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> 118 struct neigh_table *clip_tbl_hook; 119 #endif 120 121 #include <asm/system.h> 122 #include <asm/uaccess.h> 123 124 #include <linux/netfilter_arp.h> 125 126 /* 127 * Interface to generic neighbour cache. 128 */ 129 static u32 arp_hash(const void *pkey, const struct net_device *dev); 130 static int arp_constructor(struct neighbour *neigh); 131 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 132 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 133 static void parp_redo(struct sk_buff *skb); 134 135 static const struct neigh_ops arp_generic_ops = { 136 .family = AF_INET, 137 .solicit = arp_solicit, 138 .error_report = arp_error_report, 139 .output = neigh_resolve_output, 140 .connected_output = neigh_connected_output, 141 .hh_output = dev_queue_xmit, 142 .queue_xmit = dev_queue_xmit, 143 }; 144 145 static const struct neigh_ops arp_hh_ops = { 146 .family = AF_INET, 147 .solicit = arp_solicit, 148 .error_report = arp_error_report, 149 .output = neigh_resolve_output, 150 .connected_output = neigh_resolve_output, 151 .hh_output = dev_queue_xmit, 152 .queue_xmit = dev_queue_xmit, 153 }; 154 155 static const struct neigh_ops arp_direct_ops = { 156 .family = AF_INET, 157 .output = dev_queue_xmit, 158 .connected_output = dev_queue_xmit, 159 .hh_output = dev_queue_xmit, 160 .queue_xmit = dev_queue_xmit, 161 }; 162 163 const struct neigh_ops arp_broken_ops = { 164 .family = AF_INET, 165 .solicit = arp_solicit, 166 .error_report = arp_error_report, 167 .output = neigh_compat_output, 168 .connected_output = neigh_compat_output, 169 .hh_output = dev_queue_xmit, 170 .queue_xmit = dev_queue_xmit, 171 }; 172 173 struct neigh_table arp_tbl = { 174 .family = AF_INET, 175 .entry_size = sizeof(struct neighbour) + 4, 176 .key_len = 4, 177 .hash = arp_hash, 178 .constructor = arp_constructor, 179 .proxy_redo = parp_redo, 180 .id = "arp_cache", 181 .parms = { 182 .tbl = &arp_tbl, 183 .base_reachable_time = 30 * HZ, 184 .retrans_time = 1 * HZ, 185 .gc_staletime = 60 * HZ, 186 .reachable_time = 30 * HZ, 187 .delay_probe_time = 5 * HZ, 188 .queue_len = 3, 189 .ucast_probes = 3, 190 .mcast_probes = 3, 191 .anycast_delay = 1 * HZ, 192 .proxy_delay = (8 * HZ) / 10, 193 .proxy_qlen = 64, 194 .locktime = 1 * HZ, 195 }, 196 .gc_interval = 30 * HZ, 197 .gc_thresh1 = 128, 198 .gc_thresh2 = 512, 199 .gc_thresh3 = 1024, 200 }; 201 202 int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir) 203 { 204 switch (dev->type) { 205 case ARPHRD_ETHER: 206 case ARPHRD_FDDI: 207 case ARPHRD_IEEE802: 208 ip_eth_mc_map(addr, haddr); 209 return 0; 210 case ARPHRD_IEEE802_TR: 211 ip_tr_mc_map(addr, haddr); 212 return 0; 213 case ARPHRD_INFINIBAND: 214 ip_ib_mc_map(addr, dev->broadcast, haddr); 215 return 0; 216 default: 217 if (dir) { 218 memcpy(haddr, dev->broadcast, dev->addr_len); 219 return 0; 220 } 221 } 222 return -EINVAL; 223 } 224 225 226 static u32 arp_hash(const void *pkey, const struct net_device *dev) 227 { 228 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 229 } 230 231 static int arp_constructor(struct neighbour *neigh) 232 { 233 __be32 addr = *(__be32*)neigh->primary_key; 234 struct net_device *dev = neigh->dev; 235 struct in_device *in_dev; 236 struct neigh_parms *parms; 237 238 rcu_read_lock(); 239 in_dev = __in_dev_get_rcu(dev); 240 if (in_dev == NULL) { 241 rcu_read_unlock(); 242 return -EINVAL; 243 } 244 245 neigh->type = inet_addr_type(dev_net(dev), addr); 246 247 parms = in_dev->arp_parms; 248 __neigh_parms_put(neigh->parms); 249 neigh->parms = neigh_parms_clone(parms); 250 rcu_read_unlock(); 251 252 if (!dev->header_ops) { 253 neigh->nud_state = NUD_NOARP; 254 neigh->ops = &arp_direct_ops; 255 neigh->output = neigh->ops->queue_xmit; 256 } else { 257 /* Good devices (checked by reading texts, but only Ethernet is 258 tested) 259 260 ARPHRD_ETHER: (ethernet, apfddi) 261 ARPHRD_FDDI: (fddi) 262 ARPHRD_IEEE802: (tr) 263 ARPHRD_METRICOM: (strip) 264 ARPHRD_ARCNET: 265 etc. etc. etc. 266 267 ARPHRD_IPDDP will also work, if author repairs it. 268 I did not it, because this driver does not work even 269 in old paradigm. 270 */ 271 272 #if 1 273 /* So... these "amateur" devices are hopeless. 274 The only thing, that I can say now: 275 It is very sad that we need to keep ugly obsolete 276 code to make them happy. 277 278 They should be moved to more reasonable state, now 279 they use rebuild_header INSTEAD OF hard_start_xmit!!! 280 Besides that, they are sort of out of date 281 (a lot of redundant clones/copies, useless in 2.1), 282 I wonder why people believe that they work. 283 */ 284 switch (dev->type) { 285 default: 286 break; 287 case ARPHRD_ROSE: 288 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 289 case ARPHRD_AX25: 290 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 291 case ARPHRD_NETROM: 292 #endif 293 neigh->ops = &arp_broken_ops; 294 neigh->output = neigh->ops->output; 295 return 0; 296 #endif 297 ;} 298 #endif 299 if (neigh->type == RTN_MULTICAST) { 300 neigh->nud_state = NUD_NOARP; 301 arp_mc_map(addr, neigh->ha, dev, 1); 302 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 303 neigh->nud_state = NUD_NOARP; 304 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 305 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 306 neigh->nud_state = NUD_NOARP; 307 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 308 } 309 310 if (dev->header_ops->cache) 311 neigh->ops = &arp_hh_ops; 312 else 313 neigh->ops = &arp_generic_ops; 314 315 if (neigh->nud_state&NUD_VALID) 316 neigh->output = neigh->ops->connected_output; 317 else 318 neigh->output = neigh->ops->output; 319 } 320 return 0; 321 } 322 323 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 324 { 325 dst_link_failure(skb); 326 kfree_skb(skb); 327 } 328 329 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 330 { 331 __be32 saddr = 0; 332 u8 *dst_ha = NULL; 333 struct net_device *dev = neigh->dev; 334 __be32 target = *(__be32*)neigh->primary_key; 335 int probes = atomic_read(&neigh->probes); 336 struct in_device *in_dev = in_dev_get(dev); 337 338 if (!in_dev) 339 return; 340 341 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 342 default: 343 case 0: /* By default announce any local IP */ 344 if (skb && inet_addr_type(dev_net(dev), ip_hdr(skb)->saddr) == RTN_LOCAL) 345 saddr = ip_hdr(skb)->saddr; 346 break; 347 case 1: /* Restrict announcements of saddr in same subnet */ 348 if (!skb) 349 break; 350 saddr = ip_hdr(skb)->saddr; 351 if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) { 352 /* saddr should be known to target */ 353 if (inet_addr_onlink(in_dev, target, saddr)) 354 break; 355 } 356 saddr = 0; 357 break; 358 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 359 break; 360 } 361 362 if (in_dev) 363 in_dev_put(in_dev); 364 if (!saddr) 365 saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); 366 367 if ((probes -= neigh->parms->ucast_probes) < 0) { 368 if (!(neigh->nud_state&NUD_VALID)) 369 printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); 370 dst_ha = neigh->ha; 371 read_lock_bh(&neigh->lock); 372 } else if ((probes -= neigh->parms->app_probes) < 0) { 373 #ifdef CONFIG_ARPD 374 neigh_app_ns(neigh); 375 #endif 376 return; 377 } 378 379 arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, 380 dst_ha, dev->dev_addr, NULL); 381 if (dst_ha) 382 read_unlock_bh(&neigh->lock); 383 } 384 385 static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip) 386 { 387 int scope; 388 389 switch (IN_DEV_ARP_IGNORE(in_dev)) { 390 case 0: /* Reply, the tip is already validated */ 391 return 0; 392 case 1: /* Reply only if tip is configured on the incoming interface */ 393 sip = 0; 394 scope = RT_SCOPE_HOST; 395 break; 396 case 2: /* 397 * Reply only if tip is configured on the incoming interface 398 * and is in same subnet as sip 399 */ 400 scope = RT_SCOPE_HOST; 401 break; 402 case 3: /* Do not reply for scope host addresses */ 403 sip = 0; 404 scope = RT_SCOPE_LINK; 405 break; 406 case 4: /* Reserved */ 407 case 5: 408 case 6: 409 case 7: 410 return 0; 411 case 8: /* Do not reply */ 412 return 1; 413 default: 414 return 0; 415 } 416 return !inet_confirm_addr(in_dev, sip, tip, scope); 417 } 418 419 static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev) 420 { 421 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 422 .saddr = tip } } }; 423 struct rtable *rt; 424 int flag = 0; 425 /*unsigned long now; */ 426 struct net *net = dev_net(dev); 427 428 if (ip_route_output_key(net, &rt, &fl) < 0) 429 return 1; 430 if (rt->u.dst.dev != dev) { 431 NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER); 432 flag = 1; 433 } 434 ip_rt_put(rt); 435 return flag; 436 } 437 438 /* OBSOLETE FUNCTIONS */ 439 440 /* 441 * Find an arp mapping in the cache. If not found, post a request. 442 * 443 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 444 * even if it exists. It is supposed that skb->dev was mangled 445 * by a virtual device (eql, shaper). Nobody but broken devices 446 * is allowed to use this function, it is scheduled to be removed. --ANK 447 */ 448 449 static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev) 450 { 451 switch (addr_hint) { 452 case RTN_LOCAL: 453 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 454 memcpy(haddr, dev->dev_addr, dev->addr_len); 455 return 1; 456 case RTN_MULTICAST: 457 arp_mc_map(paddr, haddr, dev, 1); 458 return 1; 459 case RTN_BROADCAST: 460 memcpy(haddr, dev->broadcast, dev->addr_len); 461 return 1; 462 } 463 return 0; 464 } 465 466 467 int arp_find(unsigned char *haddr, struct sk_buff *skb) 468 { 469 struct net_device *dev = skb->dev; 470 __be32 paddr; 471 struct neighbour *n; 472 473 if (!skb_dst(skb)) { 474 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 475 kfree_skb(skb); 476 return 1; 477 } 478 479 paddr = skb_rtable(skb)->rt_gateway; 480 481 if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, paddr, dev)) 482 return 0; 483 484 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 485 486 if (n) { 487 n->used = jiffies; 488 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 489 read_lock_bh(&n->lock); 490 memcpy(haddr, n->ha, dev->addr_len); 491 read_unlock_bh(&n->lock); 492 neigh_release(n); 493 return 0; 494 } 495 neigh_release(n); 496 } else 497 kfree_skb(skb); 498 return 1; 499 } 500 501 /* END OF OBSOLETE FUNCTIONS */ 502 503 int arp_bind_neighbour(struct dst_entry *dst) 504 { 505 struct net_device *dev = dst->dev; 506 struct neighbour *n = dst->neighbour; 507 508 if (dev == NULL) 509 return -EINVAL; 510 if (n == NULL) { 511 __be32 nexthop = ((struct rtable *)dst)->rt_gateway; 512 if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) 513 nexthop = 0; 514 n = __neigh_lookup_errno( 515 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 516 dev->type == ARPHRD_ATM ? clip_tbl_hook : 517 #endif 518 &arp_tbl, &nexthop, dev); 519 if (IS_ERR(n)) 520 return PTR_ERR(n); 521 dst->neighbour = n; 522 } 523 return 0; 524 } 525 526 /* 527 * Check if we can use proxy ARP for this path 528 */ 529 static inline int arp_fwd_proxy(struct in_device *in_dev, 530 struct net_device *dev, struct rtable *rt) 531 { 532 struct in_device *out_dev; 533 int imi, omi = -1; 534 535 if (rt->u.dst.dev == dev) 536 return 0; 537 538 if (!IN_DEV_PROXY_ARP(in_dev)) 539 return 0; 540 541 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 542 return 1; 543 if (imi == -1) 544 return 0; 545 546 /* place to check for proxy_arp for routes */ 547 548 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 549 omi = IN_DEV_MEDIUM_ID(out_dev); 550 in_dev_put(out_dev); 551 } 552 return (omi != imi && omi != -1); 553 } 554 555 /* 556 * Check for RFC3069 proxy arp private VLAN (allow to send back to same dev) 557 * 558 * RFC3069 supports proxy arp replies back to the same interface. This 559 * is done to support (ethernet) switch features, like RFC 3069, where 560 * the individual ports are not allowed to communicate with each 561 * other, BUT they are allowed to talk to the upstream router. As 562 * described in RFC 3069, it is possible to allow these hosts to 563 * communicate through the upstream router, by proxy_arp'ing. 564 * 565 * RFC 3069: "VLAN Aggregation for Efficient IP Address Allocation" 566 * 567 * This technology is known by different names: 568 * In RFC 3069 it is called VLAN Aggregation. 569 * Cisco and Allied Telesyn call it Private VLAN. 570 * Hewlett-Packard call it Source-Port filtering or port-isolation. 571 * Ericsson call it MAC-Forced Forwarding (RFC Draft). 572 * 573 */ 574 static inline int arp_fwd_pvlan(struct in_device *in_dev, 575 struct net_device *dev, struct rtable *rt, 576 __be32 sip, __be32 tip) 577 { 578 /* Private VLAN is only concerned about the same ethernet segment */ 579 if (rt->u.dst.dev != dev) 580 return 0; 581 582 /* Don't reply on self probes (often done by windowz boxes)*/ 583 if (sip == tip) 584 return 0; 585 586 if (IN_DEV_PROXY_ARP_PVLAN(in_dev)) 587 return 1; 588 else 589 return 0; 590 } 591 592 /* 593 * Interface to link layer: send routine and receive handler. 594 */ 595 596 /* 597 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 598 * message. 599 */ 600 struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip, 601 struct net_device *dev, __be32 src_ip, 602 const unsigned char *dest_hw, 603 const unsigned char *src_hw, 604 const unsigned char *target_hw) 605 { 606 struct sk_buff *skb; 607 struct arphdr *arp; 608 unsigned char *arp_ptr; 609 610 /* 611 * Allocate a buffer 612 */ 613 614 skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC); 615 if (skb == NULL) 616 return NULL; 617 618 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 619 skb_reset_network_header(skb); 620 arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev)); 621 skb->dev = dev; 622 skb->protocol = htons(ETH_P_ARP); 623 if (src_hw == NULL) 624 src_hw = dev->dev_addr; 625 if (dest_hw == NULL) 626 dest_hw = dev->broadcast; 627 628 /* 629 * Fill the device header for the ARP frame 630 */ 631 if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0) 632 goto out; 633 634 /* 635 * Fill out the arp protocol part. 636 * 637 * The arp hardware type should match the device type, except for FDDI, 638 * which (according to RFC 1390) should always equal 1 (Ethernet). 639 */ 640 /* 641 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 642 * DIX code for the protocol. Make these device structure fields. 643 */ 644 switch (dev->type) { 645 default: 646 arp->ar_hrd = htons(dev->type); 647 arp->ar_pro = htons(ETH_P_IP); 648 break; 649 650 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 651 case ARPHRD_AX25: 652 arp->ar_hrd = htons(ARPHRD_AX25); 653 arp->ar_pro = htons(AX25_P_IP); 654 break; 655 656 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 657 case ARPHRD_NETROM: 658 arp->ar_hrd = htons(ARPHRD_NETROM); 659 arp->ar_pro = htons(AX25_P_IP); 660 break; 661 #endif 662 #endif 663 664 #if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 665 case ARPHRD_FDDI: 666 arp->ar_hrd = htons(ARPHRD_ETHER); 667 arp->ar_pro = htons(ETH_P_IP); 668 break; 669 #endif 670 #if defined(CONFIG_TR) || defined(CONFIG_TR_MODULE) 671 case ARPHRD_IEEE802_TR: 672 arp->ar_hrd = htons(ARPHRD_IEEE802); 673 arp->ar_pro = htons(ETH_P_IP); 674 break; 675 #endif 676 } 677 678 arp->ar_hln = dev->addr_len; 679 arp->ar_pln = 4; 680 arp->ar_op = htons(type); 681 682 arp_ptr=(unsigned char *)(arp+1); 683 684 memcpy(arp_ptr, src_hw, dev->addr_len); 685 arp_ptr += dev->addr_len; 686 memcpy(arp_ptr, &src_ip, 4); 687 arp_ptr += 4; 688 if (target_hw != NULL) 689 memcpy(arp_ptr, target_hw, dev->addr_len); 690 else 691 memset(arp_ptr, 0, dev->addr_len); 692 arp_ptr += dev->addr_len; 693 memcpy(arp_ptr, &dest_ip, 4); 694 695 return skb; 696 697 out: 698 kfree_skb(skb); 699 return NULL; 700 } 701 702 /* 703 * Send an arp packet. 704 */ 705 void arp_xmit(struct sk_buff *skb) 706 { 707 /* Send it off, maybe filter it using firewalling first. */ 708 NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 709 } 710 711 /* 712 * Create and send an arp packet. 713 */ 714 void arp_send(int type, int ptype, __be32 dest_ip, 715 struct net_device *dev, __be32 src_ip, 716 const unsigned char *dest_hw, const unsigned char *src_hw, 717 const unsigned char *target_hw) 718 { 719 struct sk_buff *skb; 720 721 /* 722 * No arp on this interface. 723 */ 724 725 if (dev->flags&IFF_NOARP) 726 return; 727 728 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 729 dest_hw, src_hw, target_hw); 730 if (skb == NULL) { 731 return; 732 } 733 734 arp_xmit(skb); 735 } 736 737 /* 738 * Process an arp request. 739 */ 740 741 static int arp_process(struct sk_buff *skb) 742 { 743 struct net_device *dev = skb->dev; 744 struct in_device *in_dev = in_dev_get(dev); 745 struct arphdr *arp; 746 unsigned char *arp_ptr; 747 struct rtable *rt; 748 unsigned char *sha; 749 __be32 sip, tip; 750 u16 dev_type = dev->type; 751 int addr_type; 752 struct neighbour *n; 753 struct net *net = dev_net(dev); 754 755 /* arp_rcv below verifies the ARP header and verifies the device 756 * is ARP'able. 757 */ 758 759 if (in_dev == NULL) 760 goto out; 761 762 arp = arp_hdr(skb); 763 764 switch (dev_type) { 765 default: 766 if (arp->ar_pro != htons(ETH_P_IP) || 767 htons(dev_type) != arp->ar_hrd) 768 goto out; 769 break; 770 case ARPHRD_ETHER: 771 case ARPHRD_IEEE802_TR: 772 case ARPHRD_FDDI: 773 case ARPHRD_IEEE802: 774 /* 775 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 776 * devices, according to RFC 2625) devices will accept ARP 777 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 778 * This is the case also of FDDI, where the RFC 1390 says that 779 * FDDI devices should accept ARP hardware of (1) Ethernet, 780 * however, to be more robust, we'll accept both 1 (Ethernet) 781 * or 6 (IEEE 802.2) 782 */ 783 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 784 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 785 arp->ar_pro != htons(ETH_P_IP)) 786 goto out; 787 break; 788 case ARPHRD_AX25: 789 if (arp->ar_pro != htons(AX25_P_IP) || 790 arp->ar_hrd != htons(ARPHRD_AX25)) 791 goto out; 792 break; 793 case ARPHRD_NETROM: 794 if (arp->ar_pro != htons(AX25_P_IP) || 795 arp->ar_hrd != htons(ARPHRD_NETROM)) 796 goto out; 797 break; 798 } 799 800 /* Understand only these message types */ 801 802 if (arp->ar_op != htons(ARPOP_REPLY) && 803 arp->ar_op != htons(ARPOP_REQUEST)) 804 goto out; 805 806 /* 807 * Extract fields 808 */ 809 arp_ptr= (unsigned char *)(arp+1); 810 sha = arp_ptr; 811 arp_ptr += dev->addr_len; 812 memcpy(&sip, arp_ptr, 4); 813 arp_ptr += 4; 814 arp_ptr += dev->addr_len; 815 memcpy(&tip, arp_ptr, 4); 816 /* 817 * Check for bad requests for 127.x.x.x and requests for multicast 818 * addresses. If this is one such, delete it. 819 */ 820 if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip)) 821 goto out; 822 823 /* 824 * Special case: We must set Frame Relay source Q.922 address 825 */ 826 if (dev_type == ARPHRD_DLCI) 827 sha = dev->broadcast; 828 829 /* 830 * Process entry. The idea here is we want to send a reply if it is a 831 * request for us or if it is a request for someone else that we hold 832 * a proxy for. We want to add an entry to our cache if it is a reply 833 * to us or if it is a request for our address. 834 * (The assumption for this last is that if someone is requesting our 835 * address, they are probably intending to talk to us, so it saves time 836 * if we cache their address. Their address is also probably not in 837 * our cache, since ours is not in their cache.) 838 * 839 * Putting this another way, we only care about replies if they are to 840 * us, in which case we add them to the cache. For requests, we care 841 * about those for us and those for our proxies. We reply to both, 842 * and in the case of requests for us we add the requester to the arp 843 * cache. 844 */ 845 846 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 847 if (sip == 0) { 848 if (arp->ar_op == htons(ARPOP_REQUEST) && 849 inet_addr_type(net, tip) == RTN_LOCAL && 850 !arp_ignore(in_dev, sip, tip)) 851 arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, 852 dev->dev_addr, sha); 853 goto out; 854 } 855 856 if (arp->ar_op == htons(ARPOP_REQUEST) && 857 ip_route_input_noref(skb, tip, sip, 0, dev) == 0) { 858 859 rt = skb_rtable(skb); 860 addr_type = rt->rt_type; 861 862 if (addr_type == RTN_LOCAL) { 863 int dont_send = 0; 864 865 if (!dont_send) 866 dont_send |= arp_ignore(in_dev,sip,tip); 867 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 868 dont_send |= arp_filter(sip,tip,dev); 869 if (!dont_send) { 870 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 871 if (n) { 872 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 873 neigh_release(n); 874 } 875 } 876 goto out; 877 } else if (IN_DEV_FORWARD(in_dev)) { 878 if (addr_type == RTN_UNICAST && 879 (arp_fwd_proxy(in_dev, dev, rt) || 880 arp_fwd_pvlan(in_dev, dev, rt, sip, tip) || 881 pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) 882 { 883 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 884 if (n) 885 neigh_release(n); 886 887 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 888 skb->pkt_type == PACKET_HOST || 889 in_dev->arp_parms->proxy_delay == 0) { 890 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 891 } else { 892 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 893 in_dev_put(in_dev); 894 return 0; 895 } 896 goto out; 897 } 898 } 899 } 900 901 /* Update our ARP tables */ 902 903 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 904 905 if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) { 906 /* Unsolicited ARP is not accepted by default. 907 It is possible, that this option should be enabled for some 908 devices (strip is candidate) 909 */ 910 if (n == NULL && 911 (arp->ar_op == htons(ARPOP_REPLY) || 912 (arp->ar_op == htons(ARPOP_REQUEST) && tip == sip)) && 913 inet_addr_type(net, sip) == RTN_UNICAST) 914 n = __neigh_lookup(&arp_tbl, &sip, dev, 1); 915 } 916 917 if (n) { 918 int state = NUD_REACHABLE; 919 int override; 920 921 /* If several different ARP replies follows back-to-back, 922 use the FIRST one. It is possible, if several proxy 923 agents are active. Taking the first reply prevents 924 arp trashing and chooses the fastest router. 925 */ 926 override = time_after(jiffies, n->updated + n->parms->locktime); 927 928 /* Broadcast replies and request packets 929 do not assert neighbour reachability. 930 */ 931 if (arp->ar_op != htons(ARPOP_REPLY) || 932 skb->pkt_type != PACKET_HOST) 933 state = NUD_STALE; 934 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 935 neigh_release(n); 936 } 937 938 out: 939 if (in_dev) 940 in_dev_put(in_dev); 941 consume_skb(skb); 942 return 0; 943 } 944 945 static void parp_redo(struct sk_buff *skb) 946 { 947 arp_process(skb); 948 } 949 950 951 /* 952 * Receive an arp request from the device layer. 953 */ 954 955 static int arp_rcv(struct sk_buff *skb, struct net_device *dev, 956 struct packet_type *pt, struct net_device *orig_dev) 957 { 958 struct arphdr *arp; 959 960 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 961 if (!pskb_may_pull(skb, arp_hdr_len(dev))) 962 goto freeskb; 963 964 arp = arp_hdr(skb); 965 if (arp->ar_hln != dev->addr_len || 966 dev->flags & IFF_NOARP || 967 skb->pkt_type == PACKET_OTHERHOST || 968 skb->pkt_type == PACKET_LOOPBACK || 969 arp->ar_pln != 4) 970 goto freeskb; 971 972 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 973 goto out_of_mem; 974 975 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 976 977 return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 978 979 freeskb: 980 kfree_skb(skb); 981 out_of_mem: 982 return 0; 983 } 984 985 /* 986 * User level interface (ioctl) 987 */ 988 989 /* 990 * Set (create) an ARP cache entry. 991 */ 992 993 static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) 994 { 995 if (dev == NULL) { 996 IPV4_DEVCONF_ALL(net, PROXY_ARP) = on; 997 return 0; 998 } 999 if (__in_dev_get_rtnl(dev)) { 1000 IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on); 1001 return 0; 1002 } 1003 return -ENXIO; 1004 } 1005 1006 static int arp_req_set_public(struct net *net, struct arpreq *r, 1007 struct net_device *dev) 1008 { 1009 __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1010 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1011 1012 if (mask && mask != htonl(0xFFFFFFFF)) 1013 return -EINVAL; 1014 if (!dev && (r->arp_flags & ATF_COM)) { 1015 dev = dev_getbyhwaddr(net, r->arp_ha.sa_family, 1016 r->arp_ha.sa_data); 1017 if (!dev) 1018 return -ENODEV; 1019 } 1020 if (mask) { 1021 if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL) 1022 return -ENOBUFS; 1023 return 0; 1024 } 1025 1026 return arp_req_set_proxy(net, dev, 1); 1027 } 1028 1029 static int arp_req_set(struct net *net, struct arpreq *r, 1030 struct net_device * dev) 1031 { 1032 __be32 ip; 1033 struct neighbour *neigh; 1034 int err; 1035 1036 if (r->arp_flags & ATF_PUBL) 1037 return arp_req_set_public(net, r, dev); 1038 1039 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1040 if (r->arp_flags & ATF_PERM) 1041 r->arp_flags |= ATF_COM; 1042 if (dev == NULL) { 1043 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1044 .tos = RTO_ONLINK } } }; 1045 struct rtable * rt; 1046 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1047 return err; 1048 dev = rt->u.dst.dev; 1049 ip_rt_put(rt); 1050 if (!dev) 1051 return -EINVAL; 1052 } 1053 switch (dev->type) { 1054 #if defined(CONFIG_FDDI) || defined(CONFIG_FDDI_MODULE) 1055 case ARPHRD_FDDI: 1056 /* 1057 * According to RFC 1390, FDDI devices should accept ARP 1058 * hardware types of 1 (Ethernet). However, to be more 1059 * robust, we'll accept hardware types of either 1 (Ethernet) 1060 * or 6 (IEEE 802.2). 1061 */ 1062 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1063 r->arp_ha.sa_family != ARPHRD_ETHER && 1064 r->arp_ha.sa_family != ARPHRD_IEEE802) 1065 return -EINVAL; 1066 break; 1067 #endif 1068 default: 1069 if (r->arp_ha.sa_family != dev->type) 1070 return -EINVAL; 1071 break; 1072 } 1073 1074 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1075 err = PTR_ERR(neigh); 1076 if (!IS_ERR(neigh)) { 1077 unsigned state = NUD_STALE; 1078 if (r->arp_flags & ATF_PERM) 1079 state = NUD_PERMANENT; 1080 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1081 r->arp_ha.sa_data : NULL, state, 1082 NEIGH_UPDATE_F_OVERRIDE| 1083 NEIGH_UPDATE_F_ADMIN); 1084 neigh_release(neigh); 1085 } 1086 return err; 1087 } 1088 1089 static unsigned arp_state_to_flags(struct neighbour *neigh) 1090 { 1091 unsigned flags = 0; 1092 if (neigh->nud_state&NUD_PERMANENT) 1093 flags = ATF_PERM|ATF_COM; 1094 else if (neigh->nud_state&NUD_VALID) 1095 flags = ATF_COM; 1096 return flags; 1097 } 1098 1099 /* 1100 * Get an ARP cache entry. 1101 */ 1102 1103 static int arp_req_get(struct arpreq *r, struct net_device *dev) 1104 { 1105 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1106 struct neighbour *neigh; 1107 int err = -ENXIO; 1108 1109 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1110 if (neigh) { 1111 read_lock_bh(&neigh->lock); 1112 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1113 r->arp_flags = arp_state_to_flags(neigh); 1114 read_unlock_bh(&neigh->lock); 1115 r->arp_ha.sa_family = dev->type; 1116 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1117 neigh_release(neigh); 1118 err = 0; 1119 } 1120 return err; 1121 } 1122 1123 static int arp_req_delete_public(struct net *net, struct arpreq *r, 1124 struct net_device *dev) 1125 { 1126 __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1127 __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1128 1129 if (mask == htonl(0xFFFFFFFF)) 1130 return pneigh_delete(&arp_tbl, net, &ip, dev); 1131 1132 if (mask) 1133 return -EINVAL; 1134 1135 return arp_req_set_proxy(net, dev, 0); 1136 } 1137 1138 static int arp_req_delete(struct net *net, struct arpreq *r, 1139 struct net_device * dev) 1140 { 1141 int err; 1142 __be32 ip; 1143 struct neighbour *neigh; 1144 1145 if (r->arp_flags & ATF_PUBL) 1146 return arp_req_delete_public(net, r, dev); 1147 1148 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1149 if (dev == NULL) { 1150 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1151 .tos = RTO_ONLINK } } }; 1152 struct rtable * rt; 1153 if ((err = ip_route_output_key(net, &rt, &fl)) != 0) 1154 return err; 1155 dev = rt->u.dst.dev; 1156 ip_rt_put(rt); 1157 if (!dev) 1158 return -EINVAL; 1159 } 1160 err = -ENXIO; 1161 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1162 if (neigh) { 1163 if (neigh->nud_state&~NUD_NOARP) 1164 err = neigh_update(neigh, NULL, NUD_FAILED, 1165 NEIGH_UPDATE_F_OVERRIDE| 1166 NEIGH_UPDATE_F_ADMIN); 1167 neigh_release(neigh); 1168 } 1169 return err; 1170 } 1171 1172 /* 1173 * Handle an ARP layer I/O control request. 1174 */ 1175 1176 int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1177 { 1178 int err; 1179 struct arpreq r; 1180 struct net_device *dev = NULL; 1181 1182 switch (cmd) { 1183 case SIOCDARP: 1184 case SIOCSARP: 1185 if (!capable(CAP_NET_ADMIN)) 1186 return -EPERM; 1187 case SIOCGARP: 1188 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1189 if (err) 1190 return -EFAULT; 1191 break; 1192 default: 1193 return -EINVAL; 1194 } 1195 1196 if (r.arp_pa.sa_family != AF_INET) 1197 return -EPFNOSUPPORT; 1198 1199 if (!(r.arp_flags & ATF_PUBL) && 1200 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1201 return -EINVAL; 1202 if (!(r.arp_flags & ATF_NETMASK)) 1203 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1204 htonl(0xFFFFFFFFUL); 1205 rtnl_lock(); 1206 if (r.arp_dev[0]) { 1207 err = -ENODEV; 1208 if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL) 1209 goto out; 1210 1211 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1212 if (!r.arp_ha.sa_family) 1213 r.arp_ha.sa_family = dev->type; 1214 err = -EINVAL; 1215 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1216 goto out; 1217 } else if (cmd == SIOCGARP) { 1218 err = -ENODEV; 1219 goto out; 1220 } 1221 1222 switch (cmd) { 1223 case SIOCDARP: 1224 err = arp_req_delete(net, &r, dev); 1225 break; 1226 case SIOCSARP: 1227 err = arp_req_set(net, &r, dev); 1228 break; 1229 case SIOCGARP: 1230 err = arp_req_get(&r, dev); 1231 if (!err && copy_to_user(arg, &r, sizeof(r))) 1232 err = -EFAULT; 1233 break; 1234 } 1235 out: 1236 rtnl_unlock(); 1237 return err; 1238 } 1239 1240 static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1241 { 1242 struct net_device *dev = ptr; 1243 1244 switch (event) { 1245 case NETDEV_CHANGEADDR: 1246 neigh_changeaddr(&arp_tbl, dev); 1247 rt_cache_flush(dev_net(dev), 0); 1248 break; 1249 default: 1250 break; 1251 } 1252 1253 return NOTIFY_DONE; 1254 } 1255 1256 static struct notifier_block arp_netdev_notifier = { 1257 .notifier_call = arp_netdev_event, 1258 }; 1259 1260 /* Note, that it is not on notifier chain. 1261 It is necessary, that this routine was called after route cache will be 1262 flushed. 1263 */ 1264 void arp_ifdown(struct net_device *dev) 1265 { 1266 neigh_ifdown(&arp_tbl, dev); 1267 } 1268 1269 1270 /* 1271 * Called once on startup. 1272 */ 1273 1274 static struct packet_type arp_packet_type __read_mostly = { 1275 .type = cpu_to_be16(ETH_P_ARP), 1276 .func = arp_rcv, 1277 }; 1278 1279 static int arp_proc_init(void); 1280 1281 void __init arp_init(void) 1282 { 1283 neigh_table_init(&arp_tbl); 1284 1285 dev_add_pack(&arp_packet_type); 1286 arp_proc_init(); 1287 #ifdef CONFIG_SYSCTL 1288 neigh_sysctl_register(NULL, &arp_tbl.parms, "ipv4", NULL); 1289 #endif 1290 register_netdevice_notifier(&arp_netdev_notifier); 1291 } 1292 1293 #ifdef CONFIG_PROC_FS 1294 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1295 1296 /* ------------------------------------------------------------------------ */ 1297 /* 1298 * ax25 -> ASCII conversion 1299 */ 1300 static char *ax2asc2(ax25_address *a, char *buf) 1301 { 1302 char c, *s; 1303 int n; 1304 1305 for (n = 0, s = buf; n < 6; n++) { 1306 c = (a->ax25_call[n] >> 1) & 0x7F; 1307 1308 if (c != ' ') *s++ = c; 1309 } 1310 1311 *s++ = '-'; 1312 1313 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1314 *s++ = '1'; 1315 n -= 10; 1316 } 1317 1318 *s++ = n + '0'; 1319 *s++ = '\0'; 1320 1321 if (*buf == '\0' || *buf == '-') 1322 return "*"; 1323 1324 return buf; 1325 1326 } 1327 #endif /* CONFIG_AX25 */ 1328 1329 #define HBUFFERLEN 30 1330 1331 static void arp_format_neigh_entry(struct seq_file *seq, 1332 struct neighbour *n) 1333 { 1334 char hbuffer[HBUFFERLEN]; 1335 int k, j; 1336 char tbuf[16]; 1337 struct net_device *dev = n->dev; 1338 int hatype = dev->type; 1339 1340 read_lock(&n->lock); 1341 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1342 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1343 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1344 ax2asc2((ax25_address *)n->ha, hbuffer); 1345 else { 1346 #endif 1347 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1348 hbuffer[k++] = hex_asc_hi(n->ha[j]); 1349 hbuffer[k++] = hex_asc_lo(n->ha[j]); 1350 hbuffer[k++] = ':'; 1351 } 1352 if (k != 0) 1353 --k; 1354 hbuffer[k] = 0; 1355 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1356 } 1357 #endif 1358 sprintf(tbuf, "%pI4", n->primary_key); 1359 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1360 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1361 read_unlock(&n->lock); 1362 } 1363 1364 static void arp_format_pneigh_entry(struct seq_file *seq, 1365 struct pneigh_entry *n) 1366 { 1367 struct net_device *dev = n->dev; 1368 int hatype = dev ? dev->type : 0; 1369 char tbuf[16]; 1370 1371 sprintf(tbuf, "%pI4", n->key); 1372 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1373 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1374 dev ? dev->name : "*"); 1375 } 1376 1377 static int arp_seq_show(struct seq_file *seq, void *v) 1378 { 1379 if (v == SEQ_START_TOKEN) { 1380 seq_puts(seq, "IP address HW type Flags " 1381 "HW address Mask Device\n"); 1382 } else { 1383 struct neigh_seq_state *state = seq->private; 1384 1385 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1386 arp_format_pneigh_entry(seq, v); 1387 else 1388 arp_format_neigh_entry(seq, v); 1389 } 1390 1391 return 0; 1392 } 1393 1394 static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1395 { 1396 /* Don't want to confuse "arp -a" w/ magic entries, 1397 * so we tell the generic iterator to skip NUD_NOARP. 1398 */ 1399 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1400 } 1401 1402 /* ------------------------------------------------------------------------ */ 1403 1404 static const struct seq_operations arp_seq_ops = { 1405 .start = arp_seq_start, 1406 .next = neigh_seq_next, 1407 .stop = neigh_seq_stop, 1408 .show = arp_seq_show, 1409 }; 1410 1411 static int arp_seq_open(struct inode *inode, struct file *file) 1412 { 1413 return seq_open_net(inode, file, &arp_seq_ops, 1414 sizeof(struct neigh_seq_state)); 1415 } 1416 1417 static const struct file_operations arp_seq_fops = { 1418 .owner = THIS_MODULE, 1419 .open = arp_seq_open, 1420 .read = seq_read, 1421 .llseek = seq_lseek, 1422 .release = seq_release_net, 1423 }; 1424 1425 1426 static int __net_init arp_net_init(struct net *net) 1427 { 1428 if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops)) 1429 return -ENOMEM; 1430 return 0; 1431 } 1432 1433 static void __net_exit arp_net_exit(struct net *net) 1434 { 1435 proc_net_remove(net, "arp"); 1436 } 1437 1438 static struct pernet_operations arp_net_ops = { 1439 .init = arp_net_init, 1440 .exit = arp_net_exit, 1441 }; 1442 1443 static int __init arp_proc_init(void) 1444 { 1445 return register_pernet_subsys(&arp_net_ops); 1446 } 1447 1448 #else /* CONFIG_PROC_FS */ 1449 1450 static int __init arp_proc_init(void) 1451 { 1452 return 0; 1453 } 1454 1455 #endif /* CONFIG_PROC_FS */ 1456 1457 EXPORT_SYMBOL(arp_broken_ops); 1458 EXPORT_SYMBOL(arp_find); 1459 EXPORT_SYMBOL(arp_create); 1460 EXPORT_SYMBOL(arp_xmit); 1461 EXPORT_SYMBOL(arp_send); 1462 EXPORT_SYMBOL(arp_tbl); 1463 1464 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1465 EXPORT_SYMBOL(clip_tbl_hook); 1466 #endif 1467