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[net-next-2.6.git] / net / ipv4 / arp.c
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1/* linux/net/ipv4/arp.c
2 *
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:
18 * Alan Cox : Removed the Ethernet assumptions in
19 * Florian's code
20 * Alan Cox : Fixed some small errors in the ARP
21 * 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.
42 * Craig Schlenter : Don't modify permanent entry
43 * during arp_rcv.
44 * Russ Nelson : Tidied up a few bits.
45 * Alexey Kuznetsov: Major changes to caching and behaviour,
46 * eg intelligent arp probing and
47 * 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.
53 * Jonathan Layes : Added arpd support through kerneld
54 * 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>
81#include <linux/capability.h>
82#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>
88#include <linux/inetdevice.h>
89#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/net_namespace.h>
107#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
206int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
207{
208 switch (dev->type) {
209 case ARPHRD_ETHER:
210 case ARPHRD_FDDI:
211 case ARPHRD_IEEE802:
212 ip_eth_mc_map(addr, haddr);
213 return 0;
214 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{
237 __be32 addr = *(__be32*)neigh->primary_key;
238 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();
245 in_dev = __in_dev_get_rcu(dev);
246 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
256 if (dev->hard_header == NULL) {
257 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;
291 case ARPHRD_ROSE:
292#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 }
313 if (dev->hard_header_cache)
314 neigh->ops = &arp_hh_ops;
315 else
316 neigh->ops = &arp_generic_ops;
317 if (neigh->nud_state&NUD_VALID)
318 neigh->output = neigh->ops->connected_output;
319 else
320 neigh->output = neigh->ops->output;
321 }
322 return 0;
323}
324
325static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
326{
327 dst_link_failure(skb);
328 kfree_skb(skb);
329}
330
331static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
332{
333 __be32 saddr = 0;
334 u8 *dst_ha = NULL;
335 struct net_device *dev = neigh->dev;
336 __be32 target = *(__be32*)neigh->primary_key;
337 int probes = atomic_read(&neigh->probes);
338 struct in_device *in_dev = in_dev_get(dev);
339
340 if (!in_dev)
341 return;
342
343 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
344 default:
345 case 0: /* By default announce any local IP */
346 if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL)
347 saddr = ip_hdr(skb)->saddr;
348 break;
349 case 1: /* Restrict announcements of saddr in same subnet */
350 if (!skb)
351 break;
352 saddr = ip_hdr(skb)->saddr;
353 if (inet_addr_type(saddr) == RTN_LOCAL) {
354 /* saddr should be known to target */
355 if (inet_addr_onlink(in_dev, target, saddr))
356 break;
357 }
358 saddr = 0;
359 break;
360 case 2: /* Avoid secondary IPs, get a primary/preferred one */
361 break;
362 }
363
364 if (in_dev)
365 in_dev_put(in_dev);
366 if (!saddr)
367 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
368
369 if ((probes -= neigh->parms->ucast_probes) < 0) {
370 if (!(neigh->nud_state&NUD_VALID))
371 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
372 dst_ha = neigh->ha;
373 read_lock_bh(&neigh->lock);
374 } else if ((probes -= neigh->parms->app_probes) < 0) {
375#ifdef CONFIG_ARPD
376 neigh_app_ns(neigh);
377#endif
378 return;
379 }
380
381 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
382 dst_ha, dev->dev_addr, NULL);
383 if (dst_ha)
384 read_unlock_bh(&neigh->lock);
385}
386
387static int arp_ignore(struct in_device *in_dev, struct net_device *dev,
388 __be32 sip, __be32 tip)
389{
390 int scope;
391
392 switch (IN_DEV_ARP_IGNORE(in_dev)) {
393 case 0: /* Reply, the tip is already validated */
394 return 0;
395 case 1: /* Reply only if tip is configured on the incoming interface */
396 sip = 0;
397 scope = RT_SCOPE_HOST;
398 break;
399 case 2: /*
400 * Reply only if tip is configured on the incoming interface
401 * and is in same subnet as sip
402 */
403 scope = RT_SCOPE_HOST;
404 break;
405 case 3: /* Do not reply for scope host addresses */
406 sip = 0;
407 scope = RT_SCOPE_LINK;
408 dev = NULL;
409 break;
410 case 4: /* Reserved */
411 case 5:
412 case 6:
413 case 7:
414 return 0;
415 case 8: /* Do not reply */
416 return 1;
417 default:
418 return 0;
419 }
420 return !inet_confirm_addr(dev, sip, tip, scope);
421}
422
423static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
424{
425 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
426 .saddr = tip } } };
427 struct rtable *rt;
428 int flag = 0;
429 /*unsigned long now; */
430
431 if (ip_route_output_key(&rt, &fl) < 0)
432 return 1;
433 if (rt->u.dst.dev != dev) {
434 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER);
435 flag = 1;
436 }
437 ip_rt_put(rt);
438 return flag;
439}
440
441/* OBSOLETE FUNCTIONS */
442
443/*
444 * Find an arp mapping in the cache. If not found, post a request.
445 *
446 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
447 * even if it exists. It is supposed that skb->dev was mangled
448 * by a virtual device (eql, shaper). Nobody but broken devices
449 * is allowed to use this function, it is scheduled to be removed. --ANK
450 */
451
452static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev)
453{
454 switch (addr_hint) {
455 case RTN_LOCAL:
456 printk(KERN_DEBUG "ARP: arp called for own IP address\n");
457 memcpy(haddr, dev->dev_addr, dev->addr_len);
458 return 1;
459 case RTN_MULTICAST:
460 arp_mc_map(paddr, haddr, dev, 1);
461 return 1;
462 case RTN_BROADCAST:
463 memcpy(haddr, dev->broadcast, dev->addr_len);
464 return 1;
465 }
466 return 0;
467}
468
469
470int arp_find(unsigned char *haddr, struct sk_buff *skb)
471{
472 struct net_device *dev = skb->dev;
473 __be32 paddr;
474 struct neighbour *n;
475
476 if (!skb->dst) {
477 printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
478 kfree_skb(skb);
479 return 1;
480 }
481
482 paddr = ((struct rtable*)skb->dst)->rt_gateway;
483
484 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev))
485 return 0;
486
487 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
488
489 if (n) {
490 n->used = jiffies;
491 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
492 read_lock_bh(&n->lock);
493 memcpy(haddr, n->ha, dev->addr_len);
494 read_unlock_bh(&n->lock);
495 neigh_release(n);
496 return 0;
497 }
498 neigh_release(n);
499 } else
500 kfree_skb(skb);
501 return 1;
502}
503
504/* END OF OBSOLETE FUNCTIONS */
505
506int arp_bind_neighbour(struct dst_entry *dst)
507{
508 struct net_device *dev = dst->dev;
509 struct neighbour *n = dst->neighbour;
510
511 if (dev == NULL)
512 return -EINVAL;
513 if (n == NULL) {
514 __be32 nexthop = ((struct rtable*)dst)->rt_gateway;
515 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
516 nexthop = 0;
517 n = __neigh_lookup_errno(
518#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
519 dev->type == ARPHRD_ATM ? clip_tbl_hook :
520#endif
521 &arp_tbl, &nexthop, dev);
522 if (IS_ERR(n))
523 return PTR_ERR(n);
524 dst->neighbour = n;
525 }
526 return 0;
527}
528
529/*
530 * Check if we can use proxy ARP for this path
531 */
532
533static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
534{
535 struct in_device *out_dev;
536 int imi, omi = -1;
537
538 if (!IN_DEV_PROXY_ARP(in_dev))
539 return 0;
540
541 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
542 return 1;
543 if (imi == -1)
544 return 0;
545
546 /* place to check for proxy_arp for routes */
547
548 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
549 omi = IN_DEV_MEDIUM_ID(out_dev);
550 in_dev_put(out_dev);
551 }
552 return (omi != imi && omi != -1);
553}
554
555/*
556 * Interface to link layer: send routine and receive handler.
557 */
558
559/*
560 * Create an arp packet. If (dest_hw == NULL), we create a broadcast
561 * message.
562 */
563struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
564 struct net_device *dev, __be32 src_ip,
565 unsigned char *dest_hw, unsigned char *src_hw,
566 unsigned char *target_hw)
567{
568 struct sk_buff *skb;
569 struct arphdr *arp;
570 unsigned char *arp_ptr;
571
572 /*
573 * Allocate a buffer
574 */
575
576 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
577 + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
578 if (skb == NULL)
579 return NULL;
580
581 skb_reserve(skb, LL_RESERVED_SPACE(dev));
582 skb_reset_network_header(skb);
583 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
584 skb->dev = dev;
585 skb->protocol = htons(ETH_P_ARP);
586 if (src_hw == NULL)
587 src_hw = dev->dev_addr;
588 if (dest_hw == NULL)
589 dest_hw = dev->broadcast;
590
591 /*
592 * Fill the device header for the ARP frame
593 */
594 if (dev->hard_header &&
595 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0)
596 goto out;
597
598 /*
599 * Fill out the arp protocol part.
600 *
601 * The arp hardware type should match the device type, except for FDDI,
602 * which (according to RFC 1390) should always equal 1 (Ethernet).
603 */
604 /*
605 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the
606 * DIX code for the protocol. Make these device structure fields.
607 */
608 switch (dev->type) {
609 default:
610 arp->ar_hrd = htons(dev->type);
611 arp->ar_pro = htons(ETH_P_IP);
612 break;
613
614#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
615 case ARPHRD_AX25:
616 arp->ar_hrd = htons(ARPHRD_AX25);
617 arp->ar_pro = htons(AX25_P_IP);
618 break;
619
620#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
621 case ARPHRD_NETROM:
622 arp->ar_hrd = htons(ARPHRD_NETROM);
623 arp->ar_pro = htons(AX25_P_IP);
624 break;
625#endif
626#endif
627
628#ifdef CONFIG_FDDI
629 case ARPHRD_FDDI:
630 arp->ar_hrd = htons(ARPHRD_ETHER);
631 arp->ar_pro = htons(ETH_P_IP);
632 break;
633#endif
634#ifdef CONFIG_TR
635 case ARPHRD_IEEE802_TR:
636 arp->ar_hrd = htons(ARPHRD_IEEE802);
637 arp->ar_pro = htons(ETH_P_IP);
638 break;
639#endif
640 }
641
642 arp->ar_hln = dev->addr_len;
643 arp->ar_pln = 4;
644 arp->ar_op = htons(type);
645
646 arp_ptr=(unsigned char *)(arp+1);
647
648 memcpy(arp_ptr, src_hw, dev->addr_len);
649 arp_ptr+=dev->addr_len;
650 memcpy(arp_ptr, &src_ip,4);
651 arp_ptr+=4;
652 if (target_hw != NULL)
653 memcpy(arp_ptr, target_hw, dev->addr_len);
654 else
655 memset(arp_ptr, 0, dev->addr_len);
656 arp_ptr+=dev->addr_len;
657 memcpy(arp_ptr, &dest_ip, 4);
658
659 return skb;
660
661out:
662 kfree_skb(skb);
663 return NULL;
664}
665
666/*
667 * Send an arp packet.
668 */
669void arp_xmit(struct sk_buff *skb)
670{
671 /* Send it off, maybe filter it using firewalling first. */
672 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
673}
674
675/*
676 * Create and send an arp packet.
677 */
678void arp_send(int type, int ptype, __be32 dest_ip,
679 struct net_device *dev, __be32 src_ip,
680 unsigned char *dest_hw, unsigned char *src_hw,
681 unsigned char *target_hw)
682{
683 struct sk_buff *skb;
684
685 /*
686 * No arp on this interface.
687 */
688
689 if (dev->flags&IFF_NOARP)
690 return;
691
692 skb = arp_create(type, ptype, dest_ip, dev, src_ip,
693 dest_hw, src_hw, target_hw);
694 if (skb == NULL) {
695 return;
696 }
697
698 arp_xmit(skb);
699}
700
701/*
702 * Process an arp request.
703 */
704
705static int arp_process(struct sk_buff *skb)
706{
707 struct net_device *dev = skb->dev;
708 struct in_device *in_dev = in_dev_get(dev);
709 struct arphdr *arp;
710 unsigned char *arp_ptr;
711 struct rtable *rt;
712 unsigned char *sha, *tha;
713 __be32 sip, tip;
714 u16 dev_type = dev->type;
715 int addr_type;
716 struct neighbour *n;
717
718 /* arp_rcv below verifies the ARP header and verifies the device
719 * is ARP'able.
720 */
721
722 if (in_dev == NULL)
723 goto out;
724
725 arp = arp_hdr(skb);
726
727 switch (dev_type) {
728 default:
729 if (arp->ar_pro != htons(ETH_P_IP) ||
730 htons(dev_type) != arp->ar_hrd)
731 goto out;
732 break;
733#ifdef CONFIG_NET_ETHERNET
734 case ARPHRD_ETHER:
735#endif
736#ifdef CONFIG_TR
737 case ARPHRD_IEEE802_TR:
738#endif
739#ifdef CONFIG_FDDI
740 case ARPHRD_FDDI:
741#endif
742#ifdef CONFIG_NET_FC
743 case ARPHRD_IEEE802:
744#endif
745#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
746 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
747 /*
748 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
749 * devices, according to RFC 2625) devices will accept ARP
750 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
751 * This is the case also of FDDI, where the RFC 1390 says that
752 * FDDI devices should accept ARP hardware of (1) Ethernet,
753 * however, to be more robust, we'll accept both 1 (Ethernet)
754 * or 6 (IEEE 802.2)
755 */
756 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
757 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
758 arp->ar_pro != htons(ETH_P_IP))
759 goto out;
760 break;
761#endif
762#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
763 case ARPHRD_AX25:
764 if (arp->ar_pro != htons(AX25_P_IP) ||
765 arp->ar_hrd != htons(ARPHRD_AX25))
766 goto out;
767 break;
768#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
769 case ARPHRD_NETROM:
770 if (arp->ar_pro != htons(AX25_P_IP) ||
771 arp->ar_hrd != htons(ARPHRD_NETROM))
772 goto out;
773 break;
774#endif
775#endif
776 }
777
778 /* Understand only these message types */
779
780 if (arp->ar_op != htons(ARPOP_REPLY) &&
781 arp->ar_op != htons(ARPOP_REQUEST))
782 goto out;
783
784/*
785 * Extract fields
786 */
787 arp_ptr= (unsigned char *)(arp+1);
788 sha = arp_ptr;
789 arp_ptr += dev->addr_len;
790 memcpy(&sip, arp_ptr, 4);
791 arp_ptr += 4;
792 tha = arp_ptr;
793 arp_ptr += dev->addr_len;
794 memcpy(&tip, arp_ptr, 4);
795/*
796 * Check for bad requests for 127.x.x.x and requests for multicast
797 * addresses. If this is one such, delete it.
798 */
799 if (LOOPBACK(tip) || MULTICAST(tip))
800 goto out;
801
802/*
803 * Special case: We must set Frame Relay source Q.922 address
804 */
805 if (dev_type == ARPHRD_DLCI)
806 sha = dev->broadcast;
807
808/*
809 * Process entry. The idea here is we want to send a reply if it is a
810 * request for us or if it is a request for someone else that we hold
811 * a proxy for. We want to add an entry to our cache if it is a reply
812 * to us or if it is a request for our address.
813 * (The assumption for this last is that if someone is requesting our
814 * address, they are probably intending to talk to us, so it saves time
815 * if we cache their address. Their address is also probably not in
816 * our cache, since ours is not in their cache.)
817 *
818 * Putting this another way, we only care about replies if they are to
819 * us, in which case we add them to the cache. For requests, we care
820 * about those for us and those for our proxies. We reply to both,
821 * and in the case of requests for us we add the requester to the arp
822 * cache.
823 */
824
825 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
826 if (sip == 0) {
827 if (arp->ar_op == htons(ARPOP_REQUEST) &&
828 inet_addr_type(tip) == RTN_LOCAL &&
829 !arp_ignore(in_dev,dev,sip,tip))
830 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
831 goto out;
832 }
833
834 if (arp->ar_op == htons(ARPOP_REQUEST) &&
835 ip_route_input(skb, tip, sip, 0, dev) == 0) {
836
837 rt = (struct rtable*)skb->dst;
838 addr_type = rt->rt_type;
839
840 if (addr_type == RTN_LOCAL) {
841 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
842 if (n) {
843 int dont_send = 0;
844
845 if (!dont_send)
846 dont_send |= arp_ignore(in_dev,dev,sip,tip);
847 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
848 dont_send |= arp_filter(sip,tip,dev);
849 if (!dont_send)
850 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
851
852 neigh_release(n);
853 }
854 goto out;
855 } else if (IN_DEV_FORWARD(in_dev)) {
856 if ((rt->rt_flags&RTCF_DNAT) ||
857 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev &&
858 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
859 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
860 if (n)
861 neigh_release(n);
862
863 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
864 skb->pkt_type == PACKET_HOST ||
865 in_dev->arp_parms->proxy_delay == 0) {
866 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
867 } else {
868 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
869 in_dev_put(in_dev);
870 return 0;
871 }
872 goto out;
873 }
874 }
875 }
876
877 /* Update our ARP tables */
878
879 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
880
881 if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) {
882 /* Unsolicited ARP is not accepted by default.
883 It is possible, that this option should be enabled for some
884 devices (strip is candidate)
885 */
886 if (n == NULL &&
887 arp->ar_op == htons(ARPOP_REPLY) &&
888 inet_addr_type(sip) == RTN_UNICAST)
889 n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
890 }
891
892 if (n) {
893 int state = NUD_REACHABLE;
894 int override;
895
896 /* If several different ARP replies follows back-to-back,
897 use the FIRST one. It is possible, if several proxy
898 agents are active. Taking the first reply prevents
899 arp trashing and chooses the fastest router.
900 */
901 override = time_after(jiffies, n->updated + n->parms->locktime);
902
903 /* Broadcast replies and request packets
904 do not assert neighbour reachability.
905 */
906 if (arp->ar_op != htons(ARPOP_REPLY) ||
907 skb->pkt_type != PACKET_HOST)
908 state = NUD_STALE;
909 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0);
910 neigh_release(n);
911 }
912
913out:
914 if (in_dev)
915 in_dev_put(in_dev);
916 kfree_skb(skb);
917 return 0;
918}
919
920static void parp_redo(struct sk_buff *skb)
921{
922 arp_process(skb);
923}
924
925
926/*
927 * Receive an arp request from the device layer.
928 */
929
930static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
931 struct packet_type *pt, struct net_device *orig_dev)
932{
933 struct arphdr *arp;
934
935 if (dev->nd_net != &init_net)
936 goto freeskb;
937
938 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
939 if (!pskb_may_pull(skb, (sizeof(struct arphdr) +
940 (2 * dev->addr_len) +
941 (2 * sizeof(u32)))))
942 goto freeskb;
943
944 arp = arp_hdr(skb);
945 if (arp->ar_hln != dev->addr_len ||
946 dev->flags & IFF_NOARP ||
947 skb->pkt_type == PACKET_OTHERHOST ||
948 skb->pkt_type == PACKET_LOOPBACK ||
949 arp->ar_pln != 4)
950 goto freeskb;
951
952 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
953 goto out_of_mem;
954
955 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
956
957 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
958
959freeskb:
960 kfree_skb(skb);
961out_of_mem:
962 return 0;
963}
964
965/*
966 * User level interface (ioctl)
967 */
968
969/*
970 * Set (create) an ARP cache entry.
971 */
972
973static int arp_req_set(struct arpreq *r, struct net_device * dev)
974{
975 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
976 struct neighbour *neigh;
977 int err;
978
979 if (r->arp_flags&ATF_PUBL) {
980 __be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
981 if (mask && mask != htonl(0xFFFFFFFF))
982 return -EINVAL;
983 if (!dev && (r->arp_flags & ATF_COM)) {
984 dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family, r->arp_ha.sa_data);
985 if (!dev)
986 return -ENODEV;
987 }
988 if (mask) {
989 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
990 return -ENOBUFS;
991 return 0;
992 }
993 if (dev == NULL) {
994 IPV4_DEVCONF_ALL(PROXY_ARP) = 1;
995 return 0;
996 }
997 if (__in_dev_get_rtnl(dev)) {
998 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1);
999 return 0;
1000 }
1001 return -ENXIO;
1002 }
1003
1004 if (r->arp_flags & ATF_PERM)
1005 r->arp_flags |= ATF_COM;
1006 if (dev == NULL) {
1007 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1008 .tos = RTO_ONLINK } } };
1009 struct rtable * rt;
1010 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1011 return err;
1012 dev = rt->u.dst.dev;
1013 ip_rt_put(rt);
1014 if (!dev)
1015 return -EINVAL;
1016 }
1017 switch (dev->type) {
1018#ifdef CONFIG_FDDI
1019 case ARPHRD_FDDI:
1020 /*
1021 * According to RFC 1390, FDDI devices should accept ARP
1022 * hardware types of 1 (Ethernet). However, to be more
1023 * robust, we'll accept hardware types of either 1 (Ethernet)
1024 * or 6 (IEEE 802.2).
1025 */
1026 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1027 r->arp_ha.sa_family != ARPHRD_ETHER &&
1028 r->arp_ha.sa_family != ARPHRD_IEEE802)
1029 return -EINVAL;
1030 break;
1031#endif
1032 default:
1033 if (r->arp_ha.sa_family != dev->type)
1034 return -EINVAL;
1035 break;
1036 }
1037
1038 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1039 err = PTR_ERR(neigh);
1040 if (!IS_ERR(neigh)) {
1041 unsigned state = NUD_STALE;
1042 if (r->arp_flags & ATF_PERM)
1043 state = NUD_PERMANENT;
1044 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
1045 r->arp_ha.sa_data : NULL, state,
1046 NEIGH_UPDATE_F_OVERRIDE|
1047 NEIGH_UPDATE_F_ADMIN);
1048 neigh_release(neigh);
1049 }
1050 return err;
1051}
1052
1053static unsigned arp_state_to_flags(struct neighbour *neigh)
1054{
1055 unsigned flags = 0;
1056 if (neigh->nud_state&NUD_PERMANENT)
1057 flags = ATF_PERM|ATF_COM;
1058 else if (neigh->nud_state&NUD_VALID)
1059 flags = ATF_COM;
1060 return flags;
1061}
1062
1063/*
1064 * Get an ARP cache entry.
1065 */
1066
1067static int arp_req_get(struct arpreq *r, struct net_device *dev)
1068{
1069 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1070 struct neighbour *neigh;
1071 int err = -ENXIO;
1072
1073 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1074 if (neigh) {
1075 read_lock_bh(&neigh->lock);
1076 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1077 r->arp_flags = arp_state_to_flags(neigh);
1078 read_unlock_bh(&neigh->lock);
1079 r->arp_ha.sa_family = dev->type;
1080 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1081 neigh_release(neigh);
1082 err = 0;
1083 }
1084 return err;
1085}
1086
1087static int arp_req_delete(struct arpreq *r, struct net_device * dev)
1088{
1089 int err;
1090 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
1091 struct neighbour *neigh;
1092
1093 if (r->arp_flags & ATF_PUBL) {
1094 __be32 mask =
1095 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1096 if (mask == htonl(0xFFFFFFFF))
1097 return pneigh_delete(&arp_tbl, &ip, dev);
1098 if (mask == 0) {
1099 if (dev == NULL) {
1100 IPV4_DEVCONF_ALL(PROXY_ARP) = 0;
1101 return 0;
1102 }
1103 if (__in_dev_get_rtnl(dev)) {
1104 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev),
1105 PROXY_ARP, 0);
1106 return 0;
1107 }
1108 return -ENXIO;
1109 }
1110 return -EINVAL;
1111 }
1112
1113 if (dev == NULL) {
1114 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1115 .tos = RTO_ONLINK } } };
1116 struct rtable * rt;
1117 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1118 return err;
1119 dev = rt->u.dst.dev;
1120 ip_rt_put(rt);
1121 if (!dev)
1122 return -EINVAL;
1123 }
1124 err = -ENXIO;
1125 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1126 if (neigh) {
1127 if (neigh->nud_state&~NUD_NOARP)
1128 err = neigh_update(neigh, NULL, NUD_FAILED,
1129 NEIGH_UPDATE_F_OVERRIDE|
1130 NEIGH_UPDATE_F_ADMIN);
1131 neigh_release(neigh);
1132 }
1133 return err;
1134}
1135
1136/*
1137 * Handle an ARP layer I/O control request.
1138 */
1139
1140int arp_ioctl(unsigned int cmd, void __user *arg)
1141{
1142 int err;
1143 struct arpreq r;
1144 struct net_device *dev = NULL;
1145
1146 switch (cmd) {
1147 case SIOCDARP:
1148 case SIOCSARP:
1149 if (!capable(CAP_NET_ADMIN))
1150 return -EPERM;
1151 case SIOCGARP:
1152 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1153 if (err)
1154 return -EFAULT;
1155 break;
1156 default:
1157 return -EINVAL;
1158 }
1159
1160 if (r.arp_pa.sa_family != AF_INET)
1161 return -EPFNOSUPPORT;
1162
1163 if (!(r.arp_flags & ATF_PUBL) &&
1164 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
1165 return -EINVAL;
1166 if (!(r.arp_flags & ATF_NETMASK))
1167 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1168 htonl(0xFFFFFFFFUL);
1169 rtnl_lock();
1170 if (r.arp_dev[0]) {
1171 err = -ENODEV;
1172 if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL)
1173 goto out;
1174
1175 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1176 if (!r.arp_ha.sa_family)
1177 r.arp_ha.sa_family = dev->type;
1178 err = -EINVAL;
1179 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1180 goto out;
1181 } else if (cmd == SIOCGARP) {
1182 err = -ENODEV;
1183 goto out;
1184 }
1185
1186 switch (cmd) {
1187 case SIOCDARP:
1188 err = arp_req_delete(&r, dev);
1189 break;
1190 case SIOCSARP:
1191 err = arp_req_set(&r, dev);
1192 break;
1193 case SIOCGARP:
1194 err = arp_req_get(&r, dev);
1195 if (!err && copy_to_user(arg, &r, sizeof(r)))
1196 err = -EFAULT;
1197 break;
1198 }
1199out:
1200 rtnl_unlock();
1201 return err;
1202}
1203
1204static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1205{
1206 struct net_device *dev = ptr;
1207
1208 if (dev->nd_net != &init_net)
1209 return NOTIFY_DONE;
1210
1211 switch (event) {
1212 case NETDEV_CHANGEADDR:
1213 neigh_changeaddr(&arp_tbl, dev);
1214 rt_cache_flush(0);
1215 break;
1216 default:
1217 break;
1218 }
1219
1220 return NOTIFY_DONE;
1221}
1222
1223static struct notifier_block arp_netdev_notifier = {
1224 .notifier_call = arp_netdev_event,
1225};
1226
1227/* Note, that it is not on notifier chain.
1228 It is necessary, that this routine was called after route cache will be
1229 flushed.
1230 */
1231void arp_ifdown(struct net_device *dev)
1232{
1233 neigh_ifdown(&arp_tbl, dev);
1234}
1235
1236
1237/*
1238 * Called once on startup.
1239 */
1240
1241static struct packet_type arp_packet_type = {
1242 .type = __constant_htons(ETH_P_ARP),
1243 .func = arp_rcv,
1244};
1245
1246static int arp_proc_init(void);
1247
1248void __init arp_init(void)
1249{
1250 neigh_table_init(&arp_tbl);
1251
1252 dev_add_pack(&arp_packet_type);
1253 arp_proc_init();
1254#ifdef CONFIG_SYSCTL
1255 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
1256 NET_IPV4_NEIGH, "ipv4", NULL, NULL);
1257#endif
1258 register_netdevice_notifier(&arp_netdev_notifier);
1259}
1260
1261#ifdef CONFIG_PROC_FS
1262#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1263
1264/* ------------------------------------------------------------------------ */
1265/*
1266 * ax25 -> ASCII conversion
1267 */
1268static char *ax2asc2(ax25_address *a, char *buf)
1269{
1270 char c, *s;
1271 int n;
1272
1273 for (n = 0, s = buf; n < 6; n++) {
1274 c = (a->ax25_call[n] >> 1) & 0x7F;
1275
1276 if (c != ' ') *s++ = c;
1277 }
1278
1279 *s++ = '-';
1280
1281 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
1282 *s++ = '1';
1283 n -= 10;
1284 }
1285
1286 *s++ = n + '0';
1287 *s++ = '\0';
1288
1289 if (*buf == '\0' || *buf == '-')
1290 return "*";
1291
1292 return buf;
1293
1294}
1295#endif /* CONFIG_AX25 */
1296
1297#define HBUFFERLEN 30
1298
1299static void arp_format_neigh_entry(struct seq_file *seq,
1300 struct neighbour *n)
1301{
1302 char hbuffer[HBUFFERLEN];
1303 const char hexbuf[] = "0123456789ABCDEF";
1304 int k, j;
1305 char tbuf[16];
1306 struct net_device *dev = n->dev;
1307 int hatype = dev->type;
1308
1309 read_lock(&n->lock);
1310 /* Convert hardware address to XX:XX:XX:XX ... form. */
1311#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1312 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1313 ax2asc2((ax25_address *)n->ha, hbuffer);
1314 else {
1315#endif
1316 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
1317 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15];
1318 hbuffer[k++] = hexbuf[n->ha[j] & 15];
1319 hbuffer[k++] = ':';
1320 }
1321 hbuffer[--k] = 0;
1322#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1323 }
1324#endif
1325 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
1326 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1327 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1328 read_unlock(&n->lock);
1329}
1330
1331static void arp_format_pneigh_entry(struct seq_file *seq,
1332 struct pneigh_entry *n)
1333{
1334 struct net_device *dev = n->dev;
1335 int hatype = dev ? dev->type : 0;
1336 char tbuf[16];
1337
1338 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
1339 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1340 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1341 dev ? dev->name : "*");
1342}
1343
1344static int arp_seq_show(struct seq_file *seq, void *v)
1345{
1346 if (v == SEQ_START_TOKEN) {
1347 seq_puts(seq, "IP address HW type Flags "
1348 "HW address Mask Device\n");
1349 } else {
1350 struct neigh_seq_state *state = seq->private;
1351
1352 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1353 arp_format_pneigh_entry(seq, v);
1354 else
1355 arp_format_neigh_entry(seq, v);
1356 }
1357
1358 return 0;
1359}
1360
1361static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1362{
1363 /* Don't want to confuse "arp -a" w/ magic entries,
1364 * so we tell the generic iterator to skip NUD_NOARP.
1365 */
1366 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1367}
1368
1369/* ------------------------------------------------------------------------ */
1370
1371static const struct seq_operations arp_seq_ops = {
1372 .start = arp_seq_start,
1373 .next = neigh_seq_next,
1374 .stop = neigh_seq_stop,
1375 .show = arp_seq_show,
1376};
1377
1378static int arp_seq_open(struct inode *inode, struct file *file)
1379{
1380 struct seq_file *seq;
1381 int rc = -ENOMEM;
1382 struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
1383
1384 if (!s)
1385 goto out;
1386
1387 rc = seq_open(file, &arp_seq_ops);
1388 if (rc)
1389 goto out_kfree;
1390
1391 seq = file->private_data;
1392 seq->private = s;
1393out:
1394 return rc;
1395out_kfree:
1396 kfree(s);
1397 goto out;
1398}
1399
1400static const struct file_operations arp_seq_fops = {
1401 .owner = THIS_MODULE,
1402 .open = arp_seq_open,
1403 .read = seq_read,
1404 .llseek = seq_lseek,
1405 .release = seq_release_private,
1406};
1407
1408static int __init arp_proc_init(void)
1409{
1410 if (!proc_net_fops_create(&init_net, "arp", S_IRUGO, &arp_seq_fops))
1411 return -ENOMEM;
1412 return 0;
1413}
1414
1415#else /* CONFIG_PROC_FS */
1416
1417static int __init arp_proc_init(void)
1418{
1419 return 0;
1420}
1421
1422#endif /* CONFIG_PROC_FS */
1423
1424EXPORT_SYMBOL(arp_broken_ops);
1425EXPORT_SYMBOL(arp_find);
1426EXPORT_SYMBOL(arp_create);
1427EXPORT_SYMBOL(arp_xmit);
1428EXPORT_SYMBOL(arp_send);
1429EXPORT_SYMBOL(arp_tbl);
1430
1431#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1432EXPORT_SYMBOL(clip_tbl_hook);
1433#endif
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