blob: 933a92820d265e07b8c42300c7be6742565723b5 [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);
Eric W. Biederman60395a22015-03-03 17:10:44 -0600125static bool arp_key_eq(const struct neighbour *n, const void *pkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126static int arp_constructor(struct neighbour *neigh);
127static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
128static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
129static void parp_redo(struct sk_buff *skb);
130
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000131static const struct neigh_ops arp_generic_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 .family = AF_INET,
133 .solicit = arp_solicit,
134 .error_report = arp_error_report,
135 .output = neigh_resolve_output,
136 .connected_output = neigh_connected_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137};
138
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000139static const struct neigh_ops arp_hh_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 .family = AF_INET,
141 .solicit = arp_solicit,
142 .error_report = arp_error_report,
143 .output = neigh_resolve_output,
144 .connected_output = neigh_resolve_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145};
146
Stephen Hemminger89d69d22009-09-01 11:13:19 +0000147static const struct neigh_ops arp_direct_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 .family = AF_INET,
David S. Miller8f40b162011-07-17 13:34:11 -0700149 .output = neigh_direct_output,
150 .connected_output = neigh_direct_output,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151};
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153struct neigh_table arp_tbl = {
Changli Gaodeffd772010-09-02 03:56:51 +0000154 .family = AF_INET,
Changli Gaodeffd772010-09-02 03:56:51 +0000155 .key_len = 4,
Eric W. Biedermanbdf53c52015-03-02 00:13:22 -0600156 .protocol = cpu_to_be16(ETH_P_IP),
Changli Gaodeffd772010-09-02 03:56:51 +0000157 .hash = arp_hash,
Eric W. Biederman60395a22015-03-03 17:10:44 -0600158 .key_eq = arp_key_eq,
Changli Gaodeffd772010-09-02 03:56:51 +0000159 .constructor = arp_constructor,
160 .proxy_redo = parp_redo,
161 .id = "arp_cache",
162 .parms = {
163 .tbl = &arp_tbl,
Changli Gaodeffd772010-09-02 03:56:51 +0000164 .reachable_time = 30 * HZ,
Jiri Pirko1f9248e2013-12-07 19:26:53 +0100165 .data = {
166 [NEIGH_VAR_MCAST_PROBES] = 3,
167 [NEIGH_VAR_UCAST_PROBES] = 3,
168 [NEIGH_VAR_RETRANS_TIME] = 1 * HZ,
169 [NEIGH_VAR_BASE_REACHABLE_TIME] = 30 * HZ,
170 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ,
171 [NEIGH_VAR_GC_STALETIME] = 60 * HZ,
172 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024,
173 [NEIGH_VAR_PROXY_QLEN] = 64,
174 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ,
175 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10,
176 [NEIGH_VAR_LOCKTIME] = 1 * HZ,
177 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 },
Changli Gaodeffd772010-09-02 03:56:51 +0000179 .gc_interval = 30 * HZ,
180 .gc_thresh1 = 128,
181 .gc_thresh2 = 512,
182 .gc_thresh3 = 1024,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183};
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000184EXPORT_SYMBOL(arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Al Viro714e85b2006-11-14 20:51:49 -0800186int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
188 switch (dev->type) {
189 case ARPHRD_ETHER:
190 case ARPHRD_FDDI:
191 case ARPHRD_IEEE802:
192 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900193 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 case ARPHRD_INFINIBAND:
Rolf Manderscheida9e527e2007-12-10 13:38:41 -0700195 ip_ib_mc_map(addr, dev->broadcast, haddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 return 0;
Timo Teräs93ca3bb2011-03-28 22:40:53 +0000197 case ARPHRD_IPGRE:
198 ip_ipgre_mc_map(addr, dev->broadcast, haddr);
199 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 default:
201 if (dir) {
202 memcpy(haddr, dev->broadcast, dev->addr_len);
203 return 0;
204 }
205 }
206 return -EINVAL;
207}
208
209
Eric Dumazetd6bf7812010-10-04 06:15:44 +0000210static u32 arp_hash(const void *pkey,
211 const struct net_device *dev,
David S. Miller2c2aba62011-12-28 15:06:58 -0500212 __u32 *hash_rnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
Eric W. Biederman60395a22015-03-03 17:10:44 -0600214 return arp_hashfn(pkey, dev, hash_rnd);
215}
216
217static bool arp_key_eq(const struct neighbour *neigh, const void *pkey)
218{
219 return neigh_key_eq32(neigh, pkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220}
221
222static int arp_constructor(struct neighbour *neigh)
223{
Changli Gaodeffd772010-09-02 03:56:51 +0000224 __be32 addr = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 struct net_device *dev = neigh->dev;
226 struct in_device *in_dev;
227 struct neigh_parms *parms;
228
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700230 in_dev = __in_dev_get_rcu(dev);
Ian Morris51456b22015-04-03 09:17:26 +0100231 if (!in_dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 rcu_read_unlock();
233 return -EINVAL;
234 }
235
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900236 neigh->type = inet_addr_type(dev_net(dev), addr);
Denis V. Luneva79878f2008-01-14 22:56:01 -0800237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 parms = in_dev->arp_parms;
239 __neigh_parms_put(neigh->parms);
240 neigh->parms = neigh_parms_clone(parms);
241 rcu_read_unlock();
242
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700243 if (!dev->header_ops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 neigh->nud_state = NUD_NOARP;
245 neigh->ops = &arp_direct_ops;
David S. Miller8f40b162011-07-17 13:34:11 -0700246 neigh->output = neigh_direct_output;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 } else {
248 /* Good devices (checked by reading texts, but only Ethernet is
249 tested)
250
251 ARPHRD_ETHER: (ethernet, apfddi)
252 ARPHRD_FDDI: (fddi)
253 ARPHRD_IEEE802: (tr)
254 ARPHRD_METRICOM: (strip)
255 ARPHRD_ARCNET:
256 etc. etc. etc.
257
258 ARPHRD_IPDDP will also work, if author repairs it.
259 I did not it, because this driver does not work even
260 in old paradigm.
261 */
262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 if (neigh->type == RTN_MULTICAST) {
264 neigh->nud_state = NUD_NOARP;
265 arp_mc_map(addr, neigh->ha, dev, 1);
Changli Gaodeffd772010-09-02 03:56:51 +0000266 } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 neigh->nud_state = NUD_NOARP;
268 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
Changli Gaodeffd772010-09-02 03:56:51 +0000269 } else if (neigh->type == RTN_BROADCAST ||
270 (dev->flags & IFF_POINTOPOINT)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 neigh->nud_state = NUD_NOARP;
272 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
273 }
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700274
275 if (dev->header_ops->cache)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 neigh->ops = &arp_hh_ops;
277 else
278 neigh->ops = &arp_generic_ops;
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700279
Changli Gaodeffd772010-09-02 03:56:51 +0000280 if (neigh->nud_state & NUD_VALID)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 neigh->output = neigh->ops->connected_output;
282 else
283 neigh->output = neigh->ops->output;
284 }
285 return 0;
286}
287
288static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
289{
290 dst_link_failure(skb);
291 kfree_skb(skb);
292}
293
294static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
295{
Al Viroa61ced52006-09-26 21:27:54 -0700296 __be32 saddr = 0;
Cong Wangcf0be8802012-12-23 15:23:16 +0000297 u8 dst_ha[MAX_ADDR_LEN], *dst_hw = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 struct net_device *dev = neigh->dev;
Changli Gaodeffd772010-09-02 03:56:51 +0000299 __be32 target = *(__be32 *)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 int probes = atomic_read(&neigh->probes);
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000301 struct in_device *in_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000303 rcu_read_lock();
304 in_dev = __in_dev_get_rcu(dev);
305 if (!in_dev) {
306 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 return;
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000308 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
310 default:
311 case 0: /* By default announce any local IP */
Changli Gaodeffd772010-09-02 03:56:51 +0000312 if (skb && inet_addr_type(dev_net(dev),
313 ip_hdr(skb)->saddr) == RTN_LOCAL)
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700314 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 break;
316 case 1: /* Restrict announcements of saddr in same subnet */
317 if (!skb)
318 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700319 saddr = ip_hdr(skb)->saddr;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900320 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 /* saddr should be known to target */
322 if (inet_addr_onlink(in_dev, target, saddr))
323 break;
324 }
325 saddr = 0;
326 break;
327 case 2: /* Avoid secondary IPs, get a primary/preferred one */
328 break;
329 }
Eric Dumazet4b4194c2010-06-22 07:43:15 +0000330 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 if (!saddr)
333 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
334
Jiri Pirko1f9248e2013-12-07 19:26:53 +0100335 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES);
Changli Gaodeffd772010-09-02 03:56:51 +0000336 if (probes < 0) {
337 if (!(neigh->nud_state & NUD_VALID))
Joe Perches91df42b2012-05-15 14:11:54 +0000338 pr_debug("trying to ucast probe in NUD_INVALID\n");
Eric Dumazet96503882012-12-21 07:32:10 +0000339 neigh_ha_snapshot(dst_ha, neigh, dev);
Cong Wangcf0be8802012-12-23 15:23:16 +0000340 dst_hw = dst_ha;
Changli Gaodeffd772010-09-02 03:56:51 +0000341 } else {
Jiri Pirko1f9248e2013-12-07 19:26:53 +0100342 probes -= NEIGH_VAR(neigh->parms, APP_PROBES);
Changli Gaodeffd772010-09-02 03:56:51 +0000343 if (probes < 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000344 neigh_app_ns(neigh);
Changli Gaodeffd772010-09-02 03:56:51 +0000345 return;
346 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 }
348
349 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
Cong Wangcf0be8802012-12-23 15:23:16 +0000350 dst_hw, dev->dev_addr, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351}
352
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800353static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354{
Nicolas Dichtelb601fa192013-12-10 15:02:40 +0100355 struct net *net = dev_net(in_dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 int scope;
357
358 switch (IN_DEV_ARP_IGNORE(in_dev)) {
359 case 0: /* Reply, the tip is already validated */
360 return 0;
361 case 1: /* Reply only if tip is configured on the incoming interface */
362 sip = 0;
363 scope = RT_SCOPE_HOST;
364 break;
365 case 2: /*
366 * Reply only if tip is configured on the incoming interface
367 * and is in same subnet as sip
368 */
369 scope = RT_SCOPE_HOST;
370 break;
371 case 3: /* Do not reply for scope host addresses */
372 sip = 0;
373 scope = RT_SCOPE_LINK;
Nicolas Dichtelb601fa192013-12-10 15:02:40 +0100374 in_dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 break;
376 case 4: /* Reserved */
377 case 5:
378 case 6:
379 case 7:
380 return 0;
381 case 8: /* Do not reply */
382 return 1;
383 default:
384 return 0;
385 }
Nicolas Dichtelb601fa192013-12-10 15:02:40 +0100386 return !inet_confirm_addr(net, in_dev, sip, tip, scope);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387}
388
Al Viroed9bad02006-09-27 18:36:36 -0700389static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900392 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 /*unsigned long now; */
Pavel Emelyanovca12a1a2008-07-16 20:28:42 -0700394 struct net *net = dev_net(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
David S. Miller78fbfd82011-03-12 00:00:52 -0500396 rt = ip_route_output(net, sip, tip, 0, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800397 if (IS_ERR(rt))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 return 1;
Changli Gaod8d1f302010-06-10 23:31:35 -0700399 if (rt->dst.dev != dev) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700400 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900402 }
403 ip_rt_put(rt);
404 return flag;
405}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407/*
408 * Check if we can use proxy ARP for this path
409 */
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000410static inline int arp_fwd_proxy(struct in_device *in_dev,
411 struct net_device *dev, struct rtable *rt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412{
413 struct in_device *out_dev;
414 int imi, omi = -1;
415
Changli Gaod8d1f302010-06-10 23:31:35 -0700416 if (rt->dst.dev == dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000417 return 0;
418
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 if (!IN_DEV_PROXY_ARP(in_dev))
420 return 0;
Changli Gaodeffd772010-09-02 03:56:51 +0000421 imi = IN_DEV_MEDIUM_ID(in_dev);
422 if (imi == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 return 1;
424 if (imi == -1)
425 return 0;
426
427 /* place to check for proxy_arp for routes */
428
Changli Gaod8d1f302010-06-10 23:31:35 -0700429 out_dev = __in_dev_get_rcu(rt->dst.dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000430 if (out_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 omi = IN_DEV_MEDIUM_ID(out_dev);
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000432
Eric Dumazeta02cec22010-09-22 20:43:57 +0000433 return omi != imi && omi != -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434}
435
436/*
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000437 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev)
438 *
439 * RFC3069 supports proxy arp replies back to the same interface. This
440 * is done to support (ethernet) switch features, like RFC 3069, where
441 * the individual ports are not allowed to communicate with each
442 * other, BUT they are allowed to talk to the upstream router. As
443 * described in RFC 3069, it is possible to allow these hosts to
444 * communicate through the upstream router, by proxy_arp'ing.
445 *
446 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation"
447 *
448 * This technology is known by different names:
449 * In RFC 3069 it is called VLAN Aggregation.
450 * Cisco and Allied Telesyn call it Private VLAN.
451 * Hewlett-Packard call it Source-Port filtering or port-isolation.
452 * Ericsson call it MAC-Forced Forwarding (RFC Draft).
453 *
454 */
455static inline int arp_fwd_pvlan(struct in_device *in_dev,
456 struct net_device *dev, struct rtable *rt,
457 __be32 sip, __be32 tip)
458{
459 /* Private VLAN is only concerned about the same ethernet segment */
Changli Gaod8d1f302010-06-10 23:31:35 -0700460 if (rt->dst.dev != dev)
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000461 return 0;
462
463 /* Don't reply on self probes (often done by windowz boxes)*/
464 if (sip == tip)
465 return 0;
466
467 if (IN_DEV_PROXY_ARP_PVLAN(in_dev))
468 return 1;
469 else
470 return 0;
471}
472
473/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 * Interface to link layer: send routine and receive handler.
475 */
476
477/*
Ian Morris51456b22015-04-03 09:17:26 +0100478 * Create an arp packet. If dest_hw is not set, we create a broadcast
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 * message.
480 */
Al Viroed9bad02006-09-27 18:36:36 -0700481struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
482 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800483 const unsigned char *dest_hw,
484 const unsigned char *src_hw,
485 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486{
487 struct sk_buff *skb;
488 struct arphdr *arp;
489 unsigned char *arp_ptr;
Herbert Xu66088242011-11-18 02:20:04 +0000490 int hlen = LL_RESERVED_SPACE(dev);
491 int tlen = dev->needed_tailroom;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
493 /*
494 * Allocate a buffer
495 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900496
Herbert Xu66088242011-11-18 02:20:04 +0000497 skb = alloc_skb(arp_hdr_len(dev) + hlen + tlen, GFP_ATOMIC);
Ian Morris51456b22015-04-03 09:17:26 +0100498 if (!skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 return NULL;
500
Herbert Xu66088242011-11-18 02:20:04 +0000501 skb_reserve(skb, hlen);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700502 skb_reset_network_header(skb);
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800503 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 skb->dev = dev;
505 skb->protocol = htons(ETH_P_ARP);
Ian Morris51456b22015-04-03 09:17:26 +0100506 if (!src_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 src_hw = dev->dev_addr;
Ian Morris51456b22015-04-03 09:17:26 +0100508 if (!dest_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 dest_hw = dev->broadcast;
510
511 /*
512 * Fill the device header for the ARP frame
513 */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700514 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 goto out;
516
517 /*
518 * Fill out the arp protocol part.
519 *
520 * The arp hardware type should match the device type, except for FDDI,
521 * which (according to RFC 1390) should always equal 1 (Ethernet).
522 */
523 /*
524 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
525 * DIX code for the protocol. Make these device structure fields.
526 */
527 switch (dev->type) {
528 default:
529 arp->ar_hrd = htons(dev->type);
530 arp->ar_pro = htons(ETH_P_IP);
531 break;
532
Igor Maravic40e47832011-12-05 02:25:57 +0000533#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 case ARPHRD_AX25:
535 arp->ar_hrd = htons(ARPHRD_AX25);
536 arp->ar_pro = htons(AX25_P_IP);
537 break;
538
Igor Maravic40e47832011-12-05 02:25:57 +0000539#if IS_ENABLED(CONFIG_NETROM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 case ARPHRD_NETROM:
541 arp->ar_hrd = htons(ARPHRD_NETROM);
542 arp->ar_pro = htons(AX25_P_IP);
543 break;
544#endif
545#endif
546
Igor Maravic40e47832011-12-05 02:25:57 +0000547#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 case ARPHRD_FDDI:
549 arp->ar_hrd = htons(ARPHRD_ETHER);
550 arp->ar_pro = htons(ETH_P_IP);
551 break;
552#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 }
554
555 arp->ar_hln = dev->addr_len;
556 arp->ar_pln = 4;
557 arp->ar_op = htons(type);
558
Changli Gaodeffd772010-09-02 03:56:51 +0000559 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560
561 memcpy(arp_ptr, src_hw, dev->addr_len);
Jianjun Kongf4cca7f2008-11-03 02:48:14 -0800562 arp_ptr += dev->addr_len;
563 memcpy(arp_ptr, &src_ip, 4);
564 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000565
566 switch (dev->type) {
567#if IS_ENABLED(CONFIG_FIREWIRE_NET)
568 case ARPHRD_IEEE1394:
569 break;
570#endif
571 default:
Ian Morris00db4122015-04-03 09:17:27 +0100572 if (target_hw)
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000573 memcpy(arp_ptr, target_hw, dev->addr_len);
574 else
575 memset(arp_ptr, 0, dev->addr_len);
576 arp_ptr += dev->addr_len;
577 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 memcpy(arp_ptr, &dest_ip, 4);
579
580 return skb;
581
582out:
583 kfree_skb(skb);
584 return NULL;
585}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000586EXPORT_SYMBOL(arp_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588/*
589 * Send an arp packet.
590 */
591void arp_xmit(struct sk_buff *skb)
592{
593 /* Send it off, maybe filter it using firewalling first. */
David Miller7026b1d2015-04-05 22:19:04 -0400594 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, NULL, skb,
595 NULL, skb->dev, dev_queue_xmit_sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000597EXPORT_SYMBOL(arp_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598
599/*
600 * Create and send an arp packet.
601 */
Al Viroed9bad02006-09-27 18:36:36 -0700602void arp_send(int type, int ptype, __be32 dest_ip,
603 struct net_device *dev, __be32 src_ip,
Jan Engelhardtabfdf1c2008-01-31 03:59:24 -0800604 const unsigned char *dest_hw, const unsigned char *src_hw,
605 const unsigned char *target_hw)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606{
607 struct sk_buff *skb;
608
609 /*
610 * No arp on this interface.
611 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 if (dev->flags&IFF_NOARP)
614 return;
615
616 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
617 dest_hw, src_hw, target_hw);
Ian Morris51456b22015-04-03 09:17:26 +0100618 if (!skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
621 arp_xmit(skb);
622}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000623EXPORT_SYMBOL(arp_send);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625/*
626 * Process an arp request.
627 */
628
David Miller7026b1d2015-04-05 22:19:04 -0400629static int arp_process(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630{
631 struct net_device *dev = skb->dev;
Eric Dumazetfaa9dcf2010-06-03 04:09:10 +0000632 struct in_device *in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 struct arphdr *arp;
634 unsigned char *arp_ptr;
635 struct rtable *rt;
Mark Rydene0260fe2007-12-19 23:38:11 -0800636 unsigned char *sha;
Al Viro9e12bb22006-09-26 21:25:20 -0700637 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 u16 dev_type = dev->type;
639 int addr_type;
640 struct neighbour *n;
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900641 struct net *net = dev_net(dev);
Salam Noureddine56022a82013-12-24 14:17:02 -0800642 bool is_garp = false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
644 /* arp_rcv below verifies the ARP header and verifies the device
645 * is ARP'able.
646 */
647
Ian Morris51456b22015-04-03 09:17:26 +0100648 if (!in_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 goto out;
650
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300651 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
653 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900654 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 if (arp->ar_pro != htons(ETH_P_IP) ||
656 htons(dev_type) != arp->ar_hrd)
657 goto out;
658 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 case ARPHRD_ETHER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 case ARPHRD_FDDI:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 case ARPHRD_IEEE802:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 /*
Paul Gortmaker211ed862012-05-10 17:14:35 -0400663 * ETHERNET, and Fibre Channel (which are IEEE 802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 * devices, according to RFC 2625) devices will accept ARP
665 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
666 * This is the case also of FDDI, where the RFC 1390 says that
667 * FDDI devices should accept ARP hardware of (1) Ethernet,
668 * however, to be more robust, we'll accept both 1 (Ethernet)
669 * or 6 (IEEE 802.2)
670 */
671 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
672 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
673 arp->ar_pro != htons(ETH_P_IP))
674 goto out;
675 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 case ARPHRD_AX25:
677 if (arp->ar_pro != htons(AX25_P_IP) ||
678 arp->ar_hrd != htons(ARPHRD_AX25))
679 goto out;
680 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 case ARPHRD_NETROM:
682 if (arp->ar_pro != htons(AX25_P_IP) ||
683 arp->ar_hrd != htons(ARPHRD_NETROM))
684 goto out;
685 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 }
687
688 /* Understand only these message types */
689
690 if (arp->ar_op != htons(ARPOP_REPLY) &&
691 arp->ar_op != htons(ARPOP_REQUEST))
692 goto out;
693
694/*
695 * Extract fields
696 */
Changli Gaodeffd772010-09-02 03:56:51 +0000697 arp_ptr = (unsigned char *)(arp + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 sha = arp_ptr;
699 arp_ptr += dev->addr_len;
700 memcpy(&sip, arp_ptr, 4);
701 arp_ptr += 4;
YOSHIFUJI Hideaki / 吉藤英明6752c8d2013-03-25 08:26:16 +0000702 switch (dev_type) {
703#if IS_ENABLED(CONFIG_FIREWIRE_NET)
704 case ARPHRD_IEEE1394:
705 break;
706#endif
707 default:
708 arp_ptr += dev->addr_len;
709 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900711/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 * Check for bad requests for 127.x.x.x and requests for multicast
713 * addresses. If this is one such, delete it.
714 */
Thomas Grafd0daebc32012-06-12 00:44:01 +0000715 if (ipv4_is_multicast(tip) ||
716 (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 goto out;
718
719/*
720 * Special case: We must set Frame Relay source Q.922 address
721 */
722 if (dev_type == ARPHRD_DLCI)
723 sha = dev->broadcast;
724
725/*
726 * Process entry. The idea here is we want to send a reply if it is a
727 * request for us or if it is a request for someone else that we hold
728 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900729 * to us or if it is a request for our address.
730 * (The assumption for this last is that if someone is requesting our
731 * address, they are probably intending to talk to us, so it saves time
732 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900734 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 * Putting this another way, we only care about replies if they are to
736 * us, in which case we add them to the cache. For requests, we care
737 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900738 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 * cache.
740 */
741
Eric W. Biedermanf8a68e72009-06-30 16:27:17 +0000742 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
743 if (sip == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 if (arp->ar_op == htons(ARPOP_REQUEST) &&
Denis V. Lunev49e8a272008-03-24 15:28:12 -0700745 inet_addr_type(net, tip) == RTN_LOCAL &&
Denis V. Lunev9bd85e32008-01-14 23:05:55 -0800746 !arp_ignore(in_dev, sip, tip))
Jonas Danielssonb4a98112007-11-20 17:38:16 -0800747 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
748 dev->dev_addr, sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 goto out;
750 }
751
752 if (arp->ar_op == htons(ARPOP_REQUEST) &&
David S. Millerc6cffba2012-07-26 11:14:38 +0000753 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
Eric Dumazet511c3f92009-06-02 05:14:27 +0000755 rt = skb_rtable(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 addr_type = rt->rt_type;
757
758 if (addr_type == RTN_LOCAL) {
Changli Gaodeffd772010-09-02 03:56:51 +0000759 int dont_send;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
Changli Gaodeffd772010-09-02 03:56:51 +0000761 dont_send = arp_ignore(in_dev, sip, tip);
Ben Greear8164f1b2008-11-16 19:19:38 -0800762 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
Changli Gaoae9c4162010-12-01 20:07:31 +0000763 dont_send = arp_filter(sip, tip, dev);
Ben Greear8164f1b2008-11-16 19:19:38 -0800764 if (!dont_send) {
765 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
766 if (n) {
Changli Gaodeffd772010-09-02 03:56:51 +0000767 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
768 dev, tip, sha, dev->dev_addr,
769 sha);
Ben Greear8164f1b2008-11-16 19:19:38 -0800770 neigh_release(n);
771 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 }
773 goto out;
774 } else if (IN_DEV_FORWARD(in_dev)) {
Jesper Dangaard Brouer65324142010-01-05 05:50:47 +0000775 if (addr_type == RTN_UNICAST &&
776 (arp_fwd_proxy(in_dev, dev, rt) ||
777 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) ||
Thomas Graf70620c42012-02-10 04:07:11 +0000778 (rt->dst.dev != dev &&
779 pneigh_lookup(&arp_tbl, net, &tip, dev, 0)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
781 if (n)
782 neigh_release(n);
783
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900784 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 skb->pkt_type == PACKET_HOST ||
Jiri Pirko1f9248e2013-12-07 19:26:53 +0100786 NEIGH_VAR(in_dev->arp_parms, PROXY_DELAY) == 0) {
Changli Gaodeffd772010-09-02 03:56:51 +0000787 arp_send(ARPOP_REPLY, ETH_P_ARP, sip,
788 dev, tip, sha, dev->dev_addr,
789 sha);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 } else {
Changli Gaodeffd772010-09-02 03:56:51 +0000791 pneigh_enqueue(&arp_tbl,
792 in_dev->arp_parms, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 return 0;
794 }
795 goto out;
796 }
797 }
798 }
799
800 /* Update our ARP tables */
801
802 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
803
Neil Horman124d37e2012-03-15 05:25:58 +0000804 if (IN_DEV_ARP_ACCEPT(in_dev)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800805 /* Unsolicited ARP is not accepted by default.
806 It is possible, that this option should be enabled for some
807 devices (strip is candidate)
808 */
Salam Noureddine56022a82013-12-24 14:17:02 -0800809 is_garp = arp->ar_op == htons(ARPOP_REQUEST) && tip == sip &&
810 inet_addr_type(net, sip) == RTN_UNICAST;
811
Ian Morris51456b22015-04-03 09:17:26 +0100812 if (!n &&
Salam Noureddine56022a82013-12-24 14:17:02 -0800813 ((arp->ar_op == htons(ARPOP_REPLY) &&
814 inet_addr_type(net, sip) == RTN_UNICAST) || is_garp))
Jean Delvare1b1ac752007-07-14 20:51:44 -0700815 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800816 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817
818 if (n) {
819 int state = NUD_REACHABLE;
820 int override;
821
822 /* If several different ARP replies follows back-to-back,
823 use the FIRST one. It is possible, if several proxy
824 agents are active. Taking the first reply prevents
825 arp trashing and chooses the fastest router.
826 */
Salam Noureddine56022a82013-12-24 14:17:02 -0800827 override = time_after(jiffies,
828 n->updated +
829 NEIGH_VAR(n->parms, LOCKTIME)) ||
830 is_garp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
832 /* Broadcast replies and request packets
833 do not assert neighbour reachability.
834 */
835 if (arp->ar_op != htons(ARPOP_REPLY) ||
836 skb->pkt_type != PACKET_HOST)
837 state = NUD_STALE;
Changli Gaodeffd772010-09-02 03:56:51 +0000838 neigh_update(n, sha, state,
839 override ? NEIGH_UPDATE_F_OVERRIDE : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 neigh_release(n);
841 }
842
843out:
Neil Hormanead2ceb2009-03-11 09:49:55 +0000844 consume_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 return 0;
846}
847
Herbert Xu444fc8f2005-10-03 14:18:10 -0700848static void parp_redo(struct sk_buff *skb)
849{
David Miller7026b1d2015-04-05 22:19:04 -0400850 arp_process(NULL, skb);
Herbert Xu444fc8f2005-10-03 14:18:10 -0700851}
852
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
854/*
855 * Receive an arp request from the device layer.
856 */
857
Adrian Bunk6c97e722006-04-12 13:57:59 -0700858static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
859 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860{
Eric Dumazet044453b2013-02-08 18:48:21 +0000861 const struct arphdr *arp;
862
Rick Jones825bae52014-09-25 10:55:28 -0700863 /* do not tweak dropwatch on an ARP we will ignore */
Eric Dumazet044453b2013-02-08 18:48:21 +0000864 if (dev->flags & IFF_NOARP ||
865 skb->pkt_type == PACKET_OTHERHOST ||
866 skb->pkt_type == PACKET_LOOPBACK)
Rick Jones825bae52014-09-25 10:55:28 -0700867 goto consumeskb;
Eric Dumazet044453b2013-02-08 18:48:21 +0000868
869 skb = skb_share_check(skb, GFP_ATOMIC);
870 if (!skb)
871 goto out_of_mem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
873 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
Pavel Emelyanov988b7052008-03-03 12:20:57 -0800874 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 goto freeskb;
876
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300877 arp = arp_hdr(skb);
Eric Dumazet044453b2013-02-08 18:48:21 +0000878 if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 goto freeskb;
880
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700881 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
882
David Miller7026b1d2015-04-05 22:19:04 -0400883 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, NULL, skb,
884 dev, NULL, arp_process);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885
Rick Jones825bae52014-09-25 10:55:28 -0700886consumeskb:
887 consume_skb(skb);
888 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889freeskb:
890 kfree_skb(skb);
891out_of_mem:
892 return 0;
893}
894
895/*
896 * User level interface (ioctl)
897 */
898
899/*
900 * Set (create) an ARP cache entry.
901 */
902
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800903static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on)
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800904{
Ian Morris51456b22015-04-03 09:17:26 +0100905 if (!dev) {
Pavel Emelyanov586f1212007-12-16 13:32:48 -0800906 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800907 return 0;
908 }
Eric Dumazetc5066532011-01-24 13:16:16 -0800909 if (__in_dev_get_rtnl(dev)) {
910 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800911 return 0;
912 }
913 return -ENXIO;
914}
915
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800916static int arp_req_set_public(struct net *net, struct arpreq *r,
917 struct net_device *dev)
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800918{
919 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
920 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
921
922 if (mask && mask != htonl(0xFFFFFFFF))
923 return -EINVAL;
924 if (!dev && (r->arp_flags & ATF_COM)) {
Eric Dumazet941666c2010-12-05 01:23:53 +0000925 dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family,
Changli Gaodeffd772010-09-02 03:56:51 +0000926 r->arp_ha.sa_data);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800927 if (!dev)
928 return -ENODEV;
929 }
930 if (mask) {
Ian Morris51456b22015-04-03 09:17:26 +0100931 if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1))
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800932 return -ENOBUFS;
933 return 0;
934 }
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -0800935
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800936 return arp_req_set_proxy(net, dev, 1);
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800937}
938
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800939static int arp_req_set(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +0000940 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941{
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800942 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 struct neighbour *neigh;
944 int err;
945
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800946 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -0800947 return arp_req_set_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948
Pavel Emelyanov43dc1702007-12-05 21:19:44 -0800949 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 if (r->arp_flags & ATF_PERM)
951 r->arp_flags |= ATF_COM;
Ian Morris51456b22015-04-03 09:17:26 +0100952 if (!dev) {
David S. Miller78fbfd82011-03-12 00:00:52 -0500953 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800954
955 if (IS_ERR(rt))
956 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -0700957 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 ip_rt_put(rt);
959 if (!dev)
960 return -EINVAL;
961 }
962 switch (dev->type) {
Igor Maravic40e47832011-12-05 02:25:57 +0000963#if IS_ENABLED(CONFIG_FDDI)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 case ARPHRD_FDDI:
965 /*
966 * According to RFC 1390, FDDI devices should accept ARP
967 * hardware types of 1 (Ethernet). However, to be more
968 * robust, we'll accept hardware types of either 1 (Ethernet)
969 * or 6 (IEEE 802.2).
970 */
971 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
972 r->arp_ha.sa_family != ARPHRD_ETHER &&
973 r->arp_ha.sa_family != ARPHRD_IEEE802)
974 return -EINVAL;
975 break;
976#endif
977 default:
978 if (r->arp_ha.sa_family != dev->type)
979 return -EINVAL;
980 break;
981 }
982
983 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
984 err = PTR_ERR(neigh);
985 if (!IS_ERR(neigh)) {
Eric Dumazet95c96172012-04-15 05:58:06 +0000986 unsigned int state = NUD_STALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 if (r->arp_flags & ATF_PERM)
988 state = NUD_PERMANENT;
Changli Gaodeffd772010-09-02 03:56:51 +0000989 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900990 r->arp_ha.sa_data : NULL, state,
Changli Gaodeffd772010-09-02 03:56:51 +0000991 NEIGH_UPDATE_F_OVERRIDE |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 NEIGH_UPDATE_F_ADMIN);
993 neigh_release(neigh);
994 }
995 return err;
996}
997
Eric Dumazet95c96172012-04-15 05:58:06 +0000998static unsigned int arp_state_to_flags(struct neighbour *neigh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 if (neigh->nud_state&NUD_PERMANENT)
Changli Gaodeffd772010-09-02 03:56:51 +00001001 return ATF_PERM | ATF_COM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 else if (neigh->nud_state&NUD_VALID)
Changli Gaodeffd772010-09-02 03:56:51 +00001003 return ATF_COM;
1004 else
1005 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006}
1007
1008/*
1009 * Get an ARP cache entry.
1010 */
1011
1012static int arp_req_get(struct arpreq *r, struct net_device *dev)
1013{
Al Viroed9bad02006-09-27 18:36:36 -07001014 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 struct neighbour *neigh;
1016 int err = -ENXIO;
1017
1018 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1019 if (neigh) {
1020 read_lock_bh(&neigh->lock);
1021 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1022 r->arp_flags = arp_state_to_flags(neigh);
1023 read_unlock_bh(&neigh->lock);
1024 r->arp_ha.sa_family = dev->type;
1025 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1026 neigh_release(neigh);
1027 err = 0;
1028 }
1029 return err;
1030}
1031
Stephen Hemminger7195cf72013-12-28 11:07:18 -08001032static int arp_invalidate(struct net_device *dev, __be32 ip)
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001033{
1034 struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev);
1035 int err = -ENXIO;
1036
1037 if (neigh) {
1038 if (neigh->nud_state & ~NUD_NOARP)
1039 err = neigh_update(neigh, NULL, NUD_FAILED,
1040 NEIGH_UPDATE_F_OVERRIDE|
1041 NEIGH_UPDATE_F_ADMIN);
1042 neigh_release(neigh);
1043 }
1044
1045 return err;
1046}
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001047
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001048static int arp_req_delete_public(struct net *net, struct arpreq *r,
1049 struct net_device *dev)
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001050{
1051 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1052 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1053
1054 if (mask == htonl(0xFFFFFFFF))
Denis V. Lunev2db82b52008-01-14 22:58:55 -08001055 return pneigh_delete(&arp_tbl, net, &ip, dev);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001056
Pavel Emelyanovf8b33fd2007-12-05 21:20:50 -08001057 if (mask)
1058 return -EINVAL;
1059
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001060 return arp_req_set_proxy(net, dev, 0);
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001061}
1062
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001063static int arp_req_delete(struct net *net, struct arpreq *r,
Changli Gaodeffd772010-09-02 03:56:51 +00001064 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065{
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001066 __be32 ip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001068 if (r->arp_flags & ATF_PUBL)
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001069 return arp_req_delete_public(net, r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070
Pavel Emelyanov46479b42007-12-05 21:20:18 -08001071 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Ian Morris51456b22015-04-03 09:17:26 +01001072 if (!dev) {
David S. Miller78fbfd82011-03-12 00:00:52 -05001073 struct rtable *rt = ip_route_output(net, ip, 0, RTO_ONLINK, 0);
David S. Millerb23dd4f2011-03-02 14:31:35 -08001074 if (IS_ERR(rt))
1075 return PTR_ERR(rt);
Changli Gaod8d1f302010-06-10 23:31:35 -07001076 dev = rt->dst.dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 ip_rt_put(rt);
1078 if (!dev)
1079 return -EINVAL;
1080 }
Maxim Levitsky545ecdc2011-01-08 13:57:12 +00001081 return arp_invalidate(dev, ip);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082}
1083
1084/*
1085 * Handle an ARP layer I/O control request.
1086 */
1087
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001088int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089{
1090 int err;
1091 struct arpreq r;
1092 struct net_device *dev = NULL;
1093
1094 switch (cmd) {
Changli Gaodeffd772010-09-02 03:56:51 +00001095 case SIOCDARP:
1096 case SIOCSARP:
Eric W. Biederman52e804c2012-11-16 03:03:05 +00001097 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
Changli Gaodeffd772010-09-02 03:56:51 +00001098 return -EPERM;
1099 case SIOCGARP:
1100 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1101 if (err)
1102 return -EFAULT;
1103 break;
1104 default:
1105 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 }
1107
1108 if (r.arp_pa.sa_family != AF_INET)
1109 return -EPFNOSUPPORT;
1110
1111 if (!(r.arp_flags & ATF_PUBL) &&
Changli Gaodeffd772010-09-02 03:56:51 +00001112 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113 return -EINVAL;
1114 if (!(r.arp_flags & ATF_NETMASK))
1115 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1116 htonl(0xFFFFFFFFUL);
Eric Dumazetc5066532011-01-24 13:16:16 -08001117 rtnl_lock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118 if (r.arp_dev[0]) {
1119 err = -ENODEV;
Eric Dumazetc5066532011-01-24 13:16:16 -08001120 dev = __dev_get_by_name(net, r.arp_dev);
Ian Morris51456b22015-04-03 09:17:26 +01001121 if (!dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 goto out;
1123
1124 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1125 if (!r.arp_ha.sa_family)
1126 r.arp_ha.sa_family = dev->type;
1127 err = -EINVAL;
1128 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1129 goto out;
1130 } else if (cmd == SIOCGARP) {
1131 err = -ENODEV;
1132 goto out;
1133 }
1134
Stephen Hemminger132adf52007-03-08 20:44:43 -08001135 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 case SIOCDARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001137 err = arp_req_delete(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 break;
1139 case SIOCSARP:
Pavel Emelyanov32e569b2007-12-16 13:30:39 -08001140 err = arp_req_set(net, &r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 break;
1142 case SIOCGARP:
1143 err = arp_req_get(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 break;
1145 }
1146out:
Eric Dumazetc5066532011-01-24 13:16:16 -08001147 rtnl_unlock();
Eric Dumazet941666c2010-12-05 01:23:53 +00001148 if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r)))
1149 err = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 return err;
1151}
1152
Changli Gaodeffd772010-09-02 03:56:51 +00001153static int arp_netdev_event(struct notifier_block *this, unsigned long event,
1154 void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155{
Jiri Pirko351638e2013-05-28 01:30:21 +00001156 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
Timo Teräs6c8b4e32013-05-28 01:30:23 +00001157 struct netdev_notifier_change_info *change_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158
1159 switch (event) {
1160 case NETDEV_CHANGEADDR:
1161 neigh_changeaddr(&arp_tbl, dev);
Nicolas Dichtelbafa6d92012-09-07 00:45:29 +00001162 rt_cache_flush(dev_net(dev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 break;
Timo Teräs6c8b4e32013-05-28 01:30:23 +00001164 case NETDEV_CHANGE:
1165 change_info = ptr;
1166 if (change_info->flags_changed & IFF_NOARP)
1167 neigh_changeaddr(&arp_tbl, dev);
1168 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 default:
1170 break;
1171 }
1172
1173 return NOTIFY_DONE;
1174}
1175
1176static struct notifier_block arp_netdev_notifier = {
1177 .notifier_call = arp_netdev_event,
1178};
1179
1180/* Note, that it is not on notifier chain.
1181 It is necessary, that this routine was called after route cache will be
1182 flushed.
1183 */
1184void arp_ifdown(struct net_device *dev)
1185{
1186 neigh_ifdown(&arp_tbl, dev);
1187}
1188
1189
1190/*
1191 * Called once on startup.
1192 */
1193
Stephen Hemminger7546dd92009-03-09 08:18:29 +00001194static struct packet_type arp_packet_type __read_mostly = {
Harvey Harrison09640e62009-02-01 00:45:17 -08001195 .type = cpu_to_be16(ETH_P_ARP),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196 .func = arp_rcv,
1197};
1198
1199static int arp_proc_init(void);
1200
1201void __init arp_init(void)
1202{
WANG Congd7480fd2014-11-10 15:59:36 -08001203 neigh_table_init(NEIGH_ARP_TABLE, &arp_tbl);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204
1205 dev_add_pack(&arp_packet_type);
1206 arp_proc_init();
1207#ifdef CONFIG_SYSCTL
Jiri Pirko73af6142013-12-07 19:26:55 +01001208 neigh_sysctl_register(NULL, &arp_tbl.parms, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209#endif
1210 register_netdevice_notifier(&arp_netdev_notifier);
1211}
1212
1213#ifdef CONFIG_PROC_FS
Igor Maravic40e47832011-12-05 02:25:57 +00001214#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215
1216/* ------------------------------------------------------------------------ */
1217/*
1218 * ax25 -> ASCII conversion
1219 */
1220static char *ax2asc2(ax25_address *a, char *buf)
1221{
1222 char c, *s;
1223 int n;
1224
1225 for (n = 0, s = buf; n < 6; n++) {
1226 c = (a->ax25_call[n] >> 1) & 0x7F;
1227
Changli Gaodeffd772010-09-02 03:56:51 +00001228 if (c != ' ')
1229 *s++ = c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001231
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 *s++ = '-';
Changli Gaodeffd772010-09-02 03:56:51 +00001233 n = (a->ax25_call[6] >> 1) & 0x0F;
1234 if (n > 9) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 *s++ = '1';
1236 n -= 10;
1237 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001238
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 *s++ = n + '0';
1240 *s++ = '\0';
1241
1242 if (*buf == '\0' || *buf == '-')
Changli Gaodeffd772010-09-02 03:56:51 +00001243 return "*";
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244
1245 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246}
1247#endif /* CONFIG_AX25 */
1248
1249#define HBUFFERLEN 30
1250
1251static void arp_format_neigh_entry(struct seq_file *seq,
1252 struct neighbour *n)
1253{
1254 char hbuffer[HBUFFERLEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 int k, j;
1256 char tbuf[16];
1257 struct net_device *dev = n->dev;
1258 int hatype = dev->type;
1259
1260 read_lock(&n->lock);
1261 /* Convert hardware address to XX:XX:XX:XX ... form. */
Igor Maravic40e47832011-12-05 02:25:57 +00001262#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1264 ax2asc2((ax25_address *)n->ha, hbuffer);
1265 else {
1266#endif
1267 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
Denis Cheng51f82a22008-05-21 17:34:32 -07001268 hbuffer[k++] = hex_asc_hi(n->ha[j]);
1269 hbuffer[k++] = hex_asc_lo(n->ha[j]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 hbuffer[k++] = ':';
1271 }
roel kluina3e8ee62009-07-29 23:46:59 +00001272 if (k != 0)
1273 --k;
1274 hbuffer[k] = 0;
Igor Maravic40e47832011-12-05 02:25:57 +00001275#if IS_ENABLED(CONFIG_AX25)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 }
1277#endif
Harvey Harrison673d57e2008-10-31 00:53:57 -07001278 sprintf(tbuf, "%pI4", n->primary_key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1280 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1281 read_unlock(&n->lock);
1282}
1283
1284static void arp_format_pneigh_entry(struct seq_file *seq,
1285 struct pneigh_entry *n)
1286{
1287 struct net_device *dev = n->dev;
1288 int hatype = dev ? dev->type : 0;
1289 char tbuf[16];
1290
Harvey Harrison673d57e2008-10-31 00:53:57 -07001291 sprintf(tbuf, "%pI4", n->key);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1293 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1294 dev ? dev->name : "*");
1295}
1296
1297static int arp_seq_show(struct seq_file *seq, void *v)
1298{
1299 if (v == SEQ_START_TOKEN) {
1300 seq_puts(seq, "IP address HW type Flags "
1301 "HW address Mask Device\n");
1302 } else {
1303 struct neigh_seq_state *state = seq->private;
1304
1305 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1306 arp_format_pneigh_entry(seq, v);
1307 else
1308 arp_format_neigh_entry(seq, v);
1309 }
1310
1311 return 0;
1312}
1313
1314static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1315{
1316 /* Don't want to confuse "arp -a" w/ magic entries,
1317 * so we tell the generic iterator to skip NUD_NOARP.
1318 */
1319 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1320}
1321
1322/* ------------------------------------------------------------------------ */
1323
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001324static const struct seq_operations arp_seq_ops = {
Changli Gaodeffd772010-09-02 03:56:51 +00001325 .start = arp_seq_start,
1326 .next = neigh_seq_next,
1327 .stop = neigh_seq_stop,
1328 .show = arp_seq_show,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329};
1330
1331static int arp_seq_open(struct inode *inode, struct file *file)
1332{
Eric W. Biederman426b5302008-01-24 00:13:18 -08001333 return seq_open_net(inode, file, &arp_seq_ops,
1334 sizeof(struct neigh_seq_state));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335}
1336
Arjan van de Ven9a321442007-02-12 00:55:35 -08001337static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 .owner = THIS_MODULE,
1339 .open = arp_seq_open,
1340 .read = seq_read,
1341 .llseek = seq_lseek,
Eric W. Biederman426b5302008-01-24 00:13:18 -08001342 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343};
1344
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001345
1346static int __net_init arp_net_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347{
Gao fengd4beaa62013-02-18 01:34:54 +00001348 if (!proc_create("arp", S_IRUGO, net->proc_net, &arp_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349 return -ENOMEM;
1350 return 0;
1351}
1352
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001353static void __net_exit arp_net_exit(struct net *net)
1354{
Gao fengece31ff2013-02-18 01:34:56 +00001355 remove_proc_entry("arp", net->proc_net);
Denis V. Lunevffc31d32008-03-24 15:28:43 -07001356}
1357
1358static struct pernet_operations arp_net_ops = {
1359 .init = arp_net_init,
1360 .exit = arp_net_exit,
1361};
1362
1363static int __init arp_proc_init(void)
1364{
1365 return register_pernet_subsys(&arp_net_ops);
1366}
1367
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368#else /* CONFIG_PROC_FS */
1369
1370static int __init arp_proc_init(void)
1371{
1372 return 0;
1373}
1374
1375#endif /* CONFIG_PROC_FS */