blob: d8248198bcd721611336f38276ce84310ea53384 [file] [log] [blame]
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02001/* linux/net/ipv4/arp.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
3 * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $
4 *
5 * Copyright (C) 1994 by Florian La Roche
6 *
7 * This module implements the Address Resolution Protocol ARP (RFC 826),
8 * which is used to convert IP addresses (or in the future maybe other
9 * high-level addresses) into a low-level hardware address (like an Ethernet
10 * address).
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Fixes:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090018 * Alan Cox : Removed the Ethernet assumptions in
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * Florian's code
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090020 * Alan Cox : Fixed some small errors in the ARP
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * logic
22 * Alan Cox : Allow >4K in /proc
23 * Alan Cox : Make ARP add its own protocol entry
24 * Ross Martin : Rewrote arp_rcv() and arp_get_info()
25 * Stephen Henson : Add AX25 support to arp_get_info()
26 * Alan Cox : Drop data when a device is downed.
27 * Alan Cox : Use init_timer().
28 * Alan Cox : Double lock fixes.
29 * Martin Seine : Move the arphdr structure
30 * to if_arp.h for compatibility.
31 * with BSD based programs.
32 * Andrew Tridgell : Added ARP netmask code and
33 * re-arranged proxy handling.
34 * Alan Cox : Changed to use notifiers.
35 * Niibe Yutaka : Reply for this device or proxies only.
36 * Alan Cox : Don't proxy across hardware types!
37 * Jonathan Naylor : Added support for NET/ROM.
38 * Mike Shaver : RFC1122 checks.
39 * Jonathan Naylor : Only lookup the hardware address for
40 * the correct hardware type.
41 * Germano Caronni : Assorted subtle races.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090042 * Craig Schlenter : Don't modify permanent entry
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 * during arp_rcv.
44 * Russ Nelson : Tidied up a few bits.
45 * Alexey Kuznetsov: Major changes to caching and behaviour,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090046 * eg intelligent arp probing and
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 * generation
48 * of host down events.
49 * Alan Cox : Missing unlock in device events.
50 * Eckes : ARP ioctl control errors.
51 * Alexey Kuznetsov: Arp free fix.
52 * Manuel Rodriguez: Gratuitous ARP.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090053 * Jonathan Layes : Added arpd support through kerneld
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 * message queue (960314)
55 * Mike Shaver : /proc/sys/net/ipv4/arp_* support
56 * Mike McLagan : Routing by source
57 * Stuart Cheshire : Metricom and grat arp fixes
58 * *** FOR 2.1 clean this up ***
59 * Lawrence V. Stefani: (08/12/96) Added FDDI support.
60 * Alan Cox : Took the AP1000 nasty FDDI hack and
61 * folded into the mainstream FDDI code.
62 * Ack spit, Linus how did you allow that
63 * one in...
64 * Jes Sorensen : Make FDDI work again in 2.1.x and
65 * clean up the APFDDI & gen. FDDI bits.
66 * Alexey Kuznetsov: new arp state machine;
67 * now it is in net/core/neighbour.c.
68 * Krzysztof Halasa: Added Frame Relay ARP support.
69 * Arnaldo C. Melo : convert /proc/net/arp to seq_file
70 * Shmulik Hen: Split arp_send to arp_create and
71 * arp_xmit so intermediate drivers like
72 * bonding can change the skb before
73 * sending (e.g. insert 8021q tag).
74 * Harald Welte : convert to make use of jenkins hash
75 */
76
77#include <linux/module.h>
78#include <linux/types.h>
79#include <linux/string.h>
80#include <linux/kernel.h>
Randy Dunlap4fc268d2006-01-11 12:17:47 -080081#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070082#include <linux/socket.h>
83#include <linux/sockios.h>
84#include <linux/errno.h>
85#include <linux/in.h>
86#include <linux/mm.h>
87#include <linux/inet.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020088#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#include <linux/netdevice.h>
90#include <linux/etherdevice.h>
91#include <linux/fddidevice.h>
92#include <linux/if_arp.h>
93#include <linux/trdevice.h>
94#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>
101#include <linux/jhash.h>
102#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>
114#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
115#include <net/ax25.h>
116#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
117#include <net/netrom.h>
118#endif
119#endif
120#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
121#include <net/atmclip.h>
122struct neigh_table *clip_tbl_hook;
123#endif
124
125#include <asm/system.h>
126#include <asm/uaccess.h>
127
128#include <linux/netfilter_arp.h>
129
130/*
131 * Interface to generic neighbour cache.
132 */
133static u32 arp_hash(const void *pkey, const struct net_device *dev);
134static int arp_constructor(struct neighbour *neigh);
135static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
136static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
137static void parp_redo(struct sk_buff *skb);
138
139static struct neigh_ops arp_generic_ops = {
140 .family = AF_INET,
141 .solicit = arp_solicit,
142 .error_report = arp_error_report,
143 .output = neigh_resolve_output,
144 .connected_output = neigh_connected_output,
145 .hh_output = dev_queue_xmit,
146 .queue_xmit = dev_queue_xmit,
147};
148
149static struct neigh_ops arp_hh_ops = {
150 .family = AF_INET,
151 .solicit = arp_solicit,
152 .error_report = arp_error_report,
153 .output = neigh_resolve_output,
154 .connected_output = neigh_resolve_output,
155 .hh_output = dev_queue_xmit,
156 .queue_xmit = dev_queue_xmit,
157};
158
159static struct neigh_ops arp_direct_ops = {
160 .family = AF_INET,
161 .output = dev_queue_xmit,
162 .connected_output = dev_queue_xmit,
163 .hh_output = dev_queue_xmit,
164 .queue_xmit = dev_queue_xmit,
165};
166
167struct neigh_ops arp_broken_ops = {
168 .family = AF_INET,
169 .solicit = arp_solicit,
170 .error_report = arp_error_report,
171 .output = neigh_compat_output,
172 .connected_output = neigh_compat_output,
173 .hh_output = dev_queue_xmit,
174 .queue_xmit = dev_queue_xmit,
175};
176
177struct neigh_table arp_tbl = {
178 .family = AF_INET,
179 .entry_size = sizeof(struct neighbour) + 4,
180 .key_len = 4,
181 .hash = arp_hash,
182 .constructor = arp_constructor,
183 .proxy_redo = parp_redo,
184 .id = "arp_cache",
185 .parms = {
186 .tbl = &arp_tbl,
187 .base_reachable_time = 30 * HZ,
188 .retrans_time = 1 * HZ,
189 .gc_staletime = 60 * HZ,
190 .reachable_time = 30 * HZ,
191 .delay_probe_time = 5 * HZ,
192 .queue_len = 3,
193 .ucast_probes = 3,
194 .mcast_probes = 3,
195 .anycast_delay = 1 * HZ,
196 .proxy_delay = (8 * HZ) / 10,
197 .proxy_qlen = 64,
198 .locktime = 1 * HZ,
199 },
200 .gc_interval = 30 * HZ,
201 .gc_thresh1 = 128,
202 .gc_thresh2 = 512,
203 .gc_thresh3 = 1024,
204};
205
Al Viro714e85b2006-11-14 20:51:49 -0800206int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
208 switch (dev->type) {
209 case ARPHRD_ETHER:
210 case ARPHRD_FDDI:
211 case ARPHRD_IEEE802:
212 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900213 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 case ARPHRD_IEEE802_TR:
215 ip_tr_mc_map(addr, haddr);
216 return 0;
217 case ARPHRD_INFINIBAND:
218 ip_ib_mc_map(addr, haddr);
219 return 0;
220 default:
221 if (dir) {
222 memcpy(haddr, dev->broadcast, dev->addr_len);
223 return 0;
224 }
225 }
226 return -EINVAL;
227}
228
229
230static u32 arp_hash(const void *pkey, const struct net_device *dev)
231{
232 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd);
233}
234
235static int arp_constructor(struct neighbour *neigh)
236{
Al Virofd683222006-09-26 22:17:51 -0700237 __be32 addr = *(__be32*)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 struct net_device *dev = neigh->dev;
239 struct in_device *in_dev;
240 struct neigh_parms *parms;
241
242 neigh->type = inet_addr_type(addr);
243
244 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700245 in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (in_dev == NULL) {
247 rcu_read_unlock();
248 return -EINVAL;
249 }
250
251 parms = in_dev->arp_parms;
252 __neigh_parms_put(neigh->parms);
253 neigh->parms = neigh_parms_clone(parms);
254 rcu_read_unlock();
255
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700256 if (!dev->header_ops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 neigh->nud_state = NUD_NOARP;
258 neigh->ops = &arp_direct_ops;
259 neigh->output = neigh->ops->queue_xmit;
260 } else {
261 /* Good devices (checked by reading texts, but only Ethernet is
262 tested)
263
264 ARPHRD_ETHER: (ethernet, apfddi)
265 ARPHRD_FDDI: (fddi)
266 ARPHRD_IEEE802: (tr)
267 ARPHRD_METRICOM: (strip)
268 ARPHRD_ARCNET:
269 etc. etc. etc.
270
271 ARPHRD_IPDDP will also work, if author repairs it.
272 I did not it, because this driver does not work even
273 in old paradigm.
274 */
275
276#if 1
277 /* So... these "amateur" devices are hopeless.
278 The only thing, that I can say now:
279 It is very sad that we need to keep ugly obsolete
280 code to make them happy.
281
282 They should be moved to more reasonable state, now
283 they use rebuild_header INSTEAD OF hard_start_xmit!!!
284 Besides that, they are sort of out of date
285 (a lot of redundant clones/copies, useless in 2.1),
286 I wonder why people believe that they work.
287 */
288 switch (dev->type) {
289 default:
290 break;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900291 case ARPHRD_ROSE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
293 case ARPHRD_AX25:
294#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
295 case ARPHRD_NETROM:
296#endif
297 neigh->ops = &arp_broken_ops;
298 neigh->output = neigh->ops->output;
299 return 0;
300#endif
301 ;}
302#endif
303 if (neigh->type == RTN_MULTICAST) {
304 neigh->nud_state = NUD_NOARP;
305 arp_mc_map(addr, neigh->ha, dev, 1);
306 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
307 neigh->nud_state = NUD_NOARP;
308 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
309 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) {
310 neigh->nud_state = NUD_NOARP;
311 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
312 }
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700313
314 if (dev->header_ops->cache)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 neigh->ops = &arp_hh_ops;
316 else
317 neigh->ops = &arp_generic_ops;
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700318
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 if (neigh->nud_state&NUD_VALID)
320 neigh->output = neigh->ops->connected_output;
321 else
322 neigh->output = neigh->ops->output;
323 }
324 return 0;
325}
326
327static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
328{
329 dst_link_failure(skb);
330 kfree_skb(skb);
331}
332
333static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
334{
Al Viroa61ced52006-09-26 21:27:54 -0700335 __be32 saddr = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 u8 *dst_ha = NULL;
337 struct net_device *dev = neigh->dev;
Al Viroa61ced52006-09-26 21:27:54 -0700338 __be32 target = *(__be32*)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 int probes = atomic_read(&neigh->probes);
340 struct in_device *in_dev = in_dev_get(dev);
341
342 if (!in_dev)
343 return;
344
345 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
346 default:
347 case 0: /* By default announce any local IP */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700348 if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
349 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 break;
351 case 1: /* Restrict announcements of saddr in same subnet */
352 if (!skb)
353 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700354 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 if (inet_addr_type(saddr) == RTN_LOCAL) {
356 /* saddr should be known to target */
357 if (inet_addr_onlink(in_dev, target, saddr))
358 break;
359 }
360 saddr = 0;
361 break;
362 case 2: /* Avoid secondary IPs, get a primary/preferred one */
363 break;
364 }
365
366 if (in_dev)
367 in_dev_put(in_dev);
368 if (!saddr)
369 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
370
371 if ((probes -= neigh->parms->ucast_probes) < 0) {
372 if (!(neigh->nud_state&NUD_VALID))
373 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
374 dst_ha = neigh->ha;
375 read_lock_bh(&neigh->lock);
376 } else if ((probes -= neigh->parms->app_probes) < 0) {
377#ifdef CONFIG_ARPD
378 neigh_app_ns(neigh);
379#endif
380 return;
381 }
382
383 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
384 dst_ha, dev->dev_addr, NULL);
385 if (dst_ha)
386 read_unlock_bh(&neigh->lock);
387}
388
389static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
Al Viroed9bad02006-09-27 18:36:36 -0700390 __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391{
392 int scope;
393
394 switch (IN_DEV_ARP_IGNORE(in_dev)) {
395 case 0: /* Reply, the tip is already validated */
396 return 0;
397 case 1: /* Reply only if tip is configured on the incoming interface */
398 sip = 0;
399 scope = RT_SCOPE_HOST;
400 break;
401 case 2: /*
402 * Reply only if tip is configured on the incoming interface
403 * and is in same subnet as sip
404 */
405 scope = RT_SCOPE_HOST;
406 break;
407 case 3: /* Do not reply for scope host addresses */
408 sip = 0;
409 scope = RT_SCOPE_LINK;
410 dev = NULL;
411 break;
412 case 4: /* Reserved */
413 case 5:
414 case 6:
415 case 7:
416 return 0;
417 case 8: /* Do not reply */
418 return 1;
419 default:
420 return 0;
421 }
422 return !inet_confirm_addr(dev, sip, tip, scope);
423}
424
Al Viroed9bad02006-09-27 18:36:36 -0700425static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426{
427 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
428 .saddr = tip } } };
429 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900430 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 /*unsigned long now; */
432
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900433 if (ip_route_output_key(&rt, &fl) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 return 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900435 if (rt->u.dst.dev != dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER);
437 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900438 }
439 ip_rt_put(rt);
440 return flag;
441}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442
443/* OBSOLETE FUNCTIONS */
444
445/*
446 * Find an arp mapping in the cache. If not found, post a request.
447 *
448 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
449 * even if it exists. It is supposed that skb->dev was mangled
450 * by a virtual device (eql, shaper). Nobody but broken devices
451 * is allowed to use this function, it is scheduled to be removed. --ANK
452 */
453
Al Viroed9bad02006-09-27 18:36:36 -0700454static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455{
456 switch (addr_hint) {
457 case RTN_LOCAL:
458 printk(KERN_DEBUG "ARP: arp called for own IP address\n");
459 memcpy(haddr, dev->dev_addr, dev->addr_len);
460 return 1;
461 case RTN_MULTICAST:
462 arp_mc_map(paddr, haddr, dev, 1);
463 return 1;
464 case RTN_BROADCAST:
465 memcpy(haddr, dev->broadcast, dev->addr_len);
466 return 1;
467 }
468 return 0;
469}
470
471
472int arp_find(unsigned char *haddr, struct sk_buff *skb)
473{
474 struct net_device *dev = skb->dev;
Al Virofd683222006-09-26 22:17:51 -0700475 __be32 paddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 struct neighbour *n;
477
478 if (!skb->dst) {
479 printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
480 kfree_skb(skb);
481 return 1;
482 }
483
484 paddr = ((struct rtable*)skb->dst)->rt_gateway;
485
486 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev))
487 return 0;
488
489 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
490
491 if (n) {
492 n->used = jiffies;
493 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
494 read_lock_bh(&n->lock);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900495 memcpy(haddr, n->ha, dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 read_unlock_bh(&n->lock);
497 neigh_release(n);
498 return 0;
499 }
500 neigh_release(n);
501 } else
502 kfree_skb(skb);
503 return 1;
504}
505
506/* END OF OBSOLETE FUNCTIONS */
507
508int arp_bind_neighbour(struct dst_entry *dst)
509{
510 struct net_device *dev = dst->dev;
511 struct neighbour *n = dst->neighbour;
512
513 if (dev == NULL)
514 return -EINVAL;
515 if (n == NULL) {
Al Viroed9bad02006-09-27 18:36:36 -0700516 __be32 nexthop = ((struct rtable*)dst)->rt_gateway;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
518 nexthop = 0;
519 n = __neigh_lookup_errno(
520#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
521 dev->type == ARPHRD_ATM ? clip_tbl_hook :
522#endif
523 &arp_tbl, &nexthop, dev);
524 if (IS_ERR(n))
525 return PTR_ERR(n);
526 dst->neighbour = n;
527 }
528 return 0;
529}
530
531/*
532 * Check if we can use proxy ARP for this path
533 */
534
535static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
536{
537 struct in_device *out_dev;
538 int imi, omi = -1;
539
540 if (!IN_DEV_PROXY_ARP(in_dev))
541 return 0;
542
543 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
544 return 1;
545 if (imi == -1)
546 return 0;
547
548 /* place to check for proxy_arp for routes */
549
550 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
551 omi = IN_DEV_MEDIUM_ID(out_dev);
552 in_dev_put(out_dev);
553 }
554 return (omi != imi && omi != -1);
555}
556
557/*
558 * Interface to link layer: send routine and receive handler.
559 */
560
561/*
562 * Create an arp packet. If (dest_hw == NULL), we create a broadcast
563 * message.
564 */
Al Viroed9bad02006-09-27 18:36:36 -0700565struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
566 struct net_device *dev, __be32 src_ip,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 unsigned char *dest_hw, unsigned char *src_hw,
568 unsigned char *target_hw)
569{
570 struct sk_buff *skb;
571 struct arphdr *arp;
572 unsigned char *arp_ptr;
573
574 /*
575 * Allocate a buffer
576 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900577
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
579 + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
580 if (skb == NULL)
581 return NULL;
582
583 skb_reserve(skb, LL_RESERVED_SPACE(dev));
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700584 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
586 skb->dev = dev;
587 skb->protocol = htons(ETH_P_ARP);
588 if (src_hw == NULL)
589 src_hw = dev->dev_addr;
590 if (dest_hw == NULL)
591 dest_hw = dev->broadcast;
592
593 /*
594 * Fill the device header for the ARP frame
595 */
Stephen Hemminger0c4e8582007-10-09 01:36:32 -0700596 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 goto out;
598
599 /*
600 * Fill out the arp protocol part.
601 *
602 * The arp hardware type should match the device type, except for FDDI,
603 * which (according to RFC 1390) should always equal 1 (Ethernet).
604 */
605 /*
606 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
607 * DIX code for the protocol. Make these device structure fields.
608 */
609 switch (dev->type) {
610 default:
611 arp->ar_hrd = htons(dev->type);
612 arp->ar_pro = htons(ETH_P_IP);
613 break;
614
615#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
616 case ARPHRD_AX25:
617 arp->ar_hrd = htons(ARPHRD_AX25);
618 arp->ar_pro = htons(AX25_P_IP);
619 break;
620
621#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
622 case ARPHRD_NETROM:
623 arp->ar_hrd = htons(ARPHRD_NETROM);
624 arp->ar_pro = htons(AX25_P_IP);
625 break;
626#endif
627#endif
628
629#ifdef CONFIG_FDDI
630 case ARPHRD_FDDI:
631 arp->ar_hrd = htons(ARPHRD_ETHER);
632 arp->ar_pro = htons(ETH_P_IP);
633 break;
634#endif
635#ifdef CONFIG_TR
636 case ARPHRD_IEEE802_TR:
637 arp->ar_hrd = htons(ARPHRD_IEEE802);
638 arp->ar_pro = htons(ETH_P_IP);
639 break;
640#endif
641 }
642
643 arp->ar_hln = dev->addr_len;
644 arp->ar_pln = 4;
645 arp->ar_op = htons(type);
646
647 arp_ptr=(unsigned char *)(arp+1);
648
649 memcpy(arp_ptr, src_hw, dev->addr_len);
650 arp_ptr+=dev->addr_len;
651 memcpy(arp_ptr, &src_ip,4);
652 arp_ptr+=4;
653 if (target_hw != NULL)
654 memcpy(arp_ptr, target_hw, dev->addr_len);
655 else
656 memset(arp_ptr, 0, dev->addr_len);
657 arp_ptr+=dev->addr_len;
658 memcpy(arp_ptr, &dest_ip, 4);
659
660 return skb;
661
662out:
663 kfree_skb(skb);
664 return NULL;
665}
666
667/*
668 * Send an arp packet.
669 */
670void arp_xmit(struct sk_buff *skb)
671{
672 /* Send it off, maybe filter it using firewalling first. */
673 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
674}
675
676/*
677 * Create and send an arp packet.
678 */
Al Viroed9bad02006-09-27 18:36:36 -0700679void arp_send(int type, int ptype, __be32 dest_ip,
680 struct net_device *dev, __be32 src_ip,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 unsigned char *dest_hw, unsigned char *src_hw,
682 unsigned char *target_hw)
683{
684 struct sk_buff *skb;
685
686 /*
687 * No arp on this interface.
688 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 if (dev->flags&IFF_NOARP)
691 return;
692
693 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
694 dest_hw, src_hw, target_hw);
695 if (skb == NULL) {
696 return;
697 }
698
699 arp_xmit(skb);
700}
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702/*
703 * Process an arp request.
704 */
705
706static int arp_process(struct sk_buff *skb)
707{
708 struct net_device *dev = skb->dev;
709 struct in_device *in_dev = in_dev_get(dev);
710 struct arphdr *arp;
711 unsigned char *arp_ptr;
712 struct rtable *rt;
713 unsigned char *sha, *tha;
Al Viro9e12bb22006-09-26 21:25:20 -0700714 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 u16 dev_type = dev->type;
716 int addr_type;
717 struct neighbour *n;
718
719 /* arp_rcv below verifies the ARP header and verifies the device
720 * is ARP'able.
721 */
722
723 if (in_dev == NULL)
724 goto out;
725
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300726 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
728 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900729 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 if (arp->ar_pro != htons(ETH_P_IP) ||
731 htons(dev_type) != arp->ar_hrd)
732 goto out;
733 break;
734#ifdef CONFIG_NET_ETHERNET
735 case ARPHRD_ETHER:
736#endif
737#ifdef CONFIG_TR
738 case ARPHRD_IEEE802_TR:
739#endif
740#ifdef CONFIG_FDDI
741 case ARPHRD_FDDI:
742#endif
743#ifdef CONFIG_NET_FC
744 case ARPHRD_IEEE802:
745#endif
746#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
747 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
748 /*
749 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
750 * devices, according to RFC 2625) devices will accept ARP
751 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
752 * This is the case also of FDDI, where the RFC 1390 says that
753 * FDDI devices should accept ARP hardware of (1) Ethernet,
754 * however, to be more robust, we'll accept both 1 (Ethernet)
755 * or 6 (IEEE 802.2)
756 */
757 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
758 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
759 arp->ar_pro != htons(ETH_P_IP))
760 goto out;
761 break;
762#endif
763#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
764 case ARPHRD_AX25:
765 if (arp->ar_pro != htons(AX25_P_IP) ||
766 arp->ar_hrd != htons(ARPHRD_AX25))
767 goto out;
768 break;
769#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
770 case ARPHRD_NETROM:
771 if (arp->ar_pro != htons(AX25_P_IP) ||
772 arp->ar_hrd != htons(ARPHRD_NETROM))
773 goto out;
774 break;
775#endif
776#endif
777 }
778
779 /* Understand only these message types */
780
781 if (arp->ar_op != htons(ARPOP_REPLY) &&
782 arp->ar_op != htons(ARPOP_REQUEST))
783 goto out;
784
785/*
786 * Extract fields
787 */
788 arp_ptr= (unsigned char *)(arp+1);
789 sha = arp_ptr;
790 arp_ptr += dev->addr_len;
791 memcpy(&sip, arp_ptr, 4);
792 arp_ptr += 4;
793 tha = arp_ptr;
794 arp_ptr += dev->addr_len;
795 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900796/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 * Check for bad requests for 127.x.x.x and requests for multicast
798 * addresses. If this is one such, delete it.
799 */
800 if (LOOPBACK(tip) || MULTICAST(tip))
801 goto out;
802
803/*
804 * Special case: We must set Frame Relay source Q.922 address
805 */
806 if (dev_type == ARPHRD_DLCI)
807 sha = dev->broadcast;
808
809/*
810 * Process entry. The idea here is we want to send a reply if it is a
811 * request for us or if it is a request for someone else that we hold
812 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900813 * to us or if it is a request for our address.
814 * (The assumption for this last is that if someone is requesting our
815 * address, they are probably intending to talk to us, so it saves time
816 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900818 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 * Putting this another way, we only care about replies if they are to
820 * us, in which case we add them to the cache. For requests, we care
821 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900822 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 * cache.
824 */
825
826 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
827 if (sip == 0) {
828 if (arp->ar_op == htons(ARPOP_REQUEST) &&
829 inet_addr_type(tip) == RTN_LOCAL &&
830 !arp_ignore(in_dev,dev,sip,tip))
831 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
832 goto out;
833 }
834
835 if (arp->ar_op == htons(ARPOP_REQUEST) &&
836 ip_route_input(skb, tip, sip, 0, dev) == 0) {
837
838 rt = (struct rtable*)skb->dst;
839 addr_type = rt->rt_type;
840
841 if (addr_type == RTN_LOCAL) {
842 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
843 if (n) {
844 int dont_send = 0;
845
846 if (!dont_send)
847 dont_send |= arp_ignore(in_dev,dev,sip,tip);
848 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900849 dont_send |= arp_filter(sip,tip,dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 if (!dont_send)
851 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
852
853 neigh_release(n);
854 }
855 goto out;
856 } else if (IN_DEV_FORWARD(in_dev)) {
857 if ((rt->rt_flags&RTCF_DNAT) ||
858 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev &&
859 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
860 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
861 if (n)
862 neigh_release(n);
863
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900864 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 skb->pkt_type == PACKET_HOST ||
866 in_dev->arp_parms->proxy_delay == 0) {
867 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
868 } else {
869 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
870 in_dev_put(in_dev);
871 return 0;
872 }
873 goto out;
874 }
875 }
876 }
877
878 /* Update our ARP tables */
879
880 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
881
Herbert Xu42f811b2007-06-04 23:34:44 -0700882 if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800883 /* Unsolicited ARP is not accepted by default.
884 It is possible, that this option should be enabled for some
885 devices (strip is candidate)
886 */
887 if (n == NULL &&
888 arp->ar_op == htons(ARPOP_REPLY) &&
889 inet_addr_type(sip) == RTN_UNICAST)
Jean Delvare1b1ac752007-07-14 20:51:44 -0700890 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 if (n) {
894 int state = NUD_REACHABLE;
895 int override;
896
897 /* If several different ARP replies follows back-to-back,
898 use the FIRST one. It is possible, if several proxy
899 agents are active. Taking the first reply prevents
900 arp trashing and chooses the fastest router.
901 */
902 override = time_after(jiffies, n->updated + n->parms->locktime);
903
904 /* Broadcast replies and request packets
905 do not assert neighbour reachability.
906 */
907 if (arp->ar_op != htons(ARPOP_REPLY) ||
908 skb->pkt_type != PACKET_HOST)
909 state = NUD_STALE;
910 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0);
911 neigh_release(n);
912 }
913
914out:
915 if (in_dev)
916 in_dev_put(in_dev);
917 kfree_skb(skb);
918 return 0;
919}
920
Herbert Xu444fc8f2005-10-03 14:18:10 -0700921static void parp_redo(struct sk_buff *skb)
922{
923 arp_process(skb);
924}
925
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926
927/*
928 * Receive an arp request from the device layer.
929 */
930
Adrian Bunk6c97e722006-04-12 13:57:59 -0700931static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
932 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933{
934 struct arphdr *arp;
935
Eric W. Biedermane730c152007-09-17 11:53:39 -0700936 if (dev->nd_net != &init_net)
937 goto freeskb;
938
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
940 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
941 (2 * dev->addr_len) +
942 (2 * sizeof(u32)))))
943 goto freeskb;
944
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300945 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 if (arp->ar_hln != dev->addr_len ||
947 dev->flags & IFF_NOARP ||
948 skb->pkt_type == PACKET_OTHERHOST ||
949 skb->pkt_type == PACKET_LOOPBACK ||
950 arp->ar_pln != 4)
951 goto freeskb;
952
953 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
954 goto out_of_mem;
955
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700956 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
959
960freeskb:
961 kfree_skb(skb);
962out_of_mem:
963 return 0;
964}
965
966/*
967 * User level interface (ioctl)
968 */
969
970/*
971 * Set (create) an ARP cache entry.
972 */
973
974static int arp_req_set(struct arpreq *r, struct net_device * dev)
975{
Al Viroed9bad02006-09-27 18:36:36 -0700976 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 struct neighbour *neigh;
978 int err;
979
980 if (r->arp_flags&ATF_PUBL) {
Al Viroed9bad02006-09-27 18:36:36 -0700981 __be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
982 if (mask && mask != htonl(0xFFFFFFFF))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 return -EINVAL;
984 if (!dev && (r->arp_flags & ATF_COM)) {
Eric W. Biederman881d9662007-09-17 11:56:21 -0700985 dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family, r->arp_ha.sa_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 if (!dev)
987 return -ENODEV;
988 }
989 if (mask) {
990 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
991 return -ENOBUFS;
992 return 0;
993 }
994 if (dev == NULL) {
Herbert Xu42f811b2007-06-04 23:34:44 -0700995 IPV4_DEVCONF_ALL(PROXY_ARP) = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 return 0;
997 }
Herbert Xue5ed6392005-10-03 14:35:55 -0700998 if (__in_dev_get_rtnl(dev)) {
Herbert Xu42f811b2007-06-04 23:34:44 -0700999 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 return 0;
1001 }
1002 return -ENXIO;
1003 }
1004
1005 if (r->arp_flags & ATF_PERM)
1006 r->arp_flags |= ATF_COM;
1007 if (dev == NULL) {
1008 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1009 .tos = RTO_ONLINK } } };
1010 struct rtable * rt;
1011 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1012 return err;
1013 dev = rt->u.dst.dev;
1014 ip_rt_put(rt);
1015 if (!dev)
1016 return -EINVAL;
1017 }
1018 switch (dev->type) {
1019#ifdef CONFIG_FDDI
1020 case ARPHRD_FDDI:
1021 /*
1022 * According to RFC 1390, FDDI devices should accept ARP
1023 * hardware types of 1 (Ethernet). However, to be more
1024 * robust, we'll accept hardware types of either 1 (Ethernet)
1025 * or 6 (IEEE 802.2).
1026 */
1027 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1028 r->arp_ha.sa_family != ARPHRD_ETHER &&
1029 r->arp_ha.sa_family != ARPHRD_IEEE802)
1030 return -EINVAL;
1031 break;
1032#endif
1033 default:
1034 if (r->arp_ha.sa_family != dev->type)
1035 return -EINVAL;
1036 break;
1037 }
1038
1039 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1040 err = PTR_ERR(neigh);
1041 if (!IS_ERR(neigh)) {
1042 unsigned state = NUD_STALE;
1043 if (r->arp_flags & ATF_PERM)
1044 state = NUD_PERMANENT;
1045 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001046 r->arp_ha.sa_data : NULL, state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 NEIGH_UPDATE_F_OVERRIDE|
1048 NEIGH_UPDATE_F_ADMIN);
1049 neigh_release(neigh);
1050 }
1051 return err;
1052}
1053
1054static unsigned arp_state_to_flags(struct neighbour *neigh)
1055{
1056 unsigned flags = 0;
1057 if (neigh->nud_state&NUD_PERMANENT)
1058 flags = ATF_PERM|ATF_COM;
1059 else if (neigh->nud_state&NUD_VALID)
1060 flags = ATF_COM;
1061 return flags;
1062}
1063
1064/*
1065 * Get an ARP cache entry.
1066 */
1067
1068static int arp_req_get(struct arpreq *r, struct net_device *dev)
1069{
Al Viroed9bad02006-09-27 18:36:36 -07001070 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 struct neighbour *neigh;
1072 int err = -ENXIO;
1073
1074 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1075 if (neigh) {
1076 read_lock_bh(&neigh->lock);
1077 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1078 r->arp_flags = arp_state_to_flags(neigh);
1079 read_unlock_bh(&neigh->lock);
1080 r->arp_ha.sa_family = dev->type;
1081 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1082 neigh_release(neigh);
1083 err = 0;
1084 }
1085 return err;
1086}
1087
1088static int arp_req_delete(struct arpreq *r, struct net_device * dev)
1089{
1090 int err;
Al Viroed9bad02006-09-27 18:36:36 -07001091 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 struct neighbour *neigh;
1093
1094 if (r->arp_flags & ATF_PUBL) {
Al Viroed9bad02006-09-27 18:36:36 -07001095 __be32 mask =
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
Al Viroed9bad02006-09-27 18:36:36 -07001097 if (mask == htonl(0xFFFFFFFF))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 return pneigh_delete(&arp_tbl, &ip, dev);
1099 if (mask == 0) {
1100 if (dev == NULL) {
Herbert Xu42f811b2007-06-04 23:34:44 -07001101 IPV4_DEVCONF_ALL(PROXY_ARP) = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 return 0;
1103 }
Herbert Xue5ed6392005-10-03 14:35:55 -07001104 if (__in_dev_get_rtnl(dev)) {
Herbert Xu42f811b2007-06-04 23:34:44 -07001105 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev),
1106 PROXY_ARP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 return 0;
1108 }
1109 return -ENXIO;
1110 }
1111 return -EINVAL;
1112 }
1113
1114 if (dev == NULL) {
1115 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1116 .tos = RTO_ONLINK } } };
1117 struct rtable * rt;
1118 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1119 return err;
1120 dev = rt->u.dst.dev;
1121 ip_rt_put(rt);
1122 if (!dev)
1123 return -EINVAL;
1124 }
1125 err = -ENXIO;
1126 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1127 if (neigh) {
1128 if (neigh->nud_state&~NUD_NOARP)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001129 err = neigh_update(neigh, NULL, NUD_FAILED,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 NEIGH_UPDATE_F_OVERRIDE|
1131 NEIGH_UPDATE_F_ADMIN);
1132 neigh_release(neigh);
1133 }
1134 return err;
1135}
1136
1137/*
1138 * Handle an ARP layer I/O control request.
1139 */
1140
1141int arp_ioctl(unsigned int cmd, void __user *arg)
1142{
1143 int err;
1144 struct arpreq r;
1145 struct net_device *dev = NULL;
1146
1147 switch (cmd) {
1148 case SIOCDARP:
1149 case SIOCSARP:
1150 if (!capable(CAP_NET_ADMIN))
1151 return -EPERM;
1152 case SIOCGARP:
1153 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1154 if (err)
1155 return -EFAULT;
1156 break;
1157 default:
1158 return -EINVAL;
1159 }
1160
1161 if (r.arp_pa.sa_family != AF_INET)
1162 return -EPFNOSUPPORT;
1163
1164 if (!(r.arp_flags & ATF_PUBL) &&
1165 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
1166 return -EINVAL;
1167 if (!(r.arp_flags & ATF_NETMASK))
1168 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1169 htonl(0xFFFFFFFFUL);
1170 rtnl_lock();
1171 if (r.arp_dev[0]) {
1172 err = -ENODEV;
Eric W. Biederman881d9662007-09-17 11:56:21 -07001173 if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 goto out;
1175
1176 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1177 if (!r.arp_ha.sa_family)
1178 r.arp_ha.sa_family = dev->type;
1179 err = -EINVAL;
1180 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1181 goto out;
1182 } else if (cmd == SIOCGARP) {
1183 err = -ENODEV;
1184 goto out;
1185 }
1186
Stephen Hemminger132adf52007-03-08 20:44:43 -08001187 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 case SIOCDARP:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001189 err = arp_req_delete(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 break;
1191 case SIOCSARP:
1192 err = arp_req_set(&r, dev);
1193 break;
1194 case SIOCGARP:
1195 err = arp_req_get(&r, dev);
1196 if (!err && copy_to_user(arg, &r, sizeof(r)))
1197 err = -EFAULT;
1198 break;
1199 }
1200out:
1201 rtnl_unlock();
1202 return err;
1203}
1204
1205static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1206{
1207 struct net_device *dev = ptr;
1208
Eric W. Biedermane9dc8652007-09-12 13:02:17 +02001209 if (dev->nd_net != &init_net)
1210 return NOTIFY_DONE;
1211
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 switch (event) {
1213 case NETDEV_CHANGEADDR:
1214 neigh_changeaddr(&arp_tbl, dev);
1215 rt_cache_flush(0);
1216 break;
1217 default:
1218 break;
1219 }
1220
1221 return NOTIFY_DONE;
1222}
1223
1224static struct notifier_block arp_netdev_notifier = {
1225 .notifier_call = arp_netdev_event,
1226};
1227
1228/* Note, that it is not on notifier chain.
1229 It is necessary, that this routine was called after route cache will be
1230 flushed.
1231 */
1232void arp_ifdown(struct net_device *dev)
1233{
1234 neigh_ifdown(&arp_tbl, dev);
1235}
1236
1237
1238/*
1239 * Called once on startup.
1240 */
1241
1242static struct packet_type arp_packet_type = {
1243 .type = __constant_htons(ETH_P_ARP),
1244 .func = arp_rcv,
1245};
1246
1247static int arp_proc_init(void);
1248
1249void __init arp_init(void)
1250{
1251 neigh_table_init(&arp_tbl);
1252
1253 dev_add_pack(&arp_packet_type);
1254 arp_proc_init();
1255#ifdef CONFIG_SYSCTL
1256 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
1257 NET_IPV4_NEIGH, "ipv4", NULL, NULL);
1258#endif
1259 register_netdevice_notifier(&arp_netdev_notifier);
1260}
1261
1262#ifdef CONFIG_PROC_FS
1263#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1264
1265/* ------------------------------------------------------------------------ */
1266/*
1267 * ax25 -> ASCII conversion
1268 */
1269static char *ax2asc2(ax25_address *a, char *buf)
1270{
1271 char c, *s;
1272 int n;
1273
1274 for (n = 0, s = buf; n < 6; n++) {
1275 c = (a->ax25_call[n] >> 1) & 0x7F;
1276
1277 if (c != ' ') *s++ = c;
1278 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001279
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 *s++ = '-';
1281
1282 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
1283 *s++ = '1';
1284 n -= 10;
1285 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001286
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 *s++ = n + '0';
1288 *s++ = '\0';
1289
1290 if (*buf == '\0' || *buf == '-')
1291 return "*";
1292
1293 return buf;
1294
1295}
1296#endif /* CONFIG_AX25 */
1297
1298#define HBUFFERLEN 30
1299
1300static void arp_format_neigh_entry(struct seq_file *seq,
1301 struct neighbour *n)
1302{
1303 char hbuffer[HBUFFERLEN];
1304 const char hexbuf[] = "0123456789ABCDEF";
1305 int k, j;
1306 char tbuf[16];
1307 struct net_device *dev = n->dev;
1308 int hatype = dev->type;
1309
1310 read_lock(&n->lock);
1311 /* Convert hardware address to XX:XX:XX:XX ... form. */
1312#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1313 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1314 ax2asc2((ax25_address *)n->ha, hbuffer);
1315 else {
1316#endif
1317 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
1318 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15];
1319 hbuffer[k++] = hexbuf[n->ha[j] & 15];
1320 hbuffer[k++] = ':';
1321 }
1322 hbuffer[--k] = 0;
1323#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1324 }
1325#endif
1326 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
1327 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1328 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1329 read_unlock(&n->lock);
1330}
1331
1332static void arp_format_pneigh_entry(struct seq_file *seq,
1333 struct pneigh_entry *n)
1334{
1335 struct net_device *dev = n->dev;
1336 int hatype = dev ? dev->type : 0;
1337 char tbuf[16];
1338
1339 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
1340 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1341 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1342 dev ? dev->name : "*");
1343}
1344
1345static int arp_seq_show(struct seq_file *seq, void *v)
1346{
1347 if (v == SEQ_START_TOKEN) {
1348 seq_puts(seq, "IP address HW type Flags "
1349 "HW address Mask Device\n");
1350 } else {
1351 struct neigh_seq_state *state = seq->private;
1352
1353 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1354 arp_format_pneigh_entry(seq, v);
1355 else
1356 arp_format_neigh_entry(seq, v);
1357 }
1358
1359 return 0;
1360}
1361
1362static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1363{
1364 /* Don't want to confuse "arp -a" w/ magic entries,
1365 * so we tell the generic iterator to skip NUD_NOARP.
1366 */
1367 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1368}
1369
1370/* ------------------------------------------------------------------------ */
1371
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001372static const struct seq_operations arp_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 .start = arp_seq_start,
1374 .next = neigh_seq_next,
1375 .stop = neigh_seq_stop,
1376 .show = arp_seq_show,
1377};
1378
1379static int arp_seq_open(struct inode *inode, struct file *file)
1380{
1381 struct seq_file *seq;
1382 int rc = -ENOMEM;
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07001383 struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001384
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 if (!s)
1386 goto out;
1387
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388 rc = seq_open(file, &arp_seq_ops);
1389 if (rc)
1390 goto out_kfree;
1391
1392 seq = file->private_data;
1393 seq->private = s;
1394out:
1395 return rc;
1396out_kfree:
1397 kfree(s);
1398 goto out;
1399}
1400
Arjan van de Ven9a321442007-02-12 00:55:35 -08001401static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 .owner = THIS_MODULE,
1403 .open = arp_seq_open,
1404 .read = seq_read,
1405 .llseek = seq_lseek,
1406 .release = seq_release_private,
1407};
1408
1409static int __init arp_proc_init(void)
1410{
Eric W. Biederman457c4cb2007-09-12 12:01:34 +02001411 if (!proc_net_fops_create(&init_net, "arp", S_IRUGO, &arp_seq_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 return -ENOMEM;
1413 return 0;
1414}
1415
1416#else /* CONFIG_PROC_FS */
1417
1418static int __init arp_proc_init(void)
1419{
1420 return 0;
1421}
1422
1423#endif /* CONFIG_PROC_FS */
1424
1425EXPORT_SYMBOL(arp_broken_ops);
1426EXPORT_SYMBOL(arp_find);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427EXPORT_SYMBOL(arp_create);
1428EXPORT_SYMBOL(arp_xmit);
1429EXPORT_SYMBOL(arp_send);
1430EXPORT_SYMBOL(arp_tbl);
1431
1432#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1433EXPORT_SYMBOL(clip_tbl_hook);
1434#endif