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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,
169 .base_reachable_time = 30 * HZ,
170 .retrans_time = 1 * HZ,
171 .gc_staletime = 60 * HZ,
172 .reachable_time = 30 * HZ,
173 .delay_probe_time = 5 * HZ,
Eric Dumazet8b5c1712011-11-09 12:07:14 +0000174 .queue_len_bytes = 64*1024,
Changli Gaodeffd772010-09-02 03:56:51 +0000175 .ucast_probes = 3,
176 .mcast_probes = 3,
177 .anycast_delay = 1 * HZ,
178 .proxy_delay = (8 * HZ) / 10,
179 .proxy_qlen = 64,
180 .locktime = 1 * HZ,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 },
Changli Gaodeffd772010-09-02 03:56:51 +0000182 .gc_interval = 30 * HZ,
183 .gc_thresh1 = 128,
184 .gc_thresh2 = 512,
185 .gc_thresh3 = 1024,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186};
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000187EXPORT_SYMBOL(arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Al Viro714e85b2006-11-14 20:51:49 -0800189int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190{
191 switch (dev->type) {
192 case ARPHRD_ETHER:
193 case ARPHRD_FDDI:
194 case ARPHRD_IEEE802:
195 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900196 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 case ARPHRD_INFINIBAND:
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700198 ip_ib_mc_map(addr, dev->broadcast, haddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 return 0;
Timo Teräs93ca3bb2011-03-28 22:40:53 +0000200 case ARPHRD_IPGRE:
201 ip_ipgre_mc_map(addr, dev->broadcast, haddr);
202 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 default:
204 if (dir) {
205 memcpy(haddr, dev->broadcast, dev->addr_len);
206 return 0;
207 }
208 }
209 return -EINVAL;
210}
211
212
Eric Dumazetd6bf7812010-10-04 06:15:44 +0000213static u32 arp_hash(const void *pkey,
214 const struct net_device *dev,
David S. Miller2c2aba62011-12-28 15:06:58 -0500215 __u32 *hash_rnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
David S. Miller2c2aba62011-12-28 15:06:58 -0500217 return arp_hashfn(*(u32 *)pkey, dev, *hash_rnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218}
219
220static int arp_constructor(struct neighbour *neigh)
221{
Changli Gaodeffd772010-09-02 03:56:51 +0000222 __be32 addr = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 struct net_device *dev = neigh->dev;
224 struct in_device *in_dev;
225 struct neigh_parms *parms;
226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700228 in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (in_dev == NULL) {
230 rcu_read_unlock();
231 return -EINVAL;
232 }
233
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900234 neigh->type = inet_addr_type(dev_net(dev), addr);
Denis V. Luneva79878f2008-01-14 22:56:01 -0800235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 parms = in_dev->arp_parms;
237 __neigh_parms_put(neigh->parms);
238 neigh->parms = neigh_parms_clone(parms);
239 rcu_read_unlock();
240
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700241 if (!dev->header_ops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 neigh->nud_state = NUD_NOARP;
243 neigh->ops = &arp_direct_ops;
David S. Miller8f40b162011-07-17 13:34:11 -0700244 neigh->output = neigh_direct_output;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 } else {
246 /* Good devices (checked by reading texts, but only Ethernet is
247 tested)
248
249 ARPHRD_ETHER: (ethernet, apfddi)
250 ARPHRD_FDDI: (fddi)
251 ARPHRD_IEEE802: (tr)
252 ARPHRD_METRICOM: (strip)
253 ARPHRD_ARCNET:
254 etc. etc. etc.
255
256 ARPHRD_IPDDP will also work, if author repairs it.
257 I did not it, because this driver does not work even
258 in old paradigm.
259 */
260
261#if 1
262 /* So... these "amateur" devices are hopeless.
263 The only thing, that I can say now:
264 It is very sad that we need to keep ugly obsolete
265 code to make them happy.
266
267 They should be moved to more reasonable state, now
268 they use rebuild_header INSTEAD OF hard_start_xmit!!!
269 Besides that, they are sort of out of date
270 (a lot of redundant clones/copies, useless in 2.1),
271 I wonder why people believe that they work.
272 */
273 switch (dev->type) {
274 default:
275 break;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900276 case ARPHRD_ROSE:
Igor Maravic40e47832011-12-05 02:25:57 +0000277#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 case ARPHRD_AX25:
Igor Maravic40e47832011-12-05 02:25:57 +0000279#if IS_ENABLED(CONFIG_NETROM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 case ARPHRD_NETROM:
281#endif
282 neigh->ops = &arp_broken_ops;
283 neigh->output = neigh->ops->output;
284 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000285#else
286 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287#endif
Changli Gaodeffd772010-09-02 03:56:51 +0000288 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289#endif
290 if (neigh->type == RTN_MULTICAST) {
291 neigh->nud_state = NUD_NOARP;
292 arp_mc_map(addr, neigh->ha, dev, 1);
Changli Gaodeffd772010-09-02 03:56:51 +0000293 } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 neigh->nud_state = NUD_NOARP;
295 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
Changli Gaodeffd772010-09-02 03:56:51 +0000296 } else if (neigh->type == RTN_BROADCAST ||
297 (dev->flags & IFF_POINTOPOINT)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 neigh->nud_state = NUD_NOARP;
299 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
300 }
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700301
302 if (dev->header_ops->cache)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 neigh->ops = &arp_hh_ops;
304 else
305 neigh->ops = &arp_generic_ops;
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700306
Changli Gaodeffd772010-09-02 03:56:51 +0000307 if (neigh->nud_state & NUD_VALID)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 neigh->output = neigh->ops->connected_output;
309 else
310 neigh->output = neigh->ops->output;
311 }
312 return 0;
313}
314
315static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
316{
317 dst_link_failure(skb);
318 kfree_skb(skb);
319}
320
321static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
322{
Al Viroa61ced52006-09-26 21:27:54 -0700323 __be32 saddr = 0;
Cong Wangcf0be8802012-12-23 15:23:16 +0000324 u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 struct net_device *dev = neigh->dev;
Changli Gaodeffd772010-09-02 03:56:51 +0000326 __be32 target = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 int probes = atomic_read(&neigh->probes);
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000328 struct in_device *in_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000330 rcu_read_lock();
331 in_dev = __in_dev_get_rcu(dev);
332 if (!in_dev) {
333 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return;
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000335 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
337 default:
338 case 0: /* By default announce any local IP */
Changli Gaodeffd772010-09-02 03:56:51 +0000339 if (skb && inet_addr_type(dev_net(dev),
340 ip_hdr(skb)->saddr) == RTN_LOCAL)
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700341 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 break;
343 case 1: /* Restrict announcements of saddr in same subnet */
344 if (!skb)
345 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700346 saddr = ip_hdr(skb)->saddr;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900347 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 /* saddr should be known to target */
349 if (inet_addr_onlink(in_dev, target, saddr))
350 break;
351 }
352 saddr = 0;
353 break;
354 case 2: /* Avoid secondary IPs, get a primary/preferred one */
355 break;
356 }
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000357 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 if (!saddr)
360 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
361
Changli Gaodeffd772010-09-02 03:56:51 +0000362 probes -= neigh->parms->ucast_probes;
363 if (probes < 0) {
364 if (!(neigh->nud_state & NUD_VALID))
Joe Perches91df42b2012-05-15 14:11:54 +0000365 pr_debug("trying to ucast probe in NUD_INVALID\n");
Eric Dumazet96503882012-12-21 07:32:10 +0000366 neigh_ha_snapshot(dst_ha, neigh, dev);
Cong Wangcf0be8802012-12-23 15:23:16 +0000367 dst_hw = dst_ha;
Changli Gaodeffd772010-09-02 03:56:51 +0000368 } else {
369 probes -= neigh->parms->app_probes;
370 if (probes < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371#ifdef CONFIG_ARPD
Changli Gaodeffd772010-09-02 03:56:51 +0000372 neigh_app_ns(neigh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373#endif
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{
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 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 }
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800413 return !inet_confirm_addr(in_dev, sip, tip, scope);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414}
415
Al Viroed9bad02006-09-27 18:36:36 -0700416static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900419 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 /*unsigned long now; */
Pavel Emelyanovca12a1a2008-07-16 20:28:42 -0700421 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
David S. Miller78fbfd82011-03-12 00:00:52 -0500423 rt = ip_route_output(net, sip, tip, 0, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800424 if (IS_ERR(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 return 1;
Changli Gaod8d1f302010-06-10 23:31:35 -0700426 if (rt->dst.dev != dev) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700427 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900429 }
430 ip_rt_put(rt);
431 return flag;
432}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
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
Changli Gaodeffd772010-09-02 03:56:51 +0000445static int arp_set_predefined(int addr_hint, unsigned char *haddr,
446 __be32 paddr, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447{
448 switch (addr_hint) {
449 case RTN_LOCAL:
Joe Perches91df42b2012-05-15 14:11:54 +0000450 pr_debug("arp called for own IP address\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 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
464int arp_find(unsigned char *haddr, struct sk_buff *skb)
465{
466 struct net_device *dev = skb->dev;
Al Virofd683222006-09-26 22:17:51 -0700467 __be32 paddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 struct neighbour *n;
469
Eric Dumazetadf30902009-06-02 05:19:30 +0000470 if (!skb_dst(skb)) {
Joe Perches91df42b2012-05-15 14:11:54 +0000471 pr_debug("arp_find is called with dst==NULL\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 kfree_skb(skb);
473 return 1;
474 }
475
David S. Millerf8126f12012-07-13 05:03:45 -0700476 paddr = rt_nexthop(skb_rtable(skb), ip_hdr(skb)->daddr);
Changli Gaodeffd772010-09-02 03:56:51 +0000477 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr,
478 paddr, dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 return 0;
480
481 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
482
483 if (n) {
484 n->used = jiffies;
Eric Dumazet0ed8ddf2010-10-07 10:44:07 +0000485 if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) {
486 neigh_ha_snapshot(haddr, n, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 neigh_release(n);
488 return 0;
489 }
490 neigh_release(n);
491 } else
492 kfree_skb(skb);
493 return 1;
494}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000495EXPORT_SYMBOL(arp_find);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
497/* END OF OBSOLETE FUNCTIONS */
498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499/*
500 * Check if we can use proxy ARP for this path
501 */
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000502static inline int arp_fwd_proxy(struct in_device *in_dev,
503 struct net_device *dev, struct rtable *rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
505 struct in_device *out_dev;
506 int imi, omi = -1;
507
Changli Gaod8d1f302010-06-10 23:31:35 -0700508 if (rt->dst.dev == dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000509 return 0;
510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 if (!IN_DEV_PROXY_ARP(in_dev))
512 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000513 imi = IN_DEV_MEDIUM_ID(in_dev);
514 if (imi == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 return 1;
516 if (imi == -1)
517 return 0;
518
519 /* place to check for proxy_arp for routes */
520
Changli Gaod8d1f302010-06-10 23:31:35 -0700521 out_dev = __in_dev_get_rcu(rt->dst.dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000522 if (out_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 omi = IN_DEV_MEDIUM_ID(out_dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000524
Eric Dumazeta02cec22010-09-22 20:43:57 +0000525 return omi != imi && omi != -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526}
527
528/*
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000529 * 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 */
547static 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 */
Changli Gaod8d1f302010-06-10 23:31:35 -0700552 if (rt->dst.dev != dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000553 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
565/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 * 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 */
Al Viroed9bad02006-09-27 18:36:36 -0700573struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
574 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800575 const unsigned char *dest_hw,
576 const unsigned char *src_hw,
577 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578{
579 struct sk_buff *skb;
580 struct arphdr *arp;
581 unsigned char *arp_ptr;
Herbert Xu66088242011-11-18 02:20:04 +0000582 int hlen = LL_RESERVED_SPACE(dev);
583 int tlen = dev->needed_tailroom;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
585 /*
586 * Allocate a buffer
587 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900588
Herbert Xu66088242011-11-18 02:20:04 +0000589 skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 if (skb == NULL)
591 return NULL;
592
Herbert Xu66088242011-11-18 02:20:04 +0000593 skb_reserve(skb, hlen);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700594 skb_reset_network_header(skb);
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800595 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 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 */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700606 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 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
Igor Maravic40e47832011-12-05 02:25:57 +0000625#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 case ARPHRD_AX25:
627 arp->ar_hrd = htons(ARPHRD_AX25);
628 arp->ar_pro = htons(AX25_P_IP);
629 break;
630
Igor Maravic40e47832011-12-05 02:25:57 +0000631#if IS_ENABLED(CONFIG_NETROM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 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
Igor Maravic40e47832011-12-05 02:25:57 +0000639#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 case ARPHRD_FDDI:
641 arp->ar_hrd = htons(ARPHRD_ETHER);
642 arp->ar_pro = htons(ETH_P_IP);
643 break;
644#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 }
646
647 arp->ar_hln = dev->addr_len;
648 arp->ar_pln = 4;
649 arp->ar_op = htons(type);
650
Changli Gaodeffd772010-09-02 03:56:51 +0000651 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
653 memcpy(arp_ptr, src_hw, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800654 arp_ptr += dev->addr_len;
655 memcpy(arp_ptr, &src_ip, 4);
656 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000657
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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 memcpy(arp_ptr, &dest_ip, 4);
671
672 return skb;
673
674out:
675 kfree_skb(skb);
676 return NULL;
677}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000678EXPORT_SYMBOL(arp_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680/*
681 * Send an arp packet.
682 */
683void arp_xmit(struct sk_buff *skb)
684{
685 /* Send it off, maybe filter it using firewalling first. */
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700686 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000688EXPORT_SYMBOL(arp_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690/*
691 * Create and send an arp packet.
692 */
Al Viroed9bad02006-09-27 18:36:36 -0700693void arp_send(int type, int ptype, __be32 dest_ip,
694 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800695 const unsigned char *dest_hw, const unsigned char *src_hw,
696 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697{
698 struct sk_buff *skb;
699
700 /*
701 * No arp on this interface.
702 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900703
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 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);
Changli Gaodeffd772010-09-02 03:56:51 +0000709 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
712 arp_xmit(skb);
713}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000714EXPORT_SYMBOL(arp_send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716/*
717 * Process an arp request.
718 */
719
720static int arp_process(struct sk_buff *skb)
721{
722 struct net_device *dev = skb->dev;
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000723 struct in_device *in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 struct arphdr *arp;
725 unsigned char *arp_ptr;
726 struct rtable *rt;
Mark Rydene0260fe2007-12-19 23:38:11 -0800727 unsigned char *sha;
Al Viro9e12bb22006-09-26 21:25:20 -0700728 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 u16 dev_type = dev->type;
730 int addr_type;
731 struct neighbour *n;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900732 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
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
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300741 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900744 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 if (arp->ar_pro != htons(ETH_P_IP) ||
746 htons(dev_type) != arp->ar_hrd)
747 goto out;
748 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 case ARPHRD_ETHER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 case ARPHRD_FDDI:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 case ARPHRD_IEEE802:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 /*
Paul Gortmaker211ed862012-05-10 17:14:35 -0400753 * ETHERNET, and Fibre Channel (which are IEEE 802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 * 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 case ARPHRD_AX25:
767 if (arp->ar_pro != htons(AX25_P_IP) ||
768 arp->ar_hrd != htons(ARPHRD_AX25))
769 goto out;
770 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 case ARPHRD_NETROM:
772 if (arp->ar_pro != htons(AX25_P_IP) ||
773 arp->ar_hrd != htons(ARPHRD_NETROM))
774 goto out;
775 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 }
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 */
Changli Gaodeffd772010-09-02 03:56:51 +0000787 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 sha = arp_ptr;
789 arp_ptr += dev->addr_len;
790 memcpy(&sip, arp_ptr, 4);
791 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000792 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900801/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 * Check for bad requests for 127.x.x.x and requests for multicast
803 * addresses. If this is one such, delete it.
804 */
Thomas Grafd0daebc32012-06-12 00:44:01 +0000805 if (ipv4_is_multicast(tip) ||
806 (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 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
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900819 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900824 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 * 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,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900828 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 * cache.
830 */
831
Eric W. Biedermanf8a68e72009-06-30 16:27:17 +0000832 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
833 if (sip == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700835 inet_addr_type(net, tip) == RTN_LOCAL &&
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800836 !arp_ignore(in_dev, sip, tip))
Jonas Danielssonb4a98112007-11-20 17:38:16 -0800837 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
838 dev->dev_addr, sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 goto out;
840 }
841
842 if (arp->ar_op == htons(ARPOP_REQUEST) &&
David S. Millerc6cffba2012-07-26 11:14:38 +0000843 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
Eric Dumazet511c3f92009-06-02 05:14:27 +0000845 rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 addr_type = rt->rt_type;
847
848 if (addr_type == RTN_LOCAL) {
Changli Gaodeffd772010-09-02 03:56:51 +0000849 int dont_send;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
Changli Gaodeffd772010-09-02 03:56:51 +0000851 dont_send = arp_ignore(in_dev, sip, tip);
Ben Greear8164f1b2008-11-16 19:19:38 -0800852 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
Changli Gaoae9c4162010-12-01 20:07:31 +0000853 dont_send = arp_filter(sip, tip, dev);
Ben Greear8164f1b2008-11-16 19:19:38 -0800854 if (!dont_send) {
855 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
856 if (n) {
Changli Gaodeffd772010-09-02 03:56:51 +0000857 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
858 dev, tip, sha, dev->dev_addr,
859 sha);
Ben Greear8164f1b2008-11-16 19:19:38 -0800860 neigh_release(n);
861 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 }
863 goto out;
864 } else if (IN_DEV_FORWARD(in_dev)) {
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000865 if (addr_type == RTN_UNICAST &&
866 (arp_fwd_proxy(in_dev, dev, rt) ||
867 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) ||
Thomas Graf70620c42012-02-10 04:07:11 +0000868 (rt->dst.dev != dev &&
869 pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
871 if (n)
872 neigh_release(n);
873
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900874 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 skb->pkt_type == PACKET_HOST ||
876 in_dev->arp_parms->proxy_delay == 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000877 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
878 dev, tip, sha, dev->dev_addr,
879 sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 } else {
Changli Gaodeffd772010-09-02 03:56:51 +0000881 pneigh_enqueue(&arp_tbl,
882 in_dev->arp_parms, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 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
Neil Horman124d37e2012-03-15 05:25:58 +0000894 if (IN_DEV_ARP_ACCEPT(in_dev)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800895 /* 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 &&
Octavian Purdila6d955182010-01-18 12:58:44 +0000900 (arp->ar_op == htons(ARPOP_REPLY) ||
901 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700902 inet_addr_type(net, sip) == RTN_UNICAST)
Jean Delvare1b1ac752007-07-14 20:51:44 -0700903 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800904 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
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 */
915 override = time_after(jiffies, n->updated + n->parms->locktime);
916
917 /* Broadcast replies and request packets
918 do not assert neighbour reachability.
919 */
920 if (arp->ar_op != htons(ARPOP_REPLY) ||
921 skb->pkt_type != PACKET_HOST)
922 state = NUD_STALE;
Changli Gaodeffd772010-09-02 03:56:51 +0000923 neigh_update(n, sha, state,
924 override ? NEIGH_UPDATE_F_OVERRIDE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 neigh_release(n);
926 }
927
928out:
Neil Hormanead2ceb2009-03-11 09:49:55 +0000929 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 return 0;
931}
932
Herbert Xu444fc8f2005-10-03 14:18:10 -0700933static void parp_redo(struct sk_buff *skb)
934{
935 arp_process(skb);
936}
937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938
939/*
940 * Receive an arp request from the device layer.
941 */
942
Adrian Bunk6c97e722006-04-12 13:57:59 -0700943static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
944 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945{
Eric Dumazet044453b2013-02-08 18:48:21 +0000946 const struct arphdr *arp;
947
948 if (dev->flags & IFF_NOARP ||
949 skb->pkt_type == PACKET_OTHERHOST ||
950 skb->pkt_type == PACKET_LOOPBACK)
951 goto freeskb;
952
953 skb = skb_share_check(skb, GFP_ATOMIC);
954 if (!skb)
955 goto out_of_mem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956
957 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800958 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 goto freeskb;
960
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300961 arp = arp_hdr(skb);
Eric Dumazet044453b2013-02-08 18:48:21 +0000962 if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 goto freeskb;
964
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700965 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
966
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700967 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
969freeskb:
970 kfree_skb(skb);
971out_of_mem:
972 return 0;
973}
974
975/*
976 * User level interface (ioctl)
977 */
978
979/*
980 * Set (create) an ARP cache entry.
981 */
982
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800983static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on)
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800984{
985 if (dev == NULL) {
Pavel Emelyanov586f1212007-12-16 13:32:48 -0800986 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800987 return 0;
988 }
Eric Dumazetc5066532011-01-24 13:16:16 -0800989 if (__in_dev_get_rtnl(dev)) {
990 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800991 return 0;
992 }
993 return -ENXIO;
994}
995
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800996static int arp_req_set_public(struct net *net, struct arpreq *r,
997 struct net_device *dev)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800998{
999 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
1000 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1001
1002 if (mask && mask != htonl(0xFFFFFFFF))
1003 return -EINVAL;
1004 if (!dev && (r->arp_flags & ATF_COM)) {
Eric Dumazet941666c2010-12-05 01:23:53 +00001005 dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family,
Changli Gaodeffd772010-09-02 03:56:51 +00001006 r->arp_ha.sa_data);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001007 if (!dev)
1008 return -ENODEV;
1009 }
1010 if (mask) {
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001011 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001012 return -ENOBUFS;
1013 return 0;
1014 }
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001015
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001016 return arp_req_set_proxy(net, dev, 1);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001017}
1018
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001019static int arp_req_set(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001020 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021{
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001022 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 struct neighbour *neigh;
1024 int err;
1025
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001026 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001027 return arp_req_set_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001029 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 if (r->arp_flags & ATF_PERM)
1031 r->arp_flags |= ATF_COM;
1032 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001033 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001034
1035 if (IS_ERR(rt))
1036 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001037 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 ip_rt_put(rt);
1039 if (!dev)
1040 return -EINVAL;
1041 }
1042 switch (dev->type) {
Igor Maravic40e47832011-12-05 02:25:57 +00001043#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 case ARPHRD_FDDI:
1045 /*
1046 * According to RFC 1390, FDDI devices should accept ARP
1047 * hardware types of 1 (Ethernet). However, to be more
1048 * robust, we'll accept hardware types of either 1 (Ethernet)
1049 * or 6 (IEEE 802.2).
1050 */
1051 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1052 r->arp_ha.sa_family != ARPHRD_ETHER &&
1053 r->arp_ha.sa_family != ARPHRD_IEEE802)
1054 return -EINVAL;
1055 break;
1056#endif
1057 default:
1058 if (r->arp_ha.sa_family != dev->type)
1059 return -EINVAL;
1060 break;
1061 }
1062
1063 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1064 err = PTR_ERR(neigh);
1065 if (!IS_ERR(neigh)) {
Eric Dumazet95c96172012-04-15 05:58:06 +00001066 unsigned int state = NUD_STALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 if (r->arp_flags & ATF_PERM)
1068 state = NUD_PERMANENT;
Changli Gaodeffd772010-09-02 03:56:51 +00001069 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001070 r->arp_ha.sa_data : NULL, state,
Changli Gaodeffd772010-09-02 03:56:51 +00001071 NEIGH_UPDATE_F_OVERRIDE |
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 NEIGH_UPDATE_F_ADMIN);
1073 neigh_release(neigh);
1074 }
1075 return err;
1076}
1077
Eric Dumazet95c96172012-04-15 05:58:06 +00001078static unsigned int arp_state_to_flags(struct neighbour *neigh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080 if (neigh->nud_state&NUD_PERMANENT)
Changli Gaodeffd772010-09-02 03:56:51 +00001081 return ATF_PERM | ATF_COM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 else if (neigh->nud_state&NUD_VALID)
Changli Gaodeffd772010-09-02 03:56:51 +00001083 return ATF_COM;
1084 else
1085 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086}
1087
1088/*
1089 * Get an ARP cache entry.
1090 */
1091
1092static int arp_req_get(struct arpreq *r, struct net_device *dev)
1093{
Al Viroed9bad02006-09-27 18:36:36 -07001094 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 struct neighbour *neigh;
1096 int err = -ENXIO;
1097
1098 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1099 if (neigh) {
1100 read_lock_bh(&neigh->lock);
1101 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1102 r->arp_flags = arp_state_to_flags(neigh);
1103 read_unlock_bh(&neigh->lock);
1104 r->arp_ha.sa_family = dev->type;
1105 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1106 neigh_release(neigh);
1107 err = 0;
1108 }
1109 return err;
1110}
1111
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001112int arp_invalidate(struct net_device *dev, __be32 ip)
1113{
1114 struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
1115 int err = -ENXIO;
1116
1117 if (neigh) {
1118 if (neigh->nud_state & ~NUD_NOARP)
1119 err = neigh_update(neigh, NULL, NUD_FAILED,
1120 NEIGH_UPDATE_F_OVERRIDE|
1121 NEIGH_UPDATE_F_ADMIN);
1122 neigh_release(neigh);
1123 }
1124
1125 return err;
1126}
1127EXPORT_SYMBOL(arp_invalidate);
1128
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001129static int arp_req_delete_public(struct net *net, struct arpreq *r,
1130 struct net_device *dev)
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001131{
1132 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1133 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1134
1135 if (mask == htonl(0xFFFFFFFF))
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001136 return pneigh_delete(&arp_tbl, net, &ip, dev);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001137
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001138 if (mask)
1139 return -EINVAL;
1140
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001141 return arp_req_set_proxy(net, dev, 0);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001142}
1143
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001144static int arp_req_delete(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001145 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146{
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001147 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001149 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001150 return arp_req_delete_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001152 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001154 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001155 if (IS_ERR(rt))
1156 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001157 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 ip_rt_put(rt);
1159 if (!dev)
1160 return -EINVAL;
1161 }
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001162 return arp_invalidate(dev, ip);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163}
1164
1165/*
1166 * Handle an ARP layer I/O control request.
1167 */
1168
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001169int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170{
1171 int err;
1172 struct arpreq r;
1173 struct net_device *dev = NULL;
1174
1175 switch (cmd) {
Changli Gaodeffd772010-09-02 03:56:51 +00001176 case SIOCDARP:
1177 case SIOCSARP:
Eric W. Biederman52e804c2012-11-16 03:03:05 +00001178 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
Changli Gaodeffd772010-09-02 03:56:51 +00001179 return -EPERM;
1180 case SIOCGARP:
1181 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1182 if (err)
1183 return -EFAULT;
1184 break;
1185 default:
1186 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 }
1188
1189 if (r.arp_pa.sa_family != AF_INET)
1190 return -EPFNOSUPPORT;
1191
1192 if (!(r.arp_flags & ATF_PUBL) &&
Changli Gaodeffd772010-09-02 03:56:51 +00001193 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 return -EINVAL;
1195 if (!(r.arp_flags & ATF_NETMASK))
1196 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1197 htonl(0xFFFFFFFFUL);
Eric Dumazetc5066532011-01-24 13:16:16 -08001198 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 if (r.arp_dev[0]) {
1200 err = -ENODEV;
Eric Dumazetc5066532011-01-24 13:16:16 -08001201 dev = __dev_get_by_name(net, r.arp_dev);
Changli Gaodeffd772010-09-02 03:56:51 +00001202 if (dev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 goto out;
1204
1205 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1206 if (!r.arp_ha.sa_family)
1207 r.arp_ha.sa_family = dev->type;
1208 err = -EINVAL;
1209 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1210 goto out;
1211 } else if (cmd == SIOCGARP) {
1212 err = -ENODEV;
1213 goto out;
1214 }
1215
Stephen Hemminger132adf52007-03-08 20:44:43 -08001216 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 case SIOCDARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001218 err = arp_req_delete(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 break;
1220 case SIOCSARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001221 err = arp_req_set(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 break;
1223 case SIOCGARP:
1224 err = arp_req_get(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 break;
1226 }
1227out:
Eric Dumazetc5066532011-01-24 13:16:16 -08001228 rtnl_unlock();
Eric Dumazet941666c2010-12-05 01:23:53 +00001229 if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r)))
1230 err = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 return err;
1232}
1233
Changli Gaodeffd772010-09-02 03:56:51 +00001234static int arp_netdev_event(struct notifier_block *this, unsigned long event,
1235 void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236{
1237 struct net_device *dev = ptr;
1238
1239 switch (event) {
1240 case NETDEV_CHANGEADDR:
1241 neigh_changeaddr(&arp_tbl, dev);
Nicolas Dichtelbafa6d92012-09-07 00:45:29 +00001242 rt_cache_flush(dev_net(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243 break;
1244 default:
1245 break;
1246 }
1247
1248 return NOTIFY_DONE;
1249}
1250
1251static struct notifier_block arp_netdev_notifier = {
1252 .notifier_call = arp_netdev_event,
1253};
1254
1255/* Note, that it is not on notifier chain.
1256 It is necessary, that this routine was called after route cache will be
1257 flushed.
1258 */
1259void arp_ifdown(struct net_device *dev)
1260{
1261 neigh_ifdown(&arp_tbl, dev);
1262}
1263
1264
1265/*
1266 * Called once on startup.
1267 */
1268
Stephen Hemminger7546dd92009-03-09 08:18:29 +00001269static struct packet_type arp_packet_type __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -08001270 .type = cpu_to_be16(ETH_P_ARP),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271 .func = arp_rcv,
1272};
1273
1274static int arp_proc_init(void);
1275
1276void __init arp_init(void)
1277{
1278 neigh_table_init(&arp_tbl);
1279
1280 dev_add_pack(&arp_packet_type);
1281 arp_proc_init();
1282#ifdef CONFIG_SYSCTL
Eric W. Biederman54716e32010-02-14 03:27:03 +00001283 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284#endif
1285 register_netdevice_notifier(&arp_netdev_notifier);
1286}
1287
1288#ifdef CONFIG_PROC_FS
Igor Maravic40e47832011-12-05 02:25:57 +00001289#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290
1291/* ------------------------------------------------------------------------ */
1292/*
1293 * ax25 -> ASCII conversion
1294 */
1295static char *ax2asc2(ax25_address *a, char *buf)
1296{
1297 char c, *s;
1298 int n;
1299
1300 for (n = 0, s = buf; n < 6; n++) {
1301 c = (a->ax25_call[n] >> 1) & 0x7F;
1302
Changli Gaodeffd772010-09-02 03:56:51 +00001303 if (c != ' ')
1304 *s++ = c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001306
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 *s++ = '-';
Changli Gaodeffd772010-09-02 03:56:51 +00001308 n = (a->ax25_call[6] >> 1) & 0x0F;
1309 if (n > 9) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310 *s++ = '1';
1311 n -= 10;
1312 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001313
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 *s++ = n + '0';
1315 *s++ = '\0';
1316
1317 if (*buf == '\0' || *buf == '-')
Changli Gaodeffd772010-09-02 03:56:51 +00001318 return "*";
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319
1320 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321}
1322#endif /* CONFIG_AX25 */
1323
1324#define HBUFFERLEN 30
1325
1326static void arp_format_neigh_entry(struct seq_file *seq,
1327 struct neighbour *n)
1328{
1329 char hbuffer[HBUFFERLEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 int k, j;
1331 char tbuf[16];
1332 struct net_device *dev = n->dev;
1333 int hatype = dev->type;
1334
1335 read_lock(&n->lock);
1336 /* Convert hardware address to XX:XX:XX:XX ... form. */
Igor Maravic40e47832011-12-05 02:25:57 +00001337#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1339 ax2asc2((ax25_address *)n->ha, hbuffer);
1340 else {
1341#endif
1342 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
Denis Cheng51f82a22008-05-21 17:34:32 -07001343 hbuffer[k++] = hex_asc_hi(n->ha[j]);
1344 hbuffer[k++] = hex_asc_lo(n->ha[j]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 hbuffer[k++] = ':';
1346 }
roel kluina3e8ee62009-07-29 23:46:59 +00001347 if (k != 0)
1348 --k;
1349 hbuffer[k] = 0;
Igor Maravic40e47832011-12-05 02:25:57 +00001350#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351 }
1352#endif
Harvey Harrison673d57e2008-10-31 00:53:57 -07001353 sprintf(tbuf, "%pI4", n->primary_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1355 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1356 read_unlock(&n->lock);
1357}
1358
1359static void arp_format_pneigh_entry(struct seq_file *seq,
1360 struct pneigh_entry *n)
1361{
1362 struct net_device *dev = n->dev;
1363 int hatype = dev ? dev->type : 0;
1364 char tbuf[16];
1365
Harvey Harrison673d57e2008-10-31 00:53:57 -07001366 sprintf(tbuf, "%pI4", n->key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1368 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1369 dev ? dev->name : "*");
1370}
1371
1372static int arp_seq_show(struct seq_file *seq, void *v)
1373{
1374 if (v == SEQ_START_TOKEN) {
1375 seq_puts(seq, "IP address HW type Flags "
1376 "HW address Mask Device\n");
1377 } else {
1378 struct neigh_seq_state *state = seq->private;
1379
1380 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1381 arp_format_pneigh_entry(seq, v);
1382 else
1383 arp_format_neigh_entry(seq, v);
1384 }
1385
1386 return 0;
1387}
1388
1389static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1390{
1391 /* Don't want to confuse "arp -a" w/ magic entries,
1392 * so we tell the generic iterator to skip NUD_NOARP.
1393 */
1394 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1395}
1396
1397/* ------------------------------------------------------------------------ */
1398
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001399static const struct seq_operations arp_seq_ops = {
Changli Gaodeffd772010-09-02 03:56:51 +00001400 .start = arp_seq_start,
1401 .next = neigh_seq_next,
1402 .stop = neigh_seq_stop,
1403 .show = arp_seq_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404};
1405
1406static int arp_seq_open(struct inode *inode, struct file *file)
1407{
Eric W. Biederman426b5302008-01-24 00:13:18 -08001408 return seq_open_net(inode, file, &arp_seq_ops,
1409 sizeof(struct neigh_seq_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410}
1411
Arjan van de Ven9a321442007-02-12 00:55:35 -08001412static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 .owner = THIS_MODULE,
1414 .open = arp_seq_open,
1415 .read = seq_read,
1416 .llseek = seq_lseek,
Eric W. Biederman426b5302008-01-24 00:13:18 -08001417 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418};
1419
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001420
1421static int __net_init arp_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422{
Gao fengd4beaa62013-02-18 01:34:54 +00001423 if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 return -ENOMEM;
1425 return 0;
1426}
1427
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001428static void __net_exit arp_net_exit(struct net *net)
1429{
Gao fengece31ff2013-02-18 01:34:56 +00001430 remove_proc_entry("arp", net->proc_net);
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001431}
1432
1433static struct pernet_operations arp_net_ops = {
1434 .init = arp_net_init,
1435 .exit = arp_net_exit,
1436};
1437
1438static int __init arp_proc_init(void)
1439{
1440 return register_pernet_subsys(&arp_net_ops);
1441}
1442
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443#else /* CONFIG_PROC_FS */
1444
1445static int __init arp_proc_init(void)
1446{
1447 return 0;
1448}
1449
1450#endif /* CONFIG_PROC_FS */