blob: 205e1472aa7819784091d588818e1ab602f6006f [file] [log] [blame]
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02001/* linux/net/ipv4/arp.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * 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:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090016 * Alan Cox : Removed the Ethernet assumptions in
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * Florian's code
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090018 * Alan Cox : Fixed some small errors in the ARP
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * 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.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090040 * Craig Schlenter : Don't modify permanent entry
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 * during arp_rcv.
42 * Russ Nelson : Tidied up a few bits.
43 * Alexey Kuznetsov: Major changes to caching and behaviour,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090044 * eg intelligent arp probing and
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 * 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.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090051 * Jonathan Layes : Added arpd support through kerneld
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 * 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.
Changli Gaodeffd772010-09-02 03:56:51 +000058 * Alan Cox : Took the AP1000 nasty FDDI hack and
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * 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
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +000073 * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support.
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 */
75
Joe Perches91df42b2012-05-15 14:11:54 +000076#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
77
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#include <linux/module.h>
79#include <linux/types.h>
80#include <linux/string.h>
81#include <linux/kernel.h>
Randy Dunlap4fc268d2006-01-11 12:17:47 -080082#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070083#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>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020089#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070090#include <linux/netdevice.h>
91#include <linux/etherdevice.h>
92#include <linux/fddidevice.h>
93#include <linux/if_arp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070094#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +0900101#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102#ifdef CONFIG_SYSCTL
103#include <linux/sysctl.h>
104#endif
105
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200106#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114#include <net/ax25.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115#include <net/netrom.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Changli Gaodeffd772010-09-02 03:56:51 +0000117#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119#include <linux/netfilter_arp.h>
120
121/*
122 * Interface to generic neighbour cache.
123 */
David S. Miller2c2aba62011-12-28 15:06:58 -0500124static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 *hash_rnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125static int arp_constructor(struct neighbour *neigh);
126static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
127static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
128static void parp_redo(struct sk_buff *skb);
129
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000130static const struct neigh_ops arp_generic_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 .family = AF_INET,
132 .solicit = arp_solicit,
133 .error_report = arp_error_report,
134 .output = neigh_resolve_output,
135 .connected_output = neigh_connected_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136};
137
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000138static const struct neigh_ops arp_hh_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 .family = AF_INET,
140 .solicit = arp_solicit,
141 .error_report = arp_error_report,
142 .output = neigh_resolve_output,
143 .connected_output = neigh_resolve_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144};
145
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000146static const struct neigh_ops arp_direct_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 .family = AF_INET,
David S. Miller8f40b162011-07-17 13:34:11 -0700148 .output = neigh_direct_output,
149 .connected_output = neigh_direct_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150};
151
stephen hemmingera64de472010-09-28 17:08:02 +0000152static const struct neigh_ops arp_broken_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 .family = AF_INET,
154 .solicit = arp_solicit,
155 .error_report = arp_error_report,
156 .output = neigh_compat_output,
157 .connected_output = neigh_compat_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158};
159
160struct neigh_table arp_tbl = {
Changli Gaodeffd772010-09-02 03:56:51 +0000161 .family = AF_INET,
Changli Gaodeffd772010-09-02 03:56:51 +0000162 .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,
Changli Gaodeffd772010-09-02 03:56:51 +0000169 .reachable_time = 30 * HZ,
Jiri Pirko1f9248e52013-12-07 19:26:53 +0100170 .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 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 },
Changli Gaodeffd772010-09-02 03:56:51 +0000184 .gc_interval = 30 * HZ,
185 .gc_thresh1 = 128,
186 .gc_thresh2 = 512,
187 .gc_thresh3 = 1024,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188};
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000189EXPORT_SYMBOL(arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Al Viro714e85b2006-11-14 20:51:49 -0800191int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
193 switch (dev->type) {
194 case ARPHRD_ETHER:
195 case ARPHRD_FDDI:
196 case ARPHRD_IEEE802:
197 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900198 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 case ARPHRD_INFINIBAND:
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700200 ip_ib_mc_map(addr, dev->broadcast, haddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 return 0;
Timo Teräs93ca3bb2011-03-28 22:40:53 +0000202 case ARPHRD_IPGRE:
203 ip_ipgre_mc_map(addr, dev->broadcast, haddr);
204 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 default:
206 if (dir) {
207 memcpy(haddr, dev->broadcast, dev->addr_len);
208 return 0;
209 }
210 }
211 return -EINVAL;
212}
213
214
Eric Dumazetd6bf7812010-10-04 06:15:44 +0000215static u32 arp_hash(const void *pkey,
216 const struct net_device *dev,
David S. Miller2c2aba62011-12-28 15:06:58 -0500217 __u32 *hash_rnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
David S. Miller2c2aba62011-12-28 15:06:58 -0500219 return arp_hashfn(*(u32 *)pkey, dev, *hash_rnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220}
221
222static int arp_constructor(struct neighbour *neigh)
223{
Changli Gaodeffd772010-09-02 03:56:51 +0000224 __be32 addr = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 struct net_device *dev = neigh->dev;
226 struct in_device *in_dev;
227 struct neigh_parms *parms;
228
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700230 in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 if (in_dev == NULL) {
232 rcu_read_unlock();
233 return -EINVAL;
234 }
235
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900236 neigh->type = inet_addr_type(dev_net(dev), addr);
Denis V. Luneva79878f2008-01-14 22:56:01 -0800237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 parms = in_dev->arp_parms;
239 __neigh_parms_put(neigh->parms);
240 neigh->parms = neigh_parms_clone(parms);
241 rcu_read_unlock();
242
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700243 if (!dev->header_ops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 neigh->nud_state = NUD_NOARP;
245 neigh->ops = &arp_direct_ops;
David S. Miller8f40b162011-07-17 13:34:11 -0700246 neigh->output = neigh_direct_output;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 } 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;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900278 case ARPHRD_ROSE:
Igor Maravic40e47832011-12-05 02:25:57 +0000279#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 case ARPHRD_AX25:
Igor Maravic40e47832011-12-05 02:25:57 +0000281#if IS_ENABLED(CONFIG_NETROM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 case ARPHRD_NETROM:
283#endif
284 neigh->ops = &arp_broken_ops;
285 neigh->output = neigh->ops->output;
286 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000287#else
288 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289#endif
Changli Gaodeffd772010-09-02 03:56:51 +0000290 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291#endif
292 if (neigh->type == RTN_MULTICAST) {
293 neigh->nud_state = NUD_NOARP;
294 arp_mc_map(addr, neigh->ha, dev, 1);
Changli Gaodeffd772010-09-02 03:56:51 +0000295 } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 neigh->nud_state = NUD_NOARP;
297 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
Changli Gaodeffd772010-09-02 03:56:51 +0000298 } else if (neigh->type == RTN_BROADCAST ||
299 (dev->flags & IFF_POINTOPOINT)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 neigh->nud_state = NUD_NOARP;
301 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
302 }
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700303
304 if (dev->header_ops->cache)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 neigh->ops = &arp_hh_ops;
306 else
307 neigh->ops = &arp_generic_ops;
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700308
Changli Gaodeffd772010-09-02 03:56:51 +0000309 if (neigh->nud_state & NUD_VALID)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 neigh->output = neigh->ops->connected_output;
311 else
312 neigh->output = neigh->ops->output;
313 }
314 return 0;
315}
316
317static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
318{
319 dst_link_failure(skb);
320 kfree_skb(skb);
321}
322
323static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
324{
Al Viroa61ced52006-09-26 21:27:54 -0700325 __be32 saddr = 0;
Cong Wangcf0be8802012-12-23 15:23:16 +0000326 u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 struct net_device *dev = neigh->dev;
Changli Gaodeffd772010-09-02 03:56:51 +0000328 __be32 target = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 int probes = atomic_read(&neigh->probes);
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000330 struct in_device *in_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000332 rcu_read_lock();
333 in_dev = __in_dev_get_rcu(dev);
334 if (!in_dev) {
335 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 return;
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000337 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
339 default:
340 case 0: /* By default announce any local IP */
Changli Gaodeffd772010-09-02 03:56:51 +0000341 if (skb && inet_addr_type(dev_net(dev),
342 ip_hdr(skb)->saddr) == RTN_LOCAL)
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700343 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 break;
345 case 1: /* Restrict announcements of saddr in same subnet */
346 if (!skb)
347 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700348 saddr = ip_hdr(skb)->saddr;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900349 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 /* 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 }
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000359 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 if (!saddr)
362 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
363
Jiri Pirko1f9248e52013-12-07 19:26:53 +0100364 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
Changli Gaodeffd772010-09-02 03:56:51 +0000365 if (probes < 0) {
366 if (!(neigh->nud_state & NUD_VALID))
Joe Perches91df42b2012-05-15 14:11:54 +0000367 pr_debug("trying to ucast probe in NUD_INVALID\n");
Eric Dumazet96503882012-12-21 07:32:10 +0000368 neigh_ha_snapshot(dst_ha, neigh, dev);
Cong Wangcf0be8802012-12-23 15:23:16 +0000369 dst_hw = dst_ha;
Changli Gaodeffd772010-09-02 03:56:51 +0000370 } else {
Jiri Pirko1f9248e52013-12-07 19:26:53 +0100371 probes -= NEIGH_VAR(neigh->parms, APP_PROBES);
Changli Gaodeffd772010-09-02 03:56:51 +0000372 if (probes < 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000373 neigh_app_ns(neigh);
Changli Gaodeffd772010-09-02 03:56:51 +0000374 return;
375 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 }
377
378 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
Cong Wangcf0be8802012-12-23 15:23:16 +0000379 dst_hw, dev->dev_addr, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380}
381
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800382static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383{
Nicolas Dichtelb601fa12013-12-10 15:02:40 +0100384 struct net *net = dev_net(in_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 int scope;
386
387 switch (IN_DEV_ARP_IGNORE(in_dev)) {
388 case 0: /* Reply, the tip is already validated */
389 return 0;
390 case 1: /* Reply only if tip is configured on the incoming interface */
391 sip = 0;
392 scope = RT_SCOPE_HOST;
393 break;
394 case 2: /*
395 * Reply only if tip is configured on the incoming interface
396 * and is in same subnet as sip
397 */
398 scope = RT_SCOPE_HOST;
399 break;
400 case 3: /* Do not reply for scope host addresses */
401 sip = 0;
402 scope = RT_SCOPE_LINK;
Nicolas Dichtelb601fa12013-12-10 15:02:40 +0100403 in_dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 break;
405 case 4: /* Reserved */
406 case 5:
407 case 6:
408 case 7:
409 return 0;
410 case 8: /* Do not reply */
411 return 1;
412 default:
413 return 0;
414 }
Nicolas Dichtelb601fa12013-12-10 15:02:40 +0100415 return !inet_confirm_addr(net, in_dev, sip, tip, scope);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
417
Al Viroed9bad02006-09-27 18:36:36 -0700418static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900421 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 /*unsigned long now; */
Pavel Emelyanovca12a1a2008-07-16 20:28:42 -0700423 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
David S. Miller78fbfd82011-03-12 00:00:52 -0500425 rt = ip_route_output(net, sip, tip, 0, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800426 if (IS_ERR(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 return 1;
Changli Gaod8d1f302010-06-10 23:31:35 -0700428 if (rt->dst.dev != dev) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700429 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900431 }
432 ip_rt_put(rt);
433 return flag;
434}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
436/* OBSOLETE FUNCTIONS */
437
438/*
439 * Find an arp mapping in the cache. If not found, post a request.
440 *
441 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
442 * even if it exists. It is supposed that skb->dev was mangled
443 * by a virtual device (eql, shaper). Nobody but broken devices
444 * is allowed to use this function, it is scheduled to be removed. --ANK
445 */
446
Changli Gaodeffd772010-09-02 03:56:51 +0000447static int arp_set_predefined(int addr_hint, unsigned char *haddr,
448 __be32 paddr, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449{
450 switch (addr_hint) {
451 case RTN_LOCAL:
Joe Perches91df42b2012-05-15 14:11:54 +0000452 pr_debug("arp called for own IP address\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 memcpy(haddr, dev->dev_addr, dev->addr_len);
454 return 1;
455 case RTN_MULTICAST:
456 arp_mc_map(paddr, haddr, dev, 1);
457 return 1;
458 case RTN_BROADCAST:
459 memcpy(haddr, dev->broadcast, dev->addr_len);
460 return 1;
461 }
462 return 0;
463}
464
465
466int arp_find(unsigned char *haddr, struct sk_buff *skb)
467{
468 struct net_device *dev = skb->dev;
Al Virofd683222006-09-26 22:17:51 -0700469 __be32 paddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 struct neighbour *n;
471
Eric Dumazetadf30902009-06-02 05:19:30 +0000472 if (!skb_dst(skb)) {
Joe Perches91df42b2012-05-15 14:11:54 +0000473 pr_debug("arp_find is called with dst==NULL\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 kfree_skb(skb);
475 return 1;
476 }
477
David S. Millerf8126f12012-07-13 05:03:45 -0700478 paddr = rt_nexthop(skb_rtable(skb), ip_hdr(skb)->daddr);
Changli Gaodeffd772010-09-02 03:56:51 +0000479 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr,
480 paddr, dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 return 0;
482
483 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
484
485 if (n) {
486 n->used = jiffies;
Eric Dumazet0ed8ddf2010-10-07 10:44:07 +0000487 if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) {
488 neigh_ha_snapshot(haddr, n, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 neigh_release(n);
490 return 0;
491 }
492 neigh_release(n);
493 } else
494 kfree_skb(skb);
495 return 1;
496}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000497EXPORT_SYMBOL(arp_find);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499/* END OF OBSOLETE FUNCTIONS */
500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501/*
502 * Check if we can use proxy ARP for this path
503 */
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000504static inline int arp_fwd_proxy(struct in_device *in_dev,
505 struct net_device *dev, struct rtable *rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506{
507 struct in_device *out_dev;
508 int imi, omi = -1;
509
Changli Gaod8d1f302010-06-10 23:31:35 -0700510 if (rt->dst.dev == dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000511 return 0;
512
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 if (!IN_DEV_PROXY_ARP(in_dev))
514 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000515 imi = IN_DEV_MEDIUM_ID(in_dev);
516 if (imi == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 return 1;
518 if (imi == -1)
519 return 0;
520
521 /* place to check for proxy_arp for routes */
522
Changli Gaod8d1f302010-06-10 23:31:35 -0700523 out_dev = __in_dev_get_rcu(rt->dst.dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000524 if (out_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 omi = IN_DEV_MEDIUM_ID(out_dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000526
Eric Dumazeta02cec22010-09-22 20:43:57 +0000527 return omi != imi && omi != -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528}
529
530/*
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000531 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
532 *
533 * RFC3069 supports proxy arp replies back to the same interface. This
534 * is done to support (ethernet) switch features, like RFC 3069, where
535 * the individual ports are not allowed to communicate with each
536 * other, BUT they are allowed to talk to the upstream router. As
537 * described in RFC 3069, it is possible to allow these hosts to
538 * communicate through the upstream router, by proxy_arp'ing.
539 *
540 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation"
541 *
542 * This technology is known by different names:
543 * In RFC 3069 it is called VLAN Aggregation.
544 * Cisco and Allied Telesyn call it Private VLAN.
545 * Hewlett-Packard call it Source-Port filtering or port-isolation.
546 * Ericsson call it MAC-Forced Forwarding (RFC Draft).
547 *
548 */
549static inline int arp_fwd_pvlan(struct in_device *in_dev,
550 struct net_device *dev, struct rtable *rt,
551 __be32 sip, __be32 tip)
552{
553 /* Private VLAN is only concerned about the same ethernet segment */
Changli Gaod8d1f302010-06-10 23:31:35 -0700554 if (rt->dst.dev != dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000555 return 0;
556
557 /* Don't reply on self probes (often done by windowz boxes)*/
558 if (sip == tip)
559 return 0;
560
561 if (IN_DEV_PROXY_ARP_PVLAN(in_dev))
562 return 1;
563 else
564 return 0;
565}
566
567/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 * Interface to link layer: send routine and receive handler.
569 */
570
571/*
572 * Create an arp packet. If (dest_hw == NULL), we create a broadcast
573 * message.
574 */
Al Viroed9bad02006-09-27 18:36:36 -0700575struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
576 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800577 const unsigned char *dest_hw,
578 const unsigned char *src_hw,
579 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580{
581 struct sk_buff *skb;
582 struct arphdr *arp;
583 unsigned char *arp_ptr;
Herbert Xu66088242011-11-18 02:20:04 +0000584 int hlen = LL_RESERVED_SPACE(dev);
585 int tlen = dev->needed_tailroom;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586
587 /*
588 * Allocate a buffer
589 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900590
Herbert Xu66088242011-11-18 02:20:04 +0000591 skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 if (skb == NULL)
593 return NULL;
594
Herbert Xu66088242011-11-18 02:20:04 +0000595 skb_reserve(skb, hlen);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700596 skb_reset_network_header(skb);
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800597 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 skb->dev = dev;
599 skb->protocol = htons(ETH_P_ARP);
600 if (src_hw == NULL)
601 src_hw = dev->dev_addr;
602 if (dest_hw == NULL)
603 dest_hw = dev->broadcast;
604
605 /*
606 * Fill the device header for the ARP frame
607 */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700608 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 goto out;
610
611 /*
612 * Fill out the arp protocol part.
613 *
614 * The arp hardware type should match the device type, except for FDDI,
615 * which (according to RFC 1390) should always equal 1 (Ethernet).
616 */
617 /*
618 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
619 * DIX code for the protocol. Make these device structure fields.
620 */
621 switch (dev->type) {
622 default:
623 arp->ar_hrd = htons(dev->type);
624 arp->ar_pro = htons(ETH_P_IP);
625 break;
626
Igor Maravic40e47832011-12-05 02:25:57 +0000627#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 case ARPHRD_AX25:
629 arp->ar_hrd = htons(ARPHRD_AX25);
630 arp->ar_pro = htons(AX25_P_IP);
631 break;
632
Igor Maravic40e47832011-12-05 02:25:57 +0000633#if IS_ENABLED(CONFIG_NETROM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 case ARPHRD_NETROM:
635 arp->ar_hrd = htons(ARPHRD_NETROM);
636 arp->ar_pro = htons(AX25_P_IP);
637 break;
638#endif
639#endif
640
Igor Maravic40e47832011-12-05 02:25:57 +0000641#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 case ARPHRD_FDDI:
643 arp->ar_hrd = htons(ARPHRD_ETHER);
644 arp->ar_pro = htons(ETH_P_IP);
645 break;
646#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 }
648
649 arp->ar_hln = dev->addr_len;
650 arp->ar_pln = 4;
651 arp->ar_op = htons(type);
652
Changli Gaodeffd772010-09-02 03:56:51 +0000653 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
655 memcpy(arp_ptr, src_hw, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800656 arp_ptr += dev->addr_len;
657 memcpy(arp_ptr, &src_ip, 4);
658 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000659
660 switch (dev->type) {
661#if IS_ENABLED(CONFIG_FIREWIRE_NET)
662 case ARPHRD_IEEE1394:
663 break;
664#endif
665 default:
666 if (target_hw != NULL)
667 memcpy(arp_ptr, target_hw, dev->addr_len);
668 else
669 memset(arp_ptr, 0, dev->addr_len);
670 arp_ptr += dev->addr_len;
671 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 memcpy(arp_ptr, &dest_ip, 4);
673
674 return skb;
675
676out:
677 kfree_skb(skb);
678 return NULL;
679}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000680EXPORT_SYMBOL(arp_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
682/*
683 * Send an arp packet.
684 */
685void arp_xmit(struct sk_buff *skb)
686{
687 /* Send it off, maybe filter it using firewalling first. */
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700688 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000690EXPORT_SYMBOL(arp_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691
692/*
693 * Create and send an arp packet.
694 */
Al Viroed9bad02006-09-27 18:36:36 -0700695void arp_send(int type, int ptype, __be32 dest_ip,
696 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800697 const unsigned char *dest_hw, const unsigned char *src_hw,
698 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699{
700 struct sk_buff *skb;
701
702 /*
703 * No arp on this interface.
704 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900705
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 if (dev->flags&IFF_NOARP)
707 return;
708
709 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
710 dest_hw, src_hw, target_hw);
Changli Gaodeffd772010-09-02 03:56:51 +0000711 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713
714 arp_xmit(skb);
715}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000716EXPORT_SYMBOL(arp_send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718/*
719 * Process an arp request.
720 */
721
722static int arp_process(struct sk_buff *skb)
723{
724 struct net_device *dev = skb->dev;
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000725 struct in_device *in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 struct arphdr *arp;
727 unsigned char *arp_ptr;
728 struct rtable *rt;
Mark Rydene0260fe2007-12-19 23:38:11 -0800729 unsigned char *sha;
Al Viro9e12bb22006-09-26 21:25:20 -0700730 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 u16 dev_type = dev->type;
732 int addr_type;
733 struct neighbour *n;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900734 struct net *net = dev_net(dev);
Salam Noureddine56022a82013-12-24 14:17:02 -0800735 bool is_garp = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 /* arp_rcv below verifies the ARP header and verifies the device
738 * is ARP'able.
739 */
740
741 if (in_dev == NULL)
742 goto out;
743
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300744 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745
746 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900747 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 if (arp->ar_pro != htons(ETH_P_IP) ||
749 htons(dev_type) != arp->ar_hrd)
750 goto out;
751 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 case ARPHRD_ETHER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 case ARPHRD_FDDI:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 case ARPHRD_IEEE802:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 /*
Paul Gortmaker211ed862012-05-10 17:14:35 -0400756 * ETHERNET, and Fibre Channel (which are IEEE 802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 * devices, according to RFC 2625) devices will accept ARP
758 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
759 * This is the case also of FDDI, where the RFC 1390 says that
760 * FDDI devices should accept ARP hardware of (1) Ethernet,
761 * however, to be more robust, we'll accept both 1 (Ethernet)
762 * or 6 (IEEE 802.2)
763 */
764 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
765 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
766 arp->ar_pro != htons(ETH_P_IP))
767 goto out;
768 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 case ARPHRD_AX25:
770 if (arp->ar_pro != htons(AX25_P_IP) ||
771 arp->ar_hrd != htons(ARPHRD_AX25))
772 goto out;
773 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 case ARPHRD_NETROM:
775 if (arp->ar_pro != htons(AX25_P_IP) ||
776 arp->ar_hrd != htons(ARPHRD_NETROM))
777 goto out;
778 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 }
780
781 /* Understand only these message types */
782
783 if (arp->ar_op != htons(ARPOP_REPLY) &&
784 arp->ar_op != htons(ARPOP_REQUEST))
785 goto out;
786
787/*
788 * Extract fields
789 */
Changli Gaodeffd772010-09-02 03:56:51 +0000790 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 sha = arp_ptr;
792 arp_ptr += dev->addr_len;
793 memcpy(&sip, arp_ptr, 4);
794 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000795 switch (dev_type) {
796#if IS_ENABLED(CONFIG_FIREWIRE_NET)
797 case ARPHRD_IEEE1394:
798 break;
799#endif
800 default:
801 arp_ptr += dev->addr_len;
802 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900804/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 * Check for bad requests for 127.x.x.x and requests for multicast
806 * addresses. If this is one such, delete it.
807 */
Thomas Grafd0daebc32012-06-12 00:44:01 +0000808 if (ipv4_is_multicast(tip) ||
809 (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 goto out;
811
812/*
813 * Special case: We must set Frame Relay source Q.922 address
814 */
815 if (dev_type == ARPHRD_DLCI)
816 sha = dev->broadcast;
817
818/*
819 * Process entry. The idea here is we want to send a reply if it is a
820 * request for us or if it is a request for someone else that we hold
821 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900822 * to us or if it is a request for our address.
823 * (The assumption for this last is that if someone is requesting our
824 * address, they are probably intending to talk to us, so it saves time
825 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900827 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 * Putting this another way, we only care about replies if they are to
829 * us, in which case we add them to the cache. For requests, we care
830 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900831 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 * cache.
833 */
834
Eric W. Biedermanf8a68e72009-06-30 16:27:17 +0000835 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
836 if (sip == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700838 inet_addr_type(net, tip) == RTN_LOCAL &&
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800839 !arp_ignore(in_dev, sip, tip))
Jonas Danielssonb4a98112007-11-20 17:38:16 -0800840 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
841 dev->dev_addr, sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 goto out;
843 }
844
845 if (arp->ar_op == htons(ARPOP_REQUEST) &&
David S. Millerc6cffba2012-07-26 11:14:38 +0000846 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847
Eric Dumazet511c3f92009-06-02 05:14:27 +0000848 rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 addr_type = rt->rt_type;
850
851 if (addr_type == RTN_LOCAL) {
Changli Gaodeffd772010-09-02 03:56:51 +0000852 int dont_send;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
Changli Gaodeffd772010-09-02 03:56:51 +0000854 dont_send = arp_ignore(in_dev, sip, tip);
Ben Greear8164f1b2008-11-16 19:19:38 -0800855 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
Changli Gaoae9c4162010-12-01 20:07:31 +0000856 dont_send = arp_filter(sip, tip, dev);
Ben Greear8164f1b2008-11-16 19:19:38 -0800857 if (!dont_send) {
858 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
859 if (n) {
Changli Gaodeffd772010-09-02 03:56:51 +0000860 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
861 dev, tip, sha, dev->dev_addr,
862 sha);
Ben Greear8164f1b2008-11-16 19:19:38 -0800863 neigh_release(n);
864 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 }
866 goto out;
867 } else if (IN_DEV_FORWARD(in_dev)) {
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000868 if (addr_type == RTN_UNICAST &&
869 (arp_fwd_proxy(in_dev, dev, rt) ||
870 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) ||
Thomas Graf70620c42012-02-10 04:07:11 +0000871 (rt->dst.dev != dev &&
872 pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
874 if (n)
875 neigh_release(n);
876
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900877 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 skb->pkt_type == PACKET_HOST ||
Jiri Pirko1f9248e52013-12-07 19:26:53 +0100879 NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000880 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
881 dev, tip, sha, dev->dev_addr,
882 sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 } else {
Changli Gaodeffd772010-09-02 03:56:51 +0000884 pneigh_enqueue(&arp_tbl,
885 in_dev->arp_parms, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 return 0;
887 }
888 goto out;
889 }
890 }
891 }
892
893 /* Update our ARP tables */
894
895 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
896
Neil Horman124d37e2012-03-15 05:25:58 +0000897 if (IN_DEV_ARP_ACCEPT(in_dev)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800898 /* Unsolicited ARP is not accepted by default.
899 It is possible, that this option should be enabled for some
900 devices (strip is candidate)
901 */
Salam Noureddine56022a82013-12-24 14:17:02 -0800902 is_garp = arp->ar_op == htons(ARPOP_REQUEST) && tip == sip &&
903 inet_addr_type(net, sip) == RTN_UNICAST;
904
Neil Hormanabd596a2006-03-20 22:39:47 -0800905 if (n == NULL &&
Salam Noureddine56022a82013-12-24 14:17:02 -0800906 ((arp->ar_op == htons(ARPOP_REPLY) &&
907 inet_addr_type(net, sip) == RTN_UNICAST) || is_garp))
Jean Delvare1b1ac752007-07-14 20:51:44 -0700908 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800909 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
911 if (n) {
912 int state = NUD_REACHABLE;
913 int override;
914
915 /* If several different ARP replies follows back-to-back,
916 use the FIRST one. It is possible, if several proxy
917 agents are active. Taking the first reply prevents
918 arp trashing and chooses the fastest router.
919 */
Salam Noureddine56022a82013-12-24 14:17:02 -0800920 override = time_after(jiffies,
921 n->updated +
922 NEIGH_VAR(n->parms, LOCKTIME)) ||
923 is_garp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 /* Broadcast replies and request packets
926 do not assert neighbour reachability.
927 */
928 if (arp->ar_op != htons(ARPOP_REPLY) ||
929 skb->pkt_type != PACKET_HOST)
930 state = NUD_STALE;
Changli Gaodeffd772010-09-02 03:56:51 +0000931 neigh_update(n, sha, state,
932 override ? NEIGH_UPDATE_F_OVERRIDE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 neigh_release(n);
934 }
935
936out:
Neil Hormanead2ceb2009-03-11 09:49:55 +0000937 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 return 0;
939}
940
Herbert Xu444fc8f2005-10-03 14:18:10 -0700941static void parp_redo(struct sk_buff *skb)
942{
943 arp_process(skb);
944}
945
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
947/*
948 * Receive an arp request from the device layer.
949 */
950
Adrian Bunk6c97e722006-04-12 13:57:59 -0700951static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
952 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953{
Eric Dumazet044453b2013-02-08 18:48:21 +0000954 const struct arphdr *arp;
955
Rick Jones825bae52014-09-25 10:55:28 -0700956 /* do not tweak dropwatch on an ARP we will ignore */
Eric Dumazet044453b2013-02-08 18:48:21 +0000957 if (dev->flags & IFF_NOARP ||
958 skb->pkt_type == PACKET_OTHERHOST ||
959 skb->pkt_type == PACKET_LOOPBACK)
Rick Jones825bae52014-09-25 10:55:28 -0700960 goto consumeskb;
Eric Dumazet044453b2013-02-08 18:48:21 +0000961
962 skb = skb_share_check(skb, GFP_ATOMIC);
963 if (!skb)
964 goto out_of_mem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965
966 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800967 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 goto freeskb;
969
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300970 arp = arp_hdr(skb);
Eric Dumazet044453b2013-02-08 18:48:21 +0000971 if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 goto freeskb;
973
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700974 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
975
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700976 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
Rick Jones825bae52014-09-25 10:55:28 -0700978consumeskb:
979 consume_skb(skb);
980 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981freeskb:
982 kfree_skb(skb);
983out_of_mem:
984 return 0;
985}
986
987/*
988 * User level interface (ioctl)
989 */
990
991/*
992 * Set (create) an ARP cache entry.
993 */
994
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800995static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on)
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800996{
997 if (dev == NULL) {
Pavel Emelyanov586f1212007-12-16 13:32:48 -0800998 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800999 return 0;
1000 }
Eric Dumazetc5066532011-01-24 13:16:16 -08001001 if (__in_dev_get_rtnl(dev)) {
1002 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001003 return 0;
1004 }
1005 return -ENXIO;
1006}
1007
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001008static int arp_req_set_public(struct net *net, struct arpreq *r,
1009 struct net_device *dev)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001010{
1011 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
1012 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1013
1014 if (mask && mask != htonl(0xFFFFFFFF))
1015 return -EINVAL;
1016 if (!dev && (r->arp_flags & ATF_COM)) {
Eric Dumazet941666c2010-12-05 01:23:53 +00001017 dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family,
Changli Gaodeffd772010-09-02 03:56:51 +00001018 r->arp_ha.sa_data);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001019 if (!dev)
1020 return -ENODEV;
1021 }
1022 if (mask) {
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001023 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001024 return -ENOBUFS;
1025 return 0;
1026 }
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001027
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001028 return arp_req_set_proxy(net, dev, 1);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001029}
1030
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001031static int arp_req_set(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001032 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033{
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001034 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 struct neighbour *neigh;
1036 int err;
1037
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001038 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001039 return arp_req_set_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001041 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 if (r->arp_flags & ATF_PERM)
1043 r->arp_flags |= ATF_COM;
1044 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001045 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001046
1047 if (IS_ERR(rt))
1048 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001049 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 ip_rt_put(rt);
1051 if (!dev)
1052 return -EINVAL;
1053 }
1054 switch (dev->type) {
Igor Maravic40e47832011-12-05 02:25:57 +00001055#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 case ARPHRD_FDDI:
1057 /*
1058 * According to RFC 1390, FDDI devices should accept ARP
1059 * hardware types of 1 (Ethernet). However, to be more
1060 * robust, we'll accept hardware types of either 1 (Ethernet)
1061 * or 6 (IEEE 802.2).
1062 */
1063 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1064 r->arp_ha.sa_family != ARPHRD_ETHER &&
1065 r->arp_ha.sa_family != ARPHRD_IEEE802)
1066 return -EINVAL;
1067 break;
1068#endif
1069 default:
1070 if (r->arp_ha.sa_family != dev->type)
1071 return -EINVAL;
1072 break;
1073 }
1074
1075 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1076 err = PTR_ERR(neigh);
1077 if (!IS_ERR(neigh)) {
Eric Dumazet95c96172012-04-15 05:58:06 +00001078 unsigned int state = NUD_STALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 if (r->arp_flags & ATF_PERM)
1080 state = NUD_PERMANENT;
Changli Gaodeffd772010-09-02 03:56:51 +00001081 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001082 r->arp_ha.sa_data : NULL, state,
Changli Gaodeffd772010-09-02 03:56:51 +00001083 NEIGH_UPDATE_F_OVERRIDE |
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 NEIGH_UPDATE_F_ADMIN);
1085 neigh_release(neigh);
1086 }
1087 return err;
1088}
1089
Eric Dumazet95c96172012-04-15 05:58:06 +00001090static unsigned int arp_state_to_flags(struct neighbour *neigh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 if (neigh->nud_state&NUD_PERMANENT)
Changli Gaodeffd772010-09-02 03:56:51 +00001093 return ATF_PERM | ATF_COM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 else if (neigh->nud_state&NUD_VALID)
Changli Gaodeffd772010-09-02 03:56:51 +00001095 return ATF_COM;
1096 else
1097 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098}
1099
1100/*
1101 * Get an ARP cache entry.
1102 */
1103
1104static int arp_req_get(struct arpreq *r, struct net_device *dev)
1105{
Al Viroed9bad02006-09-27 18:36:36 -07001106 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 struct neighbour *neigh;
1108 int err = -ENXIO;
1109
1110 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1111 if (neigh) {
1112 read_lock_bh(&neigh->lock);
1113 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1114 r->arp_flags = arp_state_to_flags(neigh);
1115 read_unlock_bh(&neigh->lock);
1116 r->arp_ha.sa_family = dev->type;
1117 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1118 neigh_release(neigh);
1119 err = 0;
1120 }
1121 return err;
1122}
1123
Stephen Hemminger7195cf72013-12-28 11:07:18 -08001124static int arp_invalidate(struct net_device *dev, __be32 ip)
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001125{
1126 struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
1127 int err = -ENXIO;
1128
1129 if (neigh) {
1130 if (neigh->nud_state & ~NUD_NOARP)
1131 err = neigh_update(neigh, NULL, NUD_FAILED,
1132 NEIGH_UPDATE_F_OVERRIDE|
1133 NEIGH_UPDATE_F_ADMIN);
1134 neigh_release(neigh);
1135 }
1136
1137 return err;
1138}
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001139
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001140static int arp_req_delete_public(struct net *net, struct arpreq *r,
1141 struct net_device *dev)
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001142{
1143 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1144 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1145
1146 if (mask == htonl(0xFFFFFFFF))
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001147 return pneigh_delete(&arp_tbl, net, &ip, dev);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001148
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001149 if (mask)
1150 return -EINVAL;
1151
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001152 return arp_req_set_proxy(net, dev, 0);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001153}
1154
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001155static int arp_req_delete(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001156 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157{
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001158 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001160 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001161 return arp_req_delete_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001163 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001165 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001166 if (IS_ERR(rt))
1167 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001168 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 ip_rt_put(rt);
1170 if (!dev)
1171 return -EINVAL;
1172 }
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001173 return arp_invalidate(dev, ip);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174}
1175
1176/*
1177 * Handle an ARP layer I/O control request.
1178 */
1179
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001180int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181{
1182 int err;
1183 struct arpreq r;
1184 struct net_device *dev = NULL;
1185
1186 switch (cmd) {
Changli Gaodeffd772010-09-02 03:56:51 +00001187 case SIOCDARP:
1188 case SIOCSARP:
Eric W. Biederman52e804c2012-11-16 03:03:05 +00001189 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
Changli Gaodeffd772010-09-02 03:56:51 +00001190 return -EPERM;
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 }
1199
1200 if (r.arp_pa.sa_family != AF_INET)
1201 return -EPFNOSUPPORT;
1202
1203 if (!(r.arp_flags & ATF_PUBL) &&
Changli Gaodeffd772010-09-02 03:56:51 +00001204 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 return -EINVAL;
1206 if (!(r.arp_flags & ATF_NETMASK))
1207 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1208 htonl(0xFFFFFFFFUL);
Eric Dumazetc5066532011-01-24 13:16:16 -08001209 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 if (r.arp_dev[0]) {
1211 err = -ENODEV;
Eric Dumazetc5066532011-01-24 13:16:16 -08001212 dev = __dev_get_by_name(net, r.arp_dev);
Changli Gaodeffd772010-09-02 03:56:51 +00001213 if (dev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 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
Stephen Hemminger132adf52007-03-08 20:44:43 -08001227 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 case SIOCDARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001229 err = arp_req_delete(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 break;
1231 case SIOCSARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001232 err = arp_req_set(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 break;
1234 case SIOCGARP:
1235 err = arp_req_get(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 break;
1237 }
1238out:
Eric Dumazetc5066532011-01-24 13:16:16 -08001239 rtnl_unlock();
Eric Dumazet941666c2010-12-05 01:23:53 +00001240 if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r)))
1241 err = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242 return err;
1243}
1244
Changli Gaodeffd772010-09-02 03:56:51 +00001245static int arp_netdev_event(struct notifier_block *this, unsigned long event,
1246 void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247{
Jiri Pirko351638e2013-05-28 01:30:21 +00001248 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Timo Teräs6c8b4e32013-05-28 01:30:23 +00001249 struct netdev_notifier_change_info *change_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250
1251 switch (event) {
1252 case NETDEV_CHANGEADDR:
1253 neigh_changeaddr(&arp_tbl, dev);
Nicolas Dichtelbafa6d92012-09-07 00:45:29 +00001254 rt_cache_flush(dev_net(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 break;
Timo Teräs6c8b4e32013-05-28 01:30:23 +00001256 case NETDEV_CHANGE:
1257 change_info = ptr;
1258 if (change_info->flags_changed & IFF_NOARP)
1259 neigh_changeaddr(&arp_tbl, dev);
1260 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001261 default:
1262 break;
1263 }
1264
1265 return NOTIFY_DONE;
1266}
1267
1268static struct notifier_block arp_netdev_notifier = {
1269 .notifier_call = arp_netdev_event,
1270};
1271
1272/* Note, that it is not on notifier chain.
1273 It is necessary, that this routine was called after route cache will be
1274 flushed.
1275 */
1276void arp_ifdown(struct net_device *dev)
1277{
1278 neigh_ifdown(&arp_tbl, dev);
1279}
1280
1281
1282/*
1283 * Called once on startup.
1284 */
1285
Stephen Hemminger7546dd92009-03-09 08:18:29 +00001286static struct packet_type arp_packet_type __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -08001287 .type = cpu_to_be16(ETH_P_ARP),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 .func = arp_rcv,
1289};
1290
1291static int arp_proc_init(void);
1292
1293void __init arp_init(void)
1294{
WANG Congd7480fd2014-11-10 15:59:36 -08001295 neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296
1297 dev_add_pack(&arp_packet_type);
1298 arp_proc_init();
1299#ifdef CONFIG_SYSCTL
Jiri Pirko73af6142013-12-07 19:26:55 +01001300 neigh_sysctl_register(NULL, &arp_tbl.parms, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301#endif
1302 register_netdevice_notifier(&arp_netdev_notifier);
1303}
1304
1305#ifdef CONFIG_PROC_FS
Igor Maravic40e47832011-12-05 02:25:57 +00001306#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307
1308/* ------------------------------------------------------------------------ */
1309/*
1310 * ax25 -> ASCII conversion
1311 */
1312static char *ax2asc2(ax25_address *a, char *buf)
1313{
1314 char c, *s;
1315 int n;
1316
1317 for (n = 0, s = buf; n < 6; n++) {
1318 c = (a->ax25_call[n] >> 1) & 0x7F;
1319
Changli Gaodeffd772010-09-02 03:56:51 +00001320 if (c != ' ')
1321 *s++ = c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001323
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 *s++ = '-';
Changli Gaodeffd772010-09-02 03:56:51 +00001325 n = (a->ax25_call[6] >> 1) & 0x0F;
1326 if (n > 9) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 *s++ = '1';
1328 n -= 10;
1329 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001330
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 *s++ = n + '0';
1332 *s++ = '\0';
1333
1334 if (*buf == '\0' || *buf == '-')
Changli Gaodeffd772010-09-02 03:56:51 +00001335 return "*";
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
1337 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338}
1339#endif /* CONFIG_AX25 */
1340
1341#define HBUFFERLEN 30
1342
1343static void arp_format_neigh_entry(struct seq_file *seq,
1344 struct neighbour *n)
1345{
1346 char hbuffer[HBUFFERLEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 int k, j;
1348 char tbuf[16];
1349 struct net_device *dev = n->dev;
1350 int hatype = dev->type;
1351
1352 read_lock(&n->lock);
1353 /* Convert hardware address to XX:XX:XX:XX ... form. */
Igor Maravic40e47832011-12-05 02:25:57 +00001354#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1356 ax2asc2((ax25_address *)n->ha, hbuffer);
1357 else {
1358#endif
1359 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
Denis Cheng51f82a22008-05-21 17:34:32 -07001360 hbuffer[k++] = hex_asc_hi(n->ha[j]);
1361 hbuffer[k++] = hex_asc_lo(n->ha[j]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 hbuffer[k++] = ':';
1363 }
roel kluina3e8ee62009-07-29 23:46:59 +00001364 if (k != 0)
1365 --k;
1366 hbuffer[k] = 0;
Igor Maravic40e47832011-12-05 02:25:57 +00001367#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368 }
1369#endif
Harvey Harrison673d57e2008-10-31 00:53:57 -07001370 sprintf(tbuf, "%pI4", n->primary_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1372 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1373 read_unlock(&n->lock);
1374}
1375
1376static void arp_format_pneigh_entry(struct seq_file *seq,
1377 struct pneigh_entry *n)
1378{
1379 struct net_device *dev = n->dev;
1380 int hatype = dev ? dev->type : 0;
1381 char tbuf[16];
1382
Harvey Harrison673d57e2008-10-31 00:53:57 -07001383 sprintf(tbuf, "%pI4", n->key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1385 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1386 dev ? dev->name : "*");
1387}
1388
1389static int arp_seq_show(struct seq_file *seq, void *v)
1390{
1391 if (v == SEQ_START_TOKEN) {
1392 seq_puts(seq, "IP address HW type Flags "
1393 "HW address Mask Device\n");
1394 } else {
1395 struct neigh_seq_state *state = seq->private;
1396
1397 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1398 arp_format_pneigh_entry(seq, v);
1399 else
1400 arp_format_neigh_entry(seq, v);
1401 }
1402
1403 return 0;
1404}
1405
1406static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1407{
1408 /* Don't want to confuse "arp -a" w/ magic entries,
1409 * so we tell the generic iterator to skip NUD_NOARP.
1410 */
1411 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1412}
1413
1414/* ------------------------------------------------------------------------ */
1415
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001416static const struct seq_operations arp_seq_ops = {
Changli Gaodeffd772010-09-02 03:56:51 +00001417 .start = arp_seq_start,
1418 .next = neigh_seq_next,
1419 .stop = neigh_seq_stop,
1420 .show = arp_seq_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421};
1422
1423static int arp_seq_open(struct inode *inode, struct file *file)
1424{
Eric W. Biederman426b5302008-01-24 00:13:18 -08001425 return seq_open_net(inode, file, &arp_seq_ops,
1426 sizeof(struct neigh_seq_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427}
1428
Arjan van de Ven9a321442007-02-12 00:55:35 -08001429static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430 .owner = THIS_MODULE,
1431 .open = arp_seq_open,
1432 .read = seq_read,
1433 .llseek = seq_lseek,
Eric W. Biederman426b5302008-01-24 00:13:18 -08001434 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001435};
1436
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001437
1438static int __net_init arp_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439{
Gao fengd4beaa62013-02-18 01:34:54 +00001440 if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 return -ENOMEM;
1442 return 0;
1443}
1444
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001445static void __net_exit arp_net_exit(struct net *net)
1446{
Gao fengece31ff2013-02-18 01:34:56 +00001447 remove_proc_entry("arp", net->proc_net);
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001448}
1449
1450static struct pernet_operations arp_net_ops = {
1451 .init = arp_net_init,
1452 .exit = arp_net_exit,
1453};
1454
1455static int __init arp_proc_init(void)
1456{
1457 return register_pernet_subsys(&arp_net_ops);
1458}
1459
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460#else /* CONFIG_PROC_FS */
1461
1462static int __init arp_proc_init(void)
1463{
1464 return 0;
1465}
1466
1467#endif /* CONFIG_PROC_FS */