arp.c revision cf7732e4cc14b56d593ff53352673e1fd5e3ba52
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->header_ops) { 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 } 313 314 if (dev->header_ops->cache) 315 neigh->ops = &arp_hh_ops; 316 else 317 neigh->ops = &arp_generic_ops; 318 319 if (neigh->nud_state&NUD_VALID) 320 neigh->output = neigh->ops->connected_output; 321 else 322 neigh->output = neigh->ops->output; 323 } 324 return 0; 325} 326 327static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 328{ 329 dst_link_failure(skb); 330 kfree_skb(skb); 331} 332 333static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 334{ 335 __be32 saddr = 0; 336 u8 *dst_ha = NULL; 337 struct net_device *dev = neigh->dev; 338 __be32 target = *(__be32*)neigh->primary_key; 339 int probes = atomic_read(&neigh->probes); 340 struct in_device *in_dev = in_dev_get(dev); 341 342 if (!in_dev) 343 return; 344 345 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 346 default: 347 case 0: /* By default announce any local IP */ 348 if (skb && inet_addr_type(ip_hdr(skb)->saddr) == RTN_LOCAL) 349 saddr = ip_hdr(skb)->saddr; 350 break; 351 case 1: /* Restrict announcements of saddr in same subnet */ 352 if (!skb) 353 break; 354 saddr = ip_hdr(skb)->saddr; 355 if (inet_addr_type(saddr) == RTN_LOCAL) { 356 /* saddr should be known to target */ 357 if (inet_addr_onlink(in_dev, target, saddr)) 358 break; 359 } 360 saddr = 0; 361 break; 362 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 363 break; 364 } 365 366 if (in_dev) 367 in_dev_put(in_dev); 368 if (!saddr) 369 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 370 371 if ((probes -= neigh->parms->ucast_probes) < 0) { 372 if (!(neigh->nud_state&NUD_VALID)) 373 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 374 dst_ha = neigh->ha; 375 read_lock_bh(&neigh->lock); 376 } else if ((probes -= neigh->parms->app_probes) < 0) { 377#ifdef CONFIG_ARPD 378 neigh_app_ns(neigh); 379#endif 380 return; 381 } 382 383 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 384 dst_ha, dev->dev_addr, NULL); 385 if (dst_ha) 386 read_unlock_bh(&neigh->lock); 387} 388 389static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 390 __be32 sip, __be32 tip) 391{ 392 int scope; 393 394 switch (IN_DEV_ARP_IGNORE(in_dev)) { 395 case 0: /* Reply, the tip is already validated */ 396 return 0; 397 case 1: /* Reply only if tip is configured on the incoming interface */ 398 sip = 0; 399 scope = RT_SCOPE_HOST; 400 break; 401 case 2: /* 402 * Reply only if tip is configured on the incoming interface 403 * and is in same subnet as sip 404 */ 405 scope = RT_SCOPE_HOST; 406 break; 407 case 3: /* Do not reply for scope host addresses */ 408 sip = 0; 409 scope = RT_SCOPE_LINK; 410 dev = NULL; 411 break; 412 case 4: /* Reserved */ 413 case 5: 414 case 6: 415 case 7: 416 return 0; 417 case 8: /* Do not reply */ 418 return 1; 419 default: 420 return 0; 421 } 422 return !inet_confirm_addr(dev, sip, tip, scope); 423} 424 425static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 426{ 427 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 428 .saddr = tip } } }; 429 struct rtable *rt; 430 int flag = 0; 431 /*unsigned long now; */ 432 433 if (ip_route_output_key(&rt, &fl) < 0) 434 return 1; 435 if (rt->u.dst.dev != dev) { 436 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 437 flag = 1; 438 } 439 ip_rt_put(rt); 440 return flag; 441} 442 443/* OBSOLETE FUNCTIONS */ 444 445/* 446 * Find an arp mapping in the cache. If not found, post a request. 447 * 448 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 449 * even if it exists. It is supposed that skb->dev was mangled 450 * by a virtual device (eql, shaper). Nobody but broken devices 451 * is allowed to use this function, it is scheduled to be removed. --ANK 452 */ 453 454static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 455{ 456 switch (addr_hint) { 457 case RTN_LOCAL: 458 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 459 memcpy(haddr, dev->dev_addr, dev->addr_len); 460 return 1; 461 case RTN_MULTICAST: 462 arp_mc_map(paddr, haddr, dev, 1); 463 return 1; 464 case RTN_BROADCAST: 465 memcpy(haddr, dev->broadcast, dev->addr_len); 466 return 1; 467 } 468 return 0; 469} 470 471 472int arp_find(unsigned char *haddr, struct sk_buff *skb) 473{ 474 struct net_device *dev = skb->dev; 475 __be32 paddr; 476 struct neighbour *n; 477 478 if (!skb->dst) { 479 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 480 kfree_skb(skb); 481 return 1; 482 } 483 484 paddr = ((struct rtable*)skb->dst)->rt_gateway; 485 486 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) 487 return 0; 488 489 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 490 491 if (n) { 492 n->used = jiffies; 493 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 494 read_lock_bh(&n->lock); 495 memcpy(haddr, n->ha, dev->addr_len); 496 read_unlock_bh(&n->lock); 497 neigh_release(n); 498 return 0; 499 } 500 neigh_release(n); 501 } else 502 kfree_skb(skb); 503 return 1; 504} 505 506/* END OF OBSOLETE FUNCTIONS */ 507 508int arp_bind_neighbour(struct dst_entry *dst) 509{ 510 struct net_device *dev = dst->dev; 511 struct neighbour *n = dst->neighbour; 512 513 if (dev == NULL) 514 return -EINVAL; 515 if (n == NULL) { 516 __be32 nexthop = ((struct rtable*)dst)->rt_gateway; 517 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 518 nexthop = 0; 519 n = __neigh_lookup_errno( 520#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 521 dev->type == ARPHRD_ATM ? clip_tbl_hook : 522#endif 523 &arp_tbl, &nexthop, dev); 524 if (IS_ERR(n)) 525 return PTR_ERR(n); 526 dst->neighbour = n; 527 } 528 return 0; 529} 530 531/* 532 * Check if we can use proxy ARP for this path 533 */ 534 535static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 536{ 537 struct in_device *out_dev; 538 int imi, omi = -1; 539 540 if (!IN_DEV_PROXY_ARP(in_dev)) 541 return 0; 542 543 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 544 return 1; 545 if (imi == -1) 546 return 0; 547 548 /* place to check for proxy_arp for routes */ 549 550 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 551 omi = IN_DEV_MEDIUM_ID(out_dev); 552 in_dev_put(out_dev); 553 } 554 return (omi != imi && omi != -1); 555} 556 557/* 558 * Interface to link layer: send routine and receive handler. 559 */ 560 561/* 562 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 563 * message. 564 */ 565struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 566 struct net_device *dev, __be32 src_ip, 567 unsigned char *dest_hw, unsigned char *src_hw, 568 unsigned char *target_hw) 569{ 570 struct sk_buff *skb; 571 struct arphdr *arp; 572 unsigned char *arp_ptr; 573 574 /* 575 * Allocate a buffer 576 */ 577 578 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 579 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 580 if (skb == NULL) 581 return NULL; 582 583 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 584 skb_reset_network_header(skb); 585 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 586 skb->dev = dev; 587 skb->protocol = htons(ETH_P_ARP); 588 if (src_hw == NULL) 589 src_hw = dev->dev_addr; 590 if (dest_hw == NULL) 591 dest_hw = dev->broadcast; 592 593 /* 594 * Fill the device header for the ARP frame 595 */ 596 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 597 goto out; 598 599 /* 600 * Fill out the arp protocol part. 601 * 602 * The arp hardware type should match the device type, except for FDDI, 603 * which (according to RFC 1390) should always equal 1 (Ethernet). 604 */ 605 /* 606 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 607 * DIX code for the protocol. Make these device structure fields. 608 */ 609 switch (dev->type) { 610 default: 611 arp->ar_hrd = htons(dev->type); 612 arp->ar_pro = htons(ETH_P_IP); 613 break; 614 615#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 616 case ARPHRD_AX25: 617 arp->ar_hrd = htons(ARPHRD_AX25); 618 arp->ar_pro = htons(AX25_P_IP); 619 break; 620 621#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 622 case ARPHRD_NETROM: 623 arp->ar_hrd = htons(ARPHRD_NETROM); 624 arp->ar_pro = htons(AX25_P_IP); 625 break; 626#endif 627#endif 628 629#ifdef CONFIG_FDDI 630 case ARPHRD_FDDI: 631 arp->ar_hrd = htons(ARPHRD_ETHER); 632 arp->ar_pro = htons(ETH_P_IP); 633 break; 634#endif 635#ifdef CONFIG_TR 636 case ARPHRD_IEEE802_TR: 637 arp->ar_hrd = htons(ARPHRD_IEEE802); 638 arp->ar_pro = htons(ETH_P_IP); 639 break; 640#endif 641 } 642 643 arp->ar_hln = dev->addr_len; 644 arp->ar_pln = 4; 645 arp->ar_op = htons(type); 646 647 arp_ptr=(unsigned char *)(arp+1); 648 649 memcpy(arp_ptr, src_hw, dev->addr_len); 650 arp_ptr+=dev->addr_len; 651 memcpy(arp_ptr, &src_ip,4); 652 arp_ptr+=4; 653 if (target_hw != NULL) 654 memcpy(arp_ptr, target_hw, dev->addr_len); 655 else 656 memset(arp_ptr, 0, dev->addr_len); 657 arp_ptr+=dev->addr_len; 658 memcpy(arp_ptr, &dest_ip, 4); 659 660 return skb; 661 662out: 663 kfree_skb(skb); 664 return NULL; 665} 666 667/* 668 * Send an arp packet. 669 */ 670void arp_xmit(struct sk_buff *skb) 671{ 672 /* Send it off, maybe filter it using firewalling first. */ 673 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 674} 675 676/* 677 * Create and send an arp packet. 678 */ 679void arp_send(int type, int ptype, __be32 dest_ip, 680 struct net_device *dev, __be32 src_ip, 681 unsigned char *dest_hw, unsigned char *src_hw, 682 unsigned char *target_hw) 683{ 684 struct sk_buff *skb; 685 686 /* 687 * No arp on this interface. 688 */ 689 690 if (dev->flags&IFF_NOARP) 691 return; 692 693 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 694 dest_hw, src_hw, target_hw); 695 if (skb == NULL) { 696 return; 697 } 698 699 arp_xmit(skb); 700} 701 702/* 703 * Process an arp request. 704 */ 705 706static int arp_process(struct sk_buff *skb) 707{ 708 struct net_device *dev = skb->dev; 709 struct in_device *in_dev = in_dev_get(dev); 710 struct arphdr *arp; 711 unsigned char *arp_ptr; 712 struct rtable *rt; 713 unsigned char *sha, *tha; 714 __be32 sip, tip; 715 u16 dev_type = dev->type; 716 int addr_type; 717 struct neighbour *n; 718 719 /* arp_rcv below verifies the ARP header and verifies the device 720 * is ARP'able. 721 */ 722 723 if (in_dev == NULL) 724 goto out; 725 726 arp = arp_hdr(skb); 727 728 switch (dev_type) { 729 default: 730 if (arp->ar_pro != htons(ETH_P_IP) || 731 htons(dev_type) != arp->ar_hrd) 732 goto out; 733 break; 734#ifdef CONFIG_NET_ETHERNET 735 case ARPHRD_ETHER: 736#endif 737#ifdef CONFIG_TR 738 case ARPHRD_IEEE802_TR: 739#endif 740#ifdef CONFIG_FDDI 741 case ARPHRD_FDDI: 742#endif 743#ifdef CONFIG_NET_FC 744 case ARPHRD_IEEE802: 745#endif 746#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \ 747 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC) 748 /* 749 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 750 * devices, according to RFC 2625) devices will accept ARP 751 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 752 * This is the case also of FDDI, where the RFC 1390 says that 753 * FDDI devices should accept ARP hardware of (1) Ethernet, 754 * however, to be more robust, we'll accept both 1 (Ethernet) 755 * or 6 (IEEE 802.2) 756 */ 757 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 758 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 759 arp->ar_pro != htons(ETH_P_IP)) 760 goto out; 761 break; 762#endif 763#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 764 case ARPHRD_AX25: 765 if (arp->ar_pro != htons(AX25_P_IP) || 766 arp->ar_hrd != htons(ARPHRD_AX25)) 767 goto out; 768 break; 769#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 770 case ARPHRD_NETROM: 771 if (arp->ar_pro != htons(AX25_P_IP) || 772 arp->ar_hrd != htons(ARPHRD_NETROM)) 773 goto out; 774 break; 775#endif 776#endif 777 } 778 779 /* Understand only these message types */ 780 781 if (arp->ar_op != htons(ARPOP_REPLY) && 782 arp->ar_op != htons(ARPOP_REQUEST)) 783 goto out; 784 785/* 786 * Extract fields 787 */ 788 arp_ptr= (unsigned char *)(arp+1); 789 sha = arp_ptr; 790 arp_ptr += dev->addr_len; 791 memcpy(&sip, arp_ptr, 4); 792 arp_ptr += 4; 793 tha = arp_ptr; 794 arp_ptr += dev->addr_len; 795 memcpy(&tip, arp_ptr, 4); 796/* 797 * Check for bad requests for 127.x.x.x and requests for multicast 798 * addresses. If this is one such, delete it. 799 */ 800 if (LOOPBACK(tip) || MULTICAST(tip)) 801 goto out; 802 803/* 804 * Special case: We must set Frame Relay source Q.922 address 805 */ 806 if (dev_type == ARPHRD_DLCI) 807 sha = dev->broadcast; 808 809/* 810 * Process entry. The idea here is we want to send a reply if it is a 811 * request for us or if it is a request for someone else that we hold 812 * a proxy for. We want to add an entry to our cache if it is a reply 813 * to us or if it is a request for our address. 814 * (The assumption for this last is that if someone is requesting our 815 * address, they are probably intending to talk to us, so it saves time 816 * if we cache their address. Their address is also probably not in 817 * our cache, since ours is not in their cache.) 818 * 819 * Putting this another way, we only care about replies if they are to 820 * us, in which case we add them to the cache. For requests, we care 821 * about those for us and those for our proxies. We reply to both, 822 * and in the case of requests for us we add the requester to the arp 823 * cache. 824 */ 825 826 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 827 if (sip == 0) { 828 if (arp->ar_op == htons(ARPOP_REQUEST) && 829 inet_addr_type(tip) == RTN_LOCAL && 830 !arp_ignore(in_dev,dev,sip,tip)) 831 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); 832 goto out; 833 } 834 835 if (arp->ar_op == htons(ARPOP_REQUEST) && 836 ip_route_input(skb, tip, sip, 0, dev) == 0) { 837 838 rt = (struct rtable*)skb->dst; 839 addr_type = rt->rt_type; 840 841 if (addr_type == RTN_LOCAL) { 842 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 843 if (n) { 844 int dont_send = 0; 845 846 if (!dont_send) 847 dont_send |= arp_ignore(in_dev,dev,sip,tip); 848 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 849 dont_send |= arp_filter(sip,tip,dev); 850 if (!dont_send) 851 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 852 853 neigh_release(n); 854 } 855 goto out; 856 } else if (IN_DEV_FORWARD(in_dev)) { 857 if ((rt->rt_flags&RTCF_DNAT) || 858 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 859 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { 860 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 861 if (n) 862 neigh_release(n); 863 864 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 865 skb->pkt_type == PACKET_HOST || 866 in_dev->arp_parms->proxy_delay == 0) { 867 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 868 } else { 869 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 870 in_dev_put(in_dev); 871 return 0; 872 } 873 goto out; 874 } 875 } 876 } 877 878 /* Update our ARP tables */ 879 880 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 881 882 if (IPV4_DEVCONF_ALL(ARP_ACCEPT)) { 883 /* Unsolicited ARP is not accepted by default. 884 It is possible, that this option should be enabled for some 885 devices (strip is candidate) 886 */ 887 if (n == NULL && 888 arp->ar_op == htons(ARPOP_REPLY) && 889 inet_addr_type(sip) == RTN_UNICAST) 890 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 891 } 892 893 if (n) { 894 int state = NUD_REACHABLE; 895 int override; 896 897 /* If several different ARP replies follows back-to-back, 898 use the FIRST one. It is possible, if several proxy 899 agents are active. Taking the first reply prevents 900 arp trashing and chooses the fastest router. 901 */ 902 override = time_after(jiffies, n->updated + n->parms->locktime); 903 904 /* Broadcast replies and request packets 905 do not assert neighbour reachability. 906 */ 907 if (arp->ar_op != htons(ARPOP_REPLY) || 908 skb->pkt_type != PACKET_HOST) 909 state = NUD_STALE; 910 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 911 neigh_release(n); 912 } 913 914out: 915 if (in_dev) 916 in_dev_put(in_dev); 917 kfree_skb(skb); 918 return 0; 919} 920 921static void parp_redo(struct sk_buff *skb) 922{ 923 arp_process(skb); 924} 925 926 927/* 928 * Receive an arp request from the device layer. 929 */ 930 931static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 932 struct packet_type *pt, struct net_device *orig_dev) 933{ 934 struct arphdr *arp; 935 936 if (dev->nd_net != &init_net) 937 goto freeskb; 938 939 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 940 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 941 (2 * dev->addr_len) + 942 (2 * sizeof(u32))))) 943 goto freeskb; 944 945 arp = arp_hdr(skb); 946 if (arp->ar_hln != dev->addr_len || 947 dev->flags & IFF_NOARP || 948 skb->pkt_type == PACKET_OTHERHOST || 949 skb->pkt_type == PACKET_LOOPBACK || 950 arp->ar_pln != 4) 951 goto freeskb; 952 953 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 954 goto out_of_mem; 955 956 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 957 958 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 959 960freeskb: 961 kfree_skb(skb); 962out_of_mem: 963 return 0; 964} 965 966/* 967 * User level interface (ioctl) 968 */ 969 970/* 971 * Set (create) an ARP cache entry. 972 */ 973 974static int arp_req_set(struct arpreq *r, struct net_device * dev) 975{ 976 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 977 struct neighbour *neigh; 978 int err; 979 980 if (r->arp_flags&ATF_PUBL) { 981 __be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; 982 if (mask && mask != htonl(0xFFFFFFFF)) 983 return -EINVAL; 984 if (!dev && (r->arp_flags & ATF_COM)) { 985 dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family, r->arp_ha.sa_data); 986 if (!dev) 987 return -ENODEV; 988 } 989 if (mask) { 990 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) 991 return -ENOBUFS; 992 return 0; 993 } 994 if (dev == NULL) { 995 IPV4_DEVCONF_ALL(PROXY_ARP) = 1; 996 return 0; 997 } 998 if (__in_dev_get_rtnl(dev)) { 999 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, 1); 1000 return 0; 1001 } 1002 return -ENXIO; 1003 } 1004 1005 if (r->arp_flags & ATF_PERM) 1006 r->arp_flags |= ATF_COM; 1007 if (dev == NULL) { 1008 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1009 .tos = RTO_ONLINK } } }; 1010 struct rtable * rt; 1011 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1012 return err; 1013 dev = rt->u.dst.dev; 1014 ip_rt_put(rt); 1015 if (!dev) 1016 return -EINVAL; 1017 } 1018 switch (dev->type) { 1019#ifdef CONFIG_FDDI 1020 case ARPHRD_FDDI: 1021 /* 1022 * According to RFC 1390, FDDI devices should accept ARP 1023 * hardware types of 1 (Ethernet). However, to be more 1024 * robust, we'll accept hardware types of either 1 (Ethernet) 1025 * or 6 (IEEE 802.2). 1026 */ 1027 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1028 r->arp_ha.sa_family != ARPHRD_ETHER && 1029 r->arp_ha.sa_family != ARPHRD_IEEE802) 1030 return -EINVAL; 1031 break; 1032#endif 1033 default: 1034 if (r->arp_ha.sa_family != dev->type) 1035 return -EINVAL; 1036 break; 1037 } 1038 1039 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1040 err = PTR_ERR(neigh); 1041 if (!IS_ERR(neigh)) { 1042 unsigned state = NUD_STALE; 1043 if (r->arp_flags & ATF_PERM) 1044 state = NUD_PERMANENT; 1045 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1046 r->arp_ha.sa_data : NULL, state, 1047 NEIGH_UPDATE_F_OVERRIDE| 1048 NEIGH_UPDATE_F_ADMIN); 1049 neigh_release(neigh); 1050 } 1051 return err; 1052} 1053 1054static unsigned arp_state_to_flags(struct neighbour *neigh) 1055{ 1056 unsigned flags = 0; 1057 if (neigh->nud_state&NUD_PERMANENT) 1058 flags = ATF_PERM|ATF_COM; 1059 else if (neigh->nud_state&NUD_VALID) 1060 flags = ATF_COM; 1061 return flags; 1062} 1063 1064/* 1065 * Get an ARP cache entry. 1066 */ 1067 1068static int arp_req_get(struct arpreq *r, struct net_device *dev) 1069{ 1070 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1071 struct neighbour *neigh; 1072 int err = -ENXIO; 1073 1074 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1075 if (neigh) { 1076 read_lock_bh(&neigh->lock); 1077 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1078 r->arp_flags = arp_state_to_flags(neigh); 1079 read_unlock_bh(&neigh->lock); 1080 r->arp_ha.sa_family = dev->type; 1081 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1082 neigh_release(neigh); 1083 err = 0; 1084 } 1085 return err; 1086} 1087 1088static int arp_req_delete(struct arpreq *r, struct net_device * dev) 1089{ 1090 int err; 1091 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1092 struct neighbour *neigh; 1093 1094 if (r->arp_flags & ATF_PUBL) { 1095 __be32 mask = 1096 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1097 if (mask == htonl(0xFFFFFFFF)) 1098 return pneigh_delete(&arp_tbl, &ip, dev); 1099 if (mask == 0) { 1100 if (dev == NULL) { 1101 IPV4_DEVCONF_ALL(PROXY_ARP) = 0; 1102 return 0; 1103 } 1104 if (__in_dev_get_rtnl(dev)) { 1105 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), 1106 PROXY_ARP, 0); 1107 return 0; 1108 } 1109 return -ENXIO; 1110 } 1111 return -EINVAL; 1112 } 1113 1114 if (dev == NULL) { 1115 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1116 .tos = RTO_ONLINK } } }; 1117 struct rtable * rt; 1118 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1119 return err; 1120 dev = rt->u.dst.dev; 1121 ip_rt_put(rt); 1122 if (!dev) 1123 return -EINVAL; 1124 } 1125 err = -ENXIO; 1126 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1127 if (neigh) { 1128 if (neigh->nud_state&~NUD_NOARP) 1129 err = neigh_update(neigh, NULL, NUD_FAILED, 1130 NEIGH_UPDATE_F_OVERRIDE| 1131 NEIGH_UPDATE_F_ADMIN); 1132 neigh_release(neigh); 1133 } 1134 return err; 1135} 1136 1137/* 1138 * Handle an ARP layer I/O control request. 1139 */ 1140 1141int arp_ioctl(unsigned int cmd, void __user *arg) 1142{ 1143 int err; 1144 struct arpreq r; 1145 struct net_device *dev = NULL; 1146 1147 switch (cmd) { 1148 case SIOCDARP: 1149 case SIOCSARP: 1150 if (!capable(CAP_NET_ADMIN)) 1151 return -EPERM; 1152 case SIOCGARP: 1153 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1154 if (err) 1155 return -EFAULT; 1156 break; 1157 default: 1158 return -EINVAL; 1159 } 1160 1161 if (r.arp_pa.sa_family != AF_INET) 1162 return -EPFNOSUPPORT; 1163 1164 if (!(r.arp_flags & ATF_PUBL) && 1165 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1166 return -EINVAL; 1167 if (!(r.arp_flags & ATF_NETMASK)) 1168 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1169 htonl(0xFFFFFFFFUL); 1170 rtnl_lock(); 1171 if (r.arp_dev[0]) { 1172 err = -ENODEV; 1173 if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL) 1174 goto out; 1175 1176 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1177 if (!r.arp_ha.sa_family) 1178 r.arp_ha.sa_family = dev->type; 1179 err = -EINVAL; 1180 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1181 goto out; 1182 } else if (cmd == SIOCGARP) { 1183 err = -ENODEV; 1184 goto out; 1185 } 1186 1187 switch (cmd) { 1188 case SIOCDARP: 1189 err = arp_req_delete(&r, dev); 1190 break; 1191 case SIOCSARP: 1192 err = arp_req_set(&r, dev); 1193 break; 1194 case SIOCGARP: 1195 err = arp_req_get(&r, dev); 1196 if (!err && copy_to_user(arg, &r, sizeof(r))) 1197 err = -EFAULT; 1198 break; 1199 } 1200out: 1201 rtnl_unlock(); 1202 return err; 1203} 1204 1205static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1206{ 1207 struct net_device *dev = ptr; 1208 1209 if (dev->nd_net != &init_net) 1210 return NOTIFY_DONE; 1211 1212 switch (event) { 1213 case NETDEV_CHANGEADDR: 1214 neigh_changeaddr(&arp_tbl, dev); 1215 rt_cache_flush(0); 1216 break; 1217 default: 1218 break; 1219 } 1220 1221 return NOTIFY_DONE; 1222} 1223 1224static struct notifier_block arp_netdev_notifier = { 1225 .notifier_call = arp_netdev_event, 1226}; 1227 1228/* Note, that it is not on notifier chain. 1229 It is necessary, that this routine was called after route cache will be 1230 flushed. 1231 */ 1232void arp_ifdown(struct net_device *dev) 1233{ 1234 neigh_ifdown(&arp_tbl, dev); 1235} 1236 1237 1238/* 1239 * Called once on startup. 1240 */ 1241 1242static struct packet_type arp_packet_type = { 1243 .type = __constant_htons(ETH_P_ARP), 1244 .func = arp_rcv, 1245}; 1246 1247static int arp_proc_init(void); 1248 1249void __init arp_init(void) 1250{ 1251 neigh_table_init(&arp_tbl); 1252 1253 dev_add_pack(&arp_packet_type); 1254 arp_proc_init(); 1255#ifdef CONFIG_SYSCTL 1256 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1257 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1258#endif 1259 register_netdevice_notifier(&arp_netdev_notifier); 1260} 1261 1262#ifdef CONFIG_PROC_FS 1263#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1264 1265/* ------------------------------------------------------------------------ */ 1266/* 1267 * ax25 -> ASCII conversion 1268 */ 1269static char *ax2asc2(ax25_address *a, char *buf) 1270{ 1271 char c, *s; 1272 int n; 1273 1274 for (n = 0, s = buf; n < 6; n++) { 1275 c = (a->ax25_call[n] >> 1) & 0x7F; 1276 1277 if (c != ' ') *s++ = c; 1278 } 1279 1280 *s++ = '-'; 1281 1282 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1283 *s++ = '1'; 1284 n -= 10; 1285 } 1286 1287 *s++ = n + '0'; 1288 *s++ = '\0'; 1289 1290 if (*buf == '\0' || *buf == '-') 1291 return "*"; 1292 1293 return buf; 1294 1295} 1296#endif /* CONFIG_AX25 */ 1297 1298#define HBUFFERLEN 30 1299 1300static void arp_format_neigh_entry(struct seq_file *seq, 1301 struct neighbour *n) 1302{ 1303 char hbuffer[HBUFFERLEN]; 1304 const char hexbuf[] = "0123456789ABCDEF"; 1305 int k, j; 1306 char tbuf[16]; 1307 struct net_device *dev = n->dev; 1308 int hatype = dev->type; 1309 1310 read_lock(&n->lock); 1311 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1312#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1313 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1314 ax2asc2((ax25_address *)n->ha, hbuffer); 1315 else { 1316#endif 1317 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1318 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1319 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1320 hbuffer[k++] = ':'; 1321 } 1322 hbuffer[--k] = 0; 1323#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1324 } 1325#endif 1326 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1327 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1328 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1329 read_unlock(&n->lock); 1330} 1331 1332static void arp_format_pneigh_entry(struct seq_file *seq, 1333 struct pneigh_entry *n) 1334{ 1335 struct net_device *dev = n->dev; 1336 int hatype = dev ? dev->type : 0; 1337 char tbuf[16]; 1338 1339 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1340 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1341 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1342 dev ? dev->name : "*"); 1343} 1344 1345static int arp_seq_show(struct seq_file *seq, void *v) 1346{ 1347 if (v == SEQ_START_TOKEN) { 1348 seq_puts(seq, "IP address HW type Flags " 1349 "HW address Mask Device\n"); 1350 } else { 1351 struct neigh_seq_state *state = seq->private; 1352 1353 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1354 arp_format_pneigh_entry(seq, v); 1355 else 1356 arp_format_neigh_entry(seq, v); 1357 } 1358 1359 return 0; 1360} 1361 1362static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1363{ 1364 /* Don't want to confuse "arp -a" w/ magic entries, 1365 * so we tell the generic iterator to skip NUD_NOARP. 1366 */ 1367 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1368} 1369 1370/* ------------------------------------------------------------------------ */ 1371 1372static const struct seq_operations arp_seq_ops = { 1373 .start = arp_seq_start, 1374 .next = neigh_seq_next, 1375 .stop = neigh_seq_stop, 1376 .show = arp_seq_show, 1377}; 1378 1379static int arp_seq_open(struct inode *inode, struct file *file) 1380{ 1381 return seq_open_private(file, &arp_seq_ops, 1382 sizeof(struct neigh_seq_state)); 1383} 1384 1385static const struct file_operations arp_seq_fops = { 1386 .owner = THIS_MODULE, 1387 .open = arp_seq_open, 1388 .read = seq_read, 1389 .llseek = seq_lseek, 1390 .release = seq_release_private, 1391}; 1392 1393static int __init arp_proc_init(void) 1394{ 1395 if (!proc_net_fops_create(&init_net, "arp", S_IRUGO, &arp_seq_fops)) 1396 return -ENOMEM; 1397 return 0; 1398} 1399 1400#else /* CONFIG_PROC_FS */ 1401 1402static int __init arp_proc_init(void) 1403{ 1404 return 0; 1405} 1406 1407#endif /* CONFIG_PROC_FS */ 1408 1409EXPORT_SYMBOL(arp_broken_ops); 1410EXPORT_SYMBOL(arp_find); 1411EXPORT_SYMBOL(arp_create); 1412EXPORT_SYMBOL(arp_xmit); 1413EXPORT_SYMBOL(arp_send); 1414EXPORT_SYMBOL(arp_tbl); 1415 1416#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1417EXPORT_SYMBOL(clip_tbl_hook); 1418#endif 1419