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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv4/arp.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv4/arp.c')
-rw-r--r--net/ipv4/arp.c1425
1 files changed, 1425 insertions, 0 deletions
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
new file mode 100644
index 000000000000..a642fd612853
--- /dev/null
+++ b/net/ipv4/arp.c
@@ -0,0 +1,1425 @@
1/* linux/net/inet/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/sched.h>
82#include <linux/config.h>
83#include <linux/socket.h>
84#include <linux/sockios.h>
85#include <linux/errno.h>
86#include <linux/in.h>
87#include <linux/mm.h>
88#include <linux/inet.h>
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/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
205int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir)
206{
207 switch (dev->type) {
208 case ARPHRD_ETHER:
209 case ARPHRD_FDDI:
210 case ARPHRD_IEEE802:
211 ip_eth_mc_map(addr, haddr);
212 return 0;
213 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{
236 u32 addr = *(u32*)neigh->primary_key;
237 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();
244 in_dev = rcu_dereference(__in_dev_get(dev));
245 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;
290 case ARPHRD_ROSE:
291#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{
332 u32 saddr = 0;
333 u8 *dst_ha = NULL;
334 struct net_device *dev = neigh->dev;
335 u32 target = *(u32*)neigh->primary_key;
336 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 */
345 if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL)
346 saddr = skb->nh.iph->saddr;
347 break;
348 case 1: /* Restrict announcements of saddr in same subnet */
349 if (!skb)
350 break;
351 saddr = skb->nh.iph->saddr;
352 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,
387 u32 sip, u32 tip)
388{
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
422static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev)
423{
424 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
425 .saddr = tip } } };
426 struct rtable *rt;
427 int flag = 0;
428 /*unsigned long now; */
429
430 if (ip_route_output_key(&rt, &fl) < 0)
431 return 1;
432 if (rt->u.dst.dev != dev) {
433 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER);
434 flag = 1;
435 }
436 ip_rt_put(rt);
437 return flag;
438}
439
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
451static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev)
452{
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;
472 u32 paddr;
473 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);
492 memcpy(haddr, n->ha, dev->addr_len);
493 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) {
513 u32 nexthop = ((struct rtable*)dst)->rt_gateway;
514 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 */
562struct sk_buff *arp_create(int type, int ptype, u32 dest_ip,
563 struct net_device *dev, u32 src_ip,
564 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 */
574
575 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));
581 skb->nh.raw = skb->data;
582 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 */
677void arp_send(int type, int ptype, u32 dest_ip,
678 struct net_device *dev, u32 src_ip,
679 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 */
687
688 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
700static void parp_redo(struct sk_buff *skb)
701{
702 nf_reset(skb);
703 arp_rcv(skb, skb->dev, NULL);
704}
705
706/*
707 * Process an arp request.
708 */
709
710static int arp_process(struct sk_buff *skb)
711{
712 struct net_device *dev = skb->dev;
713 struct in_device *in_dev = in_dev_get(dev);
714 struct arphdr *arp;
715 unsigned char *arp_ptr;
716 struct rtable *rt;
717 unsigned char *sha, *tha;
718 u32 sip, tip;
719 u16 dev_type = dev->type;
720 int addr_type;
721 struct neighbour *n;
722
723 /* arp_rcv below verifies the ARP header and verifies the device
724 * is ARP'able.
725 */
726
727 if (in_dev == NULL)
728 goto out;
729
730 arp = skb->nh.arph;
731
732 switch (dev_type) {
733 default:
734 if (arp->ar_pro != htons(ETH_P_IP) ||
735 htons(dev_type) != arp->ar_hrd)
736 goto out;
737 break;
738#ifdef CONFIG_NET_ETHERNET
739 case ARPHRD_ETHER:
740#endif
741#ifdef CONFIG_TR
742 case ARPHRD_IEEE802_TR:
743#endif
744#ifdef CONFIG_FDDI
745 case ARPHRD_FDDI:
746#endif
747#ifdef CONFIG_NET_FC
748 case ARPHRD_IEEE802:
749#endif
750#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
751 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC)
752 /*
753 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
754 * devices, according to RFC 2625) devices will accept ARP
755 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
756 * This is the case also of FDDI, where the RFC 1390 says that
757 * FDDI devices should accept ARP hardware of (1) Ethernet,
758 * however, to be more robust, we'll accept both 1 (Ethernet)
759 * or 6 (IEEE 802.2)
760 */
761 if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
762 arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
763 arp->ar_pro != htons(ETH_P_IP))
764 goto out;
765 break;
766#endif
767#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
768 case ARPHRD_AX25:
769 if (arp->ar_pro != htons(AX25_P_IP) ||
770 arp->ar_hrd != htons(ARPHRD_AX25))
771 goto out;
772 break;
773#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
774 case ARPHRD_NETROM:
775 if (arp->ar_pro != htons(AX25_P_IP) ||
776 arp->ar_hrd != htons(ARPHRD_NETROM))
777 goto out;
778 break;
779#endif
780#endif
781 }
782
783 /* Understand only these message types */
784
785 if (arp->ar_op != htons(ARPOP_REPLY) &&
786 arp->ar_op != htons(ARPOP_REQUEST))
787 goto out;
788
789/*
790 * Extract fields
791 */
792 arp_ptr= (unsigned char *)(arp+1);
793 sha = arp_ptr;
794 arp_ptr += dev->addr_len;
795 memcpy(&sip, arp_ptr, 4);
796 arp_ptr += 4;
797 tha = arp_ptr;
798 arp_ptr += dev->addr_len;
799 memcpy(&tip, arp_ptr, 4);
800/*
801 * Check for bad requests for 127.x.x.x and requests for multicast
802 * addresses. If this is one such, delete it.
803 */
804 if (LOOPBACK(tip) || MULTICAST(tip))
805 goto out;
806
807/*
808 * Special case: We must set Frame Relay source Q.922 address
809 */
810 if (dev_type == ARPHRD_DLCI)
811 sha = dev->broadcast;
812
813/*
814 * Process entry. The idea here is we want to send a reply if it is a
815 * request for us or if it is a request for someone else that we hold
816 * a proxy for. We want to add an entry to our cache if it is a reply
817 * to us or if it is a request for our address.
818 * (The assumption for this last is that if someone is requesting our
819 * address, they are probably intending to talk to us, so it saves time
820 * if we cache their address. Their address is also probably not in
821 * our cache, since ours is not in their cache.)
822 *
823 * Putting this another way, we only care about replies if they are to
824 * us, in which case we add them to the cache. For requests, we care
825 * about those for us and those for our proxies. We reply to both,
826 * and in the case of requests for us we add the requester to the arp
827 * cache.
828 */
829
830 /* Special case: IPv4 duplicate address detection packet (RFC2131) */
831 if (sip == 0) {
832 if (arp->ar_op == htons(ARPOP_REQUEST) &&
833 inet_addr_type(tip) == RTN_LOCAL &&
834 !arp_ignore(in_dev,dev,sip,tip))
835 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
836 goto out;
837 }
838
839 if (arp->ar_op == htons(ARPOP_REQUEST) &&
840 ip_route_input(skb, tip, sip, 0, dev) == 0) {
841
842 rt = (struct rtable*)skb->dst;
843 addr_type = rt->rt_type;
844
845 if (addr_type == RTN_LOCAL) {
846 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
847 if (n) {
848 int dont_send = 0;
849
850 if (!dont_send)
851 dont_send |= arp_ignore(in_dev,dev,sip,tip);
852 if (!dont_send && IN_DEV_ARPFILTER(in_dev))
853 dont_send |= arp_filter(sip,tip,dev);
854 if (!dont_send)
855 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
856
857 neigh_release(n);
858 }
859 goto out;
860 } else if (IN_DEV_FORWARD(in_dev)) {
861 if ((rt->rt_flags&RTCF_DNAT) ||
862 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev &&
863 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
864 n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
865 if (n)
866 neigh_release(n);
867
868 if (skb->stamp.tv_sec == LOCALLY_ENQUEUED ||
869 skb->pkt_type == PACKET_HOST ||
870 in_dev->arp_parms->proxy_delay == 0) {
871 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
872 } else {
873 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
874 in_dev_put(in_dev);
875 return 0;
876 }
877 goto out;
878 }
879 }
880 }
881
882 /* Update our ARP tables */
883
884 n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
885
886#ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP
887 /* Unsolicited ARP is not accepted by default.
888 It is possible, that this option should be enabled for some
889 devices (strip is candidate)
890 */
891 if (n == NULL &&
892 arp->ar_op == htons(ARPOP_REPLY) &&
893 inet_addr_type(sip) == RTN_UNICAST)
894 n = __neigh_lookup(&arp_tbl, &sip, dev, -1);
895#endif
896
897 if (n) {
898 int state = NUD_REACHABLE;
899 int override;
900
901 /* If several different ARP replies follows back-to-back,
902 use the FIRST one. It is possible, if several proxy
903 agents are active. Taking the first reply prevents
904 arp trashing and chooses the fastest router.
905 */
906 override = time_after(jiffies, n->updated + n->parms->locktime);
907
908 /* Broadcast replies and request packets
909 do not assert neighbour reachability.
910 */
911 if (arp->ar_op != htons(ARPOP_REPLY) ||
912 skb->pkt_type != PACKET_HOST)
913 state = NUD_STALE;
914 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0);
915 neigh_release(n);
916 }
917
918out:
919 if (in_dev)
920 in_dev_put(in_dev);
921 kfree_skb(skb);
922 return 0;
923}
924
925
926/*
927 * Receive an arp request from the device layer.
928 */
929
930int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
931{
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
940 arp = skb->nh.arph;
941 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
951 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
952
953freeskb:
954 kfree_skb(skb);
955out_of_mem:
956 return 0;
957}
958
959/*
960 * User level interface (ioctl)
961 */
962
963/*
964 * Set (create) an ARP cache entry.
965 */
966
967static int arp_req_set(struct arpreq *r, struct net_device * dev)
968{
969 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
970 struct neighbour *neigh;
971 int err;
972
973 if (r->arp_flags&ATF_PUBL) {
974 u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
975 if (mask && mask != 0xFFFFFFFF)
976 return -EINVAL;
977 if (!dev && (r->arp_flags & ATF_COM)) {
978 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data);
979 if (!dev)
980 return -ENODEV;
981 }
982 if (mask) {
983 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
984 return -ENOBUFS;
985 return 0;
986 }
987 if (dev == NULL) {
988 ipv4_devconf.proxy_arp = 1;
989 return 0;
990 }
991 if (__in_dev_get(dev)) {
992 __in_dev_get(dev)->cnf.proxy_arp = 1;
993 return 0;
994 }
995 return -ENXIO;
996 }
997
998 if (r->arp_flags & ATF_PERM)
999 r->arp_flags |= ATF_COM;
1000 if (dev == NULL) {
1001 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1002 .tos = RTO_ONLINK } } };
1003 struct rtable * rt;
1004 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1005 return err;
1006 dev = rt->u.dst.dev;
1007 ip_rt_put(rt);
1008 if (!dev)
1009 return -EINVAL;
1010 }
1011 switch (dev->type) {
1012#ifdef CONFIG_FDDI
1013 case ARPHRD_FDDI:
1014 /*
1015 * According to RFC 1390, FDDI devices should accept ARP
1016 * hardware types of 1 (Ethernet). However, to be more
1017 * robust, we'll accept hardware types of either 1 (Ethernet)
1018 * or 6 (IEEE 802.2).
1019 */
1020 if (r->arp_ha.sa_family != ARPHRD_FDDI &&
1021 r->arp_ha.sa_family != ARPHRD_ETHER &&
1022 r->arp_ha.sa_family != ARPHRD_IEEE802)
1023 return -EINVAL;
1024 break;
1025#endif
1026 default:
1027 if (r->arp_ha.sa_family != dev->type)
1028 return -EINVAL;
1029 break;
1030 }
1031
1032 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
1033 err = PTR_ERR(neigh);
1034 if (!IS_ERR(neigh)) {
1035 unsigned state = NUD_STALE;
1036 if (r->arp_flags & ATF_PERM)
1037 state = NUD_PERMANENT;
1038 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
1039 r->arp_ha.sa_data : NULL, state,
1040 NEIGH_UPDATE_F_OVERRIDE|
1041 NEIGH_UPDATE_F_ADMIN);
1042 neigh_release(neigh);
1043 }
1044 return err;
1045}
1046
1047static unsigned arp_state_to_flags(struct neighbour *neigh)
1048{
1049 unsigned flags = 0;
1050 if (neigh->nud_state&NUD_PERMANENT)
1051 flags = ATF_PERM|ATF_COM;
1052 else if (neigh->nud_state&NUD_VALID)
1053 flags = ATF_COM;
1054 return flags;
1055}
1056
1057/*
1058 * Get an ARP cache entry.
1059 */
1060
1061static int arp_req_get(struct arpreq *r, struct net_device *dev)
1062{
1063 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
1064 struct neighbour *neigh;
1065 int err = -ENXIO;
1066
1067 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1068 if (neigh) {
1069 read_lock_bh(&neigh->lock);
1070 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
1071 r->arp_flags = arp_state_to_flags(neigh);
1072 read_unlock_bh(&neigh->lock);
1073 r->arp_ha.sa_family = dev->type;
1074 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
1075 neigh_release(neigh);
1076 err = 0;
1077 }
1078 return err;
1079}
1080
1081static int arp_req_delete(struct arpreq *r, struct net_device * dev)
1082{
1083 int err;
1084 u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
1085 struct neighbour *neigh;
1086
1087 if (r->arp_flags & ATF_PUBL) {
1088 u32 mask =
1089 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
1090 if (mask == 0xFFFFFFFF)
1091 return pneigh_delete(&arp_tbl, &ip, dev);
1092 if (mask == 0) {
1093 if (dev == NULL) {
1094 ipv4_devconf.proxy_arp = 0;
1095 return 0;
1096 }
1097 if (__in_dev_get(dev)) {
1098 __in_dev_get(dev)->cnf.proxy_arp = 0;
1099 return 0;
1100 }
1101 return -ENXIO;
1102 }
1103 return -EINVAL;
1104 }
1105
1106 if (dev == NULL) {
1107 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
1108 .tos = RTO_ONLINK } } };
1109 struct rtable * rt;
1110 if ((err = ip_route_output_key(&rt, &fl)) != 0)
1111 return err;
1112 dev = rt->u.dst.dev;
1113 ip_rt_put(rt);
1114 if (!dev)
1115 return -EINVAL;
1116 }
1117 err = -ENXIO;
1118 neigh = neigh_lookup(&arp_tbl, &ip, dev);
1119 if (neigh) {
1120 if (neigh->nud_state&~NUD_NOARP)
1121 err = neigh_update(neigh, NULL, NUD_FAILED,
1122 NEIGH_UPDATE_F_OVERRIDE|
1123 NEIGH_UPDATE_F_ADMIN);
1124 neigh_release(neigh);
1125 }
1126 return err;
1127}
1128
1129/*
1130 * Handle an ARP layer I/O control request.
1131 */
1132
1133int arp_ioctl(unsigned int cmd, void __user *arg)
1134{
1135 int err;
1136 struct arpreq r;
1137 struct net_device *dev = NULL;
1138
1139 switch (cmd) {
1140 case SIOCDARP:
1141 case SIOCSARP:
1142 if (!capable(CAP_NET_ADMIN))
1143 return -EPERM;
1144 case SIOCGARP:
1145 err = copy_from_user(&r, arg, sizeof(struct arpreq));
1146 if (err)
1147 return -EFAULT;
1148 break;
1149 default:
1150 return -EINVAL;
1151 }
1152
1153 if (r.arp_pa.sa_family != AF_INET)
1154 return -EPFNOSUPPORT;
1155
1156 if (!(r.arp_flags & ATF_PUBL) &&
1157 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
1158 return -EINVAL;
1159 if (!(r.arp_flags & ATF_NETMASK))
1160 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
1161 htonl(0xFFFFFFFFUL);
1162 rtnl_lock();
1163 if (r.arp_dev[0]) {
1164 err = -ENODEV;
1165 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL)
1166 goto out;
1167
1168 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */
1169 if (!r.arp_ha.sa_family)
1170 r.arp_ha.sa_family = dev->type;
1171 err = -EINVAL;
1172 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
1173 goto out;
1174 } else if (cmd == SIOCGARP) {
1175 err = -ENODEV;
1176 goto out;
1177 }
1178
1179 switch(cmd) {
1180 case SIOCDARP:
1181 err = arp_req_delete(&r, dev);
1182 break;
1183 case SIOCSARP:
1184 err = arp_req_set(&r, dev);
1185 break;
1186 case SIOCGARP:
1187 err = arp_req_get(&r, dev);
1188 if (!err && copy_to_user(arg, &r, sizeof(r)))
1189 err = -EFAULT;
1190 break;
1191 }
1192out:
1193 rtnl_unlock();
1194 return err;
1195}
1196
1197static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
1198{
1199 struct net_device *dev = ptr;
1200
1201 switch (event) {
1202 case NETDEV_CHANGEADDR:
1203 neigh_changeaddr(&arp_tbl, dev);
1204 rt_cache_flush(0);
1205 break;
1206 default:
1207 break;
1208 }
1209
1210 return NOTIFY_DONE;
1211}
1212
1213static struct notifier_block arp_netdev_notifier = {
1214 .notifier_call = arp_netdev_event,
1215};
1216
1217/* Note, that it is not on notifier chain.
1218 It is necessary, that this routine was called after route cache will be
1219 flushed.
1220 */
1221void arp_ifdown(struct net_device *dev)
1222{
1223 neigh_ifdown(&arp_tbl, dev);
1224}
1225
1226
1227/*
1228 * Called once on startup.
1229 */
1230
1231static struct packet_type arp_packet_type = {
1232 .type = __constant_htons(ETH_P_ARP),
1233 .func = arp_rcv,
1234};
1235
1236static int arp_proc_init(void);
1237
1238void __init arp_init(void)
1239{
1240 neigh_table_init(&arp_tbl);
1241
1242 dev_add_pack(&arp_packet_type);
1243 arp_proc_init();
1244#ifdef CONFIG_SYSCTL
1245 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
1246 NET_IPV4_NEIGH, "ipv4", NULL, NULL);
1247#endif
1248 register_netdevice_notifier(&arp_netdev_notifier);
1249}
1250
1251#ifdef CONFIG_PROC_FS
1252#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1253
1254/* ------------------------------------------------------------------------ */
1255/*
1256 * ax25 -> ASCII conversion
1257 */
1258static char *ax2asc2(ax25_address *a, char *buf)
1259{
1260 char c, *s;
1261 int n;
1262
1263 for (n = 0, s = buf; n < 6; n++) {
1264 c = (a->ax25_call[n] >> 1) & 0x7F;
1265
1266 if (c != ' ') *s++ = c;
1267 }
1268
1269 *s++ = '-';
1270
1271 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
1272 *s++ = '1';
1273 n -= 10;
1274 }
1275
1276 *s++ = n + '0';
1277 *s++ = '\0';
1278
1279 if (*buf == '\0' || *buf == '-')
1280 return "*";
1281
1282 return buf;
1283
1284}
1285#endif /* CONFIG_AX25 */
1286
1287#define HBUFFERLEN 30
1288
1289static void arp_format_neigh_entry(struct seq_file *seq,
1290 struct neighbour *n)
1291{
1292 char hbuffer[HBUFFERLEN];
1293 const char hexbuf[] = "0123456789ABCDEF";
1294 int k, j;
1295 char tbuf[16];
1296 struct net_device *dev = n->dev;
1297 int hatype = dev->type;
1298
1299 read_lock(&n->lock);
1300 /* Convert hardware address to XX:XX:XX:XX ... form. */
1301#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1302 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
1303 ax2asc2((ax25_address *)n->ha, hbuffer);
1304 else {
1305#endif
1306 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
1307 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15];
1308 hbuffer[k++] = hexbuf[n->ha[j] & 15];
1309 hbuffer[k++] = ':';
1310 }
1311 hbuffer[--k] = 0;
1312#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
1313 }
1314#endif
1315 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
1316 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1317 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
1318 read_unlock(&n->lock);
1319}
1320
1321static void arp_format_pneigh_entry(struct seq_file *seq,
1322 struct pneigh_entry *n)
1323{
1324 struct net_device *dev = n->dev;
1325 int hatype = dev ? dev->type : 0;
1326 char tbuf[16];
1327
1328 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
1329 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n",
1330 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
1331 dev ? dev->name : "*");
1332}
1333
1334static int arp_seq_show(struct seq_file *seq, void *v)
1335{
1336 if (v == SEQ_START_TOKEN) {
1337 seq_puts(seq, "IP address HW type Flags "
1338 "HW address Mask Device\n");
1339 } else {
1340 struct neigh_seq_state *state = seq->private;
1341
1342 if (state->flags & NEIGH_SEQ_IS_PNEIGH)
1343 arp_format_pneigh_entry(seq, v);
1344 else
1345 arp_format_neigh_entry(seq, v);
1346 }
1347
1348 return 0;
1349}
1350
1351static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
1352{
1353 /* Don't want to confuse "arp -a" w/ magic entries,
1354 * so we tell the generic iterator to skip NUD_NOARP.
1355 */
1356 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
1357}
1358
1359/* ------------------------------------------------------------------------ */
1360
1361static struct seq_operations arp_seq_ops = {
1362 .start = arp_seq_start,
1363 .next = neigh_seq_next,
1364 .stop = neigh_seq_stop,
1365 .show = arp_seq_show,
1366};
1367
1368static int arp_seq_open(struct inode *inode, struct file *file)
1369{
1370 struct seq_file *seq;
1371 int rc = -ENOMEM;
1372 struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
1373
1374 if (!s)
1375 goto out;
1376
1377 memset(s, 0, sizeof(*s));
1378 rc = seq_open(file, &arp_seq_ops);
1379 if (rc)
1380 goto out_kfree;
1381
1382 seq = file->private_data;
1383 seq->private = s;
1384out:
1385 return rc;
1386out_kfree:
1387 kfree(s);
1388 goto out;
1389}
1390
1391static struct file_operations arp_seq_fops = {
1392 .owner = THIS_MODULE,
1393 .open = arp_seq_open,
1394 .read = seq_read,
1395 .llseek = seq_lseek,
1396 .release = seq_release_private,
1397};
1398
1399static int __init arp_proc_init(void)
1400{
1401 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops))
1402 return -ENOMEM;
1403 return 0;
1404}
1405
1406#else /* CONFIG_PROC_FS */
1407
1408static int __init arp_proc_init(void)
1409{
1410 return 0;
1411}
1412
1413#endif /* CONFIG_PROC_FS */
1414
1415EXPORT_SYMBOL(arp_broken_ops);
1416EXPORT_SYMBOL(arp_find);
1417EXPORT_SYMBOL(arp_rcv);
1418EXPORT_SYMBOL(arp_create);
1419EXPORT_SYMBOL(arp_xmit);
1420EXPORT_SYMBOL(arp_send);
1421EXPORT_SYMBOL(arp_tbl);
1422
1423#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1424EXPORT_SYMBOL(clip_tbl_hook);
1425#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-13 04:48:53 -0500