arp.c revision 5811662b15db018c740c57d037523683fd3e6123
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 if (ip_route_output_key(net, &rt, &fl) < 0) 444 return 1; 445 if (rt->dst.dev != dev) { 446 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); 447 flag = 1; 448 } 449 ip_rt_put(rt); 450 return flag; 451} 452 453/* OBSOLETE FUNCTIONS */ 454 455/* 456 * Find an arp mapping in the cache. If not found, post a request. 457 * 458 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 459 * even if it exists. It is supposed that skb->dev was mangled 460 * by a virtual device (eql, shaper). Nobody but broken devices 461 * is allowed to use this function, it is scheduled to be removed. --ANK 462 */ 463 464static int arp_set_predefined(int addr_hint, unsigned char *haddr, 465 __be32 paddr, struct net_device *dev) 466{ 467 switch (addr_hint) { 468 case RTN_LOCAL: 469 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 470 memcpy(haddr, dev->dev_addr, dev->addr_len); 471 return 1; 472 case RTN_MULTICAST: 473 arp_mc_map(paddr, haddr, dev, 1); 474 return 1; 475 case RTN_BROADCAST: 476 memcpy(haddr, dev->broadcast, dev->addr_len); 477 return 1; 478 } 479 return 0; 480} 481 482 483int arp_find(unsigned char *haddr, struct sk_buff *skb) 484{ 485 struct net_device *dev = skb->dev; 486 __be32 paddr; 487 struct neighbour *n; 488 489 if (!skb_dst(skb)) { 490 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 491 kfree_skb(skb); 492 return 1; 493 } 494 495 paddr = skb_rtable(skb)->rt_gateway; 496 497 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, 498 paddr, dev)) 499 return 0; 500 501 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 502 503 if (n) { 504 n->used = jiffies; 505 if (n->nud_state & NUD_VALID || neigh_event_send(n, skb) == 0) { 506 neigh_ha_snapshot(haddr, n, dev); 507 neigh_release(n); 508 return 0; 509 } 510 neigh_release(n); 511 } else 512 kfree_skb(skb); 513 return 1; 514} 515EXPORT_SYMBOL(arp_find); 516 517/* END OF OBSOLETE FUNCTIONS */ 518 519int arp_bind_neighbour(struct dst_entry *dst) 520{ 521 struct net_device *dev = dst->dev; 522 struct neighbour *n = dst->neighbour; 523 524 if (dev == NULL) 525 return -EINVAL; 526 if (n == NULL) { 527 __be32 nexthop = ((struct rtable *)dst)->rt_gateway; 528 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) 529 nexthop = 0; 530 n = __neigh_lookup_errno( 531#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 532 dev->type == ARPHRD_ATM ? 533 clip_tbl_hook : 534#endif 535 &arp_tbl, &nexthop, dev); 536 if (IS_ERR(n)) 537 return PTR_ERR(n); 538 dst->neighbour = n; 539 } 540 return 0; 541} 542 543/* 544 * Check if we can use proxy ARP for this path 545 */ 546static inline int arp_fwd_proxy(struct in_device *in_dev, 547 struct net_device *dev, struct rtable *rt) 548{ 549 struct in_device *out_dev; 550 int imi, omi = -1; 551 552 if (rt->dst.dev == dev) 553 return 0; 554 555 if (!IN_DEV_PROXY_ARP(in_dev)) 556 return 0; 557 imi = IN_DEV_MEDIUM_ID(in_dev); 558 if (imi == 0) 559 return 1; 560 if (imi == -1) 561 return 0; 562 563 /* place to check for proxy_arp for routes */ 564 565 out_dev = __in_dev_get_rcu(rt->dst.dev); 566 if (out_dev) 567 omi = IN_DEV_MEDIUM_ID(out_dev); 568 569 return omi != imi && omi != -1; 570} 571 572/* 573 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) 574 * 575 * RFC3069 supports proxy arp replies back to the same interface. This 576 * is done to support (ethernet) switch features, like RFC 3069, where 577 * the individual ports are not allowed to communicate with each 578 * other, BUT they are allowed to talk to the upstream router. As 579 * described in RFC 3069, it is possible to allow these hosts to 580 * communicate through the upstream router, by proxy_arp'ing. 581 * 582 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" 583 * 584 * This technology is known by different names: 585 * In RFC 3069 it is called VLAN Aggregation. 586 * Cisco and Allied Telesyn call it Private VLAN. 587 * Hewlett-Packard call it Source-Port filtering or port-isolation. 588 * Ericsson call it MAC-Forced Forwarding (RFC Draft). 589 * 590 */ 591static inline int arp_fwd_pvlan(struct in_device *in_dev, 592 struct net_device *dev, struct rtable *rt, 593 __be32 sip, __be32 tip) 594{ 595 /* Private VLAN is only concerned about the same ethernet segment */ 596 if (rt->dst.dev != dev) 597 return 0; 598 599 /* Don't reply on self probes (often done by windowz boxes)*/ 600 if (sip == tip) 601 return 0; 602 603 if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) 604 return 1; 605 else 606 return 0; 607} 608 609/* 610 * Interface to link layer: send routine and receive handler. 611 */ 612 613/* 614 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 615 * message. 616 */ 617struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 618 struct net_device *dev, __be32 src_ip, 619 const unsigned char *dest_hw, 620 const unsigned char *src_hw, 621 const unsigned char *target_hw) 622{ 623 struct sk_buff *skb; 624 struct arphdr *arp; 625 unsigned char *arp_ptr; 626 627 /* 628 * Allocate a buffer 629 */ 630 631 skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC); 632 if (skb == NULL) 633 return NULL; 634 635 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 636 skb_reset_network_header(skb); 637 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); 638 skb->dev = dev; 639 skb->protocol = htons(ETH_P_ARP); 640 if (src_hw == NULL) 641 src_hw = dev->dev_addr; 642 if (dest_hw == NULL) 643 dest_hw = dev->broadcast; 644 645 /* 646 * Fill the device header for the ARP frame 647 */ 648 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 649 goto out; 650 651 /* 652 * Fill out the arp protocol part. 653 * 654 * The arp hardware type should match the device type, except for FDDI, 655 * which (according to RFC 1390) should always equal 1 (Ethernet). 656 */ 657 /* 658 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 659 * DIX code for the protocol. Make these device structure fields. 660 */ 661 switch (dev->type) { 662 default: 663 arp->ar_hrd = htons(dev->type); 664 arp->ar_pro = htons(ETH_P_IP); 665 break; 666 667#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 668 case ARPHRD_AX25: 669 arp->ar_hrd = htons(ARPHRD_AX25); 670 arp->ar_pro = htons(AX25_P_IP); 671 break; 672 673#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 674 case ARPHRD_NETROM: 675 arp->ar_hrd = htons(ARPHRD_NETROM); 676 arp->ar_pro = htons(AX25_P_IP); 677 break; 678#endif 679#endif 680 681#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 682 case ARPHRD_FDDI: 683 arp->ar_hrd = htons(ARPHRD_ETHER); 684 arp->ar_pro = htons(ETH_P_IP); 685 break; 686#endif 687#if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE) 688 case ARPHRD_IEEE802_TR: 689 arp->ar_hrd = htons(ARPHRD_IEEE802); 690 arp->ar_pro = htons(ETH_P_IP); 691 break; 692#endif 693 } 694 695 arp->ar_hln = dev->addr_len; 696 arp->ar_pln = 4; 697 arp->ar_op = htons(type); 698 699 arp_ptr = (unsigned char *)(arp + 1); 700 701 memcpy(arp_ptr, src_hw, dev->addr_len); 702 arp_ptr += dev->addr_len; 703 memcpy(arp_ptr, &src_ip, 4); 704 arp_ptr += 4; 705 if (target_hw != NULL) 706 memcpy(arp_ptr, target_hw, dev->addr_len); 707 else 708 memset(arp_ptr, 0, dev->addr_len); 709 arp_ptr += dev->addr_len; 710 memcpy(arp_ptr, &dest_ip, 4); 711 712 return skb; 713 714out: 715 kfree_skb(skb); 716 return NULL; 717} 718EXPORT_SYMBOL(arp_create); 719 720/* 721 * Send an arp packet. 722 */ 723void arp_xmit(struct sk_buff *skb) 724{ 725 /* Send it off, maybe filter it using firewalling first. */ 726 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 727} 728EXPORT_SYMBOL(arp_xmit); 729 730/* 731 * Create and send an arp packet. 732 */ 733void arp_send(int type, int ptype, __be32 dest_ip, 734 struct net_device *dev, __be32 src_ip, 735 const unsigned char *dest_hw, const unsigned char *src_hw, 736 const unsigned char *target_hw) 737{ 738 struct sk_buff *skb; 739 740 /* 741 * No arp on this interface. 742 */ 743 744 if (dev->flags&IFF_NOARP) 745 return; 746 747 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 748 dest_hw, src_hw, target_hw); 749 if (skb == NULL) 750 return; 751 752 arp_xmit(skb); 753} 754EXPORT_SYMBOL(arp_send); 755 756/* 757 * Process an arp request. 758 */ 759 760static int arp_process(struct sk_buff *skb) 761{ 762 struct net_device *dev = skb->dev; 763 struct in_device *in_dev = __in_dev_get_rcu(dev); 764 struct arphdr *arp; 765 unsigned char *arp_ptr; 766 struct rtable *rt; 767 unsigned char *sha; 768 __be32 sip, tip; 769 u16 dev_type = dev->type; 770 int addr_type; 771 struct neighbour *n; 772 struct net *net = dev_net(dev); 773 774 /* arp_rcv below verifies the ARP header and verifies the device 775 * is ARP'able. 776 */ 777 778 if (in_dev == NULL) 779 goto out; 780 781 arp = arp_hdr(skb); 782 783 switch (dev_type) { 784 default: 785 if (arp->ar_pro != htons(ETH_P_IP) || 786 htons(dev_type) != arp->ar_hrd) 787 goto out; 788 break; 789 case ARPHRD_ETHER: 790 case ARPHRD_IEEE802_TR: 791 case ARPHRD_FDDI: 792 case ARPHRD_IEEE802: 793 /* 794 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 795 * devices, according to RFC 2625) devices will accept ARP 796 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 797 * This is the case also of FDDI, where the RFC 1390 says that 798 * FDDI devices should accept ARP hardware of (1) Ethernet, 799 * however, to be more robust, we'll accept both 1 (Ethernet) 800 * or 6 (IEEE 802.2) 801 */ 802 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 803 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 804 arp->ar_pro != htons(ETH_P_IP)) 805 goto out; 806 break; 807 case ARPHRD_AX25: 808 if (arp->ar_pro != htons(AX25_P_IP) || 809 arp->ar_hrd != htons(ARPHRD_AX25)) 810 goto out; 811 break; 812 case ARPHRD_NETROM: 813 if (arp->ar_pro != htons(AX25_P_IP) || 814 arp->ar_hrd != htons(ARPHRD_NETROM)) 815 goto out; 816 break; 817 } 818 819 /* Understand only these message types */ 820 821 if (arp->ar_op != htons(ARPOP_REPLY) && 822 arp->ar_op != htons(ARPOP_REQUEST)) 823 goto out; 824 825/* 826 * Extract fields 827 */ 828 arp_ptr = (unsigned char *)(arp + 1); 829 sha = arp_ptr; 830 arp_ptr += dev->addr_len; 831 memcpy(&sip, arp_ptr, 4); 832 arp_ptr += 4; 833 arp_ptr += dev->addr_len; 834 memcpy(&tip, arp_ptr, 4); 835/* 836 * Check for bad requests for 127.x.x.x and requests for multicast 837 * addresses. If this is one such, delete it. 838 */ 839 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 840 goto out; 841 842/* 843 * Special case: We must set Frame Relay source Q.922 address 844 */ 845 if (dev_type == ARPHRD_DLCI) 846 sha = dev->broadcast; 847 848/* 849 * Process entry. The idea here is we want to send a reply if it is a 850 * request for us or if it is a request for someone else that we hold 851 * a proxy for. We want to add an entry to our cache if it is a reply 852 * to us or if it is a request for our address. 853 * (The assumption for this last is that if someone is requesting our 854 * address, they are probably intending to talk to us, so it saves time 855 * if we cache their address. Their address is also probably not in 856 * our cache, since ours is not in their cache.) 857 * 858 * Putting this another way, we only care about replies if they are to 859 * us, in which case we add them to the cache. For requests, we care 860 * about those for us and those for our proxies. We reply to both, 861 * and in the case of requests for us we add the requester to the arp 862 * cache. 863 */ 864 865 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 866 if (sip == 0) { 867 if (arp->ar_op == htons(ARPOP_REQUEST) && 868 inet_addr_type(net, tip) == RTN_LOCAL && 869 !arp_ignore(in_dev, sip, tip)) 870 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 871 dev->dev_addr, sha); 872 goto out; 873 } 874 875 if (arp->ar_op == htons(ARPOP_REQUEST) && 876 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { 877 878 rt = skb_rtable(skb); 879 addr_type = rt->rt_type; 880 881 if (addr_type == RTN_LOCAL) { 882 int dont_send; 883 884 dont_send = arp_ignore(in_dev, sip, tip); 885 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 886 dont_send |= arp_filter(sip, tip, dev); 887 if (!dont_send) { 888 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 889 if (n) { 890 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, 891 dev, tip, sha, dev->dev_addr, 892 sha); 893 neigh_release(n); 894 } 895 } 896 goto out; 897 } else if (IN_DEV_FORWARD(in_dev)) { 898 if (addr_type == RTN_UNICAST && 899 (arp_fwd_proxy(in_dev, dev, rt) || 900 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || 901 pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) { 902 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 903 if (n) 904 neigh_release(n); 905 906 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 907 skb->pkt_type == PACKET_HOST || 908 in_dev->arp_parms->proxy_delay == 0) { 909 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, 910 dev, tip, sha, dev->dev_addr, 911 sha); 912 } else { 913 pneigh_enqueue(&arp_tbl, 914 in_dev->arp_parms, skb); 915 return 0; 916 } 917 goto out; 918 } 919 } 920 } 921 922 /* Update our ARP tables */ 923 924 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 925 926 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { 927 /* Unsolicited ARP is not accepted by default. 928 It is possible, that this option should be enabled for some 929 devices (strip is candidate) 930 */ 931 if (n == NULL && 932 (arp->ar_op == htons(ARPOP_REPLY) || 933 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && 934 inet_addr_type(net, sip) == RTN_UNICAST) 935 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 936 } 937 938 if (n) { 939 int state = NUD_REACHABLE; 940 int override; 941 942 /* If several different ARP replies follows back-to-back, 943 use the FIRST one. It is possible, if several proxy 944 agents are active. Taking the first reply prevents 945 arp trashing and chooses the fastest router. 946 */ 947 override = time_after(jiffies, n->updated + n->parms->locktime); 948 949 /* Broadcast replies and request packets 950 do not assert neighbour reachability. 951 */ 952 if (arp->ar_op != htons(ARPOP_REPLY) || 953 skb->pkt_type != PACKET_HOST) 954 state = NUD_STALE; 955 neigh_update(n, sha, state, 956 override ? NEIGH_UPDATE_F_OVERRIDE : 0); 957 neigh_release(n); 958 } 959 960out: 961 consume_skb(skb); 962 return 0; 963} 964 965static void parp_redo(struct sk_buff *skb) 966{ 967 arp_process(skb); 968} 969 970 971/* 972 * Receive an arp request from the device layer. 973 */ 974 975static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 976 struct packet_type *pt, struct net_device *orig_dev) 977{ 978 struct arphdr *arp; 979 980 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 981 if (!pskb_may_pull(skb, arp_hdr_len(dev))) 982 goto freeskb; 983 984 arp = arp_hdr(skb); 985 if (arp->ar_hln != dev->addr_len || 986 dev->flags & IFF_NOARP || 987 skb->pkt_type == PACKET_OTHERHOST || 988 skb->pkt_type == PACKET_LOOPBACK || 989 arp->ar_pln != 4) 990 goto freeskb; 991 992 skb = skb_share_check(skb, GFP_ATOMIC); 993 if (skb == NULL) 994 goto out_of_mem; 995 996 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 997 998 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 999 1000freeskb: 1001 kfree_skb(skb); 1002out_of_mem: 1003 return 0; 1004} 1005 1006/* 1007 * User level interface (ioctl) 1008 */ 1009 1010/* 1011 * Set (create) an ARP cache entry. 1012 */ 1013 1014static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 1015{ 1016 if (dev == NULL) { 1017 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 1018 return 0; 1019 } 1020 if (__in_dev_get_rtnl(dev)) { 1021 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 1022 return 0; 1023 } 1024 return -ENXIO; 1025} 1026 1027static int arp_req_set_public(struct net *net, struct arpreq *r, 1028 struct net_device *dev) 1029{ 1030 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1031 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1032 1033 if (mask && mask != htonl(0xFFFFFFFF)) 1034 return -EINVAL; 1035 if (!dev && (r->arp_flags & ATF_COM)) { 1036 dev = dev_getbyhwaddr(net, r->arp_ha.sa_family, 1037 r->arp_ha.sa_data); 1038 if (!dev) 1039 return -ENODEV; 1040 } 1041 if (mask) { 1042 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) 1043 return -ENOBUFS; 1044 return 0; 1045 } 1046 1047 return arp_req_set_proxy(net, dev, 1); 1048} 1049 1050static int arp_req_set(struct net *net, struct arpreq *r, 1051 struct net_device *dev) 1052{ 1053 __be32 ip; 1054 struct neighbour *neigh; 1055 int err; 1056 1057 if (r->arp_flags & ATF_PUBL) 1058 return arp_req_set_public(net, r, dev); 1059 1060 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1061 if (r->arp_flags & ATF_PERM) 1062 r->arp_flags |= ATF_COM; 1063 if (dev == NULL) { 1064 struct flowi fl = { .fl4_dst = ip, 1065 .fl4_tos = RTO_ONLINK }; 1066 struct rtable *rt; 1067 err = ip_route_output_key(net, &rt, &fl); 1068 if (err != 0) 1069 return err; 1070 dev = rt->dst.dev; 1071 ip_rt_put(rt); 1072 if (!dev) 1073 return -EINVAL; 1074 } 1075 switch (dev->type) { 1076#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 1077 case ARPHRD_FDDI: 1078 /* 1079 * According to RFC 1390, FDDI devices should accept ARP 1080 * hardware types of 1 (Ethernet). However, to be more 1081 * robust, we'll accept hardware types of either 1 (Ethernet) 1082 * or 6 (IEEE 802.2). 1083 */ 1084 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1085 r->arp_ha.sa_family != ARPHRD_ETHER && 1086 r->arp_ha.sa_family != ARPHRD_IEEE802) 1087 return -EINVAL; 1088 break; 1089#endif 1090 default: 1091 if (r->arp_ha.sa_family != dev->type) 1092 return -EINVAL; 1093 break; 1094 } 1095 1096 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1097 err = PTR_ERR(neigh); 1098 if (!IS_ERR(neigh)) { 1099 unsigned state = NUD_STALE; 1100 if (r->arp_flags & ATF_PERM) 1101 state = NUD_PERMANENT; 1102 err = neigh_update(neigh, (r->arp_flags & ATF_COM) ? 1103 r->arp_ha.sa_data : NULL, state, 1104 NEIGH_UPDATE_F_OVERRIDE | 1105 NEIGH_UPDATE_F_ADMIN); 1106 neigh_release(neigh); 1107 } 1108 return err; 1109} 1110 1111static unsigned arp_state_to_flags(struct neighbour *neigh) 1112{ 1113 if (neigh->nud_state&NUD_PERMANENT) 1114 return ATF_PERM | ATF_COM; 1115 else if (neigh->nud_state&NUD_VALID) 1116 return ATF_COM; 1117 else 1118 return 0; 1119} 1120 1121/* 1122 * Get an ARP cache entry. 1123 */ 1124 1125static int arp_req_get(struct arpreq *r, struct net_device *dev) 1126{ 1127 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1128 struct neighbour *neigh; 1129 int err = -ENXIO; 1130 1131 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1132 if (neigh) { 1133 read_lock_bh(&neigh->lock); 1134 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1135 r->arp_flags = arp_state_to_flags(neigh); 1136 read_unlock_bh(&neigh->lock); 1137 r->arp_ha.sa_family = dev->type; 1138 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1139 neigh_release(neigh); 1140 err = 0; 1141 } 1142 return err; 1143} 1144 1145static int arp_req_delete_public(struct net *net, struct arpreq *r, 1146 struct net_device *dev) 1147{ 1148 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1149 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1150 1151 if (mask == htonl(0xFFFFFFFF)) 1152 return pneigh_delete(&arp_tbl, net, &ip, dev); 1153 1154 if (mask) 1155 return -EINVAL; 1156 1157 return arp_req_set_proxy(net, dev, 0); 1158} 1159 1160static int arp_req_delete(struct net *net, struct arpreq *r, 1161 struct net_device *dev) 1162{ 1163 int err; 1164 __be32 ip; 1165 struct neighbour *neigh; 1166 1167 if (r->arp_flags & ATF_PUBL) 1168 return arp_req_delete_public(net, r, dev); 1169 1170 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1171 if (dev == NULL) { 1172 struct flowi fl = { .fl4_dst = ip, 1173 .fl4_tos = RTO_ONLINK }; 1174 struct rtable *rt; 1175 err = ip_route_output_key(net, &rt, &fl); 1176 if (err != 0) 1177 return err; 1178 dev = rt->dst.dev; 1179 ip_rt_put(rt); 1180 if (!dev) 1181 return -EINVAL; 1182 } 1183 err = -ENXIO; 1184 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1185 if (neigh) { 1186 if (neigh->nud_state & ~NUD_NOARP) 1187 err = neigh_update(neigh, NULL, NUD_FAILED, 1188 NEIGH_UPDATE_F_OVERRIDE| 1189 NEIGH_UPDATE_F_ADMIN); 1190 neigh_release(neigh); 1191 } 1192 return err; 1193} 1194 1195/* 1196 * Handle an ARP layer I/O control request. 1197 */ 1198 1199int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1200{ 1201 int err; 1202 struct arpreq r; 1203 struct net_device *dev = NULL; 1204 1205 switch (cmd) { 1206 case SIOCDARP: 1207 case SIOCSARP: 1208 if (!capable(CAP_NET_ADMIN)) 1209 return -EPERM; 1210 case SIOCGARP: 1211 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1212 if (err) 1213 return -EFAULT; 1214 break; 1215 default: 1216 return -EINVAL; 1217 } 1218 1219 if (r.arp_pa.sa_family != AF_INET) 1220 return -EPFNOSUPPORT; 1221 1222 if (!(r.arp_flags & ATF_PUBL) && 1223 (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) 1224 return -EINVAL; 1225 if (!(r.arp_flags & ATF_NETMASK)) 1226 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1227 htonl(0xFFFFFFFFUL); 1228 rtnl_lock(); 1229 if (r.arp_dev[0]) { 1230 err = -ENODEV; 1231 dev = __dev_get_by_name(net, r.arp_dev); 1232 if (dev == NULL) 1233 goto out; 1234 1235 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1236 if (!r.arp_ha.sa_family) 1237 r.arp_ha.sa_family = dev->type; 1238 err = -EINVAL; 1239 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1240 goto out; 1241 } else if (cmd == SIOCGARP) { 1242 err = -ENODEV; 1243 goto out; 1244 } 1245 1246 switch (cmd) { 1247 case SIOCDARP: 1248 err = arp_req_delete(net, &r, dev); 1249 break; 1250 case SIOCSARP: 1251 err = arp_req_set(net, &r, dev); 1252 break; 1253 case SIOCGARP: 1254 err = arp_req_get(&r, dev); 1255 if (!err && copy_to_user(arg, &r, sizeof(r))) 1256 err = -EFAULT; 1257 break; 1258 } 1259out: 1260 rtnl_unlock(); 1261 return err; 1262} 1263 1264static int arp_netdev_event(struct notifier_block *this, unsigned long event, 1265 void *ptr) 1266{ 1267 struct net_device *dev = ptr; 1268 1269 switch (event) { 1270 case NETDEV_CHANGEADDR: 1271 neigh_changeaddr(&arp_tbl, dev); 1272 rt_cache_flush(dev_net(dev), 0); 1273 break; 1274 default: 1275 break; 1276 } 1277 1278 return NOTIFY_DONE; 1279} 1280 1281static struct notifier_block arp_netdev_notifier = { 1282 .notifier_call = arp_netdev_event, 1283}; 1284 1285/* Note, that it is not on notifier chain. 1286 It is necessary, that this routine was called after route cache will be 1287 flushed. 1288 */ 1289void arp_ifdown(struct net_device *dev) 1290{ 1291 neigh_ifdown(&arp_tbl, dev); 1292} 1293 1294 1295/* 1296 * Called once on startup. 1297 */ 1298 1299static struct packet_type arp_packet_type __read_mostly = { 1300 .type = cpu_to_be16(ETH_P_ARP), 1301 .func = arp_rcv, 1302}; 1303 1304static int arp_proc_init(void); 1305 1306void __init arp_init(void) 1307{ 1308 neigh_table_init(&arp_tbl); 1309 1310 dev_add_pack(&arp_packet_type); 1311 arp_proc_init(); 1312#ifdef CONFIG_SYSCTL 1313 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); 1314#endif 1315 register_netdevice_notifier(&arp_netdev_notifier); 1316} 1317 1318#ifdef CONFIG_PROC_FS 1319#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1320 1321/* ------------------------------------------------------------------------ */ 1322/* 1323 * ax25 -> ASCII conversion 1324 */ 1325static char *ax2asc2(ax25_address *a, char *buf) 1326{ 1327 char c, *s; 1328 int n; 1329 1330 for (n = 0, s = buf; n < 6; n++) { 1331 c = (a->ax25_call[n] >> 1) & 0x7F; 1332 1333 if (c != ' ') 1334 *s++ = c; 1335 } 1336 1337 *s++ = '-'; 1338 n = (a->ax25_call[6] >> 1) & 0x0F; 1339 if (n > 9) { 1340 *s++ = '1'; 1341 n -= 10; 1342 } 1343 1344 *s++ = n + '0'; 1345 *s++ = '\0'; 1346 1347 if (*buf == '\0' || *buf == '-') 1348 return "*"; 1349 1350 return buf; 1351} 1352#endif /* CONFIG_AX25 */ 1353 1354#define HBUFFERLEN 30 1355 1356static void arp_format_neigh_entry(struct seq_file *seq, 1357 struct neighbour *n) 1358{ 1359 char hbuffer[HBUFFERLEN]; 1360 int k, j; 1361 char tbuf[16]; 1362 struct net_device *dev = n->dev; 1363 int hatype = dev->type; 1364 1365 read_lock(&n->lock); 1366 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1367#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1368 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1369 ax2asc2((ax25_address *)n->ha, hbuffer); 1370 else { 1371#endif 1372 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1373 hbuffer[k++] = hex_asc_hi(n->ha[j]); 1374 hbuffer[k++] = hex_asc_lo(n->ha[j]); 1375 hbuffer[k++] = ':'; 1376 } 1377 if (k != 0) 1378 --k; 1379 hbuffer[k] = 0; 1380#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1381 } 1382#endif 1383 sprintf(tbuf, "%pI4", n->primary_key); 1384 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1385 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1386 read_unlock(&n->lock); 1387} 1388 1389static void arp_format_pneigh_entry(struct seq_file *seq, 1390 struct pneigh_entry *n) 1391{ 1392 struct net_device *dev = n->dev; 1393 int hatype = dev ? dev->type : 0; 1394 char tbuf[16]; 1395 1396 sprintf(tbuf, "%pI4", n->key); 1397 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1398 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1399 dev ? dev->name : "*"); 1400} 1401 1402static int arp_seq_show(struct seq_file *seq, void *v) 1403{ 1404 if (v == SEQ_START_TOKEN) { 1405 seq_puts(seq, "IP address HW type Flags " 1406 "HW address Mask Device\n"); 1407 } else { 1408 struct neigh_seq_state *state = seq->private; 1409 1410 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1411 arp_format_pneigh_entry(seq, v); 1412 else 1413 arp_format_neigh_entry(seq, v); 1414 } 1415 1416 return 0; 1417} 1418 1419static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1420{ 1421 /* Don't want to confuse "arp -a" w/ magic entries, 1422 * so we tell the generic iterator to skip NUD_NOARP. 1423 */ 1424 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1425} 1426 1427/* ------------------------------------------------------------------------ */ 1428 1429static const struct seq_operations arp_seq_ops = { 1430 .start = arp_seq_start, 1431 .next = neigh_seq_next, 1432 .stop = neigh_seq_stop, 1433 .show = arp_seq_show, 1434}; 1435 1436static int arp_seq_open(struct inode *inode, struct file *file) 1437{ 1438 return seq_open_net(inode, file, &arp_seq_ops, 1439 sizeof(struct neigh_seq_state)); 1440} 1441 1442static const struct file_operations arp_seq_fops = { 1443 .owner = THIS_MODULE, 1444 .open = arp_seq_open, 1445 .read = seq_read, 1446 .llseek = seq_lseek, 1447 .release = seq_release_net, 1448}; 1449 1450 1451static int __net_init arp_net_init(struct net *net) 1452{ 1453 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) 1454 return -ENOMEM; 1455 return 0; 1456} 1457 1458static void __net_exit arp_net_exit(struct net *net) 1459{ 1460 proc_net_remove(net, "arp"); 1461} 1462 1463static struct pernet_operations arp_net_ops = { 1464 .init = arp_net_init, 1465 .exit = arp_net_exit, 1466}; 1467 1468static int __init arp_proc_init(void) 1469{ 1470 return register_pernet_subsys(&arp_net_ops); 1471} 1472 1473#else /* CONFIG_PROC_FS */ 1474 1475static int __init arp_proc_init(void) 1476{ 1477 return 0; 1478} 1479 1480#endif /* CONFIG_PROC_FS */ 1481