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more reasonable state, now 282 they use rebuild_header INSTEAD OF hard_start_xmit!!! 283 Besides that, they are sort of out of date 284 (a lot of redundant clones/copies, useless in 2.1), 285 I wonder why people believe that they work. 286 */ 287 switch (dev-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