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 <asm/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); 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 164const 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}; 173EXPORT_SYMBOL(arp_broken_ops); 174 175struct neigh_table arp_tbl = { 176 .family = AF_INET, 177 .entry_size = sizeof(struct neighbour) + 4, 178 .key_len = 4, 179 .hash = arp_hash, 180 .constructor = arp_constructor, 181 .proxy_redo = parp_redo, 182 .id = "arp_cache", 183 .parms = { 184 .tbl = &arp_tbl, 185 .base_reachable_time = 30 * HZ, 186 .retrans_time = 1 * HZ, 187 .gc_staletime = 60 * HZ, 188 .reachable_time = 30 * HZ, 189 .delay_probe_time = 5 * HZ, 190 .queue_len = 3, 191 .ucast_probes = 3, 192 .mcast_probes = 3, 193 .anycast_delay = 1 * HZ, 194 .proxy_delay = (8 * HZ) / 10, 195 .proxy_qlen = 64, 196 .locktime = 1 * HZ, 197 }, 198 .gc_interval = 30 * HZ, 199 .gc_thresh1 = 128, 200 .gc_thresh2 = 512, 201 .gc_thresh3 = 1024, 202}; 203EXPORT_SYMBOL(arp_tbl); 204 205int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) 206{ 207 switch (dev->type) { 208 case ARPHRD_ETHER: 209 case ARPHRD_FDDI: 210 case ARPHRD_IEEE802: 211 ip_eth_mc_map(addr, haddr); 212 return 0; 213 case ARPHRD_IEEE802_TR: 214 ip_tr_mc_map(addr, haddr); 215 return 0; 216 case ARPHRD_INFINIBAND: 217 ip_ib_mc_map(addr, dev->broadcast, haddr); 218 return 0; 219 default: 220 if (dir) { 221 memcpy(haddr, dev->broadcast, dev->addr_len); 222 return 0; 223 } 224 } 225 return -EINVAL; 226} 227 228 229static u32 arp_hash(const void *pkey, const struct net_device *dev) 230{ 231 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 232} 233 234static int arp_constructor(struct neighbour *neigh) 235{ 236 __be32 addr = *(__be32*)neigh->primary_key; 237 struct net_device *dev = neigh->dev; 238 struct in_device *in_dev; 239 struct neigh_parms *parms; 240 241 rcu_read_lock(); 242 in_dev = __in_dev_get_rcu(dev); 243 if (in_dev == NULL) { 244 rcu_read_unlock(); 245 return -EINVAL; 246 } 247 248 neigh->type = inet_addr_type(dev_net(dev), addr); 249 250 parms = in_dev->arp_parms; 251 __neigh_parms_put(neigh->parms); 252 neigh->parms = neigh_parms_clone(parms); 253 rcu_read_unlock(); 254 255 if (!dev->header_ops) { 256 neigh->nud_state = NUD_NOARP; 257 neigh->ops = &arp_direct_ops; 258 neigh->output = neigh->ops->queue_xmit; 259 } else { 260 /* Good devices (checked by reading texts, but only Ethernet is 261 tested) 262 263 ARPHRD_ETHER: (ethernet, apfddi) 264 ARPHRD_FDDI: (fddi) 265 ARPHRD_IEEE802: (tr) 266 ARPHRD_METRICOM: (strip) 267 ARPHRD_ARCNET: 268 etc. etc. etc. 269 270 ARPHRD_IPDDP will also work, if author repairs it. 271 I did not it, because this driver does not work even 272 in old paradigm. 273 */ 274 275 /* So... these "amateur" devices are hopeless. 276 The only thing, that I can say now: 277 It is very sad that we need to keep ugly obsolete 278 code to make them happy. 279 280 They should be moved to more reasonable state, now 281 they use rebuild_header INSTEAD OF hard_start_xmit!!! 282 Besides that, they are sort of out of date 283 (a lot of redundant clones/copies, useless in 2.1), 284 I wonder why people believe that they work. 285 */ 286 switch (dev->type) { 287 default: 288 break; 289 case ARPHRD_ROSE: 290#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 291 case ARPHRD_AX25: 292#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 293 case ARPHRD_NETROM: 294#endif 295 neigh->ops = &arp_broken_ops; 296 neigh->output = neigh->ops->output; 297 return 0; 298#endif 299 ;} 300 if (neigh->type == RTN_MULTICAST) { 301 neigh->nud_state = NUD_NOARP; 302 arp_mc_map(addr, neigh->ha, dev, 1); 303 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 304 neigh->nud_state = NUD_NOARP; 305 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 306 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 307 neigh->nud_state = NUD_NOARP; 308 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 309 } 310 311 if (dev->header_ops->cache) 312 neigh->ops = &arp_hh_ops; 313 else 314 neigh->ops = &arp_generic_ops; 315 316 if (neigh->nud_state&NUD_VALID) 317 neigh->output = neigh->ops->connected_output; 318 else 319 neigh->output = neigh->ops->output; 320 } 321 return 0; 322} 323 324static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 325{ 326 dst_link_failure(skb); 327 kfree_skb(skb); 328} 329 330static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 331{ 332 __be32 saddr = 0; 333 u8 *dst_ha = NULL; 334 struct net_device *dev = neigh->dev; 335 __be32 target = *(__be32*)neigh->primary_key; 336 int probes = atomic_read(&neigh->probes); 337 struct in_device *in_dev; 338 339 rcu_read_lock(); 340 in_dev = __in_dev_get_rcu(dev); 341 if (!in_dev) { 342 rcu_read_unlock(); 343 return; 344 } 345 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 346 default: 347 case 0: /* By default announce any local IP */ 348 if (skb && inet_addr_type(dev_net(dev), ip_hdr(skb)->saddr) == RTN_LOCAL) 349 saddr = ip_hdr(skb)->saddr; 350 break; 351 case 1: /* Restrict announcements of saddr in same subnet */ 352 if (!skb) 353 break; 354 saddr = ip_hdr(skb)->saddr; 355 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { 356 /* saddr should be known to target */ 357 if (inet_addr_onlink(in_dev, target, saddr)) 358 break; 359 } 360 saddr = 0; 361 break; 362 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 363 break; 364 } 365 rcu_read_unlock(); 366 367 if (!saddr) 368 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 369 370 if ((probes -= neigh->parms->ucast_probes) < 0) { 371 if (!(neigh->nud_state&NUD_VALID)) 372 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 373 dst_ha = neigh->ha; 374 read_lock_bh(&neigh->lock); 375 } else if ((probes -= neigh->parms->app_probes) < 0) { 376#ifdef CONFIG_ARPD 377 neigh_app_ns(neigh); 378#endif 379 return; 380 } 381 382 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 383 dst_ha, dev->dev_addr, NULL); 384 if (dst_ha) 385 read_unlock_bh(&neigh->lock); 386} 387 388static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) 389{ 390 int scope; 391 392 switch (IN_DEV_ARP_IGNORE(in_dev)) { 393 case 0: /* Reply, the tip is already validated */ 394 return 0; 395 case 1: /* Reply only if tip is configured on the incoming interface */ 396 sip = 0; 397 scope = RT_SCOPE_HOST; 398 break; 399 case 2: /* 400 * Reply only if tip is configured on the incoming interface 401 * and is in same subnet as sip 402 */ 403 scope = RT_SCOPE_HOST; 404 break; 405 case 3: /* Do not reply for scope host addresses */ 406 sip = 0; 407 scope = RT_SCOPE_LINK; 408 break; 409 case 4: /* Reserved */ 410 case 5: 411 case 6: 412 case 7: 413 return 0; 414 case 8: /* Do not reply */ 415 return 1; 416 default: 417 return 0; 418 } 419 return !inet_confirm_addr(in_dev, sip, tip, scope); 420} 421 422static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 423{ 424 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 425 .saddr = tip } } }; 426 struct rtable *rt; 427 int flag = 0; 428 /*unsigned long now; */ 429 struct net *net = dev_net(dev); 430 431 if (ip_route_output_key(net, &rt, &fl) < 0) 432 return 1; 433 if (rt->dst.dev != dev) { 434 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); 435 flag = 1; 436 } 437 ip_rt_put(rt); 438 return flag; 439} 440 441/* OBSOLETE FUNCTIONS */ 442 443/* 444 * Find an arp mapping in the cache. If not found, post a request. 445 * 446 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 447 * even if it exists. It is supposed that skb->dev was mangled 448 * by a virtual device (eql, shaper). Nobody but broken devices 449 * is allowed to use this function, it is scheduled to be removed. --ANK 450 */ 451 452static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 453{ 454 switch (addr_hint) { 455 case RTN_LOCAL: 456 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 457 memcpy(haddr, dev->dev_addr, dev->addr_len); 458 return 1; 459 case RTN_MULTICAST: 460 arp_mc_map(paddr, haddr, dev, 1); 461 return 1; 462 case RTN_BROADCAST: 463 memcpy(haddr, dev->broadcast, dev->addr_len); 464 return 1; 465 } 466 return 0; 467} 468 469 470int arp_find(unsigned char *haddr, struct sk_buff *skb) 471{ 472 struct net_device *dev = skb->dev; 473 __be32 paddr; 474 struct neighbour *n; 475 476 if (!skb_dst(skb)) { 477 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 478 kfree_skb(skb); 479 return 1; 480 } 481 482 paddr = skb_rtable(skb)->rt_gateway; 483 484 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, paddr, dev)) 485 return 0; 486 487 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 488 489 if (n) { 490 n->used = jiffies; 491 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 492 read_lock_bh(&n->lock); 493 memcpy(haddr, n->ha, dev->addr_len); 494 read_unlock_bh(&n->lock); 495 neigh_release(n); 496 return 0; 497 } 498 neigh_release(n); 499 } else 500 kfree_skb(skb); 501 return 1; 502} 503EXPORT_SYMBOL(arp_find); 504 505/* END OF OBSOLETE FUNCTIONS */ 506 507int arp_bind_neighbour(struct dst_entry *dst) 508{ 509 struct net_device *dev = dst->dev; 510 struct neighbour *n = dst->neighbour; 511 512 if (dev == NULL) 513 return -EINVAL; 514 if (n == NULL) { 515 __be32 nexthop = ((struct rtable *)dst)->rt_gateway; 516 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 517 nexthop = 0; 518 n = __neigh_lookup_errno( 519#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 520 dev->type == ARPHRD_ATM ? clip_tbl_hook : 521#endif 522 &arp_tbl, &nexthop, dev); 523 if (IS_ERR(n)) 524 return PTR_ERR(n); 525 dst->neighbour = n; 526 } 527 return 0; 528} 529 530/* 531 * Check if we can use proxy ARP for this path 532 */ 533static inline int arp_fwd_proxy(struct in_device *in_dev, 534 struct net_device *dev, struct rtable *rt) 535{ 536 struct in_device *out_dev; 537 int imi, omi = -1; 538 539 if (rt->dst.dev == dev) 540 return 0; 541 542 if (!IN_DEV_PROXY_ARP(in_dev)) 543 return 0; 544 545 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 546 return 1; 547 if (imi == -1) 548 return 0; 549 550 /* place to check for proxy_arp for routes */ 551 552 out_dev = __in_dev_get_rcu(rt->dst.dev); 553 if (out_dev) 554 omi = IN_DEV_MEDIUM_ID(out_dev); 555 556 return (omi != imi && omi != -1); 557} 558 559/* 560 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) 561 * 562 * RFC3069 supports proxy arp replies back to the same interface. This 563 * is done to support (ethernet) switch features, like RFC 3069, where 564 * the individual ports are not allowed to communicate with each 565 * other, BUT they are allowed to talk to the upstream router. As 566 * described in RFC 3069, it is possible to allow these hosts to 567 * communicate through the upstream router, by proxy_arp'ing. 568 * 569 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" 570 * 571 * This technology is known by different names: 572 * In RFC 3069 it is called VLAN Aggregation. 573 * Cisco and Allied Telesyn call it Private VLAN. 574 * Hewlett-Packard call it Source-Port filtering or port-isolation. 575 * Ericsson call it MAC-Forced Forwarding (RFC Draft). 576 * 577 */ 578static inline int arp_fwd_pvlan(struct in_device *in_dev, 579 struct net_device *dev, struct rtable *rt, 580 __be32 sip, __be32 tip) 581{ 582 /* Private VLAN is only concerned about the same ethernet segment */ 583 if (rt->dst.dev != dev) 584 return 0; 585 586 /* Don't reply on self probes (often done by windowz boxes)*/ 587 if (sip == tip) 588 return 0; 589 590 if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) 591 return 1; 592 else 593 return 0; 594} 595 596/* 597 * Interface to link layer: send routine and receive handler. 598 */ 599 600/* 601 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 602 * message. 603 */ 604struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 605 struct net_device *dev, __be32 src_ip, 606 const unsigned char *dest_hw, 607 const unsigned char *src_hw, 608 const unsigned char *target_hw) 609{ 610 struct sk_buff *skb; 611 struct arphdr *arp; 612 unsigned char *arp_ptr; 613 614 /* 615 * Allocate a buffer 616 */ 617 618 skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC); 619 if (skb == NULL) 620 return NULL; 621 622 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 623 skb_reset_network_header(skb); 624 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); 625 skb->dev = dev; 626 skb->protocol = htons(ETH_P_ARP); 627 if (src_hw == NULL) 628 src_hw = dev->dev_addr; 629 if (dest_hw == NULL) 630 dest_hw = dev->broadcast; 631 632 /* 633 * Fill the device header for the ARP frame 634 */ 635 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 636 goto out; 637 638 /* 639 * Fill out the arp protocol part. 640 * 641 * The arp hardware type should match the device type, except for FDDI, 642 * which (according to RFC 1390) should always equal 1 (Ethernet). 643 */ 644 /* 645 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 646 * DIX code for the protocol. Make these device structure fields. 647 */ 648 switch (dev->type) { 649 default: 650 arp->ar_hrd = htons(dev->type); 651 arp->ar_pro = htons(ETH_P_IP); 652 break; 653 654#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 655 case ARPHRD_AX25: 656 arp->ar_hrd = htons(ARPHRD_AX25); 657 arp->ar_pro = htons(AX25_P_IP); 658 break; 659 660#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 661 case ARPHRD_NETROM: 662 arp->ar_hrd = htons(ARPHRD_NETROM); 663 arp->ar_pro = htons(AX25_P_IP); 664 break; 665#endif 666#endif 667 668#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 669 case ARPHRD_FDDI: 670 arp->ar_hrd = htons(ARPHRD_ETHER); 671 arp->ar_pro = htons(ETH_P_IP); 672 break; 673#endif 674#if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE) 675 case ARPHRD_IEEE802_TR: 676 arp->ar_hrd = htons(ARPHRD_IEEE802); 677 arp->ar_pro = htons(ETH_P_IP); 678 break; 679#endif 680 } 681 682 arp->ar_hln = dev->addr_len; 683 arp->ar_pln = 4; 684 arp->ar_op = htons(type); 685 686 arp_ptr=(unsigned char *)(arp+1); 687 688 memcpy(arp_ptr, src_hw, dev->addr_len); 689 arp_ptr += dev->addr_len; 690 memcpy(arp_ptr, &src_ip, 4); 691 arp_ptr += 4; 692 if (target_hw != NULL) 693 memcpy(arp_ptr, target_hw, dev->addr_len); 694 else 695 memset(arp_ptr, 0, dev->addr_len); 696 arp_ptr += dev->addr_len; 697 memcpy(arp_ptr, &dest_ip, 4); 698 699 return skb; 700 701out: 702 kfree_skb(skb); 703 return NULL; 704} 705EXPORT_SYMBOL(arp_create); 706 707/* 708 * Send an arp packet. 709 */ 710void arp_xmit(struct sk_buff *skb) 711{ 712 /* Send it off, maybe filter it using firewalling first. */ 713 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 714} 715EXPORT_SYMBOL(arp_xmit); 716 717/* 718 * Create and send an arp packet. 719 */ 720void arp_send(int type, int ptype, __be32 dest_ip, 721 struct net_device *dev, __be32 src_ip, 722 const unsigned char *dest_hw, const unsigned char *src_hw, 723 const unsigned char *target_hw) 724{ 725 struct sk_buff *skb; 726 727 /* 728 * No arp on this interface. 729 */ 730 731 if (dev->flags&IFF_NOARP) 732 return; 733 734 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 735 dest_hw, src_hw, target_hw); 736 if (skb == NULL) { 737 return; 738 } 739 740 arp_xmit(skb); 741} 742EXPORT_SYMBOL(arp_send); 743 744/* 745 * Process an arp request. 746 */ 747 748static int arp_process(struct sk_buff *skb) 749{ 750 struct net_device *dev = skb->dev; 751 struct in_device *in_dev = __in_dev_get_rcu(dev); 752 struct arphdr *arp; 753 unsigned char *arp_ptr; 754 struct rtable *rt; 755 unsigned char *sha; 756 __be32 sip, tip; 757 u16 dev_type = dev->type; 758 int addr_type; 759 struct neighbour *n; 760 struct net *net = dev_net(dev); 761 762 /* arp_rcv below verifies the ARP header and verifies the device 763 * is ARP'able. 764 */ 765 766 if (in_dev == NULL) 767 goto out; 768 769 arp = arp_hdr(skb); 770 771 switch (dev_type) { 772 default: 773 if (arp->ar_pro != htons(ETH_P_IP) || 774 htons(dev_type) != arp->ar_hrd) 775 goto out; 776 break; 777 case ARPHRD_ETHER: 778 case ARPHRD_IEEE802_TR: 779 case ARPHRD_FDDI: 780 case ARPHRD_IEEE802: 781 /* 782 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 783 * devices, according to RFC 2625) devices will accept ARP 784 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 785 * This is the case also of FDDI, where the RFC 1390 says that 786 * FDDI devices should accept ARP hardware of (1) Ethernet, 787 * however, to be more robust, we'll accept both 1 (Ethernet) 788 * or 6 (IEEE 802.2) 789 */ 790 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 791 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 792 arp->ar_pro != htons(ETH_P_IP)) 793 goto out; 794 break; 795 case ARPHRD_AX25: 796 if (arp->ar_pro != htons(AX25_P_IP) || 797 arp->ar_hrd != htons(ARPHRD_AX25)) 798 goto out; 799 break; 800 case ARPHRD_NETROM: 801 if (arp->ar_pro != htons(AX25_P_IP) || 802 arp->ar_hrd != htons(ARPHRD_NETROM)) 803 goto out; 804 break; 805 } 806 807 /* Understand only these message types */ 808 809 if (arp->ar_op != htons(ARPOP_REPLY) && 810 arp->ar_op != htons(ARPOP_REQUEST)) 811 goto out; 812 813/* 814 * Extract fields 815 */ 816 arp_ptr= (unsigned char *)(arp+1); 817 sha = arp_ptr; 818 arp_ptr += dev->addr_len; 819 memcpy(&sip, arp_ptr, 4); 820 arp_ptr += 4; 821 arp_ptr += dev->addr_len; 822 memcpy(&tip, arp_ptr, 4); 823/* 824 * Check for bad requests for 127.x.x.x and requests for multicast 825 * addresses. If this is one such, delete it. 826 */ 827 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 828 goto out; 829 830/* 831 * Special case: We must set Frame Relay source Q.922 address 832 */ 833 if (dev_type == ARPHRD_DLCI) 834 sha = dev->broadcast; 835 836/* 837 * Process entry. The idea here is we want to send a reply if it is a 838 * request for us or if it is a request for someone else that we hold 839 * a proxy for. We want to add an entry to our cache if it is a reply 840 * to us or if it is a request for our address. 841 * (The assumption for this last is that if someone is requesting our 842 * address, they are probably intending to talk to us, so it saves time 843 * if we cache their address. Their address is also probably not in 844 * our cache, since ours is not in their cache.) 845 * 846 * Putting this another way, we only care about replies if they are to 847 * us, in which case we add them to the cache. For requests, we care 848 * about those for us and those for our proxies. We reply to both, 849 * and in the case of requests for us we add the requester to the arp 850 * cache. 851 */ 852 853 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 854 if (sip == 0) { 855 if (arp->ar_op == htons(ARPOP_REQUEST) && 856 inet_addr_type(net, tip) == RTN_LOCAL && 857 !arp_ignore(in_dev, sip, tip)) 858 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 859 dev->dev_addr, sha); 860 goto out; 861 } 862 863 if (arp->ar_op == htons(ARPOP_REQUEST) && 864 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { 865 866 rt = skb_rtable(skb); 867 addr_type = rt->rt_type; 868 869 if (addr_type == RTN_LOCAL) { 870 int dont_send = 0; 871 872 if (!dont_send) 873 dont_send |= arp_ignore(in_dev,sip,tip); 874 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 875 dont_send |= arp_filter(sip,tip,dev); 876 if (!dont_send) { 877 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 878 if (n) { 879 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 880 neigh_release(n); 881 } 882 } 883 goto out; 884 } else if (IN_DEV_FORWARD(in_dev)) { 885 if (addr_type == RTN_UNICAST && 886 (arp_fwd_proxy(in_dev, dev, rt) || 887 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || 888 pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) 889 { 890 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 891 if (n) 892 neigh_release(n); 893 894 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 895 skb->pkt_type == PACKET_HOST || 896 in_dev->arp_parms->proxy_delay == 0) { 897 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 898 } else { 899 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 900 return 0; 901 } 902 goto out; 903 } 904 } 905 } 906 907 /* Update our ARP tables */ 908 909 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 910 911 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { 912 /* Unsolicited ARP is not accepted by default. 913 It is possible, that this option should be enabled for some 914 devices (strip is candidate) 915 */ 916 if (n == NULL && 917 (arp->ar_op == htons(ARPOP_REPLY) || 918 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && 919 inet_addr_type(net, sip) == RTN_UNICAST) 920 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 921 } 922 923 if (n) { 924 int state = NUD_REACHABLE; 925 int override; 926 927 /* If several different ARP replies follows back-to-back, 928 use the FIRST one. It is possible, if several proxy 929 agents are active. Taking the first reply prevents 930 arp trashing and chooses the fastest router. 931 */ 932 override = time_after(jiffies, n->updated + n->parms->locktime); 933 934 /* Broadcast replies and request packets 935 do not assert neighbour reachability. 936 */ 937 if (arp->ar_op != htons(ARPOP_REPLY) || 938 skb->pkt_type != PACKET_HOST) 939 state = NUD_STALE; 940 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 941 neigh_release(n); 942 } 943 944out: 945 consume_skb(skb); 946 return 0; 947} 948 949static void parp_redo(struct sk_buff *skb) 950{ 951 arp_process(skb); 952} 953 954 955/* 956 * Receive an arp request from the device layer. 957 */ 958 959static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 960 struct packet_type *pt, struct net_device *orig_dev) 961{ 962 struct arphdr *arp; 963 964 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 965 if (!pskb_may_pull(skb, arp_hdr_len(dev))) 966 goto freeskb; 967 968 arp = arp_hdr(skb); 969 if (arp->ar_hln != dev->addr_len || 970 dev->flags & IFF_NOARP || 971 skb->pkt_type == PACKET_OTHERHOST || 972 skb->pkt_type == PACKET_LOOPBACK || 973 arp->ar_pln != 4) 974 goto freeskb; 975 976 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 977 goto out_of_mem; 978 979 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 980 981 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 982 983freeskb: 984 kfree_skb(skb); 985out_of_mem: 986 return 0; 987} 988 989/* 990 * User level interface (ioctl) 991 */ 992 993/* 994 * Set (create) an ARP cache entry. 995 */ 996 997static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 998{ 999 if (dev == NULL) { 1000 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 1001 return 0; 1002 } 1003 if (__in_dev_get_rtnl(dev)) { 1004 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 1005 return 0; 1006 } 1007 return -ENXIO; 1008} 1009 1010static int arp_req_set_public(struct net *net, struct arpreq *r, 1011 struct net_device *dev) 1012{ 1013 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1014 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1015 1016 if (mask && mask != htonl(0xFFFFFFFF)) 1017 return -EINVAL; 1018 if (!dev && (r->arp_flags & ATF_COM)) { 1019 dev = dev_getbyhwaddr(net, r->arp_ha.sa_family, 1020 r->arp_ha.sa_data); 1021 if (!dev) 1022 return -ENODEV; 1023 } 1024 if (mask) { 1025 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) 1026 return -ENOBUFS; 1027 return 0; 1028 } 1029 1030 return arp_req_set_proxy(net, dev, 1); 1031} 1032 1033static int arp_req_set(struct net *net, struct arpreq *r, 1034 struct net_device * dev) 1035{ 1036 __be32 ip; 1037 struct neighbour *neigh; 1038 int err; 1039 1040 if (r->arp_flags & ATF_PUBL) 1041 return arp_req_set_public(net, r, dev); 1042 1043 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1044 if (r->arp_flags & ATF_PERM) 1045 r->arp_flags |= ATF_COM; 1046 if (dev == NULL) { 1047 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1048 .tos = RTO_ONLINK } } }; 1049 struct rtable * rt; 1050 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1051 return err; 1052 dev = rt->dst.dev; 1053 ip_rt_put(rt); 1054 if (!dev) 1055 return -EINVAL; 1056 } 1057 switch (dev->type) { 1058#if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 1059 case ARPHRD_FDDI: 1060 /* 1061 * According to RFC 1390, FDDI devices should accept ARP 1062 * hardware types of 1 (Ethernet). However, to be more 1063 * robust, we'll accept hardware types of either 1 (Ethernet) 1064 * or 6 (IEEE 802.2). 1065 */ 1066 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1067 r->arp_ha.sa_family != ARPHRD_ETHER && 1068 r->arp_ha.sa_family != ARPHRD_IEEE802) 1069 return -EINVAL; 1070 break; 1071#endif 1072 default: 1073 if (r->arp_ha.sa_family != dev->type) 1074 return -EINVAL; 1075 break; 1076 } 1077 1078 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1079 err = PTR_ERR(neigh); 1080 if (!IS_ERR(neigh)) { 1081 unsigned state = NUD_STALE; 1082 if (r->arp_flags & ATF_PERM) 1083 state = NUD_PERMANENT; 1084 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1085 r->arp_ha.sa_data : NULL, state, 1086 NEIGH_UPDATE_F_OVERRIDE| 1087 NEIGH_UPDATE_F_ADMIN); 1088 neigh_release(neigh); 1089 } 1090 return err; 1091} 1092 1093static unsigned arp_state_to_flags(struct neighbour *neigh) 1094{ 1095 unsigned flags = 0; 1096 if (neigh->nud_state&NUD_PERMANENT) 1097 flags = ATF_PERM|ATF_COM; 1098 else if (neigh->nud_state&NUD_VALID) 1099 flags = ATF_COM; 1100 return flags; 1101} 1102 1103/* 1104 * Get an ARP cache entry. 1105 */ 1106 1107static int arp_req_get(struct arpreq *r, struct net_device *dev) 1108{ 1109 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1110 struct neighbour *neigh; 1111 int err = -ENXIO; 1112 1113 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1114 if (neigh) { 1115 read_lock_bh(&neigh->lock); 1116 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1117 r->arp_flags = arp_state_to_flags(neigh); 1118 read_unlock_bh(&neigh->lock); 1119 r->arp_ha.sa_family = dev->type; 1120 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1121 neigh_release(neigh); 1122 err = 0; 1123 } 1124 return err; 1125} 1126 1127static int arp_req_delete_public(struct net *net, struct arpreq *r, 1128 struct net_device *dev) 1129{ 1130 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1131 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1132 1133 if (mask == htonl(0xFFFFFFFF)) 1134 return pneigh_delete(&arp_tbl, net, &ip, dev); 1135 1136 if (mask) 1137 return -EINVAL; 1138 1139 return arp_req_set_proxy(net, dev, 0); 1140} 1141 1142static int arp_req_delete(struct net *net, struct arpreq *r, 1143 struct net_device * dev) 1144{ 1145 int err; 1146 __be32 ip; 1147 struct neighbour *neigh; 1148 1149 if (r->arp_flags & ATF_PUBL) 1150 return arp_req_delete_public(net, r, dev); 1151 1152 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1153 if (dev == NULL) { 1154 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1155 .tos = RTO_ONLINK } } }; 1156 struct rtable * rt; 1157 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1158 return err; 1159 dev = rt->dst.dev; 1160 ip_rt_put(rt); 1161 if (!dev) 1162 return -EINVAL; 1163 } 1164 err = -ENXIO; 1165 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1166 if (neigh) { 1167 if (neigh->nud_state&~NUD_NOARP) 1168 err = neigh_update(neigh, NULL, NUD_FAILED, 1169 NEIGH_UPDATE_F_OVERRIDE| 1170 NEIGH_UPDATE_F_ADMIN); 1171 neigh_release(neigh); 1172 } 1173 return err; 1174} 1175 1176/* 1177 * Handle an ARP layer I/O control request. 1178 */ 1179 1180int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1181{ 1182 int err; 1183 struct arpreq r; 1184 struct net_device *dev = NULL; 1185 1186 switch (cmd) { 1187 case SIOCDARP: 1188 case SIOCSARP: 1189 if (!capable(CAP_NET_ADMIN)) 1190 return -EPERM; 1191 case SIOCGARP: 1192 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1193 if (err) 1194 return -EFAULT; 1195 break; 1196 default: 1197 return -EINVAL; 1198 } 1199 1200 if (r.arp_pa.sa_family != AF_INET) 1201 return -EPFNOSUPPORT; 1202 1203 if (!(r.arp_flags & ATF_PUBL) && 1204 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1205 return -EINVAL; 1206 if (!(r.arp_flags & ATF_NETMASK)) 1207 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1208 htonl(0xFFFFFFFFUL); 1209 rtnl_lock(); 1210 if (r.arp_dev[0]) { 1211 err = -ENODEV; 1212 if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL) 1213 goto out; 1214 1215 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1216 if (!r.arp_ha.sa_family) 1217 r.arp_ha.sa_family = dev->type; 1218 err = -EINVAL; 1219 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1220 goto out; 1221 } else if (cmd == SIOCGARP) { 1222 err = -ENODEV; 1223 goto out; 1224 } 1225 1226 switch (cmd) { 1227 case SIOCDARP: 1228 err = arp_req_delete(net, &r, dev); 1229 break; 1230 case SIOCSARP: 1231 err = arp_req_set(net, &r, dev); 1232 break; 1233 case SIOCGARP: 1234 err = arp_req_get(&r, dev); 1235 if (!err && copy_to_user(arg, &r, sizeof(r))) 1236 err = -EFAULT; 1237 break; 1238 } 1239out: 1240 rtnl_unlock(); 1241 return err; 1242} 1243 1244static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1245{ 1246 struct net_device *dev = ptr; 1247 1248 switch (event) { 1249 case NETDEV_CHANGEADDR: 1250 neigh_changeaddr(&arp_tbl, dev); 1251 rt_cache_flush(dev_net(dev), 0); 1252 break; 1253 default: 1254 break; 1255 } 1256 1257 return NOTIFY_DONE; 1258} 1259 1260static struct notifier_block arp_netdev_notifier = { 1261 .notifier_call = arp_netdev_event, 1262}; 1263 1264/* Note, that it is not on notifier chain. 1265 It is necessary, that this routine was called after route cache will be 1266 flushed. 1267 */ 1268void arp_ifdown(struct net_device *dev) 1269{ 1270 neigh_ifdown(&arp_tbl, dev); 1271} 1272 1273 1274/* 1275 * Called once on startup. 1276 */ 1277 1278static struct packet_type arp_packet_type __read_mostly = { 1279 .type = cpu_to_be16(ETH_P_ARP), 1280 .func = arp_rcv, 1281}; 1282 1283static int arp_proc_init(void); 1284 1285void __init arp_init(void) 1286{ 1287 neigh_table_init(&arp_tbl); 1288 1289 dev_add_pack(&arp_packet_type); 1290 arp_proc_init(); 1291#ifdef CONFIG_SYSCTL 1292 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); 1293#endif 1294 register_netdevice_notifier(&arp_netdev_notifier); 1295} 1296 1297#ifdef CONFIG_PROC_FS 1298#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1299 1300/* ------------------------------------------------------------------------ */ 1301/* 1302 * ax25 -> ASCII conversion 1303 */ 1304static char *ax2asc2(ax25_address *a, char *buf) 1305{ 1306 char c, *s; 1307 int n; 1308 1309 for (n = 0, s = buf; n < 6; n++) { 1310 c = (a->ax25_call[n] >> 1) & 0x7F; 1311 1312 if (c != ' ') *s++ = c; 1313 } 1314 1315 *s++ = '-'; 1316 1317 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1318 *s++ = '1'; 1319 n -= 10; 1320 } 1321 1322 *s++ = n + '0'; 1323 *s++ = '\0'; 1324 1325 if (*buf == '\0' || *buf == '-') 1326 return "*"; 1327 1328 return buf; 1329 1330} 1331#endif /* CONFIG_AX25 */ 1332 1333#define HBUFFERLEN 30 1334 1335static void arp_format_neigh_entry(struct seq_file *seq, 1336 struct neighbour *n) 1337{ 1338 char hbuffer[HBUFFERLEN]; 1339 int k, j; 1340 char tbuf[16]; 1341 struct net_device *dev = n->dev; 1342 int hatype = dev->type; 1343 1344 read_lock(&n->lock); 1345 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1346#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1347 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1348 ax2asc2((ax25_address *)n->ha, hbuffer); 1349 else { 1350#endif 1351 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1352 hbuffer[k++] = hex_asc_hi(n->ha[j]); 1353 hbuffer[k++] = hex_asc_lo(n->ha[j]); 1354 hbuffer[k++] = ':'; 1355 } 1356 if (k != 0) 1357 --k; 1358 hbuffer[k] = 0; 1359#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1360 } 1361#endif 1362 sprintf(tbuf, "%pI4", n->primary_key); 1363 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1364 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1365 read_unlock(&n->lock); 1366} 1367 1368static void arp_format_pneigh_entry(struct seq_file *seq, 1369 struct pneigh_entry *n) 1370{ 1371 struct net_device *dev = n->dev; 1372 int hatype = dev ? dev->type : 0; 1373 char tbuf[16]; 1374 1375 sprintf(tbuf, "%pI4", n->key); 1376 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1377 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1378 dev ? dev->name : "*"); 1379} 1380 1381static int arp_seq_show(struct seq_file *seq, void *v) 1382{ 1383 if (v == SEQ_START_TOKEN) { 1384 seq_puts(seq, "IP address HW type Flags " 1385 "HW address Mask Device\n"); 1386 } else { 1387 struct neigh_seq_state *state = seq->private; 1388 1389 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1390 arp_format_pneigh_entry(seq, v); 1391 else 1392 arp_format_neigh_entry(seq, v); 1393 } 1394 1395 return 0; 1396} 1397 1398static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1399{ 1400 /* Don't want to confuse "arp -a" w/ magic entries, 1401 * so we tell the generic iterator to skip NUD_NOARP. 1402 */ 1403 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1404} 1405 1406/* ------------------------------------------------------------------------ */ 1407 1408static const struct seq_operations arp_seq_ops = { 1409 .start = arp_seq_start, 1410 .next = neigh_seq_next, 1411 .stop = neigh_seq_stop, 1412 .show = arp_seq_show, 1413}; 1414 1415static int arp_seq_open(struct inode *inode, struct file *file) 1416{ 1417 return seq_open_net(inode, file, &arp_seq_ops, 1418 sizeof(struct neigh_seq_state)); 1419} 1420 1421static const struct file_operations arp_seq_fops = { 1422 .owner = THIS_MODULE, 1423 .open = arp_seq_open, 1424 .read = seq_read, 1425 .llseek = seq_lseek, 1426 .release = seq_release_net, 1427}; 1428 1429 1430static int __net_init arp_net_init(struct net *net) 1431{ 1432 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) 1433 return -ENOMEM; 1434 return 0; 1435} 1436 1437static void __net_exit arp_net_exit(struct net *net) 1438{ 1439 proc_net_remove(net, "arp"); 1440} 1441 1442static struct pernet_operations arp_net_ops = { 1443 .init = arp_net_init, 1444 .exit = arp_net_exit, 1445}; 1446 1447static int __init arp_proc_init(void) 1448{ 1449 return register_pernet_subsys(&arp_net_ops); 1450} 1451 1452#else /* CONFIG_PROC_FS */ 1453 1454static int __init arp_proc_init(void) 1455{ 1456 return 0; 1457} 1458 1459#endif /* CONFIG_PROC_FS */ 1460