blob: 9ab9d534fbac28597f0a5b2b5c0c07d3e4485f29 [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
106#include <net/ip.h>
107#include <net/icmp.h>
108#include <net/route.h>
109#include <net/protocol.h>
110#include <net/tcp.h>
111#include <net/sock.h>
112#include <net/arp.h>
113#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
114#include <net/ax25.h>
115#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
116#include <net/netrom.h>
117#endif
118#endif
119#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
120#include <net/atmclip.h>
121struct neigh_table *clip_tbl_hook;
122#endif
123
124#include <asm/system.h>
125#include <asm/uaccess.h>
126
127#include <linux/netfilter_arp.h>
128
129/*
130 * Interface to generic neighbour cache.
131 */
132static u32 arp_hash(const void *pkey, const struct net_device *dev);
133static int arp_constructor(struct neighbour *neigh);
134static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
135static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
136static void parp_redo(struct sk_buff *skb);
137
138static struct neigh_ops arp_generic_ops = {
139 .family = AF_INET,
140 .solicit = arp_solicit,
141 .error_report = arp_error_report,
142 .output = neigh_resolve_output,
143 .connected_output = neigh_connected_output,
144 .hh_output = dev_queue_xmit,
145 .queue_xmit = dev_queue_xmit,
146};
147
148static struct neigh_ops arp_hh_ops = {
149 .family = AF_INET,
150 .solicit = arp_solicit,
151 .error_report = arp_error_report,
152 .output = neigh_resolve_output,
153 .connected_output = neigh_resolve_output,
154 .hh_output = dev_queue_xmit,
155 .queue_xmit = dev_queue_xmit,
156};
157
158static struct neigh_ops arp_direct_ops = {
159 .family = AF_INET,
160 .output = dev_queue_xmit,
161 .connected_output = dev_queue_xmit,
162 .hh_output = dev_queue_xmit,
163 .queue_xmit = dev_queue_xmit,
164};
165
166struct neigh_ops arp_broken_ops = {
167 .family = AF_INET,
168 .solicit = arp_solicit,
169 .error_report = arp_error_report,
170 .output = neigh_compat_output,
171 .connected_output = neigh_compat_output,
172 .hh_output = dev_queue_xmit,
173 .queue_xmit = dev_queue_xmit,
174};
175
176struct neigh_table arp_tbl = {
177 .family = AF_INET,
178 .entry_size = sizeof(struct neighbour) + 4,
179 .key_len = 4,
180 .hash = arp_hash,
181 .constructor = arp_constructor,
182 .proxy_redo = parp_redo,
183 .id = "arp_cache",
184 .parms = {
185 .tbl = &arp_tbl,
186 .base_reachable_time = 30 * HZ,
187 .retrans_time = 1 * HZ,
188 .gc_staletime = 60 * HZ,
189 .reachable_time = 30 * HZ,
190 .delay_probe_time = 5 * HZ,
191 .queue_len = 3,
192 .ucast_probes = 3,
193 .mcast_probes = 3,
194 .anycast_delay = 1 * HZ,
195 .proxy_delay = (8 * HZ) / 10,
196 .proxy_qlen = 64,
197 .locktime = 1 * HZ,
198 },
199 .gc_interval = 30 * HZ,
200 .gc_thresh1 = 128,
201 .gc_thresh2 = 512,
202 .gc_thresh3 = 1024,
203};
204
Al Viro714e85b2006-11-14 20:51:49 -0800205int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
207 switch (dev->type) {
208 case ARPHRD_ETHER:
209 case ARPHRD_FDDI:
210 case ARPHRD_IEEE802:
211 ip_eth_mc_map(addr, haddr);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900212 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 case ARPHRD_IEEE802_TR:
214 ip_tr_mc_map(addr, haddr);
215 return 0;
216 case ARPHRD_INFINIBAND:
217 ip_ib_mc_map(addr, haddr);
218 return 0;
219 default:
220 if (dir) {
221 memcpy(haddr, dev->broadcast, dev->addr_len);
222 return 0;
223 }
224 }
225 return -EINVAL;
226}
227
228
229static u32 arp_hash(const void *pkey, const struct net_device *dev)
230{
231 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd);
232}
233
234static int arp_constructor(struct neighbour *neigh)
235{
Al Virofd683222006-09-26 22:17:51 -0700236 __be32 addr = *(__be32*)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 struct net_device *dev = neigh->dev;
238 struct in_device *in_dev;
239 struct neigh_parms *parms;
240
241 neigh->type = inet_addr_type(addr);
242
243 rcu_read_lock();
Herbert Xue5ed6392005-10-03 14:35:55 -0700244 in_dev = __in_dev_get_rcu(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (in_dev == NULL) {
246 rcu_read_unlock();
247 return -EINVAL;
248 }
249
250 parms = in_dev->arp_parms;
251 __neigh_parms_put(neigh->parms);
252 neigh->parms = neigh_parms_clone(parms);
253 rcu_read_unlock();
254
255 if (dev->hard_header == NULL) {
256 neigh->nud_state = NUD_NOARP;
257 neigh->ops = &arp_direct_ops;
258 neigh->output = neigh->ops->queue_xmit;
259 } else {
260 /* Good devices (checked by reading texts, but only Ethernet is
261 tested)
262
263 ARPHRD_ETHER: (ethernet, apfddi)
264 ARPHRD_FDDI: (fddi)
265 ARPHRD_IEEE802: (tr)
266 ARPHRD_METRICOM: (strip)
267 ARPHRD_ARCNET:
268 etc. etc. etc.
269
270 ARPHRD_IPDDP will also work, if author repairs it.
271 I did not it, because this driver does not work even
272 in old paradigm.
273 */
274
275#if 1
276 /* So... these "amateur" devices are hopeless.
277 The only thing, that I can say now:
278 It is very sad that we need to keep ugly obsolete
279 code to make them happy.
280
281 They should be moved to more reasonable state, now
282 they use rebuild_header INSTEAD OF hard_start_xmit!!!
283 Besides that, they are sort of out of date
284 (a lot of redundant clones/copies, useless in 2.1),
285 I wonder why people believe that they work.
286 */
287 switch (dev->type) {
288 default:
289 break;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900290 case ARPHRD_ROSE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
292 case ARPHRD_AX25:
293#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
294 case ARPHRD_NETROM:
295#endif
296 neigh->ops = &arp_broken_ops;
297 neigh->output = neigh->ops->output;
298 return 0;
299#endif
300 ;}
301#endif
302 if (neigh->type == RTN_MULTICAST) {
303 neigh->nud_state = NUD_NOARP;
304 arp_mc_map(addr, neigh->ha, dev, 1);
305 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
306 neigh->nud_state = NUD_NOARP;
307 memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
308 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) {
309 neigh->nud_state = NUD_NOARP;
310 memcpy(neigh->ha, dev->broadcast, dev->addr_len);
311 }
312 if (dev->hard_header_cache)
313 neigh->ops = &arp_hh_ops;
314 else
315 neigh->ops = &arp_generic_ops;
316 if (neigh->nud_state&NUD_VALID)
317 neigh->output = neigh->ops->connected_output;
318 else
319 neigh->output = neigh->ops->output;
320 }
321 return 0;
322}
323
324static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
325{
326 dst_link_failure(skb);
327 kfree_skb(skb);
328}
329
330static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
331{
Al Viroa61ced52006-09-26 21:27:54 -0700332 __be32 saddr = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 u8 *dst_ha = NULL;
334 struct net_device *dev = neigh->dev;
Al Viroa61ced52006-09-26 21:27:54 -0700335 __be32 target = *(__be32*)neigh->primary_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 int probes = atomic_read(&neigh->probes);
337 struct in_device *in_dev = in_dev_get(dev);
338
339 if (!in_dev)
340 return;
341
342 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
343 default:
344 case 0: /* By default announce any local IP */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700345 if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
346 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 break;
348 case 1: /* Restrict announcements of saddr in same subnet */
349 if (!skb)
350 break;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700351 saddr = ip_hdr(skb)->saddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 if (inet_addr_type(saddr) == RTN_LOCAL) {
353 /* saddr should be known to target */
354 if (inet_addr_onlink(in_dev, target, saddr))
355 break;
356 }
357 saddr = 0;
358 break;
359 case 2: /* Avoid secondary IPs, get a primary/preferred one */
360 break;
361 }
362
363 if (in_dev)
364 in_dev_put(in_dev);
365 if (!saddr)
366 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
367
368 if ((probes -= neigh->parms->ucast_probes) < 0) {
369 if (!(neigh->nud_state&NUD_VALID))
370 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
371 dst_ha = neigh->ha;
372 read_lock_bh(&neigh->lock);
373 } else if ((probes -= neigh->parms->app_probes) < 0) {
374#ifdef CONFIG_ARPD
375 neigh_app_ns(neigh);
376#endif
377 return;
378 }
379
380 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
381 dst_ha, dev->dev_addr, NULL);
382 if (dst_ha)
383 read_unlock_bh(&neigh->lock);
384}
385
386static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
Al Viroed9bad02006-09-27 18:36:36 -0700387 __be32 sip, __be32 tip)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388{
389 int scope;
390
391 switch (IN_DEV_ARP_IGNORE(in_dev)) {
392 case 0: /* Reply, the tip is already validated */
393 return 0;
394 case 1: /* Reply only if tip is configured on the incoming interface */
395 sip = 0;
396 scope = RT_SCOPE_HOST;
397 break;
398 case 2: /*
399 * Reply only if tip is configured on the incoming interface
400 * and is in same subnet as sip
401 */
402 scope = RT_SCOPE_HOST;
403 break;
404 case 3: /* Do not reply for scope host addresses */
405 sip = 0;
406 scope = RT_SCOPE_LINK;
407 dev = NULL;
408 break;
409 case 4: /* Reserved */
410 case 5:
411 case 6:
412 case 7:
413 return 0;
414 case 8: /* Do not reply */
415 return 1;
416 default:
417 return 0;
418 }
419 return !inet_confirm_addr(dev, sip, tip, scope);
420}
421
Al Viroed9bad02006-09-27 18:36:36 -0700422static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423{
424 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
425 .saddr = tip } } };
426 struct rtable *rt;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900427 int flag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 /*unsigned long now; */
429
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900430 if (ip_route_output_key(&rt, &fl) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 return 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900432 if (rt->u.dst.dev != dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER);
434 flag = 1;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900435 }
436 ip_rt_put(rt);
437 return flag;
438}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440/* OBSOLETE FUNCTIONS */
441
442/*
443 * Find an arp mapping in the cache. If not found, post a request.
444 *
445 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
446 * even if it exists. It is supposed that skb->dev was mangled
447 * by a virtual device (eql, shaper). Nobody but broken devices
448 * is allowed to use this function, it is scheduled to be removed. --ANK
449 */
450
Al Viroed9bad02006-09-27 18:36:36 -0700451static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
453 switch (addr_hint) {
454 case RTN_LOCAL:
455 printk(KERN_DEBUG "ARP: arp called for own IP address\n");
456 memcpy(haddr, dev->dev_addr, dev->addr_len);
457 return 1;
458 case RTN_MULTICAST:
459 arp_mc_map(paddr, haddr, dev, 1);
460 return 1;
461 case RTN_BROADCAST:
462 memcpy(haddr, dev->broadcast, dev->addr_len);
463 return 1;
464 }
465 return 0;
466}
467
468
469int arp_find(unsigned char *haddr, struct sk_buff *skb)
470{
471 struct net_device *dev = skb->dev;
Al Virofd683222006-09-26 22:17:51 -0700472 __be32 paddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 struct neighbour *n;
474
475 if (!skb->dst) {
476 printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
477 kfree_skb(skb);
478 return 1;
479 }
480
481 paddr = ((struct rtable*)skb->dst)->rt_gateway;
482
483 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev))
484 return 0;
485
486 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
487
488 if (n) {
489 n->used = jiffies;
490 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
491 read_lock_bh(&n->lock);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900492 memcpy(haddr, n->ha, dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 read_unlock_bh(&n->lock);
494 neigh_release(n);
495 return 0;
496 }
497 neigh_release(n);
498 } else
499 kfree_skb(skb);
500 return 1;
501}
502
503/* END OF OBSOLETE FUNCTIONS */
504
505int arp_bind_neighbour(struct dst_entry *dst)
506{
507 struct net_device *dev = dst->dev;
508 struct neighbour *n = dst->neighbour;
509
510 if (dev == NULL)
511 return -EINVAL;
512 if (n == NULL) {
Al Viroed9bad02006-09-27 18:36:36 -0700513 __be32 nexthop = ((struct rtable*)dst)->rt_gateway;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
515 nexthop = 0;
516 n = __neigh_lookup_errno(
517#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
518 dev->type == ARPHRD_ATM ? clip_tbl_hook :
519#endif
520 &arp_tbl, &nexthop, dev);
521 if (IS_ERR(n))
522 return PTR_ERR(n);
523 dst->neighbour = n;
524 }
525 return 0;
526}
527
528/*
529 * Check if we can use proxy ARP for this path
530 */
531
532static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
533{
534 struct in_device *out_dev;
535 int imi, omi = -1;
536
537 if (!IN_DEV_PROXY_ARP(in_dev))
538 return 0;
539
540 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
541 return 1;
542 if (imi == -1)
543 return 0;
544
545 /* place to check for proxy_arp for routes */
546
547 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
548 omi = IN_DEV_MEDIUM_ID(out_dev);
549 in_dev_put(out_dev);
550 }
551 return (omi != imi && omi != -1);
552}
553
554/*
555 * Interface to link layer: send routine and receive handler.
556 */
557
558/*
559 * Create an arp packet. If (dest_hw == NULL), we create a broadcast
560 * message.
561 */
Al Viroed9bad02006-09-27 18:36:36 -0700562struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
563 struct net_device *dev, __be32 src_ip,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 unsigned char *dest_hw, unsigned char *src_hw,
565 unsigned char *target_hw)
566{
567 struct sk_buff *skb;
568 struct arphdr *arp;
569 unsigned char *arp_ptr;
570
571 /*
572 * Allocate a buffer
573 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900574
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
576 + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
577 if (skb == NULL)
578 return NULL;
579
580 skb_reserve(skb, LL_RESERVED_SPACE(dev));
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700581 skb_reset_network_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
583 skb->dev = dev;
584 skb->protocol = htons(ETH_P_ARP);
585 if (src_hw == NULL)
586 src_hw = dev->dev_addr;
587 if (dest_hw == NULL)
588 dest_hw = dev->broadcast;
589
590 /*
591 * Fill the device header for the ARP frame
592 */
593 if (dev->hard_header &&
594 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0)
595 goto out;
596
597 /*
598 * Fill out the arp protocol part.
599 *
600 * The arp hardware type should match the device type, except for FDDI,
601 * which (according to RFC 1390) should always equal 1 (Ethernet).
602 */
603 /*
604 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
605 * DIX code for the protocol. Make these device structure fields.
606 */
607 switch (dev->type) {
608 default:
609 arp->ar_hrd = htons(dev->type);
610 arp->ar_pro = htons(ETH_P_IP);
611 break;
612
613#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
614 case ARPHRD_AX25:
615 arp->ar_hrd = htons(ARPHRD_AX25);
616 arp->ar_pro = htons(AX25_P_IP);
617 break;
618
619#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
620 case ARPHRD_NETROM:
621 arp->ar_hrd = htons(ARPHRD_NETROM);
622 arp->ar_pro = htons(AX25_P_IP);
623 break;
624#endif
625#endif
626
627#ifdef CONFIG_FDDI
628 case ARPHRD_FDDI:
629 arp->ar_hrd = htons(ARPHRD_ETHER);
630 arp->ar_pro = htons(ETH_P_IP);
631 break;
632#endif
633#ifdef CONFIG_TR
634 case ARPHRD_IEEE802_TR:
635 arp->ar_hrd = htons(ARPHRD_IEEE802);
636 arp->ar_pro = htons(ETH_P_IP);
637 break;
638#endif
639 }
640
641 arp->ar_hln = dev->addr_len;
642 arp->ar_pln = 4;
643 arp->ar_op = htons(type);
644
645 arp_ptr=(unsigned char *)(arp+1);
646
647 memcpy(arp_ptr, src_hw, dev->addr_len);
648 arp_ptr+=dev->addr_len;
649 memcpy(arp_ptr, &src_ip,4);
650 arp_ptr+=4;
651 if (target_hw != NULL)
652 memcpy(arp_ptr, target_hw, dev->addr_len);
653 else
654 memset(arp_ptr, 0, dev->addr_len);
655 arp_ptr+=dev->addr_len;
656 memcpy(arp_ptr, &dest_ip, 4);
657
658 return skb;
659
660out:
661 kfree_skb(skb);
662 return NULL;
663}
664
665/*
666 * Send an arp packet.
667 */
668void arp_xmit(struct sk_buff *skb)
669{
670 /* Send it off, maybe filter it using firewalling first. */
671 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
672}
673
674/*
675 * Create and send an arp packet.
676 */
Al Viroed9bad02006-09-27 18:36:36 -0700677void arp_send(int type, int ptype, __be32 dest_ip,
678 struct net_device *dev, __be32 src_ip,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 unsigned char *dest_hw, unsigned char *src_hw,
680 unsigned char *target_hw)
681{
682 struct sk_buff *skb;
683
684 /*
685 * No arp on this interface.
686 */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900687
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 if (dev->flags&IFF_NOARP)
689 return;
690
691 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
692 dest_hw, src_hw, target_hw);
693 if (skb == NULL) {
694 return;
695 }
696
697 arp_xmit(skb);
698}
699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700/*
701 * Process an arp request.
702 */
703
704static int arp_process(struct sk_buff *skb)
705{
706 struct net_device *dev = skb->dev;
707 struct in_device *in_dev = in_dev_get(dev);
708 struct arphdr *arp;
709 unsigned char *arp_ptr;
710 struct rtable *rt;
711 unsigned char *sha, *tha;
Al Viro9e12bb22006-09-26 21:25:20 -0700712 __be32 sip, tip;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 u16 dev_type = dev->type;
714 int addr_type;
715 struct neighbour *n;
716
717 /* arp_rcv below verifies the ARP header and verifies the device
718 * is ARP'able.
719 */
720
721 if (in_dev == NULL)
722 goto out;
723
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300724 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 switch (dev_type) {
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900727 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 if (arp->ar_pro != htons(ETH_P_IP) ||
729 htons(dev_type) != arp->ar_hrd)
730 goto out;
731 break;
732#ifdef CONFIG_NET_ETHERNET
733 case ARPHRD_ETHER:
734#endif
735#ifdef CONFIG_TR
736 case ARPHRD_IEEE802_TR:
737#endif
738#ifdef CONFIG_FDDI
739 case ARPHRD_FDDI:
740#endif
741#ifdef CONFIG_NET_FC
742 case ARPHRD_IEEE802:
743#endif
744#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
745 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
746 /*
747 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
748 * devices, according to RFC 2625) devices will accept ARP
749 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
750 * This is the case also of FDDI, where the RFC 1390 says that
751 * FDDI devices should accept ARP hardware of (1) Ethernet,
752 * however, to be more robust, we'll accept both 1 (Ethernet)
753 * or 6 (IEEE 802.2)
754 */
755 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
756 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
757 arp->ar_pro != htons(ETH_P_IP))
758 goto out;
759 break;
760#endif
761#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
762 case ARPHRD_AX25:
763 if (arp->ar_pro != htons(AX25_P_IP) ||
764 arp->ar_hrd != htons(ARPHRD_AX25))
765 goto out;
766 break;
767#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
768 case ARPHRD_NETROM:
769 if (arp->ar_pro != htons(AX25_P_IP) ||
770 arp->ar_hrd != htons(ARPHRD_NETROM))
771 goto out;
772 break;
773#endif
774#endif
775 }
776
777 /* Understand only these message types */
778
779 if (arp->ar_op != htons(ARPOP_REPLY) &&
780 arp->ar_op != htons(ARPOP_REQUEST))
781 goto out;
782
783/*
784 * Extract fields
785 */
786 arp_ptr= (unsigned char *)(arp+1);
787 sha = arp_ptr;
788 arp_ptr += dev->addr_len;
789 memcpy(&sip, arp_ptr, 4);
790 arp_ptr += 4;
791 tha = arp_ptr;
792 arp_ptr += dev->addr_len;
793 memcpy(&tip, arp_ptr, 4);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900794/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 * Check for bad requests for 127.x.x.x and requests for multicast
796 * addresses. If this is one such, delete it.
797 */
798 if (LOOPBACK(tip) || MULTICAST(tip))
799 goto out;
800
801/*
802 * Special case: We must set Frame Relay source Q.922 address
803 */
804 if (dev_type == ARPHRD_DLCI)
805 sha = dev->broadcast;
806
807/*
808 * Process entry. The idea here is we want to send a reply if it is a
809 * request for us or if it is a request for someone else that we hold
810 * a proxy for. We want to add an entry to our cache if it is a reply
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900811 * to us or if it is a request for our address.
812 * (The assumption for this last is that if someone is requesting our
813 * address, they are probably intending to talk to us, so it saves time
814 * if we cache their address. Their address is also probably not in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 * our cache, since ours is not in their cache.)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900816 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 * Putting this another way, we only care about replies if they are to
818 * us, in which case we add them to the cache. For requests, we care
819 * about those for us and those for our proxies. We reply to both,
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900820 * and in the case of requests for us we add the requester to the arp
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 * cache.
822 */
823
824 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
825 if (sip == 0) {
826 if (arp->ar_op == htons(ARPOP_REQUEST) &&
827 inet_addr_type(tip) == RTN_LOCAL &&
828 !arp_ignore(in_dev,dev,sip,tip))
829 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
830 goto out;
831 }
832
833 if (arp->ar_op == htons(ARPOP_REQUEST) &&
834 ip_route_input(skb, tip, sip, 0, dev) == 0) {
835
836 rt = (struct rtable*)skb->dst;
837 addr_type = rt->rt_type;
838
839 if (addr_type == RTN_LOCAL) {
840 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
841 if (n) {
842 int dont_send = 0;
843
844 if (!dont_send)
845 dont_send |= arp_ignore(in_dev,dev,sip,tip);
846 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900847 dont_send |= arp_filter(sip,tip,dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 if (!dont_send)
849 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
850
851 neigh_release(n);
852 }
853 goto out;
854 } else if (IN_DEV_FORWARD(in_dev)) {
855 if ((rt->rt_flags&RTCF_DNAT) ||
856 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev &&
857 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
858 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
859 if (n)
860 neigh_release(n);
861
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900862 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 skb->pkt_type == PACKET_HOST ||
864 in_dev->arp_parms->proxy_delay == 0) {
865 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
866 } else {
867 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
868 in_dev_put(in_dev);
869 return 0;
870 }
871 goto out;
872 }
873 }
874 }
875
876 /* Update our ARP tables */
877
878 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
879
Herbert Xu42f811b2007-06-04 23:34:44 -0700880 if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) {
Neil Hormanabd596a2006-03-20 22:39:47 -0800881 /* Unsolicited ARP is not accepted by default.
882 It is possible, that this option should be enabled for some
883 devices (strip is candidate)
884 */
885 if (n == NULL &&
886 arp->ar_op == htons(ARPOP_REPLY) &&
887 inet_addr_type(sip) == RTN_UNICAST)
Jean Delvare1b1ac752007-07-14 20:51:44 -0700888 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
Neil Hormanabd596a2006-03-20 22:39:47 -0800889 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890
891 if (n) {
892 int state = NUD_REACHABLE;
893 int override;
894
895 /* If several different ARP replies follows back-to-back,
896 use the FIRST one. It is possible, if several proxy
897 agents are active. Taking the first reply prevents
898 arp trashing and chooses the fastest router.
899 */
900 override = time_after(jiffies, n->updated + n->parms->locktime);
901
902 /* Broadcast replies and request packets
903 do not assert neighbour reachability.
904 */
905 if (arp->ar_op != htons(ARPOP_REPLY) ||
906 skb->pkt_type != PACKET_HOST)
907 state = NUD_STALE;
908 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0);
909 neigh_release(n);
910 }
911
912out:
913 if (in_dev)
914 in_dev_put(in_dev);
915 kfree_skb(skb);
916 return 0;
917}
918
Herbert Xu444fc8f2005-10-03 14:18:10 -0700919static void parp_redo(struct sk_buff *skb)
920{
921 arp_process(skb);
922}
923
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925/*
926 * Receive an arp request from the device layer.
927 */
928
Adrian Bunk6c97e722006-04-12 13:57:59 -0700929static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
930 struct packet_type *pt, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931{
932 struct arphdr *arp;
933
934 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
935 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
936 (2 * dev->addr_len) +
937 (2 * sizeof(u32)))))
938 goto freeskb;
939
Arnaldo Carvalho de Melod0a92be2007-03-12 20:56:31 -0300940 arp = arp_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 if (arp->ar_hln != dev->addr_len ||
942 dev->flags & IFF_NOARP ||
943 skb->pkt_type == PACKET_OTHERHOST ||
944 skb->pkt_type == PACKET_LOOPBACK ||
945 arp->ar_pln != 4)
946 goto freeskb;
947
948 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
949 goto out_of_mem;
950
Patrick McHardya61bbcf2005-08-14 17:24:31 -0700951 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
954
955freeskb:
956 kfree_skb(skb);
957out_of_mem:
958 return 0;
959}
960
961/*
962 * User level interface (ioctl)
963 */
964
965/*
966 * Set (create) an ARP cache entry.
967 */
968
969static int arp_req_set(struct arpreq *r, struct net_device * dev)
970{
Al Viroed9bad02006-09-27 18:36:36 -0700971 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 struct neighbour *neigh;
973 int err;
974
975 if (r->arp_flags&ATF_PUBL) {
Al Viroed9bad02006-09-27 18:36:36 -0700976 __be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
977 if (mask && mask != htonl(0xFFFFFFFF))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 return -EINVAL;
979 if (!dev && (r->arp_flags & ATF_COM)) {
980 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data);
981 if (!dev)
982 return -ENODEV;
983 }
984 if (mask) {
985 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
986 return -ENOBUFS;
987 return 0;
988 }
989 if (dev == NULL) {
Herbert Xu42f811b2007-06-04 23:34:44 -0700990 IPV4_DEVCONF_ALL(PROXY_ARP) = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 return 0;
992 }
Herbert Xue5ed6392005-10-03 14:35:55 -0700993 if (__in_dev_get_rtnl(dev)) {
Herbert Xu42f811b2007-06-04 23:34:44 -0700994 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 return 0;
996 }
997 return -ENXIO;
998 }
999
1000 if (r->arp_flags & ATF_PERM)
1001 r->arp_flags |= ATF_COM;
1002 if (dev == NULL) {
1003 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1004 .tos = RTO_ONLINK } } };
1005 struct rtable * rt;
1006 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1007 return err;
1008 dev = rt->u.dst.dev;
1009 ip_rt_put(rt);
1010 if (!dev)
1011 return -EINVAL;
1012 }
1013 switch (dev->type) {
1014#ifdef CONFIG_FDDI
1015 case ARPHRD_FDDI:
1016 /*
1017 * According to RFC 1390, FDDI devices should accept ARP
1018 * hardware types of 1 (Ethernet). However, to be more
1019 * robust, we'll accept hardware types of either 1 (Ethernet)
1020 * or 6 (IEEE 802.2).
1021 */
1022 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1023 r->arp_ha.sa_family != ARPHRD_ETHER &&
1024 r->arp_ha.sa_family != ARPHRD_IEEE802)
1025 return -EINVAL;
1026 break;
1027#endif
1028 default:
1029 if (r->arp_ha.sa_family != dev->type)
1030 return -EINVAL;
1031 break;
1032 }
1033
1034 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1035 err = PTR_ERR(neigh);
1036 if (!IS_ERR(neigh)) {
1037 unsigned state = NUD_STALE;
1038 if (r->arp_flags & ATF_PERM)
1039 state = NUD_PERMANENT;
1040 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001041 r->arp_ha.sa_data : NULL, state,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 NEIGH_UPDATE_F_OVERRIDE|
1043 NEIGH_UPDATE_F_ADMIN);
1044 neigh_release(neigh);
1045 }
1046 return err;
1047}
1048
1049static unsigned arp_state_to_flags(struct neighbour *neigh)
1050{
1051 unsigned flags = 0;
1052 if (neigh->nud_state&NUD_PERMANENT)
1053 flags = ATF_PERM|ATF_COM;
1054 else if (neigh->nud_state&NUD_VALID)
1055 flags = ATF_COM;
1056 return flags;
1057}
1058
1059/*
1060 * Get an ARP cache entry.
1061 */
1062
1063static int arp_req_get(struct arpreq *r, struct net_device *dev)
1064{
Al Viroed9bad02006-09-27 18:36:36 -07001065 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 struct neighbour *neigh;
1067 int err = -ENXIO;
1068
1069 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1070 if (neigh) {
1071 read_lock_bh(&neigh->lock);
1072 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1073 r->arp_flags = arp_state_to_flags(neigh);
1074 read_unlock_bh(&neigh->lock);
1075 r->arp_ha.sa_family = dev->type;
1076 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1077 neigh_release(neigh);
1078 err = 0;
1079 }
1080 return err;
1081}
1082
1083static int arp_req_delete(struct arpreq *r, struct net_device * dev)
1084{
1085 int err;
Al Viroed9bad02006-09-27 18:36:36 -07001086 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087 struct neighbour *neigh;
1088
1089 if (r->arp_flags & ATF_PUBL) {
Al Viroed9bad02006-09-27 18:36:36 -07001090 __be32 mask =
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
Al Viroed9bad02006-09-27 18:36:36 -07001092 if (mask == htonl(0xFFFFFFFF))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 return pneigh_delete(&arp_tbl, &ip, dev);
1094 if (mask == 0) {
1095 if (dev == NULL) {
Herbert Xu42f811b2007-06-04 23:34:44 -07001096 IPV4_DEVCONF_ALL(PROXY_ARP) = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 return 0;
1098 }
Herbert Xue5ed6392005-10-03 14:35:55 -07001099 if (__in_dev_get_rtnl(dev)) {
Herbert Xu42f811b2007-06-04 23:34:44 -07001100 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev),
1101 PROXY_ARP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 return 0;
1103 }
1104 return -ENXIO;
1105 }
1106 return -EINVAL;
1107 }
1108
1109 if (dev == NULL) {
1110 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1111 .tos = RTO_ONLINK } } };
1112 struct rtable * rt;
1113 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1114 return err;
1115 dev = rt->u.dst.dev;
1116 ip_rt_put(rt);
1117 if (!dev)
1118 return -EINVAL;
1119 }
1120 err = -ENXIO;
1121 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1122 if (neigh) {
1123 if (neigh->nud_state&~NUD_NOARP)
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001124 err = neigh_update(neigh, NULL, NUD_FAILED,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 NEIGH_UPDATE_F_OVERRIDE|
1126 NEIGH_UPDATE_F_ADMIN);
1127 neigh_release(neigh);
1128 }
1129 return err;
1130}
1131
1132/*
1133 * Handle an ARP layer I/O control request.
1134 */
1135
1136int arp_ioctl(unsigned int cmd, void __user *arg)
1137{
1138 int err;
1139 struct arpreq r;
1140 struct net_device *dev = NULL;
1141
1142 switch (cmd) {
1143 case SIOCDARP:
1144 case SIOCSARP:
1145 if (!capable(CAP_NET_ADMIN))
1146 return -EPERM;
1147 case SIOCGARP:
1148 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1149 if (err)
1150 return -EFAULT;
1151 break;
1152 default:
1153 return -EINVAL;
1154 }
1155
1156 if (r.arp_pa.sa_family != AF_INET)
1157 return -EPFNOSUPPORT;
1158
1159 if (!(r.arp_flags & ATF_PUBL) &&
1160 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
1161 return -EINVAL;
1162 if (!(r.arp_flags & ATF_NETMASK))
1163 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1164 htonl(0xFFFFFFFFUL);
1165 rtnl_lock();
1166 if (r.arp_dev[0]) {
1167 err = -ENODEV;
1168 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL)
1169 goto out;
1170
1171 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1172 if (!r.arp_ha.sa_family)
1173 r.arp_ha.sa_family = dev->type;
1174 err = -EINVAL;
1175 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1176 goto out;
1177 } else if (cmd == SIOCGARP) {
1178 err = -ENODEV;
1179 goto out;
1180 }
1181
Stephen Hemminger132adf52007-03-08 20:44:43 -08001182 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 case SIOCDARP:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001184 err = arp_req_delete(&r, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 break;
1186 case SIOCSARP:
1187 err = arp_req_set(&r, dev);
1188 break;
1189 case SIOCGARP:
1190 err = arp_req_get(&r, dev);
1191 if (!err && copy_to_user(arg, &r, sizeof(r)))
1192 err = -EFAULT;
1193 break;
1194 }
1195out:
1196 rtnl_unlock();
1197 return err;
1198}
1199
1200static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1201{
1202 struct net_device *dev = ptr;
1203
1204 switch (event) {
1205 case NETDEV_CHANGEADDR:
1206 neigh_changeaddr(&arp_tbl, dev);
1207 rt_cache_flush(0);
1208 break;
1209 default:
1210 break;
1211 }
1212
1213 return NOTIFY_DONE;
1214}
1215
1216static struct notifier_block arp_netdev_notifier = {
1217 .notifier_call = arp_netdev_event,
1218};
1219
1220/* Note, that it is not on notifier chain.
1221 It is necessary, that this routine was called after route cache will be
1222 flushed.
1223 */
1224void arp_ifdown(struct net_device *dev)
1225{
1226 neigh_ifdown(&arp_tbl, dev);
1227}
1228
1229
1230/*
1231 * Called once on startup.
1232 */
1233
1234static struct packet_type arp_packet_type = {
1235 .type = __constant_htons(ETH_P_ARP),
1236 .func = arp_rcv,
1237};
1238
1239static int arp_proc_init(void);
1240
1241void __init arp_init(void)
1242{
1243 neigh_table_init(&arp_tbl);
1244
1245 dev_add_pack(&arp_packet_type);
1246 arp_proc_init();
1247#ifdef CONFIG_SYSCTL
1248 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
1249 NET_IPV4_NEIGH, "ipv4", NULL, NULL);
1250#endif
1251 register_netdevice_notifier(&arp_netdev_notifier);
1252}
1253
1254#ifdef CONFIG_PROC_FS
1255#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1256
1257/* ------------------------------------------------------------------------ */
1258/*
1259 * ax25 -> ASCII conversion
1260 */
1261static char *ax2asc2(ax25_address *a, char *buf)
1262{
1263 char c, *s;
1264 int n;
1265
1266 for (n = 0, s = buf; n < 6; n++) {
1267 c = (a->ax25_call[n] >> 1) & 0x7F;
1268
1269 if (c != ' ') *s++ = c;
1270 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001271
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 *s++ = '-';
1273
1274 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
1275 *s++ = '1';
1276 n -= 10;
1277 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001278
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 *s++ = n + '0';
1280 *s++ = '\0';
1281
1282 if (*buf == '\0' || *buf == '-')
1283 return "*";
1284
1285 return buf;
1286
1287}
1288#endif /* CONFIG_AX25 */
1289
1290#define HBUFFERLEN 30
1291
1292static void arp_format_neigh_entry(struct seq_file *seq,
1293 struct neighbour *n)
1294{
1295 char hbuffer[HBUFFERLEN];
1296 const char hexbuf[] = "0123456789ABCDEF";
1297 int k, j;
1298 char tbuf[16];
1299 struct net_device *dev = n->dev;
1300 int hatype = dev->type;
1301
1302 read_lock(&n->lock);
1303 /* Convert hardware address to XX:XX:XX:XX ... form. */
1304#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1305 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1306 ax2asc2((ax25_address *)n->ha, hbuffer);
1307 else {
1308#endif
1309 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
1310 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15];
1311 hbuffer[k++] = hexbuf[n->ha[j] & 15];
1312 hbuffer[k++] = ':';
1313 }
1314 hbuffer[--k] = 0;
1315#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1316 }
1317#endif
1318 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
1319 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1320 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1321 read_unlock(&n->lock);
1322}
1323
1324static void arp_format_pneigh_entry(struct seq_file *seq,
1325 struct pneigh_entry *n)
1326{
1327 struct net_device *dev = n->dev;
1328 int hatype = dev ? dev->type : 0;
1329 char tbuf[16];
1330
1331 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
1332 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1333 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1334 dev ? dev->name : "*");
1335}
1336
1337static int arp_seq_show(struct seq_file *seq, void *v)
1338{
1339 if (v == SEQ_START_TOKEN) {
1340 seq_puts(seq, "IP address HW type Flags "
1341 "HW address Mask Device\n");
1342 } else {
1343 struct neigh_seq_state *state = seq->private;
1344
1345 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1346 arp_format_pneigh_entry(seq, v);
1347 else
1348 arp_format_neigh_entry(seq, v);
1349 }
1350
1351 return 0;
1352}
1353
1354static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1355{
1356 /* Don't want to confuse "arp -a" w/ magic entries,
1357 * so we tell the generic iterator to skip NUD_NOARP.
1358 */
1359 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1360}
1361
1362/* ------------------------------------------------------------------------ */
1363
Stephen Hemmingerf6908082007-03-12 14:34:29 -07001364static const struct seq_operations arp_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 .start = arp_seq_start,
1366 .next = neigh_seq_next,
1367 .stop = neigh_seq_stop,
1368 .show = arp_seq_show,
1369};
1370
1371static int arp_seq_open(struct inode *inode, struct file *file)
1372{
1373 struct seq_file *seq;
1374 int rc = -ENOMEM;
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07001375 struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001376
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 if (!s)
1378 goto out;
1379
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 rc = seq_open(file, &arp_seq_ops);
1381 if (rc)
1382 goto out_kfree;
1383
1384 seq = file->private_data;
1385 seq->private = s;
1386out:
1387 return rc;
1388out_kfree:
1389 kfree(s);
1390 goto out;
1391}
1392
Arjan van de Ven9a321442007-02-12 00:55:35 -08001393static const struct file_operations arp_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 .owner = THIS_MODULE,
1395 .open = arp_seq_open,
1396 .read = seq_read,
1397 .llseek = seq_lseek,
1398 .release = seq_release_private,
1399};
1400
1401static int __init arp_proc_init(void)
1402{
1403 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops))
1404 return -ENOMEM;
1405 return 0;
1406}
1407
1408#else /* CONFIG_PROC_FS */
1409
1410static int __init arp_proc_init(void)
1411{
1412 return 0;
1413}
1414
1415#endif /* CONFIG_PROC_FS */
1416
1417EXPORT_SYMBOL(arp_broken_ops);
1418EXPORT_SYMBOL(arp_find);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001419EXPORT_SYMBOL(arp_create);
1420EXPORT_SYMBOL(arp_xmit);
1421EXPORT_SYMBOL(arp_send);
1422EXPORT_SYMBOL(arp_tbl);
1423
1424#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1425EXPORT_SYMBOL(clip_tbl_hook);
1426#endif