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

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