blob: 47800459e4cb341c395f54f2d161c300a112c1cf [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,
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 u8 *dst_ha = NULL;
325 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");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 dst_ha = neigh->ha;
David S. Miller9ff56602008-02-17 18:39:54 -0800367 read_lock_bh(&neigh->lock);
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,
379 dst_ha, dev->dev_addr, NULL);
David S. Miller9ff56602008-02-17 18:39:54 -0800380 if (dst_ha)
381 read_unlock_bh(&neigh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382}
383
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800384static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
386 int scope;
387
388 switch (IN_DEV_ARP_IGNORE(in_dev)) {
389 case 0: /* Reply, the tip is already validated */
390 return 0;
391 case 1: /* Reply only if tip is configured on the incoming interface */
392 sip = 0;
393 scope = RT_SCOPE_HOST;
394 break;
395 case 2: /*
396 * Reply only if tip is configured on the incoming interface
397 * and is in same subnet as sip
398 */
399 scope = RT_SCOPE_HOST;
400 break;
401 case 3: /* Do not reply for scope host addresses */
402 sip = 0;
403 scope = RT_SCOPE_LINK;
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 }
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800415 return !inet_confirm_addr(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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 if (target_hw != NULL)
660 memcpy(arp_ptr, target_hw, dev->addr_len);
661 else
662 memset(arp_ptr, 0, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800663 arp_ptr += dev->addr_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 memcpy(arp_ptr, &dest_ip, 4);
665
666 return skb;
667
668out:
669 kfree_skb(skb);
670 return NULL;
671}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000672EXPORT_SYMBOL(arp_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
674/*
675 * Send an arp packet.
676 */
677void arp_xmit(struct sk_buff *skb)
678{
679 /* Send it off, maybe filter it using firewalling first. */
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700680 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000682EXPORT_SYMBOL(arp_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684/*
685 * Create and send an arp packet.
686 */
Al Viroed9bad02006-09-27 18:36:36 -0700687void arp_send(int type, int ptype, __be32 dest_ip,
688 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800689 const unsigned char *dest_hw, const unsigned char *src_hw,
690 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691{
692 struct sk_buff *skb;
693
694 /*
695 * No arp on this interface.
696 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900697
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 if (dev->flags&IFF_NOARP)
699 return;
700
701 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
702 dest_hw, src_hw, target_hw);
Changli Gaodeffd772010-09-02 03:56:51 +0000703 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
706 arp_xmit(skb);
707}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000708EXPORT_SYMBOL(arp_send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710/*
711 * Process an arp request.
712 */
713
714static int arp_process(struct sk_buff *skb)
715{
716 struct net_device *dev = skb->dev;
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000717 struct in_device *in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 struct arphdr *arp;
719 unsigned char *arp_ptr;
720 struct rtable *rt;
Mark Rydene0260fe2007-12-19 23:38:11 -0800721 unsigned char *sha;
Al Viro9e12bb22006-09-26 21:25:20 -0700722 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 u16 dev_type = dev->type;
724 int addr_type;
725 struct neighbour *n;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900726 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
728 /* arp_rcv below verifies the ARP header and verifies the device
729 * is ARP'able.
730 */
731
732 if (in_dev == NULL)
733 goto out;
734
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300735 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900738 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 if (arp->ar_pro != htons(ETH_P_IP) ||
740 htons(dev_type) != arp->ar_hrd)
741 goto out;
742 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 case ARPHRD_ETHER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 case ARPHRD_FDDI:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 case ARPHRD_IEEE802:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 /*
Paul Gortmaker211ed862012-05-10 17:14:35 -0400747 * ETHERNET, and Fibre Channel (which are IEEE 802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 * devices, according to RFC 2625) devices will accept ARP
749 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
750 * This is the case also of FDDI, where the RFC 1390 says that
751 * FDDI devices should accept ARP hardware of (1) Ethernet,
752 * however, to be more robust, we'll accept both 1 (Ethernet)
753 * or 6 (IEEE 802.2)
754 */
755 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
756 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
757 arp->ar_pro != htons(ETH_P_IP))
758 goto out;
759 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 case ARPHRD_AX25:
761 if (arp->ar_pro != htons(AX25_P_IP) ||
762 arp->ar_hrd != htons(ARPHRD_AX25))
763 goto out;
764 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 case ARPHRD_NETROM:
766 if (arp->ar_pro != htons(AX25_P_IP) ||
767 arp->ar_hrd != htons(ARPHRD_NETROM))
768 goto out;
769 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 }
771
772 /* Understand only these message types */
773
774 if (arp->ar_op != htons(ARPOP_REPLY) &&
775 arp->ar_op != htons(ARPOP_REQUEST))
776 goto out;
777
778/*
779 * Extract fields
780 */
Changli Gaodeffd772010-09-02 03:56:51 +0000781 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 sha = arp_ptr;
783 arp_ptr += dev->addr_len;
784 memcpy(&sip, arp_ptr, 4);
785 arp_ptr += 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 arp_ptr += dev->addr_len;
787 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900788/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 * Check for bad requests for 127.x.x.x and requests for multicast
790 * addresses. If this is one such, delete it.
791 */
Thomas Grafd0daebc32012-06-12 00:44:01 +0000792 if (ipv4_is_multicast(tip) ||
793 (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 goto out;
795
796/*
797 * Special case: We must set Frame Relay source Q.922 address
798 */
799 if (dev_type == ARPHRD_DLCI)
800 sha = dev->broadcast;
801
802/*
803 * Process entry. The idea here is we want to send a reply if it is a
804 * request for us or if it is a request for someone else that we hold
805 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900806 * to us or if it is a request for our address.
807 * (The assumption for this last is that if someone is requesting our
808 * address, they are probably intending to talk to us, so it saves time
809 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900811 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 * Putting this another way, we only care about replies if they are to
813 * us, in which case we add them to the cache. For requests, we care
814 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900815 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 * cache.
817 */
818
Eric W. Biedermanf8a68e72009-06-30 16:27:17 +0000819 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
820 if (sip == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700822 inet_addr_type(net, tip) == RTN_LOCAL &&
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800823 !arp_ignore(in_dev, sip, tip))
Jonas Danielssonb4a98112007-11-20 17:38:16 -0800824 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
825 dev->dev_addr, sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 goto out;
827 }
828
829 if (arp->ar_op == htons(ARPOP_REQUEST) &&
David S. Millerc6cffba2012-07-26 11:14:38 +0000830 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
Eric Dumazet511c3f92009-06-02 05:14:27 +0000832 rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 addr_type = rt->rt_type;
834
835 if (addr_type == RTN_LOCAL) {
Changli Gaodeffd772010-09-02 03:56:51 +0000836 int dont_send;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837
Changli Gaodeffd772010-09-02 03:56:51 +0000838 dont_send = arp_ignore(in_dev, sip, tip);
Ben Greear8164f1b2008-11-16 19:19:38 -0800839 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
Changli Gaoae9c4162010-12-01 20:07:31 +0000840 dont_send = arp_filter(sip, tip, dev);
Ben Greear8164f1b2008-11-16 19:19:38 -0800841 if (!dont_send) {
842 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
843 if (n) {
Changli Gaodeffd772010-09-02 03:56:51 +0000844 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
845 dev, tip, sha, dev->dev_addr,
846 sha);
Ben Greear8164f1b2008-11-16 19:19:38 -0800847 neigh_release(n);
848 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 }
850 goto out;
851 } else if (IN_DEV_FORWARD(in_dev)) {
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000852 if (addr_type == RTN_UNICAST &&
853 (arp_fwd_proxy(in_dev, dev, rt) ||
854 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) ||
Thomas Graf70620c42012-02-10 04:07:11 +0000855 (rt->dst.dev != dev &&
856 pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
858 if (n)
859 neigh_release(n);
860
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900861 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 skb->pkt_type == PACKET_HOST ||
863 in_dev->arp_parms->proxy_delay == 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000864 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
865 dev, tip, sha, dev->dev_addr,
866 sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 } else {
Changli Gaodeffd772010-09-02 03:56:51 +0000868 pneigh_enqueue(&arp_tbl,
869 in_dev->arp_parms, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 return 0;
871 }
872 goto out;
873 }
874 }
875 }
876
877 /* Update our ARP tables */
878
879 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
880
Neil Horman124d37e2012-03-15 05:25:58 +0000881 if (IN_DEV_ARP_ACCEPT(in_dev)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800882 /* Unsolicited ARP is not accepted by default.
883 It is possible, that this option should be enabled for some
884 devices (strip is candidate)
885 */
886 if (n == NULL &&
Octavian Purdila6d955182010-01-18 12:58:44 +0000887 (arp->ar_op == htons(ARPOP_REPLY) ||
888 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700889 inet_addr_type(net, sip) == RTN_UNICAST)
Jean Delvare1b1ac752007-07-14 20:51:44 -0700890 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 if (n) {
894 int state = NUD_REACHABLE;
895 int override;
896
897 /* If several different ARP replies follows back-to-back,
898 use the FIRST one. It is possible, if several proxy
899 agents are active. Taking the first reply prevents
900 arp trashing and chooses the fastest router.
901 */
902 override = time_after(jiffies, n->updated + n->parms->locktime);
903
904 /* Broadcast replies and request packets
905 do not assert neighbour reachability.
906 */
907 if (arp->ar_op != htons(ARPOP_REPLY) ||
908 skb->pkt_type != PACKET_HOST)
909 state = NUD_STALE;
Changli Gaodeffd772010-09-02 03:56:51 +0000910 neigh_update(n, sha, state,
911 override ? NEIGH_UPDATE_F_OVERRIDE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 neigh_release(n);
913 }
914
915out:
Neil Hormanead2ceb2009-03-11 09:49:55 +0000916 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 return 0;
918}
919
Herbert Xu444fc8f2005-10-03 14:18:10 -0700920static void parp_redo(struct sk_buff *skb)
921{
922 arp_process(skb);
923}
924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925
926/*
927 * Receive an arp request from the device layer.
928 */
929
Adrian Bunk6c97e722006-04-12 13:57:59 -0700930static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
931 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932{
933 struct arphdr *arp;
934
935 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800936 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 goto freeskb;
938
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300939 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 if (arp->ar_hln != dev->addr_len ||
941 dev->flags & IFF_NOARP ||
942 skb->pkt_type == PACKET_OTHERHOST ||
943 skb->pkt_type == PACKET_LOOPBACK ||
944 arp->ar_pln != 4)
945 goto freeskb;
946
Changli Gaodeffd772010-09-02 03:56:51 +0000947 skb = skb_share_check(skb, GFP_ATOMIC);
948 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 goto out_of_mem;
950
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700951 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
952
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700953 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
955freeskb:
956 kfree_skb(skb);
957out_of_mem:
958 return 0;
959}
960
961/*
962 * User level interface (ioctl)
963 */
964
965/*
966 * Set (create) an ARP cache entry.
967 */
968
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800969static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on)
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800970{
971 if (dev == NULL) {
Pavel Emelyanov586f1212007-12-16 13:32:48 -0800972 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800973 return 0;
974 }
Eric Dumazetc5066532011-01-24 13:16:16 -0800975 if (__in_dev_get_rtnl(dev)) {
976 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800977 return 0;
978 }
979 return -ENXIO;
980}
981
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800982static int arp_req_set_public(struct net *net, struct arpreq *r,
983 struct net_device *dev)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800984{
985 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
986 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
987
988 if (mask && mask != htonl(0xFFFFFFFF))
989 return -EINVAL;
990 if (!dev && (r->arp_flags & ATF_COM)) {
Eric Dumazet941666c2010-12-05 01:23:53 +0000991 dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family,
Changli Gaodeffd772010-09-02 03:56:51 +0000992 r->arp_ha.sa_data);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800993 if (!dev)
994 return -ENODEV;
995 }
996 if (mask) {
Denis V. Lunev2db82b52008-01-14 22:58:55 -0800997 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800998 return -ENOBUFS;
999 return 0;
1000 }
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001001
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001002 return arp_req_set_proxy(net, dev, 1);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001003}
1004
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001005static int arp_req_set(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001006 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007{
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001008 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 struct neighbour *neigh;
1010 int err;
1011
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001012 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001013 return arp_req_set_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
Pavel Emelyanov43dc1702007-12-05 21:19:44 -08001015 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 if (r->arp_flags & ATF_PERM)
1017 r->arp_flags |= ATF_COM;
1018 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001019 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001020
1021 if (IS_ERR(rt))
1022 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001023 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 ip_rt_put(rt);
1025 if (!dev)
1026 return -EINVAL;
1027 }
1028 switch (dev->type) {
Igor Maravic40e47832011-12-05 02:25:57 +00001029#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 case ARPHRD_FDDI:
1031 /*
1032 * According to RFC 1390, FDDI devices should accept ARP
1033 * hardware types of 1 (Ethernet). However, to be more
1034 * robust, we'll accept hardware types of either 1 (Ethernet)
1035 * or 6 (IEEE 802.2).
1036 */
1037 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1038 r->arp_ha.sa_family != ARPHRD_ETHER &&
1039 r->arp_ha.sa_family != ARPHRD_IEEE802)
1040 return -EINVAL;
1041 break;
1042#endif
1043 default:
1044 if (r->arp_ha.sa_family != dev->type)
1045 return -EINVAL;
1046 break;
1047 }
1048
1049 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1050 err = PTR_ERR(neigh);
1051 if (!IS_ERR(neigh)) {
Eric Dumazet95c96172012-04-15 05:58:06 +00001052 unsigned int state = NUD_STALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 if (r->arp_flags & ATF_PERM)
1054 state = NUD_PERMANENT;
Changli Gaodeffd772010-09-02 03:56:51 +00001055 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001056 r->arp_ha.sa_data : NULL, state,
Changli Gaodeffd772010-09-02 03:56:51 +00001057 NEIGH_UPDATE_F_OVERRIDE |
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 NEIGH_UPDATE_F_ADMIN);
1059 neigh_release(neigh);
1060 }
1061 return err;
1062}
1063
Eric Dumazet95c96172012-04-15 05:58:06 +00001064static unsigned int arp_state_to_flags(struct neighbour *neigh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 if (neigh->nud_state&NUD_PERMANENT)
Changli Gaodeffd772010-09-02 03:56:51 +00001067 return ATF_PERM | ATF_COM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 else if (neigh->nud_state&NUD_VALID)
Changli Gaodeffd772010-09-02 03:56:51 +00001069 return ATF_COM;
1070 else
1071 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072}
1073
1074/*
1075 * Get an ARP cache entry.
1076 */
1077
1078static int arp_req_get(struct arpreq *r, struct net_device *dev)
1079{
Al Viroed9bad02006-09-27 18:36:36 -07001080 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 struct neighbour *neigh;
1082 int err = -ENXIO;
1083
1084 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1085 if (neigh) {
1086 read_lock_bh(&neigh->lock);
1087 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1088 r->arp_flags = arp_state_to_flags(neigh);
1089 read_unlock_bh(&neigh->lock);
1090 r->arp_ha.sa_family = dev->type;
1091 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1092 neigh_release(neigh);
1093 err = 0;
1094 }
1095 return err;
1096}
1097
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001098int arp_invalidate(struct net_device *dev, __be32 ip)
1099{
1100 struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
1101 int err = -ENXIO;
1102
1103 if (neigh) {
1104 if (neigh->nud_state & ~NUD_NOARP)
1105 err = neigh_update(neigh, NULL, NUD_FAILED,
1106 NEIGH_UPDATE_F_OVERRIDE|
1107 NEIGH_UPDATE_F_ADMIN);
1108 neigh_release(neigh);
1109 }
1110
1111 return err;
1112}
1113EXPORT_SYMBOL(arp_invalidate);
1114
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001115static int arp_req_delete_public(struct net *net, struct arpreq *r,
1116 struct net_device *dev)
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001117{
1118 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1119 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1120
1121 if (mask == htonl(0xFFFFFFFF))
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001122 return pneigh_delete(&arp_tbl, net, &ip, dev);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001123
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001124 if (mask)
1125 return -EINVAL;
1126
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001127 return arp_req_set_proxy(net, dev, 0);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001128}
1129
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001130static int arp_req_delete(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001131 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132{
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001133 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001135 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001136 return arp_req_delete_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001138 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 if (dev == NULL) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001140 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001141 if (IS_ERR(rt))
1142 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001143 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 ip_rt_put(rt);
1145 if (!dev)
1146 return -EINVAL;
1147 }
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001148 return arp_invalidate(dev, ip);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149}
1150
1151/*
1152 * Handle an ARP layer I/O control request.
1153 */
1154
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001155int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156{
1157 int err;
1158 struct arpreq r;
1159 struct net_device *dev = NULL;
1160
1161 switch (cmd) {
Changli Gaodeffd772010-09-02 03:56:51 +00001162 case SIOCDARP:
1163 case SIOCSARP:
1164 if (!capable(CAP_NET_ADMIN))
1165 return -EPERM;
1166 case SIOCGARP:
1167 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1168 if (err)
1169 return -EFAULT;
1170 break;
1171 default:
1172 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 }
1174
1175 if (r.arp_pa.sa_family != AF_INET)
1176 return -EPFNOSUPPORT;
1177
1178 if (!(r.arp_flags & ATF_PUBL) &&
Changli Gaodeffd772010-09-02 03:56:51 +00001179 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 return -EINVAL;
1181 if (!(r.arp_flags & ATF_NETMASK))
1182 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1183 htonl(0xFFFFFFFFUL);
Eric Dumazetc5066532011-01-24 13:16:16 -08001184 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 if (r.arp_dev[0]) {
1186 err = -ENODEV;
Eric Dumazetc5066532011-01-24 13:16:16 -08001187 dev = __dev_get_by_name(net, r.arp_dev);
Changli Gaodeffd772010-09-02 03:56:51 +00001188 if (dev == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 goto out;
1190
1191 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1192 if (!r.arp_ha.sa_family)
1193 r.arp_ha.sa_family = dev->type;
1194 err = -EINVAL;
1195 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1196 goto out;
1197 } else if (cmd == SIOCGARP) {
1198 err = -ENODEV;
1199 goto out;
1200 }
1201
Stephen Hemminger132adf52007-03-08 20:44:43 -08001202 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 case SIOCDARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001204 err = arp_req_delete(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 break;
1206 case SIOCSARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001207 err = arp_req_set(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 break;
1209 case SIOCGARP:
1210 err = arp_req_get(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211 break;
1212 }
1213out:
Eric Dumazetc5066532011-01-24 13:16:16 -08001214 rtnl_unlock();
Eric Dumazet941666c2010-12-05 01:23:53 +00001215 if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r)))
1216 err = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 return err;
1218}
1219
Changli Gaodeffd772010-09-02 03:56:51 +00001220static int arp_netdev_event(struct notifier_block *this, unsigned long event,
1221 void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222{
1223 struct net_device *dev = ptr;
1224
1225 switch (event) {
1226 case NETDEV_CHANGEADDR:
1227 neigh_changeaddr(&arp_tbl, dev);
Nicolas Dichtelbafa6d92012-09-07 00:45:29 +00001228 rt_cache_flush(dev_net(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 break;
1230 default:
1231 break;
1232 }
1233
1234 return NOTIFY_DONE;
1235}
1236
1237static struct notifier_block arp_netdev_notifier = {
1238 .notifier_call = arp_netdev_event,
1239};
1240
1241/* Note, that it is not on notifier chain.
1242 It is necessary, that this routine was called after route cache will be
1243 flushed.
1244 */
1245void arp_ifdown(struct net_device *dev)
1246{
1247 neigh_ifdown(&arp_tbl, dev);
1248}
1249
1250
1251/*
1252 * Called once on startup.
1253 */
1254
Stephen Hemminger7546dd92009-03-09 08:18:29 +00001255static struct packet_type arp_packet_type __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -08001256 .type = cpu_to_be16(ETH_P_ARP),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 .func = arp_rcv,
1258};
1259
1260static int arp_proc_init(void);
1261
1262void __init arp_init(void)
1263{
1264 neigh_table_init(&arp_tbl);
1265
1266 dev_add_pack(&arp_packet_type);
1267 arp_proc_init();
1268#ifdef CONFIG_SYSCTL
Eric W. Biederman54716e32010-02-14 03:27:03 +00001269 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270#endif
1271 register_netdevice_notifier(&arp_netdev_notifier);
1272}
1273
1274#ifdef CONFIG_PROC_FS
Igor Maravic40e47832011-12-05 02:25:57 +00001275#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276
1277/* ------------------------------------------------------------------------ */
1278/*
1279 * ax25 -> ASCII conversion
1280 */
1281static char *ax2asc2(ax25_address *a, char *buf)
1282{
1283 char c, *s;
1284 int n;
1285
1286 for (n = 0, s = buf; n < 6; n++) {
1287 c = (a->ax25_call[n] >> 1) & 0x7F;
1288
Changli Gaodeffd772010-09-02 03:56:51 +00001289 if (c != ' ')
1290 *s++ = c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001292
Linus Torvalds1da177e2005-04-16 15:20:36 -07001293 *s++ = '-';
Changli Gaodeffd772010-09-02 03:56:51 +00001294 n = (a->ax25_call[6] >> 1) & 0x0F;
1295 if (n > 9) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 *s++ = '1';
1297 n -= 10;
1298 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001299
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 *s++ = n + '0';
1301 *s++ = '\0';
1302
1303 if (*buf == '\0' || *buf == '-')
Changli Gaodeffd772010-09-02 03:56:51 +00001304 return "*";
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305
1306 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307}
1308#endif /* CONFIG_AX25 */
1309
1310#define HBUFFERLEN 30
1311
1312static void arp_format_neigh_entry(struct seq_file *seq,
1313 struct neighbour *n)
1314{
1315 char hbuffer[HBUFFERLEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316 int k, j;
1317 char tbuf[16];
1318 struct net_device *dev = n->dev;
1319 int hatype = dev->type;
1320
1321 read_lock(&n->lock);
1322 /* Convert hardware address to XX:XX:XX:XX ... form. */
Igor Maravic40e47832011-12-05 02:25:57 +00001323#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1325 ax2asc2((ax25_address *)n->ha, hbuffer);
1326 else {
1327#endif
1328 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
Denis Cheng51f82a22008-05-21 17:34:32 -07001329 hbuffer[k++] = hex_asc_hi(n->ha[j]);
1330 hbuffer[k++] = hex_asc_lo(n->ha[j]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 hbuffer[k++] = ':';
1332 }
roel kluina3e8ee62009-07-29 23:46:59 +00001333 if (k != 0)
1334 --k;
1335 hbuffer[k] = 0;
Igor Maravic40e47832011-12-05 02:25:57 +00001336#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 }
1338#endif
Harvey Harrison673d57e2008-10-31 00:53:57 -07001339 sprintf(tbuf, "%pI4", n->primary_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1341 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1342 read_unlock(&n->lock);
1343}
1344
1345static void arp_format_pneigh_entry(struct seq_file *seq,
1346 struct pneigh_entry *n)
1347{
1348 struct net_device *dev = n->dev;
1349 int hatype = dev ? dev->type : 0;
1350 char tbuf[16];
1351
Harvey Harrison673d57e2008-10-31 00:53:57 -07001352 sprintf(tbuf, "%pI4", n->key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1354 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1355 dev ? dev->name : "*");
1356}
1357
1358static int arp_seq_show(struct seq_file *seq, void *v)
1359{
1360 if (v == SEQ_START_TOKEN) {
1361 seq_puts(seq, "IP address HW type Flags "
1362 "HW address Mask Device\n");
1363 } else {
1364 struct neigh_seq_state *state = seq->private;
1365
1366 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1367 arp_format_pneigh_entry(seq, v);
1368 else
1369 arp_format_neigh_entry(seq, v);
1370 }
1371
1372 return 0;
1373}
1374
1375static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1376{
1377 /* Don't want to confuse "arp -a" w/ magic entries,
1378 * so we tell the generic iterator to skip NUD_NOARP.
1379 */
1380 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1381}
1382
1383/* ------------------------------------------------------------------------ */
1384
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001385static const struct seq_operations arp_seq_ops = {
Changli Gaodeffd772010-09-02 03:56:51 +00001386 .start = arp_seq_start,
1387 .next = neigh_seq_next,
1388 .stop = neigh_seq_stop,
1389 .show = arp_seq_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001390};
1391
1392static int arp_seq_open(struct inode *inode, struct file *file)
1393{
Eric W. Biederman426b5302008-01-24 00:13:18 -08001394 return seq_open_net(inode, file, &arp_seq_ops,
1395 sizeof(struct neigh_seq_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001396}
1397
Arjan van de Ven9a321442007-02-12 00:55:35 -08001398static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001399 .owner = THIS_MODULE,
1400 .open = arp_seq_open,
1401 .read = seq_read,
1402 .llseek = seq_lseek,
Eric W. Biederman426b5302008-01-24 00:13:18 -08001403 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404};
1405
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001406
1407static int __net_init arp_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408{
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001409 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 return -ENOMEM;
1411 return 0;
1412}
1413
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001414static void __net_exit arp_net_exit(struct net *net)
1415{
1416 proc_net_remove(net, "arp");
1417}
1418
1419static struct pernet_operations arp_net_ops = {
1420 .init = arp_net_init,
1421 .exit = arp_net_exit,
1422};
1423
1424static int __init arp_proc_init(void)
1425{
1426 return register_pernet_subsys(&arp_net_ops);
1427}
1428
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429#else /* CONFIG_PROC_FS */
1430
1431static int __init arp_proc_init(void)
1432{
1433 return 0;
1434}
1435
1436#endif /* CONFIG_PROC_FS */