arp.c revision 6b175b26c1048d331508940ad3516ead1998084f
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#include <net/ax25.h> 115#include <net/netrom.h> 116#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 117#include <net/atmclip.h> 118struct neigh_table *clip_tbl_hook; 119#endif 120 121#include <asm/system.h> 122#include <asm/uaccess.h> 123 124#include <linux/netfilter_arp.h> 125 126/* 127 * Interface to generic neighbour cache. 128 */ 129static u32 arp_hash(const void *pkey, const struct net_device *dev); 130static int arp_constructor(struct neighbour *neigh); 131static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 132static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 133static void parp_redo(struct sk_buff *skb); 134 135static struct neigh_ops arp_generic_ops = { 136 .family = AF_INET, 137 .solicit = arp_solicit, 138 .error_report = arp_error_report, 139 .output = neigh_resolve_output, 140 .connected_output = neigh_connected_output, 141 .hh_output = dev_queue_xmit, 142 .queue_xmit = dev_queue_xmit, 143}; 144 145static struct neigh_ops arp_hh_ops = { 146 .family = AF_INET, 147 .solicit = arp_solicit, 148 .error_report = arp_error_report, 149 .output = neigh_resolve_output, 150 .connected_output = neigh_resolve_output, 151 .hh_output = dev_queue_xmit, 152 .queue_xmit = dev_queue_xmit, 153}; 154 155static struct neigh_ops arp_direct_ops = { 156 .family = AF_INET, 157 .output = dev_queue_xmit, 158 .connected_output = dev_queue_xmit, 159 .hh_output = dev_queue_xmit, 160 .queue_xmit = dev_queue_xmit, 161}; 162 163struct neigh_ops arp_broken_ops = { 164 .family = AF_INET, 165 .solicit = arp_solicit, 166 .error_report = arp_error_report, 167 .output = neigh_compat_output, 168 .connected_output = neigh_compat_output, 169 .hh_output = dev_queue_xmit, 170 .queue_xmit = dev_queue_xmit, 171}; 172 173struct neigh_table arp_tbl = { 174 .family = AF_INET, 175 .entry_size = sizeof(struct neighbour) + 4, 176 .key_len = 4, 177 .hash = arp_hash, 178 .constructor = arp_constructor, 179 .proxy_redo = parp_redo, 180 .id = "arp_cache", 181 .parms = { 182 .tbl = &arp_tbl, 183 .base_reachable_time = 30 * HZ, 184 .retrans_time = 1 * HZ, 185 .gc_staletime = 60 * HZ, 186 .reachable_time = 30 * HZ, 187 .delay_probe_time = 5 * HZ, 188 .queue_len = 3, 189 .ucast_probes = 3, 190 .mcast_probes = 3, 191 .anycast_delay = 1 * HZ, 192 .proxy_delay = (8 * HZ) / 10, 193 .proxy_qlen = 64, 194 .locktime = 1 * HZ, 195 }, 196 .gc_interval = 30 * HZ, 197 .gc_thresh1 = 128, 198 .gc_thresh2 = 512, 199 .gc_thresh3 = 1024, 200}; 201 202int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) 203{ 204 switch (dev->type) { 205 case ARPHRD_ETHER: 206 case ARPHRD_FDDI: 207 case ARPHRD_IEEE802: 208 ip_eth_mc_map(addr, haddr); 209 return 0; 210 case ARPHRD_IEEE802_TR: 211 ip_tr_mc_map(addr, haddr); 212 return 0; 213 case ARPHRD_INFINIBAND: 214 ip_ib_mc_map(addr, dev->broadcast, haddr); 215 return 0; 216 default: 217 if (dir) { 218 memcpy(haddr, dev->broadcast, dev->addr_len); 219 return 0; 220 } 221 } 222 return -EINVAL; 223} 224 225 226static u32 arp_hash(const void *pkey, const struct net_device *dev) 227{ 228 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 229} 230 231static int arp_constructor(struct neighbour *neigh) 232{ 233 __be32 addr = *(__be32*)neigh->primary_key; 234 struct net_device *dev = neigh->dev; 235 struct in_device *in_dev; 236 struct neigh_parms *parms; 237 238 neigh->type = inet_addr_type(&init_net, addr); 239 240 rcu_read_lock(); 241 in_dev = __in_dev_get_rcu(dev); 242 if (in_dev == NULL) { 243 rcu_read_unlock(); 244 return -EINVAL; 245 } 246 247 parms = in_dev->arp_parms; 248 __neigh_parms_put(neigh->parms); 249 neigh->parms = neigh_parms_clone(parms); 250 rcu_read_unlock(); 251 252 if (!dev->header_ops) { 253 neigh->nud_state = NUD_NOARP; 254 neigh->ops = &arp_direct_ops; 255 neigh->output = neigh->ops->queue_xmit; 256 } else { 257 /* Good devices (checked by reading texts, but only Ethernet is 258 tested) 259 260 ARPHRD_ETHER: (ethernet, apfddi) 261 ARPHRD_FDDI: (fddi) 262 ARPHRD_IEEE802: (tr) 263 ARPHRD_METRICOM: (strip) 264 ARPHRD_ARCNET: 265 etc. etc. etc. 266 267 ARPHRD_IPDDP will also work, if author repairs it. 268 I did not it, because this driver does not work even 269 in old paradigm. 270 */ 271 272#if 1 273 /* So... these "amateur" devices are hopeless. 274 The only thing, that I can say now: 275 It is very sad that we need to keep ugly obsolete 276 code to make them happy. 277 278 They should be moved to more reasonable state, now 279 they use rebuild_header INSTEAD OF hard_start_xmit!!! 280 Besides that, they are sort of out of date 281 (a lot of redundant clones/copies, useless in 2.1), 282 I wonder why people believe that they work. 283 */ 284 switch (dev->type) { 285 default: 286 break; 287 case ARPHRD_ROSE: 288#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 289 case ARPHRD_AX25: 290#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 291 case ARPHRD_NETROM: 292#endif 293 neigh->ops = &arp_broken_ops; 294 neigh->output = neigh->ops->output; 295 return 0; 296#endif 297 ;} 298#endif 299 if (neigh->type == RTN_MULTICAST) { 300 neigh->nud_state = NUD_NOARP; 301 arp_mc_map(addr, neigh->ha, dev, 1); 302 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 303 neigh->nud_state = NUD_NOARP; 304 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 305 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 306 neigh->nud_state = NUD_NOARP; 307 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 308 } 309 310 if (dev->header_ops->cache) 311 neigh->ops = &arp_hh_ops; 312 else 313 neigh->ops = &arp_generic_ops; 314 315 if (neigh->nud_state&NUD_VALID) 316 neigh->output = neigh->ops->connected_output; 317 else 318 neigh->output = neigh->ops->output; 319 } 320 return 0; 321} 322 323static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 324{ 325 dst_link_failure(skb); 326 kfree_skb(skb); 327} 328 329static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 330{ 331 __be32 saddr = 0; 332 u8 *dst_ha = NULL; 333 struct net_device *dev = neigh->dev; 334 __be32 target = *(__be32*)neigh->primary_key; 335 int probes = atomic_read(&neigh->probes); 336 struct in_device *in_dev = in_dev_get(dev); 337 338 if (!in_dev) 339 return; 340 341 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 342 default: 343 case 0: /* By default announce any local IP */ 344 if (skb && inet_addr_type(&init_net, ip_hdr(skb)->saddr) == RTN_LOCAL) 345 saddr = ip_hdr(skb)->saddr; 346 break; 347 case 1: /* Restrict announcements of saddr in same subnet */ 348 if (!skb) 349 break; 350 saddr = ip_hdr(skb)->saddr; 351 if (inet_addr_type(&init_net, saddr) == RTN_LOCAL) { 352 /* saddr should be known to target */ 353 if (inet_addr_onlink(in_dev, target, saddr)) 354 break; 355 } 356 saddr = 0; 357 break; 358 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 359 break; 360 } 361 362 if (in_dev) 363 in_dev_put(in_dev); 364 if (!saddr) 365 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 366 367 if ((probes -= neigh->parms->ucast_probes) < 0) { 368 if (!(neigh->nud_state&NUD_VALID)) 369 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 370 dst_ha = neigh->ha; 371 read_lock_bh(&neigh->lock); 372 } else if ((probes -= neigh->parms->app_probes) < 0) { 373#ifdef CONFIG_ARPD 374 neigh_app_ns(neigh); 375#endif 376 return; 377 } 378 379 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 380 dst_ha, dev->dev_addr, NULL); 381 if (dst_ha) 382 read_unlock_bh(&neigh->lock); 383} 384 385static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 386 __be32 sip, __be32 tip) 387{ 388 int scope; 389 390 switch (IN_DEV_ARP_IGNORE(in_dev)) { 391 case 0: /* Reply, the tip is already validated */ 392 return 0; 393 case 1: /* Reply only if tip is configured on the incoming interface */ 394 sip = 0; 395 scope = RT_SCOPE_HOST; 396 break; 397 case 2: /* 398 * Reply only if tip is configured on the incoming interface 399 * and is in same subnet as sip 400 */ 401 scope = RT_SCOPE_HOST; 402 break; 403 case 3: /* Do not reply for scope host addresses */ 404 sip = 0; 405 scope = RT_SCOPE_LINK; 406 dev = NULL; 407 break; 408 case 4: /* Reserved */ 409 case 5: 410 case 6: 411 case 7: 412 return 0; 413 case 8: /* Do not reply */ 414 return 1; 415 default: 416 return 0; 417 } 418 return !inet_confirm_addr(dev, sip, tip, scope); 419} 420 421static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 422{ 423 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 424 .saddr = tip } } }; 425 struct rtable *rt; 426 int flag = 0; 427 /*unsigned long now; */ 428 429 if (ip_route_output_key(&rt, &fl) < 0) 430 return 1; 431 if (rt->u.dst.dev != dev) { 432 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 433 flag = 1; 434 } 435 ip_rt_put(rt); 436 return flag; 437} 438 439/* OBSOLETE FUNCTIONS */ 440 441/* 442 * Find an arp mapping in the cache. If not found, post a request. 443 * 444 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 445 * even if it exists. It is supposed that skb->dev was mangled 446 * by a virtual device (eql, shaper). Nobody but broken devices 447 * is allowed to use this function, it is scheduled to be removed. --ANK 448 */ 449 450static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 451{ 452 switch (addr_hint) { 453 case RTN_LOCAL: 454 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 455 memcpy(haddr, dev->dev_addr, dev->addr_len); 456 return 1; 457 case RTN_MULTICAST: 458 arp_mc_map(paddr, haddr, dev, 1); 459 return 1; 460 case RTN_BROADCAST: 461 memcpy(haddr, dev->broadcast, dev->addr_len); 462 return 1; 463 } 464 return 0; 465} 466 467 468int arp_find(unsigned char *haddr, struct sk_buff *skb) 469{ 470 struct net_device *dev = skb->dev; 471 __be32 paddr; 472 struct neighbour *n; 473 474 if (!skb->dst) { 475 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 476 kfree_skb(skb); 477 return 1; 478 } 479 480 paddr = ((struct rtable*)skb->dst)->rt_gateway; 481 482 if (arp_set_predefined(inet_addr_type(&init_net, paddr), haddr, paddr, dev)) 483 return 0; 484 485 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 486 487 if (n) { 488 n->used = jiffies; 489 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 490 read_lock_bh(&n->lock); 491 memcpy(haddr, n->ha, dev->addr_len); 492 read_unlock_bh(&n->lock); 493 neigh_release(n); 494 return 0; 495 } 496 neigh_release(n); 497 } else 498 kfree_skb(skb); 499 return 1; 500} 501 502/* END OF OBSOLETE FUNCTIONS */ 503 504int arp_bind_neighbour(struct dst_entry *dst) 505{ 506 struct net_device *dev = dst->dev; 507 struct neighbour *n = dst->neighbour; 508 509 if (dev == NULL) 510 return -EINVAL; 511 if (n == NULL) { 512 __be32 nexthop = ((struct rtable*)dst)->rt_gateway; 513 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 514 nexthop = 0; 515 n = __neigh_lookup_errno( 516#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 517 dev->type == ARPHRD_ATM ? clip_tbl_hook : 518#endif 519 &arp_tbl, &nexthop, dev); 520 if (IS_ERR(n)) 521 return PTR_ERR(n); 522 dst->neighbour = n; 523 } 524 return 0; 525} 526 527/* 528 * Check if we can use proxy ARP for this path 529 */ 530 531static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 532{ 533 struct in_device *out_dev; 534 int imi, omi = -1; 535 536 if (!IN_DEV_PROXY_ARP(in_dev)) 537 return 0; 538 539 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 540 return 1; 541 if (imi == -1) 542 return 0; 543 544 /* place to check for proxy_arp for routes */ 545 546 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 547 omi = IN_DEV_MEDIUM_ID(out_dev); 548 in_dev_put(out_dev); 549 } 550 return (omi != imi && omi != -1); 551} 552 553/* 554 * Interface to link layer: send routine and receive handler. 555 */ 556 557/* 558 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 559 * message. 560 */ 561struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 562 struct net_device *dev, __be32 src_ip, 563 unsigned char *dest_hw, unsigned char *src_hw, 564 unsigned char *target_hw) 565{ 566 struct sk_buff *skb; 567 struct arphdr *arp; 568 unsigned char *arp_ptr; 569 570 /* 571 * Allocate a buffer 572 */ 573 574 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 575 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 576 if (skb == NULL) 577 return NULL; 578 579 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 580 skb_reset_network_header(skb); 581 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 582 skb->dev = dev; 583 skb->protocol = htons(ETH_P_ARP); 584 if (src_hw == NULL) 585 src_hw = dev->dev_addr; 586 if (dest_hw == NULL) 587 dest_hw = dev->broadcast; 588 589 /* 590 * Fill the device header for the ARP frame 591 */ 592 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 593 goto out; 594 595 /* 596 * Fill out the arp protocol part. 597 * 598 * The arp hardware type should match the device type, except for FDDI, 599 * which (according to RFC 1390) should always equal 1 (Ethernet). 600 */ 601 /* 602 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 603 * DIX code for the protocol. Make these device structure fields. 604 */ 605 switch (dev->type) { 606 default: 607 arp->ar_hrd = htons(dev->type); 608 arp->ar_pro = htons(ETH_P_IP); 609 break; 610 611#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 612 case ARPHRD_AX25: 613 arp->ar_hrd = htons(ARPHRD_AX25); 614 arp->ar_pro = htons(AX25_P_IP); 615 break; 616 617#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 618 case ARPHRD_NETROM: 619 arp->ar_hrd = htons(ARPHRD_NETROM); 620 arp->ar_pro = htons(AX25_P_IP); 621 break; 622#endif 623#endif 624 625#ifdef CONFIG_FDDI 626 case ARPHRD_FDDI: 627 arp->ar_hrd = htons(ARPHRD_ETHER); 628 arp->ar_pro = htons(ETH_P_IP); 629 break; 630#endif 631#ifdef CONFIG_TR 632 case ARPHRD_IEEE802_TR: 633 arp->ar_hrd = htons(ARPHRD_IEEE802); 634 arp->ar_pro = htons(ETH_P_IP); 635 break; 636#endif 637 } 638 639 arp->ar_hln = dev->addr_len; 640 arp->ar_pln = 4; 641 arp->ar_op = htons(type); 642 643 arp_ptr=(unsigned char *)(arp+1); 644 645 memcpy(arp_ptr, src_hw, dev->addr_len); 646 arp_ptr+=dev->addr_len; 647 memcpy(arp_ptr, &src_ip,4); 648 arp_ptr+=4; 649 if (target_hw != NULL) 650 memcpy(arp_ptr, target_hw, dev->addr_len); 651 else 652 memset(arp_ptr, 0, dev->addr_len); 653 arp_ptr+=dev->addr_len; 654 memcpy(arp_ptr, &dest_ip, 4); 655 656 return skb; 657 658out: 659 kfree_skb(skb); 660 return NULL; 661} 662 663/* 664 * Send an arp packet. 665 */ 666void arp_xmit(struct sk_buff *skb) 667{ 668 /* Send it off, maybe filter it using firewalling first. */ 669 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 670} 671 672/* 673 * Create and send an arp packet. 674 */ 675void arp_send(int type, int ptype, __be32 dest_ip, 676 struct net_device *dev, __be32 src_ip, 677 unsigned char *dest_hw, unsigned char *src_hw, 678 unsigned char *target_hw) 679{ 680 struct sk_buff *skb; 681 682 /* 683 * No arp on this interface. 684 */ 685 686 if (dev->flags&IFF_NOARP) 687 return; 688 689 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 690 dest_hw, src_hw, target_hw); 691 if (skb == NULL) { 692 return; 693 } 694 695 arp_xmit(skb); 696} 697 698/* 699 * Process an arp request. 700 */ 701 702static int arp_process(struct sk_buff *skb) 703{ 704 struct net_device *dev = skb->dev; 705 struct in_device *in_dev = in_dev_get(dev); 706 struct arphdr *arp; 707 unsigned char *arp_ptr; 708 struct rtable *rt; 709 unsigned char *sha; 710 __be32 sip, tip; 711 u16 dev_type = dev->type; 712 int addr_type; 713 struct neighbour *n; 714 715 /* arp_rcv below verifies the ARP header and verifies the device 716 * is ARP'able. 717 */ 718 719 if (in_dev == NULL) 720 goto out; 721 722 arp = arp_hdr(skb); 723 724 switch (dev_type) { 725 default: 726 if (arp->ar_pro != htons(ETH_P_IP) || 727 htons(dev_type) != arp->ar_hrd) 728 goto out; 729 break; 730 case ARPHRD_ETHER: 731 case ARPHRD_IEEE802_TR: 732 case ARPHRD_FDDI: 733 case ARPHRD_IEEE802: 734 /* 735 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 736 * devices, according to RFC 2625) devices will accept ARP 737 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 738 * This is the case also of FDDI, where the RFC 1390 says that 739 * FDDI devices should accept ARP hardware of (1) Ethernet, 740 * however, to be more robust, we'll accept both 1 (Ethernet) 741 * or 6 (IEEE 802.2) 742 */ 743 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 744 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 745 arp->ar_pro != htons(ETH_P_IP)) 746 goto out; 747 break; 748 case ARPHRD_AX25: 749 if (arp->ar_pro != htons(AX25_P_IP) || 750 arp->ar_hrd != htons(ARPHRD_AX25)) 751 goto out; 752 break; 753 case ARPHRD_NETROM: 754 if (arp->ar_pro != htons(AX25_P_IP) || 755 arp->ar_hrd != htons(ARPHRD_NETROM)) 756 goto out; 757 break; 758 } 759 760 /* Understand only these message types */ 761 762 if (arp->ar_op != htons(ARPOP_REPLY) && 763 arp->ar_op != htons(ARPOP_REQUEST)) 764 goto out; 765 766/* 767 * Extract fields 768 */ 769 arp_ptr= (unsigned char *)(arp+1); 770 sha = arp_ptr; 771 arp_ptr += dev->addr_len; 772 memcpy(&sip, arp_ptr, 4); 773 arp_ptr += 4; 774 arp_ptr += dev->addr_len; 775 memcpy(&tip, arp_ptr, 4); 776/* 777 * Check for bad requests for 127.x.x.x and requests for multicast 778 * addresses. If this is one such, delete it. 779 */ 780 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 781 goto out; 782 783/* 784 * Special case: We must set Frame Relay source Q.922 address 785 */ 786 if (dev_type == ARPHRD_DLCI) 787 sha = dev->broadcast; 788 789/* 790 * Process entry. The idea here is we want to send a reply if it is a 791 * request for us or if it is a request for someone else that we hold 792 * a proxy for. We want to add an entry to our cache if it is a reply 793 * to us or if it is a request for our address. 794 * (The assumption for this last is that if someone is requesting our 795 * address, they are probably intending to talk to us, so it saves time 796 * if we cache their address. Their address is also probably not in 797 * our cache, since ours is not in their cache.) 798 * 799 * Putting this another way, we only care about replies if they are to 800 * us, in which case we add them to the cache. For requests, we care 801 * about those for us and those for our proxies. We reply to both, 802 * and in the case of requests for us we add the requester to the arp 803 * cache. 804 */ 805 806 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 807 if (sip == 0) { 808 if (arp->ar_op == htons(ARPOP_REQUEST) && 809 inet_addr_type(&init_net, tip) == RTN_LOCAL && 810 !arp_ignore(in_dev,dev,sip,tip)) 811 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 812 dev->dev_addr, sha); 813 goto out; 814 } 815 816 if (arp->ar_op == htons(ARPOP_REQUEST) && 817 ip_route_input(skb, tip, sip, 0, dev) == 0) { 818 819 rt = (struct rtable*)skb->dst; 820 addr_type = rt->rt_type; 821 822 if (addr_type == RTN_LOCAL) { 823 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 824 if (n) { 825 int dont_send = 0; 826 827 if (!dont_send) 828 dont_send |= arp_ignore(in_dev,dev,sip,tip); 829 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 830 dont_send |= arp_filter(sip,tip,dev); 831 if (!dont_send) 832 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 833 834 neigh_release(n); 835 } 836 goto out; 837 } else if (IN_DEV_FORWARD(in_dev)) { 838 if (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 839 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &init_net, &tip, dev, 0))) { 840 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 841 if (n) 842 neigh_release(n); 843 844 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 845 skb->pkt_type == PACKET_HOST || 846 in_dev->arp_parms->proxy_delay == 0) { 847 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 848 } else { 849 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 850 in_dev_put(in_dev); 851 return 0; 852 } 853 goto out; 854 } 855 } 856 } 857 858 /* Update our ARP tables */ 859 860 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 861 862 if (IPV4_DEVCONF_ALL(dev->nd_net, ARP_ACCEPT)) { 863 /* Unsolicited ARP is not accepted by default. 864 It is possible, that this option should be enabled for some 865 devices (strip is candidate) 866 */ 867 if (n == NULL && 868 arp->ar_op == htons(ARPOP_REPLY) && 869 inet_addr_type(&init_net, sip) == RTN_UNICAST) 870 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 871 } 872 873 if (n) { 874 int state = NUD_REACHABLE; 875 int override; 876 877 /* If several different ARP replies follows back-to-back, 878 use the FIRST one. It is possible, if several proxy 879 agents are active. Taking the first reply prevents 880 arp trashing and chooses the fastest router. 881 */ 882 override = time_after(jiffies, n->updated + n->parms->locktime); 883 884 /* Broadcast replies and request packets 885 do not assert neighbour reachability. 886 */ 887 if (arp->ar_op != htons(ARPOP_REPLY) || 888 skb->pkt_type != PACKET_HOST) 889 state = NUD_STALE; 890 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 891 neigh_release(n); 892 } 893 894out: 895 if (in_dev) 896 in_dev_put(in_dev); 897 kfree_skb(skb); 898 return 0; 899} 900 901static void parp_redo(struct sk_buff *skb) 902{ 903 arp_process(skb); 904} 905 906 907/* 908 * Receive an arp request from the device layer. 909 */ 910 911static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 912 struct packet_type *pt, struct net_device *orig_dev) 913{ 914 struct arphdr *arp; 915 916 if (dev->nd_net != &init_net) 917 goto freeskb; 918 919 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 920 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 921 (2 * dev->addr_len) + 922 (2 * sizeof(u32))))) 923 goto freeskb; 924 925 arp = arp_hdr(skb); 926 if (arp->ar_hln != dev->addr_len || 927 dev->flags & IFF_NOARP || 928 skb->pkt_type == PACKET_OTHERHOST || 929 skb->pkt_type == PACKET_LOOPBACK || 930 arp->ar_pln != 4) 931 goto freeskb; 932 933 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 934 goto out_of_mem; 935 936 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 937 938 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 939 940freeskb: 941 kfree_skb(skb); 942out_of_mem: 943 return 0; 944} 945 946/* 947 * User level interface (ioctl) 948 */ 949 950/* 951 * Set (create) an ARP cache entry. 952 */ 953 954static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 955{ 956 if (dev == NULL) { 957 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 958 return 0; 959 } 960 if (__in_dev_get_rtnl(dev)) { 961 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 962 return 0; 963 } 964 return -ENXIO; 965} 966 967static int arp_req_set_public(struct net *net, struct arpreq *r, 968 struct net_device *dev) 969{ 970 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 971 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 972 973 if (mask && mask != htonl(0xFFFFFFFF)) 974 return -EINVAL; 975 if (!dev && (r->arp_flags & ATF_COM)) { 976 dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family, 977 r->arp_ha.sa_data); 978 if (!dev) 979 return -ENODEV; 980 } 981 if (mask) { 982 if (pneigh_lookup(&arp_tbl, &init_net, &ip, dev, 1) == NULL) 983 return -ENOBUFS; 984 return 0; 985 } 986 987 return arp_req_set_proxy(net, dev, 1); 988} 989 990static int arp_req_set(struct net *net, struct arpreq *r, 991 struct net_device * dev) 992{ 993 __be32 ip; 994 struct neighbour *neigh; 995 int err; 996 997 if (r->arp_flags & ATF_PUBL) 998 return arp_req_set_public(net, r, dev); 999 1000 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1001 if (r->arp_flags & ATF_PERM) 1002 r->arp_flags |= ATF_COM; 1003 if (dev == NULL) { 1004 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1005 .tos = RTO_ONLINK } } }; 1006 struct rtable * rt; 1007 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1008 return err; 1009 dev = rt->u.dst.dev; 1010 ip_rt_put(rt); 1011 if (!dev) 1012 return -EINVAL; 1013 } 1014 switch (dev->type) { 1015#ifdef CONFIG_FDDI 1016 case ARPHRD_FDDI: 1017 /* 1018 * According to RFC 1390, FDDI devices should accept ARP 1019 * hardware types of 1 (Ethernet). However, to be more 1020 * robust, we'll accept hardware types of either 1 (Ethernet) 1021 * or 6 (IEEE 802.2). 1022 */ 1023 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1024 r->arp_ha.sa_family != ARPHRD_ETHER && 1025 r->arp_ha.sa_family != ARPHRD_IEEE802) 1026 return -EINVAL; 1027 break; 1028#endif 1029 default: 1030 if (r->arp_ha.sa_family != dev->type) 1031 return -EINVAL; 1032 break; 1033 } 1034 1035 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1036 err = PTR_ERR(neigh); 1037 if (!IS_ERR(neigh)) { 1038 unsigned state = NUD_STALE; 1039 if (r->arp_flags & ATF_PERM) 1040 state = NUD_PERMANENT; 1041 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1042 r->arp_ha.sa_data : NULL, state, 1043 NEIGH_UPDATE_F_OVERRIDE| 1044 NEIGH_UPDATE_F_ADMIN); 1045 neigh_release(neigh); 1046 } 1047 return err; 1048} 1049 1050static unsigned arp_state_to_flags(struct neighbour *neigh) 1051{ 1052 unsigned flags = 0; 1053 if (neigh->nud_state&NUD_PERMANENT) 1054 flags = ATF_PERM|ATF_COM; 1055 else if (neigh->nud_state&NUD_VALID) 1056 flags = ATF_COM; 1057 return flags; 1058} 1059 1060/* 1061 * Get an ARP cache entry. 1062 */ 1063 1064static int arp_req_get(struct arpreq *r, struct net_device *dev) 1065{ 1066 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1067 struct neighbour *neigh; 1068 int err = -ENXIO; 1069 1070 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1071 if (neigh) { 1072 read_lock_bh(&neigh->lock); 1073 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1074 r->arp_flags = arp_state_to_flags(neigh); 1075 read_unlock_bh(&neigh->lock); 1076 r->arp_ha.sa_family = dev->type; 1077 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1078 neigh_release(neigh); 1079 err = 0; 1080 } 1081 return err; 1082} 1083 1084static int arp_req_delete_public(struct net *net, struct arpreq *r, 1085 struct net_device *dev) 1086{ 1087 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1088 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1089 1090 if (mask == htonl(0xFFFFFFFF)) 1091 return pneigh_delete(&arp_tbl, &init_net, &ip, dev); 1092 1093 if (mask) 1094 return -EINVAL; 1095 1096 return arp_req_set_proxy(net, dev, 0); 1097} 1098 1099static int arp_req_delete(struct net *net, struct arpreq *r, 1100 struct net_device * dev) 1101{ 1102 int err; 1103 __be32 ip; 1104 struct neighbour *neigh; 1105 1106 if (r->arp_flags & ATF_PUBL) 1107 return arp_req_delete_public(net, r, dev); 1108 1109 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1110 if (dev == NULL) { 1111 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1112 .tos = RTO_ONLINK } } }; 1113 struct rtable * rt; 1114 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1115 return err; 1116 dev = rt->u.dst.dev; 1117 ip_rt_put(rt); 1118 if (!dev) 1119 return -EINVAL; 1120 } 1121 err = -ENXIO; 1122 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1123 if (neigh) { 1124 if (neigh->nud_state&~NUD_NOARP) 1125 err = neigh_update(neigh, NULL, NUD_FAILED, 1126 NEIGH_UPDATE_F_OVERRIDE| 1127 NEIGH_UPDATE_F_ADMIN); 1128 neigh_release(neigh); 1129 } 1130 return err; 1131} 1132 1133/* 1134 * Handle an ARP layer I/O control request. 1135 */ 1136 1137int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1138{ 1139 int err; 1140 struct arpreq r; 1141 struct net_device *dev = NULL; 1142 1143 switch (cmd) { 1144 case SIOCDARP: 1145 case SIOCSARP: 1146 if (!capable(CAP_NET_ADMIN)) 1147 return -EPERM; 1148 case SIOCGARP: 1149 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1150 if (err) 1151 return -EFAULT; 1152 break; 1153 default: 1154 return -EINVAL; 1155 } 1156 1157 if (r.arp_pa.sa_family != AF_INET) 1158 return -EPFNOSUPPORT; 1159 1160 if (!(r.arp_flags & ATF_PUBL) && 1161 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1162 return -EINVAL; 1163 if (!(r.arp_flags & ATF_NETMASK)) 1164 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1165 htonl(0xFFFFFFFFUL); 1166 rtnl_lock(); 1167 if (r.arp_dev[0]) { 1168 err = -ENODEV; 1169 if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL) 1170 goto out; 1171 1172 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1173 if (!r.arp_ha.sa_family) 1174 r.arp_ha.sa_family = dev->type; 1175 err = -EINVAL; 1176 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1177 goto out; 1178 } else if (cmd == SIOCGARP) { 1179 err = -ENODEV; 1180 goto out; 1181 } 1182 1183 switch (cmd) { 1184 case SIOCDARP: 1185 err = arp_req_delete(net, &r, dev); 1186 break; 1187 case SIOCSARP: 1188 err = arp_req_set(net, &r, dev); 1189 break; 1190 case SIOCGARP: 1191 err = arp_req_get(&r, dev); 1192 if (!err && copy_to_user(arg, &r, sizeof(r))) 1193 err = -EFAULT; 1194 break; 1195 } 1196out: 1197 rtnl_unlock(); 1198 return err; 1199} 1200 1201static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1202{ 1203 struct net_device *dev = ptr; 1204 1205 if (dev->nd_net != &init_net) 1206 return NOTIFY_DONE; 1207 1208 switch (event) { 1209 case NETDEV_CHANGEADDR: 1210 neigh_changeaddr(&arp_tbl, dev); 1211 rt_cache_flush(0); 1212 break; 1213 default: 1214 break; 1215 } 1216 1217 return NOTIFY_DONE; 1218} 1219 1220static struct notifier_block arp_netdev_notifier = { 1221 .notifier_call = arp_netdev_event, 1222}; 1223 1224/* Note, that it is not on notifier chain. 1225 It is necessary, that this routine was called after route cache will be 1226 flushed. 1227 */ 1228void arp_ifdown(struct net_device *dev) 1229{ 1230 neigh_ifdown(&arp_tbl, dev); 1231} 1232 1233 1234/* 1235 * Called once on startup. 1236 */ 1237 1238static struct packet_type arp_packet_type = { 1239 .type = __constant_htons(ETH_P_ARP), 1240 .func = arp_rcv, 1241}; 1242 1243static int arp_proc_init(void); 1244 1245void __init arp_init(void) 1246{ 1247 neigh_table_init(&arp_tbl); 1248 1249 dev_add_pack(&arp_packet_type); 1250 arp_proc_init(); 1251#ifdef CONFIG_SYSCTL 1252 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1253 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1254#endif 1255 register_netdevice_notifier(&arp_netdev_notifier); 1256} 1257 1258#ifdef CONFIG_PROC_FS 1259#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1260 1261/* ------------------------------------------------------------------------ */ 1262/* 1263 * ax25 -> ASCII conversion 1264 */ 1265static char *ax2asc2(ax25_address *a, char *buf) 1266{ 1267 char c, *s; 1268 int n; 1269 1270 for (n = 0, s = buf; n < 6; n++) { 1271 c = (a->ax25_call[n] >> 1) & 0x7F; 1272 1273 if (c != ' ') *s++ = c; 1274 } 1275 1276 *s++ = '-'; 1277 1278 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1279 *s++ = '1'; 1280 n -= 10; 1281 } 1282 1283 *s++ = n + '0'; 1284 *s++ = '\0'; 1285 1286 if (*buf == '\0' || *buf == '-') 1287 return "*"; 1288 1289 return buf; 1290 1291} 1292#endif /* CONFIG_AX25 */ 1293 1294#define HBUFFERLEN 30 1295 1296static void arp_format_neigh_entry(struct seq_file *seq, 1297 struct neighbour *n) 1298{ 1299 char hbuffer[HBUFFERLEN]; 1300 const char hexbuf[] = "0123456789ABCDEF"; 1301 int k, j; 1302 char tbuf[16]; 1303 struct net_device *dev = n->dev; 1304 int hatype = dev->type; 1305 1306 read_lock(&n->lock); 1307 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1308#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1309 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1310 ax2asc2((ax25_address *)n->ha, hbuffer); 1311 else { 1312#endif 1313 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1314 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1315 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1316 hbuffer[k++] = ':'; 1317 } 1318 hbuffer[--k] = 0; 1319#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1320 } 1321#endif 1322 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1323 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1324 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1325 read_unlock(&n->lock); 1326} 1327 1328static void arp_format_pneigh_entry(struct seq_file *seq, 1329 struct pneigh_entry *n) 1330{ 1331 struct net_device *dev = n->dev; 1332 int hatype = dev ? dev->type : 0; 1333 char tbuf[16]; 1334 1335 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1336 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1337 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1338 dev ? dev->name : "*"); 1339} 1340 1341static int arp_seq_show(struct seq_file *seq, void *v) 1342{ 1343 if (v == SEQ_START_TOKEN) { 1344 seq_puts(seq, "IP address HW type Flags " 1345 "HW address Mask Device\n"); 1346 } else { 1347 struct neigh_seq_state *state = seq->private; 1348 1349 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1350 arp_format_pneigh_entry(seq, v); 1351 else 1352 arp_format_neigh_entry(seq, v); 1353 } 1354 1355 return 0; 1356} 1357 1358static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1359{ 1360 /* Don't want to confuse "arp -a" w/ magic entries, 1361 * so we tell the generic iterator to skip NUD_NOARP. 1362 */ 1363 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1364} 1365 1366/* ------------------------------------------------------------------------ */ 1367 1368static const struct seq_operations arp_seq_ops = { 1369 .start = arp_seq_start, 1370 .next = neigh_seq_next, 1371 .stop = neigh_seq_stop, 1372 .show = arp_seq_show, 1373}; 1374 1375static int arp_seq_open(struct inode *inode, struct file *file) 1376{ 1377 return seq_open_net(inode, file, &arp_seq_ops, 1378 sizeof(struct neigh_seq_state)); 1379} 1380 1381static const struct file_operations arp_seq_fops = { 1382 .owner = THIS_MODULE, 1383 .open = arp_seq_open, 1384 .read = seq_read, 1385 .llseek = seq_lseek, 1386 .release = seq_release_net, 1387}; 1388 1389static int __init arp_proc_init(void) 1390{ 1391 if (!proc_net_fops_create(&init_net, "arp", S_IRUGO, &arp_seq_fops)) 1392 return -ENOMEM; 1393 return 0; 1394} 1395 1396#else /* CONFIG_PROC_FS */ 1397 1398static int __init arp_proc_init(void) 1399{ 1400 return 0; 1401} 1402 1403#endif /* CONFIG_PROC_FS */ 1404 1405EXPORT_SYMBOL(arp_broken_ops); 1406EXPORT_SYMBOL(arp_find); 1407EXPORT_SYMBOL(arp_create); 1408EXPORT_SYMBOL(arp_xmit); 1409EXPORT_SYMBOL(arp_send); 1410EXPORT_SYMBOL(arp_tbl); 1411 1412#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1413EXPORT_SYMBOL(clip_tbl_hook); 1414#endif 1415