1/*
   2 * DECnet       An implementation of the DECnet protocol suite for the LINUX
   3 *              operating system.  DECnet is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              DECnet Routing Functions (Endnode and Router)
   7 *
   8 * Authors:     Steve Whitehouse <SteveW@ACM.org>
   9 *              Eduardo Marcelo Serrat <emserrat@geocities.com>
  10 *
  11 * Changes:
  12 *              Steve Whitehouse : Fixes to allow "intra-ethernet" and
  13 *                                 "return-to-sender" bits on outgoing
  14 *                                 packets.
  15 *		Steve Whitehouse : Timeouts for cached routes.
  16 *              Steve Whitehouse : Use dst cache for input routes too.
  17 *              Steve Whitehouse : Fixed error values in dn_send_skb.
  18 *              Steve Whitehouse : Rework routing functions to better fit
  19 *                                 DECnet routing design
  20 *              Alexey Kuznetsov : New SMP locking
  21 *              Steve Whitehouse : More SMP locking changes & dn_cache_dump()
  22 *              Steve Whitehouse : Prerouting NF hook, now really is prerouting.
  23 *				   Fixed possible skb leak in rtnetlink funcs.
  24 *              Steve Whitehouse : Dave Miller's dynamic hash table sizing and
  25 *                                 Alexey Kuznetsov's finer grained locking
  26 *                                 from ipv4/route.c.
  27 *              Steve Whitehouse : Routing is now starting to look like a
  28 *                                 sensible set of code now, mainly due to
  29 *                                 my copying the IPv4 routing code. The
  30 *                                 hooks here are modified and will continue
  31 *                                 to evolve for a while.
  32 *              Steve Whitehouse : Real SMP at last :-) Also new netfilter
  33 *                                 stuff. Look out raw sockets your days
  34 *                                 are numbered!
  35 *              Steve Whitehouse : Added return-to-sender functions. Added
  36 *                                 backlog congestion level return codes.
  37 *		Steve Whitehouse : Fixed bug where routes were set up with
  38 *                                 no ref count on net devices.
  39 *              Steve Whitehouse : RCU for the route cache
  40 *              Steve Whitehouse : Preparations for the flow cache
  41 *              Steve Whitehouse : Prepare for nonlinear skbs
  42 */
  43
  44/******************************************************************************
  45    (c) 1995-1998 E.M. Serrat		emserrat@geocities.com
  46
  47    This program is free software; you can redistribute it and/or modify
  48    it under the terms of the GNU General Public License as published by
  49    the Free Software Foundation; either version 2 of the License, or
  50    any later version.
  51
  52    This program is distributed in the hope that it will be useful,
  53    but WITHOUT ANY WARRANTY; without even the implied warranty of
  54    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  55    GNU General Public License for more details.
  56*******************************************************************************/
  57
  58#include <linux/errno.h>
  59#include <linux/types.h>
  60#include <linux/socket.h>
  61#include <linux/in.h>
  62#include <linux/kernel.h>
  63#include <linux/sockios.h>
  64#include <linux/net.h>
  65#include <linux/netdevice.h>
  66#include <linux/inet.h>
  67#include <linux/route.h>
  68#include <linux/in_route.h>
  69#include <linux/slab.h>
  70#include <net/sock.h>
  71#include <linux/mm.h>
  72#include <linux/proc_fs.h>
  73#include <linux/seq_file.h>
  74#include <linux/init.h>
  75#include <linux/rtnetlink.h>
  76#include <linux/string.h>
  77#include <linux/netfilter_decnet.h>
  78#include <linux/rcupdate.h>
  79#include <linux/times.h>
  80#include <linux/export.h>
  81#include <asm/errno.h>
  82#include <net/net_namespace.h>
  83#include <net/netlink.h>
  84#include <net/neighbour.h>
  85#include <net/dst.h>
  86#include <net/flow.h>
  87#include <net/fib_rules.h>
  88#include <net/dn.h>
  89#include <net/dn_dev.h>
  90#include <net/dn_nsp.h>
  91#include <net/dn_route.h>
  92#include <net/dn_neigh.h>
  93#include <net/dn_fib.h>
  94
  95struct dn_rt_hash_bucket
  96{
  97	struct dn_route __rcu *chain;
  98	spinlock_t lock;
  99};
 100
 101extern struct neigh_table dn_neigh_table;
 102
 103
 104static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
 105
 106static const int dn_rt_min_delay = 2 * HZ;
 107static const int dn_rt_max_delay = 10 * HZ;
 108static const int dn_rt_mtu_expires = 10 * 60 * HZ;
 109
 110static unsigned long dn_rt_deadline;
 111
 112static int dn_dst_gc(struct dst_ops *ops);
 113static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
 114static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
 115static unsigned int dn_dst_mtu(const struct dst_entry *dst);
 116static void dn_dst_destroy(struct dst_entry *);
 117static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
 118static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
 119static void dn_dst_link_failure(struct sk_buff *);
 120static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 121			       struct sk_buff *skb , u32 mtu);
 122static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 123			    struct sk_buff *skb);
 124static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 125					     struct sk_buff *skb,
 126					     const void *daddr);
 127static int dn_route_input(struct sk_buff *);
 128static void dn_run_flush(unsigned long dummy);
 129
 130static struct dn_rt_hash_bucket *dn_rt_hash_table;
 131static unsigned int dn_rt_hash_mask;
 132
 133static struct timer_list dn_route_timer;
 134static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
 135int decnet_dst_gc_interval = 2;
 136
 137static struct dst_ops dn_dst_ops = {
 138	.family =		PF_DECnet,
 139	.protocol =		cpu_to_be16(ETH_P_DNA_RT),
 140	.gc_thresh =		128,
 141	.gc =			dn_dst_gc,
 142	.check =		dn_dst_check,
 143	.default_advmss =	dn_dst_default_advmss,
 144	.mtu =			dn_dst_mtu,
 145	.cow_metrics =		dst_cow_metrics_generic,
 146	.destroy =		dn_dst_destroy,
 147	.ifdown =		dn_dst_ifdown,
 148	.negative_advice =	dn_dst_negative_advice,
 149	.link_failure =		dn_dst_link_failure,
 150	.update_pmtu =		dn_dst_update_pmtu,
 151	.redirect =		dn_dst_redirect,
 152	.neigh_lookup =		dn_dst_neigh_lookup,
 153};
 154
 155static void dn_dst_destroy(struct dst_entry *dst)
 156{
 157	struct dn_route *rt = (struct dn_route *) dst;
 158
 159	if (rt->n)
 160		neigh_release(rt->n);
 161	dst_destroy_metrics_generic(dst);
 162}
 163
 164static void dn_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how)
 165{
 166	if (how) {
 167		struct dn_route *rt = (struct dn_route *) dst;
 168		struct neighbour *n = rt->n;
 169
 170		if (n && n->dev == dev) {
 171			n->dev = dev_net(dev)->loopback_dev;
 172			dev_hold(n->dev);
 173			dev_put(dev);
 174		}
 175	}
 176}
 177
 178static __inline__ unsigned int dn_hash(__le16 src, __le16 dst)
 179{
 180	__u16 tmp = (__u16 __force)(src ^ dst);
 181	tmp ^= (tmp >> 3);
 182	tmp ^= (tmp >> 5);
 183	tmp ^= (tmp >> 10);
 184	return dn_rt_hash_mask & (unsigned int)tmp;
 185}
 186
 187static inline void dnrt_free(struct dn_route *rt)
 188{
 189	call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 190}
 191
 192static inline void dnrt_drop(struct dn_route *rt)
 193{
 194	dst_release(&rt->dst);
 195	call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
 196}
 197
 198static void dn_dst_check_expire(unsigned long dummy)
 199{
 200	int i;
 201	struct dn_route *rt;
 202	struct dn_route __rcu **rtp;
 203	unsigned long now = jiffies;
 204	unsigned long expire = 120 * HZ;
 205
 206	for (i = 0; i <= dn_rt_hash_mask; i++) {
 207		rtp = &dn_rt_hash_table[i].chain;
 208
 209		spin_lock(&dn_rt_hash_table[i].lock);
 210		while ((rt = rcu_dereference_protected(*rtp,
 211						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 212			if (atomic_read(&rt->dst.__refcnt) ||
 213					(now - rt->dst.lastuse) < expire) {
 214				rtp = &rt->dst.dn_next;
 215				continue;
 216			}
 217			*rtp = rt->dst.dn_next;
 218			rt->dst.dn_next = NULL;
 219			dnrt_free(rt);
 220		}
 221		spin_unlock(&dn_rt_hash_table[i].lock);
 222
 223		if ((jiffies - now) > 0)
 224			break;
 225	}
 226
 227	mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ);
 228}
 229
 230static int dn_dst_gc(struct dst_ops *ops)
 231{
 232	struct dn_route *rt;
 233	struct dn_route __rcu **rtp;
 234	int i;
 235	unsigned long now = jiffies;
 236	unsigned long expire = 10 * HZ;
 237
 238	for (i = 0; i <= dn_rt_hash_mask; i++) {
 239
 240		spin_lock_bh(&dn_rt_hash_table[i].lock);
 241		rtp = &dn_rt_hash_table[i].chain;
 242
 243		while ((rt = rcu_dereference_protected(*rtp,
 244						lockdep_is_held(&dn_rt_hash_table[i].lock))) != NULL) {
 245			if (atomic_read(&rt->dst.__refcnt) ||
 246					(now - rt->dst.lastuse) < expire) {
 247				rtp = &rt->dst.dn_next;
 248				continue;
 249			}
 250			*rtp = rt->dst.dn_next;
 251			rt->dst.dn_next = NULL;
 252			dnrt_drop(rt);
 253			break;
 254		}
 255		spin_unlock_bh(&dn_rt_hash_table[i].lock);
 256	}
 257
 258	return 0;
 259}
 260
 261/*
 262 * The decnet standards don't impose a particular minimum mtu, what they
 263 * do insist on is that the routing layer accepts a datagram of at least
 264 * 230 bytes long. Here we have to subtract the routing header length from
 265 * 230 to get the minimum acceptable mtu. If there is no neighbour, then we
 266 * assume the worst and use a long header size.
 267 *
 268 * We update both the mtu and the advertised mss (i.e. the segment size we
 269 * advertise to the other end).
 270 */
 271static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
 272			       struct sk_buff *skb, u32 mtu)
 273{
 274	struct dn_route *rt = (struct dn_route *) dst;
 275	struct neighbour *n = rt->n;
 276	u32 min_mtu = 230;
 277	struct dn_dev *dn;
 278
 279	dn = n ? rcu_dereference_raw(n->dev->dn_ptr) : NULL;
 280
 281	if (dn && dn->use_long == 0)
 282		min_mtu -= 6;
 283	else
 284		min_mtu -= 21;
 285
 286	if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= min_mtu) {
 287		if (!(dst_metric_locked(dst, RTAX_MTU))) {
 288			dst_metric_set(dst, RTAX_MTU, mtu);
 289			dst_set_expires(dst, dn_rt_mtu_expires);
 290		}
 291		if (!(dst_metric_locked(dst, RTAX_ADVMSS))) {
 292			u32 mss = mtu - DN_MAX_NSP_DATA_HEADER;
 293			u32 existing_mss = dst_metric_raw(dst, RTAX_ADVMSS);
 294			if (!existing_mss || existing_mss > mss)
 295				dst_metric_set(dst, RTAX_ADVMSS, mss);
 296		}
 297	}
 298}
 299
 300static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
 301			    struct sk_buff *skb)
 302{
 303}
 304
 305/*
 306 * When a route has been marked obsolete. (e.g. routing cache flush)
 307 */
 308static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 309{
 310	return NULL;
 311}
 312
 313static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
 314{
 315	dst_release(dst);
 316	return NULL;
 317}
 318
 319static void dn_dst_link_failure(struct sk_buff *skb)
 320{
 321}
 322
 323static inline int compare_keys(struct flowidn *fl1, struct flowidn *fl2)
 324{
 325	return ((fl1->daddr ^ fl2->daddr) |
 326		(fl1->saddr ^ fl2->saddr) |
 327		(fl1->flowidn_mark ^ fl2->flowidn_mark) |
 328		(fl1->flowidn_scope ^ fl2->flowidn_scope) |
 329		(fl1->flowidn_oif ^ fl2->flowidn_oif) |
 330		(fl1->flowidn_iif ^ fl2->flowidn_iif)) == 0;
 331}
 332
 333static int dn_insert_route(struct dn_route *rt, unsigned int hash, struct dn_route **rp)
 334{
 335	struct dn_route *rth;
 336	struct dn_route __rcu **rthp;
 337	unsigned long now = jiffies;
 338
 339	rthp = &dn_rt_hash_table[hash].chain;
 340
 341	spin_lock_bh(&dn_rt_hash_table[hash].lock);
 342	while ((rth = rcu_dereference_protected(*rthp,
 343						lockdep_is_held(&dn_rt_hash_table[hash].lock))) != NULL) {
 344		if (compare_keys(&rth->fld, &rt->fld)) {
 345			/* Put it first */
 346			*rthp = rth->dst.dn_next;
 347			rcu_assign_pointer(rth->dst.dn_next,
 348					   dn_rt_hash_table[hash].chain);
 349			rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth);
 350
 351			dst_use(&rth->dst, now);
 352			spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 353
 354			dnrt_drop(rt);
 355			*rp = rth;
 356			return 0;
 357		}
 358		rthp = &rth->dst.dn_next;
 359	}
 360
 361	rcu_assign_pointer(rt->dst.dn_next, dn_rt_hash_table[hash].chain);
 362	rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt);
 363
 364	dst_use(&rt->dst, now);
 365	spin_unlock_bh(&dn_rt_hash_table[hash].lock);
 366	*rp = rt;
 367	return 0;
 368}
 369
 370static void dn_run_flush(unsigned long dummy)
 371{
 372	int i;
 373	struct dn_route *rt, *next;
 374
 375	for (i = 0; i < dn_rt_hash_mask; i++) {
 376		spin_lock_bh(&dn_rt_hash_table[i].lock);
 377
 378		if ((rt = xchg((struct dn_route **)&dn_rt_hash_table[i].chain, NULL)) == NULL)
 379			goto nothing_to_declare;
 380
 381		for(; rt; rt = next) {
 382			next = rcu_dereference_raw(rt->dst.dn_next);
 383			RCU_INIT_POINTER(rt->dst.dn_next, NULL);
 384			dst_free((struct dst_entry *)rt);
 385		}
 386
 387nothing_to_declare:
 388		spin_unlock_bh(&dn_rt_hash_table[i].lock);
 389	}
 390}
 391
 392static DEFINE_SPINLOCK(dn_rt_flush_lock);
 393
 394void dn_rt_cache_flush(int delay)
 395{
 396	unsigned long now = jiffies;
 397	int user_mode = !in_interrupt();
 398
 399	if (delay < 0)
 400		delay = dn_rt_min_delay;
 401
 402	spin_lock_bh(&dn_rt_flush_lock);
 403
 404	if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) {
 405		long tmo = (long)(dn_rt_deadline - now);
 406
 407		if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay)
 408			tmo = 0;
 409
 410		if (delay > tmo)
 411			delay = tmo;
 412	}
 413
 414	if (delay <= 0) {
 415		spin_unlock_bh(&dn_rt_flush_lock);
 416		dn_run_flush(0);
 417		return;
 418	}
 419
 420	if (dn_rt_deadline == 0)
 421		dn_rt_deadline = now + dn_rt_max_delay;
 422
 423	dn_rt_flush_timer.expires = now + delay;
 424	add_timer(&dn_rt_flush_timer);
 425	spin_unlock_bh(&dn_rt_flush_lock);
 426}
 427
 428/**
 429 * dn_return_short - Return a short packet to its sender
 430 * @skb: The packet to return
 431 *
 432 */
 433static int dn_return_short(struct sk_buff *skb)
 434{
 435	struct dn_skb_cb *cb;
 436	unsigned char *ptr;
 437	__le16 *src;
 438	__le16 *dst;
 439
 440	/* Add back headers */
 441	skb_push(skb, skb->data - skb_network_header(skb));
 442
 443	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 444		return NET_RX_DROP;
 445
 446	cb = DN_SKB_CB(skb);
 447	/* Skip packet length and point to flags */
 448	ptr = skb->data + 2;
 449	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 450
 451	dst = (__le16 *)ptr;
 452	ptr += 2;
 453	src = (__le16 *)ptr;
 454	ptr += 2;
 455	*ptr = 0; /* Zero hop count */
 456
 457	swap(*src, *dst);
 458
 459	skb->pkt_type = PACKET_OUTGOING;
 460	dn_rt_finish_output(skb, NULL, NULL);
 461	return NET_RX_SUCCESS;
 462}
 463
 464/**
 465 * dn_return_long - Return a long packet to its sender
 466 * @skb: The long format packet to return
 467 *
 468 */
 469static int dn_return_long(struct sk_buff *skb)
 470{
 471	struct dn_skb_cb *cb;
 472	unsigned char *ptr;
 473	unsigned char *src_addr, *dst_addr;
 474	unsigned char tmp[ETH_ALEN];
 475
 476	/* Add back all headers */
 477	skb_push(skb, skb->data - skb_network_header(skb));
 478
 479	if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL)
 480		return NET_RX_DROP;
 481
 482	cb = DN_SKB_CB(skb);
 483	/* Ignore packet length and point to flags */
 484	ptr = skb->data + 2;
 485
 486	/* Skip padding */
 487	if (*ptr & DN_RT_F_PF) {
 488		char padlen = (*ptr & ~DN_RT_F_PF);
 489		ptr += padlen;
 490	}
 491
 492	*ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS;
 493	ptr += 2;
 494	dst_addr = ptr;
 495	ptr += 8;
 496	src_addr = ptr;
 497	ptr += 6;
 498	*ptr = 0; /* Zero hop count */
 499
 500	/* Swap source and destination */
 501	memcpy(tmp, src_addr, ETH_ALEN);
 502	memcpy(src_addr, dst_addr, ETH_ALEN);
 503	memcpy(dst_addr, tmp, ETH_ALEN);
 504
 505	skb->pkt_type = PACKET_OUTGOING;
 506	dn_rt_finish_output(skb, dst_addr, src_addr);
 507	return NET_RX_SUCCESS;
 508}
 509
 510/**
 511 * dn_route_rx_packet - Try and find a route for an incoming packet
 512 * @skb: The packet to find a route for
 513 *
 514 * Returns: result of input function if route is found, error code otherwise
 515 */
 516static int dn_route_rx_packet(struct sk_buff *skb)
 517{
 518	struct dn_skb_cb *cb;
 519	int err;
 520
 521	if ((err = dn_route_input(skb)) == 0)
 522		return dst_input(skb);
 523
 524	cb = DN_SKB_CB(skb);
 525	if (decnet_debug_level & 4) {
 526		char *devname = skb->dev ? skb->dev->name : "???";
 527
 528		printk(KERN_DEBUG
 529			"DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n",
 530			(int)cb->rt_flags, devname, skb->len,
 531			le16_to_cpu(cb->src), le16_to_cpu(cb->dst),
 532			err, skb->pkt_type);
 533	}
 534
 535	if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) {
 536		switch (cb->rt_flags & DN_RT_PKT_MSK) {
 537		case DN_RT_PKT_SHORT:
 538			return dn_return_short(skb);
 539		case DN_RT_PKT_LONG:
 540			return dn_return_long(skb);
 541		}
 542	}
 543
 544	kfree_skb(skb);
 545	return NET_RX_DROP;
 546}
 547
 548static int dn_route_rx_long(struct sk_buff *skb)
 549{
 550	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 551	unsigned char *ptr = skb->data;
 552
 553	if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */
 554		goto drop_it;
 555
 556	skb_pull(skb, 20);
 557	skb_reset_transport_header(skb);
 558
 559	/* Destination info */
 560	ptr += 2;
 561	cb->dst = dn_eth2dn(ptr);
 562	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 563		goto drop_it;
 564	ptr += 6;
 565
 566
 567	/* Source info */
 568	ptr += 2;
 569	cb->src = dn_eth2dn(ptr);
 570	if (memcmp(ptr, dn_hiord_addr, 4) != 0)
 571		goto drop_it;
 572	ptr += 6;
 573	/* Other junk */
 574	ptr++;
 575	cb->hops = *ptr++; /* Visit Count */
 576
 577	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
 
 578		       dn_route_rx_packet);
 579
 580drop_it:
 581	kfree_skb(skb);
 582	return NET_RX_DROP;
 583}
 584
 585
 586
 587static int dn_route_rx_short(struct sk_buff *skb)
 588{
 589	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 590	unsigned char *ptr = skb->data;
 591
 592	if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */
 593		goto drop_it;
 594
 595	skb_pull(skb, 5);
 596	skb_reset_transport_header(skb);
 597
 598	cb->dst = *(__le16 *)ptr;
 599	ptr += 2;
 600	cb->src = *(__le16 *)ptr;
 601	ptr += 2;
 602	cb->hops = *ptr & 0x3f;
 603
 604	return NF_HOOK(NFPROTO_DECNET, NF_DN_PRE_ROUTING, skb, skb->dev, NULL,
 
 605		       dn_route_rx_packet);
 606
 607drop_it:
 608	kfree_skb(skb);
 609	return NET_RX_DROP;
 610}
 611
 612static int dn_route_discard(struct sk_buff *skb)
 613{
 614	/*
 615	 * I know we drop the packet here, but thats considered success in
 616	 * this case
 617	 */
 618	kfree_skb(skb);
 619	return NET_RX_SUCCESS;
 620}
 621
 622static int dn_route_ptp_hello(struct sk_buff *skb)
 623{
 624	dn_dev_hello(skb);
 625	dn_neigh_pointopoint_hello(skb);
 626	return NET_RX_SUCCESS;
 627}
 628
 629int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
 630{
 631	struct dn_skb_cb *cb;
 632	unsigned char flags = 0;
 633	__u16 len = le16_to_cpu(*(__le16 *)skb->data);
 634	struct dn_dev *dn = rcu_dereference(dev->dn_ptr);
 635	unsigned char padlen = 0;
 636
 637	if (!net_eq(dev_net(dev), &init_net))
 638		goto dump_it;
 639
 640	if (dn == NULL)
 641		goto dump_it;
 642
 643	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 644		goto out;
 645
 646	if (!pskb_may_pull(skb, 3))
 647		goto dump_it;
 648
 649	skb_pull(skb, 2);
 650
 651	if (len > skb->len)
 652		goto dump_it;
 653
 654	skb_trim(skb, len);
 655
 656	flags = *skb->data;
 657
 658	cb = DN_SKB_CB(skb);
 659	cb->stamp = jiffies;
 660	cb->iif = dev->ifindex;
 661
 662	/*
 663	 * If we have padding, remove it.
 664	 */
 665	if (flags & DN_RT_F_PF) {
 666		padlen = flags & ~DN_RT_F_PF;
 667		if (!pskb_may_pull(skb, padlen + 1))
 668			goto dump_it;
 669		skb_pull(skb, padlen);
 670		flags = *skb->data;
 671	}
 672
 673	skb_reset_network_header(skb);
 674
 675	/*
 676	 * Weed out future version DECnet
 677	 */
 678	if (flags & DN_RT_F_VER)
 679		goto dump_it;
 680
 681	cb->rt_flags = flags;
 682
 683	if (decnet_debug_level & 1)
 684		printk(KERN_DEBUG
 685			"dn_route_rcv: got 0x%02x from %s [%d %d %d]\n",
 686			(int)flags, (dev) ? dev->name : "???", len, skb->len,
 687			padlen);
 688
 689	if (flags & DN_RT_PKT_CNTL) {
 690		if (unlikely(skb_linearize(skb)))
 691			goto dump_it;
 692
 693		switch (flags & DN_RT_CNTL_MSK) {
 694		case DN_RT_PKT_INIT:
 695			dn_dev_init_pkt(skb);
 696			break;
 697		case DN_RT_PKT_VERI:
 698			dn_dev_veri_pkt(skb);
 699			break;
 700		}
 701
 702		if (dn->parms.state != DN_DEV_S_RU)
 703			goto dump_it;
 704
 705		switch (flags & DN_RT_CNTL_MSK) {
 706		case DN_RT_PKT_HELO:
 707			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 708				       skb, skb->dev, NULL,
 709				       dn_route_ptp_hello);
 710
 711		case DN_RT_PKT_L1RT:
 712		case DN_RT_PKT_L2RT:
 713			return NF_HOOK(NFPROTO_DECNET, NF_DN_ROUTE,
 714				       skb, skb->dev, NULL,
 715				       dn_route_discard);
 716		case DN_RT_PKT_ERTH:
 717			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 718				       skb, skb->dev, NULL,
 719				       dn_neigh_router_hello);
 720
 721		case DN_RT_PKT_EEDH:
 722			return NF_HOOK(NFPROTO_DECNET, NF_DN_HELLO,
 723				       skb, skb->dev, NULL,
 724				       dn_neigh_endnode_hello);
 725		}
 726	} else {
 727		if (dn->parms.state != DN_DEV_S_RU)
 728			goto dump_it;
 729
 730		skb_pull(skb, 1); /* Pull flags */
 731
 732		switch (flags & DN_RT_PKT_MSK) {
 733		case DN_RT_PKT_LONG:
 734			return dn_route_rx_long(skb);
 735		case DN_RT_PKT_SHORT:
 736			return dn_route_rx_short(skb);
 737		}
 738	}
 739
 740dump_it:
 741	kfree_skb(skb);
 742out:
 743	return NET_RX_DROP;
 744}
 745
 746static int dn_to_neigh_output(struct sk_buff *skb)
 747{
 748	struct dst_entry *dst = skb_dst(skb);
 749	struct dn_route *rt = (struct dn_route *) dst;
 750	struct neighbour *n = rt->n;
 751
 752	return n->output(n, skb);
 753}
 754
 755static int dn_output(struct sock *sk, struct sk_buff *skb)
 756{
 757	struct dst_entry *dst = skb_dst(skb);
 758	struct dn_route *rt = (struct dn_route *)dst;
 759	struct net_device *dev = dst->dev;
 760	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 761
 762	int err = -EINVAL;
 763
 764	if (rt->n == NULL)
 765		goto error;
 766
 767	skb->dev = dev;
 768
 769	cb->src = rt->rt_saddr;
 770	cb->dst = rt->rt_daddr;
 771
 772	/*
 773	 * Always set the Intra-Ethernet bit on all outgoing packets
 774	 * originated on this node. Only valid flag from upper layers
 775	 * is return-to-sender-requested. Set hop count to 0 too.
 776	 */
 777	cb->rt_flags &= ~DN_RT_F_RQR;
 778	cb->rt_flags |= DN_RT_F_IE;
 779	cb->hops = 0;
 780
 781	return NF_HOOK(NFPROTO_DECNET, NF_DN_LOCAL_OUT, skb, NULL, dev,
 
 782		       dn_to_neigh_output);
 783
 784error:
 785	net_dbg_ratelimited("dn_output: This should not happen\n");
 786
 787	kfree_skb(skb);
 788
 789	return err;
 790}
 791
 792static int dn_forward(struct sk_buff *skb)
 793{
 794	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 795	struct dst_entry *dst = skb_dst(skb);
 796	struct dn_dev *dn_db = rcu_dereference(dst->dev->dn_ptr);
 797	struct dn_route *rt;
 798	int header_len;
 799#ifdef CONFIG_NETFILTER
 800	struct net_device *dev = skb->dev;
 801#endif
 802
 803	if (skb->pkt_type != PACKET_HOST)
 804		goto drop;
 805
 806	/* Ensure that we have enough space for headers */
 807	rt = (struct dn_route *)skb_dst(skb);
 808	header_len = dn_db->use_long ? 21 : 6;
 809	if (skb_cow(skb, LL_RESERVED_SPACE(rt->dst.dev)+header_len))
 810		goto drop;
 811
 812	/*
 813	 * Hop count exceeded.
 814	 */
 815	if (++cb->hops > 30)
 816		goto drop;
 817
 818	skb->dev = rt->dst.dev;
 819
 820	/*
 821	 * If packet goes out same interface it came in on, then set
 822	 * the Intra-Ethernet bit. This has no effect for short
 823	 * packets, so we don't need to test for them here.
 824	 */
 825	cb->rt_flags &= ~DN_RT_F_IE;
 826	if (rt->rt_flags & RTCF_DOREDIRECT)
 827		cb->rt_flags |= DN_RT_F_IE;
 828
 829	return NF_HOOK(NFPROTO_DECNET, NF_DN_FORWARD, skb, dev, skb->dev,
 
 830		       dn_to_neigh_output);
 831
 832drop:
 833	kfree_skb(skb);
 834	return NET_RX_DROP;
 835}
 836
 837/*
 838 * Used to catch bugs. This should never normally get
 839 * called.
 840 */
 841static int dn_rt_bug_sk(struct sock *sk, struct sk_buff *skb)
 842{
 843	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 844
 845	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 846			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 847
 848	kfree_skb(skb);
 849
 850	return NET_RX_DROP;
 851}
 852
 853static int dn_rt_bug(struct sk_buff *skb)
 854{
 855	struct dn_skb_cb *cb = DN_SKB_CB(skb);
 856
 857	net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
 858			    le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
 859
 860	kfree_skb(skb);
 861
 862	return NET_RX_DROP;
 863}
 864
 865static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
 866{
 867	return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
 868}
 869
 870static unsigned int dn_dst_mtu(const struct dst_entry *dst)
 871{
 872	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
 873
 874	return mtu ? : dst->dev->mtu;
 875}
 876
 877static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
 878					     struct sk_buff *skb,
 879					     const void *daddr)
 880{
 881	return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
 882}
 883
 884static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
 885{
 886	struct dn_fib_info *fi = res->fi;
 887	struct net_device *dev = rt->dst.dev;
 888	unsigned int mss_metric;
 889	struct neighbour *n;
 890
 891	if (fi) {
 892		if (DN_FIB_RES_GW(*res) &&
 893		    DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
 894			rt->rt_gateway = DN_FIB_RES_GW(*res);
 895		dst_init_metrics(&rt->dst, fi->fib_metrics, true);
 896	}
 897	rt->rt_type = res->type;
 898
 899	if (dev != NULL && rt->n == NULL) {
 900		n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
 901		if (IS_ERR(n))
 902			return PTR_ERR(n);
 903		rt->n = n;
 904	}
 905
 906	if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
 907		dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
 908	mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
 909	if (mss_metric) {
 910		unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
 911		if (mss_metric > mss)
 912			dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
 913	}
 914	return 0;
 915}
 916
 917static inline int dn_match_addr(__le16 addr1, __le16 addr2)
 918{
 919	__u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
 920	int match = 16;
 921	while(tmp) {
 922		tmp >>= 1;
 923		match--;
 924	}
 925	return match;
 926}
 927
 928static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
 929{
 930	__le16 saddr = 0;
 931	struct dn_dev *dn_db;
 932	struct dn_ifaddr *ifa;
 933	int best_match = 0;
 934	int ret;
 935
 936	rcu_read_lock();
 937	dn_db = rcu_dereference(dev->dn_ptr);
 938	for (ifa = rcu_dereference(dn_db->ifa_list);
 939	     ifa != NULL;
 940	     ifa = rcu_dereference(ifa->ifa_next)) {
 941		if (ifa->ifa_scope > scope)
 942			continue;
 943		if (!daddr) {
 944			saddr = ifa->ifa_local;
 945			break;
 946		}
 947		ret = dn_match_addr(daddr, ifa->ifa_local);
 948		if (ret > best_match)
 949			saddr = ifa->ifa_local;
 950		if (best_match == 0)
 951			saddr = ifa->ifa_local;
 952	}
 953	rcu_read_unlock();
 954
 955	return saddr;
 956}
 957
 958static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
 959{
 960	return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
 961}
 962
 963static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
 964{
 965	__le16 mask = dnet_make_mask(res->prefixlen);
 966	return (daddr&~mask)|res->fi->fib_nh->nh_gw;
 967}
 968
 969static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
 970{
 971	struct flowidn fld = {
 972		.daddr = oldflp->daddr,
 973		.saddr = oldflp->saddr,
 974		.flowidn_scope = RT_SCOPE_UNIVERSE,
 975		.flowidn_mark = oldflp->flowidn_mark,
 976		.flowidn_iif = LOOPBACK_IFINDEX,
 977		.flowidn_oif = oldflp->flowidn_oif,
 978	};
 979	struct dn_route *rt = NULL;
 980	struct net_device *dev_out = NULL, *dev;
 981	struct neighbour *neigh = NULL;
 982	unsigned int hash;
 983	unsigned int flags = 0;
 984	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
 985	int err;
 986	int free_res = 0;
 987	__le16 gateway = 0;
 988
 989	if (decnet_debug_level & 16)
 990		printk(KERN_DEBUG
 991		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 992		       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 993		       le16_to_cpu(oldflp->saddr),
 994		       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 995		       oldflp->flowidn_oif);
 996
 997	/* If we have an output interface, verify its a DECnet device */
 998	if (oldflp->flowidn_oif) {
 999		dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
1000		err = -ENODEV;
1001		if (dev_out && dev_out->dn_ptr == NULL) {
1002			dev_put(dev_out);
1003			dev_out = NULL;
1004		}
1005		if (dev_out == NULL)
1006			goto out;
1007	}
1008
1009	/* If we have a source address, verify that its a local address */
1010	if (oldflp->saddr) {
1011		err = -EADDRNOTAVAIL;
1012
1013		if (dev_out) {
1014			if (dn_dev_islocal(dev_out, oldflp->saddr))
1015				goto source_ok;
1016			dev_put(dev_out);
1017			goto out;
1018		}
1019		rcu_read_lock();
1020		for_each_netdev_rcu(&init_net, dev) {
1021			if (!dev->dn_ptr)
1022				continue;
1023			if (!dn_dev_islocal(dev, oldflp->saddr))
1024				continue;
1025			if ((dev->flags & IFF_LOOPBACK) &&
1026			    oldflp->daddr &&
1027			    !dn_dev_islocal(dev, oldflp->daddr))
1028				continue;
1029
1030			dev_out = dev;
1031			break;
1032		}
1033		rcu_read_unlock();
1034		if (dev_out == NULL)
1035			goto out;
1036		dev_hold(dev_out);
1037source_ok:
1038		;
1039	}
1040
1041	/* No destination? Assume its local */
1042	if (!fld.daddr) {
1043		fld.daddr = fld.saddr;
1044
1045		err = -EADDRNOTAVAIL;
1046		if (dev_out)
1047			dev_put(dev_out);
 
1048		dev_out = init_net.loopback_dev;
 
 
 
1049		dev_hold(dev_out);
1050		if (!fld.daddr) {
1051			fld.daddr =
1052			fld.saddr = dnet_select_source(dev_out, 0,
1053						       RT_SCOPE_HOST);
1054			if (!fld.daddr)
1055				goto out;
1056		}
1057		fld.flowidn_oif = LOOPBACK_IFINDEX;
1058		res.type = RTN_LOCAL;
1059		goto make_route;
1060	}
1061
1062	if (decnet_debug_level & 16)
1063		printk(KERN_DEBUG
1064		       "dn_route_output_slow: initial checks complete."
1065		       " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1066		       le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1067		       fld.flowidn_oif, try_hard);
1068
1069	/*
1070	 * N.B. If the kernel is compiled without router support then
1071	 * dn_fib_lookup() will evaluate to non-zero so this if () block
1072	 * will always be executed.
1073	 */
1074	err = -ESRCH;
1075	if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1076		struct dn_dev *dn_db;
1077		if (err != -ESRCH)
1078			goto out;
1079		/*
1080		 * Here the fallback is basically the standard algorithm for
1081		 * routing in endnodes which is described in the DECnet routing
1082		 * docs
1083		 *
1084		 * If we are not trying hard, look in neighbour cache.
1085		 * The result is tested to ensure that if a specific output
1086		 * device/source address was requested, then we honour that
1087		 * here
1088		 */
1089		if (!try_hard) {
1090			neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1091			if (neigh) {
1092				if ((oldflp->flowidn_oif &&
1093				    (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1094				    (oldflp->saddr &&
1095				    (!dn_dev_islocal(neigh->dev,
1096						     oldflp->saddr)))) {
1097					neigh_release(neigh);
1098					neigh = NULL;
1099				} else {
1100					if (dev_out)
1101						dev_put(dev_out);
1102					if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1103						dev_out = init_net.loopback_dev;
1104						res.type = RTN_LOCAL;
1105					} else {
1106						dev_out = neigh->dev;
1107					}
1108					dev_hold(dev_out);
1109					goto select_source;
1110				}
1111			}
1112		}
1113
1114		/* Not there? Perhaps its a local address */
1115		if (dev_out == NULL)
1116			dev_out = dn_dev_get_default();
1117		err = -ENODEV;
1118		if (dev_out == NULL)
1119			goto out;
1120		dn_db = rcu_dereference_raw(dev_out->dn_ptr);
 
 
1121		/* Possible improvement - check all devices for local addr */
1122		if (dn_dev_islocal(dev_out, fld.daddr)) {
1123			dev_put(dev_out);
1124			dev_out = init_net.loopback_dev;
1125			dev_hold(dev_out);
1126			res.type = RTN_LOCAL;
1127			goto select_source;
1128		}
1129		/* Not local either.... try sending it to the default router */
1130		neigh = neigh_clone(dn_db->router);
1131		BUG_ON(neigh && neigh->dev != dev_out);
1132
1133		/* Ok then, we assume its directly connected and move on */
1134select_source:
1135		if (neigh)
1136			gateway = ((struct dn_neigh *)neigh)->addr;
1137		if (gateway == 0)
1138			gateway = fld.daddr;
1139		if (fld.saddr == 0) {
1140			fld.saddr = dnet_select_source(dev_out, gateway,
1141						       res.type == RTN_LOCAL ?
1142						       RT_SCOPE_HOST :
1143						       RT_SCOPE_LINK);
1144			if (fld.saddr == 0 && res.type != RTN_LOCAL)
1145				goto e_addr;
1146		}
1147		fld.flowidn_oif = dev_out->ifindex;
1148		goto make_route;
1149	}
1150	free_res = 1;
1151
1152	if (res.type == RTN_NAT)
1153		goto e_inval;
1154
1155	if (res.type == RTN_LOCAL) {
1156		if (!fld.saddr)
1157			fld.saddr = fld.daddr;
1158		if (dev_out)
1159			dev_put(dev_out);
1160		dev_out = init_net.loopback_dev;
1161		dev_hold(dev_out);
 
 
1162		fld.flowidn_oif = dev_out->ifindex;
1163		if (res.fi)
1164			dn_fib_info_put(res.fi);
1165		res.fi = NULL;
1166		goto make_route;
1167	}
1168
1169	if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1170		dn_fib_select_multipath(&fld, &res);
1171
1172	/*
1173	 * We could add some logic to deal with default routes here and
1174	 * get rid of some of the special casing above.
1175	 */
1176
1177	if (!fld.saddr)
1178		fld.saddr = DN_FIB_RES_PREFSRC(res);
1179
1180	if (dev_out)
1181		dev_put(dev_out);
1182	dev_out = DN_FIB_RES_DEV(res);
1183	dev_hold(dev_out);
1184	fld.flowidn_oif = dev_out->ifindex;
1185	gateway = DN_FIB_RES_GW(res);
1186
1187make_route:
1188	if (dev_out->flags & IFF_LOOPBACK)
1189		flags |= RTCF_LOCAL;
1190
1191	rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1192	if (rt == NULL)
1193		goto e_nobufs;
1194
1195	memset(&rt->fld, 0, sizeof(rt->fld));
1196	rt->fld.saddr        = oldflp->saddr;
1197	rt->fld.daddr        = oldflp->daddr;
1198	rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1199	rt->fld.flowidn_iif  = 0;
1200	rt->fld.flowidn_mark = oldflp->flowidn_mark;
1201
1202	rt->rt_saddr      = fld.saddr;
1203	rt->rt_daddr      = fld.daddr;
1204	rt->rt_gateway    = gateway ? gateway : fld.daddr;
1205	rt->rt_local_src  = fld.saddr;
1206
1207	rt->rt_dst_map    = fld.daddr;
1208	rt->rt_src_map    = fld.saddr;
1209
1210	rt->n = neigh;
1211	neigh = NULL;
1212
1213	rt->dst.lastuse = jiffies;
1214	rt->dst.output  = dn_output;
1215	rt->dst.input   = dn_rt_bug;
1216	rt->rt_flags      = flags;
1217	if (flags & RTCF_LOCAL)
1218		rt->dst.input = dn_nsp_rx;
1219
1220	err = dn_rt_set_next_hop(rt, &res);
1221	if (err)
1222		goto e_neighbour;
1223
1224	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1225	dn_insert_route(rt, hash, (struct dn_route **)pprt);
1226
1227done:
1228	if (neigh)
1229		neigh_release(neigh);
1230	if (free_res)
1231		dn_fib_res_put(&res);
1232	if (dev_out)
1233		dev_put(dev_out);
1234out:
1235	return err;
1236
1237e_addr:
1238	err = -EADDRNOTAVAIL;
1239	goto done;
1240e_inval:
1241	err = -EINVAL;
1242	goto done;
1243e_nobufs:
1244	err = -ENOBUFS;
1245	goto done;
1246e_neighbour:
1247	dst_free(&rt->dst);
1248	goto e_nobufs;
1249}
1250
1251
1252/*
1253 * N.B. The flags may be moved into the flowi at some future stage.
1254 */
1255static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1256{
1257	unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1258	struct dn_route *rt = NULL;
1259
1260	if (!(flags & MSG_TRYHARD)) {
1261		rcu_read_lock_bh();
1262		for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1263			rt = rcu_dereference_bh(rt->dst.dn_next)) {
1264			if ((flp->daddr == rt->fld.daddr) &&
1265			    (flp->saddr == rt->fld.saddr) &&
1266			    (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1267			    dn_is_output_route(rt) &&
1268			    (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1269				dst_use(&rt->dst, jiffies);
1270				rcu_read_unlock_bh();
1271				*pprt = &rt->dst;
1272				return 0;
1273			}
1274		}
1275		rcu_read_unlock_bh();
1276	}
1277
1278	return dn_route_output_slow(pprt, flp, flags);
1279}
1280
1281static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1282{
1283	int err;
1284
1285	err = __dn_route_output_key(pprt, flp, flags);
1286	if (err == 0 && flp->flowidn_proto) {
1287		*pprt = xfrm_lookup(&init_net, *pprt,
1288				    flowidn_to_flowi(flp), NULL, 0);
1289		if (IS_ERR(*pprt)) {
1290			err = PTR_ERR(*pprt);
1291			*pprt = NULL;
1292		}
1293	}
1294	return err;
1295}
1296
1297int dn_route_output_sock(struct dst_entry __rcu **pprt, struct flowidn *fl, struct sock *sk, int flags)
1298{
1299	int err;
1300
1301	err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1302	if (err == 0 && fl->flowidn_proto) {
1303		*pprt = xfrm_lookup(&init_net, *pprt,
1304				    flowidn_to_flowi(fl), sk, 0);
1305		if (IS_ERR(*pprt)) {
1306			err = PTR_ERR(*pprt);
1307			*pprt = NULL;
1308		}
1309	}
1310	return err;
1311}
1312
1313static int dn_route_input_slow(struct sk_buff *skb)
1314{
1315	struct dn_route *rt = NULL;
1316	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1317	struct net_device *in_dev = skb->dev;
1318	struct net_device *out_dev = NULL;
1319	struct dn_dev *dn_db;
1320	struct neighbour *neigh = NULL;
1321	unsigned int hash;
1322	int flags = 0;
1323	__le16 gateway = 0;
1324	__le16 local_src = 0;
1325	struct flowidn fld = {
1326		.daddr = cb->dst,
1327		.saddr = cb->src,
1328		.flowidn_scope = RT_SCOPE_UNIVERSE,
1329		.flowidn_mark = skb->mark,
1330		.flowidn_iif = skb->dev->ifindex,
1331	};
1332	struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1333	int err = -EINVAL;
1334	int free_res = 0;
1335
1336	dev_hold(in_dev);
1337
1338	if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1339		goto out;
1340
1341	/* Zero source addresses are not allowed */
1342	if (fld.saddr == 0)
1343		goto out;
1344
1345	/*
1346	 * In this case we've just received a packet from a source
1347	 * outside ourselves pretending to come from us. We don't
1348	 * allow it any further to prevent routing loops, spoofing and
1349	 * other nasties. Loopback packets already have the dst attached
1350	 * so this only affects packets which have originated elsewhere.
1351	 */
1352	err  = -ENOTUNIQ;
1353	if (dn_dev_islocal(in_dev, cb->src))
1354		goto out;
1355
1356	err = dn_fib_lookup(&fld, &res);
1357	if (err) {
1358		if (err != -ESRCH)
1359			goto out;
1360		/*
1361		 * Is the destination us ?
1362		 */
1363		if (!dn_dev_islocal(in_dev, cb->dst))
1364			goto e_inval;
1365
1366		res.type = RTN_LOCAL;
1367	} else {
1368		__le16 src_map = fld.saddr;
1369		free_res = 1;
1370
1371		out_dev = DN_FIB_RES_DEV(res);
1372		if (out_dev == NULL) {
1373			net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1374			goto e_inval;
1375		}
1376		dev_hold(out_dev);
1377
1378		if (res.r)
1379			src_map = fld.saddr; /* no NAT support for now */
1380
1381		gateway = DN_FIB_RES_GW(res);
1382		if (res.type == RTN_NAT) {
1383			fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1384			dn_fib_res_put(&res);
1385			free_res = 0;
1386			if (dn_fib_lookup(&fld, &res))
1387				goto e_inval;
1388			free_res = 1;
1389			if (res.type != RTN_UNICAST)
1390				goto e_inval;
1391			flags |= RTCF_DNAT;
1392			gateway = fld.daddr;
1393		}
1394		fld.saddr = src_map;
1395	}
1396
1397	switch(res.type) {
1398	case RTN_UNICAST:
1399		/*
1400		 * Forwarding check here, we only check for forwarding
1401		 * being turned off, if you want to only forward intra
1402		 * area, its up to you to set the routing tables up
1403		 * correctly.
1404		 */
1405		if (dn_db->parms.forwarding == 0)
1406			goto e_inval;
1407
1408		if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1409			dn_fib_select_multipath(&fld, &res);
1410
1411		/*
1412		 * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1413		 * flag as a hint to set the intra-ethernet bit when
1414		 * forwarding. If we've got NAT in operation, we don't do
1415		 * this optimisation.
1416		 */
1417		if (out_dev == in_dev && !(flags & RTCF_NAT))
1418			flags |= RTCF_DOREDIRECT;
1419
1420		local_src = DN_FIB_RES_PREFSRC(res);
1421
1422	case RTN_BLACKHOLE:
1423	case RTN_UNREACHABLE:
1424		break;
1425	case RTN_LOCAL:
1426		flags |= RTCF_LOCAL;
1427		fld.saddr = cb->dst;
1428		fld.daddr = cb->src;
1429
1430		/* Routing tables gave us a gateway */
1431		if (gateway)
1432			goto make_route;
1433
1434		/* Packet was intra-ethernet, so we know its on-link */
1435		if (cb->rt_flags & DN_RT_F_IE) {
1436			gateway = cb->src;
1437			goto make_route;
1438		}
1439
1440		/* Use the default router if there is one */
1441		neigh = neigh_clone(dn_db->router);
1442		if (neigh) {
1443			gateway = ((struct dn_neigh *)neigh)->addr;
1444			goto make_route;
1445		}
1446
1447		/* Close eyes and pray */
1448		gateway = cb->src;
1449		goto make_route;
1450	default:
1451		goto e_inval;
1452	}
1453
1454make_route:
1455	rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1456	if (rt == NULL)
1457		goto e_nobufs;
1458
1459	memset(&rt->fld, 0, sizeof(rt->fld));
1460	rt->rt_saddr      = fld.saddr;
1461	rt->rt_daddr      = fld.daddr;
1462	rt->rt_gateway    = fld.daddr;
1463	if (gateway)
1464		rt->rt_gateway = gateway;
1465	rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1466
1467	rt->rt_dst_map    = fld.daddr;
1468	rt->rt_src_map    = fld.saddr;
1469
1470	rt->fld.saddr        = cb->src;
1471	rt->fld.daddr        = cb->dst;
1472	rt->fld.flowidn_oif  = 0;
1473	rt->fld.flowidn_iif  = in_dev->ifindex;
1474	rt->fld.flowidn_mark = fld.flowidn_mark;
1475
1476	rt->n = neigh;
1477	rt->dst.lastuse = jiffies;
1478	rt->dst.output = dn_rt_bug_sk;
1479	switch (res.type) {
1480	case RTN_UNICAST:
1481		rt->dst.input = dn_forward;
1482		break;
1483	case RTN_LOCAL:
1484		rt->dst.output = dn_output;
1485		rt->dst.input = dn_nsp_rx;
1486		rt->dst.dev = in_dev;
1487		flags |= RTCF_LOCAL;
1488		break;
1489	default:
1490	case RTN_UNREACHABLE:
1491	case RTN_BLACKHOLE:
1492		rt->dst.input = dst_discard;
1493	}
1494	rt->rt_flags = flags;
1495
1496	err = dn_rt_set_next_hop(rt, &res);
1497	if (err)
1498		goto e_neighbour;
1499
1500	hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1501	dn_insert_route(rt, hash, &rt);
1502	skb_dst_set(skb, &rt->dst);
1503
1504done:
1505	if (neigh)
1506		neigh_release(neigh);
1507	if (free_res)
1508		dn_fib_res_put(&res);
1509	dev_put(in_dev);
1510	if (out_dev)
1511		dev_put(out_dev);
1512out:
1513	return err;
1514
1515e_inval:
1516	err = -EINVAL;
1517	goto done;
1518
1519e_nobufs:
1520	err = -ENOBUFS;
1521	goto done;
1522
1523e_neighbour:
1524	dst_free(&rt->dst);
1525	goto done;
1526}
1527
1528static int dn_route_input(struct sk_buff *skb)
1529{
1530	struct dn_route *rt;
1531	struct dn_skb_cb *cb = DN_SKB_CB(skb);
1532	unsigned int hash = dn_hash(cb->src, cb->dst);
1533
1534	if (skb_dst(skb))
1535		return 0;
1536
1537	rcu_read_lock();
1538	for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1539	    rt = rcu_dereference(rt->dst.dn_next)) {
1540		if ((rt->fld.saddr == cb->src) &&
1541		    (rt->fld.daddr == cb->dst) &&
1542		    (rt->fld.flowidn_oif == 0) &&
1543		    (rt->fld.flowidn_mark == skb->mark) &&
1544		    (rt->fld.flowidn_iif == cb->iif)) {
1545			dst_use(&rt->dst, jiffies);
1546			rcu_read_unlock();
1547			skb_dst_set(skb, (struct dst_entry *)rt);
1548			return 0;
1549		}
1550	}
1551	rcu_read_unlock();
1552
1553	return dn_route_input_slow(skb);
1554}
1555
1556static int dn_rt_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
1557			   int event, int nowait, unsigned int flags)
1558{
1559	struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1560	struct rtmsg *r;
1561	struct nlmsghdr *nlh;
1562	long expires;
1563
1564	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
1565	if (!nlh)
1566		return -EMSGSIZE;
1567
1568	r = nlmsg_data(nlh);
1569	r->rtm_family = AF_DECnet;
1570	r->rtm_dst_len = 16;
1571	r->rtm_src_len = 0;
1572	r->rtm_tos = 0;
1573	r->rtm_table = RT_TABLE_MAIN;
1574	r->rtm_type = rt->rt_type;
1575	r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1576	r->rtm_scope = RT_SCOPE_UNIVERSE;
1577	r->rtm_protocol = RTPROT_UNSPEC;
1578
1579	if (rt->rt_flags & RTCF_NOTIFY)
1580		r->rtm_flags |= RTM_F_NOTIFY;
1581
1582	if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1583	    nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1584		goto errout;
1585
1586	if (rt->fld.saddr) {
1587		r->rtm_src_len = 16;
1588		if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1589			goto errout;
1590	}
1591	if (rt->dst.dev &&
1592	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1593		goto errout;
1594
1595	/*
1596	 * Note to self - change this if input routes reverse direction when
1597	 * they deal only with inputs and not with replies like they do
1598	 * currently.
1599	 */
1600	if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1601		goto errout;
1602
1603	if (rt->rt_daddr != rt->rt_gateway &&
1604	    nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1605		goto errout;
1606
1607	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1608		goto errout;
1609
1610	expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1611	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1612			       rt->dst.error) < 0)
1613		goto errout;
1614
1615	if (dn_is_input_route(rt) &&
1616	    nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1617		goto errout;
1618
1619	return nlmsg_end(skb, nlh);
 
1620
1621errout:
1622	nlmsg_cancel(skb, nlh);
1623	return -EMSGSIZE;
1624}
1625
1626const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
1627	[RTA_DST]		= { .type = NLA_U16 },
1628	[RTA_SRC]		= { .type = NLA_U16 },
1629	[RTA_IIF]		= { .type = NLA_U32 },
1630	[RTA_OIF]		= { .type = NLA_U32 },
1631	[RTA_GATEWAY]		= { .type = NLA_U16 },
1632	[RTA_PRIORITY]		= { .type = NLA_U32 },
1633	[RTA_PREFSRC]		= { .type = NLA_U16 },
1634	[RTA_METRICS]		= { .type = NLA_NESTED },
1635	[RTA_MULTIPATH]		= { .type = NLA_NESTED },
1636	[RTA_TABLE]		= { .type = NLA_U32 },
1637	[RTA_MARK]		= { .type = NLA_U32 },
1638};
1639
1640/*
1641 * This is called by both endnodes and routers now.
1642 */
1643static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
1644{
1645	struct net *net = sock_net(in_skb->sk);
1646	struct rtmsg *rtm = nlmsg_data(nlh);
1647	struct dn_route *rt = NULL;
1648	struct dn_skb_cb *cb;
1649	int err;
1650	struct sk_buff *skb;
1651	struct flowidn fld;
1652	struct nlattr *tb[RTA_MAX+1];
1653
1654	if (!net_eq(net, &init_net))
1655		return -EINVAL;
1656
1657	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
1658	if (err < 0)
1659		return err;
1660
1661	memset(&fld, 0, sizeof(fld));
1662	fld.flowidn_proto = DNPROTO_NSP;
1663
1664	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1665	if (skb == NULL)
1666		return -ENOBUFS;
1667	skb_reset_mac_header(skb);
1668	cb = DN_SKB_CB(skb);
1669
1670	if (tb[RTA_SRC])
1671		fld.saddr = nla_get_le16(tb[RTA_SRC]);
1672
1673	if (tb[RTA_DST])
1674		fld.daddr = nla_get_le16(tb[RTA_DST]);
1675
1676	if (tb[RTA_IIF])
1677		fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
1678
1679	if (fld.flowidn_iif) {
1680		struct net_device *dev;
1681		dev = __dev_get_by_index(&init_net, fld.flowidn_iif);
1682		if (!dev || !dev->dn_ptr) {
1683			kfree_skb(skb);
1684			return -ENODEV;
1685		}
1686		skb->protocol = htons(ETH_P_DNA_RT);
1687		skb->dev = dev;
1688		cb->src = fld.saddr;
1689		cb->dst = fld.daddr;
1690		local_bh_disable();
1691		err = dn_route_input(skb);
1692		local_bh_enable();
1693		memset(cb, 0, sizeof(struct dn_skb_cb));
1694		rt = (struct dn_route *)skb_dst(skb);
1695		if (!err && -rt->dst.error)
1696			err = rt->dst.error;
1697	} else {
1698		if (tb[RTA_OIF])
1699			fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
1700
1701		err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1702	}
1703
1704	skb->dev = NULL;
1705	if (err)
1706		goto out_free;
1707	skb_dst_set(skb, &rt->dst);
1708	if (rtm->rtm_flags & RTM_F_NOTIFY)
1709		rt->rt_flags |= RTCF_NOTIFY;
1710
1711	err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1712
1713	if (err == 0)
1714		goto out_free;
1715	if (err < 0) {
1716		err = -EMSGSIZE;
1717		goto out_free;
1718	}
1719
1720	return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).portid);
1721
1722out_free:
1723	kfree_skb(skb);
1724	return err;
1725}
1726
1727/*
1728 * For routers, this is called from dn_fib_dump, but for endnodes its
1729 * called directly from the rtnetlink dispatch table.
1730 */
1731int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1732{
1733	struct net *net = sock_net(skb->sk);
1734	struct dn_route *rt;
1735	int h, s_h;
1736	int idx, s_idx;
1737	struct rtmsg *rtm;
1738
1739	if (!net_eq(net, &init_net))
1740		return 0;
1741
1742	if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1743		return -EINVAL;
1744
1745	rtm = nlmsg_data(cb->nlh);
1746	if (!(rtm->rtm_flags & RTM_F_CLONED))
1747		return 0;
1748
1749	s_h = cb->args[0];
1750	s_idx = idx = cb->args[1];
1751	for(h = 0; h <= dn_rt_hash_mask; h++) {
1752		if (h < s_h)
1753			continue;
1754		if (h > s_h)
1755			s_idx = 0;
1756		rcu_read_lock_bh();
1757		for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1758			rt;
1759			rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1760			if (idx < s_idx)
1761				continue;
1762			skb_dst_set(skb, dst_clone(&rt->dst));
1763			if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).portid,
1764					cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1765					1, NLM_F_MULTI) <= 0) {
1766				skb_dst_drop(skb);
1767				rcu_read_unlock_bh();
1768				goto done;
1769			}
1770			skb_dst_drop(skb);
1771		}
1772		rcu_read_unlock_bh();
1773	}
1774
1775done:
1776	cb->args[0] = h;
1777	cb->args[1] = idx;
1778	return skb->len;
1779}
1780
1781#ifdef CONFIG_PROC_FS
1782struct dn_rt_cache_iter_state {
1783	int bucket;
1784};
1785
1786static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1787{
1788	struct dn_route *rt = NULL;
1789	struct dn_rt_cache_iter_state *s = seq->private;
1790
1791	for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1792		rcu_read_lock_bh();
1793		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1794		if (rt)
1795			break;
1796		rcu_read_unlock_bh();
1797	}
1798	return rt;
1799}
1800
1801static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1802{
1803	struct dn_rt_cache_iter_state *s = seq->private;
1804
1805	rt = rcu_dereference_bh(rt->dst.dn_next);
1806	while (!rt) {
1807		rcu_read_unlock_bh();
1808		if (--s->bucket < 0)
1809			break;
1810		rcu_read_lock_bh();
1811		rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1812	}
1813	return rt;
1814}
1815
1816static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1817{
1818	struct dn_route *rt = dn_rt_cache_get_first(seq);
1819
1820	if (rt) {
1821		while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1822			--*pos;
1823	}
1824	return *pos ? NULL : rt;
1825}
1826
1827static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1828{
1829	struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1830	++*pos;
1831	return rt;
1832}
1833
1834static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1835{
1836	if (v)
1837		rcu_read_unlock_bh();
1838}
1839
1840static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1841{
1842	struct dn_route *rt = v;
1843	char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1844
1845	seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1846		   rt->dst.dev ? rt->dst.dev->name : "*",
1847		   dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1848		   dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1849		   atomic_read(&rt->dst.__refcnt),
1850		   rt->dst.__use, 0);
1851	return 0;
1852}
1853
1854static const struct seq_operations dn_rt_cache_seq_ops = {
1855	.start	= dn_rt_cache_seq_start,
1856	.next	= dn_rt_cache_seq_next,
1857	.stop	= dn_rt_cache_seq_stop,
1858	.show	= dn_rt_cache_seq_show,
1859};
1860
1861static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1862{
1863	return seq_open_private(file, &dn_rt_cache_seq_ops,
1864			sizeof(struct dn_rt_cache_iter_state));
1865}
1866
1867static const struct file_operations dn_rt_cache_seq_fops = {
1868	.owner	 = THIS_MODULE,
1869	.open	 = dn_rt_cache_seq_open,
1870	.read	 = seq_read,
1871	.llseek	 = seq_lseek,
1872	.release = seq_release_private,
1873};
1874
1875#endif /* CONFIG_PROC_FS */
1876
1877void __init dn_route_init(void)
1878{
1879	int i, goal, order;
1880
1881	dn_dst_ops.kmem_cachep =
1882		kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1883				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1884	dst_entries_init(&dn_dst_ops);
1885	setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1886	dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1887	add_timer(&dn_route_timer);
1888
1889	goal = totalram_pages >> (26 - PAGE_SHIFT);
1890
1891	for(order = 0; (1UL << order) < goal; order++)
1892		/* NOTHING */;
1893
1894	/*
1895	 * Only want 1024 entries max, since the table is very, very unlikely
1896	 * to be larger than that.
1897	 */
1898	while(order && ((((1UL << order) * PAGE_SIZE) /
1899				sizeof(struct dn_rt_hash_bucket)) >= 2048))
1900		order--;
1901
1902	do {
1903		dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1904			sizeof(struct dn_rt_hash_bucket);
1905		while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1906			dn_rt_hash_mask--;
1907		dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1908			__get_free_pages(GFP_ATOMIC, order);
1909	} while (dn_rt_hash_table == NULL && --order > 0);
1910
1911	if (!dn_rt_hash_table)
1912		panic("Failed to allocate DECnet route cache hash table\n");
1913
1914	printk(KERN_INFO
1915		"DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1916		dn_rt_hash_mask,
1917		(long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1918
1919	dn_rt_hash_mask--;
1920	for(i = 0; i <= dn_rt_hash_mask; i++) {
1921		spin_lock_init(&dn_rt_hash_table[i].lock);
1922		dn_rt_hash_table[i].chain = NULL;
1923	}
1924
1925	dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1926
1927	proc_create("decnet_cache", S_IRUGO, init_net.proc_net,
1928		    &dn_rt_cache_seq_fops);
1929
1930#ifdef CONFIG_DECNET_ROUTER
1931	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1932		      dn_fib_dump, NULL);
1933#else
1934	rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1935		      dn_cache_dump, NULL);
1936#endif
1937}
1938
1939void __exit dn_route_cleanup(void)
1940{
1941	del_timer(&dn_route_timer);
1942	dn_run_flush(0);
1943
1944	remove_proc_entry("decnet_cache", init_net.proc_net);
1945	dst_entries_destroy(&dn_dst_ops);
1946}
1947