Commit | Line | Data |
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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 | ||
91df42be JP |
76 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
77 | ||
1da177e4 LT |
78 | #include <linux/module.h> |
79 | #include <linux/types.h> | |
80 | #include <linux/string.h> | |
81 | #include <linux/kernel.h> | |
4fc268d2 | 82 | #include <linux/capability.h> |
1da177e4 LT |
83 | #include <linux/socket.h> |
84 | #include <linux/sockios.h> | |
85 | #include <linux/errno.h> | |
86 | #include <linux/in.h> | |
87 | #include <linux/mm.h> | |
88 | #include <linux/inet.h> | |
14c85021 | 89 | #include <linux/inetdevice.h> |
1da177e4 LT |
90 | #include <linux/netdevice.h> |
91 | #include <linux/etherdevice.h> | |
92 | #include <linux/fddidevice.h> | |
93 | #include <linux/if_arp.h> | |
1da177e4 LT |
94 | #include <linux/skbuff.h> |
95 | #include <linux/proc_fs.h> | |
96 | #include <linux/seq_file.h> | |
97 | #include <linux/stat.h> | |
98 | #include <linux/init.h> | |
99 | #include <linux/net.h> | |
100 | #include <linux/rcupdate.h> | |
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 | 116 | |
deffd777 | 117 | #include <linux/uaccess.h> |
1da177e4 LT |
118 | |
119 | #include <linux/netfilter_arp.h> | |
120 | ||
121 | /* | |
122 | * Interface to generic neighbour cache. | |
123 | */ | |
2c2aba6c | 124 | static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd); |
1da177e4 LT |
125 | static int arp_constructor(struct neighbour *neigh); |
126 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); | |
127 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); | |
128 | static void parp_redo(struct sk_buff *skb); | |
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 | ||
a64de47c | 152 | static const struct neigh_ops arp_broken_ops = { |
1da177e4 LT |
153 | .family = AF_INET, |
154 | .solicit = arp_solicit, | |
155 | .error_report = arp_error_report, | |
156 | .output = neigh_compat_output, | |
157 | .connected_output = neigh_compat_output, | |
1da177e4 LT |
158 | }; |
159 | ||
160 | struct neigh_table arp_tbl = { | |
deffd777 | 161 | .family = AF_INET, |
deffd777 CG |
162 | .key_len = 4, |
163 | .hash = arp_hash, | |
164 | .constructor = arp_constructor, | |
165 | .proxy_redo = parp_redo, | |
166 | .id = "arp_cache", | |
167 | .parms = { | |
168 | .tbl = &arp_tbl, | |
deffd777 | 169 | .reachable_time = 30 * HZ, |
1f9248e5 JP |
170 | .data = { |
171 | [NEIGH_VAR_MCAST_PROBES] = 3, | |
172 | [NEIGH_VAR_UCAST_PROBES] = 3, | |
173 | [NEIGH_VAR_RETRANS_TIME] = 1 * HZ, | |
174 | [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ, | |
175 | [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, | |
176 | [NEIGH_VAR_GC_STALETIME] = 60 * HZ, | |
177 | [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, | |
178 | [NEIGH_VAR_PROXY_QLEN] = 64, | |
179 | [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, | |
180 | [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, | |
181 | [NEIGH_VAR_LOCKTIME] = 1 * HZ, | |
182 | }, | |
1da177e4 | 183 | }, |
deffd777 CG |
184 | .gc_interval = 30 * HZ, |
185 | .gc_thresh1 = 128, | |
186 | .gc_thresh2 = 512, | |
187 | .gc_thresh3 = 1024, | |
1da177e4 | 188 | }; |
4bc2f18b | 189 | EXPORT_SYMBOL(arp_tbl); |
1da177e4 | 190 | |
714e85be | 191 | int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) |
1da177e4 LT |
192 | { |
193 | switch (dev->type) { | |
194 | case ARPHRD_ETHER: | |
195 | case ARPHRD_FDDI: | |
196 | case ARPHRD_IEEE802: | |
197 | ip_eth_mc_map(addr, haddr); | |
e905a9ed | 198 | return 0; |
1da177e4 | 199 | case ARPHRD_INFINIBAND: |
a9e527e3 | 200 | ip_ib_mc_map(addr, dev->broadcast, haddr); |
1da177e4 | 201 | return 0; |
93ca3bb5 TT |
202 | case ARPHRD_IPGRE: |
203 | ip_ipgre_mc_map(addr, dev->broadcast, haddr); | |
204 | return 0; | |
1da177e4 LT |
205 | default: |
206 | if (dir) { | |
207 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
208 | return 0; | |
209 | } | |
210 | } | |
211 | return -EINVAL; | |
212 | } | |
213 | ||
214 | ||
d6bf7817 ED |
215 | static u32 arp_hash(const void *pkey, |
216 | const struct net_device *dev, | |
2c2aba6c | 217 | __u32 *hash_rnd) |
1da177e4 | 218 | { |
2c2aba6c | 219 | return arp_hashfn(*(u32 *)pkey, dev, *hash_rnd); |
1da177e4 LT |
220 | } |
221 | ||
222 | static int arp_constructor(struct neighbour *neigh) | |
223 | { | |
deffd777 | 224 | __be32 addr = *(__be32 *)neigh->primary_key; |
1da177e4 LT |
225 | struct net_device *dev = neigh->dev; |
226 | struct in_device *in_dev; | |
227 | struct neigh_parms *parms; | |
228 | ||
1da177e4 | 229 | rcu_read_lock(); |
e5ed6399 | 230 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
231 | if (in_dev == NULL) { |
232 | rcu_read_unlock(); | |
233 | return -EINVAL; | |
234 | } | |
235 | ||
c346dca1 | 236 | neigh->type = inet_addr_type(dev_net(dev), addr); |
a79878f0 | 237 | |
1da177e4 LT |
238 | parms = in_dev->arp_parms; |
239 | __neigh_parms_put(neigh->parms); | |
240 | neigh->parms = neigh_parms_clone(parms); | |
241 | rcu_read_unlock(); | |
242 | ||
3b04ddde | 243 | if (!dev->header_ops) { |
1da177e4 LT |
244 | neigh->nud_state = NUD_NOARP; |
245 | neigh->ops = &arp_direct_ops; | |
8f40b161 | 246 | neigh->output = neigh_direct_output; |
1da177e4 LT |
247 | } else { |
248 | /* Good devices (checked by reading texts, but only Ethernet is | |
249 | tested) | |
250 | ||
251 | ARPHRD_ETHER: (ethernet, apfddi) | |
252 | ARPHRD_FDDI: (fddi) | |
253 | ARPHRD_IEEE802: (tr) | |
254 | ARPHRD_METRICOM: (strip) | |
255 | ARPHRD_ARCNET: | |
256 | etc. etc. etc. | |
257 | ||
258 | ARPHRD_IPDDP will also work, if author repairs it. | |
259 | I did not it, because this driver does not work even | |
260 | in old paradigm. | |
261 | */ | |
262 | ||
263 | #if 1 | |
264 | /* So... these "amateur" devices are hopeless. | |
265 | The only thing, that I can say now: | |
266 | It is very sad that we need to keep ugly obsolete | |
267 | code to make them happy. | |
268 | ||
269 | They should be moved to more reasonable state, now | |
270 | they use rebuild_header INSTEAD OF hard_start_xmit!!! | |
271 | Besides that, they are sort of out of date | |
272 | (a lot of redundant clones/copies, useless in 2.1), | |
273 | I wonder why people believe that they work. | |
274 | */ | |
275 | switch (dev->type) { | |
276 | default: | |
277 | break; | |
e905a9ed | 278 | case ARPHRD_ROSE: |
40e4783e | 279 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 | 280 | case ARPHRD_AX25: |
40e4783e | 281 | #if IS_ENABLED(CONFIG_NETROM) |
1da177e4 LT |
282 | case ARPHRD_NETROM: |
283 | #endif | |
284 | neigh->ops = &arp_broken_ops; | |
285 | neigh->output = neigh->ops->output; | |
286 | return 0; | |
deffd777 CG |
287 | #else |
288 | break; | |
1da177e4 | 289 | #endif |
deffd777 | 290 | } |
1da177e4 LT |
291 | #endif |
292 | if (neigh->type == RTN_MULTICAST) { | |
293 | neigh->nud_state = NUD_NOARP; | |
294 | arp_mc_map(addr, neigh->ha, dev, 1); | |
deffd777 | 295 | } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { |
1da177e4 LT |
296 | neigh->nud_state = NUD_NOARP; |
297 | memcpy(neigh->ha, dev->dev_addr, dev->addr_len); | |
deffd777 CG |
298 | } else if (neigh->type == RTN_BROADCAST || |
299 | (dev->flags & IFF_POINTOPOINT)) { | |
1da177e4 LT |
300 | neigh->nud_state = NUD_NOARP; |
301 | memcpy(neigh->ha, dev->broadcast, dev->addr_len); | |
302 | } | |
3b04ddde SH |
303 | |
304 | if (dev->header_ops->cache) | |
1da177e4 LT |
305 | neigh->ops = &arp_hh_ops; |
306 | else | |
307 | neigh->ops = &arp_generic_ops; | |
3b04ddde | 308 | |
deffd777 | 309 | if (neigh->nud_state & NUD_VALID) |
1da177e4 LT |
310 | neigh->output = neigh->ops->connected_output; |
311 | else | |
312 | neigh->output = neigh->ops->output; | |
313 | } | |
314 | return 0; | |
315 | } | |
316 | ||
317 | static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) | |
318 | { | |
319 | dst_link_failure(skb); | |
320 | kfree_skb(skb); | |
321 | } | |
322 | ||
323 | static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) | |
324 | { | |
a61ced5d | 325 | __be32 saddr = 0; |
cf0be880 | 326 | u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL; |
1da177e4 | 327 | struct net_device *dev = neigh->dev; |
deffd777 | 328 | __be32 target = *(__be32 *)neigh->primary_key; |
1da177e4 | 329 | int probes = atomic_read(&neigh->probes); |
4b4194c4 | 330 | struct in_device *in_dev; |
1da177e4 | 331 | |
4b4194c4 ED |
332 | rcu_read_lock(); |
333 | in_dev = __in_dev_get_rcu(dev); | |
334 | if (!in_dev) { | |
335 | rcu_read_unlock(); | |
1da177e4 | 336 | return; |
4b4194c4 | 337 | } |
1da177e4 LT |
338 | switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { |
339 | default: | |
340 | case 0: /* By default announce any local IP */ | |
deffd777 CG |
341 | if (skb && inet_addr_type(dev_net(dev), |
342 | ip_hdr(skb)->saddr) == RTN_LOCAL) | |
eddc9ec5 | 343 | saddr = ip_hdr(skb)->saddr; |
1da177e4 LT |
344 | break; |
345 | case 1: /* Restrict announcements of saddr in same subnet */ | |
346 | if (!skb) | |
347 | break; | |
eddc9ec5 | 348 | saddr = ip_hdr(skb)->saddr; |
c346dca1 | 349 | if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { |
1da177e4 LT |
350 | /* saddr should be known to target */ |
351 | if (inet_addr_onlink(in_dev, target, saddr)) | |
352 | break; | |
353 | } | |
354 | saddr = 0; | |
355 | break; | |
356 | case 2: /* Avoid secondary IPs, get a primary/preferred one */ | |
357 | break; | |
358 | } | |
4b4194c4 | 359 | rcu_read_unlock(); |
1da177e4 | 360 | |
1da177e4 LT |
361 | if (!saddr) |
362 | saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); | |
363 | ||
1f9248e5 | 364 | probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); |
deffd777 CG |
365 | if (probes < 0) { |
366 | if (!(neigh->nud_state & NUD_VALID)) | |
91df42be | 367 | pr_debug("trying to ucast probe in NUD_INVALID\n"); |
9650388b | 368 | neigh_ha_snapshot(dst_ha, neigh, dev); |
cf0be880 | 369 | dst_hw = dst_ha; |
deffd777 | 370 | } else { |
1f9248e5 | 371 | probes -= NEIGH_VAR(neigh->parms, APP_PROBES); |
deffd777 | 372 | if (probes < 0) { |
deffd777 | 373 | neigh_app_ns(neigh); |
deffd777 CG |
374 | return; |
375 | } | |
1da177e4 LT |
376 | } |
377 | ||
378 | arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, | |
cf0be880 | 379 | dst_hw, dev->dev_addr, NULL); |
1da177e4 LT |
380 | } |
381 | ||
9bd85e32 | 382 | static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) |
1da177e4 LT |
383 | { |
384 | int scope; | |
385 | ||
386 | switch (IN_DEV_ARP_IGNORE(in_dev)) { | |
387 | case 0: /* Reply, the tip is already validated */ | |
388 | return 0; | |
389 | case 1: /* Reply only if tip is configured on the incoming interface */ | |
390 | sip = 0; | |
391 | scope = RT_SCOPE_HOST; | |
392 | break; | |
393 | case 2: /* | |
394 | * Reply only if tip is configured on the incoming interface | |
395 | * and is in same subnet as sip | |
396 | */ | |
397 | scope = RT_SCOPE_HOST; | |
398 | break; | |
399 | case 3: /* Do not reply for scope host addresses */ | |
400 | sip = 0; | |
401 | scope = RT_SCOPE_LINK; | |
1da177e4 LT |
402 | break; |
403 | case 4: /* Reserved */ | |
404 | case 5: | |
405 | case 6: | |
406 | case 7: | |
407 | return 0; | |
408 | case 8: /* Do not reply */ | |
409 | return 1; | |
410 | default: | |
411 | return 0; | |
412 | } | |
9bd85e32 | 413 | return !inet_confirm_addr(in_dev, sip, tip, scope); |
1da177e4 LT |
414 | } |
415 | ||
ed9bad06 | 416 | static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) |
1da177e4 | 417 | { |
1da177e4 | 418 | struct rtable *rt; |
e905a9ed | 419 | int flag = 0; |
1da177e4 | 420 | /*unsigned long now; */ |
ca12a1a4 | 421 | struct net *net = dev_net(dev); |
1da177e4 | 422 | |
78fbfd8a | 423 | rt = ip_route_output(net, sip, tip, 0, 0); |
b23dd4fe | 424 | if (IS_ERR(rt)) |
1da177e4 | 425 | return 1; |
d8d1f30b | 426 | if (rt->dst.dev != dev) { |
de0744af | 427 | NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); |
1da177e4 | 428 | flag = 1; |
e905a9ed YH |
429 | } |
430 | ip_rt_put(rt); | |
431 | return flag; | |
432 | } | |
1da177e4 LT |
433 | |
434 | /* OBSOLETE FUNCTIONS */ | |
435 | ||
436 | /* | |
437 | * Find an arp mapping in the cache. If not found, post a request. | |
438 | * | |
439 | * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, | |
440 | * even if it exists. It is supposed that skb->dev was mangled | |
441 | * by a virtual device (eql, shaper). Nobody but broken devices | |
442 | * is allowed to use this function, it is scheduled to be removed. --ANK | |
443 | */ | |
444 | ||
deffd777 CG |
445 | static int arp_set_predefined(int addr_hint, unsigned char *haddr, |
446 | __be32 paddr, struct net_device *dev) | |
1da177e4 LT |
447 | { |
448 | switch (addr_hint) { | |
449 | case RTN_LOCAL: | |
91df42be | 450 | pr_debug("arp called for own IP address\n"); |
1da177e4 LT |
451 | memcpy(haddr, dev->dev_addr, dev->addr_len); |
452 | return 1; | |
453 | case RTN_MULTICAST: | |
454 | arp_mc_map(paddr, haddr, dev, 1); | |
455 | return 1; | |
456 | case RTN_BROADCAST: | |
457 | memcpy(haddr, dev->broadcast, dev->addr_len); | |
458 | return 1; | |
459 | } | |
460 | return 0; | |
461 | } | |
462 | ||
463 | ||
464 | int arp_find(unsigned char *haddr, struct sk_buff *skb) | |
465 | { | |
466 | struct net_device *dev = skb->dev; | |
fd683222 | 467 | __be32 paddr; |
1da177e4 LT |
468 | struct neighbour *n; |
469 | ||
adf30907 | 470 | if (!skb_dst(skb)) { |
91df42be | 471 | pr_debug("arp_find is called with dst==NULL\n"); |
1da177e4 LT |
472 | kfree_skb(skb); |
473 | return 1; | |
474 | } | |
475 | ||
f8126f1d | 476 | paddr = rt_nexthop(skb_rtable(skb), ip_hdr(skb)->daddr); |
deffd777 CG |
477 | if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, |
478 | paddr, dev)) | |
1da177e4 LT |
479 | return 0; |
480 | ||
481 | n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); | |
482 | ||
483 | if (n) { | |
484 | n->used = jiffies; | |
0ed8ddf4 ED |
485 | if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) { |
486 | neigh_ha_snapshot(haddr, n, dev); | |
1da177e4 LT |
487 | neigh_release(n); |
488 | return 0; | |
489 | } | |
490 | neigh_release(n); | |
491 | } else | |
492 | kfree_skb(skb); | |
493 | return 1; | |
494 | } | |
4bc2f18b | 495 | EXPORT_SYMBOL(arp_find); |
1da177e4 LT |
496 | |
497 | /* END OF OBSOLETE FUNCTIONS */ | |
498 | ||
1da177e4 LT |
499 | /* |
500 | * Check if we can use proxy ARP for this path | |
501 | */ | |
65324144 JDB |
502 | static inline int arp_fwd_proxy(struct in_device *in_dev, |
503 | struct net_device *dev, struct rtable *rt) | |
1da177e4 LT |
504 | { |
505 | struct in_device *out_dev; | |
506 | int imi, omi = -1; | |
507 | ||
d8d1f30b | 508 | if (rt->dst.dev == dev) |
65324144 JDB |
509 | return 0; |
510 | ||
1da177e4 LT |
511 | if (!IN_DEV_PROXY_ARP(in_dev)) |
512 | return 0; | |
deffd777 CG |
513 | imi = IN_DEV_MEDIUM_ID(in_dev); |
514 | if (imi == 0) | |
1da177e4 LT |
515 | return 1; |
516 | if (imi == -1) | |
517 | return 0; | |
518 | ||
519 | /* place to check for proxy_arp for routes */ | |
520 | ||
d8d1f30b | 521 | out_dev = __in_dev_get_rcu(rt->dst.dev); |
faa9dcf7 | 522 | if (out_dev) |
1da177e4 | 523 | omi = IN_DEV_MEDIUM_ID(out_dev); |
faa9dcf7 | 524 | |
a02cec21 | 525 | return omi != imi && omi != -1; |
1da177e4 LT |
526 | } |
527 | ||
65324144 JDB |
528 | /* |
529 | * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) | |
530 | * | |
531 | * RFC3069 supports proxy arp replies back to the same interface. This | |
532 | * is done to support (ethernet) switch features, like RFC 3069, where | |
533 | * the individual ports are not allowed to communicate with each | |
534 | * other, BUT they are allowed to talk to the upstream router. As | |
535 | * described in RFC 3069, it is possible to allow these hosts to | |
536 | * communicate through the upstream router, by proxy_arp'ing. | |
537 | * | |
538 | * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" | |
539 | * | |
540 | * This technology is known by different names: | |
541 | * In RFC 3069 it is called VLAN Aggregation. | |
542 | * Cisco and Allied Telesyn call it Private VLAN. | |
543 | * Hewlett-Packard call it Source-Port filtering or port-isolation. | |
544 | * Ericsson call it MAC-Forced Forwarding (RFC Draft). | |
545 | * | |
546 | */ | |
547 | static inline int arp_fwd_pvlan(struct in_device *in_dev, | |
548 | struct net_device *dev, struct rtable *rt, | |
549 | __be32 sip, __be32 tip) | |
550 | { | |
551 | /* Private VLAN is only concerned about the same ethernet segment */ | |
d8d1f30b | 552 | if (rt->dst.dev != dev) |
65324144 JDB |
553 | return 0; |
554 | ||
555 | /* Don't reply on self probes (often done by windowz boxes)*/ | |
556 | if (sip == tip) | |
557 | return 0; | |
558 | ||
559 | if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) | |
560 | return 1; | |
561 | else | |
562 | return 0; | |
563 | } | |
564 | ||
1da177e4 LT |
565 | /* |
566 | * Interface to link layer: send routine and receive handler. | |
567 | */ | |
568 | ||
569 | /* | |
570 | * Create an arp packet. If (dest_hw == NULL), we create a broadcast | |
571 | * message. | |
572 | */ | |
ed9bad06 AV |
573 | struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, |
574 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
575 | const unsigned char *dest_hw, |
576 | const unsigned char *src_hw, | |
577 | const unsigned char *target_hw) | |
1da177e4 LT |
578 | { |
579 | struct sk_buff *skb; | |
580 | struct arphdr *arp; | |
581 | unsigned char *arp_ptr; | |
66088243 HX |
582 | int hlen = LL_RESERVED_SPACE(dev); |
583 | int tlen = dev->needed_tailroom; | |
1da177e4 LT |
584 | |
585 | /* | |
586 | * Allocate a buffer | |
587 | */ | |
e905a9ed | 588 | |
66088243 | 589 | skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC); |
1da177e4 LT |
590 | if (skb == NULL) |
591 | return NULL; | |
592 | ||
66088243 | 593 | skb_reserve(skb, hlen); |
c1d2bbe1 | 594 | skb_reset_network_header(skb); |
988b7050 | 595 | arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); |
1da177e4 LT |
596 | skb->dev = dev; |
597 | skb->protocol = htons(ETH_P_ARP); | |
598 | if (src_hw == NULL) | |
599 | src_hw = dev->dev_addr; | |
600 | if (dest_hw == NULL) | |
601 | dest_hw = dev->broadcast; | |
602 | ||
603 | /* | |
604 | * Fill the device header for the ARP frame | |
605 | */ | |
0c4e8581 | 606 | if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) |
1da177e4 LT |
607 | goto out; |
608 | ||
609 | /* | |
610 | * Fill out the arp protocol part. | |
611 | * | |
612 | * The arp hardware type should match the device type, except for FDDI, | |
613 | * which (according to RFC 1390) should always equal 1 (Ethernet). | |
614 | */ | |
615 | /* | |
616 | * Exceptions everywhere. AX.25 uses the AX.25 PID value not the | |
617 | * DIX code for the protocol. Make these device structure fields. | |
618 | */ | |
619 | switch (dev->type) { | |
620 | default: | |
621 | arp->ar_hrd = htons(dev->type); | |
622 | arp->ar_pro = htons(ETH_P_IP); | |
623 | break; | |
624 | ||
40e4783e | 625 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
626 | case ARPHRD_AX25: |
627 | arp->ar_hrd = htons(ARPHRD_AX25); | |
628 | arp->ar_pro = htons(AX25_P_IP); | |
629 | break; | |
630 | ||
40e4783e | 631 | #if IS_ENABLED(CONFIG_NETROM) |
1da177e4 LT |
632 | case ARPHRD_NETROM: |
633 | arp->ar_hrd = htons(ARPHRD_NETROM); | |
634 | arp->ar_pro = htons(AX25_P_IP); | |
635 | break; | |
636 | #endif | |
637 | #endif | |
638 | ||
40e4783e | 639 | #if IS_ENABLED(CONFIG_FDDI) |
1da177e4 LT |
640 | case ARPHRD_FDDI: |
641 | arp->ar_hrd = htons(ARPHRD_ETHER); | |
642 | arp->ar_pro = htons(ETH_P_IP); | |
643 | break; | |
1da177e4 LT |
644 | #endif |
645 | } | |
646 | ||
647 | arp->ar_hln = dev->addr_len; | |
648 | arp->ar_pln = 4; | |
649 | arp->ar_op = htons(type); | |
650 | ||
deffd777 | 651 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
652 | |
653 | memcpy(arp_ptr, src_hw, dev->addr_len); | |
f4cca7ff JK |
654 | arp_ptr += dev->addr_len; |
655 | memcpy(arp_ptr, &src_ip, 4); | |
656 | arp_ptr += 4; | |
6752c8db YH |
657 | |
658 | switch (dev->type) { | |
659 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
660 | case ARPHRD_IEEE1394: | |
661 | break; | |
662 | #endif | |
663 | default: | |
664 | if (target_hw != NULL) | |
665 | memcpy(arp_ptr, target_hw, dev->addr_len); | |
666 | else | |
667 | memset(arp_ptr, 0, dev->addr_len); | |
668 | arp_ptr += dev->addr_len; | |
669 | } | |
1da177e4 LT |
670 | memcpy(arp_ptr, &dest_ip, 4); |
671 | ||
672 | return skb; | |
673 | ||
674 | out: | |
675 | kfree_skb(skb); | |
676 | return NULL; | |
677 | } | |
4bc2f18b | 678 | EXPORT_SYMBOL(arp_create); |
1da177e4 LT |
679 | |
680 | /* | |
681 | * Send an arp packet. | |
682 | */ | |
683 | void arp_xmit(struct sk_buff *skb) | |
684 | { | |
685 | /* Send it off, maybe filter it using firewalling first. */ | |
fdc9314c | 686 | NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); |
1da177e4 | 687 | } |
4bc2f18b | 688 | EXPORT_SYMBOL(arp_xmit); |
1da177e4 LT |
689 | |
690 | /* | |
691 | * Create and send an arp packet. | |
692 | */ | |
ed9bad06 AV |
693 | void arp_send(int type, int ptype, __be32 dest_ip, |
694 | struct net_device *dev, __be32 src_ip, | |
abfdf1c4 JE |
695 | const unsigned char *dest_hw, const unsigned char *src_hw, |
696 | const unsigned char *target_hw) | |
1da177e4 LT |
697 | { |
698 | struct sk_buff *skb; | |
699 | ||
700 | /* | |
701 | * No arp on this interface. | |
702 | */ | |
e905a9ed | 703 | |
1da177e4 LT |
704 | if (dev->flags&IFF_NOARP) |
705 | return; | |
706 | ||
707 | skb = arp_create(type, ptype, dest_ip, dev, src_ip, | |
708 | dest_hw, src_hw, target_hw); | |
deffd777 | 709 | if (skb == NULL) |
1da177e4 | 710 | return; |
1da177e4 LT |
711 | |
712 | arp_xmit(skb); | |
713 | } | |
4bc2f18b | 714 | EXPORT_SYMBOL(arp_send); |
1da177e4 | 715 | |
1da177e4 LT |
716 | /* |
717 | * Process an arp request. | |
718 | */ | |
719 | ||
720 | static int arp_process(struct sk_buff *skb) | |
721 | { | |
722 | struct net_device *dev = skb->dev; | |
faa9dcf7 | 723 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
1da177e4 LT |
724 | struct arphdr *arp; |
725 | unsigned char *arp_ptr; | |
726 | struct rtable *rt; | |
e0260fed | 727 | unsigned char *sha; |
9e12bb22 | 728 | __be32 sip, tip; |
1da177e4 LT |
729 | u16 dev_type = dev->type; |
730 | int addr_type; | |
731 | struct neighbour *n; | |
c346dca1 | 732 | struct net *net = dev_net(dev); |
1da177e4 LT |
733 | |
734 | /* arp_rcv below verifies the ARP header and verifies the device | |
735 | * is ARP'able. | |
736 | */ | |
737 | ||
738 | if (in_dev == NULL) | |
739 | goto out; | |
740 | ||
d0a92be0 | 741 | arp = arp_hdr(skb); |
1da177e4 LT |
742 | |
743 | switch (dev_type) { | |
e905a9ed | 744 | default: |
1da177e4 LT |
745 | if (arp->ar_pro != htons(ETH_P_IP) || |
746 | htons(dev_type) != arp->ar_hrd) | |
747 | goto out; | |
748 | break; | |
1da177e4 | 749 | case ARPHRD_ETHER: |
1da177e4 | 750 | case ARPHRD_FDDI: |
1da177e4 | 751 | case ARPHRD_IEEE802: |
1da177e4 | 752 | /* |
211ed865 | 753 | * ETHERNET, and Fibre Channel (which are IEEE 802 |
1da177e4 LT |
754 | * devices, according to RFC 2625) devices will accept ARP |
755 | * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). | |
756 | * This is the case also of FDDI, where the RFC 1390 says that | |
757 | * FDDI devices should accept ARP hardware of (1) Ethernet, | |
758 | * however, to be more robust, we'll accept both 1 (Ethernet) | |
759 | * or 6 (IEEE 802.2) | |
760 | */ | |
761 | if ((arp->ar_hrd != htons(ARPHRD_ETHER) && | |
762 | arp->ar_hrd != htons(ARPHRD_IEEE802)) || | |
763 | arp->ar_pro != htons(ETH_P_IP)) | |
764 | goto out; | |
765 | break; | |
1da177e4 LT |
766 | case ARPHRD_AX25: |
767 | if (arp->ar_pro != htons(AX25_P_IP) || | |
768 | arp->ar_hrd != htons(ARPHRD_AX25)) | |
769 | goto out; | |
770 | break; | |
1da177e4 LT |
771 | case ARPHRD_NETROM: |
772 | if (arp->ar_pro != htons(AX25_P_IP) || | |
773 | arp->ar_hrd != htons(ARPHRD_NETROM)) | |
774 | goto out; | |
775 | break; | |
1da177e4 LT |
776 | } |
777 | ||
778 | /* Understand only these message types */ | |
779 | ||
780 | if (arp->ar_op != htons(ARPOP_REPLY) && | |
781 | arp->ar_op != htons(ARPOP_REQUEST)) | |
782 | goto out; | |
783 | ||
784 | /* | |
785 | * Extract fields | |
786 | */ | |
deffd777 | 787 | arp_ptr = (unsigned char *)(arp + 1); |
1da177e4 LT |
788 | sha = arp_ptr; |
789 | arp_ptr += dev->addr_len; | |
790 | memcpy(&sip, arp_ptr, 4); | |
791 | arp_ptr += 4; | |
6752c8db YH |
792 | switch (dev_type) { |
793 | #if IS_ENABLED(CONFIG_FIREWIRE_NET) | |
794 | case ARPHRD_IEEE1394: | |
795 | break; | |
796 | #endif | |
797 | default: | |
798 | arp_ptr += dev->addr_len; | |
799 | } | |
1da177e4 | 800 | memcpy(&tip, arp_ptr, 4); |
e905a9ed | 801 | /* |
1da177e4 LT |
802 | * Check for bad requests for 127.x.x.x and requests for multicast |
803 | * addresses. If this is one such, delete it. | |
804 | */ | |
d0daebc3 TG |
805 | if (ipv4_is_multicast(tip) || |
806 | (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) | |
1da177e4 LT |
807 | goto out; |
808 | ||
809 | /* | |
810 | * Special case: We must set Frame Relay source Q.922 address | |
811 | */ | |
812 | if (dev_type == ARPHRD_DLCI) | |
813 | sha = dev->broadcast; | |
814 | ||
815 | /* | |
816 | * Process entry. The idea here is we want to send a reply if it is a | |
817 | * request for us or if it is a request for someone else that we hold | |
818 | * a proxy for. We want to add an entry to our cache if it is a reply | |
e905a9ed YH |
819 | * to us or if it is a request for our address. |
820 | * (The assumption for this last is that if someone is requesting our | |
821 | * address, they are probably intending to talk to us, so it saves time | |
822 | * if we cache their address. Their address is also probably not in | |
1da177e4 | 823 | * our cache, since ours is not in their cache.) |
e905a9ed | 824 | * |
1da177e4 LT |
825 | * Putting this another way, we only care about replies if they are to |
826 | * us, in which case we add them to the cache. For requests, we care | |
827 | * about those for us and those for our proxies. We reply to both, | |
e905a9ed | 828 | * and in the case of requests for us we add the requester to the arp |
1da177e4 LT |
829 | * cache. |
830 | */ | |
831 | ||
f8a68e75 EB |
832 | /* Special case: IPv4 duplicate address detection packet (RFC2131) */ |
833 | if (sip == 0) { | |
1da177e4 | 834 | if (arp->ar_op == htons(ARPOP_REQUEST) && |
49e8a279 | 835 | inet_addr_type(net, tip) == RTN_LOCAL && |
9bd85e32 | 836 | !arp_ignore(in_dev, sip, tip)) |
b4a9811c JD |
837 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, |
838 | dev->dev_addr, sha); | |
1da177e4 LT |
839 | goto out; |
840 | } | |
841 | ||
842 | if (arp->ar_op == htons(ARPOP_REQUEST) && | |
c6cffba4 | 843 | ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { |
1da177e4 | 844 | |
511c3f92 | 845 | rt = skb_rtable(skb); |
1da177e4 LT |
846 | addr_type = rt->rt_type; |
847 | ||
848 | if (addr_type == RTN_LOCAL) { | |
deffd777 | 849 | int dont_send; |
8164f1b7 | 850 | |
deffd777 | 851 | dont_send = arp_ignore(in_dev, sip, tip); |
8164f1b7 | 852 | if (!dont_send && IN_DEV_ARPFILTER(in_dev)) |
ae9c416d | 853 | dont_send = arp_filter(sip, tip, dev); |
8164f1b7 BG |
854 | if (!dont_send) { |
855 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); | |
856 | if (n) { | |
deffd777 CG |
857 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, |
858 | dev, tip, sha, dev->dev_addr, | |
859 | sha); | |
8164f1b7 BG |
860 | neigh_release(n); |
861 | } | |
1da177e4 LT |
862 | } |
863 | goto out; | |
864 | } else if (IN_DEV_FORWARD(in_dev)) { | |
65324144 JDB |
865 | if (addr_type == RTN_UNICAST && |
866 | (arp_fwd_proxy(in_dev, dev, rt) || | |
867 | arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || | |
70620c46 TG |
868 | (rt->dst.dev != dev && |
869 | pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) { | |
1da177e4 LT |
870 | n = neigh_event_ns(&arp_tbl, sha, &sip, dev); |
871 | if (n) | |
872 | neigh_release(n); | |
873 | ||
e905a9ed | 874 | if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || |
1da177e4 | 875 | skb->pkt_type == PACKET_HOST || |
1f9248e5 | 876 | NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) { |
deffd777 CG |
877 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, |
878 | dev, tip, sha, dev->dev_addr, | |
879 | sha); | |
1da177e4 | 880 | } else { |
deffd777 CG |
881 | pneigh_enqueue(&arp_tbl, |
882 | in_dev->arp_parms, skb); | |
1da177e4 LT |
883 | return 0; |
884 | } | |
885 | goto out; | |
886 | } | |
887 | } | |
888 | } | |
889 | ||
890 | /* Update our ARP tables */ | |
891 | ||
892 | n = __neigh_lookup(&arp_tbl, &sip, dev, 0); | |
893 | ||
124d37e9 | 894 | if (IN_DEV_ARP_ACCEPT(in_dev)) { |
abd596a4 NH |
895 | /* Unsolicited ARP is not accepted by default. |
896 | It is possible, that this option should be enabled for some | |
897 | devices (strip is candidate) | |
898 | */ | |
899 | if (n == NULL && | |
6d955180 OP |
900 | (arp->ar_op == htons(ARPOP_REPLY) || |
901 | (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && | |
49e8a279 | 902 | inet_addr_type(net, sip) == RTN_UNICAST) |
1b1ac759 | 903 | n = __neigh_lookup(&arp_tbl, &sip, dev, 1); |
abd596a4 | 904 | } |
1da177e4 LT |
905 | |
906 | if (n) { | |
907 | int state = NUD_REACHABLE; | |
908 | int override; | |
909 | ||
910 | /* If several different ARP replies follows back-to-back, | |
911 | use the FIRST one. It is possible, if several proxy | |
912 | agents are active. Taking the first reply prevents | |
913 | arp trashing and chooses the fastest router. | |
914 | */ | |
1f9248e5 JP |
915 | override = time_after(jiffies, n->updated + |
916 | NEIGH_VAR(n->parms, LOCKTIME)); | |
1da177e4 LT |
917 | |
918 | /* Broadcast replies and request packets | |
919 | do not assert neighbour reachability. | |
920 | */ | |
921 | if (arp->ar_op != htons(ARPOP_REPLY) || | |
922 | skb->pkt_type != PACKET_HOST) | |
923 | state = NUD_STALE; | |
deffd777 CG |
924 | neigh_update(n, sha, state, |
925 | override ? NEIGH_UPDATE_F_OVERRIDE : 0); | |
1da177e4 LT |
926 | neigh_release(n); |
927 | } | |
928 | ||
929 | out: | |
ead2ceb0 | 930 | consume_skb(skb); |
1da177e4 LT |
931 | return 0; |
932 | } | |
933 | ||
444fc8fc HX |
934 | static void parp_redo(struct sk_buff *skb) |
935 | { | |
936 | arp_process(skb); | |
937 | } | |
938 | ||
1da177e4 LT |
939 | |
940 | /* | |
941 | * Receive an arp request from the device layer. | |
942 | */ | |
943 | ||
6c97e72a AB |
944 | static int arp_rcv(struct sk_buff *skb, struct net_device *dev, |
945 | struct packet_type *pt, struct net_device *orig_dev) | |
1da177e4 | 946 | { |
044453b3 ED |
947 | const struct arphdr *arp; |
948 | ||
949 | if (dev->flags & IFF_NOARP || | |
950 | skb->pkt_type == PACKET_OTHERHOST || | |
951 | skb->pkt_type == PACKET_LOOPBACK) | |
952 | goto freeskb; | |
953 | ||
954 | skb = skb_share_check(skb, GFP_ATOMIC); | |
955 | if (!skb) | |
956 | goto out_of_mem; | |
1da177e4 LT |
957 | |
958 | /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ | |
988b7050 | 959 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) |
1da177e4 LT |
960 | goto freeskb; |
961 | ||
d0a92be0 | 962 | arp = arp_hdr(skb); |
044453b3 | 963 | if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) |
1da177e4 LT |
964 | goto freeskb; |
965 | ||
a61bbcf2 PM |
966 | memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); |
967 | ||
fdc9314c | 968 | return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); |
1da177e4 LT |
969 | |
970 | freeskb: | |
971 | kfree_skb(skb); | |
972 | out_of_mem: | |
973 | return 0; | |
974 | } | |
975 | ||
976 | /* | |
977 | * User level interface (ioctl) | |
978 | */ | |
979 | ||
980 | /* | |
981 | * Set (create) an ARP cache entry. | |
982 | */ | |
983 | ||
32e569b7 | 984 | static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) |
f8b33fdf PE |
985 | { |
986 | if (dev == NULL) { | |
586f1211 | 987 | IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; |
f8b33fdf PE |
988 | return 0; |
989 | } | |
c506653d ED |
990 | if (__in_dev_get_rtnl(dev)) { |
991 | IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); | |
f8b33fdf PE |
992 | return 0; |
993 | } | |
994 | return -ENXIO; | |
995 | } | |
996 | ||
32e569b7 PE |
997 | static int arp_req_set_public(struct net *net, struct arpreq *r, |
998 | struct net_device *dev) | |
43dc1701 PE |
999 | { |
1000 | __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; | |
1001 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1002 | ||
1003 | if (mask && mask != htonl(0xFFFFFFFF)) | |
1004 | return -EINVAL; | |
1005 | if (!dev && (r->arp_flags & ATF_COM)) { | |
941666c2 | 1006 | dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, |
deffd777 | 1007 | r->arp_ha.sa_data); |
43dc1701 PE |
1008 | if (!dev) |
1009 | return -ENODEV; | |
1010 | } | |
1011 | if (mask) { | |
2db82b53 | 1012 | if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) |
43dc1701 PE |
1013 | return -ENOBUFS; |
1014 | return 0; | |
1015 | } | |
f8b33fdf | 1016 | |
32e569b7 | 1017 | return arp_req_set_proxy(net, dev, 1); |
43dc1701 PE |
1018 | } |
1019 | ||
32e569b7 | 1020 | static int arp_req_set(struct net *net, struct arpreq *r, |
deffd777 | 1021 | struct net_device *dev) |
1da177e4 | 1022 | { |
43dc1701 | 1023 | __be32 ip; |
1da177e4 LT |
1024 | struct neighbour *neigh; |
1025 | int err; | |
1026 | ||
43dc1701 | 1027 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1028 | return arp_req_set_public(net, r, dev); |
1da177e4 | 1029 | |
43dc1701 | 1030 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1031 | if (r->arp_flags & ATF_PERM) |
1032 | r->arp_flags |= ATF_COM; | |
1033 | if (dev == NULL) { | |
78fbfd8a | 1034 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
b23dd4fe DM |
1035 | |
1036 | if (IS_ERR(rt)) | |
1037 | return PTR_ERR(rt); | |
d8d1f30b | 1038 | dev = rt->dst.dev; |
1da177e4 LT |
1039 | ip_rt_put(rt); |
1040 | if (!dev) | |
1041 | return -EINVAL; | |
1042 | } | |
1043 | switch (dev->type) { | |
40e4783e | 1044 | #if IS_ENABLED(CONFIG_FDDI) |
1da177e4 LT |
1045 | case ARPHRD_FDDI: |
1046 | /* | |
1047 | * According to RFC 1390, FDDI devices should accept ARP | |
1048 | * hardware types of 1 (Ethernet). However, to be more | |
1049 | * robust, we'll accept hardware types of either 1 (Ethernet) | |
1050 | * or 6 (IEEE 802.2). | |
1051 | */ | |
1052 | if (r->arp_ha.sa_family != ARPHRD_FDDI && | |
1053 | r->arp_ha.sa_family != ARPHRD_ETHER && | |
1054 | r->arp_ha.sa_family != ARPHRD_IEEE802) | |
1055 | return -EINVAL; | |
1056 | break; | |
1057 | #endif | |
1058 | default: | |
1059 | if (r->arp_ha.sa_family != dev->type) | |
1060 | return -EINVAL; | |
1061 | break; | |
1062 | } | |
1063 | ||
1064 | neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); | |
1065 | err = PTR_ERR(neigh); | |
1066 | if (!IS_ERR(neigh)) { | |
95c96174 | 1067 | unsigned int state = NUD_STALE; |
1da177e4 LT |
1068 | if (r->arp_flags & ATF_PERM) |
1069 | state = NUD_PERMANENT; | |
deffd777 | 1070 | err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? |
e905a9ed | 1071 | r->arp_ha.sa_data : NULL, state, |
deffd777 | 1072 | NEIGH_UPDATE_F_OVERRIDE | |
1da177e4 LT |
1073 | NEIGH_UPDATE_F_ADMIN); |
1074 | neigh_release(neigh); | |
1075 | } | |
1076 | return err; | |
1077 | } | |
1078 | ||
95c96174 | 1079 | static unsigned int arp_state_to_flags(struct neighbour *neigh) |
1da177e4 | 1080 | { |
1da177e4 | 1081 | if (neigh->nud_state&NUD_PERMANENT) |
deffd777 | 1082 | return ATF_PERM | ATF_COM; |
1da177e4 | 1083 | else if (neigh->nud_state&NUD_VALID) |
deffd777 CG |
1084 | return ATF_COM; |
1085 | else | |
1086 | return 0; | |
1da177e4 LT |
1087 | } |
1088 | ||
1089 | /* | |
1090 | * Get an ARP cache entry. | |
1091 | */ | |
1092 | ||
1093 | static int arp_req_get(struct arpreq *r, struct net_device *dev) | |
1094 | { | |
ed9bad06 | 1095 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; |
1da177e4 LT |
1096 | struct neighbour *neigh; |
1097 | int err = -ENXIO; | |
1098 | ||
1099 | neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1100 | if (neigh) { | |
1101 | read_lock_bh(&neigh->lock); | |
1102 | memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); | |
1103 | r->arp_flags = arp_state_to_flags(neigh); | |
1104 | read_unlock_bh(&neigh->lock); | |
1105 | r->arp_ha.sa_family = dev->type; | |
1106 | strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); | |
1107 | neigh_release(neigh); | |
1108 | err = 0; | |
1109 | } | |
1110 | return err; | |
1111 | } | |
1112 | ||
545ecdc3 ML |
1113 | int arp_invalidate(struct net_device *dev, __be32 ip) |
1114 | { | |
1115 | struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); | |
1116 | int err = -ENXIO; | |
1117 | ||
1118 | if (neigh) { | |
1119 | if (neigh->nud_state & ~NUD_NOARP) | |
1120 | err = neigh_update(neigh, NULL, NUD_FAILED, | |
1121 | NEIGH_UPDATE_F_OVERRIDE| | |
1122 | NEIGH_UPDATE_F_ADMIN); | |
1123 | neigh_release(neigh); | |
1124 | } | |
1125 | ||
1126 | return err; | |
1127 | } | |
1128 | EXPORT_SYMBOL(arp_invalidate); | |
1129 | ||
32e569b7 PE |
1130 | static int arp_req_delete_public(struct net *net, struct arpreq *r, |
1131 | struct net_device *dev) | |
46479b43 PE |
1132 | { |
1133 | __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; | |
1134 | __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; | |
1135 | ||
1136 | if (mask == htonl(0xFFFFFFFF)) | |
2db82b53 | 1137 | return pneigh_delete(&arp_tbl, net, &ip, dev); |
46479b43 | 1138 | |
f8b33fdf PE |
1139 | if (mask) |
1140 | return -EINVAL; | |
1141 | ||
32e569b7 | 1142 | return arp_req_set_proxy(net, dev, 0); |
46479b43 PE |
1143 | } |
1144 | ||
32e569b7 | 1145 | static int arp_req_delete(struct net *net, struct arpreq *r, |
deffd777 | 1146 | struct net_device *dev) |
1da177e4 | 1147 | { |
46479b43 | 1148 | __be32 ip; |
1da177e4 | 1149 | |
46479b43 | 1150 | if (r->arp_flags & ATF_PUBL) |
32e569b7 | 1151 | return arp_req_delete_public(net, r, dev); |
1da177e4 | 1152 | |
46479b43 | 1153 | ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; |
1da177e4 | 1154 | if (dev == NULL) { |
78fbfd8a | 1155 | struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0); |
b23dd4fe DM |
1156 | if (IS_ERR(rt)) |
1157 | return PTR_ERR(rt); | |
d8d1f30b | 1158 | dev = rt->dst.dev; |
1da177e4 LT |
1159 | ip_rt_put(rt); |
1160 | if (!dev) | |
1161 | return -EINVAL; | |
1162 | } | |
545ecdc3 | 1163 | return arp_invalidate(dev, ip); |
1da177e4 LT |
1164 | } |
1165 | ||
1166 | /* | |
1167 | * Handle an ARP layer I/O control request. | |
1168 | */ | |
1169 | ||
32e569b7 | 1170 | int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) |
1da177e4 LT |
1171 | { |
1172 | int err; | |
1173 | struct arpreq r; | |
1174 | struct net_device *dev = NULL; | |
1175 | ||
1176 | switch (cmd) { | |
deffd777 CG |
1177 | case SIOCDARP: |
1178 | case SIOCSARP: | |
52e804c6 | 1179 | if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) |
deffd777 CG |
1180 | return -EPERM; |
1181 | case SIOCGARP: | |
1182 | err = copy_from_user(&r, arg, sizeof(struct arpreq)); | |
1183 | if (err) | |
1184 | return -EFAULT; | |
1185 | break; | |
1186 | default: | |
1187 | return -EINVAL; | |
1da177e4 LT |
1188 | } |
1189 | ||
1190 | if (r.arp_pa.sa_family != AF_INET) | |
1191 | return -EPFNOSUPPORT; | |
1192 | ||
1193 | if (!(r.arp_flags & ATF_PUBL) && | |
deffd777 | 1194 | (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) |
1da177e4 LT |
1195 | return -EINVAL; |
1196 | if (!(r.arp_flags & ATF_NETMASK)) | |
1197 | ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = | |
1198 | htonl(0xFFFFFFFFUL); | |
c506653d | 1199 | rtnl_lock(); |
1da177e4 LT |
1200 | if (r.arp_dev[0]) { |
1201 | err = -ENODEV; | |
c506653d | 1202 | dev = __dev_get_by_name(net, r.arp_dev); |
deffd777 | 1203 | if (dev == NULL) |
1da177e4 LT |
1204 | goto out; |
1205 | ||
1206 | /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ | |
1207 | if (!r.arp_ha.sa_family) | |
1208 | r.arp_ha.sa_family = dev->type; | |
1209 | err = -EINVAL; | |
1210 | if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) | |
1211 | goto out; | |
1212 | } else if (cmd == SIOCGARP) { | |
1213 | err = -ENODEV; | |
1214 | goto out; | |
1215 | } | |
1216 | ||
132adf54 | 1217 | switch (cmd) { |
1da177e4 | 1218 | case SIOCDARP: |
32e569b7 | 1219 | err = arp_req_delete(net, &r, dev); |
1da177e4 LT |
1220 | break; |
1221 | case SIOCSARP: | |
32e569b7 | 1222 | err = arp_req_set(net, &r, dev); |
1da177e4 LT |
1223 | break; |
1224 | case SIOCGARP: | |
1225 | err = arp_req_get(&r, dev); | |
1da177e4 LT |
1226 | break; |
1227 | } | |
1228 | out: | |
c506653d | 1229 | rtnl_unlock(); |
941666c2 ED |
1230 | if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) |
1231 | err = -EFAULT; | |
1da177e4 LT |
1232 | return err; |
1233 | } | |
1234 | ||
deffd777 CG |
1235 | static int arp_netdev_event(struct notifier_block *this, unsigned long event, |
1236 | void *ptr) | |
1da177e4 | 1237 | { |
351638e7 | 1238 | struct net_device *dev = netdev_notifier_info_to_dev(ptr); |
6c8b4e3f | 1239 | struct netdev_notifier_change_info *change_info; |
1da177e4 LT |
1240 | |
1241 | switch (event) { | |
1242 | case NETDEV_CHANGEADDR: | |
1243 | neigh_changeaddr(&arp_tbl, dev); | |
bafa6d9d | 1244 | rt_cache_flush(dev_net(dev)); |
1da177e4 | 1245 | break; |
6c8b4e3f TT |
1246 | case NETDEV_CHANGE: |
1247 | change_info = ptr; | |
1248 | if (change_info->flags_changed & IFF_NOARP) | |
1249 | neigh_changeaddr(&arp_tbl, dev); | |
1250 | break; | |
1da177e4 LT |
1251 | default: |
1252 | break; | |
1253 | } | |
1254 | ||
1255 | return NOTIFY_DONE; | |
1256 | } | |
1257 | ||
1258 | static struct notifier_block arp_netdev_notifier = { | |
1259 | .notifier_call = arp_netdev_event, | |
1260 | }; | |
1261 | ||
1262 | /* Note, that it is not on notifier chain. | |
1263 | It is necessary, that this routine was called after route cache will be | |
1264 | flushed. | |
1265 | */ | |
1266 | void arp_ifdown(struct net_device *dev) | |
1267 | { | |
1268 | neigh_ifdown(&arp_tbl, dev); | |
1269 | } | |
1270 | ||
1271 | ||
1272 | /* | |
1273 | * Called once on startup. | |
1274 | */ | |
1275 | ||
7546dd97 | 1276 | static struct packet_type arp_packet_type __read_mostly = { |
09640e63 | 1277 | .type = cpu_to_be16(ETH_P_ARP), |
1da177e4 LT |
1278 | .func = arp_rcv, |
1279 | }; | |
1280 | ||
1281 | static int arp_proc_init(void); | |
1282 | ||
1283 | void __init arp_init(void) | |
1284 | { | |
1285 | neigh_table_init(&arp_tbl); | |
1286 | ||
1287 | dev_add_pack(&arp_packet_type); | |
1288 | arp_proc_init(); | |
1289 | #ifdef CONFIG_SYSCTL | |
54716e3b | 1290 | neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); |
1da177e4 LT |
1291 | #endif |
1292 | register_netdevice_notifier(&arp_netdev_notifier); | |
1293 | } | |
1294 | ||
1295 | #ifdef CONFIG_PROC_FS | |
40e4783e | 1296 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1297 | |
1298 | /* ------------------------------------------------------------------------ */ | |
1299 | /* | |
1300 | * ax25 -> ASCII conversion | |
1301 | */ | |
1302 | static char *ax2asc2(ax25_address *a, char *buf) | |
1303 | { | |
1304 | char c, *s; | |
1305 | int n; | |
1306 | ||
1307 | for (n = 0, s = buf; n < 6; n++) { | |
1308 | c = (a->ax25_call[n] >> 1) & 0x7F; | |
1309 | ||
deffd777 CG |
1310 | if (c != ' ') |
1311 | *s++ = c; | |
1da177e4 | 1312 | } |
e905a9ed | 1313 | |
1da177e4 | 1314 | *s++ = '-'; |
deffd777 CG |
1315 | n = (a->ax25_call[6] >> 1) & 0x0F; |
1316 | if (n > 9) { | |
1da177e4 LT |
1317 | *s++ = '1'; |
1318 | n -= 10; | |
1319 | } | |
e905a9ed | 1320 | |
1da177e4 LT |
1321 | *s++ = n + '0'; |
1322 | *s++ = '\0'; | |
1323 | ||
1324 | if (*buf == '\0' || *buf == '-') | |
deffd777 | 1325 | return "*"; |
1da177e4 LT |
1326 | |
1327 | return buf; | |
1da177e4 LT |
1328 | } |
1329 | #endif /* CONFIG_AX25 */ | |
1330 | ||
1331 | #define HBUFFERLEN 30 | |
1332 | ||
1333 | static void arp_format_neigh_entry(struct seq_file *seq, | |
1334 | struct neighbour *n) | |
1335 | { | |
1336 | char hbuffer[HBUFFERLEN]; | |
1da177e4 LT |
1337 | int k, j; |
1338 | char tbuf[16]; | |
1339 | struct net_device *dev = n->dev; | |
1340 | int hatype = dev->type; | |
1341 | ||
1342 | read_lock(&n->lock); | |
1343 | /* Convert hardware address to XX:XX:XX:XX ... form. */ | |
40e4783e | 1344 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1345 | if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) |
1346 | ax2asc2((ax25_address *)n->ha, hbuffer); | |
1347 | else { | |
1348 | #endif | |
1349 | for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { | |
51f82a2b DC |
1350 | hbuffer[k++] = hex_asc_hi(n->ha[j]); |
1351 | hbuffer[k++] = hex_asc_lo(n->ha[j]); | |
1da177e4 LT |
1352 | hbuffer[k++] = ':'; |
1353 | } | |
a3e8ee68 | 1354 | if (k != 0) |
1355 | --k; | |
1356 | hbuffer[k] = 0; | |
40e4783e | 1357 | #if IS_ENABLED(CONFIG_AX25) |
1da177e4 LT |
1358 | } |
1359 | #endif | |
673d57e7 | 1360 | sprintf(tbuf, "%pI4", n->primary_key); |
1da177e4 LT |
1361 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
1362 | tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); | |
1363 | read_unlock(&n->lock); | |
1364 | } | |
1365 | ||
1366 | static void arp_format_pneigh_entry(struct seq_file *seq, | |
1367 | struct pneigh_entry *n) | |
1368 | { | |
1369 | struct net_device *dev = n->dev; | |
1370 | int hatype = dev ? dev->type : 0; | |
1371 | char tbuf[16]; | |
1372 | ||
673d57e7 | 1373 | sprintf(tbuf, "%pI4", n->key); |
1da177e4 LT |
1374 | seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", |
1375 | tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", | |
1376 | dev ? dev->name : "*"); | |
1377 | } | |
1378 | ||
1379 | static int arp_seq_show(struct seq_file *seq, void *v) | |
1380 | { | |
1381 | if (v == SEQ_START_TOKEN) { | |
1382 | seq_puts(seq, "IP address HW type Flags " | |
1383 | "HW address Mask Device\n"); | |
1384 | } else { | |
1385 | struct neigh_seq_state *state = seq->private; | |
1386 | ||
1387 | if (state->flags & NEIGH_SEQ_IS_PNEIGH) | |
1388 | arp_format_pneigh_entry(seq, v); | |
1389 | else | |
1390 | arp_format_neigh_entry(seq, v); | |
1391 | } | |
1392 | ||
1393 | return 0; | |
1394 | } | |
1395 | ||
1396 | static void *arp_seq_start(struct seq_file *seq, loff_t *pos) | |
1397 | { | |
1398 | /* Don't want to confuse "arp -a" w/ magic entries, | |
1399 | * so we tell the generic iterator to skip NUD_NOARP. | |
1400 | */ | |
1401 | return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); | |
1402 | } | |
1403 | ||
1404 | /* ------------------------------------------------------------------------ */ | |
1405 | ||
f690808e | 1406 | static const struct seq_operations arp_seq_ops = { |
deffd777 CG |
1407 | .start = arp_seq_start, |
1408 | .next = neigh_seq_next, | |
1409 | .stop = neigh_seq_stop, | |
1410 | .show = arp_seq_show, | |
1da177e4 LT |
1411 | }; |
1412 | ||
1413 | static int arp_seq_open(struct inode *inode, struct file *file) | |
1414 | { | |
426b5303 EB |
1415 | return seq_open_net(inode, file, &arp_seq_ops, |
1416 | sizeof(struct neigh_seq_state)); | |
1da177e4 LT |
1417 | } |
1418 | ||
9a32144e | 1419 | static const struct file_operations arp_seq_fops = { |
1da177e4 LT |
1420 | .owner = THIS_MODULE, |
1421 | .open = arp_seq_open, | |
1422 | .read = seq_read, | |
1423 | .llseek = seq_lseek, | |
426b5303 | 1424 | .release = seq_release_net, |
1da177e4 LT |
1425 | }; |
1426 | ||
ffc31d3d DL |
1427 | |
1428 | static int __net_init arp_net_init(struct net *net) | |
1da177e4 | 1429 | { |
d4beaa66 | 1430 | if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops)) |
1da177e4 LT |
1431 | return -ENOMEM; |
1432 | return 0; | |
1433 | } | |
1434 | ||
ffc31d3d DL |
1435 | static void __net_exit arp_net_exit(struct net *net) |
1436 | { | |
ece31ffd | 1437 | remove_proc_entry("arp", net->proc_net); |
ffc31d3d DL |
1438 | } |
1439 | ||
1440 | static struct pernet_operations arp_net_ops = { | |
1441 | .init = arp_net_init, | |
1442 | .exit = arp_net_exit, | |
1443 | }; | |
1444 | ||
1445 | static int __init arp_proc_init(void) | |
1446 | { | |
1447 | return register_pernet_subsys(&arp_net_ops); | |
1448 | } | |
1449 | ||
1da177e4 LT |
1450 | #else /* CONFIG_PROC_FS */ |
1451 | ||
1452 | static int __init arp_proc_init(void) | |
1453 | { | |
1454 | return 0; | |
1455 | } | |
1456 | ||
1457 | #endif /* CONFIG_PROC_FS */ |