arp.c 33.4 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2
/* linux/net/inet/arp.c
 *
Linus Torvalds's avatar
Linus Torvalds committed
3
 * Version:	$Id: arp.c,v 1.99 2001/08/30 22:55:42 davem Exp $
Linus Torvalds's avatar
Linus Torvalds committed
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
 *
 * Copyright (C) 1994 by Florian  La Roche
 *
 * This module implements the Address Resolution Protocol ARP (RFC 826),
 * which is used to convert IP addresses (or in the future maybe other
 * high-level addresses) into a low-level hardware address (like an Ethernet
 * address).
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * Fixes:
 *		Alan Cox	:	Removed the Ethernet assumptions in 
 *					Florian's code
 *		Alan Cox	:	Fixed some small errors in the ARP 
 *					logic
 *		Alan Cox	:	Allow >4K in /proc
 *		Alan Cox	:	Make ARP add its own protocol entry
 *		Ross Martin     :       Rewrote arp_rcv() and arp_get_info()
 *		Stephen Henson	:	Add AX25 support to arp_get_info()
 *		Alan Cox	:	Drop data when a device is downed.
 *		Alan Cox	:	Use init_timer().
 *		Alan Cox	:	Double lock fixes.
 *		Martin Seine	:	Move the arphdr structure
 *					to if_arp.h for compatibility.
 *					with BSD based programs.
 *		Andrew Tridgell :       Added ARP netmask code and
 *					re-arranged proxy handling.
 *		Alan Cox	:	Changed to use notifiers.
 *		Niibe Yutaka	:	Reply for this device or proxies only.
 *		Alan Cox	:	Don't proxy across hardware types!
 *		Jonathan Naylor :	Added support for NET/ROM.
 *		Mike Shaver     :       RFC1122 checks.
 *		Jonathan Naylor :	Only lookup the hardware address for
 *					the correct hardware type.
 *		Germano Caronni	:	Assorted subtle races.
 *		Craig Schlenter :	Don't modify permanent entry 
 *					during arp_rcv.
 *		Russ Nelson	:	Tidied up a few bits.
 *		Alexey Kuznetsov:	Major changes to caching and behaviour,
 *					eg intelligent arp probing and 
 *					generation
 *					of host down events.
 *		Alan Cox	:	Missing unlock in device events.
 *		Eckes		:	ARP ioctl control errors.
 *		Alexey Kuznetsov:	Arp free fix.
 *		Manuel Rodriguez:	Gratuitous ARP.
 *              Jonathan Layes  :       Added arpd support through kerneld 
 *                                      message queue (960314)
 *		Mike Shaver	:	/proc/sys/net/ipv4/arp_* support
 *		Mike McLagan    :	Routing by source
 *		Stuart Cheshire	:	Metricom and grat arp fixes
 *					*** FOR 2.1 clean this up ***
 *		Lawrence V. Stefani: (08/12/96) Added FDDI support.
 *		Alan Cox 	:	Took the AP1000 nasty FDDI hack and
 *					folded into the mainstream FDDI code.
 *					Ack spit, Linus how did you allow that
 *					one in...
 *		Jes Sorensen	:	Make FDDI work again in 2.1.x and
 *					clean up the APFDDI & gen. FDDI bits.
 *		Alexey Kuznetsov:	new arp state machine;
 *					now it is in net/core/neighbour.c.
Linus Torvalds's avatar
Linus Torvalds committed
68
 *		Krzysztof Halasa:	Added Frame Relay ARP support.
69
 *		Arnaldo C. Melo :	convert /proc/net/arp to seq_file
Linus Torvalds's avatar
Linus Torvalds committed
70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88
 */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/config.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/fddidevice.h>
#include <linux/if_arp.h>
#include <linux/trdevice.h>
#include <linux/skbuff.h>
89 90
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
Linus Torvalds's avatar
Linus Torvalds committed
91 92
#include <linux/stat.h>
#include <linux/init.h>
93
#include <linux/net.h>
Linus Torvalds's avatar
Linus Torvalds committed
94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif

#include <net/ip.h>
#include <net/icmp.h>
#include <net/route.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/arp.h>
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
#include <net/ax25.h>
#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
#include <net/netrom.h>
#endif
#endif
Chas Williams's avatar
Chas Williams committed
111
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
Linus Torvalds's avatar
Linus Torvalds committed
112
#include <net/atmclip.h>
Chas Williams's avatar
Chas Williams committed
113
struct neigh_table *clip_tbl_hook;
Linus Torvalds's avatar
Linus Torvalds committed
114 115 116 117 118
#endif

#include <asm/system.h>
#include <asm/uaccess.h>

119
#include <linux/netfilter_arp.h>
Linus Torvalds's avatar
Linus Torvalds committed
120 121 122 123 124 125 126 127 128 129

/*
 *	Interface to generic neighbour cache.
 */
static u32 arp_hash(const void *pkey, const struct net_device *dev);
static int arp_constructor(struct neighbour *neigh);
static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
static void parp_redo(struct sk_buff *skb);

Linus Torvalds's avatar
Linus Torvalds committed
130
static struct neigh_ops arp_generic_ops = {
131 132 133 134 135 136 137
	.family =		AF_INET,
	.solicit =		arp_solicit,
	.error_report =		arp_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_connected_output,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
Linus Torvalds's avatar
Linus Torvalds committed
138 139
};

Linus Torvalds's avatar
Linus Torvalds committed
140
static struct neigh_ops arp_hh_ops = {
141 142 143 144 145 146 147
	.family =		AF_INET,
	.solicit =		arp_solicit,
	.error_report =		arp_error_report,
	.output =		neigh_resolve_output,
	.connected_output =	neigh_resolve_output,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
Linus Torvalds's avatar
Linus Torvalds committed
148 149
};

Linus Torvalds's avatar
Linus Torvalds committed
150
static struct neigh_ops arp_direct_ops = {
151 152 153 154 155
	.family =		AF_INET,
	.output =		dev_queue_xmit,
	.connected_output =	dev_queue_xmit,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
Linus Torvalds's avatar
Linus Torvalds committed
156 157
};

Linus Torvalds's avatar
Linus Torvalds committed
158
struct neigh_ops arp_broken_ops = {
159 160 161 162 163 164 165
	.family =		AF_INET,
	.solicit =		arp_solicit,
	.error_report =		arp_error_report,
	.output =		neigh_compat_output,
	.connected_output =	neigh_compat_output,
	.hh_output =		dev_queue_xmit,
	.queue_xmit =		dev_queue_xmit,
Linus Torvalds's avatar
Linus Torvalds committed
166 167
};

Linus Torvalds's avatar
Linus Torvalds committed
168
struct neigh_table arp_tbl = {
169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189
	.family =	AF_INET,
	.entry_size =	sizeof(struct neighbour) + 4,
	.key_len =	4,
	.hash =		arp_hash,
	.constructor =	arp_constructor,
	.proxy_redo =	parp_redo,
	.id =		"arp_cache",
	.parms = {
		.tbl =			&arp_tbl,
		.base_reachable_time =	30 * HZ,
		.retrans_time =	1 * HZ,
		.gc_staletime =	60 * HZ,
		.reachable_time =		30 * HZ,
		.delay_probe_time =	5 * HZ,
		.queue_len =		3,
		.ucast_probes =	3,
		.mcast_probes =	3,
		.anycast_delay =	1 * HZ,
		.proxy_delay =		(8 * HZ) / 10,
		.proxy_qlen =		64,
		.locktime =		1 * HZ,
Linus Torvalds's avatar
Linus Torvalds committed
190
	},
191 192 193 194
	.gc_interval =	30 * HZ,
	.gc_thresh1 =	128,
	.gc_thresh2 =	512,
	.gc_thresh3 =	1024,
Linus Torvalds's avatar
Linus Torvalds committed
195 196 197 198 199 200 201 202
};

int arp_mc_map(u32 addr, u8 *haddr, struct net_device *dev, int dir)
{
	switch (dev->type) {
	case ARPHRD_ETHER:
	case ARPHRD_FDDI:
	case ARPHRD_IEEE802:
Linus Torvalds's avatar
Linus Torvalds committed
203 204
		ip_eth_mc_map(addr, haddr);
		return 0; 
Linus Torvalds's avatar
Linus Torvalds committed
205
	case ARPHRD_IEEE802_TR:
Linus Torvalds's avatar
Linus Torvalds committed
206
		ip_tr_mc_map(addr, haddr);
Linus Torvalds's avatar
Linus Torvalds committed
207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351
		return 0;
	default:
		if (dir) {
			memcpy(haddr, dev->broadcast, dev->addr_len);
			return 0;
		}
	}
	return -EINVAL;
}


static u32 arp_hash(const void *pkey, const struct net_device *dev)
{
	u32 hash_val;

	hash_val = *(u32*)pkey;
	hash_val ^= (hash_val>>16);
	hash_val ^= hash_val>>8;
	hash_val ^= hash_val>>3;
	hash_val = (hash_val^dev->ifindex)&NEIGH_HASHMASK;

	return hash_val;
}

static int arp_constructor(struct neighbour *neigh)
{
	u32 addr = *(u32*)neigh->primary_key;
	struct net_device *dev = neigh->dev;
	struct in_device *in_dev = in_dev_get(dev);

	if (in_dev == NULL)
		return -EINVAL;

	neigh->type = inet_addr_type(addr);
	if (in_dev->arp_parms)
		neigh->parms = in_dev->arp_parms;

	in_dev_put(in_dev);

	if (dev->hard_header == NULL) {
		neigh->nud_state = NUD_NOARP;
		neigh->ops = &arp_direct_ops;
		neigh->output = neigh->ops->queue_xmit;
	} else {
		/* Good devices (checked by reading texts, but only Ethernet is
		   tested)

		   ARPHRD_ETHER: (ethernet, apfddi)
		   ARPHRD_FDDI: (fddi)
		   ARPHRD_IEEE802: (tr)
		   ARPHRD_METRICOM: (strip)
		   ARPHRD_ARCNET:
		   etc. etc. etc.

		   ARPHRD_IPDDP will also work, if author repairs it.
		   I did not it, because this driver does not work even
		   in old paradigm.
		 */

#if 1
		/* So... these "amateur" devices are hopeless.
		   The only thing, that I can say now:
		   It is very sad that we need to keep ugly obsolete
		   code to make them happy.

		   They should be moved to more reasonable state, now
		   they use rebuild_header INSTEAD OF hard_start_xmit!!!
		   Besides that, they are sort of out of date
		   (a lot of redundant clones/copies, useless in 2.1),
		   I wonder why people believe that they work.
		 */
		switch (dev->type) {
		default:
			break;
		case ARPHRD_ROSE:	
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
		case ARPHRD_AX25:
#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
		case ARPHRD_NETROM:
#endif
			neigh->ops = &arp_broken_ops;
			neigh->output = neigh->ops->output;
			return 0;
#endif
		;}
#endif
		if (neigh->type == RTN_MULTICAST) {
			neigh->nud_state = NUD_NOARP;
			arp_mc_map(addr, neigh->ha, dev, 1);
		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
			neigh->nud_state = NUD_NOARP;
			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
		} else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) {
			neigh->nud_state = NUD_NOARP;
			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
		}
		if (dev->hard_header_cache)
			neigh->ops = &arp_hh_ops;
		else
			neigh->ops = &arp_generic_ops;
		if (neigh->nud_state&NUD_VALID)
			neigh->output = neigh->ops->connected_output;
		else
			neigh->output = neigh->ops->output;
	}
	return 0;
}

static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
{
	dst_link_failure(skb);
	kfree_skb(skb);
}

static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
{
	u32 saddr;
	u8  *dst_ha = NULL;
	struct net_device *dev = neigh->dev;
	u32 target = *(u32*)neigh->primary_key;
	int probes = atomic_read(&neigh->probes);

	if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL)
		saddr = skb->nh.iph->saddr;
	else
		saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);

	if ((probes -= neigh->parms->ucast_probes) < 0) {
		if (!(neigh->nud_state&NUD_VALID))
			printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
		dst_ha = neigh->ha;
		read_lock_bh(&neigh->lock);
	} else if ((probes -= neigh->parms->app_probes) < 0) {
#ifdef CONFIG_ARPD
		neigh_app_ns(neigh);
#endif
		return;
	}

	arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
		 dst_ha, dev->dev_addr, NULL);
	if (dst_ha)
		read_unlock_bh(&neigh->lock);
}

Linus Torvalds's avatar
Linus Torvalds committed
352 353
static int arp_filter(__u32 sip, __u32 tip, struct net_device *dev)
{
354 355
	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
						 .saddr = tip } } };
Linus Torvalds's avatar
Linus Torvalds committed
356 357 358 359
	struct rtable *rt;
	int flag = 0; 
	/*unsigned long now; */

360
	if (ip_route_output_key(&rt, &fl) < 0) 
Linus Torvalds's avatar
Linus Torvalds committed
361 362 363 364 365 366 367 368 369
		return 1;
	if (rt->u.dst.dev != dev) { 
		NET_INC_STATS_BH(ArpFilter);
		flag = 1;
	} 
	ip_rt_put(rt); 
	return flag; 
} 

Linus Torvalds's avatar
Linus Torvalds committed
370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446
/* OBSOLETE FUNCTIONS */

/*
 *	Find an arp mapping in the cache. If not found, post a request.
 *
 *	It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
 *	even if it exists. It is supposed that skb->dev was mangled
 *	by a virtual device (eql, shaper). Nobody but broken devices
 *	is allowed to use this function, it is scheduled to be removed. --ANK
 */

static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct net_device * dev)
{
	switch (addr_hint) {
	case RTN_LOCAL:
		printk(KERN_DEBUG "ARP: arp called for own IP address\n");
		memcpy(haddr, dev->dev_addr, dev->addr_len);
		return 1;
	case RTN_MULTICAST:
		arp_mc_map(paddr, haddr, dev, 1);
		return 1;
	case RTN_BROADCAST:
		memcpy(haddr, dev->broadcast, dev->addr_len);
		return 1;
	}
	return 0;
}


int arp_find(unsigned char *haddr, struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	u32 paddr;
	struct neighbour *n;

	if (!skb->dst) {
		printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
		kfree_skb(skb);
		return 1;
	}

	paddr = ((struct rtable*)skb->dst)->rt_gateway;

	if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev))
		return 0;

	n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);

	if (n) {
		n->used = jiffies;
		if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
			read_lock_bh(&n->lock);
 			memcpy(haddr, n->ha, dev->addr_len);
			read_unlock_bh(&n->lock);
			neigh_release(n);
			return 0;
		}
		neigh_release(n);
	} else
		kfree_skb(skb);
	return 1;
}

/* END OF OBSOLETE FUNCTIONS */

int arp_bind_neighbour(struct dst_entry *dst)
{
	struct net_device *dev = dst->dev;
	struct neighbour *n = dst->neighbour;

	if (dev == NULL)
		return -EINVAL;
	if (n == NULL) {
		u32 nexthop = ((struct rtable*)dst)->rt_gateway;
		if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
			nexthop = 0;
		n = __neigh_lookup_errno(
Chas Williams's avatar
Chas Williams committed
447 448
#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
		    dev->type == ARPHRD_ATM ? clip_tbl_hook :
Linus Torvalds's avatar
Linus Torvalds committed
449 450 451 452 453 454 455 456 457
#endif
		    &arp_tbl, &nexthop, dev);
		if (IS_ERR(n))
			return PTR_ERR(n);
		dst->neighbour = n;
	}
	return 0;
}

458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483
/*
 * Check if we can use proxy ARP for this path
 */

static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
{
	struct in_device *out_dev;
	int imi, omi = -1;

	if (!IN_DEV_PROXY_ARP(in_dev))
		return 0;

	if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
		return 1;
	if (imi == -1)
		return 0;

	/* place to check for proxy_arp for routes */

	if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
		omi = IN_DEV_MEDIUM_ID(out_dev);
		in_dev_put(out_dev);
	}
	return (omi != imi && omi != -1);
}

Linus Torvalds's avatar
Linus Torvalds committed
484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513
/*
 *	Interface to link layer: send routine and receive handler.
 */

/*
 *	Create and send an arp packet. If (dest_hw == NULL), we create a broadcast
 *	message.
 */

void arp_send(int type, int ptype, u32 dest_ip, 
	      struct net_device *dev, u32 src_ip, 
	      unsigned char *dest_hw, unsigned char *src_hw,
	      unsigned char *target_hw)
{
	struct sk_buff *skb;
	struct arphdr *arp;
	unsigned char *arp_ptr;

	/*
	 *	No arp on this interface.
	 */
	
	if (dev->flags&IFF_NOARP)
		return;

	/*
	 *	Allocate a buffer
	 */
	
	skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4)
514
				+ LL_RESERVED_SPACE(dev), GFP_ATOMIC);
Linus Torvalds's avatar
Linus Torvalds committed
515 516 517
	if (skb == NULL)
		return;

518
	skb_reserve(skb, LL_RESERVED_SPACE(dev));
Linus Torvalds's avatar
Linus Torvalds committed
519 520 521
	skb->nh.raw = skb->data;
	arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4));
	skb->dev = dev;
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
522
	skb->protocol = htons(ETH_P_ARP);
Linus Torvalds's avatar
Linus Torvalds committed
523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547
	if (src_hw == NULL)
		src_hw = dev->dev_addr;
	if (dest_hw == NULL)
		dest_hw = dev->broadcast;

	/*
	 *	Fill the device header for the ARP frame
	 */
	if (dev->hard_header &&
	    dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len) < 0)
		goto out;

	/*
	 * Fill out the arp protocol part.
	 *
	 * The arp hardware type should match the device type, except for FDDI,
	 * which (according to RFC 1390) should always equal 1 (Ethernet).
	 */
	/*
	 *	Exceptions everywhere. AX.25 uses the AX.25 PID value not the
	 *	DIX code for the protocol. Make these device structure fields.
	 */
	switch (dev->type) {
	default:
		arp->ar_hrd = htons(dev->type);
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
548
		arp->ar_pro = htons(ETH_P_IP);
Linus Torvalds's avatar
Linus Torvalds committed
549 550 551 552
		break;

#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
	case ARPHRD_AX25:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
553 554
		arp->ar_hrd = htons(ARPHRD_AX25);
		arp->ar_pro = htons(AX25_P_IP);
Linus Torvalds's avatar
Linus Torvalds committed
555 556 557 558
		break;

#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
	case ARPHRD_NETROM:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
559 560
		arp->ar_hrd = htons(ARPHRD_NETROM);
		arp->ar_pro = htons(AX25_P_IP);
Linus Torvalds's avatar
Linus Torvalds committed
561 562 563 564 565 566
		break;
#endif
#endif

#ifdef CONFIG_FDDI
	case ARPHRD_FDDI:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
567 568
		arp->ar_hrd = htons(ARPHRD_ETHER);
		arp->ar_pro = htons(ETH_P_IP);
Linus Torvalds's avatar
Linus Torvalds committed
569 570 571 572
		break;
#endif
#ifdef CONFIG_TR
	case ARPHRD_IEEE802_TR:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
573 574
		arp->ar_hrd = htons(ARPHRD_IEEE802);
		arp->ar_pro = htons(ETH_P_IP);
Linus Torvalds's avatar
Linus Torvalds committed
575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595
		break;
#endif
	}

	arp->ar_hln = dev->addr_len;
	arp->ar_pln = 4;
	arp->ar_op = htons(type);

	arp_ptr=(unsigned char *)(arp+1);

	memcpy(arp_ptr, src_hw, dev->addr_len);
	arp_ptr+=dev->addr_len;
	memcpy(arp_ptr, &src_ip,4);
	arp_ptr+=4;
	if (target_hw != NULL)
		memcpy(arp_ptr, target_hw, dev->addr_len);
	else
		memset(arp_ptr, 0, dev->addr_len);
	arp_ptr+=dev->addr_len;
	memcpy(arp_ptr, &dest_ip, 4);

596 597
	/* Send it off, maybe filter it using firewalling first.  */
	NF_HOOK(NF_ARP, NF_ARP_OUT, skb, NULL, dev, dev_queue_xmit);
Linus Torvalds's avatar
Linus Torvalds committed
598 599 600 601 602 603 604 605 606 607 608 609
	return;

out:
	kfree_skb(skb);
}

static void parp_redo(struct sk_buff *skb)
{
	arp_rcv(skb, skb->dev, NULL);
}

/*
610
 *	Process an arp request.
Linus Torvalds's avatar
Linus Torvalds committed
611 612
 */

613
int arp_process(struct sk_buff *skb)
Linus Torvalds's avatar
Linus Torvalds committed
614
{
615 616 617 618
	struct net_device *dev = skb->dev;
	struct in_device *in_dev = in_dev_get(dev);
	struct arphdr *arp;
	unsigned char *arp_ptr;
Linus Torvalds's avatar
Linus Torvalds committed
619 620 621 622 623 624 625
	struct rtable *rt;
	unsigned char *sha, *tha;
	u32 sip, tip;
	u16 dev_type = dev->type;
	int addr_type;
	struct neighbour *n;

626 627 628 629 630
	/* arp_rcv below verifies the ARP header, verifies the device
	 * is ARP'able, and linearizes the SKB (if needed).
	 */

	if (in_dev == NULL)
Linus Torvalds's avatar
Linus Torvalds committed
631 632
		goto out;

633 634
	arp = skb->nh.arph;
	arp_ptr= (unsigned char *)(arp+1);
Linus Torvalds's avatar
Linus Torvalds committed
635

Linus Torvalds's avatar
Linus Torvalds committed
636 637
	switch (dev_type) {
	default:	
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
638 639
		if (arp->ar_pro != htons(ETH_P_IP) ||
		    htons(dev_type) != arp->ar_hrd)
Linus Torvalds's avatar
Linus Torvalds committed
640 641 642 643 644 645 646 647 648 649 650
			goto out;
		break;
#ifdef CONFIG_NET_ETHERNET
	case ARPHRD_ETHER:
#endif
#ifdef CONFIG_TR
	case ARPHRD_IEEE802_TR:
#endif
#ifdef CONFIG_FDDI
	case ARPHRD_FDDI:
#endif
Linus Torvalds's avatar
Linus Torvalds committed
651 652
#ifdef CONFIG_NET_FC
	case ARPHRD_IEEE802:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
653 654 655
#endif
#if defined(CONFIG_NET_ETHERNET) || defined(CONFIG_TR) || \
    defined(CONFIG_FDDI)	 || defined(CONFIG_NET_FC)
Linus Torvalds's avatar
Linus Torvalds committed
656
		/*
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
657 658 659 660 661 662 663
		 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
		 * devices, according to RFC 2625) devices will accept ARP
		 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
		 * This is the case also of FDDI, where the RFC 1390 says that
		 * FDDI devices should accept ARP hardware of (1) Ethernet,
		 * however, to be more robust, we'll accept both 1 (Ethernet)
		 * or 6 (IEEE 802.2)
Linus Torvalds's avatar
Linus Torvalds committed
664
		 */
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
665 666 667
		if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
		     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
		    arp->ar_pro != htons(ETH_P_IP))
Linus Torvalds's avatar
Linus Torvalds committed
668 669 670
			goto out;
		break;
#endif
Linus Torvalds's avatar
Linus Torvalds committed
671 672
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
	case ARPHRD_AX25:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
673 674
		if (arp->ar_pro != htons(AX25_P_IP) ||
		    arp->ar_hrd != htons(ARPHRD_AX25))
Linus Torvalds's avatar
Linus Torvalds committed
675 676 677 678
			goto out;
		break;
#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
	case ARPHRD_NETROM:
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
679 680
		if (arp->ar_pro != htons(AX25_P_IP) ||
		    arp->ar_hrd != htons(ARPHRD_NETROM))
Linus Torvalds's avatar
Linus Torvalds committed
681 682 683 684 685 686 687 688
			goto out;
		break;
#endif
#endif
	}

	/* Understand only these message types */

Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
689 690
	if (arp->ar_op != htons(ARPOP_REPLY) &&
	    arp->ar_op != htons(ARPOP_REQUEST))
Linus Torvalds's avatar
Linus Torvalds committed
691 692 693 694 695
		goto out;

/*
 *	Extract fields
 */
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
696
	sha	= arp_ptr;
Linus Torvalds's avatar
Linus Torvalds committed
697 698 699
	arp_ptr += dev->addr_len;
	memcpy(&sip, arp_ptr, 4);
	arp_ptr += 4;
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
700
	tha	= arp_ptr;
Linus Torvalds's avatar
Linus Torvalds committed
701 702 703 704 705 706 707 708 709
	arp_ptr += dev->addr_len;
	memcpy(&tip, arp_ptr, 4);
/* 
 *	Check for bad requests for 127.x.x.x and requests for multicast
 *	addresses.  If this is one such, delete it.
 */
	if (LOOPBACK(tip) || MULTICAST(tip))
		goto out;

Linus Torvalds's avatar
Linus Torvalds committed
710 711 712 713 714 715
/*
 *     Special case: We must set Frame Relay source Q.922 address
 */
	if (dev_type == ARPHRD_DLCI)
		sha = dev->broadcast;

Linus Torvalds's avatar
Linus Torvalds committed
716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
/*
 *  Process entry.  The idea here is we want to send a reply if it is a
 *  request for us or if it is a request for someone else that we hold
 *  a proxy for.  We want to add an entry to our cache if it is a reply
 *  to us or if it is a request for our address.  
 *  (The assumption for this last is that if someone is requesting our 
 *  address, they are probably intending to talk to us, so it saves time 
 *  if we cache their address.  Their address is also probably not in 
 *  our cache, since ours is not in their cache.)
 * 
 *  Putting this another way, we only care about replies if they are to
 *  us, in which case we add them to the cache.  For requests, we care
 *  about those for us and those for our proxies.  We reply to both,
 *  and in the case of requests for us we add the requester to the arp 
 *  cache.
 */

	/* Special case: IPv4 duplicate address detection packet (RFC2131) */
	if (sip == 0) {
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
735
		if (arp->ar_op == htons(ARPOP_REQUEST) &&
Linus Torvalds's avatar
Linus Torvalds committed
736 737 738 739 740
		    inet_addr_type(tip) == RTN_LOCAL)
			arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr);
		goto out;
	}

Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
741
	if (arp->ar_op == htons(ARPOP_REQUEST) &&
Linus Torvalds's avatar
Linus Torvalds committed
742 743 744 745 746 747 748 749
	    ip_route_input(skb, tip, sip, 0, dev) == 0) {

		rt = (struct rtable*)skb->dst;
		addr_type = rt->rt_type;

		if (addr_type == RTN_LOCAL) {
			n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
			if (n) {
Linus Torvalds's avatar
Linus Torvalds committed
750 751 752 753 754 755
				int dont_send = 0;
				if (IN_DEV_ARPFILTER(in_dev))
					dont_send |= arp_filter(sip,tip,dev); 
				if (!dont_send)
					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);

Linus Torvalds's avatar
Linus Torvalds committed
756 757 758 759 760 761
				neigh_release(n);
			}
			goto out;
		} else if (IN_DEV_FORWARD(in_dev)) {
			if ((rt->rt_flags&RTCF_DNAT) ||
			    (addr_type == RTN_UNICAST  && rt->u.dst.dev != dev &&
762
			     (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) {
Linus Torvalds's avatar
Linus Torvalds committed
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790
				n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
				if (n)
					neigh_release(n);

				if (skb->stamp.tv_sec == 0 ||
				    skb->pkt_type == PACKET_HOST ||
				    in_dev->arp_parms->proxy_delay == 0) {
					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
				} else {
					pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
					in_dev_put(in_dev);
					return 0;
				}
				goto out;
			}
		}
	}

	/* Update our ARP tables */

	n = __neigh_lookup(&arp_tbl, &sip, dev, 0);

#ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP
	/* Unsolicited ARP is not accepted by default.
	   It is possible, that this option should be enabled for some
	   devices (strip is candidate)
	 */
	if (n == NULL &&
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
791
	    arp->ar_op == htons(ARPOP_REPLY) &&
Linus Torvalds's avatar
Linus Torvalds committed
792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
	    inet_addr_type(sip) == RTN_UNICAST)
		n = __neigh_lookup(&arp_tbl, &sip, dev, -1);
#endif

	if (n) {
		int state = NUD_REACHABLE;
		int override = 0;

		/* If several different ARP replies follows back-to-back,
		   use the FIRST one. It is possible, if several proxy
		   agents are active. Taking the first reply prevents
		   arp trashing and chooses the fastest router.
		 */
		if (jiffies - n->updated >= n->parms->locktime)
			override = 1;

		/* Broadcast replies and request packets
		   do not assert neighbour reachability.
		 */
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
811
		if (arp->ar_op != htons(ARPOP_REPLY) ||
Linus Torvalds's avatar
Linus Torvalds committed
812 813 814 815 816 817 818 819 820
		    skb->pkt_type != PACKET_HOST)
			state = NUD_STALE;
		neigh_update(n, sha, state, override, 1);
		neigh_release(n);
	}

out:
	if (in_dev)
		in_dev_put(in_dev);
Linus Torvalds's avatar
Linus Torvalds committed
821
	kfree_skb(skb);
Linus Torvalds's avatar
Linus Torvalds committed
822 823 824 825
	return 0;
}


826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855
/*
 *	Receive an arp request from the device layer.
 */

int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
{
	struct arphdr *arp = skb->nh.arph;

	if (arp->ar_hln != dev->addr_len ||
	    dev->flags & IFF_NOARP ||
	    skb->pkt_type == PACKET_OTHERHOST ||
	    skb->pkt_type == PACKET_LOOPBACK ||
	    arp->ar_pln != 4)
		goto freeskb;

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
		goto out_of_mem;

	if (skb_is_nonlinear(skb)) {
		if (skb_linearize(skb, GFP_ATOMIC) != 0)
			goto freeskb;
	}

	return NF_HOOK(NF_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);

freeskb:
	kfree_skb(skb);
out_of_mem:
	return 0;
}
Linus Torvalds's avatar
Linus Torvalds committed
856 857

/*
858
 *	User level interface (ioctl)
Linus Torvalds's avatar
Linus Torvalds committed
859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898
 */

/*
 *	Set (create) an ARP cache entry.
 */

int arp_req_set(struct arpreq *r, struct net_device * dev)
{
	u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
	struct neighbour *neigh;
	int err;

	if (r->arp_flags&ATF_PUBL) {
		u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr;
		if (mask && mask != 0xFFFFFFFF)
			return -EINVAL;
		if (!dev && (r->arp_flags & ATF_COM)) {
			dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data);
			if (!dev)
				return -ENODEV;
		}
		if (mask) {
			if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL)
				return -ENOBUFS;
			return 0;
		}
		if (dev == NULL) {
			ipv4_devconf.proxy_arp = 1;
			return 0;
		}
		if (__in_dev_get(dev)) {
			__in_dev_get(dev)->cnf.proxy_arp = 1;
			return 0;
		}
		return -ENXIO;
	}

	if (r->arp_flags & ATF_PERM)
		r->arp_flags |= ATF_COM;
	if (dev == NULL) {
899 900
		struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
							 .tos = RTO_ONLINK } } };
Linus Torvalds's avatar
Linus Torvalds committed
901
		struct rtable * rt;
902
		if ((err = ip_route_output_key(&rt, &fl)) != 0)
Linus Torvalds's avatar
Linus Torvalds committed
903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
			return err;
		dev = rt->u.dst.dev;
		ip_rt_put(rt);
		if (!dev)
			return -EINVAL;
	}
	if (r->arp_ha.sa_family != dev->type)	
		return -EINVAL;

	neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
	err = PTR_ERR(neigh);
	if (!IS_ERR(neigh)) {
		unsigned state = NUD_STALE;
		if (r->arp_flags & ATF_PERM)
			state = NUD_PERMANENT;
		err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
				   r->arp_ha.sa_data : NULL, state, 1, 0);
		neigh_release(neigh);
	}
	return err;
}

925
static unsigned arp_state_to_flags(struct neighbour *neigh)
Linus Torvalds's avatar
Linus Torvalds committed
926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951
{
	unsigned flags = 0;
	if (neigh->nud_state&NUD_PERMANENT)
		flags = ATF_PERM|ATF_COM;
	else if (neigh->nud_state&NUD_VALID)
		flags = ATF_COM;
	return flags;
}

/*
 *	Get an ARP cache entry.
 */

static int arp_req_get(struct arpreq *r, struct net_device *dev)
{
	u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
	struct neighbour *neigh;
	int err = -ENXIO;

	neigh = neigh_lookup(&arp_tbl, &ip, dev);
	if (neigh) {
		read_lock_bh(&neigh->lock);
		memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
		r->arp_flags = arp_state_to_flags(neigh);
		read_unlock_bh(&neigh->lock);
		r->arp_ha.sa_family = dev->type;
952
		strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
Linus Torvalds's avatar
Linus Torvalds committed
953 954 955 956 957 958 959 960 961 962 963 964 965
		neigh_release(neigh);
		err = 0;
	}
	return err;
}

int arp_req_delete(struct arpreq *r, struct net_device * dev)
{
	int err;
	u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
	struct neighbour *neigh;

	if (r->arp_flags & ATF_PUBL) {
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
966 967
		u32 mask =
		       ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
Linus Torvalds's avatar
Linus Torvalds committed
968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984
		if (mask == 0xFFFFFFFF)
			return pneigh_delete(&arp_tbl, &ip, dev);
		if (mask == 0) {
			if (dev == NULL) {
				ipv4_devconf.proxy_arp = 0;
				return 0;
			}
			if (__in_dev_get(dev)) {
				__in_dev_get(dev)->cnf.proxy_arp = 0;
				return 0;
			}
			return -ENXIO;
		}
		return -EINVAL;
	}

	if (dev == NULL) {
985 986
		struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
							 .tos = RTO_ONLINK } } };
Linus Torvalds's avatar
Linus Torvalds committed
987
		struct rtable * rt;
988
		if ((err = ip_route_output_key(&rt, &fl)) != 0)
Linus Torvalds's avatar
Linus Torvalds committed
989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
			return err;
		dev = rt->u.dst.dev;
		ip_rt_put(rt);
		if (!dev)
			return -EINVAL;
	}
	err = -ENXIO;
	neigh = neigh_lookup(&arp_tbl, &ip, dev);
	if (neigh) {
		if (neigh->nud_state&~NUD_NOARP)
			err = neigh_update(neigh, NULL, NUD_FAILED, 1, 0);
		neigh_release(neigh);
	}
	return err;
}

/*
 *	Handle an ARP layer I/O control request.
 */

int arp_ioctl(unsigned int cmd, void *arg)
{
	int err;
	struct arpreq r;
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
1013
	struct net_device *dev = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1014

Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
1015
	switch (cmd) {
Linus Torvalds's avatar
Linus Torvalds committed
1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
		case SIOCDARP:
		case SIOCSARP:
			if (!capable(CAP_NET_ADMIN))
				return -EPERM;
		case SIOCGARP:
			err = copy_from_user(&r, arg, sizeof(struct arpreq));
			if (err)
				return -EFAULT;
			break;
		default:
			return -EINVAL;
	}

	if (r.arp_pa.sa_family != AF_INET)
		return -EPFNOSUPPORT;

	if (!(r.arp_flags & ATF_PUBL) &&
	    (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
		return -EINVAL;
	if (!(r.arp_flags & ATF_NETMASK))
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
1036 1037
		((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
							   htonl(0xFFFFFFFFUL);
1038
	rtnl_lock();
Linus Torvalds's avatar
Linus Torvalds committed
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
	if (r.arp_dev[0]) {
		err = -ENODEV;
		if ((dev = __dev_get_by_name(r.arp_dev)) == NULL)
			goto out;

		/* Mmmm... It is wrong... ARPHRD_NETROM==0 */
		if (!r.arp_ha.sa_family)
			r.arp_ha.sa_family = dev->type;
		err = -EINVAL;
		if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
			goto out;
	} else if (cmd == SIOCGARP) {
		err = -ENODEV;
		goto out;
	}

	switch(cmd) {
	case SIOCDARP:
	        err = arp_req_delete(&r, dev);
		break;
	case SIOCSARP:
		err = arp_req_set(&r, dev);
		break;
	case SIOCGARP:
		err = arp_req_get(&r, dev);
		if (!err && copy_to_user(arg, &r, sizeof(r)))
			err = -EFAULT;
		break;
	}
out:
	rtnl_unlock();
	return err;
}

/* Note, that it is not on notifier chain.
   It is necessary, that this routine was called after route cache will be
   flushed.
 */
void arp_ifdown(struct net_device *dev)
{
	neigh_ifdown(&arp_tbl, dev);
}


/*
 *	Called once on startup.
 */

Linus Torvalds's avatar
Linus Torvalds committed
1087
static struct packet_type arp_packet_type = {
1088 1089 1090
	.type =	__constant_htons(ETH_P_ARP),
	.func =	arp_rcv,
	.data =	(void*) 1, /* understand shared skbs */
Linus Torvalds's avatar
Linus Torvalds committed
1091 1092
};

1093 1094
static int arp_proc_init(void);

1095
void __init arp_init(void)
Linus Torvalds's avatar
Linus Torvalds committed
1096 1097 1098 1099
{
	neigh_table_init(&arp_tbl);

	dev_add_pack(&arp_packet_type);
1100
	arp_proc_init();
Linus Torvalds's avatar
Linus Torvalds committed
1101
#ifdef CONFIG_SYSCTL
Arnaldo Carvalho de Melo's avatar
Arnaldo Carvalho de Melo committed
1102 1103
	neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
			      NET_IPV4_NEIGH, "ipv4");
Linus Torvalds's avatar
Linus Torvalds committed
1104 1105
#endif
}
1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146

#ifdef CONFIG_PROC_FS
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)

/* ------------------------------------------------------------------------ */
/*
 *	ax25 -> ASCII conversion
 */
static char *ax2asc2(ax25_address *a, char *buf)
{
	char c, *s;
	int n;

	for (n = 0, s = buf; n < 6; n++) {
		c = (a->ax25_call[n] >> 1) & 0x7F;

		if (c != ' ') *s++ = c;
	}
	
	*s++ = '-';

	if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
		*s++ = '1';
		n -= 10;
	}
	
	*s++ = n + '0';
	*s++ = '\0';

	if (*buf == '\0' || *buf == '-')
	   return "*";

	return buf;

}
#endif /* CONFIG_AX25 */

struct arp_iter_state {
	int is_pneigh, bucket;
};

1147
static struct neighbour *neigh_get_first(struct seq_file *seq)
1148 1149
{
	struct arp_iter_state* state = seq->private;
1150
	struct neighbour *n = NULL;
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163

	state->is_pneigh = 0;

	for (state->bucket = 0;
	     state->bucket <= NEIGH_HASHMASK;
	     ++state->bucket) {
		n = arp_tbl.hash_buckets[state->bucket];
		while (n && !(n->nud_state & ~NUD_NOARP))
			n = n->next;
		if (n)
			break;
	}

1164 1165 1166
	return n;
}

1167 1168
static struct neighbour *neigh_get_next(struct seq_file *seq,
					struct neighbour *n)
1169 1170
{
	struct arp_iter_state* state = seq->private;
1171 1172 1173 1174 1175

	do {
		n = n->next;
		/* Don't confuse "arp -a" w/ magic entries */
try_again:
1176
		;
1177 1178 1179 1180 1181 1182 1183 1184
	} while (n && !(n->nud_state & ~NUD_NOARP));

	if (n)
		goto out;
	if (++state->bucket > NEIGH_HASHMASK)
		goto out;
	n = arp_tbl.hash_buckets[state->bucket];
	goto try_again;
1185 1186 1187 1188
out:
	return n;
}

1189
static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos)
1190
{
1191
	struct neighbour *n = neigh_get_first(seq);
1192

1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
	if (n)
		while (*pos && (n = neigh_get_next(seq, n)))
			--*pos;
	return *pos ? NULL : n;
}

static struct pneigh_entry *pneigh_get_first(struct seq_file *seq)
{
	struct arp_iter_state* state = seq->private;
	struct pneigh_entry *pn;

	state->is_pneigh = 1;

	for (state->bucket = 0;
	     state->bucket <= PNEIGH_HASHMASK;
	     ++state->bucket) {
		pn = arp_tbl.phash_buckets[state->bucket];
		if (pn)
			break;
	}
	return pn;
}
1215

1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
static struct pneigh_entry *pneigh_get_next(struct seq_file *seq,
					    struct pneigh_entry *pn)
{
	struct arp_iter_state* state = seq->private;

	pn = pn->next;
	while (!pn) {
		if (++state->bucket > PNEIGH_HASHMASK)
			break;
		pn = arp_tbl.phash_buckets[state->bucket];
	}
	return pn;
}

static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t pos)
{
	struct pneigh_entry *pn = pneigh_get_first(seq);

	if (pn)
		while (pos && (pn = pneigh_get_next(seq, pn)))
			--pos;
	return pos ? NULL : pn;
}

static void *arp_get_idx(struct seq_file *seq, loff_t pos)
{
	void *rc;

	read_lock_bh(&arp_tbl.lock);
	rc = neigh_get_idx(seq, &pos);

	if (!rc) {
1248
		read_unlock_bh(&arp_tbl.lock);
1249
		rc = pneigh_get_idx(seq, pos);
1250 1251 1252 1253 1254 1255
	}
	return rc;
}

static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
{
1256
	return *pos ? arp_get_idx(seq, *pos - 1) : (void *)1;
1257 1258 1259 1260 1261 1262 1263 1264
}

static void *arp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	void *rc;
	struct arp_iter_state* state;

	if (v == (void *)1) {
1265
		rc = arp_get_idx(seq, 0);
1266 1267 1268 1269 1270
		goto out;
	}

	state = seq->private;
	if (!state->is_pneigh) {
1271
		rc = neigh_get_next(seq, v);
1272 1273 1274
		if (rc)
			goto out;
		read_unlock_bh(&arp_tbl.lock);
1275 1276 1277
		rc = pneigh_get_first(seq);
	} else
		rc = pneigh_get_next(seq, v);
1278 1279 1280 1281 1282 1283 1284 1285 1286
out:
	++*pos;
	return rc;
}

static void arp_seq_stop(struct seq_file *seq, void *v)
{
	struct arp_iter_state* state = seq->private;

1287
	if (!state->is_pneigh && v != (void *)1)
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387
		read_unlock_bh(&arp_tbl.lock);
}

#define HBUFFERLEN 30

static __inline__ void arp_format_neigh_entry(struct seq_file *seq,
					      struct neighbour *n)
{
	char hbuffer[HBUFFERLEN];
	const char hexbuf[] = "0123456789ABCDEF";
	int k, j;
	char tbuf[16];
	struct net_device *dev = n->dev;
	int hatype = dev->type;

	read_lock(&n->lock);
	/* Convert hardware address to XX:XX:XX:XX ... form. */
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
	if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
		ax2asc2((ax25_address *)n->ha, hbuffer);
	else {
#endif
	for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
		hbuffer[k++] = hexbuf[(n->ha[j] >> 4) & 15];
		hbuffer[k++] = hexbuf[n->ha[j] & 15];
		hbuffer[k++] = ':';
	}
	hbuffer[--k] = 0;
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
	}
#endif
	sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->primary_key));
	seq_printf(seq, "%-16s 0x%-10x0x%-10x%s     *        %s\n",
		   tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
	read_unlock(&n->lock);
}

static __inline__ void arp_format_pneigh_entry(struct seq_file *seq,
					       struct pneigh_entry *n)
{
	struct net_device *dev = n->dev;
	int hatype = dev ? dev->type : 0;
	char tbuf[16];

	sprintf(tbuf, "%u.%u.%u.%u", NIPQUAD(*(u32*)n->key));
	seq_printf(seq, "%-16s 0x%-10x0x%-10x%s     *        %s\n",
		   tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
		   dev ? dev->name : "*");
}

static int arp_seq_show(struct seq_file *seq, void *v)
{
	if (v == (void *)1)
		seq_puts(seq, "IP address       HW type     Flags       "
			      "HW address            Mask     Device\n");
	else {
		struct arp_iter_state* state = seq->private;

		if (state->is_pneigh)
			arp_format_pneigh_entry(seq, v);
		else
			arp_format_neigh_entry(seq, v);
	}

	return 0;
}

/* ------------------------------------------------------------------------ */

static struct seq_operations arp_seq_ops = {
	.start  = arp_seq_start,
	.next   = arp_seq_next,
	.stop   = arp_seq_stop,
	.show   = arp_seq_show,
};

static int arp_seq_open(struct inode *inode, struct file *file)
{
	struct seq_file *seq;
	int rc = -ENOMEM;
	struct arp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
       
	if (!s)
		goto out;

	rc = seq_open(file, &arp_seq_ops);
	if (rc)
		goto out_kfree;

	seq	     = file->private_data;
	seq->private = s;
	memset(s, 0, sizeof(*s));
out:
	return rc;
out_kfree:
	kfree(s);
	goto out;
}

static struct file_operations arp_seq_fops = {
1388
	.owner		= THIS_MODULE,
1389 1390 1391
	.open           = arp_seq_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
1392
	.release	= seq_release_private,
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414
};

static int __init arp_proc_init(void)
{
	int rc = 0;
	struct proc_dir_entry *p = create_proc_entry("arp", S_IRUGO, proc_net);

        if (p)
		p->proc_fops = &arp_seq_fops;
	else
		rc = -ENOMEM;
	return rc;
}

#else /* CONFIG_PROC_FS */

static int __init arp_proc_init(void)
{
	return 0;
}

#endif /* CONFIG_PROC_FS */