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

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