1 /* linux/net/ipv4/arp.c 2 * 3 * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $ 4 * 5 * Copyright (C) 1994 by Florian La Roche 6 * 7 * This module implements the Address Resolution Protocol ARP (RFC 826), 8 * which is used to convert IP addresses (or in the future maybe other 9 * high-level addresses) into a low-level hardware address (like an Ethernet 10 * address). 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Fixes: 18 * Alan Cox : Removed the Ethernet assumptions in 19 * Florian's code 20 * Alan Cox : Fixed some small errors in the ARP 21 * logic 22 * Alan Cox : Allow >4K in /proc 23 * Alan Cox : Make ARP add its own protocol entry 24 * Ross Martin : Rewrote arp_rcv() and arp_get_info() 25 * Stephen Henson : Add AX25 support to arp_get_info() 26 * Alan Cox : Drop data when a device is downed. 27 * Alan Cox : Use init_timer(). 28 * Alan Cox : Double lock fixes. 29 * Martin Seine : Move the arphdr structure 30 * to if_arp.h for compatibility. 31 * with BSD based programs. 32 * Andrew Tridgell : Added ARP netmask code and 33 * re-arranged proxy handling. 34 * Alan Cox : Changed to use notifiers. 35 * Niibe Yutaka : Reply for this device or proxies only. 36 * Alan Cox : Don't proxy across hardware types! 37 * Jonathan Naylor : Added support for NET/ROM. 38 * Mike Shaver : RFC1122 checks. 39 * Jonathan Naylor : Only lookup the hardware address for 40 * the correct hardware type. 41 * Germano Caronni : Assorted subtle races. 42 * Craig Schlenter : Don't modify permanent entry 43 * during arp_rcv. 44 * Russ Nelson : Tidied up a few bits. 45 * Alexey Kuznetsov: Major changes to caching and behaviour, 46 * eg intelligent arp probing and 47 * generation 48 * of host down events. 49 * Alan Cox : Missing unlock in device events. 50 * Eckes : ARP ioctl control errors. 51 * Alexey Kuznetsov: Arp free fix. 52 * Manuel Rodriguez: Gratuitous ARP. 53 * Jonathan Layes : Added arpd support through kerneld 54 * message queue (960314) 55 * Mike Shaver : /proc/sys/net/ipv4/arp_* support 56 * Mike McLagan : Routing by source 57 * Stuart Cheshire : Metricom and grat arp fixes 58 * *** FOR 2.1 clean this up *** 59 * Lawrence V. Stefani: (08/12/96) Added FDDI support. 60 * Alan Cox : Took the AP1000 nasty FDDI hack and 61 * folded into the mainstream FDDI code. 62 * Ack spit, Linus how did you allow that 63 * one in... 64 * Jes Sorensen : Make FDDI work again in 2.1.x and 65 * clean up the APFDDI & gen. FDDI bits. 66 * Alexey Kuznetsov: new arp state machine; 67 * now it is in net/core/neighbour.c. 68 * Krzysztof Halasa: Added Frame Relay ARP support. 69 * Arnaldo C. Melo : convert /proc/net/arp to seq_file 70 * Shmulik Hen: Split arp_send to arp_create and 71 * arp_xmit so intermediate drivers like 72 * bonding can change the skb before 73 * sending (e.g. insert 8021q tag). 74 * Harald Welte : convert to make use of jenkins hash 75 */ 76 77 #include <linux/module.h> 78 #include <linux/types.h> 79 #include <linux/string.h> 80 #include <linux/kernel.h> 81 #include <linux/capability.h> 82 #include <linux/socket.h> 83 #include <linux/sockios.h> 84 #include <linux/errno.h> 85 #include <linux/in.h> 86 #include <linux/mm.h> 87 #include <linux/inet.h> 88 #include <linux/inetdevice.h> 89 #include <linux/netdevice.h> 90 #include <linux/etherdevice.h> 91 #include <linux/fddidevice.h> 92 #include <linux/if_arp.h> 93 #include <linux/trdevice.h> 94 #include <linux/skbuff.h> 95 #include <linux/proc_fs.h> 96 #include <linux/seq_file.h> 97 #include <linux/stat.h> 98 #include <linux/init.h> 99 #include <linux/net.h> 100 #include <linux/rcupdate.h> 101 #include <linux/jhash.h> 102 #ifdef CONFIG_SYSCTL 103 #include <linux/sysctl.h> 104 #endif 105 106 #include <net/net_namespace.h> 107 #include <net/ip.h> 108 #include <net/icmp.h> 109 #include <net/route.h> 110 #include <net/protocol.h> 111 #include <net/tcp.h> 112 #include <net/sock.h> 113 #include <net/arp.h> 114 #include <net/ax25.h> 115 #include <net/netrom.h> 116 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 117 #include <net/atmclip.h> 118 struct neigh_table *clip_tbl_hook; 119 #endif 120 121 #include <asm/system.h> 122 #include <asm/uaccess.h> 123 124 #include <linux/netfilter_arp.h> 125 126 /* 127 * Interface to generic neighbour cache. 128 */ 129 static u32 arp_hash(const void *pkey, const struct net_device *dev); 130 static int arp_constructor(struct neighbour *neigh); 131 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 132 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 133 static void parp_redo(struct sk_buff *skb); 134 135 static struct neigh_ops arp_generic_ops = { 136 .family = AF_INET, 137 .solicit = arp_solicit, 138 .error_report = arp_error_report, 139 .output = neigh_resolve_output, 140 .connected_output = neigh_connected_output, 141 .hh_output = dev_queue_xmit, 142 .queue_xmit = dev_queue_xmit, 143 }; 144 145 static struct neigh_ops arp_hh_ops = { 146 .family = AF_INET, 147 .solicit = arp_solicit, 148 .error_report = arp_error_report, 149 .output = neigh_resolve_output, 150 .connected_output = neigh_resolve_output, 151 .hh_output = dev_queue_xmit, 152 .queue_xmit = dev_queue_xmit, 153 }; 154 155 static struct neigh_ops arp_direct_ops = { 156 .family = AF_INET, 157 .output = dev_queue_xmit, 158 .connected_output = dev_queue_xmit, 159 .hh_output = dev_queue_xmit, 160 .queue_xmit = dev_queue_xmit, 161 }; 162 163 struct neigh_ops arp_broken_ops = { 164 .family = AF_INET, 165 .solicit = arp_solicit, 166 .error_report = arp_error_report, 167 .output = neigh_compat_output, 168 .connected_output = neigh_compat_output, 169 .hh_output = dev_queue_xmit, 170 .queue_xmit = dev_queue_xmit, 171 }; 172 173 struct neigh_table arp_tbl = { 174 .family = AF_INET, 175 .entry_size = sizeof(struct neighbour) + 4, 176 .key_len = 4, 177 .hash = arp_hash, 178 .constructor = arp_constructor, 179 .proxy_redo = parp_redo, 180 .id = "arp_cache", 181 .parms = { 182 .tbl = &arp_tbl, 183 .base_reachable_time = 30 * HZ, 184 .retrans_time = 1 * HZ, 185 .gc_staletime = 60 * HZ, 186 .reachable_time = 30 * HZ, 187 .delay_probe_time = 5 * HZ, 188 .queue_len = 3, 189 .ucast_probes = 3, 190 .mcast_probes = 3, 191 .anycast_delay = 1 * HZ, 192 .proxy_delay = (8 * HZ) / 10, 193 .proxy_qlen = 64, 194 .locktime = 1 * HZ, 195 }, 196 .gc_interval = 30 * HZ, 197 .gc_thresh1 = 128, 198 .gc_thresh2 = 512, 199 .gc_thresh3 = 1024, 200 }; 201 202 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) 203 { 204 switch (dev->type) { 205 case ARPHRD_ETHER: 206 case ARPHRD_FDDI: 207 case ARPHRD_IEEE802: 208 ip_eth_mc_map(addr, haddr); 209 return 0; 210 case ARPHRD_IEEE802_TR: 211 ip_tr_mc_map(addr, haddr); 212 return 0; 213 case ARPHRD_INFINIBAND: 214 ip_ib_mc_map(addr, dev->broadcast, haddr); 215 return 0; 216 default: 217 if (dir) { 218 memcpy(haddr, dev->broadcast, dev->addr_len); 219 return 0; 220 } 221 } 222 return -EINVAL; 223 } 224 225 226 static u32 arp_hash(const void *pkey, const struct net_device *dev) 227 { 228 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 229 } 230 231 static int arp_constructor(struct neighbour *neigh) 232 { 233 __be32 addr = *(__be32*)neigh->primary_key; 234 struct net_device *dev = neigh->dev; 235 struct in_device *in_dev; 236 struct neigh_parms *parms; 237 238 rcu_read_lock(); 239 in_dev = __in_dev_get_rcu(dev); 240 if (in_dev == NULL) { 241 rcu_read_unlock(); 242 return -EINVAL; 243 } 244 245 neigh->type = inet_addr_type(dev_net(dev), addr); 246 247 parms = in_dev->arp_parms; 248 __neigh_parms_put(neigh->parms); 249 neigh->parms = neigh_parms_clone(parms); 250 rcu_read_unlock(); 251 252 if (!dev->header_ops) { 253 neigh->nud_state = NUD_NOARP; 254 neigh->ops = &arp_direct_ops; 255 neigh->output = neigh->ops->queue_xmit; 256 } else { 257 /* Good devices (checked by reading texts, but only Ethernet is 258 tested) 259 260 ARPHRD_ETHER: (ethernet, apfddi) 261 ARPHRD_FDDI: (fddi) 262 ARPHRD_IEEE802: (tr) 263 ARPHRD_METRICOM: (strip) 264 ARPHRD_ARCNET: 265 etc. etc. etc. 266 267 ARPHRD_IPDDP will also work, if author repairs it. 268 I did not it, because this driver does not work even 269 in old paradigm. 270 */ 271 272 #if 1 273 /* So... these "amateur" devices are hopeless. 274 The only thing, that I can say now: 275 It is very sad that we need to keep ugly obsolete 276 code to make them happy. 277 278 They should be moved to more reasonable state, now 279 they use rebuild_header INSTEAD OF hard_start_xmit!!! 280 Besides that, they are sort of out of date 281 (a lot of redundant clones/copies, useless in 2.1), 282 I wonder why people believe that they work. 283 */ 284 switch (dev->type) { 285 default: 286 break; 287 case ARPHRD_ROSE: 288 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 289 case ARPHRD_AX25: 290 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 291 case ARPHRD_NETROM: 292 #endif 293 neigh->ops = &arp_broken_ops; 294 neigh->output = neigh->ops->output; 295 return 0; 296 #endif 297 ;} 298 #endif 299 if (neigh->type == RTN_MULTICAST) { 300 neigh->nud_state = NUD_NOARP; 301 arp_mc_map(addr, neigh->ha, dev, 1); 302 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 303 neigh->nud_state = NUD_NOARP; 304 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 305 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 306 neigh->nud_state = NUD_NOARP; 307 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 308 } 309 310 if (dev->header_ops->cache) 311 neigh->ops = &arp_hh_ops; 312 else 313 neigh->ops = &arp_generic_ops; 314 315 if (neigh->nud_state&NUD_VALID) 316 neigh->output = neigh->ops->connected_output; 317 else 318 neigh->output = neigh->ops->output; 319 } 320 return 0; 321 } 322 323 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 324 { 325 dst_link_failure(skb); 326 kfree_skb(skb); 327 } 328 329 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 330 { 331 __be32 saddr = 0; 332 u8 *dst_ha = NULL; 333 struct net_device *dev = neigh->dev; 334 __be32 target = *(__be32*)neigh->primary_key; 335 int probes = atomic_read(&neigh->probes); 336 struct in_device *in_dev = in_dev_get(dev); 337 338 if (!in_dev) 339 return; 340 341 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 342 default: 343 case 0: /* By default announce any local IP */ 344 if (skb && inet_addr_type(dev_net(dev), ip_hdr(skb)->saddr) == RTN_LOCAL) 345 saddr = ip_hdr(skb)->saddr; 346 break; 347 case 1: /* Restrict announcements of saddr in same subnet */ 348 if (!skb) 349 break; 350 saddr = ip_hdr(skb)->saddr; 351 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { 352 /* saddr should be known to target */ 353 if (inet_addr_onlink(in_dev, target, saddr)) 354 break; 355 } 356 saddr = 0; 357 break; 358 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 359 break; 360 } 361 362 if (in_dev) 363 in_dev_put(in_dev); 364 if (!saddr) 365 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 366 367 if ((probes -= neigh->parms->ucast_probes) < 0) { 368 if (!(neigh->nud_state&NUD_VALID)) 369 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 370 dst_ha = neigh->ha; 371 read_lock_bh(&neigh->lock); 372 } else if ((probes -= neigh->parms->app_probes) < 0) { 373 #ifdef CONFIG_ARPD 374 neigh_app_ns(neigh); 375 #endif 376 return; 377 } 378 379 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 380 dst_ha, dev->dev_addr, NULL); 381 if (dst_ha) 382 read_unlock_bh(&neigh->lock); 383 } 384 385 static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) 386 { 387 int scope; 388 389 switch (IN_DEV_ARP_IGNORE(in_dev)) { 390 case 0: /* Reply, the tip is already validated */ 391 return 0; 392 case 1: /* Reply only if tip is configured on the incoming interface */ 393 sip = 0; 394 scope = RT_SCOPE_HOST; 395 break; 396 case 2: /* 397 * Reply only if tip is configured on the incoming interface 398 * and is in same subnet as sip 399 */ 400 scope = RT_SCOPE_HOST; 401 break; 402 case 3: /* Do not reply for scope host addresses */ 403 sip = 0; 404 scope = RT_SCOPE_LINK; 405 break; 406 case 4: /* Reserved */ 407 case 5: 408 case 6: 409 case 7: 410 return 0; 411 case 8: /* Do not reply */ 412 return 1; 413 default: 414 return 0; 415 } 416 return !inet_confirm_addr(in_dev, sip, tip, scope); 417 } 418 419 static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 420 { 421 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 422 .saddr = tip } } }; 423 struct rtable *rt; 424 int flag = 0; 425 /*unsigned long now; */ 426 427 if (ip_route_output_key(dev_net(dev), &rt, &fl) < 0) 428 return 1; 429 if (rt->u.dst.dev != dev) { 430 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 431 flag = 1; 432 } 433 ip_rt_put(rt); 434 return flag; 435 } 436 437 /* OBSOLETE FUNCTIONS */ 438 439 /* 440 * Find an arp mapping in the cache. If not found, post a request. 441 * 442 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 443 * even if it exists. It is supposed that skb->dev was mangled 444 * by a virtual device (eql, shaper). Nobody but broken devices 445 * is allowed to use this function, it is scheduled to be removed. --ANK 446 */ 447 448 static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 449 { 450 switch (addr_hint) { 451 case RTN_LOCAL: 452 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 453 memcpy(haddr, dev->dev_addr, dev->addr_len); 454 return 1; 455 case RTN_MULTICAST: 456 arp_mc_map(paddr, haddr, dev, 1); 457 return 1; 458 case RTN_BROADCAST: 459 memcpy(haddr, dev->broadcast, dev->addr_len); 460 return 1; 461 } 462 return 0; 463 } 464 465 466 int arp_find(unsigned char *haddr, struct sk_buff *skb) 467 { 468 struct net_device *dev = skb->dev; 469 __be32 paddr; 470 struct neighbour *n; 471 472 if (!skb->dst) { 473 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 474 kfree_skb(skb); 475 return 1; 476 } 477 478 paddr = skb->rtable->rt_gateway; 479 480 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, paddr, dev)) 481 return 0; 482 483 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 484 485 if (n) { 486 n->used = jiffies; 487 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 488 read_lock_bh(&n->lock); 489 memcpy(haddr, n->ha, dev->addr_len); 490 read_unlock_bh(&n->lock); 491 neigh_release(n); 492 return 0; 493 } 494 neigh_release(n); 495 } else 496 kfree_skb(skb); 497 return 1; 498 } 499 500 /* END OF OBSOLETE FUNCTIONS */ 501 502 int arp_bind_neighbour(struct dst_entry *dst) 503 { 504 struct net_device *dev = dst->dev; 505 struct neighbour *n = dst->neighbour; 506 507 if (dev == NULL) 508 return -EINVAL; 509 if (n == NULL) { 510 __be32 nexthop = ((struct rtable*)dst)->rt_gateway; 511 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 512 nexthop = 0; 513 n = __neigh_lookup_errno( 514 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 515 dev->type == ARPHRD_ATM ? clip_tbl_hook : 516 #endif 517 &arp_tbl, &nexthop, dev); 518 if (IS_ERR(n)) 519 return PTR_ERR(n); 520 dst->neighbour = n; 521 } 522 return 0; 523 } 524 525 /* 526 * Check if we can use proxy ARP for this path 527 */ 528 529 static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 530 { 531 struct in_device *out_dev; 532 int imi, omi = -1; 533 534 if (!IN_DEV_PROXY_ARP(in_dev)) 535 return 0; 536 537 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 538 return 1; 539 if (imi == -1) 540 return 0; 541 542 /* place to check for proxy_arp for routes */ 543 544 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 545 omi = IN_DEV_MEDIUM_ID(out_dev); 546 in_dev_put(out_dev); 547 } 548 return (omi != imi && omi != -1); 549 } 550 551 /* 552 * Interface to link layer: send routine and receive handler. 553 */ 554 555 /* 556 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 557 * message. 558 */ 559 struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 560 struct net_device *dev, __be32 src_ip, 561 const unsigned char *dest_hw, 562 const unsigned char *src_hw, 563 const unsigned char *target_hw) 564 { 565 struct sk_buff *skb; 566 struct arphdr *arp; 567 unsigned char *arp_ptr; 568 569 /* 570 * Allocate a buffer 571 */ 572 573 skb = alloc_skb(arp_hdr_len(dev) + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 574 if (skb == NULL) 575 return NULL; 576 577 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 578 skb_reset_network_header(skb); 579 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); 580 skb->dev = dev; 581 skb->protocol = htons(ETH_P_ARP); 582 if (src_hw == NULL) 583 src_hw = dev->dev_addr; 584 if (dest_hw == NULL) 585 dest_hw = dev->broadcast; 586 587 /* 588 * Fill the device header for the ARP frame 589 */ 590 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 591 goto out; 592 593 /* 594 * Fill out the arp protocol part. 595 * 596 * The arp hardware type should match the device type, except for FDDI, 597 * which (according to RFC 1390) should always equal 1 (Ethernet). 598 */ 599 /* 600 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 601 * DIX code for the protocol. Make these device structure fields. 602 */ 603 switch (dev->type) { 604 default: 605 arp->ar_hrd = htons(dev->type); 606 arp->ar_pro = htons(ETH_P_IP); 607 break; 608 609 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 610 case ARPHRD_AX25: 611 arp->ar_hrd = htons(ARPHRD_AX25); 612 arp->ar_pro = htons(AX25_P_IP); 613 break; 614 615 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 616 case ARPHRD_NETROM: 617 arp->ar_hrd = htons(ARPHRD_NETROM); 618 arp->ar_pro = htons(AX25_P_IP); 619 break; 620 #endif 621 #endif 622 623 #ifdef CONFIG_FDDI 624 case ARPHRD_FDDI: 625 arp->ar_hrd = htons(ARPHRD_ETHER); 626 arp->ar_pro = htons(ETH_P_IP); 627 break; 628 #endif 629 #ifdef CONFIG_TR 630 case ARPHRD_IEEE802_TR: 631 arp->ar_hrd = htons(ARPHRD_IEEE802); 632 arp->ar_pro = htons(ETH_P_IP); 633 break; 634 #endif 635 } 636 637 arp->ar_hln = dev->addr_len; 638 arp->ar_pln = 4; 639 arp->ar_op = htons(type); 640 641 arp_ptr=(unsigned char *)(arp+1); 642 643 memcpy(arp_ptr, src_hw, dev->addr_len); 644 arp_ptr+=dev->addr_len; 645 memcpy(arp_ptr, &src_ip,4); 646 arp_ptr+=4; 647 if (target_hw != NULL) 648 memcpy(arp_ptr, target_hw, dev->addr_len); 649 else 650 memset(arp_ptr, 0, dev->addr_len); 651 arp_ptr+=dev->addr_len; 652 memcpy(arp_ptr, &dest_ip, 4); 653 654 return skb; 655 656 out: 657 kfree_skb(skb); 658 return NULL; 659 } 660 661 /* 662 * Send an arp packet. 663 */ 664 void arp_xmit(struct sk_buff *skb) 665 { 666 /* Send it off, maybe filter it using firewalling first. */ 667 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 668 } 669 670 /* 671 * Create and send an arp packet. 672 */ 673 void arp_send(int type, int ptype, __be32 dest_ip, 674 struct net_device *dev, __be32 src_ip, 675 const unsigned char *dest_hw, const unsigned char *src_hw, 676 const unsigned char *target_hw) 677 { 678 struct sk_buff *skb; 679 680 /* 681 * No arp on this interface. 682 */ 683 684 if (dev->flags&IFF_NOARP) 685 return; 686 687 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 688 dest_hw, src_hw, target_hw); 689 if (skb == NULL) { 690 return; 691 } 692 693 arp_xmit(skb); 694 } 695 696 /* 697 * Process an arp request. 698 */ 699 700 static int arp_process(struct sk_buff *skb) 701 { 702 struct net_device *dev = skb->dev; 703 struct in_device *in_dev = in_dev_get(dev); 704 struct arphdr *arp; 705 unsigned char *arp_ptr; 706 struct rtable *rt; 707 unsigned char *sha; 708 __be32 sip, tip; 709 u16 dev_type = dev->type; 710 int addr_type; 711 struct neighbour *n; 712 struct net *net = dev_net(dev); 713 714 /* arp_rcv below verifies the ARP header and verifies the device 715 * is ARP'able. 716 */ 717 718 if (in_dev == NULL) 719 goto out; 720 721 arp = arp_hdr(skb); 722 723 switch (dev_type) { 724 default: 725 if (arp->ar_pro != htons(ETH_P_IP) || 726 htons(dev_type) != arp->ar_hrd) 727 goto out; 728 break; 729 case ARPHRD_ETHER: 730 case ARPHRD_IEEE802_TR: 731 case ARPHRD_FDDI: 732 case ARPHRD_IEEE802: 733 /* 734 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 735 * devices, according to RFC 2625) devices will accept ARP 736 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 737 * This is the case also of FDDI, where the RFC 1390 says that 738 * FDDI devices should accept ARP hardware of (1) Ethernet, 739 * however, to be more robust, we'll accept both 1 (Ethernet) 740 * or 6 (IEEE 802.2) 741 */ 742 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 743 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 744 arp->ar_pro != htons(ETH_P_IP)) 745 goto out; 746 break; 747 case ARPHRD_AX25: 748 if (arp->ar_pro != htons(AX25_P_IP) || 749 arp->ar_hrd != htons(ARPHRD_AX25)) 750 goto out; 751 break; 752 case ARPHRD_NETROM: 753 if (arp->ar_pro != htons(AX25_P_IP) || 754 arp->ar_hrd != htons(ARPHRD_NETROM)) 755 goto out; 756 break; 757 } 758 759 /* Understand only these message types */ 760 761 if (arp->ar_op != htons(ARPOP_REPLY) && 762 arp->ar_op != htons(ARPOP_REQUEST)) 763 goto out; 764 765 /* 766 * Extract fields 767 */ 768 arp_ptr= (unsigned char *)(arp+1); 769 sha = arp_ptr; 770 arp_ptr += dev->addr_len; 771 memcpy(&sip, arp_ptr, 4); 772 arp_ptr += 4; 773 arp_ptr += dev->addr_len; 774 memcpy(&tip, arp_ptr, 4); 775 /* 776 * Check for bad requests for 127.x.x.x and requests for multicast 777 * addresses. If this is one such, delete it. 778 */ 779 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 780 goto out; 781 782 /* 783 * Special case: We must set Frame Relay source Q.922 address 784 */ 785 if (dev_type == ARPHRD_DLCI) 786 sha = dev->broadcast; 787 788 /* 789 * Process entry. The idea here is we want to send a reply if it is a 790 * request for us or if it is a request for someone else that we hold 791 * a proxy for. We want to add an entry to our cache if it is a reply 792 * to us or if it is a request for our address. 793 * (The assumption for this last is that if someone is requesting our 794 * address, they are probably intending to talk to us, so it saves time 795 * if we cache their address. Their address is also probably not in 796 * our cache, since ours is not in their cache.) 797 * 798 * Putting this another way, we only care about replies if they are to 799 * us, in which case we add them to the cache. For requests, we care 800 * about those for us and those for our proxies. We reply to both, 801 * and in the case of requests for us we add the requester to the arp 802 * cache. 803 */ 804 805 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 806 if (sip == 0) { 807 if (arp->ar_op == htons(ARPOP_REQUEST) && 808 inet_addr_type(net, tip) == RTN_LOCAL && 809 !arp_ignore(in_dev, sip, tip)) 810 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 811 dev->dev_addr, sha); 812 goto out; 813 } 814 815 if (arp->ar_op == htons(ARPOP_REQUEST) && 816 ip_route_input(skb, tip, sip, 0, dev) == 0) { 817 818 rt = skb->rtable; 819 addr_type = rt->rt_type; 820 821 if (addr_type == RTN_LOCAL) { 822 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 823 if (n) { 824 int dont_send = 0; 825 826 if (!dont_send) 827 dont_send |= arp_ignore(in_dev,sip,tip); 828 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 829 dont_send |= arp_filter(sip,tip,dev); 830 if (!dont_send) 831 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 832 833 neigh_release(n); 834 } 835 goto out; 836 } else if (IN_DEV_FORWARD(in_dev)) { 837 if (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 838 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) { 839 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 840 if (n) 841 neigh_release(n); 842 843 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 844 skb->pkt_type == PACKET_HOST || 845 in_dev->arp_parms->proxy_delay == 0) { 846 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 847 } else { 848 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 849 in_dev_put(in_dev); 850 return 0; 851 } 852 goto out; 853 } 854 } 855 } 856 857 /* Update our ARP tables */ 858 859 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 860 861 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { 862 /* Unsolicited ARP is not accepted by default. 863 It is possible, that this option should be enabled for some 864 devices (strip is candidate) 865 */ 866 if (n == NULL && 867 arp->ar_op == htons(ARPOP_REPLY) && 868 inet_addr_type(net, sip) == RTN_UNICAST) 869 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 870 } 871 872 if (n) { 873 int state = NUD_REACHABLE; 874 int override; 875 876 /* If several different ARP replies follows back-to-back, 877 use the FIRST one. It is possible, if several proxy 878 agents are active. Taking the first reply prevents 879 arp trashing and chooses the fastest router. 880 */ 881 override = time_after(jiffies, n->updated + n->parms->locktime); 882 883 /* Broadcast replies and request packets 884 do not assert neighbour reachability. 885 */ 886 if (arp->ar_op != htons(ARPOP_REPLY) || 887 skb->pkt_type != PACKET_HOST) 888 state = NUD_STALE; 889 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 890 neigh_release(n); 891 } 892 893 out: 894 if (in_dev) 895 in_dev_put(in_dev); 896 kfree_skb(skb); 897 return 0; 898 } 899 900 static void parp_redo(struct sk_buff *skb) 901 { 902 arp_process(skb); 903 } 904 905 906 /* 907 * Receive an arp request from the device layer. 908 */ 909 910 static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 911 struct packet_type *pt, struct net_device *orig_dev) 912 { 913 struct arphdr *arp; 914 915 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 916 if (!pskb_may_pull(skb, arp_hdr_len(dev))) 917 goto freeskb; 918 919 arp = arp_hdr(skb); 920 if (arp->ar_hln != dev->addr_len || 921 dev->flags & IFF_NOARP || 922 skb->pkt_type == PACKET_OTHERHOST || 923 skb->pkt_type == PACKET_LOOPBACK || 924 arp->ar_pln != 4) 925 goto freeskb; 926 927 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 928 goto out_of_mem; 929 930 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 931 932 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 933 934 freeskb: 935 kfree_skb(skb); 936 out_of_mem: 937 return 0; 938 } 939 940 /* 941 * User level interface (ioctl) 942 */ 943 944 /* 945 * Set (create) an ARP cache entry. 946 */ 947 948 static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 949 { 950 if (dev == NULL) { 951 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 952 return 0; 953 } 954 if (__in_dev_get_rtnl(dev)) { 955 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 956 return 0; 957 } 958 return -ENXIO; 959 } 960 961 static int arp_req_set_public(struct net *net, struct arpreq *r, 962 struct net_device *dev) 963 { 964 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 965 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 966 967 if (mask && mask != htonl(0xFFFFFFFF)) 968 return -EINVAL; 969 if (!dev && (r->arp_flags & ATF_COM)) { 970 dev = dev_getbyhwaddr(net, r->arp_ha.sa_family, 971 r->arp_ha.sa_data); 972 if (!dev) 973 return -ENODEV; 974 } 975 if (mask) { 976 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) 977 return -ENOBUFS; 978 return 0; 979 } 980 981 return arp_req_set_proxy(net, dev, 1); 982 } 983 984 static int arp_req_set(struct net *net, struct arpreq *r, 985 struct net_device * dev) 986 { 987 __be32 ip; 988 struct neighbour *neigh; 989 int err; 990 991 if (r->arp_flags & ATF_PUBL) 992 return arp_req_set_public(net, r, dev); 993 994 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 995 if (r->arp_flags & ATF_PERM) 996 r->arp_flags |= ATF_COM; 997 if (dev == NULL) { 998 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 999 .tos = RTO_ONLINK } } }; 1000 struct rtable * rt; 1001 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1002 return err; 1003 dev = rt->u.dst.dev; 1004 ip_rt_put(rt); 1005 if (!dev) 1006 return -EINVAL; 1007 } 1008 switch (dev->type) { 1009 #ifdef CONFIG_FDDI 1010 case ARPHRD_FDDI: 1011 /* 1012 * According to RFC 1390, FDDI devices should accept ARP 1013 * hardware types of 1 (Ethernet). However, to be more 1014 * robust, we'll accept hardware types of either 1 (Ethernet) 1015 * or 6 (IEEE 802.2). 1016 */ 1017 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1018 r->arp_ha.sa_family != ARPHRD_ETHER && 1019 r->arp_ha.sa_family != ARPHRD_IEEE802) 1020 return -EINVAL; 1021 break; 1022 #endif 1023 default: 1024 if (r->arp_ha.sa_family != dev->type) 1025 return -EINVAL; 1026 break; 1027 } 1028 1029 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1030 err = PTR_ERR(neigh); 1031 if (!IS_ERR(neigh)) { 1032 unsigned state = NUD_STALE; 1033 if (r->arp_flags & ATF_PERM) 1034 state = NUD_PERMANENT; 1035 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1036 r->arp_ha.sa_data : NULL, state, 1037 NEIGH_UPDATE_F_OVERRIDE| 1038 NEIGH_UPDATE_F_ADMIN); 1039 neigh_release(neigh); 1040 } 1041 return err; 1042 } 1043 1044 static unsigned arp_state_to_flags(struct neighbour *neigh) 1045 { 1046 unsigned flags = 0; 1047 if (neigh->nud_state&NUD_PERMANENT) 1048 flags = ATF_PERM|ATF_COM; 1049 else if (neigh->nud_state&NUD_VALID) 1050 flags = ATF_COM; 1051 return flags; 1052 } 1053 1054 /* 1055 * Get an ARP cache entry. 1056 */ 1057 1058 static int arp_req_get(struct arpreq *r, struct net_device *dev) 1059 { 1060 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1061 struct neighbour *neigh; 1062 int err = -ENXIO; 1063 1064 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1065 if (neigh) { 1066 read_lock_bh(&neigh->lock); 1067 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1068 r->arp_flags = arp_state_to_flags(neigh); 1069 read_unlock_bh(&neigh->lock); 1070 r->arp_ha.sa_family = dev->type; 1071 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1072 neigh_release(neigh); 1073 err = 0; 1074 } 1075 return err; 1076 } 1077 1078 static int arp_req_delete_public(struct net *net, struct arpreq *r, 1079 struct net_device *dev) 1080 { 1081 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1082 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1083 1084 if (mask == htonl(0xFFFFFFFF)) 1085 return pneigh_delete(&arp_tbl, net, &ip, dev); 1086 1087 if (mask) 1088 return -EINVAL; 1089 1090 return arp_req_set_proxy(net, dev, 0); 1091 } 1092 1093 static int arp_req_delete(struct net *net, struct arpreq *r, 1094 struct net_device * dev) 1095 { 1096 int err; 1097 __be32 ip; 1098 struct neighbour *neigh; 1099 1100 if (r->arp_flags & ATF_PUBL) 1101 return arp_req_delete_public(net, r, dev); 1102 1103 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1104 if (dev == NULL) { 1105 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1106 .tos = RTO_ONLINK } } }; 1107 struct rtable * rt; 1108 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1109 return err; 1110 dev = rt->u.dst.dev; 1111 ip_rt_put(rt); 1112 if (!dev) 1113 return -EINVAL; 1114 } 1115 err = -ENXIO; 1116 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1117 if (neigh) { 1118 if (neigh->nud_state&~NUD_NOARP) 1119 err = neigh_update(neigh, NULL, NUD_FAILED, 1120 NEIGH_UPDATE_F_OVERRIDE| 1121 NEIGH_UPDATE_F_ADMIN); 1122 neigh_release(neigh); 1123 } 1124 return err; 1125 } 1126 1127 /* 1128 * Handle an ARP layer I/O control request. 1129 */ 1130 1131 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1132 { 1133 int err; 1134 struct arpreq r; 1135 struct net_device *dev = NULL; 1136 1137 switch (cmd) { 1138 case SIOCDARP: 1139 case SIOCSARP: 1140 if (!capable(CAP_NET_ADMIN)) 1141 return -EPERM; 1142 case SIOCGARP: 1143 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1144 if (err) 1145 return -EFAULT; 1146 break; 1147 default: 1148 return -EINVAL; 1149 } 1150 1151 if (r.arp_pa.sa_family != AF_INET) 1152 return -EPFNOSUPPORT; 1153 1154 if (!(r.arp_flags & ATF_PUBL) && 1155 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1156 return -EINVAL; 1157 if (!(r.arp_flags & ATF_NETMASK)) 1158 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1159 htonl(0xFFFFFFFFUL); 1160 rtnl_lock(); 1161 if (r.arp_dev[0]) { 1162 err = -ENODEV; 1163 if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL) 1164 goto out; 1165 1166 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1167 if (!r.arp_ha.sa_family) 1168 r.arp_ha.sa_family = dev->type; 1169 err = -EINVAL; 1170 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1171 goto out; 1172 } else if (cmd == SIOCGARP) { 1173 err = -ENODEV; 1174 goto out; 1175 } 1176 1177 switch (cmd) { 1178 case SIOCDARP: 1179 err = arp_req_delete(net, &r, dev); 1180 break; 1181 case SIOCSARP: 1182 err = arp_req_set(net, &r, dev); 1183 break; 1184 case SIOCGARP: 1185 err = arp_req_get(&r, dev); 1186 if (!err && copy_to_user(arg, &r, sizeof(r))) 1187 err = -EFAULT; 1188 break; 1189 } 1190 out: 1191 rtnl_unlock(); 1192 return err; 1193 } 1194 1195 static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1196 { 1197 struct net_device *dev = ptr; 1198 1199 switch (event) { 1200 case NETDEV_CHANGEADDR: 1201 neigh_changeaddr(&arp_tbl, dev); 1202 rt_cache_flush(0); 1203 break; 1204 default: 1205 break; 1206 } 1207 1208 return NOTIFY_DONE; 1209 } 1210 1211 static struct notifier_block arp_netdev_notifier = { 1212 .notifier_call = arp_netdev_event, 1213 }; 1214 1215 /* Note, that it is not on notifier chain. 1216 It is necessary, that this routine was called after route cache will be 1217 flushed. 1218 */ 1219 void arp_ifdown(struct net_device *dev) 1220 { 1221 neigh_ifdown(&arp_tbl, dev); 1222 } 1223 1224 1225 /* 1226 * Called once on startup. 1227 */ 1228 1229 static struct packet_type arp_packet_type = { 1230 .type = __constant_htons(ETH_P_ARP), 1231 .func = arp_rcv, 1232 }; 1233 1234 static int arp_proc_init(void); 1235 1236 void __init arp_init(void) 1237 { 1238 neigh_table_init(&arp_tbl); 1239 1240 dev_add_pack(&arp_packet_type); 1241 arp_proc_init(); 1242 #ifdef CONFIG_SYSCTL 1243 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1244 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1245 #endif 1246 register_netdevice_notifier(&arp_netdev_notifier); 1247 } 1248 1249 #ifdef CONFIG_PROC_FS 1250 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1251 1252 /* ------------------------------------------------------------------------ */ 1253 /* 1254 * ax25 -> ASCII conversion 1255 */ 1256 static char *ax2asc2(ax25_address *a, char *buf) 1257 { 1258 char c, *s; 1259 int n; 1260 1261 for (n = 0, s = buf; n < 6; n++) { 1262 c = (a->ax25_call[n] >> 1) & 0x7F; 1263 1264 if (c != ' ') *s++ = c; 1265 } 1266 1267 *s++ = '-'; 1268 1269 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1270 *s++ = '1'; 1271 n -= 10; 1272 } 1273 1274 *s++ = n + '0'; 1275 *s++ = '\0'; 1276 1277 if (*buf == '\0' || *buf == '-') 1278 return "*"; 1279 1280 return buf; 1281 1282 } 1283 #endif /* CONFIG_AX25 */ 1284 1285 #define HBUFFERLEN 30 1286 1287 static void arp_format_neigh_entry(struct seq_file *seq, 1288 struct neighbour *n) 1289 { 1290 char hbuffer[HBUFFERLEN]; 1291 const char hexbuf[] = "0123456789ABCDEF"; 1292 int k, j; 1293 char tbuf[16]; 1294 struct net_device *dev = n->dev; 1295 int hatype = dev->type; 1296 1297 read_lock(&n->lock); 1298 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1299 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1300 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1301 ax2asc2((ax25_address *)n->ha, hbuffer); 1302 else { 1303 #endif 1304 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1305 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1306 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1307 hbuffer[k++] = ':'; 1308 } 1309 hbuffer[--k] = 0; 1310 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1311 } 1312 #endif 1313 sprintf(tbuf, NIPQUAD_FMT, NIPQUAD(*(u32*)n->primary_key)); 1314 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1315 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1316 read_unlock(&n->lock); 1317 } 1318 1319 static void arp_format_pneigh_entry(struct seq_file *seq, 1320 struct pneigh_entry *n) 1321 { 1322 struct net_device *dev = n->dev; 1323 int hatype = dev ? dev->type : 0; 1324 char tbuf[16]; 1325 1326 sprintf(tbuf, NIPQUAD_FMT, NIPQUAD(*(u32*)n->key)); 1327 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1328 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1329 dev ? dev->name : "*"); 1330 } 1331 1332 static int arp_seq_show(struct seq_file *seq, void *v) 1333 { 1334 if (v == SEQ_START_TOKEN) { 1335 seq_puts(seq, "IP address HW type Flags " 1336 "HW address Mask Device\n"); 1337 } else { 1338 struct neigh_seq_state *state = seq->private; 1339 1340 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1341 arp_format_pneigh_entry(seq, v); 1342 else 1343 arp_format_neigh_entry(seq, v); 1344 } 1345 1346 return 0; 1347 } 1348 1349 static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1350 { 1351 /* Don't want to confuse "arp -a" w/ magic entries, 1352 * so we tell the generic iterator to skip NUD_NOARP. 1353 */ 1354 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1355 } 1356 1357 /* ------------------------------------------------------------------------ */ 1358 1359 static const struct seq_operations arp_seq_ops = { 1360 .start = arp_seq_start, 1361 .next = neigh_seq_next, 1362 .stop = neigh_seq_stop, 1363 .show = arp_seq_show, 1364 }; 1365 1366 static int arp_seq_open(struct inode *inode, struct file *file) 1367 { 1368 return seq_open_net(inode, file, &arp_seq_ops, 1369 sizeof(struct neigh_seq_state)); 1370 } 1371 1372 static const struct file_operations arp_seq_fops = { 1373 .owner = THIS_MODULE, 1374 .open = arp_seq_open, 1375 .read = seq_read, 1376 .llseek = seq_lseek, 1377 .release = seq_release_net, 1378 }; 1379 1380 1381 static int __net_init arp_net_init(struct net *net) 1382 { 1383 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) 1384 return -ENOMEM; 1385 return 0; 1386 } 1387 1388 static void __net_exit arp_net_exit(struct net *net) 1389 { 1390 proc_net_remove(net, "arp"); 1391 } 1392 1393 static struct pernet_operations arp_net_ops = { 1394 .init = arp_net_init, 1395 .exit = arp_net_exit, 1396 }; 1397 1398 static int __init arp_proc_init(void) 1399 { 1400 return register_pernet_subsys(&arp_net_ops); 1401 } 1402 1403 #else /* CONFIG_PROC_FS */ 1404 1405 static int __init arp_proc_init(void) 1406 { 1407 return 0; 1408 } 1409 1410 #endif /* CONFIG_PROC_FS */ 1411 1412 EXPORT_SYMBOL(arp_broken_ops); 1413 EXPORT_SYMBOL(arp_find); 1414 EXPORT_SYMBOL(arp_create); 1415 EXPORT_SYMBOL(arp_xmit); 1416 EXPORT_SYMBOL(arp_send); 1417 EXPORT_SYMBOL(arp_tbl); 1418 1419 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1420 EXPORT_SYMBOL(clip_tbl_hook); 1421 #endif 1422