Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
f30c2269 | 2 | /* linux/net/ipv4/arp.c |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 1994 by Florian La Roche | |
5 | * | |
6 | * This module implements the Address Resolution Protocol ARP (RFC 826), | |
7 | * which is used to convert IP addresses (or in the future maybe other | |
8 | * high-level addresses) into a low-level hardware address (like an Ethernet | |
9 | * address). | |
10 | * | |
1da177e4 | 11 | * Fixes: |
e905a9ed | 12 | * Alan Cox : Removed the Ethernet assumptions in |
1da177e4 | 13 | * Florian's code |
e905a9ed | 14 | * Alan Cox : Fixed some small errors in the ARP |
1da177e4 LT |
15 | * logic |
16 | * Alan Cox : Allow >4K in /proc | |
17 | * Alan Cox : Make ARP add its own protocol entry | |
18 | * Ross Martin : Rewrote arp_rcv() and arp_get_info() | |
19 | * Stephen Henson : Add AX25 support to arp_get_info() | |
20 | * Alan Cox : Drop data when a device is downed. | |
21 | * Alan Cox : Use init_timer(). | |
22 | * Alan Cox : Double lock fixes. | |
23 | * Martin Seine : Move the arphdr structure | |
24 | * to if_arp.h for compatibility. | |
25 | * with BSD based programs. | |
26 | * Andrew Tridgell : Added ARP netmask code and | |
27 | * re-arranged proxy handling. | |
28 | * Alan Cox : Changed to use notifiers. | |
29 | * Niibe Yutaka : Reply for this device or proxies only. | |
30 | * Alan Cox : Don't proxy across hardware types! | |
31 | * Jonathan Naylor : Added support for NET/ROM. | |
32 | * Mike Shaver : RFC1122 checks. | |
33 | * Jonathan Naylor : Only lookup the hardware address for | |
34 | * the correct hardware type. | |
35 | * Germano Caronni : Assorted subtle races. | |
e905a9ed | 36 | * Craig Schlenter : Don't modify permanent entry |
1da177e4 LT |
37 | * during arp_rcv. |
38 | * Russ Nelson : Tidied up a few bits. | |
39 | * Alexey Kuznetsov: Major changes to caching and behaviour, | |
e905a9ed | 40 | * eg intelligent arp probing and |
1da177e4 LT |
41 | * generation |
42 | * of host down events. | |
43 | * Alan Cox : Missing unlock in device events. | |
44 | * Eckes : ARP ioctl control errors. | |
45 | * Alexey Kuznetsov: Arp free fix. | |
46 | * Manuel Rodriguez: Gratuitous ARP. | |
e905a9ed | 47 | * Jonathan Layes : Added arpd support through kerneld |
1da177e4 LT |
48 | * message queue (960314) |
49 | * Mike Shaver : /proc/sys/net/ipv4/arp_* support | |
50 | * Mike McLagan : Routing by source | |
51 | * Stuart Cheshire : Metricom and grat arp fixes | |
52 | * *** FOR 2.1 clean this up *** | |
53 | * Lawrence V. Stefani: (08/12/96) Added FDDI support. | |
deffd777 | 54 | * Alan Cox : Took the AP1000 nasty FDDI hack and |
1da177e4 LT |
55 | * folded into the mainstream FDDI code. |
56 | * Ack spit, Linus how did you allow that | |
57 | * one in... | |
58 | * Jes Sorensen : Make FDDI work again in 2.1.x and | |
59 | * clean up the APFDDI & gen. FDDI bits. | |
60 | * Alexey Kuznetsov: new arp state machine; | |
61 | * now it is in net/core/neighbour.c. | |
62 | * Krzysztof Halasa: Added Frame Relay ARP support. | |
63 | * Arnaldo C. Melo : convert /proc/net/arp to seq_file | |
64 | * Shmulik Hen: Split arp_send to arp_create and | |
65 | * arp_xmit so intermediate drivers like | |
66 | * bonding can change the skb before | |
67 | * sending (e.g. insert 8021q tag). | |
68 | * Harald Welte : convert to make use of jenkins hash | |
65324144 | 69 | * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. |
1da177e4 LT |
70 | */ |
71 | ||
91df42be JP |
72 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
73 | ||
1da177e4 LT |
74 | #include <linux/module.h> |
75 | #include <linux/types.h> | |
76 | #include <linux/string.h> | |
77 | #include <linux/kernel.h> | |
4fc268d2 | 78 | #include <linux/capability.h> |
1da177e4 LT |
79 | #include <linux/socket.h> |
80 | #include <linux/sockios.h> | |
81 | #include <linux/errno.h> | |
82 | #include <linux/in.h> | |
83 | #include <linux/mm.h> | |
84 | #include <linux/inet.h> | |
14c85021 | 85 | #include <linux/inetdevice.h> |
1da177e4 LT |
86 | #include <linux/netdevice.h> |
87 | #include <linux/etherdevice.h> | |
88 | #include <linux/fddidevice.h> | |
89 | #include <linux/if_arp.h> | |
1da177e4 LT |
90 | #include <linux/skbuff.h> |
91 | #include <linux/proc_fs.h> | |
92 | #include <linux/seq_file.h> | |
93 | #include <linux/stat.h> | |
94 | #include <linux/init.h> | |
95 | #include <linux/net.h> | |
96 | #include <linux/rcupdate.h> | |
5a0e3ad6 | 97 | #include <linux/slab.h> |
1da177e4 LT |
98 | #ifdef CONFIG_SYSCTL |
99 | #include <linux/sysctl.h> | |
100 | #endif | |
101 | ||
457c4cbc | 102 | #include <net/net_namespace.h> |
1da177e4 LT |
103 | #include <net/ip.h> |
104 | #include <net/icmp.h> | |
105 | #include <net/route.h> | |
106 | #include <net/protocol.h> | |
107 | #include <net/tcp.h> | |
108 | #include <net/sock.h> | |
109 | #include <net/arp.h> | |
1da177e4 | 110 | #include <net/ax25.h> |
1da177e4 | 111 | #include <net/netrom.h> |
63d008a4 JB |
112 | #include <net/dst_metadata.h> |
113 | #include <net/ip_tunnels.h> | |
1da177e4 | 114 | |
deffd777 | 115 | #include <linux/uaccess.h> |
1da177e4 LT |
116 | |
117 | #include <linux/netfilter_arp.h> | |
118 | ||
119 | /* | |
120 | * Interface to generic neighbour cache. | |
121 | */ | |
2c2aba6c | 122 | static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); |
60395a20 | 123 | static bool arp_key_eq(const struct neighbour *n, const void *pkey); |
1da177e4 LT |
124 | static int arp_constructor(struct neighbour *neigh); |
125 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); | |
126 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); | |
127 | static void parp_redo(struct sk_buff *skb); | |
8cf8821e | 128 | static int arp_is_multicast(const void *pkey); |
1da177e4 | 129 | |
89d69d2b | 130 | static const struct neigh_ops arp_generic_ops = { |
1da177e4 LT |
131 | .family = AF_INET, |
132 | .solicit = arp_solicit, | |
133 | .error_report = arp_error_report, | |
134 | .output = neigh_resolve_output, | |
135 | .connected_output = neigh_connected_output, | |
1da177e4 LT |
136 | }; |
137 | ||
89d69d2b | 138 | static const struct neigh_ops arp_hh_ops = { |
1da177e4 LT |
139 | .family = AF_INET, |
140 | .solicit = arp_solicit, | |
141 | .error_report = arp_error_report, | |
142 | .output = neigh_resolve_output, | |
143 | .connected_output = neigh_resolve_output, | |
1da177e4 LT |
144 | }; |
145 | ||
89d69d2b | 146 | static const struct neigh_ops arp_direct_ops = { |
1da177e4 | 147 | .family = AF_INET, |
8f40b161 DM |
148 | .output = neigh_direct_output, |
149 | .connected_output = neigh_direct_output, | |
1da177e4 LT |
150 | }; |
151 | ||
1da177e4 | 152 | struct neigh_table arp_tbl = { |
deffd777 | 153 | .family = AF_INET, |
deffd777 | 154 | .key_len = 4, |
bdf53c58 | 155 | .protocol = cpu_to_be16(ETH_P_IP), |
deffd777 | 156 | .hash = arp_hash, |
60395a20 | 157 | .key_eq = arp_key_eq, |
deffd777 CG |
158 | .constructor = arp_constructor, |
159 | .proxy_redo = parp_redo, | |
8cf8821e | 160 | .is_multicast = arp_is_multicast, |
deffd777 CG |
161 | .id = "arp_cache", |
162 | .parms = { | |
163 | .tbl = &arp_tbl, | |
deffd777 | 164 | .reachable_time = 30 * HZ, |
1f9248e5 JP |
165 | .data = { |
166 | [NEIGH_VAR_MCAST_PROBES] = 3, | |
167 | [NEIGH_VAR_UCAST_PROBES] = 3, | |
168 | [NEIGH_VAR_RETRANS_TIME] = 1 * HZ, | |
169 | [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, | |
170 | [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, | |
171 | [NEIGH_VAR_GC_STALETIME] = 60 * HZ, | |
eaa72dc4 | 172 | [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, |
1f9248e5 JP |
173 | [NEIGH_VAR_PROXY_QLEN] = 64, |
174 | [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, | |
175 | [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, | |
176 | [NEIGH_VAR_LOCKTIME] = 1 * HZ, | |
177 | }, | |
1da177e4 | 178 | }, |
deffd777 CG |
179 | .gc_interval = 30 * HZ, |
180 | .gc_thresh1 = 128, | |
181 | .gc_thresh2 = 512, | |
182 | .gc_thresh3 = 1024, | |
1da177e4 | 183 | }; |
4bc2f18b | 184 | EXPORT_SYMBOL(arp_tbl); |
1da177e4 | 185 | |
714e85be | 186 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
1da177e4 LT |
187 | { |
188 | switch (dev->type) { | |
189 | case ARPHRD_ETHER: | |
190 | case ARPHRD_FDDI: | |
191 | case ARPHRD_IEEE802: | |
192 | ip_eth_mc_map(addr, haddr); | |
e905a9ed | 193 | return 0; |
1da177e4 | 194 | case ARPHRD_INFINIBAND: |
a9e527e3 | 195 | ip_ib_mc_map(addr, dev->broadcast, haddr); |
1da177e4 | 196 | return 0; |
93ca3bb5 TT |
197 | case ARPHRD_IPGRE: |
198 | ip_ipgre_mc_map(addr, dev->broadcast, haddr); | |
199 | return 0; | |
1da177e4 LT |
200 | default: |
201 | if (dir) { | |
202 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
203 | return 0; | |
204 | } | |
205 | } | |
206 | return -EINVAL; | |
207 | } | |
208 | ||
209 | ||
d6bf7817 ED |
210 | static u32 arp_hash(const void *pkey, |
211 | const struct net_device *dev, | |
2c2aba6c | 212 | __u32 *hash_rnd) |
1da177e4 | 213 | { |
60395a20 EB |
214 | return arp_hashfn(pkey, dev, hash_rnd); |
215 | } | |
216 | ||
217 | static bool arp_key_eq(const struct neighbour *neigh, const void *pkey) | |
218 | { | |
219 | return neigh_key_eq32(neigh, pkey); | |
1da177e4 LT |
220 | } |
221 | ||
222 | static int arp_constructor(struct neighbour *neigh) | |
223 | { | |
cd9ff4de | 224 | __be32 addr; |
1da177e4 LT |
225 | struct net_device *dev = neigh->dev; |
226 | struct in_device *in_dev; | |
227 | struct neigh_parms *parms; | |
cd9ff4de | 228 | u32 inaddr_any = INADDR_ANY; |
1da177e4 | 229 | |
cd9ff4de JW |
230 | if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) |
231 | memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len); | |
232 | ||
233 | addr = *(__be32 *)neigh->primary_key; | |
1da177e4 | 234 | rcu_read_lock(); |
e5ed6399 | 235 | in_dev = __in_dev_get_rcu(dev); |
51456b29 | 236 | if (!in_dev) { |
1da177e4 LT |
237 | rcu_read_unlock(); |
238 | return -EINVAL; | |
239 | } | |
240 | ||
30bbaa19 | 241 | neigh->type = inet_addr_type_dev_table(dev_net(dev), dev, addr); |
a79878f0 | 242 | |
1da177e4 LT |
243 | parms = in_dev->arp_parms; |
244 | __neigh_parms_put(neigh->parms); | |
245 | neigh->parms = neigh_parms_clone(parms); | |
246 | rcu_read_unlock(); | |
247 | ||
3b04ddde | 248 | if (!dev->header_ops) { |
1da177e4 LT |
249 | neigh->nud_state = NUD_NOARP; |
250 | neigh->ops = &arp_direct_ops; | |
8f40b161 | 251 | neigh->output = neigh_direct_output; |
1da177e4 LT |
252 | } else { |
253 | /* Good devices (checked by reading texts, but only Ethernet is | |
254 | tested) | |
255 | ||
256 | ARPHRD_ETHER: (ethernet, apfddi) | |
257 | ARPHRD_FDDI: (fddi) | |
258 | ARPHRD_IEEE802: (tr) | |
259 | ARPHRD_METRICOM: (strip) | |
260 | ARPHRD_ARCNET: | |
261 | etc. etc. etc. | |
262 | ||
263 | ARPHRD_IPDDP will also work, if author repairs it. | |
264 | I did not it, because this driver does not work even | |
265 | in old paradigm. | |
266 | */ | |
267 | ||
1da177e4 LT |
268 | if (neigh->type == RTN_MULTICAST) { |
269 | neigh->nud_state = NUD_NOARP; | |
270 | arp_mc_map(addr, neigh->ha, dev, 1); | |
deffd777 | 271 | } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { |
1da177e4 LT |
272 | neigh->nud_state = NUD_NOARP; |
273 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); | |
deffd777 CG |
274 | } else if (neigh->type == RTN_BROADCAST || |
275 | (dev->flags & IFF_POINTOPOINT)) { | |
1da177e4 LT |
276 | neigh->nud_state = NUD_NOARP; |
277 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); | |
278 | } | |
3b04ddde SH |
279 | |
280 | if (dev->header_ops->cache) | |
1da177e4 LT |
281 | neigh->ops = &arp_hh_ops; |
282 | else | |
283 | neigh->ops = &arp_generic_ops; | |
3b04ddde | 284 | |
deffd777 | 285 | if (neigh->nud_state & NUD_VALID) |
1da177e4 LT |
286 | neigh->output = neigh->ops->connected_output; |
287 | else | |
288 | neigh->output = neigh->ops->output; | |
289 | } | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) | |
294 | { | |
295 | dst_link_failure(skb); | |
296 | kfree_skb(skb); | |
297 | } | |
298 | ||
0accfc26 TG |
299 | /* Create and send an arp packet. */ |
300 | static void arp_send_dst(int type, int ptype, __be32 dest_ip, | |
301 | struct net_device *dev, __be32 src_ip, | |
302 | const unsigned char *dest_hw, | |
303 | const unsigned char *src_hw, | |
63d008a4 JB |
304 | const unsigned char *target_hw, |
305 | struct dst_entry *dst) | |
0accfc26 TG |
306 | { |
307 | struct sk_buff *skb; | |
308 | ||
309 | /* arp on this interface. */ | |
310 | if (dev->flags & IFF_NOARP) | |
311 | return; | |
312 | ||
313 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, | |
314 | dest_hw, src_hw, target_hw); | |
315 | if (!skb) | |
316 | return; | |
317 | ||
181a4224 | 318 | skb_dst_set(skb, dst_clone(dst)); |
0accfc26 TG |
319 | arp_xmit(skb); |
320 | } | |
321 | ||
322 | void arp_send(int type, int ptype, __be32 dest_ip, | |
323 | struct net_device *dev, __be32 src_ip, | |
324 | const unsigned char *dest_hw, const unsigned char *src_hw, | |
325 | const unsigned char *target_hw) | |
326 | { | |
327 | arp_send_dst(type, ptype, dest_ip, dev, src_ip, dest_hw, src_hw, | |
328 | target_hw, NULL); | |
329 | } | |
330 | EXPORT_SYMBOL(arp_send); | |
331 | ||
1da177e4 LT |
332 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) |
333 | { | |
a61ced5d | 334 | __be32 saddr = 0; |
cf0be880 | 335 | u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; |
1da177e4 | 336 | struct net_device *dev = neigh->dev; |
deffd777 | 337 | __be32 target = *(__be32 *)neigh->primary_key; |
1da177e4 | 338 | int probes = atomic_read(&neigh->probes); |
4b4194c4 | 339 | struct in_device *in_dev; |
63d008a4 | 340 | struct dst_entry *dst = NULL; |
1da177e4 | 341 | |
4b4194c4 ED |
342 | rcu_read_lock(); |
343 | in_dev = __in_dev_get_rcu(dev); | |
344 | if (!in_dev) { | |
345 | rcu_read_unlock(); | |
1da177e4 | 346 | return; |
4b4194c4 | 347 | } |
1da177e4 LT |
348 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { |
349 | default: | |
350 | case 0: /* By default announce any local IP */ | |
30bbaa19 | 351 | if (skb && inet_addr_type_dev_table(dev_net(dev), dev, |
deffd777 | 352 | ip_hdr(skb)->saddr) == RTN_LOCAL) |
eddc9ec5 | 353 | saddr = ip_hdr(skb)->saddr; |
1da177e4 LT |
354 | break; |
355 | case 1: /* Restrict announcements of saddr in same subnet */ | |
356 | if (!skb) | |
357 | break; | |
eddc9ec5 | 358 | saddr = ip_hdr(skb)->saddr; |
30bbaa19 DA |
359 | if (inet_addr_type_dev_table(dev_net(dev), dev, |
360 | saddr) == RTN_LOCAL) { | |
1da177e4 LT |
361 | /* saddr should be known to target */ |
362 | if (inet_addr_onlink(in_dev, target, saddr)) | |
363 | break; | |
364 | } | |
365 | saddr = 0; | |
366 | break; | |
367 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ | |
368 | break; | |
369 | } | |
4b4194c4 | 370 | rcu_read_unlock(); |
1da177e4 | 371 | |
1da177e4 LT |
372 | if (!saddr) |
373 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); | |
374 | ||
1f9248e5 | 375 | probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); |
deffd777 CG |
376 | if (probes < 0) { |
377 | if (!(neigh->nud_state & NUD_VALID)) | |
91df42be | 378 | pr_debug("trying to ucast probe in NUD_INVALID\n"); |
9650388b | 379 | neigh_ha_snapshot(dst_ha, neigh, dev); |
cf0be880 | 380 | dst_hw = dst_ha; |
deffd777 | 381 | } else { |
1f9248e5 | 382 | probes -= NEIGH_VAR(neigh->parms, APP_PROBES); |
deffd777 | 383 | if (probes < 0) { |
deffd777 | 384 | neigh_app_ns(neigh); |
deffd777 CG |
385 | return; |
386 | } | |
1da177e4 LT |
387 | } |
388 | ||
63d008a4 | 389 | if (skb && !(dev->priv_flags & IFF_XMIT_DST_RELEASE)) |
181a4224 | 390 | dst = skb_dst(skb); |
0accfc26 | 391 | arp_send_dst(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, |
63d008a4 | 392 | dst_hw, dev->dev_addr, NULL, dst); |
1da177e4 LT |
393 | } |
394 | ||
9bd85e32 | 395 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
1da177e4 | 396 | { |
b601fa19 | 397 | struct net *net = dev_net(in_dev->dev); |
1da177e4 LT |
398 | int scope; |
399 | ||
400 | switch (IN_DEV_ARP_IGNORE(in_dev)) { | |
401 | case 0: /* Reply, the tip is already validated */ | |
402 | return 0; | |
403 | case 1: /* Reply only if tip is configured on the incoming interface */ | |
404 | sip = 0; | |
405 | scope = RT_SCOPE_HOST; | |
406 | break; | |
407 | case 2: /* | |
408 | * Reply only if tip is configured on the incoming interface | |
409 | * and is in same subnet as sip | |
410 | */ | |
411 | scope = RT_SCOPE_HOST; | |
412 | break; | |
413 | case 3: /* Do not reply for scope host addresses */ | |
414 | sip = 0; | |
415 | scope = RT_SCOPE_LINK; | |
b601fa19 | 416 | in_dev = NULL; |
1da177e4 LT |
417 | break; |
418 | case 4: /* Reserved */ | |
419 | case 5: | |
420 | case 6: | |
421 | case 7: | |
422 | return 0; | |
423 | case 8: /* Do not reply */ | |
424 | return 1; | |
425 | default: | |
426 | return 0; | |
427 | } | |
b601fa19 | 428 | return !inet_confirm_addr(net, in_dev, sip, tip, scope); |
1da177e4 LT |
429 | } |
430 | ||
ed9bad06 | 431 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
1da177e4 | 432 | { |
1da177e4 | 433 | struct rtable *rt; |
e905a9ed | 434 | int flag = 0; |
1da177e4 | 435 | /*unsigned long now; */ |
ca12a1a4 | 436 | struct net *net = dev_net(dev); |
1da177e4 | 437 | |
58b35f27 | 438 | rt = ip_route_output(net, sip, tip, 0, l3mdev_master_ifindex_rcu(dev)); |
b23dd4fe | 439 | if (IS_ERR(rt)) |
1da177e4 | 440 | return 1; |
d8d1f30b | 441 | if (rt->dst.dev != dev) { |
02a1d6e7 | 442 | __NET_INC_STATS(net, LINUX_MIB_ARPFILTER); |
1da177e4 | 443 | flag = 1; |
e905a9ed YH |
444 | } |
445 | ip_rt_put(rt); | |
446 | return flag; | |
447 | } | |
1da177e4 | 448 | |
1da177e4 LT |
449 | /* |
450 | * Check if we can use proxy ARP for this path | |
451 | */ | |
65324144 JDB |
452 | static inline int arp_fwd_proxy(struct in_device *in_dev, |
453 | struct net_device *dev, struct rtable *rt) | |
1da177e4 LT |
454 | { |
455 | struct in_device *out_dev; | |
456 | int imi, omi = -1; | |
457 | ||
d8d1f30b | 458 | if (rt->dst.dev == dev) |
65324144 JDB |
459 | return 0; |
460 | ||
1da177e4 LT |
461 | if (!IN_DEV_PROXY_ARP(in_dev)) |
462 | return 0; | |
deffd777 CG |
463 | imi = IN_DEV_MEDIUM_ID(in_dev); |
464 | if (imi == 0) | |
1da177e4 LT |
465 | return 1; |
466 | if (imi == -1) | |
467 | return 0; | |
468 | ||
469 | /* place to check for proxy_arp for routes */ | |
470 | ||
d8d1f30b | 471 | out_dev = __in_dev_get_rcu(rt->dst.dev); |
faa9dcf7 | 472 | if (out_dev) |
1da177e4 | 473 | omi = IN_DEV_MEDIUM_ID(out_dev); |
faa9dcf7 | 474 | |
a02cec21 | 475 | return omi != imi && omi != -1; |
1da177e4 LT |
476 | } |
477 | ||
65324144 JDB |
478 | /* |
479 | * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) | |
480 | * | |
481 | * RFC3069 supports proxy arp replies back to the same interface. This | |
482 | * is done to support (ethernet) switch features, like RFC 3069, where | |
483 | * the individual ports are not allowed to communicate with each | |
484 | * other, BUT they are allowed to talk to the upstream router. As | |
485 | * described in RFC 3069, it is possible to allow these hosts to | |
486 | * communicate through the upstream router, by proxy_arp'ing. | |
487 | * | |
488 | * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" | |
489 | * | |
490 | * This technology is known by different names: | |
491 | * In RFC 3069 it is called VLAN Aggregation. | |
492 | * Cisco and Allied Telesyn call it Private VLAN. | |
493 | * Hewlett-Packard call it Source-Port filtering or port-isolation. | |
494 | * Ericsson call it MAC-Forced Forwarding (RFC Draft). | |
495 | * | |
496 | */ | |
497 | static inline int arp_fwd_pvlan(struct in_device *in_dev, | |
498 | struct net_device *dev, struct rtable *rt, | |
499 | __be32 sip, __be32 tip) | |
500 | { | |
501 | /* Private VLAN is only concerned about the same ethernet segment */ | |
d8d1f30b | 502 | if (rt->dst.dev != dev) |
65324144 JDB |
503 | return 0; |
504 | ||
505 | /* Don't reply on self probes (often done by windowz boxes)*/ | |
506 | if (sip == tip) | |
507 | return 0; | |
508 | ||
509 | if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) | |
510 | return 1; | |
511 | else | |
512 | return 0; | |
513 | } | |
514 | ||
1da177e4 LT |
515 | /* |
516 | * Interface to link layer: send routine and receive handler. | |
517 | */ | |
518 | ||
519 | /* | |
51456b29 | 520 | * Create an arp packet. If dest_hw is not set, we create a broadcast |
1da177e4 LT |
521 | * message. |
522 | */ | |
ed9bad06 AV |
523 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
524 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
525 | const unsigned char *dest_hw, |
526 | const unsigned char *src_hw, | |
527 | const unsigned char *target_hw) | |
1da177e4 LT |
528 | { |
529 | struct sk_buff *skb; | |
530 | struct arphdr *arp; | |
531 | unsigned char *arp_ptr; | |
66088243 HX |
532 | int hlen = LL_RESERVED_SPACE(dev); |
533 | int tlen = dev->needed_tailroom; | |
1da177e4 LT |
534 | |
535 | /* | |
536 | * Allocate a buffer | |
537 | */ | |
e905a9ed | 538 | |
66088243 | 539 | skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); |
51456b29 | 540 | if (!skb) |
1da177e4 LT |
541 | return NULL; |
542 | ||
66088243 | 543 | skb_reserve(skb, hlen); |
c1d2bbe1 | 544 | skb_reset_network_header(skb); |
4df864c1 | 545 | arp = skb_put(skb, arp_hdr_len(dev)); |
1da177e4 LT |
546 | skb->dev = dev; |
547 | skb->protocol = htons(ETH_P_ARP); | |
51456b29 | 548 | if (!src_hw) |
1da177e4 | 549 | src_hw = dev->dev_addr; |
51456b29 | 550 | if (!dest_hw) |
1da177e4 LT |
551 | dest_hw = dev->broadcast; |
552 | ||
553 | /* | |
554 | * Fill the device header for the ARP frame | |
555 | */ | |
0c4e8581 | 556 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
1da177e4 LT |
557 | goto out; |
558 | ||
559 | /* | |
560 | * Fill out the arp protocol part. | |
561 | * | |
562 | * The arp hardware type should match the device type, except for FDDI, | |
563 | * which (according to RFC 1390) should always equal 1 (Ethernet). | |
564 | */ | |
565 | /* | |
566 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the | |
567 | * DIX code for the protocol. Make these device structure fields. | |
568 | */ | |
569 | switch (dev->type) { | |
570 | default: | |
571 | arp->ar_hrd = htons(dev->type); | |
572 | arp->ar_pro = htons(ETH_P_IP); | |
573 | break; | |
574 | ||
40e4783e | 575 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
576 | case ARPHRD_AX25: |
577 | arp->ar_hrd = htons(ARPHRD_AX25); | |
578 | arp->ar_pro = htons(AX25_P_IP); | |
579 | break; | |
580 | ||
40e4783e | 581 | #if IS_ENABLED(CONFIG_NETROM) |
1da177e4 LT |
582 | case ARPHRD_NETROM: |
583 | arp->ar_hrd = htons(ARPHRD_NETROM); | |
584 | arp->ar_pro = htons(AX25_P_IP); | |
585 | break; | |
586 | #endif | |
587 | #endif | |
588 | ||
40e4783e | 589 | #if IS_ENABLED(CONFIG_FDDI) |
1da177e4 LT |
590 | case ARPHRD_FDDI: |
591 | arp->ar_hrd = htons(ARPHRD_ETHER); | |
592 | arp->ar_pro = htons(ETH_P_IP); | |
593 | break; | |
1da177e4 LT |
594 | #endif |
595 | } | |
596 | ||
597 | arp->ar_hln = dev->addr_len; | |
598 | arp->ar_pln = 4; | |
599 | arp->ar_op = htons(type); | |
600 | ||
deffd777 | 601 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
602 | |
603 | memcpy(arp_ptr, src_hw, dev->addr_len); | |
f4cca7ff JK |
604 | arp_ptr += dev->addr_len; |
605 | memcpy(arp_ptr, &src_ip, 4); | |
606 | arp_ptr += 4; | |
6752c8db YH |
607 | |
608 | switch (dev->type) { | |
609 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
610 | case ARPHRD_IEEE1394: | |
611 | break; | |
612 | #endif | |
613 | default: | |
00db4124 | 614 | if (target_hw) |
6752c8db YH |
615 | memcpy(arp_ptr, target_hw, dev->addr_len); |
616 | else | |
617 | memset(arp_ptr, 0, dev->addr_len); | |
618 | arp_ptr += dev->addr_len; | |
619 | } | |
1da177e4 LT |
620 | memcpy(arp_ptr, &dest_ip, 4); |
621 | ||
622 | return skb; | |
623 | ||
624 | out: | |
625 | kfree_skb(skb); | |
626 | return NULL; | |
627 | } | |
4bc2f18b | 628 | EXPORT_SYMBOL(arp_create); |
1da177e4 | 629 | |
0c4b51f0 | 630 | static int arp_xmit_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
f9e4306f EB |
631 | { |
632 | return dev_queue_xmit(skb); | |
633 | } | |
634 | ||
1da177e4 LT |
635 | /* |
636 | * Send an arp packet. | |
637 | */ | |
638 | void arp_xmit(struct sk_buff *skb) | |
639 | { | |
640 | /* Send it off, maybe filter it using firewalling first. */ | |
29a26a56 EB |
641 | NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, |
642 | dev_net(skb->dev), NULL, skb, NULL, skb->dev, | |
643 | arp_xmit_finish); | |
1da177e4 | 644 | } |
4bc2f18b | 645 | EXPORT_SYMBOL(arp_xmit); |
1da177e4 | 646 | |
d9ef2e7b IH |
647 | static bool arp_is_garp(struct net *net, struct net_device *dev, |
648 | int *addr_type, __be16 ar_op, | |
6fd05633 IH |
649 | __be32 sip, __be32 tip, |
650 | unsigned char *sha, unsigned char *tha) | |
651 | { | |
d9ef2e7b | 652 | bool is_garp = tip == sip; |
6fd05633 IH |
653 | |
654 | /* Gratuitous ARP _replies_ also require target hwaddr to be | |
655 | * the same as source. | |
656 | */ | |
657 | if (is_garp && ar_op == htons(ARPOP_REPLY)) | |
658 | is_garp = | |
659 | /* IPv4 over IEEE 1394 doesn't provide target | |
660 | * hardware address field in its ARP payload. | |
661 | */ | |
662 | tha && | |
663 | !memcmp(tha, sha, dev->addr_len); | |
664 | ||
d9ef2e7b IH |
665 | if (is_garp) { |
666 | *addr_type = inet_addr_type_dev_table(net, dev, sip); | |
667 | if (*addr_type != RTN_UNICAST) | |
668 | is_garp = false; | |
669 | } | |
6fd05633 IH |
670 | return is_garp; |
671 | } | |
672 | ||
1da177e4 LT |
673 | /* |
674 | * Process an arp request. | |
675 | */ | |
676 | ||
0c4b51f0 | 677 | static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
678 | { |
679 | struct net_device *dev = skb->dev; | |
faa9dcf7 | 680 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
681 | struct arphdr *arp; |
682 | unsigned char *arp_ptr; | |
683 | struct rtable *rt; | |
e0260fed | 684 | unsigned char *sha; |
23d268eb | 685 | unsigned char *tha = NULL; |
9e12bb22 | 686 | __be32 sip, tip; |
1da177e4 LT |
687 | u16 dev_type = dev->type; |
688 | int addr_type; | |
689 | struct neighbour *n; | |
63d008a4 | 690 | struct dst_entry *reply_dst = NULL; |
56022a8f | 691 | bool is_garp = false; |
1da177e4 LT |
692 | |
693 | /* arp_rcv below verifies the ARP header and verifies the device | |
694 | * is ARP'able. | |
695 | */ | |
696 | ||
51456b29 | 697 | if (!in_dev) |
8dfd329f | 698 | goto out_free_skb; |
1da177e4 | 699 | |
d0a92be0 | 700 | arp = arp_hdr(skb); |
1da177e4 LT |
701 | |
702 | switch (dev_type) { | |
e905a9ed | 703 | default: |
1da177e4 LT |
704 | if (arp->ar_pro != htons(ETH_P_IP) || |
705 | htons(dev_type) != arp->ar_hrd) | |
8dfd329f | 706 | goto out_free_skb; |
1da177e4 | 707 | break; |
1da177e4 | 708 | case ARPHRD_ETHER: |
1da177e4 | 709 | case ARPHRD_FDDI: |
1da177e4 | 710 | case ARPHRD_IEEE802: |
1da177e4 | 711 | /* |
211ed865 | 712 | * ETHERNET, and Fibre Channel (which are IEEE 802 |
1da177e4 LT |
713 | * devices, according to RFC 2625) devices will accept ARP |
714 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). | |
715 | * This is the case also of FDDI, where the RFC 1390 says that | |
716 | * FDDI devices should accept ARP hardware of (1) Ethernet, | |
717 | * however, to be more robust, we'll accept both 1 (Ethernet) | |
718 | * or 6 (IEEE 802.2) | |
719 | */ | |
720 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && | |
721 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || | |
722 | arp->ar_pro != htons(ETH_P_IP)) | |
8dfd329f | 723 | goto out_free_skb; |
1da177e4 | 724 | break; |
1da177e4 LT |
725 | case ARPHRD_AX25: |
726 | if (arp->ar_pro != htons(AX25_P_IP) || | |
727 | arp->ar_hrd != htons(ARPHRD_AX25)) | |
8dfd329f | 728 | goto out_free_skb; |
1da177e4 | 729 | break; |
1da177e4 LT |
730 | case ARPHRD_NETROM: |
731 | if (arp->ar_pro != htons(AX25_P_IP) || | |
732 | arp->ar_hrd != htons(ARPHRD_NETROM)) | |
8dfd329f | 733 | goto out_free_skb; |
1da177e4 | 734 | break; |
1da177e4 LT |
735 | } |
736 | ||
737 | /* Understand only these message types */ | |
738 | ||
739 | if (arp->ar_op != htons(ARPOP_REPLY) && | |
740 | arp->ar_op != htons(ARPOP_REQUEST)) | |
8dfd329f | 741 | goto out_free_skb; |
1da177e4 LT |
742 | |
743 | /* | |
744 | * Extract fields | |
745 | */ | |
deffd777 | 746 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
747 | sha = arp_ptr; |
748 | arp_ptr += dev->addr_len; | |
749 | memcpy(&sip, arp_ptr, 4); | |
750 | arp_ptr += 4; | |
6752c8db YH |
751 | switch (dev_type) { |
752 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
753 | case ARPHRD_IEEE1394: | |
754 | break; | |
755 | #endif | |
756 | default: | |
23d268eb | 757 | tha = arp_ptr; |
6752c8db YH |
758 | arp_ptr += dev->addr_len; |
759 | } | |
1da177e4 | 760 | memcpy(&tip, arp_ptr, 4); |
e905a9ed | 761 | /* |
1da177e4 LT |
762 | * Check for bad requests for 127.x.x.x and requests for multicast |
763 | * addresses. If this is one such, delete it. | |
764 | */ | |
d0daebc3 TG |
765 | if (ipv4_is_multicast(tip) || |
766 | (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) | |
8dfd329f | 767 | goto out_free_skb; |
1da177e4 | 768 | |
97daf331 JB |
769 | /* |
770 | * For some 802.11 wireless deployments (and possibly other networks), | |
771 | * there will be an ARP proxy and gratuitous ARP frames are attacks | |
772 | * and thus should not be accepted. | |
773 | */ | |
774 | if (sip == tip && IN_DEV_ORCONF(in_dev, DROP_GRATUITOUS_ARP)) | |
8dfd329f | 775 | goto out_free_skb; |
97daf331 | 776 | |
1da177e4 LT |
777 | /* |
778 | * Special case: We must set Frame Relay source Q.922 address | |
779 | */ | |
780 | if (dev_type == ARPHRD_DLCI) | |
781 | sha = dev->broadcast; | |
782 | ||
783 | /* | |
784 | * Process entry. The idea here is we want to send a reply if it is a | |
785 | * request for us or if it is a request for someone else that we hold | |
786 | * a proxy for. We want to add an entry to our cache if it is a reply | |
e905a9ed YH |
787 | * to us or if it is a request for our address. |
788 | * (The assumption for this last is that if someone is requesting our | |
789 | * address, they are probably intending to talk to us, so it saves time | |
790 | * if we cache their address. Their address is also probably not in | |
1da177e4 | 791 | * our cache, since ours is not in their cache.) |
e905a9ed | 792 | * |
1da177e4 LT |
793 | * Putting this another way, we only care about replies if they are to |
794 | * us, in which case we add them to the cache. For requests, we care | |
795 | * about those for us and those for our proxies. We reply to both, | |
e905a9ed | 796 | * and in the case of requests for us we add the requester to the arp |
1da177e4 LT |
797 | * cache. |
798 | */ | |
799 | ||
63d008a4 JB |
800 | if (arp->ar_op == htons(ARPOP_REQUEST) && skb_metadata_dst(skb)) |
801 | reply_dst = (struct dst_entry *) | |
802 | iptunnel_metadata_reply(skb_metadata_dst(skb), | |
803 | GFP_ATOMIC); | |
804 | ||
f8a68e75 EB |
805 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ |
806 | if (sip == 0) { | |
1da177e4 | 807 | if (arp->ar_op == htons(ARPOP_REQUEST) && |
30bbaa19 | 808 | inet_addr_type_dev_table(net, dev, tip) == RTN_LOCAL && |
9bd85e32 | 809 | !arp_ignore(in_dev, sip, tip)) |
63d008a4 JB |
810 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, |
811 | sha, dev->dev_addr, sha, reply_dst); | |
8dfd329f | 812 | goto out_consume_skb; |
1da177e4 LT |
813 | } |
814 | ||
815 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
c6cffba4 | 816 | ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { |
1da177e4 | 817 | |
511c3f92 | 818 | rt = skb_rtable(skb); |
1da177e4 LT |
819 | addr_type = rt->rt_type; |
820 | ||
821 | if (addr_type == RTN_LOCAL) { | |
deffd777 | 822 | int dont_send; |
8164f1b7 | 823 | |
deffd777 | 824 | dont_send = arp_ignore(in_dev, sip, tip); |
8164f1b7 | 825 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
ae9c416d | 826 | dont_send = arp_filter(sip, tip, dev); |
8164f1b7 BG |
827 | if (!dont_send) { |
828 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
829 | if (n) { | |
63d008a4 JB |
830 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
831 | sip, dev, tip, sha, | |
832 | dev->dev_addr, sha, | |
833 | reply_dst); | |
8164f1b7 BG |
834 | neigh_release(n); |
835 | } | |
1da177e4 | 836 | } |
8dfd329f | 837 | goto out_consume_skb; |
1da177e4 | 838 | } else if (IN_DEV_FORWARD(in_dev)) { |
65324144 JDB |
839 | if (addr_type == RTN_UNICAST && |
840 | (arp_fwd_proxy(in_dev, dev, rt) || | |
841 | arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || | |
70620c46 TG |
842 | (rt->dst.dev != dev && |
843 | pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { | |
1da177e4 LT |
844 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
845 | if (n) | |
846 | neigh_release(n); | |
847 | ||
e905a9ed | 848 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
1da177e4 | 849 | skb->pkt_type == PACKET_HOST || |
1f9248e5 | 850 | NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { |
63d008a4 JB |
851 | arp_send_dst(ARPOP_REPLY, ETH_P_ARP, |
852 | sip, dev, tip, sha, | |
853 | dev->dev_addr, sha, | |
854 | reply_dst); | |
1da177e4 | 855 | } else { |
deffd777 CG |
856 | pneigh_enqueue(&arp_tbl, |
857 | in_dev->arp_parms, skb); | |
181a4224 | 858 | goto out_free_dst; |
1da177e4 | 859 | } |
8dfd329f | 860 | goto out_consume_skb; |
1da177e4 LT |
861 | } |
862 | } | |
863 | } | |
864 | ||
865 | /* Update our ARP tables */ | |
866 | ||
867 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); | |
868 | ||
5990baaa | 869 | addr_type = -1; |
7d472a59 | 870 | if (n || IN_DEV_ARP_ACCEPT(in_dev)) { |
7d472a59 IH |
871 | is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op, |
872 | sip, tip, sha, tha); | |
873 | } | |
30bbaa19 | 874 | |
7d472a59 | 875 | if (IN_DEV_ARP_ACCEPT(in_dev)) { |
abd596a4 NH |
876 | /* Unsolicited ARP is not accepted by default. |
877 | It is possible, that this option should be enabled for some | |
878 | devices (strip is candidate) | |
879 | */ | |
51456b29 | 880 | if (!n && |
d9ef2e7b IH |
881 | (is_garp || |
882 | (arp->ar_op == htons(ARPOP_REPLY) && | |
883 | (addr_type == RTN_UNICAST || | |
884 | (addr_type < 0 && | |
885 | /* postpone calculation to as late as possible */ | |
886 | inet_addr_type_dev_table(net, dev, sip) == | |
887 | RTN_UNICAST))))) | |
1b1ac759 | 888 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
abd596a4 | 889 | } |
1da177e4 LT |
890 | |
891 | if (n) { | |
892 | int state = NUD_REACHABLE; | |
893 | int override; | |
894 | ||
895 | /* If several different ARP replies follows back-to-back, | |
896 | use the FIRST one. It is possible, if several proxy | |
897 | agents are active. Taking the first reply prevents | |
898 | arp trashing and chooses the fastest router. | |
899 | */ | |
56022a8f SN |
900 | override = time_after(jiffies, |
901 | n->updated + | |
902 | NEIGH_VAR(n->parms, LOCKTIME)) || | |
903 | is_garp; | |
1da177e4 LT |
904 | |
905 | /* Broadcast replies and request packets | |
906 | do not assert neighbour reachability. | |
907 | */ | |
908 | if (arp->ar_op != htons(ARPOP_REPLY) || | |
909 | skb->pkt_type != PACKET_HOST) | |
910 | state = NUD_STALE; | |
deffd777 | 911 | neigh_update(n, sha, state, |
7b8f7a40 | 912 | override ? NEIGH_UPDATE_F_OVERRIDE : 0, 0); |
1da177e4 LT |
913 | neigh_release(n); |
914 | } | |
915 | ||
8dfd329f | 916 | out_consume_skb: |
ead2ceb0 | 917 | consume_skb(skb); |
8dfd329f | 918 | |
181a4224 JB |
919 | out_free_dst: |
920 | dst_release(reply_dst); | |
8dfd329f ZS |
921 | return NET_RX_SUCCESS; |
922 | ||
923 | out_free_skb: | |
924 | kfree_skb(skb); | |
925 | return NET_RX_DROP; | |
1da177e4 LT |
926 | } |
927 | ||
444fc8fc HX |
928 | static void parp_redo(struct sk_buff *skb) |
929 | { | |
0c4b51f0 | 930 | arp_process(dev_net(skb->dev), NULL, skb); |
444fc8fc HX |
931 | } |
932 | ||
8cf8821e JD |
933 | static int arp_is_multicast(const void *pkey) |
934 | { | |
935 | return ipv4_is_multicast(*((__be32 *)pkey)); | |
936 | } | |
1da177e4 LT |
937 | |
938 | /* | |
939 | * Receive an arp request from the device layer. | |
940 | */ | |
941 | ||
6c97e72a AB |
942 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
943 | struct packet_type *pt, struct net_device *orig_dev) | |
1da177e4 | 944 | { |
044453b3 ED |
945 | const struct arphdr *arp; |
946 | ||
825bae5d | 947 | /* do not tweak dropwatch on an ARP we will ignore */ |
044453b3 ED |
948 | if (dev->flags & IFF_NOARP || |
949 | skb->pkt_type == PACKET_OTHERHOST || | |
950 | skb->pkt_type == PACKET_LOOPBACK) | |
825bae5d | 951 | goto consumeskb; |
044453b3 ED |
952 | |
953 | skb = skb_share_check(skb, GFP_ATOMIC); | |
954 | if (!skb) | |
955 | goto out_of_mem; | |
1da177e4 LT |
956 | |
957 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ | |
988b7050 | 958 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) |
1da177e4 LT |
959 | goto freeskb; |
960 | ||
d0a92be0 | 961 | arp = arp_hdr(skb); |
044453b3 | 962 | if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) |
1da177e4 LT |
963 | goto freeskb; |
964 | ||
a61bbcf2 PM |
965 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
966 | ||
29a26a56 EB |
967 | return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, |
968 | dev_net(dev), NULL, skb, dev, NULL, | |
969 | arp_process); | |
1da177e4 | 970 | |
825bae5d RJ |
971 | consumeskb: |
972 | consume_skb(skb); | |
8dfd329f | 973 | return NET_RX_SUCCESS; |
1da177e4 LT |
974 | freeskb: |
975 | kfree_skb(skb); | |
976 | out_of_mem: | |
8dfd329f | 977 | return NET_RX_DROP; |
1da177e4 LT |
978 | } |
979 | ||
980 | /* | |
981 | * User level interface (ioctl) | |
982 | */ | |
983 | ||
984 | /* | |
985 | * Set (create) an ARP cache entry. | |
986 | */ | |
987 | ||
32e569b7 | 988 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
f8b33fdf | 989 | { |
51456b29 | 990 | if (!dev) { |
586f1211 | 991 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
f8b33fdf PE |
992 | return 0; |
993 | } | |
c506653d ED |
994 | if (__in_dev_get_rtnl(dev)) { |
995 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); | |
f8b33fdf PE |
996 | return 0; |
997 | } | |
998 | return -ENXIO; | |
999 | } | |
1000 | ||
32e569b7 PE |
1001 | static int arp_req_set_public(struct net *net, struct arpreq *r, |
1002 | struct net_device *dev) | |
43dc1701 PE |
1003 | { |
1004 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
1005 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1006 | ||
1007 | if (mask && mask != htonl(0xFFFFFFFF)) | |
1008 | return -EINVAL; | |
1009 | if (!dev && (r->arp_flags & ATF_COM)) { | |
941666c2 | 1010 | dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, |
deffd777 | 1011 | r->arp_ha.sa_data); |
43dc1701 PE |
1012 | if (!dev) |
1013 | return -ENODEV; | |
1014 | } | |
1015 | if (mask) { | |
51456b29 | 1016 | if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) |
43dc1701 PE |
1017 | return -ENOBUFS; |
1018 | return 0; | |
1019 | } | |
f8b33fdf | 1020 | |
32e569b7 | 1021 | return arp_req_set_proxy(net, dev, 1); |
43dc1701 PE |
1022 | } |
1023 | ||
32e569b7 | 1024 | static int arp_req_set(struct net *net, struct arpreq *r, |
deffd777 | 1025 | struct net_device *dev) |
1da177e4 | 1026 | { |
43dc1701 | 1027 | __be32 ip; |
1da177e4 LT |
1028 | struct neighbour *neigh; |
1029 | int err; | |
1030 | ||
43dc1701 | 1031 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1032 | return arp_req_set_public(net, r, dev); |
1da177e4 | 1033 | |
43dc1701 | 1034 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1035 | if (r->arp_flags & ATF_PERM) |
1036 | r->arp_flags |= ATF_COM; | |
51456b29 | 1037 | if (!dev) { |
78fbfd8a | 1038 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
b23dd4fe DM |
1039 | |
1040 | if (IS_ERR(rt)) | |
1041 | return PTR_ERR(rt); | |
d8d1f30b | 1042 | dev = rt->dst.dev; |
1da177e4 LT |
1043 | ip_rt_put(rt); |
1044 | if (!dev) | |
1045 | return -EINVAL; | |
1046 | } | |
1047 | switch (dev->type) { | |
40e4783e | 1048 | #if IS_ENABLED(CONFIG_FDDI) |
1da177e4 LT |
1049 | case ARPHRD_FDDI: |
1050 | /* | |
1051 | * According to RFC 1390, FDDI devices should accept ARP | |
1052 | * hardware types of 1 (Ethernet). However, to be more | |
1053 | * robust, we'll accept hardware types of either 1 (Ethernet) | |
1054 | * or 6 (IEEE 802.2). | |
1055 | */ | |
1056 | if (r->arp_ha.sa_family != ARPHRD_FDDI && | |
1057 | r->arp_ha.sa_family != ARPHRD_ETHER && | |
1058 | r->arp_ha.sa_family != ARPHRD_IEEE802) | |
1059 | return -EINVAL; | |
1060 | break; | |
1061 | #endif | |
1062 | default: | |
1063 | if (r->arp_ha.sa_family != dev->type) | |
1064 | return -EINVAL; | |
1065 | break; | |
1066 | } | |
1067 | ||
1068 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); | |
1069 | err = PTR_ERR(neigh); | |
1070 | if (!IS_ERR(neigh)) { | |
95c96174 | 1071 | unsigned int state = NUD_STALE; |
1da177e4 LT |
1072 | if (r->arp_flags & ATF_PERM) |
1073 | state = NUD_PERMANENT; | |
deffd777 | 1074 | err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? |
e905a9ed | 1075 | r->arp_ha.sa_data : NULL, state, |
deffd777 | 1076 | NEIGH_UPDATE_F_OVERRIDE | |
7b8f7a40 | 1077 | NEIGH_UPDATE_F_ADMIN, 0); |
1da177e4 LT |
1078 | neigh_release(neigh); |
1079 | } | |
1080 | return err; | |
1081 | } | |
1082 | ||
95c96174 | 1083 | static unsigned int arp_state_to_flags(struct neighbour *neigh) |
1da177e4 | 1084 | { |
1da177e4 | 1085 | if (neigh->nud_state&NUD_PERMANENT) |
deffd777 | 1086 | return ATF_PERM | ATF_COM; |
1da177e4 | 1087 | else if (neigh->nud_state&NUD_VALID) |
deffd777 CG |
1088 | return ATF_COM; |
1089 | else | |
1090 | return 0; | |
1da177e4 LT |
1091 | } |
1092 | ||
1093 | /* | |
1094 | * Get an ARP cache entry. | |
1095 | */ | |
1096 | ||
1097 | static int arp_req_get(struct arpreq *r, struct net_device *dev) | |
1098 | { | |
ed9bad06 | 1099 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1100 | struct neighbour *neigh; |
1101 | int err = -ENXIO; | |
1102 | ||
1103 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1104 | if (neigh) { | |
11c91ef9 ED |
1105 | if (!(neigh->nud_state & NUD_NOARP)) { |
1106 | read_lock_bh(&neigh->lock); | |
1107 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); | |
1108 | r->arp_flags = arp_state_to_flags(neigh); | |
1109 | read_unlock_bh(&neigh->lock); | |
1110 | r->arp_ha.sa_family = dev->type; | |
1111 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); | |
1112 | err = 0; | |
1113 | } | |
1da177e4 | 1114 | neigh_release(neigh); |
1da177e4 LT |
1115 | } |
1116 | return err; | |
1117 | } | |
1118 | ||
7195cf72 | 1119 | static int arp_invalidate(struct net_device *dev, __be32 ip) |
545ecdc3 ML |
1120 | { |
1121 | struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1122 | int err = -ENXIO; | |
5071034e | 1123 | struct neigh_table *tbl = &arp_tbl; |
545ecdc3 ML |
1124 | |
1125 | if (neigh) { | |
1126 | if (neigh->nud_state & ~NUD_NOARP) | |
1127 | err = neigh_update(neigh, NULL, NUD_FAILED, | |
1128 | NEIGH_UPDATE_F_OVERRIDE| | |
7b8f7a40 | 1129 | NEIGH_UPDATE_F_ADMIN, 0); |
5071034e | 1130 | write_lock_bh(&tbl->lock); |
545ecdc3 | 1131 | neigh_release(neigh); |
5071034e SV |
1132 | neigh_remove_one(neigh, tbl); |
1133 | write_unlock_bh(&tbl->lock); | |
545ecdc3 ML |
1134 | } |
1135 | ||
1136 | return err; | |
1137 | } | |
545ecdc3 | 1138 | |
32e569b7 PE |
1139 | static int arp_req_delete_public(struct net *net, struct arpreq *r, |
1140 | struct net_device *dev) | |
46479b43 PE |
1141 | { |
1142 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1143 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1144 | ||
1145 | if (mask == htonl(0xFFFFFFFF)) | |
2db82b53 | 1146 | return pneigh_delete(&arp_tbl, net, &ip, dev); |
46479b43 | 1147 | |
f8b33fdf PE |
1148 | if (mask) |
1149 | return -EINVAL; | |
1150 | ||
32e569b7 | 1151 | return arp_req_set_proxy(net, dev, 0); |
46479b43 PE |
1152 | } |
1153 | ||
32e569b7 | 1154 | static int arp_req_delete(struct net *net, struct arpreq *r, |
deffd777 | 1155 | struct net_device *dev) |
1da177e4 | 1156 | { |
46479b43 | 1157 | __be32 ip; |
1da177e4 | 1158 | |
46479b43 | 1159 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1160 | return arp_req_delete_public(net, r, dev); |
1da177e4 | 1161 | |
46479b43 | 1162 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
51456b29 | 1163 | if (!dev) { |
78fbfd8a | 1164 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
b23dd4fe DM |
1165 | if (IS_ERR(rt)) |
1166 | return PTR_ERR(rt); | |
d8d1f30b | 1167 | dev = rt->dst.dev; |
1da177e4 LT |
1168 | ip_rt_put(rt); |
1169 | if (!dev) | |
1170 | return -EINVAL; | |
1171 | } | |
545ecdc3 | 1172 | return arp_invalidate(dev, ip); |
1da177e4 LT |
1173 | } |
1174 | ||
1175 | /* | |
1176 | * Handle an ARP layer I/O control request. | |
1177 | */ | |
1178 | ||
32e569b7 | 1179 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
1da177e4 LT |
1180 | { |
1181 | int err; | |
1182 | struct arpreq r; | |
1183 | struct net_device *dev = NULL; | |
1184 | ||
1185 | switch (cmd) { | |
deffd777 CG |
1186 | case SIOCDARP: |
1187 | case SIOCSARP: | |
52e804c6 | 1188 | if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
deffd777 | 1189 | return -EPERM; |
a8eceea8 | 1190 | fallthrough; |
deffd777 CG |
1191 | case SIOCGARP: |
1192 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); | |
1193 | if (err) | |
1194 | return -EFAULT; | |
1195 | break; | |
1196 | default: | |
1197 | return -EINVAL; | |
1da177e4 LT |
1198 | } |
1199 | ||
1200 | if (r.arp_pa.sa_family != AF_INET) | |
1201 | return -EPFNOSUPPORT; | |
1202 | ||
1203 | if (!(r.arp_flags & ATF_PUBL) && | |
deffd777 | 1204 | (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) |
1da177e4 LT |
1205 | return -EINVAL; |
1206 | if (!(r.arp_flags & ATF_NETMASK)) | |
1207 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = | |
1208 | htonl(0xFFFFFFFFUL); | |
c506653d | 1209 | rtnl_lock(); |
1da177e4 LT |
1210 | if (r.arp_dev[0]) { |
1211 | err = -ENODEV; | |
c506653d | 1212 | dev = __dev_get_by_name(net, r.arp_dev); |
51456b29 | 1213 | if (!dev) |
1da177e4 LT |
1214 | goto out; |
1215 | ||
1216 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ | |
1217 | if (!r.arp_ha.sa_family) | |
1218 | r.arp_ha.sa_family = dev->type; | |
1219 | err = -EINVAL; | |
1220 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) | |
1221 | goto out; | |
1222 | } else if (cmd == SIOCGARP) { | |
1223 | err = -ENODEV; | |
1224 | goto out; | |
1225 | } | |
1226 | ||
132adf54 | 1227 | switch (cmd) { |
1da177e4 | 1228 | case SIOCDARP: |
32e569b7 | 1229 | err = arp_req_delete(net, &r, dev); |
1da177e4 LT |
1230 | break; |
1231 | case SIOCSARP: | |
32e569b7 | 1232 | err = arp_req_set(net, &r, dev); |
1da177e4 LT |
1233 | break; |
1234 | case SIOCGARP: | |
1235 | err = arp_req_get(&r, dev); | |
1da177e4 LT |
1236 | break; |
1237 | } | |
1238 | out: | |
c506653d | 1239 | rtnl_unlock(); |
941666c2 ED |
1240 | if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) |
1241 | err = -EFAULT; | |
1da177e4 LT |
1242 | return err; |
1243 | } | |
1244 | ||
deffd777 CG |
1245 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, |
1246 | void *ptr) | |
1da177e4 | 1247 | { |
351638e7 | 1248 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
6c8b4e3f | 1249 | struct netdev_notifier_change_info *change_info; |
fcdb44d0 JP |
1250 | struct in_device *in_dev; |
1251 | bool evict_nocarrier; | |
1da177e4 LT |
1252 | |
1253 | switch (event) { | |
1254 | case NETDEV_CHANGEADDR: | |
1255 | neigh_changeaddr(&arp_tbl, dev); | |
bafa6d9d | 1256 | rt_cache_flush(dev_net(dev)); |
1da177e4 | 1257 | break; |
6c8b4e3f TT |
1258 | case NETDEV_CHANGE: |
1259 | change_info = ptr; | |
1260 | if (change_info->flags_changed & IFF_NOARP) | |
1261 | neigh_changeaddr(&arp_tbl, dev); | |
fcdb44d0 JP |
1262 | |
1263 | in_dev = __in_dev_get_rtnl(dev); | |
1264 | if (!in_dev) | |
1265 | evict_nocarrier = true; | |
1266 | else | |
1267 | evict_nocarrier = IN_DEV_ARP_EVICT_NOCARRIER(in_dev); | |
1268 | ||
1269 | if (evict_nocarrier && !netif_carrier_ok(dev)) | |
859bd2ef | 1270 | neigh_carrier_down(&arp_tbl, dev); |
6c8b4e3f | 1271 | break; |
1da177e4 LT |
1272 | default: |
1273 | break; | |
1274 | } | |
1275 | ||
1276 | return NOTIFY_DONE; | |
1277 | } | |
1278 | ||
1279 | static struct notifier_block arp_netdev_notifier = { | |
1280 | .notifier_call = arp_netdev_event, | |
1281 | }; | |
1282 | ||
1283 | /* Note, that it is not on notifier chain. | |
1284 | It is necessary, that this routine was called after route cache will be | |
1285 | flushed. | |
1286 | */ | |
1287 | void arp_ifdown(struct net_device *dev) | |
1288 | { | |
1289 | neigh_ifdown(&arp_tbl, dev); | |
1290 | } | |
1291 | ||
1292 | ||
1293 | /* | |
1294 | * Called once on startup. | |
1295 | */ | |
1296 | ||
7546dd97 | 1297 | static struct packet_type arp_packet_type __read_mostly = { |
09640e63 | 1298 | .type = cpu_to_be16(ETH_P_ARP), |
1da177e4 LT |
1299 | .func = arp_rcv, |
1300 | }; | |
1301 | ||
1302 | static int arp_proc_init(void); | |
1303 | ||
1304 | void __init arp_init(void) | |
1305 | { | |
d7480fd3 | 1306 | neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl); |
1da177e4 LT |
1307 | |
1308 | dev_add_pack(&arp_packet_type); | |
1309 | arp_proc_init(); | |
1310 | #ifdef CONFIG_SYSCTL | |
73af614a | 1311 | neigh_sysctl_register(NULL, &arp_tbl.parms, NULL); |
1da177e4 LT |
1312 | #endif |
1313 | register_netdevice_notifier(&arp_netdev_notifier); | |
1314 | } | |
1315 | ||
1316 | #ifdef CONFIG_PROC_FS | |
40e4783e | 1317 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1318 | |
1319 | /* ------------------------------------------------------------------------ */ | |
1320 | /* | |
1321 | * ax25 -> ASCII conversion | |
1322 | */ | |
4872e57c | 1323 | static void ax2asc2(ax25_address *a, char *buf) |
1da177e4 LT |
1324 | { |
1325 | char c, *s; | |
1326 | int n; | |
1327 | ||
1328 | for (n = 0, s = buf; n < 6; n++) { | |
1329 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
1330 | ||
deffd777 CG |
1331 | if (c != ' ') |
1332 | *s++ = c; | |
1da177e4 | 1333 | } |
e905a9ed | 1334 | |
1da177e4 | 1335 | *s++ = '-'; |
deffd777 CG |
1336 | n = (a->ax25_call[6] >> 1) & 0x0F; |
1337 | if (n > 9) { | |
1da177e4 LT |
1338 | *s++ = '1'; |
1339 | n -= 10; | |
1340 | } | |
e905a9ed | 1341 | |
1da177e4 LT |
1342 | *s++ = n + '0'; |
1343 | *s++ = '\0'; | |
1344 | ||
4872e57c RB |
1345 | if (*buf == '\0' || *buf == '-') { |
1346 | buf[0] = '*'; | |
1347 | buf[1] = '\0'; | |
1348 | } | |
1da177e4 LT |
1349 | } |
1350 | #endif /* CONFIG_AX25 */ | |
1351 | ||
1352 | #define HBUFFERLEN 30 | |
1353 | ||
1354 | static void arp_format_neigh_entry(struct seq_file *seq, | |
1355 | struct neighbour *n) | |
1356 | { | |
1357 | char hbuffer[HBUFFERLEN]; | |
1da177e4 LT |
1358 | int k, j; |
1359 | char tbuf[16]; | |
1360 | struct net_device *dev = n->dev; | |
1361 | int hatype = dev->type; | |
1362 | ||
1363 | read_lock(&n->lock); | |
1364 | /* Convert hardware address to XX:XX:XX:XX ... form. */ | |
40e4783e | 1365 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1366 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) |
1367 | ax2asc2((ax25_address *)n->ha, hbuffer); | |
1368 | else { | |
1369 | #endif | |
1370 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { | |
51f82a2b DC |
1371 | hbuffer[k++] = hex_asc_hi(n->ha[j]); |
1372 | hbuffer[k++] = hex_asc_lo(n->ha[j]); | |
1da177e4 LT |
1373 | hbuffer[k++] = ':'; |
1374 | } | |
a3e8ee68 | 1375 | if (k != 0) |
1376 | --k; | |
1377 | hbuffer[k] = 0; | |
40e4783e | 1378 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1379 | } |
1380 | #endif | |
673d57e7 | 1381 | sprintf(tbuf, "%pI4", n->primary_key); |
4872e57c | 1382 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%-17s * %s\n", |
1da177e4 LT |
1383 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); |
1384 | read_unlock(&n->lock); | |
1385 | } | |
1386 | ||
1387 | static void arp_format_pneigh_entry(struct seq_file *seq, | |
1388 | struct pneigh_entry *n) | |
1389 | { | |
1390 | struct net_device *dev = n->dev; | |
1391 | int hatype = dev ? dev->type : 0; | |
1392 | char tbuf[16]; | |
1393 | ||
673d57e7 | 1394 | sprintf(tbuf, "%pI4", n->key); |
1da177e4 LT |
1395 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
1396 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", | |
1397 | dev ? dev->name : "*"); | |
1398 | } | |
1399 | ||
1400 | static int arp_seq_show(struct seq_file *seq, void *v) | |
1401 | { | |
1402 | if (v == SEQ_START_TOKEN) { | |
1403 | seq_puts(seq, "IP address HW type Flags " | |
1404 | "HW address Mask Device\n"); | |
1405 | } else { | |
1406 | struct neigh_seq_state *state = seq->private; | |
1407 | ||
1408 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) | |
1409 | arp_format_pneigh_entry(seq, v); | |
1410 | else | |
1411 | arp_format_neigh_entry(seq, v); | |
1412 | } | |
1413 | ||
1414 | return 0; | |
1415 | } | |
1416 | ||
1417 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) | |
1418 | { | |
1419 | /* Don't want to confuse "arp -a" w/ magic entries, | |
1420 | * so we tell the generic iterator to skip NUD_NOARP. | |
1421 | */ | |
1422 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); | |
1423 | } | |
1424 | ||
1425 | /* ------------------------------------------------------------------------ */ | |
1426 | ||
f690808e | 1427 | static const struct seq_operations arp_seq_ops = { |
deffd777 CG |
1428 | .start = arp_seq_start, |
1429 | .next = neigh_seq_next, | |
1430 | .stop = neigh_seq_stop, | |
1431 | .show = arp_seq_show, | |
1da177e4 LT |
1432 | }; |
1433 | ||
c3506372 | 1434 | /* ------------------------------------------------------------------------ */ |
ffc31d3d DL |
1435 | |
1436 | static int __net_init arp_net_init(struct net *net) | |
1da177e4 | 1437 | { |
c3506372 CH |
1438 | if (!proc_create_net("arp", 0444, net->proc_net, &arp_seq_ops, |
1439 | sizeof(struct neigh_seq_state))) | |
1da177e4 LT |
1440 | return -ENOMEM; |
1441 | return 0; | |
1442 | } | |
1443 | ||
ffc31d3d DL |
1444 | static void __net_exit arp_net_exit(struct net *net) |
1445 | { | |
ece31ffd | 1446 | remove_proc_entry("arp", net->proc_net); |
ffc31d3d DL |
1447 | } |
1448 | ||
1449 | static struct pernet_operations arp_net_ops = { | |
1450 | .init = arp_net_init, | |
1451 | .exit = arp_net_exit, | |
1452 | }; | |
1453 | ||
1454 | static int __init arp_proc_init(void) | |
1455 | { | |
1456 | return register_pernet_subsys(&arp_net_ops); | |
1457 | } | |
1458 | ||
1da177e4 LT |
1459 | #else /* CONFIG_PROC_FS */ |
1460 | ||
1461 | static int __init arp_proc_init(void) | |
1462 | { | |
1463 | return 0; | |
1464 | } | |
1465 | ||
1466 | #endif /* CONFIG_PROC_FS */ |