arp.c revision b23dd4fe42b455af5c6e20966b7d6959fa8352ea
1/* linux/net/ipv4/arp.c 2 * 3 * Copyright (C) 1994 by Florian La Roche 4 * 5 * This module implements the Address Resolution Protocol ARP (RFC 826), 6 * which is used to convert IP addresses (or in the future maybe other 7 * high-level addresses) into a low-level hardware address (like an Ethernet 8 * address). 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 * 15 * Fixes: 16 * Alan Cox : Removed the Ethernet assumptions in 17 * Florian's code 18 * Alan Cox : Fixed some small errors in the ARP 19 * logic 20 * Alan Cox : Allow >4K in /proc 21 * Alan Cox : Make ARP add its own protocol entry 22 * Ross Martin : Rewrote arp_rcv() and arp_get_info() 23 * Stephen Henson : Add AX25 support to arp_get_info() 24 * Alan Cox : Drop data when a device is downed. 25 * Alan Cox : Use init_timer(). 26 * Alan Cox : Double lock fixes. 27 * Martin Seine : Move the arphdr structure 28 * to if_arp.h for compatibility. 29 * with BSD based programs. 30 * Andrew Tridgell : Added ARP netmask code and 31 * re-arranged proxy handling. 32 * Alan Cox : Changed to use notifiers. 33 * Niibe Yutaka : Reply for this device or proxies only. 34 * Alan Cox : Don't proxy across hardware types! 35 * Jonathan Naylor : Added support for NET/ROM. 36 * Mike Shaver : RFC1122 checks. 37 * Jonathan Naylor : Only lookup the hardware address for 38 * the correct hardware type. 39 * Germano Caronni : Assorted subtle races. 40 * Craig Schlenter : Don't modify permanent entry 41 * during arp_rcv. 42 * Russ Nelson : Tidied up a few bits. 43 * Alexey Kuznetsov: Major changes to caching and behaviour, 44 * eg intelligent arp probing and 45 * generation 46 * of host down events. 47 * Alan Cox : Missing unlock in device events. 48 * Eckes : ARP ioctl control errors. 49 * Alexey Kuznetsov: Arp free fix. 50 * Manuel Rodriguez: Gratuitous ARP. 51 * Jonathan Layes : Added arpd support through kerneld 52 * message queue (960314) 53 * Mike Shaver : /proc/sys/net/ipv4/arp_* support 54 * Mike McLagan : Routing by source 55 * Stuart Cheshire : Metricom and grat arp fixes 56 * *** FOR 2.1 clean this up *** 57 * Lawrence V. Stefani: (08/12/96) Added FDDI support. 58 * Alan Cox : Took the AP1000 nasty FDDI hack and 59 * folded into the mainstream FDDI code. 60 * Ack spit, Linus how did you allow that 61 * one in... 62 * Jes Sorensen : Make FDDI work again in 2.1.x and 63 * clean up the APFDDI & gen. FDDI bits. 64 * Alexey Kuznetsov: new arp state machine; 65 * now it is in net/core/neighbour.c. 66 * Krzysztof Halasa: Added Frame Relay ARP support. 67 * Arnaldo C. Melo : convert /proc/net/arp to seq_file 68 * Shmulik Hen: Split arp_send to arp_create and 69 * arp_xmit so intermediate drivers like 70 * bonding can change the skb before 71 * sending (e.g. insert 8021q tag). 72 * Harald Welte : convert to make use of jenkins hash 73 * Jesper D. Brouer: Proxy ARP PVLAN RFC 3069 support. 74 */ 75 76#include <linux/module.h> 77#include <linux/types.h> 78#include <linux/string.h> 79#include <linux/kernel.h> 80#include <linux/capability.h> 81#include <linux/socket.h> 82#include <linux/sockios.h> 83#include <linux/errno.h> 84#include <linux/in.h> 85#include <linux/mm.h> 86#include <linux/inet.h> 87#include <linux/inetdevice.h> 88#include <linux/netdevice.h> 89#include <linux/etherdevice.h> 90#include <linux/fddidevice.h> 91#include <linux/if_arp.h> 92#include <linux/trdevice.h> 93#include <linux/skbuff.h> 94#include <linux/proc_fs.h> 95#include <linux/seq_file.h> 96#include <linux/stat.h> 97#include <linux/init.h> 98#include <linux/net.h> 99#include <linux/rcupdate.h> 100#include <linux/jhash.h> 101#include <linux/slab.h> 102#ifdef CONFIG_SYSCTL 103#include <linux/sysctl.h> 104#endif 105 106#include <net/net_namespace.h> 107#include <net/ip.h> 108#include <net/icmp.h> 109#include <net/route.h> 110#include <net/protocol.h> 111#include <net/tcp.h> 112#include <net/sock.h> 113#include <net/arp.h> 114#include <net/ax25.h> 115#include <net/netrom.h> 116#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 117#include <net/atmclip.h> 118struct neigh_table *clip_tbl_hook; 119EXPORT_SYMBOL(clip_tbl_hook); 120#endif 121 122#include <asm/system.h> 123#include <linux/uaccess.h> 124 125#include <linux/netfilter_arp.h> 126 127/* 128 * Interface to generic neighbour cache. 129 */ 130static u32 arp_hash(const void *pkey, const struct net_device *dev, __u32 rnd); 131static int arp_constructor(struct neighbour *neigh); 132static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 133static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 134static void parp_redo(struct sk_buff *skb); 135 136static const struct neigh_ops arp_generic_ops = { 137 .family = AF_INET, 138 .solicit = arp_solicit, 139 .error_report = arp_error_report, 140 .output = neigh_resolve_output, 141 .connected_output = neigh_connected_output, 142 .hh_output = dev_queue_xmit, 143 .queue_xmit = dev_queue_xmit, 144}; 145 146static const struct neigh_ops arp_hh_ops = { 147 .family = AF_INET, 148 .solicit = arp_solicit, 149 .error_report = arp_error_report, 150 .output = neigh_resolve_output, 151 .connected_output = neigh_resolve_output, 152 .hh_output = dev_queue_xmit, 153 .queue_xmit = dev_queue_xmit, 154}; 155 156static const struct neigh_ops arp_direct_ops = { 157 .family = AF_INET, 158 .output = dev_queue_xmit, 159 .connected_output = dev_queue_xmit, 160 .hh_output = dev_queue_xmit, 161 .queue_xmit = dev_queue_xmit, 162}; 163 164static const struct neigh_ops arp_broken_ops = { 165 .family = AF_INET, 166 .solicit = arp_solicit, 167 .error_report = arp_error_report, 168 .output = neigh_compat_output, 169 .connected_output = neigh_compat_output, 170 .hh_output = dev_queue_xmit, 171 .queue_xmit = dev_queue_xmit, 172}; 173 174struct neigh_table arp_tbl = { 175 .family = AF_INET, 176 .entry_size = sizeof(struct neighbour) + 4, 177 .key_len = 4, 178 .hash = arp_hash, 179 .constructor = arp_constructor, 180 .proxy_redo = parp_redo, 181 .id = "arp_cache", 182 .parms = { 183 .tbl = &arp_tbl, 184 .base_reachable_time = 30 * HZ, 185 .retrans_time = 1 * HZ, 186 .gc_staletime = 60 * HZ, 187 .reachable_time = 30 * HZ, 188 .delay_probe_time = 5 * HZ, 189 .queue_len = 3, 190 .ucast_probes = 3, 191 .mcast_probes = 3, 192 .anycast_delay = 1 * HZ, 193 .proxy_delay = (8 * HZ) / 10, 194 .proxy_qlen = 64, 195 .locktime = 1 * HZ, 196 }, 197 .gc_interval = 30 * HZ, 198 .gc_thresh1 = 128, 199 .gc_thresh2 = 512, 200 .gc_thresh3 = 1024, 201}; 202EXPORT_SYMBOL(arp_tbl); 203 204int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) 205{ 206 switch (dev->type) { 207 case ARPHRD_ETHER: 208 case ARPHRD_FDDI: 209 case ARPHRD_IEEE802: 210 ip_eth_mc_map(addr, haddr); 211 return 0; 212 case ARPHRD_IEEE802_TR: 213 ip_tr_mc_map(addr, haddr); 214 return 0; 215 case ARPHRD_INFINIBAND: 216 ip_ib_mc_map(addr, dev->broadcast, haddr); 217 return 0; 218 default: 219 if (dir) { 220 memcpy(haddr, dev->broadcast, dev->addr_len); 221 return 0; 222 } 223 } 224 return -EINVAL; 225} 226 227 228static u32 arp_hash(const void *pkey, 229 const struct net_device *dev, 230 __u32 hash_rnd) 231{ 232 return jhash_2words(*(u32 *)pkey, dev->ifindex, 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 rcu_read_lock(); 243 in_dev = __in_dev_get_rcu(dev); 244 if (in_dev == NULL) { 245 rcu_read_unlock(); 246 return -EINVAL; 247 } 248 249 neigh->type = inet_addr_type(dev_net(dev), addr); 250 251 parms = in_dev->arp_parms; 252 __neigh_parms_put(neigh->parms); 253 neigh->parms = neigh_parms_clone(parms); 254 rcu_read_unlock(); 255 256 if (!dev->header_ops) { 257 neigh->nud_state = NUD_NOARP; 258 neigh->ops = &arp_direct_ops; 259 neigh->output = neigh->ops->queue_xmit; 260 } else { 261 /* Good devices (checked by reading texts, but only Ethernet is 262 tested) 263 264 ARPHRD_ETHER: (ethernet, apfddi) 265 ARPHRD_FDDI: (fddi) 266 ARPHRD_IEEE802: (tr) 267 ARPHRD_METRICOM: (strip) 268 ARPHRD_ARCNET: 269 etc. etc. etc. 270 271 ARPHRD_IPDDP will also work, if author repairs it. 272 I did not it, because this driver does not work even 273 in old paradigm. 274 */ 275 276#if 1 277 /* So... these "amateur" devices are hopeless. 278 The only thing, that I can say now: 279 It is very sad that we need to keep ugly obsolete 280 code to make them happy. 281 282 They should be moved to more reasonable state, now 283 they use rebuild_header INSTEAD OF hard_start_xmit!!! 284 Besides that, they are sort of out of date 285 (a lot of redundant clones/copies, useless in 2.1), 286 I wonder why people believe that they work. 287 */ 288 switch (dev->type) { 289 default: 290 break; 291 case ARPHRD_ROSE: 292#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 293 case ARPHRD_AX25: 294#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 295 case ARPHRD_NETROM: 296#endif 297 neigh->ops = &arp_broken_ops; 298 neigh->output = neigh->ops->output; 299 return 0; 300#else 301 break; 302#endif 303 } 304#endif 305 if (neigh->type == RTN_MULTICAST) { 306 neigh->nud_state = NUD_NOARP; 307 arp_mc_map(addr, neigh->ha, dev, 1); 308 } else if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) { 309 neigh->nud_state = NUD_NOARP; 310 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 311 } else if (neigh->type == RTN_BROADCAST || 312 (dev->flags & IFF_POINTOPOINT)) { 313 neigh->nud_state = NUD_NOARP; 314 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 315 } 316 317 if (dev->header_ops->cache) 318 neigh->ops = &arp_hh_ops; 319 else 320 neigh->ops = &arp_generic_ops; 321 322 if (neigh->nud_state & NUD_VALID) 323 neigh->output = neigh->ops->connected_output; 324 else 325 neigh->output = neigh->ops->output; 326 } 327 return 0; 328} 329 330static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 331{ 332 dst_link_failure(skb); 333 kfree_skb(skb); 334} 335 336static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 337{ 338 __be32 saddr = 0; 339 u8 *dst_ha = NULL; 340 struct net_device *dev = neigh->dev; 341 __be32 target = *(__be32 *)neigh->primary_key; 342 int probes = atomic_read(&neigh->probes); 343 struct in_device *in_dev; 344 345 rcu_read_lock(); 346 in_dev = __in_dev_get_rcu(dev); 347 if (!in_dev) { 348 rcu_read_unlock(); 349 return; 350 } 351 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 352 default: 353 case 0: /* By default announce any local IP */ 354 if (skb && inet_addr_type(dev_net(dev), 355 ip_hdr(skb)->saddr) == RTN_LOCAL) 356 saddr = ip_hdr(skb)->saddr; 357 break; 358 case 1: /* Restrict announcements of saddr in same subnet */ 359 if (!skb) 360 break; 361 saddr = ip_hdr(skb)->saddr; 362 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { 363 /* saddr should be known to target */ 364 if (inet_addr_onlink(in_dev, target, saddr)) 365 break; 366 } 367 saddr = 0; 368 break; 369 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 370 break; 371 } 372 rcu_read_unlock(); 373 374 if (!saddr) 375 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 376 377 probes -= neigh->parms->ucast_probes; 378 if (probes < 0) { 379 if (!(neigh->nud_state & NUD_VALID)) 380 printk(KERN_DEBUG 381 "trying to ucast probe in NUD_INVALID\n"); 382 dst_ha = neigh->ha; 383 read_lock_bh(&neigh->lock); 384 } else { 385 probes -= neigh->parms->app_probes; 386 if (probes < 0) { 387#ifdef CONFIG_ARPD 388 neigh_app_ns(neigh); 389#endif 390 return; 391 } 392 } 393 394 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 395 dst_ha, dev->dev_addr, NULL); 396 if (dst_ha) 397 read_unlock_bh(&neigh->lock); 398} 399 400static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) 401{ 402 int scope; 403 404 switch (IN_DEV_ARP_IGNORE(in_dev)) { 405 case 0: /* Reply, the tip is already validated */ 406 return 0; 407 case 1: /* Reply only if tip is configured on the incoming interface */ 408 sip = 0; 409 scope = RT_SCOPE_HOST; 410 break; 411 case 2: /* 412 * Reply only if tip is configured on the incoming interface 413 * and is in same subnet as sip 414 */ 415 scope = RT_SCOPE_HOST; 416 break; 417 case 3: /* Do not reply for scope host addresses */ 418 sip = 0; 419 scope = RT_SCOPE_LINK; 420 break; 421 case 4: /* Reserved */ 422 case 5: 423 case 6: 424 case 7: 425 return 0; 426 case 8: /* Do not reply */ 427 return 1; 428 default: 429 return 0; 430 } 431 return !inet_confirm_addr(in_dev, sip, tip, scope); 432} 433 434static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 435{ 436 struct flowi fl = { .fl4_dst = sip, 437 .fl4_src = tip }; 438 struct rtable *rt; 439 int flag = 0; 440 /*unsigned long now; */ 441 struct net *net = dev_net(dev); 442 443 rt = ip_route_output_key(net, &fl); 444 if (IS_ERR(rt)) 445 return 1; 446 if (rt->dst.dev != dev) { 447 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); 448 flag = 1; 449 } 450 ip_rt_put(rt); 451 return flag; 452} 453 454/* OBSOLETE FUNCTIONS */ 455 456/* 457 * Find an arp mapping in the cache. If not found, post a request. 458 * 459 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 460 * even if it exists. It is supposed that skb->dev was mangled 461 * by a virtual device (eql, shaper). Nobody but broken devices 462 * is allowed to use this function, it is scheduled to be removed. --ANK 463 */ 464 465static int arp_set_predefined(int addr_hint, unsigned char *haddr, 466 __be32 paddr, struct net_device *dev) 467{ 468 switch (addr_hint) { 469 case RTN_LOCAL: 470 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 471 memcpy(haddr, dev->dev_addr, dev->addr_len); 472 return 1; 473 case RTN_MULTICAST: 474 arp_mc_map(paddr, haddr, dev, 1); 475 return 1; 476 case RTN_BROADCAST: 477 memcpy(haddr, dev->broadcast, dev->addr_len); 478 return 1; 479 } 480 return 0; 481} 482 483 484int arp_find(unsigned char *haddr, struct sk_buff *skb) 485{ 486 struct net_device *dev = skb->dev; 487 __be32 paddr; 488 struct neighbour *n; 489 490 if (!skb_dst(skb)) { 491 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 492 kfree_skb(skb); 493 return 1; 494 } 495 496 paddr = skb_rtable(skb)->rt_gateway; 497 498 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, 499 paddr, dev)) 500 return 0; 501 502 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 503 504 if (n) { 505 n->used = jiffies; 506 if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) { 507 neigh_ha_snapshot(haddr, n, dev); 508 neigh_release(n); 509 return 0; 510 } 511 neigh_release(n); 512 } else 513 kfree_skb(skb); 514 return 1; 515} 516EXPORT_SYMBOL(arp_find); 517 518/* END OF OBSOLETE FUNCTIONS */ 519 520int arp_bind_neighbour(struct dst_entry *dst) 521{ 522 struct net_device *dev = dst->dev; 523 struct neighbour *n = dst->neighbour; 524 525 if (dev == NULL) 526 return -EINVAL; 527 if (n == NULL) { 528 __be32 nexthop = ((struct rtable *)dst)->rt_gateway; 529 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) 530 nexthop = 0; 531 n = __neigh_lookup_errno( 532#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 533 dev->type == ARPHRD_ATM ? 534 clip_tbl_hook : 535#endif 536 &arp_tbl, &nexthop, dev); 537 if (IS_ERR(n)) 538 return PTR_ERR(n); 539 dst->neighbour = n; 540 } 541 return 0; 542} 543 544/* 545 * Check if we can use proxy ARP for this path 546 */ 547static inline int arp_fwd_proxy(struct in_device *in_dev, 548 struct net_device *dev, struct rtable *rt) 549{ 550 struct in_device *out_dev; 551 int imi, omi = -1; 552 553 if (rt->dst.dev == dev) 554 return 0; 555 556 if (!IN_DEV_PROXY_ARP(in_dev)) 557 return 0; 558 imi = IN_DEV_MEDIUM_ID(in_dev); 559 if (imi == 0) 560 return 1; 561 if (imi == -1) 562 return 0; 563 564 /* place to check for proxy_arp for routes */ 565 566 out_dev = __in_dev_get_rcu(rt->dst.dev); 567 if (out_dev) 568 omi = IN_DEV_MEDIUM_ID(out_dev); 569 570 return omi != imi && omi != -1; 571} 572 573/* 574 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) 575 * 576 * RFC3069 supports proxy arp replies back to the same interface. This 577 * is done to support (ethernet) switch features, like RFC 3069, where 578 * the individual ports are not allowed to communicate with each 579 * other, BUT they are allowed to talk to the upstream router. As 580 * described in RFC 3069, it is possible to allow these hosts to 581 * communicate through the upstream router, by proxy_arp'ing. 582 * 583 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" 584 * 585 * This technology is known by different names: 586 * In RFC 3069 it is called VLAN Aggregation. 587 * Cisco and Allied Telesyn call it Private VLAN. 588 * Hewlett-Packard call it Source-Port filtering or port-isolation. 589 * Ericsson call it MAC-Forced Forwarding (RFC Draft). 590 * 591 */ 592static inline int arp_fwd_pvlan(struct in_device *in_dev, 593 struct net_device *dev, struct rtable *rt, 594 __be32 sip, __be32 tip) 595{ 596 /* Private VLAN is only concerned about the same ethernet segment */ 597 if (rt->dst.dev != dev) 598 return 0; 599 600 /* Don't reply on self probes (often done by windowz boxes)*/ 601 if (sip == tip) 602 return 0; 603 604 if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) 605 return 1; 606 else 607 return 0; 608} 609 610/* 611 * Interface to link layer: send routine and receive handler. 612 */ 613 614/* 615 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 616 * message. 617 */ 618struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 619 struct net_device *dev, __be32 src_ip, 620 const unsigned char *dest_hw, 621 const unsigned char *src_hw, 622 const unsigned char *target_hw) 623{ 624 struct sk_buff *skb; 625 struct arphdr *arp; 626 unsigned char *arp_ptr; 627 628 /* 629 * Allocate a buffer 630 */ 631 632 skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC); 633 if (skb == NULL) 634 return NULL; 635 636 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 637 skb_reset_network_header(skb); 638 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); 639 skb->dev = dev; 640 skb->protocol = htons(ETH_P_ARP); 641 if (src_hw == NULL) 642 src_hw = dev->dev_addr; 643 if (dest_hw == NULL) 644 dest_hw = dev->broadcast; 645 646 /* 647 * Fill the device header for the ARP frame 648 */ 649 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 650 goto out; 651 652 /* 653 * Fill out the arp protocol part. 654 * 655 * The arp hardware type should match the device type, except for FDDI, 656 * which (according to RFC 1390) should always equal 1 (Ethernet). 657 */ 658 /* 659 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 660 * DIX code for the protocol. Make these device structure fields. 661 */ 662 switch (dev->type) { 663 default: 664 arp->ar_hrd = htons(dev->type); 665 arp->ar_pro = htons(ETH_P_IP); 666 break; 667 668#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 669 case ARPHRD_AX25: 670 arp->ar_hrd = htons(ARPHRD_AX25); 671 arp->ar_pro = htons(AX25_P_IP); 672 break; 673 674#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 675 case ARPHRD_NETROM: 676 arp->ar_hrd = htons(ARPHRD_NETROM); 677 arp->ar_pro = htons(AX25_P_IP); 678 break; 679#endif 680#endif 681 682#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 683 case ARPHRD_FDDI: 684 arp->ar_hrd = htons(ARPHRD_ETHER); 685 arp->ar_pro = htons(ETH_P_IP); 686 break; 687#endif 688#if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE) 689 case ARPHRD_IEEE802_TR: 690 arp->ar_hrd = htons(ARPHRD_IEEE802); 691 arp->ar_pro = htons(ETH_P_IP); 692 break; 693#endif 694 } 695 696 arp->ar_hln = dev->addr_len; 697 arp->ar_pln = 4; 698 arp->ar_op = htons(type); 699 700 arp_ptr = (unsigned char *)(arp + 1); 701 702 memcpy(arp_ptr, src_hw, dev->addr_len); 703 arp_ptr += dev->addr_len; 704 memcpy(arp_ptr, &src_ip, 4); 705 arp_ptr += 4; 706 if (target_hw != NULL) 707 memcpy(arp_ptr, target_hw, dev->addr_len); 708 else 709 memset(arp_ptr, 0, dev->addr_len); 710 arp_ptr += dev->addr_len; 711 memcpy(arp_ptr, &dest_ip, 4); 712 713 return skb; 714 715out: 716 kfree_skb(skb); 717 return NULL; 718} 719EXPORT_SYMBOL(arp_create); 720 721/* 722 * Send an arp packet. 723 */ 724void arp_xmit(struct sk_buff *skb) 725{ 726 /* Send it off, maybe filter it using firewalling first. */ 727 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 728} 729EXPORT_SYMBOL(arp_xmit); 730 731/* 732 * Create and send an arp packet. 733 */ 734void arp_send(int type, int ptype, __be32 dest_ip, 735 struct net_device *dev, __be32 src_ip, 736 const unsigned char *dest_hw, const unsigned char *src_hw, 737 const unsigned char *target_hw) 738{ 739 struct sk_buff *skb; 740 741 /* 742 * No arp on this interface. 743 */ 744 745 if (dev->flags&IFF_NOARP) 746 return; 747 748 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 749 dest_hw, src_hw, target_hw); 750 if (skb == NULL) 751 return; 752 753 arp_xmit(skb); 754} 755EXPORT_SYMBOL(arp_send); 756 757/* 758 * Process an arp request. 759 */ 760 761static int arp_process(struct sk_buff *skb) 762{ 763 struct net_device *dev = skb->dev; 764 struct in_device *in_dev = __in_dev_get_rcu(dev); 765 struct arphdr *arp; 766 unsigned char *arp_ptr; 767 struct rtable *rt; 768 unsigned char *sha; 769 __be32 sip, tip; 770 u16 dev_type = dev->type; 771 int addr_type; 772 struct neighbour *n; 773 struct net *net = dev_net(dev); 774 775 /* arp_rcv below verifies the ARP header and verifies the device 776 * is ARP'able. 777 */ 778 779 if (in_dev == NULL) 780 goto out; 781 782 arp = arp_hdr(skb); 783 784 switch (dev_type) { 785 default: 786 if (arp->ar_pro != htons(ETH_P_IP) || 787 htons(dev_type) != arp->ar_hrd) 788 goto out; 789 break; 790 case ARPHRD_ETHER: 791 case ARPHRD_IEEE802_TR: 792 case ARPHRD_FDDI: 793 case ARPHRD_IEEE802: 794 /* 795 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 796 * devices, according to RFC 2625) devices will accept ARP 797 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 798 * This is the case also of FDDI, where the RFC 1390 says that 799 * FDDI devices should accept ARP hardware of (1) Ethernet, 800 * however, to be more robust, we'll accept both 1 (Ethernet) 801 * or 6 (IEEE 802.2) 802 */ 803 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 804 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 805 arp->ar_pro != htons(ETH_P_IP)) 806 goto out; 807 break; 808 case ARPHRD_AX25: 809 if (arp->ar_pro != htons(AX25_P_IP) || 810 arp->ar_hrd != htons(ARPHRD_AX25)) 811 goto out; 812 break; 813 case ARPHRD_NETROM: 814 if (arp->ar_pro != htons(AX25_P_IP) || 815 arp->ar_hrd != htons(ARPHRD_NETROM)) 816 goto out; 817 break; 818 } 819 820 /* Understand only these message types */ 821 822 if (arp->ar_op != htons(ARPOP_REPLY) && 823 arp->ar_op != htons(ARPOP_REQUEST)) 824 goto out; 825 826/* 827 * Extract fields 828 */ 829 arp_ptr = (unsigned char *)(arp + 1); 830 sha = arp_ptr; 831 arp_ptr += dev->addr_len; 832 memcpy(&sip, arp_ptr, 4); 833 arp_ptr += 4; 834 arp_ptr += dev->addr_len; 835 memcpy(&tip, arp_ptr, 4); 836/* 837 * Check for bad requests for 127.x.x.x and requests for multicast 838 * addresses. If this is one such, delete it. 839 */ 840 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 841 goto out; 842 843/* 844 * Special case: We must set Frame Relay source Q.922 address 845 */ 846 if (dev_type == ARPHRD_DLCI) 847 sha = dev->broadcast; 848 849/* 850 * Process entry. The idea here is we want to send a reply if it is a 851 * request for us or if it is a request for someone else that we hold 852 * a proxy for. We want to add an entry to our cache if it is a reply 853 * to us or if it is a request for our address. 854 * (The assumption for this last is that if someone is requesting our 855 * address, they are probably intending to talk to us, so it saves time 856 * if we cache their address. Their address is also probably not in 857 * our cache, since ours is not in their cache.) 858 * 859 * Putting this another way, we only care about replies if they are to 860 * us, in which case we add them to the cache. For requests, we care 861 * about those for us and those for our proxies. We reply to both, 862 * and in the case of requests for us we add the requester to the arp 863 * cache. 864 */ 865 866 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 867 if (sip == 0) { 868 if (arp->ar_op == htons(ARPOP_REQUEST) && 869 inet_addr_type(net, tip) == RTN_LOCAL && 870 !arp_ignore(in_dev, sip, tip)) 871 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 872 dev->dev_addr, sha); 873 goto out; 874 } 875 876 if (arp->ar_op == htons(ARPOP_REQUEST) && 877 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { 878 879 rt = skb_rtable(skb); 880 addr_type = rt->rt_type; 881 882 if (addr_type == RTN_LOCAL) { 883 int dont_send; 884 885 dont_send = arp_ignore(in_dev, sip, tip); 886 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 887 dont_send = arp_filter(sip, tip, dev); 888 if (!dont_send) { 889 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 890 if (n) { 891 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, 892 dev, tip, sha, dev->dev_addr, 893 sha); 894 neigh_release(n); 895 } 896 } 897 goto out; 898 } else if (IN_DEV_FORWARD(in_dev)) { 899 if (addr_type == RTN_UNICAST && 900 (arp_fwd_proxy(in_dev, dev, rt) || 901 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || 902 pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) { 903 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 904 if (n) 905 neigh_release(n); 906 907 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 908 skb->pkt_type == PACKET_HOST || 909 in_dev->arp_parms->proxy_delay == 0) { 910 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, 911 dev, tip, sha, dev->dev_addr, 912 sha); 913 } else { 914 pneigh_enqueue(&arp_tbl, 915 in_dev->arp_parms, skb); 916 return 0; 917 } 918 goto out; 919 } 920 } 921 } 922 923 /* Update our ARP tables */ 924 925 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 926 927 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { 928 /* Unsolicited ARP is not accepted by default. 929 It is possible, that this option should be enabled for some 930 devices (strip is candidate) 931 */ 932 if (n == NULL && 933 (arp->ar_op == htons(ARPOP_REPLY) || 934 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && 935 inet_addr_type(net, sip) == RTN_UNICAST) 936 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 937 } 938 939 if (n) { 940 int state = NUD_REACHABLE; 941 int override; 942 943 /* If several different ARP replies follows back-to-back, 944 use the FIRST one. It is possible, if several proxy 945 agents are active. Taking the first reply prevents 946 arp trashing and chooses the fastest router. 947 */ 948 override = time_after(jiffies, n->updated + n->parms->locktime); 949 950 /* Broadcast replies and request packets 951 do not assert neighbour reachability. 952 */ 953 if (arp->ar_op != htons(ARPOP_REPLY) || 954 skb->pkt_type != PACKET_HOST) 955 state = NUD_STALE; 956 neigh_update(n, sha, state, 957 override ? NEIGH_UPDATE_F_OVERRIDE : 0); 958 neigh_release(n); 959 } 960 961out: 962 consume_skb(skb); 963 return 0; 964} 965 966static void parp_redo(struct sk_buff *skb) 967{ 968 arp_process(skb); 969} 970 971 972/* 973 * Receive an arp request from the device layer. 974 */ 975 976static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 977 struct packet_type *pt, struct net_device *orig_dev) 978{ 979 struct arphdr *arp; 980 981 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 982 if (!pskb_may_pull(skb, arp_hdr_len(dev))) 983 goto freeskb; 984 985 arp = arp_hdr(skb); 986 if (arp->ar_hln != dev->addr_len || 987 dev->flags & IFF_NOARP || 988 skb->pkt_type == PACKET_OTHERHOST || 989 skb->pkt_type == PACKET_LOOPBACK || 990 arp->ar_pln != 4) 991 goto freeskb; 992 993 skb = skb_share_check(skb, GFP_ATOMIC); 994 if (skb == NULL) 995 goto out_of_mem; 996 997 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 998 999 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 1000 1001freeskb: 1002 kfree_skb(skb); 1003out_of_mem: 1004 return 0; 1005} 1006 1007/* 1008 * User level interface (ioctl) 1009 */ 1010 1011/* 1012 * Set (create) an ARP cache entry. 1013 */ 1014 1015static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 1016{ 1017 if (dev == NULL) { 1018 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 1019 return 0; 1020 } 1021 if (__in_dev_get_rtnl(dev)) { 1022 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 1023 return 0; 1024 } 1025 return -ENXIO; 1026} 1027 1028static int arp_req_set_public(struct net *net, struct arpreq *r, 1029 struct net_device *dev) 1030{ 1031 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1032 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1033 1034 if (mask && mask != htonl(0xFFFFFFFF)) 1035 return -EINVAL; 1036 if (!dev && (r->arp_flags & ATF_COM)) { 1037 dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, 1038 r->arp_ha.sa_data); 1039 if (!dev) 1040 return -ENODEV; 1041 } 1042 if (mask) { 1043 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) 1044 return -ENOBUFS; 1045 return 0; 1046 } 1047 1048 return arp_req_set_proxy(net, dev, 1); 1049} 1050 1051static int arp_req_set(struct net *net, struct arpreq *r, 1052 struct net_device *dev) 1053{ 1054 __be32 ip; 1055 struct neighbour *neigh; 1056 int err; 1057 1058 if (r->arp_flags & ATF_PUBL) 1059 return arp_req_set_public(net, r, dev); 1060 1061 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1062 if (r->arp_flags & ATF_PERM) 1063 r->arp_flags |= ATF_COM; 1064 if (dev == NULL) { 1065 struct flowi fl = { .fl4_dst = ip, 1066 .fl4_tos = RTO_ONLINK }; 1067 struct rtable *rt = ip_route_output_key(net, &fl); 1068 1069 if (IS_ERR(rt)) 1070 return PTR_ERR(rt); 1071 dev = rt->dst.dev; 1072 ip_rt_put(rt); 1073 if (!dev) 1074 return -EINVAL; 1075 } 1076 switch (dev->type) { 1077#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 1078 case ARPHRD_FDDI: 1079 /* 1080 * According to RFC 1390, FDDI devices should accept ARP 1081 * hardware types of 1 (Ethernet). However, to be more 1082 * robust, we'll accept hardware types of either 1 (Ethernet) 1083 * or 6 (IEEE 802.2). 1084 */ 1085 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1086 r->arp_ha.sa_family != ARPHRD_ETHER && 1087 r->arp_ha.sa_family != ARPHRD_IEEE802) 1088 return -EINVAL; 1089 break; 1090#endif 1091 default: 1092 if (r->arp_ha.sa_family != dev->type) 1093 return -EINVAL; 1094 break; 1095 } 1096 1097 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1098 err = PTR_ERR(neigh); 1099 if (!IS_ERR(neigh)) { 1100 unsigned state = NUD_STALE; 1101 if (r->arp_flags & ATF_PERM) 1102 state = NUD_PERMANENT; 1103 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? 1104 r->arp_ha.sa_data : NULL, state, 1105 NEIGH_UPDATE_F_OVERRIDE | 1106 NEIGH_UPDATE_F_ADMIN); 1107 neigh_release(neigh); 1108 } 1109 return err; 1110} 1111 1112static unsigned arp_state_to_flags(struct neighbour *neigh) 1113{ 1114 if (neigh->nud_state&NUD_PERMANENT) 1115 return ATF_PERM | ATF_COM; 1116 else if (neigh->nud_state&NUD_VALID) 1117 return ATF_COM; 1118 else 1119 return 0; 1120} 1121 1122/* 1123 * Get an ARP cache entry. 1124 */ 1125 1126static int arp_req_get(struct arpreq *r, struct net_device *dev) 1127{ 1128 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1129 struct neighbour *neigh; 1130 int err = -ENXIO; 1131 1132 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1133 if (neigh) { 1134 read_lock_bh(&neigh->lock); 1135 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1136 r->arp_flags = arp_state_to_flags(neigh); 1137 read_unlock_bh(&neigh->lock); 1138 r->arp_ha.sa_family = dev->type; 1139 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1140 neigh_release(neigh); 1141 err = 0; 1142 } 1143 return err; 1144} 1145 1146int arp_invalidate(struct net_device *dev, __be32 ip) 1147{ 1148 struct neighbour *neigh = neigh_lookup(&arp_tbl, &ip, dev); 1149 int err = -ENXIO; 1150 1151 if (neigh) { 1152 if (neigh->nud_state & ~NUD_NOARP) 1153 err = neigh_update(neigh, NULL, NUD_FAILED, 1154 NEIGH_UPDATE_F_OVERRIDE| 1155 NEIGH_UPDATE_F_ADMIN); 1156 neigh_release(neigh); 1157 } 1158 1159 return err; 1160} 1161EXPORT_SYMBOL(arp_invalidate); 1162 1163static int arp_req_delete_public(struct net *net, struct arpreq *r, 1164 struct net_device *dev) 1165{ 1166 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1167 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1168 1169 if (mask == htonl(0xFFFFFFFF)) 1170 return pneigh_delete(&arp_tbl, net, &ip, dev); 1171 1172 if (mask) 1173 return -EINVAL; 1174 1175 return arp_req_set_proxy(net, dev, 0); 1176} 1177 1178static int arp_req_delete(struct net *net, struct arpreq *r, 1179 struct net_device *dev) 1180{ 1181 __be32 ip; 1182 1183 if (r->arp_flags & ATF_PUBL) 1184 return arp_req_delete_public(net, r, dev); 1185 1186 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1187 if (dev == NULL) { 1188 struct flowi fl = { .fl4_dst = ip, 1189 .fl4_tos = RTO_ONLINK }; 1190 struct rtable *rt = ip_route_output_key(net, &fl); 1191 if (IS_ERR(rt)) 1192 return PTR_ERR(rt); 1193 dev = rt->dst.dev; 1194 ip_rt_put(rt); 1195 if (!dev) 1196 return -EINVAL; 1197 } 1198 return arp_invalidate(dev, ip); 1199} 1200 1201/* 1202 * Handle an ARP layer I/O control request. 1203 */ 1204 1205int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1206{ 1207 int err; 1208 struct arpreq r; 1209 struct net_device *dev = NULL; 1210 1211 switch (cmd) { 1212 case SIOCDARP: 1213 case SIOCSARP: 1214 if (!capable(CAP_NET_ADMIN)) 1215 return -EPERM; 1216 case SIOCGARP: 1217 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1218 if (err) 1219 return -EFAULT; 1220 break; 1221 default: 1222 return -EINVAL; 1223 } 1224 1225 if (r.arp_pa.sa_family != AF_INET) 1226 return -EPFNOSUPPORT; 1227 1228 if (!(r.arp_flags & ATF_PUBL) && 1229 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) 1230 return -EINVAL; 1231 if (!(r.arp_flags & ATF_NETMASK)) 1232 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1233 htonl(0xFFFFFFFFUL); 1234 rtnl_lock(); 1235 if (r.arp_dev[0]) { 1236 err = -ENODEV; 1237 dev = __dev_get_by_name(net, r.arp_dev); 1238 if (dev == NULL) 1239 goto out; 1240 1241 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1242 if (!r.arp_ha.sa_family) 1243 r.arp_ha.sa_family = dev->type; 1244 err = -EINVAL; 1245 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1246 goto out; 1247 } else if (cmd == SIOCGARP) { 1248 err = -ENODEV; 1249 goto out; 1250 } 1251 1252 switch (cmd) { 1253 case SIOCDARP: 1254 err = arp_req_delete(net, &r, dev); 1255 break; 1256 case SIOCSARP: 1257 err = arp_req_set(net, &r, dev); 1258 break; 1259 case SIOCGARP: 1260 err = arp_req_get(&r, dev); 1261 break; 1262 } 1263out: 1264 rtnl_unlock(); 1265 if (cmd == SIOCGARP && !err && copy_to_user(arg, &r, sizeof(r))) 1266 err = -EFAULT; 1267 return err; 1268} 1269 1270static int arp_netdev_event(struct notifier_block *this, unsigned long event, 1271 void *ptr) 1272{ 1273 struct net_device *dev = ptr; 1274 1275 switch (event) { 1276 case NETDEV_CHANGEADDR: 1277 neigh_changeaddr(&arp_tbl, dev); 1278 rt_cache_flush(dev_net(dev), 0); 1279 break; 1280 default: 1281 break; 1282 } 1283 1284 return NOTIFY_DONE; 1285} 1286 1287static struct notifier_block arp_netdev_notifier = { 1288 .notifier_call = arp_netdev_event, 1289}; 1290 1291/* Note, that it is not on notifier chain. 1292 It is necessary, that this routine was called after route cache will be 1293 flushed. 1294 */ 1295void arp_ifdown(struct net_device *dev) 1296{ 1297 neigh_ifdown(&arp_tbl, dev); 1298} 1299 1300 1301/* 1302 * Called once on startup. 1303 */ 1304 1305static struct packet_type arp_packet_type __read_mostly = { 1306 .type = cpu_to_be16(ETH_P_ARP), 1307 .func = arp_rcv, 1308}; 1309 1310static int arp_proc_init(void); 1311 1312void __init arp_init(void) 1313{ 1314 neigh_table_init(&arp_tbl); 1315 1316 dev_add_pack(&arp_packet_type); 1317 arp_proc_init(); 1318#ifdef CONFIG_SYSCTL 1319 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); 1320#endif 1321 register_netdevice_notifier(&arp_netdev_notifier); 1322} 1323 1324#ifdef CONFIG_PROC_FS 1325#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1326 1327/* ------------------------------------------------------------------------ */ 1328/* 1329 * ax25 -> ASCII conversion 1330 */ 1331static char *ax2asc2(ax25_address *a, char *buf) 1332{ 1333 char c, *s; 1334 int n; 1335 1336 for (n = 0, s = buf; n < 6; n++) { 1337 c = (a->ax25_call[n] >> 1) & 0x7F; 1338 1339 if (c != ' ') 1340 *s++ = c; 1341 } 1342 1343 *s++ = '-'; 1344 n = (a->ax25_call[6] >> 1) & 0x0F; 1345 if (n > 9) { 1346 *s++ = '1'; 1347 n -= 10; 1348 } 1349 1350 *s++ = n + '0'; 1351 *s++ = '\0'; 1352 1353 if (*buf == '\0' || *buf == '-') 1354 return "*"; 1355 1356 return buf; 1357} 1358#endif /* CONFIG_AX25 */ 1359 1360#define HBUFFERLEN 30 1361 1362static void arp_format_neigh_entry(struct seq_file *seq, 1363 struct neighbour *n) 1364{ 1365 char hbuffer[HBUFFERLEN]; 1366 int k, j; 1367 char tbuf[16]; 1368 struct net_device *dev = n->dev; 1369 int hatype = dev->type; 1370 1371 read_lock(&n->lock); 1372 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1373#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1374 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1375 ax2asc2((ax25_address *)n->ha, hbuffer); 1376 else { 1377#endif 1378 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1379 hbuffer[k++] = hex_asc_hi(n->ha[j]); 1380 hbuffer[k++] = hex_asc_lo(n->ha[j]); 1381 hbuffer[k++] = ':'; 1382 } 1383 if (k != 0) 1384 --k; 1385 hbuffer[k] = 0; 1386#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1387 } 1388#endif 1389 sprintf(tbuf, "%pI4", n->primary_key); 1390 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1391 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1392 read_unlock(&n->lock); 1393} 1394 1395static void arp_format_pneigh_entry(struct seq_file *seq, 1396 struct pneigh_entry *n) 1397{ 1398 struct net_device *dev = n->dev; 1399 int hatype = dev ? dev->type : 0; 1400 char tbuf[16]; 1401 1402 sprintf(tbuf, "%pI4", n->key); 1403 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1404 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1405 dev ? dev->name : "*"); 1406} 1407 1408static int arp_seq_show(struct seq_file *seq, void *v) 1409{ 1410 if (v == SEQ_START_TOKEN) { 1411 seq_puts(seq, "IP address HW type Flags " 1412 "HW address Mask Device\n"); 1413 } else { 1414 struct neigh_seq_state *state = seq->private; 1415 1416 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1417 arp_format_pneigh_entry(seq, v); 1418 else 1419 arp_format_neigh_entry(seq, v); 1420 } 1421 1422 return 0; 1423} 1424 1425static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1426{ 1427 /* Don't want to confuse "arp -a" w/ magic entries, 1428 * so we tell the generic iterator to skip NUD_NOARP. 1429 */ 1430 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1431} 1432 1433/* ------------------------------------------------------------------------ */ 1434 1435static const struct seq_operations arp_seq_ops = { 1436 .start = arp_seq_start, 1437 .next = neigh_seq_next, 1438 .stop = neigh_seq_stop, 1439 .show = arp_seq_show, 1440}; 1441 1442static int arp_seq_open(struct inode *inode, struct file *file) 1443{ 1444 return seq_open_net(inode, file, &arp_seq_ops, 1445 sizeof(struct neigh_seq_state)); 1446} 1447 1448static const struct file_operations arp_seq_fops = { 1449 .owner = THIS_MODULE, 1450 .open = arp_seq_open, 1451 .read = seq_read, 1452 .llseek = seq_lseek, 1453 .release = seq_release_net, 1454}; 1455 1456 1457static int __net_init arp_net_init(struct net *net) 1458{ 1459 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) 1460 return -ENOMEM; 1461 return 0; 1462} 1463 1464static void __net_exit arp_net_exit(struct net *net) 1465{ 1466 proc_net_remove(net, "arp"); 1467} 1468 1469static struct pernet_operations arp_net_ops = { 1470 .init = arp_net_init, 1471 .exit = arp_net_exit, 1472}; 1473 1474static int __init arp_proc_init(void) 1475{ 1476 return register_pernet_subsys(&arp_net_ops); 1477} 1478 1479#else /* CONFIG_PROC_FS */ 1480 1481static int __init arp_proc_init(void) 1482{ 1483 return 0; 1484} 1485 1486#endif /* CONFIG_PROC_FS */ 1487