arp.c revision f30c2269544bffc7bf1b0d7c0abe5be1be83b8cb
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/sched.h> 82#include <linux/capability.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/inetdevice.h> 90#include <linux/netdevice.h> 91#include <linux/etherdevice.h> 92#include <linux/fddidevice.h> 93#include <linux/if_arp.h> 94#include <linux/trdevice.h> 95#include <linux/skbuff.h> 96#include <linux/proc_fs.h> 97#include <linux/seq_file.h> 98#include <linux/stat.h> 99#include <linux/init.h> 100#include <linux/net.h> 101#include <linux/rcupdate.h> 102#include <linux/jhash.h> 103#ifdef CONFIG_SYSCTL 104#include <linux/sysctl.h> 105#endif 106 107#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(u32 addr, u8 *haddr, struct net_device *dev, int dir) 207{ 208 switch (dev->type) { 209 case ARPHRD_ETHER: 210 case ARPHRD_FDDI: 211 case ARPHRD_IEEE802: 212 ip_eth_mc_map(addr, haddr); 213 return 0; 214 case ARPHRD_IEEE802_TR: 215 ip_tr_mc_map(addr, haddr); 216 return 0; 217 case ARPHRD_INFINIBAND: 218 ip_ib_mc_map(addr, haddr); 219 return 0; 220 default: 221 if (dir) { 222 memcpy(haddr, dev->broadcast, dev->addr_len); 223 return 0; 224 } 225 } 226 return -EINVAL; 227} 228 229 230static u32 arp_hash(const void *pkey, const struct net_device *dev) 231{ 232 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 233} 234 235static int arp_constructor(struct neighbour *neigh) 236{ 237 __be32 addr = *(__be32*)neigh->primary_key; 238 struct net_device *dev = neigh->dev; 239 struct in_device *in_dev; 240 struct neigh_parms *parms; 241 242 neigh->type = inet_addr_type(addr); 243 244 rcu_read_lock(); 245 in_dev = __in_dev_get_rcu(dev); 246 if (in_dev == NULL) { 247 rcu_read_unlock(); 248 return -EINVAL; 249 } 250 251 parms = in_dev->arp_parms; 252 __neigh_parms_put(neigh->parms); 253 neigh->parms = neigh_parms_clone(parms); 254 rcu_read_unlock(); 255 256 if (dev->hard_header == NULL) { 257 neigh->nud_state = NUD_NOARP; 258 neigh->ops = &arp_direct_ops; 259 neigh->output = neigh->ops->queue_xmit; 260 } else { 261 /* Good devices (checked by reading texts, but only Ethernet is 262 tested) 263 264 ARPHRD_ETHER: (ethernet, apfddi) 265 ARPHRD_FDDI: (fddi) 266 ARPHRD_IEEE802: (tr) 267 ARPHRD_METRICOM: (strip) 268 ARPHRD_ARCNET: 269 etc. etc. etc. 270 271 ARPHRD_IPDDP will also work, if author repairs it. 272 I did not it, because this driver does not work even 273 in old paradigm. 274 */ 275 276#if 1 277 /* So... these "amateur" devices are hopeless. 278 The only thing, that I can say now: 279 It is very sad that we need to keep ugly obsolete 280 code to make them happy. 281 282 They should be moved to more reasonable state, now 283 they use rebuild_header INSTEAD OF hard_start_xmit!!! 284 Besides that, they are sort of out of date 285 (a lot of redundant clones/copies, useless in 2.1), 286 I wonder why people believe that they work. 287 */ 288 switch (dev->type) { 289 default: 290 break; 291 case ARPHRD_ROSE: 292#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 293 case ARPHRD_AX25: 294#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 295 case ARPHRD_NETROM: 296#endif 297 neigh->ops = &arp_broken_ops; 298 neigh->output = neigh->ops->output; 299 return 0; 300#endif 301 ;} 302#endif 303 if (neigh->type == RTN_MULTICAST) { 304 neigh->nud_state = NUD_NOARP; 305 arp_mc_map(addr, neigh->ha, dev, 1); 306 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 307 neigh->nud_state = NUD_NOARP; 308 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 309 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 310 neigh->nud_state = NUD_NOARP; 311 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 312 } 313 if (dev->hard_header_cache) 314 neigh->ops = &arp_hh_ops; 315 else 316 neigh->ops = &arp_generic_ops; 317 if (neigh->nud_state&NUD_VALID) 318 neigh->output = neigh->ops->connected_output; 319 else 320 neigh->output = neigh->ops->output; 321 } 322 return 0; 323} 324 325static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 326{ 327 dst_link_failure(skb); 328 kfree_skb(skb); 329} 330 331static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 332{ 333 __be32 saddr = 0; 334 u8 *dst_ha = NULL; 335 struct net_device *dev = neigh->dev; 336 __be32 target = *(__be32*)neigh->primary_key; 337 int probes = atomic_read(&neigh->probes); 338 struct in_device *in_dev = in_dev_get(dev); 339 340 if (!in_dev) 341 return; 342 343 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 344 default: 345 case 0: /* By default announce any local IP */ 346 if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) 347 saddr = skb->nh.iph->saddr; 348 break; 349 case 1: /* Restrict announcements of saddr in same subnet */ 350 if (!skb) 351 break; 352 saddr = skb->nh.iph->saddr; 353 if (inet_addr_type(saddr) == RTN_LOCAL) { 354 /* saddr should be known to target */ 355 if (inet_addr_onlink(in_dev, target, saddr)) 356 break; 357 } 358 saddr = 0; 359 break; 360 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 361 break; 362 } 363 364 if (in_dev) 365 in_dev_put(in_dev); 366 if (!saddr) 367 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 368 369 if ((probes -= neigh->parms->ucast_probes) < 0) { 370 if (!(neigh->nud_state&NUD_VALID)) 371 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 372 dst_ha = neigh->ha; 373 read_lock_bh(&neigh->lock); 374 } else if ((probes -= neigh->parms->app_probes) < 0) { 375#ifdef CONFIG_ARPD 376 neigh_app_ns(neigh); 377#endif 378 return; 379 } 380 381 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 382 dst_ha, dev->dev_addr, NULL); 383 if (dst_ha) 384 read_unlock_bh(&neigh->lock); 385} 386 387static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 388 __be32 sip, __be32 tip) 389{ 390 int scope; 391 392 switch (IN_DEV_ARP_IGNORE(in_dev)) { 393 case 0: /* Reply, the tip is already validated */ 394 return 0; 395 case 1: /* Reply only if tip is configured on the incoming interface */ 396 sip = 0; 397 scope = RT_SCOPE_HOST; 398 break; 399 case 2: /* 400 * Reply only if tip is configured on the incoming interface 401 * and is in same subnet as sip 402 */ 403 scope = RT_SCOPE_HOST; 404 break; 405 case 3: /* Do not reply for scope host addresses */ 406 sip = 0; 407 scope = RT_SCOPE_LINK; 408 dev = NULL; 409 break; 410 case 4: /* Reserved */ 411 case 5: 412 case 6: 413 case 7: 414 return 0; 415 case 8: /* Do not reply */ 416 return 1; 417 default: 418 return 0; 419 } 420 return !inet_confirm_addr(dev, sip, tip, scope); 421} 422 423static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 424{ 425 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 426 .saddr = tip } } }; 427 struct rtable *rt; 428 int flag = 0; 429 /*unsigned long now; */ 430 431 if (ip_route_output_key(&rt, &fl) < 0) 432 return 1; 433 if (rt->u.dst.dev != dev) { 434 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 435 flag = 1; 436 } 437 ip_rt_put(rt); 438 return flag; 439} 440 441/* OBSOLETE FUNCTIONS */ 442 443/* 444 * Find an arp mapping in the cache. If not found, post a request. 445 * 446 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 447 * even if it exists. It is supposed that skb->dev was mangled 448 * by a virtual device (eql, shaper). Nobody but broken devices 449 * is allowed to use this function, it is scheduled to be removed. --ANK 450 */ 451 452static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 453{ 454 switch (addr_hint) { 455 case RTN_LOCAL: 456 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 457 memcpy(haddr, dev->dev_addr, dev->addr_len); 458 return 1; 459 case RTN_MULTICAST: 460 arp_mc_map(paddr, haddr, dev, 1); 461 return 1; 462 case RTN_BROADCAST: 463 memcpy(haddr, dev->broadcast, dev->addr_len); 464 return 1; 465 } 466 return 0; 467} 468 469 470int arp_find(unsigned char *haddr, struct sk_buff *skb) 471{ 472 struct net_device *dev = skb->dev; 473 __be32 paddr; 474 struct neighbour *n; 475 476 if (!skb->dst) { 477 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 478 kfree_skb(skb); 479 return 1; 480 } 481 482 paddr = ((struct rtable*)skb->dst)->rt_gateway; 483 484 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) 485 return 0; 486 487 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 488 489 if (n) { 490 n->used = jiffies; 491 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 492 read_lock_bh(&n->lock); 493 memcpy(haddr, n->ha, dev->addr_len); 494 read_unlock_bh(&n->lock); 495 neigh_release(n); 496 return 0; 497 } 498 neigh_release(n); 499 } else 500 kfree_skb(skb); 501 return 1; 502} 503 504/* END OF OBSOLETE FUNCTIONS */ 505 506int arp_bind_neighbour(struct dst_entry *dst) 507{ 508 struct net_device *dev = dst->dev; 509 struct neighbour *n = dst->neighbour; 510 511 if (dev == NULL) 512 return -EINVAL; 513 if (n == NULL) { 514 __be32 nexthop = ((struct rtable*)dst)->rt_gateway; 515 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 516 nexthop = 0; 517 n = __neigh_lookup_errno( 518#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 519 dev->type == ARPHRD_ATM ? clip_tbl_hook : 520#endif 521 &arp_tbl, &nexthop, dev); 522 if (IS_ERR(n)) 523 return PTR_ERR(n); 524 dst->neighbour = n; 525 } 526 return 0; 527} 528 529/* 530 * Check if we can use proxy ARP for this path 531 */ 532 533static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 534{ 535 struct in_device *out_dev; 536 int imi, omi = -1; 537 538 if (!IN_DEV_PROXY_ARP(in_dev)) 539 return 0; 540 541 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 542 return 1; 543 if (imi == -1) 544 return 0; 545 546 /* place to check for proxy_arp for routes */ 547 548 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 549 omi = IN_DEV_MEDIUM_ID(out_dev); 550 in_dev_put(out_dev); 551 } 552 return (omi != imi && omi != -1); 553} 554 555/* 556 * Interface to link layer: send routine and receive handler. 557 */ 558 559/* 560 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 561 * message. 562 */ 563struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 564 struct net_device *dev, __be32 src_ip, 565 unsigned char *dest_hw, unsigned char *src_hw, 566 unsigned char *target_hw) 567{ 568 struct sk_buff *skb; 569 struct arphdr *arp; 570 unsigned char *arp_ptr; 571 572 /* 573 * Allocate a buffer 574 */ 575 576 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 577 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 578 if (skb == NULL) 579 return NULL; 580 581 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 582 skb->nh.raw = skb->data; 583 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 584 skb->dev = dev; 585 skb->protocol = htons(ETH_P_ARP); 586 if (src_hw == NULL) 587 src_hw = dev->dev_addr; 588 if (dest_hw == NULL) 589 dest_hw = dev->broadcast; 590 591 /* 592 * Fill the device header for the ARP frame 593 */ 594 if (dev->hard_header && 595 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0) 596 goto out; 597 598 /* 599 * Fill out the arp protocol part. 600 * 601 * The arp hardware type should match the device type, except for FDDI, 602 * which (according to RFC 1390) should always equal 1 (Ethernet). 603 */ 604 /* 605 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 606 * DIX code for the protocol. Make these device structure fields. 607 */ 608 switch (dev->type) { 609 default: 610 arp->ar_hrd = htons(dev->type); 611 arp->ar_pro = htons(ETH_P_IP); 612 break; 613 614#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 615 case ARPHRD_AX25: 616 arp->ar_hrd = htons(ARPHRD_AX25); 617 arp->ar_pro = htons(AX25_P_IP); 618 break; 619 620#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 621 case ARPHRD_NETROM: 622 arp->ar_hrd = htons(ARPHRD_NETROM); 623 arp->ar_pro = htons(AX25_P_IP); 624 break; 625#endif 626#endif 627 628#ifdef CONFIG_FDDI 629 case ARPHRD_FDDI: 630 arp->ar_hrd = htons(ARPHRD_ETHER); 631 arp->ar_pro = htons(ETH_P_IP); 632 break; 633#endif 634#ifdef CONFIG_TR 635 case ARPHRD_IEEE802_TR: 636 arp->ar_hrd = htons(ARPHRD_IEEE802); 637 arp->ar_pro = htons(ETH_P_IP); 638 break; 639#endif 640 } 641 642 arp->ar_hln = dev->addr_len; 643 arp->ar_pln = 4; 644 arp->ar_op = htons(type); 645 646 arp_ptr=(unsigned char *)(arp+1); 647 648 memcpy(arp_ptr, src_hw, dev->addr_len); 649 arp_ptr+=dev->addr_len; 650 memcpy(arp_ptr, &src_ip,4); 651 arp_ptr+=4; 652 if (target_hw != NULL) 653 memcpy(arp_ptr, target_hw, dev->addr_len); 654 else 655 memset(arp_ptr, 0, dev->addr_len); 656 arp_ptr+=dev->addr_len; 657 memcpy(arp_ptr, &dest_ip, 4); 658 659 return skb; 660 661out: 662 kfree_skb(skb); 663 return NULL; 664} 665 666/* 667 * Send an arp packet. 668 */ 669void arp_xmit(struct sk_buff *skb) 670{ 671 /* Send it off, maybe filter it using firewalling first. */ 672 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 673} 674 675/* 676 * Create and send an arp packet. 677 */ 678void arp_send(int type, int ptype, __be32 dest_ip, 679 struct net_device *dev, __be32 src_ip, 680 unsigned char *dest_hw, unsigned char *src_hw, 681 unsigned char *target_hw) 682{ 683 struct sk_buff *skb; 684 685 /* 686 * No arp on this interface. 687 */ 688 689 if (dev->flags&IFF_NOARP) 690 return; 691 692 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 693 dest_hw, src_hw, target_hw); 694 if (skb == NULL) { 695 return; 696 } 697 698 arp_xmit(skb); 699} 700 701/* 702 * Process an arp request. 703 */ 704 705static int arp_process(struct sk_buff *skb) 706{ 707 struct net_device *dev = skb->dev; 708 struct in_device *in_dev = in_dev_get(dev); 709 struct arphdr *arp; 710 unsigned char *arp_ptr; 711 struct rtable *rt; 712 unsigned char *sha, *tha; 713 __be32 sip, tip; 714 u16 dev_type = dev->type; 715 int addr_type; 716 struct neighbour *n; 717 718 /* arp_rcv below verifies the ARP header and verifies the device 719 * is ARP'able. 720 */ 721 722 if (in_dev == NULL) 723 goto out; 724 725 arp = skb->nh.arph; 726 727 switch (dev_type) { 728 default: 729 if (arp->ar_pro != htons(ETH_P_IP) || 730 htons(dev_type) != arp->ar_hrd) 731 goto out; 732 break; 733#ifdef CONFIG_NET_ETHERNET 734 case ARPHRD_ETHER: 735#endif 736#ifdef CONFIG_TR 737 case ARPHRD_IEEE802_TR: 738#endif 739#ifdef CONFIG_FDDI 740 case ARPHRD_FDDI: 741#endif 742#ifdef CONFIG_NET_FC 743 case ARPHRD_IEEE802: 744#endif 745#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \ 746 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC) 747 /* 748 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 749 * devices, according to RFC 2625) devices will accept ARP 750 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 751 * This is the case also of FDDI, where the RFC 1390 says that 752 * FDDI devices should accept ARP hardware of (1) Ethernet, 753 * however, to be more robust, we'll accept both 1 (Ethernet) 754 * or 6 (IEEE 802.2) 755 */ 756 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 757 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 758 arp->ar_pro != htons(ETH_P_IP)) 759 goto out; 760 break; 761#endif 762#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 763 case ARPHRD_AX25: 764 if (arp->ar_pro != htons(AX25_P_IP) || 765 arp->ar_hrd != htons(ARPHRD_AX25)) 766 goto out; 767 break; 768#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 769 case ARPHRD_NETROM: 770 if (arp->ar_pro != htons(AX25_P_IP) || 771 arp->ar_hrd != htons(ARPHRD_NETROM)) 772 goto out; 773 break; 774#endif 775#endif 776 } 777 778 /* Understand only these message types */ 779 780 if (arp->ar_op != htons(ARPOP_REPLY) && 781 arp->ar_op != htons(ARPOP_REQUEST)) 782 goto out; 783 784/* 785 * Extract fields 786 */ 787 arp_ptr= (unsigned char *)(arp+1); 788 sha = arp_ptr; 789 arp_ptr += dev->addr_len; 790 memcpy(&sip, arp_ptr, 4); 791 arp_ptr += 4; 792 tha = arp_ptr; 793 arp_ptr += dev->addr_len; 794 memcpy(&tip, arp_ptr, 4); 795/* 796 * Check for bad requests for 127.x.x.x and requests for multicast 797 * addresses. If this is one such, delete it. 798 */ 799 if (LOOPBACK(tip) || MULTICAST(tip)) 800 goto out; 801 802/* 803 * Special case: We must set Frame Relay source Q.922 address 804 */ 805 if (dev_type == ARPHRD_DLCI) 806 sha = dev->broadcast; 807 808/* 809 * Process entry. The idea here is we want to send a reply if it is a 810 * request for us or if it is a request for someone else that we hold 811 * a proxy for. We want to add an entry to our cache if it is a reply 812 * to us or if it is a request for our address. 813 * (The assumption for this last is that if someone is requesting our 814 * address, they are probably intending to talk to us, so it saves time 815 * if we cache their address. Their address is also probably not in 816 * our cache, since ours is not in their cache.) 817 * 818 * Putting this another way, we only care about replies if they are to 819 * us, in which case we add them to the cache. For requests, we care 820 * about those for us and those for our proxies. We reply to both, 821 * and in the case of requests for us we add the requester to the arp 822 * cache. 823 */ 824 825 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 826 if (sip == 0) { 827 if (arp->ar_op == htons(ARPOP_REQUEST) && 828 inet_addr_type(tip) == RTN_LOCAL && 829 !arp_ignore(in_dev,dev,sip,tip)) 830 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); 831 goto out; 832 } 833 834 if (arp->ar_op == htons(ARPOP_REQUEST) && 835 ip_route_input(skb, tip, sip, 0, dev) == 0) { 836 837 rt = (struct rtable*)skb->dst; 838 addr_type = rt->rt_type; 839 840 if (addr_type == RTN_LOCAL) { 841 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 842 if (n) { 843 int dont_send = 0; 844 845 if (!dont_send) 846 dont_send |= arp_ignore(in_dev,dev,sip,tip); 847 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 848 dont_send |= arp_filter(sip,tip,dev); 849 if (!dont_send) 850 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 851 852 neigh_release(n); 853 } 854 goto out; 855 } else if (IN_DEV_FORWARD(in_dev)) { 856 if ((rt->rt_flags&RTCF_DNAT) || 857 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 858 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { 859 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 860 if (n) 861 neigh_release(n); 862 863 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 864 skb->pkt_type == PACKET_HOST || 865 in_dev->arp_parms->proxy_delay == 0) { 866 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 867 } else { 868 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 869 in_dev_put(in_dev); 870 return 0; 871 } 872 goto out; 873 } 874 } 875 } 876 877 /* Update our ARP tables */ 878 879 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 880 881 if (ipv4_devconf.arp_accept) { 882 /* Unsolicited ARP is not accepted by default. 883 It is possible, that this option should be enabled for some 884 devices (strip is candidate) 885 */ 886 if (n == NULL && 887 arp->ar_op == htons(ARPOP_REPLY) && 888 inet_addr_type(sip) == RTN_UNICAST) 889 n = __neigh_lookup(&arp_tbl, &sip, dev, -1); 890 } 891 892 if (n) { 893 int state = NUD_REACHABLE; 894 int override; 895 896 /* If several different ARP replies follows back-to-back, 897 use the FIRST one. It is possible, if several proxy 898 agents are active. Taking the first reply prevents 899 arp trashing and chooses the fastest router. 900 */ 901 override = time_after(jiffies, n->updated + n->parms->locktime); 902 903 /* Broadcast replies and request packets 904 do not assert neighbour reachability. 905 */ 906 if (arp->ar_op != htons(ARPOP_REPLY) || 907 skb->pkt_type != PACKET_HOST) 908 state = NUD_STALE; 909 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 910 neigh_release(n); 911 } 912 913out: 914 if (in_dev) 915 in_dev_put(in_dev); 916 kfree_skb(skb); 917 return 0; 918} 919 920static void parp_redo(struct sk_buff *skb) 921{ 922 arp_process(skb); 923} 924 925 926/* 927 * Receive an arp request from the device layer. 928 */ 929 930static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 931 struct packet_type *pt, struct net_device *orig_dev) 932{ 933 struct arphdr *arp; 934 935 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 936 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 937 (2 * dev->addr_len) + 938 (2 * sizeof(u32))))) 939 goto freeskb; 940 941 arp = skb->nh.arph; 942 if (arp->ar_hln != dev->addr_len || 943 dev->flags & IFF_NOARP || 944 skb->pkt_type == PACKET_OTHERHOST || 945 skb->pkt_type == PACKET_LOOPBACK || 946 arp->ar_pln != 4) 947 goto freeskb; 948 949 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 950 goto out_of_mem; 951 952 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 953 954 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 955 956freeskb: 957 kfree_skb(skb); 958out_of_mem: 959 return 0; 960} 961 962/* 963 * User level interface (ioctl) 964 */ 965 966/* 967 * Set (create) an ARP cache entry. 968 */ 969 970static int arp_req_set(struct arpreq *r, struct net_device * dev) 971{ 972 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 973 struct neighbour *neigh; 974 int err; 975 976 if (r->arp_flags&ATF_PUBL) { 977 __be32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; 978 if (mask && mask != htonl(0xFFFFFFFF)) 979 return -EINVAL; 980 if (!dev && (r->arp_flags & ATF_COM)) { 981 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data); 982 if (!dev) 983 return -ENODEV; 984 } 985 if (mask) { 986 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) 987 return -ENOBUFS; 988 return 0; 989 } 990 if (dev == NULL) { 991 ipv4_devconf.proxy_arp = 1; 992 return 0; 993 } 994 if (__in_dev_get_rtnl(dev)) { 995 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 1; 996 return 0; 997 } 998 return -ENXIO; 999 } 1000 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(struct arpreq *r, struct net_device * dev) 1085{ 1086 int err; 1087 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1088 struct neighbour *neigh; 1089 1090 if (r->arp_flags & ATF_PUBL) { 1091 __be32 mask = 1092 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1093 if (mask == htonl(0xFFFFFFFF)) 1094 return pneigh_delete(&arp_tbl, &ip, dev); 1095 if (mask == 0) { 1096 if (dev == NULL) { 1097 ipv4_devconf.proxy_arp = 0; 1098 return 0; 1099 } 1100 if (__in_dev_get_rtnl(dev)) { 1101 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 0; 1102 return 0; 1103 } 1104 return -ENXIO; 1105 } 1106 return -EINVAL; 1107 } 1108 1109 if (dev == NULL) { 1110 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1111 .tos = RTO_ONLINK } } }; 1112 struct rtable * rt; 1113 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1114 return err; 1115 dev = rt->u.dst.dev; 1116 ip_rt_put(rt); 1117 if (!dev) 1118 return -EINVAL; 1119 } 1120 err = -ENXIO; 1121 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1122 if (neigh) { 1123 if (neigh->nud_state&~NUD_NOARP) 1124 err = neigh_update(neigh, NULL, NUD_FAILED, 1125 NEIGH_UPDATE_F_OVERRIDE| 1126 NEIGH_UPDATE_F_ADMIN); 1127 neigh_release(neigh); 1128 } 1129 return err; 1130} 1131 1132/* 1133 * Handle an ARP layer I/O control request. 1134 */ 1135 1136int arp_ioctl(unsigned int cmd, void __user *arg) 1137{ 1138 int err; 1139 struct arpreq r; 1140 struct net_device *dev = NULL; 1141 1142 switch (cmd) { 1143 case SIOCDARP: 1144 case SIOCSARP: 1145 if (!capable(CAP_NET_ADMIN)) 1146 return -EPERM; 1147 case SIOCGARP: 1148 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1149 if (err) 1150 return -EFAULT; 1151 break; 1152 default: 1153 return -EINVAL; 1154 } 1155 1156 if (r.arp_pa.sa_family != AF_INET) 1157 return -EPFNOSUPPORT; 1158 1159 if (!(r.arp_flags & ATF_PUBL) && 1160 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1161 return -EINVAL; 1162 if (!(r.arp_flags & ATF_NETMASK)) 1163 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1164 htonl(0xFFFFFFFFUL); 1165 rtnl_lock(); 1166 if (r.arp_dev[0]) { 1167 err = -ENODEV; 1168 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL) 1169 goto out; 1170 1171 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1172 if (!r.arp_ha.sa_family) 1173 r.arp_ha.sa_family = dev->type; 1174 err = -EINVAL; 1175 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1176 goto out; 1177 } else if (cmd == SIOCGARP) { 1178 err = -ENODEV; 1179 goto out; 1180 } 1181 1182 switch(cmd) { 1183 case SIOCDARP: 1184 err = arp_req_delete(&r, dev); 1185 break; 1186 case SIOCSARP: 1187 err = arp_req_set(&r, dev); 1188 break; 1189 case SIOCGARP: 1190 err = arp_req_get(&r, dev); 1191 if (!err && copy_to_user(arg, &r, sizeof(r))) 1192 err = -EFAULT; 1193 break; 1194 } 1195out: 1196 rtnl_unlock(); 1197 return err; 1198} 1199 1200static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1201{ 1202 struct net_device *dev = ptr; 1203 1204 switch (event) { 1205 case NETDEV_CHANGEADDR: 1206 neigh_changeaddr(&arp_tbl, dev); 1207 rt_cache_flush(0); 1208 break; 1209 default: 1210 break; 1211 } 1212 1213 return NOTIFY_DONE; 1214} 1215 1216static struct notifier_block arp_netdev_notifier = { 1217 .notifier_call = arp_netdev_event, 1218}; 1219 1220/* Note, that it is not on notifier chain. 1221 It is necessary, that this routine was called after route cache will be 1222 flushed. 1223 */ 1224void arp_ifdown(struct net_device *dev) 1225{ 1226 neigh_ifdown(&arp_tbl, dev); 1227} 1228 1229 1230/* 1231 * Called once on startup. 1232 */ 1233 1234static struct packet_type arp_packet_type = { 1235 .type = __constant_htons(ETH_P_ARP), 1236 .func = arp_rcv, 1237}; 1238 1239static int arp_proc_init(void); 1240 1241void __init arp_init(void) 1242{ 1243 neigh_table_init(&arp_tbl); 1244 1245 dev_add_pack(&arp_packet_type); 1246 arp_proc_init(); 1247#ifdef CONFIG_SYSCTL 1248 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1249 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1250#endif 1251 register_netdevice_notifier(&arp_netdev_notifier); 1252} 1253 1254#ifdef CONFIG_PROC_FS 1255#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1256 1257/* ------------------------------------------------------------------------ */ 1258/* 1259 * ax25 -> ASCII conversion 1260 */ 1261static char *ax2asc2(ax25_address *a, char *buf) 1262{ 1263 char c, *s; 1264 int n; 1265 1266 for (n = 0, s = buf; n < 6; n++) { 1267 c = (a->ax25_call[n] >> 1) & 0x7F; 1268 1269 if (c != ' ') *s++ = c; 1270 } 1271 1272 *s++ = '-'; 1273 1274 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1275 *s++ = '1'; 1276 n -= 10; 1277 } 1278 1279 *s++ = n + '0'; 1280 *s++ = '\0'; 1281 1282 if (*buf == '\0' || *buf == '-') 1283 return "*"; 1284 1285 return buf; 1286 1287} 1288#endif /* CONFIG_AX25 */ 1289 1290#define HBUFFERLEN 30 1291 1292static void arp_format_neigh_entry(struct seq_file *seq, 1293 struct neighbour *n) 1294{ 1295 char hbuffer[HBUFFERLEN]; 1296 const char hexbuf[] = "0123456789ABCDEF"; 1297 int k, j; 1298 char tbuf[16]; 1299 struct net_device *dev = n->dev; 1300 int hatype = dev->type; 1301 1302 read_lock(&n->lock); 1303 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1304#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1305 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1306 ax2asc2((ax25_address *)n->ha, hbuffer); 1307 else { 1308#endif 1309 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1310 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1311 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1312 hbuffer[k++] = ':'; 1313 } 1314 hbuffer[--k] = 0; 1315#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1316 } 1317#endif 1318 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1319 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1320 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1321 read_unlock(&n->lock); 1322} 1323 1324static void arp_format_pneigh_entry(struct seq_file *seq, 1325 struct pneigh_entry *n) 1326{ 1327 struct net_device *dev = n->dev; 1328 int hatype = dev ? dev->type : 0; 1329 char tbuf[16]; 1330 1331 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1332 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1333 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1334 dev ? dev->name : "*"); 1335} 1336 1337static int arp_seq_show(struct seq_file *seq, void *v) 1338{ 1339 if (v == SEQ_START_TOKEN) { 1340 seq_puts(seq, "IP address HW type Flags " 1341 "HW address Mask Device\n"); 1342 } else { 1343 struct neigh_seq_state *state = seq->private; 1344 1345 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1346 arp_format_pneigh_entry(seq, v); 1347 else 1348 arp_format_neigh_entry(seq, v); 1349 } 1350 1351 return 0; 1352} 1353 1354static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1355{ 1356 /* Don't want to confuse "arp -a" w/ magic entries, 1357 * so we tell the generic iterator to skip NUD_NOARP. 1358 */ 1359 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1360} 1361 1362/* ------------------------------------------------------------------------ */ 1363 1364static struct seq_operations arp_seq_ops = { 1365 .start = arp_seq_start, 1366 .next = neigh_seq_next, 1367 .stop = neigh_seq_stop, 1368 .show = arp_seq_show, 1369}; 1370 1371static int arp_seq_open(struct inode *inode, struct file *file) 1372{ 1373 struct seq_file *seq; 1374 int rc = -ENOMEM; 1375 struct neigh_seq_state *s = kzalloc(sizeof(*s), GFP_KERNEL); 1376 1377 if (!s) 1378 goto out; 1379 1380 rc = seq_open(file, &arp_seq_ops); 1381 if (rc) 1382 goto out_kfree; 1383 1384 seq = file->private_data; 1385 seq->private = s; 1386out: 1387 return rc; 1388out_kfree: 1389 kfree(s); 1390 goto out; 1391} 1392 1393static struct file_operations arp_seq_fops = { 1394 .owner = THIS_MODULE, 1395 .open = arp_seq_open, 1396 .read = seq_read, 1397 .llseek = seq_lseek, 1398 .release = seq_release_private, 1399}; 1400 1401static int __init arp_proc_init(void) 1402{ 1403 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops)) 1404 return -ENOMEM; 1405 return 0; 1406} 1407 1408#else /* CONFIG_PROC_FS */ 1409 1410static int __init arp_proc_init(void) 1411{ 1412 return 0; 1413} 1414 1415#endif /* CONFIG_PROC_FS */ 1416 1417EXPORT_SYMBOL(arp_broken_ops); 1418EXPORT_SYMBOL(arp_find); 1419EXPORT_SYMBOL(arp_create); 1420EXPORT_SYMBOL(arp_xmit); 1421EXPORT_SYMBOL(arp_send); 1422EXPORT_SYMBOL(arp_tbl); 1423 1424#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1425EXPORT_SYMBOL(clip_tbl_hook); 1426#endif 1427