1 /* linux/net/inet/arp.c 2 * 3 * Version: $Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $ 4 * 5 * Copyright (C) 1994 by Florian La Roche 6 * 7 * This module implements the Address Resolution Protocol ARP (RFC 826), 8 * which is used to convert IP addresses (or in the future maybe other 9 * high-level addresses) into a low-level hardware address (like an Ethernet 10 * address). 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Fixes: 18 * Alan Cox : Removed the Ethernet assumptions in 19 * Florian's code 20 * Alan Cox : Fixed some small errors in the ARP 21 * logic 22 * Alan Cox : Allow >4K in /proc 23 * Alan Cox : Make ARP add its own protocol entry 24 * Ross Martin : Rewrote arp_rcv() and arp_get_info() 25 * Stephen Henson : Add AX25 support to arp_get_info() 26 * Alan Cox : Drop data when a device is downed. 27 * Alan Cox : Use init_timer(). 28 * Alan Cox : Double lock fixes. 29 * Martin Seine : Move the arphdr structure 30 * to if_arp.h for compatibility. 31 * with BSD based programs. 32 * Andrew Tridgell : Added ARP netmask code and 33 * re-arranged proxy handling. 34 * Alan Cox : Changed to use notifiers. 35 * Niibe Yutaka : Reply for this device or proxies only. 36 * Alan Cox : Don't proxy across hardware types! 37 * Jonathan Naylor : Added support for NET/ROM. 38 * Mike Shaver : RFC1122 checks. 39 * Jonathan Naylor : Only lookup the hardware address for 40 * the correct hardware type. 41 * Germano Caronni : Assorted subtle races. 42 * Craig Schlenter : Don't modify permanent entry 43 * during arp_rcv. 44 * Russ Nelson : Tidied up a few bits. 45 * Alexey Kuznetsov: Major changes to caching and behaviour, 46 * eg intelligent arp probing and 47 * generation 48 * of host down events. 49 * Alan Cox : Missing unlock in device events. 50 * Eckes : ARP ioctl control errors. 51 * Alexey Kuznetsov: Arp free fix. 52 * Manuel Rodriguez: Gratuitous ARP. 53 * Jonathan Layes : Added arpd support through kerneld 54 * message queue (960314) 55 * Mike Shaver : /proc/sys/net/ipv4/arp_* support 56 * Mike McLagan : Routing by source 57 * Stuart Cheshire : Metricom and grat arp fixes 58 * *** FOR 2.1 clean this up *** 59 * Lawrence V. Stefani: (08/12/96) Added FDDI support. 60 * Alan Cox : Took the AP1000 nasty FDDI hack and 61 * folded into the mainstream FDDI code. 62 * Ack spit, Linus how did you allow that 63 * one in... 64 * Jes Sorensen : Make FDDI work again in 2.1.x and 65 * clean up the APFDDI & gen. FDDI bits. 66 * Alexey Kuznetsov: new arp state machine; 67 * now it is in net/core/neighbour.c. 68 * Krzysztof Halasa: Added Frame Relay ARP support. 69 * Arnaldo C. Melo : convert /proc/net/arp to seq_file 70 * Shmulik Hen: Split arp_send to arp_create and 71 * arp_xmit so intermediate drivers like 72 * bonding can change the skb before 73 * sending (e.g. insert 8021q tag). 74 * Harald Welte : convert to make use of jenkins hash 75 */ 76 77 #include <linux/module.h> 78 #include <linux/types.h> 79 #include <linux/string.h> 80 #include <linux/kernel.h> 81 #include <linux/sched.h> 82 #include <linux/capability.h> 83 #include <linux/config.h> 84 #include <linux/socket.h> 85 #include <linux/sockios.h> 86 #include <linux/errno.h> 87 #include <linux/in.h> 88 #include <linux/mm.h> 89 #include <linux/inet.h> 90 #include <linux/inetdevice.h> 91 #include <linux/netdevice.h> 92 #include <linux/etherdevice.h> 93 #include <linux/fddidevice.h> 94 #include <linux/if_arp.h> 95 #include <linux/trdevice.h> 96 #include <linux/skbuff.h> 97 #include <linux/proc_fs.h> 98 #include <linux/seq_file.h> 99 #include <linux/stat.h> 100 #include <linux/init.h> 101 #include <linux/net.h> 102 #include <linux/rcupdate.h> 103 #include <linux/jhash.h> 104 #ifdef CONFIG_SYSCTL 105 #include <linux/sysctl.h> 106 #endif 107 108 #include <net/ip.h> 109 #include <net/icmp.h> 110 #include <net/route.h> 111 #include <net/protocol.h> 112 #include <net/tcp.h> 113 #include <net/sock.h> 114 #include <net/arp.h> 115 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 116 #include <net/ax25.h> 117 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 118 #include <net/netrom.h> 119 #endif 120 #endif 121 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 122 #include <net/atmclip.h> 123 struct neigh_table *clip_tbl_hook; 124 #endif 125 126 #include <asm/system.h> 127 #include <asm/uaccess.h> 128 129 #include <linux/netfilter_arp.h> 130 131 /* 132 * Interface to generic neighbour cache. 133 */ 134 static u32 arp_hash(const void *pkey, const struct net_device *dev); 135 static int arp_constructor(struct neighbour *neigh); 136 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); 137 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); 138 static void parp_redo(struct sk_buff *skb); 139 140 static struct neigh_ops arp_generic_ops = { 141 .family = AF_INET, 142 .solicit = arp_solicit, 143 .error_report = arp_error_report, 144 .output = neigh_resolve_output, 145 .connected_output = neigh_connected_output, 146 .hh_output = dev_queue_xmit, 147 .queue_xmit = dev_queue_xmit, 148 }; 149 150 static struct neigh_ops arp_hh_ops = { 151 .family = AF_INET, 152 .solicit = arp_solicit, 153 .error_report = arp_error_report, 154 .output = neigh_resolve_output, 155 .connected_output = neigh_resolve_output, 156 .hh_output = dev_queue_xmit, 157 .queue_xmit = dev_queue_xmit, 158 }; 159 160 static struct neigh_ops arp_direct_ops = { 161 .family = AF_INET, 162 .output = dev_queue_xmit, 163 .connected_output = dev_queue_xmit, 164 .hh_output = dev_queue_xmit, 165 .queue_xmit = dev_queue_xmit, 166 }; 167 168 struct neigh_ops arp_broken_ops = { 169 .family = AF_INET, 170 .solicit = arp_solicit, 171 .error_report = arp_error_report, 172 .output = neigh_compat_output, 173 .connected_output = neigh_compat_output, 174 .hh_output = dev_queue_xmit, 175 .queue_xmit = dev_queue_xmit, 176 }; 177 178 struct neigh_table arp_tbl = { 179 .family = AF_INET, 180 .entry_size = sizeof(struct neighbour) + 4, 181 .key_len = 4, 182 .hash = arp_hash, 183 .constructor = arp_constructor, 184 .proxy_redo = parp_redo, 185 .id = "arp_cache", 186 .parms = { 187 .tbl = &arp_tbl, 188 .base_reachable_time = 30 * HZ, 189 .retrans_time = 1 * HZ, 190 .gc_staletime = 60 * HZ, 191 .reachable_time = 30 * HZ, 192 .delay_probe_time = 5 * HZ, 193 .queue_len = 3, 194 .ucast_probes = 3, 195 .mcast_probes = 3, 196 .anycast_delay = 1 * HZ, 197 .proxy_delay = (8 * HZ) / 10, 198 .proxy_qlen = 64, 199 .locktime = 1 * HZ, 200 }, 201 .gc_interval = 30 * HZ, 202 .gc_thresh1 = 128, 203 .gc_thresh2 = 512, 204 .gc_thresh3 = 1024, 205 }; 206 207 int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir) 208 { 209 switch (dev->type) { 210 case ARPHRD_ETHER: 211 case ARPHRD_FDDI: 212 case ARPHRD_IEEE802: 213 ip_eth_mc_map(addr, haddr); 214 return 0; 215 case ARPHRD_IEEE802_TR: 216 ip_tr_mc_map(addr, haddr); 217 return 0; 218 case ARPHRD_INFINIBAND: 219 ip_ib_mc_map(addr, haddr); 220 return 0; 221 default: 222 if (dir) { 223 memcpy(haddr, dev->broadcast, dev->addr_len); 224 return 0; 225 } 226 } 227 return -EINVAL; 228 } 229 230 231 static u32 arp_hash(const void *pkey, const struct net_device *dev) 232 { 233 return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd); 234 } 235 236 static int arp_constructor(struct neighbour *neigh) 237 { 238 u32 addr = *(u32*)neigh->primary_key; 239 struct net_device *dev = neigh->dev; 240 struct in_device *in_dev; 241 struct neigh_parms *parms; 242 243 neigh->type = inet_addr_type(addr); 244 245 rcu_read_lock(); 246 in_dev = __in_dev_get_rcu(dev); 247 if (in_dev == NULL) { 248 rcu_read_unlock(); 249 return -EINVAL; 250 } 251 252 parms = in_dev->arp_parms; 253 __neigh_parms_put(neigh->parms); 254 neigh->parms = neigh_parms_clone(parms); 255 rcu_read_unlock(); 256 257 if (dev->hard_header == NULL) { 258 neigh->nud_state = NUD_NOARP; 259 neigh->ops = &arp_direct_ops; 260 neigh->output = neigh->ops->queue_xmit; 261 } else { 262 /* Good devices (checked by reading texts, but only Ethernet is 263 tested) 264 265 ARPHRD_ETHER: (ethernet, apfddi) 266 ARPHRD_FDDI: (fddi) 267 ARPHRD_IEEE802: (tr) 268 ARPHRD_METRICOM: (strip) 269 ARPHRD_ARCNET: 270 etc. etc. etc. 271 272 ARPHRD_IPDDP will also work, if author repairs it. 273 I did not it, because this driver does not work even 274 in old paradigm. 275 */ 276 277 #if 1 278 /* So... these "amateur" devices are hopeless. 279 The only thing, that I can say now: 280 It is very sad that we need to keep ugly obsolete 281 code to make them happy. 282 283 They should be moved to more reasonable state, now 284 they use rebuild_header INSTEAD OF hard_start_xmit!!! 285 Besides that, they are sort of out of date 286 (a lot of redundant clones/copies, useless in 2.1), 287 I wonder why people believe that they work. 288 */ 289 switch (dev->type) { 290 default: 291 break; 292 case ARPHRD_ROSE: 293 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 294 case ARPHRD_AX25: 295 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 296 case ARPHRD_NETROM: 297 #endif 298 neigh->ops = &arp_broken_ops; 299 neigh->output = neigh->ops->output; 300 return 0; 301 #endif 302 ;} 303 #endif 304 if (neigh->type == RTN_MULTICAST) { 305 neigh->nud_state = NUD_NOARP; 306 arp_mc_map(addr, neigh->ha, dev, 1); 307 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 308 neigh->nud_state = NUD_NOARP; 309 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 310 } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { 311 neigh->nud_state = NUD_NOARP; 312 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 313 } 314 if (dev->hard_header_cache) 315 neigh->ops = &arp_hh_ops; 316 else 317 neigh->ops = &arp_generic_ops; 318 if (neigh->nud_state&NUD_VALID) 319 neigh->output = neigh->ops->connected_output; 320 else 321 neigh->output = neigh->ops->output; 322 } 323 return 0; 324 } 325 326 static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) 327 { 328 dst_link_failure(skb); 329 kfree_skb(skb); 330 } 331 332 static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) 333 { 334 u32 saddr = 0; 335 u8 *dst_ha = NULL; 336 struct net_device *dev = neigh->dev; 337 u32 target = *(u32*)neigh->primary_key; 338 int probes = atomic_read(&neigh->probes); 339 struct in_device *in_dev = in_dev_get(dev); 340 341 if (!in_dev) 342 return; 343 344 switch (IN_DEV_ARP_ANNOUNCE(in_dev)) { 345 default: 346 case 0: /* By default announce any local IP */ 347 if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) 348 saddr = skb->nh.iph->saddr; 349 break; 350 case 1: /* Restrict announcements of saddr in same subnet */ 351 if (!skb) 352 break; 353 saddr = skb->nh.iph->saddr; 354 if (inet_addr_type(saddr) == RTN_LOCAL) { 355 /* saddr should be known to target */ 356 if (inet_addr_onlink(in_dev, target, saddr)) 357 break; 358 } 359 saddr = 0; 360 break; 361 case 2: /* Avoid secondary IPs, get a primary/preferred one */ 362 break; 363 } 364 365 if (in_dev) 366 in_dev_put(in_dev); 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 } 387 388 static int arp_ignore(struct in_device *in_dev, struct net_device *dev, 389 u32 sip, u32 tip) 390 { 391 int scope; 392 393 switch (IN_DEV_ARP_IGNORE(in_dev)) { 394 case 0: /* Reply, the tip is already validated */ 395 return 0; 396 case 1: /* Reply only if tip is configured on the incoming interface */ 397 sip = 0; 398 scope = RT_SCOPE_HOST; 399 break; 400 case 2: /* 401 * Reply only if tip is configured on the incoming interface 402 * and is in same subnet as sip 403 */ 404 scope = RT_SCOPE_HOST; 405 break; 406 case 3: /* Do not reply for scope host addresses */ 407 sip = 0; 408 scope = RT_SCOPE_LINK; 409 dev = NULL; 410 break; 411 case 4: /* Reserved */ 412 case 5: 413 case 6: 414 case 7: 415 return 0; 416 case 8: /* Do not reply */ 417 return 1; 418 default: 419 return 0; 420 } 421 return !inet_confirm_addr(dev, sip, tip, scope); 422 } 423 424 static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev) 425 { 426 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip, 427 .saddr = tip } } }; 428 struct rtable *rt; 429 int flag = 0; 430 /*unsigned long now; */ 431 432 if (ip_route_output_key(&rt, &fl) < 0) 433 return 1; 434 if (rt->u.dst.dev != dev) { 435 NET_INC_STATS_BH(LINUX_MIB_ARPFILTER); 436 flag = 1; 437 } 438 ip_rt_put(rt); 439 return flag; 440 } 441 442 /* OBSOLETE FUNCTIONS */ 443 444 /* 445 * Find an arp mapping in the cache. If not found, post a request. 446 * 447 * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, 448 * even if it exists. It is supposed that skb->dev was mangled 449 * by a virtual device (eql, shaper). Nobody but broken devices 450 * is allowed to use this function, it is scheduled to be removed. --ANK 451 */ 452 453 static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev) 454 { 455 switch (addr_hint) { 456 case RTN_LOCAL: 457 printk(KERN_DEBUG "ARP: arp called for own IP address\n"); 458 memcpy(haddr, dev->dev_addr, dev->addr_len); 459 return 1; 460 case RTN_MULTICAST: 461 arp_mc_map(paddr, haddr, dev, 1); 462 return 1; 463 case RTN_BROADCAST: 464 memcpy(haddr, dev->broadcast, dev->addr_len); 465 return 1; 466 } 467 return 0; 468 } 469 470 471 int arp_find(unsigned char *haddr, struct sk_buff *skb) 472 { 473 struct net_device *dev = skb->dev; 474 u32 paddr; 475 struct neighbour *n; 476 477 if (!skb->dst) { 478 printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); 479 kfree_skb(skb); 480 return 1; 481 } 482 483 paddr = ((struct rtable*)skb->dst)->rt_gateway; 484 485 if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) 486 return 0; 487 488 n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); 489 490 if (n) { 491 n->used = jiffies; 492 if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { 493 read_lock_bh(&n->lock); 494 memcpy(haddr, n->ha, dev->addr_len); 495 read_unlock_bh(&n->lock); 496 neigh_release(n); 497 return 0; 498 } 499 neigh_release(n); 500 } else 501 kfree_skb(skb); 502 return 1; 503 } 504 505 /* END OF OBSOLETE FUNCTIONS */ 506 507 int 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 u32 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 */ 533 534 static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt) 535 { 536 struct in_device *out_dev; 537 int imi, omi = -1; 538 539 if (!IN_DEV_PROXY_ARP(in_dev)) 540 return 0; 541 542 if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0) 543 return 1; 544 if (imi == -1) 545 return 0; 546 547 /* place to check for proxy_arp for routes */ 548 549 if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) { 550 omi = IN_DEV_MEDIUM_ID(out_dev); 551 in_dev_put(out_dev); 552 } 553 return (omi != imi && omi != -1); 554 } 555 556 /* 557 * Interface to link layer: send routine and receive handler. 558 */ 559 560 /* 561 * Create an arp packet. If (dest_hw == NULL), we create a broadcast 562 * message. 563 */ 564 struct sk_buff *arp_create(int type, int ptype, u32 dest_ip, 565 struct net_device *dev, u32 src_ip, 566 unsigned char *dest_hw, unsigned char *src_hw, 567 unsigned char *target_hw) 568 { 569 struct sk_buff *skb; 570 struct arphdr *arp; 571 unsigned char *arp_ptr; 572 573 /* 574 * Allocate a buffer 575 */ 576 577 skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) 578 + LL_RESERVED_SPACE(dev), GFP_ATOMIC); 579 if (skb == NULL) 580 return NULL; 581 582 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 583 skb->nh.raw = skb->data; 584 arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); 585 skb->dev = dev; 586 skb->protocol = htons(ETH_P_ARP); 587 if (src_hw == NULL) 588 src_hw = dev->dev_addr; 589 if (dest_hw == NULL) 590 dest_hw = dev->broadcast; 591 592 /* 593 * Fill the device header for the ARP frame 594 */ 595 if (dev->hard_header && 596 dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0) 597 goto out; 598 599 /* 600 * Fill out the arp protocol part. 601 * 602 * The arp hardware type should match the device type, except for FDDI, 603 * which (according to RFC 1390) should always equal 1 (Ethernet). 604 */ 605 /* 606 * Exceptions everywhere. AX.25 uses the AX.25 PID value not the 607 * DIX code for the protocol. Make these device structure fields. 608 */ 609 switch (dev->type) { 610 default: 611 arp->ar_hrd = htons(dev->type); 612 arp->ar_pro = htons(ETH_P_IP); 613 break; 614 615 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 616 case ARPHRD_AX25: 617 arp->ar_hrd = htons(ARPHRD_AX25); 618 arp->ar_pro = htons(AX25_P_IP); 619 break; 620 621 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 622 case ARPHRD_NETROM: 623 arp->ar_hrd = htons(ARPHRD_NETROM); 624 arp->ar_pro = htons(AX25_P_IP); 625 break; 626 #endif 627 #endif 628 629 #ifdef CONFIG_FDDI 630 case ARPHRD_FDDI: 631 arp->ar_hrd = htons(ARPHRD_ETHER); 632 arp->ar_pro = htons(ETH_P_IP); 633 break; 634 #endif 635 #ifdef CONFIG_TR 636 case ARPHRD_IEEE802_TR: 637 arp->ar_hrd = htons(ARPHRD_IEEE802); 638 arp->ar_pro = htons(ETH_P_IP); 639 break; 640 #endif 641 } 642 643 arp->ar_hln = dev->addr_len; 644 arp->ar_pln = 4; 645 arp->ar_op = htons(type); 646 647 arp_ptr=(unsigned char *)(arp+1); 648 649 memcpy(arp_ptr, src_hw, dev->addr_len); 650 arp_ptr+=dev->addr_len; 651 memcpy(arp_ptr, &src_ip,4); 652 arp_ptr+=4; 653 if (target_hw != NULL) 654 memcpy(arp_ptr, target_hw, dev->addr_len); 655 else 656 memset(arp_ptr, 0, dev->addr_len); 657 arp_ptr+=dev->addr_len; 658 memcpy(arp_ptr, &dest_ip, 4); 659 660 return skb; 661 662 out: 663 kfree_skb(skb); 664 return NULL; 665 } 666 667 /* 668 * Send an arp packet. 669 */ 670 void arp_xmit(struct sk_buff *skb) 671 { 672 /* Send it off, maybe filter it using firewalling first. */ 673 NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit); 674 } 675 676 /* 677 * Create and send an arp packet. 678 */ 679 void arp_send(int type, int ptype, u32 dest_ip, 680 struct net_device *dev, u32 src_ip, 681 unsigned char *dest_hw, unsigned char *src_hw, 682 unsigned char *target_hw) 683 { 684 struct sk_buff *skb; 685 686 /* 687 * No arp on this interface. 688 */ 689 690 if (dev->flags&IFF_NOARP) 691 return; 692 693 skb = arp_create(type, ptype, dest_ip, dev, src_ip, 694 dest_hw, src_hw, target_hw); 695 if (skb == NULL) { 696 return; 697 } 698 699 arp_xmit(skb); 700 } 701 702 /* 703 * Process an arp request. 704 */ 705 706 static int arp_process(struct sk_buff *skb) 707 { 708 struct net_device *dev = skb->dev; 709 struct in_device *in_dev = in_dev_get(dev); 710 struct arphdr *arp; 711 unsigned char *arp_ptr; 712 struct rtable *rt; 713 unsigned char *sha, *tha; 714 u32 sip, tip; 715 u16 dev_type = dev->type; 716 int addr_type; 717 struct neighbour *n; 718 719 /* arp_rcv below verifies the ARP header and verifies the device 720 * is ARP'able. 721 */ 722 723 if (in_dev == NULL) 724 goto out; 725 726 arp = skb->nh.arph; 727 728 switch (dev_type) { 729 default: 730 if (arp->ar_pro != htons(ETH_P_IP) || 731 htons(dev_type) != arp->ar_hrd) 732 goto out; 733 break; 734 #ifdef CONFIG_NET_ETHERNET 735 case ARPHRD_ETHER: 736 #endif 737 #ifdef CONFIG_TR 738 case ARPHRD_IEEE802_TR: 739 #endif 740 #ifdef CONFIG_FDDI 741 case ARPHRD_FDDI: 742 #endif 743 #ifdef CONFIG_NET_FC 744 case ARPHRD_IEEE802: 745 #endif 746 #if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \ 747 defined(CONFIG_FDDI) || defined(CONFIG_NET_FC) 748 /* 749 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802 750 * devices, according to RFC 2625) devices will accept ARP 751 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2). 752 * This is the case also of FDDI, where the RFC 1390 says that 753 * FDDI devices should accept ARP hardware of (1) Ethernet, 754 * however, to be more robust, we'll accept both 1 (Ethernet) 755 * or 6 (IEEE 802.2) 756 */ 757 if ((arp->ar_hrd != htons(ARPHRD_ETHER) && 758 arp->ar_hrd != htons(ARPHRD_IEEE802)) || 759 arp->ar_pro != htons(ETH_P_IP)) 760 goto out; 761 break; 762 #endif 763 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 764 case ARPHRD_AX25: 765 if (arp->ar_pro != htons(AX25_P_IP) || 766 arp->ar_hrd != htons(ARPHRD_AX25)) 767 goto out; 768 break; 769 #if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) 770 case ARPHRD_NETROM: 771 if (arp->ar_pro != htons(AX25_P_IP) || 772 arp->ar_hrd != htons(ARPHRD_NETROM)) 773 goto out; 774 break; 775 #endif 776 #endif 777 } 778 779 /* Understand only these message types */ 780 781 if (arp->ar_op != htons(ARPOP_REPLY) && 782 arp->ar_op != htons(ARPOP_REQUEST)) 783 goto out; 784 785 /* 786 * Extract fields 787 */ 788 arp_ptr= (unsigned char *)(arp+1); 789 sha = arp_ptr; 790 arp_ptr += dev->addr_len; 791 memcpy(&sip, arp_ptr, 4); 792 arp_ptr += 4; 793 tha = arp_ptr; 794 arp_ptr += dev->addr_len; 795 memcpy(&tip, arp_ptr, 4); 796 /* 797 * Check for bad requests for 127.x.x.x and requests for multicast 798 * addresses. If this is one such, delete it. 799 */ 800 if (LOOPBACK(tip) || MULTICAST(tip)) 801 goto out; 802 803 /* 804 * Special case: We must set Frame Relay source Q.922 address 805 */ 806 if (dev_type == ARPHRD_DLCI) 807 sha = dev->broadcast; 808 809 /* 810 * Process entry. The idea here is we want to send a reply if it is a 811 * request for us or if it is a request for someone else that we hold 812 * a proxy for. We want to add an entry to our cache if it is a reply 813 * to us or if it is a request for our address. 814 * (The assumption for this last is that if someone is requesting our 815 * address, they are probably intending to talk to us, so it saves time 816 * if we cache their address. Their address is also probably not in 817 * our cache, since ours is not in their cache.) 818 * 819 * Putting this another way, we only care about replies if they are to 820 * us, in which case we add them to the cache. For requests, we care 821 * about those for us and those for our proxies. We reply to both, 822 * and in the case of requests for us we add the requester to the arp 823 * cache. 824 */ 825 826 /* Special case: IPv4 duplicate address detection packet (RFC2131) */ 827 if (sip == 0) { 828 if (arp->ar_op == htons(ARPOP_REQUEST) && 829 inet_addr_type(tip) == RTN_LOCAL && 830 !arp_ignore(in_dev,dev,sip,tip)) 831 arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); 832 goto out; 833 } 834 835 if (arp->ar_op == htons(ARPOP_REQUEST) && 836 ip_route_input(skb, tip, sip, 0, dev) == 0) { 837 838 rt = (struct rtable*)skb->dst; 839 addr_type = rt->rt_type; 840 841 if (addr_type == RTN_LOCAL) { 842 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 843 if (n) { 844 int dont_send = 0; 845 846 if (!dont_send) 847 dont_send |= arp_ignore(in_dev,dev,sip,tip); 848 if (!dont_send && IN_DEV_ARPFILTER(in_dev)) 849 dont_send |= arp_filter(sip,tip,dev); 850 if (!dont_send) 851 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 852 853 neigh_release(n); 854 } 855 goto out; 856 } else if (IN_DEV_FORWARD(in_dev)) { 857 if ((rt->rt_flags&RTCF_DNAT) || 858 (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && 859 (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { 860 n = neigh_event_ns(&arp_tbl, sha, &sip, dev); 861 if (n) 862 neigh_release(n); 863 864 if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED || 865 skb->pkt_type == PACKET_HOST || 866 in_dev->arp_parms->proxy_delay == 0) { 867 arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); 868 } else { 869 pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); 870 in_dev_put(in_dev); 871 return 0; 872 } 873 goto out; 874 } 875 } 876 } 877 878 /* Update our ARP tables */ 879 880 n = __neigh_lookup(&arp_tbl, &sip, dev, 0); 881 882 if (ipv4_devconf.arp_accept) { 883 /* Unsolicited ARP is not accepted by default. 884 It is possible, that this option should be enabled for some 885 devices (strip is candidate) 886 */ 887 if (n == NULL && 888 arp->ar_op == htons(ARPOP_REPLY) && 889 inet_addr_type(sip) == RTN_UNICAST) 890 n = __neigh_lookup(&arp_tbl, &sip, dev, -1); 891 } 892 893 if (n) { 894 int state = NUD_REACHABLE; 895 int override; 896 897 /* If several different ARP replies follows back-to-back, 898 use the FIRST one. It is possible, if several proxy 899 agents are active. Taking the first reply prevents 900 arp trashing and chooses the fastest router. 901 */ 902 override = time_after(jiffies, n->updated + n->parms->locktime); 903 904 /* Broadcast replies and request packets 905 do not assert neighbour reachability. 906 */ 907 if (arp->ar_op != htons(ARPOP_REPLY) || 908 skb->pkt_type != PACKET_HOST) 909 state = NUD_STALE; 910 neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0); 911 neigh_release(n); 912 } 913 914 out: 915 if (in_dev) 916 in_dev_put(in_dev); 917 kfree_skb(skb); 918 return 0; 919 } 920 921 static void parp_redo(struct sk_buff *skb) 922 { 923 arp_process(skb); 924 } 925 926 927 /* 928 * Receive an arp request from the device layer. 929 */ 930 931 int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) 932 { 933 struct arphdr *arp; 934 935 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ 936 if (!pskb_may_pull(skb, (sizeof(struct arphdr) + 937 (2 * dev->addr_len) + 938 (2 * sizeof(u32))))) 939 goto freeskb; 940 941 arp = skb->nh.arph; 942 if (arp->ar_hln != dev->addr_len || 943 dev->flags & IFF_NOARP || 944 skb->pkt_type == PACKET_OTHERHOST || 945 skb->pkt_type == PACKET_LOOPBACK || 946 arp->ar_pln != 4) 947 goto freeskb; 948 949 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) 950 goto out_of_mem; 951 952 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 953 954 return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); 955 956 freeskb: 957 kfree_skb(skb); 958 out_of_mem: 959 return 0; 960 } 961 962 /* 963 * User level interface (ioctl) 964 */ 965 966 /* 967 * Set (create) an ARP cache entry. 968 */ 969 970 static int arp_req_set(struct arpreq *r, struct net_device * dev) 971 { 972 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 973 struct neighbour *neigh; 974 int err; 975 976 if (r->arp_flags&ATF_PUBL) { 977 u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; 978 if (mask && mask != 0xFFFFFFFF) 979 return -EINVAL; 980 if (!dev && (r->arp_flags & ATF_COM)) { 981 dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data); 982 if (!dev) 983 return -ENODEV; 984 } 985 if (mask) { 986 if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) 987 return -ENOBUFS; 988 return 0; 989 } 990 if (dev == NULL) { 991 ipv4_devconf.proxy_arp = 1; 992 return 0; 993 } 994 if (__in_dev_get_rtnl(dev)) { 995 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 1; 996 return 0; 997 } 998 return -ENXIO; 999 } 1000 1001 if (r->arp_flags & ATF_PERM) 1002 r->arp_flags |= ATF_COM; 1003 if (dev == NULL) { 1004 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1005 .tos = RTO_ONLINK } } }; 1006 struct rtable * rt; 1007 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1008 return err; 1009 dev = rt->u.dst.dev; 1010 ip_rt_put(rt); 1011 if (!dev) 1012 return -EINVAL; 1013 } 1014 switch (dev->type) { 1015 #ifdef CONFIG_FDDI 1016 case ARPHRD_FDDI: 1017 /* 1018 * According to RFC 1390, FDDI devices should accept ARP 1019 * hardware types of 1 (Ethernet). However, to be more 1020 * robust, we'll accept hardware types of either 1 (Ethernet) 1021 * or 6 (IEEE 802.2). 1022 */ 1023 if (r->arp_ha.sa_family != ARPHRD_FDDI && 1024 r->arp_ha.sa_family != ARPHRD_ETHER && 1025 r->arp_ha.sa_family != ARPHRD_IEEE802) 1026 return -EINVAL; 1027 break; 1028 #endif 1029 default: 1030 if (r->arp_ha.sa_family != dev->type) 1031 return -EINVAL; 1032 break; 1033 } 1034 1035 neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev); 1036 err = PTR_ERR(neigh); 1037 if (!IS_ERR(neigh)) { 1038 unsigned state = NUD_STALE; 1039 if (r->arp_flags & ATF_PERM) 1040 state = NUD_PERMANENT; 1041 err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? 1042 r->arp_ha.sa_data : NULL, state, 1043 NEIGH_UPDATE_F_OVERRIDE| 1044 NEIGH_UPDATE_F_ADMIN); 1045 neigh_release(neigh); 1046 } 1047 return err; 1048 } 1049 1050 static unsigned arp_state_to_flags(struct neighbour *neigh) 1051 { 1052 unsigned flags = 0; 1053 if (neigh->nud_state&NUD_PERMANENT) 1054 flags = ATF_PERM|ATF_COM; 1055 else if (neigh->nud_state&NUD_VALID) 1056 flags = ATF_COM; 1057 return flags; 1058 } 1059 1060 /* 1061 * Get an ARP cache entry. 1062 */ 1063 1064 static int arp_req_get(struct arpreq *r, struct net_device *dev) 1065 { 1066 u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; 1067 struct neighbour *neigh; 1068 int err = -ENXIO; 1069 1070 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1071 if (neigh) { 1072 read_lock_bh(&neigh->lock); 1073 memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); 1074 r->arp_flags = arp_state_to_flags(neigh); 1075 read_unlock_bh(&neigh->lock); 1076 r->arp_ha.sa_family = dev->type; 1077 strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); 1078 neigh_release(neigh); 1079 err = 0; 1080 } 1081 return err; 1082 } 1083 1084 static int arp_req_delete(struct arpreq *r, struct net_device * dev) 1085 { 1086 int err; 1087 u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; 1088 struct neighbour *neigh; 1089 1090 if (r->arp_flags & ATF_PUBL) { 1091 u32 mask = 1092 ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; 1093 if (mask == 0xFFFFFFFF) 1094 return pneigh_delete(&arp_tbl, &ip, dev); 1095 if (mask == 0) { 1096 if (dev == NULL) { 1097 ipv4_devconf.proxy_arp = 0; 1098 return 0; 1099 } 1100 if (__in_dev_get_rtnl(dev)) { 1101 __in_dev_get_rtnl(dev)->cnf.proxy_arp = 0; 1102 return 0; 1103 } 1104 return -ENXIO; 1105 } 1106 return -EINVAL; 1107 } 1108 1109 if (dev == NULL) { 1110 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip, 1111 .tos = RTO_ONLINK } } }; 1112 struct rtable * rt; 1113 if ((err = ip_route_output_key(&rt, &fl)) != 0) 1114 return err; 1115 dev = rt->u.dst.dev; 1116 ip_rt_put(rt); 1117 if (!dev) 1118 return -EINVAL; 1119 } 1120 err = -ENXIO; 1121 neigh = neigh_lookup(&arp_tbl, &ip, dev); 1122 if (neigh) { 1123 if (neigh->nud_state&~NUD_NOARP) 1124 err = neigh_update(neigh, NULL, NUD_FAILED, 1125 NEIGH_UPDATE_F_OVERRIDE| 1126 NEIGH_UPDATE_F_ADMIN); 1127 neigh_release(neigh); 1128 } 1129 return err; 1130 } 1131 1132 /* 1133 * Handle an ARP layer I/O control request. 1134 */ 1135 1136 int arp_ioctl(unsigned int cmd, void __user *arg) 1137 { 1138 int err; 1139 struct arpreq r; 1140 struct net_device *dev = NULL; 1141 1142 switch (cmd) { 1143 case SIOCDARP: 1144 case SIOCSARP: 1145 if (!capable(CAP_NET_ADMIN)) 1146 return -EPERM; 1147 case SIOCGARP: 1148 err = copy_from_user(&r, arg, sizeof(struct arpreq)); 1149 if (err) 1150 return -EFAULT; 1151 break; 1152 default: 1153 return -EINVAL; 1154 } 1155 1156 if (r.arp_pa.sa_family != AF_INET) 1157 return -EPFNOSUPPORT; 1158 1159 if (!(r.arp_flags & ATF_PUBL) && 1160 (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) 1161 return -EINVAL; 1162 if (!(r.arp_flags & ATF_NETMASK)) 1163 ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = 1164 htonl(0xFFFFFFFFUL); 1165 rtnl_lock(); 1166 if (r.arp_dev[0]) { 1167 err = -ENODEV; 1168 if ((dev = __dev_get_by_name(r.arp_dev)) == NULL) 1169 goto out; 1170 1171 /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ 1172 if (!r.arp_ha.sa_family) 1173 r.arp_ha.sa_family = dev->type; 1174 err = -EINVAL; 1175 if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) 1176 goto out; 1177 } else if (cmd == SIOCGARP) { 1178 err = -ENODEV; 1179 goto out; 1180 } 1181 1182 switch(cmd) { 1183 case SIOCDARP: 1184 err = arp_req_delete(&r, dev); 1185 break; 1186 case SIOCSARP: 1187 err = arp_req_set(&r, dev); 1188 break; 1189 case SIOCGARP: 1190 err = arp_req_get(&r, dev); 1191 if (!err && copy_to_user(arg, &r, sizeof(r))) 1192 err = -EFAULT; 1193 break; 1194 } 1195 out: 1196 rtnl_unlock(); 1197 return err; 1198 } 1199 1200 static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1201 { 1202 struct net_device *dev = ptr; 1203 1204 switch (event) { 1205 case NETDEV_CHANGEADDR: 1206 neigh_changeaddr(&arp_tbl, dev); 1207 rt_cache_flush(0); 1208 break; 1209 default: 1210 break; 1211 } 1212 1213 return NOTIFY_DONE; 1214 } 1215 1216 static struct notifier_block arp_netdev_notifier = { 1217 .notifier_call = arp_netdev_event, 1218 }; 1219 1220 /* Note, that it is not on notifier chain. 1221 It is necessary, that this routine was called after route cache will be 1222 flushed. 1223 */ 1224 void arp_ifdown(struct net_device *dev) 1225 { 1226 neigh_ifdown(&arp_tbl, dev); 1227 } 1228 1229 1230 /* 1231 * Called once on startup. 1232 */ 1233 1234 static struct packet_type arp_packet_type = { 1235 .type = __constant_htons(ETH_P_ARP), 1236 .func = arp_rcv, 1237 }; 1238 1239 static int arp_proc_init(void); 1240 1241 void __init arp_init(void) 1242 { 1243 neigh_table_init(&arp_tbl); 1244 1245 dev_add_pack(&arp_packet_type); 1246 arp_proc_init(); 1247 #ifdef CONFIG_SYSCTL 1248 neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, 1249 NET_IPV4_NEIGH, "ipv4", NULL, NULL); 1250 #endif 1251 register_netdevice_notifier(&arp_netdev_notifier); 1252 } 1253 1254 #ifdef CONFIG_PROC_FS 1255 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1256 1257 /* ------------------------------------------------------------------------ */ 1258 /* 1259 * ax25 -> ASCII conversion 1260 */ 1261 static char *ax2asc2(ax25_address *a, char *buf) 1262 { 1263 char c, *s; 1264 int n; 1265 1266 for (n = 0, s = buf; n < 6; n++) { 1267 c = (a->ax25_call[n] >> 1) & 0x7F; 1268 1269 if (c != ' ') *s++ = c; 1270 } 1271 1272 *s++ = '-'; 1273 1274 if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { 1275 *s++ = '1'; 1276 n -= 10; 1277 } 1278 1279 *s++ = n + '0'; 1280 *s++ = '\0'; 1281 1282 if (*buf == '\0' || *buf == '-') 1283 return "*"; 1284 1285 return buf; 1286 1287 } 1288 #endif /* CONFIG_AX25 */ 1289 1290 #define HBUFFERLEN 30 1291 1292 static void arp_format_neigh_entry(struct seq_file *seq, 1293 struct neighbour *n) 1294 { 1295 char hbuffer[HBUFFERLEN]; 1296 const char hexbuf[] = "0123456789ABCDEF"; 1297 int k, j; 1298 char tbuf[16]; 1299 struct net_device *dev = n->dev; 1300 int hatype = dev->type; 1301 1302 read_lock(&n->lock); 1303 /* Convert hardware address to XX:XX:XX:XX ... form. */ 1304 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1305 if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) 1306 ax2asc2((ax25_address *)n->ha, hbuffer); 1307 else { 1308 #endif 1309 for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) { 1310 hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15]; 1311 hbuffer[k++] = hexbuf[n->ha[j] & 15]; 1312 hbuffer[k++] = ':'; 1313 } 1314 hbuffer[--k] = 0; 1315 #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) 1316 } 1317 #endif 1318 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key)); 1319 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1320 tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name); 1321 read_unlock(&n->lock); 1322 } 1323 1324 static void arp_format_pneigh_entry(struct seq_file *seq, 1325 struct pneigh_entry *n) 1326 { 1327 struct net_device *dev = n->dev; 1328 int hatype = dev ? dev->type : 0; 1329 char tbuf[16]; 1330 1331 sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key)); 1332 seq_printf(seq, "%-16s 0x%-10x0x%-10x%s * %s\n", 1333 tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00", 1334 dev ? dev->name : "*"); 1335 } 1336 1337 static int arp_seq_show(struct seq_file *seq, void *v) 1338 { 1339 if (v == SEQ_START_TOKEN) { 1340 seq_puts(seq, "IP address HW type Flags " 1341 "HW address Mask Device\n"); 1342 } else { 1343 struct neigh_seq_state *state = seq->private; 1344 1345 if (state->flags & NEIGH_SEQ_IS_PNEIGH) 1346 arp_format_pneigh_entry(seq, v); 1347 else 1348 arp_format_neigh_entry(seq, v); 1349 } 1350 1351 return 0; 1352 } 1353 1354 static void *arp_seq_start(struct seq_file *seq, loff_t *pos) 1355 { 1356 /* Don't want to confuse "arp -a" w/ magic entries, 1357 * so we tell the generic iterator to skip NUD_NOARP. 1358 */ 1359 return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP); 1360 } 1361 1362 /* ------------------------------------------------------------------------ */ 1363 1364 static struct seq_operations arp_seq_ops = { 1365 .start = arp_seq_start, 1366 .next = neigh_seq_next, 1367 .stop = neigh_seq_stop, 1368 .show = arp_seq_show, 1369 }; 1370 1371 static int arp_seq_open(struct inode *inode, struct file *file) 1372 { 1373 struct seq_file *seq; 1374 int rc = -ENOMEM; 1375 struct neigh_seq_state *s = kmalloc(sizeof(*s), GFP_KERNEL); 1376 1377 if (!s) 1378 goto out; 1379 1380 memset(s, 0, sizeof(*s)); 1381 rc = seq_open(file, &arp_seq_ops); 1382 if (rc) 1383 goto out_kfree; 1384 1385 seq = file->private_data; 1386 seq->private = s; 1387 out: 1388 return rc; 1389 out_kfree: 1390 kfree(s); 1391 goto out; 1392 } 1393 1394 static struct file_operations arp_seq_fops = { 1395 .owner = THIS_MODULE, 1396 .open = arp_seq_open, 1397 .read = seq_read, 1398 .llseek = seq_lseek, 1399 .release = seq_release_private, 1400 }; 1401 1402 static int __init arp_proc_init(void) 1403 { 1404 if (!proc_net_fops_create("arp", S_IRUGO, &arp_seq_fops)) 1405 return -ENOMEM; 1406 return 0; 1407 } 1408 1409 #else /* CONFIG_PROC_FS */ 1410 1411 static int __init arp_proc_init(void) 1412 { 1413 return 0; 1414 } 1415 1416 #endif /* CONFIG_PROC_FS */ 1417 1418 EXPORT_SYMBOL(arp_broken_ops); 1419 EXPORT_SYMBOL(arp_find); 1420 EXPORT_SYMBOL(arp_rcv); 1421 EXPORT_SYMBOL(arp_create); 1422 EXPORT_SYMBOL(arp_xmit); 1423 EXPORT_SYMBOL(arp_send); 1424 EXPORT_SYMBOL(arp_tbl); 1425 1426 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE) 1427 EXPORT_SYMBOL(clip_tbl_hook); 1428 #endif 1429