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Linux/net/decnet/dn_route.c

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  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 
 95 struct dn_rt_hash_bucket
 96 {
 97         struct dn_route __rcu *chain;
 98         spinlock_t lock;
 99 };
100 
101 extern struct neigh_table dn_neigh_table;
102 
103 
104 static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00};
105 
106 static const int dn_rt_min_delay = 2 * HZ;
107 static const int dn_rt_max_delay = 10 * HZ;
108 static const int dn_rt_mtu_expires = 10 * 60 * HZ;
109 
110 static unsigned long dn_rt_deadline;
111 
112 static int dn_dst_gc(struct dst_ops *ops);
113 static struct dst_entry *dn_dst_check(struct dst_entry *, __u32);
114 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst);
115 static unsigned int dn_dst_mtu(const struct dst_entry *dst);
116 static void dn_dst_destroy(struct dst_entry *);
117 static void dn_dst_ifdown(struct dst_entry *, struct net_device *dev, int how);
118 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *);
119 static void dn_dst_link_failure(struct sk_buff *);
120 static void dn_dst_update_pmtu(struct dst_entry *dst, struct sock *sk,
121                                struct sk_buff *skb , u32 mtu);
122 static void dn_dst_redirect(struct dst_entry *dst, struct sock *sk,
123                             struct sk_buff *skb);
124 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
125                                              struct sk_buff *skb,
126                                              const void *daddr);
127 static int dn_route_input(struct sk_buff *);
128 static void dn_run_flush(unsigned long dummy);
129 
130 static struct dn_rt_hash_bucket *dn_rt_hash_table;
131 static unsigned int dn_rt_hash_mask;
132 
133 static struct timer_list dn_route_timer;
134 static DEFINE_TIMER(dn_rt_flush_timer, dn_run_flush, 0, 0);
135 int decnet_dst_gc_interval = 2;
136 
137 static 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 
155 static 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 
164 static 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 
178 static __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 
187 static inline void dnrt_free(struct dn_route *rt)
188 {
189         call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
190 }
191 
192 static 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 
198 static 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 
230 static 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  */
271 static 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 
300 static 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  */
308 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
309 {
310         return NULL;
311 }
312 
313 static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst)
314 {
315         dst_release(dst);
316         return NULL;
317 }
318 
319 static void dn_dst_link_failure(struct sk_buff *skb)
320 {
321 }
322 
323 static 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 
333 static 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 
370 static 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 
387 nothing_to_declare:
388                 spin_unlock_bh(&dn_rt_hash_table[i].lock);
389         }
390 }
391 
392 static DEFINE_SPINLOCK(dn_rt_flush_lock);
393 
394 void 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  */
433 static 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  */
469 static 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  */
516 static 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 
548 static 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 
580 drop_it:
581         kfree_skb(skb);
582         return NET_RX_DROP;
583 }
584 
585 
586 
587 static 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 
607 drop_it:
608         kfree_skb(skb);
609         return NET_RX_DROP;
610 }
611 
612 static 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 
622 static 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 
629 int 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 
740 dump_it:
741         kfree_skb(skb);
742 out:
743         return NET_RX_DROP;
744 }
745 
746 static 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 
755 static int dn_output(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 
784 error:
785         net_dbg_ratelimited("dn_output: This should not happen\n");
786 
787         kfree_skb(skb);
788 
789         return err;
790 }
791 
792 static 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 
832 drop:
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  */
841 static int dn_rt_bug(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 
853 static unsigned int dn_dst_default_advmss(const struct dst_entry *dst)
854 {
855         return dn_mss_from_pmtu(dst->dev, dst_mtu(dst));
856 }
857 
858 static unsigned int dn_dst_mtu(const struct dst_entry *dst)
859 {
860         unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
861 
862         return mtu ? : dst->dev->mtu;
863 }
864 
865 static struct neighbour *dn_dst_neigh_lookup(const struct dst_entry *dst,
866                                              struct sk_buff *skb,
867                                              const void *daddr)
868 {
869         return __neigh_lookup_errno(&dn_neigh_table, daddr, dst->dev);
870 }
871 
872 static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res)
873 {
874         struct dn_fib_info *fi = res->fi;
875         struct net_device *dev = rt->dst.dev;
876         unsigned int mss_metric;
877         struct neighbour *n;
878 
879         if (fi) {
880                 if (DN_FIB_RES_GW(*res) &&
881                     DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
882                         rt->rt_gateway = DN_FIB_RES_GW(*res);
883                 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
884         }
885         rt->rt_type = res->type;
886 
887         if (dev != NULL && rt->n == NULL) {
888                 n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev);
889                 if (IS_ERR(n))
890                         return PTR_ERR(n);
891                 rt->n = n;
892         }
893 
894         if (dst_metric(&rt->dst, RTAX_MTU) > rt->dst.dev->mtu)
895                 dst_metric_set(&rt->dst, RTAX_MTU, rt->dst.dev->mtu);
896         mss_metric = dst_metric_raw(&rt->dst, RTAX_ADVMSS);
897         if (mss_metric) {
898                 unsigned int mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->dst));
899                 if (mss_metric > mss)
900                         dst_metric_set(&rt->dst, RTAX_ADVMSS, mss);
901         }
902         return 0;
903 }
904 
905 static inline int dn_match_addr(__le16 addr1, __le16 addr2)
906 {
907         __u16 tmp = le16_to_cpu(addr1) ^ le16_to_cpu(addr2);
908         int match = 16;
909         while(tmp) {
910                 tmp >>= 1;
911                 match--;
912         }
913         return match;
914 }
915 
916 static __le16 dnet_select_source(const struct net_device *dev, __le16 daddr, int scope)
917 {
918         __le16 saddr = 0;
919         struct dn_dev *dn_db;
920         struct dn_ifaddr *ifa;
921         int best_match = 0;
922         int ret;
923 
924         rcu_read_lock();
925         dn_db = rcu_dereference(dev->dn_ptr);
926         for (ifa = rcu_dereference(dn_db->ifa_list);
927              ifa != NULL;
928              ifa = rcu_dereference(ifa->ifa_next)) {
929                 if (ifa->ifa_scope > scope)
930                         continue;
931                 if (!daddr) {
932                         saddr = ifa->ifa_local;
933                         break;
934                 }
935                 ret = dn_match_addr(daddr, ifa->ifa_local);
936                 if (ret > best_match)
937                         saddr = ifa->ifa_local;
938                 if (best_match == 0)
939                         saddr = ifa->ifa_local;
940         }
941         rcu_read_unlock();
942 
943         return saddr;
944 }
945 
946 static inline __le16 __dn_fib_res_prefsrc(struct dn_fib_res *res)
947 {
948         return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope);
949 }
950 
951 static inline __le16 dn_fib_rules_map_destination(__le16 daddr, struct dn_fib_res *res)
952 {
953         __le16 mask = dnet_make_mask(res->prefixlen);
954         return (daddr&~mask)|res->fi->fib_nh->nh_gw;
955 }
956 
957 static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *oldflp, int try_hard)
958 {
959         struct flowidn fld = {
960                 .daddr = oldflp->daddr,
961                 .saddr = oldflp->saddr,
962                 .flowidn_scope = RT_SCOPE_UNIVERSE,
963                 .flowidn_mark = oldflp->flowidn_mark,
964                 .flowidn_iif = init_net.loopback_dev->ifindex,
965                 .flowidn_oif = oldflp->flowidn_oif,
966         };
967         struct dn_route *rt = NULL;
968         struct net_device *dev_out = NULL, *dev;
969         struct neighbour *neigh = NULL;
970         unsigned int hash;
971         unsigned int flags = 0;
972         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST };
973         int err;
974         int free_res = 0;
975         __le16 gateway = 0;
976 
977         if (decnet_debug_level & 16)
978                 printk(KERN_DEBUG
979                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
980                        " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
981                        le16_to_cpu(oldflp->saddr),
982                        oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
983                        oldflp->flowidn_oif);
984 
985         /* If we have an output interface, verify its a DECnet device */
986         if (oldflp->flowidn_oif) {
987                 dev_out = dev_get_by_index(&init_net, oldflp->flowidn_oif);
988                 err = -ENODEV;
989                 if (dev_out && dev_out->dn_ptr == NULL) {
990                         dev_put(dev_out);
991                         dev_out = NULL;
992                 }
993                 if (dev_out == NULL)
994                         goto out;
995         }
996 
997         /* If we have a source address, verify that its a local address */
998         if (oldflp->saddr) {
999                 err = -EADDRNOTAVAIL;
1000 
1001                 if (dev_out) {
1002                         if (dn_dev_islocal(dev_out, oldflp->saddr))
1003                                 goto source_ok;
1004                         dev_put(dev_out);
1005                         goto out;
1006                 }
1007                 rcu_read_lock();
1008                 for_each_netdev_rcu(&init_net, dev) {
1009                         if (!dev->dn_ptr)
1010                                 continue;
1011                         if (!dn_dev_islocal(dev, oldflp->saddr))
1012                                 continue;
1013                         if ((dev->flags & IFF_LOOPBACK) &&
1014                             oldflp->daddr &&
1015                             !dn_dev_islocal(dev, oldflp->daddr))
1016                                 continue;
1017 
1018                         dev_out = dev;
1019                         break;
1020                 }
1021                 rcu_read_unlock();
1022                 if (dev_out == NULL)
1023                         goto out;
1024                 dev_hold(dev_out);
1025 source_ok:
1026                 ;
1027         }
1028 
1029         /* No destination? Assume its local */
1030         if (!fld.daddr) {
1031                 fld.daddr = fld.saddr;
1032 
1033                 err = -EADDRNOTAVAIL;
1034                 if (dev_out)
1035                         dev_put(dev_out);
1036                 dev_out = init_net.loopback_dev;
1037                 dev_hold(dev_out);
1038                 if (!fld.daddr) {
1039                         fld.daddr =
1040                         fld.saddr = dnet_select_source(dev_out, 0,
1041                                                        RT_SCOPE_HOST);
1042                         if (!fld.daddr)
1043                                 goto out;
1044                 }
1045                 fld.flowidn_oif = init_net.loopback_dev->ifindex;
1046                 res.type = RTN_LOCAL;
1047                 goto make_route;
1048         }
1049 
1050         if (decnet_debug_level & 16)
1051                 printk(KERN_DEBUG
1052                        "dn_route_output_slow: initial checks complete."
1053                        " dst=%o4x src=%04x oif=%d try_hard=%d\n",
1054                        le16_to_cpu(fld.daddr), le16_to_cpu(fld.saddr),
1055                        fld.flowidn_oif, try_hard);
1056 
1057         /*
1058          * N.B. If the kernel is compiled without router support then
1059          * dn_fib_lookup() will evaluate to non-zero so this if () block
1060          * will always be executed.
1061          */
1062         err = -ESRCH;
1063         if (try_hard || (err = dn_fib_lookup(&fld, &res)) != 0) {
1064                 struct dn_dev *dn_db;
1065                 if (err != -ESRCH)
1066                         goto out;
1067                 /*
1068                  * Here the fallback is basically the standard algorithm for
1069                  * routing in endnodes which is described in the DECnet routing
1070                  * docs
1071                  *
1072                  * If we are not trying hard, look in neighbour cache.
1073                  * The result is tested to ensure that if a specific output
1074                  * device/source address was requested, then we honour that
1075                  * here
1076                  */
1077                 if (!try_hard) {
1078                         neigh = neigh_lookup_nodev(&dn_neigh_table, &init_net, &fld.daddr);
1079                         if (neigh) {
1080                                 if ((oldflp->flowidn_oif &&
1081                                     (neigh->dev->ifindex != oldflp->flowidn_oif)) ||
1082                                     (oldflp->saddr &&
1083                                     (!dn_dev_islocal(neigh->dev,
1084                                                      oldflp->saddr)))) {
1085                                         neigh_release(neigh);
1086                                         neigh = NULL;
1087                                 } else {
1088                                         if (dev_out)
1089                                                 dev_put(dev_out);
1090                                         if (dn_dev_islocal(neigh->dev, fld.daddr)) {
1091                                                 dev_out = init_net.loopback_dev;
1092                                                 res.type = RTN_LOCAL;
1093                                         } else {
1094                                                 dev_out = neigh->dev;
1095                                         }
1096                                         dev_hold(dev_out);
1097                                         goto select_source;
1098                                 }
1099                         }
1100                 }
1101 
1102                 /* Not there? Perhaps its a local address */
1103                 if (dev_out == NULL)
1104                         dev_out = dn_dev_get_default();
1105                 err = -ENODEV;
1106                 if (dev_out == NULL)
1107                         goto out;
1108                 dn_db = rcu_dereference_raw(dev_out->dn_ptr);
1109                 /* Possible improvement - check all devices for local addr */
1110                 if (dn_dev_islocal(dev_out, fld.daddr)) {
1111                         dev_put(dev_out);
1112                         dev_out = init_net.loopback_dev;
1113                         dev_hold(dev_out);
1114                         res.type = RTN_LOCAL;
1115                         goto select_source;
1116                 }
1117                 /* Not local either.... try sending it to the default router */
1118                 neigh = neigh_clone(dn_db->router);
1119                 BUG_ON(neigh && neigh->dev != dev_out);
1120 
1121                 /* Ok then, we assume its directly connected and move on */
1122 select_source:
1123                 if (neigh)
1124                         gateway = ((struct dn_neigh *)neigh)->addr;
1125                 if (gateway == 0)
1126                         gateway = fld.daddr;
1127                 if (fld.saddr == 0) {
1128                         fld.saddr = dnet_select_source(dev_out, gateway,
1129                                                        res.type == RTN_LOCAL ?
1130                                                        RT_SCOPE_HOST :
1131                                                        RT_SCOPE_LINK);
1132                         if (fld.saddr == 0 && res.type != RTN_LOCAL)
1133                                 goto e_addr;
1134                 }
1135                 fld.flowidn_oif = dev_out->ifindex;
1136                 goto make_route;
1137         }
1138         free_res = 1;
1139 
1140         if (res.type == RTN_NAT)
1141                 goto e_inval;
1142 
1143         if (res.type == RTN_LOCAL) {
1144                 if (!fld.saddr)
1145                         fld.saddr = fld.daddr;
1146                 if (dev_out)
1147                         dev_put(dev_out);
1148                 dev_out = init_net.loopback_dev;
1149                 dev_hold(dev_out);
1150                 fld.flowidn_oif = dev_out->ifindex;
1151                 if (res.fi)
1152                         dn_fib_info_put(res.fi);
1153                 res.fi = NULL;
1154                 goto make_route;
1155         }
1156 
1157         if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1158                 dn_fib_select_multipath(&fld, &res);
1159 
1160         /*
1161          * We could add some logic to deal with default routes here and
1162          * get rid of some of the special casing above.
1163          */
1164 
1165         if (!fld.saddr)
1166                 fld.saddr = DN_FIB_RES_PREFSRC(res);
1167 
1168         if (dev_out)
1169                 dev_put(dev_out);
1170         dev_out = DN_FIB_RES_DEV(res);
1171         dev_hold(dev_out);
1172         fld.flowidn_oif = dev_out->ifindex;
1173         gateway = DN_FIB_RES_GW(res);
1174 
1175 make_route:
1176         if (dev_out->flags & IFF_LOOPBACK)
1177                 flags |= RTCF_LOCAL;
1178 
1179         rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
1180         if (rt == NULL)
1181                 goto e_nobufs;
1182 
1183         memset(&rt->fld, 0, sizeof(rt->fld));
1184         rt->fld.saddr        = oldflp->saddr;
1185         rt->fld.daddr        = oldflp->daddr;
1186         rt->fld.flowidn_oif  = oldflp->flowidn_oif;
1187         rt->fld.flowidn_iif  = 0;
1188         rt->fld.flowidn_mark = oldflp->flowidn_mark;
1189 
1190         rt->rt_saddr      = fld.saddr;
1191         rt->rt_daddr      = fld.daddr;
1192         rt->rt_gateway    = gateway ? gateway : fld.daddr;
1193         rt->rt_local_src  = fld.saddr;
1194 
1195         rt->rt_dst_map    = fld.daddr;
1196         rt->rt_src_map    = fld.saddr;
1197 
1198         rt->n = neigh;
1199         neigh = NULL;
1200 
1201         rt->dst.lastuse = jiffies;
1202         rt->dst.output  = dn_output;
1203         rt->dst.input   = dn_rt_bug;
1204         rt->rt_flags      = flags;
1205         if (flags & RTCF_LOCAL)
1206                 rt->dst.input = dn_nsp_rx;
1207 
1208         err = dn_rt_set_next_hop(rt, &res);
1209         if (err)
1210                 goto e_neighbour;
1211 
1212         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1213         dn_insert_route(rt, hash, (struct dn_route **)pprt);
1214 
1215 done:
1216         if (neigh)
1217                 neigh_release(neigh);
1218         if (free_res)
1219                 dn_fib_res_put(&res);
1220         if (dev_out)
1221                 dev_put(dev_out);
1222 out:
1223         return err;
1224 
1225 e_addr:
1226         err = -EADDRNOTAVAIL;
1227         goto done;
1228 e_inval:
1229         err = -EINVAL;
1230         goto done;
1231 e_nobufs:
1232         err = -ENOBUFS;
1233         goto done;
1234 e_neighbour:
1235         dst_free(&rt->dst);
1236         goto e_nobufs;
1237 }
1238 
1239 
1240 /*
1241  * N.B. The flags may be moved into the flowi at some future stage.
1242  */
1243 static int __dn_route_output_key(struct dst_entry **pprt, const struct flowidn *flp, int flags)
1244 {
1245         unsigned int hash = dn_hash(flp->saddr, flp->daddr);
1246         struct dn_route *rt = NULL;
1247 
1248         if (!(flags & MSG_TRYHARD)) {
1249                 rcu_read_lock_bh();
1250                 for (rt = rcu_dereference_bh(dn_rt_hash_table[hash].chain); rt;
1251                         rt = rcu_dereference_bh(rt->dst.dn_next)) {
1252                         if ((flp->daddr == rt->fld.daddr) &&
1253                             (flp->saddr == rt->fld.saddr) &&
1254                             (flp->flowidn_mark == rt->fld.flowidn_mark) &&
1255                             dn_is_output_route(rt) &&
1256                             (rt->fld.flowidn_oif == flp->flowidn_oif)) {
1257                                 dst_use(&rt->dst, jiffies);
1258                                 rcu_read_unlock_bh();
1259                                 *pprt = &rt->dst;
1260                                 return 0;
1261                         }
1262                 }
1263                 rcu_read_unlock_bh();
1264         }
1265 
1266         return dn_route_output_slow(pprt, flp, flags);
1267 }
1268 
1269 static int dn_route_output_key(struct dst_entry **pprt, struct flowidn *flp, int flags)
1270 {
1271         int err;
1272 
1273         err = __dn_route_output_key(pprt, flp, flags);
1274         if (err == 0 && flp->flowidn_proto) {
1275                 *pprt = xfrm_lookup(&init_net, *pprt,
1276                                     flowidn_to_flowi(flp), NULL, 0);
1277                 if (IS_ERR(*pprt)) {
1278                         err = PTR_ERR(*pprt);
1279                         *pprt = NULL;
1280                 }
1281         }
1282         return err;
1283 }
1284 
1285 int dn_route_output_sock(struct dst_entry **pprt, struct flowidn *fl, struct sock *sk, int flags)
1286 {
1287         int err;
1288 
1289         err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD);
1290         if (err == 0 && fl->flowidn_proto) {
1291                 if (!(flags & MSG_DONTWAIT))
1292                         fl->flowidn_flags |= FLOWI_FLAG_CAN_SLEEP;
1293                 *pprt = xfrm_lookup(&init_net, *pprt,
1294                                     flowidn_to_flowi(fl), sk, 0);
1295                 if (IS_ERR(*pprt)) {
1296                         err = PTR_ERR(*pprt);
1297                         *pprt = NULL;
1298                 }
1299         }
1300         return err;
1301 }
1302 
1303 static int dn_route_input_slow(struct sk_buff *skb)
1304 {
1305         struct dn_route *rt = NULL;
1306         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1307         struct net_device *in_dev = skb->dev;
1308         struct net_device *out_dev = NULL;
1309         struct dn_dev *dn_db;
1310         struct neighbour *neigh = NULL;
1311         unsigned int hash;
1312         int flags = 0;
1313         __le16 gateway = 0;
1314         __le16 local_src = 0;
1315         struct flowidn fld = {
1316                 .daddr = cb->dst,
1317                 .saddr = cb->src,
1318                 .flowidn_scope = RT_SCOPE_UNIVERSE,
1319                 .flowidn_mark = skb->mark,
1320                 .flowidn_iif = skb->dev->ifindex,
1321         };
1322         struct dn_fib_res res = { .fi = NULL, .type = RTN_UNREACHABLE };
1323         int err = -EINVAL;
1324         int free_res = 0;
1325 
1326         dev_hold(in_dev);
1327 
1328         if ((dn_db = rcu_dereference(in_dev->dn_ptr)) == NULL)
1329                 goto out;
1330 
1331         /* Zero source addresses are not allowed */
1332         if (fld.saddr == 0)
1333                 goto out;
1334 
1335         /*
1336          * In this case we've just received a packet from a source
1337          * outside ourselves pretending to come from us. We don't
1338          * allow it any further to prevent routing loops, spoofing and
1339          * other nasties. Loopback packets already have the dst attached
1340          * so this only affects packets which have originated elsewhere.
1341          */
1342         err  = -ENOTUNIQ;
1343         if (dn_dev_islocal(in_dev, cb->src))
1344                 goto out;
1345 
1346         err = dn_fib_lookup(&fld, &res);
1347         if (err) {
1348                 if (err != -ESRCH)
1349                         goto out;
1350                 /*
1351                  * Is the destination us ?
1352                  */
1353                 if (!dn_dev_islocal(in_dev, cb->dst))
1354                         goto e_inval;
1355 
1356                 res.type = RTN_LOCAL;
1357         } else {
1358                 __le16 src_map = fld.saddr;
1359                 free_res = 1;
1360 
1361                 out_dev = DN_FIB_RES_DEV(res);
1362                 if (out_dev == NULL) {
1363                         net_crit_ratelimited("Bug in dn_route_input_slow() No output device\n");
1364                         goto e_inval;
1365                 }
1366                 dev_hold(out_dev);
1367 
1368                 if (res.r)
1369                         src_map = fld.saddr; /* no NAT support for now */
1370 
1371                 gateway = DN_FIB_RES_GW(res);
1372                 if (res.type == RTN_NAT) {
1373                         fld.daddr = dn_fib_rules_map_destination(fld.daddr, &res);
1374                         dn_fib_res_put(&res);
1375                         free_res = 0;
1376                         if (dn_fib_lookup(&fld, &res))
1377                                 goto e_inval;
1378                         free_res = 1;
1379                         if (res.type != RTN_UNICAST)
1380                                 goto e_inval;
1381                         flags |= RTCF_DNAT;
1382                         gateway = fld.daddr;
1383                 }
1384                 fld.saddr = src_map;
1385         }
1386 
1387         switch(res.type) {
1388         case RTN_UNICAST:
1389                 /*
1390                  * Forwarding check here, we only check for forwarding
1391                  * being turned off, if you want to only forward intra
1392                  * area, its up to you to set the routing tables up
1393                  * correctly.
1394                  */
1395                 if (dn_db->parms.forwarding == 0)
1396                         goto e_inval;
1397 
1398                 if (res.fi->fib_nhs > 1 && fld.flowidn_oif == 0)
1399                         dn_fib_select_multipath(&fld, &res);
1400 
1401                 /*
1402                  * Check for out_dev == in_dev. We use the RTCF_DOREDIRECT
1403                  * flag as a hint to set the intra-ethernet bit when
1404                  * forwarding. If we've got NAT in operation, we don't do
1405                  * this optimisation.
1406                  */
1407                 if (out_dev == in_dev && !(flags & RTCF_NAT))
1408                         flags |= RTCF_DOREDIRECT;
1409 
1410                 local_src = DN_FIB_RES_PREFSRC(res);
1411 
1412         case RTN_BLACKHOLE:
1413         case RTN_UNREACHABLE:
1414                 break;
1415         case RTN_LOCAL:
1416                 flags |= RTCF_LOCAL;
1417                 fld.saddr = cb->dst;
1418                 fld.daddr = cb->src;
1419 
1420                 /* Routing tables gave us a gateway */
1421                 if (gateway)
1422                         goto make_route;
1423 
1424                 /* Packet was intra-ethernet, so we know its on-link */
1425                 if (cb->rt_flags & DN_RT_F_IE) {
1426                         gateway = cb->src;
1427                         goto make_route;
1428                 }
1429 
1430                 /* Use the default router if there is one */
1431                 neigh = neigh_clone(dn_db->router);
1432                 if (neigh) {
1433                         gateway = ((struct dn_neigh *)neigh)->addr;
1434                         goto make_route;
1435                 }
1436 
1437                 /* Close eyes and pray */
1438                 gateway = cb->src;
1439                 goto make_route;
1440         default:
1441                 goto e_inval;
1442         }
1443 
1444 make_route:
1445         rt = dst_alloc(&dn_dst_ops, out_dev, 0, DST_OBSOLETE_NONE, DST_HOST);
1446         if (rt == NULL)
1447                 goto e_nobufs;
1448 
1449         memset(&rt->fld, 0, sizeof(rt->fld));
1450         rt->rt_saddr      = fld.saddr;
1451         rt->rt_daddr      = fld.daddr;
1452         rt->rt_gateway    = fld.daddr;
1453         if (gateway)
1454                 rt->rt_gateway = gateway;
1455         rt->rt_local_src  = local_src ? local_src : rt->rt_saddr;
1456 
1457         rt->rt_dst_map    = fld.daddr;
1458         rt->rt_src_map    = fld.saddr;
1459 
1460         rt->fld.saddr        = cb->src;
1461         rt->fld.daddr        = cb->dst;
1462         rt->fld.flowidn_oif  = 0;
1463         rt->fld.flowidn_iif  = in_dev->ifindex;
1464         rt->fld.flowidn_mark = fld.flowidn_mark;
1465 
1466         rt->n = neigh;
1467         rt->dst.lastuse = jiffies;
1468         rt->dst.output = dn_rt_bug;
1469         switch (res.type) {
1470         case RTN_UNICAST:
1471                 rt->dst.input = dn_forward;
1472                 break;
1473         case RTN_LOCAL:
1474                 rt->dst.output = dn_output;
1475                 rt->dst.input = dn_nsp_rx;
1476                 rt->dst.dev = in_dev;
1477                 flags |= RTCF_LOCAL;
1478                 break;
1479         default:
1480         case RTN_UNREACHABLE:
1481         case RTN_BLACKHOLE:
1482                 rt->dst.input = dst_discard;
1483         }
1484         rt->rt_flags = flags;
1485 
1486         err = dn_rt_set_next_hop(rt, &res);
1487         if (err)
1488                 goto e_neighbour;
1489 
1490         hash = dn_hash(rt->fld.saddr, rt->fld.daddr);
1491         dn_insert_route(rt, hash, &rt);
1492         skb_dst_set(skb, &rt->dst);
1493 
1494 done:
1495         if (neigh)
1496                 neigh_release(neigh);
1497         if (free_res)
1498                 dn_fib_res_put(&res);
1499         dev_put(in_dev);
1500         if (out_dev)
1501                 dev_put(out_dev);
1502 out:
1503         return err;
1504 
1505 e_inval:
1506         err = -EINVAL;
1507         goto done;
1508 
1509 e_nobufs:
1510         err = -ENOBUFS;
1511         goto done;
1512 
1513 e_neighbour:
1514         dst_free(&rt->dst);
1515         goto done;
1516 }
1517 
1518 static int dn_route_input(struct sk_buff *skb)
1519 {
1520         struct dn_route *rt;
1521         struct dn_skb_cb *cb = DN_SKB_CB(skb);
1522         unsigned int hash = dn_hash(cb->src, cb->dst);
1523 
1524         if (skb_dst(skb))
1525                 return 0;
1526 
1527         rcu_read_lock();
1528         for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt != NULL;
1529             rt = rcu_dereference(rt->dst.dn_next)) {
1530                 if ((rt->fld.saddr == cb->src) &&
1531                     (rt->fld.daddr == cb->dst) &&
1532                     (rt->fld.flowidn_oif == 0) &&
1533                     (rt->fld.flowidn_mark == skb->mark) &&
1534                     (rt->fld.flowidn_iif == cb->iif)) {
1535                         dst_use(&rt->dst, jiffies);
1536                         rcu_read_unlock();
1537                         skb_dst_set(skb, (struct dst_entry *)rt);
1538                         return 0;
1539                 }
1540         }
1541         rcu_read_unlock();
1542 
1543         return dn_route_input_slow(skb);
1544 }
1545 
1546 static int dn_rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq,
1547                            int event, int nowait, unsigned int flags)
1548 {
1549         struct dn_route *rt = (struct dn_route *)skb_dst(skb);
1550         struct rtmsg *r;
1551         struct nlmsghdr *nlh;
1552         long expires;
1553 
1554         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
1555         if (!nlh)
1556                 return -EMSGSIZE;
1557 
1558         r = nlmsg_data(nlh);
1559         r->rtm_family = AF_DECnet;
1560         r->rtm_dst_len = 16;
1561         r->rtm_src_len = 0;
1562         r->rtm_tos = 0;
1563         r->rtm_table = RT_TABLE_MAIN;
1564         r->rtm_type = rt->rt_type;
1565         r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
1566         r->rtm_scope = RT_SCOPE_UNIVERSE;
1567         r->rtm_protocol = RTPROT_UNSPEC;
1568 
1569         if (rt->rt_flags & RTCF_NOTIFY)
1570                 r->rtm_flags |= RTM_F_NOTIFY;
1571 
1572         if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN) < 0 ||
1573             nla_put_le16(skb, RTA_DST, rt->rt_daddr) < 0)
1574                 goto errout;
1575 
1576         if (rt->fld.saddr) {
1577                 r->rtm_src_len = 16;
1578                 if (nla_put_le16(skb, RTA_SRC, rt->fld.saddr) < 0)
1579                         goto errout;
1580         }
1581         if (rt->dst.dev &&
1582             nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex) < 0)
1583                 goto errout;
1584 
1585         /*
1586          * Note to self - change this if input routes reverse direction when
1587          * they deal only with inputs and not with replies like they do
1588          * currently.
1589          */
1590         if (nla_put_le16(skb, RTA_PREFSRC, rt->rt_local_src) < 0)
1591                 goto errout;
1592 
1593         if (rt->rt_daddr != rt->rt_gateway &&
1594             nla_put_le16(skb, RTA_GATEWAY, rt->rt_gateway) < 0)
1595                 goto errout;
1596 
1597         if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
1598                 goto errout;
1599 
1600         expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
1601         if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires,
1602                                rt->dst.error) < 0)
1603                 goto errout;
1604 
1605         if (dn_is_input_route(rt) &&
1606             nla_put_u32(skb, RTA_IIF, rt->fld.flowidn_iif) < 0)
1607                 goto errout;
1608 
1609         return nlmsg_end(skb, nlh);
1610 
1611 errout:
1612         nlmsg_cancel(skb, nlh);
1613         return -EMSGSIZE;
1614 }
1615 
1616 /*
1617  * This is called by both endnodes and routers now.
1618  */
1619 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
1620 {
1621         struct net *net = sock_net(in_skb->sk);
1622         struct rtattr **rta = arg;
1623         struct rtmsg *rtm = nlmsg_data(nlh);
1624         struct dn_route *rt = NULL;
1625         struct dn_skb_cb *cb;
1626         int err;
1627         struct sk_buff *skb;
1628         struct flowidn fld;
1629 
1630         if (!net_eq(net, &init_net))
1631                 return -EINVAL;
1632 
1633         memset(&fld, 0, sizeof(fld));
1634         fld.flowidn_proto = DNPROTO_NSP;
1635 
1636         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1637         if (skb == NULL)
1638                 return -ENOBUFS;
1639         skb_reset_mac_header(skb);
1640         cb = DN_SKB_CB(skb);
1641 
1642         if (rta[RTA_SRC-1])
1643                 memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
1644         if (rta[RTA_DST-1])
1645                 memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
1646         if (rta[RTA_IIF-1])
1647                 memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
1648 
1649         if (fld.flowidn_iif) {
1650                 struct net_device *dev;
1651                 if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) {
1652                         kfree_skb(skb);
1653                         return -ENODEV;
1654                 }
1655                 if (!dev->dn_ptr) {
1656                         dev_put(dev);
1657                         kfree_skb(skb);
1658                         return -ENODEV;
1659                 }
1660                 skb->protocol = htons(ETH_P_DNA_RT);
1661                 skb->dev = dev;
1662                 cb->src = fld.saddr;
1663                 cb->dst = fld.daddr;
1664                 local_bh_disable();
1665                 err = dn_route_input(skb);
1666                 local_bh_enable();
1667                 memset(cb, 0, sizeof(struct dn_skb_cb));
1668                 rt = (struct dn_route *)skb_dst(skb);
1669                 if (!err && -rt->dst.error)
1670                         err = rt->dst.error;
1671         } else {
1672                 int oif = 0;
1673                 if (rta[RTA_OIF - 1])
1674                         memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
1675                 fld.flowidn_oif = oif;
1676                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
1677         }
1678 
1679         if (skb->dev)
1680                 dev_put(skb->dev);
1681         skb->dev = NULL;
1682         if (err)
1683                 goto out_free;
1684         skb_dst_set(skb, &rt->dst);
1685         if (rtm->rtm_flags & RTM_F_NOTIFY)
1686                 rt->rt_flags |= RTCF_NOTIFY;
1687 
1688         err = dn_rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0);
1689 
1690         if (err == 0)
1691                 goto out_free;
1692         if (err < 0) {
1693                 err = -EMSGSIZE;
1694                 goto out_free;
1695         }
1696 
1697         return rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
1698 
1699 out_free:
1700         kfree_skb(skb);
1701         return err;
1702 }
1703 
1704 /*
1705  * For routers, this is called from dn_fib_dump, but for endnodes its
1706  * called directly from the rtnetlink dispatch table.
1707  */
1708 int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb)
1709 {
1710         struct net *net = sock_net(skb->sk);
1711         struct dn_route *rt;
1712         int h, s_h;
1713         int idx, s_idx;
1714         struct rtmsg *rtm;
1715 
1716         if (!net_eq(net, &init_net))
1717                 return 0;
1718 
1719         if (nlmsg_len(cb->nlh) < sizeof(struct rtmsg))
1720                 return -EINVAL;
1721 
1722         rtm = nlmsg_data(cb->nlh);
1723         if (!(rtm->rtm_flags & RTM_F_CLONED))
1724                 return 0;
1725 
1726         s_h = cb->args[0];
1727         s_idx = idx = cb->args[1];
1728         for(h = 0; h <= dn_rt_hash_mask; h++) {
1729                 if (h < s_h)
1730                         continue;
1731                 if (h > s_h)
1732                         s_idx = 0;
1733                 rcu_read_lock_bh();
1734                 for(rt = rcu_dereference_bh(dn_rt_hash_table[h].chain), idx = 0;
1735                         rt;
1736                         rt = rcu_dereference_bh(rt->dst.dn_next), idx++) {
1737                         if (idx < s_idx)
1738                                 continue;
1739                         skb_dst_set(skb, dst_clone(&rt->dst));
1740                         if (dn_rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
1741                                         cb->nlh->nlmsg_seq, RTM_NEWROUTE,
1742                                         1, NLM_F_MULTI) <= 0) {
1743                                 skb_dst_drop(skb);
1744                                 rcu_read_unlock_bh();
1745                                 goto done;
1746                         }
1747                         skb_dst_drop(skb);
1748                 }
1749                 rcu_read_unlock_bh();
1750         }
1751 
1752 done:
1753         cb->args[0] = h;
1754         cb->args[1] = idx;
1755         return skb->len;
1756 }
1757 
1758 #ifdef CONFIG_PROC_FS
1759 struct dn_rt_cache_iter_state {
1760         int bucket;
1761 };
1762 
1763 static struct dn_route *dn_rt_cache_get_first(struct seq_file *seq)
1764 {
1765         struct dn_route *rt = NULL;
1766         struct dn_rt_cache_iter_state *s = seq->private;
1767 
1768         for(s->bucket = dn_rt_hash_mask; s->bucket >= 0; --s->bucket) {
1769                 rcu_read_lock_bh();
1770                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1771                 if (rt)
1772                         break;
1773                 rcu_read_unlock_bh();
1774         }
1775         return rt;
1776 }
1777 
1778 static struct dn_route *dn_rt_cache_get_next(struct seq_file *seq, struct dn_route *rt)
1779 {
1780         struct dn_rt_cache_iter_state *s = seq->private;
1781 
1782         rt = rcu_dereference_bh(rt->dst.dn_next);
1783         while (!rt) {
1784                 rcu_read_unlock_bh();
1785                 if (--s->bucket < 0)
1786                         break;
1787                 rcu_read_lock_bh();
1788                 rt = rcu_dereference_bh(dn_rt_hash_table[s->bucket].chain);
1789         }
1790         return rt;
1791 }
1792 
1793 static void *dn_rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
1794 {
1795         struct dn_route *rt = dn_rt_cache_get_first(seq);
1796 
1797         if (rt) {
1798                 while(*pos && (rt = dn_rt_cache_get_next(seq, rt)))
1799                         --*pos;
1800         }
1801         return *pos ? NULL : rt;
1802 }
1803 
1804 static void *dn_rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1805 {
1806         struct dn_route *rt = dn_rt_cache_get_next(seq, v);
1807         ++*pos;
1808         return rt;
1809 }
1810 
1811 static void dn_rt_cache_seq_stop(struct seq_file *seq, void *v)
1812 {
1813         if (v)
1814                 rcu_read_unlock_bh();
1815 }
1816 
1817 static int dn_rt_cache_seq_show(struct seq_file *seq, void *v)
1818 {
1819         struct dn_route *rt = v;
1820         char buf1[DN_ASCBUF_LEN], buf2[DN_ASCBUF_LEN];
1821 
1822         seq_printf(seq, "%-8s %-7s %-7s %04d %04d %04d\n",
1823                    rt->dst.dev ? rt->dst.dev->name : "*",
1824                    dn_addr2asc(le16_to_cpu(rt->rt_daddr), buf1),
1825                    dn_addr2asc(le16_to_cpu(rt->rt_saddr), buf2),
1826                    atomic_read(&rt->dst.__refcnt),
1827                    rt->dst.__use, 0);
1828         return 0;
1829 }
1830 
1831 static const struct seq_operations dn_rt_cache_seq_ops = {
1832         .start  = dn_rt_cache_seq_start,
1833         .next   = dn_rt_cache_seq_next,
1834         .stop   = dn_rt_cache_seq_stop,
1835         .show   = dn_rt_cache_seq_show,
1836 };
1837 
1838 static int dn_rt_cache_seq_open(struct inode *inode, struct file *file)
1839 {
1840         return seq_open_private(file, &dn_rt_cache_seq_ops,
1841                         sizeof(struct dn_rt_cache_iter_state));
1842 }
1843 
1844 static const struct file_operations dn_rt_cache_seq_fops = {
1845         .owner   = THIS_MODULE,
1846         .open    = dn_rt_cache_seq_open,
1847         .read    = seq_read,
1848         .llseek  = seq_lseek,
1849         .release = seq_release_private,
1850 };
1851 
1852 #endif /* CONFIG_PROC_FS */
1853 
1854 void __init dn_route_init(void)
1855 {
1856         int i, goal, order;
1857 
1858         dn_dst_ops.kmem_cachep =
1859                 kmem_cache_create("dn_dst_cache", sizeof(struct dn_route), 0,
1860                                   SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1861         dst_entries_init(&dn_dst_ops);
1862         setup_timer(&dn_route_timer, dn_dst_check_expire, 0);
1863         dn_route_timer.expires = jiffies + decnet_dst_gc_interval * HZ;
1864         add_timer(&dn_route_timer);
1865 
1866         goal = totalram_pages >> (26 - PAGE_SHIFT);
1867 
1868         for(order = 0; (1UL << order) < goal; order++)
1869                 /* NOTHING */;
1870 
1871         /*
1872          * Only want 1024 entries max, since the table is very, very unlikely
1873          * to be larger than that.
1874          */
1875         while(order && ((((1UL << order) * PAGE_SIZE) /
1876                                 sizeof(struct dn_rt_hash_bucket)) >= 2048))
1877                 order--;
1878 
1879         do {
1880                 dn_rt_hash_mask = (1UL << order) * PAGE_SIZE /
1881                         sizeof(struct dn_rt_hash_bucket);
1882                 while(dn_rt_hash_mask & (dn_rt_hash_mask - 1))
1883                         dn_rt_hash_mask--;
1884                 dn_rt_hash_table = (struct dn_rt_hash_bucket *)
1885                         __get_free_pages(GFP_ATOMIC, order);
1886         } while (dn_rt_hash_table == NULL && --order > 0);
1887 
1888         if (!dn_rt_hash_table)
1889                 panic("Failed to allocate DECnet route cache hash table\n");
1890 
1891         printk(KERN_INFO
1892                 "DECnet: Routing cache hash table of %u buckets, %ldKbytes\n",
1893                 dn_rt_hash_mask,
1894                 (long)(dn_rt_hash_mask*sizeof(struct dn_rt_hash_bucket))/1024);
1895 
1896         dn_rt_hash_mask--;
1897         for(i = 0; i <= dn_rt_hash_mask; i++) {
1898                 spin_lock_init(&dn_rt_hash_table[i].lock);
1899                 dn_rt_hash_table[i].chain = NULL;
1900         }
1901 
1902         dn_dst_ops.gc_thresh = (dn_rt_hash_mask + 1);
1903 
1904         proc_net_fops_create(&init_net, "decnet_cache", S_IRUGO, &dn_rt_cache_seq_fops);
1905 
1906 #ifdef CONFIG_DECNET_ROUTER
1907         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1908                       dn_fib_dump, NULL);
1909 #else
1910         rtnl_register(PF_DECnet, RTM_GETROUTE, dn_cache_getroute,
1911                       dn_cache_dump, NULL);
1912 #endif
1913 }
1914 
1915 void __exit dn_route_cleanup(void)
1916 {
1917         del_timer(&dn_route_timer);
1918         dn_run_flush(0);
1919 
1920         proc_net_remove(&init_net, "decnet_cache");
1921         dst_entries_destroy(&dn_dst_ops);
1922 }
1923 
1924 

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