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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
76#include <linux/module.h>
77#include <linux/types.h>
78#include <linux/string.h>
79#include <linux/kernel.h>
Randy Dunlap4fc268d2006-01-11 12:17:47 -080080#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#include <linux/socket.h>
82#include <linux/sockios.h>
83#include <linux/errno.h>
84#include <linux/in.h>
85#include <linux/mm.h>
86#include <linux/inet.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020087#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#include <linux/netdevice.h>
89#include <linux/etherdevice.h>
90#include <linux/fddidevice.h>
91#include <linux/if_arp.h>
92#include <linux/trdevice.h>
93#include <linux/skbuff.h>
94#include <linux/proc_fs.h>
95#include <linux/seq_file.h>
96#include <linux/stat.h>
97#include <linux/init.h>
98#include <linux/net.h>
99#include <linux/rcupdate.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +0900100#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101#ifdef CONFIG_SYSCTL
102#include <linux/sysctl.h>
103#endif
104
Eric W. Biederman457c4cb2007-09-12 12:01:34 +0200105#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106#include <net/ip.h>
107#include <net/icmp.h>
108#include <net/route.h>
109#include <net/protocol.h>
110#include <net/tcp.h>
111#include <net/sock.h>
112#include <net/arp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113#include <net/ax25.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114#include <net/netrom.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
116#include <net/atmclip.h>
117struct neigh_table *clip_tbl_hook;
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000118EXPORT_SYMBOL(clip_tbl_hook);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119#endif
120
121#include <asm/system.h>
Changli Gaodeffd772010-09-02 03:56:51 +0000122#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124#include <linux/netfilter_arp.h>
125
126/*
127 * Interface to generic neighbour cache.
128 */
Eric Dumazetd6bf7812010-10-04 06:15:44 +0000129static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 rnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130static int arp_constructor(struct neighbour *neigh);
131static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
132static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
133static void parp_redo(struct sk_buff *skb);
134
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000135static const struct neigh_ops arp_generic_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 .family = AF_INET,
137 .solicit = arp_solicit,
138 .error_report = arp_error_report,
139 .output = neigh_resolve_output,
140 .connected_output = neigh_connected_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141};
142
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000143static const struct neigh_ops arp_hh_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 .family = AF_INET,
145 .solicit = arp_solicit,
146 .error_report = arp_error_report,
147 .output = neigh_resolve_output,
148 .connected_output = neigh_resolve_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149};
150
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000151static const struct neigh_ops arp_direct_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 .family = AF_INET,
David S. Miller8f40b162011-07-17 13:34:11 -0700153 .output = neigh_direct_output,
154 .connected_output = neigh_direct_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155};
156
stephen hemmingera64de472010-09-28 17:08:02 +0000157static const struct neigh_ops arp_broken_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 .family = AF_INET,
159 .solicit = arp_solicit,
160 .error_report = arp_error_report,
161 .output = neigh_compat_output,
162 .connected_output = neigh_compat_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163};
164
165struct neigh_table arp_tbl = {
Changli Gaodeffd772010-09-02 03:56:51 +0000166 .family = AF_INET,
167 .entry_size = sizeof(struct neighbour) + 4,
168 .key_len = 4,
169 .hash = arp_hash,
170 .constructor = arp_constructor,
171 .proxy_redo = parp_redo,
172 .id = "arp_cache",
173 .parms = {
174 .tbl = &arp_tbl,
175 .base_reachable_time = 30 * HZ,
176 .retrans_time = 1 * HZ,
177 .gc_staletime = 60 * HZ,
178 .reachable_time = 30 * HZ,
179 .delay_probe_time = 5 * HZ,
Eric Dumazet8b5c1712011-11-09 12:07:14 +0000180 .queue_len_bytes = 64*1024,
Changli Gaodeffd772010-09-02 03:56:51 +0000181 .ucast_probes = 3,
182 .mcast_probes = 3,
183 .anycast_delay = 1 * HZ,
184 .proxy_delay = (8 * HZ) / 10,
185 .proxy_qlen = 64,
186 .locktime = 1 * HZ,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 },
Changli Gaodeffd772010-09-02 03:56:51 +0000188 .gc_interval = 30 * HZ,
189 .gc_thresh1 = 128,
190 .gc_thresh2 = 512,
191 .gc_thresh3 = 1024,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192};
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000193EXPORT_SYMBOL(arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Al Viro714e85b2006-11-14 20:51:49 -0800195int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196{
197 switch (dev->type) {
198 case ARPHRD_ETHER:
199 case ARPHRD_FDDI:
200 case ARPHRD_IEEE802:
201 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900202 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 case ARPHRD_IEEE802_TR:
204 ip_tr_mc_map(addr, haddr);
205 return 0;
206 case ARPHRD_INFINIBAND:
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700207 ip_ib_mc_map(addr, dev->broadcast, haddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 return 0;
Timo Teräs93ca3bb2011-03-28 22:40:53 +0000209 case ARPHRD_IPGRE:
210 ip_ipgre_mc_map(addr, dev->broadcast, haddr);
211 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 default:
213 if (dir) {
214 memcpy(haddr, dev->broadcast, dev->addr_len);
215 return 0;
216 }
217 }
218 return -EINVAL;
219}
220
221
Eric Dumazetd6bf7812010-10-04 06:15:44 +0000222static u32 arp_hash(const void *pkey,
223 const struct net_device *dev,
224 __u32 hash_rnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225{
David S. Millerf610b742011-07-11 01:37:28 -0700226 return arp_hashfn(*(u32 *)pkey, dev, hash_rnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
229static int arp_constructor(struct neighbour *neigh)
230{
Changli Gaodeffd772010-09-02 03:56:51 +0000231 __be32 addr = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 struct net_device *dev = neigh->dev;
233 struct in_device *in_dev;
234 struct neigh_parms *parms;
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700237 in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 if (in_dev == NULL) {
239 rcu_read_unlock();
240 return -EINVAL;
241 }
242
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900243 neigh->type = inet_addr_type(dev_net(dev), addr);
Denis V. Luneva79878f2008-01-14 22:56:01 -0800244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 parms = in_dev->arp_parms;
246 __neigh_parms_put(neigh->parms);
247 neigh->parms = neigh_parms_clone(parms);
248 rcu_read_unlock();
249
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700250 if (!dev->header_ops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 neigh->nud_state = NUD_NOARP;
252 neigh->ops = &arp_direct_ops;
David S. Miller8f40b162011-07-17 13:34:11 -0700253 neigh->output = neigh_direct_output;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 } else {
255 /* Good devices (checked by reading texts, but only Ethernet is
256 tested)
257
258 ARPHRD_ETHER: (ethernet, apfddi)
259 ARPHRD_FDDI: (fddi)
260 ARPHRD_IEEE802: (tr)
261 ARPHRD_METRICOM: (strip)
262 ARPHRD_ARCNET:
263 etc. etc. etc.
264
265 ARPHRD_IPDDP will also work, if author repairs it.
266 I did not it, because this driver does not work even
267 in old paradigm.
268 */
269
270#if 1
271 /* So... these "amateur" devices are hopeless.
272 The only thing, that I can say now:
273 It is very sad that we need to keep ugly obsolete
274 code to make them happy.
275
276 They should be moved to more reasonable state, now
277 they use rebuild_header INSTEAD OF hard_start_xmit!!!
278 Besides that, they are sort of out of date
279 (a lot of redundant clones/copies, useless in 2.1),
280 I wonder why people believe that they work.
281 */
282 switch (dev->type) {
283 default:
284 break;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900285 case ARPHRD_ROSE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
287 case ARPHRD_AX25:
288#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
289 case ARPHRD_NETROM:
290#endif
291 neigh->ops = &arp_broken_ops;
292 neigh->output = neigh->ops->output;
293 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000294#else
295 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296#endif
Changli Gaodeffd772010-09-02 03:56:51 +0000297 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298#endif
299 if (neigh->type == RTN_MULTICAST) {
300 neigh->nud_state = NUD_NOARP;
301 arp_mc_map(addr, neigh->ha, dev, 1);
Changli Gaodeffd772010-09-02 03:56:51 +0000302 } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 neigh->nud_state = NUD_NOARP;
304 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
Changli Gaodeffd772010-09-02 03:56:51 +0000305 } else if (neigh->type == RTN_BROADCAST ||
306 (dev->flags & IFF_POINTOPOINT)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 neigh->nud_state = NUD_NOARP;
308 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
309 }
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700310
311 if (dev->header_ops->cache)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 neigh->ops = &arp_hh_ops;
313 else
314 neigh->ops = &arp_generic_ops;
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700315
Changli Gaodeffd772010-09-02 03:56:51 +0000316 if (neigh->nud_state & NUD_VALID)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 neigh->output = neigh->ops->connected_output;
318 else
319 neigh->output = neigh->ops->output;
320 }
321 return 0;
322}
323
324static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
325{
326 dst_link_failure(skb);
327 kfree_skb(skb);
328}
329
330static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
331{
Al Viroa61ced52006-09-26 21:27:54 -0700332 __be32 saddr = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 u8 *dst_ha = NULL;
334 struct net_device *dev = neigh->dev;
Changli Gaodeffd772010-09-02 03:56:51 +0000335 __be32 target = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 int probes = atomic_read(&neigh->probes);
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000337 struct in_device *in_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000339 rcu_read_lock();
340 in_dev = __in_dev_get_rcu(dev);
341 if (!in_dev) {
342 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 return;
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000344 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
346 default:
347 case 0: /* By default announce any local IP */
Changli Gaodeffd772010-09-02 03:56:51 +0000348 if (skb && inet_addr_type(dev_net(dev),
349 ip_hdr(skb)->saddr) == RTN_LOCAL)
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700350 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 break;
352 case 1: /* Restrict announcements of saddr in same subnet */
353 if (!skb)
354 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700355 saddr = ip_hdr(skb)->saddr;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900356 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 /* saddr should be known to target */
358 if (inet_addr_onlink(in_dev, target, saddr))
359 break;
360 }
361 saddr = 0;
362 break;
363 case 2: /* Avoid secondary IPs, get a primary/preferred one */
364 break;
365 }
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000366 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 if (!saddr)
369 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
370
Changli Gaodeffd772010-09-02 03:56:51 +0000371 probes -= neigh->parms->ucast_probes;
372 if (probes < 0) {
373 if (!(neigh->nud_state & NUD_VALID))
374 printk(KERN_DEBUG
375 "trying to ucast probe in NUD_INVALID\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 dst_ha = neigh->ha;
David S. Miller9ff56602008-02-17 18:39:54 -0800377 read_lock_bh(&neigh->lock);
Changli Gaodeffd772010-09-02 03:56:51 +0000378 } else {
379 probes -= neigh->parms->app_probes;
380 if (probes < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381#ifdef CONFIG_ARPD
Changli Gaodeffd772010-09-02 03:56:51 +0000382 neigh_app_ns(neigh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383#endif
Changli Gaodeffd772010-09-02 03:56:51 +0000384 return;
385 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 }
387
388 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
389 dst_ha, dev->dev_addr, NULL);
David S. Miller9ff56602008-02-17 18:39:54 -0800390 if (dst_ha)
391 read_unlock_bh(&neigh->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392}
393
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800394static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
396 int scope;
397
398 switch (IN_DEV_ARP_IGNORE(in_dev)) {
399 case 0: /* Reply, the tip is already validated */
400 return 0;
401 case 1: /* Reply only if tip is configured on the incoming interface */
402 sip = 0;
403 scope = RT_SCOPE_HOST;
404 break;
405 case 2: /*
406 * Reply only if tip is configured on the incoming interface
407 * and is in same subnet as sip
408 */
409 scope = RT_SCOPE_HOST;
410 break;
411 case 3: /* Do not reply for scope host addresses */
412 sip = 0;
413 scope = RT_SCOPE_LINK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 break;
415 case 4: /* Reserved */
416 case 5:
417 case 6:
418 case 7:
419 return 0;
420 case 8: /* Do not reply */
421 return 1;
422 default:
423 return 0;
424 }
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800425 return !inet_confirm_addr(in_dev, sip, tip, scope);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426}
427
Al Viroed9bad02006-09-27 18:36:36 -0700428static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900431 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 /*unsigned long now; */
Pavel Emelyanovca12a1a2008-07-16 20:28:42 -0700433 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
David S. Miller78fbfd82011-03-12 00:00:52 -0500435 rt = ip_route_output(net, sip, tip, 0, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800436 if (IS_ERR(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return 1;
Changli Gaod8d1f302010-06-10 23:31:35 -0700438 if (rt->dst.dev != dev) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700439 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900441 }
442 ip_rt_put(rt);
443 return flag;
444}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445
446/* OBSOLETE FUNCTIONS */
447
448/*
449 * Find an arp mapping in the cache. If not found, post a request.
450 *
451 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
452 * even if it exists. It is supposed that skb->dev was mangled
453 * by a virtual device (eql, shaper). Nobody but broken devices
454 * is allowed to use this function, it is scheduled to be removed. --ANK
455 */
456
Changli Gaodeffd772010-09-02 03:56:51 +0000457static int arp_set_predefined(int addr_hint, unsigned char *haddr,
458 __be32 paddr, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
460 switch (addr_hint) {
461 case RTN_LOCAL:
462 printk(KERN_DEBUG "ARP: arp called for own IP address\n");
463 memcpy(haddr, dev->dev_addr, dev->addr_len);
464 return 1;
465 case RTN_MULTICAST:
466 arp_mc_map(paddr, haddr, dev, 1);
467 return 1;
468 case RTN_BROADCAST:
469 memcpy(haddr, dev->broadcast, dev->addr_len);
470 return 1;
471 }
472 return 0;
473}
474
475
476int arp_find(unsigned char *haddr, struct sk_buff *skb)
477{
478 struct net_device *dev = skb->dev;
Al Virofd683222006-09-26 22:17:51 -0700479 __be32 paddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 struct neighbour *n;
481
Eric Dumazetadf30902009-06-02 05:19:30 +0000482 if (!skb_dst(skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
484 kfree_skb(skb);
485 return 1;
486 }
487
Eric Dumazet511c3f92009-06-02 05:14:27 +0000488 paddr = skb_rtable(skb)->rt_gateway;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Changli Gaodeffd772010-09-02 03:56:51 +0000490 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr,
491 paddr, dev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 return 0;
493
494 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
495
496 if (n) {
497 n->used = jiffies;
Eric Dumazet0ed8ddf2010-10-07 10:44:07 +0000498 if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) {
499 neigh_ha_snapshot(haddr, n, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 neigh_release(n);
501 return 0;
502 }
503 neigh_release(n);
504 } else
505 kfree_skb(skb);
506 return 1;
507}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000508EXPORT_SYMBOL(arp_find);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509
510/* END OF OBSOLETE FUNCTIONS */
511
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512/*
513 * Check if we can use proxy ARP for this path
514 */
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000515static inline int arp_fwd_proxy(struct in_device *in_dev,
516 struct net_device *dev, struct rtable *rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517{
518 struct in_device *out_dev;
519 int imi, omi = -1;
520
Changli Gaod8d1f302010-06-10 23:31:35 -0700521 if (rt->dst.dev == dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000522 return 0;
523
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (!IN_DEV_PROXY_ARP(in_dev))
525 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000526 imi = IN_DEV_MEDIUM_ID(in_dev);
527 if (imi == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 return 1;
529 if (imi == -1)
530 return 0;
531
532 /* place to check for proxy_arp for routes */
533
Changli Gaod8d1f302010-06-10 23:31:35 -0700534 out_dev = __in_dev_get_rcu(rt->dst.dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000535 if (out_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 omi = IN_DEV_MEDIUM_ID(out_dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000537
Eric Dumazeta02cec22010-09-22 20:43:57 +0000538 return omi != imi && omi != -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539}
540
541/*
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000542 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
543 *
544 * RFC3069 supports proxy arp replies back to the same interface. This
545 * is done to support (ethernet) switch features, like RFC 3069, where
546 * the individual ports are not allowed to communicate with each
547 * other, BUT they are allowed to talk to the upstream router. As
548 * described in RFC 3069, it is possible to allow these hosts to
549 * communicate through the upstream router, by proxy_arp'ing.
550 *
551 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation"
552 *
553 * This technology is known by different names:
554 * In RFC 3069 it is called VLAN Aggregation.
555 * Cisco and Allied Telesyn call it Private VLAN.
556 * Hewlett-Packard call it Source-Port filtering or port-isolation.
557 * Ericsson call it MAC-Forced Forwarding (RFC Draft).
558 *
559 */
560static inline int arp_fwd_pvlan(struct in_device *in_dev,
561 struct net_device *dev, struct rtable *rt,
562 __be32 sip, __be32 tip)
563{
564 /* Private VLAN is only concerned about the same ethernet segment */
Changli Gaod8d1f302010-06-10 23:31:35 -0700565 if (rt->dst.dev != dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000566 return 0;
567
568 /* Don't reply on self probes (often done by windowz boxes)*/
569 if (sip == tip)
570 return 0;
571
572 if (IN_DEV_PROXY_ARP_PVLAN(in_dev))
573 return 1;
574 else
575 return 0;
576}
577
578/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 * Interface to link layer: send routine and receive handler.
580 */
581
582/*
583 * Create an arp packet. If (dest_hw == NULL), we create a broadcast
584 * message.
585 */
Al Viroed9bad02006-09-27 18:36:36 -0700586struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
587 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800588 const unsigned char *dest_hw,
589 const unsigned char *src_hw,
590 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591{
592 struct sk_buff *skb;
593 struct arphdr *arp;
594 unsigned char *arp_ptr;
595
596 /*
597 * Allocate a buffer
598 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900599
Johannes Bergf5184d22008-05-12 20:48:31 -0700600 skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 if (skb == NULL)
602 return NULL;
603
604 skb_reserve(skb, LL_RESERVED_SPACE(dev));
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700605 skb_reset_network_header(skb);
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800606 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 skb->dev = dev;
608 skb->protocol = htons(ETH_P_ARP);
609 if (src_hw == NULL)
610 src_hw = dev->dev_addr;
611 if (dest_hw == NULL)
612 dest_hw = dev->broadcast;
613
614 /*
615 * Fill the device header for the ARP frame
616 */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700617 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 goto out;
619
620 /*
621 * Fill out the arp protocol part.
622 *
623 * The arp hardware type should match the device type, except for FDDI,
624 * which (according to RFC 1390) should always equal 1 (Ethernet).
625 */
626 /*
627 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
628 * DIX code for the protocol. Make these device structure fields.
629 */
630 switch (dev->type) {
631 default:
632 arp->ar_hrd = htons(dev->type);
633 arp->ar_pro = htons(ETH_P_IP);
634 break;
635
636#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
637 case ARPHRD_AX25:
638 arp->ar_hrd = htons(ARPHRD_AX25);
639 arp->ar_pro = htons(AX25_P_IP);
640 break;
641
642#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
643 case ARPHRD_NETROM:
644 arp->ar_hrd = htons(ARPHRD_NETROM);
645 arp->ar_pro = htons(AX25_P_IP);
646 break;
647#endif
648#endif
649
David S. Millerf0ecde12010-05-10 04:59:07 -0700650#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 case ARPHRD_FDDI:
652 arp->ar_hrd = htons(ARPHRD_ETHER);
653 arp->ar_pro = htons(ETH_P_IP);
654 break;
655#endif
David S. Millerf0ecde12010-05-10 04:59:07 -0700656#if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 case ARPHRD_IEEE802_TR:
658 arp->ar_hrd = htons(ARPHRD_IEEE802);
659 arp->ar_pro = htons(ETH_P_IP);
660 break;
661#endif
662 }
663
664 arp->ar_hln = dev->addr_len;
665 arp->ar_pln = 4;
666 arp->ar_op = htons(type);
667
Changli Gaodeffd772010-09-02 03:56:51 +0000668 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
670 memcpy(arp_ptr, src_hw, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800671 arp_ptr += dev->addr_len;
672 memcpy(arp_ptr, &src_ip, 4);
673 arp_ptr += 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 if (target_hw != NULL)
675 memcpy(arp_ptr, target_hw, dev->addr_len);
676 else
677 memset(arp_ptr, 0, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800678 arp_ptr += dev->addr_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 memcpy(arp_ptr, &dest_ip, 4);
680
681 return skb;
682
683out:
684 kfree_skb(skb);
685 return NULL;
686}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000687EXPORT_SYMBOL(arp_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
689/*
690 * Send an arp packet.
691 */
692void arp_xmit(struct sk_buff *skb)
693{
694 /* Send it off, maybe filter it using firewalling first. */
Jan Engelhardtfdc93142008-10-20 03:34:51 -0700695 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000697EXPORT_SYMBOL(arp_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698
699/*
700 * Create and send an arp packet.
701 */
Al Viroed9bad02006-09-27 18:36:36 -0700702void arp_send(int type, int ptype, __be32 dest_ip,
703 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800704 const unsigned char *dest_hw, const unsigned char *src_hw,
705 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706{
707 struct sk_buff *skb;
708
709 /*
710 * No arp on this interface.
711 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (dev->flags&IFF_NOARP)
714 return;
715
716 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
717 dest_hw, src_hw, target_hw);
Changli Gaodeffd772010-09-02 03:56:51 +0000718 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
721 arp_xmit(skb);
722}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000723EXPORT_SYMBOL(arp_send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725/*
726 * Process an arp request.
727 */
728
729static int arp_process(struct sk_buff *skb)
730{
731 struct net_device *dev = skb->dev;
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000732 struct in_device *in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 struct arphdr *arp;
734 unsigned char *arp_ptr;
735 struct rtable *rt;
Mark Rydene0260fe2007-12-19 23:38:11 -0800736 unsigned char *sha;
Al Viro9e12bb22006-09-26 21:25:20 -0700737 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 u16 dev_type = dev->type;
739 int addr_type;
740 struct neighbour *n;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900741 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743 /* arp_rcv below verifies the ARP header and verifies the device
744 * is ARP'able.
745 */
746
747 if (in_dev == NULL)
748 goto out;
749
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300750 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751
752 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900753 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 if (arp->ar_pro != htons(ETH_P_IP) ||
755 htons(dev_type) != arp->ar_hrd)
756 goto out;
757 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 case ARPHRD_ETHER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 case ARPHRD_IEEE802_TR:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 case ARPHRD_FDDI:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 case ARPHRD_IEEE802:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 /*
763 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
764 * devices, according to RFC 2625) devices will accept ARP
765 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
766 * This is the case also of FDDI, where the RFC 1390 says that
767 * FDDI devices should accept ARP hardware of (1) Ethernet,
768 * however, to be more robust, we'll accept both 1 (Ethernet)
769 * or 6 (IEEE 802.2)
770 */
771 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
772 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
773 arp->ar_pro != htons(ETH_P_IP))
774 goto out;
775 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 case ARPHRD_AX25:
777 if (arp->ar_pro != htons(AX25_P_IP) ||
778 arp->ar_hrd != htons(ARPHRD_AX25))
779 goto out;
780 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 case ARPHRD_NETROM:
782 if (arp->ar_pro != htons(AX25_P_IP) ||
783 arp->ar_hrd != htons(ARPHRD_NETROM))
784 goto out;
785 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 }
787
788 /* Understand only these message types */
789
790 if (arp->ar_op != htons(ARPOP_REPLY) &&
791 arp->ar_op != htons(ARPOP_REQUEST))
792 goto out;
793
794/*
795 * Extract fields
796 */
Changli Gaodeffd772010-09-02 03:56:51 +0000797 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 sha = arp_ptr;
799 arp_ptr += dev->addr_len;
800 memcpy(&sip, arp_ptr, 4);
801 arp_ptr += 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 arp_ptr += dev->addr_len;
803 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900804/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 * Check for bad requests for 127.x.x.x and requests for multicast
806 * addresses. If this is one such, delete it.
807 */
Joe Perchesf97c1e02007-12-16 13:45:43 -0800808 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 goto out;
810
811/*
812 * Special case: We must set Frame Relay source Q.922 address
813 */
814 if (dev_type == ARPHRD_DLCI)
815 sha = dev->broadcast;
816
817/*
818 * Process entry. The idea here is we want to send a reply if it is a
819 * request for us or if it is a request for someone else that we hold
820 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900821 * to us or if it is a request for our address.
822 * (The assumption for this last is that if someone is requesting our
823 * address, they are probably intending to talk to us, so it saves time
824 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900826 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 * Putting this another way, we only care about replies if they are to
828 * us, in which case we add them to the cache. For requests, we care
829 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900830 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 * cache.
832 */
833
Eric W. Biedermanf8a68e72009-06-30 16:27:17 +0000834 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
835 if (sip == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700837 inet_addr_type(net, tip) == RTN_LOCAL &&
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800838 !arp_ignore(in_dev, sip, tip))
Jonas Danielssonb4a98112007-11-20 17:38:16 -0800839 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
840 dev->dev_addr, sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 goto out;
842 }
843
844 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Eric Dumazet4a944452010-05-10 11:33:06 +0000845 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
Eric Dumazet511c3f92009-06-02 05:14:27 +0000847 rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 addr_type = rt->rt_type;
849
850 if (addr_type == RTN_LOCAL) {
Changli Gaodeffd772010-09-02 03:56:51 +0000851 int dont_send;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Changli Gaodeffd772010-09-02 03:56:51 +0000853 dont_send = arp_ignore(in_dev, sip, tip);
Ben Greear8164f1b2008-11-16 19:19:38 -0800854 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
Changli Gaoae9c4162010-12-01 20:07:31 +0000855 dont_send = arp_filter(sip, tip, dev);
Ben Greear8164f1b2008-11-16 19:19:38 -0800856 if (!dont_send) {
857 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
858 if (n) {
Changli Gaodeffd772010-09-02 03:56:51 +0000859 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
860 dev, tip, sha, dev->dev_addr,
861 sha);
Ben Greear8164f1b2008-11-16 19:19:38 -0800862 neigh_release(n);
863 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 }
865 goto out;
866 } else if (IN_DEV_FORWARD(in_dev)) {
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000867 if (addr_type == RTN_UNICAST &&
868 (arp_fwd_proxy(in_dev, dev, rt) ||
869 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) ||
Changli Gaodeffd772010-09-02 03:56:51 +0000870 pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
872 if (n)
873 neigh_release(n);
874
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900875 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 skb->pkt_type == PACKET_HOST ||
877 in_dev->arp_parms->proxy_delay == 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000878 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
879 dev, tip, sha, dev->dev_addr,
880 sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 } else {
Changli Gaodeffd772010-09-02 03:56:51 +0000882 pneigh_enqueue(&arp_tbl,
883 in_dev->arp_parms, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 return 0;
885 }
886 goto out;
887 }
888 }
889 }
890
891 /* Update our ARP tables */
892
893 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
894
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900895 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800896 /* Unsolicited ARP is not accepted by default.
897 It is possible, that this option should be enabled for some
898 devices (strip is candidate)
899 */
900 if (n == NULL &&
Octavian Purdila6d955182010-01-18 12:58:44 +0000901 (arp->ar_op == htons(ARPOP_REPLY) ||
902 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700903 inet_addr_type(net, sip) == RTN_UNICAST)
Jean Delvare1b1ac752007-07-14 20:51:44 -0700904 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800905 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
907 if (n) {
908 int state = NUD_REACHABLE;
909 int override;
910
911 /* If several different ARP replies follows back-to-back,
912 use the FIRST one. It is possible, if several proxy
913 agents are active. Taking the first reply prevents
914 arp trashing and chooses the fastest router.
915 */
916 override = time_after(jiffies, n->updated + n->parms->locktime);
917
918 /* Broadcast replies and request packets
919 do not assert neighbour reachability.
920 */
921 if (arp->ar_op != htons(ARPOP_REPLY) ||
922 skb->pkt_type != PACKET_HOST)
923 state = NUD_STALE;
Changli Gaodeffd772010-09-02 03:56:51 +0000924 neigh_update(n, sha, state,
925 override ? NEIGH_UPDATE_F_OVERRIDE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 neigh_release(n);
927 }
928
929out:
Neil Hormanead2ceb2009-03-11 09:49:55 +0000930 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 return 0;
932}
933
Herbert Xu444fc8f2005-10-03 14:18:10 -0700934static void parp_redo(struct sk_buff *skb)
935{
936 arp_process(skb);
937}
938
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939
940/*
941 * Receive an arp request from the device layer.
942 */
943
Adrian Bunk6c97e722006-04-12 13:57:59 -0700944static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
945 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946{
947 struct arphdr *arp;
948
949 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800950 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 goto freeskb;
952
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300953 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 if (arp->ar_hln != dev->addr_len ||
955 dev->flags & IFF_NOARP ||
956 skb->pkt_type == PACKET_OTHERHOST ||
957 skb->pkt_type == PACKET_LOOPBACK ||
958 arp->ar_pln != 4)
959 goto freeskb;
960
Changli Gaodeffd772010-09-02 03:56:51 +0000961 skb = skb_share_check(skb, GFP_ATOMIC);
962 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 goto out_of_mem;
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) {
David S. Millerf0ecde12010-05-10 04:59:07 -07001043#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE)
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)) {
1066 unsigned state = NUD_STALE;
1067 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
1078static unsigned arp_state_to_flags(struct neighbour *neigh)
1079{
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:
1178 if (!capable(CAP_NET_ADMIN))
1179 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);
Denis V. Lunev76e6ebf2008-07-05 19:00:44 -07001242 rt_cache_flush(dev_net(dev), 0);
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
1289#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1290
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. */
1337#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1338 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1351 }
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{
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001423 if (!proc_net_fops_create(net, "arp", S_IRUGO, &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{
1430 proc_net_remove(net, "arp");
1431}
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 */