arp.c revision f2ccd8fa06c8e302116e71df372f5c1f83432e03
1/* linux/net/inet/arp.c 2 * 3 * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $ 4 * 5 * Copyright (C) 1994 by Florian La Roche 6 * 7 * This module implements the Address Resolution Protocol ARP (RFC 826), 8 * which is used to convert IP addresses (or in the future maybe other 9 * high-level addresses) into a low-level hardware address (like an Ethernet 10 * address). 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Fixes: 18 * Alan Cox : Removed the Ethernet assumptions in 19 * Florian's code 20 * Alan Cox : Fixed some small errors in the ARP 21 * logic 22 * Alan Cox : Allow >4K in /proc 23 * Alan Cox : Make ARP add its own protocol entry 24 * Ross Martin : Rewrote arp_rcv() and arp_get_info() 25 * Stephen Henson : Add AX25 support to arp_get_info() 26 * Alan Cox : Drop data when a device is downed. 27 * Alan Cox : Use init_timer(). 28 * Alan Cox : Double lock fixes. 29 * Martin Seine : Move the arphdr structure 30 * to if_arp.h for compatibility. 31 * with BSD based programs. 32 * Andrew Tridgell : Added ARP netmask code and 33 * re-arranged proxy handling. 34 * Alan Cox : Changed to use notifiers. 35 * Niibe Yutaka : Reply for this device or proxies only. 36 * Alan Cox : Don't proxy across hardware types! 37 * Jonathan Naylor : Added support for NET/ROM. 38 * Mike Shaver : RFC1122 checks. 39 * Jonathan Naylor : Only lookup the hardware address for 40 * the correct hardware type. 41 * Germano Caronni : Assorted subtle races. 42 * Craig Schlenter : Don't modify permanent entry 43 * during arp_rcv. 44 * Russ Nelson : Tidied up a few bits. 45 * Alexey Kuznetsov: Major changes to caching and behaviour, 46 * eg intelligent arp probing and 47 * generation 48 * of host down events. 49 * Alan Cox : Missing unlock in device events. 50 * Eckes : ARP ioctl control errors. 51 * Alexey Kuznetsov: Arp free fix. 52 * Manuel Rodriguez: Gratuitous ARP. 53 * Jonathan Layes : Added arpd support through kerneld 54 * message queue (960314) 55 * Mike Shaver : /proc/sys/net/ipv4/arp_* support 56 * Mike McLagan : Routing by source 57 * Stuart Cheshire : Metricom and grat arp fixes 58 * *** FOR 2.1 clean this up *** 59 * Lawrence V. Stefani: (08/12/96) Added FDDI support. 60 * Alan Cox : Took the AP1000 nasty FDDI hack and 61 * folded into the mainstream FDDI code. 62 * Ack spit, Linus how did you allow that 63 * one in... 64 * Jes Sorensen : Make FDDI work again in 2.1.x and 65 * clean up the APFDDI & gen. FDDI bits. 66 * Alexey Kuznetsov: new arp state machine; 67 * now it is in net/core/neighbour.c. 68 * Krzysztof Halasa: Added Frame Relay ARP support. 69 * Arnaldo C. Melo : convert /proc/net/arp to seq_file 70 * Shmulik Hen: Split arp_send to arp_create and 71 * arp_xmit so intermediate drivers like 72 * bonding can change the skb before 73 * sending (e.g. insert 8021q tag). 74 * Harald Welte : convert to make use of jenkins hash 75 */ 76 77#include <linux/module.h> 78#include <linux/types.h> 79#include <linux/string.h> 80#include <linux/kernel.h> 81#include <linux/sched.h> 82#include <linux/config.h> 83#include <linux/socket.h> 84#include <linux/sockios.h> 85#include <linux/errno.h> 86#include <linux/in.h> 87#include <linux/mm.h> 88#include <linux/inet.h> 89#include <linux/netdevice.h> 90#include <linux/etherdevice.h> 91#include <linux/fddidevice.h> 92#include <linux/if_arp.h> 93#include <linux/trdevice.h> 94#include <linux/skbuff.h> 95#include <linux/proc_fs.h> 96#include <linux/seq_file.h> 97#include <linux/stat.h> 98#include <linux/init.h> 99#include <linux/net.h> 100#include <linux/rcupdate.h> 101#include <linux/jhash.h> 102#ifdef CONFIG_SYSCTL 103#include <linux/sysctl.h> 104#endif 105 106#include <net/ip.h> 107#include <net/icmp.h> 108#include <net/route.h> 109#include <net/protocol.h> 110#include <net/tcp.h> 111#include <net/sock.h> 112#include <net/arp.h> 113#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 114#include <net/ax25.h> 115#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 116#include <net/netrom.h> 117#endif 118#endif 119#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 120#include <net/atmclip.h> 121struct neigh_table *clip_tbl_hook; 122#endif 123 124#include <asm/system.h> 125#include <asm/uaccess.h> 126 127#include <linux/netfilter_arp.h> 128 129/* 130 * Interface to generic neighbour cache. 131 */ 132static u32 arp_hash(const void *pkey, const struct net_device *dev); 133static int arp_constructor(struct neighbour *neigh); 134static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 135static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 136static void parp_redo(struct sk_buff *skb); 137 138static struct neigh_ops arp_generic_ops = { 139 .family = AF_INET, 140 .solicit = arp_solicit, 141 .error_report = arp_error_report, 142 .output = neigh_resolve_output, 143 .connected_output = neigh_connected_output, 144 .hh_output = dev_queue_xmit, 145 .queue_xmit = dev_queue_xmit, 146}; 147 148static struct neigh_ops arp_hh_ops = { 149 .family = AF_INET, 150 .solicit = arp_solicit, 151 .error_report = arp_error_report, 152 .output = neigh_resolve_output, 153 .connected_output = neigh_resolve_output, 154 .hh_output = dev_queue_xmit, 155 .queue_xmit = dev_queue_xmit, 156}; 157 158static struct neigh_ops arp_direct_ops = { 159 .family = AF_INET, 160 .output = dev_queue_xmit, 161 .connected_output = dev_queue_xmit, 162 .hh_output = dev_queue_xmit, 163 .queue_xmit = dev_queue_xmit, 164}; 165 166struct neigh_ops arp_broken_ops = { 167 .family = AF_INET, 168 .solicit = arp_solicit, 169 .error_report = arp_error_report, 170 .output = neigh_compat_output, 171 .connected_output = neigh_compat_output, 172 .hh_output = dev_queue_xmit, 173 .queue_xmit = dev_queue_xmit, 174}; 175 176struct neigh_table arp_tbl = { 177 .family = AF_INET, 178 .entry_size = sizeof(struct neighbour) + 4, 179 .key_len = 4, 180 .hash = arp_hash, 181 .constructor = arp_constructor, 182 .proxy_redo = parp_redo, 183 .id = "arp_cache", 184 .parms = { 185 .tbl = &arp_tbl, 186 .base_reachable_time = 30 * HZ, 187 .retrans_time = 1 * HZ, 188 .gc_staletime = 60 * HZ, 189 .reachable_time = 30 * HZ, 190 .delay_probe_time = 5 * HZ, 191 .queue_len = 3, 192 .ucast_probes = 3, 193 .mcast_probes = 3, 194 .anycast_delay = 1 * HZ, 195 .proxy_delay = (8 * HZ) / 10, 196 .proxy_qlen = 64, 197 .locktime = 1 * HZ, 198 }, 199 .gc_interval = 30 * HZ, 200 .gc_thresh1 = 128, 201 .gc_thresh2 = 512, 202 .gc_thresh3 = 1024, 203}; 204 205int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir) 206{ 207 switch (dev->type) { 208 case ARPHRD_ETHER: 209 case ARPHRD_FDDI: 210 case ARPHRD_IEEE802: 211 ip_eth_mc_map(addr, haddr); 212 return 0; 213 case ARPHRD_IEEE802_TR: 214 ip_tr_mc_map(addr, haddr); 215 return 0; 216 case ARPHRD_INFINIBAND: 217 ip_ib_mc_map(addr, haddr); 218 return 0; 219 default: 220 if (dir) { 221 memcpy(haddr, dev->broadcast, dev->addr_len); 222 return 0; 223 } 224 } 225 return -EINVAL; 226} 227 228 229static u32 arp_hash(const void *pkey, const struct net_device *dev) 230{ 231 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 232} 233 234static int arp_constructor(struct neighbour *neigh) 235{ 236 u32 addr = *(u32*)neigh->primary_key; 237 struct net_device *dev = neigh->dev; 238 struct in_device *in_dev; 239 struct neigh_parms *parms; 240 241 neigh->type = inet_addr_type(addr); 242 243 rcu_read_lock(); 244 in_dev = rcu_dereference(__in_dev_get(dev)); 245 if (in_dev == NULL) { 246 rcu_read_unlock(); 247 return -EINVAL; 248 } 249 250 parms = in_dev->arp_parms; 251 __neigh_parms_put(neigh->parms); 252 neigh->parms = neigh_parms_clone(parms); 253 rcu_read_unlock(); 254 255 if (dev->hard_header == NULL) { 256 neigh->nud_state = NUD_NOARP; 257 neigh->ops = &arp_direct_ops; 258 neigh->output = neigh->ops->queue_xmit; 259 } else { 260 /* Good devices (checked by reading texts, but only Ethernet is 261 tested) 262 263 ARPHRD_ETHER: (ethernet, apfddi) 264 ARPHRD_FDDI: (fddi) 265 ARPHRD_IEEE802: (tr) 266 ARPHRD_METRICOM: (strip) 267 ARPHRD_ARCNET: 268 etc. etc. etc. 269 270 ARPHRD_IPDDP will also work, if author repairs it. 271 I did not it, because this driver does not work even 272 in old paradigm. 273 */ 274 275#if 1 276 /* So... these "amateur" devices are hopeless. 277 The only thing, that I can say now: 278 It is very sad that we need to keep ugly obsolete 279 code to make them happy. 280 281 They should be moved to more reasonable state, now 282 they use rebuild_header INSTEAD OF hard_start_xmit!!! 283 Besides that, they are sort of out of date 284 (a lot of redundant clones/copies, useless in 2.1), 285 I wonder why people believe that they work. 286 */ 287 switch (dev->type) { 288 default: 289 break; 290 case ARPHRD_ROSE: 291#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 292 case ARPHRD_AX25: 293#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 294 case ARPHRD_NETROM: 295#endif 296 neigh->ops = &arp_broken_ops; 297 neigh->output = neigh->ops->output; 298 return 0; 299#endif 300 ;} 301#endif 302 if (neigh->type == RTN_MULTICAST) { 303 neigh->nud_state = NUD_NOARP; 304 arp_mc_map(addr, neigh->ha, dev, 1); 305 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 306 neigh->nud_state = NUD_NOARP; 307 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 308 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 309 neigh->nud_state = NUD_NOARP; 310 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 311 } 312 if (dev->hard_header_cache) 313 neigh->ops = &arp_hh_ops; 314 else 315 neigh->ops = &arp_generic_ops; 316 if (neigh->nud_state&NUD_VALID) 317 neigh->output = neigh->ops->connected_output; 318 else 319 neigh->output = neigh->ops->output; 320 } 321 return 0; 322} 323 324static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 325{ 326 dst_link_failure(skb); 327 kfree_skb(skb); 328} 329 330static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 331{ 332 u32 saddr = 0; 333 u8 *dst_ha = NULL; 334 struct net_device *dev = neigh->dev; 335 u32 target = *(u32*)neigh->primary_key; 336 int probes = atomic_read(&neigh->probes); 337 struct in_device *in_dev = in_dev_get(dev); 338 339 if (!in_dev) 340 return; 341 342 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 343 default: 344 case 0: /* By default announce any local IP */ 345 if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) 346 saddr = skb->nh.iph->saddr; 347 break; 348 case 1: /* Restrict announcements of saddr in same subnet */ 349 if (!skb) 350 break; 351 saddr = skb->nh.iph->saddr; 352 if (inet_addr_type(saddr) == RTN_LOCAL) { 353 /* saddr should be known to target */ 354 if (inet_addr_onlink(in_dev, target, saddr)) 355 break; 356 } 357 saddr = 0; 358 break; 359 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 360 break; 361 } 362 363 if (in_dev) 364 in_dev_put(in_dev); 365 if (!saddr) 366 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 367 368 if ((probes -= neigh->parms->ucast_probes) < 0) { 369 if (!(neigh->nud_state&NUD_VALID)) 370 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 371 dst_ha = neigh->ha; 372 read_lock_bh(&neigh->lock); 373 } else if ((probes -= neigh->parms->app_probes) < 0) { 374#ifdef CONFIG_ARPD 375 neigh_app_ns(neigh); 376#endif 377 return; 378 } 379 380 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 381 dst_ha, dev->dev_addr, NULL); 382 if (dst_ha) 383 read_unlock_bh(&neigh->lock); 384} 385 386static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 387 u32 sip, u32 tip) 388{ 389 int scope; 390 391 switch (IN_DEV_ARP_IGNORE(in_dev)) { 392 case 0: /* Reply, the tip is already validated */ 393 return 0; 394 case 1: /* Reply only if tip is configured on the incoming interface */ 395 sip = 0; 396 scope = RT_SCOPE_HOST; 397 break; 398 case 2: /* 399 * Reply only if tip is configured on the incoming interface 400 * and is in same subnet as sip 401 */ 402 scope = RT_SCOPE_HOST; 403 break; 404 case 3: /* Do not reply for scope host addresses */ 405 sip = 0; 406 scope = RT_SCOPE_LINK; 407 dev = NULL; 408 break; 409 case 4: /* Reserved */ 410 case 5: 411 case 6: 412 case 7: 413 return 0; 414 case 8: /* Do not reply */ 415 return 1; 416 default: 417 return 0; 418 } 419 return !inet_confirm_addr(dev, sip, tip, scope); 420} 421 422static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev) 423{ 424 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 425 .saddr = tip } } }; 426 struct rtable *rt; 427 int flag = 0; 428 /*unsigned long now; */ 429 430 if (ip_route_output_key(&rt, &fl) < 0) 431 return 1; 432 if (rt->u.dst.dev != dev) { 433 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 434 flag = 1; 435 } 436 ip_rt_put(rt); 437 return flag; 438} 439 440/* OBSOLETE FUNCTIONS */ 441 442/* 443 * Find an arp mapping in the cache. If not found, post a request. 444 * 445 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 446 * even if it exists. It is supposed that skb->dev was mangled 447 * by a virtual device (eql, shaper). Nobody but broken devices 448 * is allowed to use this function, it is scheduled to be removed. --ANK 449 */ 450 451static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev) 452{ 453 switch (addr_hint) { 454 case RTN_LOCAL: 455 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 456 memcpy(haddr, dev->dev_addr, dev->addr_len); 457 return 1; 458 case RTN_MULTICAST: 459 arp_mc_map(paddr, haddr, dev, 1); 460 return 1; 461 case RTN_BROADCAST: 462 memcpy(haddr, dev->broadcast, dev->addr_len); 463 return 1; 464 } 465 return 0; 466} 467 468 469int arp_find(unsigned char *haddr, struct sk_buff *skb) 470{ 471 struct net_device *dev = skb->dev; 472 u32 paddr; 473 struct neighbour *n; 474 475 if (!skb->dst) { 476 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 477 kfree_skb(skb); 478 return 1; 479 } 480 481 paddr = ((struct rtable*)skb->dst)->rt_gateway; 482 483 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) 484 return 0; 485 486 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 487 488 if (n) { 489 n->used = jiffies; 490 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 491 read_lock_bh(&n->lock); 492 memcpy(haddr, n->ha, dev->addr_len); 493 read_unlock_bh(&n->lock); 494 neigh_release(n); 495 return 0; 496 } 497 neigh_release(n); 498 } else 499 kfree_skb(skb); 500 return 1; 501} 502 503/* END OF OBSOLETE FUNCTIONS */ 504 505int arp_bind_neighbour(struct dst_entry *dst) 506{ 507 struct net_device *dev = dst->dev; 508 struct neighbour *n = dst->neighbour; 509 510 if (dev == NULL) 511 return -EINVAL; 512 if (n == NULL) { 513 u32 nexthop = ((struct rtable*)dst)->rt_gateway; 514 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 515 nexthop = 0; 516 n = __neigh_lookup_errno( 517#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 518 dev->type == ARPHRD_ATM ? clip_tbl_hook : 519#endif 520 &arp_tbl, &nexthop, dev); 521 if (IS_ERR(n)) 522 return PTR_ERR(n); 523 dst->neighbour = n; 524 } 525 return 0; 526} 527 528/* 529 * Check if we can use proxy ARP for this path 530 */ 531 532static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 533{ 534 struct in_device *out_dev; 535 int imi, omi = -1; 536 537 if (!IN_DEV_PROXY_ARP(in_dev)) 538 return 0; 539 540 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 541 return 1; 542 if (imi == -1) 543 return 0; 544 545 /* place to check for proxy_arp for routes */ 546 547 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 548 omi = IN_DEV_MEDIUM_ID(out_dev); 549 in_dev_put(out_dev); 550 } 551 return (omi != imi && omi != -1); 552} 553 554/* 555 * Interface to link layer: send routine and receive handler. 556 */ 557 558/* 559 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 560 * message. 561 */ 562struct sk_buff *arp_create(int type, int ptype, u32 dest_ip, 563 struct net_device *dev, u32 src_ip, 564 unsigned char *dest_hw, unsigned char *src_hw, 565 unsigned char *target_hw) 566{ 567 struct sk_buff *skb; 568 struct arphdr *arp; 569 unsigned char *arp_ptr; 570 571 /* 572 * Allocate a buffer 573 */ 574 575 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 576 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 577 if (skb == NULL) 578 return NULL; 579 580 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 581 skb->nh.raw = skb->data; 582 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 583 skb->dev = dev; 584 skb->protocol = htons(ETH_P_ARP); 585 if (src_hw == NULL) 586 src_hw = dev->dev_addr; 587 if (dest_hw == NULL) 588 dest_hw = dev->broadcast; 589 590 /* 591 * Fill the device header for the ARP frame 592 */ 593 if (dev->hard_header && 594 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0) 595 goto out; 596 597 /* 598 * Fill out the arp protocol part. 599 * 600 * The arp hardware type should match the device type, except for FDDI, 601 * which (according to RFC 1390) should always equal 1 (Ethernet). 602 */ 603 /* 604 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 605 * DIX code for the protocol. Make these device structure fields. 606 */ 607 switch (dev->type) { 608 default: 609 arp->ar_hrd = htons(dev->type); 610 arp->ar_pro = htons(ETH_P_IP); 611 break; 612 613#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 614 case ARPHRD_AX25: 615 arp->ar_hrd = htons(ARPHRD_AX25); 616 arp->ar_pro = htons(AX25_P_IP); 617 break; 618 619#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 620 case ARPHRD_NETROM: 621 arp->ar_hrd = htons(ARPHRD_NETROM); 622 arp->ar_pro = htons(AX25_P_IP); 623 break; 624#endif 625#endif 626 627#ifdef CONFIG_FDDI 628 case ARPHRD_FDDI: 629 arp->ar_hrd = htons(ARPHRD_ETHER); 630 arp->ar_pro = htons(ETH_P_IP); 631 break; 632#endif 633#ifdef CONFIG_TR 634 case ARPHRD_IEEE802_TR: 635 arp->ar_hrd = htons(ARPHRD_IEEE802); 636 arp->ar_pro = htons(ETH_P_IP); 637 break; 638#endif 639 } 640 641 arp->ar_hln = dev->addr_len; 642 arp->ar_pln = 4; 643 arp->ar_op = htons(type); 644 645 arp_ptr=(unsigned char *)(arp+1); 646 647 memcpy(arp_ptr, src_hw, dev->addr_len); 648 arp_ptr+=dev->addr_len; 649 memcpy(arp_ptr, &src_ip,4); 650 arp_ptr+=4; 651 if (target_hw != NULL) 652 memcpy(arp_ptr, target_hw, dev->addr_len); 653 else 654 memset(arp_ptr, 0, dev->addr_len); 655 arp_ptr+=dev->addr_len; 656 memcpy(arp_ptr, &dest_ip, 4); 657 658 return skb; 659 660out: 661 kfree_skb(skb); 662 return NULL; 663} 664 665/* 666 * Send an arp packet. 667 */ 668void arp_xmit(struct sk_buff *skb) 669{ 670 /* Send it off, maybe filter it using firewalling first. */ 671 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 672} 673 674/* 675 * Create and send an arp packet. 676 */ 677void arp_send(int type, int ptype, u32 dest_ip, 678 struct net_device *dev, u32 src_ip, 679 unsigned char *dest_hw, unsigned char *src_hw, 680 unsigned char *target_hw) 681{ 682 struct sk_buff *skb; 683 684 /* 685 * No arp on this interface. 686 */ 687 688 if (dev->flags&IFF_NOARP) 689 return; 690 691 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 692 dest_hw, src_hw, target_hw); 693 if (skb == NULL) { 694 return; 695 } 696 697 arp_xmit(skb); 698} 699 700static void parp_redo(struct sk_buff *skb) 701{ 702 nf_reset(skb); 703 arp_rcv(skb, skb->dev, NULL, skb->dev); 704} 705 706/* 707 * Process an arp request. 708 */ 709 710static int arp_process(struct sk_buff *skb) 711{ 712 struct net_device *dev = skb->dev; 713 struct in_device *in_dev = in_dev_get(dev); 714 struct arphdr *arp; 715 unsigned char *arp_ptr; 716 struct rtable *rt; 717 unsigned char *sha, *tha; 718 u32 sip, tip; 719 u16 dev_type = dev->type; 720 int addr_type; 721 struct neighbour *n; 722 723 /* arp_rcv below verifies the ARP header and verifies the device 724 * is ARP'able. 725 */ 726 727 if (in_dev == NULL) 728 goto out; 729 730 arp = skb->nh.arph; 731 732 switch (dev_type) { 733 default: 734 if (arp->ar_pro != htons(ETH_P_IP) || 735 htons(dev_type) != arp->ar_hrd) 736 goto out; 737 break; 738#ifdef CONFIG_NET_ETHERNET 739 case ARPHRD_ETHER: 740#endif 741#ifdef CONFIG_TR 742 case ARPHRD_IEEE802_TR: 743#endif 744#ifdef CONFIG_FDDI 745 case ARPHRD_FDDI: 746#endif 747#ifdef CONFIG_NET_FC 748 case ARPHRD_IEEE802: 749#endif 750#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \ 751 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC) 752 /* 753 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 754 * devices, according to RFC 2625) devices will accept ARP 755 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 756 * This is the case also of FDDI, where the RFC 1390 says that 757 * FDDI devices should accept ARP hardware of (1) Ethernet, 758 * however, to be more robust, we'll accept both 1 (Ethernet) 759 * or 6 (IEEE 802.2) 760 */ 761 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 762 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 763 arp->ar_pro != htons(ETH_P_IP)) 764 goto out; 765 break; 766#endif 767#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 768 case ARPHRD_AX25: 769 if (arp->ar_pro != htons(AX25_P_IP) || 770 arp->ar_hrd != htons(ARPHRD_AX25)) 771 goto out; 772 break; 773#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 774 case ARPHRD_NETROM: 775 if (arp->ar_pro != htons(AX25_P_IP) || 776 arp->ar_hrd != htons(ARPHRD_NETROM)) 777 goto out; 778 break; 779#endif 780#endif 781 } 782 783 /* Understand only these message types */ 784 785 if (arp->ar_op != htons(ARPOP_REPLY) && 786 arp->ar_op != htons(ARPOP_REQUEST)) 787 goto out; 788 789/* 790 * Extract fields 791 */ 792 arp_ptr= (unsigned char *)(arp+1); 793 sha = arp_ptr; 794 arp_ptr += dev->addr_len; 795 memcpy(&sip, arp_ptr, 4); 796 arp_ptr += 4; 797 tha = arp_ptr; 798 arp_ptr += dev->addr_len; 799 memcpy(&tip, arp_ptr, 4); 800/* 801 * Check for bad requests for 127.x.x.x and requests for multicast 802 * addresses. If this is one such, delete it. 803 */ 804 if (LOOPBACK(tip) || MULTICAST(tip)) 805 goto out; 806 807/* 808 * Special case: We must set Frame Relay source Q.922 address 809 */ 810 if (dev_type == ARPHRD_DLCI) 811 sha = dev->broadcast; 812 813/* 814 * Process entry. The idea here is we want to send a reply if it is a 815 * request for us or if it is a request for someone else that we hold 816 * a proxy for. We want to add an entry to our cache if it is a reply 817 * to us or if it is a request for our address. 818 * (The assumption for this last is that if someone is requesting our 819 * address, they are probably intending to talk to us, so it saves time 820 * if we cache their address. Their address is also probably not in 821 * our cache, since ours is not in their cache.) 822 * 823 * Putting this another way, we only care about replies if they are to 824 * us, in which case we add them to the cache. For requests, we care 825 * about those for us and those for our proxies. We reply to both, 826 * and in the case of requests for us we add the requester to the arp 827 * cache. 828 */ 829 830 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 831 if (sip == 0) { 832 if (arp->ar_op == htons(ARPOP_REQUEST) && 833 inet_addr_type(tip) == RTN_LOCAL && 834 !arp_ignore(in_dev,dev,sip,tip)) 835 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); 836 goto out; 837 } 838 839 if (arp->ar_op == htons(ARPOP_REQUEST) && 840 ip_route_input(skb, tip, sip, 0, dev) == 0) { 841 842 rt = (struct rtable*)skb->dst; 843 addr_type = rt->rt_type; 844 845 if (addr_type == RTN_LOCAL) { 846 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 847 if (n) { 848 int dont_send = 0; 849 850 if (!dont_send) 851 dont_send |= arp_ignore(in_dev,dev,sip,tip); 852 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 853 dont_send |= arp_filter(sip,tip,dev); 854 if (!dont_send) 855 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 856 857 neigh_release(n); 858 } 859 goto out; 860 } else if (IN_DEV_FORWARD(in_dev)) { 861 if ((rt->rt_flags&RTCF_DNAT) || 862 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 863 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { 864 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 865 if (n) 866 neigh_release(n); 867 868 if (skb->stamp.tv_sec == LOCALLY_ENQUEUED || 869 skb->pkt_type == PACKET_HOST || 870 in_dev->arp_parms->proxy_delay == 0) { 871 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 872 } else { 873 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 874 in_dev_put(in_dev); 875 return 0; 876 } 877 goto out; 878 } 879 } 880 } 881 882 /* Update our ARP tables */ 883 884 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 885 886#ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP 887 /* Unsolicited ARP is not accepted by default. 888 It is possible, that this option should be enabled for some 889 devices (strip is candidate) 890 */ 891 if (n == NULL && 892 arp->ar_op == htons(ARPOP_REPLY) && 893 inet_addr_type(sip) == RTN_UNICAST) 894 n = __neigh_lookup(&arp_tbl, &sip, dev, -1); 895#endif 896 897 if (n) { 898 int state = NUD_REACHABLE; 899 int override; 900 901 /* If several different ARP replies follows back-to-back, 902 use the FIRST one. It is possible, if several proxy 903 agents are active. Taking the first reply prevents 904 arp trashing and chooses the fastest router. 905 */ 906 override = time_after(jiffies, n->updated + n->parms->locktime); 907 908 /* Broadcast replies and request packets 909 do not assert neighbour reachability. 910 */ 911 if (arp->ar_op != htons(ARPOP_REPLY) || 912 skb->pkt_type != PACKET_HOST) 913 state = NUD_STALE; 914 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 915 neigh_release(n); 916 } 917 918out: 919 if (in_dev) 920 in_dev_put(in_dev); 921 kfree_skb(skb); 922 return 0; 923} 924 925 926/* 927 * Receive an arp request from the device layer. 928 */ 929 930int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 931{ 932 struct arphdr *arp; 933 934 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 935 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 936 (2 * dev->addr_len) + 937 (2 * sizeof(u32))))) 938 goto freeskb; 939 940 arp = skb->nh.arph; 941 if (arp->ar_hln != dev->addr_len || 942 dev->flags & IFF_NOARP || 943 skb->pkt_type == PACKET_OTHERHOST || 944 skb->pkt_type == PACKET_LOOPBACK || 945 arp->ar_pln != 4) 946 goto freeskb; 947 948 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 949 goto out_of_mem; 950 951 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 952 953freeskb: 954 kfree_skb(skb); 955out_of_mem: 956 return 0; 957} 958 959/* 960 * User level interface (ioctl) 961 */ 962 963/* 964 * Set (create) an ARP cache entry. 965 */ 966 967static int arp_req_set(struct arpreq *r, struct net_device * dev) 968{ 969 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 970 struct neighbour *neigh; 971 int err; 972 973 if (r->arp_flags&ATF_PUBL) { 974 u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; 975 if (mask && mask != 0xFFFFFFFF) 976 return -EINVAL; 977 if (!dev && (r->arp_flags & ATF_COM)) { 978 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data); 979 if (!dev) 980 return -ENODEV; 981 } 982 if (mask) { 983 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) 984 return -ENOBUFS; 985 return 0; 986 } 987 if (dev == NULL) { 988 ipv4_devconf.proxy_arp = 1; 989 return 0; 990 } 991 if (__in_dev_get(dev)) { 992 __in_dev_get(dev)->cnf.proxy_arp = 1; 993 return 0; 994 } 995 return -ENXIO; 996 } 997 998 if (r->arp_flags & ATF_PERM) 999 r->arp_flags |= ATF_COM; 1000 if (dev == NULL) { 1001 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1002 .tos = RTO_ONLINK } } }; 1003 struct rtable * rt; 1004 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1005 return err; 1006 dev = rt->u.dst.dev; 1007 ip_rt_put(rt); 1008 if (!dev) 1009 return -EINVAL; 1010 } 1011 switch (dev->type) { 1012#ifdef CONFIG_FDDI 1013 case ARPHRD_FDDI: 1014 /* 1015 * According to RFC 1390, FDDI devices should accept ARP 1016 * hardware types of 1 (Ethernet). However, to be more 1017 * robust, we'll accept hardware types of either 1 (Ethernet) 1018 * or 6 (IEEE 802.2). 1019 */ 1020 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1021 r->arp_ha.sa_family != ARPHRD_ETHER && 1022 r->arp_ha.sa_family != ARPHRD_IEEE802) 1023 return -EINVAL; 1024 break; 1025#endif 1026 default: 1027 if (r->arp_ha.sa_family != dev->type) 1028 return -EINVAL; 1029 break; 1030 } 1031 1032 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1033 err = PTR_ERR(neigh); 1034 if (!IS_ERR(neigh)) { 1035 unsigned state = NUD_STALE; 1036 if (r->arp_flags & ATF_PERM) 1037 state = NUD_PERMANENT; 1038 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1039 r->arp_ha.sa_data : NULL, state, 1040 NEIGH_UPDATE_F_OVERRIDE| 1041 NEIGH_UPDATE_F_ADMIN); 1042 neigh_release(neigh); 1043 } 1044 return err; 1045} 1046 1047static unsigned arp_state_to_flags(struct neighbour *neigh) 1048{ 1049 unsigned flags = 0; 1050 if (neigh->nud_state&NUD_PERMANENT) 1051 flags = ATF_PERM|ATF_COM; 1052 else if (neigh->nud_state&NUD_VALID) 1053 flags = ATF_COM; 1054 return flags; 1055} 1056 1057/* 1058 * Get an ARP cache entry. 1059 */ 1060 1061static int arp_req_get(struct arpreq *r, struct net_device *dev) 1062{ 1063 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1064 struct neighbour *neigh; 1065 int err = -ENXIO; 1066 1067 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1068 if (neigh) { 1069 read_lock_bh(&neigh->lock); 1070 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1071 r->arp_flags = arp_state_to_flags(neigh); 1072 read_unlock_bh(&neigh->lock); 1073 r->arp_ha.sa_family = dev->type; 1074 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1075 neigh_release(neigh); 1076 err = 0; 1077 } 1078 return err; 1079} 1080 1081static int arp_req_delete(struct arpreq *r, struct net_device * dev) 1082{ 1083 int err; 1084 u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1085 struct neighbour *neigh; 1086 1087 if (r->arp_flags & ATF_PUBL) { 1088 u32 mask = 1089 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1090 if (mask == 0xFFFFFFFF) 1091 return pneigh_delete(&arp_tbl, &ip, dev); 1092 if (mask == 0) { 1093 if (dev == NULL) { 1094 ipv4_devconf.proxy_arp = 0; 1095 return 0; 1096 } 1097 if (__in_dev_get(dev)) { 1098 __in_dev_get(dev)->cnf.proxy_arp = 0; 1099 return 0; 1100 } 1101 return -ENXIO; 1102 } 1103 return -EINVAL; 1104 } 1105 1106 if (dev == NULL) { 1107 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1108 .tos = RTO_ONLINK } } }; 1109 struct rtable * rt; 1110 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1111 return err; 1112 dev = rt->u.dst.dev; 1113 ip_rt_put(rt); 1114 if (!dev) 1115 return -EINVAL; 1116 } 1117 err = -ENXIO; 1118 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1119 if (neigh) { 1120 if (neigh->nud_state&~NUD_NOARP) 1121 err = neigh_update(neigh, NULL, NUD_FAILED, 1122 NEIGH_UPDATE_F_OVERRIDE| 1123 NEIGH_UPDATE_F_ADMIN); 1124 neigh_release(neigh); 1125 } 1126 return err; 1127} 1128 1129/* 1130 * Handle an ARP layer I/O control request. 1131 */ 1132 1133int arp_ioctl(unsigned int cmd, void __user *arg) 1134{ 1135 int err; 1136 struct arpreq r; 1137 struct net_device *dev = NULL; 1138 1139 switch (cmd) { 1140 case SIOCDARP: 1141 case SIOCSARP: 1142 if (!capable(CAP_NET_ADMIN)) 1143 return -EPERM; 1144 case SIOCGARP: 1145 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1146 if (err) 1147 return -EFAULT; 1148 break; 1149 default: 1150 return -EINVAL; 1151 } 1152 1153 if (r.arp_pa.sa_family != AF_INET) 1154 return -EPFNOSUPPORT; 1155 1156 if (!(r.arp_flags & ATF_PUBL) && 1157 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1158 return -EINVAL; 1159 if (!(r.arp_flags & ATF_NETMASK)) 1160 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1161 htonl(0xFFFFFFFFUL); 1162 rtnl_lock(); 1163 if (r.arp_dev[0]) { 1164 err = -ENODEV; 1165 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL) 1166 goto out; 1167 1168 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1169 if (!r.arp_ha.sa_family) 1170 r.arp_ha.sa_family = dev->type; 1171 err = -EINVAL; 1172 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1173 goto out; 1174 } else if (cmd == SIOCGARP) { 1175 err = -ENODEV; 1176 goto out; 1177 } 1178 1179 switch(cmd) { 1180 case SIOCDARP: 1181 err = arp_req_delete(&r, dev); 1182 break; 1183 case SIOCSARP: 1184 err = arp_req_set(&r, dev); 1185 break; 1186 case SIOCGARP: 1187 err = arp_req_get(&r, dev); 1188 if (!err && copy_to_user(arg, &r, sizeof(r))) 1189 err = -EFAULT; 1190 break; 1191 } 1192out: 1193 rtnl_unlock(); 1194 return err; 1195} 1196 1197static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1198{ 1199 struct net_device *dev = ptr; 1200 1201 switch (event) { 1202 case NETDEV_CHANGEADDR: 1203 neigh_changeaddr(&arp_tbl, dev); 1204 rt_cache_flush(0); 1205 break; 1206 default: 1207 break; 1208 } 1209 1210 return NOTIFY_DONE; 1211} 1212 1213static struct notifier_block arp_netdev_notifier = { 1214 .notifier_call = arp_netdev_event, 1215}; 1216 1217/* Note, that it is not on notifier chain. 1218 It is necessary, that this routine was called after route cache will be 1219 flushed. 1220 */ 1221void arp_ifdown(struct net_device *dev) 1222{ 1223 neigh_ifdown(&arp_tbl, dev); 1224} 1225 1226 1227/* 1228 * Called once on startup. 1229 */ 1230 1231static struct packet_type arp_packet_type = { 1232 .type = __constant_htons(ETH_P_ARP), 1233 .func = arp_rcv, 1234}; 1235 1236static int arp_proc_init(void); 1237 1238void __init arp_init(void) 1239{ 1240 neigh_table_init(&arp_tbl); 1241 1242 dev_add_pack(&arp_packet_type); 1243 arp_proc_init(); 1244#ifdef CONFIG_SYSCTL 1245 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1246 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1247#endif 1248 register_netdevice_notifier(&arp_netdev_notifier); 1249} 1250 1251#ifdef CONFIG_PROC_FS 1252#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1253 1254/* ------------------------------------------------------------------------ */ 1255/* 1256 * ax25 -> ASCII conversion 1257 */ 1258static char *ax2asc2(ax25_address *a, char *buf) 1259{ 1260 char c, *s; 1261 int n; 1262 1263 for (n = 0, s = buf; n < 6; n++) { 1264 c = (a->ax25_call[n] >> 1) & 0x7F; 1265 1266 if (c != ' ') *s++ = c; 1267 } 1268 1269 *s++ = '-'; 1270 1271 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1272 *s++ = '1'; 1273 n -= 10; 1274 } 1275 1276 *s++ = n + '0'; 1277 *s++ = '\0'; 1278 1279 if (*buf == '\0' || *buf == '-') 1280 return "*"; 1281 1282 return buf; 1283 1284} 1285#endif /* CONFIG_AX25 */ 1286 1287#define HBUFFERLEN 30 1288 1289static void arp_format_neigh_entry(struct seq_file *seq, 1290 struct neighbour *n) 1291{ 1292 char hbuffer[HBUFFERLEN]; 1293 const char hexbuf[] = "0123456789ABCDEF"; 1294 int k, j; 1295 char tbuf[16]; 1296 struct net_device *dev = n->dev; 1297 int hatype = dev->type; 1298 1299 read_lock(&n->lock); 1300 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1301#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1302 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1303 ax2asc2((ax25_address *)n->ha, hbuffer); 1304 else { 1305#endif 1306 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1307 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1308 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1309 hbuffer[k++] = ':'; 1310 } 1311 hbuffer[--k] = 0; 1312#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1313 } 1314#endif 1315 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1316 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1317 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1318 read_unlock(&n->lock); 1319} 1320 1321static void arp_format_pneigh_entry(struct seq_file *seq, 1322 struct pneigh_entry *n) 1323{ 1324 struct net_device *dev = n->dev; 1325 int hatype = dev ? dev->type : 0; 1326 char tbuf[16]; 1327 1328 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1329 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1330 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1331 dev ? dev->name : "*"); 1332} 1333 1334static int arp_seq_show(struct seq_file *seq, void *v) 1335{ 1336 if (v == SEQ_START_TOKEN) { 1337 seq_puts(seq, "IP address HW type Flags " 1338 "HW address Mask Device\n"); 1339 } else { 1340 struct neigh_seq_state *state = seq->private; 1341 1342 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1343 arp_format_pneigh_entry(seq, v); 1344 else 1345 arp_format_neigh_entry(seq, v); 1346 } 1347 1348 return 0; 1349} 1350 1351static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1352{ 1353 /* Don't want to confuse "arp -a" w/ magic entries, 1354 * so we tell the generic iterator to skip NUD_NOARP. 1355 */ 1356 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1357} 1358 1359/* ------------------------------------------------------------------------ */ 1360 1361static struct seq_operations arp_seq_ops = { 1362 .start = arp_seq_start, 1363 .next = neigh_seq_next, 1364 .stop = neigh_seq_stop, 1365 .show = arp_seq_show, 1366}; 1367 1368static int arp_seq_open(struct inode *inode, struct file *file) 1369{ 1370 struct seq_file *seq; 1371 int rc = -ENOMEM; 1372 struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL); 1373 1374 if (!s) 1375 goto out; 1376 1377 memset(s, 0, sizeof(*s)); 1378 rc = seq_open(file, &arp_seq_ops); 1379 if (rc) 1380 goto out_kfree; 1381 1382 seq = file->private_data; 1383 seq->private = s; 1384out: 1385 return rc; 1386out_kfree: 1387 kfree(s); 1388 goto out; 1389} 1390 1391static struct file_operations arp_seq_fops = { 1392 .owner = THIS_MODULE, 1393 .open = arp_seq_open, 1394 .read = seq_read, 1395 .llseek = seq_lseek, 1396 .release = seq_release_private, 1397}; 1398 1399static int __init arp_proc_init(void) 1400{ 1401 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops)) 1402 return -ENOMEM; 1403 return 0; 1404} 1405 1406#else /* CONFIG_PROC_FS */ 1407 1408static int __init arp_proc_init(void) 1409{ 1410 return 0; 1411} 1412 1413#endif /* CONFIG_PROC_FS */ 1414 1415EXPORT_SYMBOL(arp_broken_ops); 1416EXPORT_SYMBOL(arp_find); 1417EXPORT_SYMBOL(arp_rcv); 1418EXPORT_SYMBOL(arp_create); 1419EXPORT_SYMBOL(arp_xmit); 1420EXPORT_SYMBOL(arp_send); 1421EXPORT_SYMBOL(arp_tbl); 1422 1423#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1424EXPORT_SYMBOL(clip_tbl_hook); 1425#endif 1426