG_PROC_FS | |
1325 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
1326 | ||
1327 | /* ------------------------------------------------------------------------ */ | |
1328 | /* | |
1329 | * ax25 -> ASCII conversion | |
1330 | */ | |
1331 | static char *ax2asc2(ax25_address *a, char *buf) | |
1332 | { | |
1333 | char c, *s; | |
1334 | int n; | |
1335 | ||
1336 | for (n = 0, s = buf; n < 6; n++) { | |
1337 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
1338 | ||
deffd777 CG |
1339 | if (c != ' ') |
1340 | *s++ = c; | |
1da177e4 | 1341 | } |
e905a9ed | 1342 | |
1da177e4 | 1343 | *s++ = '-'; |
deffd777 CG |
1344 | n = (a->ax25_call[6] >> 1) & 0x0F; |
1345 | if (n > 9) { | |
1da177e4 LT |
1346 | *s++ = '1'; |
1347 | n -= 10; | |
1348 | } | |
e905a9ed | 1349 | |
1da177e4 LT |
1350 | *s++ = n + '0'; |
1351 | *s++ = '\0'; | |
1352 | ||
1353 | if (*buf == '\0' || *buf == '-') | |
deffd777 | 1354 | return "*"; |
1da177e4 LT |
1355 | |
1356 | return buf; | |
1da177e4 LT |
1357 | } |
1358 | #endif /* CONFIG_AX25 */ | |
1359 | ||
1360 | #define HBUFFERLEN 30 | |
1361 | ||
1362 | static void arp_format_neigh_entry(struct seq_file *seq, | |
1363 | struct neighbour *n) | |
1364 | { | |
1365 | char hbuffer[HBUFFERLEN]; | |
1da177e4 LT |
1366 | int k, j; |
1367 | char tbuf[16]; | |
1368 | struct net_device *dev = n->dev; | |
1369 | int hatype = dev->type; | |
1370 | ||
1371 | read_lock(&n->lock); | |
1372 | /* Convert hardware address to XX:XX:XX:XX ... form. */ | |
1373 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) | |
1374 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) | |
1375 | ax2asc2((ax25_address *)n->ha, hbuffer); | |
1376 | else { | |
1377 | #endif | |
1378 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { | |
51f82a2b DC |
1379 | hbuffer[k++] = hex_asc_hi(n->ha[j]); |
1380 | hbuffer[k++] = hex_asc_lo(n->ha[j]); | |
1da177e4 LT |
1381 | hbuffer[k++] = ':'; |
1382 | } | |
a3e8ee68 | 1383 | if (k != 0) |
1384 | --k; | |
1385 | hbuffer[k] = 0; | |
1da177e4 LT |
1386 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) |
1387 | } | |
1388 | #endif | |
673d57e7 | 1389 | sprintf(tbuf, "%pI4", n->primary_key); |
1da177e4 LT |
1390 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
1391 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); | |
1392 | read_unlock(&n->lock); | |
1393 | } | |
1394 | ||
1395 | static void arp_format_pneigh_entry(struct seq_file *seq, | |
1396 | struct pneigh_entry *n) | |
1397 | { | |
1398 | struct net_device *dev = n->dev; | |
1399 | int hatype = dev ? dev->type : 0; | |
1400 | char tbuf[16]; | |
1401 | ||
673d57e7 | 1402 | sprintf(tbuf, "%pI4", n->key); |
1da177e4 LT |
1403 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
1404 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", | |
1405 | dev ? dev->name : "*"); | |
1406 | } | |
1407 | ||
1408 | static int arp_seq_show(struct seq_file *seq, void *v) | |
1409 | { | |
1410 | if (v == SEQ_START_TOKEN) { | |
1411 | seq_puts(seq, "IP address HW type Flags " | |
1412 | "HW address Mask Device\n"); | |
1413 | } else { | |
1414 | struct neigh_seq_state *state = seq->private; | |
1415 | ||
1416 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) | |
1417 | arp_format_pneigh_entry(seq, v); | |
1418 | else | |
1419 | arp_format_neigh_entry(seq, v); | |
1420 | } | |
1421 | ||
1422 | return 0; | |
1423 | } | |
1424 | ||
1425 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) | |
1426 | { | |
1427 | /* Don't want to confuse "arp -a" w/ magic entries, | |
1428 | * so we tell the generic iterator to skip NUD_NOARP. | |
1429 | */ | |
1430 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); | |
1431 | } | |
1432 | ||
1433 | /* ------------------------------------------------------------------------ */ | |
1434 | ||
f690808e | 1435 | static const struct seq_operations arp_seq_ops = { |
deffd777 CG |
1436 | .start = arp_seq_start, |
1437 | .next = neigh_seq_next, | |
1438 | .stop = neigh_seq_stop, | |
1439 | .show = arp_seq_show, | |
1da177e4 LT |
1440 | }; |
1441 | ||
1442 | static int arp_seq_open(struct inode *inode, struct file *file) | |
1443 | { | |
426b5303 EB |
1444 | return seq_open_net(inode, file, &arp_seq_ops, |
1445 | sizeof(struct neigh_seq_state)); | |
1da177e4 LT |
1446 | } |
1447 | ||
9a32144e | 1448 | static const struct file_operations arp_seq_fops = { |
1da177e4 LT |
1449 | .owner = THIS_MODULE, |
1450 | .open = arp_seq_open, | |
1451 | .read = seq_read, | |
1452 | .llseek = seq_lseek, | |
426b5303 | 1453 | .release = seq_release_net, |
1da177e4 LT |
1454 | }; |
1455 | ||
ffc31d3d DL |
1456 | |
1457 | static int __net_init arp_net_init(struct net *net) | |
1da177e4 | 1458 | { |
ffc31d3d | 1459 | if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) |
1da177e4 LT |
1460 | return -ENOMEM; |
1461 | return 0; | |
1462 | } | |
1463 | ||
ffc31d3d DL |
1464 | static void __net_exit arp_net_exit(struct net *net) |
1465 | { | |
1466 | proc_net_remove(net, "arp"); | |
1467 | } | |
1468 | ||
1469 | static struct pernet_operations arp_net_ops = { | |
1470 | .init = arp_net_init, | |
1471 | .exit = arp_net_exit, | |
1472 | }; | |
1473 | ||
1474 | static int __init arp_proc_init(void) | |
1475 | { | |
1476 | return register_pernet_subsys(&arp_net_ops); | |
1477 | } | |
1478 | ||
1da177e4 LT |
1479 | #else /* CONFIG_PROC_FS */ |
1480 | ||
1481 | static int __init arp_proc_init(void) | |
1482 | { | |
1483 | return 0; | |
1484 | } | |
1485 | ||
1486 | #endif /* CONFIG_PROC_FS */ |